960 research outputs found

    Deleterious effects of xanthine oxidase on rat liver endothelial cells after ischemia/reperfusion

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    AbstractPrevious studies have demonstrated that reactive oxygen species are involved in ischemic injury. The present work was undertaken to determine in vivo the role of xanthine oxidase in the oxygen free radical production during rat liver ischemia and to examine the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) during the same period. Our results indicate a 4-fold increase in xanthine oxidase activity between 2 and 3 hours of normothermic ischemia, in parallel with a decrease in cell viability. Moderate hypothermia delays both events. Under the same conditions, the activity of oxygen radical scavenging enzymes remains unchanged. Moreover, we have compared in vitro the susceptibility of isolated liver cells to an oxidative stress induced by O2·−, H2O2 and OH. Our results reveal that endothelial cells are much more susceptible to reactive oxygen species than hepatocytes, probably because they lack H2O2-detoxifying enzymes. These findings suggest that xanthine oxidase might play a major role in the ischemic injury mainly at the level of the sinusoidal space where most endothelial cells are located

    Procjena dotoka slatke vode uzduž istočne obale Jadrana kao mogućeg izvora stresa za morske organizme

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    Seawater salinity changes and thermal stress have been considered to be among the most important determinants of rocky intertidal zone organism distribution. The aim of present study was to determine the freshwater influx and evaluate the mussel Mytilus galloprovincialis shells as indicators of natural environmental conditions by comparing δ13C of shell carbonate layers with seawater salinity and tem- perature values measured over the 1998-2007 period. Our results show that the salinity was relatively constant in the open sea, with typical values of the northern and southern Adriatic being 37.65 ± 0.40 and 38.37 ± 0.19 respectively. It varied in intertidal zones, estuaries, locations close to under-sea freshwa- ter springs and during rainy days in closed lagoons on different locations along eastern Adriatic coast. Sa- linity and temperature variations at investigated sites showed freshwater influx which was also reflected in lower δ13C values of mussel M. galloprovincialis shell carbonates. Based on the measured parameters, three groups of locations in the investigated area (25 locations) can be defined: locations with strong to medium freshwater influence (9), with minor freshwater influence (6) and marine environment locations (10). Our results confirm that mussel M. galloprovincialis responds sensitively to subtle changes in the environmental conditions. Results of the isotopic analyses presented in this study support the hypothesis that the δ13C in mussel’s shell might be used as an indicator of environmental salinity conditions and hypo-osmotic stress. Therefore such investigations might represent an additional tool for waste water management and environmental protection.Promjena saliniteta i temperature morske vode u stjenovitom obalnom području ograničava i utječe na raspodjela morskih organizama. U području otvorenog mora salinitet je relativno stalan, a u istraživanom razdoblju (1998.-2007.) se kretao od 37,65 ± 0,40 za sjeverni i do 38,37 ± 0,19 za južni Jadran. Salinitet značajno koleba u zoni plime i oseke, na području ušća rijeka i podmorskim izvorima slatke vode te tijekom kišnih dana u zatvorenim lagunama. Zbog dotoka slatke vode temperatura mora na istraživanim postajama pokazuje unutar sezonske razlike, uz jaka sezonska kolebanja. Kolebanje vrijednosti saliniteta i temperature morske vode na području od Limskog kanala do Dubrovnika (sjeverni - južni Jadran) pod utjecajem dotoka slatke vode izravno su se odrazili i na vrijednosti δ13C u ljušturama dagnje Mytilus galloprovincialis. Vrijednosti δ13C iz 1998. godine su rangirane i korelirane s prosječnim vrijednostima temperature i saliniteta morske vode tijekom devetogodišnjeg istraživanog razdoblja (1998.-2007.). Na temelju sadržaja d13C u ljušturama, temperature i saliniteta morske vode istraživano područje (25 postaja) je grupirano u tri skupine: srednje do jak utjecaj slatke vode (9), manji utjecaj slatke vode (6) i lokacije morskog okoliša (10). Utvrđeno je da su ljušture školjkaša, odnosno vrijednosti δ13C, dobri pokazatelji kolebanja prirodnih čimbenika, naročito saliniteta, posredstvom dotoka slatkih voda. Dagnja M. galloprovincialis se može koristiti kao indikator kolebanja ekoloških čimbenika i možebitnih onečišćenja. Stoga navedena istraživanja predstavljaju dodatni koristan alat u biomonitoring programima, primjerice ispitivanju kvalitete okoliša, upravljanju otpadnim vodama i zaštiti okoliša

    Quantitative Daily Maps of PM 2.5 Episodes for California and Other Regions: Satellite Column Water and Optical Depth as Allied Tracers of Dilution

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    The Western US and many regions globally present daunting difficulties in understanding PM 2.5 episodes. We evaluate extensions of a method independent of modeled source-description and transport/transformation and using several satellite remote sensing products from imaging spectrometers. The San Joaquin Valley (SJV) especially suffers few-day episodes due to shallow mixing; PM 2.5 retrieval suffers low satellite AOT (Aerosol Optical Thickness) and bright surfaces.Nevertheless, we find residual errors in our maps of of typically 5-8 micrograms per cubic meter. Episodes in the Valley reaching 60-100 micrograms per cubic meter. These maps detail pollution from Interstate 5 at the scale of a few kilometers. The maps are based on NASA's MODerate resolution Imaging Spectrometer (MODIS) data at circa 1 kilometer as processed with the Multi-Angle Implementation of Atmospheric Correction. The Bay Area Air Quality Management District has requested that we test our methods in their challenging environment characterized by multiple sub-basins defined by complex topography. Our tests suggest that nearly similar precision may be expected for wintertime conditions with high PM 2.5 . We note difficulties when measured PM 2.5 is less than 8-10 micrograms per cubic meter, but good relative precision when PM 2.5 rises above 20; i.e. in episodes of concern for morbidity and mortality. Our method stresses physically meaningful functions of MODIS-MAIAC (Multi-Angle Implementation of Atmospheric Correction)-derived AOD (Aerosol Optical Depth) and total water vapor column. A mixed-effects statistical model exploiting existing station data works powerfully to allow us daily AOT-to-PM 2.5 relationships that allow a calibration of the map. In those cases where water vapor and particles have generally similar surface sources, using the ratio of AOT / Column_water can improve the daily calibrations so as to reach our quoted precision. We briefly present some cartoon idealizations that explain this success and also the likely reasons that our mixed effects model (or "daily calibration") works; also when it should not work. The combined satellite/mixed-effects model works best for wintertime San Joaquin Valley episodes, where the meteorology of particle and H2O(v) dilution is quite appropriate. We extended and tested the methodology (a) for the Bay Area wintertime situations and (b) for smoke plume events (e.g. the October 2017 fire events of the Sonoma area). Our SJV work was evaluated using NASA's DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) airborne measurements, and by season- long measurements in Fresno. If the composition and size distribution of the aerosols can be assessed for the regions we describe, retrievals should have improved accuracy

    A Randomized Clinical Trial of a Money Management Intervention for Veterans With Psychiatric Disabilities

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    OBJECTIVE: The study evaluated an intervention to help veterans with psychiatric disabilities, who face a unique set of challenges concerning money management. METHODS: A randomized clinical trial was conducted of a brief (one to three hours) psychoeducational, recovery-oriented money management intervention called tepsforAchievingFinancialEmpowerment(teps for Achieving Financial Empowerment (AFE). RESULTS: Analyses revealed no main effects on outcomes of random assignment to AFE(N=67)oracontrolconditionconsistingofusualcare(N=77).VeteranswhoreportedusingAFE (N=67) or a control condition consisting of usual care (N=77). Veterans who reported using AFE skills showed significantly lower impulsive buying, more responsible spending, higher rates of engaging in vocational activities, and greater number of work hours compared with veterans in the control condition. CONCLUSIONS: Findings have clinical implications for case management services involving informal money management assistance. Offering veterans with psychiatric disabilities a one-time money management intervention is unlikely to lead to substantial changes. Results imply that efforts to improve psychosocial outcomes among veterans must not only teach but also increase use of money management skills

    Vitamin A and zinc supplementation among pregnant women to prevent placental malaria: a randomized, double-blind, placebo-controlled trial in Tanzania

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    BACKGROUND: Malaria causes nearly 200 million clinical cases and approximately half a million deaths each year, primarily in sub-Saharan Africa.1 The risk of malaria increases during pregnancy,2 a period during which its prevention is especially important. Not only do pregnant women experience greater severity of illness compared with nonpregnant women,2 but studies have shown strong associations between prenatal malaria and maternal anemia,2 fetal loss, low birthweight, and infant mortality.2 Improving preventive measures that specifically target malaria in pregnancy is a global health priority.3 METHODS: Study design and participants. This randomized, doubleblind, placebo-controlled trial was implemented at 8 antenatal care clinics in the urban Temeke and Ilala districts of Dar es Salaam, Tanzania. The trial was registered RESULTS: A total of 2,500 screened participants were enrolled in the trial. The trial profile is shown in Figure 1. It was not possible to collect placentas from 875 participants for the following reasons: miscarriages (fetal loss before 28 weeks of gestation) (N = 234), delivery outside of Dar es Salaam or at a non-study hospital (N = 577), or withdrawal from the study (N = 34). Of the remaining 1,589 women, 1,404 placental samples were obtained (88%); histology results were available for 1,361 participants. PCR results were available for 1,158 participants, and 1,404 participants had either histology or PCR results available. CONCLUSION: This study is the first to examine the impact of vitamin A and zinc supplementation starting in early pregnancy on placental malaria. We observed that supplementation with 25 mg zinc per day from the first trimester until delivery was associated with a 36% (95% CI = 9–56%) reduced risk of histopathology-positive placental infection, but not PCRpositive infection. Vitamin A supplementation had no impact on placental malaria, but was associated with an increased risk for severe anemia

    Radiofrequency thermal ablation of giant placental chorioangioma complicated with fetal hydrops: a case report and successful outcome

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    ObjectivesChorioangiomas are the most frequently occurring type of benign tumour of the placenta. However, large chorioangiomas greater than 4 cm are rare and can be more frequently associated with serious complications such as: polyhydramnios, hydrops fetalis, fetal anaemia, intrauterine growth restriction, preterm birth, and an increased risk of perinatal mortality. Importantly timely prenatal diagnosis with close surveillance alongside potential intrauterine intervention can prove impactful on pregnancy outcome and fetal survival.Case presentationWe present a case of a 36-year-old female referred to our tertiary fetal medicine unit at 28 weeks’ gestation with a large chorioangioma measuring 9.4×8.8×5.5 cm and ultrasonographic evidence of severe fetal anaemia and fetal hydrops. The patient underwent an intrauterine transfusion and in utero surgical therapy with radiofrequency ablation (RFA). Immediately following the procedure, the fetus sustained a period of bradycardia, followed by asystole. Delivery was expedited via emergency caesarean section. Careful planning and rapid delivery after fetal intervention within the most appropriate surgical setting mitigated risks for the baby and resulted in a positive outcome. The baby was discharged from the neonatal unit on day 84 of life.ConclusionsLarge placental chorioangiomas are a rare occurrence, however, when associated with fetal complications present a high incidence of adverse perinatal outcomes. In utero interventions require careful planning and surgical expertise to ensure improved fetal and neonatal outcomes. To the best of our knowledge this case is the first recorded instance of a successful postnatal outcome following RFA for a large placental chorioangioma, whereby the fetus was complicated by fetal hydrops

    Testing Extensions of Our Quantitative Daily of San Joaquin Wintertime Aerosols Using MAIAC and Meteorology Without Transport/Transformation Assumptions

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    The Western US and many regions globally present daunting difficulties in understanding and mapping PM2.5 episodes. We evaluate extensions of a method independent of source-description and transport/transformation. These regions suffer frequent few-day episodes due to shallow mixing; low satellite AOT and bright surfaces complicate the description. Nevertheless, we expect residual errors in our maps of less than 8 ug/m^3 in episodes reaching 60-100 ug/m^3; maps which detail pollution from Interstate 5. Our current success is due to use of physically meaningful functions of MODIS-MAIAC-derived AOD, afternoon mixed-layer height, and relative humidity for a basin in which the latter are correlated. A mixed-effects model then describes a daily AOT-to-PM2.5 relationship. (Note: in other published mixed-effects models, AOT contributes minimally. We seek to extend on these to develop useful estimation methods for similar situations. We evaluate existing but more spotty information on size distribution (AERONET, MISR, MAIA, CALIPSO, other remote sensing). We also describe the usefulness of an equivalent mixing depth for water vapor vs meteorological boundary layer height. Each has virtues and limitations. Finally, we begin to evaluate methods for removing the complications due to detached but polluted layers (which don't mix to the surface) using geographical, meteorological, and remotely sensed data

    Honing the in silico

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