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  • Articles  (17)
  • Springer  (17)
  • American Geophysical Union
  • American Meteorological Society
  • 2010-2014  (4)
  • 1980-1984  (5)
  • 1960-1964  (8)
  • Medicine  (15)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (2)
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  • Articles  (17)
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  • 1
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Chromosoma 15 (1964), S. 478-502 
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The extensive genetical analysis of the T-locus in mice, carried out by Dunn and his co-workers, has revealed that the breeding pattern of t-alleles is very peculiar. The complexity of the T-locus indicates that some structural rearrangements are involved here. The purpose of the present work was to gain some informations on the structure of chromosomes in which t-alleles are present. 2. The course of spermatogenesis in the lines of mice of the following genotypes was investigated: +/+; T/+; T/t n — namely T/t 0, T/t12, T/tw1, T/tw6, T/tw18; tn/tx — namely t 0/t12, t0/tw18, t12/tw18, tw1/t12, tw1/t0, tw1/tw6, tw1/tw18, and in heterozygotes for translocations T138 and T190, both involving the fragment of linkage group IX in which some t-alleles are present and used as markers. 3. The alleles T and t w1 are not connected with structural rearrangements, as far as detectable by the methods used. The alleles t 0, tw6 and t w18 are interstitial deficiencies involving different chromosomal regions. The most complete data were obtained for t 0: in T/t 0 heterozygotes a loop corresponding to a big interstitial deficiency was present, in all t 0/tn compounds the aberrant structure of one of the bivalents indicated that an interstitial deficiency is here involved. By analysis of translocation T190 the deficiency loop is localized in the chromosome representing linkage group IX. The identification of t w6 as a small interstitial deficiency is based on the analysis of T/t w6 heterozygotes and its localization in linkage group IX on the presence of this deficiency in translocation T138. The description of tw18 as a small interstitial deficiency stems from the analysis of T/tw18 and t 0/tw18, the localization in linkage group IX is shown by its presence in t 0/tw18 in the same bivalent as t 0. The evidence obtained for t 12 indicates that it is either a big terminal deficiency or a small interstitial one inducing constant asynapsis in adjacent terminal segments of the bivalent. 4. The reasons why loops encountered in genotypes involving t 0, tw6 and t w18 are considered as deficiencies and not as duplications are based on available embryological and genetical data. The possible connections between the mode of action of the investigated t-alleles as embryonic lethals and the cytological results on their structure and localization are discussed. 5. Most of the lethal t-alleles suppress crossing-over in the region T-tf. Factors reducing the frequency of recombination in other organisms are discussed in comparison. It is concluded that the pattern of aberation in meiotic behavior of the bivalent carrying t-alleles is for almost each of the studied alleles rather specific and does not permit for suggesting any general mechanism which could account for the action of investigated lethal t-alleles as crossing-over suppressors. 6. A diagram of the presumable localisation of genetical factors in linkage group IX is presented. It is concluded that the so-called T-locus occupies the main part of the long arm of the chromosome corresponding to linkage group IX and that the investigated t-alleles are not unilocal neither with the gene T nor each with other, but scattered along the chromosome. 7. The possible modes of the origin of new t-alleles are discussed, and the hypothesis is advanced that this event might be connected with mistakes of replication of the strand on which a new t-allele arises.
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  • 3
    Electronic Resource
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    Springer
    Chromosoma 13 (1962), S. 521-525 
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure and behavior of XY bivalent in mice is discussed. The view that XY bivalent in pachytene is embedded within the sex vesicle was fully confirmed. X and Y are paired end-to-end by a nonchiasmatic connection, which is established already in pachytene and persists until first meiotic metaphase. The pachytene complement in mice consists of 19 rod-shaped autosomal bivalents and the XY bivalent embedded within the sex vesicle. A satisfactory identification of individual autosomes in male pachytene has not been found possible.
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  • 4
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    Springer
    Chromosoma 11 (1960), S. 499-513 
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The first spermatocyte division has been investigated in Rhabdophaga batatas Walsh and Wachtliella persicariae L. It was shown that the course of this division cannot be described as mitosis, either “unipolar” or “modified bipolar”. Its essential features are: complete absence of pairing and the segregation of the chromosomes into two groups composed of 4 and 30-odd chromosomes. The segregation is accomplished by a peculiar expulsion of the group of 4 chromosomes from the main nucleus followed by an unequal cytokinesis. The spindle is absent and the nuclear membrane remains present during the entire course of the division. The second spermatocyte division occurs only in the smaller cell, which contains 4 chromosomes and bears all features of normal mitosis. For the description of the course of the first spermatocyte division and chromosome distribution, which occurs in this division, the terms “segregating division” and “monocentric configuration” were proposed. The available descriptions of the first spermatocyte division in other species of Cecidomyiidae have been analyzed. The pattern of this division in all so far investigated cecidomyiid species is very uniform and the terms “unipolar” or “modified bipolar” mitoses are here also inadequate. The cases were discussed in which the peculiar chromosome arrangements arise merely as a result of positive or negative interrelations between the centriole and the chromosome parts. With this as background, the monocentric configurations in Cecidomyiidae were explained in terms of an attraction between the centriole and centromeres, operating in one group, and a repulsion between the centriole and the chromosome ends acting in the second. The other so-called unipolar mitoses have been analyzed. It was shown that under this term at least three intrinsically different configurations have been described. For the cases of Sciara, Micromalthus debilis and Cecidomyiidae, the common denominator can be found: the chromosome movements in Sciara and M. debilis can also be explained as set forth above for Cecidomyiidae, i.e. in terms of two kinds of forces operating between the centriole and the chromosomes. The several spindle fibers present in Sciara and Micromalthus do not seem to be crucial for the chromosome movements.
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  • 5
    Electronic Resource
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    Springer
    Chromosoma 12 (1961), S. 233-247 
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Currently available data on chromosome elimination in Cecidomyiidae are still inadequate to support any definite conclusions regarding its immediate causes. It seems that some evidence on the mechanism of elimination could be obtained from observation of the behavior of E chromosomes in complete absence of spindle. To bring about such absence of spindle, ultraviolet microbeams would appear promising, since they have already been used to destroy spindles in cells of other organisms. 2. For irradiation the embryos of Rhabdophaga batatas Walsh were chosen. It was established that in this species 2 S+E=40 and 2 S (for female)=8. Elimination of 30-odd chromosomes regularly occurs in the fifth cleavage. Embryos were irradiated with 8μ and 16μ heterochromatic ultraviolet microbeams not only in this fifth cleavage but also in the fourth, in which elimination was never observed. The irradiated regions were small parts of somatic cytoplasm or small parts of germ cells. 3. The effects of irradiation were multifold: complete degeneration of nuclei in the vicinity of irradiated cytoplasm; disappearance of spindle and formation of quasi-rosettes; multipolar mitosis. The polar substance present in germ cells was often severely damaged and fragmented. All these effects are evidently indirect. 4. In mitoses thus deprived of spindles, the separation of chromosomes into daughter chromatids was suppressed but some of their active movements persisted. All chromosomes were gathered into a quasirosette, which afterwards divided into two quasi-rosettes. The daughter quasi-rosettes moved apart and formed telophase nuclei. In both irradiated divisions (fourth and fifth) E chromosomes behaved in exactly the same manner as S chromosomes; they showed the same kind of peculiar movement and were incorporated into telophase nuclei. Suppression of elimination of E chromosomes in the fifth division can be regarded as one more indirect effect of irradiation to be added to the list above. 5. These results show that elimination of E chromosomes does not result from failures in chromosomal spindle fibers or from intrinsic morphological defects in the centromeres. The fact that elimination can be suppressed by indirect action of ultraviolet light strongly supports the assumption that elimination occurs because of chemical changes in adjacent cytoplasm that are injurious to the centromeres of E chromosomes. Most probably the indirect action of ultraviolet interferes with the production of some substance that is normally injurious to the centromeres in the fifth division. 6. Since in Cecidomyiidae the general features of the metabolism are known to be stable up to the mid-blastoderm stage, it would appear that the chemical changes involved in elimination cleavage are probably quite specific.
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  • 6
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    Mycopathologia 73 (1981), S. 29-31 
    ISSN: 1573-0832
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract During a seventeen day period an A. niger fungus ball evolved within a healed tuberculous cavity of a patient. Symptoms were a cough with a chocolate brown expectoration and dyspnea. The patient died and necropsy was performed. Crystals of calcium oxalate were deposited in the cavity lining and in the adjacent tissue of the lung. Fibrosis, mononuclear infiltration and intraalveolar purulent exudate were seen in these tissues. Some small vessels presented recent thrombosis and deposition of calcium oxalate. The bronchus connected with the cavity presented a disrupted epithelial layer, edema, polymorphonuclear infiltration and birefringent crystals. Scattered areas of tubular atrophy, glomerular sclerosis and lymphoid infiltration were seen in the cortex of the kidney. Oxalate crystals were also seen within the renal tubuli.
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  • 7
    ISSN: 1432-1955
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Nach Röntgenbestrahlung embryonierterCapillaria hepatica-Eier mit 0.5, 1 bzw. 2 Krd war bei den aus den Eilarven nach Infektion vonMastomys natalensis hervorgegangenen weiblichen Nematoden die Eiproduktion zunehmend reduziert. Sie unterblieb nach Bestrahlung mit 3, 4, 5, 10, 30, 50 bzw. 70 Krd. Die Leberinvasionsfähigkeit der Parasiten war nicht beeinträchtigt. Die Infektion vonM. natalensis mit unbestrahlten embryonierten Eiern führte bereits zwischen dem 6. und 8. Tag p.i. zu einem Anstieg der Serum-GLDH-Aktivitäten. Er erreichte in dieser Phase der Infektion die Höchstwerte. Hohe Werte wurden auch nach Beginn der Patenz festgestellt. Die erhöhte Aktivität hielt bis zum Versuchsende am 36. Tag p.i. an. Nach Infektion mit 2,2 bzw. 5 Krd bestrahlten Eiern waren die Aktivitätserhöhungen geringer und traten im Verlauf der Infektion mit 5 Krd bestrahlten Eiern auch verzögert auf. Nach Infektion mit unbestrahlten Eiern ließen sich im indirekten Hämagglutinationstest mit wässrigem Antigenextrakt aus nicht embryonierten Eiern die ersten Antikörper bereits 1 Woche p.i. nachweisen. Die Höchsttiter traten mit Beginn der Patenz auf. Nach anschließendem fast plateauartigem Verlauf setzte etwa mit Beendigung der Eiproduktion ungefähr um die 7. Woche p.i. ein kontinuierlicher Titerabfall ein. Der Antikörpernachweis gelang jedoch bis zum Versuchsende 17 Wochen p.i. — Nach Infektionen mit 2,2 bzw. 5 Krd bestrahlten Eiern gelang der Antikörpernachweis erst später. Die erreichten Höchsttiter waren geringfügig (2,2 Krd) bzw. auffällig (5 Krd) niedriger. Der anschließende Titerabfall führte zur Annäherung an die Werte nicht infizierterM. natalensis. Die Ergebnisse werden vergleichend mit an anderer Stelle mitgeteilten Befunden zur Leberpathohistologie der Capillariasis diskutiert.
    Notes: Abstract X-ray irradiation of embryonatedCapillaria hepatica eggs using 0.5, 1, or 2 Krd resulted in a progressive decrease of egg production of the female nematodes which had developed from irradiated first stage larvae inMastomys natalensis. Egg production did not occur after irradiation with 3, 4, 5, 10, 30, 50, or 70 Krd. The capacity of the parasites to invade the liver was not influenced. Infection ofM. natalensis using unirradiated eggs was followed by an increase of serum-GLDH-activities between days 6 and 8 post infection reaching maximum values in this period of infection. Furthermore high values have been determined after the beginning of patency. Increased activity persisted up to the end of the experiment on day 36 post infection. After infection with eggs which had received 2.2 or 5 Krd the increase of serum-GLDH-activities was decreased and occurred later in the course of infection using 5 Krd irradiated eggs. Antibodies could be demonstrated as early as one week after infection with unirradiated eggs. Employing the indirect haemagglutination test, using an aqueous extract from non-embryonated eggs as antigen, maximum titres occurred at the beginning of patency. After a nearly plateau-like course titres began to drop about 7 weeks p.i., i.e. about the end of egg production by the female worms, but antibodies were still detectable 17 weeks p.i. (end of the observation period). After infection with eggs which had received 2.2 or 5 Krd antibody development was delayed. Maximum titres were some-what (2.2 Krd) or markedly (5 Krd) lower. Thereafter titres dropped to values comparable to those of uninfectedM. natalensis. The results are compared with published reports on the pathohistology of capillariasis.
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  • 8
    ISSN: 1432-1955
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The results presented deal with the humoral immune response of golden hamsters to primary experimental infection withD. dendriticum. The development of serum antibodies has been comparatively investigated with three hamster groups (n=43) harbouring different burdens of adult flukes. The mean numbers of parasites were 11, 30, or 130 per animal. Serum antibody response was studied during an observation period of at least 331 and up to 496 days postinfection. For antibody detection the sensitivities of precipitation tests (PTs) (double diffusion test, immuno- and counterimmunoelectrophoresis), of the indirect haemagglutination test (IHAT), the complement fixation test (CFT), and the enzyme linked immuno sorbent assay (ELISA) were compared using aqueous crude fluke antigen and crude egg antigen. CFT and ELISA were most sensitive for the early detection of initial response. Thereafter all the tests employed revealed increasing antibody titres, which in general remained at constant levels and persisted until the end of the observation period with the exception of CF-antibodies. In general fluke antigen was found to be more sensitive than egg antigen. However, in CFT this antigen occasionally has been associated with unspecific inhibition of haemolysis. Comparison of the results shows that ELISA using crude fluke antigen gave the most realistic picture of the actual fluke burden. Also preliminary results on the precipitin response of rabbits (n=3) after primary experimental exposure to different numbers of metacercariae (500, 1,000, and 3,000 per animal respectively) are reported. Employing the above mentioned PTs a persisting antibody response could be demonstrated only after exposure to at least 3,000 infective larvae. The initial response was found on day 63, the observation period was 550 days.
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  • 9
    ISSN: 1432-1955
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Crude aqueousLitomosoides carinii adult worm extract was used as antigen for the detection of antibodies in sera from African patients with proven onchocerciasis (n=45) resident in rural endemic areas of Togo and Sierra Leone. In 71% of cases this extract was found to produce 1 to 5 precipitation arcs in immunoelectrophoresis. Using a crude aqueous extract from adultOnchocerca volvulus, precipitation tests were positive in 75% of cases. The complexity of theL. carinii curde extract was shown by PAG-disc electrophoresis, PAG-electrofocusing, immunoelectrophoresis and crossed immunoelectrophoresis with the appropriate rabbit-antiserum. An antigen detecting onchocercal antibodies was isolated by two step preparative flat bed electrofocusing in granulated gel (PEGG). The antigen (pI 6.55, molecular weight 55 to 60 kd as estimated by SDS-PAG electrophoresis) was very suitable for antibody demonstration in double diffusion test and immunoelectrophoresis. Preliminary controls for specificity were performed by diffusing the antigen against sera from human and animal helminthoses including filarial infections. In contrast to the crudeL. carinii extract no reaction was observed with sera from helminthic infections others than filariasis.
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  • 10
    ISSN: 1432-1955
    Keywords: Capillaria hepatica ; X-ray attenuation ; Immunization ; Capillaria hepatica ; Röntgenstrahlenaltenuierung ; Immunisierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß von Erstinfektionen mit embryonierten Eiern, von röntgenattenuierten Stadien, von nicht embryonierten Eiern und löslichen Eiextrakten auf Belastungsinfektionen mitCapillaria hepatica wurde untersucht. Die Reproduktivität einer Wurmpopulation aus einer subletalen Belastungsinfektion wurde inMastomys natalensis durch eine 11 Tage vorher gesetzte Erstinfektion mit 50, 150, 400 oder 800 embryonierten Eiern/Tier signifikant reduziert. Ein signifikanter Einfluß von röntgenattenuierten, infektiösen Eiern bzw. von intraperitoneal injizierten, nicht embryonierten Eiern (bei steigenden Dosen über 10 Tage wurde die Eiproduktion normaler Infektionen simuliert) beschränkte sich auf schwache (50 Eier/Tier) Belasnungsinfektionen. Die Kombination attenuierten Infektionsmaterials mit nicht embryonierten Eiern i.p. führte zu keiner gesteigerten Wirkung. In Albinomäusen ließ sich durch vorherige, wiederholte subkutane Injektion von löslichen Eiextrakten die Eiproduktion einer mittleren Belastungsinfektion bis zum 60. Tag p.i. hochsignifikant reduzieren. Die durch Infektionsdosen von 230 embryonierten Eiern/g Körpergewicht beiM. natalensis zwischen dem 20. und 35. Tag p.i. 100% erreichende Mortalität ließ sich durch vorherige Applikation von 50, 150, 400 und 800 Eiern/Tier bei nach 36 und 52 Tagen gesetzten Belastungsinfektionen auf 0–30% reduzieren. Bei Verwendung attenuierten Infektionsmaterials war für einen 70–80% igen Schutz eine wiederholte Vakzinierung notwendig. Die intraperitoneale Injektion von nicht embryonierten Eiern führte bei 40% der Tiere zu einem Schutz. Der Eintritt des Todes verzögerte sich i.d.R. bei vorbehandelten Tieren.
    Notes: Abstract The influence of primary infections with embryonated infective eggs or with X-irradiated infective eggs, and of non-embryonated eggs, and egg homogenate extracts on challenge infections withCapillaria hepatica was investigated. The worm reproductivity was significantly suppressed in a sublethal challenge infection given 11 days after a primary infection ofMastomys natalensis with 50, 150, 400, and 800 eggs per animal. The administration of 600 X-irradiated (2.2 Krd) embryonated eggs 36 days before challenge as well as an intraperitoneal injection of non-embryonated eggs 12, 10, 8, 6, 4, and 2 days before challenge (simulating the egg production of a normal infection) also reduced significantly the egg production of a weak (50 eggs/animal) infection. No effect was observed on a moderate challenge (300 eggs/animal). The effect was not markedly enhanced by the repeated administration of X-irradiated eggs or by the combination of X-irradiated infective eggs and non-embryonated eggs. Immunization of mice with soluble egg extracts resulted in significant reduction of egg production determined 60 days after challenge. Two hundred and thirty eggs ofC. hepatica/g bodyweight proved to be a lethal infection dose forM. natalensis. The animals died between 20 and 35 days after infection. After single infections with 50, 150, 400, or 800 eggs per animal the mortality ofMastomys challenged 36 or 52 days later was reduced to 0–30%. Using X-irradiated embryonated eggs for immunization only repeated administration led to protection in 70 to 80% of the animals. About 40% of the animals could be protected by the intraperitoneal injection of non-embryonated eggs. If death occurred it was delayed. The combination of X-irradiated stages and eggs did not enhance the protection.
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