小儿保暖过度综合征

小儿保暖过度综合征并非一种独立性疾病，而是因人工护理不当引起小儿发热等症状的一组症候群。与惯称的捂（闷）热综合征不同，无原发缺氧表现，往往因原发病的存在被掩盖而误为感染或感染加重。至今尚未被临床儿科医师所共识。从预防及临床的实用出发，笔者对人工护理不当引起的小儿高热、出汗、缺氧一组综合征因情况不同建议作以下命名分型：保暖过度综合征（发热型）、蒙盖缺氧综合征（缺氧型）、捂热缺氧综合征（混合型）。本文就６０例病例作报告，并就有关病理、诊治。

Hyperthermia inhibits hypoxia-induced epithelial-mesenchymal transition in HepG2 hepatocellular carcinoma cells

AIM:To investigate the effect of hyperthermia on hy-poxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism. METHODS:Cells were treated with hyperthermia at 43 ℃ for 0.5 h, followed by incubation under hypoxic or normoxic conditions for 72 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or Western blot. The protein and mRNA expressions of Snail were also determined by Western blot and reverse transcrip-tion-polymerase chain reaction. Cell migratory capacity was evaluated. RESULTS:Hypoxia induced EMT in HepG2 cells, which was evidenced by morphological, molecular and func-tional changes, including the formation of a spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin was increased; also, the migratory capability was increased by 2.2 ± 0.20-fold as compared with normoxia. However, those effects were inhibited by hyperthermia pretreatment. Furthermore, protein synthesis and mRNA expression of Snail in the cells were enhanced by hy-poxia as compared with normoxia, and also significantly inhibited by hyperthermia pretreatment. CONCLUSION:Hyperthermia may inhibit hypoxia-induced EMT in HepG2 HCC cells, and the mechanism may involve inhibition of induced expression of Snail.

Can hypobaric hypoxia affect human thermal comfort?An experimental study in Tibet,China

Hypobaric hypoxia is the main environmental feature of the Tibetan plateau which would influence the efficiency of human metabolic heat production and the ability of thermal regulation.In order to understand the influence of the hypoxic environment on the plateau on the thermal comfort of short-term sojourners in Tibet,China,oxygen generators were used to create oxygen-enriched environments,and physiological and psychological reactions of subjects were compared under different oxygen partial pressures(p_(O_(2)))and air temperatures(t_(a)).The results showed that subjects’thermal sensation,thermal comfort and mean skin temperature decreased with a decrease in the oxygen partial pressure.When t_(a)=17℃,the influence of oxygen partial pressure was more pronounced,compared to p_(O_(2))=16.4 kPa,the thermal sensation of subjects under p_(O_(2))=13.7 kPa decreased by 33%.The rate of subjects feeling comfortable decreased by 25%,and the mean skin temperature decreased by 0.7℃.The hypoxic environment of the plateau exacerbates human discomfort.Therefore,it is necessary to fully understand the actual thermal requirements of sojourners in Tibet,China.The results of this study would have implications for a better understanding of thermal comfort characteristics in the hypoxia environment in plateau.

The origin of the extraordinary stability of mercury catalysts on the carbon support: the synergy effects between oxygen groups and defects revealed from a combined experimental and DFT study

Thermal stability of HgCl2 has a pivotal importance for the hydrochlorination reaction as the loss of mercuric compounds is toxic and detrimental to environment.Here we report a low-mercury catalyst which has durability over 10000 h for acetylene hydrochlorination under the industrial condition.The stability of the catalyst is carefully analyzed from a combined experimental and density functional theory study.The analysis shows that the extraordinary stability of mercury catalyst is resulted from the synergy effects between surface oxygen groups and defective edge sites.The binding energy of HgCl2 is increased to be higher than 130 kJ/mol when adsorption is at the edge site with a nearby oxygen group.Therefore,the present study revealed that the thermal stability problem of mercury-based catalyst can be solved by simply adjusting the surface chemistry of activated carbon.Furthermore,the reported catalyst has already been successfully applied in the commercialized production of vinyl chloride.

Intestinal parameters of oxidative imbalance in celiac adults with extraintestinal manifestations

AIM To evaluate selected intestinal parameters of oxidative stress, and antioxidant capacity in adult celiac disease patients with extraintestinal manifestations.METHODS The study involved 85 adult patients divided into the following subgroups:(1) patients with newly diagnosed celiac disease(CD)(n = 7);(2) celiac patients not adhering to a gluten-free diet(GFD)(n = 22);(3) patients with CD on the GFD(n = 31); and(4) patients with functional disorders of the gastrointestinal tract, serving as controls(n = 25). Celiac patients presented with non-classic symptoms or extraintestinal manifestations. Standard blood tests including serum antioxidant levels(uric acid, bilirubin, and vitamin D), celiac antibody levels, and histopathological status of duodenal biopsy specimens have been determined. The expression of m RNA for tumor necrosis factor α(TNF-α), interleukin 1β(IL-1β), interleukin 10(IL-10), superoxide dismutase(SOD), heat-shock protein 70(HSP-70), hypoxia-inducible factor 1(HIF-1α), and BAX in the duodenal mucosa of patients was analyzed by reverse transcriptase-polymerase chain reaction. RESULTS The mean plasma uric acid level in patients with active CD(newly diagnosed and nonadherent patients) and treated celiac patients was significantly higher than in controls(260.17 ± 53.65 vs 190.8 ± 22.98, P < 0.001, and 261.7 ± 51.79 vs 190.8 ± 22.98, P < 0.001, respectively). The mean bilirubin concentration in active and treated celiac patients was significantly lower than in controls(8.23 ± 5.04 vs 10.48 ± 4.08, P < 0.05 and 8.06 ± 3.31 vs 10.48 ± 4.08, P < 0.05, respectively). The mean plasma vitamin D level was significantly lower in active celiac patients than in treated celiac patients and controls(19.37 ± 9.03 vs 25.15 ± 11.2, P < 0.05 and 19.37 ± 9.03 vs 29.67 ± 5.12, P < 0.001, respectively). The expression of TNF-α, IL-10, and HSP-70 m RNAs was significantly elevated in the celiac groups regardless of the diet when compared with controls. Patients on the GFD presented a significantly lower m RNA expression of TNF-α and IL-10 than in newly diagnosed and nonadherent patients(P < 0.05). The expression of SOD m RNA was significantly elevated in celiac patients compared with controls(P < 0.05), with a significant difference between treated and untreated patients(P < 0.05). The expression of HIF-1α m RNA and BAX m RNA was significantly higher in patients with active CD compared with controls and patients on GFD, while no difference was observed between the latter two groups. CONCLUSION Increased intestinal expression of HSP-70 despite GFD indicates that GFD only partially reduced oxidative stress. CD patients exhibited an oxidative imbalance and inflammatory response despite GFD. Uric acid may act as an important antioxidant in CD.