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Shweta Sharma

Publications and source records attributed to Shweta Sharma.

18 recordsLinked to original sources
PubMed2025

Prevalence and causes of anemia among older adults in India: findings from wave 2 of the Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD).

Anemia among older adults aged&#x2009;&#x2265;&#x2009;60 years is a well-described risk factor that increases the risk of falls, cardiovascular diseases, and mortality. In India, objectively measured national estimates of anemia prevalence and the causes of anemia among older adults are lacking. The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) collected venous blood samples from a nationally representative sample of 3,252 individuals in wave 2 of the study. Out of these, 3,009 samples were used to estimate national prevalence and regional differences in anemia prevalence and its underlying causes. Anemia was defined as hemoglobin&#x2009;<&#x2009;13&#xa0;mg/dl in males and <&#x2009;12&#xa0;mg/dl in females and further categorized into nutritional and non-nutritional anemia based on several nutritional (ferritin, Vitamin B12, and folate), inflammatory (ferritin, C-reactive protein), and renal (serum creatinine) biomarkers. The overall national anemia prevalence was 49.92%. Anemia prevalence was significantly higher among women (53.9%) than men (45.8%). Among those with anemia, nutritional anemia was found in 63.5% of the respondents, with isolated iron deficiency anemia being the most common cause (51.8%). Among the non-nutritional category, anemia of chronic disease was the most common type (31.4%). About 10% of all anemia cases could not be classified into either category using the available data. Regional differences were seen with the highest prevalence of anemia in Assam, West Bengal, Jharkhand, and Odisha, and the lowest prevalence (<&#x2009;30%) in Jammu & Kashmir and Haryana. Multivariate adjustment showed that age, sex, and region of residence are independently associated with anemia status. The study provides valuable insights into the overall anemia prevalence among older adults in India, its underlying causes, and regional differences to lay a strong foundation for making informed decisions toward anemia control in India.

Humans↗
PubMed2006

Predictors of attendance and dropout at the Lung Health Study 11-year follow-up.

Participant attrition and attendance at follow-up were examined in a multicenter, randomized, clinical trial. The Lung Health Study (LHS) enrolled a total of 5887 adults to examine the impact of smoking cessation coupled with the use of an inhaled bronchodilator on chronic obstructive pulmonary disease (COPD). Of the initial LHS 1 volunteers still living at the time of enrolment in LHS 3 (5332), 4457 (84%) attended the LHS 3 clinic visit, a follow-up session to determine current smoking status and lung function. The average period between the beginning of LHS 1 and baseline interview for LHS 3 was 11 years. In univariate analyses, attenders were older, more likely female, more likely to be married, smoked fewer cigarettes per day, and were more likely to have children who smoked at the start of LHS 1 than non-attenders. Attenders were also less likely to experience respiratory symptoms, such as cough, but had decreased baseline lung function compared with non-attenders. Volunteers recruited via mass mailing were more likely to attend the long-term follow-up visit. Those recruited by public site, worksite, or referral methods were less likely to attend. In multivariate models, age, gender, cigarettes smoked per day, married status, and whether participants' children smoked were identified as significant predictors of attendance versus non-attendance at LHS 3 using stepwise logistic regression. Treatment condition (smoking intervention or usual care) was not a significant predictor of attendance at LHS 3. Older females who smoked less heavily were most likely to participate. These findings may be applied to improve participant recruitment and retention in future clinical trials.

Adult↗
PubMed2006

A unique preovulatory expression pattern plays a key role in the physiological functions of BMP-15 in the mouse.

Mutations in the bone morphogenetic protein 15 (BMP-15) gene cause female infertility in the monoovulatory human and sheep; however, in the polyovulatory mouse, loss-of-function of BMP-15 results only in reduced ovulation rate. To elucidate the cause of these species-specific differences, we investigated the functional role of BMP-15 in the mouse ovary. Here, we found that the functional mature form of BMP-15 is barely detectable in the mouse oocytes until just before ovulation, when it is markedly increased. Further, we found that BMP-15 induces cumulus expansion in mouse cumulus-oocyte complexes. The oocyte culture medium from immature mice primed with pregnant mare serum gonadotropin followed by human chorionic gonadotropin also stimulated cumulus expansion, and this activity was attenuated by BMP-15 antibody. Interestingly, the oocyte culture medium from mice treated with pregnant mare serum gonadotropin alone had no effect. Moreover, BMP-15 stimulated the expression of EGF-like growth factors in cumulus cells as well as a series of molecules downstream of EGF-like growth factor signaling, including cyclooxygenase 2, hyaluronan synthase 2, tumor necrosis factor-stimulated gene 6, and pentraxin 3, all of which are necessary for normal cumulus expansion. An antagonist of the EGF receptor completely abolished the effect of BMP-15 in inducing cumulus expansion. These results are consistent with the phenotype of BMP-15-null mice, which exhibit normal folliculogenesis but have defects in the ovulation process. The species-specific differences in the phenotypes caused by BMP-15 mutations may thus be attributed to the temporal variations in the production of the mature form of BMP-15.

Animals↗
PubMed2006

Melatonin prevents X-ray irradiation induced oxidative damagein peripheral blood and spleen of the seasonally breeding rodent, Funambulus pennanti during reproductively active phase.

PURPOSE: Biological effects of X-ray irradiation and protection by melatonin on the immune status of a tropical rodent, Funambulus pennanti, was examined by estimating oxidative damage of peripheral blood and spleen and protection by melatonin treatment. MATERIAL AND METHODS: Seventy squirrels were divided into 4 sets of 25, 25, 10 and 10 having subdivisions into a total of eight groups. Squirrels of set 1 (groups A and B) received only normal saline, set 2 (groups C and D) received 25 microg/100 g body weight (bwt) melatonin and set 3 (groups E and F) received 25 microg/100 g bwt vitamin E for four weeks. Groups G and H of set 4 received high doses of melatonin (0.5 mg/100 g bwt) 30 min prior to and 30 min after X-ray irradiation, respectively, and were sacrificed 1 h after irradiation. Groups B and D were sacrificed after 4 h, 24 h, 48 h and 72 h of irradiation for total leukocyte count (TLC) in peripheral blood, percent apoptotic cells and lipid peroxidation (LPO) in spleen while group F was sacrificed after 4 h of irradiation to measure LPO. RESULTS: Pre-melatonin treatment (25 microg/100 g bwt) restored TLC, percent apoptotic cells and LPO levels of X-ray exposed squirrels. High dose pre-melatonin treatment (0.5 mg/100 g bwt) restored the above conditions significantly while post treatment did not. Vitamin E reduced elevated LPO level in irradiated tissue, but the effect of melatonin was more potent. CONCLUSION: Melatonin administration prior to X-ray irradiation prevented radiation-induced oxidative damage during the reproductively active phase of the seasonally breeding rodent suggesting a high protective role of melatonin following X-ray irradiation.

Animals↗
PubMed2005

Temperature-induced percolation behavior of AOT reverse micelles affected by poly(ethylene glycol)s.

The influence of poly(ethylene glycol)s additives viz. mono- (EG), di- (DEG), tri- (TEG), tetra- (TeEG) and poly(ethylene glycol)-400 (PEG-400) on temperature-induced electrical percolation of water/AOT/isooctane microemulsion system has been investigated. The composition of microemulsion systems has been kept constant to omega=22 and [additive] = 0.1 M w.r.t. dispersion medium. The effect of increase in the non-polar continuum (S= [Oil]/[AOT]) is indicated by increase in the percolation threshold, theta(c). The findings have been elaborated in terms of validity of scaling laws in the light of the dynamic percolation theory. The activation energy of the process, DeltaEp, has been estimated from Arrhenius plots. Pseudophase concept of the micellar aggregation has been utilized to assess the thermodynamics of clustering of the nanodroplets. The state of trapped water in the micellar core and the corresponding interactions with the AOT head group has been visualized through 1H NMR and FTIR analysis. Results show that at higher omega (>16.0), encapsulated water behaves like free or the bulk water.

Journal Article↗
PubMed2005

Bone morphogenetic protein-15 in the zebrafish ovary: complementary deoxyribonucleic acid cloning, genomic organization, tissue distribution, and role in oocyte maturation.

Bone morphogenetic protein-15 (BMP-15) is a member of the TGFbeta family known to regulate ovarian functions in mammals. The structure and function of BMP-15 in lower vertebrates are less known. In this study, we cloned the zebrafish BMP-15 (zfBMP-15) cDNA and depicted its genomic organization. The zfBMP-15 cDNA encodes a protein of 384 amino acids. The mature protein has 46-51% sequence identities to fugu, chicken, and mammalian BMP-15. It also shares 38-46% homology with growth and differentiation factor-9 in fishes, chicken, and mammals. Phylogenetic analysis further confirms that the zfBMP-15 is most closely related to BMP-15 from other species, whereas the growth and differentiation factor-9 peptides from fish to mammals form a distinct branch. Comparison of zfBMP-15 cDNA with zebrafish genome database revealed that zfBMP-15 is encoded by a gene with two exons and one intron, located on chromosome 6. BMP-15 mRNA is expressed in the ovary and testis and, to a lesser extent, brain, liver, gut, heart, and muscle. Real-time PCR revealed that BMP-15 is expressed in follicles at all stages of development with no significant changes over the course of folliculogenesis. Using in situ hybridization and immunocytochemistry, we detected BMP-15 in both oocytes and follicular cells. Incubation of follicles with antiserum against zfBMP15 increased oocyte maturation, whereas incubation with recombinant human BMP-15 suppressed human chorionic gonadotropin-induced oocyte maturation. These findings suggest that BMP-15 plays a role in regulating gonadal functions in fish, in particular oocyte maturation.

Amino Acid Sequence↗
PubMed2005

On the temperature percolation in a w/o microemulsion in the presence of organic derivatives of chalcogens.

The course of temperature percolation in a w/o microemulsion system comprising water/bis(2-ethylhexyl) sulfosuccinate sodium, AOT/isooctane affected by the presence of additives has been investigated. Additives, viz., organic derivatives of chalcogens including dipyridyl diselenide (Py2Se2), diphenyl diselenide (Ph2Se2), and dipyridyl ditelluride (Py2Te2), have been assimilated in the reverse micellar system. Formulations have been studied in terms of (i) the concentration variation of additives, (ii) the change in omega (= [H2O]/[AOT]), and (iii) the change in the nonpolar continuum, S (= [oil]/[AOT]). Phenyl derivatives hinder the percolation, whereas the pyridyl derivative in moderate amounts favors the phenomenon. The estimated values of the critical exponents are lower than those predicted by the dynamic percolation theory. The association model has been implemented to access the thermodynamic parameters of droplet clustering. Pyridyl compounds are expected to alter the rigidity of the surfactant monolayer, which could help to promote the attractive interdroplet interaction. FT-IR spectroscopy has been used to elucidate the changes occurring in the core water in the presence of organic derivatives of chalcogens as the droplet size is increased. Results have been rationalized in terms of the alteration in the physicochemical behavior of the water/AOT/isooctane microemulsion in the presence of additives.

Journal Article↗
PubMed2005

Essential role of the oocyte in estrogen amplification of follicle-stimulating hormone signaling in granulosa cells.

The establishment of dominant ovarian follicles that are capable of ovulating fertilizable oocytes is a fundamental determinant of female fertility. This process is governed by pituitary gonadotropins as well as local ovarian factors. Within the follicle, estrogen acts in an autocrine/paracrine manner to enhance FSH action in the granulosa cells. These effects include the augmentation of P450aromatase expression and estradiol production. This feed-forward effect of estrogen is believed to play a key role in follicle dominance. Here we found the essential role of the oocyte in this physiological process using primary cultures of rat granulosa cells. In the presence, but not absence, of oocytes, estrogen amplified FSH-stimulated increases in mRNA expression of P450aromatase, FSH receptor, LH receptor, and inhibin alpha-, betaA-, and betaB-subunits as well as cAMP production. Thus, oocytes mediate the estrogen enhancement of FSH action in the granulosa cells. In comparison with FSH, cotreatment with estrogen and oocytes failed to amplify the stimulatory effects of forskolin or 8-bromoadenosine-cAMP on granulosa cell responses including P450aromatase mRNA expression and cAMP production, indicating that estrogen/oocytes amplify FSH action at a site upstream of adenylate cyclase. These findings support the novel conclusion that communication between the oocyte and granulosa cells plays a crucial role in mediating estrogen action during FSH-dependent folliculogenesis.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2005

Protective role of Spirulina feed in a freshwater fish (Poecilia reticulata Peters) exposed to an azo dye-methyl red.

Acute toxicity of an azo dye-methyl red (5-40 ppm) was examined under starving conditions, on two groups of Poecilia reticulata--a freshwater fish, fed on different diets prior to their exposure to dye. Besides natural feed, fish of group-1 also received Spirulina feed for one month (feed population), whereas those of group-2 received only natural feed (non-feed population). The mortality data revealed non-feed population to be more tolerant to feed stress during acute toxicity study, whereas feed population exhibited better tolerance to the combined stress of both feed and methyl red; especially at higher concentrations of the latter. RBCs in methyl red treatments acquired different shapes (poikilocytosis) and an increase in their size (anisocytosis) was also noticed. Percentage of such abnormal RBCs was almost equal in both feed and non-feed populations, except at a lower concentration (5 ppm), at which percentage of poikilocytic RBCs was lesser in the feed population. RBC counts in the control non-feed fish (34.5 x 10(4)/mm3) were significantly lower than control feed population (50.0 x 10(4) /mm3). Their number decreased with an increase in methyl red concentrations in non-feed population (9-26%), but percent reduction in RBC counts was almost similar (20-26%) at various concentrations of methyl red (5-30 ppm) in the feed population. Despite reduction in RBC counts, feed population did not suffer from anemia in methyl red treatments, as evident by their RBC counts which were almost equal to control fish of non-feed population. The results suggest that Spirulina feed improves tolerance of test organism towards methyl red manifested by noticeable reduction in the cytotoxic effects on RBCs and a lower mortality rate at higher concentrations of dye.

Anemia↗
PubMed2005

Effect of an acute and chronic toxicity of four commercial detergents on the freshwater fish Gambusia affinis Baird & Gerard.

The toxic effects of four commercial detergents (two washing powders and two cakes) are reported in this paper on behavior, mortality and RBC counts of a freshwater fish Gambusia affinis. During acute toxicity studies (96h), surface movements of fish increased markedly for 24h, only at higher concentrations (>10 ppm) of all the four detergents. Thereafter, they were lethargic and bottom dwellers similar to those exposed for a period of 30 days in the longterm ecotoxicological studies made on detergent powders at a sublethal concentration (10 ppm). The detergents exposed to fish were found slippery due to mucous secretion. Hemorrhage regions were also found on their gills. The dissolved oxygen content also decreased (10-18%) in the detergent treatments of higher concentration (> 10 ppm). During acute toxicity studies, cakes (LC50 = 6.69 - 19.98ppm) were found more toxic than powders (LC50 = 18.34-20.72ppm). In comparison to the control fish, RBC counts decreased (12-64%) in the detergent exposed fish, being more pronounced among those exposed to cakes. The chronic exposure (30 days) of the fish also resulted in reduction in the RBC counts (41-58%). It is thus evident that all the four detergents are toxic to the fish Gambusia affinis.

Animals↗
PubMed2004

Smart biocatalysts: design and applications.

Smart materials respond to chemical or physical changes in their environment in a predictable fashion. One class of such materials are smart polymers which can be used to design reversibly soluble-insoluble biocatalysts. One important advantage of such soluble polymer enzyme conjugates is in bioconversion of macromolecular or insoluble substrates. In addition, they share the advantage of reusability with conventional immobilized enzymes. Stimuli that are used to "recover" smart polymer - enzyme conjugates for reuse include changes in pH, temperature, ionic strength and addition of chemical species like calcium. In addition to these, enzymes linked to photoresponsive polymers have also been described in the literature. Both adsorption and covalent coupling have been used to create such polymer conjugates. End-group conjugation and site-specific conjugation are recently described strategies to obtain biocatalysts with better designs for solving mass transfer constraints. Some important applications of such smart biocatalysts are hydrolysis of starch, cellulose and proteins. Work has also been carried out on hydrolysis of pectins and xylans. All the above applications involve hydrolysis and are hence carried out in aqueous media. For synthetic applications such as synthesis of peptides, some photoresponsive polymers linked to proteases have recently been described.

Biological Products↗
PubMed2002

Separation of an isoenzyme of polyphenol oxidase from Duranta plumieri by expanded bed chromatography.

Aqueous extracts of seeds of Duranta plumieri were found to be rich in polyphenol oxidase activity. The anion-exchange chromatography of the crude extract on Streamline DEAE resolved the activity into three fractions. The major fraction (77% of the total activity) was further purified by treating it with concanavalin A-agarose in the batch mode. The enzyme preparation eluting with alpha-methylmannoside showed a single band on SDS-PAGE. The minimum molecular weight corresponded to 14,000 Da. The K(m) and V(max) of this isoenzyme were found to be 7.1 mM and 73.5 U ml(-1) min(-1) respectively. The k(cat) of this isoenzyme was calculated to be 8235 s(-1). The isoenzyme also showed the phenomenon of latency and the activity could be enhanced by 196% on heating it at 55 degrees C for 30 min.

Catechol Oxidase↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMedDate not supplied

Acute toxicity of textile dye wastewaters (untreated and treated) of Sanganer on male reproductive systems of albino rats and mice.

This study reports on the toxic effects of 15-days oral administration of untreated (Influent) and treated (Effluent) textile dye wastewaters on male reproductive systems of adult Swiss albino rats (age: 85-90 days) and mice (40-50 days). Textile dye wastewaters decreased body weight (7-25%) and reproductive organ weight (testis, epididymis, prostate gland and seminal vesicle, 2-48%). Similar trends were noted for total protein (14-70%), cholesterol (14-91%) and total lipid (10-30%) content of reproductive organs and spermatozoa, and for fructose levels in seminal vesicle (18-44%). Acid phosphatase activity in prostate however, was increased (11-44%) in the wastewater-exposed animals. Histopathological studies of treated animals revealed altered spermatogenesis, with higher sperm abnormalities, reduction in sperm counts (10-59%), and altered motility (14-56%). The magnitude of these abnormalities was stronger in rats versus mice, while among treatments, it was stronger in the Influent animals. Adverse effects improved when treated rats were allowed to recover 45 days in the control condition. Only recovered Effluent rats were capable of fertilizing normal females indicating that treated wastewater was less toxic; however, in comparison to control rats, litter size and body weight gains of F(1) and F(2) generations were adversely affected. Thus, the present study has established toxicity of both untreated and treated textile dye wastewater on reproductive biology of male Albino mice and rats.

Acid Phosphatase↗
PubMedDate not supplied

A smart bioconjugate of chymotrypsin.

alpha-Chymotrypsin was immobilized on Eudragit S-100 via covalent coupling with 93% retention of proteolytic activity. The conjugate behaved as a smart biocatalyst and functioned as a pH-dependent reversibly soluble-insoluble biocatalyst. The pH optimum of chymotrypsin broadened on immobilization, and the immobilized preparation showed better stability at and above pH 6.5 as compared to the free enzyme. The immobilized enzyme showed a slight shift in the temperature optimum and enhanced thermal stability retaining 70% of its original activity after 1 h of exposure to 40 degrees C as compared to the 25% residual activity for the free enzyme under identical conditions. K(m) and V(max) values did not change on immobilization. Also, the immobilized preparation was quite stable to reuse, it retained almost 85% of its original activity even after a fifth precipitation cycle. UV spectroscopy and circular dichroism were used to probe structural changes in the enzyme upon immobilization.

Chymotrypsin↗