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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 919 records · Page 51Linked to original sources

Molecular basis for the development of individual differences in the hypothalamic-pituitary-adrenal stress response.

1. Several years ago, investigators described the effects of infantile handling on the development of hypothalamic-pituitary-adrenal (HPA) responses to stress in the rat. Rat pups exposed to brief periods of innocuous handling early in life showed reduced HPA responses to a wide variety of stressors, and the effect persists throughout the life of the animal. These effects are robust and provide an excellent model for understanding how early environmental stimuli, which are external to the organism, alter neural differentiation and, thus, neuroendocrine responsivity to stress. 2. This paper reviews the endocrine mechanisms affected by early handling and our current understanding of the neural transduction of environmental events and their effects at the level of the target neurons (in the hippocampus and frontal cortex). 3. In brief, handling serves to increase glucocorticoid receptor gene transcription, increasing sensitivity to glucocorticoid negative feedback regulation and, thus, altering the activity within hypothalamic corticotropin-releasing factor/vasopressin neurons. Together these changes serve to determine neuroendocrine responsivity to stress.

Adrenal Cortex↗

Studies on the development of high-protein biscuits from composite flours.

Composite flours prepared from wheat, greengram, bengalgram and blackgram flours were studied for the preparation of biscuits. Protein content of biscuits increased as the level of the pulse flours increased. Wheat flour containing bengalgram and blackgram flours adversely affected the top grain, texture and colour of biscuits. Biscuits made with higher levels of bengalgram (more than 15%) were tough and difficult to break and required higher compression force. Addition of greengram flour did not significantly affect top grain, texture and colour of biscuits. The biscuits made from 15% greengram supplemented wheat flour scored the highest for flavour characteristics. Thickness, diameter and spread ratio of biscuits containing different levels of pulse flours were significantly different from control sample. Sensory evaluation scores showed that acceptable biscuits can be prepared from wheat flour supplemented with these pulse flours at a level of 15 percent.

Carbohydrates↗

Storage changes in the quality of sound and sprouted flour.

Sound and sprouted flours (24 and 48 hr) from bread wheat (WL-1562), durum wheat (PBW-34) and triticale (TL-1210) were stored at room temperature (34.8 degrees C) and relative humidity (66.7%) for 0, 45, 90 and 135 days to assess the changes in physico-chemical and baking properties. Protein, gluten, sedimentation value, starch and crude fat decreased during storage in all the samples; however, the decrease was more in sprouted flours. Free amino acids, proteolytic activity, diastatic activity and damaged starch decreased with increase in storage period. Total sugars and free fatty acids increased more rapidly in the flours of sprouted wheats during 135 days of storage. Loaf volume of breads decreased during storage in both sound and sprouted flour but the mean percent decrease in loaf volume was more in stored sound flours. Aging of sprouted flour for 45 days improved the cookie and cake making properties but further storage was of no value for these baked products. Chapati making properties of stored sound and sprouted flour were inferior to that of fresh counterparts.

Bread↗

Role of sodium in antigen-induced contraction of tracheal smooth muscle in dogs.

We examined the role of Na+ influx in the airway response to antigen (ragweed pollen extract) in sensitized dogs, using amiloride analogs to block Na(+)-dependent processes. In in vivo studies, respiratory resistance was measured in amiloride treated and untreated groups. The resistance increased by 9.3 cmH2O.L-1.sec in response to ragweed aerosol in the untreated group, but increased only by 5.2 cmH2O.L-1.sec in the treated group. In in vitro studies, isometric tension was measured in ragweed pollen sensitized tracheal strips. Tissues were treated with amiloride or its derivatives (50 microM) for specifically blocking Na+ channels (phenamil), Na(+)-H+ exchanger [5-(N-methyl-N-guanidinocarbonyl methyl)-amiloride] or Na(+)-Ca2+ exchanger [5-(4-chlorobenzyl)-2',4'-dimethylbenzamil]. In untreated strips, tension increased in response to ragweed by 1.9 +/- 0.5 mN/mg. The increase was reduced by phenamil (95.2 +/- 2.5%; P < 0.01) and amiloride (41.7 +/- 13.1%; P < 0.01), but not by the other two agents. Furthermore, phenamil also inhibited histamine-induced tension response and histamine-induced 22Na+ uptake of the muscle. We conclude that antigen-induced airway response is attenuated by blocking Na+ influx in smooth muscle.

Amiloride↗

Balloon valvotomy for mitral restenosis after open or closed surgical commissurotomy.

Balloon mitral valvotomy was performed in 48 patients (Group I) with mitral restenosis following prior surgical commissurotomy 3-21 years previously. Their results were compared with those of balloon valvotomy in 302 patients without prior commissurotomy (Group II). The procedure was successful in 91.7% of Group I. The mitral valve area, cardiac output, mitral valve gradient, mean left atrial and pulmonary arterial pressures significantly improved following valvotomy (all P < 0.001) in Group I and similar results were obtained in Group II. A comparison of the absolute and percentage change in the mitral valve area following valvotomy amongst the two groups revealed no significant difference (P = N.S.). The baseline clinical characteristics in both the groups were similar except for a higher echocardiographic score (8.64 +/- 1.5 vs. 7 +/- 1.7; P < 0.005) in Group I. Despite the high echo score, achievement of an 'optimal' result and occurrence of postprocedural mitral regurgitation were similar in both groups. The complications included systemic embolus in one patient and increase in mitral regurgitation to > or = 2+ in 2. There were no deaths. Balloon valvotomy for mitral restenosis following surgical commissurotomy is safe, effective and produces clinical and hemodynamic results comparable to those in unoperated cases.

Adult↗

Non-specific aortoarteritis: long-term follow-up on immunosuppressive therapy.

Thirteen patients with non-specific aortoarteritis and endomyocardial biopsy evidence of myocarditis were followed-up on immunosuppressive therapy comprising of prednisolone and cyclophosphamide in addition to conventional treatment for hypertension and/or congestive heart failure. Serial determinations of erythrocyte sedimentation rate, chest roentgenogram, radionuclide ventriculogram and hemodynamic study including endomyocardial biopsy were carried out at 12, 24 and 52 weeks of therapy. Arterial lesions were also assessed by digital subtraction angiography at 0 and 52 weeks of immunosuppressive therapy. At the end of a year of treatment all patients with congestive heart failure (10/13) showed symptomatic improvement by at least one New York Heart Association (NYHA) class. There was a significant fall in erythrocyte sedimentation rate (48 +/- 12 mm/1st h to 31 +/- 12 mm/1st h, P < 0.05), pulmonary artery pressure (32 +/- 14 mmHg to 20 +/- 9 mmHg, P < 0.05), left ventricular filling pressure (20 +/- 11 mmHg to 11 +/- 7 mmHg, P < 0.05) and increase in left ventricle ejection fraction (39 +/- 16% to 51 +/- 14%, P < 0.05) associated with resolution of morphological changes on endomyocardial biopsy. Arterial lesions remained static with neither progression nor appearance of new lesions. No significant complications of therapy were noticed in any patient. Our uncontrolled observations suggest that immunosuppressive therapy is safe and results in clinical, hemodynamic and myocardial morphological improvement in a subset of patients with non-specific aortoarteritis and associated myocarditis.

Adolescent↗

Multifetal pregnancy reduction by transvaginal puncture: evaluation of the technique used in 134 cases.

OBJECTIVE: This report reviews multifetal pregnancy reductions performed transvaginally and tests the feasibility and associated pregnancy loss rates with this technique. STUDY DESIGN: One hundred thirty-four consecutive multifetal pregnancy reductions were analyzed regarding different aspects of total pregnancy losses and complications. The first 40 manually performed were compared with the last 94 procedures performed with an automated puncture device and a thin needle. The losses were also analyzed as a comparison of the reduction of the lower-lying with the higher-lying fetuses located in relation to the internal os. RESULTS: A total uncorrected total pregnancy loss rate of 12.6% and a corrected loss rate of 10.6% was observed. Of the 112 pregnancies in which the lower-lying fetus was reduced, 11 losses were seen. The loss rate in the group reducing the upper fetus was three of 22. The manual versus the puncture device groups showed the same loss rate (10%); however, the manual group had a larger number of subchorionic hematomas after the procedure. CONCLUSIONS: The data are indicative of a very low maternal complication rate (infection) and an acceptable loss rate of the entire pregnancy. The loss rates compare favorable with those for multifetal pregnancy reduction performed transabdominally.

Abortion, Induced↗

Clinical results of cryopreserved valved conduits in the pulmonary ventricle-to-pulmonary artery position.

Aortic valved homograft conduits (AVHC) have become valuable in the pulmonary ventricle (PV)-to-main pulmonary artery (MPA) reconstruction in congenital heart defects. Since 1985, 45 patients, ranging in age from 12 days to 32 years, underwent PV-to-MPA reconstruction utilizing cryopreserved AVHC. Operative deaths included seven patients (16%), six of whom died as a result of the complexity of their underlying heart defects. One late death (2%) occurred as a result of infective endocarditis 48 months after conduit placement. The 38 patients who survived the operation remained in the intensive care unit for a mean of 5.7 +/- 1.0 days (median: 4 days; range: 2 to 37 days). The mean hospital stay was 13.0 +/- 1.8 days (median: 9 days; range: 6 to 63 days). The mean follow-up was 40.0 +/- 3.6 months (median: 40 months; range: 10 months to 7.1 years). Only two patients (5%) required reoperation for conduit stenosis with systolic pressure gradients of 60 to 80 mm Hg at 10 and 14 months, respectively, after operation, and both reoperations were successful. During outpatient visits, 16 patients are totally asymptomatic, and 21 patients have minimal symptoms (New York Heart Association class II). Only 10 patients (26%) require digoxin, and 2 patients (5%) need diuretics as part of their medical regimen. Recent echocardiographic examinations show insignificant pressure gradients in all 37 currently surviving patients. Thus, barring operative mortality, which is almost always associated with the nature of the underlying heart defect, the use of cryopreserved AVHC is a safe and effective alternative for PV-to-MPA reconstruction.

Adolescent↗

Effects of venovenous extracorporeal membrane oxygenation on cardiac performance as determined by echocardiographic measurements.

We evaluated the effects of venovenous extracorporeal membrane oxygenation (ECMO) on cardiac performance by echocardiographic measurements in 15 infants. Heart rate and blood pressure were also recorded. Echocardiographic measurements included aortic and pulmonary peak blood flow velocities, pulmonary time to peak velocity, left ventricular shortening fraction, velocity of circumferential fiber shortening corrected for heart rate, and peak systolic wall stress before, during, and after venovenous ECMO. Pre-ECMO echocardiograms showed borderline or normal indexes of cardiac function. After initiation of venovenous ECMO, all infants had normalization and no infant had deterioration of cardiac performance. The inotropic agents dopamine and dobutamine were decreased from average doses of 12 and 3.6 micrograms/kg per minute, respectively, to 3.7 and 1.3 micrograms/kg per minute, respectively, within 8.8 hours of the institution of venovenous ECMO. During this time the mean arterial pressure remained stable, and the heart rate decreased (169 +/- 21 vs 136 +/- 15 beats/min; p < 0.001). During the course of ECMO there were no changes in left ventricular shortening fraction, velocity of circumferential fiber shortening corrected for heart rate, or aortic peak blood flow velocities. Pulmonary artery peak blood flow velocity (69 +/- 22 vs 92 +/- 28 cm/sec; p = 0.04) and pulmonary time to peak velocity improved (47 +/- 11 vs 65 +/- 16 msec; p = 0.026). We conclude that venovenous ECMO does not have deleterious effects on cardiac performance.

Echocardiography↗

Processing forms used in the bone marrow transplantation laboratory: toward standardization.

We developed a set of one-page data forms for each procedure that is used in the different types of bone marrow transplant processing performed in our laboratory. In this paper we duplicate this set of forms and illustrate how they can be "mixed and matched" to accommodate the type of processing that is being carried out on a particular day. Finally, we describe the benefits that we have gained from using this system and suggest interlab advantages to adopting such a system.

Bone Marrow Transplantation↗

Deletions in the ligand for CD40 in X-linked immunoglobulin deficiency with normal or elevated IgM (HIGMX-1).

Patients with X-linked Ig deficiency with normal or elevated IgM (HIGMX-1) fail to switch from IgM/IgD to other Ig isotypes. Interaction between the B cell antigen CD40 and the CD40 ligand expressed on activated T cells is critical for T cell driven isotype switching. We have reported that T lymphocytes from three unrelated male patients with HIGMX-1 failed to express CD40 ligand on their surface, but the mRNA for CD40 ligand was of an apparently normal size and level. Analysis of CD40 ligand cDNA from two of the patients revealed deletions that alter the reading frame. Patient 1 displayed two mutations: a C-->A transversion at nucleotide 590 and the deletion of an adjacent C nucleotide. The second patient had a 58 bp deletion from nucleotides 289-346. Furthermore, neither patient expressed a protein product detectable by the CD40L mAb, 5c8.

Antibodies, Monoclonal↗

An IVS-I-117 (G-->A) acceptor splice site mutation in the alpha 1-globin gene is a nondeletional alpha-thalassaemia-2 determinant in an Indian population.

In 1991 we reported the identification of two deletional alpha-thalassaemia-2 determinants (-3.7 kb and -4.2 kb) and one nondeletional alpha-thalassaemia-2 determinant (Hb Koya Dora alpha 2 codon 142, TAA-->TCA) in a tribal population in Central India (Gupta et al, 1991). Evidence was obtained at that time for the possible presence of an additional nondeletional alpha-thalassaemia-2 because of low levels of Hb S (< 28%) in some Hb S heterozygotes with a simple alpha-thalassaemia-2 heterozygosity (-alpha/alpha alpha). This abnormality has now been identified as a G-->A mutation at IVS-I-117 of the alpha 1-globin gene (acceptor splice site) which makes this gene nonfunctional. Its frequency was established at approximately 6% which raises the total frequency of alpha-thalassaemia determinants in this population to approximately 60%. Subjects with a deletional alpha-thalassaemia-2 and the newly discovered alpha 1 acceptor splice junction mutation in trans appear to have an alpha chain deficiency similar to that of an alpha-thalassaemia-2 homozygote (-alpha/-alpha). An additional change (C-->G) at the Cap -4 site was observed in six alpha 1- and one alpha 2-globin genes; this polymorphism is not associated with a decrease in alpha chain synthesis and is not linked to the IVS-I-117 (G-->A) mutation.

Adolescent↗

Aortic occlusion in nonspecific aortoarteritis (Takayasu disease): incidence and spectrum of involvement.

Nonspecific aortoarteritis (Takayasu disease) is a primary arteritis of unknown etiology which commonly involves the aorta, and results in stenosis, occlusion, dilatation or formation of aneurysm in the involved segment. Of these, occlusion is the most rare form of involvement, and is usually reported to occur in the abdominal aorta. Only one case of aortic arch occlusion has been reported. We retrospectively studied the frequency and sites of aortic occlusion in 110 consecutive patients who underwent digital subtraction angiography. Aortic occlusion was seen in three (2.7%) patients, and involved the abdominal aorta in two, and the aortic arch in one patient. The clinical presentation in all three patients was with systemic hypertension and lower limb claudication. The detection and localization of the aortic occlusion is important since this has practical implications in the management of these patients. Intravenous digital subtraction angiography is usually adequate for the diagnostic assessment.

Adolescent↗

Selective coronary angiography in intracardiac tumors.

Cardiac catheterization and selective coronary angiography were performed in ten patients with intra-cardiac tumors [left atrial myxoma (7), right atrial myxoma (1), angiosarcoma of right heart (1), and right ventricular tumor (1)]. The patient with angiosarcoma had characteristic hemodynamics suggesting cardiac compression. The coronary arteriographic finding included: neovascularization (8); filling defect due to emboli (1); and displacement of coronary artery (1). Tumor neovascularization from branches of the left circumflex or right coronary artery was invariably observed in patients with myxoma. We conclude that invasive studies are safe, provide additional information of academic interest, and occasionally aid in the diagnosis.

Adult↗

Zygomycotic necrotizing fasciitis caused by Apophysomyces elegans.

A case of necrotizing fasciitis of the anterior abdominal wall caused by the zygomycete Apophysomyces elegans in a healthy male following inguinal herniorrhaphy is reported. The portal of entry of the fungus into the incised skin and subcutaneous tissues was probably through either contaminated surgical sutures or postoperative surgical dressings. Broad, aseptate fungal hyphae were seen in the necrosed tissues with an associated necrotizing vasculitis. Extensive tissue debridements and a low dose of amphotericin B were not successful in controlling the rapid invasion of the tissues by the fungus.

Adult↗