Indera P. Singh

Sister chromatid exchanges in patients with precancerous and cancerous lesions of cervix uteri

SummaryThe frequency of sister chromatid exchanges (SCEs) was studied in leucocytes from 46 patients with cervical carcinoma, 89 precancerous lesions, and 43 age-matched control women. The frequency of SCEs was found to be 10.15 ±2.49 in cancer, 8.83±2.15 in precancerous lesions, and 7.55±2.24 in controls. The analyses of SCE data revealed a highly significant (P<0.001) increase in precancerous and cancerous lesions compared to controls. The intra-chromosomal distribution of SCEs revealed a random increase in various chromosomal groups in patients with cancer and dysplasia compared to controls. The mean SCE level among various groups of precancerous lesions according to severity of pathological condition did not show significant differences. However, 70.8% of dysplasia cases revealed SCE levels higher than the average in controls. The increased frequencies of SCEs in the majority of cancer patients and a few, precancerous lesions indicate that individuals with high SCE levels may be at a high risk of developing cancer. Thus the usefulness of SCE levels as a preclinical marker to identify the high risk group of dysplasias needs to be ascertained by follow-up studies; these are in progress.

Transferrin Subtypes in Six Indian Population Samples

Transferrin subtypings have been performed on three population samples originating from Himachal Pradesh, North India (Pangwala, Gaddi-Bharmour valley, Gaddi-Kangra district) and on three samples from Andhra Pradesh, South India (Koya, Konda Kammara, Lambadi). Among these six populations, marked differences in the distribution of Tf phenotype and allele frequencies are present. All Indian samples differ clearly from the hitherto reported TfC1 and TfC2 allele frequencies. In one of our Indian samples, the Pangwala, the most likely existence of a new Tf subtype variant (Tf Pangwala) could be demonstrated.

A genetic and anthropological study of atlanto-occipital fusion

SummaryFamilies of 20 probands with atlanto-occipital fusion were studied, and the neurological complications in these patients described. In X-ray studies of 115 close relatives, 4 additional cases (3.5%) with the same anomaly were detected. In a comparison of adult patients with closely related age- and sex-matched controls, all anthropological measurements except length and breadth of the head tended to be smaller in the patients; for height, weight, leg and foot length, and the robusticity index, these differences were statistically significant.

Genetic Markers and Malaria. Observations in Gujarat, India

189 healthy controls and 175 patients suffering from malaria vivax have been investigated with regard to associations between this disease and 22 genetic polymorphisms of the blood (ABO, MN, Ss, Rh, Kell, P, Lutheran, Kidd, Duffy, Diego, Xg; ABH-Secretor; Hp, Gc, Gm, Km; aP, AK, PGM1, 6-PGD, EsD; Hb variants) Significant associations could be demonstrated only for P and Hp systems, though in accordance with other investigations it cannot be excluded that the ABO system plays also a role in this connection.

Genetic studies in four tribal populations of the Surat District, Gujarat (India)

Four tribal populations (Chaudhuri, Vasava, Kotwalia and Gamit) of the Surat District in Gujarat (India) have been investigated for the distribution of 22 polymorphic systems of the blood. The main results of this study are as follows: The allele frequencies show considerable heterogeneity among these populations. From the genetic structure analysis it is seen that only a small fraction of the total gene diversity accounts for genetic differences among them, and the major portion of it is due to genetic variation within them. Analysis of genetic distance according to Nei (1972) reveals that the Vasava and Kotwalia show a rather close genetic relationship, while the Chaudhuri and Gamit differ from both the Vasava and Kotwalia.

Ventilatory capacity among highland Bods: a possible adaptive mechanism at high altitude

Ventilatory capacity (forced vital capacity, forced expiratory volume and maximal voluntary ventilation) among Highland Bods (3514 m altitude) was higher than in an ethnically similar population residing at a lower altitude in Kulu Valley (1500--2200 m). Increased ventilatory capacity appears to have developed among native highlanders as a consequence of a biological response to high altitude. Numerous factors such as low oxygen pressure, increased work-load and minimal air pollution may explain these findings.

Morphologic variability of human chromosomes: Polymorphism of constitutive heterochromatin

SummaryPolymorphism of constitutive heterochromatin has been studied in a series of 30 normal individuals. A high frequency of C-band variants were observed. Twenty-six of the 30 individuals studied had at least one polymorphic variant of the C band. A total of 42 variants were recorded which were predominately localized near the centromeric heterochromatin block of chromosome 9 (26.19%), chromosome 16 (19.05%), and chromosome 1 (16.66%). These results are discussed together with the findings revealed by different studies.

Blood Groups in Relation to Carcinoma of Cervix Uteri

Data are presented on AB0 and RhD blood groups in 186 patients suffering from carcinoma of cervix uteri and 274 controls from Delhi, India. A strong association is observed between carcinoma patients and blood group A, and a slightly weaker association with blood group B. There is no significant association with RhD blood group. The available data in other populations confirm the association with AB0 blood group.

Heteromorphisms of C-bands in patients with precancerous and cancerous lesions of the cervix uteri.

C-band heteromorphisms of chromosomes 1, 9 and 16 were studied in 62 patients with cervical cancer, 100 women with various grades of precancerous lesions and 47 normal women as controls. The data showed an increased frequency of heteromorphisms of chromosome 1 in patients with cancer (48.39%) and severe dysplasias (40%) as compared to controls (29.8%) and lower grades of dysplastic lesions, i.e. mild and moderate (28.8%). The increase in the incidence of chromosome 1 heteromorphisms in cancer was found to be statistically significant (p less than 0.05) compared to controls. The present study indicates that C-band heteromorphisms may play some role in the development of malignancy of the uterine cervix.

Ecology and Human Physiology in Ladak

Situated at lat. 34°09′ and long. 77°34′, the Ladak Plateau is the most west-wardly region of the Indian subcontinent occupied by the Tibetan people. It is surrounded by China in the northeast and southeast, by Lahaul and Spiti in the south, and by Kashmir in the west. It consists of several snow-covered parallel mountain ranges running southeast to northwest. These ranges and the plateau support very scanty vegetation that is concentrated along the Indus River. This sacred river originates between the ranges of Kabas and Tibet and flows about 370 km before it reaches Leh, the capital of Ladak.