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Biomedical subjects

A Goyal

Publications and source records attributed to A Goyal.

At least 19 recordsLinked to original sources
PubMed1995

A component of the chloroplastic protein import apparatus is targeted to the outer envelope membrane via a novel pathway.

A chloroplastic outer envelope membrane protein of 75 kDa (OEP75) was identified previously as a component of the protein import machinery. Here we provide additional evidence that OEP75 is a component of protein import, present the isolation of a cDNA clone encoding this protein, briefly describe its developmental expression and tissue specificity, and characterize its insertion into the outer envelope membrane. OEP75 was synthesized as a higher molecular weight precursor (prOEP75) which bound to isolated chloroplasts in an in vitro import assay and subsequently was processed to the mature form (mOEP75). During this import assay, two proteins intermediate in size between prOEP75 and mOEP75 were detected. One of these intermediates was also detected in chloroplast envelopes isolated from young pea leaves. Binding and processing of prOEP75 required ATP and one or more surface-exposed proteinaceous components, and was competed by prSSU, a stromal-targeted protein. We propose that the N-terminus of the prOEP75 transit peptide acts as a stromal-targeting domain and a central, hydrophobic region of this transit peptide acts as a stop-transfer domain. A complex route of insertion and processing of prOEP75 may exist to ensure high fidelity targeting of this import component.

Adenosine Triphosphate↗
PubMed1995

Inactivation of Leuconostoc mesenteroids NRRL B-512F dextransucrase by specific modification of lysine residues with pyridoxal-5'-phosphate.

Dextransucrase from Leuconostoc mesenteroides NRRL B-512F was inactivated by pyridoxal-5'-phosphate (PLP). The inactivation was reversible in as much as the loss of enzyme activity was completely reversed by prolonged dialysis. PLP-modified dextransucrase after reduction with sodium borohydride showed a characteristic fluorescence emission maximum at 397 nm when excited at 325 nm. The stoichiometric results indicated that four lysine residues are modified by PLP under the experimental conditions. These results established for the first time that lysine residues are essential for the activity of dextransucrase.

Binding Sites↗
PubMed1995

Involvement of a lysine residue in the inactivation of Leuconostoc mesenteroides NRRL B-512F dextransucrase by o-phthalaldehyde.

Leuconostoc mesenteroides NRRL B-512F dextransucrase was rapidly and irreversibly inactivated by o-phthalaldehyde. The dextransucrase-o-phthalaldehyde adduct showed a characteristic fluorescence maxima at 417 nm when excited at 337 nm. These results were consistent with the isoindole derivative formation in which the sulfhydryl group of cysteine and epsilon-amino group of lysine participate in the reaction. The stoichiometric determinations gave one isoindole derivative per enzyme molecule upon complete inactivation by o-phthalaldehyde. The enzyme showed no inhibition on treatment with thiol specific reagents. This indicated that cysteine is present in close proximity of the lysine and is involved in the isoindole derivative formation but is not participating in the catalysis. These results established for the first time that one lysine residue present at the active site is required for the activity of dextransucrase.

Enzyme Repression↗
PubMed1995

2,4,6-Trinitrobenzenesulphonic acid as a probe for lysine at the active site of dextransucrase from Leuconostoc mesenteroides NRRL B-512F.

Modification of Leuconostoc mesenteroides NRRL B-512F dextransucrase with 2,4,6-trinitrobenzenesulphonic acid (TNBS) at pH 5.2 and 30 degrees C resulted in the loss of enzyme activity. The kinetic profiles of inactivation showed that the reaction followed pseudo-first order reaction. Absorption spectra of TNBS modified enzyme gave characteristic maxima at 367 nm. The inactivation could not be reversed by dilution or dialysis. The substrate sucrose, provided protection to the enzyme against inactivation by TNBS, indicating that the essential residues are present at or near the active site. The stoichiometric results indicated that four mol of lysine are modified per mol of dextransucrase upon complete inactivation. However, more than 50% of the activity loss was accompanied by modification of 1 lysine residue. All these approaches suggested that one lysine residue present near or at the active site is essential for the enzymatic activity of dextransucrase.

Binding Sites↗
PubMed1995

Congenital cytomegalovirus infection in Shimla Hills, Himachal Pradesh, India.

We came across some cases clinically suggestive of intrauterine infection which were confirmed to be congenital cytomegalovirus infection. A clinical profile of these patients is presented. Intracranial calcification was not seen in any of these patients. Mental retardation was profound in all the patients and all had hepatomegaly. Uncommon findings encountered included hydrocephalus, patent ductus arteriosus and corneal opacities. Other clinical findings and investigation are also discussed.

Altitude↗
PubMed1995

Prevalence, group pattern, T pattern and seasonal variation of beta haemolytic streptococci in and around Shimla.

One hundred and seventy two strains of beta haemolytic streptococci were isolated from various clinical specimens over a period of one year. Group A was isolated in 69.70% and group C in 16.80 percent. Majority of the strains were isolated during winter season and only 21.00 percent in summer 93.30 percent strains were bacitracin sensitive and all were sensitive to penicillin. The most common T pattern among group A was found to be 5/11/12/27/44 followed by 3/13/B 3264.

Adolescent↗
PubMed1994

Five-year follow-up of microsurgical multiple internal thoracic artery grafts.

In a consecutive series of 143 patients requiring multiple coronary artery bypass grafts, 317 of 441 anastomoses (72%) were constructed from internal thoracic arteries. Of these 143 patients, 103 had bilateral, 51 sequential, and 49 free internal thoracic artery grafts. When compared with an earlier series of 494 patients who underwent only one internal thoracic artery anastomosis, the surgical morbidity and mortality were not increased, but, during 5 years of follow-up, the incidences of postoperative angina and myocardial infarction were found to decrease significantly--32.5% versus 10.5% (p < 0.001) and 5.7% versus 1.4% (p < 0.03), respectively. We conclude that, for patients with multivessel disease, multiple internal thoracic artery grafts confer better protection from the clinical manifestations of ischemic heart disease than does one internal thoracic artery graft. The use of high magnification (8 to 12x, surgical microscope) was essential to the success of this method.

Coronary Disease↗
PubMed1994

Relevance of platelet serotonergic mechanisms in pregnancy induced hypertension.

Platelet functions are becoming the useful tool for delineating the etiology of pregnancy induced hypertension. Electronmicroscopic studies, efflux and content of 5-HT in platelets and platelet aggregation responses towards various aggregating agents have been measured in 25 normotensive pregnant subjects and 31 PIH subjects. Marked decrease changes have been noted in aggregation parameters with transformation from discoid to "spiny sphere" of platelets with long pseudopods along with prolonged time for spontaneous aggregation by platelets in PIH. Serotonin release from platelets was decreased and reserpine-induced release-reaction showed enhanced kinetics in PIH. Platelet serotonin content was raised and was inversely related to platelet count with severity of syndrome. Hence, a check and balance for platelet activation and aggregation in PIH might be crucial in the development of PIH.

Adolescent↗
PubMed1994

Severe upper gastrointestinal bleeding in healthy full-term neonates.

Severe upper gastrointestinal bleeding is unusual in newborns, and is usually seen in sick premature infants. We report on three healthy full-term neonates who, after uneventful deliveries, presented with profuse bleeding in the first 48 h of life. Two infants had duodenal ulcers and one had diffuse hemorrhagic gastritis. All three patients responded to conservative medical therapy and have shown no recurrence of symptoms during a follow-up period of 1-4 yr.

Duodenal Ulcer↗
PubMed1992

Evaluation of KAP of oral hygiene measures following oral health education through existing health and educational infrastructure.

This study is a part of a larger preventive oral health feasibility module embarked on a population of 120,000 of Raipurrani, district Ambala (Haryana). The KAP analysis of about 2000 individuals (including school children) on cross-sectional basis at baseline, one and two years after the implementation of knowledge about oral health measures to the community utilizing the existing health infrastructure at CHC, the Anganwadi workers (ICDS Scheme) and through school teachers in the schools revealed that at baseline datun was the most prevalent (63%) oral hygiene measure used in the community and students. After implementation, the practice of brushing thrice, twice and once daily increased but the most prevalent frequency remained once a day (39% out of 66 percent using brush in community and 37% out of 76 percent in students after 2 and 11/2 years of implementation respectively) followed by twice a day (23 & 31% respectively). A similar pattern of frequency was observed about datun users also, though the number using datun substantially declined from 62% to 33% in community and 63 to 23% in students after implementation.

Adolescent↗
PubMed1991

Seroprevalence of HIV antibodies, Australia antigen and VDRL reactivity in Himachal Pradesh.

3000 subjects from four high risk groups--patients attending STD clinics, hospital personnel, blood donors and foreign nationals were screened for the presence of HIV antibodies HBsAg and VDRL reactivity. No evidence of HIV infection was found in Himachiali population. However, there of the 150 foreign nationals screened were found positive for HIV antibodies. Overall HBsAg positivity and VDRL reactivity was found to be 5.53 per cent and 9.07 per cent respectively. The importance of circumspected and unswerving machinery for the surveillance of HIV antibodies in the high risk population of the state is emphasised.

Adult↗
PubMed1991

Evaluation of existing status of knowledge, practice and attitude towards oral health of rural communities of Haryana--India.

The KAP survey on oral health practices of 3247 individuals, 6-60 years of age, of Sidhaura block of Haryana revealed that use of dattan was more prevalent (56% in adult community & 49% students) than tooth brush (35% adult community & 34% students). 37% of the total community had the knowledge of brush being the best oral hygiene measure. 25% of the community using brush were brushing only once/day. The knowledge of the community regarding the role of fluorides in prevention of dental caries was completely lacking: 1.8% of the community was using fluoride dentifrice. 35-45 percent of the community were practising sweet foods/drinks etc. four times a day. The snyder test showed a positive relation with frequency of sugar intake.

Adolescent↗
PubMed1991

Seroprevalence of HIV infection in Himachal Pradesh.

Serum samples from 2645 individuals representing all the twelve districts of Himachal Pradesh were screened for antibodies to Human immunodeficiency virus (HIV), employing ELISA test. These were categorised into four major high risk groups, viz, patients attending STD clinics (1305), voluntary blood donors (1012), hospital staff dealing with blood and blood products (200) and foreign nationals (128). No evidence of HIV infection was found in Himachali population. Two foreign nationals were repeatedly found positive for HIV antibodies by ELISA test and these were confirmed by Western Blot technique.

Adult↗
PubMed1991

Unsuspected mitral stenosis.

PURPOSE AND PATIENTS AND METHODS: We observed a series of patients in whom the diagnosis of mitral stenosis was first discovered in the echocardiography laboratory. Because of this experience, we examined the records of 152 patients with echocardiographic evidence of rheumatic mitral stenosis to determine the clinical characteristics and course of patients with unsuspected mitral stenosis as well as those factors that may have obscured the diagnosis. RESULTS: Of these 152 patients, 18 had mitral stenosis that was unsuspected clinically until the echocardiogram. These patients were elderly, with a median age of 72 years. They were all referred for echocardiography because of cardiac symptoms. Eight patients were referred for evaluation of congestive heart failure. Five patients were referred for evaluation of aortic valve disease. Three patients were referred because of cerebrovascular accidents and atrial fibrillation. The Doppler-determined mean diastolic mitral gradient ranged from 4 to 15 mm Hg (mean: 7 mm Hg). Mitral stenosis ranged in severity from trivial to very severe. Eight patients had moderate to severe mitral stenosis with estimated mitral valve areas less than or equal to 1.5 cm2. Seven had mild or trivial mitral stenosis with estimated mitral valve areas greater than 1.5 cm2. After further evaluation, two patients underwent mitral valve surgery with improvement of congestive failure. In three patients, warfarin therapy was begun to prevent emboli. Thus, five of 18 patients had a significant immediate change in therapy because of the discovery of mitral stenosis. CONCLUSION: The diagnosis of mitral stenosis may not be suspected in the presence of advanced age, other serious cardiac and medical conditions, or mechanical factors that complicate the physical examination. In these patients, mitral stenosis may be hemodynamically significant and may cause significant symptoms.

Adult↗
PubMed1991

Plaque pH modulations of children's favourite snacks.

Cariogenic potential of a few children's favourite snacks, assessed by evaluation of pH modulations on their respective consumption after 2,5,10,20,30 and 40 minutes compared to 10 percent sucrose control using pooled plaque method, in 8-12 years old children revealed lollipop (hard sucking candy) to be the most cariogenic and samosa without chutney to be the least cariogenic. The cariogenic potential of ice creams were similar, however, low as compared to sucrose solution of 10 percent.

Candy↗