Browsing by Author "M. Chatterjee"

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Conjugal roles and social networks in an Indian urban sweeper locality
(1977) M. Chatterjee
[No abstract available]
Differential gene expression analysis in antimony-unresponsive Indian kala azar (visceral leishmaniasis) clinical isolates by DNA microarray
(2007) N. Singh; R. Almeida; H. Kothari; P. Kumar; G. Mandal; M. Chatterjee; S. Venkatachalam; M.K. Govind; S.K. Mandal; S. Sundar
In this study, cDNA microarray analysis of a closely related species, Leishmania major, was used as a screening tool to compare antimonial-resistant and susceptible clinical isolates of Leishmania donovani in order to to identify candidate genes on the basis of antimony resistance. Clinically confirmed resistant isolate 39 and sensitive isolate 2001 were used in this study. Many differentially regulated genes were identified whose expression levels differ in sodium antimony gluconate (SAG)-treated patients. Interestingly, genes on the array, showing changes in expression of over 2-fold revealed the identity of ABC transporters, which are known determinants of drug resistance in laboratory mutants. The functionality of the transporters was validated by flow cytometry which, being biologically informative, provides direct clues to gene function. The results suggest that isolate 39 could have developed resistance by an increased multidrug resistance protein (MRP)-like pump. This study provides preliminary clues to the role of a thiol-dependent efflux system in antimonial resistant clinical isolates of Leishmania donovani. © 2007 Cambridge University Press.
Fetal growth variations. I. Influence of maternal size and nutrition on identification of fetal growth retardation
(1983) V. Bhargava; M. Chatterjee; A. Prakash; B. Bhatia; A. Mishra
[No abstract available]
Increased levels of thiols protect antimony unresponsive Leishmania donovani field isolates against reactive oxygen species generated by trivalent antimony
(2007) G. Mandal; S. Wyllie; N. Singh; S. Sundar; A.H. Fairlamb; M. Chatterjee
The current trend of antimony (Sb) unresponsiveness in the Indian subcontinent is a major impediment to effective chemotherapy of visceral leishmaniasis (VL). Although contributory mechanisms studied in laboratory-raised Sb-R parasites include an up-regulation of drug efflux pumps and increased thiols, their role in clinical isolates is not yet substantiated. Accordingly, our objectives were to study the contributory role of thiols in the generation of Sb unresponsiveness in clinical isolates. Promastigotes were isolated from VL patients who were either Sb responsive (n=2) or unresponsive (n=3). Levels of thiols as measured by HPLC and flow cytometry showed higher basal levels of thiols and a faster rate of thiol regeneration in Sb unresponsive strains as compared with sensitive strains. The effects of antimony on generation of reactive oxygen species (ROS) in normal and thiol-depleted conditions as also their H2O2 scavenging activity indicated that in unresponsive parasites, Sb-mediated ROS generation was curtailed, which could be reversed by depletion of thiols and was accompanied by a higher H2O2 scavenging activity. Higher levels of thiols in Sb-unresponsive field isolates from patients with VL protect parasites from Sb-mediated oxidative stress, thereby contributing to the antimony resistance phenotype. © 2007 Cambridge University Press.
Studies on fetal growth patterns: Intrauterine growth percentiles for singleton live born babies
(1981) B.D. Bhatia; V. Bhargava; M. Chatterjee; V.L. Kota; L.I. Singh; N.P. Jain
5321 singleton live born babies were studied for their intra-uterine growth (IUG) pattern from 26-44 weeks of gestation and the measurements for birth weight (BW), crown-heel length (CHL) and head circumference (HC) at each gestation were expressed as smoothed percentiles. All three parameters showed a uniform increase until 35-37 weeks after which the increments gradually reduced and the IUG curves started flattening out. The birth weights after 41 weeks showed an appreciable decrease for the lower percentiles but not so much for the higher percentiles. This declining trend beyond 41 weeks was less marked for the crown-heel length and head circumference. In comparison with two other Indian studies the weights and the head circumferences in the present study were smaller whereas the crown-heel lengths were slightly greater. The identification limits for small-for-date infants were, however, very much similar in all three studies.