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Biomedical subjects

A Sharma

Publications and source records attributed to A Sharma.

At least 307 records · Page 17Linked to original sources
PubMed2000

Clastogenic effects of zinc chloride on human peripheral blood leucocytes in vitro.

The clastogenic effects of three different concentrations of zinc chloride on human peripheral blood leucocytes were studied in vitro. The highest concentration (1.5 x 10(-3) M) was lethal after 48 and 72 h of culture and no blast cells were formed. The two lower concentrations (3.0 x 10(-4) M and 3.0 x 10(-5) M) significantly reduced the frequency of cell division, induced chromatid breaks and damaged cells in frequencies significantly higher than in control experiments maintained in sodium chloride and in distilled water.

Adult↗
PubMed2000

Diuretic MAG3 scintirenography in children with HIV nephropathy: diffuse parenchymal dysfunction.

UNLABELLED: HIV nephropathy (HIVN) is prevalent in 15%-56% of HIV-infected children and induces mild to severe progressive nephropathy. METHODS: A total of 33 renal diuretic scintirenographic studies with 99mTc-mercaptoacetyltriglycine (MAG3) were reviewed and analyzed from 23 HIV pediatric patients, 21 of whom had HIVN with varying degrees of renal impairment. Results were compared with 10 studies of control patients of matching ages. Visual interpretation of images and renograms as well as semiquantitative analyses were performed. Variables compared were size of kidneys, time of peak and one-half peak activities, residual (or retained) cortical activity at 20 min, ratio of cortical activity at 2.5-20 min, and ratio of kidney activity to kidney plus background activity at 2 min. The results of MAG3 renal studies were also compared with laboratory data pertaining to creatinine clearance in all patients and with sonography in 17 patients. RESULTS: In most patients with HIVN (18/21), the kidneys were larger than normal, with a diffuse parenchymal dysfunction (decreased uptake, slow processing, and increased retention of activity) and flat renograms, findings similar to those observed in other diffuse parenchymal diseases. In all patients with HIVN, semiquantitative analysis (paired t test) showed statistically significant differences from control patients for all variables. On ANOVA, a statistically significant correlation was found between most scintigraphic parameters and the severity of renal impairment. Of the 17 concurrent sonographic studies in HIVN patients, 7 showed no abnormalities, whereas the results of scintigraphy were abnormal. CONCLUSION: Diuretic MAG3 scintirenography shows nonspecific diffuse parenchymal dysfunction in pediatric patients with HIVN. Such dysfunction may provide corroborative evidence of HIVN and should be recognized when the test is performed for standard indications. Further work is necessary to prove that the test has indeed the high sensitivity and good correlation with the seventy of HIVN suggested in this population; the test may be useful to follow up the progression of disease and the effect of treatment.

AIDS-Associated Nephropathy↗
PubMed2000

Enantiomeric synthesis of (3R)-3-amino-5-methyl-2-oxo-hexan-1-ol hydrochloride from cyclohexylideneglyceraldehyde

The first enantioselective synthesis of the title compound, (3R)-3-amino-5-methyl-2-oxo-hexan-1-ol hydrochloride (9a), an inhibitor of metalloprotein aminopeptidases has been developed from an enantiomerically pure 3-alkylglycerol. The required 3-alkylglycerol was, in turn, prepared by simple Grignard addition to cyclohexylideneglyceraldehyde 1 followed by separation of the epimeric product carbinols by normal column chromatography. The other attractive features of the synthesis was the use of inexpensive reagents and operationally simple synthetic protocols.

Journal Article↗
PubMed2000

The management of Mirizzi syndrome in the laparoscopic era.

Mirizzi syndrome is a rare complication of long-standing gallstone disease resulting in obstructive jaundice. Careful perioperative management is of utmost importance because of an increased risk of bile duct injury intraoperatively. Experience with Mirizzi syndrome over a period of 3 years, from January 1996 to December 1998, was reviewed. Twenty-seven patients were operated upon, which constituted 0.9% of 2840 patients who underwent laparoscopic cholecystectomy in the authors' department. There were 12 patients with Mirizzi type I syndrome and 15 patients with Mirizzi type II syndrome, according to McSherry classification. Six (22%) conversions were reported, all because of unclear anatomy and inherent limitations of the laparoscopic approach. For the remaining 21 (78%) patients, the procedure was completed laparoscopically. No bilioenteric anastomosis was required. A preoperative stent insertion in the common bile duct (CBD) during endoscopic retrograde cholangiopancreatography (ERCP) enabled us to achieve primary closure of CBD in every case. There was no perioperative mortality, and patients remained well for an average 2.1-year follow-up. It is highly desirable to have a preoperative diagnosis of Mirizzi syndrome, and the laparoscopic approach is not a contraindication in specialized centers. Our current management protocol to treat Mirizzi syndrome consists of a high degree of suspicion at ERCP, with stenting preoperatively and a complete stone clearance with subtotal cholecystectomy intraoperatively.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed2000

Changing scenario of cryptococcosis in a tertiary care hospital in north India.

BACKGROUND & OBJECTIVES: With the increase in the number of patients of AIDS, the incidence of cryptococcosis is on the rise in India. It was therefore considered important to evaluate the predisposing factors, laboratory investigations and outcome of patients with cryptococcosis in this changed scenario. METHODS: We assessed 58 patients with cryptococcosis retrospectively over a five year period (January 1995-December 1999) at the Nehru Hospital, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh. RESULTS: The annual incidence of cryptococcosis in PGIMER, Chandigarh has increased about 15 fold from 1970-1982 (pre AIDS era) to 1995-1999 (present series). Of the 47 patients studied for predisposing factors, 36 patients were identified with predisposing factors, HIV infection (57.4%) was the commonest followed by haematologic malignancies (6.3%) and renal transplant (4.2%). Forty one patients were diagnosed by isolation of the organism as well as antigen detection in cerebrospinal fluid/serum, 9 by isolation alone and 8 by antigen detection alone. Quantitative antigen titres were done in 38 patients and a significantly higher (P < 0.01) antigen titre (> 512) was observed in HIV positive patients as compared to HIV negative patients. All isolates tested were of Cryptococcous neoformans var neoformans biotype and no resistance to antifungal agents was noted. Twenty of 41 patients receiving treatment improved. The results were compared with other studies available from India. INTERPRETATION & CONCLUSION: The incidence of cryptococcosis is on the rise in this part of north India and this can be attributed to an increase in AIDS cases.

Adult↗
PubMed2000

Surgery for stage 5 retinopathy of prematurity: the learning curve and evolving technique.

PURPOSE: To describe our experience with management of eyes with stage 5 retinopathy of prematurity (ROP). METHODS: Closed vitreoretinal surgery was done on 96 eyes of patients with stage 5 ROP. Lens was sacrificed in all but one eye. Surgery involved an attempt to clear all preretinal tissue and open the peripheral trough all round. In most instances bimanual surgery under viscoelastic was performed. RESULTS: At last follow up, anatomical success (defined as attached posterior pole) was achieved in 22.5% cases. Significant postoperative problems included reproliferation and secondary glaucoma. Only two infants obtained mobile vision. CONCLUSION: Late identification of disease, lack of prior treatment such as laser or cryo, and higher incidence of narrow-narrow funnel configuration were responsible for the poor surgical results noted in this series. The poor surgical and functional results reemphasize the need for prompt screening and management of infants at risk.

Clinical Competence↗
PubMed2000

Variation of axillary temperature and its correlation with oral temperature.

UNLABELLED: Unilateral axillary temperature is recorded in unconscious patients and children due to its easy approach. OBJECTIVE: To evaluate variation of axillary temperature on the two sides and its correlation with oral temperature. SUBJECTS: One hundred and 46 healthy men and women, aged 12 through 52 years. METHODS: Axillary temperature from both sides and oral temperature were recorded using digital electronic thermometer in supine position with due precautions. RESULTS: Difference in temperature on the two sides of axilla was found to vary by as much as 0 degree F to 3.4 degrees F. Therefore, the data was grouped into higher and lower temperature ranges. The difference between mean oral and mean higher axillary temperature was found to be 0.5 degree F +/- 0.6 degree F (r = 0.564) while that in comparison to mean lower axillary temperature was 1.0 degree F +/- 0.89 degree F (r = 0.64). The difference between mean oral and mean axillary temperature was 1.0 degree F +/- 0.80 degree F (r = 0.84). CONCLUSIONS: Based on our observations, it is found that an average of temperature of both sides of axilla represents the axillary temperature more accurately and to get the correct oral equivalent of axillary temperature one should add 1 degree F to the mean axillary temperature.

Adolescent↗
PubMed2000

Role of oxygen free radicals in shock.

AIMS OF THE STUDY: To study lipid peroxidation, magnesium levels (Mg) in plasma and red cells (RBC), superoxide dismutase (SOD) and catalase (CAT) activities in the plasma and RBC of shock patients. METHODOLOGY: Twenty five patients with clinically defined septic shock and 30 healthy volunteers were selected for the study to study the parameters of oxidative stress. RESULTS: Septic shock patients had higher activities of plasma and RBC SOD and CAT activities as compared to control. Also, plasma Mg and malonaldehyde (MDA) levels were higher in shock patients as compared to controls. While, RBC Mg levels were similar in two groups. CONCLUSIONS: The finding of increased concentration of MDA, Mg, SOD and CAT in sepsis implicates oxygen free radicals in the pathophysiology and free radical scavengers may have a role in organ preservation.

Adult↗
PubMed2000

Evaluation of oxidative stress before and after haemodialysis in chronic renal failure.

OBJECTIVE: To evaluate the oxidative stress before and after haemodialysis in chronic renal failure patients. METHODS: A prospective study comprising of 22 patients of CRF who have to receive their first haemodialysis. All patients were subjected to standard four hours haemodialysis. The parameters of oxidative stress i.e. erythrocyte malonaldehyde (MDA), reduced glutathione (GSH) and superoxide dismutase (SOD) were measured before and after haemodialysis. RESULTS: The value of mean erythrocyte MDA (9.40 +/- 3.36 mumol/L) and SOD (617 +/- 64.33 units/ml) were significantly higher in patients of CRF before haemodialysis than in controls (p < 0.001). The mean GSH levels were significantly lower (451 +/- 63.91 micrograms/ml) in patients than in controls before haemodialysis (p < 0.001). After haemodialysis MDA levels further increased (12.27 +/- 4.38 mumol/L), SOD levels decreased (458 +/- 69.58 EU/ml) and GSH levels further decreased (396 +/- 41.41 micrograms/ml) (p < 0.001). CONCLUSIONS: There was an evidence of oxidative stress in patients of CRF before haemodialysis which increased further after haemodialysis, the mechanisms of which is not delineated. The procedural factors may be contributing in the increased oxidative stress after haemodialysis.

Adult↗
PubMed2000

Leptospirosis in the causation of hepato-renal syndrome in and around Pune.

Fifty cases of hepato-renal dysfunction of unknown etiology were studied over a two-year period. Urine samples were examined microscopically and cultured for Leptospira. Serum samples were examined for antibodies against Leptospira by the Macroscopic slide agglutination test (MSAT). Seventeen out of fifty patients (34%) showed evidence of Leptospiral infection by at least two diagnostic techniques used. 15/17 i.e. 88.2% were positive by dark ground microscopy, 7/17 were diagnosed by culture technique and 16/17 i.e. 94% were confirmed by serology. There was a good correlation between Microscopic agglutination test (MAT) and MSAT. Thus Leptospires seem to play a major role in the causation of hepato-renal dysfunction in and around Pune, Maharashtra.

Adult↗
PubMed2000

A study of the influence of insulin resistance on left ventricular mass in hypertensive patients.

OBJECTIVES: To study the influence of insulin resistance on the left ventricular mass in hypertensive subjects. MATERIAL AND METHODS: Thirty patients having uncomplicated essential hypertension were included in the study. Post-oral glucose load serum insulin level (2 hrs) was determined and this was used as a marker for insulin resistance. Two D-echocardiography was performed and left ventricular mass and left ventricular mass index were calculated. RESULT: Out of the 30 patients 18 were males and 12 were females. Eight were obese while the remaining 22 were non-obese. The patients were 27 to 70 years old. The mean age, height and weight were 54.83 +/- 9.46 years, 159.07 +/- 8.81 cm and 58.38 +/- 11.03 kg, respectively. The post oral glucose load serum insulin levels in the study ranged from 57.65 to 210.81 microU/ml. The left ventricular mass and left ventricular mass index ranged from 42.58 to 310.8 g (mean 196.60 +/- 65.13 g) and 42.74 to 185.59 g/m2 (mean 118.71 +/- 37.75 g/m2), respectively. The correlation coefficient ('r' value) between post oral glucose load serum insulin levels and left ventricular mass and left ventricular mass index were calculated. CONCLUSION: A strong positive correlation was observed between the post oral glucose load serum insulin levels and left ventricular mass ('r' = +0.750). A strong positive correlation between post oral glucose load serum insulin levels and left ventricular mass index ('r' = +0.757) was also observed. These correlations were found to be statistically highly significant (p < 0.01). This association was demonstrated independently of age, anthropometric measurements, systolic and diastolic blood pressure levels. Thus, in patients with essential hypertension, hyperinsulinemia (insulin resistance) has a role in promoting left ventricular hypertrophy.

Adult↗
PubMed2000

Glutathione levels in health and sickness.

We speculate that the glutathione (GSH) status of human subjects could be an indicator of health and functional age. In this regard, in a study in which, 80 young and 40 elderly healthy individuals were selected as control. We also studied 145 patients with chronic illnesses namely, ischaemic heart disease, diabetes, preeclampsia, cataract, chronic renal failure and leukaemia (age 52 +/- 8.6 years). We observed that all the subjects had high malonadildehyde and low glutathione levels as compared to control. These early observations support the hypothesis that oxidative stress may have an important aetiological rule and antioxidants a potential therapeutic role.

Adult↗
PubMed2000

Role of KATP channels in reduced antinociceptive effect of morphine in streptozotocin-induced diabetic mice.

The nociceptive effect was measured using withdrawal latency in tail flick test in mice rendered diabetic by administering streptozotocin (200 mg/kg, i.p.). The antinociceptive effect of morphine (4 and 8 mg/kg, s.c.) and cromakalim, a KATP channel opener, (0.3, 1 and 2 micrograms, i.c.v.) was significantly reduced in diabetic mice. Moreover, co-administration of cromakalim(0.3 microgram) did not alter the reduced antinociceptive effect of morphine(4 mg/kg) in diabetic mice. Spleenectomy in diabetic mice restored the decrease in antinociceptive effect of morphine and cromakalim. Multiple dose treatment with insulin to maintain euglycaemia for 3 days in diabetic mice prevented the decrease in antinociceptive effect of morphine and cromakalim. However, hyperglycaemic tyrode's buffer did not alter the pD2 value of morphine in isolated guinea pig ileum suggesting that hyperglycaemia does not interfere with mu receptor mediated responses in vitro. The results suggest that hyperglycaemia induced decrease in antinociceptive effect of morphine and cromakalim may be due to alteration in KATP channels. Some unknown factor from spleen in diabetic mice may be responsible for this alteration in KATP channels in diabetic mice.

Adenosine Triphosphate↗
PubMed2000

Effect of actinomycin D and cycloheximide on ischemic preconditioning-induced delayed cardioprotective effect in rats.

The present study was designed to investigate the effect of actinomycin D, a transcription inhibitor, and cycloheximide, a translation inhibitor, on the delayed cardioprotective effect of ischemic preconditioning. Left thoracotomy was performed in anaesthetized rats at 4th/5th intercostal space and polypropylene suture (5-0) was employed to occlude left common coronary artery. Ischemic preconditioning was produced by four episodes of 5 min of coronary artery occlusion followed by 5 min of reperfusion and thoracic cavity was sutured. Left thoracotomy was performed again after 24 hr of ischemic preconditioning and left coronary artery was occluded for 30 min followed by reperfusion for 120 min. Area at risk and infarct size was estimated by patent blue and TTC staining respectively. Total left ventricular RNA was isolated and estimated quantitatively. Ischemic preconditioning, 24 hr after its induction, produced significant decrease in myocardial infarct size occurred as a result of sustained ischemia and reperfusion but produced no marked effect on ventricular RNA content. Actinomycin D and cycloheximide only, in high dose, markedly attenuated ischemic preconditioning induced decrease in myocardial infarct size. However, no such effect was noted with low dose of cycloheximide. The results suggest that delayed cardioprotective effect of ischemic preconditioning may be mediated through denovo synthesis of protein(s) which is regulated both at transcriptional and translational level.

Animals↗
PubMed2000

Conservative management of malocclusion in mixed dentition.

The treatment planning in mixed dentition period has changed from extraction to non extraction. Any orthodontic treatment must take into consideration the growth trends and the pubertal growth spurt. The two cases presented here were treated during mixed dentition period in different ways: one with fixed appliances and the other with removable myofunctional appliance therapy, with satisfactory results. Hence for a conservative treatment approach, the non-extraction treatment is recommended in mixed dentition period.

Child↗
PubMed2000

Occlusal considerations for implant restorations in the partially edentulous patient.

The type and frequency of complications associated with dental implants has changed during the past decade. As more-successful rates of osseointegration have resulted from improved surgical protocols and materials, the major complications have become restorative-related rather than surgery-related. Recent studies indicate that restorative complications with implant-retained restorations occur at rates of 10 percent to 77 percent over a three-year period. Many of the restorative complications can be minimized with careful treatment planning and coordination of care. However, because implants lack the stress release associated with a periodontal ligament, impact loading to restorative materials and the crestal bone remains potentially more damaging with implant-supported restorations. This article discusses the biomechanical implications of implant restorations and outlines occlusal considerations designed to decrease restorative complications.

Biomechanical Phenomena↗
PubMed2000

Protein tyrosine kinase activity in human malaria parasite Plasmodium falciparum.

Protein tyrosine kinases (PTKs) are believed to be implicated in the parasite growth, maturation and differentiation functions. Protein tyrosine kinase activity was found to be distributed in all the stages of P. falciparum parasite maturation. Membrane bound PTK activity was found to be increased during maturation process (ring stage to trophozoite stage) in chloroquine sensitive strains. In vivo conversion of the schizont stage to ring stage via release of merozoites was associated with a decrease in PTK activity. Chloroquine inhibited the membrane bound PTK activity in a dose dependent manner (IC50 = 45 microM). Kinetic studies show that chloroquine is a competitive inhibitor of PTK with respect to peptide substrate and noncompetitive with respect to ATP indicating that chloroquine inhibits PTK activity by binding with protein substrate binding site. The results suggest that maturation of malaria parasite is related to PTK and inhibition of this activity by chloroquine could provide a hypothesis to explain the mechanism of action of chloroquine.

Animals↗