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Biomedical subjects

B M Das

Publications and source records attributed to B M Das.

At least 19 recordsLinked to original sources
PubMed1990

The distribution of the Hb constant spring gene in Southeast Asian populations.

The distribution of the hemoglobin Constant Spring (Hb CS) gene in eight populations in Southeast Asia (including Assam) was determined using oligonucleotide hybridization. Hb CS was absent in two Assamese populations with a high prevalence of Hb E. The Hb CS gene frequency was 0.033 in northern Thailand and near 0.01 in central Thailand and Cambodia. High frequencies, between 0.05 and 0.06, were observed in northeastern Thailand. The present data and a similar study in Laotians suggest that the Lao-speaking populations of the Mekong River basin in northeastern Thailand and Laos have the highest frequencies of the Hb CS gene in Southeast Asia.

Asia, Southeastern↗
PubMed1989

Anthropological studies in Assam, India. 7. Socio-biological observations on Assamese populations.

Three population groups of Assam, viz., the Hindus, Muslims and Mongoloids have been investigated for certain bio-social variables, e.g., size and composition of family, sex distribution, menarcheal age, age at marriage, marriage distance, conception, pregnancy wastage and fertility. The results are discussed on comparative basis, and attempts are made to offer possible reasons for differences.

Adolescent↗
PubMed1989

Aberrant right hepatic artery vena cava fistula: a case report.

An unusual case of visceral arterial venous fistula between an aberrant right hepatic artery and the inferior vena cava is presented. A critical review of the anatomic relationships in this location offers a plausible explanation to account for the rarity of this type of fistula. The second issue deals with the ligation of the hepatic artery. We caution against hepatic artery ligation, especially when dealing with an aberrant right hepatic artery.

Adult↗
PubMed1988

Natural history of nonoperated, significant carotid stenosis.

One-hundred sixty-seven patients with 190 carotid arteries (109 asymptomatic) demonstrating 50-99% stenosis by arteriography (80), duplex scanning, or other noninvasive techniques were followed from 1-84 months (mean 24.2) for evidence of brain infarct, transient ischemic attacks, or vertebrobasilar symptoms. Thirty-nine arteries (20.5%) were symptomatic at last follow-up, including 13 (6.8%) producing ipsilateral strokes. Twenty-eight sides underwent carotid endarterectomy, 16 for symptomatic lesions at a mean interval of 14.5 months after the initial diagnostic study, with no neurologic deficit. Twenty-seven patients (16.2%) died, eight from stroke (30%), and 12 from cardiac causes (44%). In initially symptomatic sides, the incidence of any subsequent neurologic event (28.7%) or stroke/transient ischemic attack (25%) was significantly greater than in asymptomatic arteries (14.6% and 12%, respectively) (p less than .05). Carotid arteries with greater than 80% stenosis by arteriography and duplex scanning had a 46% incidence of further symptoms and 41.6% stroke/transient ischemic attack rate compared to 19.6% and 15%, respectively, in arteries with less than 80% stenosis (p less than .01). Cumulative life table analysis at 12, 24 and 36 months showed greater than 80% stenosed arteries to have stroke/transient ischemic attack free rates of 69%, 50.5%, and 21.6% compared to 91%, 83.7%, and 76% for arteries with less than 80% stenosis (p less than .05). At a mean follow-up of over two years, nonoperated carotid stenosis (greater than 50%) carries a 20.5% risk of neurologic symptoms and a 6.8% risk of stroke, 61.5% of strokes being fatal. Symptomatic carotid stenosis had a significantly greater incidence of ensuing neurologic events than asymptomatic arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Occlusive Diseases↗
PubMed1988

Hemoglobin E distribution in ten endogamous population groups of Assam, India.

Previous studies have reported a high incidence of hemoglobin E (HbE) in Northeast Indian populations. In the present study 10 endogamous populations of Assam belonging to two racial groups, Caucasoid and Mongoloid, were examined. The frequency of HbE gene (Hb beta E) in the Caucasoid caste populations is around 0.1, whereas the gene is highly prevalent in the Mongoloid populations, frequencies ranging between 0.2 and 0.6. Predominance of Hb beta E in the Tibeto-Burman speakers is contrary to observations made in Southeast Asia, where an association between Austro-Asiatic speakers and high prevalence of HbE exist. The highest occurrence of the gene in this area, which is on the far end of the proposed centre of distribution in Northern Kampuchea and Northeast Thailand, is also a deviation from the expected pattern of gene distribution. It is speculated that Hb beta E in the Tibeto-Burman populations of Assam arose by an independent mutation which contributed to the high frequencies of Hb beta E in the Northeast Indian populations.

Asian People↗
PubMed1988

Hypercholesterolemia.

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Arterial Occlusive Diseases↗
PubMed1988

Anthropological studies in Assam, India. 6. Differentiation processes among Assamese populations.

In 1978-79 13 Assamese populations--two Muslim groups, five Mongoloid groups and 6 Hindu caste groups--have been investigated for the distribution of anthropometric, anthroposcopic and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. Except for finger ridge patterns all traits under investigation showed a marked intergroup variability. For anthropometric, anthroposcopic and dermatoglyphic traits a clear differentiation in Mongoloid populations on one hand and Hindu caste groups on the other could be observed and be substantiated by results of corresponding distance analyses. With regard to Muslims it has to be distinguished between Marias who seem to be more closely related to Mongoloid populations and Sheikhs whose phenotypic appearance is more like that of the Hindu caste groups. The results are discussed.

ABO Blood-Group System↗
PubMed1987

Distribution of Gm and Km allotypes among ten populations of Assam, India.

Serum samples from ten endogamous populations of Assam, India-Brahmins, Kalitas, Kaibartas, Muslims, Ahoms, Karbis, Kacharis, Sonowals, Chutiyas, and Rajbanshis-were typed for G1m (1, 2, 3, 17), G3m (5, 10, 11, 13, 14, 15, 16, 21, 26), and Km (1). Among Brahmins, Kalitas, Kaibartas, Muslims, Ahoms, Sonowals, Chutiyas, and Rajbanshis, five different Gm haplotypes were found: Gm1,17;21,26; Gm1,17;10,11,13,15,16; Gm1,2,17;21,26; Gm1,3;5,10,11,13,14,26; and Gm3;5,10,11,13,14,26. Kacharis and Karbis show only four of these haplotypes: Gm3;5,10,11,13,14,26 is absent among them. The intergroup variability in the distribution of these haplotypes is considerable, which can be explained by the ethnohistory of these populations. Genetic distance analysis, in which five Chinese population samples were included, revealed the existence of three main clusters: 1) North and Central Chinese; 2) Kalitas, Kaibartas, Chutiyas, Rajbanshis, Muslims, and Brahmins; and 3) Ahoms, Sonowals, Kacharis, South Chinese, and Karbis. The clusters suggest some genetic relation between these four Assamese populations and South Chinese, which is again understandable considering the ethnohistory of the populations of Northeast India. In the Km system, too, a remarkable variability is seen in distribution of phenotype and allele frequency.

Asian People↗
PubMed1987

Reconstruction of the external carotid artery.

The external carotid artery (ECA) is an underestimated but important collateral to the cerebral hemisphere and eye in patients with severe disease of the internal carotid artery. Fifteen symptomatic patients with total occlusion of the internal carotid artery underwent ECA reconstruction. Ipsilateral ECA reconstruction was performed upon all patients with no mortality or neurologic deficits. Contralateral disease of the carotid artery was noted in 11 and required correction in seven patients. Follow-up study of the patients ranged from one to 68 months (a mean of 26.8 months) after operation. Vertebrobasilar symptoms persisted in two patients, both with contralateral disease. One of these patients successfully underwent extracranial-intracranial bypass. One ipsilateral and one contralateral stroke occurred during follow-up study, both in patients with contralateral disease. Eleven patients were alive and asymptomatic at last follow-up examination. Symptomatic selected patients with occlusion of the internal carotid artery and ECA stenosis or cul-de-sac formation should be considered for operation. ECA reconstruction is associated with little morbidity and three-fourths of the patients remain asymptomatic. A high incidence of contralateral disease of the carotid artery is present. Extracranial-intracranial bypass should only be considered when symptoms persist after correction of contralateral disease of the carotid artery and any ECA lesions.

Aged↗
PubMed1986

The role of echocardiography in patients with acute peripheral arterial embolization.

Forty-seven patients with acute arterial embolism requiring urgent embolectomy had postoperative echocardiography (36 2-D, 11 M-mode) in an attempt to identify a cardiac source of emboli. On the basis of history, physical examination, electrocardiogram, and chest roentgenogram, 37 patients were believed to have an apparent cardiac source. All histories and physical examinations in this group reaffirmed significant underlying cardiac disease. Nine of the 47 patients had no discernible source based on clinical data, and one had an arterioarterial embolus. In the presence of a clinically obvious source, although echocardiography (26 2-D, 11 M-mode) helped to clearly define evident cardiac disease in these patients, it failed to demonstrate a cardiac embolic source in those without clinical evidence of cardiac disease or to influence subsequent management. The continued use of echocardiography for the sole purpose of identifying a potential cardiac embolic source should be reconsidered.

Adult↗
PubMed1986

Investigations on the variability of haptoglobin, transferrin and Gc polymorphisms in Assam, India.

Ten different population groups of Assam - Brahmins, Kalitas, Kaibartas, Rajbanshis, Muslims, Ahoms, Chutias, Kacharis, Karbis and Sandwals - have been typed for haptoglobin and for transferrin (Tf) and Gc subtype polymorphisms. Tf and Gc allele subtype frequencies show a considerable inter-population heterogeneity. From genetic distance analysis it appears that the populations under study form some distinct clusters, which can be explained by the historical and ethnic affiliations of these populations. Especially the distribution of Gc subtype alleles reveals some Mongoloid admixture among Assamese populations, which is reflected by the presence of Gc1A8 alleles in them.

Gene Frequency↗
PubMed1986

Predictors of success in bypass grafts to the isolated popliteal segment.

Of 130 infrainguinal bypasses, 25 grafts to an isolated popliteal segment (IPS) were examined for clinical, anatomic and hemodynamic predictors of success. Fourteen autogenous veins (AV) and 11 polytetrafluoroethylene (PTFE) grafts were performed, all for limb salvage. A discontinuous tibial vessel was present in 72 per cent but only 24 per cent were graftable. A mean of 1.7 named collaterals were seen in IPS. Mean preoperative ankle pressure (APR) was 26.29 and ankle to brachial index (ABI) was 0.17. Segmental pressure gradient indices were also measured. Mean follow-up time was 13.6 months (a range of two to 43 months). One hundred per cent immediate graft patency and patient survival rates were obtained. Postoperative APR improved to 86.3 millimeters of mercury and ABI to 0.63 (p less than 0.05). Crude late patency rate was 72 per cent and limb salvage rate was 76 per cent. Cumulative life table patency rate was 58.8 per cent and limb salvage was 68 per cent at 36 months. Patency rate for AV (84.1 per cent) was better than PTFE (41.7 per cent). In 39 concurrent tibial grafts, cumulative patency rate at 36 months was 68 per cent for simple bypass grafts. Success could not be predicted by the length of the IPS, number of collaterals, profunda disease, number of discontinuous or graftable tibial vessels, APR or ABI and profunda popliteal collateral index. The tibial gradient index reflecting poor runoff was significantly greater in failed grafts (p less than 0.05). Bypass grafts to the IPS are a safe and reliable alternative to tibial bypass grafts. The AV performed better than PTFE grafts. The tibial gradient index appears to be a promising indicator for predicting graft success.

Aged↗
PubMed1986

Anthropological studies in Assam, India. 4. Observations on the Kalitas.

Five regional groups of the Kalitas, an Assamese caste group, have been investigated for the distribution of anthropometric and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. The intergroup variability is to some extent considerable. The possible reasons for that are discussed.

ABO Blood-Group System↗
PubMed1986

Anthropological studies in Assam, India.

Four Assamese caste groups--Jogis, Hiras, Kumars and Kaibartas--have been analysed for the distribution of anthropometric and dermatoglyphic traits as well as for the distribution of ABO blood groups and PTC taste sensitivity. The differences among these four caste groups are statistically mostly significant, which can be connected with the history of these groups and their genetic isolation from each other.

ABO Blood-Group System↗
PubMed1985

Population study in Assam: ABO blood groups, haemoglobin E and G-6-PD deficiency.

An attempt has been made to give a comprehensive picture of occurrence of ABO blood groups, haemoglobin E and G-6-PD deficiency among certain representative populations of the two major racial groups--Mongoloids and Caucasoids--of Assam, India. The qualitative pattern of distribution of ABO gene frequencies shows a clear demarcation between these two major groups. The same is true in respect of HbE gene, too. The Mongoloids present high frequencies of this gene, while among the Caucasoids its frequency is comparatively much lower. With regard to G-6-PD deficiency the distinction between the two groups is not so clear cut, yet some Mongoloid populations show relatively higher incidence of the trait in comparison to that in the Caucasoid populations.

ABO Blood-Group System↗
PubMed1985

Anthropological studies in Assam, India. 1. Observations on five Mongoloid populations.

Five Mongoloid population groups from Upper Assam (Ahom, Chutia, Deuri, Mishing and Moran) have been investigated for the distribution of anthropometric and dermatoglyphic traits as well as for that of ABO blood groups and PTC taste sensitivity. The results are discussed with special reference to extent and causes of intergroup variability.

ABO Blood-Group System↗