The soybean cyst nematode (SCN), Heterodera glycines, causes economically significant damage to soybeans (Glycine max) in many parts of the world. The cysts of this nematode can remain quiescent in soils for many years as a reservoir of infection for future crops. To investigate bacterial communities associated with SCN cysts, cysts were obtained from eight SCN-infested farms in southern Ontario, Canada, and analyzed by culture-dependent and -independent means. Confocal laser scanning microscopy observations of cyst contents revealed a microbial flora located on the cyst exterior, within a polymer plug region and within the cyst. Microscopic counts using 5-(4,6-dichlorotriazine-2-yl)aminofluorescein staining and in situ hybridization (EUB 338) indicated that the cysts contained (2.6 ± 0.5) × 105 bacteria (mean ± standard deviation) with various cellular morphologies. Filamentous fungi were also observed. Live-dead staining indicated that the majority of cyst bacteria were viable. The probe Nile red also bound to the interior polymer, indicating that it is lipid rich in nature. Bacterial community profiles determined by denaturing gradient gel electrophoresis analysis were simple in composition. Bands shared by all eight samples included the actinobacterium genera Actinomadura and Streptomyces. A collection of 290 bacteria were obtained by plating macerated surface-sterilized cysts onto nutrient broth yeast extract agar or on actinomycete medium. These were clustered into groups of siblings by repetitive extragenic palindromic PCR fingerprinting, and representative isolates were tentatively identified on the basis of 16S rRNA gene sequence. Thirty phylotypes were detected, with the collection dominated by Lysobacter and Variovorax spp. This study has revealed the cysts of this important plant pathogen to be rich in a variety of bacteria, some of which could presumably play a role in the ecology of SCN or have potential as biocontrol agents. 相似文献
The 16S-23S intergenic spacer region (spacer region 1) of Streptococcus salivarius, S. thermophilus, and Lactococcus lactis subsp. cremoris and the 23S-5S intergenic spacer region (spacer region 2) of S. salivarius and L. lactis subsp. cremoriswere sequenced and compared with the spacer regions 1 and 2 of other streptococci. A high degree of intraspecific conservation was observed for S. thermophilus and L. lactis, and very similar sequences were found for S. salivarius and S. thermophilus. Whereas spacer region 1 is highly conserved in the genus Streptococcus sensu-stricto,only the tRNA gene and the rRNA processing stems are highly conserved in the three genera: Streptococcussensu-stricto, Lactococcus, and Enterococcus. The presence of a unique tRNAAla gene without the 3 terminal CCA sequence seems to be a general feature of the streptococci spacer region 1. A secondary structure model was built to show the interaction between the spacer regions 1 and 2 of S. thermophilus and S. salivarius. The rapid evolution of spacer region 1 in streptococci is in part due to insertions and deletions of small RNA stem/loop structures. 相似文献
Summary The formation of itaconic, aconitic and other acids from glucose in the presence of some enzyme inhibitors or organic acids by Aspergillus terreus was studied. Moreover, the metabolic activities of the preformed mats when floated on solutions of some organic acids were traced.When the resulting information were collected together a presumed condensation reaction between acetate and succinate could be formulated. The reaction product, presumably 1, 2, 3 propane tricarboxylic acid, would undergo a dehydrogenation reaction to yield aconitic acid and subsequently itaconic acid. It has also been suggested that aconityl CoA may be the metabolic form which suits the reactions leading to the formation of itaconic acid. The presumed aconityl CoA may be formed either through a condensation reaction between acetyl CoA and succinate or acetate with succinyl CoA. 相似文献
Plasmodium vivax is the most prevalent human malaria parasite, causing serious public health problems in malaria-endemic countries. Until recently the Duffy-negative blood group phenotype was considered to confer resistance to vivax malaria for most African ethnicities. We and others have reported that P. vivax strains in African countries from Madagascar to Mauritania display capacity to cause clinical vivax malaria in Duffy-negative people. New insights must now explain Duffy-independent P. vivax invasion of human erythrocytes.
Methods/Principal Findings
Through recent whole genome sequencing we obtained ≥70× coverage of the P. vivax genome from five field-isolates, resulting in ≥93% of the Sal I reference sequenced at coverage greater than 20×. Combined with sequences from one additional Malagasy field isolate and from five monkey-adapted strains, we describe here identification of DNA sequence rearrangements in the P. vivax genome, including discovery of a duplication of the P. vivax Duffy binding protein (PvDBP) gene. A survey of Malagasy patients infected with P. vivax showed that the PvDBP duplication was present in numerous locations in Madagascar and found in over 50% of infected patients evaluated. Extended geographic surveys showed that the PvDBP duplication was detected frequently in vivax patients living in East Africa and in some residents of non-African P. vivax-endemic countries. Additionally, the PvDBP duplication was observed in travelers seeking treatment of vivax malaria upon returning home. PvDBP duplication prevalence was highest in west-central Madagascar sites where the highest frequencies of P. vivax-infected, Duffy-negative people were reported.
Conclusions/Significance
The highly conserved nature of the sequence involved in the PvDBP duplication suggests that it has occurred in a recent evolutionary time frame. These data suggest that PvDBP, a merozoite surface protein involved in red cell adhesion is rapidly evolving, possibly in response to constraints imposed by erythrocyte Duffy negativity in some human populations. 相似文献
Using phages is a novel field of cancer therapy and phage nanobioparticles (NBPs) such as λ phage could be modified to deliver and express genetic cassettes into eukaryotic cells safely in contrast with animal viruses. Apoptin, a protein from chicken anemia virus (CAV) has the ability to specifically induce apoptosis only in carcinoma cells. We presented a safe method of breast tumor therapy via the apoptin expressing λ NBPs. Here, we constructed a λ ZAP-CMV-apoptin recombinant NBP and investigated the effectiveness of its apoptotic activity on BT-474, MDA-MB-361, SKBR-3, UACC-812 and ZR-75 cell lines that over-expressing her-2 marker. Apoptosis was evaluated via annexin-V fluorescent iso-thiocyanate/propidium iodide staining, flow-cytometric method and TUNEL assay. Transfection with NBPs carrying λ ZAP-CMV-apoptin significantly inhibited growth of all the breast carcinoma cell lines in vitro. Also nude mice model implanted BT-474 human breast tumor was successfully responded to the systemic and local injection of untargeted recombinant λ NBPs. The results presented here reveal important features of recombinant λ nanobioparticles to serve as safe delivery and expression platform for human cancer therapy. 相似文献
ABSTRACT Chronotype reflects time of day preferences for performing daily activities. Previous research within Asian and European cohorts indicates evening chronotype is associated with elevated cardiometabolic risk. However, evidence is limited from population-based US cohorts, particularly among women in whom evening chronotype prevalence may become higher after middle-age, coinciding with life stages associated with higher cardiovascular disease (CVD) risk. This cross-sectional study evaluated associations of chronotype with overall cardiovascular health (CVH), health behaviors, and cardiometabolic risk factors among 506 women (mean age = 37 ± 16y, 62% racial/ethnic minority) in the American Heart Association (AHA)’s Go Red for Women Strategically-Focused Research Network cohort at Columbia University (New York City, NY, USA). Chronotype was assessed using the validated Morningness-Eveningness Questionnaire (MEQ) and categorized as “evening”, “intermediate”, and “morning” chronotypes. Health behaviors (diet, physical activity, and sleep) were assessed using validated questionnaires. Anthropometrics, clinical blood pressure, and blood biomarkers were assessed at the clinic visit. CVH was evaluated using the AHA Life’s Simple 7 (LS7) metrics; LS7 scores of 0–8 and 9–14 were considered indicative of poor and moderate-to-high CVH, respectively. Linear and logistic regression models adjusted for age, race/ethnicity, education, health insurance, and menopausal status were used to examine associations of MEQ scores and chronotype categories with overall CVH, clinical cardiometabolic risk factors, and health behaviors. Overall, 13% of women identified as evening chronotypes, while 55% and 32% reported being intermediate and morning types. In linear models, higher MEQ scores were associated with higher AHA LS7 scores (β(SE) = 0.02(0.01); p = .014), indicative of more favorable CVH, and with health behaviors not included in the LS7. Higher MEQ scores were also associated with lower Pittsburgh Sleep Quality Index, i.e. better sleep quality, (β(SE) = ?0.07(0.02), p < .0001), lower insomnia severity (β(SE) = ?0.14(0.01), p < .0001), shorter time to fall asleep (β(SE) = ?0.28(0.14), p = .044), and less sedentary time (β(SE) = ?0.11(0.03), p = .001). In logistic regression models, evening chronotype, compared to intermediate/morning type, was associated with higher odds of having poor CVH (OR(95%CI):2.41(1.20–4.85)), not meeting AHA diet (OR(95%CI):2.89(1.59–5.23)) and physical activity guidelines (OR(95%CI):1.78(1.03–3.07)), and having short sleep (OR(95%CI):2.15(1.24–3.73)) or insomnia (OR(95%CI):2.69(1.53–4.75)). The evening type compared to morning type was also associated with being a current smoker (OR(95%CI):2.14(1.02–4.52)) and having poor sleep quality (OR(95%CI:2.35(1.27–4.37)) and long sleep onset latency (OR(95%CI:1.89(1.00–3.56)). In our cohort of women, evening chronotype was related to poor CVH, likely driven by its influence on health behaviors. These findings, although warranting confirmation prospectively in other populations, suggest chronotype is an important factor to consider and possibly target when designing lifestyle interventions for CVD prevention. 相似文献
Genetic variations of microRNA encoding genes influence various sorts of diseases by modifying the expression or activity of microRNAs. MicroRNA 146a is an epigenetic regulator of immune response through controlling the type I interferon (IFN) and nuclear factor kappa B (NF-κB) pathways. Genetic variations of microRNA 146a impact the susceptibility to systemic lupus erythematosus (SLE) and its clinical presentations. This study aimed to investigate the polymorphisms of microRNA-146a gene (rs2431697 and rs57095329) in patients with SLE and its association with disease activity. Sixty-five patients with SLE and 40 apparently healthy controls were enrolled in this study. Patients were subjected to history taking, clinical examination, and disease activity evaluation by SLEDAI score. The microRNA-146a variants were determined by allele discrimination real-time PCR method in all participants. We found a statistically significant association between rs2431697 T allele and SLE (P-value?<?0.05), but there was no significant association between rs57095329 and SLE. The T/T genotype of microRNA-146a rs2431697 was associated with lupus nephritis, higher disease activity, and autoantibodies production. The microRNA-146a rs2431697 T allele could be a potential risk factor that contributes to SLE susceptibility, development of lupus nephritis, and disease activity.
The first checklist of black fungus gnats is established; new faunistic records of Sciaridae are presented, providing a list of 10 genera and 55 species. Forty-eight species are newly listed for Morocco, increasing the total of Sciaridae known from Morocco to 69 species, belonging to 12 genera, of which six (Austrosciara Schmitz & Mjöberg, 1924, Bradysiopsis Tuomikoski, 1960, Epidapus Haliday, 1851, Lycoriella Frey, 1942, Pseudolycoriella Menzel & Mohrig, 1998 and Sciara Meigen, 1803) are newly reported for Moroccan fauna. 相似文献
BackgroundStudies revealed that insulin resistance is associated with fibrosis progression and has negative impact on sustained virological response after standard antiviral therapy in patients with chronic hepatitis C (CHC).AimTo assess the role of IR on progression of liver fibrosis and early virological response (EVR) rates in patients with chronic hepatitis C infection.Patients and methodsThe study population comprised 79 subjects who underwent combination therapy for CHC. Laboratory investigations in the form of glucose, insulin, bilirubin, alanine aminotransferase (ALT), cholesterol and triglycerides and liver biopsy were done for all patients. Insulin resistance was calculated using the homeostasis model of IR (HOMA-IR).ResultsIR was increased (>2 IU) in 31 (40.7%) of patients. Early virological response was achieved among 37 patients (48.7%). No difference in EVR, viral load or grade of liver fibrosis between patients with and without IR. A significant positive correlation was found between IR and liver steatosis.ConclusionInsulin resistance is a common finding in CHC, it is associated with increase liver steatosis. However it has no impact on EVR to combined interferon ribavirin therapy, viral load or necroinflammation. 相似文献
Germination of Bacillus anthracis spores into the vegetative form is an essential step in anthrax pathogenicity. This process can be triggered in vitro by the common germinants inosine and alanine. Kinetic analysis of B. anthracis spore germination revealed synergy and a sequential mechanism between inosine and alanine binding to their cognate receptors. Because inosine is a critical germinant in vitro, we screened inosine analogs for the ability to block in vitro germination of B. anthracis spores. Seven analogs efficiently blocked this process in vitro. This led to the identification of 6-thioguanosine, which also efficiently blocked spore germination in macrophages and prevented killing of these cells mediated by B. anthracis spores. 6-Thioguanosine shows potential as an anti-anthrax therapeutic agent. 相似文献