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Biomedical subjects

M Sharma

Publications and source records attributed to M Sharma.

At least 271 records · Page 15Linked to original sources
PubMed1991

Micellar electrokinetic capillary chromatographic separation and laser-induced fluorescence detection of 2'-deoxynucleoside 5'-monophosphates of normal and modified bases.

Micellar electrokinetic chromatography is used to separate dansylated nucleotides, both normal and modified species. The high separation power allows detection of minor components present in less than 1 part per thousand of the major components. Laser-excited fluorescence is used to detect the separated components at the 6 x 10(-18) mol level or 10(-9) M injected material. Combined with high-performance liquid chromatographic enrichment prior to labeling, this technique can be used to assess DNA damage in carcinogenesis studies.

Animals↗
PubMed1991

Effect of chronic microwave radiation on T cell-mediated immunity in the rabbit.

Experiments were conducted to elucidate the effects of chronic low power-level microwave radiation on the immunological systems of rabbits. Fourteen male Belgian white rabbits were exposed to microwave radiation at 5 mW/cm2, 2.1 GHz, 3 h daily, 6 days/week for 3 months in two batches of 7 each in specially designed miniature anechoic chambers. Seven rabbits were subjected to sham exposure for identical duration. The microwave energy was provided through S band standard gain horns connected to a 4K3SJ2 Klystron power amplifier. The first batch of animals were assessed for T lymphocyte-mediated cellular immune response mechanisms and the second batch of animals for B lymphocyte-mediated humoral immune response mechanisms. The peripheral blood samples collected monthly during microwave/sham exposure and during follow-up (5/14 days after termination of exposures, in the second batch animals only) were analysed for T lymphocyte numbers and their mitogen responsiveness to ConA and PHA. Significant suppression of T lymphocyte numbers was noted in the microwave group at 2 months (P less than 0.01, delta % 21.5%) and during follow-up (P less than 0.01, delta % 30.2%). The first batch animals were initially sensitised with BCG and challenged with tuberculin (0.03 ml) at the termination of microwave irradiation/sham exposure and the increase in foot pad thickness (delta mm), which is a measure of T cell-mediated immunity (delayed type hypersensitivity response, DTH) was noted in both the groups. The microwave group revealed a better response than the control group (delta % +12.4 vs. +7.54). The animals were sacrificed and the tissue T lymphocyte counts (spleen and lymph node) were analysed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Atrial septal defect presenting as recurrent primary amoebic lung abscess.

A middle-aged female with an atrial septal defect (secundum type) presented with a primary pulmonary amoebic abscess. She was successfully treated with antiamoebic therapy. One year later she presented with a similar lung abscess which again responded to antiamboebic treatment. Attention is drawn to the fact that a patient with a left to right shunt can present with a recurrent rare primary parasitic infection of the lung.

Amebicides↗
PubMed1991

Seminal vesiculitis due to Mycobacterium gastri leading to male infertility.

Tuberculosis of the genitourinary tract is a well-known cause of male infertility. However, infertility from infection by nontuberculous mycobacterium has not been reported. Herein, we present a case of seminal vesiculitis due to Mycobacterium gastri in a diabetic patient leading to male infertility. Improvement in semen quality was noticed after 6 months of therapy with isoniazid, ethambutol and rifampicin.

Adult↗
PubMed1991

Protective immunity to entamoeba histolytica infection in subjects with antiamoebic antibodies residing in a hyperendemic zone.

To investigate the relationship between amoebic gut infection and the presence of serum antiamoebic antibodies in a community where amoebiasis is highly endemic, a cross-sectional population survey was conducted covering 982 subjects in 2 adjacent villages in rural India. E. histolytica was detected in fecal smears in 18.1% (88/487) and antiamoebic antibodies by micro-ELISA in 28.7% (251/874) subjects. In 450 subjects in whom there was no clinical evidence of invasive amoebic disease or history of ingestion of antiamoebic drugs in the previous year and from whom both stool and matched serum samples were obtained, correlation of gut infection with seropositivity was attempted. Seropositivity in 80 cyst passers (23.8%) was significantly lower than in 370 non-cyst passers (35.1%; p less than 0.05). Conversely the rate of gut infection with E. histolytica was lower in seropositive subjects (19/149; 12.8%) as compared to seronegative subjects (61/301; 23%, p less than 0.05). In the population where E. histolytica infection was highly endemic, the rate of gut infection with the parasite was inversely related to seropositivity. Our data suggests that invasive E. histolytica infection (mostly asymptomatic) evokes good gut immunity in the host with clearing of the parasite from the colon and/or resistance to reinfection. High prevalence rate of amoebic antibodies indicates good "herd" immunity.

Adolescent↗
PubMed1991

Enzyme linked immunosorbent assay (ELISA) for detection of meningococcal antibodies in north India.

Serological response was studied in 16-30 years high risk age group, during the period December 1986-April, 1988, following meningococcal vaccine (Biomerieux, France). A total of 200 serum samples were collected from 50 individuals before vaccination and at 3 intervals of 1, 3 and 6 months post-vaccination respectively. Antibody response was measured by Enzyme Linked Immuno-Sorbent Assay (ELISA) and indirect haemagglutination assay (IHA). In the vaccinees antibody response by IHA test showed 56%, 82%, 78% and 74% positivity in the pre-vaccination, 1 month, 3 months and 6 months post vaccination samples. By ELISA 2%, 80%, 74% and 66% of the above groups showed serological response. Difference in the pre-vaccination and titres/O.D. of various post-vaccination groups was found to be statistically significant (p less than 0.001). There was, however, no significant difference (p greater than 0.05) amongst the titres/O.D. of three post-vaccination groups. Similarly acute and convalescent blood samples of 25 patients and one sample each of 31 contacts was studied for antibody response. In general, higher antibody titres are produced with systemic infection than with local nasopharyngeal infection or following vaccination.

Adolescent↗
PubMed1991

Valproic acid.

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Dosage Forms↗
PubMed1990

Fluorinated carbohydrates as potential plasma membrane modifiers. Synthesis of 4- and 6-fluoro derivatives of 2-acetamido-2-deoxy-D-hexopyranoses.

2-Amino-2,4-dideoxy-4-fluoro- and 2-amino-2,4,6-trideoxy-4, 6-difluoro-D-galactose, and 2-amino-2,4-dideoxy-4-fluoro- and 2-amino-4-deoxy-4, 4-difluoro-D-xylo-hexose were synthesized, as potential modifiers of tumor cell-surface glyco-conjugate, from benzyl 2-acetamido-3-O-benzyl-2-deoxy-4, 6-di-O-mesyl-alpha-D-glucopyranoside and benzyl 2-acetamido-3, 6-di-O-benzyl-2-deoxy-4-O-mesyl-alpha-D-glucopyranoside, which were converted into the corresponding 4,6-difluoro-2,4, 6-trideoxy and 2,4-dideoxy-4-fluoro derivatives. Benzyl 2-acetamido-2-deoxy-4-O-mesyl-alpha-D-galactopyranoside and benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-alpha-D-xylo-hexo-4-ulopyra noside were treated with diethylaminosulfur trifluoride to give 2-amino-2,4-dideoxy-4-fluoro-D-glucose and 2-amino-2,4-dideoxy-4, 4-di-fluoro-D-xylo-hexose derivatives, respectively, to give after deprotection the target compounds. Several of the peracetylated sugar derivatives inhibited L1210 tumor-cell growth in vitro at concentrations of 1-5 10(-5) M. The peracetylated derivative of 2-amino-2,4-dideoxy-4-fluoro-D-galactose inhibited protein and glycoconjugate biosynthesis, and also exhibited antitumor activity in mice with L1210 leukemia.

Acetylgalactosamine↗
PubMed1990

Detection and quantitation of 8-hydroxydeoxyguanosine 5'-monophosphate in X-irradiated calf-thymus DNA by fluorescence postlabeling.

8-Hydroxydeoxyguanosine 5'-monophosphate (8-OH dGmp) was synthesized from deoxyguanosine 5'-monophosphate (dGmp) by ascorbic acid in the presence of hydrogen peroxide and labeled with dansyl chloride through a phosphoramidate linkage with ethylenediamine (EDA). A DNA model 8-OHd(TACG), isolated intact by high pressure liquid chromatography (HPLC) from x-irradiated d(TACG) and characterized by nmr, was digested enzymatically to 5'-mononucleotides. The modified nucleotide was enriched by HPLC and dansylated. Analysis of the dansylated product by HPLC, using a fluorescent detector, detected a peak with retention time corresponding to that of the dansyl labeled authentic marker. The same overall procedure was used to detect 8-OHdGmp from x-irradiated calf-thymus DNA. The content of 8-OHdGmp in the irradiated DNA increased linearly with increasing levels of x-irradiation in the dose range of 6-60 Gy.

Animals↗
PubMed1990

Fluorescence postlabeling assay of cis-thymidine glycol monophosphate in X-irradiated calf-thymus DNA.

DNA damage was induced by irradiating calf-thymus DNA with a GE Maxitron-250 as an X-ray source. The use of nitrous oxide as a scavenger of solvated electrons in the irradiation process, resulted in essentially a monoreactant system of the biologically important hydroxyl radical. A novel approach combining the enzymatic digestion of the irradiated DNA to nucleoside 5' monophosphates and fluorescence postlabeling was applied to detect a specific modified nucleotide induced by ionizing radiation, namely the 5,6-dihydroxy-5,6-dihydrothymine lesion. This modification, often referred to as the glycol lesion, is polar and is generated mainly as the cis stereoisomers. In order to demonstrate the detection of this lesion in DNA by fluorescence labeling, the lesion was first produced chemically in a DNA model compound d(CGTA). The modified oligomers were isolated intact by HPLC and characterized by NMR as cis stereoisomers of glycol derivatives of d(CGTA). The major isomer of the modified d(CGTA) was enzymatically digested to yield 5' monophosphates. The digest was chromatographed by HPLC to enrich the modified nucleotide. The fraction containing the modified nucleotide was labeled with dansyl chloride. The fluorescent labeled nucleotide was chromatographed by HPLC. The same overall procedure was applied to DNA X-irradiated in aqueous solution. With a conventional fluorescence detector, HPLC analysis of the fluorescence labeled nucleotides detected 1 modified nucleotide/10(6) normal nucleotides from 100 micrograms DNA. The two cis glycol lesions were detected in the irradiated DNA by co-chromatography with fluorescent labeled markers. The initial assay of the modified oligomer demonstrated that the same stereoisomer of cis glycol was induced as a major modified nucleotide by both chemical oxidation and ionizing radiation.

Animals↗
PubMed1990

The Indian experience with hypertrophic pyloric stenosis.

A study of 58 consecutive Indian infants operated for congenital hypertrophic pyloric stenosis revealed an accentuated male predominance in the incidence of the disease and far less preoperative hemetemesis as compared to that in their Western counterparts. 'Pyloric tumor' was palpable in 89% of cases. Only 34.5% of these infants were first born. Postoperative vomiting occurred in 13.8% of patients and wound sepsis was not encountered. Air contrast radiography confirmed the diagnosis in clinically doubtful cases.

Female↗
PubMed1990

Syphilis serology and human immunodeficiency virus positivity in Chandigarh.

AIDS and other sexually transmitted diseases are interlinked. VDRL positivity may indicate that the individual has an increased risk of being HIV positive as the epidemiological risk factors for developing syphilis and AIDS are similar. We analysed 323 (5.8%) VDRL positive serum samples (out of 5592 screened) for HIV positivity. All were HIV negative. While syphilitic infection in India at present is not commonly associated with HIV infection, experience in other countries indicates caution.

Adolescent↗
PubMed1990

Isolation rates of different mycobacterial species from Chandigarh (north India).

A total of 4958 patients, clinically suspected to have tuberculosis were screened for mycobacteria by acid fast staining and culture procedures. Mycobacterial species were isolated from 462 (9.3%) patients while acid fast bacilli were demonstrated on smear examination in 83 (1.7%) patients. Mycobacterium tuberculosis was the most common isolate (92%). Among the nontuberculous mycobacteria, M. fortuitum was isolated in 13 (2.8%), M. avium in 2 (0.4%) and M. szulgai in 1 (0.2%). In 22 individuals clinically suspected of tubercular pleural effusion, pleural biopsy specimen gave higher isolation of mycobacteria (27.3%) as compared to isolations from pleural fluid specimens (9.1%).

Child↗
PubMed1990

Microcalorimetric studies on cell survival and repair after UV induced damage.

Rate of heat production during cell proliferation following UV-irradiation of respiratory-deficient yeast cells was measured as a function of time (p-t curve) in a batch microcalorimeter. Following observations were made: (a) All growing cell cultures showed 3 distinct phases of heat production namely lag, exponential and declining phases of rate of heat production. (b) Duration of the lag phase is inversely proportional to the number of cells capable of proliferation. (c) After UV-irradiation, lag phase increased in a dose dependent manner. (d) Liquid-holding reactivation increased the surviving fraction and reduced the lag phase in p-t curves. Presence of 2-deoxy-D-glucose during liquid-holding prevented the reduction in lag phase due to the inhibition of repair processes.

Calorimetry↗
PubMed1990

Effect of salbutamol on premature labour.

Salbutamol, a beta-adrenergic stimulant, with a property of smooth muscle inhibition has been used in prevention of premature labour on 40 patients. To 540 ml of 5% dextrose solution 5 mg of salbutamol was added. The infusion was started at the rate of 10 drops per minute and then increased by 10 drops every 5-10 minutes, until uterine contractions ceased. It was observed that in 62.5% patients pregnancy was prolonged for more than 7 days and in 80% for more than 3 days. The mean gain in days was 14.8 days and the maximum was 48 days. The drug was more effective in patients with cervical dilatation less than 2 cm and with uterine contractions less than 3 per 10 minutes.

Adult↗
PubMed1990

Acute intussusception: referral in relation to presentation and aetiology.

A study of 42 consecutive children with acute intussusception was undertaken. The emphasis was on the time taken for surgical referral in relation to the presenting symptom. Operative findings and outcome revealed late referral (greater than 72 h) in cases presenting with diarrhoea and bleeding per rectum. A higher incidence of gangrenous gut and irreducibility of intussusception was found in the ileoileal variety of intussusception. Some interesting facts about the aetiology have also been noted. Rupture of intussuscipiens was also encountered.

Acute Disease↗