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Biomedical subjects

A Sharma

Publications and source records attributed to A Sharma.

At least 127 records · Page 7Linked to original sources

Antioxidant activity of bakuchiol: experimental evidences and theoretical treatments on the possible involvement of the terpenoid chain.

The protective activity of the plant-derived meroterpene, bakuchiol [1-(4-hydroxyphenyl)-3,7-dimethyl-3-vinyl-1,6-octadiene, 1], against oxidative damages to lipids and proteins has been investigated and rationalized based on the scavenging activity of 1 against various oxidizing radicals (Cl(3)CO(2)(*), linoleic acid peroxyl radicals, LOO(*), DPPH radicals, (*)OH, and glutathiyl radicals). The rate constants of the scavenging reactions, transients formed in these reactions, and their mechanistic pathways have been probed using optical pulse radiolysis technique. Besides 1, its methyl ether derivative 2 also could prevent lipid peroxidation in rat brain homogenate, indicating the probable participation of their terpenoid chains in scavenging LOO(*). This was further corroborated from the pulse radiolytic studies on the reaction between the glutathiyl radicals and the compounds 1 and 2 as well as two other congeners, 3 and 4, which showed transient absorptions at approximately 300 nm attributable to some C-centered allylic radicals. On the basis of the strong signals at approximately 300 nm with 1-3 as compared to compound 4, formation of the allylic radical adjacent to the trisubstituted olefin function in 1-3 was envisaged. This was confirmed by quantum chemical calculations of the relative energies of the probable radical species derivable from 2 using Hartree-Fock and density functional theory along with self-consistent reaction field model. In the case of 1, the allylic radical was found to be transformed into the phenoxyl radical at a later stage. All of these data revealed, for the first time, the importance of the terpenoid moiety of bakuchiol in controlling its antioxidant action via radical scavenging.

Animals↗

Variations in the length of the Y chromosome and the seminal attributes of Karan Fries bulls.

Fresh semen and blood samples from 20 Karan Fries bulls (4-6 years of age), maintained at the Artificial Breeding Complex of the National Dairy Research Institute, Karnal, were collected for one year. All the bulls had 60 chromosomes, comprising 58 acrocentric autosomes and 2 sex chromosomes, with X as the larger and Y as the smaller submetacentric. The mean lengths of Yp and Yq; the total length of the Y chromosome and the length ratio were 1.10 +/- 0.01 microm, 1.83 +/- 0.02 microm, 2.92 +/- 0.02 microm and 62.46% +/- 0.18%, respectively. Analysis of the length measurements of the the Y chromosomes in Karan Fries bulls showed that all the measurements, viz., the short arm of the Y chromosome, the long arm of the Y chromosome, the total length of the Y chromosome and the variation in length of Y chromosome, varied significantly among bulls. All the seminal parameters, the volume of semen, mass activity, initial motility, concentration, live sperm count and the total abnormal sperm count, were significantly affected by bulls, whereas season had a significant effect on all the seminal parameters except the total abnormal sperm count. No significant relationship between the ratio of the long arm to the total length of the Y chromosome and seminal attributes was observed.

Animals↗

Frequency of C3435T single nucleotide MDR1 genetic polymorphism in an Asian population: phenotypic-genotypic correlates.

AIMS: To investigate the frequency of the single nucleotide polymorphism C3435T in exon 26 of the MDR1 gene in Asians and to determine the functional significance of this SNP with the clinical pharmacokinetics of oral cyclosporin (Neoral) in 10 stable heart transplant patients. METHODS: The MDR1 C3435T polymorphism was investigated in 290 healthy Asian subjects (98 Chinese, 99 Malays and 93 Indians). We also compared the MDR1 polymorphism between the Asian population studied here and the published data on Africans and Caucasians. The clinical relevance of this SNP on oral bioavailability of a known P-gp substrate, cyclosporin, was assessed in 10 stable Chinese heart transplant patients. RESULTS: The homozygous TT genotype was observed in 32%, 28% and 43% of Chinese, Malays and Indians. The homozygous CC genotype was found in 25% of Chinese and Malays compared with 18% of Indians. The Indians had a lower frequency of the C allele [0.38 (0.31-0.45)] compared with the Chinese [0.46 (0.39-0.53)] and Malays [0.48 (0.42-0.55)]. Chi-squared test showed that the distribution of allele frequencies between the Malays and Indians differed significantly (P = 0.04). In this Asian population, the overall distribution of genotypes (CC, CT and TT) and allele frequencies were significantly different from those in Africans (P < 0.001). The results were also significant when the Chinese, Malays and Indians were compared separately with the African group (P < 0.001). Compared with the Caucasian data, the overall distribution of genotype and allele frequencies in the Asian population were also significantly different (P < or = 0.05). However, when each Asian ethnic group was compared separately with the Caucasians, only the Indians were found to be significantly different (P < or = 0.004). Genotypic-phenotypic correlations of this SNP were assessed in 10 stable Chinese heart transplant patients. The median AUC(0,4 h) was 11% lower in patients with CC genotype compared with subjects with TT genotype. However, the interpatient variability in AUC(0,4 h) was high in patients, especially in those with CC genotype. CONCLUSIONS: The distribution of the SNP C3435T in exon 26 in the Chinese and Malay population was found to be similar to the Caucasians whereas the Indians were different. The Asian population also differed significantly from the African and Caucasian population in the distribution of the C3435T SNP. The low frequency of the T allele in the Indian population implies lower expression of P-gp and may have important therapeutic and prognostic implications for use of P-gp dependent drugs in individuals of Indian origin.

Asia↗

Microwave-assisted rapid synthesis of methyl 2,4,5-trimethoxyphenylpropionate, a metabolite of Cordia alliodora.

Microwave assisted condensation of asaronaldehyde (2) with malonic acid in piperidine-AcOH provides 2,4,5-trimethoxycinnamic acid (3) in 87% yield within 4 min, which upon further reduction with PdCl2- HCOOH-aq. NaOH gives 3-(2,4,5-trimethoxy)phenyl propionic acid (4) in 88% yield within 3 min. Esterification of 4 with MeOH-H+ gives methyl 2,4,5-trimethoxyphenylpropionate (1), a metabolite of Cordia alliodora, in 94% yield within 3 min (overall 69% yield).

Aldehydes↗

Minimal access surgery for hydatid cyst disease: laparoscopic, thoracoscopic, and retroperitoneoscopic approach.

Surgery has remained the mainstay for the treatment of hydatid cyst. The rapid development of laparoscopic techniques has encouraged surgeons to replicate principles of conventional hydatid surgery using a minimally invasive approach. Several reports have confirmed the feasibility of laparoscopic hepatic hydatid surgery. We report the use of a laparoscopic approach for cysts located in the liver, lung, and retroperitoneum. Fifteen patients with hydatid cysts, including one patient with a recurrent cyst, of various organs, including the liver, lung, and retroperitoneum, were operated on laparoscopically. Sixteen hydatid cysts were drained in a total of 15 patients. The mean operative time was 84 +/- 6 minutes (60-125 minutes). The mean duration of the hospital stay was 2.3 days (1-6 days). The mean cyst diameter was 9.2 cm (6.4-13.5 cm). No conversions to open surgery were required. One complication, a trocar-induced bowel perforation, occurred, and there was no mortality. During 3 to 44 months (mean, 27 months) of follow-up, no recurrences developed. Minimal access surgery is a safe, effective, and viable option for the management of selected patients with hydatid cysts in various locations, such as the liver, lung, and retroperitoneum.

Adolescent↗

Studies of human polyclonal and monoclonal antibodies binding to lupus autoantigens and cross-reactive antigens.

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease serologically characterized by production of a variety of autoantibodies. Antibodies to double-stranded (ds) DNA are considered to be a diagnostic marker in SLE and their presence often correlates with active disease. The murine R4A anti-dsDNA antibody was found to cross-react with a peptide, D/EWD/EYS/G (R4A peptide), identified by analysing decapeptides selected from a peptide library. The R4A peptide inhibited binding of antibody to dsDNA and antibody deposition in kidneys in vivo. In other previous work, mice immunized with the peptide in a decapeptide form bound to a polylysine backbone, multiple antigenic peptide, were found to develop both anti-DNA and anticardiolipin antibodies. METHODS: To determine if human anti-DNA antibodies bind R4A peptide, we investigated the binding of monoclonal and polyclonal anti-dsDNA and anticardiolipin antibodies to the R4A peptide from patients with SLE. RESULTS: DNA binding by four immunoglobulin (Ig) G and two IgM human monoclonal anti-DNA antibodies was inhibited by the R4A peptide. While monomeric peptide was unable to inhibit affinity-purified polyclonal anti-DNA antibodies, serum anti-DNA reactivity was inhibited by an octameric form of the peptide in 10 SLE patients. CONCLUSIONS: Human anti-DNA reactivity includes the same fine specificity as that present in murine anti-DNA reactivity. Peptide binding might be a useful surrogate marker for SLE.

Adult↗

Extraperitoneal endoscopic groin hernia repair under epidural anesthesia.

We performed a prospective study to evaluate the feasibility of performing endoscopic total extraperitoneal repair of groin hernia (TEP) under epidural anesthesia in selected patients considered to be at high risk or unfit for general anesthesia. Fifty-eight endoscopic total extraperitoneal hernia repairs were performed in 36 patients between January 1997 and December 1999 under epidural anesthesia since they were considered a high risk or unfit for general anesthesia. All patients received intramuscular diclofenac sodium for preemptive analgesia. Intraoperatively, all were sedated with intravenous midazolam and fentanyl. Endoscopic TEP repair was successful under epidural anesthesia in 33 of 36 patients. In the remaining three patients, the procedure had to be converted to Lichtenstein's repair due to shoulder discomfort experienced by the patients as a result of pneumoperitoneum, which was produced by incidental peritoneal tears during extraperitoneal dissection. Intraoperatively, one patient had bleeding from the inferior epigastric artery, which was controlled with clipping of the artery. The mean operative time was 48 minutes (range, 28-72 minutes) in the TEP group and 94 minutes (range, 84-102 minutes) in the converted group. All the patients received an epidural top-up dose at the end of surgery for postoperative analgesia. All patients were ambulatory the same day. Postoperative pain was assessed by a visual analogue scale (VAS). The mean pain score was 1.2 (+/- 0.8) on discharge in the TEP group. During follow-up, seven patients developed scrotal swelling with cord induration, which was treated conservatively with scrotal support and analgesics. In all patients, resolution was observed within 6 weeks. One patient was detected to have a recurrence 4 months after surgery. Endoscopic TEP repair under epidural anesthesia appears to be safe, technically feasible, and an acceptable alternative in patients who are at high risk or unfit for general anesthesia.

Anesthesia, Epidural↗

Outer-membrane-protein subtypes of Haemophilus influenzae isolates from North India.

Haemophilus influenzae serotype b and non-typable isolates from blood, cerebrospinal fluid, sputum and throat swabs of patients and carriers in North India were analysed by outer-membrane protein (OMP) profiling. OMP analysis could differentiate the samples into 18 different subtypes. The non-typable isolates were more variable than the serotype b samples. OMP subtypes 1-6 were found only among the serotype b isolates and subtypes 7-18 among the non-typable isolates, while subtypes 2 and 8 were exhibited by both. The OMP profiles of isolates from blood, cerebrospinal fluid and sputum are in complete agreement with their ribotypes and RAPD fingerprints. The present study demonstrates for the first time the subtyping of Indian H. influenzae isolates by an easy and less-expensive method that is applicable to developing countries like India.

Bacterial Outer Membrane Proteins↗

A comparison of perimetric results with the Medmont and Humphrey perimeters.

BACKGROUND: The Humphrey field analyser (HFA), Humphrey-Zeiss frequency doubling perimeter, and the Medmont automated perimeter (MAP) are three commonly used automated perimeters with threshold achromatic methodologies. Visual field loss may be detected earlier with strategies that target cell lines with reduced redundancy or which suffer selective damage. METHOD: To compare these three perimeters, 63 subjects who were glaucoma suspects, ocular hypertensives, glaucoma patients, or normal controls were recruited selectively. All subjects underwent testing using MAP central threshold, MAP flicker perimetry, HFA full threshold, HFA SITA perimetry, HFA short wavelength perimetry (SWAP), and frequency doubling perimetry (FDP). After visual field testing, equivalent tests were compared: MAP central threshold with HFA full threshold and HFA SITA perimetry; Medmont flicker perimetry with HFA SWAP and FDP. RESULTS: On analysis of the MAP central threshold a kappa statistic and an area under the receiver operator curve (AUC) of 0.90 and 0.94, respectively, were found compared with HFA full threshold strategies, and 0.87 and 0.92 respectively, compared with HFA SITA. For MAP flicker a kappa statistic and an AUC of 0.65 and 0.81, respectively, were found compared with HFA SWAP and 0.87 and 0.96, respectively, compared with FDP. A quadrant analysis and comparison of mean defect between tests was also highly significant. CONCLUSION: Medmont and Humphrey perimeters correlated well; both may be used for clinical and research purposes with similar confidence.

Area Under Curve↗

Modification of polymer surfaces: optimization of approaches.

Modification of polymer surfaces to achieve a surface with enhanced compatibility is an important means of obtaining improved biomaterials. Techniques are available for altering the hydrophilicity or charge of a surface, attaching macromolecules or attempting to resemble cell membranes. Relevant to the clinical success of a modified surface is the modification procedure and a procedure based on incorporation as opposed to surface treatment has potential advantages. The modification of plasticized vinyl chloride (PVC) by the incorporation of cyclodextrins is described. In comparison to unmodified PVC controls, cyclodextrin incorporation reduced fibrinogen adsorption, with the extent of reduction dependent on the type and quantity of cyclodextrin incorporated.

Adsorption↗

Report from the Faculty of Family Planning and Reproductive Health Care AGM, May 2003: Medical termination of pregnancy in the late first trimester.

In the UK, mifepristone and gemeprost are licensed for medical termination of pregnancy (TOP) in the first trimester up to 63 days' amenorrhoea. Current practice, however, is to use low-dose (200 mg) mifepristone and misoprostol. We report a large cohort study using these drugs for medical TOP in the first trimester after 63 days amenorrhoea. Of 415 patients undergoing the procedure, 392 (95%) aborted completely and 96% required only two doses of misoprostol. We conclude that the regime is effective with few complications, however certain safeguards may be necessary for its widespread introduction

Abortifacient Agents, Nonsteroidal↗

Classic histamine H1 receptor antagonists: a critical review of their metabolic and pharmacokinetic fate from a bird's eye view.

The so-called "classic" histamine H(1) receptor antagonists are highly lipophilic compounds associated with significant biotransformation and tissue distribution. They are categorized according to their chemical structure into ethanolamines, alkylamines, ethylenediamines, piperazines, phenothiazines and piperidines, all of which have characteristic metabolic fates. The former four categories undergo primarily cytochrome P450-mediated oxidative N-desalkylations and deamination whereas the aromatic rings of the latter two undergo P450-mediated oxidative hydroxylation and/or epoxide formation. The common tertiary amino group is susceptible to oxidative metabolism by flavin containing monooxygenases forming N-oxides, and the alicyclic tertiary amines produce small amounts (up to 7%) of N-glucuronides in humans. Species, sex and racial differences in the metabolism and pharmacokinetics of antihistamines are known. Specific P450-isozymes implicated in the metabolism were identified in a few cases, such as CYP2D6 that contributes to the metabolism of promethazine, diphenhydramine and chlorpheniramine. Low circulating plasma concentrations of antihistamines are in part explained by significant first-pass effect and tissue distribution. Antihistaminic effects last up to 6 hours though some compounds exhibit a longer duration of action due to circulating active metabolites. Importantly, diphenhydramine inhibited CYP2D6 leading to a clinically significant drug-drug interaction with metoprolol. Other classic antihistamines were shown to be potent in vitro inhibitors of CYP2D6 and CYP3A4. The prescription-free access to most classic antihistamines can easily lead to their co-administration with other drugs metabolized by the same enzyme system thereby leading to drug accumulation and adverse effects. In depth knowledge of the metabolic pathways of classic antihistamines and the enzymes involved is crucial to prevent the high incidence of drug interactions in humans, which are predictable based on pre-clinical data but unexpected when such data is unavailable.

Animals↗

Duodenal diverticular haemorrhage in a patient taking NSAID.

We present a 55 years old male with severe anemia with history of pain abdomen for 2 weeks and malena of 10 days duration. He was taking NSAID (Diclofenac sodium). Upper GI endoscopy done twice did not reveal any abnormality. Upper gastrointestinal (UGI) barium series with small bowel follow through revealed a diverticulum on medial wall of second part of duodenum and there was evidence of ulcer in diverticulum. He underwent diverticulectomy. On follow up after 6 months patient was asymptomatic.

Anti-Inflammatory Agents, Non-Steroidal↗

Virtual waterless manufacturing: zero intake, zero emission.

Innovative application of a systematic approach to reduce freshwater intake and achieve zero emissions could help in reducing the adverse impact of industrial activity on world water resources. Cleantech is a strategic enviro-management technique to reduce the generation of pollutants in a process at source, through minor process modification, material substitution, improved manufacturing practices or low cost treatment.

Conservation of Natural Resources↗

Bone marrow metastasis in anaplastic oligodendroglioma.

Oligodendroglioma is a rare primary brain tumour. These tumours rarely metastasis extraneurally because of the absence of a lymphatic system, the presence of the blood-brain barrier and the patient's poor overall survival. Oligodendroglioma may spread via the cerebrospinal fluid or after surgical intervention. Metastasis to bone marrow is extremely rare. Oligodendroglioma is now considered a chemosensitive disease. If chemotherapy leads to prolonged survival, we may see more extraneural metastases in future.

Antineoplastic Agents↗

Olivopontocerebellar atrophy presenting with stridor.

The spectrum of degenerative ataxia includes the symptomatic degenerative ataxias and the primary degenerative ataxias. The later may be sporadic and idiopathic or hereditary, being genetically determined. When an individual ataxic patient presents with an adult-onset degenerative ataxia and has a negative family history, the physician is faced with a diagnosis of pure idiopathic sporadic degenerative ataxia or one of the hereditary ataxias. The clinical spectrum of olivopontocerebellar atrophy (OPCA) usually consists of pancerebellar signs with pyramidal and abnormal eye movements. Although Stridor is more commonly found in multisystem atrophy, it is rarely seen in OPCA. We, here report a case of third decade onset of ataxia presenting with stridor.

Cerebellum↗