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Biomedical subjects

D Büttner

Publications and source records attributed to D Büttner.

At least 37 records · Page 2Linked to original sources
PubMed1984

Blood pressure in rats: a comparison of a multifactorial experimental design to measurements in an outbred stock.

Systolic blood pressure was measured in males of 8 inbred strains and 1 outbred stock of rats 5 times over a period of 20 min on 5 consecutive days. The strain means ranged between 107.9 mmHg and 149.3 mmHg. The estimated variance between strains (V = 248.7 mmHg) was about 5 times higher than the variance within strains (V = 54.3 mmHg). The intraindividual variance within strains was relatively constant (V = 24.0-37.6 mmHg), while the interindividual variance varied to a great extent (V = 4.5-44.5 mmHg) from strain to strain. The outbred stock showed values of blood pressure and components of variance similar to those of a single inbred strain. Thus, by investigation of a battery of 8 inbred strains in a multifactorial experimental design a greater phenotypic variability due to genetic strain differences is achieved than by measurements in a single outbred stock.

Analysis of Variance↗
PubMed1984

Biological, analytical and experimental components of variance in a long-term study of plasma constituents in rat.

Statistical analysis of variance was applied to data from determinations of 14 plasma constituents in 25 rats in order to evaluate the analytical, experimental and biological (inter-and intraindividual) component of variance. Blood was taken seven times in intervals of 8-10 days, the last one by catheter technique and the other by heart puncture. The analytical portion of variance was determined by the concurrent analysis of a pool plasma standard. The experimental component of variance was evaluated by the comparison of the variation of the catheter values with that of the pooled data from heart puncture. The coefficient of variation for the latter may be grouped into three categories: less than 10% for protein, Na+, K+, Ca2+; 10-20% for urea, phosphate and the enzymes as alanine aminotransferase, choline esterase, alkaline phosphatase and leucine arylamidase and 20-65% for the other enzymes lactate dehydrogenase, malate dehydrogenase, aspartate aminotransferase and creatine kinase. The results from the samples taken by catheter technique generally revealed the lower values for the mean as well as for the variance. It became evident that the procedure of heart puncture is afflicted with the most aggravating interference factors, thus accounting for most of the experimental component of variance. The observed differences between the single blood drawings, the non-Gaussian distribution for several constituents, and the interactions between the components of variance do not always fit for the statistical concept of additivity of the single components.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1983

Distribution of glomeruli in the renal cortex of Munich Wistar Frömter (MWF) rats.

The glomerular distribution in the renal cortex of the Munich Wistar Frömter (MWF) rat, a substrain of the Munich Wistar rat selected for superficial glomeruli, was compared to that of a control strain (LEW/Ztm) between 10 and 150 days of age. While there were no significant differences in body growth, kidney weight, or growth of the renal cortex in these two strains, the average diameter of Bowman's capsule and of the glomerular tuft was significantly larger (about 12%) in rats of the MWF strain which were older than 60 days. In histological sections of kidneys of MWF rats in all age groups, many glomeruli in direct contact with the renal capsule were found; thus, this developmental step must have taken place before 10 days of age. The appearance of superficial glomeruli was due to a shift of glomeruli to a position just under the renal surface, the subcapsular zone or 'cortex corticis', which is normally free of glomeruli. For the rest of the renal cortex there were only slight differences in glomerular density and in total number of glomeruli per section between these two strains. These results lead us to suppose that superficial glomeruli belong to a special nephron type; thus, these glomeruli are not enveloped by parts of the proximal tubule.

Animals↗
PubMed1983

Influence of bleeding procedure and some environmental conditions on stress-dependent blood constituents of laboratory rats.

The influence of experimental conditions on 10 haematological and blood chemical constituents were investigated in male Han:Wistar rats. Significant differences existed between values of haematological and chemical constituents of blood, sampled within 10 s, between 10 and 30, or between 30 and 60 s after decapitation respectively, The leucocyte count decreased quickly but the lactate concentration rose after decapitation. The interindividual coefficient of variance for the majority of the blood constituents was reduced markedly if blood was sampled within 10 s of decapitation. Significant differences in plasma protein and blood lactate concentrations existed between 2 rats kept in one cage, when the first rat was decapitated 20 s before the second one. Plasma protein concentrations differed significantly between rats bled at 9.00 am and 11.00 am. Significant differences in blood glucose and lactate concentrations existed between rats bled on 5 different days within a period of 10 days. Packed cell volume, eosinophilic granulocytes and plasma protein concentration differed significantly between rats kept in a room with a 12:12 light: darkness (LD) cycle and those living in a room with a 2.3:2.3 LD cycle.

Analysis of Variance↗
PubMed1982

Intraspecies allometry: correlation between kidney weight and glomerular filtration rate vs. body weight.

Allometric equations of the form of Y = a*BWb were calculated between body weight (BW) on the one hand and either kidney weight (KW) or glomerular filtration rate (GFR) on the other. By using strain and sex means obtained from 24 different inbred strains of adult mice or F1-hybrids environmental and genetical influences could be separated statistically. Thus, allometric equations reported in this study describe exclusively genetic influence. The parameters for intraspecies allometric equations obtained in these studies were compared to those in the literature presenting interspecies relationships. The double logarithmic regressions of KW vs. BW gave results different from the interspecies equation. The difference between intra- and interspecies results of allometric relationships may be due to the experimental exclusion of environmental influences. The regression parameters for GFR vs. BW obtained for the inbred strains, however, agreed very well with those of the empirical equation for interspecies relationship and also with the theoretically expected value. The dependence of GFR on BW was found to be GFR = 0.036*BW0.74 +/- 0.15, where GFR is measured in ml/min and BW in g. The exponent of 0.74 seems to be a valid biological constant that is genetically determined within and across species lines.

Animals↗
PubMed1982

Spontaneous short-term fluctuations in the daily pattern of heart rate, body temperature and locomotor activity in the laboratory rat.

Heart rate (HR), body temperature (BT) and locomotor activity (LA) were measured continuously over 5 days in freely moving rats. In addition to the well-known circadian rhythms, all variables exhibited considerable fluctuations in amplitude mainly during the dark, but also in the light periods. The values of HR varied from 286 +/- 12 to 470 +/- 26 b.p.m. and BT from 36.15 +/- 0.15 degrees C to 38.45 +/- 0.25 degrees C. The large variability of HR, BT and LA within a single day was due more to large short-term fluctuations within periods of about 3-5 hours duration, than to differences between the light and the dark period. Good consistency of daily patterns and similarity of the 3 variables was found within the animals. Usually there were 3 or 4 regular peaks during the dark and often another peak 3-4 hours after the onset of light. Correlation coefficients, calculated on the basis of 5-min mean values, were highly significant (P less than 0.001) for LA vs HR (0.61-0.73), LA vs BT (0.40-0.53), and HR vs BT (0.61-0.68). Between-hour correlations were higher than these common correlations of 5-min values. HR vs BT (0.76-0.83) and LA vs BT (0.63-0.79) correlated as well as LA vs HR (0.72-0.83). The short-term fluctuations (within-hours) gave lower correlation coefficients for LA vs BT (0.23-0.32) and HR vs BT (0.29-0.41) than LA vs HR (0.40-0.70). This seems to result from a physiological delay of BT relative to HR and LA.

Animals↗
PubMed1980

pH dependency in uptake of sulfonamides by bacteria.

Sulfonamide-sensitive cells of Escherichia coli were incubated under standarized conditions with various sulfonamides and the quantity of sulfonamide uptake into the bacteria measured. The test substances reached a higher concentration inside the bacteria than in the incubation medium, the degree of accumulation varying for the individual substances despite uniformly applied incubation conditions. In all cases a pH dependency was detected which varied with the pKa values of the substances tested. On the basis of the pKa dependency of the pH effect, the sulfonamide uptake can be interpreted as being a passive diffusion process. Knowing the intracellular pH value, which was determined by the DMO method, it was then possible to calculate the theoretically expected value for the accumulation as a concentration coefficient. Since the calculated and experimentally determined values differ approximately by a factor of 2, an intracellular binding of the sulfonamides is assumed. The same results were obtained in cells of sulfonamide-resistant E. coli strains.

Bacteria↗
PubMed1978

[Acute pancreatitis following gastric secretion analysis by pentagastrin stimulation (author's transl)].

A picture of acute abdomen developed in a 25-year-old patient with recurrent duodenal ulcers after subcutaneous injection of pentagastrin for a gastric secretion test. Laparotomy undertaken for suspected perforated ulcer revealed an acute hemorrhagic pancreatitis. Healing and freedom from complaint occurred rapidly with drug therapy. The following are to be considered as possible causes for pancreatitis after subcutaneous application of pentagastrin: exacerbation of the ulcer, an acute exacerbation of chronic pancreatitis, a direct effect of pentagastrin on the pancreas, increased pancreatic secretion due to the stimulation of gastric acid, reflux of duodenal contents or bile, arterial hypotension with local acidosis in the pancreas. Attention must always be paid to contra-indications of gastric juice analysis.

Acute Disease↗
PubMed1977

[Crohn's disease with several intestinal foci ("skip lesions")].

A 35-year-old man underwent a resection of part of the ileum due to six "skip lesions" in Crohn's disease. At reoperation four years later, in addition to a typical terminal ileitis, two stenosing lesions were found at the ileal-jejunal junction. In connection with this rare observation, a report is made on multiple lesions and the diffuse type of Crohn's disease, both of which must be included in the therapeutic concept. "Adequate" resections including all segmental lesions are demanded, different resections in additional distant lesions, and conservative medical treatment in the widespread diffuse type of the disease.

Adult↗
PubMed1976

[Reoperation in recurrence of carcinoma of the esophagus, Cardia and stomach (author's transl)].

Reoperative surgery is performed with the object of restoring gastrointestinal passage or of pain relief and only rarely, for example in recurrence of an early carcinoma, with the object of curative resection. Out of 31 reoperations for such a purpose, a second resection (total or extended gastrectomy) was possible in 9 cases, gastric bypass or some other palliative operation in 12; in 10 cases, only a laparotomy was possible. The interval between the 1st and 2nd operations was 29 months in the resectable group and 17 months in the nonresectable group, the survival times 11 and 3.3 months respectively. Indications have to be considered separately for each patient.

Adult↗