Counter-immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes

Counter-immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter-immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases.
Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter-immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.     

Potassium uptake efficiency and dynamics in the rhizosphere of maize (Zea mays L.), wheat (Triticum aestivum L.), and sugar beet (Beta vulgaris L.) evaluated with a mechanistic model

Plant species differ in nutrient uptake efficiency. With a pot experiment, we evaluated potassium (K) uptake efficiency of maize (Zea mays L.), wheat (Triticum aestivum L.), and sugar beet (Beta vulgaris L.) grown on a low-K soil. Sugar beet and wheat maintained higher shoot K concentrations, indicating higher K uptake efficiency. Wheat acquired more K because of a greater root length to shoot dry weight ratio. Sugar beet accumulated more shoot K as a result of a 3- to 4-fold higher K influx as compared to wheat and maize, respectively. Nutrient uptake model NST 3.0 closely predicted K influx when 250 mg K kg^?1 were added to the soil, but under-predicted K influx under low K supply. Sensitivity analysis showed that increasing soil solution K concentration (C_Li) by a factor of 1.6–3.5 or buffer power (b) 10- to 50-fold resulted in 100% prediction of K influx. When both maximum influx (I_max) and b were increased by a factor of 2.5 in maize and wheat and 25 in sugar beet, the model could predict measured K influx 100%. In general, the parameter changes affected mostly calculated K influx of root hairs, demonstrating their possible important role in plant K efficiency.     

Genotypic variation in partitioning of dry matter and manganese between source and sink organs of rice under manganese stress

Key message

Genetic variability in dry matter and manganese partitioning between source and sink organs was the key mechanism for Mn efficient rice genotypes to cope with Mn stress.

Abstract

Considerable differences exist among cereal genotypes to cope manganese (Mn) deficiency, but the underlying mechanisms are poorly understood. Minimal information regarding partitioning and/or remobilization of dry matter and Mn between source and sink organs exists in rice genotypes differing in Mn efficiency. The present study was aimed to assess the growth dynamics in terms of dry matter and Mn remobilization in the whole plant (leaves and tillers as source and panicles and grains as sink) during the grain development in diverse rice genotypes. The efficient genotypes accumulated higher dry matter than inefficient genotypes under low Mn level. The translocation index i.e., uptake in grain/total uptake was 0.11 in efficient genotype (PR 116) and 0.04 in inefficient genotypes (PR 111). The efficient genotype had higher grain Mn utilization efficiency of 0.71 in comparison to 0.48 of inefficient genotype indicating that in efficient genotype, Mn in grain produces more dry matter than inefficient genotypes. The efficient genotypes also had higher flag leaf area and nitrate reductase activity. The source of efficient genotypes contributed to a greater extent to developing sink but further mobilization to grain was hindered by panicle. The panicle of inefficient genotypes had higher per cent of Mn uptake than efficient genotypes indicating that Mn was least mobilized from panicle to grain in inefficient genotypes. The lower per cent uptake of Mn in efficient genotypes indicated that Mn was mobilized from panicle to developing grain and this led to higher Mn translocation index in grain of efficient genotypes. The uptake partitioning revealed that source of all genotypes mobilized the Mn towards the sink to almost same extent but it was the panicle where highest per cent uptake per plant was in inefficient genotypes and lowest in efficient genotypes. The lowest per cent uptake in panicle of efficient genotypes revealed that it supported developing grain to have highest translocation index.     

WsSGTL1 gene from Withania somnifera,modulates glycosylation profile,antioxidant system and confers biotic and salt stress tolerance in transgenic tobacco

Glycosylation of sterols, catalysed by sterol glycosyltransferases (SGTs), improves the sterol solubility, chemical stability and compartmentalization, and helps plants to adapt to environmental changes. The SGTs in medicinal plants are of particular interest for their role in the biosynthesis of pharmacologically active substances. WsSGTL1, a SGT isolated from Withania somnifera, was expressed and functionally characterized in transgenic tobacco plants. Transgenic WsSGTL1-Nt lines showed an adaptive mechanism through demonstrating late germination, stunted growth, yellowish-green leaves and enhanced antioxidant system. The reduced chlorophyll content and chlorophyll fluorescence with decreased photosynthetic parameters were observed in WsSGTL1-Nt plants. These changes could be due to the enhanced glycosylation by WsSGTL1, as no modulation in chlorophyll biogenesis-related genes was observed in transgenic lines as compared to wildtype (WT) plants. Enhanced accumulation of main sterols like, campesterol, stigmasterol and sitosterol in glycosylated form was observed in WsSGTL1-Nt plants. Apart from these, other secondary metabolites related to plant’s antioxidant system along with activities of antioxidant enzymes (SOD, CAT; two to fourfold) were enhanced in WsSGTL1-Nt as compared to WT. WsSGTL1-Nt plants showed significant resistance towards Spodoptera litura (biotic stress) with up to 27 % reduced larval weight as well as salt stress (abiotic stress) with improved survival capacity of leaf discs. The present study demonstrates that higher glycosylation of sterols and enhanced antioxidant system caused by expression of WsSGTL1 gene confers specific functions in plants to adapt under different environmental challenges.     

Diindolylmethane-mediated Gli1 Protein Suppression Induces Anoikis in Ovarian Cancer Cells in Vitro and Blocks Tumor Formation Ability in Vivo

Anoikis is a cell death that occurs due to detachment of a cell from the extracellular matrix (ECM). Resistance to anoikis is a primary feature of a cell that undergoes metastasis. In this study for the first time, we demonstrated the potential role of Gli1 in anoikis resistance. Treatment of various ovarian cancer cells by different concentrations of diindolylmethane (DIM), an active ingredient of cruciferous vegetables, reduced the anoikis resistance in a concentration-dependent manner. Reduction in anoikis resistance was associated with a decrease in the expression of Gli1 and an increase in the cleavage of poly(ADP-ribose) polymerase (PARP). Sonic hedgehog (Shh) treatment not only increased the expression of Gli1, but also blocked anoikis induced by DIM and abrogated the change in the expression of Gli1 and cleaved PARP by DIM. To confirm the role of Gli1, hedgehog inhibitor cyclopamine, Gli1 siRNA and Gli1(-/-) mouse embryonic fibroblasts (MEFs) were used. Cyclopamine treatment alone significantly reduced anoikis resistance in A2780 and OVCAR-429 cells. Cyclopamine-mediated reduction in anoikis resistance was associated with reduced expression of Gli1 and induction of cleaved PARP. Shh treatment blocked cyclopamine-induced anoikis. Silencing Gli1 expression induced anoikis and cleavage of PARP in A2780 and OVCAR-429 cells. Furthermore, Gli1(-/-) MEFs were more sensitive to anoikis compared with Gli1(+/+) MEFs. Our in vivo studies established that DIM- or cyclopamine-treated ovarian cancer cells under suspension culture conditions drastically lost their ability of tumor formation in vivo in mice. Taken together, our results establish that Gli1 is a critical player in anoikis resistance in ovarian cancer.     

Bridging the gaps between research,policy and practice in low- and middle-income countries: a survey of researchers

Background

Many international statements have urged researchers, policy-makers and health care providers to collaborate in efforts to bridge the gaps between research, policy and practice in low- and middle-income countries. We surveyed researchers in 10 countries about their involvement in such efforts.

Methods

We surveyed 308 researchers who conducted research on one of four clinical areas relevant to the Millennium Development Goals (prevention of malaria, care of women seeking contraception, care of children with diarrhea and care of patients with tuberculosis) in each of 10 low- and middle-income countries (China, Ghana, India, Iran, Kazakhstan, Laos, Mexico, Pakistan, Senegal and Tanzania). We focused on their engagement in three promising bridging activities and examined system-level, organizational and individual correlates of these activities.

Results

Less than half of the researchers surveyed reported that they engaged in one or more of the three promising bridging activities: 27% provided systematic reviews of the research literature to their target audiences, 40% provided access to a searchable database of research products on their topic, and 43% established or maintained long-term partnerships related to their topic with representatives of the target audience. Three factors emerged as statistically significant predictors of respondents’ engagement in these activities: the existence of structures and processes to link researchers and their target audiences predicted both the provision of access to a database (odds ratio [OR] 2.62, 95% CI 1.30–5.27) and the establishment or maintenance of partnerships (OR 2.65, 95% CI 1.25–5.64); stability in their contacts predicted the provision of systematic reviews (OR 2.88, 95% CI 1.35–6.13); and having managers and public (government) policy-makers among their target audiences predicted the provision of both systematic reviews (OR 4.57, 95% CI 1.78–11.72) and access to a database (OR 2.55, 95% CI 1.20–5.43).

Interpretation

Our findings suggest potential areas for improvement in light of the bridging strategies targeted at health care providers that have been found to be effective in some contexts and the factors that appear to increase the prospects for using research in policy-making.The need to bridge the gaps between research, policy and practice appears to be a global phenomenon. Three recent, highly visible resolutions — the Mexico Action Statement on Health Research in 2004 (58 countries),¹ the related World Health Assembly resolution in 2005 (193 countries)² and the Bamako Call to Action on Research for Health in 2008 (53 countries) ³ — urged researchers, policy-makers and health care providers to collaborate in efforts to bridge these gaps. These efforts can range from bringing research-based evidence to the attention of those who could use it, to making research-based evidence available so that it can be readily retrieved when needed.We are not aware of a survey having been conducted in a range of low- and middle-income countries about researchers’ bridging activities related to specific high-priority health topics. Researchers and research organizations have been surveyed about their bridging activities in single high-income countries such as Canada.^4–6 Guideline-producing organizations and health technology assessment agencies have also been surveyed about their bridging activities;⁷ only in one case was the focus on bridging activities in low- and middle-income countries.⁸ Select research funding agencies have been studied in low- and middle-income countries.⁹ Yet the Millennium Development Goals and the goals of many countries call for topic-focused efforts to bridge the gaps between research, policy and practice.We studied efforts to bridge the gaps between research, policy and practice in 10 low- and middle-income countries (China, Ghana, India, Iran, Kazakhstan, Laos, Mexico, Pakistan, Senegal and Tanzania). In this article, we describe the findings from a survey of researchers in these countries who conducted research in one of four clinical areas relevant to the Millennium Development Goals: prevention of malaria (Ghana, Laos, Senegal and Tanzania), care of women seeking contraception (China, Kazakhstan, Laos and Mexico), care of children with diarrhea (Ghana, India, Pakistan and Senegal) and care of patients with tuberculosis (China, India, Iran and Mexico). In a related article, we describe the findings from a survey of health care providers in these countries who were practising in one of these clinical areas about their awareness of, access to and use of research-based evidence in these clinical areas and the influence of such evidence on their professional practice.¹⁰The challenges associated with documenting such efforts include cross-country differences in the capacity to conduct surveys of researchers; the visibility of researchers depending on their alignment with priorities of government, development agencies, research funding agencies and industry (and hence their likelihood of being identified to participate in these surveys); and researchers’ familiarity with and attitudes toward the bridging activities asked about in these surveys.