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Biomedical subjects

B Jasani

Publications and source records attributed to B Jasani.

At least 145 records · Page 8Linked to original sources
PubMed1986

Immunogold electron-microscopic localisation of calpain I in skeletal muscle of rats.

By using a double-affinity-purified first antibody and colloidal gold-conjugated second antibody, it is shown that calpain I (a cysteine proteinase activated by micromolar concentrations of Ca2+) has a predominant intracellular location in the I-band region of the extensor digitorum longus (EDL) muscle of the rat, but is not exclusively associated with the Z-line.

Animals↗
PubMed1986

Immunohistochemical localization of cell surface receptors using a novel method permitting simple, rapid and reliable LM/EM correlation.

A method is presented which allows correlative serial section analysis by light and electron microscopy of cell surface antigens in monolayer cultures. Sites of antigenicity are shown by deposition of diaminobenzidine after pre-embedding, immunoperoxidase immunocytochemistry. Osmication is replaced by the use of gold chloride which specifically enhances the electron density of diaminobenzidine. In addition gold chloride bound to diaminobenzidine survives embedding and provides the basis for a post-embedding photochemical amplification method. Immunostained cells are embedded in LR White by a rapid technique which preserves their structure and leaves them available for subsequent post-embedding immunocytochemistry. The method is illustrated by the demonstration of epidermal growth factor (EGF) receptors on the EGF receptor-rich human carcinoma cell line A431 using a well characterized monoclonal antibody raised against EGF receptor.

Antigens, Surface↗
PubMed1986

Immunohistochemical identification of prolactin and 24K protein in secretory endometrium.

Inadequate endometrial differentiation is a cause of infertility and recurrent pregnancy loss. Diagnostic histologic dating criteria may be supplemented by the immunohistochemical identification of protein markers in late secretory endometrium. Late secretory endometrium has been shown to contain prolactin. The authors report the immunohistochemical localization of prolactin and 24K protein in late secretory endometrium using monoclonal antisera and the dinitrophenyl hapten sandwich-staining technique. The appearance of these proteins in decidualized stromal cells of late secretory endometrium may provide a more specific indicator of endometrial development and differentiation, if their late appearance or absence can be correlated with pregnancy wastage.

Antibodies, Monoclonal↗
PubMed1985

The use of vimentin antibodies in the diagnosis of malignant mesothelioma.

An immunohistochemical investigation of vimentin, an intermediate filament, was carried out on formalin fixed paraffin embedded sections of 44 malignant mesotheliomas of the pleura and 24 pulmonary adenocarcinomas, in order to assess its value in differential diagnosis. Seventy-five percent of the malignant mesotheliomas showed positive staining for vimentin. An unexpected finding was the presence of vimentin in 46% of the pulmonary adenocarcinomas. In either case there was no correlation between the presence of vimentin and the histological types or grades of differentiation. The overall level of vimentin staining was significantly greater in the malignant mesotheliomas than in the pulmonary adenocarcinomas but no single antibody dilution was found to provide clear cut separation of the two groups. Vimentin does not appear to be a simple discriminatory marker of malignant mesothelioma.

Adenocarcinoma↗
PubMed1985

A system for accurate immunolocalization of Tamm-Horsfall protein in renal biopsies.

The distribution of Tamm-Horsfall protein (THP) was studied in the human kidney using formalin-fixed, paraffin-embedded sections with a monoclonal antibody specific for human THP applied in conjunction with a modified dinitrophenyl hapten sandwich staining (DHSS) procedure. The method was found to be highly sensitive producing very strong specific staining at antibody dilutions up to 1 in 64 000. Counterstaining with Haematoxylin and Eosin was possible without significant masking of the specific staining. This provided excellent structural definition of the background tissue which proved especially important in the study of THP localization in randomly oriented biopsy material. THP was found in all segments of the thick ascending limbs of loops of Henle, most segments of distal convoluted tubules and occasionally in distended collecting ducts and in the glomerular capsular space. Maculae densae did not contain THP. The combination of the modified DHSS procedure and the human THP specific antibody represents a highly sensitive and reliable method for specific staining of the THP in kidney sections.

Antibodies, Monoclonal↗
PubMed1985

Histological demonstration of immunoreactive zinc metallothionein in liver and ileum of rat and man.

A sensitive immunohistochemical technique was used to demonstrate zinc metallothionein in rat and human liver and ileum. In the liver, immunoreactivity was observed within the hepatocyte nucleus and cytoplasm, in sinusoids, canaliculi and blood vessels. In the ileum, immunoreactivity was present in the enterocyte nucleus and cytoplasm, and in the lamina propria. The effects of fasting alone and fasting with zinc injection were studied. In the liver, maximum staining was observed after 6 h fasting in the sinusoids, canaliculi and hepatocyte cytoplasm, and this pattern was not present in zinc injected animals. In the ileum, the greatest staining in the enterocyte cytoplasm and basal region was in control animals and after 6 and 12 h fasting. A similar pattern was observed in zinc-injected animals. Decreased staining was seen after 18 h fasting in both liver and ileum. In human ileum, the patients with colitis had less metallothionein immunoreactivity and those on steroid therapy had more immunoreactivity than the controls. We suggest a physiological transport and short term storage function for zinc metallothionein in rat and man.

Animals↗
PubMed1985

Histogenesis of haemangioblastomas: an immunocytochemical and ultrastructural study in a case of von Hippel-Lindau syndrome.

The cerebellar, retinal, and one of the spinal haemangioblastomas in a case of von Hippel-Lindau syndrome were studied by immunocytochemistry and electron microscopy. The tumours were positive for neurone specific enolase and variably positive for somatostatin, pancreatic polypeptide, and bombesin. Electron microscopy of the cerebellar tumour showed secretory granules with an average diameter of 170 nm. This report is believed to be the first description of neurone specific enolase positivity and polypeptide hormones within the intervascular cells of haemangioblastomas. In the light of these findings it is suggested that haemangioblastomas are tumours of neuroectodermal origin, derived either from neural or neuroendocrine cells.

Angiomatosis↗
PubMed1985

Comparison of tumour markers in malignant mesothelioma and pulmonary adenocarcinoma.

Immunohistological methods were used to investigate the presence of carcinoembryonic antigen, beta 1 pregnancy specific glycoprotein, beta subunit of human chorionic gonadotrophin, human placental lactogen, calcitonin, and keratin in formalin fixed tissue from 29 malignant mesotheliomas and 27 pulmonary adenocarcinomas. Malignant mesotheliomas were negative for tumour markers except for the beta subunit of human chorionic gonadotrophin and keratin, one and 13 cases respectively being positive for these. Pulmonary adenocarcinomas, however, were frequently positive for tumour markers--namely, carcinoembryonic antigen, beta 1 pregnancy specific glycoprotein, beta subunit of human chorionic gonadotrophin, human placental lactogen, calcitonin, and keratin. The presence of carcinoembryonic antigen and beta 1 pregnancy specific glycoprotein within an intrathoracic tumour is strong evidence against its being of mesothelial origin.

Adenocarcinoma↗
PubMed1984

DNA and enzyme studies on chorionic villi for use in antenatal diagnosis.

A study has been undertaken to determine the efficiency of current methods in providing an adequate amount of chorionic villus DNA for antenatal diagnosis using recombinant DNA techniques or enzyme assay. Chorionic biopsies were obtained from 40 women undergoing elective first trimester termination of pregnancy (8-12 weeks) under general anaesthesia. The villus tissue was isolated from maternal tissue under a dissection microscope and the presence of any remaining contamination was ascertained by conventional histology and immuno-cytochemical examinations. A high level of success was achieved in obtaining a pure fetal sample. In the first 20 samples the DNA yield obtained using the method of Williamson et al [1] was found to be 0.5 +/- 0.5 micrograms/mg wet weight of villus tissue (mean +/- 1 SD). In the subsequent 20 biopsies using a modified procedure, the yield was significantly improved to 1.0 +/- 0.65 (p less than 0.002). A normal range for the enzyme iduronate sulphatase, which is deficient in Hunter's syndrome (mucopolysaccharidosis II), is also reported. It is suggested that as little as 20 mg of chorionic villi may be used to provide sufficient material for a reliable study using recombinant DNA or biochemical methods.

Amniotic Fluid↗
PubMed1984

Non-deleterious dinitrophenyl (DNP) hapten labelling of antibody protein. Preparation and properties of some short-chain DNP imidoesters.

Methyl 3-(2,4- dinitrophenylamino ) propionimidate hydrochloride (DNP-N-IE), methyl 3-(2,4-dinitrophenyl-N-methylamino) propionimidate hydrochloride (DNP- NMe -IE), and methyl 3-(2,4- dinitrophenylthio ) propionimidate hydrochloride (DNP-S-IE) have been prepared. DNP-N-IE and DNP- NMe -IE both react efficiently at 0-2 degrees C and pH 7-9.5 with sheep immunoglobulin G. At least 12 DNP groups can be introduced into the antibody protein without causing any significant change in its antigen binding affinity or capacity.

Affinity Labels↗
PubMed1984

Glandular duodenal carcinoid--a somatostatin rich tumour with neuroendocrine associations.

The clinical and pathological features of four cases of duodenal carcinoid tumour are presented. All four tumours showed a glandular pattern, and in three cases this was associated with psammoma bodies. In three tumours somatostatin was identified by immunocytochemistry in most tumour cells. In two cases the duodenal tumours were associated with von Recklinghausen's disease and phaeochromocytoma. The importance of these unusual features is discussed, and it is suggested that these glandular carcinoids are a specific subgroup of endocrine cell tumours which appear to have potentially important clinical and pathological associations.

Adrenal Gland Neoplasms↗
PubMed1984

Hypothyroid pituitary cells in culture: an analysis of thyrotropin and prolactin responses to dopamine (DA) and DA receptor binding.

Monolayer cultures were prepared from the anterior pituitary (AP) lobes of normal male rats and male rats made hypothyroid by treatment with aminotriazole. After 3 days in culture, the cells from hypothyroid animals showed significantly greater TSH and PRL secretory activity and significantly less GH secretory activity than did parallel euthyroid cultures. The responses of euthyroid and hypothyroid cultures to dopaminergic agonists and antagonists were examined. Bromocriptine, apomorphine, and dopamine (DA) inhibited euthyroid TSH secretion by approximately 30%, whereas each drug inhibited hypothyroid TSH secretion by approximately 60% (P less than 0.01 for each drug). In contrast, the three agonists were less effective in inhibiting PRL secretion from hypothyroid cells (P less than 0.05 for each drug). The rank order of potency [bromocriptine greater than (+)butaclamol greater than apomorphine greater than DA greater than (-)butaclamol] shown against secretion was the same for TSH and PRL in both euthyroid and hypothyroid cell cultures and is typical of a DA receptor-mediated process. The binding of [3H]dihydroergocryptine (DHE) to DA receptors on euthyroid and hypothyroid cells was examined under the same conditions in which the secretory responses were determined. One micromolar concentration of (+)butaclamol was used to define nonspecific binding. Specific binding was saturable and stereospecific in each case. The rank order of potency of dopaminergic agonists and antagonists in competing for [3H] DHE binding was the same as that demonstrated against the secretion of TSH and PRL. Each compound displaced significantly more [3H]DHE from hypothyroid cells than from euthyroid cells (P less than 0.05 for each drug). Construction of adsorption isotherms for [3H]DHE binding to DA receptors on euthyroid and hypothyroid cells and subsequent Scatchard analysis revealed a 3- to 4-fold increase in receptor number without a significant change in affinity. Immunohistochemistry on AP lobes before and after dispersion revealed an increase in thyrotrophs and thyroidectomy cells in hypothyroid rats relative to those in control animals. In euthyroid animals thyrotrophs were 10.1% of the total AP cell population, in hypothyroid animals they plus the thyroidectomy cells were 36.3% of the total AP cells. Therefore, the increased number of DA receptors per lobe could be accounted for by increased numbers of thyrotrophs. The mechanism of the altered sensitivity to DA induced by hypothyroidism in lactotrophs and thyrotrophs remains to be clarified.

Animals↗