[Risk factors of postoperative voiding dysfunction in children with congenital anorectal malformation].

This study analyzed the clinical data of children with anorectal malformation (ARM)who underwent surgery from 2006 to 2021, and explored the related factors of postoperative voiding dysfunction (VD).A total of 60 children including 51 males and 9 females, aged 4-15 years, were enrolled. During follow up, normal voiding function were found in 43 cases, VD in 17 cases. It was found that middle to high clinical classification (OR＝6.732, 95%CI:1.854-24.443), multiple surgeries (OR＝3.712, 95%CI:1.133-12.160), associated spinal deformity (OR＝3.297, 95%CI:1.029-10.566) and abnormal postoperative defecation (OR＝4.971, 95%CI:1.387-17.816) were the risk factors of VD after ARM (all P<0.05). Urodynamic study and early intervention should be carried out in children with VD after ARM surgery.

K+ channels inhibited by hydrogen peroxide mediate abscisic acid signaling in Vicia guard cells.

A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2O2) levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulating guard cell ion transport, little is known concerning the relationship between ABA and H2O2 in signal transduction leading to stomatal movement. Epidermal strip bioassay illustrated that ABA-inhibited stomatal opening and ABA-induced stomatal closure were abolished partly by externally added catalase (CAT) or diphenylene iodonium (DPI), which are a H2O2 scavenger and a NADPH oxidase inhibitor respectively. In contrast, internally added CAT or DPI nearly completely or partly reversed ABA-induced closure in half-stoma. Consistent with these results, whole-cell patch-clamp analysis showed that intracellular application of CAT or DPI partly abolished ABA-inhibited inward K+ current across the plasma membrane of guard cells. H2O2 mimicked ABA to inhibit inward K+ current, an effect which was reversed by the addition of ascorbic acid (Vc) in patch clamping micropipettes. These results suggested that H2O2 mediated ABA-induced stomatal movement by targeting inward K+ channels at plasma membrane.

Hydrogen peroxide is involved in abscisic acid-induced stomatal closure in Vicia faba.

One of the most important functions of the plant hormone abscisic acid (ABA) is to induce stomatal closure by reducing the turgor of guard cells under water deficit. Under environmental stresses, hydrogen peroxide (H(2)O(2)), an active oxygen species, is widely generated in many biological systems. Here, using an epidermal strip bioassay and laser-scanning confocal microscopy, we provide evidence that H(2)O(2) may function as an intermediate in ABA signaling in Vicia faba guard cells. H(2)O(2) inhibited induced closure of stomata, and this effect was reversed by ascorbic acid at concentrations lower than 10(-5) M. Further, ABA-induced stomatal closure also was abolished partly by addition of exogenous catalase (CAT) and diphenylene iodonium (DPI), which are an H(2)O(2) scavenger and an NADPH oxidase inhibitor, respectively. Time course experiments of single-cell assays based on the fluorescent probe dichlorofluorescein showed that the generation of H(2)O(2) was dependent on ABA concentration and an increase in the fluorescence intensity of the chloroplast occurred significantly earlier than within the other regions of guard cells. The ABA-induced change in fluorescence intensity in guard cells was abolished by the application of CAT and DPI. In addition, ABA microinjected into guard cells markedly induced H(2)O(2) production, which preceded stomatal closure. These effects were abolished by CAT or DPI micro-injection. Our results suggest that guard cells treated with ABA may close the stomata via a pathway with H(2)O(2) production involved, and H(2)O(2) may be an intermediate in ABA signaling.

Hydrogen peroxide-induced changes in intracellular pH of guard cells precede stomatal closure.

Epidermal bioassay demonstrated that benzylamine, a membrane-permeable weak base, can mimick hydrogen peroxide (H2O2) to induce stomatal closure, and butyric acid, a membrane-permeable weak acid, can partly abolish the H2O2-induced stomatal closure. Confocal pH mapping with the probe 5-(and-6)-carboxy seminaphthorhodafluor-1-acetoxymethylester (SNARF-1-AM) revealed that H2O2 leads to rapid changes in cytoplasmic and vacuolar pH in guard cells of Vicia faba L, i. e. alkalinization of cytoplasmic areas occur red in parallel with a decrease of the vacuolar pH, and that butyric acid pretreatment can abolish alkalinization of cytoplasmic areas and acidification of vacuolar areas of guard cells challenged with H2O2. These results imply that the alkalinization of cytoplasm via efflux of cytosol protons into the vacuole in guard cells challenged with H2O2 is important at an early stage in the signal cascade leading to stomatal closure.

[Studies on ABA-induced H2O2 in Vicia guard cells by means of confocal laser scanning microscopy].

The methods of confocal laser scanning microscopy (CLSM) and microinjection were used to study ABA-induced H2O2 in guard cells (Vicia faba), which were labeled with H2O2 specific probe-2, 7-dichlorofluorescin diacetate(H2DCFDA). The results indicated 100 U/mL catalase (CAT) could inhibit partly stomatal closure induced by ABA. 10(-3) mmol/L ABA could significantly induce H2O2 production in chloroplast in guard cells of Vicia faba following microinjection, and 100 U/mL CAT could partly abolish the effects following simultaneous microinjection of ABA and CAT. These suggest that H2O2 is possibly involved in ABA signaling leading to stomatal closure.

[Health effects on workers exposed to low concentration carbon monoxide at high altitude].

Workers exposed to carbon monoxide (CO) at a concentration of 26.8mg/m3 at an altitude of 2,300 metres above sea level were compared with a control group of local inhabitants. There were significant differences in symptoms of headache, vertige fatigue and weakness memory impairment, insomnia, palpitation and neurobehavioral functions. CO concentration in respiratory air and HbCO in blood was higher but partial pressure of oxygen (PO2) and saturation of oxygen (SaO2) in blood was lower in the exposed group than the control group. Self-comparison of CO in respiratory air and HbCO in blood was higher after work than before work. Neurasthenia rate was significantly higher but PO2 and SaO2 significantly lower at high altitude than in the plain. The results indicated that under same CO concentrations the hazards to workers at high altitude were greater than to those working in the plain. The author recommends that at high altitude the CO permissible level should be appropriately lowered.