Extracellular Ca2+-dependent and independent calcium transient in fetal myotubes

Spatio-temporal changes in the intracellular calcium concentration [Ca²⁺]_i of dissociated mice myotubes from 14-day and 18-day-old fetuses were studied using digital imaging analysis of the Ca²⁺ indicator fura-2. Myotubes from 18-day-old fetuses displayed a transient [Ca²⁺]_i increase upon electrical stimulation either in nominally calcium-free external solution or in Krebs solution containing 100 M lanthanum. Thus, at this developmental stage, membrane depolarization appears to increase [Ca²⁺]_i by stimulating Ca²⁺ release from the sarcoplasmic reticulum independently of extracellular Ca²⁺ influx. Similarly, myotubes from 14-day-old fetuses also showed a calcium transient upon electrical stimulation in Krebs solution. However, in 46% of these myotubes the calcium transient was abolished when Ca²⁺ entry through calcium channels was suppressed.     

Acoustic voice analysis by means of the hoarseness diagram.

The hoarseness diagram (Michaelis, Fr?hlich, & Strube, 1998a) has been proposed as a new approach to describe different acoustic properties of voices. To test its performance in the analysis of pathologically disturbed and normal voices five requirements are suggested that should be met by any acoustic voice-analysis protocol to be used in voice research and clinical practice. The hoarseness diagram is then tested with regard to these requirements. Individual voices are found to show a satisfactory localization in the diagram. Aspects of stationarity are discussed in the context of four case studies. The different cases illustrate that changes in the acoustic analysis results are observed if the voice-generation conditions change, whereas results are stationary if phonation conditions do not change. Different pathological voice groups defined on grounds of the specific phonation mechanism are found to map to specific regions of the hoarseness diagram, with differences between group locations being significant. All results can be interpreted without exceptions if the two hoarseness diagram coordinates are taken to reflect the vibrational irregularity of the voice-generation mechanisms on the one side and the degree of closure of the vibrating structures on the other side. The hoarseness diagram and its underlying algorithms are thus shown to constitute a useful approach to acoustic voice analysis in research and clinical practice. The tests themselves demonstrate several application possibilities, including the quantitative monitoring of individual voices.     

玻璃体切除术治疗外伤性眼内炎62例

0　引言　外伤性眼内炎是眼外伤的常见并发症 ,对视力及眼球威协极大 .由于病原体随致伤物直接进入眼内 ,在眼内和玻璃体繁殖 ,产生剧烈炎症反应 ,对眼内组织造成严重破坏 .如不及时而有效的控制 ,终使视力丧失 ,眼球萎缩 .近年随着现代玻璃体手术的发展 ,外伤性眼内炎的治愈率明显提高 .现将我科收治的 6 2例报告如下 .1　对象和方法1 .1　对象 1 996 - 0 6 / 1 998- 0 6我院连续收治 6 2例外伤性眼内炎 ,其中男 5 0例 ,女 1 2例 ,年龄 2～ 45岁 ,平均 1 6 .5岁 .1 4岁以下儿童 38例 ,占 6 1 .3% .以致伤原因分类 :角膜穿通伤30例 ,巩膜穿…     

Wright hang-back recession with fibrin glue compared with standard fixed suture recession for the treatment of horizontal strabismus

ObjectiveTo evaluate the clinical safety and efficacy of the novel Wright hang-back recession with fibrin glue for the treatment of horizontal strabismus.Study DesignRetrospective, case-controlled clinical study comparing surgical outcomes of the Wright hang-back rectus recession with fibrin glue (WHBG) versus standard fixed suture rectus recession (SFR).MethodsMedical records of all patients who underwent strabismus surgery by one strabismus surgeon between 2016 and 2018 for horizontal deviations only, including cases of WHBG (group 1) or SFR (group 2), were reviewed. Good surgical outcome was defined as a postoperative deviation ≤10 prism diopters (PD) at a minimum 2 months of follow-up.Results32 eyes of 17 patients underwent WHBG and 32 eyes of 17 patients underwent SFR; in each group, 35% had esotropia and 65% had exotropia. Mean preoperative deviations between groups were similar: esotropia 25.5 PD and exotropia 26.6 PD in WHBG; esotropia 28.3 PD and exotropia 23.8 PD in SFR. The mean postoperative deviation was <7 PD for both groups. Good surgical outcomes were similar between groups, 16/17 (94%) in WHBG and 15/17 (88%) in SFR, with no complications.ConclusionsWHBG was safe and effective with postoperative results similar to SFR. WHBG has an important advantage, eliminating the complication of retinal perforation that can occur with SFR while avoiding under- or overcorrection that can occur with traditional hang-back recession. This technique increases patient safety without sacrificing surgical outcomes and is especially useful in patients with thin sclera such as patients with high myopia or with difficult posterior exposure.     

Absence of the β subunit (cchb1) of the skeletal muscle dihydropyridine receptor alters expression of the α1 subunit and eliminates excitation-contraction coupling

The multisubunit (α_1S, α₂/δ, β₁, and γ) skeletal muscle dihydropyridine receptor transduces transverse tubule membrane depolarization into release of Ca²⁺ from the sarcoplasmic reticulum, and also acts as an L-type Ca²⁺ channel. The α_1S subunit contains the voltage sensor and channel pore, the kinetics of which are modified by the other subunits. To determine the role of the β₁ subunit in channel activity and excitation-contraction coupling we have used gene targeting to inactivate the β₁ gene. β₁-null mice die at birth from asphyxia. Electrical stimulation of β₁-null muscle fails to induce twitches, however, contractures are induced by caffeine. In isolated β₁-null myotubes, action potentials are normal, but fail to elicit a Ca²⁺ transient. L-type Ca²⁺ current is decreased 10- to 20-fold in the β₁-null cells compared with littermate controls. Immunohistochemistry of cultured myotubes shows that not only is the β₁ subunit absent, but the amount of α_1S in the membrane also is undetectable. In contrast, the β₁ subunit is localized appropriately in dysgenic, mdg/mdg, (α_1S-null) cells. Therefore, the β₁ subunit may not only play an important role in the transport/insertion of the α_1S subunit into the membrane, but may be vital for the targeting of the muscle dihydropyridine receptor complex to the transverse tubule/sarcoplasmic reticulum junction.     

国内六大行政区域六城市中老年人群膝关节骨性关节炎患病危险因素比较

目的：了解中国不同地区间中老年人群膝关节骨性关节炎患病危险因素。方法：调查时间为2005—07／08。①从中国六大行政区（西北，华北，华东。中南，东北，西南）选出六城市（西安，石家庄，上海。广州，哈尔滨市，成都），用分层多阶段整群抽样方法，抽取6218名40岁及以上具有正式户口常住男女人群进行膝关节骨性关节炎的流行病学问卷调查（包括一般情况、现病史、既往史、体格检查、X射线片检查情况和疾病诊断6个方面，共计94个问题141个变量指标），并对其中4808名有症状者进行X射线平片膝正侧位投照。②膝关节骨性关节炎诊断标准为临床症状阳性加X射线Kellgren ＆ Lawrence分级二级及以上者。③计算患病率，并采用Epilnf06．0和SPSS 10．0软件对其中83个变量进行多因素非条件Logistfc回归分析，表示疾病与暴露因素之间联系强度的指标用比值比（OR），若OR〉1，说明疾病发生危险性增加，与暴露因素呈正关联；若OR〈1，说明疾病发生危险性减少，与暴露因素呈负关联。 结果：①六城市膝关节骨性关节炎总患病率为15．6％，其中西安7．7％，石家庄11．2％，上海9．8％。广州30．5％，哈尔滨16．9％，成都17．5％，各城市患病率比较差异显著（P〈0．01）。②Logistic回归分析膝关节骨性关节炎在大部分城市有共同的危险因素如年龄大（OR=1．032—1．181），使用蹲坑排便年限长（OR=1．021-1．077），体质量高（OR=1．048—1．073），和开始饮酒年龄大（OR=1．008～1．028）；而从事专职体育运动（OR=1．651，西安），骨质疏松病史（OR=3．311，石家庄），吸烟（OR=2．654，石家庄），类风湿关节炎病史（OR=4．964，上海），文化程度高（OR=2．593，上海），女性（OR=2．510，广州），姐妹骨关节炎史（OR=13．251，哈尔滨），母亲骨关节炎史（OR=5．683，成都）等危险因素分别在不同地区出现． 结论：年龄大、使用蹲坑排便年限长、体质量高和开始饮酒年龄大是中国六地区膝关节骨性关节炎患病的共同危险因素，同时，不同地区主要危险因素又有一定差异。     

广地龙中促进子宫收缩的成分

本文研究了自广地龙中提出来的一种引湿性、淡黄色針状結晶(含量約0.2%)对平滑肌器官(特别是对子宮)的作用。介紹了該結晶的提取方法。該結晶0.1毫克加入25毫升Locke液中,能使已孕和未孕大鼠或豚鼠离体子宮角紧张度明显升高,0.3毫克可使之呈痙攣收縮状态。按1毫克/公斤給已孕和未孕麻醉家兔靜脉注射后15—30分钟,在位子宮紧张度升高,作用維持1.5—3小时。按8—10毫克/公斤注射,子宮紧张度立卽升高和血压急剧下降到零而死亡。9只慢性子宫瘻家兔靜脉注射(3—6毫克/公斤)或灌胃給药(10—20毫克/公斤)后15—45分钟,子宮收縮明显增强,作用維持1.5—3小时(注射給药)和7小时以上(灌胃給药)。多数实驗家兔在子宮兴奋同时有排便現象。該結晶对家兔在位腸管和大鼠后肢血管均有强烈兴奋作用,但对豚鼠支气管肌作用极弱。当給小鼠靜脉注射时,LD₅₀为38.7毫克/公斤。