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Biomedical subjects

R Tepper

Publications and source records attributed to R Tepper.

117 records · Page 7Linked to original sources

A polypeptide secreted by transformed cells that modulates human plasminogen activator production.

A diffusible factor produced and secreted by malignant murine cells was capable of inducing plasminogen activator production by normal diploid human fibroblasts. The factor's ability to induce plasminogen activator was insensitive to treatment with nucleases, but its activity was destroyed by digestion with proteases. It is proposed that such a factor would play a role in malignancy if it would recruit normal cells that were adjacent to transformed cells to produce plasminogen activator which could result in tumor-promoted proteolysis.

Animals↗

Modulation and mapping of a human plasminogen activator by cell fusion.

Neoplastic cells, transformed cells and some normal mammalian cells secrete large amounts of plasminogen activator (PA), an arginine-specific protease which converts plasminogen to plasmin. To study the regulation of PA, we have obtained two classes of mouse-human somatic cell hybrids. PG19, a mouse PA+ cell line, was fused with C32 (human PA+) or human diploid fibroblasts (PA-). All hybrids secreted PA. Human- and mouse-specific forms of PA were distinguished in these hybrids by electrophoretic methods. While all hybrids produced the murine PA, many produced the human PA and some did not. All hybrids which produced human PA had chromosome 6 in common. The absence of each of the other human chromosomes did not affect PA expression, while the absence of chromosome 6 correlated with the lack of human PA. We conclude that chromosome 6 carries the structural gene for human PA. These experiments also show that the fusion of mouse PA+ cells with human PA- cells results in the activation of the human PA gene.

Animals↗

Value of experience of general practice in geriatric medicine.

This is a review of lessons learned during thirteen years in general practice and experience of caring for elderly patients in three different types of practice. Attitudes and relationships with general practitioners as a consultant geriatrician are described. There is comment on the future training of general practitioners in geriatric medicine, the value of prophylactic care and the use of geriatric clinics in health centres. The need is stressed for proper management of acute disease, the better use of drugs and of ancillary services and the correct handling of relatives. Death should be regarded as a positive and not a negative end to life.

Aged↗

Magnetic resonance imaging of inflammatory lung disorders: preliminary studies in children.

Magnetic resonance(MR) scans were performed on 14 children with a variety of inflammatory disorders of the lungs. MR successfully identified disease in all of the children and accurately localized the disease within the lung fields. In patients with pneumonia and lung abscesses the acute inflammation was associated with a marked increase in signal intensity on T2 when compared with T1 weighted images. One patient with an inflammatory pseudotumor demonstrated a smaller increase in signal intensity on T2 weighted images than was seen in acute pneumonia. Abscess cavities were well identified along with the wall thickness. In patients with diffuse lung disease (diffuse histoplasmosis, miliary tuberculosis, Letterer-Siwe disease, and allergic alveolitis), each disease appeared different on the MR images. These preliminary studies indicate that magnetic resonance imaging is effective for identifying pulmonary disease in children and may improve the radiologist's ability to differentiate pulmonary disorders.

Adolescent↗

Granulosa cell tumors of the ovary: do they have any unique ultrasonographic and color Doppler flow features?

The aim of this study was to describe the ultrasonographic and Doppler flow attributes of granulosa cell tumors (GCT) of the ovary and to compare these attributes to those of epithelial tumors of the ovary. Among 13,475 gynecological patients who were scanned in our ultrasound unit between 1992 and 1996, seven patients had GCT. The final diagnosis was confirmed, postoperatively, by pathologic examination and by applying the WHO classification. The ultrasonographic findings of the GCT patients were compared to those recorded in a second group of 29 patients who had been diagnosed with epithelial tumor of the ovary. The sonographic appearance of GCT of the ovary was semi-solid and the endometrium was thick in six of the seven patients. Doppler flow studies of vessels within or in the contour of the lesions showed the resistive index (RI) to be 0.448 +/- 0.018. The epithelial tumors had a similar appearance and flow pattern except for the presence of ascites in one-third of the patients. Ultrasound scanning, including color Doppler flow, did not contribute data that could assist in differentiating between GCT and epithelial tumors of the ovary.

Adult↗

Comparison of different follicle-stimulating hormone and luteinizing hormone ratios for ovulation induction during in vitro fertilization.

Five normally menstruating women were treated in an attempt to induce development of multiple follicles. They were randomly divided into two groups. The first group, consisting of three women, was treated with a combination of follicle stimulating hormone (FSH) and human menopausal gonadotropin (hMG) (combination FSH/hMG). The second group, two women, was treated with hMG only. Following a nonconceptual cycle, the treatments were exchanged. The increment patterns of serum estradiol during the follicular phase and progesterone levels in both groups were identical. Ultrasonographic scanning revealed similar number and size of the growing follicles, which subsequently terminated in the same oocyte recovery rate in both groups (7.6 +/- 3.4 oocytes/procedure in the combination FSH/hMG and 8.0 +/- 2.5 in the hMG-only group). Fertilization and cleavage rates were also similar. These data indicate that high FSH/LH levels in different ratios do not alter ovarian response and oocyte fertilization potential.

Adult↗