The Effect of Current on Skin Barrier Function In Vivo: Recovery Kinetics Post-Iontophoresis

Purpose. The objective of this study was to determine the extent to which current passage perturbed the skin's intrinsic permeability, and to quantify how quickly and to what extent the barrier properties recovered from the effects of iontophoresis. Methods. Laser scanning confocal microscopy (LSCM) and impedance spectroscopy (IS) were employed, respectively, to visualize and quantify the recovery kinetics. Results. LSCM images were obtained following passivecalcein diffusion through pre-iontophoresed HMS skin in vivothat had been allowed to recover for progressively longer periods of time. IS was used to quantify the rate and extent of skin permeability recovery following current pretreatment. Impedance spectra were recorded 0, 3, 5, 7, 9 and 18 hrs after current termination. Conclusions. Enhanced calcein permeability as assessed by confocal microscopy persisted for up to 24 hrs following current passage. Consistent with these LSCM findings, IS indicated that the time required for the impedance of hairless mouse skin to return to pre-iontophoresis levels (following 2-hr current passage at 0.5 mA/cm²) was at least 18 hrs.     

儿童特应性皮炎皮肤屏障功能相关蛋白表达情况

目的:了解特应性皮炎患儿皮肤屏障功能相关蛋白的表达情况。方法:应用免疫组化方法检测特应性皮炎患儿和正常儿童的中间丝聚合蛋白、内披蛋白、兜甲蛋白等皮肤屏障功能相关蛋白(表皮终端分化蛋白)的表达差异,采用染色强度(0~5 分)反映相关蛋白的表达水平。结果:正常儿童皮肤的中间丝聚合蛋白、内披蛋白、兜甲蛋白的染色强度分别为(4.49±0.14)分、(4.39±0.14)分、(4.56±0.15)分,特应性皮炎患儿受累部分皮肤分别为(2.19±0.17)分、(2.29±0.11)分、(1.89±0±22)分,两组比较差异均有统计学意义(P均<0.01)。特应性皮炎患儿和正常儿童的中间丝聚合蛋白、兜甲蛋白均主要表达于颗粒层,正常儿童内披蛋白主要表达于棘细胞上层和颗粒层,特应性皮炎患儿内披蛋白主要表达于棘细胞上层。结论:特应性皮炎患儿皮肤屏障功能相关蛋白表达下降,提示存在皮肤屏障功能障碍。     

氚的经皮渗透速率在离体皮肤屏障功能评价中的应用

采用液体闪烁法测定氚的经皮渗透行为,以氚经皮渗透速率的变化作为离体皮肤屏障功能的评价指标,体外释放试验表明,30%聚乙二醇200溶液中加入0.2%叠氮化钠可在短期内维持离体皮肤的屏障功能.试验时间超过7 d,皮肤屏障功能受损:离体裸鼠皮肤-30℃贮存6个月内屏障功能未受影响,但贮存10个月则会受损.     

复方龙胆合剂对小鼠激光损伤后皮肤屏障功能修复的研究

目的 研究复方龙胆合剂对于小鼠皮肤激光损伤后屏障修复的作用。方法 选择40只BALB/c小鼠,将小鼠背部脱毛后随机选取10只为正常组,其他30只使用Q开关1064激光机,以5 Hz频率、3 mm光斑、6 J能量照射脱毛区,构建激光损伤皮肤模型。将激光损伤模型小鼠随机分为模型组、对照组、实验组。模型组小鼠不做处理,对照组小鼠单一使用基质涂抹,实验组小鼠在基质涂抹的基础上每日灌胃给药复方龙胆合剂。分别在干预后6,24,48 h,7,14 d测试小鼠皮肤含水量、经皮失水量、小鼠皮肤中增殖细胞核抗原染色,ELISA法检测皮肤组织中髓样分化因子88（myeloid differentiation factor 88,MyD88）、白细胞介素6（interleukin-6,IL-6）的蛋白表达,RT-QPCR检测皮肤中表皮抗菌肽S100a8、S100a9、MyD88以及IL-6的mRNA水平。结果 模型组和对照组在皮肤含水量和经皮失水量的比较中无显著统计学意义,而实验组皮肤含水量显著高于模型组、经皮失水量显著低于模型组（P<0.05）。实验组增殖细胞核抗原表达较强。模型组和对照组皮肤中MyD88、IL-6的蛋白水平以及S100a8、S100a9、MyD88以及IL-6的mRNA水平无统计学意义,但是显著高于正常组（P<0.05）,而实验组皮肤中MyD88、IL-6的蛋白水平,S100a8、S100a9、MyD88以及IL-6的mRNA水平显著低于模型组（P<0.05）。结论 复方龙胆合剂可以促进小鼠皮肤激光损伤后屏障功能的恢复,其作用和炎症抑制相关。     

Differences in Executive Function Among Patients With Schizophrenia,Their Unaffected First-Degree Relatives,and Healthy Participants

BackgroundPatients with schizophrenia (SCZ) display impaired executive functions compared with healthy controls (HCs). Furthermore, unaffected first-degree relatives (FRs) of patients with SCZ independently perform worse executive functions than do HCs. However, few studies have investigated the differences in executive functions assessed among patients with SCZ, FRs, and HCs, and the findings are inconsistent.MethodsWe investigated diagnostic differences in executive functions, namely (1) numbers of categories achieved (CA), (2) total errors (TE), and (3) percentage of perseverative errors of Nelson types (%PEN), using the Wisconsin card sorting test among patients with SCZ (n = 116), unaffected FRs (n = 62), and HCs (n = 146) at a single institute. Correlations between these executive functions and clinical variables were investigated.ResultsSignificant differences existed in all executive functions among diagnostic groups (CA, F_2,319 = 15.5, P = 3.71 × 10^–7; TE, F_2,319 = 16.2, P = 2.06 × 10^–7; and %PEN, F_2,319 = 21.3, P = 2.15 × 10^–9). Patients with SCZ had fewer CA and more TE and %PEN than those of HCs (CA, Cohen’s d = −0.70, P = 5.49 × 10^–8; TE, d = 0.70, P = 5.62 × 10^–8; and %PEN, d = 0.82, P = 2.85 × 10⁻¹⁰) and FRs (TE, d = 0.46, P = 3.73 × 10^–3 and %PEN, d = 0.38, P = .017). Of the 3 executive functions, CA and %PEN of FRs were intermediately impaired between patients with SCZ and HCs (CA, d = −0.41, P = .011 and %PEN, d = 0.41, P = .012). In contrast, no significant difference in TE existed between FRs and HCs (d = 0.22, P = .18). Although CA and TE were affected by the duration of illness (P < .017), %PEN was not affected by any clinical variable in patients with SCZ (P > .017).ConclusionsExecutive function, particularly %PEN, could be a useful intermediate phenotype for understanding the genetic mechanisms implicated in SCZ pathophysiology.     

膝关节腔注射氨甲环酸对单纯半月板损伤患者关节肿胀、疼痛、关节功能恢复的影响

目的:探讨膝关节腔注射氨甲环酸对单纯半月板损伤患者关节肿胀程度、疼痛以及关节功能恢复的影响。方法:选择2016年10月-2017年4月重庆市人民医院骨科收治的62例拟行膝关节镜手术的单纯半月板损伤患者,按随机数字表法分为对照组和观察组,各31例。两组患者均于膝关节镜下行半月板切除或修整术。对照组患者术中伤口缝合后给予0.9%氯化钠注射液10 m L,膝关节腔注射;观察组患者术中伤口缝合后给予注射用氨甲环酸2.0 g,加入0.9%氯化钠注射液10 m L中,膝关节腔注射。所有患者均未安置引流管,加压包扎伤口后松止血带。观察两组患者术前及术后1、3、5、7 d膝关节周径、视觉模拟评分法(VAS)评分,术前及术后1个月Lysholm评分,并记录不良反应发生情况。结果:术前,两组患者膝关节周径、VAS评分、Lysholm评分比较,差异均无统计学意义(P>0.05)。术后,两组患者1、3、5、7 d膝关节周径均显著大于同组术前,但观察组术后1、3 d显著小于同期对照组,差异均有统计学意义(P<0.05);术后5、7 d,两组患者膝关节周径比较,差异均无统计学意义(P>0.05)。术后,观察组患者1、3 d及对照组患者1、3、5 d的VAS评分均显著高于同组术前,但观察组术后1、3、5 d显著低于同期对照组,差异均有统计学意义(P<0.05);观察组术后5、7 d及对照组术后7 d与同组术前比较,两组间术后7 d比较,差异均无统计学意义(P>0.05)。术后1个月,两组患者Lysholm评分均显著高于同组术前,且观察组显著高于对照组,差异均有统计学意义(P<0.05)。两组患者用药期间均未见严重不良反应发生,术后均无深静脉血栓发生。结论:膝关节镜术后关节腔注射氨甲环酸可有效减轻单纯半月板损伤患者的早期关节肿胀程度,缓解术后早期疼痛,促进术后关节功能恢复,且安全性较高。     

Human Skin is Permselective for the Small,Monovalent Cations Sodium and Potassium but not for Nickel and Chromium

The molar conductance of excised human skin (Λ_skin) immersed in electrolyte solutions comprising four cationic (Na⁺, K⁺, Ni^2 +, and Cr^3 +) and five anionic (Cl^?, NO₃^?, SO₄^2 ?, CrO₄^2 ?, and Cr₂O₇^2 ?) species was determined as a function of concentration in Franz diffusion cells. Cation transport numbers for four of these electrolytes were measured in Franz cells by the electromotive force method. Parallel experiments were conducted in solutions alone to establish the validity of the technique. Molar conductance decreased with increasing concentration, following the Kohlrausch law, over a 4–12-fold concentration range. Molar conductance and cation transport values at infinite dilution were extrapolated from these data and used to estimate ionic conductances at infinite dilution. These values were subsequently used to calculate limiting ion mobilities and diffusivities in solution and skin. Results for skin showed the expected increase in cation permselectivity for monovalent cations and a 40–110-fold reduction in effective diffusivities with respect to those in solution. However, Ni^2 + and Cr^3 + were relatively less mobile in skin than in solution. Salt diffusivities calculated from ionic mobilities in skin provided a partial explanation for the difference in allergenic potency of NiCl₂compared with NiSO₄ and Cr^3 + versus Cr^6 + salts.     

Production of nitric oxide,but not prostacyclin,is reduced in klotho mice

A novel murine model of aging (kl/kl mice) has been developed by in vivo mutagenesis. We analyzed endothelial function in this strain. Ring preparations of the thoracic aorta were obtained from 6- to 9-week old wild-type (+/+) and heterozygous (kl/+) klotho mice. The aortas of kl/+ mice showed an exaggerated contractile response to norepinephrine and attenuated vasodilator responses to acetylcholine and lecithinized superoxide dismutase (SOD) compared to +/+ mice. The response to sodium nitroprusside was unaltered in kl/+ mice. The contraction in response to norepinephrine was augmented by treatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-5) M) to a greater extent in +/+ mice than in kl/+ mice. Treatment with L-NAME abolished the vasodilator responses to both acetylcholine and lecithinized SOD. NO metabolites (NO2- and NO3-) and cGMP concentrations in the urine were significantly reduced in kl/+ mice compared to +/+ mice. However, the urinary excretion of 6-keto-prostaglandin F1alpha was unaltered. There was little immunostaining for NO synthase and vascular endothelial growth factor (VEGF) in the aorta of kl/+ mice. No immunostaining for NO synthase was noted in the aorta of kl/kl mice. The expression of the klotho gene product may have a role in the regulation of VEGF expression and is tightly linked to endothelial release of NO.     

Helix I of beta-arrestin is involved in postendocytic trafficking but is not required for membrane translocation, receptor binding, and internalization

beta-Arrestins bind to phosphorylated, seven-transmembrane-spanning, G protein-coupled receptors (GPCRs), including the type 1 angiotensin II receptor (AT(1)R), to promote receptor desensitization and internalization. The AT(1) R is a class B GPCR that recruits both beta-arrestin1 and beta-arrestin2, forming stable complexes that cotraffic to deep-core endocytic vesicles. beta-Arrestins contain one amphipathic and potentially amphitropic (membrane-targeting) alpha-helix (helix I) that may promote translocation to the membrane or influence receptor internalization or trafficking. Here, we investigated the trafficking and function of beta-arrestin1 and beta-arrestin2 mutants bearing substitutions in both the hydrophobic and positively charged faces of helix I. The level of expression of these mutants and their cytoplasmic localization (in the absence of receptor activation) was similar to wild-type beta-arrestins. After angiotensin II stimulation, both wild-type and beta-arrestin mutants translocated to the cell membrane, although recruitment was weaker for mutants of the hydrophobic face of helix I. For all beta-arrestin mutants, the formation of deep-core vesicles was less observed compared with wild-type beta-arrestins. Furthermore, helix I conjugated to green fluorescent protein is not membrane-localized, suggesting that helix I, in isolation, is not amphitropic. Bioluminescence resonance energy transfer analysis revealed that both wild-type and beta-arrestin mutants retained a capacity to interact with the AT(1)R, although the interaction with the mutants was less stable. Finally, wild-type and mutant beta-arrestins fully supported receptor internalization in human embryonic kidney cells and mouse embryonic fibroblasts deficient in beta-arrestin1 and -2. Thus, helix I is implicated in postmembrane trafficking but is not strongly amphitropic.     

Monomethylarsonous acid,but not inorganic arsenic,is a mitochondria-specific toxicant in vascular smooth muscle cells

Arsenic exposure has been implicated as a risk factor for cardiovascular diseases, metabolic disorders, and cancer, yet the role mitochondrial dysfunction plays in the cellular mechanisms of pathology is largely unknown. To investigate arsenic-induced mitochondrial dysfunction in vascular smooth muscle cells (VSMCs), we exposed rat aortic smooth muscle cells (A7r5) to inorganic arsenic (iAs(III)) and its metabolite monomethylarsonous acid (MMA(III)) and compared their effects on mitochondrial function and oxidative stress. Our results indicate that MMA(III) is significantly more toxic to mitochondria than iAs(III). Exposure of VSMCs to MMA(III), but not iAs(III), significantly decreased basal and maximal oxygen consumption rates and concomitantly increased compensatory extracellular acidification rates, a proxy for glycolysis. Treatment with MMA(III) significantly increased hydrogen peroxide and superoxide levels compared to iAs(III). Exposure to MMA(III) resulted in significant decreases in mitochondrial ATP, aberrant perinuclear clustering of mitochondria, and decreased mitochondrial content. Mechanistically, we observed that mitochondrial superoxide and hydrogen peroxide contribute to mitochondrial toxicity, as treatment of cells with MnTBAP (a mitochondrial superoxide dismutase mimetic) and catalase significantly reduced mitochondrial respiration deficits and cell death induced by both arsenic compounds. Overall, our data demonstrates that MMA(III) is a mitochondria-specific toxicant that elevates mitochondrial and non-mitochondrial sources of ROS.     

cGMP, but not cAMP, in rat hippocampus is involved in early stages of object memory consolidation

The present study investigates the role of cGMP and cAMP on the memory performance in the object recognition task in rats. The analogue 8-Br-GMP or 8-Br-cAMP was administered bilaterally into the hippocampus (0, 1, 3 and 10 microg in 0.5 microl saline/site) immediately after the exposure to two identical objects. After 24 h, saline-treated animals spent equal times exploring a new and the familiar object demonstrating that they did not recognize the familiar one. However, a dose-dependent improvement in object recognition was found after injection of 8-Br-cGMP. In contrast, 8-Br-cAMP did not improve the memory performance at the doses tested. These results indicate that hippocampal cGMP but not cAMP is involved in early stages of consolidation of object memory.     

d-Propoxyphene is a potent inhibitor of debrisoquine, but not S-mephenytoin 4-hydroxylation in vivo

The debrisoquine and S-mephenytoin 4-hydroxylation phenotyping tests were performed in 14 healthy subjects. All were extensive metabolizers of both drugs. After at least 4 weeks, they received a 150 mg tablet of d-propoxyphene and 5 h later the debrisoquine-mephenytoin test was repeated. This single dose of d-propoxyphene caused no change in mephenytoin S/R ratio, but increased the debrisoquine metabolic ratio (MR) in each subject (p less than 0.025). The four subjects with a relatively high MR (5.1-8.3) in the first test had an MR of debrisoquine in the second test ranging between 22 and 40, falsely classifying them as "poor metabolizers" of debrisoquine. This shows that d-propoxyphene is a potent inhibitor of debrisoquine, but not of S-mephenytoin 4-hydroxylase in vivo. A previous in vitro study has shown that d-propoxyphene inhibits the hydroxylation of desipramine, which is a substrate of the debrisoquine hydroxylase.     

Negative affect is associated with alcohol,but not cigarette use in heavy drinking smokers

Co-use of alcohol and cigarettes is highly prevalent, and heavy drinking smokers represent a large and difficult-to-treat subgroup of smokers. Negative affect, including anxiety and depressive symptomatology, has been associated with both cigarette and alcohol use independently, but less is known about the role of negative affect in heavy drinking smokers. Furthermore, while some studies have shown negative affect to precede substance use, a precise biobehavioral mechanism has not been established. The aims of the present study were twofold. First, to test whether negative affect is associated with alcohol and cigarette use in a large community sample of heavy drinking smokers (n = 461). And second, to examine craving as a plausible statistical mediator of the association between negative affect and alcohol and/or cigarette use. Hypothesis testing was conducted using a structural equation modeling approach with cross-sectional data. Analysis revealed a significant main effect of negative affect on alcohol use (β = 0.210, p < 0.05), but not cigarette use (β = 0.131, p > 0.10) in this sample. Mediational analysis revealed that alcohol craving was a full statistical mediator of this association (p < 0.05), such that there was no direct association between negative affect and alcohol use after accounting for alcohol craving. These results are consistent with a negative reinforcement and relief craving models of alcohol use insofar as the experience of negative affect was associated with increased alcohol use, and the relationship was statistically mediated by alcohol craving, presumably to alleviate negative affect. Further longitudinal or experimental studies are warranted to enhance the causal inferences of this mediated effect.