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Biomedical subjects

S Sinha

Publications and source records attributed to S Sinha.

At least 73 records · Page 4Linked to original sources
PubMed2005

Lead in paint and soil in Karnataka and Gujarat, India.

Blood lead surveys in several areas of India have found very high percentages of children with elevated blood lead levels. Fifty-three percent of children under 12 years of age in a seven-city screening had blood lead levels equal to or greater than 10 microg/dL, the level currently considered elevated by the U.S. Centers for Disease Control and Prevention (CDC). A number of these surveys focused on populations near lead smelters or in areas with high lead levels from combustion of lead-containing gasoline. There is little information available, however, on the levels of lead in paint in India and in soil. Field portable X-ray fluorescence analyzers were used to determine environmental lead levels in paint, dust, air, soil, and other bulk samples near several lead-using industries and in the residential environments of children with very high blood lead levels, at least four times as high as the CDC limit. Soils near industrial operations, such as secondary lead smelters, and battery dismantling units contained levels up to 100,000 ppm of lead. Four of 29 currently available paints from five manufacturers measured 1.0 mg/cm2 or above--the current U.S. definition of lead-based paint in housing-after the application of a single coat; four others measured at least 1.0 after three coats, and three others likely reached this level after the application of an additional one or two coats. In 5 of 10 homes of the elevated blood lead children, three or more locations in or around the home were found to have lead paint levels of 1.0 mg/cm2 or higher. Soil exceeding the U.S. standard for residential areas (400 ppm) was found at only one of the houses. Other sources of lead exposure, including traditional ayurvedic medicine tablets, were also observed. Similar surveys would be useful elsewhere in India and in other developing countries.

Data Collection↗
PubMed2005

A 5-year audit of haemodialysis access.

This is a review of our experience with vascular access procedures over a 5-year period at Derriford Hospital, Plymouth, UK. The aims of the study were to examine the outcome of vascular access procedures and factors influencing access survival. Between April 1995 and March 2000, 151 patients who underwent 221 vascular access procedures were studied. Of these, 136 had autogenous arteriovenous fistulae, whereas 85 had prosthetic AV grafts (41% in the thigh). The overall primary failure rate was 21% whereas the 1- and 5-year cumulative access survival rates were 60 and 41%, respectively. Thigh grafts have a mean survival of 36 months compared with 32 months for prosthetic upper limb and 43 months for autogenous fistulae. Age, diabetes and predialysis status did not significantly influence access survival. Thrombosis was responsible for access failure in 62 cases (28%). Avoiding subclavian vein canulation and performing vessel mapping prior to access placement should reduce the risk of access failure due to outflow obstruction.

Adolescent↗
PubMed2005

Do creatine kinase (CK) levels influence the diagnosis or outcome in patients with compartment syndrome?

We report a retrospective study in patients with compartment syndrome with the aim to analyse: 1) whether the level of rise in CK levels is a useful marker to the presence of compartment syndrome and; 2) whether an early fasciotomy assists in lowering of the elevated CK levels. The results of our study suggest that although raised CK levels are not diagnostic, they are a useful adjunct in making a diagnosis, and hence CK estimation should be done in all patients with suspected compartment syndrome. Moreover, an early fasciotomy (< 12 hours) has a statistically significant influence in lowering elevated CK levels, confirming the view that the earlier the decompression, the lesser the muscle damage.

Adult↗
PubMed2005

Overexpression and purification of recombinant eel calcitonin and its phylogenetic analysis.

Calcitonin (CT), a peptide hormone that is widely used for the treatment of osteoporosis, Paget's disease, hypercalcemic shock and chronic pain in terminal cancer patients, is produced by the para-follicular cells of the thyroid gland in mammals and by the ultimobranchial gland of birds and fish. Fish calcitonin, like eel calcitonin (eCT), is more potent and longer lasting than human CT and is one of the many bioactive peptides that require C-terminal amidation for full biological activity. In this study we describe the over-expression and over-production of C-terminal amidated eCT in recombinant Streptomyces avermitilis. A phylogenetic analysis was performed with all the known CT amino acid sequences.

Amino Acid Sequence↗
PubMed2005

Neurological manifestations of Ehlers-Danlos Syndrome.

Ehlers-Danlos Syndrome (EDS) is more identified for its cutaneous features but its neurological manifestations have not received the focused attention. Four patients of Ehlers-Danlos Syndrome (EDS) with neurological manifestations were evaluated for phenotypic data. These four men were from three families and two had consanguineous parentage. The mean age at onset and presentation of neurological symptoms were 10.5 years and 19 years respectively. Patient 1 presented with bilateral optic atrophy, sensorineural deafness, cerebellar ataxia and neuropathy. Patient 2 had marfanoid habitus, chorea and cerebellar ataxia. Patient 3 had action and percussion myotonia, wasting and weakness of sternocleidomastoid and distal limb muscles. Patient 4 had action myotonia, mirror movements of both hands and neuropathy. MRI of brain showed right parietal polymicrogyria. Neuroaxis involvement at multiple levels in EDS may have prognostic significance.

Adolescent↗
PubMed2005

Fresh water blue green algae from three agro-climatic zones of Uttar Pradesh, India: distribution pattern with seasonal variation.

The paper deals with 45 species of 21 genera of fresh water blue green algae (BGA) from three different agro-climatic zones of Uttar Pradesh. Samples were collected from different habitats varying in physico-chemical properties. Out of 45 species, 13 species belonged to order Chroococcales, 31 to order Nostocales, while only 1 species belonged to order Stigonimatales i.e. Fischerella mucicola. The physico-chemical parameters like pH, temperature, dissolved oxygen, electrical conductivity, nitrate, nitrite and rainfall play an important role in the periodicity of BGA. A positive correlation was found between dissolved oxygen (DO) of different ponds and species diversity, except in the case of western region of Uttar Pradesh (Farukhabad and Mahoba districts) where a positive correlation was found in electrical conductivity and total dissolved solids.

Climate↗
PubMed2005

Fly-ash induced synthesis of phytochelatins in chickpea (Cicer arietinum L.) plants.

Phytochelatins and related metabolites (cysteine and GSH) were found to be induced in the shoots of two varieties of Cicer arietinum viz., CSG-8962 and C-235 grown under different amendments of fly-ash with garden soil and press mud. Cysteine, GSH, PCs and its speciation were found in higher concentrations in amended fly-ash than in the control 100% soil. Two species of metal binding peptides i.e., PC2 and PC4 were found in both varieties and in amendments, however, their concentration varied depending upon the fly-ash concentrations in both amendments. Further, var. CSG-8962 was found more tolerant than var. C-235 because of higher concentrations of PCs and related metabolites.

Carbon↗
PubMed2005

Neuropraxia of the palmar cutaneous branch of the ulnar nerve during carpal tunnel decompression.

Carpal tunnel syndrome is one of the most commonly encountered conditions in the hand clinic and carpal tunnel decompression is the most frequently performed procedure in hand surgery. It is an effective procedure for patients with carpal tunnel syndrome. However, there is a high risk of complications that can be avoided with an understanding of wrist anatomy, appropriate planning and execution. We highlight one such complication, a case of neuropraxia of the palmar cutaneous branch of the ulnar nerve that followed carpal tunnel decompression.

Carpal Tunnel Syndrome↗
PubMed2004

A G/C element mediates repression of the SM22alpha promoter within phenotypically modulated smooth muscle cells in experimental atherosclerosis.

A hallmark of smooth muscle cell (SMC) phenotypic switching in atherosclerotic lesions is suppression of SMC differentiation marker gene expression. Yet little is known regarding the molecular mechanisms that control this process. Here we show that transcription of the SMC differentiation marker gene SM22alpha is reduced in atherosclerotic lesions and identify a cis regulatory element in the SM22alpha promoter required for this process. Transgenic mice carrying the SM22alpha promoter-beta-galactosidase (beta-gal) reporter transgene were crossed to apolipoprotein E (ApoE)-/- mice. Cells of the fibrous cap, intima, and underlying media showed complete loss of beta-gal activity in advanced atherosclerotic lesions. Of major significance, mutation of a G/C-rich cis element in the SM22alpha promoter prevented the decrease in SM22alpha promoter-beta-gal reporter transgene expression, including in cells that compose the fibrous cap of the lesion and in medial cells in proximity to the lesion. To begin to assess mechanisms whereby the G/C repressor element mediates suppression of SM22alpha in atherosclerosis, we tested the hypothesis that effects may be mediated by platelet-derived growth factor (PDGF)-BB-induced increases in the G/C binding transcription factor Sp1. Consistent with this hypothesis, results of studies in cultured SMCs showed that: (1) PDGF-BB increased expression of Sp1; (2) PDGF-BB and Sp1 profoundly suppressed SM22alpha promoter activity as well as smooth muscle myosin heavy chain promoter activity through mechanisms that were at least partially dependent on the G/C cis element; and (3) a short interfering RNA to Sp1 increased basal expression and attenuated PDGF-BB induced suppression of SM22alpha. Together, these results support a model whereby a G/C repressor element within the SM22alpha promoter mediates transcriptional repression of this gene within phenotypically modulated SMCs in experimental atherosclerosis and provide indirect evidence implicating PDGF-BB and Sp1 as possible mediators of these effects.

Animals↗
PubMed2004

L-type voltage-gated Ca2+ channels modulate expression of smooth muscle differentiation marker genes via a rho kinase/myocardin/SRF-dependent mechanism.

Vascular smooth muscle cell (SMC) contraction is mediated in part by calcium influx through L-type voltage-gated Ca2+ channels (VGCC) and activation of the RhoA/Rho kinase (ROK) signaling cascade. We tested the hypothesis that Ca2+ influx through VGCCs regulates SMC differentiation marker expression and that these effects are dependent on RhoA/ROK signaling. Depolarization-induced activation of VGCCs resulted in a nifedipine-sensitive increase in endogenous smooth muscle myosin heavy chain (SMMHC) and SM alpha-actin expression and CArG-dependent promoter activity, as well as c-fos promoter activity. The ROK inhibitor, Y-27632, prevented depolarization-induced increase in SMMHC/SM alpha-actin but had no effect on c-fos expression. Conversely, the Ca2+/calmodulin-dependent kinase inhibitor, KN93, prevented depolarization-induced increases in c-fos expression with no effect on SMMHC/SM alpha-actin. Depolarization increased expression of myocardin, a coactivator of SRF that mediates CArG-dependent transcription of SMC marker gene promoters containing paired CArG cis regulatory elements (SMMHC/SM alpha-actin). Both nifedipine and Y-27632 prevented the depolarization-induced increase in myocardin expression. Moreover, short interfering RNA (siRNA) specific for myocardin attenuated depolarization-induced SMMHC/SM alpha-actin transcription. Chromatin immunoprecipitation (ChIP) assays revealed that depolarization increased SRF enrichment of the CArG regions in the SMMHC, SM alpha-actin, and c-fos promoters in intact chromatin. Whereas Y-27632 decreased basal and depolarization-induced SRF enrichment in the SMMHC/SM alpha-actin promoter regions, it had no effect of SRF enrichment of c-fos. Taken together, these results provide evidence for a novel mechanism whereby Ca2+ influx via VGCCs stimulates expression of SMC differentiation marker genes through mechanisms that are dependent on ROK, myocardin, and increased binding of SRF to CArG cis regulatory elements.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed2004

Is the nuclear spin-orbit interaction changing with neutron excess?

The difference in the energies of the lowest states corresponding to the two nodeless single-particle orbitals outside the Z=50 closed proton shell, h(11/2) and g(7/2), increases with neutron excess. We have measured the Sn(alpha,t) reaction for all seven stable even Sn isotopes and found that the spectroscopic factors are constant for these two states, confirming their characterization as single-particle states. The trend in energies is consistent with a decrease in the nuclear spin-orbit interaction. A similar trend, also suggesting a decreasing spin-orbit splitting, is seen in the energies of the neutron single-particle states outside the N=82 core, i(13/2) and h(9/2).

Journal Article↗
PubMed2004

Synthesis of galactopyranosyl amino alcohols as a new class of antitubercular and antifungal agents.

The galactopyranosyl amino alcohols (3-16) were synthesised by regioselective oxirane ring opening of compound 2 with variety of amines and screened for antitubercular and antifungal activities. One of the compounds (16) showed potent activity against Mycobacterium tuberculosis H37 Rv in vitro and also displayed activity in MDR TB. The compound (16) was found to be superior to ethambutol clinically used anti TB drug in in vitro screen.

Amino Alcohols↗
PubMed2004

Portable lead analyzer to locate source of lead.

OBJECTIVE: To investigate the sources of lead in the environment in children with elevated blood, with the help of a Field Portable X-Ray Fluorescence Analyzer. METHODS: One hundred and seven school children were chosen for this study on a random basis, from Mangalore and Karnataka. Their blood lead was analyzed. Of the cases analyzed, 10 students whose blood lead level was more than 40 microg/dl were investigated using a field portable X-Ray Fluorescence Analyzer. This is the first time such a device has been available for this purpose in India. RESULTS: The 'likely' source of lead exposure could be determined in eight cases which was from the immediate environment of the children like 'lead-based' paint on surfaces in the house, on playground and other exterior equipment; lead storage batteries, contaminated dust and soil and other lead-containing substances. CONCLUSION: The use of an X-Ray Fluorescence Analyser appeared to be useful in determining the source of lead.

Child↗