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Biomedical subjects

R Sarkar

Publications and source records attributed to R Sarkar.

At least 109 records · Page 6Linked to original sources
PubMed1983

Association between the degree of mosaicism and the severity of syndrome in Turner mosaics and Klinefelter mosaics.

This study, based on the investigations carried on 82 cases of Turners of which 50 of them were mosaics and 85 cases of Klinefelters of which 70 of them were mosaics, is an attempt to explain the vast range of clinical variations observed in cytogenetically established Turner mosaics (45,X/46,XX) and Klinefelter mosaics (47,XXY/46,XY) in the light of the degree of mosaicism present in them. It was observed that the severity of the syndrome in Turner mosaics and Klinefelter mosaics increased with the relative increase in the abnormal cell line population.

Adult↗
PubMedDate not supplied

Hematological status of beta-thalassemics in Madras.

Although rapid technical advances have taken place in the diagnosis of beta-thalassemia, still the hematological factors were found to be suitable screening test in areas like Indian subcontinent where a high prevalence of beta-thalassemia trait was observed. Among various thalassemias reported in Asian Indians, beta-thalassemia account for about 80% and is responsible for very high infantile mortality. Despite this, little is known about the hematological status of beta-thalassemias among this ethnic group which is associated with more than five different predominant beta-globin mutation with high frequency and variable number of rare ones. The present study is the first report of hematological status of beta-thalassemia among this ethnic group particularly from Tamil Nadu, Southern India, who are still practising high degree of consanguinity. In the present study, a total number of 364 beta-thalassemics were investigated. This includes 84 cases of homozygous beta-thalassemias and the remaining 280 were heterozygotes. The hematological factors such as red cell indices, hemoglobin F and hemoglobin A2 were assessed. The results revealed a wide spectrum of hematological variables ranging from severe form as that of Mediterranean thalassemias to very mild form of anemia as that of African Negro population.

Adolescent↗
PubMedDate not supplied

Amelioration of clinical severity through raised fetal hemoglobin in sickle cell anaemia.

In the present study, the levels of fetal hemoglobin (HbF) in sickle cell anemia patients were compared with sickle cell trait, beta thalassemia major and control. The mean HbF levels in beta thalassemia major and sickle cell anemia were 51.62 and 19.63% respectively. However, when the amount of HbF was expressed in terms of gram hemoglobin per deciliter whole blood, the mean values were 2.88 and 1.81 respectively between the two groups, suggesting that the genetic mechanism controlling the different threshold levels of increased HbF in these disorders could probably be similar. The elevated. HbF level in sickle cell anemia along with moderate hematologic profile observed in the present study is suggested to provide amelioration of the clinical severity unlike in beta thalassemia major where despite raised HbF levels, the severe clinical implications are attributed to marked imbalance in the globin chain synthesis.

Anemia, Sickle Cell↗
PubMedDate not supplied

Plasma-mediated excimer laser ablation of bone: a potential microsurgical tool.

A pulsed ultraviolet excimer laser was used to ablate bone in vitro at 193, 248, 308, and 351 nm and in vivo at 193 nm. Ablation was dependent on sufficient fluence (energy delivered per unit area per pulse) for plasma formation at the target site at all wavelengths. Adjacent tissue damage at various fluences for each wavelength was examined using a light microscope. Damage was minimal at 193 nm (1 to 3 microns) and most extensive at 351 nm (60 to 75 microns). This is in sharp contrast to the 1 to 3 mm of adjacent thermal damage produced when carbon dioxide lasers are used to ablate bone. Differences in the degree and type of damage to adjacent tissues among the wavelengths studied indicated that other ablation mechanisms and tissue interactions are involved in addition to simple plasma vaporization of bone. Bleeding during and after ablation demonstrated that the use of this laser does not cause thermal damage, which would cauterize adjacent vessels. Pre- and post-mortem lesions made at identical power and pulse settings were of equal depth, indicating that bleeding does not affect the ablation rate. The excimer laser has potential as a microsurgical instrument for the precise removal of bone with minimal damage to adjacent structures.

Animals↗
PubMedDate not supplied

Superiority of acridine orange-stained buffy coat smears for diagnosis of partially treated neonatal septicemia.

Early diagnosis of neonatal septicemia is a vexing problem because of its non-specific clinical picture. Many of the neonates with septicemia reaching a referral centre have already been exposed to antibiotics and their blood cultures are often sterile. Scarcity of studies evaluating acridine orange-stained buffy coat smears in detecting neonatal septicemia after administration of antibiotics prompted us to undertake this study. The population studied consisted of 34 cases of neonatal septicemia with positive blood cultures and/or positive buffy coat smears (of these 25 had a positive blood culture) and 25 neonates with a clinical course not suggestive of any infection. Venous blood was drawn for culture, preparation of buffy coat smears, blood counts and micro ESR. The culture and smears were repeated after administration of antibiotics for 48-72 h. Acridine orange stain was the most sensitive test and was significantly more sensitive than Gram's stain (p < 0.005). After the administration of antibiotics, acridine orange was significantly more sensitive than Gram's stain and blood culture (p < 0.05).

Acridine Orange↗
PubMedDate not supplied

Does nitric oxide regulate smooth muscle cell proliferation? A critical appraisal.

Smooth muscle proliferation is involved in the pathogenesis of atherosclerosis, restenosis after angioplasty and vein graft failure due to neointimal hyperplasia. Nitric oxide (NO) inhibits smooth muscle cell growth in vitro and experimental neointimal hyperplasia in vivo, suggesting a role for NO as a regulator of smooth muscle cell proliferation. NO is also involved in the control of numerous other vascular functions including platelet and inflammatory cell adhesion, vascular reactivity and endothelial permeability. This review critically examines the experimental and clinical evidence that supports a role for NO as a modulator of smooth muscle cell proliferation, with an emphasis on the multiple mechanisms by which NO acts on vascular lesions.

Animals↗
PubMedDate not supplied

Extended iliac exposure from the groin.

Knowledge of iliac artery and inguinal anatomy enables extraperitoneal exposure of the iliac arteries for surgical treatment of unilateral inflow disease. A method is presented for exposing the distal common iliac artery, the iliac bifurcation, and the full length of the external iliac artery by detachment and retraction of the inguinal ligament though a single extended groin incision. The indications for unilateral iliac artery exposure, revascularization, surgical anatomy, and technique of iliofemoral exposure through a single, extended groin incision are presented. Extended iliac exposure through a single, extraperitoneal exposure facilitates all methods of unilateral iliac revascularization and provides access for delivery of endovascular devices.

Aged↗
PubMedDate not supplied

Plasma plasminogen activator inhibitor-1 activity in normoglycemic hypertriglyceridemic north Asian Indian subjects: a preliminary case-control study.

BACKGROUND: Recent evidence suggests that increased activity of plasma plasminogen activator inhibitor-1, an important component of the insulin resistance syndrome, plays a crucial role in the pathogenesis of atherosclerosis. METHODS AND RESULTS: In this case-control study, relationships between plasma plasminogen activator inhibitor-1 activity, serum triglyceride levels and hyperinsulinemia were explored in 40 non-diabetic patients with primary hypertriglyceridemia (Group 1) and 40 non-diabetic normotriglyceridemic controls (Group 2) matched for potential confounders like smoking and physical activity. Mean values of fasting serum insulin levels were increased in Group 1 (p>0.05). Hyperinsulinemia was observed in 14 (17.5%) individuals in Group 1 and 11 (13.8%) individuals in Group 2. Mean plasma plasminogen activator inhibitor-I activity in Group 1 (9.8+/-8.4 IU) was higher than in Group 2 (7.0+/-7.7 IU), though the difference was not significant (p>0.05). However, when only subjects with elevated levels of plasma plasminogen activator inhibitor-1 activity were taken into account, mean values were significantly higher in Group 1 (p<0.05). The plasma plasminogen activator inhibitor-1 activity was higher in subjects with body mass index >25 in both the groups, significantly so in males (p=0.05). Hyperinsulinemic subjects with a body mass index >25 and raised serum triglyceride levels had higher mean values of plasma plasminogen activator inhibitor-1 activity (18.42+/-11.15 IU) than subjects with similar characteristics and normal triglyceride levels (14.22+/-8.20 IU, p<0.05). CONCLUSIONS: Though in the current study a trend for hyperinsulinemia and high plasma plasminogen activator inhibitor-1 activity was observed in hypertriglyceridemic subjects, a larger study is needed to achieve significant differences and correlations. Obese male subjects, irrespective of their lipid profile, are at risk for thrombotic events in view of their significantly higher plasma plasminogen activator inhibitor-1 values. Procoagulant tendency is further enhanced if hypertriglyceridemia and hyperinsulinemia are added on to obesity.

Adolescent↗
PubMedDate not supplied

The surgical treatment of atrial myxomas. Clinical experience and results in eight patients.

Between 1983 and 1988, eight patients underwent excision of left atrial myxomas at the Institute of Postgraduate Medical Education & Research, Calcutta. There were five females and three males. The presenting symptoms and signs often simulated mitral stenosis or insufficiency, and the diagnosis was confirmed by echocardiography and angiocardiography. One patient presented with features of cerebral embolism. The myxomas were successfully removed under cardiopulmonary bypass in all patients, either by shaving them from the atrial septum, or by excising a portion of normal atrial septum with the tumour. Small tumours were removed through left atriotomy, while a biatrial approach was utilised for large tumours. There was one perioperative death, and another patient died one and half years later, probably due to tumour embolisation in brain. Late functional results have been excellent in all the other patients. Two dimensional echocardiography has proved to be extremely accurate in early diagnosis of myxomas and in the late follow up of patients. The pertinent literature is reviewed.

Adult↗