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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 469 records · Page 26Linked to original sources
PubMed1996

Seasonal variation in sudden infant death syndrome and bronchiolitis--a common mechanism?

The purpose of this study was to compare epidemiologic features of sudden infant death syndrome (SIDS) and bronchiolitis and to apply statistical examination in order to examine the hypothesis that similar mechanisms could be at work in both conditions. The setting was Scotland from 1982 through 1990. We compared 1,211 deaths from SIDS with 10,058 hospital admissions for bronchiolitis in infancy. The comparisons included age, sex ratio, and seasonality. The sex ratios were similar (SIDS [M:F]:1.61:1; bronchiolitis: 1.63:1), but age distribution was different (chi 2 = 104.6, p < 0.001). When monthly rates throughout the year were compared using correlation of residuals from average season variation and by autocorrelation of residual series, no significant relationships were found between the two conditions (r2 = 0.0004). Once the seasonal pattern common to both conditions was accounted for, SIDS was not autocorrelated between months whereas bronchiolitis exhibited a high level of autocorrelation indicating an epidemic pattern for the latter but not for the former. While a common seasonal variation may indicate some shared etiologic factors associated with winter season, the two conditions do not appear to be closely related. The hypothesis that a common host susceptibility is at work is not supported. Further investigations of seasonal influences are warranted.

Age Distribution↗
PubMed1996

Spontaneous remission of ectopic Cushing's syndrome due to pheochromocytoma: a case report.

A young female adult with Cushing's syndrome arising from ectopic production of corticotropin (ACTH) from an adrenal pheochromocytoma showed spontaneous clinical and biochemical remission of hypercortisolism after a brief period of ketoconazole administration. Despite continued remission of the hypercortisolism over the next 18 months, there was progressive catecholamine hypersecretion with significant morbidity as a result of the pheochromocytoma. Surgical resection of the left adrenal gland revealed a pheochromocytoma showing focal cytoplasmic immunostaining for ACTH and marked diffuse compact cell hyperplasia in the adrenocortical tissue. To our knowledge this is the first reported case of spontaneous clinical and biochemical remission of ectopic ACTH production from a pheochromocytoma. The pathogenesis of the remission remains unknown.

ACTH Syndrome, Ectopic↗
PubMed1996

Left atrial enlargement in healthy obese: prevalence and relation to left ventricular mass and diastolic function.

BACKGROUND: Left atrial (LA) enlargement has been reported in the obese. However, its prevalence in the healthy obese, clinical correlates and relation to left ventricular (LV) mass and diastolic function have been little investigated. METHODS: Thirty-five consecutive, healthy, normotensive obese (body mass index greater than 28, mean +/- SD 34.2 +/- 2.3 kg/m2) and 35 nonobese subjects (body mass index 24.6 +/- 2.3 kg/m2) comparable in age and sex underwent echocardiographic measurements of LA posteroanterior (parasternal view), mediolateral and superoinferior (apical views) dimensions, aortic root diameter, LV mass and Doppler assessment of LV diastolic function. LA enlargement was defined as a posteroanterior dimension greater than 40 mm. A ratio of LA posteroanterior dimension to aortic root diameter greater than 1.4 was used as an index for disproportionate LA enlargement. RESULTS: LA enlargement was more frequent in the obese than in the nonobese (37% versus 6%, P<0.0001). Similarity, disproportionate LA enlargement was more frequent in the obese (34% versus 6%, P<0.0001). LA posteroanterior dimension correlated well with body mass index (r=0.52, P<0.0001) and LV mass (r=0.56, P<0.0001), and weakly with blood pressure (r=0.28, P<0.02). There was no significant correlation with LV diastolic function, age or sex. In multivariate analysis (multiple r=0.61, P<0.0001), LA posteroanterior dimension correlated significantly only with mass (P<0.005), and the association with body mass index and blood pressure became nonsignificant. Similar results were obtained when LA posteroanterior dimension was replaced with mediolateral or superoinferior dimensions. CONCLUSIONS: LA enlargement is frequent in the normotensive, otherwise healthy obese and correlates well with LV mass. It is not mediated through impairment of LV diastolic function, and likely reflects a physiological adaptation of the heart to the obese state. Further studies are needed to determine whether LA enlargement in the obese is associated with adverse long term outcome.

Adult↗
PubMed1996

Design, synthesis, cytotoxic properties and preliminary DNA sequencing evaluation of CPI--N-methylpyrrole hybrids. Enhancing effect of a trans double bond linker and role of the terminal amide functionality on cytotoxic potency.

In an approach to the design and exploration of the properties of cyclopropylindole (CPI)-lexitropsin conjugates as potential anticancer agents. CPI--N-methylpyrroles of two separate classes have been synthesized and characterized. These comprise structures (i) in which the N-methylpyrrole moiety bears amide groups of different sizes and (ii) in which both flexible and rigid linkers are introduced between the CPI and N-methylpyrrole units. The extent and the relative rates of DNA cleavage following alkylation and thermal treatment by these CPI conjugates were determined by an agarose gel mobility shift assay. The DNA sequence preferences of the seven new agents were also determined in a preliminary study by high-resolution polyacrylamide gel electrophoresis and contrasted with that of CC-1065. The CPI--N-methylpyrrole agents avoid the major alkylation sites of CC-1065, but all alkylate the minor CC-1065 site of 5'AATA and exhibit a consensus sequence of 5'-N.A/T.A/T.A. The cytotoxicities of these compounds were determined against KB human tumor cells in vitro. Compound 6, bearing a 4-butyramide group in the N-methylpyrrole, is 100 times more potent that 7 which lacks an amide group, while 10 which bears a rigid trans double bond linker is 1000 times more potent than its flexible ethyl-linked counterpart.

Alkylating Agents↗
PubMed1996

Haematological traits, religion and rural/urban residence among the Lepchas of Kalimpong subdivision, Darjeeling district, West Bengal (India).

As a part of an ongoing multidisciplinary biomedical research programme, initiated by the Indian Statistical Institute in early 1976, entitled "Human Adaptability Programme", the present study was undertaken among the Lepchas of Kalimpong subdivision, Darjeeling district, West Bengal (India) to enquire at a micro-level into the possible relationship between the major sociocultural factors, viz. religious practices and rural/urban residence, on the one hand, and haematological traits such as haemoglobin level, haematocrit and anaemia, on the other. The results show that while effects of religious practices do not seem to exist on the haematological traits considered, significant effects of rural/urban residence do.

Adult↗
PubMed1996

Design, synthesis and topoisomerase II inhibition activity of 4'-demethylepipodophyllotoxin-lexitropsin conjugates.

The design and synthesis of 4'-demethylepipodophyllotoxin-lexitropsin conjugates capable of inhibiting the actions of topoisomerase II are described. Siteselective topoisomerase II cleavage was observed in the presence of the new inhibitors, as determined by DNA sequencing. Additional topoisomerase II cleavage sites were observed with the new compounds that seem to be characteristic of the minor groove-binding lexitropsin moieties. Compound 17, having three pyrrole units in its binding moiety, exhibited distinct topoisomerase-mediated sites of cleavage at positions 4258, 4257, 4255 and 4247 of the pBR322 DNA fragment. These results demonstrate that conjugation with minor groove-binding moieties can alter or increase the number of topoisomerase II-induced cleavable sites and contribute to our understanding of the cytostatic activity of these compounds against KB cancer cell lines.

Antineoplastic Agents↗
PubMed1996

Efficacy and safety of unguided percutaneous fine needle aspiration cytology in peripheral lung lesions.

The efficacy and safety of unguided percutaneous fine needle aspiration cytology in peripheral lung lesions were studied in 42 patients. The diagnostic yield of unguided aspiration was 83.3%. The yield in malignant lesion was 85.7% while in benign lesion it was 78.6%. There was no false positive report. Complications seen were asymptomatic pneumothorax and blood tinged sputum in a few cases following aspiration. The procedure was well accepted by the patients. Unguided FNAC is a simple, quick, economical, safe and reliable procedure for the diagnosis of peripheral lung lesions.

Adolescent↗
PubMed1996

Microbial lipases: production and applications.

Lipases occupy a prominent place among biocatalysts and have a wide spectrum of biotechnological applications. Lipases are unique as they hydrolyse fats into fatty acids and glycerol at the water-lipid interface and can reverse the reaction in non-aqueous media. The stability of these enzymes in organic solvents have pushed them into the frontier areas of organic synthesis leading to the designing of novel drugs, surfactants, bioactive compounds and oleochemicals. In addition, lipase-catalysed trans-esterification and inter-esterification reactions have been exploited in the fat industry. Looking into the wide scenario of lipase applications, commercialization of lipase production is a prime area of interest for microbiologists, process engineers and biochemists. Research carried out in this field has revealed that microbes, especially fungi and bacteria, are the tools of choice for commercial production. Recently, the structure determination of a few microbial lipases has widened our knowledge about the unique mechanism of catalysis of this enzyme.

Animals↗
PubMed1996

Amphotericin B lipid complex compared with amphotericin B in the treatment of cryptococcal meningitis in patients with AIDS.

The study objective was to obtain preliminary information regarding the safety and efficacy of amphotericin B (AmB) lipid complex (ABLC) in the treatment of AIDS-associated cryptococcal meningitis. Of 55 patients randomly assigned to 6 weeks of therapy with ABLC (1.2-5.0 mg/[kg.d], with ascending doses for three sequential cohorts) or AmB (0.7-1.2 mg/[kg.d]), 46 received > or = 12 doses. Transfusion requirements, mean decreases in hemoglobin level, and mean increases in creatinine level were significantly greater with AmB than with ABLC. The total number of adverse events, infusion-related events, and occurrences of hypomagnesemia and hypokalemia associated with each form of therapy were similar. Among 21 recipients of ABLC at a dosage of 5 mg/kg (daily for 2 weeks and then thrice weekly for 4 weeks), symptoms and signs resolved for 18 (86%). Of those receiving > or = 12 doses of ABLC, cultures converted to negative for 8 (42%), were undeterminable for 3 (16%), and remained positive for 8 (42%) despite resolution of symptoms. Although preliminary, these data suggest ABLC has significant activity in patients with AIDS-associated cryptococcal meningitis. Because this formulation has less hematologic and renal toxicity than does AmB, further evaluation of ABLC is warranted.

AIDS-Related Opportunistic Infections↗
PubMed1996

Hypertension epidemiology in India: meta-analysis of 50 year prevalence rates and blood pressure trends.

Recent studies among Indians have shown a high prevalence of hypertension. To determine changing trends in hypertension prevalence, in mean blood pressure (BP) levels and to study urban and rural differences we performed meta-analysis of all available Indian studies. The first such study was reported by Chopra in 1942. Since then many studies (n = 33) in urban and rural areas of India have been performed. In urban populations earlier studies of Dotto (1949), Dubey (1954) and Sathe (1959) showed prevalence of hypertension of 1.24 +/- 0.2, 4.24 +/- 0.4 and 3.03 +/- 0.3% in populations of Calcutta, Kanpur and Bombay respectively. Studies since 1959 used World Health Organisation (WHO) guidelines and have shown increasing trend in hypertension prevalence. Recent studies from Ludhiana (1985) and Jaipur (1995) show that prevalence is 14.08 +/- 1.1 and 10.99 +/- 0.7% respectively. Trend analysis in studies among urban areas (n = 10) shows a significant increase in hypertension prevalence (Mantel-Haenzel chi 2 = 5.99, P = 0.014). Studies in rural areas (n = 14) also show a significant increase in hypertension prevalence (Mantel-Haenzel chi 2 = 5.93, P = 0.014) although the rise is not as sharp as in urban populations (r value, urban = 0.70, rural = 0.67). Changes in mean BP levels were analysed by using mean systolic (S) and diastolic (D) BP in urban men aged 40-49 years from 1959-1995. For SBP there was a significant increase (r = 0.95, P < 0.001) and not with DBP (r = 0.43, P > 0.2). It is concluded that in India hypertension is emerging as a major health problem more so in urban than in rural subjects. The increasing prevalence is related to a rising mean SBP.

Adult↗
PubMed1996

Novel DNA-directed alkylating agents consisting of naphthalimide, nitrogen mustard and lexitropsin moieties: synthesis, DNA sequence specificity and biological evaluation.

Novel DNA-directed alkylating agents comprising naphthalimide, nitrogen mustard and lexitropsin moieties have been designed, synthesized and characterized. Their properties have been evaluated with respect to DNA binding ability, sequence preference, influence of flanking sequences on alkylation efficiency and cytotoxic potency against KB human nasopharangeal tumour cells. The results indicate that, in contrast to distamycin and bis-benzimidazole-bearing nitrogen mustard moieties where DNA alkylation is directed to adenine N3 sites in the minor groove, the naphthalimide nitrogen mustards alkylate DNA at accessible guanine N7 sites within the major groove. Structural factors that may affect cytotoxic efficacy are discussed.

1-Naphthylamine↗
PubMed1996

Sensitivity of EIA in the diagnosis of tuberculosis using 38-kDa antigen.

Patients, who reported to Government Medical College Hospital, Chandigarh with suspected signs and symptoms of pulmonary tuberculosis, were examined. Their sputum was investigated for the presence of acid-fast bacilli, using the routine Ziehl-Neelsen staining, for 3 consecutive days. The positive cases were referred for treatment and the rest were referred for supplementary tests like x-ray, Mantoux test, FNAC and the presence of IgG antibodies in their serum against recombinant 38-kDa antigen derived from Mycobacterium tuberculosis, using micro-ELISA plates. It was found that 37.8% of the cases who were negative for acid-fast bacilli found to be positive for the presence of antimycobacterial IgG antibodies with an antibody titre greater than the cut off value in addition to one of the above mentioned positive supplementary finding. Hence, EIA for tuberculosis is more sensitive as compared to the routine acid-fast bacilli staining.

Adult↗