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Biomedical subjects

M Bhaskar

Publications and source records attributed to M Bhaskar.

At least 19 recordsLinked to original sources

Isolation and antimicrobial susceptibility pattern of Nocardia among people with culture-proven ocular infections attending a tertiary care eye hospital in Tamilnadu, South India.

AIMS: To evaluate the epidemiology, microbiological features, as well as antibiotic susceptibility patterns of Nocardiafrom cases with ocular nocardial infections seen over a period of 8 years in a tertiary eye care hospital. METHODS: Microbiology records of 164 cases of culture-proven ocular nocardial infection diagnosed between March 1997 and February 2005 were reviewed retrospectively. The outcome data included isolation rate, predisposing factors, demography (age and sex), and category of infection, utility of conventional diagnostic methods, microbiological profile, and antibiogram-resistogram patterns. RESULTS: A total of 164 (3.1%) Nocardiaspecies were identified among 5378 culture-proven cases. Ninety-six (58.5%) isolates were from corneal scrapings followed by vitreous biopsy (17.0%). Most (58.0%) of the cases were between 51 and 80 age groups. Male preponderance was obvious. All the 164 (100%) nocardial infections were identified by culture. Of 125 ocular specimens subjected to Gram's staining, nocaridal filaments were identified in 70 (56%) specimens. In addition to KOH mounting, modified AFB staining was also found to be helpful. Upon in vitrosusceptibility testing, 98.7 and 90.2% of nocardial isolates showed sensitivity towards amikacin and ciprofloxacin, respectively. CONCLUSIONS: Ocular nocardiosis is relatively rare among ocular infections. Amikacin and ciprofloxacin are highly effective in treating ocular nocardiasis. Prompt and accurate microbiological diagnosis and early administration of these antibiotics may have a positive effect on the ocular outcome as well as in controlling nocardial prevalence.

Adolescent↗

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: a multicentre study.

PURPOSE: Methicillin resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu. METHODS: A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates. RESULTS: Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1%) and 39 (37.9%) were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6%) were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100%) of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin. CONCLUSION: The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

Anti-Bacterial Agents↗

Subtenons infection by Dirofilaria repens.

Zoonotic filariasis caused by Dirofilaria repens, a parasite of carnivores occurs mainly in countries surrounding Mediterranean region. The infection occurs in and around eye among animal handlers through vector transmission. We are reporting a case of human Dirofilariasis affecting subtenons region in a 63 year-old woman from Coimbatore, South India. The purpose of this article is to review the clinical course and management of ocular Dirofilariasis.

Animals↗

Chemical and enzymatic interactions of Direct Black 38 and Direct Brown 1 on release of carcinogenic amines.

Release of amine products from azo compounds is of considerable interest, since most of the metabolized amine products have toxic and carcinogenic characters. Moreover, most of the azo dyes are extensively used as coloring agents in inks, textiles, leathers, food and pharmaceutical industries. The present study emphasis on the quantification and comparison of amines released from water soluble dyes by (i) extra cellular protein (ECP) of Streptomyces sp. SS07 and by (ii) chemical methods. It has been observed that both the methods release considerable quantities of similar type of amine products. Release of amine compounds by ECP and chemical reduction in acid and alkaline sweat medium from a leather garment sample was also assessed. ECP (0.7852 mg protein/mg of ECP) releases benzidine and 4-amino biphenyl from Direct Black 38 and Direct Brown 1 as stable products at pH 9.2 and at 37 degrees C for a contact period of 24 h. On comparison with chemical reduction, it was observed that about 5-20% increase in the release of amine products by ECP was observed. However, more than 60% of amine products were released by chemical method from leather garment samples than direct treatment with ECP.

Amines↗

Detection of pneumolysin in cerebrospinal fluid for rapid diagnosis of Pneumococcal meningitis.

BACKGROUND & OBJECTIVES: Pneumolysin, a toxin produced by Streptococcus pneumoniae is associated with virulence and is found in all invasive isolates. Its role as a diagnostic tool has recently been exploited. Most of the methods used are based on molecular techniques and are not cost-effective. The present study was undertaken to evaluate a simple, rapid and cost-effective method to detect pneumolysin in CSF as a diagnostic test for pneumococcal meningitis. METHODS: A total of 75 CSF samples from children with presumptive diagnosis of acute pyogenic meningitis or encephalitis were subjected to Gram stain, culture and pneumolysin detection by Cowan 1 staphylococcal protein A co-agglutination technique. RESULTS: Pneumolysin was detected in 26(78.8%) of 33 culture proven CSF samples and 4(9.5%) of 42 culture negative samples. Antigen detection by Co-A had a specificity of 90 per cent and a sensitivity of 79 per cent when compared with culture. Compared to Gram stain, pneumolysin Co-A had a specificity and sensitivity of 91.0 and 92.0 per cent respectively. INTERPRETATION & CONCLUSION: Detection of pneumolysin was found to be a simple, low cost antigen detection assay for rapid diagnosis of pneumococcal meningitis, for routine use in the developing countries.

Agglutination Tests↗

Prevalence of beta hemolytic streptococci carrier rate among schoolchildren in Salem.

A preliminary study was conducted to identify the carriers of beta hemolytic streptococci (BHS) among school children. BHS were identified, grouped by latex agglutination test and tested for susceptibility to penicillin, erythromycin and cefazolin from their throat swabs. Prevalence of BHS was found to be 21.6% with group G (43.2%) as the predominant group followed by group A (28.8%). All the isolates were sensitive to the antibiotics tested. Health cards were issued to the carriers of group A beta hemolytic streptococci.

Adolescent↗

Separation of xylidine isomers by micellar electrokinetic chromatography.

Xylidines are important precursors for the production of dyes, drugs, and various other products. Because of the high carcinogenic nature of some xylidine isomers it becomes very essential and relevant to develop suitable analytical procedures to separate isomers as well as enhance detection at very low concentrations. Micellar electrokinetic chromatography has been standardized at various influencing parameters such as pH, ionic strength, and micelle modifiers, and the optimum conditions have been ascertained for the best separation and sensitivity of standard mixtures. The applicability of the procedure in environmental samples is studied.

Journal Article↗

Influence of zinc on cardiac and serum biochemical parameters in rabbits.

The pattern of lipid profiles and organic constituents of cardiac and serum tissues of rabbits were studied on treatment with cholesterol, zinc and zinc + cholesterol. Total carbohydrate and total protein levels were decreased with elevated lipid levels in cholesterol fed rabbits. However, the zinc and cholesterol + zinc fed rabbits showed decreased lipid fractions in cardiac and serum tissues leading to reduced atherosclerotic process in rabbits. These results suggest that the zinc is acting as a hypolipidaemic and anti atherogenic agent in experimental rabbits.

Animals↗

Detection of antipneumolysin in invasive childhood pneumococcal infections.

Antibody levels against pneumolysin, a virulence factor in pneumococcal infections were evaluated by a neutralization test, using crude pneumolysin. A study population of 28 hospitalised children with culture proven pneumococcal meningitis and pneumonia were tested for detection of antipneumolysin antibodies in their serum. Results were compared with age and sex matched controls who were admitted with infections other than pneumococcal. Geometric mean titer (GMT) of antipneumolysin in serum of patients with pneumococcal infections showed a significant difference when compared with controls, GMT of 196.1 and 185.2 were noted in patients with meningitis and pneumonia respectively, in contrast to a titer of 40.32 among controls. A difference of more than 4-fold antibody titers between patients and controls was considered significant. Detection of antipneumolysin in serum can therefore be considered as a useful laboratory investigation in diagnosing invasive pneumococcal infections.

Antibodies, Bacterial↗

Interactions of monocrotophos and quinalphos with Anabaena torulosa isolated from rice soil.

The interaction of insecticide combinations of monocrotophos and quinalphos on Anabaena torulosa, by the criteria of absorbance (OD) and packed cell volume (PCV) of the culture, content of chlorophyll a, phycocyanin, carotenoids, total protein, DNA and RNA, heterocyst differentiation and nitrogen fixation, were assessed. In general, monocrotophos and quinalphos, in combination, interacted significantly yielding three different responses viz., additive, antagonistic or synergistic. The nature of the interaction found with OD and PCV was nearly the same for a particular concentration of the insecticides. However, no consistent interaction was observed with respect to carotenoids and phycocyanin. The three types of interaction were noticed for total protein, DNA and RNA. Interestingly, the insecticide combinations at lower concentrations yielded all interaction responses for heterocyst frequency and nitrogenase activity. But, higher concentrations, in combination, resulted in synergism for heterocyst differentiation and nitrogen fixation.

Anabaena↗

Changes in myocardial contractile protein ATPases in chronically adrenalectomized rats with and without glucocorticoid replacement.

Studies were conducted to examine the effects of chronic adrenalectomy (Adx) and adrenalectomy plus glucocorticoid replacement therapy on rat cardiac contractile protein ATPase activities. The Ca2+-dependent Mg-ATPase activity of myofibrils isolated from rat ventricles 3 weeks postadrenalectomy (Adx) was significantly decreased at all pCa2+ concentrations (P less than 0.01), compared to sham-operated (SO) rats. Similarly, Ca2+-, K+-EDTA, and actin-activated myosin ATPase activities of Adx rat hearts were markedly decreased below that of SO rats (P less than 0.01). Dexamethasone administration to Adx rats prevented the decrease of Ca2+- and K+-ATPase activities of myosin, but not of myofibrillar Ca2+-dependent Mg-ATPase or actin-activated myosin Mg-ATPase activities. These studies suggest that glucocorticoid insufficiency induced by adrenalectomy results in altered myocardial contractile protein ATPase activity which may underlie impaired cardiac performance.

Adenosine Triphosphatases↗

Cardiovascular changes in chronically adrenalectomized conscious rats.

Mean arterial blood pressure (MABP), heart rate (HR), stroke volume index (SVI), cardiac index (CI), systemic vascular resistance index (SVRI), and central venous pressure (CVP) were measured in conscious, freely moving, sham-operated (SO) and chronically adrenalectomized (ADX) rats. After 3 weeks of ADX, the rats exhibited hypotension, tachycardia, and diminished SVI and CI. From 3 to 6 weeks after surgery, the HR decreased and SVRI increased. These changes were obscured when the same measurements were obtained in the same rats under enflurane anesthesia. Cardiovascular responses to an epinephrine (0.4 microgram/kg/min) infusion were measured in conscious SO and ADX rats. The magnitude of change from baseline to peak was similar in all groups, indicating that ADX did not alter the responsiveness of the cardiovascular system to epinephrine. The peak MABP response to epinephrine in ADX rats was significantly below that of SO control rats, suggesting that ADX impaired the ability of the cardiovascular system to maintain normal arterial blood pressure. No differences were found in plasma concentrations of Na+, K+, Cl-, PO4 =, or hematocrit that would help to explain the effect of long-term adrenalectomy. The data underscore the cardio-depressant effect of enflurane anesthesia, demonstrate the importance of a conscious rat model in studying the effects of ADX on the cardiovascular system, and emphasize that the full effects of ADX occur over a period of several weeks.

Adrenal Insufficiency↗

Tissue compensatory metabolic profiles in Tilapia mossambica (Peters) on acclimation to sublethal acidic and alkaline media. Gill glycogen metabolism.

Freshwater Fish, Tilapia mossambica (Peters) was acclimated to sublethal acidic and alkaline media and branchial tissue glycogen metabolism was studied. In acidic media, the glycogenolysis is elevated in the tissues and glycolysis is suppressed. In contrast, in alkaline media, the tissue glycolytic pathway is accelerated with accumulation of organic acids. In both the cases tissue had elevated G-6-PDH activity indicating stress conditions on the tissue metabolism. The tissue compensatory changes provided survival value to the fish under altered pH media.

Acclimatization↗

Effects of riboflavin analogues and diuretics on the spontaneously hypertensive rat heart.

The chronic treatment of spontaneously hypertensive rats (SHR) with 7,8-dimethyl-10-(3-chlorobenzyl) isoalloxazine [CBI], 7,8-diethyl-10-aminol isoalloxazine [DEAI], enduron (methyclothiazide) and amiloride were studied for their effects on blood pressure and cardiac contractile protein ATPase activities. After 35 weeks of treatment all the above antihypertensive agents showed a decrease in blood pressure in the SHR (p less than 0.01). Chronic treatment with CBI, DEAI, enduron, and amiloride significantly improved the myofibrillar ATPase activity at all pCa2+ concentrations (p less than 0.01). Furthermore, CBI, DEAI, enduron, and amiloride drug treatments enhanced actin-activated myosin ATPase activity (p less than 0.01). The Ca2(+)-activated myosin ATPase activity was significantly elevated after treating with CBI and DEAI (p less than 0.01). These results suggest that the antihypertensive agents used in this study helped in reducing the blood pressure with a subsequent increase in myocardial contractile protein ATPase activity.

Actins↗