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Biomedical subjects

Sushma Sharma

Publications and source records attributed to Sushma Sharma.

12 recordsLinked to original sources
PubMed2006

Ultrastructural findings for the mitochondrial subpopulation of mice skeletal muscle after adrenergic stimulation by clenbuterol.

Clenbuterol, a beta-adrenoceptor agonist, has been reported to induce skeletal muscle hypertrophy. However, it has also been known to reduce aerobic exercise performance and to deleteriously affect endurance and sprint exercise performance in rats. In the present study, the chronic administration of clenbuterol (2 mg/kg body weight; 30 days) resulted in various ultrastructural changes in three different types of muscles, gastrocnemius, a mixed-fiber type; anterior latissimus dorsi (ALD), a predominantly fast-twitch type; and diaphragm, a largely oxidative-type. The most prominent changes included mitochondrial swelling, matricular vesiculation in mitochondria, mitochondrial hyperplasia, sarcoplasmic vesiculation, and intermyofibrillar dilations. An increase in the cross-sectional area of both the subsarcolemmal (170, 167, and 79%) and the intermyofibrillar (129, 134, and 84%) mitochondria is noticed in the gastrocnemius, ALD, and diaphragm, respectively. The ultramicroscopic and morphometric results suggest drug-induced defects in contractile and oxidative activities.

Adrenergic beta-Agonists↗
PubMed2006

Refractive issues in pregnancy.

Pregnancy is known to cause refractive changes as a result of various hormonal changes occurring during pregnancy. These changes may persist for a few weeks post-partum and during lactation. In this article we discuss various refractive issues in pregnancy that have an effect on contact lens use, myopia and the outcome of refractive surgery.

Contact Lenses↗
PubMed2006

Rapid tests for group B Streptococcus colonization in laboring women: a systematic review.

OBJECTIVES: We set out to determine the accuracy and rapidity of various intrapartum group B Streptococcus (GBS) colonization tests. STUDY DESIGN: We performed a systematic review of test-accuracy studies, which were identified without language restriction from Medline and Cochrane databases; bibliographies of known primary and review articles; and contact with authors, experts, and manufacturers. Studies were selected if they tested pregnant women intrapartum for GBS colonization and confirmed by "gold-standard" laboratory cultures. Two reviewers independently selected studies and extracted data on their characteristics, quality, and results. Accuracy data were used to form 2 x 2 contingency tables. Heterogeneity was assessed, and LRs for positive and negative test results were pooled in subgroups of studies of various tests. RESULTS: There were 29 test-accuracy studies in 15,691 women, evaluating 6 different tests: polymerase chain reaction (PCR), optical immunoassay (OIA), DNA hybridization, enzyme immunoassay, latex agglutination, and Islam starch medium tests. The methodologic quality of the studies was generally poor. The most accurate was the real-time PCR test, but it was less rapid than OIA test. Real-time PCR took 40 minutes to complete, whereas the OIA took 30 minutes. CONCLUSIONS: Real-time PCR and OIA are candidates for rapid near patient intrapartum GBS testing to determine the need for antibiotic prophylaxis to prevent neonatal GBS disease. Before implementation in practice, a robust technology assessment of their accuracy, acceptability, and cost-effectiveness is required.

Adult↗
PubMed2006

Remodeling of extracellular matrix protein, collagen by beta-adrenoceptor stimulation and denervation in mouse gastrocnemius muscle.

A chronic administration of isoproterenol hydrochloride (60 mg/kg body weight; 30 days) alters the collagen metabolism in denervated gastrocnemius muscle of mice. Hydroxyproline assay for collagen showed an increase in collagen content by 47%, 44%, and 61% in innervated gastrocnemius + drug, denervated control, and denervated + drug, respectively, in gastrocnemius muscles after 30 days of drug administration. Collagen proliferation is beta-agonist (isoproterenol) specific confirmed with the simultaneous administration of beta-antagonist propranolol (100 mg/kg body weight; 30 days). Van Gieson staining showed heavy collagen proliferation in the epimysium region of the muscle section and adventitia of blood vessels and some specialized regions. However, denervated gastrocnemius muscle represented a heavy collagen proliferation in the endomysium region, which also is probably responsible for extensive collagen proliferation in denervated muscle after drug administration. The SDS-PAGE of pepsin-soluble collagen revealed five bands from origin to the point of migration, gamma, beta1, beta2, alpha1, and alpha2. The SDS-PAGE of CNBr-treated pepsin-insoluble collagen pointed toward the more prominent remodeling of collagen metabolism in the beta-agonist-induced denervated gastrocnemius muscle after drug administration. From the present study, we can conclude that beta-agonist, isoproterenol hydrochloride, augments collagen proliferation in innervated as well as in denervated gastrocnemius muscle.

Adrenergic beta-Agonists↗
PubMed2006

Beta-adrenoceptor agonist treatment reverses denervation atrophy with augmentation of collagen proliferation in denervated mice gastrocnemius muscle.

Daily oral administration of isoproterenol hydrochloride (60 mg/kg body weight; for 30 days) a beta-receptor agonist to normal innervated and denervated adult male Swiss albino mice confirmed its ability to induce skeletal muscle hypertrophy and reverse denervation atrophy respectively. Measurement of total tissue proteins and dry muscle mass showed 15-17% increase with 6% rise of hypertrophy index in gastrocnemius muscle. Hydroxyproline assay employed to measure the total tissue collagen exhibited 45% increase in collagen in normal innervated gastrocnemius muscle in response to beta agonist treatment. beta-adrenoceptor agonist ameliorated denervation atrophy along with further increase in collagen content of denervated gastrocnemius muscle.

Adrenergic beta-Agonists↗
PubMed2006

Histological evidences of reparative and regenerative effects of beta-adrenoceptor agonists, clenbuterol and isoproterenol, in denervated rat skeletal muscle.

The aim of this study was to determine the contribution of beta-adrenoceptor activation in the reconstruction of the structural and functional organization of denervated skeletal muscle. beta-agonists, clenbuterol (1.2 mg/kg body weight) and isoproterenol (2 mg/kg body weight), administration (daily oral administration; maximum 7 days) to normal innervated rats as well as denervated animals caused muscle hypertrophy. An increase in mean fiber diameter confirmed this stimulated growth both in normal innervated and denervated rat gastrocnemius muscle. Examination of muscle nuclei from treated but normal innervated rat gastrocnemius exhibited features like large size, active nucleoplasm and an increase in their number per fiber cross section and per mm mean fiber length indicating towards an elevated biosynthetic activity in tissue in the presence of beta adrenoceptor agonists. Administration of drugs to normal innervated animals resulted in an emergence of central muscle nuclei. The hyperactive and enlarged muscle nuclei ultimately organized themselves into unusually elongated nuclear streaks. beta agonist treatment to denervated rats resulted in amelioration of atrophic state of tissue characterized by hypertrophy of muscle fibers thus lending to a restoration of structural organization of tissue. Bizarre shapes of nuclei in denervated muscle tend to recover to that characteristic to normal innervated muscle in presence of clenbuterol and isoproterenol hydrochloride. All observations were confirmed by administering butoxamine, a beta-adrenoceptor antagonist along with beta-agonists. The results suggests that both clenbuterol and isoproterenol hydrochloride are capable of mimicking normal innervation functions in skeletal muscle and thus play important role in the structural and functional reorganization of tissue. Amelioration of denervation atrophy in rat gastrocnemius in the presence of beta-agonists supports this.

Adrenergic beta-Agonists↗
PubMed2006

Isoproterenol ameliorates workstress-induced rat skeletal muscle degeneration.

Beta-Agonists though have been widely studied for their protein anabolic effects in skeletal muscles, but the lipid status under work stress and agonist treatment have not been understood well in the skeletal muscles and heart of rat. In the present study, adult male Wistar rats were subjected to work overload stress and beta agonist isoproterenol treatment (2 mg kg(-1) day(-1) intraperitoneally) to examine, whether it attenuates work stress-induced changes or not. Simultaneously, beta2 antagonist butoxamine (2 mg kg(-1) day(-1) intraperitoneally) was administered to another isoproterenol-treated group. Work stress led to myofibrillar degeneration as well as rapid utilization of lipid to meet increased energy demands and for muscle repair, which was reflected through histochemical localization of lipids and biochemical estimation of cholesterol and triglycerides. Significantly decreased cholesterol levels in skeletal muscles and heart muscles were noticed. As expected, isoproterenol reversed the conditions by raising cholesterol and triglyceride levels significantly in the skeletal muscles and also by ameliorating the degenerative changes in muscle fibres as induced by work overload. However, severe accumulation of lipids in heart infers towards deleterious effects of isoproterenol on heart and thus remains a limiting factor for its immediate clinical application. Further research is needed to separate desirable effects of beta agonists on skeletal muscles from any undesirable effects on the heart, so as to optimize their therapeutic potential.

Adrenergic beta-Agonists↗
PubMed2006

Metabolic and physiologic characteristics of skeletal muscle determine its response to clenbuterol treatment.

beta-Adrenoceptor agonists are reported to induce skeletal muscle hypertrophy and hence serve as valuable adjunct to the treatment of wasting disorders. In the present study, we attempted to find out whether metabolic and physiologic characteristics of fibres are important in determining skeletal muscle response to clenbuterol (an adrenergic receptor agonist) therapy, as proposed in the treatment of wasting disorders. The treatment of mice with clenbuterol (2 mg/kg body wt for 30 days) resulted in skeletal muscle hypertrophy, more common amongst fast-twitch glycolytic fibres/muscle, with increase in body mass and a parallel rise in muscle mass to body mass ratio. Measurement of fibre diameters in soleus (rich in slow-twitch oxidative fibres), ALD or anterior latissimus dorsi (with a predominance of fast-twitch glycolytic fibres) and gastrocnemius (a mixed-type of muscle) from clenbuterol-treated mice for 30 days revealed noticeable increase in the per cent population of narrow slow-twitch fibre and a corresponding decline in white-type or fast-twitch glycolytic fibres in gastrocnemius and ALD. As revealed by counting of muscle cells in soleus, narrow red fibres declined with corresponding increase in white-type glycolytic fibres population. A significant decline in the succinic dehydrogenase activity was observed, thereby suggesting abnormality in oxidative activity of skeletal muscles in response to clenbuterol therapy.

Adrenergic beta-Agonists↗
PubMed2005

Dietary intake and growth pattern of children 9-36 months of age in an urban slum in Delhi.

This investigation deals with the dietary intakes and growth in early childhood in poor communities. Five hundred and forty five children, 9-36 months of age, and their caretakers (mothers) were selected randomly and invited to participate in the study. The food and nutrient intake of children was assessed using a 10-item food frequency and amount questionnaire (FAQ). The anthropometric nutritional status was assessed by the indices height-for-age (H/A), weight-for-age (W/A), weight-for-height (Wt/Ht) and MUAC, according to Indian and NCHS standards. The results showed that the intake of cereals, pulses, roots, green leafy vegetables (GLVs), other vegetables, fruits, sugar, fats and oils among children was grossly inadequate. The nutrient intake for energy was 56% of the current RDA. Anthropometric analysis revealed that the children were grossly undernourished. Seventy five per cent children were underweight (<-2 SD), while 35% severely undernourished (<-3 SD). Approximately, 74% children were having short stature (chronic malnutrition) with 39% severely stunted. Nineteen per cent children were excessively thin (wasted). The data regarding the degree of malnutrition among children demonstrated that 9.6% girls in 9-36 months of age had severe malnutrition as compared to 6.5% males. The maximum prevalence of severe malnutrition was in the age 31-36 months (10%) followed by 9.6% in 13-18 months. The moderate degree of malnutrition was around 30 to 33% in age group 13-36 months. The evidence from the study provides a strong basis to suggest low food intake as the main cause of under/malnutrition and growth retardation (stunting) in early childhood in poor communities.

Anthropometry↗
PubMed2003

Clenbuterol induced changes in cholesterol and triglyceride levels of gastrocnemius, pectoralis and heart of rat under work induced stress.

Work induced stress led to decreased cholesterol and fluctuating triglyceride levels in gastrocnemius and pectoralis muscles in rats. But the drug (clenbuterol, 2 mg kg(-1) day(-1)) treatment increased cholesterol and triglyceride levels in both the muscles. However, heart showed decreased cholesterol and increased triglyceride level in the animals under work stress, but at the same time drug treatment led to a significant increase in levels of the two lipid fractions, inferring towards deleterious effect of the drug on heart.

Animals↗
PubMed2002

Iron status of children aged 9-36 months in an urban slum Integrated Child Development Services project in Delhi.

OBJECTIVE: To assess the magnitude/severity and possible etiology of anemia and iron deficiency among children 9-36 months of age. METHODS: A population-based study on the prevalence, etiology of anemia and iron status in 545 children, 9-36 months of age, was conducted in an urban slum ICDS (Integrated Child Development Services) project in North-East Delhi. Hemoglobin and serum ferritin was estimated and information on socio-economic, demographic, parasitic infection/infestation and dietary intake was collected. RESULTS: Prevalence of anemia (using WHO cut-off values of Hb >11.0 g/dl) among children, 9-36 months of age, was 64%, of these 7.8% had severe anemia (Hb >7.0 g/dl). Using 10.0 g/dl as the Hb cut-off point 44% children less than 18 months of age in the present study population were anemic. On a sub-sample study, 88% children were estimated to be iron deficient, with serum ferritin concentration less than 12 microg/L. The peripheral smear red cell morphology showed 33.9% as microcytic-hypochromic and 37.1% as dimorphic. Dimorphic anemia was 55% in moderate anemia group. The energy and iron intakes were 56% and 45%, respectively of the Recommended Dietary Allowances (RDA). The parasitic infestation/infection was not related to the prevalence or severity of anemia. CONCLUSION: In Delhi, high prevalence of moderate to severe anemia and iron deficiency with vitamins folate and/or B12 among children under 3 years of age in an ICDS block in operation for 20 years is of concern. Dietary origin was the main cause of anemia in this age group.

Anemia, Iron-Deficiency↗