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Biomedical subjects

B Bloch

Publications and source records attributed to B Bloch.

At least 145 records · Page 8Linked to original sources

Comparative immunohistochemical study of the distribution of neuropeptide Y, growth hormone-releasing factor and the carboxyterminus of precursor protein GHRF in the human hypothalamic infundibular area.

It is now well documented that various polyclonal antisera to the human growth hormone-releasing factor (hGHRF, somatocrinin) visualize in the brain by immunohistochemistry the classical hypothalamic hypophysiotropic neurons and also antigens present in otherwise characterized peptidergic neuronal systems. The nature of these antigens is still an open question. One of these hGHRF antisera, raised against an immunogen of hGHRF1-44NH2, labels in the arcuate nucleus of the human mediobasal hypothalamus the neuropeptide Y (NPY) containing neurons which for the most part constitute a tuberoextrainfundibular system. The identity of the hGHRF-like substance present in these neurons with true somatocrinin has been assessed by performing a comparative immunohistochemical study including sequential double and triple labeling using the antiserum to hGHRF1-44NH2 in conjunction with antisera to the carboxyterminus of preprosomatocrinin (CTPG) and to NPY. This made it feasible to dissociate the hGHRF1-44NH2-immunoreactive neurons into two major subpopulations costaining either for CTPG of NPY, and a minor neuronal group displaying simultaneously the three labelings. A subset of arcuate neurons also showed NPY staining only. These results suggest that (1) the hGHRF-like antigen present in the majority of the NPY neurons is not true somatocrinin, or alternatively that preprosomatocrinin undergoes a unique maturational processing in these neurons, and (2) a subset of tuberoinfundibular somatocrininergic neurons produces and releases NPY which may be involved in the multifactorial control of the pituitary function.

Adult↗

Flow cytometric detection of bovine viral diarrhea virus in peripheral blood leukocytes of persistently infected cattle.

Flow cytometry was investigated for detection of bovine viral diarrhea virus (BVDV) in peripheral blood mononuclear leukocytes of persistently infected cattle. The mononuclear leukocytes were purified by sedimentation in a gradient of Ficoll-Paque, fixed, permeabilized, and then labelled by indirect immunofluorescence using biotinylated immunoglobulins from a porcine antiserum to BVDV. Flow cytometric analysis of blood samples obtained from persistently infected cattle revealed virus in 3.0-21.0% (mean +/- SD, 11.2% +/- 6.4%) of the mononuclear leukocytes. Fluorescent cells were not observed in controls. Flow cytometric detection of BVDV in blood cells of persistently infected bovines is a rapid and objective technique which does not require cell culture facilities.

Animals↗

Tumour marker CA125 levels in a variety of benign and malignant conditions.

The levels of tumour marker CA125 were established in 515 patients with a variety of benign and malignant conditions. With a specificity of 60.3% and an overall sensitivity for malignant tumours of 54% (extra-ovarian serous papillary carcinomas 100%), it is the most reliable tumour marker at present available for epithelial ovarian cancer and is of considerable value in the management of this condition when considered in conjunction with other clinical measurements.

Antigens, Tumor-Associated, Carbohydrate↗

Distribution of CCK mRNA in particular regions (hippocampus, periaqueductal grey and thalamus) of the rat by in situ hybridization.

Cholecystokinin (CCK) mRNA was detected by in situ hybridization at high magnification in some rat brain regions where CCK octapeptide (CCK-8) is thought to produce its pharmacological effects. The labeling of the dentate gyrus and the sparse but intensively stained cells found in the CA1 layer, stratum radiatum and hilus could correspond to interneurons involved in hippocampal neural activity, in agreement with excitatory responses induced by local injection of CCK-8. The intense labeling of the Edinger-Westphal nucleus and more generally the presence of CCK mRNA in the periaqueductal gray and thalamus ventrobasal nuclei could account for the various effects of CCK in pain transmission.

Animals↗

Ultrastructural detection of the vasopressin messenger RNA in the normal and Brattleboro rat.

The messenger RNA coding for vasopressin has been detected at the ultrastructural level in normal and Brattleboro rat neurons, by using an oligonucleotide rat AVP prove labelled with 35SdATP. Vibratome sections of rat hypothalamus fixed with a mixture of 4% formaldehyde and 0.1% glutaraldehyde were hybridized with the probe, osmicated, included in Araldite and cut in semi-thin and thin sections that were coated with emulsion. The results demonstrate that vasopressin mRNA can be visualized in the cytoplasm of normal and Brattleboro rat neurons with an acceptable preservation of the ultrastructural aspect of the tissue. In Brattleboro rat neurons, the vasopressin mRNA is preferentially located at the periphery of the cytoplasm and is less abundant than in normal rat, this suggesting that the single base gene deletion observed in the Brattleboro rat provokes an altered transcription and compartmentation of the corresponding mRNA.

Animals↗

A clinical appraisal of stage 1 mucinous carcinoma of the ovary.

Thirty patients with stage I mucinous carcinoma of the ovary are reviewed with special reference to possible prognostic factors. The role of adjuvant therapy is discussed. Adjuvant therapy is recommended only for patients with poorly differentiated tumours and with stage Ic disease.

Adenocarcinoma, Mucinous↗

Combined chemotherapy and radiotherapy in patients with advanced squamous carcinoma of the cervix (cis-platinum-bleomycin-vinblastine).

In a pilot study, nine patients with advanced carcinoma of the cervix were treated with combination chemotherapy including cis-platinum, vinblastine, and bleomycin repeated at 3-week intervals for three courses followed by radiotherapy. Only one patient showed a partial response (reduction of tumor size more than 50%). There were no complete responses. Five of the nine patients have died from the disease with a median survival time of 20 months. These findings suggest that this particular combination of chemotherapy with radiotherapy does not have a significant effect in patients with advanced stage carcinoma of the cervix.

Adult↗

Vasopressin gene expression in the normal and Brattleboro rat: a histological analysis in semi-thin sections with biotinylated oligonucleotide probes.

We analyzed expression of the vasopressin (AVP) gene in semi-thin sections in normal and Brattleboro rats by using in situ hybridization and immunohistochemistry. AVP mRNA was detected as follows: vibratome sections of rat hypothalamus were hybridized with a biotinylated oligonucleotide probe, embedded in Araldite, and cut into semi-thin sections which were reacted with streptavidin-alkaline phosphatase and the appropriate substrate. Adjacent serial sections were treated by immunohistochemistry to detect AVP or oxytocin immunoreactivity. In normal rat, AVP mRNA can be detected in magnocellular neurons of the supraoptic and paraventricular nuclei and in parvocellular neurons of the suprachiasmatic nucleus. AVP mRNA was present throughout the cytoplasm of the cell bodies, their processes, and in punctate structures in the vicinity of the AVP cell bodies. Most neurons containing AVP mRNA also contain AVP immunoreactivity, but the staining intensity was not consistently correlated for each reaction. A few neurons contained AVP mRNA without detectable AVP immunoreactivity. In the Brattleboro rat, staining intensity of the reaction was lower than in normal rat and the AVP mRNA was restricted mostly to the periphery of the cytoplasm. In this strain, the neurons containing the AVP mRNA did not contain AVP or oxytocin immunoreactivity. These results demonstrate that neuropeptide mRNA can be detected in semi-thin sections with a biotinylated oligonucleotide probe, and that AVP gene deletion provokes modification of the intracellular localization of the AVP mRNA.

Animals↗

Prevalence of dental caries among children in a rural Tanzanian community.

The age specific prevalences of mixed caries were determined in 346 children aged 1 to 15 years in a rural community in Morogoro Region, south-eastern Tanzania. In primary dentition 58.9% of children were caries free while dmf index averages 1.08. In permanent dentition 74.3% were caries free while DMF index averaged 0.43. Permanent dentition showed a constant increase in caries prevalence with age such that over half of 15 year old children had caries experience with a DMF index of 1.2. This relatively low prevalence of caries is associated with low consumption of refined sugars. Recommendations are made to support preventive dental health services and programmes in primary schools and maternal and child health clinics.

Adolescent↗

High-risk factors for cervical cancer. An epidemiological study in SWA/Namibia.

In an epidemiological study conducted in SWA/Namibia to document the prevalence of high-risk factors for cervical cancer 754 women belonging to a number of ethnic groups were examined. The prevalence of cervical intra-epithelial neoplasia and human papillomavirus infection was among the highest reported in the world. There was also an alarming incidence of other sexually transmitted diseases and disturbingly low usage of contraceptive methods. There is an urgent need for a comprehensive, well-organised cytological screening programme if an 'epidemic' of cervical cancer is to be prevented in SWA/Namibia. There was good evidence to suggest that an identical situation exists in the RSA.

Adult↗

Endometrial cytology--the Endo-pap direct endometrial sampler.

A study was designed to assess the clinical characteristics and diagnostic cytological accuracy of an endometrial sampler, the Endo-pap (Monoject; Sherwood Medical, St Louis, Mo., USA), a disposable plastic curette. The Endo-pap was compared with the Accurette (Rolon, Watford, UK), another plastic endometrial sampler used for histological investigation. Microcolpohysteroscopy was also employed as part of the procedure. Fifty symptomatic patients, median age 50 years, were studied; the majority (55.6%) had been referred for postmenopausal bleeding. The Endo-pap yielded adequate specimens in 90% of patients compared with 82% with the Accurette. In 7 patients, endometrial carcinoma was correctly diagnosed with all three diagnostic methods and no false-positive diagnosis was made.

Adult↗

Itraconazole in the treatment of acute vaginal candidiasis.

In a multicentre open prospective study itraconazole was evaluated in the treatment of acute vaginal candidiasis. Two dosage regimens were tested--200 mg twice a day for 1 day and 200 mg twice a day for 2 days. There were no statistically significant differences between these dosages, and cure rates at 7 and 28 days after treatment were 83% and 75% respectively. These are marginally lower than those produced by longer courses of oral ketoconazole (Nizoral; Janssen) and vaginal econazole nitrate but the advantages are better patient compliance and greater cost-effectiveness.

Adolescent↗

Dopaminergic neurons of the substantia nigra modulate preproenkephalin A gene expression in rat striatal neurons.

The messenger RNA coding for preproenkephalin A (PPA) was detected by in situ hybridization in striatal neurons in normal rats and in rats having had the right substantia nigra destroyed by an injection of 6-hydroxydopamine or by electrolysis. Animals were killed 15, 30, 45 and 70 days following the lesion. A double-stranded PPA cDNA and a single-stranded PPA cRNA labeled with 32P or 35S were used as probes to detect the PPA mRNA in brain sections. The controls demonstrated the specificity of the labeling. The darkening of X-ray film in contact with the striatum was appraised, the optical density was measured, and the density of the cells expressing the PPA gene in sections was calculated using an image analyzer. The mean number of silver grains per labeled cell (reflecting the number of PPA mRNA copies per cell) was also calculated using an image analyzer. The 6-hydroxydopamine lesion which destroyed all dopaminergic neurons in the right substantia nigra, provoked a large increase in the number of PPA mRNA copies in enkephalin neurons of the right striatum, and decreased the number of cells expressing the PPA mRNA in the left striatum. These variations substantia nigra provoked similar variations, but less intense.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

The role of cancer antigen 125 (CA 125) in the management of ovarian epithelial carcinomas.

From June 1, 1984, to May 31, 1985, 98 cases of epithelial ovarian carcinomas were assessed and followed prospectively using a new murine monoclonal antibody OC 125 which detects the antigen CA 125. Serous tumors comprised 43.7% of cases, mucinous tumors 20.4%, endometrioid tumors 16%, and other epithelial tumors 19.4%. Tumors of low malignant potential and benign epithelial cystadenomas were not included. For this study the upper limit of normal for CA 125 was 20 U/ml. Thirty-six were new cases. In this group the initial CA 125 levels greater than 20 U/ml, greater than 35 U/ml, and greater than 65 U/ml were 97.2, 94.4, and 86.1%, respectively. When mucinous types were excluded the specificity rate did not change significantly. There was no significant difference in initial CA 125 levels between early stages I and II and late stages III and IV. No correlation between tumor bulk and the serum level of antigen was observed. The remaining 62 patients were being followed and in this group 50 were considered to be in remission. Six cases in the remission group had elevated CA 125 levels greater than 20 U/ml and 5 of these developed clinical recurrence. The correlation between the clinical status and concordant fluctuations in the serum levels of CA 125 in all histological types was 87.8 and 93.5% when 10 cases of mucinous tumors were excluded. The contingency coefficient was 0.746. Seven SLOs were performed. All had CA 125 levels less than 20 U/ml and the mean was 6.9 U/ml. Only 1 case was positive with microscopic disease. In our experience CA 125 was invaluable in the management and follow-up of patients with ovarian carcinoma especially for the early detection of recurrent disease and for the monitoring of patients on therapy.

Adult↗