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Biomedical subjects

M Roy

Publications and source records attributed to M Roy.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Regulation of cellular immune responses by selenium.

Selenium (Se) is an essential nutritional factor that affects the development and expression of cell-mediated immune responses directed toward malignant cells. These studies have shown that dietary (2 ppm for 8 wk) or in in vitro (1 x 10(-7)M) supplementation with Se (as sodium selenite) results in a significant enhancement of the proliferative responses of spleen lymphocytes from C57Bl/6J mice in response to stimulation with mitogen or antigen. Se deficiency (0.02 ppm for 8 wk) had the opposite effect. The alterations in the ability of the cells to proliferate, which occurred in the absence of changes in the endogenous levels of interleukin-2 (Il2) or interleukin 1, were apparently related to the ability of Se to alter the kinetics of expression of high-affinity Il2 receptors on the surface of activated lymphocytes. This resulted in an enhanced or delayed clonal expansion of the cells, and in an increased or decreased frequency of cytotoxic cells within a given cell population. The changes in tumor cytotoxicity were paralleled by changes in the amounts of lymphotoxin produced by the activated cells. Dietary Se modulations had a comparable effect on macrophage-mediated tumor cytodestruction. The results also suggested that Se exerts its effect 8-24 h after stimulation, and that it most likely affects processes in the cytoplasmic and/or nuclear compartments of activated lymphocytes.

Animals↗
PubMedDate not supplied

Supplementation with selenium and human immune cell functions. I. Effect on lymphocyte proliferation and interleukin 2 receptor expression.

Selenium (Se) is an essential nutritional factor that was shown by us to alter the expression of the high affinity interleukin 2 receptor (Il2-R) and its subunits, cell proliferation, and clonal expansion of cytotoxic T-lymphocytes in mice. This study shows that dietary supplementation of Se-replete humans with 200 micrograms/d of sodium selenite for 8 wk, or in vitro supplementation with 1 x 10(-7) M Se (as sodium selenite), result in a significant augmentation of the ability of peripheral blood lymphocytes to respond to stimulation with 1 microgram/mL of phytohemagglutinin or alloantigen (mixed lymphocyte reaction) and to express high affinity Il2-R on their surface. There was a clear correlation between supplementation with Se and enhanced 3H-thymidine incorporation into nuclear DNA, preceded by enhanced expression of high affinity Il2-R. Supplementation with Se can apparently modulate T-lymphocyte mediated immune responses in humans that depend on signals generated by the interaction of interleukin 2 with Il2-R.

Adult↗
PubMedDate not supplied

Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells.

This study examined the effect of dietary (200 micrograms/d for 8 wk) supplementation with selenium (as sodium selenite) on the ability of human peripheral blood lymphocytes to respond to stimulation with alloantigen, develop into cytotoxic lymphocytes, and to destroy tumor cells, and on the activity of natural killer cells. The participants in the study were randomized for age, sex, weight, height, and nutritional habits and given selenite or placebo tablets; all participants had a selenium replete status as indicated by their plasma Se levels prior to supplementation. The data indicated that the supplementation regimen resulted in 118% increase in cytotoxic lymphocyte-mediated tumor cytotoxicity and 82.3% increase in natural killer cell activity as compared to baseline values. This apparently was related to the ability of the nutrient to enhance the expression of receptors for the growth regulatory lymphokine interleukin-2, and consequently, the rate of cell proliferation and differentiation into cytotoxic cells. The supplementation regimen did not produce significant changes in the plasma Se levels of the participants. The results indicated that the immunoenhancing effects of selenium in humans require supplementation above the replete levels produced by normal dietary intake.

Adult↗
PubMedDate not supplied

Excess of depressive symptoms and life events among diabetics.

We compared a group of insulin-dependent diabetic outpatients with normal control subjects for their scores on the Beck Depression Inventory (BDI) and for their experience of recent life events. Diabetic patients had significantly higher BDI scores than controls and had experienced significantly more life events during the previous 6 months. These results suggest that psychiatric symptoms and social problems are common among insulin-dependent diabetics. Longitudinal studies of psychiatric disorder among diabetic patients appear to be indicated.

Adult↗
PubMedDate not supplied

Dysregulation of the hypothalamo-pituitary-adrenal axis and duration of diabetes.

We compared insulin-dependent diabetic outpatients with and without retinopathy for plasma indices of hypothalamo-pituitary-adrenal (HPA) axis activity. Diabetic patients with moderate-to-severe retinopathy had significantly higher postdexamethasone plasma levels of adrenocorticotropic hormone than patients with minimal or no retinopathy. However, when duration of diabetes was taken into account this difference was no longer significant. These data suggest that dysregulation of the HPA axis and retinal microvascular complications found in diabetic patients may both be a function of duration of diabetes.

Adrenocorticotropic Hormone↗
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Human-specific insertion/deletion polymorphisms in Indian populations and their possible evolutionary implications.

DNA samples from 396 unrelated individuals belonging to 14 ethnic populations of India, inhabiting various geographical locations and occupying various positions in the socio-cultural hierarchy, were analysed in respect of 8 human-specific polymorphic insertion/deletion loci. All loci, except Alu CD4, were found to be highly polymorphic in all populations. The levels of average heterozygosities were found to be very high in all populations and, in most populations, also higher than those predicted by the island model of population structure. The coefficient of gene differentiation among Indian populations was found to be higher than populations in most other global regions, except Africa. These results are discussed in the light of two possible scenarios of evolution of Indian populations in the broader context of human evolution.

Alleles↗
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Immunoglobulin (Gm and Km) allotypes in nine endogamous groups of West Bengal, India.

Blood samples from 898 individuals of nine endogamous groups of West Bengal, India were typed for determining the haplotypic structure in the gamma-light chain (Gm) and kappa-light chain (Km) of immunoglobulin (IgG). The Gm haplotype frequencies detected by Glm (1), Glm (2) and G3m (5) markers suggest that in this eastern state of India there is considerable variation of frequencies of the typical Mongoloid haplotype Gm1,5, which shows a high incidence in Rajbanshi, Rabha, Garo and Lodha groups. On the contrary, this haplotype is probably absent in the high caste groups, Rarhi Brahmin and Vaidya, and is relatively infrequent in Jalia Kaibarta, a scheduled caste of the south-western part of the state. The Km1 allele is also high in frequency among Rajbanshi, Rabha, Garo and Munda in comparison with Rarhi Brahmin and Vaidya, suggesting the former four groups' strong Mongoloid affiliation. This survey signifies that there is considerable variation in the extent of Mongoloid admixture in Bengali populations. Such admixture is not restricted in specific social class either. It further demonstrates that heterogeneity of the genetic structure of Bengali populations do not correspond to the present social ranking on the basis of caste hierarchy.

Asian People↗
PubMedDate not supplied

Are Muslim women less susceptible to oncogenic human papillomavirus infection? A study from rural eastern India.

Muslim women are known to have lower incidences of cervical cancer and/or human papillomavirus (HPV) infection. Here we aim to determine any association that may be present between the oncogenic HPV16/18 infections and abnormal cytological lesions along with demographic and other attributes among Indian Muslim women (n = 478) and compare with the neighboring Hindus (n = 534) from a prospective cohort study. Agewise distribution of both subject-groups is similar. HPV16/18 infection is present in 9.6% Muslims and 7.5% Hindu women. Jointly atypical cells of undetermined significance (a typical cells of undetermined significance) and HPV16/18 are present in seven Muslim and two Hindu women. No high squamous intraepithelial lesions or cervical cancer is detected at the baseline. HPV16/18 infections show trends that varied with age, a nonlinear trend among Muslim women. In Hindu women the prevalence is highest at age < or =24 years, which linearly drops with increasing age. Abnormal cytology increases significantly in both religion-groups with increasing age. The data show that these Indian Muslim women are equally susceptible to HPV16/18 infection and for the development of abnormal cytology. There is a paucity in epidemiological data, which justifies the need to screen women of all religions for cervical cancer (that includes oncogenic HPV testing).

Adult↗
PubMedDate not supplied

Psychiatric syndromes in Persian Gulf War veterans: an association of handling dead bodies with somatoform disorders.

BACKGROUND: Traumatic combat experience has been associated with the development of posttraumatic stress disorder, but there have been few studies about the association of military combat experience and the development of somatoform disorders. METHODS: The authors evaluated 131 referred Gulf War veterans for medical and psychiatric syndromes thought related to their involvement in the Gulf War. Patients completed questionnaires regarding their traumatic experiences and were interviewed using the Structured Clinical Interview for DSM III-R. RESULTS: For the sample, 69% had axis I conditions. Major depression, undifferentiated somatoform and posttraumatic stress disorders were the most common diagnoses. Reports of traumatic events were associated with both posttraumatic stress disorder (p < 0.05) and somatoform diagnoses (p < 0.05). Veterans who handled dead bodies had a 3-fold risk of receiving a somatoform diagnosis (p < 0.05). CONCLUSIONS: Psychiatric syndromes may explain some medical complaints following involvement in the Persian Gulf War. The results suggest that some psychological and nonspecific somatic symptoms persisting since the Gulf War may be related to exposure to psychological trauma.

Adult↗
PubMedDate not supplied

Neuronal injuries induced by perinatal hypoxic-ischemic insults are potentiated by prenatal exposure to lipopolysaccharide: animal model for perinatally acquired encephalopathy.

We developed an original rat model for neonatal brain lesions whereby we explored the sequential effects of infectious and hypoxic-ischemic aggressions. We investigated the influence of combined exposure to prenatal infection with neonatal hypoxic-ischemic insult. Infectious effect was produced by administrating lipopolysaccharide (LPS) intraperitoneally to pregnant rats starting on embryonic day 17. Hypoxia-ischemia (H/I) was induced in the pups at postnatal day 1 (P1) by ligature of the right common carotid artery followed by exposure to hypoxia (8% O(2)) for 3.5 h. Animals were randomized into four groups: (1) control group: pups born to mothers subjected to intraperitoneal saline injection; (2) LPS group: pups exposed in utero to LPS; (3) H/I group: pups exposed to postnatal hypoxia after ligation of the right carotid artery, and (4) H/I plus LPS group: in utero exposure to LPS followed by postnatal hypoxia after ligation of the right carotid artery. Neuropathological findings in pups examined at P3 and P8 showed that groups 2, 3, and 4 presented a pattern of neuronal injury similar to those characterized as 'selective neuronal necrosis' within the context of human perinatal encephalopathy. Neuronal cellular injuries were particularly seen in the neocortex, mainly in parasagittal areas. The extent of neuronal cell injury in the brain of rats exposed to postnatal H/I was significantly increased by antenatal exposure to LPS. This animal model provides an experimental means to explore the respective roles of anoxic and infectious components in the pathogenesis of perinatal brain lesions and consequent cerebral palsy.

Animals↗
PubMedDate not supplied

Cytologic predictors of cervical intraepithelial neoplasia in women with an ASCUS Pap smear.

OBJECTIVE: To identify cytologic parameters on Pap smears of women with an atypical squamous cells of undetermined significance (ASCUS) diagnosis that could help cytologists to indicate whether a particular ASCUS case is most likely related to cervical intraepithelial neoplasia (CIN) grade 1 or 2/3. STUDY DESIGN: A total of 360 eligible women diagnosed with ASCUS and referred to the colposcopy clinic of Saint-Sacrement Hospital participated in the study. Eligible women were those aged 18-50 years, newly diagnosed with ASCUS, with no history of cervical biopsies or treatment, and not pregnant at the time of the visit. Colposcopically directed biopsies of lesions were obtained. All Pap smears were reviewed according to 36 different cytomorphologic criteria. The regression logistic model was used to estimate the odds ratios (ORs) for the associations between cytologic criteria observed in smears and the diagnosis of CIN made on biopsies. All cytologic criteria significantly (P < .05) associated with CIN were entered in the models, and a backward selection was done to determine independent cytologic predictors of CIN 1 and 2/3. RESULTS: Biopsies revealed that 22.2% of the study population had concurrent CIN. CIN I and 2/3 were identified in 61 (16.9%) and 19 women (5.3%), respectively. Clear perinuclear spaces (OR = 2.5, P = .002) and moderate nuclear atypia (OR = 4.4, P = .02) were two cytologic criteria independently associated with CIN 1. Four independent predictors of CIN 2/3 were identified: the presence of clear perinuclear spaces (OR = 5.9, P = .004), hyperchromasia (OR = 3.9, P = .04), moderate anisokaryosis (OR = 13.1, P = .01 and increased nuclear volume of metaplastic cells (OR = 5.1, P = .007). CONCLUSION: These observations may help cytologists to better categorize ASCUS lesions as intraepithelial ones and will also contribute to improving the Bethesda definition of ASCUS. Further studies are planned to validate these observations.

Adolescent↗
PubMedDate not supplied

Apolipoprotein E polymorphism association with lipoprotein profile in endogenous hypertriglyceridemia and familial hypercholesterolemia.

Apolipoprotein (apo) E polymorphism was among the first-reported genetic polymorphisms that explained part of the normal variation in plasma cholesterol concentrations in humans. The aim of this study was to assess the influence of allelic variation at the apo E gene locus on the plasma lipoprotein profile in hyperlipidemia. The lipoprotein levels of hyperlipidemic subjects of the major apo E phenotypes (E3/2, E3/3, and E4/3) were compared. One hundred eighty-two subjects with endogenous hypertriglyceridemia and 98 subjects with familial hypercholesterolemia due to a 10-kb deletion in their low density lipoprotein (LDL) receptor genes were compared with 424 normolipidemic controls from the same environmental background. LDL concentrations were lower in the E3/2 subset than in the E3/3 or E4/3 subset in the control, hypertriglyceridemic, and familial hypercholesterolemic groups. In absolute values, the magnitude of the effect was greatest in the familial hypercholesterolemic group. However, the direction and percentage change were identical in the presence or absence of the LDL receptor defect, indicating that the apo E phenotype effect is independent of LDL receptor status. Triglyceride and very low density lipoprotein (VLDL) cholesterol concentrations were higher in E3/2 than in E3/3 or E4/3 hypertriglyceridemic subjects, but this difference was not found in the familial hypercholesterolemic or control group. Thus, there seems to be a specific interaction between apo E isoforms and VLDL metabolism in hypertriglyceridemia; allelic variation at the apo E gene locus seems to be associated with specific alterations in the plasma lipoprotein profile of subjects with well-defined types of hyperlipidemia.

Adult↗
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Homozygous familial hypercholesterolemia among French Canadians in Québec Province.

Nineteen patients with homozygous familial hypercholesterolemia (FH) living at the time of the 1981 Canada census are the subject of this report. Their mean age at that time was 15, with a range of 1 to 26 years. All patients had extensive xanthomatosis but showed variable clinical manifestations of coronary heart disease (CHD); five (mean age, 21; range, 11 to 27 years) died from sudden death due to CHD. Plasma cholesterol levels varied more than twofold (557 to 1532 mg/dl). Variation in the concentrations of both plasma and low density lipoprotein cholesterol, as well as apolipoprotein B, were related neither to age at death from CHD nor to the clinical course of CHD. The mean high density lipoprotein cholesterol concentration (37 mg/dl) was lower than the mean value (49 mg/dl) in the control population (p less than 0.001). Both the clinical and biochemical features of this cohort are typical of homozygous FH. The prevalence of homozygotes among French Canadians in Québec was approximately 1:275,000, and the minimum estimated frequency of heterozygotes was 1:270. In northeastern Québec, the frequency of homozygotes was approximately 1:100,000, and the minimum estimated frequency of heterozygotes was 1:154. Only Afrikaaners in South Africa have correspondingly higher frequencies.

Adolescent↗
PubMedDate not supplied

Cytologic findings in stilbestrol exposed females with emphasis on detection of vaginal adenosis.

This prospective study of 271 females believed to have had prenatal exposure to stilbestrol documents the cytologic findings in separate vaginal and cervical preparations. In 233 patients, direct circumferential scrapings of the upper vaginal wall were taken after potentially contaminating mucous secretions had been removed. These specimens were considered evaluable for the cytologic detection of vaginal adenosis. Cellular evidence of vaginal adenosis was observed in 105 (45%) of these patients as determined by the identification of columnar cells and/or metaplastic squamous cells in the vaginal samples. Columnar cells were observed in 87 (37%) of the 233 patients. Metaplastic squamous cells accompanied the columnar cells in 54 cases. In an additional 18 patients (8%) metaplastic squamous cells were the only cytologic evidence of adenosis. Similar cellular changes were observed in 88 per cent of the vaginal samples from 25 patients with biopsy-proven vaginal adenosis. Malignant cells were not found in any of the cytologic or histologic specimens. Dysplastic squamous cells, however, were present in cytosmears from four patients. Biopsies from two of these patients confirmed the diagnosis of squamous dysplasia. Dysplasia also was identified by biopsy in four others. We believe cytology is a valuable aid in the evaluation of patients with a history of intrauterine exposure to stilbestrol. Vaginal adenosis as well as neoplastic and dysplastic lesions can be reflected in properly obtained cellular specimens.

Adolescent↗