Intracellular calcium ions activate a low-conductance chloride channel in smooth-muscle cells isolated from human mesenteric artery

Calcium-activated chloride currents were studied by the patch-clamp technique in vascular smooth muscle cells (VSMC) isolated from human mesenteric arteries. Bath application of 20 mM caffeine caused the cell membrane to depolarize by a calcium-activated inward current that peaked to –654±230 pA (holding potential –50 mV). Cell-attached, at the same time inwardly directed single-channel currents were detected with an amplitude of –0.22 pA. In open-cell-attached patches channel activity was triggered by elevating [Ca²⁺]_i to 10 M. At –60 mV the mean amplitude of the current was –0.24 pA and the mean open time of the channels was 28 ms. Plotting the amplitude of the current versus the test potential yielded a single-channel conductance of 2.8±0.5 pS. The currents disappeared when [Cl^–] was reduced from 150 mM to 5 mM at the cytosolic side of the inside-out patch at a holding potential of -60 mV (calculated reversal potential –58 mV) suggesting that the calcium-activated current was a chloride current. This suggests that, in human mesenteric VSMC, elevation of [Ca²⁺]_i activates a low-conductance chloride channel, which may mediate the agonist-induced depolarization of the cell membrane.     

Properties of the inactivating outward current in single smooth muscle cells isolated from the rat anococcygeus

The properties of the voltage- and time-dependent outward current in single smooth muscle cells isolated from the rat anococcygeus were studied. The outward current was activated by depolarizations to membrane potentials positive to –40 mV. Activation followed third order kinetics; at + 20 mV, the time for the current to reach half its maximal amplitude was around 55 ms. The current inactivated with a time course that could best be described by a single exponential with a time constant around 1500 ms. The steady-state inactivation curve was voltage dependent over the range –110 to –30 mV, with a half-inactivation point of –67 mV. Recovery from inactivation followed an exponential time course with a time constant of around 770 ms at –90 mV. Deactivating tail current analysis revealed that a 10-fold change in the extracellular potassium ion concentration resulted in a 42 mV change in the reversal potential of the current. The current was blocked by 4-aminopyridine, tetraethylammonium, quinine and verapamil with IC₅₀'s — the concentrations producing 50% inhibition of the peak current — of 2 mM, 4 mM, 12 M and 20 M respectively. The current was not blocked by Toxin I (100 nM) or glibenclamide (10 M). The current was still present in cells containing 5 mM EGTA; in these cells, replacing extracellular calcium with cadmium depressed the peak current by around 12%. This could be explained, at least in part, by a negative shift in the voltage dependence of inactivation.     

Tetraethylammonium-insetisitive,Ca2+-activated whole-cell K+ currents in rat submandibular acinar cells

Using whole-cell patch-clamp techniques, we demonstrate, for the first time, that rat submandibular acinar cells contain a tetraethylammonium (TEA)-insensitive, Ca²⁺-activated K⁺ conductance which is not attributable to large conductance, voltage-sensitive, Ca²⁺-dependent K⁺ channels (maxi-K⁺ channels). Taken together with our recent K⁺ efflux and fluid secretion studies in intact rat submandibular gland, we postulate that the K⁺ conductance reported here may be involved in the basolateral K⁺ efflux pathway activated by cytosolic Ca²⁺ concentration during secretion by this gland.     

Endplate channel actions of a hemicholinium-3 analog,DMAE

Summary The effect of the hemicholium-3 analog, DMAE, on endplate currents (EPC) was investigated in the transected cutaneous pectoris muscle of the frog using a conventional two-microelectrode voltage clamp. At a low concentration (5 M), DMAE produced a long-lasting decrease in the rate constant of decay () and an increase in the peak current amplitude (Ip). At higher concentrations (10–100 M), DMAE produced biphasic changes characterized by a transient, marked decrease of and increase of Ip followed by a long-lasting marked increase of and decrease of Ip. When DMAE was removed from the bath recovery from block was asymmetrical in that recovered more quickly than did Ip. Pretreatment with neostigmine or collagenase partially antagonized the initial effects without affecting the steady state effects of DMAE, indicating that the initial effects of DMAE may be, at least in part, due to inhibition of the enzyme acetylcholinesterase. The drug reverses the normal voltage dependence of without altering the single exponential nature of decay of the EPC. The inward EPC was more markedly blocked than outward EPC, resulting in a highly non-linear current-voltage relation with Ip decreasing with increasing hyperpolarization. This effect may indicate that DMAE causes a voltage-dependent block of closed acetylcholine-activated ion channels.     

Caffeine actions on currents induced by calcium-overload in Purkinje fibers

The ionic events underlying the changes induced by caffeine in calcium-overloaded Purkinje fibers were studied by means of a voltage-clamp technique. The following results were obtained. In fibers exposed to strophanthidin (5 X 10(-7) M), a depolarizing clamp of suitable magnitude or duration is followed by an oscillatory current (Ios) often superimposed on a decaying inward tail current (the "tail current"). Caffeine (9 mM) abolishes Ios and increases the tail current. Caffeine has similar actions when calcium overload is induced by increasing [Ca]0 or decreasing [Na]0. The magnitude of the tail current is reduced by decreasing [Ca]0. The tail current appears with repolarizations to -40 mV or more negative values as Ios appears in the absence of caffeine. As with Ios the tail current can be triggered twice (during and after a test clamp of suitable characteristics), becomes more inward with repeated clamps and becomes larger with larger or longer conditioning clamps. During the recovery from caffeine exposure, the tail current decreases gradually as Ios returns progressively. It is concluded that both Ios and tail current are caused by calcium overload but are affected in opposite direction by caffeine, apparently because caffeine decreases the calcium overload in the sarcoplasmic reticulum (abolition of Ios) and increases the calcium to be extruded from the sarcoplasm (increase in the tail current).     

2005-2019年理塘县法定传染病疫情分析

目的了解理塘县近15年法定传染病疫情形势及流行特征,为政府制定防控措施提供科学依据。方法对2005—2019年理塘县法定传染病疫情进行描述性流行病学分析。采用ArcGIS 10.3软件绘制各乡镇发病情况分布图,SPSS 21.0软件进行χ²检验、趋势性χ²检验。结果2005—2019年理塘县共计报告甲乙丙类传染病21种6154例,年均发病率为644.33/10万,发病呈上升趋势。死亡37例,年均死亡率3.87/10万,病死率0.60%。呼吸道传染病发病最高(341.12/10万);发病前3位的病种为肺结核(271.91/10万)、乙肝(103.24/10万)及包虫病(67.22/10万);肺结核、其他感染性腹泻病、艾滋病/HIV、梅毒发病呈上升趋势。3月、9月分别出现1次发病高峰;20~29岁、30~39岁和10~19岁组发病居前3位;男女性别比为1.24∶1;发病以农民、牧民及学生为主。结论2005-2019年理塘县法定传染病发病率较高且呈上升趋势,应针对高发传染病、上升趋势明显的传染病、重点人群进行分析研究,采取针对性措施控制疫情。     

2018年四川省贫困县区居民健康素养监测结果分析

目的掌握四川省贫困地区居民的健康素养现况及其影响因素,为贫困地区居民健康素养的提升及健康扶贫工作的落实提供科学依据。方法采用分层多阶段、PPS、方便抽样相结合的方法,2018年在四川省88个贫困县区抽取18个县,对非集体居住的15~69岁常住人口进行健康素养问卷调查。采用SPSS 20.0软件进行t检验和单因素ANOVA分析,校验水准α=0.05。结果共调查四川省贫困地区5 797名居民,经过加权调整后,2018年四川省贫困地区居民具备健康素养的比例是1.5%;健康素养得分为(21.76±9.66)分,不同性别(t=4.221,P<0.001)、民族(t=18.900,P<0.001)、年龄组(F=2.952,P=0.012)、文化程度(F=10.941,P<0.001)、职业(F=3.152,P=0.001)、家庭常住人口数(F=3.232,P=0.040)、家庭人均年收入(F=4.581,P=0.003)的居民健康素养得分的差异具有统计学意义;具备基本知识和理念、健康生活方式与行为、健康技能3个维度健康素养的比例分别是9.2%、13.7%和5.8%。结论 2018年四川省贫困地区居民健康素养水平较低,健康素养水平在不同人群特征的居民中表现出差异,应结合健康扶贫相关政策,加大健康教育工作力度,进一步提高贫困地区居民健康知识知晓率,健康技能掌握率和健康行为形成率,并针对健康知识、健康技能的掌握环节进行重点干预。     

重庆市北碚区居民丙肝知识知晓率及相关行为现状调查

目的了解重庆市北碚区居民丙肝知识知晓率、高危行为现状及两者之间的关系,为构建提高居民丙肝安全行为的干预方式提供科学依据。方法2018—2019年期间根据《重庆市丙肝防治知识知晓率基线调查方案》要求采取分层随机抽样法抽取重庆市北碚区居民开展丙肝知识、高危行为问卷调查,采用SPSS 20.0软件对数据进行分析,以P<0.05为差异有统计学意义。结果共调查200名居民,丙肝防治知识问题回答对6道及以上51人(25.5%),全部答对仅4人(2.0%),全部答错103人(51.5%)。丙肝防治知识知晓率与文化程度有关(P<0.05),与人群类别、家庭人均月收入、年龄、性别等因素不相关(P均>0.05)。丙肝防治知识知晓与不知晓的高危行为发生率比较,差异无统计学意义(χ²=0.966,P=0.367)。结论该地区人群丙肝防治知识知晓率还处于较低水平,建议在今后的工作中应针对丙肝制定详细宣教计划,组织开展各种形式的宣教活动,有效引导公众提高丙肝防治意识。     

高校附属医院文化建设和党建工作的关系研究

文化建设与党建工作之间存在着一定的关联,随着经济的不断发展,我国卫生管理体制改革也不断深入,在此过程中,对于高校附属医院文化建设和党建工作提出更高水平的要求。从医院层面来看,通过加强文化建设以及发展党建工作,能够有效提高医院的凝聚力,促进医院树立良好的形象、培养优秀的医护人员等。文化建设和党建工作息息相关,在医院管理与发展的过程中,两者之间相辅相成。文章在研究的过程中,采用访谈法、问卷调查法等方法,通过访谈法、问卷调查法对医院各个方面人员进行调查,根据调查结果总结高校附属医院文化建设和党建工作的关系。     

医院档案管理工作基于新形势的开展途径分析

医院是为人类提供公共卫生服务的一个单位,其存在具有至关重要的影响意义,是人们医疗卫生事业的主要承担场所,医院所提供的公共卫生服务水平主要受到两个方面因素的影响,其一是医疗卫生发展水平,其二是人们生活水平;而这两种因素均受到人类社会经济发展水平的影响,由此可见,医院可以直接反映人类社会的发展水平,医院管理治疗会对其实际运行水平产生直接性影响,同时也侧面体现了我国公共卫生服务质量。因此,基于此种社会现实下,结合新形势要求,分析医院档案管理工作存在的弊端,并探讨创新途径具有至关重要的影响意义,这不仅是国家发展、社会发展的要求,同时也是医院实现可持续运行的根本条件,是当前医院刻不容缓需要解决的主要问题。