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Biomedical subjects

R Weiner

Publications and source records attributed to R Weiner.

At least 55 records · Page 3Linked to original sources
PubMed1994

Dust and pneumoconiosis in the South African foundry industry.

The objectives of this study were to estimate the extent of occupational health monitoring for dust and pneumoconiosis in the foundry industry and to assess dust levels and the prevalence of pneumoconiosis in a group of foundries. In only 13 (16%) of the 82 foundries that responded to a postal questionnaire were regular periodic full-sized chest radiographs done. Dust levels were measured every 3 years or more frequently in 20 foundries (24%). An uncontrolled dust hazard was evident in all 9 foundries surveyed between 1983 and 1992. The prevalence of silicosis ranged from 0% to 10.3% and increased with duration of service. The study provided convincing evidence of neglect of occupational health by the foundry industry.

Dust↗
PubMed1994

Third wave of asbestos-related disease from secondary use of asbestos. A case report from industry.

An occupational health survey conducted in a workshop in which asbestos cement was used showed initial atmospheric asbestos levels ranging from 1.9 to 27.5 fibres per millilitre of air. Radiological changes suggestive of asbestos-related pleural disease were found in 2 workers (2.5%), while 3 (3.8%) had borderline features of asbestosis. The survey confirmed that uncontrolled and hazardous use of asbestos continues in industry despite public awareness of its dangers and the Asbestos Regulations of 1987.

Asbestos↗
PubMed1993

Membranous glomerulonephritis in association with hepatitis C virus infection.

Two bone marrow transplant recipients are described who developed nephrotic syndrome in association with hepatitis C virus (HCV) infection. Renal biopsies of both patients revealed stage I membranous glomerulonephritis. Detection of HCV genome was performed by nonisotopic in situ hybridization and reverse transcriptase polymerase chain reaction on paraffin-embedded renal biopsy specimens. Hepatitis C virus genome was detected by reverse transcription nested polymerase chain reaction on the RNA extracted from 15 5-microns paraffin sections. However, HCV genome was not revealed by nonisotopic in situ hybridization, which was likely due to the low copy number of HCV genomes present. These studies suggest that chronic HCV infection is associated with membranous glomerulonephritis.

Adult↗
PubMed1991

Measurement of albumin synthesis in perfused rat liver using stable isotopes: [15N] hippurate as a measure of the intracellular [15N] glycine precursor enrichment.

Rat livers were perfused by the non-recirculating technique with medium containing [15N] glycine and sodium benzoate. At various times, the 15N-concentration and the isotopic enrichment of perfusate hippurate, albumin, globulines, urea, creatinine and other fractions were measured by MS. Hippurate was used to represent the intracellular precursor pool for albumin synthesis. After start of glycine administration the ratio APE product/APE precursor pool had reached approximately maximal values. After 30 min, the precursor pool size and its use in protein synthesis decreased due to amino-acid-deficient perfusion with no further decrease between 30 and 105 min. Additionally, rates of protein synthesis were determined. The albumin synthesis rate was 3.27 mg/g liver weight per hour.

Editorial↗
PubMed1991

The 16K fragment of prolactin specifically inhibits basal or fibroblast growth factor stimulated growth of capillary endothelial cells.

Intact 23 kilodalton (kDa), rat PRL is enzymatically cleaved in many target tissues to a 16 kDa (16K PRL) and an 8 kDa fragment. After reduction of an internal disulfide bond the fragments are released. 16K PRL was shown to be a potent mitogen on mammary epithelial cells via PRL receptors. Since estradiol-induced prolactinomas develop a new blood supply we tested the action of intact PRL and 16K PRL on growth of new vessels (angiogenesis). The angiogenic action of intact PRL and 16K PRL was tested in cultured bovine brain and adrenal cortex endothelial cells. Basal (b) or b-fibroblast growth factor (FGF) stimulated growth was estimated by counting cells or measuring the level of incorporation of 3H-thymidine into DNA. Paradoxically, 16K PRL inhibited the basal and FGF-stimulated growth of cultured endothelial cells in a dose-dependent fashion. Intact PRL or the cleaved but not reduced PRL were inactive even at a 100-fold higher concentration. When reformation of disulfide bonds was inhibited by carbamidomethylation of 16K PRL the preparations were more potent. 16K PRL had no effect on the mitogenic action of bFGF on baby hamster kidney cells which are known to have FGF receptors. These data demonstrate that in vitro 16K PRL is a potent and specific angiolytic factor, i.e. it inhibits angiogenesis. Furthermore, the action of 16K PRL does not appear to be via the known PRL or FGF receptors. Since angiogenesis is an essential component of tumor growth 16K PRL has potential as a therapeutic agent for the treatment of cancer.

Adrenal Cortex↗
PubMed1991

Changes in basic fibroblast growth factor coincident with estradiol-induced hyperplasia of the anterior pituitaries of Fischer 344 and Sprague-Dawley rats.

Adult female Fischer 344 (F344) and Sprague-Dawley (SD) rats were treated with estradiol via Silastic implants for 10 and 20 days. This treatment period in F344 rats is sufficient to produce dramatic hyperplasia of anterior pituitary lactotropes, activation of folliculo-stellate cells (FS) as phagocytes, and reorganization of the blood supply, i.e. hemorrhagic lakes and arteriogenesis from vessels in the adjacent meninges. Estradiol-treated SD rats do not demonstrate a comparable response. We now report intense focal concentrations of cells immunopositive for basic fibroblast growth factor (FGF) in estradiol-treated F344 rats predominantly near the posterolateral edge of the anterior pituitary, a zone rich in gonadotropes and lactotropes. Immunostaining for FGF, by both light and electron microscopy, revealed that the immunopositive cells were gonadotropes, and that the immunoprecipitate was cytosolic and was most abundant in the cytosol facing the capillaries. Immunostaining for extracellular matrix-associated FGF also revealed foci of positivity at the postero-lateral edge. Estradiol-treated SD rats did not reveal comparable localization for FGF. Morphological analysis and immunolocalization of S-100 protein, a marker for FS cells, revealed that the periphery of the anterior pituitary of estradiol-treated F344 rats included numerous disrupted gonadotropes and, furthermore, was largely devoid of FS cells. This zone was more intact in control F344 rats, but lacked FS cells. The peripheral parenchyma of control and estradiol-treated SD rats was intact compared to that of F344 rats and consistently included FS cells. These results suggest that disruptions of gonadotropes at the pituitary periphery may release FGF, which could then stimulate angiogenesis from blood vessels within the adjacent meninges. The resultant systemic blood supply would stimulate lactotrope hypertrophy and hyperplasia. Since FS cells are known phagocytes within the anterior pituitary, their absence from the periphery of F344 rats may intensify or prolong the effect of the peripherally released FGF.

Animals↗
PubMed1990

Intestinal absorption of D-xylose in the early post-operative period.

To assess intestinal absorption in the early post-operative period, portal and subclavian vein catheters were implanted into 8 pigs. For direct d-xylose infusion into the upper small intestine a feeding tube was inserted via a gastrostomy. Four control animals (Group 1) underwent an open and close laparotomy after catheter and tube implantation. Four pigs (Group 2) underwent a standardised ileocoecostomy. At 6, 24, 36, 48 and 72 h after surgery, d-xylose was infused into the small intestine in both groups of animals. After single-dose administration the absorption kinetics were measured in the pre- and post-hepatic blood compartment. With increasing time after operation the rate and extent of d-xylose absorption returned towards normal but there were significant differences in the d-xylose kinetics between the two groups. The absorption kinetics and d-xylose uptake recovered more rapidly in the control group than in those who underwent ileocoecostomy. Effective enteral feeding in controls after 36 h was achieved, but in Group 2 was delayed until 48 h post-operatively. Absorption capacity returned to normal after 48 h in controls and after 72 h in Group 2.

Journal Article↗
PubMed1989

Primary renal angiosarcoma mimicking a renal cell carcinoma.

Primary renal angiosarcoma is a very rare malignant tumor that closely mimics the more common renal cell adenocarcinoma (hypernephroma) in radiologic appearance. Both tumors are hypervascular masses and the diagnosis must be confirmed histologically. However, in the presence of a tumor with a capsular blood supply, and in the absence of venous invasion, the diagnosis of renal angiosarcoma may be suggested, especially in a patient with a new onset of consumption coagulopathy.

Carcinoma, Renal Cell↗
PubMed1989

Cavernous lymphohemangioendothelioma of the right atrium--a case report.

The authors report a successful resection of a rare cystic tumor in the right atrium, discovered in an asymptomatic patient with atrial fibrillation. The cystic nature of the tumor was characterized by two-dimensional echocardiogram preoperatively. The site of attachment and movement of the tumor were clearly shown by cine computed tomography preoperatively. The tumor contained numerous endothelium-lined cavernous channels and groups of red blood cells. These features are distinctly different from those of other cystic tumors.

Echocardiography↗
PubMed1989

[Nutritional therapy using tubes and pumps in cancer patients].

The success in the therapy of patients suffering from malignant tumours is among others depending on nutritional treatment. If correctly indicated, the enteral nutrition is more economic, complication reduced, easier to maintain and a biologically optimal alternative method to the parenteral nutrition. Nutritional solutions via tube have to be given continuously or intermittently. For that purpose a pump had been developed meeting certain special requirements. It is reported on the technique of an electronically controlled, partly net independently working pump.

Enteral Nutrition↗