346 research outputs found

    Interpopulation crosses, inheritance study, and genetic variability in the brown planthopper complex, Nilaparvata lugens (Homoptera: Delphacidae)

    Get PDF
    Studies on hybridization, inheritance, and population genetics of brown planthoppers that infest rice and weeds were undertaken using starch gel electrophoresis to determine whether the weed-infesting population represents a biological race or a species. F(1) and F(2) generations were produced by crosses between parental insects from the two populations with little indication of hybrid sterility. Gpi, Mdh, and Idh loci were inherited in a simple Mendelian fashion in families of two sympatric populations. Sixteen populations of Nilaparvata spp. from eight locations were collected. The Mdh, Idh, Pgm, Gpi, 6Pgd, and Acp loci were polymorphic. The N. lugens of rice with high esterase activity were clustered into a group and characterized by the presence of alleles Gpi (110) and Gpi (120), whereas N. lugens from weeds with low esterase activity were clustered into another group and characterized by Gpi (100) and Gpi (90) . There was a lack of heterozygotes between the common alleles of the two populations. This means that the two groups of individuals belong to different gene pools

    Inter-hemispheric EEG coherence analysis in Parkinson's disease : Assessing brain activity during emotion processing

    Get PDF
    Parkinson’s disease (PD) is not only characterized by its prominent motor symptoms but also associated with disturbances in cognitive and emotional functioning. The objective of the present study was to investigate the influence of emotion processing on inter-hemispheric electroencephalography (EEG) coherence in PD. Multimodal emotional stimuli (happiness, sadness, fear, anger, surprise, and disgust) were presented to 20 PD patients and 30 age-, education level-, and gender-matched healthy controls (HC) while EEG was recorded. Inter-hemispheric coherence was computed from seven homologous EEG electrode pairs (AF3–AF4, F7–F8, F3–F4, FC5–FC6, T7–T8, P7–P8, and O1–O2) for delta, theta, alpha, beta, and gamma frequency bands. In addition, subjective ratings were obtained for a representative of emotional stimuli. Interhemispherically, PD patients showed significantly lower coherence in theta, alpha, beta, and gamma frequency bands than HC during emotion processing. No significant changes were found in the delta frequency band coherence. We also found that PD patients were more impaired in recognizing negative emotions (sadness, fear, anger, and disgust) than relatively positive emotions (happiness and surprise). Behaviorally, PD patients did not show impairment in emotion recognition as measured by subjective ratings. These findings suggest that PD patients may have an impairment of inter-hemispheric functional connectivity (i.e., a decline in cortical connectivity) during emotion processing. This study may increase the awareness of EEG emotional response studies in clinical practice to uncover potential neurophysiologic abnormalities

    Clonal Structure of Rapid-Onset MDV-Driven CD4+ Lymphomas and Responding CD8+ T Cells

    Get PDF
    Lymphoid oncogenesis is a life threatening complication associated with a number of persistent viral infections (e.g. EBV and HTLV-1 in humans). With many of these infections it is difficult to study their natural history and the dynamics of tumor formation. Marek's Disease Virus (MDV) is a prevalent α-herpesvirus of poultry, inducing CD4+ TCRαβ+ T cell tumors in susceptible hosts. The high penetrance and temporal predictability of tumor induction raises issues related to the clonal structure of these lymphomas. Similarly, the clonality of responding CD8 T cells that infiltrate the tumor sites is unknown. Using TCRβ repertoire analysis tools, we demonstrated that MDV driven CD4+ T cell tumors were dominated by one to three large clones within an oligoclonal framework of smaller clones of CD4+ T cells. Individual birds had multiple tumor sites, some the result of metastasis (i.e. shared dominant clones) and others derived from distinct clones of transformed cells. The smaller oligoclonal CD4+ cells may represent an anti-tumor response, although on one occasion a low frequency clone was transformed and expanded after culture. Metastatic tumor clones were detected in the blood early during infection and dominated the circulating T cell repertoire, leading to MDV associated immune suppression. We also demonstrated that the tumor-infiltrating CD8+ T cell response was dominated by large oligoclonal expansions containing both “public” and “private” CDR3 sequences. The frequency of CD8+ T cell CDR3 sequences suggests initial stimulation during the early phases of infection. Collectively, our results indicate that MDV driven tumors are dominated by a highly restricted number of CD4+ clones. Moreover, the responding CD8+ T cell infiltrate is oligoclonal indicating recognition of a limited number of MDV antigens. These studies improve our understanding of the biology of MDV, an important poultry pathogen and a natural infection model of virus-induced tumor formation

    Assessment of vitamin D intake among Libyan women - adaptation and validation of specific food frequency questionnaire

    Get PDF
    Vitamin D deficiency (VDD) has pandemic proportions worldwide. Numerous studies report on high prevalence of VDD in sunny regions like Near East and North Africa (NENA). Previous studies indicated that Libyan population was at risk of VDD. To contribute to the body of evidence, measurement of vitamin D status on children, adults, in Misurata region was conducted, and confirmed with validated dietary intake study. Serum 25(OH)D was analysed using electrochemiluminescence protein binding assay. Existing Food Frequency Questionnaires (FFQ) were adapted to Libyan Women Food Frequency Questionnaire (LW-FFQ). Repeated 24h dietary recalls and LW-FFQ were employed in vitamin D intake evaluation. LW-FFQ was validated using 24h dietary recall and vitamin D status as referent methods. The questionnaires included anthropometry and lifestyle information. Vitamin D status assessment revealed inadequate levels (25(OH)D lt 50nmol/l) in almost 80% of participants. Women (25-64y) were identified as the most vulnerable group with vitamin D inadequacy present in 82% (61.6% had 25(OH)D lt 25nmol/l, and 20.2% had 25-50nmol/l 25(OH)D). Average Vitamin D intake within the study sample (n=316) was 3.9 +/- 7.9 mu g/d, with 92% participants below both Institute of Medicine (IOM) (10 mu g/d) and European Food Safety Authority (15 mu g/d) recommendations. Measured vitamin D status, in 13% of this group, correlated significantly (p=0.015) with intake estimates. Based on self-report, consumption of vitamin D supplements does not exist among study participants. Additional lifestyle factors influencing vitamin D status were analysed. Only 2% of study participants spend approximately 11 min on the sun daily, 60.4% were obese, 23.1% were overweight and 71.2% reported low physical activity. These findings confirm previous reports on high prevalence of VDD in women across NENA, and in Libya. The situation calls for multi-sectoral actions and public health initiatives to address dietary and lifestyle habits

    Lack of association between gene polymorphisms of Angiotensin converting enzyme, Nod-like receptor 1, Toll-like receptor 4, FAS/FASL and the presence of Helicobacter pylori-induced premalignant gastric lesions and gastric cancer in Caucasians

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Several polymorphisms of genes involved in the immunological recognition of <it>Helicobacter pylori </it>and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding <it>Angiotensin converting enzyme </it>(<it>ACE</it>), <it>Nod-like receptor 1 </it>(<it>NOD1</it>), <it>Toll-like receptor 4 </it>(<it>TLR4</it>) and <it>FAS/FASL</it>.</p> <p>Methods</p> <p>Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. <it>ACE I/D </it>(rs4646994), <it>NOD1 796G>A </it>(rs5743336), <it>TLR4 3725G>C </it>(rs11536889), <it>FAS 1377G>A </it>(rs2234767), <it>FAS 670A>G </it>(rs1800682) and <it>FASL 844T>C </it>(rs763110) were genotyped by different PCR approaches and restriction fragment length polymorphism analysis.</p> <p>Results</p> <p>Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for <it>NOD1 796G/G </it>genotype to be associated with increased risk of HRAG (62.4% <it>vs</it>. 54.5% in controls, <it>p </it>= 0.082). <it>FAS 670G/G </it>genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (<it>p </it>= 0.077). We did not find any significant associations for all polymorphisms in relation to GC or HRAG. <it>NOD1 796G>A </it>and <it>TLR4 3725G>C </it>gene polymorphisms were also not associated with <it>Helicobacter pylori </it>infection.</p> <p>Conclusions</p> <p><it>ACE, NOD1, TRL4 </it>and <it>FAS/FASL </it>gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC.</p

    Regulation of the Na,K-ATPase Gamma-Subunit FXYD2 by Runx1 and Ret Signaling in Normal and Injured Non-Peptidergic Nociceptive Sensory Neurons

    Get PDF
    Dorsal root ganglia (DRGs) contain the cell bodies of sensory neurons which relay nociceptive, thermoceptive, mechanoceptive and proprioceptive information from peripheral tissues toward the central nervous system. These neurons establish constant communication with their targets which insures correct maturation and functioning of the somato-sensory nervous system. Interfering with this two-way communication leads to cellular, electrophysiological and molecular modifications that can eventually cause neuropathic conditions. In this study we reveal that FXYD2, which encodes the gamma-subunit of the Na,K-ATPase reported so far to be mainly expressed in the kidney, is induced in the mouse DRGs at postnatal stages where it is restricted specifically to the TrkB-expressing mechanoceptive and Ret-positive/IB4-binding non-peptidergic nociceptive neurons. In non-peptidergic nociceptors, we show that the transcription factor Runx1 controls FXYD2 expression during the maturation of the somato-sensory system, partly through regulation of the tyrosine kinase receptor Ret. Moreover, Ret signaling maintains FXYD2 expression in adults as demonstrated by the axotomy-induced down-regulation of the gene that can be reverted by in vivo delivery of GDNF family ligands. Altogether, these results establish FXYD2 as a specific marker of defined sensory neuron subtypes and a new target of the Ret signaling pathway during normal maturation of the non-peptidergic nociceptive neurons and after sciatic nerve injury

    Pepsinogen A, pepsinogen C, and gastrin as markers of atrophic chronic gastritis in European dyspeptics

    Get PDF
    Serum levels of pepsinogen and gastrin are parameters that can be used as biomarkers for gastric mucosa. The aim of this study was to validate these serum biomarkers, that is pepsinogen A (PGA), pepsinogen C (PGC), PGA/PGC ratio, and gastrin, as screening tests for precancerous lesions: atrophic chronic gastritis (ACG) or Helicobacter pylori-related corpus-predominant or multifocal atrophy. The study population was comprised of a subsample of 284 patients from the 451 included in the Eurohepygast cohort, between 1995 and 1997. The concentrations of PGA, PGC, and gastrin were measured by radioimmunoassays. Histological diagnosis was the gold standard. Cut-off points were calculated using receiving operator characteristics (ROC) curves. Factors linked to variation of biomarkers were identified using multivariate linear regression. The mean of each biomarker in the sample was: PGA, 77.4 μg l−1; PGC, 13.2 μg l−1; PGA/PGC, 6.7; and gastrin, 62.4 ng l−1. For ACG patients, the areas under the PGA, PGC, PGA/PGC, and gastrin ROC curves were 0.55, 0.62, 0.73, and 0.58, respectively. The best cut-off point for PGA/PGC was 5.6, with sensitivity 65% and specificity 77.9%. For H. pylori-related corpus-predominant or multifocal atrophy, the areas under the respective ROC curves were 0.57, 0.67, 0.84, and 0.69. The best cut-off point for PGA/PGC was 4.7, with sensitivity 77.1% and specificity 87.4%. The results suggested that only the PGA/PGC ratio can be considered as a biomarker for precancerous lesions of the stomach, and may be useful as a screening test
    corecore