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  • Krefeld : Geologischer Dienst Nordhein-Westfalen
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  • 1
    ISSN: 1435-604X
    Schlagwort(e): Brain tumour ; Rat ; Detection ; Fluorescence ; Laser ; Haematoporphyrin derivative
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Physik , Technik allgemein
    Notizen: Abstract Laser-induced fluorescence has been used for the identification of brain tumours in rats, which have been previously given tumour-seeking haematoporphyrin derivative. A pulsed nitrogen laser (λ=337 nm) was used in conjunction with an optical multichannel analyzer. For both inoculated RG-2 and TCVC rat-brain-tumour models, the blue autofluorescence was strongly reduced in the tumour compared with normal brain tissue, and at the same time the characteristic red-drug signal increased. The contrast between tumour and normal tissue was strongly enhanced by forming the ratio between the two signals. Implications for possible improvement of tumour delineation in brain tumour surgery are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular evolution 28 (1989), S. 220-224 
    ISSN: 1432-1432
    Schlagwort(e): Drosophila ; Foldback element ; Transposable element
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Foldback elements are a family of transposable elements described inDrosophila melanogaster. The members of this dispersed repetitive family have terminal inverted repeats that sometimes flank a central region. The inverted repeats of all the family members are homologous. The study of the distribution and conservation of the foldback elements in differentDrosophila species shows that this distribution is different from that of the hybrid dysgenesis systems (PM and IR). Sequences homologous to foldback elements were observed by Southern blots and in situ hybridization in all species of themelanogaster subgroup and in some species of themontium andtakahashii subgroups. The element was probably already present before the radiation of these subgroups. No evidence of horizontal transmission of the foldback element could be observed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    ISSN: 1432-1432
    Schlagwort(e): Carcinoembryonic antigen ; Evolution ; Gene family ; Human ; Rat ; Synonymous substitutions ; Silent molecular clock ; Evolutionary trees
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Various rodent and primate DNAs exhibit a stronger intra- than interspecies cross-hybridization with probes derived from the N-terminal domain exons of human and rat carcinoembryonic antigen (CEA)-like genes. Southern analyses also reveal that the human and rat CEA gene families are of similar complexity. We counted at least 10 different genes per human haploid genome. In the rat, approximately seven to nine different N-terminal domain exons that presumably represent different genes appear to be present. We were able to assign the corresponding genomic restriction endonuclease fragments to already isolated CEA gene family members of both human and rat. Highly similar subgroups, as found within the human CEA gene family, seem to be absent from the rat genome. Hybridization with an intron probe from the human nonspecific cross-reacting antigen (NCA) gene and analysis of DNA sequence data indicate the conservation of noncoding regions among CEA-like genes within primates, implicating that whole gene units may have been duplicated. With the help of a computer program and by calculating the rate of synonymous substitutions, evolutionary trees have been derived. From this, we propose that an independent parallel evolution, leading to different CEA gene families, must have taken place in, at least, the primate and rodent orders.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 198 (1989), S. 227-232 
    ISSN: 1432-041X
    Schlagwort(e): Campaniform sensilla ; Drosophila ; Achaete-scute complex ; Cis regulatory sites
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We have analysed the role of the achaete-scute gene complex in the development of the pattern of campaniform sensilla on the wing blade of Drosophila. We show that the complete pattern results from the superimposition of two independent subpatterns, one of which depends on the achaete gene and the other on scute. The scute subpattern comprises several clusters of sensilla, most of which seem to require the presence of control regions located upstream of the transcribed region. This is in contrast with the pattern of scute-dependent bristles, most of which depends on control elements located downstream of the transcribed region.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 198 (1989), S. 65-77 
    ISSN: 1432-041X
    Schlagwort(e): Cell communication ; Pattern formation ; Cell differentiation ; trans-regulatory genes ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The effects ofpolyhomeotic (ph) mutants in imaginal cells have been studied in a clonal analysis. Clones of cells, homozygous forph, sort-out after a few divisions, probably as a consequence of modified cell affinities. The dorso-ventral margin of the wing has special characteristics that retard this phenomenon. The formation and exclusion of a clone of 8–16 cells affect the polarity of the wild-type neighbour cells and can provoke pattern triplications. The results suggest that a defect in intercellular communication prevents the wild-type cells from maintaining coordinated positional information. The cells react by regenerative growth, and reorganize into a new pattern. The pleiotropic phenotypes ofph mutants are explained according to a common hypothesis aboutph + function.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 198 (1989), S. 157-169 
    ISSN: 1432-041X
    Schlagwort(e): Distal less ; Limb development ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The development of all of the adult limbs inDrosophila depends upon the activity of theDistal-less gene. We report here the phenotypic characterization of a number of hypomorphicDistal-less alleles which indicates that there is a graded requirement forDistal-less activity in the developing limbs. Previous analysis of genetically mosaic animals indicated that cells in the early primordia of the limb imaginal dises possess a graded proximal-distal positional information which depends on the presence of theDistal-less gene for its expression. Taken together these data suggest thatDistal-less may directly encode the graded positional information that is required to organise the proximal-distal axis of the developing limbs.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 198 (1989), S. 185-190 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Oogenesis ; Follicle cells ; Egg shell ; Ovarian tumor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The developmental potential of the cells of the somatic follicular epithelium (follicle cells) was studied in mutants in which the differentiation of the germ-line cells is blocked at different stages of oogenesis. In two mutants, sn 36a and kelch, nurse cell regression does not occur, yet the follicle cells around the small oocyte continue their normal developmental program and produce an egg shell with micropylar cone and often deformed operculum and respiratory appendages. Neither the influx of nurse cell cytoplasm into the oocyte nor the few follicle cells covering the nurse cells are apparently required for the formation of the egg shell. In the tumor mutant benign gonial cell neoplasm (bgcn) the follicle cells can also differentiate to some extent although the germ-line cells remain morphologically undifferentiated. Vitelline membrane material was synthesized by the follicle cells in some bgcn chambers and in rare cases a columnar epithelium, which resembled morphologically that of wild-type stage-9 follicles, formed around the follicle's posterior end. The normal polarity of the follicular epithelium that is characteristic for mid-vitellogenic stages may, therefore, be established in the absence of morphologically differentiating germ-line cells. However, the tumorous germ-line cells do not constitute a homogeneous cell population since in about 30% of the analyzed follicles a cell cluster at or near the posterior pole can be identified by virtue of its high number of concanavalin A binding sites. This molecular marker reveals an anteroposterior polarity of the tumorous chambers. In follicles mutant for both bgcn and the polarity gene dicephalic the cluster of concanavalin A-stained germ-line cells shifts to more anterior positions in the follicle.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    ISSN: 1432-1939
    Schlagwort(e): Drosophila ; Microbial associations ; Resource partitioning
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The distributions of five Drosophila species and four components of the microflora have been compared across a total of 48 traps baited with four different fruit and vegetable substrates in two domestic compost heaps in Canberra (Australia). Large and consistent differences are found, both among the Drosophila and among the microbial classes, in their distributions across traps baited with different substrates. Moreover the distribution of each Drosophila species shows a unique set of strong associations with the microbial distributions. Thus the distributions of both D. simulans and D. melanogaster are found to be strongly negatively correlated with the abundance of bacteria while D. simulans is also strongly positively correlated with the titre of fermenter yeasts. D. immigrans is strongly positively correlated both with bacteria and with non-fermenter yeasts. D. hydei is positively correlated with nonfermentery yeasts and D. busckii is negatively correlated with fermenter yeasts. Moulds are the only microbial class not consistently associated with the distribution of any of the Drosophila species. The correlations with the other microbial classes are sufficient to explain the majority of the abundance differences of the Drosophila species among the trap types. It is therefore proposed that the clear partitioning of the fruit resources by the Drosophila is due to their differing primary interactions with the microflora.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    ISSN: 1432-1041
    Schlagwort(e): ramipril ; renal insufficiency ; hypertension ; pharmacokinetics ; ramiprilat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In an open trial, the pharmacokinetics of ramipril and its active metabolite ramiprilat were studied in 25 hypertensive patients with various degrees of renal insufficiency given 5 mg ramipril p.o. for 14 days. Ramipril was rapidly absorbed and reached a peak concentration after 1–2 h. Cmax was greater in patients with severe renal insufficiency, which might indicate a reduced renal elimination rate, although, the rapid decline of the concentration-time curve for ramipril was almost independent of renal function. The mean initial apparent half-lives on Days 1 and 12, respectively, were 2.8 and 3.4 h (Group I: creatinine clearance 5–15 ml/min), 1.8 and 2.3 h (Group II: creatinine clearance 15–40 ml/min), and 1.9 and 1.9 h (Group III: creatinine clearance 40–80 ml/min). No accumulation was observed after multiple dosing. In contrast, the kinetics of its active acid metabolite ramiprilat was significantly influenced by renal function. The mean times to the peak plasma concentration were 5.7 h in Group I, 4.4 h in Group II and 3.8 h in Group III. The initial decline in plasma ramiprilat was dependent upon renal function; the mean initial apparent half-lives (Days 1 and 12, respectively) were 16.0 and 14.8 h (Group I), 10.1 and 9.5 h (Group II) and 10.6 and 8.0 h (Group III). Mean trough concentrations and absolute accumulation also increased with worsening renal function, and the renal clearance of ramiprilat was significantly correlated with the creatinine clearance. The subsequent long terminal phase at low plasma ramiprilat concentrations represented slow dissociation of the ACE-inhibitor complex. The study indicates that in patients with severe renal insufficiency (creatinine clearance below 30 ml/min) smaller doses of ramipril are required than in patients with normal or borderline renal function.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 575-578 
    ISSN: 1432-1041
    Schlagwort(e): bunazosin ; hypertension ; alpha1-adrenoceptor blocker ; blood pressure ; renal blood flow ; renal function ; renin ; aldosterone ; atrial natriuretic peptide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The renal and hormonal effects of the α1-adrenoceptor blocker bunazosin were examined in 6 patients with essential hypertension. Oral bunazosin for 4 to 12 weeks significantly decreased mean blood pressure by 10%, increased effective renal blood flow and creatinine clearance by 34% and 37%, respectively, the plasma norepinephrine concentration was elevated by 60%, and the plasma atrial natriuretic peptide level was lowered by 22%. The plasma renin activity and aldosterone concentration were unchanged. Thus, a moderate reduction in blood pressure was produced by bunazosin treatment while maintaining renal perfusion.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    ISSN: 1432-1041
    Schlagwort(e): felodipine ; metoprolol ; atenolol ; hypertension ; exercise ; pharmacokinetics ; adverse effects ; hypotensive action
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary A study has been performed in thirteen patients with essential hypertension, WHO Class I–II, and a diastolic blood pressure ≥95 mm Hg, on beta-blocker (metoprolol or atenolol) monotherapy, who were also given felodipine 10 mg b.d. for 28 days. The acute and steady state blood pressure response at rest and during exercise, and the pharmacokinetics of felodipine and metoprolol, were examined. Felodipine in combination with the beta-blocker reduced the systolic and diastolic blood pressures acutely and at steady-state. The duration of the effect was longer at steady-state. There was a significant correlation between the plasma concentration of felodipine and the change in blood pressure. The increase in systolic blood pressure during exercise was of the same magnitude before and after felodipine administration. No change in resting supine heart rate was found after the administration of felodipine. There were no significant differences in the pharmacokinetics of felodipine during long-term treatment, except for the trough plasma concentration, which was increased at steady-state, even though cumulation of felodipine and its metabolite did not occur. There was a significant decrease in the maximal plasma concentration and AUC of metoprolol after 28 days of treatment with felodipine, but its elimination half-life was not changed. The adverse reactions reported during this study were those generally seen after dihydropyridines and, except for two patients who were withdrawn after the first study day, the effects were well tolerated.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 229-234 
    ISSN: 1432-1041
    Schlagwort(e): enalapril ; hydrochlorothiazide ; hypertension ; side-effects ; Africans
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The antihypertensive efficacy both of angiotensin converting enzyme (ACE) inhibitors and thiazide diuretics has been claimed to be influenced by plasma renin activity, which declines with age and is low in blacks. In a double-blind, placebo-controlled, double-dummy, randomized, parallel-group preliminary study, the antihypertensive efficacy and tolerability of the ACE inhibitor enalapril (20 mg day−1) and hydrochlorothiazide (50 mg day−1) were evaluated and compared for 4 weeks in 20 African patients with essential hypertension. The two groups had similar baseline clinical features and serum Na+ and K+ levels. Hydrochlorothiazide caused a significant and sustained fall in erect blood pressure with a reflex tachycardia. Enalapril exerted only a modest antihypertensive action, but significantly reduced erect heart rate. Direct comparison of hydrochlorothiazide — and enalapril — induced hypotension suggested a greater fall in subjects on the thiazide. The 95% confidence limits for the thiazide-enalapril difference in antihypertensive action at the end of the study was 39.5 to −7.5 mm Hg systolic and 22.0 to −6.6 mm Hg diastolic. The maximal blood pressure fall after hydrochlorothiazide was positively correlated with age (r=0.50;p〈0.05), whilst that of enalapril was inversely related age to (r=−0.57,p〈0.05). The results are compatible with the notion that ACE inhibitor monotherapy may be less effective than thiazide diuretic treatment in African and black patients with essential hypertension. The findings also support the concept that age and racial factors may influence the response to antihypertensive treatment.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 567-573 
    ISSN: 1432-1041
    Schlagwort(e): isradipine ; hypertension ; blood pressure ; calcium entry blockade ; renin angiotensin system ; aldosterone plasma renin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effects of acute calcium entry blockade by isradipine (IS) and placebo (P) on the haemodynamic and humoral responses to angiotensin II (A II) have been compared in two groups of 9 patients with essential hypertension. During 4 sequential periods each of 20 min, an i.v. infusion of A II 0, 2, 4 and 8 ng · kg−1 · min−1 was given before (control) and 30 min after the oral administration either of IS or P. After IS, both the blood pressure and the angiotensin II-induced pressor effect were significantly reduced. Isradipine increased the heart rate and this cardio-acceleration was potentiated by A II. In contrast, when A II was infused in the absence of IS, heart rate tended to decrease. IS stimulated plasma renin activity and reduced plasma aldosterone. However, it did not affect either the inhibition of plasma renin activity or the rise in plasma aldosterone in response to A II. In conclusion, acute calcium entry blockade in patients with essential hypertension reduces the pressor response to A II, but not the A II-induced inhibition of renin and increase in plasma aldosterone.
    Materialart: Digitale Medien
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  • 14
    ISSN: 1432-1041
    Schlagwort(e): felodipine ; hypertension ; ambulatory blood pressure monitoring ; slow-release formulation ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary To assess the duration of the antihypertensive effect of the dihydropiridine calcium antagonist felodipine in conventional (C-F) and slow-release (ER-F) formulations, 12 patients with essential hypertension underwent ambulatory blood pressure monitoring (ABPM) at the end of a 2-week treatment period with C-F 5 mg b.d., ER-F 10 mg once daily (o.d.) and placebo. C-F, ER-F and placebo were given in a double-blind 3×3 latin square design 4 times replicated. There was no systematic change in the ABP profile over the three study periods regardless of the treatment. In comparison to placebo, the mean 24-h systolic and diastolic blood pressures showed a significant and similar reduction after both formulations of F. Compared to placebo, C-F and ER-F induced a significant reduction in systolic blood pressure for 15 and 21 h, respectively, and of diastolic blood pressure for 16 and 21 h, respectively. Three patients complained of headache (mild in 2, moderately severe in 1), and two patients of nocturia, with either formulation of F.
    Materialart: Digitale Medien
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  • 15
    ISSN: 1432-1041
    Schlagwort(e): nicardipine ; insulin ; glucose ; diabetes ; hypertension ; metabolic effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Certain acute and chronic metabolic effects of nicardipine have been studied in 20 patients with non-insulin dependent diabetes (NIDD). An intravenous glucose tolerance test (i.v. GTT, glucose 0.33 g/kg as a bolus) and the corresponding insulin response were assessed at the end of a 4 week placebo period, after the first dose and on administration for 12 weeks of nicardipine 20 mg t.i.d. The glucose and insulin responses to the i.v. GTT, evaluated as incremental AUCs, did not change significantly (glucose 30.5 mg/dl·90 min on placebo, 33.1 mg/dl·90 min acutely and 31.4 mg/dl·90 min on chronic administration of nicardipine; insulin 2.08 µU/ml·90 min on placebo, 1.87 µU/ml·90 min acutely and 1.93 µU/ml·90 min after chronic nicardipine). Glucose removal rate (KG) following the i.v. GTT was 0.73%/min on placebo 0.75%/min on acute administration and 0.8%. min−1 with chronic nicardipine. Active treatment produced a significant reduction of blood pressure (from 187/96 mm Hg on placebo to 166/89 mm Hg acutely and 152/83 mm Hg after 12 weeks of nicardipine treatment). It is concluded that the calcium antagonist nicardipine was an effective antihypertensive drug, and that it did not cause deterioration of metabolic control in hypertensive patients with NIDD.
    Materialart: Digitale Medien
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 11-15 
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; captopril ; once-daily administration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Twelve patients with essential hypertension receiving captopril monotherapy or captopril in conjunction with a diuretic had their 24-h blood pressure profiles monitored using an automatic, non-invasive ambulatory method. The study examined the efficacy of once a day versus twice a day administration of the ACE inhibitor in controlling blood pressure. Six untreated subjects with borderline hypertension were also studied using the same monitoring equipment and with the same frequency, to act as controls because of the possibility of repeated use of the device causing a ‘familiarisation’ effect. The results obtained indicated that if anything, the once daily dosing produced marginally better blood pressure values. The amplitude of the diurnal blood pressure variation was reduced on a ‘second-wearing’ of the monitoring equipment suggesting some degree of familiarisation with the apparatus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 83-86 
    ISSN: 1432-1041
    Schlagwort(e): carteolol ; hypertension ; chronic renal failure ; renal function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of short- and long-term administration of carteolol on renal function has been examined in healthy subjects and in hypertensive patients with or without renal failure. In healthy subjects neither a single dose of 10 mg carteolol nor continuous administration of 20 mg/day for 7 days had any effect on creatinine clearance and renal blood flow. In all subjects the clearance rate of carteolol was about 400 ml/min and its fractional excretion of carteolol exceeded 300%, suggesting that the drug is secreted actively from renal tubules. Twenty-three hypertensive patients with or without renal dysfunction were given carteolol 10 to 20 mg/day for more than 50 weeks in addition to their standard antihypertensive regimens, which were left changed. Laboratory results were compared with the mean values of 50 weeks before and after the addition of carteolol, and none, including plasma creatinine, blood urea nitrogen and electrolytes, were significantly changed. Neither the estimated glomerular filtration rate nor the effect of the drug on blood pressure changed significantly during this prolonged treatment. It is concluded that carteolol had no effect on renal function in healthy subjects and in hypertensive patients with or without renal failure.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 119-125 
    ISSN: 1432-1041
    Schlagwort(e): co-dergocrine ; hypertension ; presynaptic dopamine2-receptors ; norepinephrine ; haemodynamic effects ; side-effects ; renin-angiotensin-aldosterone system ; lipoproteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Co-dergocrine has recently been demonstrated acutely to lower plasma norepinephrine (NE) and blood pressure (BP) in patients with essential hypertension, and similar results have been obtained during chronic administration of co-dergocrine to healthy men. The present study investigated the effect of 3 weeks of treatment with co-dergocrine 4 mg/day on BP, plasma catecholamines, certain other BP-regulating factors and serum lipoproteins in patients with essential hypertension. Compared to placebo conditions, co-dergocrine decreased supine BP and heart rate by −7% and the upright plasma NE level by −24%. Supine plasma NE also fell (−24%). Total cholesterol and the LDL + VLDL-cholesterol lipoprotein fraction were lowered by −6%. No significant change was observed in plasma renin activity, angiotensin II, aldosterone and epinephrine levels, whole blood and plasma volume, exchangeable sodium, and the cardiovascular responsiveness to NE, angiotensin II and isoproterenol. The findings suggest that in patients with essential hypertension, chronic treatment with co-dergocrine may slightly decrease sympathetic outflow and, at least in the short-term, lower the potentially atherogenic serum LDL + VLDL − cholesterol fraction.
    Materialart: Digitale Medien
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 223-227 
    ISSN: 1432-1041
    Schlagwort(e): nitrendipine ; renal failure ; hypertension ; uric acid excretion ; metabolic effects ; cardiovascular risk factors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary To evaluate the potential therapeutic value of calcium antagonists in hypertension associated with impaired renal function, blood pressure (BP), certain regulatory factors, and metabolic correlates of cardiovascular risk have been assessed in 15 patients with mild to marked chronic renal failure before and after 6 weeks of therapy with nitrendipine. Compared to placebo, nitrendipine (mean final dose 55 mg/day) decreased supine BP from 173/102 to 146/81 mm Hg and upright BP from 170/105 to 145/86 mm Hg. Heart rate, body weight (+0.8 kg) and exchangeable sodium (+176 mmol, not significant) were minimally increased, and plasma and whole blood volume, plasma angiotensin II and creatinine concentrations, and urinary electrolyte and creatinine excretion were not significantly changed. Nitrendipine increased uric acid excretion and lowered plasma uric acid by 24%; glucose, insulin, serum total lipids, and lipoprotein fractions were unchanged.
    Materialart: Digitale Medien
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  • 20
    ISSN: 1432-1041
    Schlagwort(e): metoprolol ; pindolol ; renal haemodynamics ; salt-water handling ; hypertension ; beta-adrenoceptor blockade ; ISA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effects on renal hemodynamics and salt-water handling of equipotent doses of the cardioselective β-blocker metoprolol (M, 100 mg) and of the non-selective (intrinsic sympathetic activity) β-antagonist pindolol (P, 10 mg) were compared in 30 WHO Grade 1–2 hypertensive men. M lowered pulse rate more than P. Systolic pressure was equally reduced by both agents, and diastolic and mean pressures were decreased only after P. Glomerular filtration rate was not significantly altered by either antagonist, and renal blood flow decreased by approximately 11% both after M and P. Renal vascular resistance was unchanged after P, and was increased by 10% after M. It is concluded that, like the effects on central haemodynamics, ISA is more important in the renal response to β-adrenoceptor blockade than is β-receptor selectivity.
    Materialart: Digitale Medien
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 36 (1989), S. 347-350 
    ISSN: 1432-1041
    Schlagwort(e): pindolol ; hypertension ; hyperlipidaemia ; chronic treatment ; cholesterol ; HDL ; LDL ; triglycerides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary This is the first long-term study of pindolol in a population-based sample of men with newly diagnosed hypertension. Eighty-two patients, with a diastolic pressure of 100 mm Hg or more, were identified after screening 6000 men. Many patients were overweight. 82 population controls, matched by sex, age and body mass index, were also recruited. Fourty-eight per cent of the patients and 25% of the controls had a family history of hypertension. Serum triglyceride and urate values were higher in patients than controls at the baseline investigation. Seventy-four patients were followed for 1 year. The dose of pindolol averaged 7.7 mg once daily after 1 year. The diastolic blood pressure was reduced by 13.4 mm Hg. The target pressure of 95 mm Hg or less was achieved in 89% of the patients. The HDL-cholesterol concentration was normal and did not change, whereas the LDL-cholesterol concentration decreased by 0.15 mmol · l−1 during treatment. The total triglyceride values increased transiently up to 6 months, but no significant increase was seen after one year. It is concluded that pindolol had no adverse effect on serum cholesterol and its HDL- and LDL-fractions during 1 year of treatment.
    Materialart: Digitale Medien
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  • 22
    ISSN: 1432-1041
    Schlagwort(e): calcium antagonists ; nicardipine ; hypertension ; placebo effect ; slow-release preparation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The magnitude and duration of the anti-hypertensive effect of slow-release nicardipine (SR-Nicardipine) have been compared with placebo in 36 uncomplicated essential hypertensives (diastolic BP 95 to 115 mm Hg after 1-month placebo washout). According to a double-blind, randomized, cross-over design they received SR-Nicardipine 40 mg b.d. and placebo for 1 month. At the end of each treatment period, blood pressure and heart rate were measured 12 h after the evening dose and 1, 2, 3 and 4 h after the morning dose. SR-Nicardipine significantly reduced systolic (SBP) and diastolic (DBP) blood pressure at each time after dosing. The absolute decrements peaked 4 h after dosing (−18.3 and −11.7 mm Hg, respectively) and more than 90% of the peak effect persisted 12 h after dosing, both for SBP and DBP. The heart rate was slightly increased by SR-Nicardipine. Adverse effects monitored with a check-list occurred in 31% of patients during SR-Nicardipine treatment and in 28% on placebo. Thus, SR-Nicardipine 40 mg b.d. has a maintained and significant antihypertensive effect lasting up to 12 h in essential hypertension.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 37 (1989), S. 333-335 
    ISSN: 1432-1041
    Schlagwort(e): diabetes mellitus ; nifedipine ; hypertension ; oedema ; vasodilator ; blood flow
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary We studied the incidence of oedema 2 weeks following initation of nifedipine therapy for hypertension in a group of 10 diabetic subjects, and also measured skin blood flow (SBF) with a laser Doppler flowmeter, before and after lowering the foot. SBF with the foot horizontal increased after nifedipine from 0.31V (arbitrary units of flow) to 0.51V (NS). The postural fall in blood flow in dependency was significantly attenuated by nifedipine from 64.4 to 24.0%. Five patients developed ankle oedema. Results were similar in a small group of non-diabetic subjects starting nifedipine. The attenuation of reflex postural vasoconstriction is therefore likely to contribute to development of the oedema associated with starting nifedipine therapy, which should be monitored carefully in diabetic patients.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    ISSN: 1432-1041
    Schlagwort(e): ketanserin ; ritanserin ; hypertension ; haemodynamics ; alpha1-adrenoceptor blockade
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effects of ketanserin (40 mg p.o.) on blood pressure and brachial haemodynamics (brachial artery diameter, brachial blood velocity and blood flow) have been compared in a double-blind study with those of ritanserin (10 mg p.o.) and placebo. Haemodynamic parameters were measured before and 1 h after treatment. Patients with mild to moderate essential hypertension participated in this study, 6 each on ketanserin, ritanserin and placebo. Placebo significantly reduced heart rate and did not modify the other parameters. Compared to placebo, ketanserin significantly reduced systolic and diastolic blood pressure, increased brachial blood velocity and flow, and decreased forearm vascular resistance. Compared to placebo, ritanserin slightly decreased blood pressure and slightly increased blood flow, but neither effect was significant. When blood circulation to the hand was excluded, neither ketanserin nor ritanserin modified the proximal arterial resistance or blood flow. It is concluded that the actions of ketanserin and ritanserin essentially occurred in the distal part of the upper limb, and alpha1-receptor blockade is probably involved.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    ISSN: 1432-1041
    Schlagwort(e): nisoldipine ; hypertension ; renal function/-impairment ; calcium antagonist
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of nisoldipine on renal function after 6 weeks treatment was investigated in hypertensive patients with and without renal impairment. Nisoldipine was well tolerated and an effective antihypertensive agent when administered over a period of 6 weeks. There were no significant changes in glomerular filtration, cardiac output, plasma renin activity or serum biochemistry during nisoldipine administration. Effective renal plasma flow was unaffected by treatment in the patients with normal renal function, but in the patients with renal insufficiency, the value decreased by a mean of 12%. Nisoldipine had no major untoward effects on renal function after 6 weeks administration, but minor changes in renal haemodynamics in the patients with renal insufficiency would suggest that careful monitoring of renal function is indicated in such patients.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 37 (1989), S. 551-554 
    ISSN: 1432-1041
    Schlagwort(e): nisoldipine ; hypertension ; ambulatory monitoring ; cuff blood pressure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Cuff blood pressure data has suggested that the calcium channel antagonist nisoldipine has full twenty four hour efficacy. To test this, 24 h ambulatory intra-arterial blood pressure monitoring was performed on 18 untreated hypertensive subjects (12 men, 6 women) (cuff blood pressure 〉150/95 mm Hg) before and after chronic treatment with 10–20 mg oral nisoldipine taken daily at 08.00 h. Twelve patients completed the study, six being withdrawn, four because of side-effects. After baseline intra-arterial monitoring patients were started on 10 mg nisoldipine daily. Response was assessed by cuff pressures taken 24 h after dosing at fortnightly intervals, and if not controlled (〈150/95 or at least 10 mm Hg reduction in diastolic BP) the dose was increased to 20 mg. All patients received at least six weeks' therapy before the second intra-arterial blood pressure monitoring. There was a slight but insignificant reduction in mean daytime heart rate of 3 beats·min−1. Mean significant reduction in daytime systolic and diastolic BP was 19 mm Hg and 13 mm Hg respectively but there was no significant mean night-time reduction. By comparison 8 out of 12 patients were apparently controlled more than 24 h post dose according to cuff pressures. This study suggests that this formulation of nisoldipine does not control blood pressure over a full 24-h period, and emphasises the importance of 24 h ambulatory monitoring in assessing the efficacy of once-daily antihypertensive agents.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    ISSN: 1432-1351
    Schlagwort(e): Rat ; Melatonin ; Circadian rhythm ; 5-hydroxytryptophan
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The rhythm in melatonin production in the rat is driven by a circadian rhythm in the pineal N-acetyltransferase (NAT) activity. Rats adapted to an artificial lighting regime of 12 h of light and 12 h of darkness per day were exposed to an 8-h advance of the light-dark regime accomplished by the shortening of one dark period; the effect of melatonin, triazolam and fluoxetine, together with 5-hydroxytryptophan, on the reentrainment of the NAT rhythm was studied. In control rats, the NAT rhythm was abolished during the first 3 cycles following the advance shift. It reappeared during the 4th cycle; however, the phase relationship between the evening rise in activity and the morning decline was still compressed. Melatonin accelerated the NAT rhythm reentrainment. In rats treated chronically with melatonin at the new dark onset, the rhythm had already reappeared during the 3rd cycle, in the middle of the advanced night, and during the 4th cycle, the phase relationship between the evening onset and the morning decline of the NAT activity was the same as before the advance shift. In rats treated chronically with melatonin at the old dark onset or in those treated with melatonin 8 h, 5 h and 2 h after the new dark onset during the 1st, 2nd and 3rd cycle, respectively, following the advance shift, the NAT rhythm reappeared during the 3rd cycle as well but in the last third of the advanced night only. Neither triazolam nor fluoxetine together with 5-hydroxytryptophan administered around the new dark onset facilitated NAT rhythm reentrainment after the 8-h advance of the light-dark cycle.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Journal of comparative physiology 166 (1989), S. 179-187 
    ISSN: 1432-1351
    Schlagwort(e): Blowfly ; Drosophila ; Photoreceptor ; Lanthanum ; trp mutant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of lanthanum on the light response of blowfly (Calliphora erythrocephala) photoreceptors was studied. The electrophysiological behaviour of the photoreceptors in the presence of La can be summarized as follows: 1. Upon long stimulation the photoreceptors responded with a ‘transient receptor potential’, i.e. the cells depolarized at the onset of the stimulus and then repolarized to (or below) the resting potential. This effect was dependent on stimulus intensity and occurred only at high intensities. During illumination membrane noise was reduced. 2. The light-induced changes in membrane potential were paralleled by changes in membrane resistance. 3. The time course of the receptor response was slowed down. 4. Light adaptation led to an increase in response latency. 5. The recovery of the receptor response after light adaptation was slowed down. 6. The sensitivity of the receptor cells measured by the response to short light stimuli was reduced. In summary, the electrophysiological behaviour of Calliphora photoreceptors in the presence of La was very similar to that of the photoreceptors of the trp (transient receptor potential) mutant of Drosophila melanogaster. This result suggests that La and trp mutation affect the same cellular processes in the photoreceptors.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Ecological research 4 (1989), S. 209-218 
    ISSN: 1440-1703
    Schlagwort(e): Annual life cycle ; Drosophila ; Fungus preference ; Nematode parasitism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Food preferences and nematode parasitism were studied in natural populations of mycophagousDrosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species-specific responses toPleurotus mushrooms:D. pirka bred only onPleurotus cornucopiae, D. trivitata onP. cornucopiae andP. ostreatus, D. trilineata on these twoPleurotus mushrooms and some other mushrooms, whileD. sexvittata bred on a wide variety of mushrooms but seldom onPleurotus mushrooms. Species which preferred decayed mushrooms (D. quadrivittata, D. histrioides, D. testacea and species of thequinaria species-group) showed host preferences different from those of the above species. The rate of parasitism by nematodes was generally higher in species which prefer decayed mushrooms than in species which prefer fresh mushrooms. Among species which prefer fresh mushrooms, onlyD. trilineata was parasitized frequently by nematodes. It was not clear what factors determine the rate of parasitism in these mycophagousDrosophila. D. pirka, D. trivittata andD. trilineata passed through three or four generations per year and entered reproductive diapause in early September in and near Sapporo.
    Materialart: Digitale Medien
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 90 (1989), S. 27-35 
    ISSN: 1573-4919
    Schlagwort(e): zerknullt gene ; homeobox protein ; Drosophila ; filter binding
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Summary The region upstream from the zerknullt (zen) gene contains three sites that specifically bind the zen protein product of the gene. Evidence for these binding sites was obtained by the filter binding technique and the DNase footprinting technique. The filter binding technique was used to scan various segments of DNA for the presence of possible specific binding sites. Segments that were selectively retained by the filter binding technique invariably contained one or more specific binding sites according to the DNase footprinting technique. Two of the zen protein binding sites were spaced only 30 base pairs apart. These sites could be separated without any loss in their specific binding properties. It is concluded that these two sites function independently in the binding of zen protein.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 91 (1989), S. 3-11 
    ISSN: 1573-4919
    Schlagwort(e): calcium ATPase ; glucose transport ; herpes virus ; hypertension ; leaks ; pore-formation ; sodium channels ; stress ; toxins ; transport ; viruses
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Four situations in which membrane transport is altered by disease are discussed: (a) non-specific leaks induced by poreforming agents; (b) glucose transport and cellular stress; (c) Ca+-ATPase and hypertension; (d) Na− channels and HSV infection.
    Materialart: Digitale Medien
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Biochemical genetics 27 (1989), S. 507-520 
    ISSN: 1573-4927
    Schlagwort(e): Drosophila ; sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ; glue proteins ; glycosylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The patterns of protein fractions from total salivary glands and from glue plugs were compared in seven members of theDrosophila nasuta subgroup by the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The glue protein patterns are member specific concerning the numbers and the electrophoretic mobilities of major and minor glue protein fractions. However, the major fractions of all subgroup members could be grouped into five SDS-PAGE domains according to the homologies of their electrophoretic mobilities, prominence of Coomassie blue staining, and PAS reaction. In all subgroup members, major fractions are involved in posttranslational modifications into larger protein molecules of the final glue. Quantitative estimations of the glue proteins inD. n. nasuta andD. n. albomicans reveal that they constitute between 55 and 60% of the total salivary gland proteins, whereas inD. melanogaster and inD. hydei the fraction is only 32 and 35%, respectively.
    Materialart: Digitale Medien
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Biochemical genetics 27 (1989), S. 507-520 
    ISSN: 1573-4927
    Schlagwort(e): Drosophila ; sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ; glue proteins ; glycosylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The patterns of protein fractions from total salivary glands and from glue plugs were compared in seven members of theDrosophila nasuta subgroup by the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The glue protein patterns are member specific concerning the numbers and the electrophoretic mobilities of major and minor glue protein fractions. However, the major fractions of all subgroup members could be grouped into five SDS-PAGE domains according to the homologies of their electrophoretic mobilities, prominence of Coomassie blue staining, and PAS reaction. In all subgroup members, major fractions are involved in posttranslational modifications into larger protein molecules of the final glue. Quantitative estimations of the glue proteins inD. n. nasuta andD. n. albomicans reveal that they constitute between 55 and 60% of the total salivary gland proteins, whereas inD. melanogaster and inD. hydei the fraction is only 32 and 35%, respectively.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Biochemical genetics 27 (1989), S. 263-277 
    ISSN: 1573-4927
    Schlagwort(e): Drosophila ; kinetic plate reader ; enzyme polymorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Techniques for performing numerous enzyme kinetic assays with minimum time and effort would be valuable to studies of the evolutionary genetics of metabolic control and the quantitative genetics of determinants of kinetic parameters. Microtiter plate readers have been used for a variety of repetitious analytical techniques, and instruments are available that can take repetitive readings with sufficient speed to perform kinetic assays. The ability of these instruments to assay rapidly the kinetic properties of small samples makes them potentially useful for a number of problems in population genetics. While the ability to handle large numbers of samples is very attractive, the small sample volumes and optical imprecision of microtiter plates result in some sacrifice in accuracy. This paper presents methods for performing kinetic assays on individual field-caughtDrosophila, quantifies the precision of these methods, and characterizes differences amongDrosophila melanogaster andD. simulans from samples caught in California and Pennsylvania. Comparisons between field-caught and laboratory rearedD. melanogaster show that most of the characters are very similar, with the exception of αGPDH, which has a threefold higher mean activity among field-caught flies. The phenotypic correlations are presented with a brief discussion of their relevance to assessing the evolution of metabolic control of these enzymes.
    Materialart: Digitale Medien
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Biochemical genetics 27 (1989), S. 99-118 
    ISSN: 1573-4927
    Schlagwort(e): Drosophila ; aldox-2 ; molybdoenzymes ; sulfite oxidase ; molybdenum ; tungsten
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Mutation at thealdox-2 locus inDrosophila melanogaster affects the specific activities of four molybdoenzymes differentially during development. Sulfite oxidase activity is normal during late larval and pupal stages but is reduced during early adult stages inaldox-2 organisms. There was complete concordance among the effects ofaldox-2 on sulfite oxidase, aldehyde oxidase, xanthine dehydrogenase, and pyridoxal oxidase, when 38 stocks were analyzed which were derived from single recombination events betweenc andpx, markers which flankaldox-2. Several different biochemical analyses indicate that the active molybdoenzymes present in thealdox-2 strain are normal with respect to size, shape,pH-activity profile,K m , and molecular weight. Significant differences were found between thealdox-2 strain and the OR control strain in their responses to dietary Na2MoO4 and Na2WO4. The mutant strain is much more resistant to the effects of dietary Na2WO4 and much more responsive to the administration of Na2MoO4 than the OR control strain when these effects are quantitated by measurements of molybdoenzyme specific activities. This evidence suggests that thealdox-2 + gene product has a molybdenum binding site which can also bind tungsten and that this site is altered in the mutant strain. The hypothesis presented explains the observed effects of thealdox-2 mutation and relates them to the other mutations reported in this gene-enzyme system.
    Materialart: Digitale Medien
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  • 36
    ISSN: 1573-3297
    Schlagwort(e): Drosophila ; circadian clock ; ultradian oscillations ; disconnected mutant ; visual system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Psychologie
    Notizen: Abstract Free-running locomotor activity and eclosion rhythms ofDrosophila melanogaster, mutant at thedisconnected (disco) locus, are substantially different from the wild-type phenotype. Initial periodogram analysis revealed little or no rhythmicity (Dushayet al., 1989). We have reanalyzed the locomotor activity data using high-resolution signal analysis (maximum-entropy spectral analysis, or MESA). These analyses, corroborated by autocorrelograms, uncovered significant residual circadian rhythmicity and strong ultradian rhythms in most of the animals tested. In this regard thedisco mutants are much like flies expressing mutant alleles of theperiod gene, as well as wild-type flies reared throughout life in constant darkness. We hypothesize that light normally triggers the coupling of multiple ultradian oscillators into a functional circadian clock and that this process is disrupted indisco flies as a result of the neural lesion.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 77 (1989), S. 123-127 
    ISSN: 1432-2242
    Schlagwort(e): Inbreeding depression ; Drosophila ; Natural selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary This experiment was designed to study the relationship between rate of inbreeding and observed inbreeding depression of larval viability, adult fecundity and cold shock mortality in Drosophila melanogaster. Rates of inbreeding used were full-sib mating and closed lines of N=4 and N=20. Eight generations of mating in the N=20 lines, three generations in the N=4 lines and one generation of full-sib mating were synchronised to simultaneously produce individuals with an expected level of inbreeding coefficient (F) of approximately 0.25. Inbreeding depression for the three traits was significant at F=0.25. N=20 lines showed significantly less inbreeding depression than full-sib mated lines for larval viability at approximately the same level of F. A similar trend was observed for fecundity. No effect of rate of inbreeding depression was found for cold shock mortality, but this trait was measured with less precision than the other two. Natural selection acting on loci influencing larval viability and fecundity during the process of inbreeding could explain these results. Selection is expected to be more effective with slow rates of inbreeding because there are more generations and greater opportunity for selection to act before F=0.25 is reached. Selection intensities seem to have been different in the three traits measured. Selection was most intense for larval viability, less intense for fecundity and, perhaps, negligible at loci influencing cold shock mortality.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Theoretical and applied genetics 77 (1989), S. 253-259 
    ISSN: 1432-2242
    Schlagwort(e): Heterosis ; Selection ; Drosophila ; Genotype x environment
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Experiments were designed to examine whether heterosis would occur in crosses of Drosophila melanogaster populations adapted to 18 °C or 28 °C environments. Crosses were examined in parental environments, an intermediate environment (23 °C) and a mixed environment (alternating 18°/28°C). Parental populations did not show divergence for larval viability, cold shock or high temperature mortalities when tested in a common environment. However, the 28 °C population was less fecund than the 18 °C population, but had higher larval competitive ability and higher adult longevity. Heterosis for viability, cold shock mortality and high temperature mortality occurred in crosses between a population adapted to 18 °C and another adapted to 28 °C, but not in crosses between two populations adapted to the same temperature. The results suggest that, in the absence of drift, heterosis is expected in crosses between lines or populations with different histories of selection but not between lines with the same selection histories.
    Materialart: Digitale Medien
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 256 (1989), S. 553-558 
    ISSN: 1432-0878
    Schlagwort(e): Transforming growth factor (TGF)-β ; Myocardium ; mRNA ; Fibroblast ; Cardiomyocyte ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Transforming growth factor-β (TGF-β) is a biologically active polypeptide present in normal tissues as well as transformed cells. Two structurally related forms of this peptide are TGF-β 1 and TGF-β 2. Using freshly isolated cardiomyocytes and non-myocyte heart cells, and a [32P]-labelled cDNA probe to human TGF-β 1, we demonstrated that mRNA for TGF-β 1 could be detected only in the nonmyocyte fraction of heart cells. In the present study, the distribution of TGF-β 1 in the heart was determined by immunofluorescence staining by use of a polyclonal antibody to porcine TGF-β 1 in cryostat sections of rat heart. Immunofluorescence staining was intense around the blood vessels and radially diffuse in the surrounding myocardium.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 256 (1989), S. 303-307 
    ISSN: 1432-0878
    Schlagwort(e): Arachnoid cells ; Tight and gap junctions ; Cold injury ; Ultrastructure ; Freeze-fracture technique ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The junctional complexes of cells in the outer arachnoid layer overlying the cerebral cortex of 2-week-old rats were examined with freeze-fracture electron microscopy up to 60 min after transcranial cold injury to the dorsal surface of the brain. Within 30 min after injury, areas of gap and tight junctions with morphological features characteristic of junction formation and/or junction disruption were found scattered among normal junctional complexes in some arachnoid cells. Within 60 min after injury, tight junctions with features typical of less leaky zonulae occludentes were present in all arachnoid cells examined. These morphological features include increases in the number of tight junctional strands and the number of strand-to-strand anatomoses. Gap junctions were interspersed among the tight junctional strands, and many were completely encircled by the strands. The increase in the number and complexity of the tight junctional strands in response to brain injury may be the morphological basis for the maintenance of the cerebrospinal fluid-blood dural barrier.
    Materialart: Digitale Medien
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 256 (1989), S. 559-565 
    ISSN: 1432-0878
    Schlagwort(e): Retrograde tracing ; Immunocytochemistry ; Vascular innervation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The origin of nerve fibers to the superficial temporal artery of the rat was studied by retrograde tracing with the fluorescent dye True Blue (TB). Application of TB to the rat superficial temporal artery labeled perikarya in the superior cervical ganglion, the otic ganglion, the sphenopalatine ganglion, the jugular-nodose ganglionic complex, and the trigeminal ganglion. The labeled perikarya were located in ipsilateral ganglia; a few neuronal somata were, in addition, seen in contralateral ganglia. Judging from the number of labeled nerve cell bodies the majority of fibers contributing to the perivascular innervation originate from the superior cervical, sphenopalatine and trigeminal ganglia. A moderate labeling was seen in the otic ganglion, whereas only few perikarya were labeled in the jugular-nodose ganglionic complex. Furthermore, TB-labeled perikarya were examined for the presence of neuropeptides. In the superior cervical ganglion, all TB-labeled nerve cell bodies contained neuropeptide Y. In the sphenopalatine and otic ganglia, the majority of the labeled perikarya were endowed with vasoactive intestinal polypeptide. In the trigeminal ganglion, the majority of the TB-labeled nerve cell bodies displayed calcitonin gene-related peptide, while a small population of the TB-labeled neuronal elements contained, in addition, substance P. In conclusion, these findings indicate that the majority of peptide-containing nerve fibers to the superficial temporal artery originate in ipsilateral cranial ganglia; a few fibers, however, may originate in contralateral ganglia.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 256 (1989), S. 447-456 
    ISSN: 1432-0878
    Schlagwort(e): MAP2 ; Actin ; Dendritic spines ; Spine apparatus ; Spine synapses ; Postsynaptic density ; Synaptic plasticity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of MAP2 and actin in dendritic spines of the visual and cerebellar cortices, dentate fascia, and hippocampus was determined by using immunogold electron microscopy. By this approach, we have confirmed the presence of MAP2 in dendritic spines and identified substructures within the spine compartment showing MAP2 immunoreactivity. MAP2 immunolabeling was mainly associated with filaments which reacted with a monoclonal anti-actin antibody. Also, by immunogold double-labeling we colocalized MAP2 with actin on the endomembranes of the spine apparatus, smooth endoplasmic reticulum, and in the postsynaptic density. Labeling was nearly absent in axons and axonal terminals. These results indicate that MAP2 is an actin-associated protein in dendritic spines. Thus, MAP2 may organize actin filaments in the spine and endow the actin network of the spine with dynamic properties that are necessary for synaptic plasticity.
    Materialart: Digitale Medien
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  • 43
    ISSN: 1432-0878
    Schlagwort(e): Adrenal medullary endothelial cells ; Pheochromocytoma (PC12) cells ; Co-culture ; Cell surface extracts ; Adhesion ; Cell-cell interactions ; Bovine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Chromaffin cells in the adrenal medulla are found in close proximity to capillary endothelial cells, thereby forming the classical endocrine complex. To examine the possible chemical basis of their interaction in more detail, we have grown bovine adrenal medullary endothelial (BAME) cells in monolayer cultures and added to them pheochromocytoma (PC12) cells, a chromaffin tumor cell line of rats. The PC12 cells were chosen because of the similarities they share with adrenal medullary chromaffin cells. PC12 cells rapidly attached to BAME cells cultures, their rate of adhesion being significantly enhanced over binding of PC12 cells to either uncoated plates or to monolayers of unrelated cell cultures. Consistent with this observation, we noted that the extracellular matrix (ECM) derived from the BAME cells did not enhance PC12 cell adhesion and did not promote neurite sprouting as previously described for ECM derived from corneal endothelial cells. The specific adhesion between PC12 and BAME cells could be abolished by cell surface extracts derived from these two cells but not by extracts derived from unrelated cell types. This activity was heat-labile, sensitive to trypsin and, to a lesser extent, to neuraminidase. We therefore conclude that PC12 cells may interact with BAME cells by specific proteinaceous adhesive factors associated with their plasma membranes. These interactions might represent the formative role of cell-cell contacts in the organization of the developing adrenal gland.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    ISSN: 1432-0878
    Schlagwort(e): SEM ; TEM ; Interstitial cell ; Myenteric plexus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An extensive cellular network becomes visible over the myenteric plexus of the rat after removal of the overlying tissues under the scanning electron microscope. The cells are mainly stellate and have many slender processes via which they interconnect. They form a three-dimensional network and are closely associated with the ganglia and nerve bundles, and also extend over the smooth muscle cells. They are considered to correspond to the interstitial cells of Cajal because of their peculiar arrangement and their topography. Transmission electron-microscopic evidence demonstrates that the majority of those cells have features of fibroblasts. Gap junctions and intermediate junctions are observed between these fibroblast-like cells, and also between them and smooth muscle cells. Examination of serial thin sections reveals that single fibroblast-like interstitial cells connect to both circular and longitudinal muscle cells via gap junctions. It is suggested that the network of interstitial cells conducts electrical signals.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    ISSN: 1432-0878
    Schlagwort(e): Gastrin ; Gastrin-releasing peptide ; Bombesin ; Stomach ; Autonomic innervation ; Immunohistochemistry ; Guinea pig ; Rat ; Dog ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The relationship between bombesin-like immunoreactive (bombesin-LI) nerve fibres and gastrin-LI G-cells was examined in gastric antral mucosa from guineapig, rat, dog and man using a double-labelling fluorescence immunohistochemical technique. The greatest density of bombesin-LI nerve fibres was found within the basal mucosa in all species and the density of innervation decreased towards the luminal surface. Most G-cells were in a band occupying approximately the middle third of the mucosa. The proportion of G-cells found within a distance of 2 μm from bombesin-LI nerve fibres was low in all species (6% in the guinea-pig, 22% in the rat, 14% in the dog, and 9% in the human). It is proposed that the neuropeptide released from bombesin-LI antral mucosal nerve fibres traverses distances of greater than several μm to reach the target G-cells. This may be achieved by passage through the mucosal microcirculation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 257 (1989), S. 263-268 
    ISSN: 1432-0878
    Schlagwort(e): Retinol ; Vacuoles ; Immunohistochemistry ; Plasma proteins ; Hepatocytes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The vacuoles occurring in rat hepatocytes after intraportal injection of retinol (33 or 67 μg) were examined immunohistochemically using respective antibodies against rat albumin, human retinol-binding protein, human ceruloplasmin, human α 1-antitrypsin, human transferrin, and human prealbumin as representative plasma proteins. The occurrence of the vacuoles reached a numerical maximum 30 min after injection of 67 μg retinol, followed by a temporal decrease. Hepatocytes from control rats, which had been intraportally injected with either blood plasma diluted to 2/3 concentration or with retinol palmitate solvent (castor oil) dissolved in blood plasma, showed immunoreactive fine granules without the occurrence of vacuoles in the cytoplasm. Identical vacuoles in serial sections appeared immunohistochemically either immunoreactive or non-immunoreactive for all the antibodies used, with rare exceptions. The occurrence of several rare exceptions suggested that 2 kinds of vacuoles might be formed in different cytoplasmic compartments. A zonal distribution of vacuoles was apparent in the hepatic laminae (or acini) within the liver lobules. The vacuoles were predominantly distributed in zone 2, and to a lesser extent in zone 3 and zone 1 in that order.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    ISSN: 1617-4623
    Schlagwort(e): Drosophila ; Vestigial ; Dihydrofolate reductase ; Aminopterin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Vestigial (vg) mutants of Drosophila melanogaster are characterized by atrophied wings. In this paper we show that: (1) aminopterin an inhibitor of dihydrofolate reductase (DHFR) and fluorodeoxyuridine (FUdR), an inhibitor of thymidylate synthetase induce nicks in the wings of wild-type flies and phenocopies of the vg mutant phenotype when vg/+ and vg B/+ flies are reared on these substances (vgB is a deficiency of the vg locus). Only thymidine and thymidylate can rescue the flies from the effect of aminopterin. We propose that the vg phenotype is due to a decrease in the dTMP pool in the wings. (2) Mutant vg strains yield more offspring on medium containing aminopterin than on normal medium. The resistance of vg larvae to the inhibitor seems specific to the gene. This is the first case of aminopterin resistance in living eucaryotes. In contrast sensitivity of the vg larvae to FUdR is observed. (3) An increase in the activity and amount of DHFR is observed in mutant strains as compared with the wild-type flies. Our data suggest that the vg + gene is a regulatory gene acting on the DHFR gene or a structural gene involved in the same metabolic pathway.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 218 (1989), S. 118-126 
    ISSN: 1617-4623
    Schlagwort(e): Drosophila ; Regulation ; yellow gene ; Germline transformation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We have assessed the DNA sequence requirements for the correct spatial pattern and phenotypic expression of y in the late embryo/larvae. The wild-type larval phenotype requires both the regions between-294 bp and-92 bp and a portion of the intron; the sequence element(s) located within the intron can act in a position independent manner to effect the wild-type larval phenotype. The larval expression pattern was examined by tissue experiments in situ and by staining germline transformants derived from various y/lacZ fusion constructs. The larval expression of y is restricted to the mouthparts, microsetae and anal plates. While the-495 bp to+194 bp region alone cannot effect a wild-type larval expression pattern, this region in conjunction with the intron appears to be sufficient to drive β-gal expression in an essentially wild-type pattern. Our data further suggest that the-294 bp to-92 bp region contains elements which specify the larval pattern and that the element(s) in the intron normally act to enhance the level of expression necessary for the wild-type larval phenotype. We also present a phenotypic analysis of the adult cuticle structures of germline transformants derived from a variety of deletion and rearrangement constructs of the y gene. This analysis has revealed several new features associated with the regulation of y expression.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 215 (1989), S. 281-285 
    ISSN: 1617-4623
    Schlagwort(e): Drosophila ; achaete-scute complex ; myc ; Protein domains ; Genomic search
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Several genes of the achaete-scute complex (ASC) of Drosophila melanogaster encode a 60 amino acids long conserved domain which shares a significant homology with a region of the vertebrate myc proteins. Based on these results, the existence of a family of Drosophila genes that would share both this conserved domain and the neurogenic function of the AS-C has been postulated. To test this proposal, we have searched a D. melanogaster genomic library with a probe that encodes the conserved domain. Only under very low stringency hybridization conditions, clones not belonging to the AS-C cross-hybridized with the probe. Those that gave the strongest signals were characterized. Sequencing of the cross-hybridizing regions showed that they had no significant homology with the conserved domain, the sequence similarity extending at the most for 37 nucleotides. Although our results do not conclusively disprove the existence of a family of AS-C-like genes, they indicate that the conservation of the domain would be lower than that found for shared motifs in other families of Drosophila developmental genes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Neuroscience and behavioral physiology 19 (1989), S. 399-407 
    ISSN: 1573-899X
    Schlagwort(e): hemodynamics ; stress ; hypertension
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract In the article, we present experimental data indicating that negative emotional states evoked by electrical stimulation of the ventromedial hypothalamus or by behavioral conflicts are accompanied by a predominance of vascular responses of a presser character possessing the property of summation. In contrast, positive emotional states during a self-stimulation reaction or when animals attain behavioral results satisfying their major biological demands are accompanied by a predominance of pressor-depressor vascular reactions. In individual animals under conditions of experimental emotional stress in conflicting situations of a prolonged character, pronounced disturbances of cardiac-vascular functions occur. Predominantly pressor vascular reactions arise in response to forced stimulation of the ventromedial hypothalamus in such cases. It is shown that changes in vascular tonus plays a leading role in disturbances of AP regulation during stress of immobilization. The most frequent cause of death in animals under such conditions is a progressive fall of AP due to an abrupt decrease in the total peripheral resistance. The resistance of the cardiac-vascular functions to emotional stress is determined to a significant degree by genetic mechanisms.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Evolutionary ecology 3 (1989), S. 31-39 
    ISSN: 1573-8477
    Schlagwort(e): Genetic elements ; isozymes ; life span ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Analysis of electrophoretic loci shows that at least four differences exist in isozymes of long- and short-lived populations ofD. melanogaster, descended by selection from a common ancestral stock. Adults of longlived populations differ in gene dosage of phosphoglucomutase (PGM), NAD malate dehydrogenase (MHD), NADP malic enzyme (ME) and by additional mobility variants of glucose-6-phosphate dehydrogenase (G6PD). Larvae, however, differ only by variants of G6PD. The differences in these enzymes, considered together with the greater flight endurance that long-lived populations have shown elsewhere, suggest that increased glycogen synthesis plays a significant role in the improved life span of selected populations. Adaptation to selection for increased life span may, therefore, derive from an improved ability to use dietary sucrose in the media provided. The distribution of electrophoretic loci agrees with the results of a study indicating the position of genetic elements contributing to life span.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Evolutionary ecology 3 (1989), S. 189-201 
    ISSN: 1573-8477
    Schlagwort(e): Developmental homeostasis ; life history traits ; Drosophila ; breeding site variation ; cactus ; Sonoran desert
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Variation in life histories among populations of cactophilicDrosophila mojavensis has been hypothesized to be a by-product of a shift to one of two alternate host plants. When cultured on the ancestral and a secondary host cactus, a Baja population expressed shorter development times and smaller thorax sizes than a mainland population, but viability did not differ. Comparisons with all reciprocal F1 and F2 crosses between populations revealed that genetic differences in development time and thorax size were largely additive. Homeostasis in these life history traits was population specific, except for viability. Homeostasis in development time was greater in the Baja population than in the other crosses, suggesting dominance for decreased homeostasis in the mainland population. Underdominance in viability homeostasis of the F1 hybrids suggested some incompatibility between populations. Homeostasis in thorax size was greater in females than in males and differed among parental populations. Maintenance of heritable differences and genetic variation for homeostasis in these traits suggested a role for cactus-specific differences in environmental uncertainty caused by variation in breeding site duration and abundance in nature.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    ISSN: 1617-4623
    Schlagwort(e): Chromosomal walking ; Cut locus ; Drosophila ; Unstable mutations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have cloned from the Oregon R strain of Drosophila melanogaster a 240 kb segment of DNA that contains the cut (ct) locus, and characterized the region for the presence of repetitive elements. Within this region at least five copies of the suffix element were detected, as well as several putatively novel mobile elements. A number of mutations obtained from the unstable ct MR2 strain and its derivatives were mapped within the cut locus. Comparison between parental and daughter strains indicates that frequently two or more independent transposition events involving the cut locus occur simultaneously within a single germ cell, thus providing a molecular basis for the transposition explosion phenomenon.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 219 (1989), S. 397-403 
    ISSN: 1617-4623
    Schlagwort(e): Drosophila ; Pyrimidine biosynthesis ; Dihydroorotate dehydrogenase ; Molecular mapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The dhod locus encodes dihydroorotate dehydrogenase, the fourth enzymatic step of de novo pyrimidine biosynthesis. This locus was cloned previously by a chromosome walk in cytogenetic region 85A. The location of dhod within 85A DNA has been determined by mapping two rearrangement mutations to a small DNA region. A nearly full-length cDNA clone of the dhod transcript was isolated and partially sequenced, to confirm its identity. The cDNA clone was also used to map the transcribed DNA. A 1.5 kb dhod RNA is described which is most abundant in embryos and displays minor length heterogeneity in pupae and adults. The developmental expression of this transcript is discussed relative to the expression of dihydroorotate dehydrogenase activity and other genes of the pyrimidine biosynthetic pathway.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 215 (1989), S. 190-199 
    ISSN: 1617-4623
    Schlagwort(e): Mutagen sensitivity ; Recombination ; Gene structure ; Drosophila ; mei-41
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The mutagen-sensitive mutant mus(1)104 D1 of Drosophila melanogaster maps to a position on the X chromosome very close to the meiotic mutant mei-41 D5 . Both mutants have been characterized as mutagen-sensitive and defective in post-replication repair. In the present report we show by complementation studies that mus(1)104 and mus(1)103 are allelic with mei-41. In addition, two reported alleles of mus(1)104 lie between the mei-41 alleles A10 and D5. The size of the mei-41 locus is estimated to be about 0.1 centimorgans (cM). Because several alleles of mei-41 have been shown to reduce recombination and increase meiotic chromosome loss and nondisjunction, mus(1)104 D1 females were examined for defects in meiosis. Although there was no evidence for reduced recombination on the second chromosome in homozygous mus(1)104 D1 females, heterozygous mus(1)104 D1 /mei-41 〉D5 and mus(1)104 D1 /deficiency females showed reduced levels of recombination. However, there was no evidence of an increase in nondijunction in these females.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 215 (1989), S. 257-265 
    ISSN: 1617-4623
    Schlagwort(e): Drosophila ; Maternal effect ; Syngamy ; Embryonic development ; Molecular cloning
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The maternal effect locus fs(1) Ya is required for the fusion of the apposed sperm and egg pronuclei (syngamy) following fertilization in Drosophila. It is tightly linked to another complementation group, fs(1) Yb, needed for both oogenesis and embryogenesis. We have isolated a set of overlapping cloned sequences in the 3B4-6 region of the X chromosome encompassing the fs(1) Ya-fs(1) Yb region. A single 2.4 kb maternal transcript is encoded with-in this region, and an 8.5 kb DNA fragment that contains this transcript complements both fs(1) Ya and fs(1) Yb mutations. Northern and in situ hybridization analyses show that the maternal transcript is only present in nurse cells and oocytes beginning in previtellogenic stages, and is evenly distributed in the cytoplasm of 0–2 h syncytial embryos. The transcript is not detected in later stages of embryonic development. This expression pattern correlates closely with the genetic and developmental characteristics expected of the fs(1) Ya gene product.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 215 (1989), S. 469-477 
    ISSN: 1617-4623
    Schlagwort(e): Drosophila ; Y chromosome ; Repetitive DNA ; Testis RNA ; Transposable elements
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A cDNA clone bank was constructed from testis poly(A)+ RNA of Drosophila hydei and screened for clones which hybridize to Y chromosomal DNA sequences. The insert of clone cDhT14 hybridizes to a family of repeated DNA sequences with members distributed within the Y chromosome and elsewhere in the genome. This type of sequence has earlier been described as the Y-associated class of DNA. Southern blot analysis of DNA from different wild-type strains of D. hydei suggests that members of the T14 family of repeated DNA sequences are parts of a family of transposable elements. The genomic localization of the T14 family of repeated DNA sequences was revealed by in situ hybridization to metaphase and polytene chromosomes, and to transcripts of Y chromosomal lampbrush loops. Approximately 10–15 members (20%–30%) of the T14 sequence family reside in 8.3 kb PstI restriction fragments. A genomic clone of one of these DNA fragments, DhT14-8.3, hybridizes to transcripts on the Y chromosomal lampbrush loop “cones”, and in conventional in situ hybridization experments to region 12D/13A of the X chromosome and to region 112 of chromosome 5. The cDNA clone cDhT14 represents a part of an abundant testis RNA species of 5.0 kb. This RNA is also present in ovaries and in 0–3 h, 3–6 h and 6–12 h embryos, but less abundantly than in testes. Both the Y chromosomal site of the 8.3 kb PstI fragments and sites elsewhere in the genome are actively transcribed. At least one of the latter genomic sites is transcribed into the 5.0 kb RNA species. This poly(A)+ RNA is present in the cytoplasm of primary spermatocytes as shown by transcript in situ hybridization. The potential function of transcripts from Y chromosomal lampbrush loops is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Journal of comparative physiology 159 (1989), S. 237-242 
    ISSN: 1432-136X
    Schlagwort(e): Amylase ; Mosquitofish ; Rat ; Drosophila ; Structure ; Function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Amylases from the mosquitofish (Gambusia affinis holbrooki, Pisces: Poeciliidae) and rat were purified and compared withDrosophila amylases in terms of structure and function. At the structural level, amino acid compositions of the three amylases were compared. At the functional level, amylase activities were compared on various substrates and in the presence of inhibitors. While the amylases from all three organisms had properties typical of alpha-amylases, both structural and functional differences were observed. Using resemblance coefficients of distance and similarity from numerical taxonomy, it was determined that the amylases from the rat andDrosophila were more similar to each other than either was to amylase from the mosquitofish, and that structural differences between the amylases did not reflect functional differences, i.e. there was no correlation between amylase structural and functional distances.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 15 (1989), S. 663-676 
    ISSN: 1573-1561
    Schlagwort(e): Drosophila ; Diptera ; Drosophilidae ; triterpene glycosides ; cactus ; fitness components ; host-plant relationships
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The effects of pentacyclic triterpene glycosides extracted from agria and organ pipe cacti on three fitness parameters of the cactophilic fruit fly,Drosophila mojavensis were tested. Triterpene glycosides from organ pipe increased development time and reduced larval viability while those from agria produced smaller adults (reduced fecundity). In addition, the microbial communities in the organ pipe saponin media were less dense than those in the media to which agria saponins had been added. The role of cactus triterpene glycosides in the ecology of thisDrosophila species is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Bulletin of experimental biology and medicine 107 (1989), S. 200-202 
    ISSN: 1573-8221
    Schlagwort(e): hypertension ; platelets ; sodium-proton exchange
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    ISSN: 1573-8221
    Schlagwort(e): hypertension ; erythrocyte membrane permeability ; electron microscopy ; erythrocyte transformation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    ISSN: 1573-8221
    Schlagwort(e): wound healing ; morphine ; hypertension ; substance P
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Journal of insect behavior 1 (1988), S. 3-15 
    ISSN: 1572-8889
    Schlagwort(e): host preference ; habitat selection ; experience ; learning ; Drosophila ; host races ; population genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A field experiment with Drosophila melanogasterrevealed that when flies encounter a particular food type soon after emergence, the probability of their subsequently being attracted to such a resource is increased. In this experiment, the length of time flies experienced their postemergence environments was under the control of the flies themselves. The experiment thus realistically mimicked one form of experiential effect that may be important in nature. A theoretical model is developed which shows that enhanced adult preferences for the types of resources fed on as larvae can substantially increase the degree of host-based genetic subdivision within a polyphagous population.
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 47 (1988), S. 81-88 
    ISSN: 1570-7458
    Schlagwort(e): imaginal diapause ; male mating activity ; genetics ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Les femelles de D. triauraria Bock & Wheeler (Dipt. Drosophilidae) sont connues pour présenter une diapause reproductrice aux photophases courtes. Les mâles eux aussi ont révélé une activité sexuelle réduite aux photophases courtes, c'est-à-dire qu'ils sont entrés comme les femelles en diapause reproductive. Les photophases critiques pour l'induction de la diapause des mâles et des femelles n'ont pas présenté de différences. Les diapause des mâles et des femelles s'achèvent même sous courtes photophases, mais la diapause mâle était quelque peu plus faible que la diapause femelle. La photophase critique et le taux de diapause ont varié en fonction de l'origine géographique dans l'espèce actuelle. Lors de croisements entre lignées diapausantes et non-diapausantes, la photophase critique et la durée de la diapause ont été héritées quantitativement. A partir de ces expériences et d'expériences précédentes de croisements (Kimura, 1983), quelques modèles de méchnisme d'induction de la diapause de cette espèce sont proposés.
    Notizen: Abstract In Drosophila triauraria Bock & Wheeler (Diptera: Drosophilidae) of which females were known to enter reproductive diapause at short daylengths, males also showed reduced mating activity at short daylengths, i.e., males as well as females entered reproductive diapause. The critical daylength for diapause induction did not differ between females and males. Both male and female diapause ended even under short daylengths, but the male diapause was somewhat weaker than the female diapause. The critical daylength and the diapause rate varied geographically in this species. In the cross between diapausing and non-diapausing strains, the critical daylength and the diapause duration inherited in a quantitative manner. On the basis of the present and previous crossing experiments, some models are proposed on the mechanism of diapause induction of this species.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 13 (1988), S. 235-239 
    ISSN: 1432-0983
    Schlagwort(e): Ribosomal protein ; Immunological homology ; Yeast ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Polyclonal antibodies raised against ribosomal protein (r-protein) L2 of Schizosaccharomyces pombe were used to check for cross-reaktions with total r-proteins of rat liver. Using this procedure, the rat liver r-proteins, L4 and L24, were identified as being immunologically related to yeast L2. In addtional, homologies between rat liver L4 and L24 were detected. The possible implications for the regulation of r-protein synthesis are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Journal of molecular evolution 28 (1988), S. 145-150 
    ISSN: 1432-1432
    Schlagwort(e): Alcohol dehydrogenase ; Drosophila ; Enzyme kinetics ; Product inhibition ; Microevolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Because natural populations ofDrosophila melanogaster are polymorphic for different allozymes of alcohol dehydrogenase (ADH) and becauseD. melanogaster is more tolerant to the toxic effects of ethanol than its sibling speciesD. simulans, information regarding the sensitivities of the different forms of ADH to the products of ethanol degradation are of ecological importance. ADH-F, ADH-S, ADH-71k ofD. melanogaster and the ADH ofD. simulans were inhibited by NADH, but the inhibition was relieved by NAD+. The order of sensitivity of NADH was ADH-F〈ADH-71k, ADH-S〈ADH-simulans with ADH-F being about four times less sensitive than theD. melanogaster enzymes and 12 times less sensitive than theD. simulans enzyme. Acetaldehyde inhibited the ethanolto-acetaldehyde activity of the ADHs, but at low acetaldehyde concentrations ethanol and NAD+ reduced the inhibition. ADH-71k and ADH-F were more subject to the inhibitory action of acetaldehyde than ADH-S and ADH-simulans, with ADH-71k being seven times more sensitive than ADH-S. The pattern of product inhibition of ADH-71k suggests a rapid equilibrium random mechanism for ethanol oxidation. Thus, although the ADH variants only differ by a few amino acids, these differences exert a far larger impact on their intrinsic properties than previously thought. How differences in product inhibition may be of significance in the evolution of the ADHs is discussed.
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 19-26 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Morphogenesis ; Appendages
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The phenotype of rotund (rn) null alleles is described, and compared to wild type. The mutants are expressed zygotically and cause position specific defects in certain imaginal discs (antenna, legs, wing, haltere and proboscis) and their corresponding adult derivatives. In the discs, specific folds are absent in rn mutants compared to wild type. Clonal analysis shows that the rn + gene is partially autonomous in its expression in cells destined to form certain distal parts of the adult appendages. The results are consistent with the idea that the rn + gene is required for normal morphogenesis of specific distal parts of the adult appendages.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 40-48 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Homeosis ; Tumorous-head ; Bithorax-complex mutant ; Morphology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Transformations of tumorous-head Drosophila melanogaster were examined in order to investigate whether head structures were replaced by specific abdominal structures. Heads selected for the presence of genital structures were analyzed in detail. Female abnormalities included any combination of vaginal teeth, vulvar papillae, sensilla trichodea, abdominal tergites 6 (T6), 7 (T7), 8 (T8) and anal plate. Anal plate was observed in the prefrons and rostral membrane, while all other genital structures were intimately associated with modified shingle cuticle. Male abnormalities included transformation of antennal structures to penis, clasper teeth, lateral plate, anal plate and eye to T6. The distribution of each type of homeotic structure was confined to general regions of the eye-antenna, with no precise dividing lines between them. However, the spatial sequence of homeotic structures in the eye-antenna was generally the same as the sequence of the same structures in the posterior abdomen.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 457-470 
    ISSN: 1432-041X
    Schlagwort(e): Neurogenesis ; Neurogenic genes ; Achaetescute complex ; Daughterless ; Genetic interactions ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In Drosophila melanogaster the neuroblasts separate from epidermoblasts to give rise to the neural primordium. This process is under the control of several genes. The group of the so-called neurogenic genes is required for epidermal development; other genes, comprising those of the achaete-scute complex and daughterless, are required for neural development. We have studied the relationships between both groups of genes in two different ways. We have analyzed the phenotype of double-mutant embryos and our results show that the neural hyperplasia caused by neurogenic mutations can be partially prevented if a mutation in one of the other genes is present in the same genome. Only the neural cells that do not require the function of a particular gene of the achaete-scute complex in the wild-type seem to develop to a neural fate in the double mutant embryos. At least some of the genetic interactions affect the transcriptional level, as shown by in situ hybridization, since the territories of transcription of the achaetescute genes are expanded in neurogenic mutants. All cells of the neurogenic region of the double mutants apparently initiate neural development. However, during later development some of these cells switch their fate either to epidermogenesis or to cell death and this leads to the final phenotype of the double mutants. We discuss these results with respect to the events of early neurogenesis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 70
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; shibire ; Neuronal development ; Muscle ; Giant fiber pathway
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The temperature-sensitive mutation shibire (shi) in Drosophila melanogaster is thought to disrupt membrane recycling processes, including endocytotic vesicle pinch-off. This mutation can perturb the development of nerves and muscles of the adult escape response. After exposure to a heat pulse (6 h at 30° C) at 20 h of pupal development, adults have abnormal flight muscles. Wing depressor muscles (DLM) are reduced in number from the normal six to one or two fibers, and are composed of enlarged fibers that appear to represent fiber fusion; large spaces devoid of muscle fibers suggested fiber deletion. The normal five motor axons are present in the peripheral nerve PDMN near the ganglion. However, while some motor axons pass dorsally to the extant fibers, other motor axons lacking end targets pass into an abnormal posterior branch and terminate in a neuroma, i.e., a tangle of axons and glia without muscle target tissue. Hemisynapses are common in axons of the proximal PDMN and within the neuroma, but they are rarely seen in control (no heat pulse) shi or wild-type flies. All surviving muscle fibers are innervated; no muscle tissue exists without innervation. Fibrillar fine structure and neuromuscular synapses appear normal. Fused fibers have dual innervation, suggesting correct and specific matching of target tissue and motor axons. Motor axons lacking target fibers do not innervate erroneous targets but instead terminate in the neuroma. These results suggest developmental constraints and rules, which may contribute to the orderly, stereotyped development in the normal flight system. The nature of the anomalies inducible in the flight motor system in shi flies implies that membrane recycling events at about 20 h of pupal development are critical to the formation of the normal adult nerve-muscle pattern for DLM flight muscles.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 413-418 
    ISSN: 1432-041X
    Schlagwort(e): Cell interactions ; Cell commitment ; Neurogenesis ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Cell-cell interactions are involved in mediating developmental fate. An example is the decision of the neuroectodermal cells of Drosophila to develop as neural or epidermal progenitors, where cellular interactions participate in the process of acquisition of either cell fate. The results of heterochronic cell transplantations we describe here suggest that both neuroblasts and epidermoblasts are not irreversibly committed to a particular developmental fate. Rather, they retain the ability to interact with neighbouring cells and, under our experimental conditions, are capable of switching their fate during a relatively long period of time, i.e. until the end of embryonic stage 11.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 435-440 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Homoeotic genes ; Segment differentiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Regulator of bithorax (Rg-bx)−, or trithorax (trx)− lethal larvae occasionally show a homoeotic transformation of the dorsal prothorax to mesothoracic structures. This transformation suggests a reduced activity of the Sex combs reduced (Scr) gene on the basis of gene dosage studies, as well as enhanced expression of the phenotypes of the weak Scr − alleles in Rg-bx − larvae. Morphological observations of adult flies doubly heterozygous for Rg-bx and Scr mutations also suggest the enhancement of an aspect of Scr adult phenotypes. I conclude that the Rg-bx + gene function is required for the optimal expression of the Scr gene in larval and imaginai cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 507-512 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Reporter gene ; hairy ; Segmentation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Random insertions of a promotor fused to a reporter gene, such as Lac-Z, reveal regulatory sequences that confer temporal and spatial patterns of gene expression in eukaryotes. These patterns may reflect the activity of a neighbouring gene and thus lead to the isolation of new genes essential for normal development. Here, we demonstrate that this hypothesis is true for an insertion into the well characterized segmentation gene, hairy, in Drosophila. The insertion is homozygous lethal and fails to complement other hairy alleles, giving the phenotype described for hairy mutations. The insertion is located at 66D on the polytene chromosome map, is within 300–600 bp 5′ to the first hairy exon, and is orientated in the same sense (5′-3′) as the hairy transcription unit. Expression of β-galactosidase (β-gal), deriving from the insertion, follows closely the spatio-temporal patterns of expression of hairy gene product during embryogenesis. In addition, other sites of β-galactosidase expression are shown in the third larval instar stage and in the adult ovary. The results show that some insertions, giving restricted patterns of reporter gene expression, will reflect the temporo-spatial activity of a nearby gene.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 74
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Injection of embryo ; Daudi conditioned medium ; Rudimentary ovaries ; Mean number of ovarioles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Drosophila melanogaster embryos were injected before the blastoderm stage with conditioned media from several male Burkitt's lymphoma human cell lines and the Daudi cell line. Such injections do not have any effect on the male genital apparatus or on the female tract. The Daudi conditioned medium modifies the ovarian morphogenesis of the flies and the rudimentary ovaries obtained look like nymphal gonads. Moreover, they have a drastically reduced number of germ cells. The ovaries that looked functional contain numerous necrotic germ cells and the mean number of ovarioles per fly is significantly smaller than that of the controls. The abnormalities observed resemble the results of experimental and genetic lack of germ cells. They disappear at very high dilution (1×10−6).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 231-238 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Electrical polarity ; Ovarian follicles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Distribution of rhodamine-conjugated lysozyme injected into the sixteen-cell syncytium comprising the germ-line portion of theDrosophila follicle is shown to be affected by charge. Positive molecules are able to migrate through intercellular bridges from the oocyte to the nurse cells, but are unable to migrate detectably from nurse cells to the oocyte. Their negatively charged counterparts can move from the nurse cells to the oocyte, but are unable to traverse the intercellular bridges in the counter direction. This charge-dependent movement of molecules is accompanied by an electrical potential difference, focused across the nurse cell-oocyte bridges, which makes the nurse cells negatively charged to the oocyte. The addition of insect hemolymph to the physiological salt solution in which the experiments were performed resulted in only a small increase in the transmembrane resistance, but enhanced the potential difference between oocyte and nurse cells from 0.2±0.3 (SE) mV (nurse cells negative) to 2.3±0.45 (SE) mV (nurse cells negative).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 76
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Homeosis ; Epidermal development ; Embryology ; Clonal analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The complex genetic locuspolyhomeotic (ph) is a member of thePolycomb (Pc)-group of genes and as such is required for the normal expression of ANT-C and BX-C genes. It also has probably other functions since amorphicph alleles display a cell death phenotype in the ventral epidermis of 12-h-old embryos. Here it is shown that lethal alleles ofph (amorph and strong hypomorph) show transformation of most of their segments towards AB8. Theph + product is required autonomously in imaginal cells. The total lack ofph + function prevents viability of the cuticular derivatives of these cells.ph has a strong maternal effect on segmental identity and epidermal development that can not be rescued by one paternally supplied dose ofph + in the zygote. These phenotypes differ substantially from those of previously describedPc-group genes. AmongPc-group genes,ph seems to be the only one that is strongly required both maternally and zygotically for normal embryonic development.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 77
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Ultrabithorax ; Development ; Regulation ; Protein distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Most viable alleles of homeotic genes cause partial transformations within given lineages in a topographically specific fashion. We study this phenomenon as a way to understand the normal mechanisms involved in the spatial regulation of homeotic gene expression. To this end we have investigated the distribution of Ultrabithorax (Ubx) proteins in imaginai discs mutant for hypomorphic and neomorphic alleles of Ubx and alleles of trans-acting genes. We find that the morphological discontinuities observed in the adult transformations are caused by corresponding new patterns of the Ubx proteins in the imaginai anlagen. These novel patterns of Ubx proteins are understood as a consequence of a process of reinforcement-extinction of Ubx expression. The evidence suggesting that this process results from a positive feed-back loop and cell-cell interactions is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 78
    ISSN: 1432-041X
    Schlagwort(e): Bithorax complex ; Drosophila ; Abdominal-B mutations ; Genetic mosaics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The phenotypic effects in imaginal hypodermal tissue of a number of Abdominal-B mutations of the bithorax complex are described. Evidence is given from complementation analysis that the phenotypic heterogeneity in both the spatial limits and the nature of the homeotic transformations produced is not an arbitrary classification of allelic differences that we find. We have used genetic mosaic analysis to support the interpretation that the Abdominal-B genetic unit can exist in a number of alternative functional states of expression during development and that individual Abdominal-B mutations may abolish some states whilst leaving others unaffected.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 79
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Segment polarity gene ; Maternal effect
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Fused is a segmentation gene belonging to the segment-polarity class. Mutations at thefused locus are known to display pleiotropic effects, causing zygotically determined anomalies of ovaries and of some adult cuticular structures, and maternally determined embryonic segmentation defects. In order to determine the amorphic phenotype offused and to study the genetical basis of its pleiotropy, newfused alleles (18 viable and 11 lethal) were isolated. The phenotype of these mutants and of others already known are described, taking into account zygotic and maternal effects. The main results provided by this analysis are as follows. Firstly, allfused alleles show the whole complex fused phenotype, and a good correlation is observed between the strength of the wing and segmentation defects, suggesting that a single function is involved in both processes. Secondly, all embryonic and larval lethals carry deficiencies which allow us to localizefused between the 17C4 and 17D2 bands of the X-chromosome. Thirdly, the 24 viable and 2 pupal lethals examined behave as point mutants, as shown cytologically or by Southern blot analysis. However, only one of them, the pupal lethalfu mH63 was proven to carry a nullfused allele, since it displays in germ-line clones a strong maternal phenotype and a very low zygotic rescue, similar to those of the small deficiencyDf(1)fu z4. The phenotype of the amorphic mutant indicates that zygotic ezpression offused is required for normal metamorphosis, while maternal expression is necessary for a normal segmentation pattern, since a complete loss offused expression during oogenesis cannot be compensated zygotically.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 75-91 
    ISSN: 1432-041X
    Schlagwort(e): Drosophila ; Maternal effect mutation ; Pattern formation ; Gastrulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The gastrulation defective (gd) locus is a maternally expressed gene in Drosophila required for normal differentiation of structures along the embryonic dorso-ventral axis. Cuticular defects of the offspring from females with different combinations of gd alleles comprised a phenotypic continuum. Complementation among several alleles produced normal offspring while progressively more severe mutations produced a graded loss of structures from ventral, and then lateral, blastoderm cells. The most severely affected embryos consisted entirely of structures derived from dorsal blastoderm cells. Histological examination of staged siblings from selected allelic combinations showed that internal tissues were similarly affected. The tissues observed in amorphic embryos support new, more dorsal, assignments of fate map positions for blastoderm precursors of the cephalopharyngeal apparatus, hindgut and ventral nerve cord. The loss of ventral and lateral structures did not occur through cell death and appeared to involve a change in blastoderm cell fate. A direct effect of the mutations on blastoderm cell determination, however, was insufficient to explain the development of the dorsalized embryos. Intermediate phenotypes suggested that cell interactions or movements associated with morphogenesis are required for the determination of some cell fates in the dorsoventral axis. Thus, the developmental fate of all blastoderm cells may not be fixed at the time of blastoderm formation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 197 (1988), S. 115-123 
    ISSN: 1432-041X
    Schlagwort(e): X-Chromosome Loci ; Dominant maternal effect ; Segmentation genes ; Drosophila
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A systematic search for X chromosome loci showing a dominant maternal interaction with the segmentation genes Krüppel, hunchback, knirps and hairy was performed using deficiencies spanning 65% of the X chromosome. No interaction with the knirps gene was observed, but five regions of the X chromosome showed a maternal dominant interaction with the Krüppel gene. Two of these regions also show a maternal dominant interaction with either hunchback (region 10A7–10A8) or hairy (region 10E1–10F3). In all of these interactions dead embryos were observed which showed the same defects as embryos homozygous for the segmentation gene tested. These results suggest that a complex repartition of maternal products necessary for subsequent segmentation may occur in the Drosophila egg.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    International journal of biometeorology 32 (1988), S. 17-20 
    ISSN: 1432-1254
    Schlagwort(e): Epilepsy ; Electromagnetic fields ; Rat ; Audiogenic seizure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geographie , Physik
    Notizen: Abstract In order to study the possible association between epileptic seizures and natural electromagnetic fields, 32 female audiogenic seizure (AGS)-susceptible rats were exposed to simulated 10 kHz and 28 kHz atmospherics and to a sinusoidally oscillating magnetic field with a frequency of 100 Hz and field strength of 1 A/m. After the electromagnetic exposure, seizures were induced in the rats with a sound stimulus. The severity of the seizure was determined on an ordinal scale, the audiogenic response score (ARS). The time from the beginning of the sound stimulus to the onset of the seizure (seizure latency) and the duration of the convulsion was measured. No differences from the control experiments were found in the experiments with simulated atmospherics, but the 100 Hz magnetic field increased the seizure latency by about 13% (P〈0.02). The results do not support the hypothesis that natural atmospheric electromagnetic signals could affect the onset of epileptic seizures, but they suggest that AGS-susceptible rats may be a useful model for studying the biological effects of electromagnetic fields.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 83
    ISSN: 1432-1254
    Schlagwort(e): Atmospherics ; Carrageenan inflammation ; Rat ; Susceptibility ; Correlations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geographie , Physik
    Notizen: Abstract Between the mean daily density of 28 kHz atmospherics and the onset of epileptic fits there is a highly significant correlation coefficient (r) of 0.30; there is a negative coefficient of −0.20 between the fits and the mean daily density of 10 kHz atmospherics. The onset of heart infarction is correlated with 28 kHz atmospherics (r=0.15). Furthermore, we have discovered that sudden deafness is also correlated with certain configurations of atmospherics. In this paper we report the following correlation coefficients between the inflammatory reaction of rats to a carrageenan injection (rci) into a hind paw and the mean daily pulse rate of atmospherics of the same day:r=0.49 for the 8 kHz atmospherics (P〈0.02) andr=0.44 for the 10 kHz atmospherics (P〈0.04). The correlations between rci reaction and other atmospherics (12 and 28 kHz) are smaller and not significant. By the method of multiple linear regression we found a multipleR=0.54 between rci reaction and the 8 and 10 kHz atmospherics (the regression function for the rci reaction is 0.15+0.004×8 kHz+0.002×10 kHz,P〈0.05).
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 84
    Digitale Medien
    Digitale Medien
    Springer
    Oecologia 75 (1988), S. 400-404 
    ISSN: 1432-1939
    Schlagwort(e): Vectoring ; Drosophila ; Cactophilic yeasts ; Dispersal ; Community structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary At two locations in the Sonoran Desert, yeasts were sampled from species of Drosophila, the flies' cactus hosts, and other neighboring sources of cactophilic yeasts to determine the relation between the yeasts vectored by the fly and the yeasts found in their breeding sites. D. mojavensis, D. nigrospiracula, and D. mettleri vectored yeast assemblages significantly more similar to the yeast species found on the rot from which the flies were collected than to the yeasts found on other rots from the flies host cactus or other rotting cactus at the same site. Rots with Drosophila had fewer yeast species than those without flies, suggesting that flies were associated with younger rots. Rots with flies and the Drosophila also had more yeast species with the capability to produce ethyl acetate than rots without flies. The results support the contention that cactophilic Drosophila feed on a subset of the yeasts available in an area, and may act to maintain differences among the yeast communities found on different species of cactus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Oecologia 75 (1988), S. 516-520 
    ISSN: 1432-1939
    Schlagwort(e): Drosophila ; Picornavirus ; Fertility ; Embryonic and larvo-pupal death rate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Drosophila C virus (DCV) has a considerable impact on ovarian morphogenesis inDrosophila melanogaster host populations. This virus also affects the developmental time and the fresh weight of infected females. In order to investigate the hypothesis that DCV may play a role in the dynamics ofDrosophila populations, the fertility and embryonic and larvo-pupal death rates of a host population and that of five DCV-free populations were determined. A comparison of two populations, one of them DCV-free, the other infected, suggested that the fertility of the DCV-infected flies was higher than that of uninfected flies, despite a greater larvo-pupal death rate. Fertility of the infected flies was greater among the infected population than for the DCV-free populations. The DCV-free populations originated from five different localities. The virus clearly does have an impact on the biotic potential of its host population. This paper reports for the first time a positive interaction between a viral population and a host population as it increases certain parameters of host population dynamics.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 34 (1988), S. 513-515 
    ISSN: 1432-1041
    Schlagwort(e): methyldopa ; prolactin ; hypertension ; sustained release formulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In a group of ten hypertensive patients, the effects of methyldopa administration in two different formulations on serum prolactin (PRL) were studied. A single oral dose of normal release methyldopa significantly increased serum prolactin levels, peak concentrations occurring 3 to 6 h after drug administration. On the contrary, administration of sustained release methyldopa at the same dose was only followed by slight and not significant fluctuations in prolactin plasma levels. Both formulations produced a significant decrease of systolic and diastolic blood pressures, without significant differences between sustained and normal release methyldopa effects.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 34 (1988), S. 605-611 
    ISSN: 1432-1041
    Schlagwort(e): oxprenolol ; hypertension ; osmotic delivery system ; blood pressure control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effects of two oxprenolol oral osmotic (OROS) delivery systems on heart rate and blood pressure before and during recovery from exercise at a predetermined load were examined in twelve patients with hypertension previously responding to beta-blocker monotherapy. Haemodynamic responses were attenuated during the 24 h after single and repeated (15 days') once daily administrations of 10/170 and 16/260 oxprenolol OROS. At 24 h after repeated doses, compared to placebo there were significant reductions in resting blood pressure and in heart rate immediately following exercise. Attenuation of heart rate after exercise was dose related but differences between the systems with respect to resting heart rate and blood pressure were inconsistent. Antihypertensive responses after repeated doses were greater than those after single doses. However, reductions in resting and exercise heart rates were consistently less on chronic therapy. This may reflect enhanced expression of the partial agonist activity of oxprenolol due to altered receptor sensitivity after prolonged beta-blockade. The plasma oxprenolol profiles after both systems indicated slow absorption and substantial concentrations were apparent 24 h after drug administration. These observations suggest that both oxprenolol OROS systems display sustained drug release and on once daily dosing provide 24 h beta-blockade and control of blood pressure at rest and following exercise.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 88
    ISSN: 1432-1041
    Schlagwort(e): metoprolol ; hypertension ; controlled-release metoprolol ; systolic and diastolic blood pressure ; heart rate ; adverse effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In a double-blind study with parallel groups 195 hypertensive patients were randomly allocated to treatment with either conventional tablets of metoprolol, 100 mg once daily, or a new controlled-release (CR) formulation of metoprolol1, 100 mg once daily. The dose was doubled if the patient's diastolic blood pressure remained ≥95 mmHg after six weeks on 100 mg, whereas well-controlled patients continued on 100 mg once daily for a further six-week period. In the metoprolol tablet group the 200 mg dose was administered in the form of Durules. There was a significant reduction from the placebo baseline in systolic and diastolic blood pressure and heart rate at 24 h after both six weeks and 12 weeks of active treatment; no significant difference in the mean reduction from baseline between the two groups was demonstrated. However, significantly more patients responded to treatment with metoprolol CR when compared with those patients taking metoprolol tablets. After six weeks of active treatment 61% of the metoprolol CR group and 56% of the conventional metoprolol tablet group had a diastolic blood pressure 〈95 mmHg. After another six weeks the corresponding figures were 83% and 69% respectively. Between week 6 and 12, 36% of patients in the metoprolol CR group and 42% of patients in the conventional metoprolol tablet group were receiving a 200 mg dose. All formulations of metoprolol were well-tolerated. Fewer subjective symptoms were reported during active treatment than during the placebo phase. There were no differences between the groups with regard to changes in laboratory variables from baseline, changes in all combined symptoms, or changes in any one symptom.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 89
    ISSN: 1432-1041
    Schlagwort(e): felodipine ; propranolol ; hydrochlorothiazide ; hypertension ; general practice ; blood pressure ; adverse effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Eighty one patients with uncomplicated hypertension who required additional antihypertensive medication (diastolic Phase V [dBP]≧95 mm Hg) after 4 weeks treatment with hydrochlorothiazide (HCTZ) 25 mg o.m. were randomized to receive felodipine 5 mg b.i.d. (n=40) or propranolol (n=41) 80 mg b.i.d. in addition to HCTZ 25 mg o.m. If the dBP measured about 12 h post-dose was not ≦90 mm Hg after 4 weeks, the dose of felodipine or propranolol was doubled. The double blind trial period was 8 weeks for all patients. Over the 8 week period, felodipine reduced the seated dBP from 100 to 83 mm Hg and propranolol from 101 to 86 mm Hg. The attained seated dBPs were significantly different in the two groups. About one third of patients in each group received the high dose of second-line therapy. After 8 weeks 91% of patients receiving HCTZ+felodipine and 84% receiving HCTZ+propranolol had a dBP ≦ 90 mm Hg. Both regimens were well-tolerated with an equal incidence but different pattern of adverse events (felodipine: flushing, headache and peripheral oedema; propranolol: dyspepsia, fatigue and vasospasm). In this 8-week study, felodipine and propranolol were safe and effective second-line antihypertensive drugs when added to hydrochlorothiazide. At the doses selected, felodipine was at least as effective as propranolol.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 90
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 34 (1988), S. 411-413 
    ISSN: 1432-1041
    Schlagwort(e): bopindolol ; hypertension ; beta-adrenoceptor blocker ; haemodynamics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Ten patients (mean age 53 years) with essential hypertension have been studied at rest and during exercise following oral treatment for 6 weeks with a new beta-adrenoceptor blocking agent, bopindolol. The treatment caused a significant decrease in systolic and diastolic arterial blood pressure and heart rate, both at rest and during exercise. Stroke volume fell, too, and therefore so did cardiac output, whereas the systemic vascular resistance was increased. Left ventricular filling pressure was elevated both at rest and during exercise following bopindolol therapy. However, a different haemodynamic pattern was noted in patients with elevated total peripheral resistance prior to therapy (Group 1) compared to patients with normal or subnormal peripheral resistance (Group 2). A decrease in systemic vascular resistance seemed to be the cause of the fall in blood pressure in Group 1, as the expected increase in vascular resistance did not occur, whereas a reduction in cardiac output was of greater importance in Group 2. During exercise the lowering of arterial blood pressure in both groups was mediated by a reduction in cardiac output.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 34 (1988), S. 543-548 
    ISSN: 1432-1041
    Schlagwort(e): atenolol ; nifedipine ; hypertension ; adverse effects ; fixed combination ; drug efficacy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In this randomized, double-blind, crossover study we investigated the haemodynamic effects of a beta-blocker (atenolol 50 mg) and a calcium antagonist (nifedipine SR 20 mg) given either separately or in combination in three groups of hypertensive patients. Each treatment was administered twice daily. The fixed combination given twice daily for four weeks produced reductions in blood pressure which lasted for at least 12 h after administration of the last dose. The control of blood pressure by the combination was superior to that achieved by its individual components. Adverse effects normally associated with nifedipine were less frequent when it was given with atenolol. Compliance with treatment was good, but best when the drugs were given together rather than separately. A fixed combination of atenolol and nifedipine may prove useful in treating hypertensive patients inadequately controlled on beta-blocker therapy alone.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 35 (1988), S. 21-24 
    ISSN: 1432-1041
    Schlagwort(e): doxazosin ; hypertension ; alpha-adrenergic blockade ; bioavailability ; pharmacokinetics ; adverse effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The antihypertensive effects and steady-state pharmacokinetics of doxazosin, as well as the bioequivalence of four dosage forms, were studied in 25 hypertensive patients. For an 8 mg daily dose mean Cmax at steady-state for all patients was 108 ng/ml; the mean tmax was 1.8 h. The mean terminal elimination half-life was 22 h. The four tablets containing 1, 2, 4, or 8 mg of doxazosin were bioequivalent in delivering the 8 mg dose. In patients with mild to moderate hypertension, 26-day treatment with doxazosin resulted in blood pressure reduction of 10/7 mm Hg in the supine and 13/18 mm Hg in the standing position. Adverse effects were generally mild and of brief duration.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 35 (1988), S. 131-135 
    ISSN: 1432-1041
    Schlagwort(e): metoprolol ; hydralazine ; hypertension ; pregnancy ; pharmacokinetics ; drug interactions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary We have studied the plasma concentrations levels of metoprolol after its twice daily administration in a dose of 50 mg for 4 days in ten, hypertensive pregnant women to the during monotherapy and in combination with 25 mg of hydralazine given twice daily. Hydralazine increased the median AUC and Cmax of metoprolol by 38% and 88% respectively, and decreased the tmax from 1.5 h to 1.0 h. Hydralazine had no effect on the plasma concentrations of alpha-OH-metoprolol. These results suggest that the effect of hydralazine on metoprolol plasma concentrations is primarily due to a reduction in first-pass elimination.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 35 (1988), S. 431-432 
    ISSN: 1432-1041
    Schlagwort(e): rifampicin ; enalapril ; hypertension ; drug interaction ; case report
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary When a 35-year-old man with essential hypertension was treated with antibiotics for brucellosis his blood pressure rose significantly. While all other treatment was kept constant rifampicin was discontinued. On rechallenge rifampicin did not alter serum concentrations of enalapril or the area under the curve (AUC) between 0 and 7 h, but it did reduce the AUC of the active metabolite enalaprilat by 31%. These observations suggest that there may be an interaction between rifampicin and enalapril, causing reduced hypotensive efficacy of enalapril. The mechanism of such an interaction merits further study, but it could be due to enhanced renal clearance of enalaprilat.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 33 (1988), S. 549-555 
    ISSN: 1432-1041
    Schlagwort(e): verapamil ; sustained release formulation ; hypertension ; renal disease ; kidney function ; angiotensin II ; aldosterone ; arginine vasopressin ; atrial natriuretic peptide ; lipids and lipoproteins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In 14 patients with arterial hypertension secondary to chronic renal parenchymal disease and impaired renal function, 24-h ambulatory and casual blood pressure readings plasma, angiotensin II, aldosterone, arginine vasopressin and atrial natriuretic peptide, creatinine clearance, plasma lipids and lipoproteins, and body weight were determined after consecutive 3-week periods on placebo and sustained release verapamil 240 mg/day. Verapamil reduced the mean 24-h ambulatory blood pressure from 152/104 to 142/97 mm Hg. Blood pressure was significantly reduced during the daytime and the evening, but not at night. Casual blood pressure was also significantly reduced from 176/106 mm Hg to 154/96 mm Hg. No significant changes were found in the hormones, creatinine clearance, plasma lipids and lipoproteins, heart rate or body weight. The atrial natriuretic peptide level was significantly correlated with the calculated creatinine clearance (r=−0.797). Thus, sustained release verapamil 240 mg as a single daily dose had a moderate hypotensive effect in patients with chronic renal disease without inducing tachycardia, activation of the renin-angiotensin-aldosterone system, or increasing body weight, and without altering renal function and plasma lipids and lipoproteins. The negative correlation between atrial natriuretic peptide and glomerular filtration rate supports the hypothesis that the extracellular volume increases during progression of renal disease.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    ISSN: 1432-1041
    Schlagwort(e): felodipine ; metoprolol ; hydrochlorothiazide ; hypertension ; blood pressure ; adverse effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Seventy-six uncomplicated hypertensive patients treated in General Practice, whose seated diastolic blood pressure (Phase V) (dBP) remained ≥95 mmHg after a minimum of 4 weeks treatment with metoprolol 50 mg b.i.d. as antihypertensive monotherapy, were randomized to receive the selective ‘calcium antagonist’ felodipine 5 mg b.i.d. or hydrochlorothiazide 12.5 mg b.i.d. in addition to metroprolol 50 mg b.i.d. The trial duration was 8 weeks, the dose of the felodipine or hydrochlorothiazide being doubled after 4 weeks if ‘control’ of BP (dBP 〈90 mmHg) was not achieved on the initial doses. Over the trial period of 8 weeks, felodipine reduced dBP from 102 to 85 mmHg and hydrochlorothiazide from 101 to 91 mmHg; the dBP reduction in the felodipine group was greater than that in the hydrochlorothiazide group (17 vs 9 mmHg) and the attained dBP lower in the felodipine group. About half of the patients in each group required the higher dose. Both regimes were effective and well tolerated. In the dosages used, felodipine was a slightly more effective antihypertensive drug than hydrochlorothiazide when added to metoprolol. There was no apparent difference in the tolerability of the two regimes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 34 (1988), S. 61-65 
    ISSN: 1432-1041
    Schlagwort(e): lisinopril ; renal failure ; half-life ; drug dose ; pharmacokinetics ; hypertension
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics of lisinopril was studied after administration of single and multiple doses of 5 mg to hypertensive patients with normal and impaired renal function. In patients with severe renal failure the peak concentrations were higher, the decline in serum concentration was slower and the time to peak concentration was extended. Accumulation of lisinopril was highly correlated with the creatinine clearance. The effective half-life was doubled and tripled in patients with mild and severe renal impairment, respectively, as compared to patients with a normal renal function. Lisinopril lowered blood pressure in all three groups over 24 h. It is suggested that smaller doses of lisinopril should be administered to patients with severe renal failure.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 34 (1988), S. 119-123 
    ISSN: 1432-1041
    Schlagwort(e): doxazosin ; hypertension ; alpha1-adrenoceptor inhibitor ; elderly patients ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The α1-adrenoceptor antagonist doxazosin has been compared with placebo in 40 elderly hypertensive patients (mean age 71.4 years). At the end of 10 weeks once daily treatment with doxazosin the mean 24-h post-dose changes in standing and supine blood pressure compared with placebo were −6.9/−5.6 mmHg (systolic/diastolic) and −6.2/−5.5 mmHg respectively. The reductions in standing and supine diastolic blood pressures were statistically significant compared with placebo. At the end of treatment steady-state pharmacokinetics were evaluated in 18 patients. The plasma elimination half-life during the dose interval in these patients was 16.1 h (range 10.1–27.1 h) and the median time to peak plasma concentration was 3 h (range 1–4 h). One patient was withdrawn because of adverse effects (headache, weakness, and sweating) during doxazosin treatment. Once daily doxazosin reduced diastolic blood pressure and was well tolerated in these elderly hypertensive patients.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 35 (1988), S. 571-572 
    ISSN: 1432-1041
    Schlagwort(e): cadralazine ; pharmacokinetics ; hypertension
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    ISSN: 1432-1041
    Schlagwort(e): ketanserin ; hypertension ; combination therapy ; diuretic ; beta-adrenergic blocker ; adverse effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The antihypertensive effect of ketanserin 40 mg b.d. in combination with a beta-adrenergic blocking agent or a diuretic was assessed in an open study in 35 patients with essential hypertension, who had not responded to treatment with beta-blockers, diuretics or their combination. The ketanserin/beta-blocker combination decreased mean sitting systolic/diastolic blood pressure (SBP/DBP) from 169/107 mm Hg to 156/91 mm Hg at the end of the 12-week active treatment period. The decrease in systolic blood pressure was significant only at Week 8, while the decrease in diastolic blood pressure was highly significant at all times. A significant reduction in heart rate by 10 beats·min−1 was observed with the ketanserin + β-blocker combination. The ketanserin/diuretic combination led to a significant reduction in mean SBP/DBP from 164/106 mm Hg to 146/92 mm Hg after 12 weeks, with no significant change in heart rate. Body weight slightly increased in both groups. There were significantly fewer adverse reactions with the ketanserin/diuretic combination than with the ketanserin/beta-blocker combination. The results indicate a potentially useful therapeutic role for ketanserin in combination with beta-blockers or diuretics.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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