Browsing by Author "Nalini, S"

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    Albumin bound nonesterified fatty acids inhibit in vitro lipid peroxidation.
    (1989-12-01) Nalini, S; Balasubramanian, K A
    Individual nonesterified fatty acids were bound to albumin in vitro and these fatty acid albumin complexes were used to study their effect on lipid peroxidation in liver microsomes. Peroxidation was induced by various methods and malondialdehyde (MDA) was measured as an index of peroxidation. Among the fatty acids tested, albumin-bound monounsaturated fatty acids showed more inhibition of peroxidation as compared to other fatty acids. Increasing the concentration of iron in the peroxidizing system, partially reversed the inhibition by fatty acids. Moreover, albumin-bound fatty acid did not inhibit iron independent peroxidation. This suggests that, like nonesterified fatty acids, albumin-bound fatty acids inhibit peroxidation by chelating the iron. Albumin fatty acid complex, similar to the fatty acid composition present in the circulating albumin, also showed inhibition of peroxidation. These data indicate that nonesterified fatty acids even when bound to albumin are capable of inhibiting peroxidation and circulating albumin, which contains various fatty acids bound to it, may impart some antioxidant effect in addition to other plasma antioxidants.
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    Amoebiasis with pericardial involvement.
    (1974-07-16) Haranath, K; Rajagopal, K R; Nalini, S; Thiruvengadam, K V
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    Combined drug medium with isoniazid and rifampicin for identification of multi-drug resistant Mycobacterium tuberculosis.
    (2010-04) Nalini, S; Lakshmi, R; Devika, K; Ravikumar, D; Ramachandran, R
    A low-cost method of detecting multi-drug resistant Mycobacterium tuberculosis (MDR-TB) with the possibility of quick adoption in a resource limited setting is urgently required. We conducted a study combining isoniazid and rifampicin in a single LJ medium, to detect MDR-TB strains. Combined and individual drug media showed 100% concordance for the detection of MDR-TB and susceptible strains by proportion method. Considering the results, combined isoniazid and rifampicin containing medium could be considered for use in settings where the sole detection of MDR-TB strains is justified.
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    Comparison of different methods of assessing in vitro resistance of Mycobacterium tuberculosis to rifampicin.
    (2001-12-04) Paramasivan, C N; Rahman, F; Nalini, S; Dakshayani, G; Venkataraman, P
    BACKGROUND & OBJECTIVES: Definitions of in vitro resistance to rifampicin in strains of Mycobacterium tuberculosis by different methods have not been consistent, leading to variations in the interpretation and validity of results. This study compared three methods of defining in vitro resistance to rifampicin. METHODS: (i) A total of 598 clinical isolates of M. tuberculosis were concurrently compared by the minimal inhibitory concentration (MIC) and the proportion method on Lowenstein-Jensen medium; (ii) 54 strains tested by the MIC method were retested by the proportion method and the BACTEC radiometric method; and (iii) 72 strains which yielded an MIC of 64 mg/l by the MIC method were retested by the same method. RESULTS: Out of 598 cultures tested by the MIC and the proportion methods, identical classification as susceptible or resistant was observed in 99.7 per cent. A 100 per cent agreement was observed when 54 strains were tested by the MIC, proportion and BACTEC radiometric methods. When 72 strains with an MIC of 64 mg/l were retested by the same method, 61 (85%) yielded a lower MIC, 9 (12%) gave the same MIC while 2 (3%) yielded a higher MIC of 128 mg/l, reflecting perhaps the inherent limitations of the variations in the inoculum size. INTERPRETATION & CONCLUSION: All 3 definitions of resistance, viz., an MIC of 128 mg/l, a proportion of 1 per cent or more on 40 mg/l by the proportion method, both on L-J medium and a growth of 1 per cent or more on 2 mg/l by the radiometric method were found to be equally satisfactory.
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    Comparison of double disc and three dimensional methods to screen for ESBL producers in a tertiary care hospital.
    (2006-04-12) Menon, T; Bindu, D; Kumar, C P G; Nalini, S; Thirunarayan, M A
    Extended spectrum beta lactamases (ESBLs) continue to be a major problem in clinical setups world over, conferring resistance to the expanded spectrum cephalosporins. An attempt was made to study ESBL production among Enterobacteriaceae members from a tertiary care center in Chennai. A total of seventy randomly collected isolates of the family Enterobacteriaceae from a tertiary care center was studied for their susceptibility patterns to various antibiotics and detection of ESBL producers by double disc synergy (DDS) test and three dimensional test (TDT). Eighty percent of the isolates were multidrug resistant (MDR) and 20% were ESBL producers. TDT detected 85.7% whereas only 14.2% were detected by DDS. In the present study, a large number of isolates were found to be MDR and ESBL producers. TDTs were found to be better than DDS in the detection of ESBLs. Continued monitoring of drug resistance is necessary in clinical settings for proper disease management.
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    Studies on iron binding by free fatty acids.
    (1993-08-01) Nalini, S; Balasubramanian, K A
    The effect of various saturated and unsaturated fatty acids on iron binding and the translocation of this complex into the organic phase were studied. The amount of iron translocated into the organic phase depended on the affinity of the respective fatty acid to iron. It was seen that saturated and monounsaturated fatty acids translocated more iron compared to polyunsaturated fatty acids. Positional isomers of oleic acid were as effective as oleic acid in translocating iron. It appears that the free carboxyl group on the fatty acid is essential, as the methyl ester of the fatty acid failed to translocate iron. Effect of varying the concentration of fatty acid and iron on iron translocation suggested the requirement of 3 to 4 moles of fatty acid for 1 mole of iron binding. Divalent cations such as Ca2+ and Mg2+ or lipids such as cholesterol or triolein did not compete with fatty acids but there was reduced translocation when phosphate buffer or phospholipid was included in the incubation medium, suggesting that phosphate interferes with the formation of fatty acid-iron complex. Thus it seems that free fatty acids are capable of forming a complex with iron.