Reduced Hornbill Abundance Associated with Low Seed Arrival and Altered Recruitment in a Hunted and Logged Tropical Forest

Logging and hunting are two key direct threats to the survival of wildlife in the tropics, and also disrupt important ecosystem processes. We investigated the impacts of these two factors on the different stages of the seed dispersal cycle, including abundance of plants and their dispersers and dispersal of seeds and recruitment, in a tropical forest in north-east India. We focused on hornbills, which are important seed dispersers in these forests, and their food tree species. We compared abundances of hornbill food tree species in a site with high logging and hunting pressures (heavily disturbed) with a site that had no logging and relatively low levels of hunting (less disturbed) to understand logging impacts on hornbill food tree abundance. We compared hornbill abundances across these two sites. We, then, compared the scatter-dispersed seed arrival of five large-seeded tree species and the recruitment of four of those species. Abundances of hornbill food trees that are preferentially targeted by logging were two times higher in the less disturbed site as compared to the heavily disturbed site while that of hornbills was 22 times higher. The arrival of scatter-dispersed seeds was seven times higher in the less disturbed site. Abundances of recruits of two tree species were significantly higher in the less disturbed site. For another species, abundances of younger recruits were significantly lower while that of older recruits were higher in the heavily disturbed site. Our findings suggest that logging reduces food plant abundance for an important frugivore-seed disperser group, while hunting diminishes disperser abundances, with an associated reduction in seed arrival and altered recruitment of animal-dispersed tree species in the disturbed site. Based on our results, we present a conceptual model depicting the relationships and pathways between vertebrate-dispersed trees, their dispersers, and the impacts of hunting and logging on these pathways.     

Status of women in two Bengals: evidence from large scale surveys

Greater female autonomy is mirrored through better performance in the major demographic and social indicators. This study attempts to capture the effect of religion on the status of women considering 'Greater Bengal'. There is much evidence suggesting that when cultural factors are constant, religion does not have a significant effect on any demographic issue. In this paper, the validity of this proposition is examined using two datasets, namely NFHS II (98-99) and BDHS 2000. It is clear from the analyses that not only region but also religion has a distinct effect on the status of women. In West Bengal, the religious gap for all the indicators considered is pretty high, whereas in Bangladesh the gap is not that wide. A state-level population policy is needed in West Bengal to act as a social leveller.     

Amelioration of vanadium-induced testicular toxicity and adrenocortical hyperactivity by vitamin E acetate in rats

Vanadium toxicity is a challenging problem to the health professionals and a cutting-edge medical problem. Vanadium has been recognized as industrial hazards that adversely affect human and animal reproductive health. Since testicular function is exquisitely susceptible to reactive-oxygen species, the present study elucidates the possible involvement of oxidative stress in vanadium-induced testicular toxicity and the prophylactic effects of vitamin E acetate against such adverse effects of vanadium. The study also characterizes the effects of vanadium on rat adrenal steroidogenesis and determines the underlying mechanisms of testicular and adrenal interactions in response to vanadium exposure. Significantly reduced sperm count associated with decreased serum testosterone and gonadotropins level in the vanadium-injected group of rats compared to control substantially proves the ongoing damaging effects of vanadium-induced ROS on developing germ cells. This is in turn reflected in the appreciable increase in testicular lipid peroxidation level and decline in the activities of steroidogenic and antioxidant enzymes. However, oral administration of vitamin E acetate could protect testes from the toxic effects of vanadium. Vanadium also results in adrenocortical hyperactivity, as evidenced by the elevated secretion of glucocorticoids, adrenal gland hypertrophy and increased activity of adrenal Δ⁵3β-HSD. However, reversibility of these alterations in adrenocortical activities was vividly reflected after vitamin E acetate supplementation. All these studies reveal that oxidative stress is the major mechanism of health deterioration and that vanadium can act as a stressor metal causing chronic stress effects through excitation of hypothalamo-pituitary-adrenal axis. However antioxidant support by vitamin E acetate may provide significant protection.     

Identification of suitable reference genes for expression profiling studies using qRT-PCR in an important insect pest,Maruca vitrata

Molecular Biology Reports - Maruca vitrata is one of the potential insect pests that cause devastating losses to legume cultivation worldwide. Gene functional studies facilitate dissecting the...     

Evidence for cytochrome P450 2E1 catalytic activity and expression in rat blood lymphocytes

Studies initiated to characterize cytochrome P450 2E1(CYP2E1) in freshly isolated rat blood lymphocytes revealed significant mRNA of CYP2E1 in control blood lymphocytes. RT-PCR studies have shown that as observed in liver, acute treatment of ethanol (single oral dose of 0.8 ml/kg b.wt, i.p), resulted in increase in the mRNA expression of CYP2E1 in freshly isolated rat blood lymphocytes. Western blotting studies using polyclonal antibody raised against rat liver CYP2E1 demonstrated significant immunoreactivity, comigrating with the liver isoenzyme, in freshly isolated control rat blood lymphocytes. Similar to that seen in liver, pretreatment of ethanol was found to produce an increase in the CYP2E1 isoenzyme in the blood lymphocytes. Blood lymphocytes were also found to catalyze the CYP dependent N-demethylation of N-nitrosodimethylamine (NDMA), which like in liver increased 2-3 fold following pretreatment of rats with known CYP2E1 inducers. Kinetic studies have further shown significant increase in the apparent Vmax and the affinity towards the substrate in rat blood lymphocytes indicating that as observed in liver, the increase in mRNA and protein expression following exposure to CYP2E1 inducers is associated with the increased catalytic activity of CYP2E1 in freshly isolated rat blood lymphocytes. The data indicating similarities of the blood lymphocyte CYP2E1 with the liver enzyme suggest that lymphocyte CYP2E1 levels in freshly isolated rat blood lymphocytes could be used to monitor tissue enzyme levels.     

Combination of cytosine deaminase with uracil phosphoribosyl transferase leads to local and distant bystander effects against RM1 prostate cancer in mice

BACKGROUND: We aimed to evaluate the efficacy of gene-directed enzyme-prodrug therapy (GDEPT) using cytosine deaminase in combination with uracil phosphoribosyl transferase (CDUPRT) against intraprostatic mouse androgen-refractory prostate (RM1) tumors in immunocompetent mice. The product of the fusion gene, CDUPRT, converts the prodrug, 5-fluorocytosine (5FC), into 5-fluorouracil (5FU) and other cytotoxic metabolites that kill both CDUPRT-expressing and surrounding cells, via a 'bystander effect'. METHODS: Stably transformed andogen-independent mouse prostate cancer (PC) cells, RM1-CDUPRT, -GFP or GFP/LacZ cells were used. To assess the local bystander effects of CDUPRT-GDEPT, immunocompetent C57BL/6 mice implanted with cell mixtures of RM1-GFP/CDUPRT and RM1-GFP cells in different proportions intraprostatically were treated with 5FC. Pseudo-metastases in the lungs were established by a tail vein injection of untransfected RM1 cells. At necropsy, prostate weight/volume and lung colony counts were assessed. Tumors, lymph nodes, spleens and lungs were frozen or fixed for immunohistochemistry. RESULTS: CDUPRT expression in RM1-GFP/CDUPRT cells or tumors was confirmed by enzymic conversion of 5FC into 5FU, using HPLC. Treatment of mice bearing intraprostatic RM1-GFP/CDUPRT tumors with 5FC resulted in complete regression of the tumors. A 'local bystander effect' was seen, even though only 20% of the cells expressed CDUPRT. More importantly a significant reduction in pseudo-metastases of RM1 cells in lungs indicated a 'distant bystander effect'. Immunohistochemical evaluation of the treated tumors showed increased necrosis and apoptosis, with decreased tumor vascularity. There was also a significant increase in tumour-infiltration by macrophages, CD4+ T and natural killer cells. CONCLUSIONS: We conclude that CDUPRT-GDEPT significantly suppressed the aggressive growth of RM1 prostate tumors and lung pseudo-metastases via immune mechanisms involving necrosis and apoptosis.     

Introgression of a novel salt-tolerant L-myo-inositol 1-phosphate synthase from Porteresia coarctata (Roxb.) Tateoka (PcINO1) confers salt tolerance to evolutionary diverse organisms

We have previously demonstrated that introgression of PcINO1 gene from Porteresia coarctata (Roxb.) Tateoka, coding for a novel salt-tolerant L-myo-inositol 1-phosphate synthase (MIPS) protein, confers salt tolerance to transgenic tobacco plants (Majee, M., Maitra, S., Dastidar, K.G., Pattnaik, S., Chatterjee, A., Hait, N.C., Das, K.P. and Majumder, A.L. (2004) A novel salt-tolerant L-myo-inositol-1-phosphate synthase from Porteresia coarctata (Roxb.) Tateoka, a halophytic wild rice: molecular cloning, bacterial overexpression, characterization, and functional introgression into tobacco-conferring salt-tolerance phenotype. J. Biol. Chem. 279, 28539-28552). In this communication we have shown that functional introgression of the PcINO1 gene confers salt-tolerance to evolutionary diverse organisms from prokaryotes to eukaryotes including crop plants albeit to a variable extent. A direct correlation between unabated increased synthesis of inositol under salinity stress by the PcINO1 gene product and salt tolerance has been demonstrated for all the systems pointing towards the universality of the application across evolutionary divergent taxa.     

In Vitro and In Vivo Prostate Cancer Metastasis and Chemoresistance Can Be Modulated by Expression of either CD44 or CD147

CD44 and CD147 are associated with cancer metastasis and progression. Our purpose in the study was to investigate the effects of down-regulation of CD44 or CD147 on the metastatic ability of prostate cancer (CaP) cells, their docetaxel (DTX) responsiveness and potential mechanisms involved in vitro and in vivo. CD44 and CD147 were knocked down (KD) in PC-3M-luc CaP cells using short hairpin RNA (shRNA). Expression of CD44, CD147, MRP2 (multi-drug resistance protein-2) and MCT4 (monocarboxylate tranporter-4) was evaluated using immunofluorescence and Western blotting. The DTX dose-response and proliferation was measured by MTT and colony assays, respectively. The invasive potential was assessed using a matrigel chamber assay. Signal transduction proteins in PI3K/Akt and MAPK/Erk pathways were assessed by Western blotting. An in vivo subcutaneous (s.c.) xenograft model was established to assess CaP tumorigenecity, lymph node metastases and DTX response. Our results indicated that KD of CD44 or CD147 decreased MCT4 and MRP2 expression, reduced CaP proliferation and invasive potential and enhanced DTX sensitivity; and KD of CD44 or CD147 down-regulated p-Akt and p-Erk, the main signal modulators associated with cell growth and survival. In vivo, CD44 or CD147-KD PC-3M-luc xenografts displayed suppressed tumor growth with increased DTX responsiveness compared to control xenografts. Both CD44 and CD147 enhance metastatic capacity and chemoresistance of CaP cells, potentially mediated by activation of the PI3K and MAPK pathways. Selective targeting of CD44/CD147 alone or combined with DTX may limit CaP metastasis and increase chemosensitivity, with promise for future CaP treatment.