Search PubMed⌕ Search

Biomedical subjects

S Sethi

Publications and source records attributed to S Sethi.

At least 91 records · Page 5Linked to original sources

VT2--a trainee's point of view.

A pilot scheme for a second year of vocational training started in January 1994 in the West Midlands region. The position involved working part time as an associate dental surgeon in an approved general dental practice and part time as a house officer rotating around the various departments at the Birmingham Dental Hospital. Throughout the year there were 15 days termed 'study days' when lectures and courses on topics requested by those involved were arranged. At the end of the year those involved in the scheme were eligible to take the DGDP examination. This paper outlines my own thoughts of the year.

Dental Clinics↗

Fish oil, atherogenesis, and thrombogenesis.

Marine fish consumption is known to reduce mortality from ischemic heart disease. The use of fish oil as a dietary supplement, however, is not universally recommended. In large doses, fish oil reduces plasma cholesterol and triacylglycerol but increases low density lipoprotein (LDL) levels and the potential for free radical generation and bleeding. Moderate marine fish consumption is known to reduce mortality without altering commonly measured variables, i.e., plasma cholesterol levels, in vitro platelet aggregation, and bleeding times. In swine, we observed that monocyte adhesions and platelet clumps over the lesion surface of proximal left anterior descending (LAD) coronary arteries are markedly reduced when an atherogenic diet was supplemented with cod-liver oil, even when the cholesterol levels were equalized with the untreated group. These findings suggest that fish oil is hypothrombogenic. We developed an in vitro assay to delineate the mechanism whereby fish oil reduced monocyte-endothelial cell interactions in vivo. The effects of supplementing the culture medium with different fatty acids on adhesions between lipopolysaccharide (LPS) stimulated swine aortic endothelial cells (SAEC) and the human monocyte-like cell line, U937, was investigated in a 10 minute adhesion assay at 37 degrees C. Exposure of SAEC for 6 hours to media containing 50-200 microMs eicosapentaenoic (EPA), stearic, oleic, linoleic, and arachidonic acid, respectively, revealed that only EPA reduced U937-SAEC adhesion. Exposure of U937 to EPA also reduced adhesions. EPA was not effective when added to the SAEC more than 2 hours after they were stimulated with LPS. Exposure of human umbilical vein endothelial cells (HUVEC) to EPA reduced the expression of VCAM-1, ELAM-1, and ICAM-1 after 5 hours of stimulation with LPS. These results suggest that EPA may functionally impair the induction/expression of adhesion molecules.

Animals↗

Outer membrane protein CD of Branhamella catarrhalis: sequence conservation in strains recovered from the human respiratory tract.

Branhamella catarrhalis causes lower respiratory tract infections in patients with chronic obstructive pulmonary disease. The outer membrane protein CD (OMP-CD) of B. catarrhalis is a major, heat-modifiable OMP. The goals of this study are to characterize the degree of conservation of OMP-CD among strains and to investigate if OMP-CD maintains its homogeneity under the effect of host immune selective pressure. Isolates of B. catarrhalis were collected prospectively from patients with bronchiectasis and chronic bronchitis. We studied the OMP-CD gene by analysis of PCR restriction fragment length polymorphisms (PCR-RFLP) and further determined DNA sequence of the CD gene of eight selected isolates. Five patterns of PCR-RFLP of the OMP-CD gene were observed among all isolates when the gene was digested with Sau3AI. The sequence analysis revealed a high degree of homogeneity in OMP-CD among strains of B. catarrhalis. Three regions of OMP-CD with minimal sequence heterogeneity were identified. The sequences of the OMP-CD gene of isolates collected from patients colonized with the same strain for up to 6 months was identical. These observations establish that the OMP-CD of B. catarrhalis recovered from clinical isolates is highly conserved among strains.

Bacterial Outer Membrane Proteins↗

The dialectic in becoming a mother: experiencing a postpartum phenomenon.

In this study of the phenomenon of the postpartum period grounded theory methodology was used to investigate the experiences of first-time mothers during the first three months following their deliveries. The sample consisted of 12 primipara women and 3 multipara women. The data were generated by using unstructured interviews and field notes. Each woman was interviewed twice, the first time between 2 and 3 weeks postpartum, and the second time between 10 and 12 weeks postpartum. The final data for analysis consisted of: data generated through interviews, field notes, and the narratives of four mothers found in the non-fiction literature. Constant comparative analysis resulted in the generation of four categories and corresponding subcategories. These were: (1) Giving of Self; (2) Redefining Self; (3) Redefining Relationships; and (4) Redefining Professional Goals. The categories were not mutually exclusive. All the categories converged to provide support for the core variable 'Dialectic in Becoming a Mother'. The dialectic perspective demonstrated that, in becoming mothers, the women experienced transition, contradictions, tensions and transformations. A theoretical model was developed to show relationships among these major concepts. The findings of this study will be useful in effecting change in the provision of care to postpartum women and their families.

Female↗

Serum antibodies to outer membrane proteins (OMPs) of Moraxella (Branhamella) catarrhalis in patients with bronchiectasis: identification of OMP B1 as an important antigen.

Moraxella (Branhamella) catarrhalis is a common cause of lower respiratory tract infections in adults and of otitis media in children. Little is known about the human immune response to this bacterium. In this study, immunoblot assays were performed to detect serum immunoglobulin G antibodies directed at purified outer membrane of M. catarrhalis. Twelve serum samples, two each from six patients with bronchiectasis who were persistently colonized with this organism, were tested with their homologous M. catarrhalis sputum isolates. In all the sera, the most prominent and consistent antibody response was to a minor 84-kDa outer membrane protein, OMP B1. Immunoblot adsorption assays show that these antibodies recognize surface exposed epitopes on OMP B1. Further analysis of human serum antibodies eluted from the surface of intact bacterial cells shows that these surface-exposed epitopes on OMP B1 are heterogeneous among strains of M. catarrhalis. OMP B1 is therefore an important OMP antigen on the surface of M. catarrhalis for the human immune response to infection by this bacterium.

Adult↗

Postprandial lipid and hormone responses to meals of varying fat contents: modulatory role of lipoprotein lipase?

OBJECTIVE: Substrate and hormone responses to meals of differing fat content were evaluated in normal subjects in order to investigate mechanisms underlying the regulation of postprandial lipoprotein concentration. DESIGN: A randomised cross-over study with three different meals on three occasions. SETTING: Free-living subjects associated with Surrey University. SUBJECTS: Ten male volunteers (aged 18-23 years) were recruited. INTERVENTIONS: Three test meals containing 20, 40 or 80 g fat but identical carbohydrate and protein content were randomly allocated to volunteers. MAJOR OUTCOME MEASURES: Pre- and postprandial blood samples were taken for the analysis of plasma triacylglycerol, non-esterified fatty acids, glucose, immunoreactive insulin and glucose-dependent insulinotrophic polypeptide levels and postheparin lipoprotein lipase activity measurements. RESULTS: Peak triacylglycerol concentrations and lipoprotein lipase activity measurements were significantly higher following the 80 g than the 20 g fat meal (P = 0.009 and P = 0.049 respectively). Areas under the glucose-dependent insulinotrophic polypeptide time-response concentration curves were significantly higher following the 80 g compared with the 20 g fat meal (P = 0.04), but no differences in insulin response to the meals were seen. The 30-360 min decrease in the non-esterified fatty acid concentration was less following the 80 g than the 20 g meal (P = 0.001). CONCLUSIONS: The results suggest that glucose-dependent insulinotrophic polypeptide may mediate increased lipoprotein lipase activity in response to fat-containing meals and may play a role in circulating lipoprotein homeostasis. This mechanism may be overloaded with high fat meals with adverse consequences on circulating triacylglycerol and NEFA concentrations.

Adolescent↗

Sudden spurt of cryptococcosis at a tertiary care hospital at New Delhi between December 1994 to February 1995.

In a short span of three months, nine patients of cryptococcal infection were diagnosed at the All India Institute of Medical Sciences (AIIMS), New Delhi with varied clinical presentation. Predisposing factors could be ascertained in two patients only. The diagnosis was based on the direct demonstration of the organism followed by successful culture supported by histopathology (in one patient) and radiology. The specific antigen was also detected in the body fluids. The increased awareness and greater suspicion helped in the diagnosis of these patients. Those who were diagnosed early, responded well with specific antifungal therapy.

Adolescent↗

Erythrocyte T-activation: clinical importance & recognition by a simple routine technique.

Erythrocyte T-activation is reported in association with bacterial infections. Although it is an unfrequent phenomenon, it has been reported in cases of septicaemia and necrotizing enterocolitis. It is important to recognize these cases as, transfusion of blood & blood products and lead to haemolytic--transfusion reactions. Here we report a case of T-activation detected during routine immunohaematological procedure in the blood transfusion laboratory. This also emphasizes the role of a routine, cost-effective test to diagnose cases of T-activation.

Antigens, Tumor-Associated, Carbohydrate↗

PMLRAR homodimers: distinct DNA binding properties and heteromeric interactions with RXR.

Fusion proteins (named PMLRAR) between PML and the retinoic acid receptor alpha (RAR alpha) are generated as a result of the t(15;17) chromosomal translocation found in acute promyelocytic leukemia (APL). We show here that PMLRAR proteins exist in solution as stable homodimers whose formation is mediated by a presumptive coiled coil in the PML moiety. In contrast to RAR alpha, which requires heterodimerization with RXR for efficient DNA binding, PMLRAR homodimers can bind to target sequences in the absence of RXR, and the binding pattern of PMLRAR homodimeric complexes to directly repeated motif (DR) response elements with 1-5 bp spacers is different from that of RAR/RXR heterodimeric complexes. We show that the presence of RXR induces the formation of PMLRAR/RXR heteromeric complexes which bind to DNA via one RAR DNA binding domain (DBD) and one RXR DBD, like 'classical' RAR/RXR heterodimers. PMLRAR interaction with RXR occurs in solution and in transfected cultured Cos cells, and PMLRAR is able to sequester RXR efficiently in the cytoplasm, suggesting that dominant 'inactivation' of RXR may be a possible mechanism of action for PMLRAR. Accordingly, we show that PMLRAR can both prevent the binding of the vitamin D3 receptor (VDR) to a target sequence in vitro and inhibit vitamin D3-dependent activation of a VDR-responsive reporter gene in transfected cells. These results suggest that both the distinct DNA binding properties of PMLRAR homodimers and the sequestration of RXR by PMLRARs may contribute to the molecular mechanisms which underlie the pathogenesis of APL. We also report that RXR alpha transcripts are down-regulated by RA-treatment in promyelocytic cells.

Amino Acid Sequence↗

Allograft in the treatment of benign cystic lesions of bone.

Seventeen patients with benign cystic osseous lesions were treated by curettage and grafting using allogenic decalcified bone. Human bones were partially decalcified using 0.6 N HCl and preserved in 90% ethanol in a deep freezer at -16 degrees C. The cystic lesions were: 5 cases of fibrous dysplasia, 4 aneurysmal bone cysts, 3 simple bone cysts, 2 giant-cell tumours, 1 chondromyxoid fibroma, 1 non-ossifying fibroma and 1 fibrous cortical defect. The bones involved were: femur, tibia, humerus, fibula and calcaneum. Infection was a complication in three patients. In two of these it did not interfere with healing, but in one it persisted for more than 1 year with partial resorption of the graft. The time to adequate incorporation of the graft varied from 6 to 9 months in children and 9 to 15 months in adults. The overall response compares favourably with that to allograft from more sophisticated bone banks.

Adolescent↗

Role of copper in Indian childhood cirrhosis.

One hundred and twenty cases of Indian childhood cirrhosis (ICC) were studied. Most of the children presented in the clinical and histological grade II of the disease. Serum copper values in 32 prospective patients were significantly raised in comparison with values in normal controls. Hepatic copper content estimated in 82 liver biopsies revealed an increase in hepatic copper content showing a significant correlation with the histological grade of the disease. All cases were breastfed. Use of brass utensils to boil or store milk fed to ICC children was not seen in 46% of cases, although their serum copper values were raised. Serum and hepatic copper is raised in ICC. Dietary copper as a source of this raised copper seems unlikely. The most probable cause could be a defect in the metabolism of copper in ICC patients.

Biopsy↗

Phenomenology of mania in eastern India.

One hundred consecutively hospitalized cases fulfilling DSM-III-R criteria for bipolar disorder, manic type, were studied by using the Hindi version of the Present State Examination. There was a preponderance of young male patients. Almost all cases showed expansive mood, subjective ideomotor pressure and grandiose delusions. Flight of ideas was rarely seen. Delusions of reference and persecution were very common and so were religious and sexual delusions. The findings are discussed in the light of cultural factors.

Adolescent↗

Anaphylactoid transfusion reaction with anti-IgA antibodies in an IgA deficient patient: a case report.

A case of anaphylactoid transfusion reaction associated with anti-IgA antibodies is reported. The patient had low levels of serum IgA. She developed serious reaction characterised by erythematous rash, pruritus, cyanosis and dyspnoea after transfusion of otherwise compatible blood. Review of literature reveals that anaphylactoid transfusion reactions are very rare although frequency of anti-IgA in general population is quite high. The IgA deficient donors (aIgA) form a unique resource of blood components for the clinical management of patients with anaphylactoid reactions caused by anti-IgA.

Adult↗