55 research outputs found
The effect of Helicobacter pylori infection on growth velocity in young children from poor urban communities in Ecuador
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 19Ā±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
The energy spectrum of neutrons from 7
The neutron beams generated at the electrostatic accelerators using nuclear reactions T(p,n)3He, D(d,n)3He, 7Li(p,n)7Be, T(d,n)4He, 7Li(d,n)8Be, 9Be(d,n)10B are widely used in neutron physics and in many practical applications. Among these reactions the least studied reactions are 7Li(d,n)8Be and 9Be(d,n)10B. The present work is devoted to the measurement of the neutron spectrum from 7Li(d,n)8Be reaction at 0ā angle to the deuteron beam axis on the electrostatic accelerator Tandetron (JSC āSSC RF ā IPPEā) using activation method and a stilbene crystal scintillation detector. The first time ever 7Li(d,n)8Be reaction was measured by activation method. The target was a thick lithium layer on metallic backing. The energy of the incident deuteron was 2.9āMeV. As activation detectors a wide range of nuclear reactions were used: 27Al(n,p)27Mg, 27Al(n,Ī±)24Na, 113In(n,n')113mIn, 115In(n,n')115mIn, 115In(n,Ī³)116mIn, 58Ni(n,p)58mCo, 58Ni(n,2n)57Ni, 197Au(n,Ī³)198Au, 197Au(n,2n)196Au, 59Co(n,p)59Fe, 59Co(n,2n)58m+gCo, 59Co (n,g)60Co. Measurement of the induced gamma-activity was carried out using HPGe detector Canberra GX5019Ā [1]. The up-to-date evaluations of the cross sections for these reactions were used in processing of the data. The program STAYSL was used toĀ unfoldĀ theĀ energy spectra. The neutron spectra obtained by activation detectors is consistent with the corresponding data measured by a stilbene crystal scintillation detector within their uncertainties
The Elderly and Waterborne Cryptosporidium Infection: Gastroenteritis Hospitalizations before and during the 1993 Milwaukee Outbreak
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 5ā6 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
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Modeling of GERDA Phase II data
The GERmanium Detector Array (Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta (0Ī½Ī²Ī²) decay of 76Ge. The technological challenge of Gerda is to operate in a ābackground-freeā regime in the region of interest (ROI) after analysis cuts for the full 100 kgĀ·yr target exposure of the experiment. A careful modeling and decomposition of the full-range energy spectrum is essential to predict the shape and composition of events in the ROI around QĪ²Ī² for the 0Ī½Ī²Ī² search, to extract a precise measurement of the half-life of the double-beta decay mode with neutrinos (2Ī½Ī²Ī²) and in order to identify the location of residual impurities. The latter will permit future experiments to build strategies in order to further lower the background and achieve even better sensitivities. In this article the background decomposition prior to analysis cuts is presented for Gerda Phase II. The background model fit yields a flat spectrum in the ROI with a background index (BI) of 16.04+0.78ā0.85ā
10ā3 cts/(keVĀ·kgĀ·yr) for the enriched BEGe data set and 14.68+0.47ā0.52ā
10ā3 cts/(keVĀ·kgĀ·yr) for the enriched coaxial data set. These values are similar to the one of Phase I despite a much larger number of detectors and hence radioactive hardware components
Preventive medicine of von Hippel-Lindau disease-associated pancreatic neuroendocrine tumors
Pancreatic neuroendocrine tumors (PanNETs) are rare in von Hippel-Lindau disease (VHL) but cause serious morbidity and mortality. Management guidelines for VHL-PanNETs continue to be based on limited evidence, and survival data to guide surgical management are lacking. We established the European-American-Asian-VHL-PanNET-Registry to assess data for risks for metastases, survival and long-term outcomes to provide best management recommendations. Of 2330 VHL patients, 273 had a total of 484 PanNETs. Median age at diagnosis of PanNET was 35 years (range 10-75). Fifty-five (20%) patients had metastatic PanNETs. Metastatic PanNETs were significantly larger (median size 5 vs 2\u2009cm; P\u20091.5\u2009cm in diameter were operated. Ten-year survival was significantly longer in operated vs non-operated patients, in particular for PanNETs <2.8\u2009cm vs 652.8\u2009cm (94% vs 85% by 10 years; P\u2009=\u20090.020; 80% vs 50% at 10 years; P\u2009=\u20090.030). This study demonstrates that patients with PanNET approaching the cut-off diameter of 2.8\u2009cm should be operated. Mutations in exon 3, especially of codons 161/167 are at enhanced risk for metastatic PanNETs. Survival is significantly longer in operated non-metastatic VHL-PanNETs
Environmental risk factors for Toxoplasma gondii infections and the impact of latent infections on allostatic load in residents of Central North Carolina
Abstract
Background
Toxoplasma gondii infection can be acquired through ingestion of infectious tissue cysts in undercooked meat or environmental oocysts excreted by cats. This cross-sectional study assessed environmental risk factors for T. gondii infections and an association between latent infections and a measure of physiologic dysregulation known as allostatic load.
Methods
Serum samples from 206 adults in the Durham-Chapel Hill, North Carolina area were tested for immunoglobulin (IgG) responses to T. gondii using commercial ELISA kits. Allostatic load was estimated as a sum of 15 serum biomarkers of metabolic, neuroendocrine and immune functions dichotomized at distribution-based cutoffs. Vegetated land cover within 500Ā m of residences was estimated using 1Ā m resolution data from US EPAās EnviroAtlas.
Results
Handling soil with bare hands at least weekly and currently owning a cat were associated with 5.3 (95% confidence limits 1.4; 20.7) and 10.0 (2.0; 50.6) adjusted odds ratios (aOR) of T. gondii seropositivity, respectively. There was also a significant positive interaction effect of handling soil and owning cats on seropositivity. An interquartile range increase in weighted mean vegetated land cover within 500Ā m of residence was associated with 3.7 (1.5; 9.1) aOR of T. gondii seropositivity. Greater age and consumption of undercooked pork were other significant predictors of seropositivity. In turn, T. gondii seropositivity was associated with 61% (13%; 130%) greater adjusted mean allostatic load compared to seronegative individuals. In contrast, greater vegetated land cover around residence was associated with significantly reduced allostatic load in both seronegative (pĀ <ā0.0001) and seropositive (pĀ =ā0.004) individuals.
Conclusions
Residents of greener areas may be at a higher risk of acquiring T. gondii infections through inadvertent ingestion of soil contaminated with cat feces. T. gondii infections may partially offset health benefits of exposure to the natural living environment
Analysis of the Irtysh surface water as natural sources of water supply and steam production in the heat and power industry
The article demonstrates the results of experimental analysis of the Irtysh and Tobol underground and surface water as natural water supply sources and steam production in the heat and power industry; priority locations for water sampling have been identified and substantiated; a qualitative analysis of the Irtysh and Tobol samples has been proved; the reasons for the deviation from the water quality and the required degree of treatment for bringing it to the required indicies are revealed; the mineral composition of water is determined taking into account the peculiarities of the hydrological layers through which the river flows; it is proved that the organic composition is formed due to compounds that are washed out of the reservoirās soil as a result of biological processes; the mineral and organic substances that are brought into the Irtysh, Tobol by waste waters of populated areas and industrial enterprises are revealed; it is proved that the water of the Irtysh River is fresh, belongs to hydrocarbonate class and is suitable for steam production in the heat and power industry
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