PubMed Health⌕ Search

Biomedical subjects

P Agarwal

Publications and source records attributed to P Agarwal.

5 recordsLinked to original sources
PubMed1991

Inhibition of prolactin gene transcription by transforming growth factor-beta in GH3 cells.

Transforming growth factor-beta (TGF beta) is a member of a large family of growth factors, several of which regulate pituitary function. TGF beta has recently been reported to reduce PRL production by GH4 cells. We have examined the effect of TGF beta on PRL gene expression in rat pituitary tumor GH3 cells. TGF beta 1 or TGF beta 2 reduced both basal and Ca(2+)-stimulated PRL mRNA levels. This inhibition was specific, as the mRNA levels for GH, glucose-regulated protein 78, and histone-3 were unaffected by TGF beta. Inhibition of PRL gene expression by TGF beta was dose dependent in the range of 0.5-10 ng/ml. TGF beta inhibited run-on PRL gene transcription in nuclei from treated cells to the same extent that it reduced PRL mRNA levels, indicating a transcriptional mechanism of action. However, TGF beta did not affect Pit-1 mRNA levels or run-on transcription of the Pit-1 gene. Thus, TGF beta does not appear to act through modification of Pit-1 gene expression. The PRL promotor contains two regions of homology, with a consensus sequence found in the promoters of other TGF beta-inhibited genes. These findings are consistent with other studies that have demonstrated transcriptional repression by TGF beta. The potency and specificity of the effects of TGF beta on PRL gene expression suggest that it may be a physiological regulator of lactotroph function.

Animals↗
PubMedDate not supplied

A new look at cervical cytology. ThinPrep multicenter trial results.

The objective of this study was to compare the sensitivity of a new test method with the smear method for detection of neoplasia of the uterine cervix. The new procedure, the ThinPrep process, is an automated, fluid-based technique for the collection and preparation of exfoliated and aspirated cytologic specimens. A single sample from each patient was split and prepared both with the smear and test methods. The diagnostic results from the two slides were compared in this blind study. Among a total of 2,655 patients, diagnoses concurred in 92% of cases and were within one diagnostic level of each other 98% of the time. The ThinPrep method facilitated the detection of more low-grade lesions (P less than .001, McNemar's test). In addition, the test method decreased the number of ambiguous interpretations. The ThinPrep method appears to improve the cervical cytologic smear quality by the harvest of a random and reproducible sample, with a reduction in artifacts. The new method improves the sensitivity of the cervical cytologic screening test.

Female↗