Biochemical studies on changes associated with enzymes of glucose metabolism in white spot syndrome virus (WSSV) infected with Penaeus monodon (Fabricius)

Tiger prawns (Penaeus monodon) were infected with white spot virus artificially by intramuscular injection of the virus inoculum. Haemolymph, hepatopancreas and muscle samples from the infectedprawns were analyzed for glucose and enzymes viz aldolase, glucose-6-phosphatase, fructose-1,6-diphosphatase and glucose-6-phosphate dehydrogenase in the carbohydrate metabolism. Glucose content reduced to 33% of its original value in 24 h of infection and to 31% in 48 h. Almost 95% loss in activity was observed in the case of fructose 1,6-diphosphatase in hepatopancreas, whereas the reduction in activity in muscle was 67%, after 48 h of infection. Glucose-6-phosphatase showed a reduction of 16 and 13% in hepatopancreas and muscle respectively during 24 h of infection. The activity of glucose-6-phosphate dehydrogenase increased by 300% of original value in hepatopancreas, while in muscle the increase was only 30% of original value during 24 h of infection. No significant change in activity was noted in the case of aldolase. Even at moribund stage, the glycolytic pathway was not affected, as evident from the normal activity of aldolase observed in the present study

Fresh water influence on nutrient stoichiometry in a tropical estuary, southwest coast of India

Cochin backwaters, a micro tidal estuary, undergo a characteristic transformation from a river-dominated system during summer monsoon to a tide-dominant system during pre-monsoon season. The present study observes that as the river flow weakens after monsoon, the flushing of the estuary diminishes and the nitrogen and phosphorous loadings through anthropogenic activities (industries) and sediment re-suspension alter the nutrient stoichiometry substantially. The increased tidal activity during pre-monsoon changes the estuary into a vertically mixed, eutrophic and flow-restricted system supporting an enhanced organic production. This implies that monsoon-induced hydrology plays an important role in regulating the nutrients, secondary production and even the migrant fauna of the estuary. The system is delicately poised, as continuous release of pollutants including nutrients into this estuary would suppress fish and shell fish production, where only pollution tolerant species can exist

Hydrography and biogeochemistry of the north western Bay of Bengal and the north eastern Arabian Sea during winter monsoon

The north eastern Arabian Sea and the north western Bay of Bengal within the Indian exclusive economic zone were explored for their environmental characteristics during the winter monsoons of 2000 and 2001 respectively. The two regions were found to respond paradoxically to comparable intensities of the atmospheric forcing. There is an asymmetry in the net heat exchange of these two basins with atmosphere because of the varying thickness of barrier layer. During winter, the convective mixing in the Arabian Sea is driven by net heat loss from the ocean, whereas the Bay of Bengal does not contribute to such large heat loss to the atmosphere. It appears that the subduction of high saline Arabian Sea water mass is the mechanism behind the formation of a barrier layer in the northeast Arabian Sea; whereas that in the Bay of Bengal and the southeast Arabian Sea are already established as due to low saline water mass. The weak barrier layer in the Arabian Sea yields to the predominance of convective mixing to bring in nitrate-rich waters from the deeper layers to the surface, thereby supporting enhanced biological production. On the other hand, the river discharge into the Bay of Bengal during this period results in the formation of a thick and stable barrier layer, which insulates vertical mixing and provide oligotrophic condition in the Bay

Delayed diagnosis of plasma cell disorder-related Fanconi syndrome in young adults presenting as osteomalacia: report of two cases with normokalemia and normal haematological parameters at the time of presentation

Adult-onset hypophosphatemic osteomalacia is rare and diagnosis is frequently delayed. Fanconi syndrome (FS) due to monoclonal gammopathy is a well-recognized, but rare cause of hypophosphatemia. The relatively young age of patients and normal routine hematological parameters often results in late recognition of this treatable disease entity. Low phosphorus, elevated alkaline phosphatase, mildly impaired renal function and hypokalemia are often the only abnormalities on routine evaluation. We summarize the clinico-pathological features of two cases who initially presented with fractures and proximal myopathy and were subsequently found to have FS secondary to light chain proximal tubulopathy. Atypical features like absence of hypokalemia at presentation  and elevated Fibroblast Growth Factor 23(FGF 23), a marker of oncogenic osteomalacia were noted. Marked clinical improvement and recovery of renal parameters were evident with phosphate supplements and  chemotherapy for the plasma cell disorder. FS due to monoclonal gammopathy  may present with atypical features  and diagnosis may be  challengin

Ly6Chi monocyte recruitment is responsible for Th2 associated host-protective macrophage accumulation in liver inflammation due to schistosomiasis

Accumulation of M2 macrophages in the liver, within the context of a strong Th2 response, is a hallmark of infection with the parasitic helminth, Schistosoma mansoni, but the origin of these cells is unclear. To explore this, we examined the relatedness of macrophages to monocytes in this setting. Our data show that both monocyte-derived and resident macrophages are engaged in the response to infection. Infection caused CCR2-dependent increases in numbers of Ly6Chi monocytes in blood and liver and of CX3CR1+ macrophages in diseased liver. Ly6Chi monocytes recovered from liver had the potential to differentiate into macrophages when cultured with M-CSF. Using pulse chase BrdU labeling, we found that most hepatic macrophages in infected mice arose from monocytes. Consistent with this, deletion of monocytes led to the loss of a subpopulation of hepatic CD11chi macrophages that was present in infected but not naïve mice. This was accompanied by a reduction in the size of egg-associated granulomas and significantly exacerbated disease. In addition to the involvement of monocytes and monocyte-derived macrophages in hepatic inflammation due to infection, we observed increased incorporation of BrdU and expression of Ki67 and MHC II in resident macrophages, indicating that these cells are participating in the response. Expression of both M2 and M1 marker genes was increased in liver from infected vs. naive mice. The M2 fingerprint in the liver was not accounted for by a single cell type, but rather reflected expression of M2 genes by various cells including macrophages, neutrophils, eosinophils and monocytes. Our data point to monocyte recruitment as the dominant process for increasing macrophage cell numbers in the liver during schistosomiasis

The landscape of inherited and de novo copy number variants in a plasmodium falciparum genetic cross

<p>Abstract</p> <p>Background</p> <p>Copy number is a major source of genome variation with important evolutionary implications. Consequently, it is essential to determine copy number variant (CNV) behavior, distributions and frequencies across genomes to understand their origins in both evolutionary and generational time frames. We use comparative genomic hybridization (CGH) microarray and the resolution provided by a segregating population of cloned progeny lines of the malaria parasite, <it>Plasmodium falciparum</it>, to identify and analyze the inheritance of 170 genome-wide CNVs.</p> <p>Results</p> <p>We describe CNVs in progeny clones derived from both Mendelian (i.e. inherited) and non-Mendelian mechanisms. Forty-five CNVs were present in the parent lines and segregated in the progeny population. Furthermore, extensive variation that did not conform to strict Mendelian inheritance patterns was observed. 124 CNVs were called in one or more progeny but in neither parent: we observed CNVs in more than one progeny clone that were not identified in either parent, located more frequently in the telomeric-subtelomeric regions of chromosomes and singleton <it>de novo </it>CNVs distributed evenly throughout the genome. Linkage analysis of CNVs revealed dynamic copy number fluctuations and suggested mechanisms that could have generated them. Five of 12 previously identified expression quantitative trait loci (eQTL) hotspots coincide with CNVs, demonstrating the potential for broad influence of CNV on the transcriptional program and phenotypic variation.</p> <p>Conclusions</p> <p>CNVs are a significant source of segregating and <it>de novo </it>genome variation involving hundreds of genes. Examination of progeny genome segments provides a framework to assess the extent and possible origins of CNVs. This segregating genetic system reveals the breadth, distribution and dynamics of CNVs in a surprisingly plastic parasite genome, providing a new perspective on the sources of diversity in parasite populations.</p