apoE~(-/-)小鼠颈总动脉斑块Fractalkine与TLR4的表达

目的探讨apo E-/-小鼠动脉粥样硬化斑块不规则趋化因子fractalkine与Toll样受体4(TLR4)的表达及其关系。方法 24只apo E-/-小鼠平均分为三组:普通饮食组、高脂饮食组、阿伐他汀干预组。12周后实验结束,检测动物血脂、颈总动脉斑块面积和血管狭窄率,评价AS病变严重程度。最后,应用免疫组织化学方法检测斑块内fractalkine和TLR4的表达情况。结果高脂饮食组颈总动脉AS斑块面积和血管狭窄率分别是普通饮食组的近4倍和3倍多;而药物干预组二者均降低,但只有血管狭窄率减少有统计学差异【(35.27±3.84)vs.(27.02±2.69),P0.05】;斑块处fractalkine、TLR4的表达在高脂饮食组升高【(3.24±0.96)vs.(10.69±2.11)、(1.29±0.57)vs(9.32±1.02)],经阿伐他汀干预后表达均下降[(10.69±2.11)vs(5.73±1.30)、(9.32±1.02)vs(3.32±0.51),(P0.05)]结论在apo E-/-小鼠AS斑块内,fractalkine和TLR4呈协同性表达,两者之间可能存在某种分子机制,并在AS的发病过程中发挥重要作用。     

AMD3100促进动脉粥样硬化病变与上调炎性因子表达及下调SDF-1α/CXCR4轴有关

探索CXCR4阻断剂AMD3100促进apoE-/-小鼠动脉粥样硬化病变的分子机制．36只8周龄雄性apoE-/-小鼠随机分为三组：普食组、高脂组和AMD3100组．ELISA法测血清基质细胞衍生因子1α(SDF-1α)水平,采用氧化酶法测定apoE-/-小鼠血清中三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)含量．HE染色检测apoE-/-小鼠主动脉根部横切面动脉粥样硬化病变．免疫组织化学检测小鼠胸主动脉CXCR4表达．RT-PCR和Western blot分别检测小鼠动脉组织TNF-α、NF-κB mRNA和蛋白质表达．AMD3100组小鼠主动脉根部横截面的动脉粥样硬化病变较高脂组严重,AMD3100组小鼠胸腹主动脉炎症因子TNF-α、NF-κB的mRNA水平和蛋白质表达增高,但血脂TG、TC、HDL-C和LDL-C含量与高脂组均无显著性差异．AMD3100组小鼠外周血SDF-1α水平和动脉壁CXCR4表达低于高脂组．结果表明：AMD3100通过上调炎性因子表达及下调SDF-1/CXCR4 轴促进apoE-/-小鼠动脉粥样硬化病变．     

ApoE~(-/-)小鼠动脉粥样硬化模型的建立

ApoE-基因敲除小鼠(ApoE-/-)经含有21%脂肪和0.15%胆固醇的高脂饲料喂食12周后进行各项血脂胆固醇水平检测,以及整体主动脉油红O染色与主动脉根部病理切片油红O染色等动脉粥样硬化病理分析。结果显示经过高脂诱导的ApoE-/-小鼠的血浆总胆固醇和甘油三酯水平均比未经饮食诱导的ApoE-/-小鼠、经同样饮食处理的野生型小鼠以及未经处理的野生型小鼠均显著升高(P0.05);低密度脂蛋白-胆固醇水平与野生型(正常饮食组和高脂组)相比升高了近3倍多;高脂诱导ApoE-/-小鼠的主动脉斑块面积占整体主动脉面积的65%,显著高于ApoE-/-小鼠的正常饮食组(21%)(P0.05),同时主动脉根部的血管壁明显增厚,管腔变窄。实验结果表明通过高脂饲料饮食诱导,成功建立了动脉粥样硬化模型小鼠,可为下游的药物筛选、基因治疗以及动脉粥样硬化机理的体内研究提供理想的实验材料。     

膜糖蛋白Ⅱb/Ⅲa单抗通过抑制HMGB1/TLR4 途径减轻ApoE-/-小鼠动脉粥样硬化

观察膜糖蛋白(GP) Ⅱb/Ⅲa 单抗对小鼠动脉粥样硬化(atherosclerosis,As)病变和HMGB1/TLR4途径基因表达变化的影响,以探讨膜糖蛋白Ⅱb/Ⅲa 受体拮抗剂对As进程的影响及其机制．30只5周龄雄性ApoE^-/-小鼠随机均分为3组：溶剂对照组(生理盐水50 μl,腹腔注射),IgG 对照组(50 μg,腹腔注射),GP Ⅱb/Ⅲa 单抗组(50 μg,腹腔注射)．实验ApoE^-/-小鼠均已高脂、高胆固醇饲料喂养,10周后处死动物．油红O染色观察主动脉窦As病变;活体荧光显微镜观察颈总动脉As病变处血小板黏附;Western blot 检测HMGB-1、TLR4与NF-κB蛋白的表达;免疫组化观察主动脉窦As病变部位MOMA-2 和VCAM-1的表达;ELISA法检测血浆中HMGB-1、IL-1β、TNF-α 与MCP-1的含量．研究结果表明：与对照组相比,GPⅡb/Ⅲa 单抗组ApoE^-/-小鼠As病变和血小板黏附显著减少(P < 0.05);且该组小鼠主动脉TLR4与NF-κB蛋白的表达明显降低;其血清中的HMGB-1、IL-1β、TNF-α 与MCP-1的水平也明显下降(P < 0.05)．此外,GP Ⅱb/Ⅲa 单抗治疗显著减少As病变处MOMA-2 和VCAM-1的表达(P < 0.05)．GP Ⅱb/Ⅲa 单抗减轻ApoE^-/-小鼠As病变可能与抑制HMGB1/TLR4途径介导的炎症有关．     

表没食子儿茶素没食子酸酯可改善高脂饮食大鼠胰腺组织炎症状态

目的探讨表没食子儿茶素没食子酸酯(epigallocatechin gallate, EGCG)对高脂饮食大鼠胰腺组织炎症状态的作用及其与胰岛素抵抗的关系。方法将30只SPF级雄性SD大鼠随机分为正常饮食组(the normal diet group as the control,NC组,n=10)和高脂饮食组(high-fat diet group,HFD组,n=20)。喂养16周,当两组大鼠体重出现显著差异后,将HFD组按随机区组原则分为单纯高脂组(high-fat diet group,HFD组,n=10)和EGCG干预组(HFD+0.32% EGCG,EGCG组,n=10);干预16周。留取血清及胰腺组织,检测每组大鼠空腹血糖(fasting blood glucose,FBG)、胰岛素(fasting insulin,FINS)及游离脂肪酸(free fatty acids,FFAs),并计算胰岛素抵抗指数(homeostasis model assessment-insulin resistance index,HOMA-IR);应用免疫组织化学方法检测胰岛中CD68^+巨噬细胞数目及TNF-α表达;应用Real-time RT-PCR及Western blot方法检测胰腺组织中CD68及Toll样受体4(Toll-like receptor 4,TLR4)、肿瘤坏死因子受体相关因子6(TNF receptor-associated factor 6,TRAF6)、肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)及白介素6(interleukin- 6,IL-6)等炎症相关因子表达水平。结果 HFD组大鼠体重、FFAs和FINS水平与HOMA-IR指数均明显升高,胰岛中巨噬细胞浸润明显增多,胰腺CD68水平及TLR4、TRAF6、TNF-α和IL-6等炎性因子表达明显上升;EGCG干预的HFD大鼠体重、FFAs和FINS水平、HOMA-IR指数、胰岛巨噬细胞浸润、胰腺CD68水平、胰腺TNF-α和IL-6表达的升高不如HFD大鼠明显,与NC大鼠接近;三组大鼠FBG水平无明显统计学差异;EGCG干预的HFD大鼠TLR4表达水平较HFD组未见明显下降。结论 EGCG可减少高脂饮食大鼠胰岛中巨噬细胞浸润,抑制炎症因子TNF-a及IL-6表达的上调,改善胰岛素敏感性;该作用并非通过TLR4信号通路实现。     

组织蛋白酶S与ApoE-/-小鼠动脉粥样硬化的实验研究

目的:观察组织蛋白酶S(Cathepsin S)在不同周龄我脂蛋白E基因缺陷(ApoE-/-)小鼠主动脉的表达,初步探讨Cathepsin S对ApoE-/-小鼠动脉粥样硬化(As)病变的影响.方法:将16只8周龄ApoE-/-小鼠随机分为两组:16周龄组(n=8),24周龄组(n=8),均饲以高脂饮食,分别在16周龄和24周龄处死动物.采用普通光镜、病理图象分析法测定主动脉As斑块面积及管腔面积;免疫组织化学染色方法观察组织蛋白酶S(Cathepsin S)在不同周龄ApoE-/-小鼠主动脉的表达.结果:16周龄组ApoE-/-小鼠主动脉根部出现As病变;与16周龄组ApoE-/-小鼠相比,24周龄组ApoE-/-小鼠主动脉根部As病变显著增强(P＜0.01),免疫组化显示Cathepsin S表达明显增加(P＜0.01).结论:Cathepsin S在ApoE-/-小鼠主动脉的表达随As病变程度增强而显著增加.     

重组腺病毒介导脂联素基因对ApoE~(-/-)小鼠动脉粥样硬化的作用机制

目的研究腺病毒介导的脂联素(APN)过表达对Apo E-/-小鼠动脉粥样硬化(AS)的抑制作用和对NF-κB信号通路的影响。方法将12周龄雄性Apo E-/-小鼠120只分为空载腺病毒对照组和脂联素干预组,每组60只。在3个不同时间点(0天、4周、8周)处死小鼠收集组织。全自动生化仪检测血脂指标;ELISA法测定血清APN浓度;油红O染色法检测小鼠主动脉血管组织的病理学变化;Masson染色法检测进展性斑块区的胶原含量和纤维帽厚度变化;免疫荧光法测定小鼠主动脉血管APN和NF-κB p65蛋白的表达;免疫印迹法检测主动脉血管APN、NF-κB p65核蛋白和炎症因子的表达。结果 APN过表达抑制了Apo E-/-小鼠动脉粥样硬化斑块形成。与对照组相比,脂联素干预组的动脉粥样硬化病理损伤面积减少(P0.01),动脉粥样硬化损伤程度降低(P0.001),总体油红O染色测定血管表面损伤百分比,4周时为(27.78±8.64)vs(33.02±5.18)%;8周时为(31.58±5.87)vs(52.16±5.79)%。脂联素减缓了高脂饮食导致的小鼠血清中TC(P0.001)、TG(P0.001)、LDL-C(P0.001)的浓度增加,使血脂水平趋向正常化。随着血清脂联素浓度增加,可以阻遏NF-κB通路的激活,抑制NF-κB p65核蛋白和炎症因子的表达。结论脂联素通过抑制NF-κB通路激活来减轻AS的炎症反应。     

耐力性运动对高脂饮食小鼠主动脉壁结构的影响

目的：在采用高脂饮食诱发C57BL／6J小鼠动脉粥样硬化（AS）的基础上,进一步观察耐力运动对实验动物已经形成的AS的治疗或干预效果。方法：选取48只8周龄C57BL／6J小鼠,随机分为4组（n=12）：正常对照组（N组）、12周高脂饮食致AS组（H组）、12周高脂饮食致AS后继续10周高脂饮食并结合游泳运动组（H＋E组）和持续22周高脂饮食不运动组（HS组）。取主动脉制备组织切片,采用电镜分析及病理学研究方法。观察耐力性运动对实验动物主动脉壁超微结构的影响。结果：12周高脂饮食可致C57BL／6J小鼠形成明显的AS;10周耐力性运动对实验动物已经形成的AS具有改善或减轻其主动脉病变程度的效果。结论：耐力性运动能有效地防治高脂饮食造成的AS。     

apoE/LDLR双基因缺失幼龄小鼠主动脉中动脉粥样硬化相关基因的表达

利用RT-PCR以及实时定量RT-PCR检测11个动脉粥样硬化(atherosclerosis,AS)相关基因在1、2和3月龄的载脂蛋白E(apolipoproteinE,aopE)/低密度脂蛋白受体(low-density lipoprotein receptor,LDLR)双基因缺失(apoE-/-/LDLR-/-)小鼠主动脉中的表达变化,同时应用血生化指标和病理形态学观察AS早期病变特点,探讨apoE和LDLR基因联合缺失引发的血脂代谢紊乱和血管炎症损伤的关系以及AS的炎症反应机制.结果显示,apoE-/-/LDLR-/-小鼠IL-18、TLR2、MCP-1、ICAM-1、VCAM-1、GM-CSF、CD36和ET-1表达在1月龄时较同龄野生型(wild type,WT)小鼠显著上调(P<0.05,P<0.01),PDGF-α和TNF-α表达在2月龄时较同龄WT小鼠显著上调,除ET-1表达在2月龄时以及了LR2、VCAM-1和ICAM-1表达在3月龄时降至WT小鼠水平以外,其余各基因表达随年龄增长继续升高(P<0.05,P<0.01),其中MCP-1表达在2月龄时达到峰值.NF-kB在各年龄段apoE-/-/LDLR-/-小鼠中的表达与同龄WT小鼠相比均无显著差异.各年龄段apoE-/-/LDLR-/-/小鼠血清了C、TG、LDL、HDL、TNF-α、IL-1β和ox-LDL含量均显著高于同龄WT小鼠(P<0.05,P<0.01),并随年龄增长逐渐升高.apoE-/-/LDLR-/-小鼠1月龄时主动脉内膜出现少量的散在的脂质沉积,随着年龄增长病变区域增多,脂质沉积增厚.上述结果提示:apoE和LDLR双基因缺失形成的高脂血症可能通过刺激主动脉中炎症基因时序表达,起始并扩大病变部位的炎症反应,共同促进AS的发生发展.     

短链脂肪酸丁酸抑制动脉粥样硬化形成及其分子机制

本研究通过观察丁酸对动脉粥样硬化斑块形成以及肠道组织结构和功能的影响,探讨丁酸防治动脉粥样硬化的效应及可能机制。选取8周龄雄性载脂蛋白E基因敲除(apolipoprotein E-knockout,ApoE-/-)小鼠,随机分成对照组(高脂高胆固醇饲料+饮水中给予200 mmol/L氯化钠,n=10)和丁酸组(高脂高胆固醇饲料+饮水中给予200 mmol/L丁酸钠,n=10),喂养12周。干预结束后麻醉处死小鼠并分离主动脉、心脏,油红O染色定量分析动脉粥样硬化斑块面积。取新鲜的小鼠肠道组织检测肠道组织长度、结构和通透性。定量PCR和酶联免疫吸附法检测炎症因子水平。结果表明:与对照组相比,丁酸组小鼠动脉粥样硬化斑块面积显著减少(P<0.01),血清总胆固醇和低密度脂蛋白胆固醇水平也明显降低(P<0.05),主动脉、肠道组织以及血液循环中炎症因子表达水平显著下降。同时,丁酸干预后小鼠肠道结构更加致密,肠道通透性降低,血液内毒素脂多糖水平也明显降低,肠道紧密连接蛋白Occludin和ZO-1基因表达水平显著升高。体外人小肠上皮细胞Caco-2实验结果显示,丁酸可以剂量依赖性地上调Occludin和ZO-1 mRNA和蛋白表达水平,这一效应可以被G蛋白耦联受体41小干扰RNA所阻断。以上结果提示,丁酸显著抑制小鼠动脉粥样硬化发生,其作用机制可能与其降低肠道通透性、减少血液脂多糖和炎症因子水平有关。     

Comparison of parameters estimated from A/Ci and A/Cc curve analysis

The parameters estimated from traditional A/C _i curve analysis are dependent upon some underlying assumptions that substomatal CO₂ concentration (C _i) equals the chloroplast CO₂ concentration (C _c) and the C _i value at which the A/C _i curve switches between Rubisco- and electron transport-limited portions of the curve (C _i-t) is set to a constant. However, the assumptions reduced the accuracy of parameter estimation significantly without taking the influence of C _i-t value and mesophyll conductance (g _m) on parameters into account. Based on the analysis of Larix gmelinii’s A/C _i curves, it showed the C _i-t value varied significantly, ranging from 24 Pa to 72 Pa and averaging 38 Pa. t-test demonstrated there were significant differences in parameters respectively estimated from A/C _i and A/C _c curve analysis (p<0.01). Compared with the maximum ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (V_cmax), the maximum electron transport rate (J_max) and J_max/V_cmax estimated from A/C _c curve analysis which considers the effects of g _m limit and simultaneously fits parameters with the whole A/C _c curve, mean V_cmax estimated from A/C _i curve analysis (V_cmax-C _i) was underestimated by 37.49%; mean Jmax estimated from A/C _i curve analysis (J_max-C _i) was overestimated by 17.8% and (J_max-C _i)/(V_cmax-C _i) was overestimated by 24.2%. However, there was a significant linear relationship between V_cmax estimated from A/C _i curve analysis and V_cmax estimated from A/C _c curve analysis, so was it J_max (p<0.05).     

ATP/ADP exchange activity of gastric (H+ + K+)-ATPase

The ATP/ADP exchange is shown to be a partial reaction of the $\text{(}\text{H}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ by the absence of measurable nucleoside diphosphokinase activity and the insensitivity of the reaction to $\text{P}{}^1$, $\text{P}{}^5$ -di(adenosine-5′) pentaphosphate, a myokinase inhibitor. The exchange demonstrates an absolute requirement for Mg²⁺ and is optimal at an ADP/ATP ratio of 2. The high ATP concentration ($\text{K}{}_{0.5}\text{= 116 μ}\text{M}$) required for maximal exchange is interpreted as evidence for the involvement of a low affinity form of nucleotide site. The ATP/ADP exchange is regarded as evidence for an ADP-sensitive form of the phosphoenzyme. In native enzyme, pre-steady state kinetics show that the formation of the phosphoenzyme is partially sensitive to ADP while modification of the enzyme by pretreatment with 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of Mg²⁺ results in a steady-state phosphoenzyme population, a component of which is ADP sensitive. The ATP/ADP exchange reaction can be either stimulated or inhibited by the presence of K⁺ as a function of pH and Mg²⁺.     

Characterization of cytochrome P-450SCC-containing liposomes

Purified cytochrome $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ from bovine adrenocortical mitochondria was incorporated into liposomes by the cholate-dilution method utilizing either dialysis or Sephadex gel filtration. Among synthetic phospholipids tested, dioleoylglycerophosphocholine showed the best stability during the incorporation of $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ into liposomes. A maximum amount of heme was incorporated into liposomes at a molar ratio of phospholipid to the cytochrome of approx. 200. When $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was incorporated into the dioleoylglycerophosphocholine liposomes by the cholate-filtration method, the $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}\text{-}\text{containing liposomes}$ showed two major populations on the elution pattern of the Sepharose 4B gel filtration, and were seen at a diameter of 200–600 Å and its aggregated forms. When the cytochrome was incorporated into dioleoylglycerophosphocholine liposomes or cholesterol-free adrenocortical mitochondrial liposomes, $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was less stable than $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ in aqueous solution. Cholesterol or adrenodoxin markedly stabilized the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. Liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ required cholesterol for its optimum reduction with adrenodoxin, adrenodoxin reductase, and NADPH in the presence of CO. About 70% of the total heme in the dioleoylglycerophosphocholine liposomes was reduced by the enzymatic reduction in the presence of cholesterol, indicating that 70% of the total molecules are exposed to the surface of the outer monolayer. In order to see the location of the heme in membrane, the dioleoylglycerophosphocholine-liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was subjected to $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ treatment. This reagent destroyed the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. These results suggest that the heme is located in the proximity of the $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ reacting sites which are exposed to the surface, or located on the vincinity of polar heads of the membrane.     

The effects of multiple features of alternatively spliced exons on the KA/KSratio test

Background  

The evolution of alternatively spliced exons (ASEs) is of primary interest because these exons are suggested to be a major source of functional diversity of proteins. Many exon features have been suggested to affect the evolution of ASEs. However, previous studies have relied on the K _A /K _S ratio test without taking into consideration information sufficiency (i.e., exon length > 75 bp, cross-species divergence > 5%) of the studied exons, leading to potentially biased interpretations. Furthermore, which exon feature dominates the results of the K _A /K _S ratio test and whether multiple exon features have additive effects have remained unexplored.     

Occurrence of N-malonyl-D-alanine in pea seedlings

One of the ninhydrin-negative alanine conjugates isolated from pea seedlings was identified as $\text{N-}\text{malonyl}\text{-}\text{D}\text{-}\text{alanine}$.The identification of this conjugate was carried out by a comparison of its gas-liquid chromatographic and mass spectrometric properties, and its nuclear magnetic resonance and infrared spectra with those of synthetic $\text{N-}\text{malonyl}\text{-}\text{D}\text{-}\text{alanine}$. The alanine in the conjugate was shown to be present as the D-isomer by enzymatic and chromatographic analyses.     

Two-Electron Reactions S2QB → S0QB and S3QB → S1QB are Involved in Deactivation of Higher S States of the Oxygen-Evolving Complex of Photosystem II

The oxygen-evolving complex of Photosystem II cycles through five oxidation states (S₀-S₄), and dark incubation leads to 25% S₀ and 75% S₁. This distribution cannot be reached with charge recombination reactions between the higher S states and the electron acceptor Q_B⁻. We measured flash-induced oxygen evolution to understand how S₃ and S₂ are converted to lower S states when the electron required to reduce the manganese cluster does not come from Q_B⁻. Thylakoid samples preconditioned to make the concentration of the S₁ state 100% and to oxidize tyrosine Y_D were illuminated by one or two laser preflashes, and flash-induced oxygen evolution sequences were recorded at various time intervals after the preflashes. The distribution of the S states was calculated from the flash-induced oxygen evolution pattern using an extended Kok model. The results suggest that S₂ and S₃ are converted to lower S states via recombination from S₂Q_B⁻ and S₃Q_B⁻ and by a slow change of the state of oxygen-evolving complex from S₃ and S₂ to S₁ and S₀ in reactions with unspecified electron donors. The slow pathway appears to contain two-electron routes, S₂Q_B → S₀Q_B, and S₃Q_B → S₁Q_B. The two-electron reactions dominate in intact thylakoid preparations in the absence of chemical additives. The two-electron reaction was replaced by a one-electron-per-step pathway, S₃Q_B → S₂Q_B → S₁Q_B in PS II-enriched membrane fragments and in thylakoids measured in the presence of artificial electron acceptors. A catalase effect suggested that H₂O₂ acts as an electron donor for the reaction S₂Q_B → S₀Q_B but added H₂O₂ did not enhance this reaction.     

Comparative study of Bifidobacteriumanimalis, Escherichiacoli, Lactobacilluscasei and Saccharomycesboulardii probiotic properties

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.     

Dermal cysts participate in reparative regeneration of epidermis in Hrhr/Hrhr mice

One of the phenotypic effects of mutation in the Hr gene in mice is disintegration of hair follicles and their degeneration into open funnel-shaped structures (utricles) opened on skin surface and cysts located in the depth of the dermis. The aim of the current study consists in analysis of the process of reparative regeneration of skin in homozygotous mice with one of the mutant alleles of the Hr gene—Hr ^hr . It is shown that epithelial cells that constitute the inner pavement of cysts take part in the process of epithelization of deep skin wounds. This indicates that the competence of ectodermal cells in relation to inductive signals from injured skin remains in Hr ^hr homozygote mice, in spite of the significant anatomic abnormalities of the hair follicles.     

Ligand-dependent reactivity of (Na+ + K+)-ATPase with showdomycin

Showdomycin inhibited pig brain ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na⁺, K⁺, Mg²⁺ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1)$\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$, (2) $\text{Mg}{}^{\mathrm{2+}}$, $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}$ and none, (3) $\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{,}\text{Na}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}$ and $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}$, (4) $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}\text{,}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}$ and $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}\text{, (5)}\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$ and ATP. The highest rate was obtained in the presence of Na⁺, Mg²⁺ and ATP. The apparent concentrations of Na⁺, Mg²⁺ and ATP for half-maximum stimulation of inhibition ($\text{K}{}_{0.5}{}^{\mathrm{<mtext>s</mtext>}}$) were 3 mM, 0.13 mM and 4μM, respectively. The rate was unchanged upon further increase in Na⁺ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E₁, E₂, ES, E₁-P and E₂-P, i.e., E₂ has higher reactivity with showdomycin than E₁, while E₂-P has almost the same reactivity as E₁-P. We conclude that the reaction of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ proceeds via at least four kinds of enzyme form (E₁, E₂, E₁ · nucleotide and EP), which all have different conformations.