Modulation of repair and fixation of UV-induced damage and its effects on mutagenesis in yeast

Modulation of repair of UVC-induced damage under different post-irradiation nutritional conditions and its effects on mutagenesis were studied in stationary phase cells of diploid strain D7 of Saccharomyces cerevisiae. Reverse mutation and gene conversion frequencies at ILV and TRP locus were measured in the respective omission media. It was observed that post-irradiation (150 x 10(-3) J/m2) repair in presence of (i) 2-deoxy-D-glucose (2-DG, 10 mM) resulted in decreased surviving fraction (56 +/- 5%) and increase in frequencies of revertants and gene convertants (122 +/- 10% & 132 +/- 14% respectively), (ii) yeast extract enhanced the frequency of revertants to a large extent (204 +/- 18%) and (iii) yeast extract and 2-DG together further increased the frequencies of revertants (304 +/- 15%) and gene convertants (151 +/- 12%); when compared with irradiated controls in phosphate buffer glucose; the observed changes being statistically significant (P < 0.05, Student's t test). These results indicate that (i) 2DG reduces the error-free DNA repair in yeast, (ii) yeast extract increases error-prone DNA repair and thus, in combination with 2-DG, further promotes mutagenesis.

Caring for adult survivors of child sexual abuse. Issues for family physicians

Traditional medical education has not taught physicians about the long-term effects of child sexual abuse. Family physicians often feel poorly equipped to appreciate the effect of such a childhood history on current health or to recognize and treat survivors. This article links the experience of the sexually abused child to long-term effects and outlines the role of family physicians in screening and caring for survivors.

Perceived self in educated employed and educated unemployed women

The purpose of this study was to compare the perceived self-concept of employed and unemployed educated women. The study also examined the relationship of perceived self-concept with the type of employment and period of service of the employed women. The sample consisted of 150 employed and 150 unemployed educated married women residing in an urban area of Patna. The self-concept scale of Deo (1985) was used in the study. The findings showed that the perceived self of the employed women scored relatively higher in each of the five attributes of the perceived self; ie. Aesthetic, Emotional, Character, Intellectual and Social. It was concluded, from this study, that employment leads to a higher self-concept among educated women, which however varied with different types of employment.

Prevalence of R-plasmids and serotypes in intestinal Escherichia coli

A total of 150 strains of E. coli isolated from faecal samples of normal population (Group I), hospital personnel (Group II) and hospitalised patients (Group III) were studied for the transfer of R-plasmids. Auto-transferable R-plasmids were observed in 72.0, 82.0 and 80.0 per cent of groups I, II and III respectively. 77.0 per cent strains were typable. 04 was the most common serotype found in groups I and II, 0134 in group III.

The natural history of familial hypopituitarism

Familial hypopituitarism in the Hutterite Brethren is an autosomal recessive disorder involving sequential loss of anterior pituitary tropic hormones. Five individuals from two closely related families have been followed for 19 years. Both families are well integrated into the Hutterite community. Three sibs elected not to be treated with growth hormone and sex steroids. These sibs developed growth hormone and gonadotropin deficiency in the first decade of life, with subsequent loss of TSH function and finally ACTH deficiency in the third decade. The pattern of hormone loss differed in the second family, in that deficiency of growth hormone, gonadotropins, and TSH was evident in the first decade. A third family has been reported to have the same disorder and is from a different endogamous subdivision from that of the two families described here. Genealogical analysis of the three families shows that there are four ancestral couples common to the six parents. Thus all affected individuals are likely to be identical by descent for the same ancestral allele. The gene for hypopituitarism is not closely linked to the gene for growth hormone nor to the HLA region.

Receptor binding and growth-promoting activity of insulin-like growth factors in human breast cancer cells (T-47D) in culture

Insulin-like growth factors (IGFs) and insulin are known to be mitogenic to a variety of cell types, although a growth-regulatory role of IGFs on human breast cancer cells has not yet been fully investigated. In the present study, we examined the receptor binding and the effect on growth of IGFs and insulin in a human breast cancer cell line (T-47D). Specific binding of 125I-basic somatomedin (BSM/IGF-I), 125I-multiplication-stimulating activity (MSA III-2/IGF-II), and 125I-insulin has been demonstrated in monolayer T-47D cells grown on plastic substratum. When the binding of 125I-BSM and 125I-MSA III-2 was studied, unlabeled BSM and unlabeled MSA were the most effective competitors for the respective binding sites. Unlabeled insulin at high concentration also inhibited the binding of 125I-BSM and 125I-MSA III-2. For 125I-insulin binding, however, unlabeled MSA III-2 and MSA II were more effective than unlabeled insulin in displacing 125I-insulin from its binding sites. These observations suggest that the binding sites for IGF-I and IGF-II are distinct in T-47D cells and that insulin cross-reacts weakly with IGF-I and IGF-II binding sites. BSM (IGF-I) and MSA (IGF-II) (1 microgram/ml) produced a 1.5-fold increase in cell proliferation of T-47D cells grown on plastic substratum. The mitogenic effect of IGFs on T-47D was more apparent when cells were grown on collagen gel. At 500 ng/ml, MSA III-2, BSM, and insulin stimulated cell growth 4-, 2.5-, and 1.5-fold, respectively. Our results suggest that the IGFs may be involved in the growth regulation of human breast cancer cells.