287 research outputs found

    Effects of sublethal doses of chlorfluazuron on the ovarian biochemical constituents of Spodoptera litura

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    This paper describes the effects of sublethal doses (LD10: 1.00 ng larva-1; LD30: 3.75 ng larva-1) of chlorfluazuron on the amounts of ovarian constituents during various stages of development in common cutworm, Spodoptera litura (F.). Chlorfluazuron was applied topically to newly ecdysed fifth instars under laboratory conditions. In newly emerged adults, the amount of ovarian protein in LD10 and LD30 treated larvae was significantly reduced, but carbohydrate and lipid were not affected compared with their respective controls. The order of relative proportion of the amount of ovarian DNA in three developmental stages was: newly emerged adults>newly pupae>newly ecdysed larvae. Moreover, the order of the amount of RNA was: newly ecdysed larvae>newly emerged adults> newly pupae. The amount of utricular DNA was greater (14.2 μgmg-1 of tissue) after first mating than the second one in the spermatheca. However, the amount of ovarian DNA was reduced more than ovarian RNA and it decreased rapidly, whereas amount of DNA decreased steadily. On the 5th day of pupae, ecdysteroid titer was 3.5 ± 0.8 pgmg-1. Initially, it was increased slowly then gradually, and furthermore, sharply during the 5th day of pupae to before adult emergence. It was peaked on the 1st day after adult emergence (52.0 ± 1.5 pgmg-1) and decreased thereafter. Therefore, it is concluded that sublethal doses of chlorfluazuron reduced the amounts of ovarian constituents during ovarian development and oogenesis in S. litura. These reductions increased with an increase in dose from LD10 to LD30. The effects of chlorfluazuron on the amounts of ovarian constituents are presumed to be responsible for the reduction in fecundity caused by sublethal exposure to chlorfluazuron.Key words: Chlorfluazuron, ecdysteroid, nucleic acids, oogenesis, Spodoptera litura, sublethal doses

    Effects of sublethal doses of chlorfluazuron on the testicular biochemical constituents of Spodoptera litura (Lepidoptera: Noctuidae)

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    The effects of sublethal doses (LD10: 1.00 ng/larva; LD30: 3.75 ng/larva) of chlorfluazuron on the amounts of testicular biochemical constituents of the common cutworm, Spodoptera litura (F.) was described. Chlorfluazuron was applied topically to newly ecdysed fifth-instar larvae under laboratory conditions. Sublethal doses of chlorfluazuron significantly reduced the amount of protein with no effect on carbohydrate and lipid. The relative proportion of the amounts of control testicular DNA was: 7.52±0.9 μg/mg at the day before adult emergence> 4.54±0.44 μg/mg at newly emerged adults> 3.52±0.49 μg/mg at 1st day after adult emergence. Sublethal doses of chlorfluazuron significantly (p < 0.05) reduced the amounts of testicular, seminal vesicular and aedeagular DNA compared with the controls. Similar reduction was observed in RNA as found in DNA. Three peaks in ecdysteroid titres were observed during 80 to 208 h. Compared with the controls, all peaks were reduced in LD10 or LD30 treated testis as follows: 11.5 or 21%; 12 or 22%; 12.5 or 23%, respectively. Sublethal doses of chlorfluazuron reduced the ecdysteroid titres with no effect on its pattern. Sublethal doses of chlorfluazuron reduced the amounts of biochemical testicular constituents during the development of testes in S. litura.Key words: Chlorfluazuron, ecdysteroid titre, nucleic acid, protein, Spodoptera litura, sublethal doses, testicular biochemical, seminal vesicle, aedeagus

    Genomic affinity between Oryza sativa and Oryza brachyantha as revealed by in situ hybridization and chromosome pairing

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    Genomic affinity between Oryza sativa (2n = 24 AA), and Oryza brachyantha (2n = 24 FF) was assessed by using three strategies: genomic in situ hybridization (GISH), meiotic chromosome pairing, pollen andspikelet sterility. The chromosome pairing was examined in pollen mother cells of O. brachyantha, O.sativa and the hybrid between O. sativa and O. brachyantha. The hybrid was highly sterile with no pollen stain ability. Both parents showed regular meiosis with normal chromosome pairing. The F1hybrid exhibited limited chromosome pairing. On an average, 0-2 bivalents and 20-24 univalents were recorded at metaphase-1 and 0 - 1 univalent at diakinesis. The most frequent configuration was twobivalents and twenty univalent. The meiosis was highly irregular showing unequal distribution of chromosomes at anaphase, formation of multipolar bodies and variation in the cell cycle of both genomes. GISH revealed unequivocal discrimination of O. brachyantha chromosomes as appeared red from O. sativa chromosomes that fluoresced yellow. No cross hybridization was examined between the labeled genomic DNA of O. brachyantha and the chromosomes of O. sativa. Mitotic chromosomes of O. brachyantha and O. sativa, in the hybrid, were discriminated by GISH. High sterility in this hybrid could be due to abnormal meiosis and lack of pairing

    Assessment of genomic relationship between Oryza sativa and Oryza australinesis

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    The genomic relationship between Oryza sativa (2n = 24 AA) and Oryza australinesis (2n = 24 EE) has not been established. Genomic relationship between these two species was assessed by using three strategies: genomic in situ hybridization (GISH), meiotic chromosome pairing, pollen and spikelet sterility. The hybrid was produced between these two species at the International Rice Research Institute using embryo rescue technique. The chromosome pairing was examined in pollen mother cellsof O. australinesis, O. sativa and the hybrid between O. sativa and O. australinesis. The hybrid was highly sterile with pollen stain ability being 0.05%. Both parents showed regular meiosis with normal chromosome pairing. The F1 hybrid exhibited limited chromosome pairing. On an average, 0 - 4 bivalents and 16 - 24 univalents were recorded at metaphase-1. The most frequent configuration was two bivalent and twenty univalent. The chromosomes of O. australiensis appeared larger and darkly stained. For genomic in situ hybridization, genomic DNA from O. australiensis was used as probe for the mitotic and meiotic chromosomes of the hybrid between O. sativa and O. australiensis. GISH revealed unequivocal discrimination of O. australiensis chromosomes that appeared yellow due to hybridization signal from O. sativa chromosomes that fluoresced red due to counterstaining with propidium iodide (PI). No cross hybridization was examined between the labeled genomic DNA of O.australiensis and the chromosomes of O. sativa. The paired chromosomes were discriminated as autosyndetic and allosyndetic pairing. Meiotic and mitotic chromosomes of the O. australiensis and O. sativa, in the hybrid were discriminated by GISH for the first time. Results showed that both genomes were highly divergent

    Caregivers knowledge, practices about childhood diarrhea and pneumonia and their perceptions of lady health worker program; findings from NIGRAAN implementation research project

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    Background: Despite 60% coverage by Lady Health Worker (LHW) Program, 30% of child deaths in Pakistan are still due to diarrhea and pneumonia. Caregivers are an important stakeholder yet there is little information on their case management practices and utilization of LHW Program. This study explored caregivers’ knowledge and practices about childhood diarrhea and pneumonia and utility of LHW services before and after a supportive supervision intervention.Methods: Cross sectional surveys were conducted with caregivers’ (mothers) pre and post intervention in project NIGRAAN. The intervention aimed to improve LHSs clinical and supervisory skills of lady health supervisors in order to improve LHW performance and ultimately impact caregiver practices. 4250 households were surveyed. Questionnaire was adapted from PDHS 2012-13. Differences between intervention and control groups were assessed using chi square test. P-value of Results: Comparing baseline to end line, there were significant overall improvements in caregivers’knowledge of loose motion (62 to 84%) and dehydration (12 to 18%) as signs and symptoms of childhood diarrhea. There was also a significant overall increase in caregivers’ knowledge of presenting features of pneumonia- i.e. fever (58 to 86%), cough (51 to 61%) and breathing problems (25 to 57%). The proportion of caregivers seeking advice for diarrhea from public sector significantly improved in intervention arm from 20% to 29%. Private sector however remained overall preferred choice for care seeking. There was significant overall improvement in awareness about LHWs functioning (93 to 99%) and household visits (91 to 98%). Actual care seeking from LHWs however stayed low (≤ 0.3%) Conclusion: In order to improve utility and expand coverage of LHW Program interventions aimed at providing supportive supervision have the potential to improve caregiver practices and utilization of available services and decrease childhood deaths due to preventable illnesses

    Historical perspective of in situ hybridization for the analysis of genomic constitution of plants

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    In situ hybridization involves hybridization of DNA or RNA probes to the cytological preparations. The technique originally used auto-radiographic labeling to map both repetitive and low copy DNA sequences. The problem associated with this technique was its short half life, lack of safety and long exposure time which hindered its widespread use in DNA hybridization. To overcome these problems, non isotopic in situ hybridization was developed for use in animal and plant species. In the last decade, the development of haptens and fluorochromes enabled simultaneous multicolored detection of differentially labeled probes. Characterization of parental genomes in interspecific hybrids, restructured chromosomes, gene mapping, detecting nature of chromosome pairing, establishing phylogenetic relationship among the species and localizing introgressed segment have been successfully achieved by fluorescence in situ hybridization. Keywords: In situ hybridization, phylogenetic relationship, homoeologous pairin

    Characterization of wide cross derivatives in rice Oryza sativa L. using genomic in situ hybridization (GISH)

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    Interspecific crosses provide a bridge by which the gene pool of rice can be increased. Introduction of alien genes requires hybridization followed by meiotic pairing and recombination between the chromosomes of cultivated and wild species. Attempts have been made to visualize the genomic constitution of wide-cross derivatives. Genomic in situ hybridization was used to detect Oryza australiensis chromosomes and introgressed segment from O. australiensis into the Oryza sativa background. Genomic DNA from O. australiensis was labeled with biotin-14-dATP and hybridized to the homologous chromosomes in hybrids, back cross progenies, monosomic alien addition line (MAAL) and introgression line. The probe hybridization fluoresced green and non-labeled O. sativa chromosomes appeared red due to counterstaining with propidium iodide (PI). This differential painting of chromosomes unequivocally detected the O. australiensis chromatin introgressed into the O. sativa genome. The probe produced uniform labeling pattern over the entire length of all the O. australiensis chromosomes. Genomic in situ hybridization (GISH) detected 12 O. australiensis chromosomes in the hybrid, O. sativa x O. australiensis in BC1 progenies, and a single chromosome in MAAL. Small segment of O. australiensis was localized on the chromosome 12 of the introgression line. However, results showed that GISH is a powerful technique to be used as an aid in selecting segregating progenies.Key words: Genomic in situ hybridization, wide hybrid, localizing introgression

    Electronic-Cigarette Vehicles and Flavoring Affect Lung Function and Immune Responses in a Murine Model

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    The use of electronic nicotine delivery systems (ENDS), also known as electronic-cigarettes (e-cigs), has raised serious public health concerns, especially in light of the 2019 outbreak of e-cig or vaping product use-associated acute lung injury (EVALI). While these cases have mostly been linked to ENDS that contain vitamin E acetate, there is limited research that has focused on the chronic pulmonary effects of the delivery vehicles (i.e., without nicotine and flavoring). Thus, we investigated lung function and immune responses in a mouse model following exposure to the nearly ubiquitous e-cig delivery vehicles, vegetable glycerin (VG) and propylene glycol (PG), used with a specific 70%/30% ratio, with or without vanilla flavoring. We hypothesized that mice exposed sub-acutely to these e-cig aerosols would exhibit lung inflammation and altered lung function. Adult female C57BL/6 mice (n= 11-12 per group) were exposed to filtered air, 70%/30% VG/PG, or 70%/30% VG/PG with a French vanilla flavoring for 2 h a day for 6 weeks. Prior to sacrifice, lung function was assessed. At sacrifice, broncho-alveolar lavage fluid and lung tissue were collected for lipid mediator analysis, flow cytometry, histopathology, and gene expression analyses. Exposures to VG/PG + vanilla e-cig aerosol increased lung tidal and minute volumes and tissue damping. Immunophenotyping of lung immune cells revealed an increased number of dendritic cells, CD4+ T cells, and CD19+ B cells in the VG/PG-exposed group compared to air, irrespective of the presence of vanilla flavoring. Quantification of bioactive lung lipids demonstrated a \u3e3-fold increase of 2-arachidonoylglycerol (2-AG), an anti-inflammatory mediator, and a 2-fold increase of 12-hydroxyeicosatetraenoic acid (12-HETE), another inflammatory mediator, following VG/PG exposure, with or without vanilla flavoring. This suggests that e-cig aerosol vehicles may affect immunoregulatory molecules. We also found that the two e-cig aerosols dysregulated the expression of lung genes. Ingenuity Pathway Analysis revealed that the gene networks that are dysregulated by the VG/PG e-cig aerosol are associated with metabolism of cellular proteins and lipids. Overall, our findings demonstrate that VG and PG, the main constituents of e-liquid formulations, when aerosolized through an e-cig device, are not harmless to the lungs, since they disrupt immune homeostasis
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