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941.
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943.
The effect of temperature on the distributions of ectothermic vertebrates is well documented. Despite the increase of 6°C expected in the next 60 years in South America, numerous vertebrates are still considered as ‘Least Concern’ species by the IUCN due to their large distribution, insufficient widespread threats and insignificant population decline. One example is the lizard Tropidurus torquatus (Squamata: Tropiduridae), commonly found thermoregulating in anthropic environments throughout the Brazilian Cerrado, but restricted to gallery forests in the equator‐ward localities. The urban areas in this warmer region have been colonised by other closely related congeners (e.g. Tropidurus oreadicus). This study aimed to understand this divergence of habitat selection by these tropirudids that may explain some of the species responses to past and future climate warming. We collected body temperatures (Tb), micro‐environmental temperatures (Ta) and operative (Te) temperatures in four sites along a latitudinal gradient: a pole‐ward and two central sites where T. torquatus inhabit urban areas and one equator‐ward site where T. torquatus and T. oreadicus occur in the gallery forest and in urban microhabitats, respectively. All three populations of T. torquatus present similar Tb (35.5–36°C) and shared microhabitats with a similar Ta (34–37.3°C). The Te in the equator‐ward urban site was considerably higher than in the gallery forest. Tropidurus oreadicus Tb was 38.2 °C (30.1–41.3°C) and was active at a Ta of 30.5–42.3°C. The overlap between the genus Tb, Ta and Te highlights a decrease in the hours of activity that lizards would experience under climate warming. The reduction of hours of activity together with the devastation of natural habitats represents threats and an alarming scenario especially for the equator‐ward populations.  相似文献   
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946.
Streptococcus pneumoniae coinfection is a major cause of influenza-associated mortality; however, the mechanisms underlying pathogenesis or protection remain unclear. Using a clinically relevant mouse model, we identify immune-mediated damage early during coinfection as a new mechanism causing susceptibility. Coinfected CCR2−/− mice lacking monocytes and monocyte-derived cells control bacterial invasion better, show reduced epithelial damage and are overall more resistant than wild-type controls. In influenza-infected wild-type lungs, monocytes and monocyte-derived cells are the major cell populations expressing the apoptosis-inducing ligand TRAIL. Accordingly, anti-TRAIL treatment reduces bacterial load and protects against coinfection if administered during viral infection, but not following bacterial exposure. Post-influenza bacterial outgrowth induces a strong proinflammatory cytokine response and massive inflammatory cell infiltrate. Depletion of neutrophils or blockade of TNF-α facilitate bacterial outgrowth, leading to increased mortality, demonstrating that these factors aid bacterial control. We conclude that inflammatory monocytes recruited early, during the viral phase of coinfection, induce TRAIL-mediated lung damage, which facilitates bacterial invasion, while TNF-α and neutrophil responses help control subsequent bacterial outgrowth. We thus identify novel determinants of protection versus pathology in influenza–Streptococcus pneumoniae coinfection.  相似文献   
947.
Selenium is an essential trace element and a component of various enzymes with antioxidant functions. High-sensitive C-reactive protein (hsCRP) is an early indicator of increased lipid peroxidation. The serum selenium concentration, lipid parameters, and hsCRP values of gestational diabetic pregnant women (GD), control pregnant women (CP), and healthy nonpregnant controls (HC) were compared. Blood was taken between the 24th and the 28th week of pregnancy when the oral glucose tolerance test was performed. Selenium concentration was determined by atomic absorption spectrometry after hydride generation. HsCRP was measured by immunturbidimetry. HC had significantly higher serum selenium concentrations than GD and CP women (HC = 77.4 ± 14.82, GD = 51.7 ± 11.62, and CP = 40.5 ± 8.03 μg/l, respectively). HsCRP values of both GD and nondiabetic pregnant women were significantly higher compared to controls. Significant negative correlations were found between serum selenium and total cholesterol, low-density lipoprotein cholesterol, and hsCRP values indicating that low selenium levels are associated with increased lipid peroxidation. Serum selenium concentrations of Hungarian pregnant women are low compared to internationally published data.  相似文献   
948.
Water-soluble complexes of the dietary carotenoid psi,psi-carotene (lycopene 1) with cyclomaltohexaose (alpha-cyclodextrin, alphaCD) and cyclomaltoheptaose (beta-cyclodextrin, betaCD) have been prepared and characterized via multiangle light scattering (MALS), ionspray/electrospray ionization (IS/ESI) mass spectrometry (MS) and tandem MS. MALS experiments point out that large aggregates of particles, on the nanometer-size scale, are present in water, with meaningful differences in the shape of the alphaCD/1 aggregates with respect to betaCD/1 analogues. The true 1:1 alphaCD/1 inclusion complex has been observed by IS/ESIMS and confirmed by tandem MS. The structure of CD/1 aggregations in water is proposed which are consistent with the combined MALS and MS experimental results.  相似文献   
949.
Maternal diabetes increases the risk of congenital malformations, placental dysfunction and diseases in both the neonate and the offspring's later life. Oxidative stress has been involved in the etiology of these abnormalities. Matrix metalloproteases (MMPs), involved in multiple developmental pathways, are increased in the fetus and placenta from diabetic experimental models. As oxidants could be involved in the activation of latent MMPs, we investigated a putative relationship between MMPs activities and oxidative stress in the feto-placental unit of diabetic rats at midgestation. We found that H2O2 enhanced and that superoxide dismutase (SOD) reduced MMPs activities in the maternal side of the placenta and in the fetuses from control and diabetic rats. MMPs were not modified by oxidative status in the fetal side of the placenta. Lipid peroxidation was enhanced in the maternal and fetal sides of the placenta and in the fetus from diabetic rats when compared to controls, and gradually decreased from the maternal placental side to the fetus in diabetic animals. The activities of the antioxidant enzymes SOD and catalase were decreased in the maternal placental side, catalase activity was enhanced in the fetal placental side and both enzymes were increased in the fetuses from diabetic rats when compared to controls. Our data demonstrate changes in the oxidative balance and capability of oxidants to upregulate MMPs activity in the feto-placental unit from diabetic rats, a basis to elucidate links between oxidative stress and alterations in the developmental pathways in which MMPs are involved.  相似文献   
950.
A phase I study of fixed-dose 5-fluorouracil (FU) and leucovorin (LCV), with excalating doses of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib, was conducted in 16 patients with advanced colorectal adenocarcinoma. At doses typically used to treat arthritis patients (100-200 mg po BID), celecoxib did not increase toxicities expected from the chemotherapy alone. 5-FU and leucovorin did not affect COX-2 inhibition by celecoxib. Preliminary data suggest it is safe to combine celecoxib with standard chemotherapeutic agents, in treatment of patients with colorectal cancer.  相似文献   
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