ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (136)
  • Articles: DFG German National Licenses  (136)
  • hypertension  (46)
  • Drosophila  (45)
  • Wheat  (45)
  • Springer  (136)
  • American Chemical Society
  • 1980-1984  (136)
  • 1925-1929
  • 1983  (75)
  • 1980  (61)
  • 1925
Collection
  • Articles  (136)
Source
  • Articles: DFG German National Licenses  (136)
Publisher
Years
  • 1980-1984  (136)
  • 1925-1929
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 16 (1980), S. 37-46 
    ISSN: 1432-1432
    Keywords: Evolution ; Drosophila ; Temperature ; Mitochondrial enzymes ; Kinetic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The evolutionary behavior of two mitochondrial enzymes (L-glycerol 3-phosphate:cytochrome c oxidoreductase E.C.1.1.1.95,αGPO, and L-malate: NAD+ oxidoreductase, E.C.1.1.1.37, m-MDH) obtained from several temperate and tropicalDrosophila species was examined by comparing their catalytic properties, which related to temperature (Km-Ea-Q10-Thermostability). MitochondrialαGPO or m-MDH obtained either from temperate or from tropical species was found to exhibit similar catalytic properties while for both cytosolic enzymes, theαGPDH and s-MDH, Km patterns were similar among species from the same thermal habitat and different between thermal habitats. In combination with other observations reported in the literature these facts support the view that the function, and probably the structure, of mitochondrial enzymes are better conserved in evolution than those of the corresponding enzymes found in the cytosol. It is proposed that the relative invariance of the mitochondrial enzymes structure is probably linked to a necessary relative invariance of molecular interactions inside the mitochondrion.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 55-63 
    ISSN: 1432-041X
    Keywords: Drosophila ; Compound eye ; shibire ts ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have analysed the effect of temperature on both developing and adult eye cell clones homozygous forshi ST139, a temperature-sensitive mutant ofDrosophila melanogaster. The mutant gene, autonomous in its cellular expression, causes structural modifications of ommatidial cells when adult clones of cells are exposed to the restrictive temperature (29°C) for several days. However, the mutant phenotype reverses to normal within 4 days at the permissive temperature (20°C). The results of pulse, shift-up and shift-down experiments show that the temperaturesensitive period for developing compound eye cells is from the late second instar up to the early pupa. Cytodifferentiation of compound eye cells is blocked by restrictive temperature treatment during this period, whereas cell proliferation does not seem to be directly affected. These results are discussed with regard to the other known aspects of the phenotype observed in mutant individuals.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 164-170 
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal disc ; Morphogenesis ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The early morphogenesis of the eye-antennal disc ofDrosophila in response to 20-hydroxy ecdysone involves the curling of the eye anlagen dorsally over the antenna. During this process, the area of the peripodial membrane is substantially reduced. The peripodial membrane is taut at this stage, and if it is cut the curling of the disc cannot continue, and the eye anlagen returns to its original position within one minute of the operation. In contrast, cutting the columnar epithelium between the eye and antennal anlagen does not disrupt curling, but actually facilitates it. During curling, the cells of the peripodial membrane appear healthy, and exhibit basal extensions. We suggest that the curling of the eye is mediated by the conversion of cuboidal peripodial membrane cells into pseudostratified columnar epithelium at the edges of the peripodial membrane. Subsequently, cells of the peripodial membrane secrete first a pupal cuticle, and then an imaginal cuticle.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 275-279 
    ISSN: 1432-041X
    Keywords: Evagination ; Morphogenesis ; Metamorphosis ; Female genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The morphology of the evaginating female genital disc ofDrosophila melanogaster was examined at different stages of metamorphosis. The observations show that the internal genital organs are derived from the anterior half of the disc and that their morphogenesis is mainly a protrusion of the different primordial areas of the disc epithelium. The external genital and anal derivatives originate from the posterior half of the disc, which undergoes complex rearrangements during metamorphosis. The disc opens along the posterior margin and the dorsal and ventral epithelia evert and thereby completely reverse their anteroposterior orientation. Dramatic elongation has been observed during the formation of the seminal receptacle. The cells of the repressed male genital primordium do not form any recognizable structures and are assumed to be eliminated during metamorphosis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 299-302 
    ISSN: 1432-041X
    Keywords: Differentiation ; Teratogens ; Drosophila ; 5-Azacytidine ; Methylation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects of cytidine and cytidine analogs were studied inDrosophila embryonic cell cultures and two wild-type established cell lines, Oregon-R and Schneider line 2. Primary embryonic cultures have been shown to be an excellent system for the study of embryonic development; a number of cell types undergo normal differentiation in vitro. Treatment of these cultures with putative teratogens resulted in an inhibition of muscle and/or neuron differentiation in our study. Treatment of these cells with cytidine and seven other analogs had no effect on neuron and muscle differentiation. The compound 5-azacytidine, when added to primary cell cultures, inhibited normal differentiation at subtoxic doses while inducing the production of three proteins that comigrate with the heat-shock proteins, hsp 23, 22a and 22b. 5-Azacytidine did not stimulate differentiation in Oregon-R or SchneiderDrosophila cell lines. The in vitro blockage of differentiation by 5-azacytidine suggests that it may act as a teratogen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 280-284 
    ISSN: 1432-041X
    Keywords: Evagination ; Morphogenesis ; Metamorphosis ; Intersexual genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Morphogenetic movements of the intersexual genital disc of thedoublesex-dominant mutant ofDrosophila melanogaster were followed during metamorphosis. Intersexual genital discs contain well developed genital primordia of both sexes as well as an anal primordium, and all of these primordia evaginate simultaneously. The female genital primordium is deflected to the ventral side by the male genital primordium which is located anterior to it. Subsequently the anterior parts of the two genital primordia project their internal appendages in parallel in the anterior direction. The morphogenetic movements closely resemble those of the corresponding parts of normal males and females. The disc opens at the stalk along the posterior edge and the two genital primordia completely evert their posterior parts. These areas undergo complex rearrangements whereby the anlage for the male genital arch as well as that for the 8th tergite evert and move around the lateral side of the disc. They both fuse dorsally after enclosing the anal tube. The formation of the characteristic abnormalities of the intersexual genitalia seems not to result simply from spatial problems of the simultaneous evagination of the genital anlagen but rather to be a direct result of the ambiguous genetic signalling in the intersexual cells of these primordia.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 337-346 
    ISSN: 1432-041X
    Keywords: Drosophila ; Gynandromorphs ; Genital disc ; Compartments ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genital imaginal disc ofDrosophila differentiates the terminalia, i.e. the genitalia and analia, of both sexes. It represents a composite anlage, containing a female genital primordium, a male genital primordium and an anal primordium. In normal males and females, only one of the two genital primordia differentiates; the other is developmentally repressed. Therefore, cell-lineage relationships between the male and female genital primordia can only be studied in sexual mosaics which differentiate female and male cells. We producedMinute (M)‖non-Minute(M+) gynandromorphs and selected those with sexually mosaic terminalia for a cell-lineage analysis. In these mosaics, either the male (XO) or female (XX) cells wereM + and thus had a growth advantage. The differential growth rates served as a tool to detect clonal restrictions. In control gynandromorphs (M +‖M +), the amount of female genitalia differentiated was largely independent of the amount of male genitalia present. In contrast, male and female anal structures, as a rule, added up to one full set. The same was true for the experimentalM‖M + gynandromorphs, but the contribution ofXX andXO cells to mosaic terminalia changed drastically due toM + cells competing successfully against the more slowly growingM cells. Specific subsamples ofM‖M + gynandromorphs showed thatM cells in a non-mosaic primordium are shielded from cell competition taking place in the neighbouring mosaic primordium. We conclude that the three primordia of the genital disc represent developmental compartments. In the genital primordia, even developmentally repressedM + cells compete successfully against developmentally activeM cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 163-177 
    ISSN: 1432-041X
    Keywords: Yolk sac ; Ultrastructure ; Embryogenesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes at the ultrastructural level during germ band extension in the embryo ofDrosophila melanogaster are described. Cytoplasmic connections between cells and the yolk sac are present during initial cellular movements. At this time, a continuous system of microfilaments is present adjacent to the membranes in the connections and at the periphery of the yolk sac. As germ band extension progresses, this system becomes discontinuous, and microfilaments are apparent only in the immediate vicinity of the connections. Cytoplasmic connections are disassembled at approximately the midpoint of extension; at the same time, extensive membrane associations develop between germ band cells and between these cells and adjacent yolk sac membranes. Positioning and orientation of cytoplasmic connections suggest that the yolk sac, via these connections, is actively involved in the cellular movements of early germ band extension.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 189 (1980), S. 57-67 
    ISSN: 1432-041X
    Keywords: Drosophila ; Ecdysone deficient mutants ; Ecdysteroid titer ; Ring gland ; Fine structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper describes two ecdysone-deficient, recessive-lethal mutants,lethal(1)giant ring gland (grg) andlethal(1)suppressor of forked mad-ts (mad-ts: Jürgens and Gateff 1979) and compares their ecdysteroid titers with that of the wild-type. Mutant larvae show a much reduced ecdysteroid content, amounting to 1/10 to 1/30 of the wild-type values, but never a true titer peak. They fail to pupate and die after 1–3 weeks. Ecdysteroid feeding elicits different responses in the larvae of the two mutants.mad-ts larvae pupate within 24 h, thus showing that their low ecdysteroid titer is directly connected to their inability to pupate.mad-ts resembles the mutantlethal (3)ecdysone-1 ts (Garen et al. 1977). Thegrg mutant larvae, on the other hand, fail to pupate after 20-hydroxyecdysone feeding as well as injection. The primary defect of thegrg mutant is not entirely clear. Thegrg larval salivary gland cells appear to possess normal ecdysteroid receptors. Furthermore, the low ecdysteroid titer ingrg is not the result of an increased ecdysteroid catabolism. The primary defect in the mutant may lie in the malfunctioning neurosecretory cells which do not show neurosecretion in histological preparations. Further support for this notion comes from electronmicrographs of the enlargedgrg ring glands which, in contrast to the wild-type, do not possess nerve endings. In the wild-type three ecdysteroid peaks were found: one shortly before puparium formation, the second at approximately 12 h and the third at about 30 h after pupation. The ecdysteroid titer peak in late third instar, wild-type larvae is mainly due to the presence of 20-dydroxyecdysone as shown by radioimmunoassays after thin layer chromatography and derivatization followed by gas liquid chromatography and mass spectroscopy. In addition, a number of unidentified polar and apolar metabolites were also present.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 157-161 
    ISSN: 1432-041X
    Keywords: Drosophila ; Imaginal discs ; Compartments ; Distal outgrowth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Peripheral tissue of the imaginal wing disc gives rise to the proximal mesothoracic structures of the adult. Pieces of peripheral tissue, which have no regenerative capacity when cultured as intact fragments, are capable of distal outgrowth (regeneration) after dissociation and reaggregation. This ability depends on the region of the disc periphery from which the fragment is taken. Extensive distal outgrowth occurs in reaggreages of a fragment containing equal proportions of tissue from anterior and posterior developmental compartments. The extent of outgrowth decreases as the proportion of posterior tissue is reduced, so that a fragment containing only anterior tissue shows no regeneration after dissociation. Limited distal outgrowth occurs in reaggregates of a wholly posterior fragment, but the regenerative capacity is increased greatly when a small amount of anterior tissue is included. It is concluded that distal outgrowth in the wing disc requires an interaction between cells of the anterior and posterior compartments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 189 (1980), S. 91-96 
    ISSN: 1432-041X
    Keywords: Epimorphic regulation ; Drosophila ; Imaginal discs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It has been known for many years that when a wing disc ofDrosophila is bisected, and the fragments cultured in adult females, regulation occurs and either a complete disc is regenerated or the fragment is duplicated. We have investigated how this regeneration process occurs. To establish which cells contribute to the regenerate, and thus determine if regeneration is the result of epimorphic regulation, fragments of discs, after culture in an adult for one to five days, were exposed to3H-thymidine to label replicating cells. Imaginal discs, both whole and as regenerating fragments, undergo some DNA replication which is distributed throughout the disc, but cut discs frequently show clusters of labelled cells around the wound, indicating that regeneration is probably epimorphic.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 48-50 
    ISSN: 1432-041X
    Keywords: Drosophila ; Hybrid lethality ; Imaginal discs ; Interspecific transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Females ofDrosophila melanogaster, crossed with males ofDrosophila mauritiana, produce only female offspring. The male hybrid larvae grow very slowly, fail to pupate and die after prolonged larval life. Imaginal discs from these male hybrids transplanted into Drosophila melanogaster larvae can give rise to adult structures with normal patterns. Differentiation of hybrid imaginal disc tissue is improved by short term culture in non-hybrid larvae prior to metamorphosis, suggesting that the hybrid larval haemolymph is inadequate to sustain normal imaginal disc growth. This may represent the physiological basis of the reproductive isolating mechanism separating the twoDrosophila species
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 270-274 
    ISSN: 1432-041X
    Keywords: Fate map ; Repressed primordium ; Sex determination ; Genital disc ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The female genital disc ofDrosophila melanogaster was cut into distinct fragments, and the prospective fates of the fragments were determined by putting them through metamorphosis in host larvae. The dorsal epithelium contains the anlagen for the anal plates and parovaria, as well as the repressed male genital primordium. The ventral epithelium gives rise to all of the female genital structures except for the parovaria. The results were compared with published fate maps and observations made in experiments with sex-transforming mutations. This allowed us to establish a detailed three-dimensional fate map of the female genital disc, which shows a well-developed female genital primordium in the ventral epithelium, a repressed male genital primordium in the anterior part of the dorsal epithelium and an anal primordium in the posterior region of the dorsal disc epithelium.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1432-041X
    Keywords: Drosophila ; Cell degeneration ; Imaginal disc ; Basal lamina ; Blood cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mutationsvestigial (vg; recessive) andUltravestigial (vg U; dominant) ofDrosophila melanogaster give rise to identical mutant adult phenotypes in which much of the cases this results from cell death in the presumptive wing margin of the wing disc in the third larval instar, but the process of cell degeneration is quite different in the two mutants. Invg cell death occurs continuously throughout the third larval instar, while invg U it occurs only in the early third instar. Cells fragment and some of the fragments condense, becoming electron dense (“apoptosis”). Both condensed and ultrastructurally normal cell fragments are extruded to the basal side of thevg disc epithelium. They accumulate under the basal lamina in the wing pouch area until they are phagocytosed by blood cells entering the wing pouch during the six hours following pupariation. Fragments are not extruded from thevg U epithelium but are apparently phagocytosed by neighboring epithelial cells. The basal lamina undergoes mophological changes following pupariation and is phagocytosed by blood cells in both wild-type andvestigial, but investigial the degenerated cell fragments are also engulfed by the same blood cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 192 (1983), S. 317-326 
    ISSN: 1432-041X
    Keywords: Neurogenic mutations ; Topological specificity ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Neurogenic mutations have been found to cause the neuralization of certain regions of the ectoderm and yet to permit normal development of the remaining embryonic cells. Thus, it seems that the activity of the wild-type alleles of these genes is dispensable in a considerable fraction of the embryo during wild-type development. This effect might be a consequence of the cells' position within the embryo; alternatively, it might be independent of the position but be due rather to the genetic activity experienced by the cells previous to their commitment. The results described in this paper indicate that genes controlling patterning along the embryonic dorso-ventral perimeter (dorsal and Toll) are epistatic to genes controlling neurogenesis, their activity deciding which ectodermal cells are susceptible to neurogenesis. Using alleles with low expressivity, evidence was obtained showing that the tracheal placodes define the boundary of the territory which has neurogenic abilities at thoracic and abdominal levels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1432-041X
    Keywords: Determination ; Germ-line ; Somatic cells ; Inhibitor gradient hypothesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A hypothesis is presented which explains the segregation of germ cells from somatic cells, and the subsequent determination of both cell types with a single mechanism. This hypothesis is in part based on that of Meinhardt (1977) and can be summarized as follows: In the newly fertilized egg, the action of a sink in the pole plasm leads to the formation of an anterior-posterior gradient of an inhibitor. The concentration of this inhibitor in the posterior 20% of the egg is below that needed to repress synthesis of an activator. When, during the nuclear division stage, nuclei enter this posterior region, synthesis of the activator begins. As the activator is autocatalytic, this leads to the formation of a peak of activator in this region; and since the activator also catalyses the synthesis of the inhibitor, a peak of inhibitor is formed in the same place. The inhibitor then diffuses anteriorly through the periplasm, forming a posterior-anterior gradient. The presence of this inhibitor in the periplasm causes the nuclei that enter the periplasm to form blastoderm cells and to take up particular segmental states appropriate to their position, while those that remain in the yolk-containing plasm develop into vitellophages. The action of the sink in the pole plasm is postulated to result in the formation of the pole cells, and subsequently to direct some of these into forming cells of the germ-line.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 189 (1980), S. 1-15 
    ISSN: 1432-041X
    Keywords: Cell line ; Drosophila ; Ecdysone ; Ecdysterone ; Hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cells of the line Kc, derived fromDrosophila melanogaster embryos, extend long processes when exposed to ecdysteroid hormones. We have devised a quantitative assay for this morphological response, using the subline Kc-H. The assay was used to characterize the conditions required for the response. A halfmaximal response is elicited by approximately 10−8M 20-hydroxyecdysone; the response is saturated by 10−7M 20-hydroxyecdysone, which causes detectable elongation within a few hours, and a maximal response after 2–3 days. The response occurs substantially normally in the absence of serum, during growth in suspension, and in over-crowded cultures. It is not elicited by cyclic nucleotides, vertebrate growth factors, or a variety of other non-ecdysteroid reagents. Of 60 ecdysteroid compounds tested, only those which were active in other insect test systems elicited the response, and the concentrations required were approximately proportional to the concentrations active in other in vitro systems. We conclude that the response of Kc cells to 20-hydroxyecdysone retains basic features of the ecdysteroid response of intact tissues and therefore that Kc cells are a useful model system for studying ecdysteroid action.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    ISSN: 1432-041X
    Keywords: Eggshell ; Chorion ; Peroxidase ; Crosslinking ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary TheDrosophila chorion contains an endogenous peroxidase activity which remains inactive until late stage 14 when it catalyzes the crosslinking of the chorionic proteins. Using explanted follicles developing in vitro, premature, but otherwise normal crosslinking can be induced with hydrogen peroxide and normal crosslinking can be prevented with peroxidase inhibitors. Inhibition or premature activation of the shell peroxidase allows characterization of chorionic filament specific proteins and establishes new criteria for the identification of eggshell components.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1432-041X
    Keywords: Early neurogenesis ; Neurogenic mutants ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The central nervous system (CNS) ofDrosophila develops from precursor cells called neuroblasts. Neuroblasts segregate in early embryogenesis from an apparantly undifferentiated ectoderm and move into the embryo, whereas most of the remaining ectodermal cells continue development as epidermal cell precursors. Segregation of neuroblasts occurs within a region called the neurogenic field. We are interested in understanding how the genome ofDrosophila controls the parcelling of the ectoderm into epidermal and neural territories. We describe here mutations belonging to seven complementation groups which effect an abnormal neurogenesis. The phenotypes produced by these mutations are similar. Essential features of these phenotypes are a conspicuous hypertrophy of the CNS accompanied by epidermal defects; the remaining organs and tissues of the mutants are apparently unaffected. The study of mutant phenotype development strongly suggests this phenotype to be due to misrouting into the neural pathway of development of ectodermal cells which in the wildtype would have given rise to epidermal cells, i.e. to an initial enlargement of the neurogenic region at the expense of the epidermogenic region. These observations indicate that the seven genetic loci revealed by the mutations described in this study contribute to control the neurogenic field. The present results suggest that in wildtype development neurogenic genes are supressed within all derivatives of the mesoderm and endoderm and some derivatives of the ectoderm, and conditionally expressed in the remaining ectoderm. The organisation of the neurogenic field in the wildtype is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 188 (1980), S. 153-156 
    ISSN: 1432-041X
    Keywords: Drosophila ; Embryogenesis ; mat (3) 1 mutation ; Two-dimensional gels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The synthesis of a protein which has been detected in blastoderm cells but not in pole cells (Gutzeit and Gehring 1979) has been studied further by means of two-dimensional gel electrophoresis. This protein could not be detected at the nuclear multiplication stage. The protein is translated from mRNA which is transcribed at the blastoderm stage since it is not synthesized in detectable amounts when embryos are injected with α-amanitin prior to the blastoderm stage. Also the protein could not be detected when RNA from freshly laid eggs was translated in vitro. Embryos from females which are homozygous for the mutationmat (3) 1 form pole cells but no blastoderm cells (Rice and Garen 1975). Thesemat (3) 1 embryos, as we will call them in this report, express the protein if aged for a period of time sufficient for completion of blastoderm cell formation in control wild-type embryos.mat (3) 1 embryos and embryos injected with α-amanitin show the same syndrome of visible developmental anomalies; however, the studied protein could only be detected inmat (3) 1 embryos but not in α-amanitin injected embryos.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1432-041X
    Keywords: Drosophila ; Geographic strains ; Chorion proteins ; Electrophoretic variants ; Chorion gene linkage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Drosophila melanogaster chorion proteins are characterized on one-dimensional isoelectric focusing (IF) gels. The six major chorion components previously identified on SDS gels are shown to resolve into at least 11 components in our IF system. IF screening of 102 geographic strains ofDrosophila melanogaster revealed seven cases of variation in major chorion components. Two strains, Crimea and Falsterbo, which were monomorphic for a variant B1 protein and two strains, Skafto and Lausanne, which were monomorphic for a variant C1 protein, were chosen for further study. After IF developmental analysis of F1 hybrids had indicated that the sources of the variation resided in the structural genes for these proteins, each variant was crossed to a multiply marked and inverted strain (BLT) to determine the linkage group of the variant gene. To localize genes to more specific sites multiply marked 3rd (SKERO) or X-chromosomal (CB1) (X-PLE) mapping strains were used. In both Crimea and Falsterbo the gene for the B1 protein is located near map location 26 on the 3rd chromosome. In both Lausanne and Skafto the C1 gene is located on the X chromosome. Hence, for the first time, we have demonstrated genetically the non-linkage of two chorion genes, B1 and C1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 189 (1980), S. 147-153 
    ISSN: 1432-041X
    Keywords: Homeotic mutant ; Drosophila ; Clonal analysis ; Timing of gene action ; Determination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Nasobemia (Ns) is a dominant homeotic mutant ofDrosophila melanogaster which converts parts or all of the antenna to mesothoracic leg.Ns has a temperature sensitive period between 48 and 60 h. The hypothesis thatNs acts during this period and is not required thereafter to maintain the homeotic transformation to leg was tested by removingNs fromNs/+ cells at different stages of development through X-ray induced somatic recombination. The expression of theNs homeotic transformation in recombinant wild type (+/+) cells increased sharply between 48 and 65 h. In clones induced after 65 h the expression of the leg transformation was equal in large and small +/+ clones. We interpret these results as supporting the hypothesis that transient action ofNs between 48 and 65 h switches antennal cells to a clonally stable leg determined state whose maintenance does not require futherNs action.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 321-326 
    ISSN: 1432-1041
    Keywords: sotalol ; hypertension ; renal impairment ; chronic administration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Ten hypertensive patients with moderate to severe impairment of renal function were treated with sotalol for 5 to 10 weeks (average 6.4 weeks). Dosage was individually titrated (range 80 to 480 mg daily). The drug was given once daily in the morning. In eight patients blood pressure was satisfactorily controlled. Higher steady-state levels were observed than have been reported after similar doses in patients with normal renal function. The apparent first-order elimination rate constant and plasma clearance were significantly correlated with glomerular filtration rate. For an anuric patient, serum half-life was calculated to be 69 h. In relation to the raised plasma levels, side effects were uncommon. Since sotalol is excreted predominantly via the kidney, therapy in patients with impaired renal function should start with a low dose and any increase in dosage should be made carefully. As the anti-hypertensive effect does not appear to be correlated with the plasma level or with tolerance, adjustment of dose should be based on clinical response.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 225-229 
    ISSN: 1432-1041
    Keywords: metoprolol ; hypertension ; slow-release preparations ; maximal exercise power ; fatigue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The treatment of hypertension with a single daily-dose of a beta-blocker gives rise to high peak-plasma concentrations 1.5 h after ingestion. After slow release-preparations of beta-blockers, the peak concentrations are half those produced by the conventional preparation at the same oral dose. A frequently occurring side-effect of beta-blocker therapy is fatigue. In this study the effect of a single dose of metoprolol 300 mg, 200 mg, 200 mg slow-release and a placebo on maximal exercise power was tested in 6 healthy subjects, 1.5 h and 24 h after ingestion. Maximal exercise power was significantly reduced 1.5 h after ingestion of metoprolol 300 mg and 200 mg. No change was found 1.5 h after 200 mg of a slow-release preparation. The possible reasons for reduced maximal exercise power are discussed. It is concluded that use of a beta-blocker for the treatment of hypertension in a single daily-dose regimen may be a reason to prefer a slow-release preparation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 399-401 
    ISSN: 1432-1041
    Keywords: prazosin ; hypertension ; central monoaminergic neurons ; monoamine metabolites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Six hypertensive patients were treated with prazosin up to a final dose of 3–4.5 mg/day. There was a significant reduction of blood pressure. The cerebrospinal fluid (CSF) concentrations of the major metabolites of noradrenaline, dopamine and serotonin were unchanged. This indicates that the antihypertensive effect is not mediated via central monoaminergic neurons as suggested by animal studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 105-108 
    ISSN: 1432-1041
    Keywords: renin ; angiotensin ; aldosterone ; hypertension ; hypoaldosteronism ; pseudohypoaldosteronism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary There is increased activity of the renin, angiotensin, aldosterone (RAA) system in infancy and childhood. An inverse relationship between plasma renin, aldosterone and age has been demonstrated. In childhood hypertension due to renovascular disease or pyelonephritic scarring peripheral plasma renin is increased. Renal vein renin measurements in children with renal hypertension have proved valuable in predicting surgical curability of the underlying lesion. The upper limit of normal for the renal venous renin ratio in normotensive children without renal disease is 1.5. Pharmacological blockade of the RAA system has a place in diagnosis and treatment of hypertensive children. The plasma renin aldosterone profile is diagnostically useful in the investigation of salt-wasting disease and can easily distinguish between aldosterone biosynthetic defects and pseudohypoaldosteronism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 135-139 
    ISSN: 1432-1041
    Keywords: hypertension ; labetalol ; propranolol ; renal haemodynamics ; glomerular filtration rate ; blood pressure ; exercise ; renal blood flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of exercise on renal haemodynamics was examined in young patients with mild essential hypertension. Four groups of subjects were studied: 13 normotensive, healthy control subjects, and 15 untreated, 11 propranolol-treated, and 6 labetalol-treated patients. Renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured during four consecutive periods, a pre-exercise control period, two exercise periods with loads of 450 kpm/min and 600 kpm/min, respectively, and a post-exercise control period. In the untreated patients RPF and GFR were lower during exercise than in the normotensive control subjects, whereas no significant differences were found at rest. In the propranolol-treated patients the reduction in RPF and GFR during exercise was more pronounced than in the untreated hypertensives. In the labetalol-treated patients however, RPF and GFR were reduced only to the same degree as in the untreated hypertensives. The reduced renal blood flow in propranolol-treated patients may be attributed to a compensatory increase in sympathetic activity caused by an impaired cardiac response to exercise. The lack of reduction in renal blood flow during labetalol therapy could partly be related to alpha-adrenergic blockade in the renal vascular bed induced by labetalol, and partly to the smaller reduction in cardiac output during labetalol than during propranolol therapy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 231-235 
    ISSN: 1432-1041
    Keywords: molsidomine ; hypertension ; hypotension ; angina pectoris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Molsidomine (M), a new long-lasting antianginal compound, was studied in 38 hypertensive patients to assess its antihypertensive properties. Six patients were selected for an acute, single dose comparative trial with placebo over 8 h after treatment. The remaining 32 patients were used in a 1 month trial to study the effect on BP of more prolonged treatment. Systolic, diastolic and mean BP were significantly reduced after a single dose of M 4 mg, and the effect lasted for about 8 h. M also inhibited the hypertensive response to isometric exercise in handgrip tests performed 1 and 8 h after M ingestion. A dose-related decrease in systolic and diastolic BP in the one month trial was also observed. In addition to its antianginal properties, M appears to possess an interesting effect on BP in mildly to moderately hypertensive patients. A fall in BP is also a valuable effect in coronary patients with augmented metabolic demands of the heart.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1432-1041
    Keywords: hypertension ; nifedipine ; beta-adrenoceptor blockade ; hypotensive action ; adverse effects ; combination therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The antihypertensive effect of nifedipine (10–20 mg t.i.d.) given alone, or in combination with a beta-adrenoceptor blocking drug, was related to the observed plasma concentration during one dosage interval at steady-state (Pl-Nifss). The study was carried out as a within-patient comparison of treatment with nifedipine or placebo for 4 weeks. A highly significant reduction in blood pressure was obtained during monotherapy, as well as during combined treatment. The blood pressure reduction when nifedipine was added to beta-adrenoceptor blockade was of the same magnitude as that observed on nifedipine monotherapy. A considerable variation in Pl-Nifss was noted (range: 2–70 ng/ml). No significant correlation was found between the percentage reduction in blood pressure and Pl-Nifss in either of the two groups. There was a close relationship between Pl-Nifss and the concentration found 4 h after the morning dose. Side-effects were common during nifedipine monotherapy and were the reason for discontinuation of treatment in 4 of 18 patients. In contrast, none of the 9 patients on combined treatment dropped-out. In neither of the treatment groups was there any evidence for sodium retention and volume expansion during the first 4 weeks expressed as weight gain or signs of cardiac insufficiency. However, in 13 patients who continued on long-term treatment for 3–14 months, a definite need for concomitant diuretic therapy was found. The results indicate that nifedipine is effective in lowering blood pressure in patients with mild to moderate essential hypertension, either when given alone or in addition to beta-adrenoceptor blockade. It appears best tolerated as combination therapy. Long-term treatment requires addition of a diuretic. Pl-Nifss did not seem to be a major determinant of the magnitude of the hypotensive response.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 375-382 
    ISSN: 1432-1041
    Keywords: calcium antagonist ; verapamil ; hypertension ; vasodilators ; plasma renin activity ; mode of action ; sodium balance ; fluid balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In 12 in-patients with moderate uncomplicated hypertension, maintained on constant sodium intake for 15 days, single-blind oral administration of verapamil 80–160 mg t. i. d. for 10 days had a significant antihypertensive effect: in the supine position systolic blood pressure decreased from 177±5 to 150±3 mmHg, and diastolic pressure from 111±3 to 96±2 mmHg; standing values were similarly lowered from 171±7 to 143±4 mmHg, systolic, and from 118±4 to 97±2 mmHg, diastolic. The heart rate did not show any significant change (from 79±3 to 77±2 beats/min, supine, and from 92±3 to 87±3 beats/min, upright). The antihypertensive effect was uniform throughout the day, being similar 2, 3, 6 and 8 h after administration of a dose. Dynamic exercise (75–100 watts on a cycle-ergometer) caused identical increases in arterial pressure and heart rate on the last day of placebo and again on the last day with verapamil, but the peak levels of systolic pressure reached during exercise were lower after verapamil than with placebo, because of the lower blood pressure before exercise. Reduction of arterial pressure by verapamil was not accompanied by increased plasma renin activity, or by renal retention of sodium and water: there was a small increase in sodium excretion, at least during the first days of verapamil administration (from 107±15 to 113±15 mEq Na+/day), and a slight significant reduction in body weight (from 74.2±3.7 to 73.5±3.7 kg). It is concluded that oral administration of verapamil significantly lowers blood pressure without simultaneously inducing cardiac stimulation, renin secretion or salt and water retention.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 157-161 
    ISSN: 1432-1041
    Keywords: hypertension ; cadralazine ; single dose ; dose response curve ; hypotensive action ; prolonged effect ; side effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Cadralazine (ISF 2469) was administered to 24 hypertensive patients in single oral doses of 7.5, 10, 15, 20 and 30 mg, according to a single-blind, placebo-controlled, within-patient change-over design. The study was done in 2 stages: in the first a range including the upper and lower doses was studied (7.5, 15, 30 mg and placebo), and in the second the range of doses was restricted (10, 15, 20 mg and placebo). The drug produced a significant decrease in blood pressure in the supine and standing positions. The decrease became clinically important starting from the 15 mg dose. Its action was still significant 12 h after administration. A significant increase in heart rate was also observed. All the effects were correlated with the dose. Side effects occurred mainly after the 30 mg dose. Thus, cadralazine, in a single oral dose in man, showed good antihypertensive activity starting from the 15 mg dose, and its effect was dose-related, slow in onset and long-lasting.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 217-220 
    ISSN: 1432-1041
    Keywords: metoprolol ; pregnancy ; hypertension ; kinetics ; pre-eclampsia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The disposition of oral metoprolol was studied in 5 women during the last trimester of pregnancy and 3 to 5 months after delivery. After a single oral dose of 100 mg the individual peak plasma concentration in the pregnant state was only 20–40% of that after pregnancy. The plasma half-lives of metoprolol were about the same during (average 1.3 h) and after pregnancy (average 1.7 h). By contrast, the area under the plasma concentration versus time curve was much smallerduring (mean 262 nmol/l×h) thanafter (mean 1298 nmol/l×h) pregnancy, resulting in an average apparent oral clearance (Clo) of metoprolol that was 4.4times higher during (362 ml×kg−1 body-weight×min−1) than after pregnancy. The increased Clo in pregnancy is assumed to be due to enhanced hepatic metabolism of the drug. The possible clinical consequence of the difference in the disposition of metoprolol is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 307-314 
    ISSN: 1432-1041
    Keywords: endralazine ; hypertension ; blood pressure ; heart rate ; renal clearance ; plasma renin activity ; plasma aldosterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effects of endralazine, a new antihypertensive hydrazinopyridazine derivative, on heart rate, mean blood pressure (mBP), glomerular filtration rate (GFR), effective renal plasma flow (CPAH), urine volume (V), the clearance of Na, K, urea (Ur) and uric acid (UA), plasma renin activity (PRA) and plasma aldosterone (PA) were studied in hypertensive patients after a single oral dose of 10–15 mg, and after 8–17 days of treatment with daily doses of 15–90 mg. In the acute experiments, heart rate increased by 27%, mBP decreased on average by 17% and GFR by 33% and CPAH fell by only 5%. Urine volume and electrolyte clearance were also depressed. There was a significant increase in PRA and PA. The fall in GFR correlated directly with mBP, CPAH and the product (mBP×CPAH). The logarithms of the Na clearance and V were correlated with GFR and mBP. The logarithms of the fractional excretion of Na and water also correlated with mBP, suggesting that tubular reabsorption of sodium and water may be affected by change in mBP. The fractional potassium excretion correlated directly with CPAH and ln PA. In contrast, on sustained daily treatment, mBP was less depressed (9%), but GFR increased strikingly by 27% and CPAH by 46%. The body weight increased by 4.5% as a consequence of salt and water retention. GFR was correlated with CPAH, the product (mBP×CPAH) and the increase in body weight. Thus, the improvement in GFR and effective renal plasma flow observed under these conditions may be due, in part, to volume expansion. However, a direct renal vasodilating effect of the drug appears to be the more important determinant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 579-583 
    ISSN: 1432-1041
    Keywords: indapamide ; hypertension ; baroreflex ; vascular reactivity ; heart rate ; blood pressure change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of chronic treatment with indapamide on blood pressure (BP), baroreceptor sensitivity (BRS) and vascular reactivity (VR) were investigated in 10 patients with essential hypertension. After 3 months of therapy with indapamide 2.5 mg/d the mean arterial pressure (MAP) had decreased from 135±6 to 112±2 mmHg (p〈0.001); the heart rate (HR) had not changed, VR had decreased from 6.1±1.2 to 4.8±1.8 (pg·min·kg)−1 (p〈0.05), and BRS had increased from 8.3±3.7 to 12.2±5.3 ms/mmHg (p〈0.005), with a leftshift of the relationship between BP and heart period. An inverse correlation was found between the pre-treatment systolic blood pressure and the change in baroreceptor sensitivity after indapamide (r=0.59; p〈0.05). In conclusion, chronic treatment with indapamide enhances BRS and resets the reflex. The resetting may account for the lack of tachycardia at rest observed after treatment with indapamide. The mechanism by which indapamide interferes with the baroreceptor reflex requires further investigations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 143-144 
    ISSN: 1432-1041
    Keywords: hypertension ; nifedipine ; plasma concentration ; blood pressure response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 1432-1041
    Keywords: furosemide ; hypertension ; plasma renin activity ; plasma adrenaline ; plasma noradrenaline ; body fluid loss ; diuretic response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To evaluate the role of adrenergic mechanisms in the acute response of renin to furosemide, plasma renin activity (PRA) and plasma catecholamine concentrations were measured for 3 h after i.v. administration of furosemide 1 mg/kg to 8 patients with mild essential hypertension. Furosemide induced a prompt and long-lasting increase in renin, with PRA more than doubled at all times. The increase in PRA within the first 30 min paralleled the peak increases in urinary water and sodium flow rates, and significant decreases in plasma volume and central venous pressure. There was no change in plasma catecholamine concentrations. Plasma noradrenaline was increased significantly at 60 min and adrenaline at 90 min, once furosemide had induced a marked loss of body-fluid and ∼65% decrease in central venous pressure. Both catecholamines remained elevated until the end of the study, whereas urinary water and sodium flow rates had returned to their pre-treatment values by 150 min. Mean blood pressure was essentially unchanged throughout the study, whereas heart rate increased significantly after 90 min. The findings suggest that in mildly hypertensive patients adrenergic mechanisms are not involved in the initial renin response to furosemide, but they come into play later, probably as a result of reflex sympathetic activation triggered by marked volume depletion.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 307-312 
    ISSN: 1432-1041
    Keywords: ketanserin ; hypertension ; blood pressure ; plasma noradrenaline ; exercise ; orthostatic reflexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Ketanserin is a new, specific serotonin receptor blocking agent, which causes vasodilatation, presumably by an action on the vascular wall. The antihypertensive response to ketanserin 40 mg twice daily as monotherapy was assessed in 8 patients with essential hypertension. The investigation was an 8 week, double-blind, cross over study, which also included measurements during isometric (handgrip) and dynamic exercise (bicycle ergometry), as well as determination of plasma catecholamines and ketanserin. Ketanserin caused a reduction of supine and standing systolic and diastolic blood pressure (BP) during rest and a slight bradycardia. Although there was attenuation of the pressor response to handgrip, treatment with ketanserin did not really affect the changes in BP or heart rate during exercise, i.e. the base-line differences remained the same. There was no significant correlation between the effect on BP and the plasma level of ketanserin. The changes in BP produced by ketanserin showed little correlation with the initial levels of plasma catecholamines or with alterations in those levels. Although the results did not indicate direct interference by ketanserin with sympathetic tone, the lack of reflexogenic tachycardia, as well as the lack of increase in plasma noradrenaline during hand grip, indicates at least some modulation of autonomic function. It is concluded that ketanserin lowers BP in essential hypertension without interference with cardiovascular reflexes during standing or exercise, and that the compound may offer an alternative approach in the treatment of hypertension.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 571-575 
    ISSN: 1432-1041
    Keywords: beta-blocker ; felodipine ; calcium antagonist ; hypertension ; vasodilator ; side effects ; plasma levels ; metoprolol ; propranolol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a double-blind, cross-over trial, 10 men with primary hypertension, not adequately controlled with a β-blocker alone, were also given felodipine or placebo for periods of one week. Placebo was administered single-blind for 2 weeks and 1 week, respectively, before randomization and between treatments. The dose of felodipine ranged from 6.25 mg to 25 mg. The addition of felodipine resulted in a pronounced (20%), statistically significant reduction in blood pressure (BP) and a small but significant increase in heart rate (HR). The effects were seen within 1–2 h and were maximal after 3–4 h. During steady state treatment the duration of BP reduction was at least 12 h. No orthostatic reaction was seen. There was a significant correlation between the plasma concentration of felodipine and change in BP. The most frequently reported side-effects were headache and ankle oedema, the latter probably being due to pronounced pre-capillary vasodilatation. There was no weight increase and thus no indication of general water retention. No clinically significant change in laboratory variables and no influence on the P-Q time were seen. Thus, felodipine in combination with a β-blocker seems to be a useful addition to the treatment of hypertensive patients whose BP is not adequately controlled with a β-blocker alone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    ISSN: 1432-1041
    Keywords: prizidilol ; hypertension ; exercise test ; beta-blockade ; vasodilatation ; haemodynamic effects ; vascular tone ; muscle blood flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Fourteen men with moderately severe essential hypertension were treated with prizidilol hydrochloride 400–700 mg once daily (mean±S.D. 612±56 mg/day). The study was open and ambulatory, with an initial placebo period followed by dose titration of prizidilol. Prior to treatment and during optimal control of blood pressure cardiovascular adaptation was examined in a submaximal exercise test. Plethysomographic assessment of vascular flow, resistance and tone in the calf musculature during supine rest and during maximal vasodilatation was also performed. A highly significant reduction in systolic (from 164±4.5 to 141±2.7 mmHg; p〈0.001) and diastolic blood pressure (from 105±1.6 to 87±1.3 mmHg; p〈0.001) at supine rest was noted during therapy with prizidilol. There was no significant change in heart rate. Systolic pressure in the standing position was reduced (from 159±4.2 to 139±2.9 mmHg; p〈0.001) and so was the diastolic pressure (from 111±2.5 to 95±1.9 mmHg; p〈0.001). The heart rate in the standing position was significantly increased compared to supine rest in the placebo period and during optimal treatment with prizidilol. The β-adrenoceptor blocking properties of prizidilol were apparent as a reduction in the exercise-induced heart rate response at even the lowest work load. During prizidilol therapy an increase in resting calf muscle blood flow was found from 3.1±1.5 ml/min·100 ml to 4.3±2.1 ml/min·100 ml (p〈0.025). Vascular resistance and vascular tone were significantly reduced. No change regarding blood flow or resistance during maximal vasodilatation was noted. It is considered that prizidilol has a clear antihypertensive effect combining β-receptor blocking and vasodilator properties.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 1432-1041
    Keywords: atenolol ; hypertension ; plasma renin activity ; pharmacokinetics ; pharmacodynamic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To show whether repeated administration of atenolol for several days would influence its pharmacokinetic parameters and the extent and duration of the pharmacologic responses, the plasma level of atenolol and changes in heart rate, blood pressure and plasma renin activity were measured in 12 hypertensive patients at various times of day (9 a. m., 12 noon, 3 p. m. and 7 p. m.) after oral administration of the first dose of atenolol 100 mg, again during the 7th and 14th days of continued once-daily administration of the same dose, and finally during the three days following withdrawal of the drug. The peak plasma concentration of atenolol (about 600 ng/ml) was found 3 h after administration of the first dose, and measurable amounts (50–70 ng/ml) were found after 24 h. None of the pharmacokinetic characteristics were changed by administration of a single daily dose for two weeks. After withdrawal of the drug, detectable amounts of atenolol were found in plasma for at least 48 h. The first dose of atenolol caused prompt (3 h) and prolonged (up to 24 h) lowering of supine and standing systolic and diastolic blood pressures, slowing of supine and standing heart rate, reduction of the blood pressure and heart rate responses to dynamic exercise, and a decrease in plasma renin activity. The extent and time-course of all these responses were not influenced by repeated once-daily administration of the 100 mg dose for two weeks. Most of the effects continued during the withdrawal days, the lowering of blood pressure being somewhat more prolonged than the slowing of heart rate. It is concluded that a once-daily dose of atenolol 100 mg decreases blood pressure and heart rate throughout the following 24 h, without excessive daily fluctuation in its effects, and without signs of tolerance or accumulation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 17 (1980), S. 239-241 
    ISSN: 1432-1041
    Keywords: timolol ; hypertension ; dose ranging ; double-blind trial
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Nine previously untreated patients with mild-moderate hypertension were included in a dose-ranging double-blind trial to determine the effectiveness of daily versus thrice daily timolol administration. In 8 patients control of blood pressure was equally effective though with significantly lower heart rate achieved in the once daily group. One patient was not satisfactorily controlled on the daily regimen demonstrating that many but not all hypertensives can be controlled with daily administration of timolol.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 18 (1980), S. 391-394 
    ISSN: 1432-1041
    Keywords: propranolol ; hypertension ; beta-adrenergic blockade ; exercise heart rate ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of propranolol in 16 hypertensive patients was compared after the first oral dose of 80 mg and during chronic treatment with 80 mg bd. The degree of beta-adrenergic blockade was estimated by the reduction in maximal exercise heart rate. No significant change in plasma half-life occurred and there was no correlation between the mean steady-state propranolol concentration and beta-adrenergic blockade or antihypertensive effect. A linear relationship was observed between the decrease in blood pressure and the reduction in heart rate during maximal exercise. Therefore, the antihypertensive effect of propranolol can be explained by its peripheral beta-adrenergic blocking properties.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 15-19 
    ISSN: 1432-1041
    Keywords: hypertension ; mianserin ; clonidine ; methyldopa ; depression ; α2 receptors ; interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The concurrent administration of tricyclic antidepressants has been shown in man to result in a clinically significant impairment of the antihypertensive effect of clonidine. This interaction is thought to be related to competition for central α2 receptors where clonidine acts as an agonist and the tricyclics act as antagonists. Although it seems to cause less cardiovascular effects than tricyclic antidepressants, the tetracyclic antidepressant, mianserin also has been reported to be an α receptor antagonist and may, therefore, also interfere with the antihypertensive activity of centrally-acting drugs. This study investigates the effects of acute and chronic mianserin administration in patients with essential hypertension established on long term treatment with either clonidine or methyldopa. The first dose of mianserin was not associated with an increase in blood pressure and during a further two weeks of mianserin therapy there were no significant alterations in blood pressure, supine or erect. Similarly, mianserin did not alter heart rate either after acute or after chronic administration. Mianserin itself had a sedative effect but there was no interference with the sedation attributable to clonidine or methyldopa. Mianserin caused no reduction in salivary flow and did not influence the reduced saliva production caused by clonidine. Both clonidine and methyldopa are associated with a reduction in sympathetic outflow but there was no evidence in this study of any further change in plasma noradrenaline or 24 h urinary catecholamine excretion. This study demonstrates that if mianserin is given acutely or chronically, it does not interfere with the effects of the centrally acting antihypertensive drugs, clonidine and methyldopa. Mianserin may therefore be a suitable antidepressant for patients receiving these antihypertensive agents if drug treatment for depression is indicated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 1-5 
    ISSN: 1432-1041
    Keywords: hypertension ; nifedipine ; calcium antagonists ; beta-blockers ; vasodilators ; diuretics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Nifedipine has been assessed as a possible alternative to other third line drugs in the management of patients with difficult to control hypertension. A group of 20 patients whose blood pressure was unsatisfactory on a 3 drug regimen had their third drug stopped and after a 2 week period nifedipine was added to their beta-blocker plus diuretic therapy. Eleven became normotensive on 30 mg nifedipine daily and a further 6 on 60 mg daily; giving on overall success rate of 85%. This result was achieved with a reduction in side effects and an absence of any haemodynamic or metabolic complications.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 301-305 
    ISSN: 1432-1041
    Keywords: endralazine ; hypertension ; pindolol ; peripheral vasodilator ; acetylator phenotypes ; antinuclear antibodies ; SLE-syndrome ; side-effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Nineteen out-patients with moderate to severe essential hypertension were treated daily for 3 years, with an average dose of 13 mg endralazine, a new peripheral vasodilator, in free combination with pindolol 3×5 mg. The blood pressure showed a statistically significant reduction from 172/110 mmHg to 154/92 mmHg after treatment for 3 weeks. Tachyphylaxis was not observed during the 3 year period. Oedema was the most frequent side-effect, but it disappeared spontaneously. No difference in efficacy and tolerance between slow and fast acetylators was found. Only 2 patients developed a weak positive antinuclear antibody titre, which disappeared spontaneously from one during continued treatment. No clinical evidence of a systemic lupus erythematosus-like syndrome was noted. It is concluded that the differences between endralazine and hydralazine in dosage and metabolism may explain the lower immunogenic activity of endralazine.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 481-490 
    ISSN: 1432-1041
    Keywords: propranolol ; pharmacokinetics ; pregnancy ; hypertension ; naphthoxylactic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of propranolol (P) and its major metabolites, propranolol glucuronide (PGLUC), 4-hydroxypropranolol (4OHP), 4-hydroxypropranolol glucuronide (4OHPGLUC) and naphthoxylactic acid (NLA), (Walle et al. 1972) were determined, whenever possible, in the first, second and third trimesters of pregnancy in thirteen patients and also when these patients were at least three months post-partum. No correlations were found between the mean arterial blood pressure (post-therapy) or the fall in blood pressure as a result of the P therapy (p〉 〉0.05) and P dose, peak P plasma concentrations, peak 4-hydroxypropranolol (4OHP) plasma concentrations or peak (P plus 4OHP) plasma concentrations. However, a positive nonlinear relationship was found between the daily P dose (independent variable) and peak P plasma concentrations over the daily dose range 30–160 mg/day. The elimination half-lives of NLA for patients in the third trimester of pregnancy were significantly shorter (p=0.072, df=13) than those when the patients were at least three months post-partum. Also, the areas under the plasma level-time curves of NLA were significantly less (p〈0.05, df=13) for patients in the third trimester of pregnancy than when these patients were at least three months post-partum. The results of this study indicate that the pharmacokinetics of P, PGLUC, 4OHP and 4OHPGLUC are not significantly altered by pregnancy. However, the kinetics of NLA do appear to be altered. The formation of NLA by N-dealkylation of P and further oxidation, appears to be competitively inhibited by unidentified substances, perhaps endogenous steroids, especially in the third trimester when compared to at least three months post-partum.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1432-1041
    Keywords: pinacidil ; hypertension ; side effects ; pharmacokinetics ; fluid retention ; retarded release tablet
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In an open study increasing doses of a retarded tablet formulation of pinacidil were given twice daily for four weeks to 9 patients with untreated essential hypertension (WHO I–II). In all patients a decrease in diastolic blood pressure to below 100 mmHg, or a fall exceeding 15 mmHg, was obtained 2 h after tablet intake (p〈0.02), but in only two patients was the effect maintained after 10 hours (n.s.). At a mean serum concentration of 100 ng/ml 2 h after pinacidil 30 mg, the mean blood pressure had decreased by 14 and 12.7 mmHg in the supine and erect positions, respectively (p〈0.05). In contrast, mean blood pressure 10 h after the same dose was unchanged, when the mean serum concentration was 47.5 ng/ml. No change in heart rate was observed. Pharmacokinetic and pharmacodynamic investigations showed a tendency towards a more gradual and longer lasting antihypertensive effect and serum concentration-time curve after the retarded tablet than the previous tablet. Pinacidil 40 mg in the retarded tablet reduced mean blood pressure and increased heart rate for at least 8 h. There was a linear correlation between the serum concentration and the changes in mean blood pressure, and between the changes in mean blood pressure and in heart rate. There was no indication of tachyphylaxis. A serum level of 50 ng/ml of pinacidil appeared to be the minimal effective concentration. The side effect consisted of fluid retention, and the body weight increased by 1.0 kg (p〈0.05); four patients complained of oedema. Therapy was discontinued in one patient after a fainting episode following an increase in the dose. Thus, pinacidil was able to lower blood pressure during monotherapy for 4 weeks provided that an adequate serum concentration was achieved. The present retarded tablet formulation is not suitable for b. d. dosing. The tendency towards fluid-retention suggests that pinacidil should be used in combination with a diuretic.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    ISSN: 1432-1041
    Keywords: captopril ; propranolol ; sympathetic nervous system ; noradrenaline ; aldosterone ; renin ; angiotensin converting enzyme ; hypertension ; isometric exercise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effects of captopril and propranolol on blood pressure, heart rate and plasma noradrenaline, renin and aldosterone, and on the responses to changes in posture and to isometric exercise were measured in patients with essential hypertension. During placebo administration blood pressure, heart rate and plasma noradrenaline rose on standing and during isometric exercise. The rise in diastolic blood pressure during isometric exercise correlated significantly with the rise in plasma noradrenaline. During captopril treatment blood pressure was significantly lower than during placebo administration when the patients were lying, standing or sitting, but the reduction during isometric exercise was not significant. Plasma renin increased, but heart rate, plasma noradrenaline and plasma aldosterone remained unchanged. The acute changes in blood pressure, heart rate and plasma noradrenaline produced by standing and isometric exercise during captopril treatment were similar to those during placebo administration. During propranolol treatment diastolic blood pressure was significantly lower than during placebo administration when the patients were lying, standing or sitting and during isometric exercise. Heart rate also fell. Plasma noradrenaline during standing, sitting and isometric exercise was significantly greater than during placebo administration. The changes in plasma noradrenaline measured during propranolol treatment with the patients supine were negatively correlated with noradrenaline values obtained during placebo administration: plasma noradrenaline fell in patients with higher, and increased in those with lower, initial concentrations. The expected acute increase in heart rate on standing and during isometric exercise was blunted by propranolol, but the changes in blood pressure and plasma noradrenaline were unaffected. We conclude that in essential hypertension noradrenaline is involved in the pressor response to isometric exercise. Angiotensin converting enzyme inhibition by captopril did not interfere with the responses of the sympathetic nervous system to postural changes and isometric exercise. During propranolol treatment there was no evidence that reduced sympathetic activity was involved in the hypotensive response.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 145-150 
    ISSN: 1432-1041
    Keywords: nifedipine ; hypertension ; pharmacokinetics ; tablet formulation ; dose-response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A tablet formulation of nifedipine was given to 8 hospitalized hypertensive men, W.H.O. stage I or II, mean age 45 years. After an initial placebo test, nifedipine 20, 40 or 60 mg was given in random order at 72-h intervals, in a single administration crossover study. The placebo and the active drug were given at 8 a.m. Blood pressure and heart rate were measured twice by the same observer, every 20 min from 7 to 8 a.m., and then hourly until 8 p.m., first in recumbency and again after 1 min of standing upright. Plasma nifedipine was assayed in samples taken hourly from 8 a.m. to noon, every 2 h from noon to 8 p.m., and 24 and 48 h after drug administration. All 3 doses significantly lowered blood pressure; the fall during recumbency was significantly larger (−18%) and lasted longer (12 h) after 60 mg than after 20 mg (−11% and 7 h). All 3 doses caused a similar increase in heart rate (+29 to +38%), which reached its maximum after 2 h and lasted for 5 h. The maximum plasma concentration and the area under the plasma concentration — time curve were dose-dependent despite large inter-subject variation. Absorption, bioavailability and elimination were linear between the 20 and 60 mg doses. Plasma nifedipine levels were strongly correlated with the concomitant decrease in mean arterial blood pressure (r=0.61,p〈0.001). Four patients experienced mild side effects (headaches, flushes, drowsiness or weakness). This tablet form of nifedipine has a potent antihypertensive action which lasts longer than that of the capsule presentation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 17 (1980), S. 329-332 
    ISSN: 1432-1041
    Keywords: reserpine ; hydrochlorothiazide ; pituitary hormones ; gonadal hormones ; hypertension ; serum concentration ; antihypertensive therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Sex histories and serum samples were obtained from 27 hypertensive men before and after 3 months of therapy with either 100 mg of hydrochlorothiazide or 0.25 mg of reserpine daily. Sera were analyzed for testosterone, dihydrotestosterone, estradiol, luteinizing hormone and prolactin. Both drugs effectively lowered blood pressure. The incidence of impaired sexual performance was low and insignificantly different in the two treatment groups. There were no significant changes in serum hormone concentrations as a result of drug therapy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 17 (1980), S. 409-413 
    ISSN: 1432-1041
    Keywords: penbutolol ; hypertension ; propranolol ; double-blind crossover comparison ; blood pressure ; heart rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Penbutolol is a potent long-acting non-cardioselective beta-adrenergic blocker with partial agonist activity. A double-blind cross-over comparison of penbutolol given in a single daily dose and propranolol given twice daily in the treatment of ambulant patients with moderate hypertension is described. Fourteen patients completed the study and were treated with each drug for 12 weeks. Penbutolol in daily doses of 20–120 mg and propranolol in daily doses of 80–400 mg produced similar significant reductions in both supine and erect blood pressure. Penbutolol did not reduce heart rate to the same extent as propranolol, in equivalent doses. Penbutolol appears to produce adequate control of moderate hypertension when administered once a day, and this effect appears to be equivalent to divided doses of propranolol. No serious adverse effects were reported, although one patient receiving penbutolol experienced severe eye pains at a dose of 40 mg which resolved on crossing over to treatment with propranolol.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1432-1041
    Keywords: papaverine ; propranolol ; pindolol ; hypertension ; isoprenaline ; haemodynamic effects ; blood pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of two β-adrenoceptor antagonists, propranolol and pindolol, on the haemodynamic effects of papaverine, isoprenaline and noradrenaline was investigated in 9 male patients with first degree essential hypertension. Propranolol and pindolol were given according to a doubleblind, crossover scheme. Heart rate and blood pressure were measured before and after each treatment. Propranolol 670 µg/kg i. v. reduced the supine and standing systolic blood pressures by 2.3% and 1.6%, respectively. Similarly, the intravenous administration of pindolol 35 µg/kg reduced supine and standing systolic blood pressure by 5.5% and 8.3% respectively (clinically insignificant). Neither drug affected diastolic blood pressure. Following propranolol, there were moderate reductions in supine and standing heart rates, respectively by 24% and 20% (p〈0.001). Similarly, but to a lesser extent, pindolol reduced supine and standing heart rate by 12% and 17% (p〈0.001). The effects of papaverine, which, at 1.5 mg/kg i. v. reduced systolic blood pressure by 5–10% and increased heart rate by 8–15%, were not significantly influenced by the β-blockers. The blood pressure and heart rate responses to isoprenaline, on the other hand, were attenuated or inhibited by both β-blockers. While the β-blockers inhibited the β-adrenoceptor component of noradrenaline, the pressor component of noradrenaline, which is mediated through the α-adrenoceptors, was not influenced by propranolol, but was inhibited after pindolol. It is concluded that pindolol differs qualitatively from propranolol in that it inhibited both the α-and β-adrenoceptor effects of noradrenaline.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 17 (1980), S. 321-328 
    ISSN: 1432-1041
    Keywords: metoprolol ; hypertension ; pharmacokinetics ; plasma renin ; blood pressure effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Eleven patients were treated for essential hypertension with metoprolol (Selokén®) for more than three months. The time course of changes in blood pressure, pulse rate and plasma renin activity was studied during treatment with an oral maintenance dose of 100 mg twice daily. Significant decreases in pulse rate, diastolic blood pressure and plasma renin activity were observed even after the first dose. The plasma concentration of metoprolol reached equilibrium after the second dose. After the third dose there was no further significant change in blood pressure. There was a significant correlation (p〈0.001) between the initial (after three doses) and final (after 〉90days) effect of metoprolol on blood pressure (r=0.86 and 0.91 for systolic and diastolic blood pressure change, respectively).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 467-473 
    ISSN: 1432-1041
    Keywords: hydralazine ; heart failure ; pharmacokinetics ; bioavailability ; metabolism ; hypertension ; dapsone ; acetylator phenotype
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of various disease states, other than hypertension, on the pharmacokinetic behaviour of hydralazine is not completely known. In the present study the pharmacokinetics of oral hydralazine has been evaluated in 7 patients with severe, chronic heart failure, using 8 compensated hypertensives as controls. The pharmacokinetics was evaluated by measuring the plasma concentrations of hydralazine (“apparent” and “real” hydralazine) and hydralazine pyruvate hydrazone, and by assessing acetylator phenotype after a small dose of dapsone. The AUC (area under the plasma concentration curve) following a single, oral 50 mg dose was significantly larger in patients with chronic heart failure NYHA Class III–IV than in patients with essential hypertension without cardiac decompensation. A decreased rate of hepatic elimination of hydralazine is suggested as a major contributory factor to this finding.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 1432-1041
    Keywords: guanfacine ; hypertension ; phenobarbital ; withdrawal syndrome ; enzyme induction ; pharmacokinetics ; renal insufficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The unusual observation of a withdrawal syndrome due to guanfacine in a hypertensive patient with chronic renal failure led to a study of the kinetics of the drug in this patient. The principal pharmacokinetic parameters of guanfacine were greatly altered, with extended biotransformation and a decrease in the half-life compared to the values observed in other cases of severe renal insufficiency. Associated treatment with phenobarbital had had a considerable effect, as shown by the results of a further kinetic study 2 months after withdrawal of the phenobarbital. The findings then were in good agreement with reference values which strongly suggests a consequence of the enzyme inducing effect of phenobarbital. Advice about the dosage regimen in such cases is given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 713-715 
    ISSN: 1432-1041
    Keywords: nifedipine ; hypertension ; calcium antagonist ; plasma renin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Nifedipine, a calcium antagonist with a predominant vasodilator action, was evaluated for the treatment of hypertension. A 20 mg-tablet, with a slower absorption and a more sustained blood-level than provided by the 10 mg-capsule was administered to 20 patients. The duration of the trial was 20 weeks. All patients achieved a significant reduction in both systolic (p〈0.05) and diastolic (p〈0.001) blood-pressure (B.P.), but 10 patients were withdrawn before completion of the trial period. Two patients, although achieving a fall in B.P. which was significant, did not reach to target level (〈160/90) on maximal dosage, one patient suffered a stroke due to a cerebral infarct, and seven patients were withdrawn because of side-effects due mainly to vasodilatation. The remaining 10 patients obtained a satisfactory response. In nine patients, who had achieved a satisfactory result, there was no change in plasma renin activity (P.R.A.) during chronic nifedipine administration.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 835-837 
    ISSN: 1432-1041
    Keywords: tienilic acid ; hydrochlorothiazide ; amiloride ; blood pressure control ; biochemical effects ; serum uric acid ; serum potassium ; prolonged treatment ; hypertension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A comparison has been made of arterial pressure and major metabolic parameters during long term treatment with tienilic acid and a hydrochlorothiazide-amiloride combination, using a randomized single-blind study without cross-over. A significant fall in systolic and diastolic blood pressure and no change in most biochemical parameters was observed with both drugs. Serum uric acid concentration was decreased during tienilic acid and was slightly increased whilst subjects took the hydrochlorothiazide-amiloride combination; serum potassium was slightly decreased on tienilic acid. No sign of hepatotoxicity was detected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    ISSN: 1432-1041
    Keywords: bufuralol ; hypotensive therapy ; pharmacokinetics ; hypertension ; 1-hydroxybufuralol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The relationship between the plasma concentrations of bufuralol and its major hydroxymetabolite (Ro 3-7410) and β-blocking activity was studied in 10 patients with uncomplicated essential hypertension. Blood samples and haemodynamic data were obtained during rest and after a single-level exercise test on a bicycle cycloergometer, prior to and up to 32 h after administration of a single oral dose of bufuralol 30 mg. Bufuralol was rapidly absorbed, following a first-order process with a lag time. The calculated maximal plasma concentration ranged from 44.6 to 200.3 ng/ml. The half-life of bufuralol was 2.75±1.15 h (mean±SD). Up to 50% of the parent drug was transformed into Ro 3-7410, which showed less interpatient variability in concentration and a fairly constant half-life, which was three times longer than that of the parent drug. In general, the heart rate (HR) was slightly decreased, although 2/10 patients showed an initial increase. The resting HR returned to its pre-treatment level within 6 h, the exercise HR took up to 32 h to return to the pre-treatment level. The drug reduced both resting and exercise blood pressure (BP). The former was reduced from 153.0±14.2/93.5±8.5 to 134.5±14.0/77.0±6.8 mmHg (systolic/diastolic BP; mean±SD) with 6 h after treatment. Similarly, the exercise BP was reduced from 199.0±15.2/98.5±8.8 to 171.0±9.9/88.5±8.5 mmHg at the 6th h post-dosing. The BP values had not returned to their pre-treatment levels even 32 h after treatment. Thus, bufuralol and its metabolite Ro 3-7410 induced a long-lasting antihypertensive effect and inhibited the cardio-acceleratory effect of exercise, and there was a good correlation between the pharmacokinetic and pharmacodynamic behaviour of the drug.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 25 (1983), S. 581-583 
    ISSN: 1432-1041
    Keywords: hypertension ; metoprolol ; hydrochlorothiazide ; drug combination ; adverse reactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In 27 hypertensive patients whose blood pressure could not be adequately controlled with 200 mg metoprolol Durules alone, the effect of a double dose of metoprolol Durules® (400 mg once daily) was compared with a fixed combination of 200 mg metoprolol and 25 mg hydrochlorothiazide (Selokomb®). The study followed a double-blind cross-over schedule in 2 parallel groups. The reduction in diastolic blood pressure (p〈0.01) was comparable in the two groups. A significant fall (p〈0.01) in systolic blood pressure occurred with the metoprolol/hydrochlorothiazide combination. The subsequent change from the double dose of metoprolol Durules to the combination therapy also resulted in a fall in systolic blood pressure (p〈0.05). Mean serum potassium and blood glucose levels did not change after each alteration in therapy. Most of the side-effects mentioned were mild and transient in character.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 17 (1980), S. 161-164 
    ISSN: 1432-1041
    Keywords: nifedipine ; hypertension ; blood pressure ; heart rate ; plasma renin activity ; aldosterone ; clinical trial
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The magnitude and duration of the antihypertensive effect of nifedipine were studied in 7 cases of moderate essential hypertension. In a double-blind crossover study, nifedipine 10 mg or a placebo were administered sublingually 4 times a day for 2 days, and the results were compared. Each dose of nifedipine reduced systolic and diastolic blood pressure by 14% both in the supine and upright positions. The antihypertensive action lasted for about 3 h and it was not cumulative. The reduction in blood pressure was associated with a temporary increase in heart rate. Administration of nifedipine 10 mg did not significantly raise plasma renin activity or plasma aldosterone. The drug was well tolerated and no side effects were detected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 17 (1980), S. 333-337 
    ISSN: 1432-1041
    Keywords: atenolol ; chlorthalidone ; hypertension ; chronic treatment ; co-administration ; plasma half-life ; urine half-life
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of atenolol with and without the co-administration of chlorthalidone were studied in five hypertensive subjects. Concomitant administration of chlorthalidone appears to have little if any effect on the pharmacokinetics of atenolol during treatment for 7 days. The atenolol elimination half-lives were 6.7±1.1 and 6.3±0.9 h, respectively, with and without chlorthalidone. Two healthy volunteers also received a single 50 mg oral dose of chlorthalidone. Their blood profiles and pharmacokinetics were similar to those observed in hypertensive subjects, but a statistically significant difference (p〈0.01) was found between the urinary excretion half-lives of chlorthalidone. This difference may be because chronic administration of the drug caused saturation of red cell binding.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 573-577 
    ISSN: 1432-1041
    Keywords: beta-blockers ; serum lipoproteins ; atenolol ; metoprolol ; hypertension ; VLDL ; HDL ; hypertriglyceridaemia ; hypercholesterolaemia ; side effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Several β-blockers increase VLDL-TG and decrease HDL-cholesterol concentrations. The underlying mechanism ist not yet clear. Some studies have suggested that the effect is less pronounced during treatment with selective β-blockers. The effects of 2 such drugs, metoprolol 200 mg/day and atenolol 50 mg/day, have been compared in 50 hypertensive patients (WHO Stage I–II), mean age 47 years. Serum lipoproteins were determined in 20 patients before treatment and after treatment with either drug for 3 months. Both drugs were equally effective in reducing blood pressure. After atenolol the initial VLDL-cholesterol concentration of 1.04 mmol/l had not changed, but it rose to 1.29 mmol/l after metoprolol (p〈0.05). The HDL-cholesterol concentration 1.42 mmol/l did not fall during atenolol treatment, but during metoprolol there was a small reduction to 1.31 mmol/l (p〈0.05). Hyperlipoproteinaemia is common in hypertensive patients, 40% of the present group had hypertriglyceridaemia and 25% had hypercholesterolaemia. Thus, atenolol 50 mg was found not to affect lipoproteins, whereas metoprolol 200 mg increased the VLDL concentration in 75% of the patients.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 49-53 
    ISSN: 1432-1041
    Keywords: felodipine ; hypertension ; cardiac failure ; haemodynamic effects ; non-invasive monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The haemodynamic effects of a new vasodilating drug, felodipine, were studied in eight, healthy, male subjects, aged 22–31 years. The drug was given as an oral solution in the dose of 0.15 mg/kg. Thirty-five minutes later further dose of 0.15 mg/kg was administered. Felodipine induced a pronounced decrease in diastolic blood pressure (maximal effect 15±4 mm Hg) and in the systemic vascular resistance. Cardiac output increased (maximum by 4.2±0.3 l/min), due to an increase both in the stroke volume and the heart rate. The maximal increase in the stroke volume (measured from echo cardiograms) and the heart rate were 33±5 ml and 23±3 beats/min, respectively. Felodipine caused a significant decrease in the pre-ejection period (23±3 ms) and an increase in the left ventricular ejection time (29±3 ms). The quotient PEP/LVET fell from 0.36±0.01 to 0.28±0.01. Significant activity of felodipine could be recorded at a plasma level of about 15 nmol/l. When the maximal haemodynamic effects were recorded the plasma level was about 40 nmol/l. After a cumulative dose of 0.30 mg/kg, there was a twofold variation in the maximal plasma level (from 31 to 61 nmol/l). The results of the present investigation are in agreement with previous haemodynamic studies in animals. It would appear that felodipine is a potent arteriolar vasodilator and it might well be of considerable value in the management of patients with hypertension or congestive cardiac failure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 24 (1983), S. 191-197 
    ISSN: 1432-1041
    Keywords: hypertension ; beta-blocker ; diuretic ; screening ; naturalistic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A naturalistic study was set up to screen, identify and treat hypertensive patients aged 20–60 years in a rural general practice. 3,222 patients (92%) of a stable population of 3,489 were screened by 2 nurse research assistants and of these 455 patients (14%) were found to be hypertensive or borderline hypertensive. After careful assessment, 192 of these patients were found suitable for treatment and subsequently 138 entered the study. Two well recognised treatment regimes were used and no significant difference between patient response resulted. 84 patients (60.9%) completed the 2 year duration of the study discussed here. The cost of the study is not feasible in an average general practice, but day to day running of such a project, run along clearly defined treatment regimes was managed easily by 2 research assistants: this reduced, therefore, the work load on individual general practitoners.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 21 (1983), S. 199-211 
    ISSN: 1573-4927
    Keywords: Drosophila ; lactate dehydrogenase ; isozymic pattern ; development ; isozymic conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Partially purified lactate dehydrogenase (LDH) from third-instar larvae displays two bands (one major and one minor) on polyacrylamide gels. Analogous preparations from pupae and adults exhibit three LDH-staining bands (one major and two minor) in a similar pattern. The migration of the major band is similar for larvae, pupae, and adults, while the two minor LDH bands of pupae and adults migrate more slowly than the minor larval band. It has been shown that larval LDH incubated with β-nicotinamide adenine dinucleotide exhibits two additional minor bands with an electrophoretic mobility similar to that of the minor bands of both pupae and adults. The intensity of the minor larval LDH band (exhibited also by untreated preparations) is drastically reduced. This fact indicates that the life-cycle stage-dependent LDH isozymic distribution is possibly due to a posttranslational effect(s). Highly purified LDH from larvae, pupae, or adults, obtained by an affinity chromatography procedure, displays just one dispersed band, located in the area between the band 5 and the band 6 exhibited by crude extract preparations. These data, in combination with the lack of difference in catalytic properties among enzymes from larvae, pupae, and adults, suggest that LDH synthesis is controlled by the same single structural gene at all developmental stages.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 21 (1983), S. 199-211 
    ISSN: 1573-4927
    Keywords: Drosophila ; lactate dehydrogenase ; isozymic pattern ; development ; isozymic conversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Partially purified lactate dehydrogenase (LDH) from third-instar larvae displays two bands (one major and one minor) on polyacrylamide gels. Analogous preparations from pupae and adults exhibit three LDH-staining bands (one major and two minor) in a similar pattern. The migration of the major band is similar for larvae, pupae, and adults, while the two minor LDH bands of pupae and adults migrate more slowly than the minor larval band. It has been shown that larval LDH incubated with β-nicotinamide adenine dinucleotide exhibits two additional minor bands with an electrophoretic mobility similar to that of the minor bands of both pupae and adults. The intensity of the minor larval LDH band (exhibited also by untreated preparations) is drastically reduced. This fact indicates that the life-cycle stage-dependent LDH isozymic distribution is possibly due to a posttranslational effect(s). Highly purified LDH from larvae, pupae, or adults, obtained by an affinity chromatography procedure, displays just one dispersed band, located in the area between the band 5 and the band 6 exhibited by crude extract preparations. These data, in combination with the lack of difference in catalytic properties among enzymes from larvae, pupae, and adults, suggest that LDH synthesis is controlled by the same single structural gene at all developmental stages.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    ISSN: 1573-4927
    Keywords: Drosophila ; alcohol dehydrogenase ; enzyme polymorphisms, activity ratios
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Representatives of five allozymic classes of Drosophila alcohol dehydrogenase have been compared with respect to their activity levels on two alcohol substrates, quantities of ADH protein, and stability in crude extracts. Within each allozymic class, strains from widely diverse geographic locations differ in their enzyme activity levels but are identical for a measure known as “activity ratio,” which is obtained by dividing the average activity reading on isopropanol by that obtained with ethanol. They are also similar in the rate at which ADH activity declines in crude extracts held at 25°C. For several of the fast-resistant and fast-moderate strains, differences in ADH activity are associated with differences in the amount of enzyme present. The catalytic efficiencies of the fast-resistant forms are considerably lower than those of the fast-moderate allozymes. The origin and persistence of the rare but ubiquitous fast-resistant allozyme is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 1573-4927
    Keywords: Drosophila ; ontogeny ; amylase ; α-glucosidases ; functional significance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Changes in amylase (E.C. 3.2.1.1), maltase (E.C. 3.2.1.20), sucrase, and PNPGase activities in relation to changes in wet weight and protein content were studied during the development of larvae and adult flies from two strains of Drosophila melanogaster, homozygous for different amylase alleles. All α-glucosidase activities increase exponentially during a large part of larval development, parallel to the increase in weight, and drop at the end of the third instar. Amylase activity of the Amy 1 strain follows the same pattern. In contrast, amylase activity of the Amy 4,6 strain continues its exponential increase longer. In the third larval instar amylase activity in the Amy 4,6 strain becomes much higher than in the Amy 1 strain. During the first hours of adult life amylase activity of the two strains does not differ. Then Amy 4,6 activity starts to rise and becomes much higher (4–5 times) than Amy 1 amylase activity, which remains approximately constant. All adult enzyme activities are much higher than in larvae. Comparison of enzyme activity of amylase and α-glucosidases in larvae and adults confirms that differences in amylase activities can become important only when starch is a limiting factor in the food.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 439-454 
    ISSN: 1573-4927
    Keywords: Drosophila ; acetylcholinesterase ; insecticide resistance ; electrophoretic variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We examined the Canton-S strain of Drosophila melanogaster for electrophoretic variation of the enzyme acetylcholinesterase. The pattern of bands obtained (stained with acetylthiocholine) depended on age, sex, and tissue (i.e., head vs. body part and hemolymph). However, through mixing experiments, it was concluded that most of these apparent differences were due to modification of the enzyme by unknown substances located in the fly's body. The electrophoretic pattern of head acetylcholinesterase was altered so that it became characteristic of the body which was present during extraction. For example, when heads of D. melanogaster were homogenized in an extract from D. lebanonensis bodies, the characteristic AChse bands of melanogaster were absent and instead the bands of lebanonensis were found. it was found that extraction of adult heads in 0.1 M potassium phosphate buffer alone or with a 2-min exposure to 1 mg/ml trypsin at 20 C gave the most reproducible results, independent of age and sex. Using these conditions, 25 strains of D. melanogaster and 30 strains of D. pseudoobscura were examined without finding any reproducible electrophoretic variant of acetylcholinesterase. In addition, 53 strains from 39 other Drosophila species produced a total of only six electrophoretic forms of the head enzyme. Additional electromorphs were found when whole flies were used, but these were not studied in detail because of the possibility that they could be due to postextraction modification.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 717-726 
    ISSN: 1573-4927
    Keywords: Drosophila ; 5-fluorouracil ; drug response ; thymidylate synthetase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mutant strains sensitive and resistant to the drug 5-fluorouracil (FU) have been isolated from the wild-type Pac strain of Drosophila melanogaster. The resistant strain, termed flur, is resistant to at least 0.0035%FU (2.7 × 10−4 m) in the food media and exhibits cross-resistance to 5-fluorodeoxyuridine (FUdR) but not to 5-fluorouridine (FUR). The sensitive strain termed flu S , exhibits over 90% mortality on 0.0008% FU (6 × 10−5 m). Genetic analysis indicates that the flu gene is located on the third chromosome, which agrees with results of previous workers. An analysis of the enzyme thymidylate synthetase from the selected sensitive and resistant strains indicates that the resistant strain enzyme possesses an elevated specific activity. Levels 4 times that of the sensitive strain were observed when the enzymes were assayed at 20 C. This increase is apparently not due to induction by FU in the food media. It is suggested that the enzyme thymidylate synthetase may be involved in the resistance process.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 781-791 
    ISSN: 1573-4927
    Keywords: Drosophila ; phenylalanine hydroxylase ; developmental regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Herein we demonstrate that Drosophila larvae possess a synthetic activity capable of converting phenylalanine to tyrosine. This system is readily extractable and displays many characteristics of phenylalanine hydroxylase systems described in other organisms, the most notable being that a tetrahydropteridine is required for full expression of activity. The level of phenylalanine hydroxylase activity present in the organism varies with the stage of development: from an undetected level of activity at the first larval instar, there is a rapid increase in phenylalanine hydroxylase activity which reaches a peak at the time of puparium formation, after which there is a rapid decrease again to an undetected level.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 18 (1980), S. 929-937 
    ISSN: 1573-4927
    Keywords: glucose oxidase ; glucose metabolism ; Drosophila ; sex specific
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A glucose oxidase (GO) has been identified in the ejaculatory duct of male Drosophila melanogaster. Evidence is given that this enzyme was previously misidentified as HEX-1. Genetic analysis indicates that the Go structural gene is located on the third chromosome at 48 ± 0.5 cm. Go is polymorphic in males in populations of D. melanogaster and D. simulans located in Athens, Georgia. Two other hexose enzymes have also been tentatively identified for the first time in Drosophila. These are NAD(P)-glucose dehydrogenase (GODH) and NAD-gluconate dehydrogenase (GNDH). GODH and GNDH are found in both males and females and may circumvent the initial steps in the pentose shunt.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 21 (1983), S. 703-711 
    ISSN: 1573-4927
    Keywords: Drosophila ; glucose-6-phosphate dehydrogenase ; polymorphism ; sequential electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Studies were undertaken to investigate two critical aspects of the glucose-6-phosphate dehydrogenase polymorphism in Drosophila melanogaster. The first investigation unequivocally maps the genetic site of the G6PD locus to the X chromosome. The second study subjects a set of isochromosomal lines to sequential electrophoresis in an attempt to uncover common molecular heterogeneity within the global polymorphism, assuming that this variation may have gone undetected under conventional electrophoretic conditions. The genetic site was mapped following the segregation of the two common electrophoretic alleles, a so-called null allele, and two rare electrophoretic variants. From the pooled results, the Zw locus mapped to 62.9 on the X chromosome relative to the flanking markers car (at 62.5) and sw (at 64.7). A set of 126 iso-X chromosomal lines of diverse geographic origin was subjected to sequential electrophoresis under three different acrylamide conditions in addition to the conventional starch electrophoretic system. No additional variation beyond the common diallele polymorphism was seen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 10 (1980), S. 401-407 
    ISSN: 1573-3297
    Keywords: sexual isolation ; Drosophila ; geographic distance ; isolation index ; resource utilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Six strains of the cosmopolitan speciesD. immigrans from the Australian life zone plus one from the USA, show weak sexual isolation and more rarely sexual selection. Levels of sexual isolation cannot be related to geographic distances. Assortative mating may have evolved as a byproduct of ecological divergence.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Behavior genetics 13 (1983), S. 17-27 
    ISSN: 1573-3297
    Keywords: pupation site ; pupation height ; artificial selection ; Drosophila ; density-dependent behavior ; genotype-environment interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Psychology
    Notes: Abstract Selection for increased pupation height was carried out for 17 generations in two lines ofDrosophila simulans derived from a genetically heterogeneous base population. The realized heritability for mean pupation height in each line, calculated over the 17 generations, did not differ significantly from zero. Both selected lines tended to pupate away from the center of the culture medium to a greater extent than the control in the latter generations of the experiment but not in earlier generations. Pupation height may have been refractory to artificial selection because of an adaptation of this species to pupate on the larval food source. In a subsequent experiment, each line was tested at three larval densities in an apparatus different from the one used for selection. Each successively higher density showed a corresponding increase in pupation height. Both selected lines had higher mean pupation heights than the control line. The differences between lines became more pronounced as the larval density increased.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Biochemical genetics 21 (1983), S. 365-374 
    ISSN: 1573-4927
    Keywords: alcohol dehydrogenase ; NAD+ levels ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Previous studies carried out in mammalian systems indicated that an organism's NAD+/NADH balance is carefully regulated but can be destabilized by dietary stresses. Since Drosophila alcohol dehydrogenase (ADH) uses NAD+ to remove a hydrogen from ethanol in the first step of alcohol catabolism, it is possible that under alcohol stress conditions the in vivo NAD+ levels in Drosophila may decrease. In this study genetically homozygous flies were stressed with maximally sublethal concentrations of ethanol (10%) for periods of up to 24 hr. The results indicate that NAD+ levels do in fact drop by at least 20% in response to ethanol stress. Evidence is presented that suggests that this decrease is the direct result of ADH-mediated catabolism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    ISSN: 1432-2242
    Keywords: Pollen irradiation ; Wheat ; Differential gene transfer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The use of irradiated pollen to bring about limited gene transfer in wheat has been investigated. Doses of X-rays of 2Kr, 3Kr and 5Kr were used to generate M1 progeny between maternal and paternal genotypes differing in quantitative and major gene characters. Cytological studies of M1 plants revealed hybrids with widespread aneuploidy and structural rearrangements in the paternal genome. These effects resulted in phenotypic variation between M1 progeny and complex multivalent formation at meiosis. All M1 plants at the 5Kr and 3Kr doses were sterile and all but 2 plants at the 2Kr dose. Studies of the two M2 families from these plants revealed disturbances in genotype frequencies for some of the marker loci with an excess of maternal homozygotes and a deficit of paternal homozygotes. This was also reflected in a more maternal appearance for quantitative characters. These results are interpreted as showing that irradiation damage to the paternal genome in M1 plants results in the differential transmission of maternal alleles.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 65 (1983), S. 171-172 
    ISSN: 1432-2242
    Keywords: Resistance ; Genetic engineering ; Yellow rust ; Wheat ; Chitinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Virulence and resistance may act on the same biochemical mechanisms. Because Erwinia-virulence on potato depends on the lysis of cell walls of the host, resistance may depend on the lysis of cell walls of the parasite. An example is given with yellow rust on wheat.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 66 (1983), S. 249-256 
    ISSN: 1432-2242
    Keywords: Wheat ; Dwarfism ; Yield ; Quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effects of the ‘Tom Thumb’ Rht3 dwarfing gene in wheat on plant height, yield components and grain quality in field trials of random inbred lines from two ‘Minister Dwarf’ (Rht3) x rht3 crosses are described. Limited genetic increases in Rht3 plant height, up to 70 cm, were achieved by incorporating genes from the extremely tall variety ‘April Bearded’. Amongst lines from the higher yielding cross, the dwarfing gene did not reduce grain yield but was associated with an increase in grain number of over 25%. Although Rht3 reduced grain protein content by up to 0.8%, breadmaking quality, as measured by SDS sedimentation values and baking tests, was not affected. A controlled environment experiment with near-isogenic Rht3 and rht3 lines indicated that reduced grain size in the dwarfs is a competitive response to the increase in fertility rather than a primary effect of the dwarfing gene.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 64 (1983), S. 255-258 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Malate dehydrogenase ; Chromosomal location
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The malate dehydrogenase (E.C. no 1.1.1. 37) of Triticum aestivum L. cv. Chinese Spring, shows two activity zones. The results obtained support the hypothesis that the malate dehydrogenase isozymes of zone II are dimers composed of the six possible combinations of subunits coded by triplicate genes located in the long arms of chromosomes of the homoeologous group 1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 66 (1983), S. 153-157 
    ISSN: 1432-2242
    Keywords: Inheritance ; Culm-length ; GA insensitivity ; Grain weight ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The study was carried out in the first year on samples of random F5 lines, uniform in height and in heading date, of three crosses between semi dwarf spring wheat cultivars (Triticum aestivum L.), differing in grain weight and in their Rht gene. In the second year only the progenies of the early heading F5 lines were studied. All the material was grown in the absence of lodging. The culm-length genotypes of the different lines were identified by test crosses and by a seedling GA response test. No differences in grain weight were found between the two semi dwarf genotypes (Rht 1Rht1 rht 2rht2 and rht 1rht1 Rht 2Rht2). The tall genotype (rht 1rht1 rht 2rht2) was significantly higher in grain weight than the two semi dwarf genotyes and the grain weight of these genotypes exceeded markedly the grain weight of the dwarf genotype (Rht 1Rht1 Rht 2Rht2). These genotypic effects were independent of differences in plant height, heading date or number of grains per spike.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 64 (1983), S. 103-107 
    ISSN: 1432-2242
    Keywords: Glutenin ; Wheat ; Co-dominance ; Bread-making
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ten pairs of reciprocal crosses have been made between wheat cultivars which show differences in their glutenin subunit compositions. The F1 seed glutenin subunit composition was studied by means of polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS). The results indicate that all the high molecular weight (HMW) and medium molecular weight (MMW) subunits (from 133,000 to 65,000 daltons) are transmitted to the F1 seed generation from the parental cultivars. In accordance with the triploid nature of the heterozygous endosperm (3n) and with the maternal and paternal gene dosage ratio (2∶1) in the endosperm itself, a significant effect of maternal parent is registered when comparing pairs of reciprocal seeds. Genes coding for the glutenin subunits are expressed whatever their doses are (one, two, or three) in the hybrid endosperm; thus the glutenin subunits inheritance is consistent with the co-dominant type. For one pair of the reciprocal crosses, two MMW parental bands (MW: 71,000 and 66,000) seemed absent in the F1 seed patterns while a new band with an intermediate, apparent MW (68,000) appears. This phenomenon was observed when the glutenins analyzed by electrophoresis were previously separated from other endosperm proteins, and not when they were directly extracted from the ground seed. We assume that the extraction can cause interactions between moieties attached to the subunits and lead to the formation of a complex having an intermediate electrophoretic mobility.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 64 (1983), S. 303-307 
    ISSN: 1432-2242
    Keywords: Crossability ; Wheat ; Rye ; Hordeum bulbosum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Crosses of wheat (Triticum aestivum L.) Group 5 chromosome substitution lines from three different cultivar backgrounds indicate that there may be multiple alleles for reduced crossability with rye (Secale cereale L.) and H. bulbosum on both 5A and 5B chromosomes. No reduction in seed set was observed from any of the 5D substitution lines. It was found that the Kr1 locus on chromosome 5B had a more pronounced affect on both rye and H. bulbosum crossability than the Kr2 locus on chromosome 5A and that the effects of both loci were cumulative. The Kr alleles affected both rye and H. bulbosum crossability in a linear, or additive, fashion. The Kr 2 allele was shown to have little effect on H. bulbosum crossability compared to a significant effect on rye crossability. Tests with tetrasomic and nulli-tetrasomic lines of ‘Chinese Spring’ indicated that the kr allele is ‘null’ or inactive in promoting crossability while the Kr allele is active in reducing crossability to both rye and H. bulbosum. Thus, extra doses of the kr allele do not increase rye or H. bulbosum crossability in the presence of the corresponding Kr allele.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 64 (1983), S. 309-316 
    ISSN: 1432-2242
    Keywords: Wheat ; α-Amylase ; Isozymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An analysis of the α-amylase isozymes in GA-treated endosperm of wheat nullisomic-tetrasomics shows that there is more variation at the α-Amy-1 and α-Amy-2 homoeoallelic loci than was previously thought. Among the 16 isozymes produced by genes on the group 7 chromosomes, most could be definitely established as products of a single homoeoallele. Inter-varietal allelic differences would be expected at such loci and clear variation was found in isozymes produced by chromosomes 6B and 7B. The latter allele, α-Amy-B2b carried by the variety ‘Hope’, was used to locate the enzyme structural gene within chromosome 7B relative to the centromere and five other gene markers. The nature of the α-Amy-B2b phenotype and the rare non-parental isozyme patterns found among the recombinant lines indicates that the locus is large and compound, probably involving some degree of intra-locus gene duplication.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    ISSN: 1432-2242
    Keywords: Gliadin ; Glutenin ; Tticum ; Wheat ; Endosperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Gliadins, here defined as those proteins of defatted wheat endosperm which dissolve in 70% (v/v) ethanol at room temperature, were fractionated by gel filtration using Sephadex G-100. The protein which eluted with the void volume of the column, often described as high-molecular-weight (HMW) gliadin, was fractionated by the two different, two dimensional gel electrophoresis procedures of O'Farrell (1975) and O'Farrell et al. (1977). The next two fractions to elute from the gel column, ω-gliadin and α-, β-, γ-gliadin, were analysed similarly. The subunits of HMW gliadin and the classical (i.e. non-aggregated) gliadins map at distinctive positions on the electrophoregrams, the majority of the HMW gliadin subunits being more basic and having a slightly slower electrophoretic mobility than the α-, β-, γ-gliadins. These experiments demonstrate that those gliadins which aggregate to form HMW gliadin are distinct molecular entities and thus coded by different genes to those gliadins which do not aggregate. Glutenin, here prepared by a modification of the pH 6.4 precipitation procedure of Orth and Bushuk (1973), was also analysed by two-dimensional electrophoresis. The low-molecular-weight subunits were found to correspond exactly with the HMW gliadin subunits. Using the nullisomic-tetrasomic lines and the ditelocentric lines of ‘Chinese Spring’, the genes controlling the synthesis of all the major HMW gliadin subunits were shown to be located on the short arms of chromosomes 1A, 1B and 1D, as are the genes coding for the ω-gliadins and the majority of the γ-gliadins.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 65 (1983), S. 41-46 
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; Wheat ; Protein ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Poor adaptability or functional quality of much germplasm used for breeding high-protein hard red winter wheats prompted mutagenesis as an alternative means of increasing grain protein content. Four hard red winter wheat genotypes — KS644 (‘Triumph// Concho/Triumph’), ‘Kaw’, ‘Parker’, and ‘Shawnee’ — were treated with 0.40 M ethyl methanesulfonate (EMS). Advanced lines (M8-M10) were selected that had a 3-year mean grain protein advantage of 0.7% to 2.0% over controls. Increased grain protein content was generally associated with decreased grain yield and kernel weight, but some high-protein mutant lines had yields or kernel weights similar to those of original genotypes. Changes in height and lodging induced by EMS were generally favorable, most mutants being shorter and lodging less than controls, but blooming date was generally delayed, a deleterious change. One line also changed from resistant to segregating for wheat soil-borne mosaic virus. Mutant lines might be utilized in cross-breeding programs, particularly if negative pleiotropic effects and linkages are absent.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 65 (1983), S. 173-180 
    ISSN: 1432-2242
    Keywords: Disruptive selection ; Linkage disequilibrium ; Genetic variance ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Theoretical predictions of changes in variance with disruptive selection have used models of infinitely many genes so the increase in variance was necessarily due to linkage disequilibrium. With small numbers of loci, the disequilibrium is shown still to comprise the major part of the changes in variance. In a replicated experiment with Drosophila melanogaster, disruptive selection was practised for three generations, and this was followed by 5 or 7 generations of random mating. The heritability, as estimated from regression of progeny on parent, rose from 37% to 68% on selection, and subsequently declined to 45% on random mating. Changes of variance can be interpreted invoking the build up of linkage disequilibrium during selection followed by its breakdown upon relaxation. The results agree well with those obtained from Monte Carlo simulation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 1432-2242
    Keywords: Drosophila ; Enzyme polymorphisms ; Latitudinal clines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The octanol dehydrogenase (Odh) and acid phosphatase (Acph) loci of Drosophila melanogaster are each polymorphic for two electrophoretically detectable alleles. The frequencies of the Odh and Acph alleles have been analysed in populations sampled from up to a 40 ° latitudinal range in each of Australasia, North America and Europe/Asia. Odh S frequency is found to be significantly negatively associated with distance from the equator in all three zones. The relationship of Acph S frequency to distance from the equator is significant and negative in Australasia but neither significant nor consistent in sign in North America and Europe/Asia.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 58 (1980), S. 107-111 
    ISSN: 1432-2242
    Keywords: Glutenin ; Wheat ; Bread-making ; Chromosomal control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The subunit composition of glutenin from 47 European wheat cultivars was studied using SDS-polyacrylamide gel electrophoresis. These cultivars are genetically related since they originate from the same stock. Moreover, the diversity of sample, containing cultivars with very different French bread-making qualities, makes it possible to investigate the relationship between glutenin subunit composition and bread-making quality. 16 electrophoretic types of glutenin subunits could be distinguished: these were grouped into four classes. Depending on the cultivar, six to eight glutenin subunits with MW more than or equal to 62,000 were detected. Subunits 3 and 5, with an approximate MW of 122,000 and 108,000 respectively, seem to play a prominent role on bread-making quality; they were found in cultivars of good quality and were absent in those unsuitable for making French bread. Two other subunits (9 and 10; MW: 71,000 and 66,000, respectively) have a less defined influence but may be needed in some types of glutenin structure. Aneuploid analysis shows that in ‘Chinese Spring’, subunit 5 is coded by a gene on the long arm of chromosome 1B. The location of genes coding for subunits 3, 9 and 10 could not be determined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 1432-2242
    Keywords: HMW glutenin subunit genes ; cDNA clones ; Tandem DNA repeats ; Chromosomal location ; Gene copy number ; Wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary cDNA clones encoding wheat HMW glutenin subunits have been isolated from a cDNA bank made to poly A+ RNA from developing wheat endosperm var. Chinese Spring. One such clone, pTag 1290, has enabled us to identify the HMW glutenin mRNA species. The DNA sequence of this clone has been partially determined and it contains several tandem DNA repeats. The sequence is discussed in relation to the generation of the HMW glutenin subunit gene family. Analysis of the organization of the HMW glutenin sequences in the wheat genome revealed that the genes encoding HMW glutenin subunits exist in low copy number and are located on the long arm of each of the homoeologous group 1 chromosomes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    ISSN: 1432-2242
    Keywords: Triticum aestivum ; T. timopheevii ; Wheat ; Photoperiod ; Vernalization ; Male sterility ; Alloplasmic hybrids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Studies were conducted to determine the influence of the male sterility-inducing cytoplasm of Triticum timopheevii (Zhuk.) Zhuk. on response of several common winter wheat (T. aestivum L.) nuclear genotypes to photoperiod and vernalization. Comparative studies of cytoplasmic substitution lines provide information on the role of the cytoplasmic genetic mechanism in growth and development. In the case of cytoplasmic male sterility-based hybrid production systems, ubiquity of sterility-inducing cytoplasm in derived hybrids warrants thorough characterization of its influence on plant phenotype. Factorial combinations of cytoplasm (T. timopheevii and T. aestivum), nuclear genotype, and photoperiod or vernalization treatments were evaluated under hydroponic conditions in controlled environment chambers. Interaction of cytoplasm, photoperiod, and nuclear genotype was significant in one or more experiments for days to anthesis and potential spikelet number, and interaction of cytoplasm, vernalization, and nuclear genotype was significant for days to spike emergence. Long day length was associated with increased percentage seed set in one study, but interactions of photoperiod and cytoplasm were not detected for percentage seed set. Interactions involving cytoplasm and photoperiod or vernalization were interpreted as evidence of the existence of genetic factors in cytoplsam of T. timopheevii which alter photoperiod or vernalization responses of alloplasmic plants relative to responses exhibited by euplasmic plants. Since photoperiod and vernalization responses are critical to adaptation, T. timopheevii cytoplasm can alter adaptability of T. aestivum. The specific effect would be nuclear genotype dependent, and does not appear to be of a magnitude greater than that induced by nuclear genetic variability at loci conditioning photoperiod or vernalization responses or other adaptation-determining characteristics. Normal multilocation/year testing of alloplasmic hybrids should therefore adequately identify zones of adaptation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 56 (1980), S. 17-23 
    ISSN: 1432-2242
    Keywords: Wheat ; Rye ; Triticale ; Highly repeated ; DNA sequences ; Heterochromatin ; Translocations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using in situ hybridization techniques, we have been able to identify the translocated chromosomes resulting from whole arm interchanges between homoeologous chromosomes of wheat and rye. This was possible because radioactive probes are available which recognize specific sites of highly repeated sequence DNA in either rye or wheat chromosomes. The translocated chromosomes analysed in detail were found in plants from a breeding programme designed to substitute chromosome 2R of rye into commercial wheat cultivars. The distribution of rye highly repeated DNA sequences showed modified chromosomes in which (a) most of the telomeric heterochromatin of the short arm and (b) all of the telomeric heterochromatin of the long arm, had disappeared. Subsequent analyses of these chromosomes assaying for wheat highly repeated DNA sequences showed that in type (a), the entire short arm of 2R had been replaced by the short arm of wheat chromosome 2B and in (b), the long arm of 2R had been replaced by the long arm of 2B. The use of these probes has also allowed us to show that rye heterochromatin has little effect on the pairing of the translocated wheat arm to its wheat homologue during meiosis. We have also characterized the chromosomes resulting from a 1B-1R translocation event. From these results, we suggest that the observed loss of telomeric heterochromatin from rye chromosomes in wheat is commonly due to wheat-rye chromosome translocations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 56 (1980), S. 65-69 
    ISSN: 1432-2242
    Keywords: Wheat ; Gliadins ; Chromosomal control ; Aneuploid analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The chromosomal location of genes affecting five components from the low molecular weight gliadin (LMWG) fraction from wheat endosperm has been investigated by aneuploid analysis. Genes controlling these proteins were assigned to chromosomes 4B, 7A and 7D. Chromosomes from homoeologous groups 1, 2 and 6, where genes controlling classical gliadins are located, are not involved in the control of LMWG.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 57 (1980), S. 257-266 
    ISSN: 1432-2242
    Keywords: Drosophila ; Ethanol ; Climatic races ; Desiccation ; Development times
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Adult tolerance of ethanol vapour in a closed system containing 12% ethanol in solution, decreases in a cline from southern to northern Australia. However a Darwin population is more tolerant than predicted from its latitude. Ethanol tolerance races in Australia have almost certainly evolved within the last 100–150 years, because of resource unavailability prior to that time. Within populations, variation among isofemale strains is lowest in the climatically extreme southern Melbourne (37°S) and northern Darwin and Melville I. (11–12°S) populations. This suggests low resource diversity within extreme populations compared with the climatically less extreme Brisbane (28°S) and especially Townsville (19°S) populations. For desiccation resistance, the population rankings are: Darwin Melbourne 〉 Townsville 〉 Brisbane Melville I. and for development time, rankings are similar: Darwin Melbourne 〈 Townsville 〈 Brisbane Melville I. Therefore resource utilization heterogeneity is greatest in populations not greatly stressed by desiccation and where development times are extended. In total therefore, the utilization of a diversity of resources is a feature of populations tending somewhat towards a K-strategy; this is emphasized by the relative heterogeneity among isofemale strains of these populations for desiccation resistance and to a lesser extent development times. The D. melanogaster gene pool can be viewed as made up of climate-associated races. Since the ethanol tolerances of adjacent (and climatically similar) Darwin and Melville I. are very different, resource utilization races may occur within climatic races. Such a mosaic of resource utilization races are more likely in climatically extreme than in optimal habitats.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 58 (1980), S. 247-252 
    ISSN: 1432-2242
    Keywords: Maternal tissues ; Grain weight ; Wheat ; Triticum aestivum ; Caryopsis ; Pericarp ; Endosperm ; Embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Reciprocal crosses were made between semi dwarf spring wheat cultivars (Triticum aestivum L.) differing in grain weight. The weights of the F1 grains (on maternal spikes), from intact as well as from defoliated plants, and those of the F2 grains (on f1 spikes), were examined. Grain weight was controlled primarily by the genotype of the maternal tissues (pericarp, testa or other floret or spikelet organs, including the vascular system), with complete dominance of heaviness. No indications suggesting maternal inheritance were obtained. The frequency distribution of the weights of the F2 grains indicated the presence of genotypic effects exerted by the endosperm or embryo. The embryo or endosperm factors for heaviness also seemed to be dominant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 64 (1983), S. 231-238 
    ISSN: 1432-2242
    Keywords: Maize ; Wheat ; Rape ; Restriction fragments ; Two dimensional electrophoresis ; Melting profiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper deals with the relationship of chloroplast DNA (ctDNA) and cytoplasmic malesterility (CMS) of maize, wheat and rape. Intramolecular heterogeneity and fragment patterns of DNA digested with restriction endonucleases were compared and analyzed. For this purpose methods of agarose gel electrophoresis and two dimensional gel electrophoresis with denaturating solvent concentration gradients were applied. 1) Heat denaturation of ctDNA from a male sterile line in maize yielded a profile with three melting regions. This base sequence heterogeneity was not observed for the ctDNA of its maintainer. 2) Maize ctDNA was digested with EcoR1 and BamH1 restriction endonucleases, wheat and rape ctDNA with EcoR1 only. No significant differences were observed in the comparison of the fragment patterns from the sterile lines and their maintainers with the exception of the sterile line in rape which lacked one fragment present in its maintainer. 3) Two dimensional electrophoresis using a gradient of denaturing agents revealed several differences in number and relative positions of the separated restriction endonuclease fragments between the sterile lines and their respective maintainers in all three tested crops. This raises the possibility that changes in ctDNA may be involved in CMS.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 180 (1980), S. 411-418 
    ISSN: 1617-4623
    Keywords: Drosophila ; Vitellogenin ; Female-sterile mutant ; Protein processing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The mutant fs(1) 1163 of Drosophila melanogaster, which was isolated by Gans et al. (1975) is a recessive homozygous female sterile at 18°C and a dominant female — sterile at 29°C. We reported previously that there are reduced quantities of the largest of the three yolk polypeptides in Drosophila melanogaster in the haemolymph and eggs of this mutant at 29°C (Bownes and Hames 1978 a). In this paper we show that the yolk protein defect maps within approximately 2.5 recombination units of the female sterility at 21±2.5 map units on the X-chromosome. The temperature-sensitive period of the yolk protein defect is after emergence. In vitro labelling of fs(1) 1163 ovaries and fat bodies showed that they were able to synthesise yolk polypeptide 1. Interestingly, studies on the proteins present in the various tissues indicate that the fat body tends to accumulate all three yolk polypeptides in the mutant. This phenotype is partially co-dominant in that an effect is seen in heterozygotes as well as homozygotes and is enhanced by increased temperature. This mutant could therefore have a defect (a) in the structural gene for yolk polypeptide 1, (b) in the processing and secretion enzyme systems; (c) in the fat body or all tissues leading to altered secretion properties. Mutants like fs(1) 1163 which alter specific steps in vitellogenesis should be of value for analysing the genetic and biochemical control of the synthesis, transport and sequestering of the yolk polypeptides during oogenesis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 114 (1983), S. 1-13 
    ISSN: 1615-6102
    Keywords: Embryo ; Endosperm ; Scutellum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The overall morphology of the developing wheat embryo in relation to its neighbouring tissues is described. The embryo is “isolated” early in development, but appears to be a powerful sink for nutrients. It is supplied initially by hydrolysis of the nucellar parenchyma and later by hydrolysis of neighbouring endosperm cells, which are completely digested. Later on, the nucellar epidermis forms specialised cells that may be transfer cells opposite the groove at the base of the embryo. The accumulation of starch and protein appears to begin first in the basal tissues of the scutellum and coleorhiza.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 115 (1983), S. 104-113 
    ISSN: 1615-6102
    Keywords: Cereals ; Embryo culture ; Triticum aestivum ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cell proliferation from the mature embryo of wheat occurs on a defined medium in the presence of 2,4-D. Unorganized growth is observed when the 2,4-D concentration is equal to or greater than 2 mg/l, but increasing levels of 2,4-D inhibit cell division. Cell divisions begin after 4 days in culture from parenchyma cells within and near the procambial tissues of the embryo axis. By day 8 continuous meristematic zones are formed in association with vascular tissues, and DNA synthesis and cell divisions are distributed throughout these zones. No morphological evidence exists to show that these zones consist of proliferating root primordia, which are formed only after the level of 2,4-D falls below some critical concentration. When the concentration of 2,4-D is lowered, the meristematic zones first become dissected and then give rise to many root meristems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 117 (1983), S. 40-44 
    ISSN: 1615-6102
    Keywords: Cereals ; Immature embryo ; Somatic embryogenesis ; Tissue culture ; Triticum aestivum L. ; Wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Tissue cultures derived from the scutellum of immature embryos ofTriticum aestivum L. (wheat) gave rise to somatic embryos with a well-defined scutellum and coleoptile as well as one or more shoot primordia and a root primordium. The normal somatic embryos were formed from compact, white callus tissue which was not observed until 4 or more weeks after culture initiation. The highest frequency of white embryogenic tissue formation and the most normal embryoids were obtained in the dark on Murashige and Skoog's medium with twice the concentration of inorganic salts plus sucrose (2%), inositol (100–200 mg/l), casein hydrolysate (100–200 mg/l), glutamine (500 mg/l), and 2,4-dichlorophenoxyacetic acid (1–2 mg/l).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...