Search PubMed⌕ Search

Biomedical subjects

J Basu

Publications and source records attributed to J Basu.

At least 73 records · Page 4Linked to original sources
PubMed1991

Plasma levels of antioxidant beta-carotene and alpha-tocopherol in uterine cervix dysplasias and cancer.

Chronic human health problems, namely arteriosclerosis, myocardial ischemia, and cancer, may be caused by highly active oxygen species and may be preventable by antioxidant vitamins. In humans, the sources of two major antioxidants, beta-carotene and alpha-tocopherol, are dietary. In this study, we measured the plasma concentrations of beta-carotene and alpha-tocopherol by reverse-phase high-pressure liquid chromatography in a cross-sectional sampling of 116 women. Significantly reduced plasma levels of beta-carotene and alpha-tocopherol were observed in women with histopathologically diagnosed cervical dysplasias or cancer (p less than 0.0001 and p less than 0.005, respectively). There was an inverse association between the plasma levels of both beta-carotene and alpha-tocopherol and increasingly severe graded cervical histopathology. In groups with advanced dysplasias, the percentage of smokers was markedly increased and the women were comparatively older (p less than 0.0001). A strong association was noted between smoking status and plasma beta-carotene levels, independent of cervical pathology. However, this was not evident with respect to alpha-tocopherol. The findings suggest that the antioxidants beta-carotene and alpha-tocopherol have biologic functions that are interdependent in the pathogenesis of cervical intraepithelial lesions and cervical cancer.

Adolescent↗
PubMed1991

Defective mycolic acid biosynthesis in a mutant of Mycobacterium smegmatis.

A mutant of Mycobacterium smegmatis defective in mycolic acid biosynthesis was isolated following chemical mutagenesis. Fatty acids were extracted from the mutant and subjected to structural analysis by thin-layer chromatography and high-performance liquid chromatography (HPLC) of both methyl and p-bromophenacyl ester derivatives. Thin-layer chromatography did not show the presence of any fatty acid of RF comparable to that of standard methyl mycolate. The HPLC profile revealed a broad peak in the standard mycolic acid ester region. No characteristic peaks of mycolic acid esters comparable to the wild-type could be resolved. Mass spectral analysis of the HPLC-purified peak demonstrated the presence of shorter-chain fatty acids in the mutant. These data support the idea that the mutant accumulates precursors of mycolic acids and is incapable of carrying out the final conversion to mycolic acids of 60-90 carbon atoms.

Chromatography, High Pressure Liquid↗
PubMed1991

Plasma ascorbic acid and beta-carotene levels in women evaluated for HPV infection, smoking, and cervix dysplasia.

The association of the plasma levels of the essential micronutrients, ascorbic acid and beta-carotene, with smoking and human papillomaviruses (HPV) infection has been studied in 75 women referred to a colposcopy clinic for an abnormal Pap smear. Each patient had a repeat Pap smear and a colposcopically directed biopsy of a visually perceived cervix abnormality. Cervicovaginal lavage specimen and peripheral venous blood sample were obtained for HPV DNA hybridization studies and nutrient analyses, respectively. Samples were obtained and analyzed without knowledge of each woman's clinical status. A group of 45 subjects had histopathologically diagnosed dysplasias of varying grades of severity. Among women with dysplasias, 53.3% were smokers. Of subjects with and of subjects without dysplasias, 66 and 34%, respectively, were positive for HPV infection. The mean plasma reduced ascorbic acid, retinol, and beta-carotene levels between the dysplastic groups were comparable. A strong association with smoking history and plasma reduced ascorbic acid level was note independent of cervical dysplasias or HPV status. The findings underscore the importance of smoking, ascorbic acid, and beta-carotene as nutritional variables, and HPV infection in the pathogenesis of cervical dysplasias.

Adult↗
PubMed1991

An unusual presentation of neuroleptic malignant syndrome.

The neuroleptic malignant syndrome is an exceedingly rare but potentially fatal condition characterized by parkinsonian type rigidity, rise of temperature and altered consciousness. This idiosyncratic side-effect of almost all psychotic drugs though rare may occur even when neuroleptics are used for a short period. Here a very rare presentation of a case, of neuroleptic malignant syndrome appearing 2 days following 2nd dose of injection fluphenazine decanoate (0.5 ml) IM in whom 1st dose having 30 days prior to the 2nd one did not show any adverse effect, is being reported.

Adult↗
PubMed1990

Smoking and the antioxidant ascorbic acid: plasma, leukocyte, and cervicovaginal cell concentrations in normal healthy women.

The influence of cigarette smoking on the plasma, leukocyte, and cervicovaginal cell ascorbic acid levels in 46 healthy smokers and healthy nonsmokers was investigated. Coded peripheral venous blood and cervicovaginal lavage specimens obtained after informed consent were analyzed simultaneously for their ascorbic acid content. The findings suggest that smoking affects the levels and distribution of ascorbic acid. In smokers (n = 16), the number of exfoliated cervicovaginal epithelial cells and leukocyte ascorbic acid levels was significantly higher (p less than 0.01, p less than 0.05, respectively) compared with nonsmokers (n = 30). In addition, cervicovaginal cell ascorbic acid, plasma reduced and total ascorbic acid levels were significantly lower (p less than 0.001, p less than 0.01, p less than 0.01, respectively). The exfoliated epithelial cell ascorbic acid levels in nonsmokers was fourfold greater than that of leukocytes. The implications of these findings within the context of free radical-induced cellular pertubations in smokers are discussed.

Adult↗
PubMed1990

Changes in membrane lipids and amino acid transport in a nystatin-resistant Aspergillus niger.

A nystatin-resistant mutant of Aspergillus niger is described that has quantitative changes in phospholipid composition compared with the wild type. The proportion of linoleic acid in total phospholipids was elevated in the mutant from 38 to 56% and the proportion of oleic acid was lowered from 28 to 12%. Amino acid transport is also altered, the Vmax values for the uptake of leucine, lysine, and glutamic acid being generally higher in the mutant; for glutamic acid the increase was from 15 to 35 nmol.mg-1.min-1.

Amino Acids↗
PubMed1990

Measurements of ascorbic acid and glutathione in exfoliated cervicovaginal epithelial cells of smokers and women with cervical dysplasias.

This report emphasizes the ability to quantify ascorbic acid (AA) and reduced glutathione (GSH) levels in exfoliated cervicovaginal epithelial cells obtained by a lavage technique. Sixty-two women with abnormal Papanicolaou smears underwent colposcopic examinations. Colposcopic lesions were biopsied and histopathologically graded. Marked variations in the number of cells and in the levels of AA and GSH were observed. In cigarette smokers, the number of exfoliated cells retrieved was significantly higher (p less than 0.05, by Student's t test). The simultaneous investigation of biochemical and virologic parameters in exfoliated cervicovaginal epithelial cells, in conjunction with the known cytopathologic and epidemiologic risk variables, provides a novel approach to elucidate factor(s) that may inhibit or promote cervical carcinogenesis in designed prospective studies.

Adult↗
PubMed1990

The use of computerized need projection methodologies to implement health planning policies.

The Maryland Health Resources Planning Commission has developed a substantial proportion of its planning effort since 1982 to the development of need projection methodologies that fulfill the policy direction established in the State Health Plan. Because each service for which need is projected has a unique set of problems, policy direction leads to service-specific approaches to forecasting need. Each methodology takes into consideration appropriate minimum sizes and distribution of services, appropriate rates of growth, and appropriate reallocation of use from overserved to underserved areas. Examples from acute medical/surgical, acute psychiatric, comprehensive rehabilitation, and institutional longterm care services are given.

Data Collection↗
PubMed1990

Abnormalities of the erythrocyte membrane in chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is a hematologic malignancy characterized by excessive growth of myeloid cells and their progenitors. The proportion of spectrin dimers compared to tetramers extracted from membranes at 4 degrees C, under low ionic strength conditions, increased in CML erythrocytes. These also displayed abnormal thermal sensitivity (between 45 and 46 instead of 49 degrees C). Crosslinking with the bifunctional reagent, dimethyl adipimidate (8.6 A) showed significant organizational modification of not only spectrin, but other cytoskeletal components such as ankyrin, bands 4.2 and 5. Enhanced concanavalin A (Con-A) agglutinability of CML erythrocytes also suggests altered topographic distribution of a functionally important membrane protein, band 3. The anion transport activities of erythrocytes from patients with CML and normal donors were comparable. In CML erythrocytes, significant reduction in the number of ankyrin-binding sites, present in the cytoplasmic domain of band 3, may lead to partial loss of cytoskeletal anchorage to the bilayer and account for their increased Con-A agglutinability and heat sensitivity and may lead to their premature removal from the circulation.

Agglutination↗
PubMed1990

Chronic myelogenous leukemia: alterations in red cell membrane band 3 and increased IgG binding.

Chronic myelogenous leukemia (CML) is a hematologic malignancy arising from an abnormal hemopoietic stem cell. Our earlier studies have identified defects in spectrin tetramer formation and organization of cytoskeletal proteins (Basu et al., Biochim. Biophys. Acta 1988, 121-126); and decreased ankyrin binding to ankyrin-depleted vesicles in CML patients. These may lead to clustering of band 3 and increased binding of autologous IgG. This has now been explored by studying the binding of 125I-protein A to normal and CML erythrocytes. There is increased binding of 125I-protein A in CML erythrocytes compared to normal erythrocytes. Since binding of autologous IgG is responsible for removal of erythrocytes from the circulation, the above findings suggest that CML erythrocytes are likely to be prematurely removed from the circulation, accounting for anemia.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1990

Depression.

Explore the source record for details and available documents.

Depression↗
PubMed1990

An insight into the structure of DNA through melting studies.

Helix-coil transition of calf thymus (CT) DNA in 0.1 M NaCl was observed under different environmental conditions for studying structural and conformational changes, if any. Pre-exposure of the DNA to different types of radiations - UV and gamma-brought different degrees of change (lowering) in the melting temperature (Tm). Interaction of drugs (daunomycin and actinomycin-D) increased the Tm inducing structural stability. There was 50% more destabilisation in case of polynucleotide-drug complex as compared to DNA-drug complex exposed to UV radiation. Thermodynamic studies on DNA in D2O (0.1 M NaCl prepared in D2O) were carried out and compared with the corresponding results in H2O. Presence of D2O increased the stability of the DNA structure. Structural and conformational aspects have been discussed in the light of the results obtained.

Animals↗
PubMed1989

Purification and characterization of an extracellular lectin from Mycobacterium smegmatis.

Mycobacteria exist naturally in aggregated form and pathogenic strains colonize macrophages. A lectin has been isolated from the culture broth of M. smegmatis, which may, possibly, have an important role in either or both of these phenomena. The lectin of Mr 12,000-14,000 agglutinates erythrocytes from different species, and agglutination is reversed by arabinogalactan isolated from mycobacteria, as well as by yeast mannan. It has a pI of 5.5 and is rich in aspartic and glutamic acid residues.

Amino Acids↗
PubMed1989

Abnormalities in erythrocyte membrane band 3 in chronic myelogenous leukemia.

The anion transport activities of erythrocytes from patients with chronic myelogenous leukemia (CML) and normal donors were comparable. In CML erythrocytes, significant reduction in the number of ankyrin-binding sites, present in the cytoplasmic domain of band 3, may lead to partial loss of cytoskeletal anchorage to the bilayer and account for their increased Con-A agglutinability and heat-sensitivity (Basu, J., Kundu, M., Rakshit, M.M. and Chakrabarti, P. (1988) Biochim. Biophys. Acta 945, 121-126).

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1989

Abnormalities in the erythrocyte membrane in acute lymphoid leukaemia.

Erythrocytes from patients suffering from acute lymphoid leukaemia (ALL) show decreased proportions of spectrin tetrameters and altered spatial distribution of band 4.1 and ankyrins. These abnormalities of the cytoskeleton are probably responsible for altered membrane fluidity and transbilayer distribution of phosphatidylethanolamine in ALL. ALL is associated with severe anaemia and usually, but not always, with overproduction of lymphocytes. To our knowledge, this is the first report of abnormalities in the erythrocyte membrane in ALL which may, in part, be responsible for the observed anaemia.

Dimethyl Adipimidate↗
PubMed1989

Effects of smoking and oral contraception on plasma beta-carotene levels in healthy women.

Oral contraceptive use and smoking have been known to affect plasma vitamin levels. Total carotenoids have been studied with spectrophotometry, a relatively insensitive technique. In this study plasma concentrations of beta-carotene and retinol were measured in coded samples by sensitive high-pressure liquid chromatography in a cross-sectional study of 149 normal healthy women attending a family planning clinic. At the time of recruitment in the morning, a general health questionnaire was administered for patient age, methods of contraception, smoking habits, and food intake at breakfast. Of the 149 enrolled volunteers, 88 were oral contraceptive users and 61 were not users. Among users, 21 smoked cigarettes, and there were 18 smokers among nonusers. Oral contraceptive users had significantly lower plasma concentrations of beta-carotene (p less than 0.001) and higher retinol levels (p less than 0.0001). Plasma beta-carotene or retinol levels did not differ among users of intrauterine contraceptive devices or barrier methods of contraception. No association was noted between the plasma levels of these two micronutrients and age greater than or less than 30 years. Cigarette smoking alone was associated with significantly reduced plasma beta-carotene levels in nonusers (p less than 0.001). Combined cigarette smoking and oral contraceptive usage were associated with low plasma beta-carotene levels; the results appear to be additive. These findings suggest a possible synergistic effect on plasma beta-carotene levels from the use of both cigarette smoking and oral contraception.

Adolescent↗
PubMed1989

Plasma reduced and total ascorbic acid in healthy women: effects of smoking and oral contraception.

This is the first report of both reduced (RAA) and total (TAA) plasma ascorbic acid levels in women who smoke and are on oral contraception. 155 normal healthy subjects were investigated. A study questionnaire was completed including age, method of contraception, smoking status, and food intake at breakfast, prior to attending the clinic. Biochemical assays were promptly carried out without knowledge of subject's clinical or dietary status. One-way analysis of variance revealed that oral contraception per se, barrier or IUD methods have no effect on plasma ascorbic acid levels. The mean values (mg/dl +/- SD) for plasma RAA between smokers and nonsmokers were 0.512 +/- 0.241 and 0.601 +/- 0.263; and that for TAA were 0.565 +/- 0.232 and 0.682 +/- 0.231, respectively. Significant decreases in both plasma RAA (p less than 0.05) and TAA levels (p less than 0.001) were observed in smokers. Age was an interacting variable. No association of smoking or oral contraceptive use was seen with RAA or TAA levels among women less than 26 years, but decreases in both RAA and TAA levels were evident among smokers aged 26 years or older. The present study emphasizes the total exposure to smoking, e.g., pack years, is a significant confounding variable in the study of plasma ascorbic acid levels.

Adolescent↗