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Biomedical subjects

M Barthel

Publications and source records attributed to M Barthel.

27 records · Page 2Linked to original sources
PubMed1990

Preservation of the porcine pancreas with HTK and Euro-Collins solution: studies in a reperfusion system.

The present study compares the preservation of the porcine pancreas by the standard Euro-Collins solution or the cardioplegic histidine-tryptophan-ketoglutarate solution (HTK). The explanted pancreas was stored at 4 degrees C for 6 and 24 h respectively, following which organ quality was assessed in a reperfusion chamber measuring physiological and biomedical parameters. After 6 h ischaemia, the amount of lactate was significantly lower when HTK was used for protection. Other parameters like insulin release, amylase release, vascular resistance and oxygen consumption of the pancreas did not indicate a significant difference. Protection with HTK significantly improved pancreas preservation after 24 h ischaemia: lactate content in the reperfusate was lower (HTK: 64.0 +/- 7.2 mumol 50 ml-1 n = 8, v. EC: 114.2 +/- 1.7 mumol 50 ml-1, n = 6), the arteriovenous flow rate was higher (HTK: 5.7 +/- 0.91 ml min-1 v. EC: 3.0 +/- 0.26 ml min-1), and the pancreatic oxygen consumption was increased (HTK: 2.15 +/- 0.22 microliter O2 min-1 g-1 v. 0.47 +/- 0.08 microliter O2 min-1 g-1). We conclude that pancreas preservation can be improved in vitro by protection with HTK solution.

Amylases↗
PubMed1989

The perfused porcine pancreas as a model for testing organ protective solutions.

The present study was designed to establish an in vitro perfused porcine pancreas preparation as a model for testing the effect of organ protective solutions on stimulated pancreatic endocrine and exocrine secretion. The pancreas was prepared and perfused for 10 min with Euro Collins solution, thereafter it was stored in the cold (4 degrees C) for various times. After 3-h and 6-h ischemia pancreatic insulin release in response to glucose was not significantly affected. After 12-h ischemia reduced pancreatic insulin secretin, increased perfusion pressure, and increased amylase and lipase release indicated pancreatic damage. Complete pancreatic dysfunction was seen after 24-h and 48-h ischemia with massive increase in perfusion pressure and low insulin secretion which did not follow a glucose-dependent release pattern, while amylase and lipase concentrations in the perfusion medium increased. Stimulated exocrine pancreatic secretion was significantly decreased already after 3-h ischemia and completely lost after 12 h.

Amylases↗
PubMed1987

Exocrine pancreatic function in dogs with denervated pancreas.

There is strong evidence that the vagus nerve plays an important role in exocrine pancreatic secretion. In the present study we examined the effect of total extrinsic denervation of the pancreas on exocrine pancreatic secretion to different stimuli in dogs. In the experiments we used the model of the orthotopic autotransplanted dog pancreas as described by Debas et al. Denervation of the gland did not significantly alter water and bicarbonate response to secretin. The dose-response curve of caerulein showed the denervated pancreas as sensitive as the intact gland. However, autotransplantation of the pancreas caused a significant decrease (p less than 0.05) in protein secretion during intraintestinal L-tryptophan in increasing doses. Furthermore, bicarbonate and protein secretion after food intake was significantly decreased in the denervated pancreas (protein: peak levels 380 mg/15 min and 135 mg/15 min; bicarbonate: 3.2 mEq/15 min and 1.4 mEq/15 min) (p less than 0.02). From our data we conclude that the denervated pancreas is as sensitive as the intact pancreas to stimulation by exogenous secretin and caerulein, whereas denervation of the pancreas causes an important influence in the intestinal phase of pancreatic secretion.

Animals↗
PubMed1985

[Comparison between the radioimmunologic measurement of plasma E2 and estrogen determination in urine using a hemagglutination inhibition test].

To prove the diagnostic value of a new haemagglutination inhibition test (HI-Estrotec), urinary and plasma oestrogens were simultaneously measured in 42 stimulated cycles of 40 women of the Erlangen IVF programme. Comparing the results of all paired samples, there was a correlation coefficient r = 0.6968. Correlating the total oestrogens in the early morning urine with the plasma-E2, the coefficient was r = 0.641. In 26 cases of the 42 stimulated cycles egg retrieval could be performed. Averaging the daily values of these women the graphs of E2 and urinary oestrogens show nearly parallel curves with maximal values on the same day, i.e. the first day after HCG application. Comparing the two curves of the individual patient, in 14 of 26 cases there are differences of more than 24 hours between the maximal values of urinary and plasma oestrogens. The advantages of the HI-Estrotec-Assay are: Simple handling without special demands on the laboratory equipment. The results can be obtained after two hours already. The possibility to measure several times a day without great effort. The disadvantage is: The delayed appearance of the hormones in the urine. To induce ovulation with HCG, however, actual parameters are indispensable. If the ovulation is triggered by the endogenous LH surge the diagnostic value of the new assay is sufficient when it is combined with an LH monitoring.

Adult↗
PubMed1982

[Cryoconservation of 8-celled stage rabbit embryos in an automated "open system"].

Rabbit embryos were successfully frozen at the 8-cell stage, employing a rapid and a slow freezing-thawing program. They were then stored at -196 degrees C (liquid nitrogen) for 10 to 60 days. After thawing the embryos were examined for viability in vitro and in vivo. Using the slow program B 82.5% were morphologically intact, compared to only 69.3% after the rapid procedure (program A). 88.8% of the group first mentioned above, and 56.8% of the latter developed to the blastocyst stage after 4 to 5 days in culture. The implantation rate was 18.1%, when embryos were transferred to minus 18 hours asynchronous recipients, after thawing. With 40%, a significantly higher implantation rate could be achieved, when the embryos were transferred to minus 24 hours asynchronous foster mothers. 18 viable young were born 30 to 32 days after transfer.

Animals↗