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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 685 records · Page 38Linked to original sources
PubMed1997

Immunoreactivity of mycobacterial 70 kDa protein in different physico-chemical forms.

The immunoreactivity of 70 kDa culture filtrate protein of Mycobacterium tuberculosis H37 Ra has been examined as such and by increasing its hydrophobicity through its conjugation to stearic acid ester (70 kDa-FAester). The cell mediated immune responses produced by 70 kDa-FAester encapsulated in phosphatidylcholine (PC) liposomes were significantly higher particularly at the 3rd week post immunization (wk p. im.) than that produced by the 70 kDa protein in PC liposomes, whereas humoral immune responses were non-significant. Further, these immune responses were comparable to that elicited by 70 kDa protein complexed with Freund's incomplete adjuvant (70 kDa-FIA). Results of this study suggest that changes in physicochemical nature of 70 kDa protein influences both the humoral and cellular immunoreactivity.

Adjuvants, Immunologic↗
PubMed1997

Haemostatic function in coronary artery disease (CAD).

Tests to evaluate haemostatic function bleeding time (BT), prothrombin time (PT) partial thromboplastin time with kaolin (PTTK), thrombin time (TT), platelet count, platelet function tests (platelet adhesiveness and microthrombus index) and plasma fibrinogen levels were performed in 30 patients of coronary artery disease (14 myocardial infarction, 16 angina pectoris) and 20 age and sex matched controls. There was no statistically significant difference in platelet adhesiveness and mean microthrombus index in patients and controls. The BT, PT, PTTK and TT were normal in all patients and controls. Stepwise logistic regression analysis showed that plasma fibrinogen was an independent risk factor in the production of CAD.

Adult↗
PubMed1997

Human papillomavirus type in anal epithelial lesions is influenced by human immunodeficiency virus.

BACKGROUND AND OBJECTIVE: Infection with human immunodeficiency virus (HIV) increases the risk for human papillomavirus (HPV)-associated genital neoplasia. Human immunodeficiency virus-infected patients also have higher rates of treatment failure and more rapid neoplastic progression. Impaired immune function does not entirely explain these clinical observations. This pilot project was designed to investigate the hypothesis that HIV infection is associated with changes in HPV type and integration within anogenital lesions that could explain the increased risk of neoplastic progression. METHODS: Anal neoplastic lesions from patients with and without HIV infection were analyzed for the presence, type, and integration status of HPV by colorimetric in situ hybridization. Tissue localization of HIV was evaluated by p24 immunohistochemistry and HIV-1 DNA polymerase chain reaction. Results for matched histology were compared for the two patient groups. RESULTS: For all lesions, the presence of high-risk HPV types and multiple HPV types was strongly associated with HIV infection (P = .003 and .0003, respectively). For lesions with matched histology there was no association of HPV integration with HIV status. Tissue localization of HIV did not significantly influence HPV type or integration. CONCLUSIONS: The presence of high-risk HPV types and multiple types within low-grade lesions may explain the increased risk of neoplastic progression in HIV patients. Colocalization of HIV and HPV does not appear to be required for this effect. There is no evidence that HPV integration is influenced by HIV infection.

Adolescent↗
PubMed1997

Novel putative protective antigens of Plasmodium falciparum.

In an attempt to identify putative host-protective antigens of the human malarial parasite P. falciparum, a differential immunoscreen of a cDNA expression library of the parasite was performed using malaria immune and patient sera. Eight expression clones were identified which showed no reactivity with acute patient sera but reacted extensively with malaria immune sera. Southern Blot analysis of five of these genes showed that these were coded by unique single genes, and sequence of the cDNA inserts showed that these were as yet unidentified genes of P. falciparum. The clone which was reactive to the largest number of immune sera, has been shown to be the ribosomal phosphoprotein, P0, of P. falciparum. The presence of multiple transcripts and a differential expression of the transcripts of P0 in different erythrocytic substages of the parasite was observed. An extensive characterisation using antibodies to the P0 protein has been performed. The results show that in addition to its role in the ribosomal assembly, the P0 protein is also localized on the parasite surface, and plays an important role in the red blood cell invasion. Most of the other differential cDNA clones were found to be rare transcripts, and the expression domains were not very immunogenic. PCR analysis of three of these genes demonstrated that these are conserved throughout the Plasmodium species. These protein domains, therefore, constitute potential protective target epitopes of the malarial parasite.

Animals↗
PubMed1997

Role of low dose aspirin in prevention of pregnancy induced hypertension.

In a prospective randomised clinical study 50 primi or multigravidae with history of essential hypertension or pregnancy induced hypertension (PIH) in previous pregnancy were selected from antenatal clinics, on the basis of positive roll over test (ROT) carried out between 28 to 30 weeks of pregnancy. The study group comprised 25 women who received 50 mg aspirin daily from day of positive ROT till 37 weeks of pregnancy. Other 25 women served as control. The incidence of PIH in study and control group was 4% versus 28% and that of pre-term birth was 4% versus 24%. The mean birth weight of newborns in the two groups was 3.04 +/- 0.38 kg and 2.71 +/- 0.48 kg respectively. All these differences were statistically significant. No adverse maternal or neonatal complication due to aspirin was observed.

Adult↗
PubMed1997

Nutritional status of the elderly.

Elderly become vulnerable to malnutrition owing to inappropriate dietary intake, poor economic status and social deprivation. Elderly are known to be easily subjected to inanition and avitaminosis resulting in multiple nutritional deficiencies. Urban slum dwellers, rural poor and those living alone appear to be at a higher risk of poor dietary intake. Though food consumption patterns of rural and urban elderly show a distinct difference, these are greatly influenced by regional dietary patterns. The diets of institutionalised and free living elderly reveal adequate nutrient intakes except iron and vitamin A. The nutrients least adequately supplied in the diets of Indian elderly are calcium, Iron, vitamin A, riboflavin and niacin along with energy deficits. Changes in body composition which mark the onset of the ageing process, include decline in lean body mass and increase in adipose tissue. A high prevalence of iron deficiency anaemia has also been reported among Indian elderly.

Aged↗
PubMed1997

Interobserver agreement in the evaluation of acute retinal artery occlusion.

OBJECTIVE: To determine the agreement between two ophthalmologists in the evaluation of two important funduscopic features related to acute retinal artery occlusion: retinal cloudy swelling and visible retinal emboli. DESIGN: An interobserver variability study in which two ophthalmologists (one trained in glaucoma, the other in neuro-ophthalmology) independently viewed fundus photographs and categorized them with respect to the presence or absence of cloudy swelling and retinal emboli. Inter- and intraobserver agreement was calculated with the kappa statistic. SETTING: Retina service at a university-affiliated hospital in Kingston, Ont. PATIENTS: The fundus photographs of 102 patients were included: 60 with acute retinal artery occlusion, 30 with conditions mimicking acute retinal artery occlusion and 12 healthy patients. RESULTS: Both interobserver and intraobserver agreement as to the presence of retinal cloudy swelling were very high (kappa = 0.835 and 0.866 respectively). More variability was seen for the presence of retinal emboli, but, overall, interobserver and intraobserver agreement were still high (kappa = 0.726 and 0.629 respectively). CONCLUSIONS: Our results suggest that clinicians use similar visual clues to categorize fundi with respect to retinal cloudy swelling and visible retinal emboli.

Acute Disease↗
PubMed1997

ESR and iron status in pregnancy.

ESR (Westergen) correlated significantly with the iron status (as measured by Hb concentration, haematocrit, red cell count, MCH, P/H ratio, serum iron, TIBC and percent saturation of transferrin) in a group of pregnant women (PW) at term. Serum ferritin correlated negatively with the ESR but the correlation was not statistically significant. Serum ferritin levels of < 50 micrograms/L were present in 9 (34.6%) PW with ESR > or = 50 mm 1st hour and 5 (19.2%) PW with ESR < 50 mm 1st hour. The mean ESR in PW was 55.7 (+/- 22.9) and was > or = 50 mm 1st hour in 50% and < 75 mm 1st hour in 82.7%. The difference in the mean ESR in anaemic and nonanaemic PW was highly significant (p < 0.001), 87.5% anaemic PW with serum ferritin > 50 micrograms/L had ESR > or = 50 mm 1st hour, suggesting the possible effect of chronic infection in raising ferritin levels in these PW.

Blood Sedimentation↗
PubMed1997

An update on eicosanoids and inhibitors of cyclooxygenase enzyme systems.

There are 3 main enzymatic pathways for synthesis of eicosanoids from arachidonic acid, however, some compounds are also formed non-enzymatically. Among the enzymatic pathways, cyclooxygenase (COX) also known as prostaglandin synthase (PGHS), generates endoperoxides (PGG/H). These are converted into prostaglandins (PGs) and thromboxanes (TXs). The second pathway involves lipooxygenase (LOX) group of enzymes to provide hydroperoxyeicosatetraenoic acid (HpETEs) which in turn can be converted into leukotrienes (LTs), hepoxilins (HXs), trioxilins and lipoxins (LXs). The third pathway involves cytochrome P-450 which catalyses the formation of a number of monohydroxy fatty acids (hydroxyeicostetraenoic acids or HETEs) dihydroxy fatty acids (dihydroxyeicostetrienoic acids or DiHETrEs) and epoxyeicosatrienoic acids (EpETrEs: formerly called EETs). This system also provides leukotoxins. The non-enzymatic pathway leads to the formation of isoprostanes by free radical catalysed peroxidation of arachidonic acid. In addition, brain cells also convert arachidonic acid into arachidonylethanolamide (anandamide) which have the ability to bind to cannabinoid receptors. Most of these eicosanoids are either biologically active or are converted into metabolites which have biological activities. Cyclooxygenase is now known to exist in two separate isoforms which are called COX-1 and COX-2. While both isoforms catalyse the same reactions, the former is a constitutive enzyme and its activity is not markedly changed once the cell is fully grown. The later isoform is however inducible and its activity is several fold increased following the exposure of body cells to a number of stimuli and its contribution in the process of inflammation is now well documented. It is now believed that eicosanoids produced by COX-1 activity are essential for the physiological (house keeping) functions while those produced by COX-2 lead to various pathological changes in body tissues. Older nonsteroidal antiinflammatory drugs like aspirin and indomethacin are non selective inhibitors of COX activity and therefore, in addition to inhibiting COX-2 activity, inhibit the formation of eicosanoids by COX-1. The later are required for normal house keeping functions such as secretion of mucus for protection of gastrointestinal mucosa, maintenance of renal function and control of haemostasis. Use of older non-selective NSAIDs has been associated with a number of gastrointestinal, renal and other side effects. Recently drugs such as nimesulide and meloxicam with selective action on COX-2 have been discovered and introduced into medicine. Evidence available so far has indicated the low incidence of side effects with these drugs. While being useful for various arthritic and other conditions, it is unlikely that these drugs will replace aspirin for the cardiovascular disease.

Animals↗