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Biomedical subjects

H Winkler

Publications and source records attributed to H Winkler.

At least 235 records · Page 13Linked to original sources
PubMed1986

Presence of chromogranin A, B and C in bovine endocrine and nervous tissues: a comparative immunohistochemical study.

Antisera against chromogranin A, B and C were used to study the distribution of these acidic proteins in bovine endocrine and nervous tissues. The three chromogranins occur together in several endocrine organs (adrenal medulla, anterior pituitary, endocrine pancreas) and in sympathetic ganglion cells. In the posterior pituitary, only chromogranin C and in the intermediate lobe only A and C are found. The parathyroid gland contains only A, and enterochromaffin cells are immunoreactive for A and B. Cells of the thyroid gland and some cells of the anterior pituitary apparently do not contain any chromogranins. It is concluded that the three chromogranins are not always stored together and that they are not present in all endocrine cells. This distinct localization of the chromogranins indicates some special, although still undiscovered, function for these proteins.

Adrenal Medulla↗
PubMed1986

Diminished respiratory sinus arrhythmia in asphyxiated term infants.

Spectral analysis techniques were used to quantitate the association between respiration and heart rate variability in eight healthy and eight asphyxiated infants born at term gestation. Respiratory sinus arrhythmia was demonstrated in all healthy infants. This arrhythmia was significantly diminished in asphyxiated newborn infants. We conclude that newborn infants with low Apgar scores have a reduced respiratory sinus arrhythmia and that this reduction could account for the loss of short-term heart rate variability commonly associated with asphyxia.

Apgar Score↗
PubMed1986

Bovine chromaffin granules: immunological studies with antisera against neuropeptide Y, [Met]enkephalin and bombesin.

Antisera against neuropeptide Y, [Met]enkephalin and bombesin were used for characterizing the immunoreactive material in subcellular fractions of bovine adrenal medulla. Neuropeptide Y was identified by high performance liquid chromatography and by immunoblotting. Subcellular fractionation established that neuropeptide Y is present in chromaffin granules. During stimulation of the adrenal it is released concomitantly with catecholamines. The soluble proteins of chromaffin granules contain 1.9 micrograms neuropeptide Y/mg protein which gives 429 copies of neuropeptide Y for a single granule. In two-dimensional immunoblots two peptides of the same molecular size, but with differing pI (6.4 and 7.3) react with the antiserum against neuropeptide Y. There was no evidence for the presence of a larger neuropeptide Y precursor in chromaffin granules. On the other hand, larger enkephalin-containing peptides could be detected by immunoblotting. The subcellular distribution of these enkephalin precursors differed. The larger peptides (23.3 and 18.2 kD) were more concentrated in lighter granules when compared to the smaller precursors (12.6 and 8.6 kD) which is consistent with proteolytic processing of these peptides during granule maturation. An antiserum against bombesin reacts in immunoblots with the chromogranin B family. This study further illustrates that chromaffin granules contain a complex mixture of neuropeptide-immunoreactive material. The combination of immunoblotting with subcellular fractionation appears as a useful tool to characterize these peptides and their precursors.

Adrenal Medulla↗
PubMed1986

A comparative evaluation of lymphoscintigraphy versus lymphangiography and computerized tomography scanning in diagnosis of lymph node metastases in advanced bladder cancer.

The potential of lymphoscintigraphy to detect lymph node metastases compared to lymphangiography and computerized tomography scanning was evaluated in 26 patients who underwent radical cystectomy for invasive bladder cancer. Four-view images of the abdominoperineal area were taken 90 to 120 minutes after 99mtechnetium-rhenium sulfide was injected into 2 interdigital spaces in each foot. Results of lymphoscintigraphy interpretation correlated with surgical and histological findings: a correct diagnosis was made in 61.5 per cent of the patients, while 23.1 per cent had false positive and 15.4 per cent had false negative results. Although computerized tomography was the most accurate method to detect lymph node metastases (correct diagnosis in 73.1 per cent of the patients) no significant difference was found among the 3 diagnostic methods. False positive interpretation of lymphoscintigraphy was twice as common as that of the radiological studies (23 versus 11.5 per cent). The possibilities that may cause image variation interpreted as a false positive result are discussed. Because lymphoscintigraphy is an easier and less time-consuming study than lymphangiography, the former method is suggested to be an additional and sometimes (for example if short-term followup studies are required) preferred modality to evaluate the extent of lymph node involvement in cases of invasive bladder cancer.

Aged↗
PubMed1986

Exocytotic exposure and recycling of membrane antigens of chromaffin granules: ultrastructural evaluation after immunolabeling.

The exocytotic exposure and retrieval of an antigen of chromaffin granule membranes were studied with chromaffin cells isolated from bovine adrenal medulla. Cells were incubated with an antiserum against glycoprotein III followed by fluorescein- or gold-labeled anti-IgG. Immunofluorescence on the cell surface was present in a patchy distribution irrespective of whether bivalent antibodies or Fab fragments were used. During subsequent incubation these fluorescent membrane patches were internalized within 45 min. At the ultrastructural level immunogold-labeled patches were present on the surface of stimulated cells. During incubation (5 min to 6 h) these immunolabeled membrane patches became coated, giving rise to coated vesicles and finally to smooth vesicles. These latter vesicles were found spread throughout the cytoplasm including the Golgi region, but Golgi stacks did not become labeled. Part of the immunolabel was transferred to multivesicular bodies, which probably represent a lysosomal pathway. 30 min after incubation immunolabel was also found in electron-dense vesicles apparently representing newly formed chromaffin granules. After 6 h of incubation immunolabel was found in vesicles indistinguishable from mature chromaffin granules. These results provide direct evidence that after exocytosis membranes of chromaffin granules are selectively retrieved from the plasma membrane and are partly recycled to newly formed chromaffin granules, providing a shuttle service from the Golgi region to the plasma membrane.

Adrenal Medulla↗
PubMed1986

Chromogranin C: a third component of the acidic proteins in chromaffin granules.

We characterized a group of acidic proteins of bovine chromaffin granules with an antiserum raised against a protein described by Rosa and Zanini [Eur. J. Cell Biol. 31, 94-98 (1983)] in pituitary gland. In adrenal medulla the proteins reacting with this antiserum are confined to chromaffin granules. Their largest component has a Mr of 86,000 and a pI of 5.0. In addition six proteins of lower molecular weight are recognized by this antiserum. In a cell-free system only one protein is synthesized that can be precipitated with this antiserum. The properties of these proteins are very similar to those of the previously described chromogranins A and B; however, there is no immunological cross-reaction between these protein groups. We suggest this third group of acidic proteins of chromaffin granules be named chromogranins C.

Animals↗
PubMed1986

Inflammatory fibroid polyp of the jejunum causing intussusception.

A case of inflammatory fibroid polyp of the jejunum is presented. This is the seventh case of this type of polyp in the jejunum and, to the best of our knowledge, the first one producing jejunojejunal intussusception. Symptoms of the inflammatory fibroid polyp in this part of the intestine are usually those of intermittent obstruction or intussusception, as in our patient. The treatment is surgical excision of the polyp.

Female↗
PubMed1986

Chromogranin A, B, and C in human adrenal medulla and endocrine tissues.

Antisera against bovine chromogranin A, B, and C were used to identify these proteins in human tissues by one- and two-dimensional immunoblotting and by immunohistochemistry. Human chromaffin granules contain all three chromogranins. Their molecular weight differs slightly from the bovine proteins. Chromogranin B and to a lesser degree chromogranin A are apparently processed by endogenous proteases yielding several smaller proteins which cross-react immunologically. In human granules the two families of chromogranins A and B represent the major protein groups, whereas in bovine granules the chromogranins A are by far the most prominent component. All three chromogranins are also found in the anterior pituitary. In immunoblotting these pituitary proteins behave identically to the adrenal chromogranins. In immunohistochemistry a portion of the pituitary cells stains for all three chromogranins. In endocrine pancreas only chromogranin A and B could be found, whereas in the parathyroid gland only chromogranin A is present. This study establishes that human chromaffin granules contain three immunologically distinct groups of acidic proteins. These chromogranins are also found in other endocrine tissues but they are not always stored together. Antisera against these three proteins might be used as immunological markers for tumors derived from endocrine tissue.

Adrenal Medulla↗
PubMed1985

Mössbauer investigation of the cofactor iron of putidamonooxin.

Mononuclear non-heme cofactor iron of putidamonooxin has been investigated in the binary oxidized 'enzyme X substrate' complex and in the ternary 'enzyme X substrate X NO' complex via Mössbauer spectroscopy. The experimental spectra were analyzed on the basis of the spin-Hamiltonian formalism. The resulting fine and hyperfine structure parameters are compared with literature values of similar compounds. From this comparison we conclude that in the binary complex (reduced and oxidized) the mononuclear non-heme cofactor iron has a coordination number higher than four. Additionally, the cofactor iron shows remarkable spectral similarities with iron in protocatechuate 3,4-dioxygenase, though the catalytic properties of the iron sites in the two proteins are different. The data obtained form the ternary 'enzyme X substrate X NO' complex indicate that the cofactor iron (a) is in the ferric intermediate spin state (S = 3/2) and (b) is pentacoordinated, which means that upon NO binding to the reduced cofactor iron at least one ligand has to be released. Comparing our data with literature values suggests that the cofactor iron in the binary as well as in the ternary NO complex is not directly bound to a sulfur atom, though biochemical arguments seem to indicate the opposite.

Binding Sites↗
PubMed1985

Chronopharmacokinetics of beta-receptor blocking drugs of different lipophilicity (propranolol, metoprolol, sotalol, atenolol) in plasma and tissues after single and multiple dosing in the rat.

Comparative pharmacokinetic studies with the beta-receptor blocking drugs propranolol, metoprolol, sotalol and atenolol, differing greatly in lipophilicity, and their main route of elimination were performed in light-dark-synchronized rats after equimolar single (6 mumoles/kg) or multiple (6 X 6 mumoles/kg) drug application. Drug concentrations were determined in plasma and various target organs of the drugs, e.g. heart, muscle, lung and brain, after drug application in the light period (L) and dark period (D), respectively. After single drug administration pharmacokinetic parameters of all drugs depended on the L and D conditions. Elimination half-lives in plasma and organs were shorter during D than during L. No L-D-differences were found in initial drug concentrations of the hydrophilic drugs sotalol and atenolol. In contrast, C0-values of the lipophilic propranolol in highly perfused organs (muscle, lung, brain) and of metoprolol in muscle tissue were significantly higher in D than in L. No obvious temporal dependency was found in other pharmacokinetic parameters (AUC, plasma clearance, Vd beta) with the exception in Vd beta of propranolol. Due to the different physico-chemical properties of the compounds inter-drug-differences in pharmacokinetic parameters including drug accumulation into lung and brain tissue were observed. Multiple drug dosing abolished the circadian-phase-dependency in the elimination half-lives of the drugs due to an increase in D. Only for the highly lipophilic propranolol half-lives in highly perfused organs were still shorter in D than in L.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1985

Immunological studies on the distribution of chromogranin A and B in endocrine and nervous tissues.

Bovine chromaffin granules contain two major families of acidic proteins, chromogranins A and B. The occurrence of these proteins in endocrine and nervous tissue was investigated by immunoblotting (one- and two-dimensional), and by immunohistochemistry. Immunoblotting revealed that in anterior hypophysis and in splenic nerve from ox, immunologically crossreacting proteins are present which in two-dimensional electrophoresis migrate to the same position as adrenal chromogranins A and B. Smaller proteins derived from chromogranin B by endogenous proteolysis were much less prominent in these tissues when compared with adrenal medulla. Immunohistochemistry performed in rat and bovine tissues established that chromogranin B is present in all cells of the adrenal medulla. It is also found in the anterior hypophysis, the endocrine pancreas, in enterochromaffin and in sympathetic ganglion cells, but e.g. is absent from posterior hypophysis and exocrine tissues. It is concluded that chromogranins A and B have a widespread distribution in endocrine and nervous tissue. Proteolytic processing of chromogranin B in the storage organelles of hypophysis and splenic nerves is apparently slower than that in chromaffin granules. The widespread distribution of the chromogranins resembling that of neuropeptides is a clear indication for some special, yet to be discovered, function.

Adrenal Medulla↗