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Biomedical subjects

G Hacker

Publications and source records attributed to G Hacker.

9 recordsLinked to original sources
PubMed2002

Caspase-2 is not required for thymocyte or neuronal apoptosis even though cleavage of caspase-2 is dependent on both Apaf-1 and caspase-9.

We have generated rat monoclonal antibodies that specifically recognise caspase-2 from many species, including mouse, rat and humans. Using these antibodies, we have investigated caspase-2 expression, subcellular localisation and processing. We demonstrate that caspase-2 is expressed in most tissues and cell types. Cell fractionation and immunohistochemistry experiments show that caspase-2 is found in the nuclear and cytosolic fractions, including a significant portion present in the Golgi complex. We found that caspase-2 is processed in response to many apoptotic stimuli but experiments with caspase-2 deficient mice demonstrated that it is not required for apoptosis of thymocytes or dorsal root ganglia (DRG) neurons in response to a variety of cytotoxic stimuli. Caspase-2 processing does not occur in thymocytes lacking Apaf-1 or caspase-9, suggesting that in this cell type, activation of caspase-2 occurs downstream of apoptosome formation.

Animals↗
PubMed1997

Proliferative cell activity in correlation to human chorionic gonadotrophin release of trophoblast tissue of tubal pregnancy.

The degree to which the relative rise of serum human chorionic gonadotrophin (HCG) concentration was related to proliferative cell activity and the biological vitality of tubal pregnancy was investigated. Salpingectomy was performed in 15 patients diagnosed as having non-ruptured tubal pregnancy. Serum HCG was evaluated twice preoperatively, with a 48-h time interval. Proliferative cell activity was measured through the use of the cell proliferation marker 'Ki-67'. A significant correlation between the relative increase in HCG over a 48-h period, independent of the initial serum HCG value, and the biological cell activity of the trophoblast was shown. Furthermore, it became evident that cell activity was also correlated to the intracellular HCG of the trophoblast. The relative increase in serum HCG over a period of 48 h can serve as a parameter for the biological activity of the trophoblast in tubal pregnancies.

Cell Division↗
PubMed1985

Phospholipase-A1 and -A2 in experimental acute pancreatitis in rats.

Using a standardized model of bile-induced acute pancreatitis, the reaction of phospholipase-A1 activity was investigated in parallel to that of phospholipase-A2, as well as their relationship to the pathomorphological spread of pancreatitis. While the measurement of the total free fatty acids (FFA) in serum as metabolites of phospholipase-A activity indicated variable reactions with the average remaining the same (0.186 +/- 0.15 to 0.192 +/- 0.153 mEq/l), phospholipase-A2 exhibited a highly significant increase from 9.6 +/- 2.2 to 18.2 +/- 5.4 nmol/ml/min (P less than 0.01). It was demonstrated that in parallel phospholipase-A1 also showed a highly significant increase from 2.5 +/- 1.2 to 6.7 +/- 3.1 nmol/ml/min (P less than 0.01). In relation to the pathomorphological score, both phospholipases showed a small increase at a low score (edema to focal necrosis), whereas in groups with a larger spread of the pancreatitis, score 5 or 6 (extended necrosis to retroperitoneal necrosis), the increase was substantially clearer. As a result of these findings, we conclude that phospholipase-A1 could possibly be used as phospholipase-A2 as an indicator of the severity of acute pancreatitis and that it should be taken into consideration in the very promising therapy with phospholipase-A-antagonists.

Acute Disease↗
PubMed1983

Somatostatin-immunoreactive cells in the gastro-entero-pancreatic endocrine system of Xenopus laevis.

Somatostatin-like immunoreactivity has been demonstrated in cells of the gastro-entero-pancreatic endocrine system of Xenopus laevis (Amphibia) using peroxidase-anti-peroxidase immunohistochemistry. The identified cells of the gastro-intestinal tract correspond to the "Open-Paraneurons" of FUJITA (1974). Somatostatin-immunoreactive cells were found in the stomach (fundic and pyloric region), the duodenum and in the anterior ileum, but not in the colon. The dimensions of these 'Somatostatin-Open-Paraneurons' were measured: mean maximum height = 41.31 micron (S.D. = 10.87 micron), mean maximum breadth = 8.73 micron (S.D. = 2.31 micron). Frequency distributions of the maximum height and of the maximum breadth were processed by use of a computer. Somatostatin-immunoreactive cells in the pancreatic islets occupied about 15 to 25% of the total islets volume. These cells are "Closed-Paraneurons" (according to FUJITA 1974) with a mean diameter of 11.68 micron (S.D. = 2.61 micron).

Animals↗