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Biomedical subjects

C Egger

Publications and source records attributed to C Egger.

26 records · Page 2Linked to original sources
PubMed1994

Protothecosis in an HIV-positive patient.

This is the first report of localized tendosynovial human protothecosis in an HIV-positive host. The lesion appeared as a nodule in the extensor face of the thumb. A simple excision was performed, and histology confirmed numerous granulomas, some with central fibrinoid necrosis. Enormous numbers of prototheca were found in periodic acid-Schiff and Gömöri methenamine silver strains, evidencing endosporulation with diagnostic morula- or daisy-like sporangia. The presence of prototheca species was confirmed by direct immunofluorescence with the specific conjugate. The cellular response estimated by the relative number of polymorphonuclear leukocytes, lymphocytes, and plasma cells was minimal, although granuloma formation was unaffected. The infective agents were found either extracellular or harbored by macrophages and giant cells.

Fluorescent Antibody Technique↗
PubMed1994

Bovine posterior pituitary: presence of p65 (synaptotagmin), PC1, PC2 and secretoneurin in large dense core vesicles.

The subcellular distribution of p65 (synaptotagmin), of the endoproteases PC1 and PC2 and of secretoneurin was studied in bovine posterior pituitary by differential and density gradient centrifugation. All these peptides were found to be present in the neurosecretory granules (large dense core vesicles). p65 can therefore participate not only in exocytosis from small synaptic vesicles but also from large dense core vesicles. Secretoneurin is a peptide derived from secretogranin II. Processing of the propeptide apparently occurs during axonal transport of the large dense core vesicles and is complete in the posterior pituitary. Thus, stimulation of the hypothalamic magnocellular neurons can lead to the release of this newly characterized, functional neuropeptide.

Animals↗
PubMed1993

Different degrees of processing of secretogranin II in large dense core vesicles of bovine adrenal medulla and sympathetic axons correlate with their content of soluble PC1 and PC2.

We investigated the processing of secretogranin II in large dense core vesicles of adrenal medulla and sympathetic nerve. Despite the fact that both types of vesicles have a very similar biochemical composition, the degree of processing of secretogranin II in vesicles from splenic nerve was significantly higher. The endoproteases PC1 and PC2, two likely candidates for secretogranin II cleavage, are found in both types of vesicles, however, relative to secretogranin II the nerve vesicles have a much higher content of these enzymes. This probably explains the fast and more extensive processing of secretogranin II in these vesicles.

Adrenal Medulla↗
PubMed1993

Histamine induces a gene-specific synthesis regulation of secretogranin II but not of chromogranin A and B in chromaffin cells in a calcium-dependent manner.

The effect of histamine on steady-state mRNA levels of three soluble secretory proteins from chromaffin granules was investigated in cultured bovine adrenal medullary cells. Histamine stimulated secretogranin II mRNA 4-fold, with no or only slight effects on chromogranin A and B transcription. After an initial lag phase, secretogranin II mRNA increased markedly between 4 and 12 h followed by a plateau phase up to 48 h. The effect of histamine on secretogranin II gene-expression was abolished by the H1 receptor antagonist promethazine but not by the H2 blocker cimetidine. The histamine-induced elevation of secretogranin II mRNA was partially reduced by the L-type calcium channel blocker nifedipine, indicating a contribution of extracellular calcium in the second messenger signaling pathway involved. At present, the H1 histaminergic receptor is the first membrane receptor found regulating secretogranin II biosynthesis in chromaffin cells. The selective up-regulation of secretogranin II mRNA but not of chromogranin A and B by histamine is another example illustrating that the synthesis regulation of secretory components co-stored in large vesicles of neuroendocrine cells is specific to the individual gene. Together with results obtained earlier, our data demonstrate a marked variation in the relative composition of peptides secreted from adrenal medulla into circulation following different physiologic conditions.

Adrenal Medulla↗
PubMed1993

Glycoprotein III (clusterin, sulfated glycoprotein 2) in endocrine, nervous, and other tissues: immunochemical characterization, subcellular localization, and regulation of biosynthesis.

Specific antisera were raised against the A and B chains of glycoprotein III. Immunoblotting revealed that in adrenal medulla both chains migrate very closely together in two-dimensional electrophoresis. Both chains with slightly differing molecular sizes are found in several endocrine tissues and in brain, kidney, liver, and serum. The mRNA has an analogous widespread distribution. In primary cultures of chromaffin cells the level of message becomes significantly increased by treatment with histamine or 12-O-tetradecanoylphorbol 13-acetate/forskolin. However, the increase is small when compared with that of secretogranin II. The subcellular localization of glycoprotein III in endocrine organs and in the posterior pituitary was investigated by subcellular fractionation and immunoelectron microscopy. Glycoprotein III was found to be confined to the large dense-core vesicles of these organs. For a discussion of the function of glycoprotein III, its localization in these organelles has to be taken into account.

Animals↗
PubMed1992

Differential subcellular distribution of PC1, PC2 and furin in bovine adrenal medulla and secretion of PC1 and PC2 from this tissue.

The subcellular distribution of PC1, PC2 and furin was determined in bovine adrenal medulla by immunoblotting of fractions obtained by density gradient centrifugation. PC1 and PC2 were found to be confined to chromaffin granules whereas furin (C-terminal-peptide) was absent from these organelles. Stimulation of bovine adrenal medulla by carbamoylcholine chloride induced the secretion of PC1 and PC2. The secreted enzymes had the same molecular size as PC1 and PC2 present in chromaffin granules.

Adrenal Medulla↗
PubMed1992

Carcinosarcoma of the urinary bladder: a distinct variant characterized by small cell undifferentiated carcinoma with neuroendocrine features.

The clinicopathological features of two carcinosarcomas of the urinary bladder are reported. The tumours occurred in a 64- and a 66-year-old patient presenting with haematuria and both were polypoid. The epithelial component was consistent with small cell undifferentiated carcinoma with neuroendocrine differentiation, whereas the sarcomatous component did not display specific features. The carcinomatous component showed immunohistochemical reactivity for different epithelial markers as well as for chromogranin and neuron specific enolase. Conversely, the sarcomatous cells stained strongly for vimentin and in one case for muscle actin and smooth muscle actin. The differential diagnosis of biphasic tumours of the bladder is discussed and the literature reviewed.

Actins↗