Envelope diversity, characteristics of V3 region and predicted co-receptor usage of human immunodeficiency viruses infecting north indians

Subtypes of human immunodeficiency virus type 1 circulating in 21 north Indian patients were characterized based on the partial sequence of the gp120 envelope protein. A majority of viruses (85.7%, 18/21) were subtype C, while 14.3% (3/21) were subtype A. Sequence analysis revealed that the V3 region was highly conserved compared with V4 and V5. The predicted use of co-receptors indicated exclusive usage of R5, except for two subtype A viruses (AIIMS279 and AIIMS281). Our results demonstrate conservation within the V3 loop of subtype C viruses, and suggest the emergence of non-clade C viruses in the north Indian population.     

Evidence for the probable oil body association of a thiol-protease, leading to oleosin degradation in sunflower seedling cotyledons

The activity of a 65 kDa, cytosolic protease from sunflower seedling cotyledons coincides with the degradation of oleosins during seed germination. Further investigations carried out in this laboratory have demonstrated the probable association of a thiol-protease with oil bodies, leading to gradual degradation of oleosins during seedling growth. Evidence to this effect have been brought out through zymographic detection of protease activity from oil bodies, degradation of oleosins by electrophoretically eluted protease from the seedling cotyledons and inhibition of protease activity by thiol-protease inhibitor, such as N-ethylmaleimide (NEM). In addition to these biochemical evidence, visualization of thiol-protease activity has also been achieved by a novel fluorescence microscopic method and confocal imaging. It involves the uptake and binding of a fluorogenic thiol-protease inhibitor (fluorescein mercuric acetate, FMA) at the intracellular thiol-protease activity sites in protoplasts, leading to fluorescence emission at 523 nm following excitation at 499 nm. Maximum protease activity is observed in 4-d-old seedling cotyledons, coinciding with the phase of active triacylglycerol (TAGs) hydrolysis. All these observations provide evidence for the expression of the said thiol-protease activity on the oil body surface, leading to gradual proteolysis of oleosins during seed germination.     

Fc gamma receptor polymorphisms in systemic lupus erythematosus and their correlation with the clinical severity of the disease

Receptors for the Fc domains of IgG (Fc γ R) play a critical role in linking humoral and cellular immune responses. The various Fc γ R genes may contribute to differences in infectious and immune related diseases in various ethnic populations. Polymorphisms of Fc γ R mainly Fc γ R IIA, IIB, IIIA, IIIB have been identified as genetic factors influencing susceptibility to disease or disease course of a prototype autoimmune disease like Systemic Lupus Erythematosus (SLE). Activated and inhibitory Fc γ Rs seem to play an important role in the pathogenesis of SLE, in initiation of autoimmunity, the subsequent development of inflammatory lesions and finally immune clearance mechanisms. This review focuses on the role of Fc γ R polymorphism and their association with clinical manifestations and initiation of autoantibody production, inflammatory handling of immune complexes and disease development in SLE patients.     

Siderophore mediated plant growth promotion at low temperature by mutant of fluorescent pseudomonad⋆

A cold resistant mutant of Pseudomonas fluorescens ATCC 13525 was developed, which could grow equally well at 25 and 10 °C and its effect on plant growth promotion under in vitro and in situ conditions was observed. Siderophore estimation revealed it to be a siderophore-overproducing mutant (17-fold increase) when compared to its wild type counterpart. A gnotobiotic root elongation assay indicated that the mutant (CRPF₉) promoted growth more than its wild type both at 25 and 10 °C, indicating its effectiveness at low temperature. Further, root colonization studies showed that CRPF₉ was an efficient rhizosphere colonizer, inducing a significant increase in root (35%) and shoot length (28%) of mung bean plants in unsterilized soil system. The persistence and stability of the mutant was evident in rhizospheric soil. A sand culture experiment showed that ferric citrate was better than Fe(OH)₃ as an iron source for plant growth, but in the presence of CRPF₉ both salts were comparable. This study demonstrates the potential of chemical mutagenesis for improving the plant growth promoting properties of a P. fluorescens strain and its stimulating impact on plant growth promotion at low temperature both under in vitro and in situ conditions.     

Insect drift over the northern Arabian sea in early summer

Air borne insects, mostly carried by wind currents, were trapped over the northern Arabian sea (16‡ to 20‡ N; 68‡ to 72‡ E), in the course of cruise No. 111, ORVSAGAR KANYA (March 14 to April 7, 1996). A total of 2,301 insects belonging to 8 different orders, 47 families and 173 species were trapped. Of these, Hymenoptera was represented by the largest number (1082), which was followed by Hemiptera (586), Diptera (552), Coleoptera (51), Neuroptera (10), Trichoptera (03), Lepidoptera (03) and Orthoptera (01). The trapped insects were mostly between 0.6 mm to over 11 mm long. The data was examined for α-diversity as well as for possible correlations between various parameters like the diversity index, size and number of insects trapped on one hand and the distance of the nearest land mass in wind direction, on the other. Deceased.     

Metabolic manipulation of glycosylation disorders in humans and animal models

In the last decade, over 40 inherited human glycosylation disorders were identified. Most patients have hypomorphic, rather than null alleles. The phenotypic spectrum is broad and most of the disorders affect embryonic and early post-natal development; a few appear in adult life. Some deficiencies can be treated with simple dietary sugar (monosaccharide) supplements. Here we focus on four glycosylation disorders that have been treated with supplements in patients or in model systems, primarily the mouse. Surprisingly, small differences in the amount of exogenous sugar have a major impact on the diseases in specific cells or organs while others are unaffected. The underlying mechanisms are mostly unknown, but changes in the contributions of the de novo, salvage and dietary pathways may contribute to the beneficial outcome. Clearly, the metabolic chart is not flat; all arrows are not equally robust at all points of time and space. This metabolic perspective may help explain some of these observations and guide the development of other vertebrate models of glycosylation disorders that can respond to dietary manipulation.     

Isolation and characterization of an Arabidopsis thaliana knockout line for phospholipid: diacylglycerol transacylase gene (At5g13640).

To more fully understand the function of phospholipid: diacylglycerol acyltransferase (PDAT, EC 2.3.1.158) in plants we have isolated and characterized a knockout mutant of Arabidopsis thaliana L. which has a T-DNA insertion in PDAT locus At5g13640. Lipid analysis was conducted on these plants to assess the contribution of the PDAT gene to lipid composition. The fatty acid content and composition in seeds do not show significant changes in the mutant. This is a contrary situation to yeast where PDAT is a major contributor to triacylglycerol (TAG) accumulation in exponential growth phase. The results indicate that PDAT activity encoded by At5g13640 is not a major determinant of TAG synthesis in Arabidopsis seeds.