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Biomedical subjects

S Singh

Publications and source records attributed to S Singh.

At least 109 records · Page 6Linked to original sources
PubMed2004

Exercise based rehabilitation for heart failure.

BACKGROUND: The prevalence of chronic heart failure is increasing, and increases with increasing age. Major symptoms include breathlessness and restricted activities of daily living due to reduced functional capacity, which in turn affects quality of life. Exercise training has been shown to be effective in patients with coronary heart disease and has been proposed as an intervention to improve exercise tolerance in patients with heart failure. OBJECTIVES: To determine the effectiveness of exercise based interventions compared with usual medical care on the mortality, morbidity, exercise capacity and health related quality of life, of patients with heart failure. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (The Cochrane Library Issue 2, 2001), MEDLINE (2000 to March 2001), EMBASE (1998 to March 2001), CINAHL (1984 to March 2001) and reference lists of articles. We also sought advice from experts. SELECTION CRITERIA: RCTs of exercise based interventions. The comparison group was usual medical care as defined by the study, or placebo. Adults of all ages with chronic heart failure. Only those studies with criteria for diagnosis of heart failure (based on clinical findings or objective indices) have been included. DATA COLLECTION AND ANALYSIS: Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information. MAIN RESULTS: Twenty-nine studies met the inclusion criteria, with 1126 patients randomised. The majority of studies included both patients with primary and secondary heart failure, NYHA class II or III. None of the studies specifically examined the effect of exercise training on mortality and morbidity as most were of short duration. Exercise training significantly increased VO(2) max by (WMD random effects model) 2.16 ml/kg/min (95% CI 2.82 to 1.49), exercise duration increased by 2.38 minutes (95% CI 2.85 to 1.9), work capacity by 15.1 Watts (95% CI 17.7 to 12.6) and distance on the six minute walk by 40.9 metres (95% CI 64.7 to 17.1). Improvements in VO(2) max were greater for training programmes of greater intensity and duration. HRQoL improved in the seven of nine trials that measured this outcome. REVIEWERS' CONCLUSIONS: Exercise training improves exercise capacity and quality of life in patients mild to moderate heart failure in the short term. There is currently no information regarding the effect of exercise training on clinical outcomes. The findings are based on small-scale trials in patients who are unrepresentative of the total population of patients with heart failure. Other groups (more severe patients, the elderly, women) may also benefit. Large-scale pragmatic trials of exercise training of longer duration, recruiting a wider spectrum of patients are needed to address these issues.

Cardiac Output, Low↗
PubMed2004

Estimation of naphthaquinones from Arnebia hispidissima (Lehm.) DC. In vivo and in vitro. I. Anti-inflammatory screening.

The hexane extract of Arnebia hispidissima yielded a mixture of naphthaquinones: arnebin-1, arnebin-7, tiglic acid (ester of dihydroxy alkannin), alkannin, arnebinol and cycloarnebin-7. To evaluate the anti-inflammatory activities of hexane extract and isolated naphthaquinones, models with carrageenan-induced acute arthritis and complete Freund's adjuvant (CFA)-induced chronic arthritis in rats were conducted. The observed results indicated that pretreatment with cycloarnebin-7 significantly inhibited the carrageenan-induced acute arthritis. Moreover, arnebin-1, significantly suppressed the development of chronic arthritis induced by CFA. The present study deals with the quantification of naphthaquinones from in vivo and in vitro cell cultures of plant species and isolated compounds from intact plant tested for their swelling inhibitory potency. It has been reported that arnebin-1 was the major naphthaquinone both in vivo (0.62%) and in vitro (0.27%) cell cultures.

Animals↗
PubMed2004

Applications of eTag trade mark assay platform to systems biology approaches in molecular oncology and toxicology studies.

We have developed a universal eTag trade mark multiplex assay platform that can be uniquely applied to survey the molecule profiles of biologic systems in sub-global large-scale analyses. The effectiveness of eTag trade mark assays when applied to focused system biology studies in molecular oncology and predictive toxicology is herein described while reviewing the current methods commonly used. The multi-analyte and multi-parameter assay approach for parallel analysis will form the basis of an emerging paradigm of multiplexed molecular profiling for signaling pathway networks and various aspects of drug development processes.

Gene Expression Profiling↗
PubMed2004

Mucocutaneous lesions in transplant recipient in a tropical country.

Dermatological manifestations are common in renal transplant patients, but differ markedly with ethnic group and geographical location. We studied mucocutaneous lesions in 54 renal allograft recipients (related donors = 30; unrelated donors = 24) living in tropical atmospheres. Their gender was 50 males, and 4 females ranging in age between 15 and 63 years (mean = 37.84 years). The mean duration of follow-up was 124 months (range = 4 to 173 months). All patients received kidneys from living donors and were kept on immunosupression with mean daily doses of prednisolone, azathioprine, and cyclosporine of 10.2 mg, 68.6 mg, and 252 mg, respectively. The mean trough concentration of cyclosporine was 185 ng/mL. The mucocutaneous lesions were divided into four groups: drug-induced (n = 24, 44.4%), fungal (n = 18, 33.3%), viral (n = 9, 16.6%), and bacterial (n = 10, 18.5%). Cushingoid features, gum hypertrophy, and hypertrichosis were seen in 7 (12.9%) patients. Steroid acne was seen in three cases. Pityriasis versicolor was the most common (20.3%) fungal infection of the skin. In addition, Tinea unguium and mucocutaneous candidiasis were noted in four and three cases respectively. Herpes virus infection (Herpes zoster 5; Herpes simplex 2) was noted in 7 (12.9%) cases. Chicken pox at 5 years posttransplant and cutaneous vasculitis associated with cytomegalovirus disease at 6 months posttransplant were seen in one case each. We have not seen warts in our patients. Pyogenic bacterial infection of skin in the form of abscess (n = 6), cellulitis (n = 3), and pyoderma (n = 1) were observed in 10 (18.5%) patients. Thus, drug-induced mucocutaneous side effects and skin fungal infections are the most common dermatological manifestations among renal transplant recipients living in a tropical country.

Adolescent↗
PubMed2004

Physical activity decreases the risk of stroke in middle-age men with left ventricular hypertrophy: 40-year follow-up (1961-2001) of the Seven Countries Study (the Corfu cohort).

Left ventricular hypertrophy (LVH) is a dominant characteristic of cardiovascular mortality. We investigated the interaction between physical activity and LVH on stroke mortality, based on a 40-year follow-up of the Corfu cohort from the Seven Countries Study. The population studied consisted of 529 rural men (40-59 years old) enrolled in the Study at 1961. LVH was electrographically confirmed according to Minnesota coding. Physical activity levels were assessed by self-reports of habitual, occupational and leisure-time activities. Cox proportional hazard models were used to evaluate exercise levels with respect to stroke mortality in people with and without LVH. During the follow-up, 461 (87%) died, and 74 (16%) of these deaths were due to stroke. LVH was present in 40 (7.5%) men. A total of 362 (68%) men were defined as physically active. Physical activity was associated with a lower risk of stroke (hazard ratio=0.65, P<0.05). On the other hand, LVH had 5.8-fold the risk of stroke (P<0.001) among sedentary and 4.5-fold the risk (P<0.001) among physically active men, after controlling for several potential confounders. However, moderate physical activity decreased the risk of stroke by 49% in men with LVH as compared to sedentary without LVH (hazard ratio=0.51, P<0.01), while hard exercise did not confer any significant reduction in stroke risk. We revealed the benefits from moderate physical activity on stroke mortality among men with LVH. Physicians and other health-care professionals should encourage patients with LVH to adopt a physically active lifestyle.

Adult↗
PubMed2004

DNA sequence variation and haplotype structure of the ICAM1 and TNF genes in 12 ethnic groups of India reveal patterns of importance in designing association studies.

We have examined the patterns of DNA sequence variation in and around the genes coding for ICAM1 and TNF, which play functional and correlated roles in inflammatory processes and immune cell responses, in 12 diverse ethnic groups of India. We aimed to (a) quantify the nature and extent of the variation, and (b) analyse the observed patterns of variation in relation to population history and ethnic background. At the ICAM1 and TNF loci, respectively, the total numbers of SNPs that were detected were 28 and 12. Many of these SNPs are not shared across ethnic groups and are unreported in the dbSNP or TSC databases, including two fairly common non-synonymous SNPs at positions 13487 and 13542 in the ICAM1 gene. Conversely, the TNF-376A SNP that is reported to be associated with susceptibility to malaria was not found in our study populations, even though some of the populations inhabit malaria endemic areas. Wide between-population variation in the frequencies of shared SNPs and coefficients of linkage disequilibrium have been observed. These findings have profound implications in case-control association studies.

Chromosome Mapping↗
PubMed2004

alpha-Tocopherol modifies lead induced functional changes at murine neuromuscular junction.

Lead impacts neuromuscular junction and might induce skeletal muscle weakness. Antioxidants may prevent toxic actions of lead on muscle. In this study, resting membrane potentials, endplate potentials, miniature endplate potentials (MEPPs) and isometric twitch tensions were recorded to investigate effects of alpha-tocopherol (Vitamin E) on lead induced changes at murine dorsiflexor muscle. Moreover, levels of endplate nicotinic receptors were measured by receptor autoradiography. Forty rats were divided into four groups (lead alone, alpha-tocopherol, lead plus alpha-tocopherol and saline). Lead (1 mg/kg, i.p.), was administered daily for 2 weeks and alpha-tocopherol (100 mg/kg, i.p.) was given daily for 3 weeks. Lead treatment significantly reduced twitch tension (from 4.4+/-0.4 to 2.2+/-0.3 g) and delayed half time of decay. MEPP frequencies and quantal content were also significantly reduced after lead treatment. Pretreatment with alpha-tocopherol reversed twitch tension reduction (4.1+/-0.3 g) and modified lead induced delay in half time of decay. Similarly, alpha-tocopherol modified the negative actions of lead exposure on MEPP frequencies and quantal content. Receptor autoradiographic studies revealed significant increase of nicotinic receptor levels at the endplate region of flexor muscle in lead treated mice. However, animals treated with lead plus alpha-tocopherol showed significantly decreased levels of nicotinic receptors. alpha-Tocopherol appears to protect against lead induced neuromuscular dysfunction. These effects of alpha-tocopherol are possibly mediated via a free radical mechanism or modification of calcium homeostasis.

Animals↗
PubMed2004

Effect of maternal malnutrition and anemia on the endocrine regulation of fetal growth.

Fetal growth retardation is a result of a complex pathology caused by multiple factors of fetal, placental, and maternal origin. Hormones and growth factors released as a result of maternal-fetal physiological interactions play an importance role in fetal well being and fetal outcome. Intrauterine Growth Retardation (IUGR) is associated with significant perinatal and childhood morbidity. It is estimated that 13.7 million infants are born annually with IUGR, comprising 11% of all births in developing countries. Both maternal malnutrition and anemia are associated with various degrees of fetal growth retardation. The relationship between decreasing birth weight percentiles and increasing fetal morbidity and mortality has been demonstrated by several investigators and epidemiological studies suggest that IUGR is a significant risk factor for the subsequent development of chronic hypertension, ischemic heart disease, diabetes, and obstructive lung disease in adult life (Barker's Hypothesis). Maternal anemia and/or malnutrition are recognized to be the most frequent cause of IUGR and SGA birth in developing countries like India. In order to investigate adaptive mechanisms by the fetus to overcome the growth disadvantage caused due to maternal nutritional limitations, we examined the quantitative variations in hormonal and growth factor profiles in paired cord blood and maternal samples obtained from neonates born to malnourished and/or anemic mothers. The results of our study show that: 1) The percentage of small for gestational age (SGA) neonates born to malnourished and anemic mothers was significantly higher than those born to mothers who were either malnourished or anemic; 2) Significantly higher levels of GH, PRL, HPL and IGF-1 were observed in the cord blood of neonates born to malnourished and anemic mothers indicative of an adaptive response on part of the fetus to over come an in-utero growth disadvantage; 3) The anoxemia-related fetal perturbations may have unique features that make them distinct from nutrient deficiency-related IUGR. Thus, these novel observations are relevant to the context of the ongoing scientific debate on Barker's hypothesis.

Adult↗
PubMed2004

'Efficacy' of esophageal peristalsis: a manometric parameter to quantify esophageal body dysfunction.

Esophageal motor abnormalities are currently categorized into separate entities based on standard manometry. The clinical significance of these categories is controversial. We evaluated whether ambulatory 24-h esophageal motility monitoring improves the assessment of patients thought to have a primary esophageal motor disorder. Standard and ambulatory 24-h esophageal motility records of 30 healthy volunteers and 136 symptomatic patients were compared. Regression analysis was used to identify parameters that relate to the presence of nonobstructive dysphagia. Prolonged ambulatory esophageal monitoring showed a marked circadian variation in the esophageal motor pattern and significant discrepancies to the findings on standard manometry in 47% of the 136 patients. Discrepancies were particularly frequent in patients categorized on standard manometry as having a 'nutcracker esophagus' or a nonspecific motor disorder. Of all data obtained, the prevalence of 'effective contractions', i.e. peristaltic contractions with an amplitude > 30 mmHg, during meal periods provided the best correlation with the presence of nonobstructive dysphagia. Of the 78 patients with nonobstructive dysphagia 71 (92%) had less than 50% of 'effective contractions' during meals. In five patients who had frequent simultaneous wave forms and less than 70%'effective contractions' during meals a long myotomy markedly reduced the severity of dysphagia. The 'efficacy' of esophageal contractions during meals best relates to patients' symptoms and allows expression of esophageal body dysfunction on a linear scale. This obviates the need for the current categories of esophageal motor disorders, permits an objective assessment of medical therapy and may improve the identification of patients that benefit from a surgical myotomy of the esophageal body.

Adolescent↗
PubMed2004

Visceral leishmaniasis in a non-endemic area of India.

The study included 57 patients with visceral leishmaniasis. The average duration of symptoms was 3.8 +/- 3.55 months and pancytopenia was the commonest haematological abnormality. The parasite load directly correlated with the degree of anaemia at presentation (P=0.03). Splenic regression took 9.58 +/- 4.5 days and haematological parameters recovered in 14.5 +/- 9.07 days. There were five deaths over the five-year study duration. Leishmaniasis was not the first diagnosis in 14 patients, of whom eight were residents of non-endemic regions. Diagnosis was achieved in 13.5 days in these patients, compared to 4.5 days in patients where leishmaniasis was suspected at the outset.

Adult↗
PubMed2004

Extrapleural anterolateral decompression in tuberculosis of the dorsal spine.

We reviewed 64 anterolateral decompressions performed on 63 patients with tuberculosis of the dorsal spine (D1 to L1). The mean age of the patients was 35 years (9 to 73) with no gender preponderance. All patients had severe paraplegia (two cases grade III, 61 cases grade IV). The mean number of vertebral bodies affected was 2.6; the mean pre-treatment kyphosis was 24.8 degrees (7 to 84). An average of 2.9 ribs were removed in the course of 64 procedures. The mean time taken at surgery was 2.45 hours when two ribs were removed and 3.15 hours when three ribs were removed. Twelve patients (19%) showed signs of neurological recovery within seven days, 33 patients (52%) within one month and 12 patients (19%) after two months; but six patients (10%) showed no neurological recovery. Forty patients were followed up for more than two years. In 34 (85%) of these patients there was no significant change in the kyphotic deformity; two patients (5%) showed an increase of more than 20 degrees.

Adolescent↗
PubMed2004

Hydroxyapatite ceramic-coated femoral stems in young patients. A prospective ten-year study.

We describe the clinical and radiological results of 38 total hip replacements (THR) using the JRI Furlong hydroxyapatite-ceramic (HAC)-coated femoral component in patients younger than 50 years. The mean age at the time of operation was 42 years (22 to 49) and the mean length of follow-up was ten years (63 to 170 months). All patients receiving a Furlong HAC THR were entered into the study regardless of the primary pathology including patients who had undergone previous hip surgery. The mean Harris hip score improved from 44 before operation to 92 at the last post-operative review. After 12 years the cumulative surivival for the stem was 100% (95% confidence interval 89 to 100). No femoral component was revised. Our results show that the Furlong HAC implant gives excellent long-term results in young patients with high demands.

Adult↗