Search PubMed⌕ Search

Biomedical subjects

B Bloch

Publications and source records attributed to B Bloch.

At least 199 records · Page 11Linked to original sources
PubMed1984

Ectopic secretion of a growth hormone-releasing factor. Report of a case of acromegaly with bronchial carcinoid tumor.

Rarely, acromegaly is produced by neuroendocrine neoplasms elaborating a substance similar to or identical with growth hormone-releasing factor. This report reviews the cases described to date and presents the clinicopathologic features of a patient with acromegaly, mild sellar enlargement, and elevated growth hormone levels associated with a large bronchial carcinoid tumor. Normalization of serum growth hormone levels and regression of acromegaly followed resection of the bronchial tumor, which was shown, by bioassay and immunocytochemistry, to contain a growth hormone-releasing factor.

Acromegaly↗
PubMed1984

Defining the severely mentally disabled.

A definition of the "known target population of severely mentally disabled" in community mental health centers is examined. Criteria include intensive treatment contact and persistent, severe disability, but not diagnosis. Feasible and reliable screening procedures are demonstrated. In the identified population, most subjects at some time had received a diagnosis of schizophrenia and had been on public assistance. These criteria apply to catchmented treatment systems and should be useful in services research.

California↗
PubMed1984

Pituitary response to growth hormone-releasing factor in rats with functional or anatomical lesions of the central nervous system that inhibit endogenous growth hormone secretion.

The pituitary growth hormone (GH) response to the growth hormone-releasing factor, hpGRF-44, was evaluated in male rats with various lesions of the central nervous system. These included an electrical lesion of the ventromedial hypothalamus, a chemical lesion of the arcuate nucleus induced by neonatal treatment with monosodium glutamate, a functional lesion of catecholamine synthesis with alpha-methyl-p-tyrosine or a functional lesion of catecholamine storage with reserpine. The first three lesions appear to partially inhibit normal somatostatin secretion since in every instance hpGRF-44 administration induced a significant increase in plasma GH concentrations. In contrast, reserpine blocked the GH response to hpGRF-44, presumably by stimulating somatostatin secretion. The pituitary GH response to hpGRF-44 in the above described models was enhanced by pretreatment of the rats with antibodies against somatostatin. The pituitary GH response to repeated injections of hpGRF-44 was also evaluated in rats with an anatomical lesion of the arcuate nucleus or a functional lesion of catecholamine synthesis. The maximum GH response did not vary over time to the repeated injections of hpGRF-44 in rats with lesions of the arcuate nucleus; however, interruption of catecholamine synthesis resulted in a significant decrease in the GH response to hpGRF-44 over time.

Animals↗
PubMed1984

Topographical and ontogenetic study of the neurons producing growth hormone-releasing factor in human hypothalamus.

Neurons producing growth hormone-releasing factor have been characterized and analyzed by immunohistochemistry in the hypothalami of human fetuses, neonates, infants and adults, using two antibodies against human pancreatic GRF (hpGRF). One of the antibodies recognized both the hpGRF(1-40)OH and hpGRF(1-44)NH2 in the mid portion (between the 28th and 39th amino acid), the other one specifically recognized the C-terminal end of hpGRF(1-44)NH2. These two antibodies stain a single neuronal system with cell bodies mainly located in the infundibular (arcuate) nucleus, and in the ventromedial and lateralis tuber nuclei. These neurons project to the median eminence where they give numerous endings in contact with portal vessels. These neurons are distinct from those containing LH-RH, somatostatin, CRF or pro-opiocortin. In fetuses, neurons immunoreactive with hpGRF antibodies are first detected at the 29th week. They display a neuroblastic aspect which persists after birth. Immunoreactive fibers are detectable in the median eminence after the 31st week. These results demonstrate that the infundibular nucleus plays a major role in control of GH secretion in man and that secretion of GRF appears late during fetal life; this suggests that the first stages of differentiation and development of GH producing cells in the human fetus do not depend on hypothalamic GRF secretion.

Adult↗
PubMed1984

Detection of the messenger RNA coding for preproenkephalin A in bovine adrenal by in situ hybridization.

The messenger RNA (mRNA) coding for the adrenal precursor of enkephalins (preproenkephalin-A) has been detected in bovine adrenal medulla cells using in situ hybridization with 32P-labelled preproenkephalin A (PPA) complementary DNA. In formaldehyde- and Carnoy-fixed tissue sections, an intense elective labelling restricted to the cells located at the periphery of the adrenal medulla can be detected after hybridization procedure, using X-ray film and classical autoradiographic procedure. Adequate controls show that this labelling is obtained only using PPA complementary DNA, inserted or not in its vector. Distribution of PPA mRNA appears identical to that of its immunoreactive end products, namely Met-enkephalin and BAM22 peptide, detected by immunohistochemistry. Norepinephrine, detectable using monoamine histofluorescence, appears restricted to the cells of the center of the gland unlabelled for PPA mRNA and its end-products. Cultured bovine adrenomedullary cells that exhibited enkephalin immunoreactivity also contain PPA mRNA located in their cytoplasm.

Adrenal Glands↗
PubMed1984

Antibodies to growth hormone-releasing factor inhibit somatic growth.

We have raised antibodies to rat growth hormone-releasing factor (GRF) which, when acutely administered to rats, cause a complete inhibition of pulsatile GH release. Using this passive immunization technique, we have evaluated the role of GRF in normal somatic growth. Twenty-two-day-old male Sprague-Dawley rats (61 +/- 2 g, mean +/- SEM) were treated for 16 days with either normal rabbit serum (n = 7) or rabbit antiserum raised against GRF (n = 7). During this period the BW of rats treated with normal rabbit serum increased 8.3 +/- 0.4 g/day while rats treated with GRF antiserum increased 4.3 +/- 0.2 g/day (P less than 0.01). These rats were then left untreated for an additional 22 days to determine whether animals treated with GRF antiserum would demonstrate a period of catch-up growth. Rats treated with normal rabbit serum continued to increase in BW at 8.1 +/- 0.4 g/day. Remarkably, rats treated with GRF antiserum continued to have a reduced growth rate, 5.4 +/- 0.6 g/day (P less than 0.01). This reduced growth rate was not due to long-term suppression of GH, since the patterns of pulsatile secretion and concentrations of plasma GH were not different between the two groups when measured three weeks after termination of the GRF antiserum treatment. These results demonstrate that GRF has a primary role in somatic growth and suggest that its presence during postnatal development is required to ensure subsequent normal somatic growth.

Animals↗
PubMed1984

Combination chemotherapy with cisplatin and bleomycin in advanced cervical cancer.

Seventeen patients with advanced and recurrent squamous cell cervical cancer were treated with a combination of cisplatin and bleomycin. One complete and nine partial responses were observed (53%). The median duration of response was 8 months and the median survival was 12.7 months (5 months for nonresponders). Response was documented, particularly in patients with nodal disease and lung metastases. No life-threatening toxic effects were reported. This combination appears to be as effective as other combinations, has low toxicity, is well-tolerated, and merits further study.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

International standards for surgical implants.

Publication of international standards for surgical implants increases as does concern for quality assurance in their manufacture. The activities of ISO/TC150 are outlined.

Biocompatible Materials↗
PubMed1983

Human hypothalamic growth hormone releasing factor (GRF): evidence for two forms identical to tumor derived GRF-44-NH2 and GRF-40.

Human hypothalamic growth hormone-releasing factor (GRF) was purified by gel filtration and reverse-phase HPLC. Bioassay and two radioimmunoassays of different specificity revealed the presence of two major forms of GRF-activity which coelute with human pancreas GRFs, hpGRF-44-NH2 and hpGRF-40 previously characterized in pancreas tumors. The bioactive material coeluting with hpGRF-44-NH2 is recognized by two antibodies which are directed against the amidated COOH-terminal sequence and the central portion of the GRF-44 peptide. The bioactive GRF which coelutes with hpGRF-40 reacts only with the antibody directed against the central portion of hpGRF. These data strongly suggest that the human hypothalamus contains the same major forms of GRF that were identified in pancreas tumors responsible for acromegaly in the absence of a pituitary tumor.

Biological Assay↗
PubMed1983

Topographical study of the neurons containing hpGRF immunoreactivity in monkey hypothalamus.

Hypothalamic neurons producing growth hormone-releasing factor (GRF) have been characterized by immunohistochemistry in monkey hypothalamus, using an antiserum raised against hpGRF1-40, a peptide with GRF activity isolated from a human pancreatic tumor. Cell bodies with hpGRF immunoreactivity were found in arcuate and ventromedial nuclei. From these neurons, bundles of fibers innervate median eminence and appear to terminate in contact with portal vessels. In addition to median eminence, hpGRF immunoreactive fibers were found mostly in the anterior hypothalamus and the arcuate and ventromedial nuclei where they give perineuronal endings. These results correlate with earlier physiological data on hypothalamic control of growth hormone secretion and suggest that GRF is also involved in interneuronal relationships related or unrelated to neurohumoral control of pituitary secretions.

Animals↗
PubMed1983

An in-service registrar-training programme in colposcopy at Groote Schuur Hospital. Reliability and results.

A scheme for the in-service training of registrars in colposcopic techniques was evaluated in a prospective study. The colposcopic interpretation was satisfactory in 79% of the 721 patients examined, and inappropriate treatment was avoided by utilizing the specified protocol of management. The value of cytological screening of the population is emphasized by the fact that in 95,7% of patients referred for colposcopy the pre-invasive cancer was not suspected on the basis of symptoms or the results of clinical examination.

Colposcopy↗
PubMed1983

An evaluation of treatment modalities in cervical intra-epithelial neoplasia.

The scheme of management of cervical intra-epithelial neoplasia presently utilized in the colposcopy service at Groote Schuur Hospital, Cape Town, is outlined, and the results of the treatment of 721 patients with the various modalities currently available are analysed. It is concluded that a radical approach (total hysterectomy was performed in 42,4% of the patients) is justified by the results obtained; the place of conservative methods of treatment, including cone biopsy, is discussed.

Biopsy↗
PubMed1983

Immunohistochemical evidence that brain enkephalins arise from a precursor similar to adrenal preproenkephalin.

We have examined rat brains by immunohistochemistry with an antiserum raised against BAM22P, a synthetic fragment of the adrenomedullary precursor of Leu- and Met-enkephalin, in order to determine whether preproenkephalin derived peptides are detectable in the central nervous system. BAM22P antiserum stained fibers, nerve endings and cell bodies in many areas of the brain, especially the striatum, the septum and the hypothalamus. Comparative topographical studies showed that neurons recognized by anti-BAM22P overlapped structures found immunoreactive for enkephalins in the present study. In addition, BAM22P antiserum stained cell bodies in cerebral cortex and in caudate putamen. The presence of BAM22P immunoreactivity in presumptive enkephalin neurons suggests that some brain enkephalins arise from a precursor identical or closely related to the preproenkephalin A found in the bovine adrenal medulla. This does not preclude the possibility of enkephalins also arising from other precursor molecules.

Adrenal Medulla↗
PubMed1983

Congenital tremor type AI: light and electron microscopical observations on the spinal cords of affected piglets.

The histology and ultrastructure of the spinal white matter from the dorsolateral funiculus of the third cervical segment was studied in normal control pigs and pigs whose dams were inoculated with the Weybridge congenital tremor strain of swine fever virus in early pregnancy. Only inoculated sows produced abnormal piglets. These showed congenital tremors and ataxia. The severity of clinical signs was related to the degree of spinal myelin deficiency. Morphologically this was quantified by determination of the thickness of myelin investing axons classed according to their diameter. In clinically affected pigs fewer axons were myelinated than normal. Though the myelin sheath thickness increased with increasing axon diameter in all pigs whether clinically normal or not, the increase was less in moderately affected and much less in severely affected pigs. The deficiency of spinal myelin was probably due to delayed or sub-normal myelination accompanied by paranodal myelin abnormalities, myelin degeneration and remyelination.

Animals↗
PubMed1983

Gestational trophoblastic disease: the significance of vaginal metastases.

Six patients with gestational trophoblastic disease whose presenting symptom was hemorrhage from vaginal metastases are discussed. The clinical features, management, and response to treatment are outlined and it is suggested that the presence of vaginal metastases should be regarded as a poor prognostic factor and an indication for multiple cytotoxic agent chemotherapy.

Adult↗
PubMed1983

Rotavirus associated diarrhoea in nursing piglets and detection of antibody against rotavirus in colostrum, milk and serum.

A blocking method of ELISA for the detection and quantification of antibody against porcine rotavirus in serum, colostrum and milk has been compared with a plaque reduction test. The results obtained with the two techniques correlated (Fig. 1). Antibody against rotavirus was demonstrated in 384 serum samples representing 25 swine farms, indicating a widely spread and dense distribution of the infection with porcine rotavirus among Danish swine. The antibody contents in milk samples from 7 gilts and sows from 2 farms with a previously diagnosed problem with rotavirus associated diarrhoe showed a rapid decline during the first few days of the lactation periods (Fig. 1). An increase in the contents of rotavirus specific antibody was observed from day 15 in the milk samples from one of the gilts. The excretion of rotavirus with feces from the 7 litters of piglets were followed through the suckling period. Rotavirus war found in all litters but one and the virus was excreted in periods ranging from 4 to 9 days.

Animal Population Groups↗