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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 73 records · Page 4Linked to original sources

Novel repeated DNA sequences in safflower (Carthamus tinctorius L.) (Asteraceae): cloning, sequencing, and physical mapping by fluorescence in situ hybridization.

Two novel repetitive DNA sequences, pCtKpnI-1 and pCtKpnI-2, were isolated from Carthamus tinctorius (2n = 2x = 24) and cloned. Both represent tandemly repeated sequences. The pCtKpnI-1 and pCtKpnI-2 clones constitute repeat units of 343-345 bp and 367 bp, respectively, with 63% sequence heterogeneity between the two. Fluorescence in situ hybridization (FISH) was employed on metaphase chromosomes of C. tinctorius using, simultaneously, pCtKpnI-1 and pCtKpnI-2 repeated sequences. The pCtKpnI-1 sequence was found to be exclusively localized at subtelomeric regions on most of the chromosomes. On the other hand, sequence of the pCtKpnI-2 clone was distributed on two nucleolar and one nonnucleolar chromosome pairs. The satellite, and the intervening chromosome segment between the primary and secondary constrictions, in the two nucleolar chromosome pairs were wholly constituted by pCtKpnI-2 repeated sequence. The pCtKpnI-2 repeated sequence, showing partial homology to intergenic spacer (IGS) of 18S-25S ribosomal RNA genes of an Asteraceae taxon (Centaurea stoebe), and the 18S-25S rRNA gene clusters were located at independent, but juxtaposed sites in the nucleolar chromosomes. Variability in the number, size, and location of the two repeated sequences provided identification of most of the chromosomes in the otherwise not too distinctive homologues within the complement. This article reports the start of a molecular cytogenetics program targeting the genome of safflower, a major world oil crop about whose genetics very little is known.

Base Sequence↗

One nanosecond photon correlation spectroscopy on smectic liquid crystal films.

We have extended photon correlation spectroscopy down to a one-nanosecond time scale, and applied it to a study of layer undulations in freestanding smectic-A films of two cyanobiphenyl liquid crystals. Temporal correlations in the intensity of scattered light reveal an interesting combination of under- and overdamped modes. The underdamped mode is accurately described by a recently calculated correlation function of the smectic layer displacement, although its frequency and damping rate exhibit stronger dispersion at large optical wave vectors than expected from current dynamical models for smectic films.

Journal Article↗

Evaluation of cross-reactivity between Holoptelea integrifolia and Parietaria judaica.

BACKGROUND: Holoptelea integrifolia and Parietaria judaica belong to the family Urticaceae, but are geographically distantly located. H. integrifolia is an important pollen allergen of India and sensitizes almost 10% of the atopic population in Delhi. P. judaica, on the other hand, is a very dominant pollen allergen of the Mediterranean region, sensitizing almost 80% of the allergic population. Since both these important pollen allergens belong to the family Urticaceae, the objective of the present study was to assess cross-reactivity between these two pollen allergens from different geographical regions. METHODS: Cross-reactivity between these two pollen allergens was assessed on the basis of skin prick tests and ELISA, ELISA inhibition and immunoblot inhibition studies. RESULTS: Out of 44 atopic Indian patients skin prick tested with H. integrifolia extract, 34% were found to be sensitized. All the patients sensitized to H. integrifolia also showed varying degrees of skin positivity to P. judaica pollen extract. ELISA and ELISA inhibition studies suggested strong cross-reactivity between H. integrifolia and P. judaica pollen. Immunoblot inhibition studies revealed that 14-, 16-, 28-, 38-, 42- and 46-kDa proteins are the cross-reactive proteins in H. integrifolia and P. judaica. However, Par j 1, the major allergen of P. judaica, is absent in H. integrifolia pollen. CONCLUSION: H. integrifolia and P. judaica pollens share cross-reactive as well as unique epitopes. The major allergen of P. judaica, Par j 1, seems to be absent in H. integrifolia pollen allergen.

Allergens↗

Genetic polymorphisms of CYP2D6, GSTM1, and GSTT1 genes and bladder cancer risk in North India.

The study consisted of 100 patients (97 males and 3 females) suffering from bladder cancer and 76 matching controls. The maximum number of patients in this study was in the age group of 61-70 years. The prevalence of genetic polymorphism in the CYP2D6, GSTM1, and GSTT1 genes has been investigated to find their association with risk of bladder cancer. While there was no association between the heterozygous (HEM) genotype of the CYP2D6 gene with the risk of bladder cancer [odds ratio (OR)=1.00; 95% confidence interval (CI)=0.46-2.16], it was 1.5-fold with poor metabolizers (PM) genotype. When stratified according to different grades of bladder cancer, a significant association was found with an OR=3.54 (95% CI=0.89-13.98) in grade II, 3.3 (95% CI=0.12-20.6) in grade III, and 1.67 (95% CI=0.15-18.45) in grade IV. When stratified in relation to smoking status, significant association of the disease was found in heavy smokers with an OR=2.13 (95% CI=0.71-6.43). Subjects with the null genotype for GSTM1 had a slightly significant association with the bladder cancer risk and the risk increased to 2-fold with the GSTT1 null genotype. Smoking status also revealed an impact on the prevalence of bladder cancer in the individuals with GSTM1 and GSTT1 null genotypes. The results indicated that there is a 3-fold increase in risk of developing this cancer in the presence of one copy of the variant CYP2D6 (HEM) allele and null GSTT1.

Aged↗

Lipopolysaccharide-mediated protection against Klebsiella pneumoniae-induced lobar pneumonia: intranasal vs. intramuscular route of immunization.

Immunoprotective potential of delivered lipopolysaccharide (LPS) preparation from Klebsiella pneumoniae was determined in a murine model of lobar pneumonia. Protection was assessed with three doses of LPS (25, 50 and 100 microg; without any adjuvant) administered intranasally or intramuscularly. After evaluation of lung tissue (bacterial load and histopathology), no significant protection was observed at 25 microg with either application. A significant decrease in lung bacterial load coupled with fall in severity of lung lesions was observed with 50 microg (again both applications). At 100 microg dose, with intramuscular route, a further decrease in the lung bacterial load was shown compared to the 50 microg dose. In contrast, 100 microg LPS, when given intranasally, resulted in a higher bacterial colonization of the lung tissue and higher lung pathology; thus we recommend intramuscular instead of the intranasal route for developing protection against K. pneumoniae-mediated pneumonia with intact LPS-based vaccines.

Administration, Intranasal↗

Antibiotic-induced release of inflammatory mediators from bacteria in experimental Klebsiella pneumoniae-induced sepsis.

In a fibrin-clot model of sepsis, developed in mice, treatment with the antibiotics ceftazidime (Cfz) and ofloxacin (Ofl) caused significant (p < 0.01) release of endotoxin and TNF-alpha after 4.5 h when compared with control (untreated) and amikacin (Ami) treated group. Except for control group, the level of bacteremia declined in all three antibiotic-treated groups. The results suggest that antibiotic therapy, irrespective of the agent used, results in an increase in endotoxin levels in vivo. The amount of endotoxin liberated by Ami was much smaller than with Cfz and Ofl therapy, which makes it an appropriate agent for the treatment of sepsis. An increase in the level of TNF-alpha along with endotoxin is suggestive of increased inflammatory response.

Amikacin↗

Phylogenetic relatedness among leptospiral strains belonging to same serovar recovered from patients with different clinical syndromes.

Leptospirosis is an emerging zoonotic disease with widespread distribution. The disease, caused by a large number of pathogenic serovars of leptospires, varies in severity from mild flu like illness to severe and fatal forms. It has often been observed that the strains of the same serovar are associated with different clinical syndromes. In this study the isolates recovered from patients with mild and severe form of leptospirosis and those isolated from rodents trapped in the same areas were analyzed by using random amplified polymorphic DNA (RAPD) fingerprinting method using the primers PB1, M16, B11 and B12. RAPD fingerprinting patterns of these strains consistently showed five different genetic clusters. Strains belonging to serovar Ratnapura that caused hepato-renal involvement in patients in South India were genetically dissimilar to strains of the same serovar isolated from patients in Andamans who had pulmonary complications. Strains of other serovars causing mild and sever illness could also be discriminated. However, isolates obtained from human patients and rodents in the same geographical areas showed identical fingerprint patterns indicating that strains circulating in different geographical regions, though belonging to same serovar, are unique to each region.

Animals↗

Lipomas where you least expect them.

Although lipomas are relatively common and found in most anatomical sites, we are not aware of any previous reports of lipomas arising between the two layers of the deep temporal fascia above the zygomatic arch. This is surprising because a fat pad is seen and used during surgery in this area to protect the frontal branch of the facial nerve. This case highlights the importance of understanding the anatomy of this region, because lipomas can potentially arise in any of three fat pads laying near the facial nerve in this area.

Facial Neoplasms↗

Contributions of the sympathetic nervous system, glutathione, body mass and gender to blood pressure increase with normal aging: influence of heredity.

Body mass and sympathetic activity increase with aging and might underlie blood pressure (BP) elevation. Increased body mass index (BMI) may elevate BP by increasing sympathetic activity. Glutathione (GSH) can decrease BP, and declines with aging. We measured systolic (SBP) and diastolic BP, BMI, plasma (NE(pl)) and urine norepinephrine (NEu), and plasma GSH in n=204 twins across the age spectrum. BP correlated directly with BMI, NEpl, and NEu, but inversely with GSH. Age correlated with BP, BMI, NEpl, and NEu. BP, BMI, NEpl, and NEu were higher in older subjects than younger subjects, whereas GSH was lower with aging. In older subjects with high (above median) NEpl, SBP was 8 mmHg higher than in those of comparable age with low NE. In younger subjects with high GSH, BP was significantly lower than in younger subjects having low GSH. NEu was significantly reduced in young high-BMI subjects vs young low-BMI subjects. The heritability (h2) of NEpl, NEu, and GSH ranged from approximately 50 to approximately 70%, and these biochemical quantities were considerably more heritable than BP. We conclude that increases in sympathetic activity contribute to aging-induced SBP elevations, especially in older females. GSH reductions apparently participate in aging-induced BP elevations, most strongly in males. BMI increases contribute to BP elevations, particularly in younger subjects. BMI elevations apparently raise BP mainly by peripheral mechanisms, with generally little sympathetic activation. Substantial h(2) for plasma GSH, NE, and urine NE suggests that such traits may be useful 'intermediate phenotypes' in the search for genetic determinants of BP.

Adult↗

Urogenital effects of selective estrogen receptor modulators: a systematic review.

OBJECTIVE: Selective estrogen receptor modulators (SERMs) include a relatively large number of compounds, each with different profiles of estrogenic/antiestrogenic actions on the genital tract. The aim of this review was to systematically evaluate all the available data from randomized, controlled studies on the effects of these compounds on pelvic organ prolapse and urinary incontinence. METHODS: Literature searches were performed using three computerized databases to identify the result of all randomized, controlled trials performed with SERMs having any effects on pelvic floor as an outcome. A manual search was performed on all related articles. RESULTS: We have identified only one randomized, placebo-controlled trial specifically designed to assess the effect of raloxifene and tamoxifen on the urogenital tract. Most of the data on genitourinary effects of various compounds derive from either questionnaires or adverse events reported during phase III clinical trials. Both tamoxifen and raloxifene appear to increase the incidence of pelvic floor prolapse in one trial, although this was not apparent from the licensing studies data for either of the drugs. Raloxifene does not appear to increase the incidence of urinary incontinence. Levormeloxifene and idoxifene, on the contrary, were noted to increase uterine prolapse and incontinence during phase III trials that prematurely terminated. No data are available on the genitourinary effect of toremifene and on the newer SERMs currently undergoing phase III trials: basedoxifene, lasofoxifene, and arzoxifene. CONCLUSION: Contrary to their effects in bone, SERMs do not have a class-specific effect on the genitourinary tract. In fact, compounds that are more estrogenic on the uterus such as levormeloxifene and idoxifene also increase the risk of prolapse and incontinence. SERMs can adversely affect the pelvic floor and incontinence but data from urodynamic studies are not yet available. Data on prolapse are contradictory. Given the increased incidence of prolapse and incontinence observed in several licensing trials, more focused research on the effect of these molecules on pelvic floor function is needed.

Clinical Trials as Topic↗

Quality medicines for the poor: experience of the Delhi programme on rational use of drugs.

Prior to 1994, most Delhi hospitals and dispensaries experienced constant shortages of essential medicines. There was erratic prescribing of expensive branded products, frequent complaints about poor drug quality and low patient satisfaction. Delhi took the lead in developing a comprehensive Drug Policy in 1994 and was the only Indian state to have such a comprehensive policy. The policy's main objective is to improve the availability and accessibility of quality essential drugs for all those in need. The Delhi Society for the Promotion of Rational Use of Drugs (DSPRUD), a non-governmental organization, worked in close collaboration with the Delhi Government and with universities to implement various components of the policy. The first Essential Drugs List (EDL) was developed, a centralized pooled procurement system was set up and activities promoting rational use of drugs were initiated. In 1997, the Delhi Programme was designated the INDIA-WHO Essential Drugs Programme by the World Health Organization. The EDL was developed by a committee consisting of a multidisciplinary group of experts using balanced criteria of efficacy, safety, suitability and cost. The first list contained 250 drugs for hospitals and 100 drugs for dispensaries; the list is revised every 2 years. The pooled procurement system, including the rigorous selection of suppliers with a minimum annual threshold turnover and the introduction of Good Manufacturing Practice inspections, resulted in the supply of good quality drugs and in holding down the procurement costs of many drugs. Bulk purchasing of carefully selected essential drugs was estimated to save nearly 30% of the annual drugs bill for the Government of Delhi, savings which were mobilized for procuring more drugs, which in turn improved availability of drugs (more than 80%) at health facilities. Further, training programmes for prescribers led to a positive change in prescribing behaviour, with more than 80% of prescriptions being from the EDL and patients receiving 70-95% of the drugs prescribed. These changes were achieved by changing managerial systems with minimal additional expenditure. The 'Delhi Model' has clearly demonstrated that such a programme can be introduced and implemented and can lead to a better use and availability of medicines.

Drugs, Essential↗

Thumb replantation: a retrospective review of 103 cases.

Replantation has become the state of the art reconstruction for an amputated thumb. The aim of our study was to review our series of thumb replantations over a period of 12 years at the Bellevue Hospital Center in New York City. The mechanism of injury, level of amputation, and use of vein grafts was reviewed and correlated with survival rates of the replanted thumbs. The overall survival rate was 91.3%. Of the 12 thumbs that were re-explored for vascular compromise, 75% were successfully salvaged. Our study also indicates that there is no statistical difference in survival of thumb replants when comparing the mechanism of injury, the level of amputation, and the use of vein grafts. However, the use of vein grafting seemed to be beneficial in the successful outcome of replantation in severe crush and avulsion injuries, even though the values did not reach statistical significance. We conclude that thumb replantation is associated with very high survival rate, regardless of the mechanism of injury or level of amputation, and should be attempted in all cases. An early reexploration for vascular problems yields a high salvage rate and should be performed in all cases. We also recommend the use of vein grafts in severe crush and avulsion injuries.

Adolescent↗

How we do it: free conchal cartilage revisited for primary reconstruction of attic defects in combined approach tympanoplasty.

Keypoints * There are concerns over the efficacy of free cartilage autografts in attic reconstruction (scutumplasty) for combined approach tympanoplasty (CAT). * Our operative technique uses free conchal cartilage autografts and an additional piece of conchal cartilage to buttress the reconstruction. * Of the 16 cases where this technique was used, there were two cases (13%) of failure of the attic reconstruction and a keratin pearl (residual disease) in one case (6%). This compares favourably with comparable series using a variety of reconstruction techniques.

Cholesteatoma, Middle Ear↗