A study of proliferative activity, angiogenesis and nuclear grading in renal cell carcinoma.

To evaluate the role of proliferative marker, proliferating cell nuclear antigen (PCNA) and microvessel density (MVD) as prognostic markers in renal cell carcinoma (RCC) and to see their relationship with the clinical stage and nuclear grades, we studied 30 cases of RCC for nuclear grading (Fuhrman's nuclear grade), MVD (using anti CD-34 antibody), and PCNA labeling index (using anti-PCNA antibody) over a period of 2.5 years. Staging was assessed by peroperative and radiologic findings. The area of highest MVD within the tumor was selected for microvessel count (MVC) per high-power field (0.1885 mm 2 area). PCNA labeling index was determined by counting percentage of positively stained tumor cell nuclei. PCNA labeling index above 60% was taken as high PCNA index and up to 60% was considered low. There was significant positive correlation between PCNA labeling index with both nuclear grade and clinical stage using Spearman's correlation coefficient. No association was noted between MVC with PCNA, nuclear grade, and clinical stages. Evaluation of proliferative status of RCC is a useful adjunct as a prognostic parameter as it is seen to correlate well with both clinical stage and nuclear grade. In our study, MVD was not seen to correlate with either of these.

A cohort study of correlation between body mass index and age at menarche in healthy Bengali girls.

There are contradictory reports of lowering of age at menarche due to increasing body mass index (BMI) in the population. It is not known if a greater BMI at menarche is associated with a lower menarcheal age in healthy Bengali girls of normal nutrition. In this study the age at menarche was determined in 273 Bengali girls of middle income families. It was assessed whether BMI standard deviation scores (SDS) at menarche, BMI SDS at one year preceding menarche and BMI increments during that year were in correlation with age at menarche. The age of the girls with adequate nutrition was 8-16 years. They were examined for BMI, pubertal breast staging and age at menarche over a 4-year follow-up period. BMI SDS were calculated from National Center for Health Statistics (NCHS) normative data. The median age at menarche of 12.0 (range 10.0 - 16.0) years did not correlate with BMI SDS at menarche or BMI SDS at one year preceding menarche in this cohort. In univariate analysis, BMI increments for a given breast stage did not significantly lower the age at menarche. The change of BMI in the year preceding menarche did not correlate with age at menarche. The age at menarche in healthy Bengali girls of middle income families was similar to that of other Indian observations. There was no influence of BMI increments or that of BMI SDS prior to or at menarche on age at menarche.

Paediatric immunisation: special emphasis on measles and MMR vaccinations.

The dictum, 'prevention is better than cure', is applicable to all ailments but it can be most easily followed for infectious diseases, increasing numbers of which are being contained by specific vaccinations since the first discovery of smallpox vaccine by Edward Jenner in 1796. Advances in immunology and laboratory techniques including cell culture, genetic engineering and animal experiments have contributed significantly to the production of more and more vaccines, used successfully in preventive programmes. Infectious diseases are widely prevalent in the developing countries. The child population is specially vulnerable to many of them. These infections contribute to high morbidity and mortality and immunisation programmes have been undertaken as preventive measures against them at the national level. Paediatricians and experts are actively engaged in formulating and improving these programmes as problems are faced in their implementation. Much new information is continuously being available in the literature, mostly in specialised journals. The general practitioners, particularly those serving in the remote and vast rural areas, are not likely to have access to these recent developments which they need for self-motivation in initiating the parents with confident advice to have their children properly immunised and also for tackling effectively any problem arising out of immunisation. This paper attempts to discuss the subject of paediatric immunisation with special emphasis being laid on measles and MMR vaccinations.

In vitro and in vivo inhibition of telomerase activity from Chinese hamster V79 cells.

While studying the inhibition of telomerase activity in Chinese hamster V79 cells using polymerase chain reaction (PCR) based telomeric repeat amplification protocol (TRAP) assay, we had earlier observed that 7-deaza deoxy guanosine triphosphate (7-deaza dGTP) and oligonucleotide (TTAGGG)4 inhibited telomerase activity in vitro. In the present study, we report inhibition of telomerase activity by modified base 7-deaza deoxy adenosine triphosphate (7-deaza dATP) and phosphorothioate TTAGGG (PS-TTAGGG). Both the compounds inhibited telomerase activity in a concentration dependent manner; 8.5 microM of 7-deaza dATP and 0.1 microM of PS-TTAGGG being the concentration for 50% of the maximum inhibition. This observation supports our earlier hypothesis that incorporation of a modified nucleotide into telomere possibly interferes with the recognition of the telomerase and TTAGGG interferes with the RNA component of telomerase. We have further shown that treatment of cells with nicotinamide (NA) and benzamide (BA), well known inhibitors of poly (ADP-ribose) polymerase, reduced telomerase activity. We speculate that modification of the telomeric binding proteins or other components by poly (ADP-ribosyl)ation may be involved in such inhibition.

Induction of apoptosis by ionizing radiation in Chinese hamster V79 cells and a radioresistant cell strain derived from V79.

DNA fragmentation into nucleosome ladder, a hall mark of apoptosis, could be obtained by as low as 0.58 Gy of gamma irradiation within 6 hr of irradiation which increased appreciably after 48 hr in V79 cells. In the same condition condensation of the nucleus and marginalization of the cytoplasm the characteristic morphology of apoptotic death were observed. Unirradiated controls had approximately 2% apoptotic cells. When cells were irradiated with 0.58 Gy, approximately 10% of the cells had the apoptotic morphology. This number increased to approximately 29% at 3.5 Gy dose. At a higher dose, apoptotic and necrotic cells were visualized. In radio resistant cells higher doses were required to induce morphological changes. The results indicated that gamma irradiation can induce apoptosis in Chinese hamster V79, fibroblast cell line and the radioresistant cell strain derived from V79 cells is also resistant to induction of apoptosis.

Possible role of glutathione in resistance to heavy metals and hydrogen peroxide in a radioresistant Chinese hamster V79 cell strain.

To understand the cellular and biochemical nature of radioresistance in the strain M5 derived from Chinese hamster V79 cells, the sensitivity of the resistant cells towards CdCl2, Zn(Ac)2, and H2O2 by the colony forming ability has been tested. D0 values for these compounds in Chinese hamster V79 cells were 5.4 microM, 27.8 microM and 4.3 micrograms/ml respectively while for M5 cells these were 8.3 microM, 142.9 microM and 11.9 micrograms/ml respectively. The resistance to heavy metals as well as the oxidative damage could be reversed by the inhibition of glutathione synthesis by the drug buthionine sulfoximine (BSO). These set of data indicate that the cellular antioxidant glutathione plays an important role in the observed oxidant-resistant phenotype as well as heavy metal resistance in M5 cells.

An in vitro qualitative assay for the detection of antibodies to HIV type 1/2 contained in human saliva.

There is ample evidence that saliva contains secretory antibody against most infections. Therefore, saliva has been recommended as a non invasive, safe and effective alternative to serum, for HIV antibody testing. The present study attempted comparative evaluation of antibody detection by serum and saliva specimens in laboratory by ELISA and Western Blot for diagnosis of HIV infection in the Indian situation. From a study of 42 test sera it is concluded that test apart from its simplicity and reproducibility, is almost free from any false positive and false negative reactions.

Mutational Pathways in Colorectal Carcinoma Cell Lines.

We studied the nature of mutational events in two highly malignant human colorectal carcinoma cell lines. In HCT116, the frequency of micro-satellite instability as detected by the electrophoretic shifts in the allele sizes of micro-satellite DNA sequence was 22% and 80% in two loci (D16S303 and D16S295) of dinucleotide repeats. In SW620, we failed to detect such mutation at any of the two micro satellite loci studied. However, there was a high frequency loss of heterozygosity in the micro satellite locus D16S303. Such high frequency loss of the D16S303 allele extended to other linked loci covering about 9 mega base pairs (Mbp). This set of data indicates that at least two pathway are involved in the development of colon tumour.

Kwashiorkor and marasmus: changing hospital incidence of syndromic presentation (1957-88).

This clinico-epidemiological study was undertaken to substantiate the impression that the pattern of clinical presentation of protein-energy malnutrition causing kwashiorkor-marasmus syndrome (KMS) is changing over time. An analysis of data for the period 1964-88, obtained from the specialised Pediatric Clinic of the Calcutta School of Tropical Medicine serving mostly the city slums showed decrease (p less than 0.01) in the incidence of chronic edematous forms of severe KMS, less decrease (p less than 0.05) in the incidence of mild-moderate KMS and increase (p less than 0.01) in the incidence of nutritional marasmus and of chronic very severe forms of KMS characterised by extreme retardation in growth and development. Incidentally, a rising incidence of rickets was observed. In the hospitalised cases (1957-88) these observations were corroborated. Data for 1985-88 of NRS Medical College Hospital, Calcutta, a general hospital serving the city as well as the neighbouring rural areas, showed that among the hospitalised city children edematous KMS was proportionately fewer than marasmus. The situation was reverse in the children from the rural areas. The observations suggested that the syndromic presentation of KMS is changing over the last three decades with some rural-urban differences for which only some recent data could be available.