355 research outputs found

    The effect of Helicobacter pylori infection on growth velocity in young children from poor urban communities in Ecuador

    Get PDF
    SummaryObjectiveTo characterize the potential effects of Helicobacter infections on growth velocity in low socioeconomic status young children in a developing country.MethodsChildren were recruited in poor suburbs of Quito, Ecuador. Normally nourished, mildly and substantially malnourished children (defined using weight-for-age Z-scores at recruitment) formed equal strata. Six height and weight measurements were collected during one year. Enrollment and exit serum samples were analyzed for anti-Helicobacter IgG and exit non-diarrheal feces tested for Helicobacter antigen.ResultsAmong 124 participants (enrollment age 19±9 months), 76 (61%) excreted fecal antigen at exit (were infected). Of these, 44 were seropositive at least once (chronic infections) and 32 tested seronegative both times (new or acute phase infections). The adjusted linear growth velocity during follow-up in children with new infections was reduced by 9.7 (3.8, 15.6) mm/year compared to uninfected controls and 6.4 (0.0, 12.9) mm/year compared to children with chronic infections. The effects of Helicobacter infections on ponderal growth were not significant.ConclusionThese results suggest that linear growth velocity is reduced in young children during the initial phase of Helicobacter infection

    16th IHIW: Immunogenetics of Aging

    Get PDF
    Ageing is a process characterised by progressive loss of function in multiple different organ systems, such as the nervous, endocrine and immune systems. Current data showing that ageing processes may be associated with alterations in the immune system suggest that some of the genetic determinants of senescence might be polymorphic genes that regulate immune responses. The ‘Immunogenetics of Aging’ programme was a component introduced in the 14th International HLA and Immunogenetics Workshop (IHIWS) and developed further within the 15th and 16th. The aim of this component was to determine the contribution of immune genes to successful ageing and an increased capacity to reach the extreme limits of lifespan. Within the 16th IHIWS, new populations were included, and the number of samples analysed was increased. Analysis was focused on innate immunity genes (KIR and MBL2) and their correlation with CMV serostatus. Collaborative studies suggested that both activating and inhibitory KIR and functionally relevant MBL2 haplotypes are important factors for control of CMV infection in the elderly and therefore for chronic low-grade inflammation. Results showed that these genes might be predictive biomarkers in ageing and longevity. Prevalence of MBL2 haplotypes determining absence of the protein (LYPB, LYQC and HYPD) was observed in elderly people with a higher CMV antibody titre. The high CMV titre was also associated with a decreased frequency of the activatory KIR2DS5 and A1B10 haplotypes in elderly. Due to the role of KIR and low or deficient MBL haplotypes in viral infections, these genetic markers could be considered as indicators of a need for CMV prophylaxis at younger age and therefore increased probability of longer lifespan

    Recent Diarrhea is Associated with Elevated Salivary IgG Responses to Cryptosporidium in Residents of an Eastern Massachusetts Community

    Get PDF
    BACKGROUND: Serological data suggest that Cryptosporidium infections are common but underreported. The invasiveness of blood sampling limits the application of serology in epidemiological surveillance. We pilot-tested a non-invasive salivary anti-Cryptosporidium antibody assay in a community survey involving children and adults. MATERIALS AND METHODS: Families with children were recruited in a Massachusetts community in July; symptoms data were collected at 3 monthly follow-up mail surveys. One saliva sample per person (n = 349) was collected via mail, with the last survey in October. Samples were analyzed for IgG and IgA responses to a recombinant C. hominis gp15 sporozoite protein using a time-resolved fluorometric immunoassay. Log-transformed assay results were regressed on age using penalized B-splines to account for the strong age-dependence of antibody reactions. Positive responses were defined as fluorescence values above the upper 99% prediction limit. RESULTS: Forty-seven (13.5%) individuals had diarrhea without concurrent respiratory symptoms during the 3-month-long follow-up; eight of them had these symptoms during the month prior to saliva sampling. Two individuals had positive IgG responses: an adult who had diarrhea during the prior month and a child who had episodes of diarrhea during each survey month (Fisher\u27s exact test for an association between diarrhea and IgG response: p = 0.0005 for symptoms during the prior month and p = 0.02 for symptoms during the entire follow-up period). The child also had a positive IgA response, along with two asymptomatic individuals (an association between diarrhea and IgA was not significant). CONCLUSION: These results suggest that the salivary IgG specific to Cryptosporidium antigens warrants further evaluation as a potential indicator of recent infections

    Role of homocysteine metabolism in the development of endothelial dysfunction and hypertension in patients with multiple myeloma

    Get PDF
    The article is devoted to the modern understanding of endothelial dysfunction development, the role of hyperhomocysteinemia, and, as a consequence, hypertension in patients with multiple myeloma receiving multiagent chemotherapy. Considering that the potential of a standard examination does not allow identifying subclinical endothelial dysfunction, using specific techniques is necessary, in particular, to determine the homocysteine level to monitor the endothelial function.The aim of this review was to summarize the current understanding of hypertension etiology and prospects for detecting early, subclinical endothelial changes, including in patients with multiple myeloma.Assessment of endothelial dysfunction can be useful for detecting precisely the subclinical cardiovascular disease in order to stratify the risk of developing cardiovascular events in patients receiving multiagent chemotherapy

    Analysis of human immune responses in quasi-experimental settings: tutorial in biostatistics

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Human immunology is a growing field of research in which experimental, clinical, and analytical methods of many life science disciplines are utilized. Classic epidemiological study designs, including observational longitudinal birth cohort studies, offer strong potential for gaining new knowledge and insights into immune response to pathogens in humans. However, rigorous discussion of methodological issues related to designs and statistical analysis that are appropriate for longitudinal studies is lacking.</p> <p>Methods</p> <p>In this communication we address key questions of quality and validity of traditional and recently developed statistical tools applied to measures of immune responses. For this purpose we use data on humoral immune response (IR) associated with the first cryptosporidial diarrhea in a birth cohort of children residing in an urban slum in south India. The main objective is to detect the difference and derive inferences for a change in IR measured at two time points, before (pre) and after (post) an event of interest. We illustrate the use and interpretation of analytical and data visualization techniques including generalized linear and additive models, data-driven smoothing, and combinations of box-, scatter-, and needle-plots.</p> <p>Results</p> <p>We provide step-by-step instructions for conducting a thorough and relatively simple analytical investigation, describe the challenges and pitfalls, and offer practical solutions for comprehensive examination of data. We illustrate how the assumption of time irrelevance can be handled in a study with a pre-post design. We demonstrate how one can study the dynamics of IR in humans by considering the timing of response following an event of interest and seasonal fluctuation of exposure by proper alignment of time of measurements. This alignment of calendar time of measurements and a child's age at the event of interest allows us to explore interactions between IR, seasonal exposures and age at first infection.</p> <p>Conclusions</p> <p>The use of traditional statistical techniques to analyze immunological data derived from observational human studies can result in loss of important information. Detailed analysis using well-tailored techniques allows the depiction of new features of immune response to a pathogen in longitudinal studies in humans. The proposed staged approach has prominent implications for future study designs and analyses.</p

    Spin valve based sensor elements for full Wheatstone bridge

    Full text link
    Present work deals with methods for creating opposite pinning directions in micro-objects based on a spin valve by one thermomagnetic treatment. The methods are based on the thermomagnetic treatment in spin-flop state of synthetic antiferromagnet. We use splitting the magnetic structure in spin-flop state of synthetic antiferromagnet to form opposite pinning directions in different micro-objects by one thermomagnetic treatment. The positive characteristic (dR/dH) was obtained in the two sensor elements of the full Wheatstone bridge, and the negative characteristic (dR/dH) in the other two elements. © Published under licence by IOP Publishing Ltd.Russian Foundation for Basic Research, RFBR: 19-02-0005718-10-2-37The research was carried out within the state assignment of Minobrnauki of Russia (theme “Alloys” АААА-А19-119070890020-3 and “Magnet” АААА-А18-118020290129-5), supported in part by RFBR (project No. 19-02-00057) and UD RAS (No. 18-10-2-37)

    Bending Deformation and Magnetoelastic Properties of a Spin Valve on a Polymer Substrate

    Full text link
    We report the results of a study of bending deformation of spin valves sputtered on polyimide substrate. It was taken into account that two factors contribute to the change in the magnetoresistance. We have obtained the dependence of the magnetoelastic anisotropy constant on substrate elongation.Работа выполнена в рамках государственного задания МИНОБРНАУКИ России по темам “Спин” АААА-А18-118020290104-2 и «Магнит» №122021000034-9 при поддержке РФФИ (грант 20-42-660018 р_а)

    The Elderly and Waterborne Cryptosporidium Infection: Gastroenteritis Hospitalizations before and during the 1993 Milwaukee Outbreak

    Get PDF
    We used the Temporal Exposure Response Surfaces modeling technique to examine the association between gastroenteritis-related emergency room visits and hospitalizations in the elderly and drinking water turbidity before and during the 1993 Milwaukee waterborne Cryptosporidium outbreak. Before the outbreak, the rate of such events increased with age in the elderly (p<0.002), suggesting that the elderly are at an increased risk. During the outbreak, strong associations between turbidity and gastroenteritis-related emergency room visits and hospitalizations occurred at temporal lags of 5–6 days (consistent with the Cryptosporidium incubation period). A pronounced second wave of these illnesses in the elderly peaked at 13 days. This wave represented approximately 40% of all excess cases in the elderly. Our findings suggest that the elderly had an increased risk of severe disease due to Cryptosporidium infection, with a shorter incubation period than has been previously reported in all adults and with a high risk for secondary person-to-person transmission

    Modern methods for identification and quantification of cardiac glycosides

    Get PDF
    Scientific relevance. Cardiac glycosides have been used in medicine for over two centuries. Current studies suggest that biologically active substances from this group can be used to treat not only heart conditions but also viral infections, cancers, and other diseases. Therefore, quality control methods for cardiac glycosides are becoming increasingly relevant.Aim. Based on a review of Russian and international quality standards, as well as up-to-date scientific data, this study aimed to identify promising methods for the identification and quantification of cardiac glycosides in herbal drugs and herbal medicinal products, as well as to evaluate the possibility of substituting physicochemical methods for biological methods.Discussion. The methods that are currently used to standardise cardiac glycosides are either not selective or require laboratory animals (biological test systems). According to a study of pharmacopoeial methods for the identification of cardiac glycosides in herbal drugs and herbal medicinal products, chemical identification tests and thin-layer chromatography continue to be relevant. Quantitative testing of herbal drugs and extracts uses biological and non-selective (spectrophotometry) methods, whereas chromatography is described only in general and individual monographs for herbal drug preparations containing individual cardiac glycosides and medicinal products containing these preparations. Upon analysing quality standards and scientific publications, the authors identified potentially promising methods for the quantification of cardiac glycosides in herbal drugs, herbal drug preparations, and herbal medicinal products, namely chromatographic methods.Conclusions. Reverse-phase high-performance liquid cjromatography (HPLC) with spectrophotometric detection is the most suitable method for pharmacopoeial analysis. The development of an HPLC-based analytical procedure to determine the cardiac glycoside content will provide an opportunity to advance from biological or non-selective methods to more ethical and selective up-to-date techniques
    corecore