Search PubMed⌕ Search

Biomedical subjects

R Weil

Publications and source records attributed to R Weil.

At least 217 records · Page 12Linked to original sources
PubMed1970

A study on the transcription of the polyoma viral genome.

The transcription of polyoma (Py) viral RNA was studied in primary mouse kidney cell cultures (a) during normal, asynchronous infection, (b) under conditions where Py-induced DNA synthesis was inhibited with 5-fluorodeoxyuridine, and (c) after the synchronized onset of Py-induced DNA synthesis. The results obtained suggest that the bulk of Py RNA transcribed after the (asynchronous or synchronized) onset of Py-induced DNA synthesis, designated as "late" Py RNA, corresponds to the polycistronic transcript of most or all of the genetic information contained in a strand of circular Py DNA. The rate at which late Py RNA is transcribed is related to the amount of free Py DNA present in the cultures. Py-infected cultures contain a second, minor component of Py RNA (of one or possibly more species), designated as "early" Py RNA. At least some of this RNA continues to be transcribed if Py-induced DNA synthesis is inhibited with 5-fluorodeoxyuridine and, possibly, also late during normal infection.

Centrifugation, Density Gradient↗
PubMed1970

Polyoma "tumor antigen": an activator of chromosome replication?

We have studied the temporal relationship between the appearance of polyoma-specific "tumor antigen" and polyoma-induced activation of the cellular DNA-synthesizing apparatus in "contact-inhibited" mouse-kidney tissue-culture cells. The experimental results are compatible with the hypothesis that virus-induced replication of the mouse cell chromosomes, which accompanies the actual production of progeny virus, is triggered by the tumor antigen. On the basis of the experimental evidence at present available we propose a tentative scheme of the lytic cycle of polyoma virus, that is of the events which lead to and accompany the production of polyoma progeny virus.

Animals↗
PubMed1969

Biochemical evidence for induction by polyoma virus of replication of the chromosomes of mouse kidney cells.

It was shown earlier that in cultures of contact-inhibited mouse kidney cells infection with polyoma virus induces replication of the chromosomal DNA. In this paper we present evidence, based on analyses of isolated chromatin, that, parallel with and as a consequence of the virus-induced synthesis of cellular DNA, the chromosomal proteins are synthesized in the proportions characteristic of normal chromosome replication. These results are compatible with the hypothesis that polyoma virus activates (or derepresses) a regulatory system of the host cell which controls initiation of chromosome replication.

Animals↗
PubMedDate not supplied

Brush cytology and biopsy in the diagnosis of colorectal cancer. A comparison.

OBJECTIVE: To determine the usefulness of brush cytology of colorectal lesions as compared to biopsy examination. STUDY DESIGN: One hundred brushing cytologies and biopsies were performed on patients who underwent colonoscopic examination for different symptoms. The cytologic smears were classified into five cytologic diagnostic categories. The histologic diagnoses were adenocarcinoma, adenoma and nonneoplastic lesion. RESULTS: Twenty-six cases were cytologically positive for malignant cells, and all were histologically diagnosed as adenocarcinoma. Nineteen cases were suspicious for malignancy on cytology; histologically, eight of them showed adenocarcinoma. Two other cases proved to be adenocarcinoma in subsequent biopsies. Nine cases were adenomas, with severe dysplasia in five of them. Fourteen cases that were cytologically negative with minimal glandular atypia showed seven adenomas and seven nonneoplastic lesions on biopsy. Forty cases negative for malignant cells showed 19 adenomas and 21 nonspecific changes in the biopsy examination. CONCLUSION: Colonoscopic brushing cytodiagnosis is a sensitive technique for the detection of colorectal cancer. The combination of brushing cytology and biopsy improves the accuracy of diagnosis.

Adenocarcinoma↗
PubMedDate not supplied

Net protein catabolic rate after kidney transplantation: impact of corticosteroid immunosuppression.

Protein catabolic rate (PCR) was measured during the first 3 to 7 weeks after kidney transplantation in nine nondiabetic patients (16-52 yr old) who were receiving azathioprine and corticosteroid immunosuppression. Five of the patients received additional amounts of corticosteroids to treat rejection episodes. The PCR paralleled the amounts of corticosteroids administered initially as prophylactic immunosuppression and later as treatment for rejection episodes. In spite of a diet containing 1.2 g of protein per kg ideal body weight, net urea generation reflected severe lean body mass breakdown, roughly equivalent in magnitude to a 50% body surface area full-thickness burn. This catabolism was accompanied by a fall in serum albumin without significant weight loss. Hypercatabolism in the early posttransplant period is severe. After transplantation diet should be modified to try to satisfy these nitrogen demands.

Adolescent↗
PubMedDate not supplied

Response of pancreatic polypeptide to a protein rich meal in diabetic autonomic neuropathy.

The response of human pancreatic polypeptide (hPP) to a protein-rich meal was investigated in 4 groups of subjects: 1) normal controls (n = 11); 2) patients with recent onset type I diabetes, showing no sign of cardiovascular autonomic neuropathy (CAN) (n = 9); 3 and 4) patients with long standing type I diabetes without and with overt CAN (n = 12 and 10 respectively). Patients belonging the group 3 and 4 had equivalent duration of diabetes (17 and 20 years respectively). The mean integrated early hPP responses (0-30 minutes) were respectively (ng. min. ml-1; mean with range): 1) 9.4 (3.3-24.2); 2) 7.4 (0.7-22); 3) 4.8 (0-14.2); 4) 5.4 (0-14.9). The integrated total responses (0-120 minutes) were respectively: 1) 44.0 (12.7-98.7); 2) 39.0 (11.6-118.1); 3) 29.8 (0-81.2); 4) 25.9 (0-71.6). In the group with long standing diabetes, the early and total integrated hPP responses of the patients with CAN did not differ significantly from those without CAN. Early hPP responses of patients with long standing diabetes (group 3 and 4) were slightly (P less than 0.05) lower than those of controls. 5 patients with long standing diabetes had no detectable post-prandial hPP rise, a feature never observed in normals or recent onset diabetics. Two of these had no sign of CAN. These data suggest that an absence of hPP response to a mixed meal may be one of the expression of digestive autonomic neuropathy in long standing diabetes and that impaired hPP response may sometimes be dissociated from overt CAN.

Adult↗