Молекулярно -эпидемиологическая характеристика стрептококков, выделенных у детей младшего школьного возраста во Вьетнаме

Objectives. The goal of the study was to isolate group A, С, and G streptococci from children and characterize them by the methods of molecular epidemiology.Materials and methods. Group A, С, and G streptococci were isolated from tonsils and back wall of pharynx of Vietnamese children during 2012–2014. сpn60 gene based PCR approach and rnpB gene sequencing were used to identify streptococcal species belonging to group С and G streptococci. The presence of scpA, lmb, nga, slo virulence genes was analyzed in S. anginosus and S. dysgalactiae subsp. equisimilis strainS. emm-typing of S. pyogenes was done as published (http://www.cdc.gov/ncidod/biotech/strep/MProteinGene_typing.htm). Antibiotic resistance of the strains was tested by the disk diffusion method.Results. A total of 1359 children were examined. Group A streptococci (S. pyogenes) were isolated from 49 children, group C streptococci – from 8 children (4 stains – S. anginosus, 1 strain – S. dysgalactiae subsp. equisimilis, 1 strain – S. parasanguinis, 1 strain – S. gordonii, 1 strain – S. constellatus), and group G streptococci – from 75 children (55 stains – S. anginosus, 8 stains – S. dysgalactiae subsp. equisimilis, 4 stains – S. sanguinis, 3 stains – S. parasanguinis, 2 stains – S. australis, 2 stains – S. constellatus, 1 stain – S. mitis). emm-typing of 47 S. pyogenes strains revealed 15 different emm-subtypes belonging to 11 different emm-typeS. The subtypes emm104.0 and emm109.1 were found to be predominant. S. anginosus strains under study were genetically heterogeneous for the presence of virulence genes. All tested strains were susceptible to cephalosporins and vancomycin, and resistant to amikacine. A total of 70% and 52,5% of S. pyogenes were resistant to tetracycline and erythromycin, respectively.Цель. Выделение стрептококков групп А, С, G у детей младшего школьного возраста и их характеристика с использованием методов молекулярной эпидемиологии.Материалы и методы. Изоляты стрептококков групп А, С и G выделяли с поверхности миндалин и задней стенки глотки у 1359 детей младшего школьного возраста во Вьетнаме в 2012–2014 гг. Видовую принадлежность стрептококков групп С и G выявляли с помощью экспресс-метода дифференциальной ПЦР-диагностики и секвенирования гена rnpB. Наличие генов вирулентности scpA, lmb, nga, slo у штаммов S. anginosus и S. dysgalactiae subsp. equisimilis анализировали с использованием ПЦР. emm-типирование штаммов S. pyogenes проводили согласно методике, опубликованной на сайте Centers for Disease Control and Prevention (http://www.cdc.gov/ncidod/biotech/strep/M-ProteinGene_typing. htm). Спектр антибиотикорезистентности штаммов определяли диско-диффузионным методом.Результаты. В результате микробиологического исследования материала с миндалин и задней стенки глотки были выделены и идентифицированы 49 штаммов стрептококков группы А (S. pyogenes), 8 штаммов стрептококков группы С (4 штамма – S. anginosus, по 1 штамму – S. dysgalactiae subsp. equisimilis, S. parasanguinis, S. gordonii, S. constellatus) и 75 штаммов стрептококков группы G (55 штаммов – S. anginosus, 8 штаммов – S. dysgalactiae subsp. equisimilis, 4 штамма – S. sanguinis, 3 штамма – S. parasanguinis, 2 – штамма S. australis, 2 штамма – S. constellatus, 1 штамм – S. mitis). Среди 47 штаммов S. pyogenes было выявлено 15 emm-подтипов, относящихся к 11 emm-типам. Доминирующими оказались редко встречающиеся генотипы emm104.0 и emm109.1. Выявлен геномный полиморфизм штаммов S. anginosus по наличию генов вирулентности. Все исследованные штаммы были чувствительны к цефалоспоринам и ванкомицину и устойчивы к амикацину. 70% штаммов S. pyogenes были устойчивы к тетрациклину и 52,5% – к эритромицину

HIV-Associated TB in An Giang Province, Vietnam, 2001–2004: Epidemiology and TB Treatment Outcomes

BACKGROUND: Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia have documented the benefits of interventions, such as co-trimoxazole (CTX), in reducing mortality during TB treatment. To help guide policy in Vietnam, we studied the epidemiology of HIV-associated TB in one province and examined factors associated with outcomes, including the impact of CTX use. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively abstracted data for all HIV-infected persons diagnosed with TB from 2001-2004 in An Giang, a province in southern Vietnam in which TB patients receive HIV counseling and testing. We used standard WHO definitions to classify TB treatment outcomes. We conducted multivariate analysis to identify risk factors for the composite outcome of death, default, or treatment failure during TB treatment. From 2001-2004, 637 HIV-infected TB patients were diagnosed in An Giang. Of these, 501 (79%) were male, 321 (50%) were aged 25-34 years, and the most common self-reported HIV risk factor was sex with a commercial sex worker in 221 (35%). TB was classified as smear-positive in 531 (83%). During TB treatment, 167 (26%) patients died, 9 (1%) defaulted, and 6 (1%) failed treatment. Of 454 patients who took CTX, 116 (26%) had an unsuccessful outcome compared with 33 (70%) of 47 patients who did not take CTX (relative risk, 0.4; 95% confidence interval [CI], 0.3-0.5). Adjusting for male sex, rural residence, TB smear status and disease location, and the occurrence of adverse events during TB treatment in multivariate analysis, the benefit of CTX persisted (adjusted odds ratio for unsuccessful outcome 0.1; CI, 0.1-0.3). CONCLUSIONS/SIGNIFICANCE: In An Giang, Vietnam, HIV-associated TB was associated with poor TB treatment outcomes. Outcomes were significantly better in those taking CTX. This finding suggests that Vietnam should consider applying WHO recommendations to prescribe CTX to all HIV-infected TB patients

Introductory programming: a systematic literature review

As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

Shell evolution of N = 40 isotones towards 60Ca: First spectroscopy of 62Ti

Excited states in the N=40 isotone 62Ti were populated via the 63V(p,2p)62Ti reaction at ∼200 MeV/nucleon at the Radioactive Isotope Beam Factory and studied using γ-ray spectroscopy. The energies of the 21+→0gs+ and 41+→21+ transitions, observed here for the first time, indicate a deformed 62Ti ground state. These energies are increased compared to the neighboring 64Cr and 66Fe isotones, suggesting a small decrease of quadrupole collectivity. The present measurement is well reproduced by large-scale shell-model calculations based on effective interactions, while ab initio and beyond mean-field calculations do not yet reproduce our findings. The shell-model calculations for 62Ti show a dominant configuration with four neutrons excited across the N=40 gap. Likewise, they indicate that the N=40 island of inversion extends down to Z=20, disfavoring a possible doubly magic character of the elusive 60Ca

IL-7 Promotes CD95-Induced Apoptosis in B Cells via the IFN-γ/STAT1 Pathway

Interleukin-7 (IL-7) concentrations are increased in the blood of CD4+ T cell depleted individuals, including HIV-1 infected patients. High IL-7 levels might stimulate T cell activation and, as we have shown earlier, IL-7 can prime resting T cell to CD95 induced apoptosis as well. HIV-1 infection leads to B cell abnormalities including increased apoptosis via the CD95 (Fas) death receptor pathway and loss of memory B cells. Peripheral B cells are not sensitive for IL-7, due to the lack of IL-7Ra expression on their surface; however, here we demonstrate that high IL-7 concentration can prime resting B cells to CD95-mediated apoptosis via an indirect mechanism. T cells cultured with IL-7 induced high CD95 expression on resting B cells together with an increased sensitivity to CD95 mediated apoptosis. As the mediator molecule responsible for B cell priming to CD95 mediated apoptosis we identified the cytokine IFN-γ that T cells secreted in high amounts in response to IL-7. These results suggest that the lymphopenia induced cytokine IL-7 can contribute to the increased B cell apoptosis observed in HIV-1 infected individuals

Effect of Rare Earth Ions on the Properties of Composites Composed of Ethylene Vinyl Acetate Copolymer and Layered Double Hydroxides

BACKGROUND: The study on the rare earth (RE)-doped layered double hydroxides (LDHs) has received considerable attention due to their potential applications in catalysts. However, the use of RE-doped LDHs as polymer halogen-free flame retardants was seldom investigated. Furthermore, the effect of rare earth elements on the hydrophobicity of LDHs materials and the compatibility of LDHs/polymer composite has seldom been reported. METHODOLOGY/PRINCIPAL FINDINGS: The stearate sodium surface modified Ni-containing LDHs and RE-doped Ni-containing LDHs were rapidly synthesized by a coprecipitation method coupled with the microwave hydrothermal treatment. The influences of trace amounts of rare earth ions La, Ce and Nd on the amount of water molecules, the crystallinity, the morphology, the hydrophobicity of modified Ni-containing LDHs and the adsorption of modifier in the surface of LDHs were investigated by TGA, XRD, TEM, contact angle and IR, respectively. Moreover, the effects of the rare earth ions on the interfacial compatibility, the flame retardancy and the mechanical properties of ethylene vinyl acetate copolymer (EVA)/LDHs composites were also explored in detail. CONCLUSIONS/SIGNIFICANCE: S-Ni₀.₁MgAl-La displayed more uniform dispersion and better interfacial compatibility in EVA matrix compared with other LDHs. Furthermore, the S-Ni₀.₁MgAl-La/EVA composite showed the best fire retardancy and mechanical properties in all composites

CD27− B-Cells Produce Class Switched and Somatically Hyper-Mutated Antibodies during Chronic HIV-1 Infection

Class switch recombination and somatic hypermutation occur in mature B-cells in response to antigen stimulation. These processes are crucial for the generation of functional antibodies. During HIV-1 infection, loss of memory B-cells, together with an altered differentiation of naïve B-cells result in production of low quality antibodies, which may be due to impaired immunoglobulin affinity maturation. In the current study, we evaluated the effect of HIV-1 infection on class switch recombination and somatic hypermutation by studying the expression of activation-induced cytidine deaminase (AID) in peripheral B-cells from a cohort of chronically HIV-1 infected patients as compared to a group of healthy controls. In parallel, we also characterized the phenotype of B-cells and their ability to produce immunoglobulins in vitro. Cells from HIV-1 infected patients showed higher baseline levels of AID expression and increased IgA production measured ex-vivo and upon CD40 and TLR9 stimulation in vitro. Moreover, the percentage of CD27−IgA+ and CD27−IgG+ B-cells in blood was significantly increased in HIV-1 infected patients as compared to controls. Interestingly, our results showed a significantly increased number of somatic hypermutations in the VH genes in CD27− cells from patients. Taken together, these results show that during HIV-1 infection, CD27− B-cells can also produce class switched and somatically hypermutated antibodies. Our data add important information for the understanding of the mechanisms underlying the loss of specific antibody production observed during HIV-1 infection