Differential effects of the pyrethroid tetramethrin on tetrodotoxin-sensitive and tetrodotoxin-resistant single sodium channels

The differential effects of the pyrethroid tetramethrin on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) single sodium channel currents in rat dorsal root ganglion (DRG) neurons were investigated using the outside-out configuration of patch-clamp technique. Channel conductances were 10.7 and 6.3 pS for TTX-S and TTX-R sodium channels, respectively, at a room temperature of 24–26°C. The single-channel current of TTX-S sodium channels at the test potential of −30 mV was −1.27 ± 0.25 pA, and was not changed after exposure to 10 μM tetramethrin (−1.28 ± 0.23 pA). The open time histogram of TTX-S single-channel currents could be fitted by a single exponential function with a time constant of 1.27 ms. After exposure to 10 μM tetramethrin, the open time histogram could be fitted by the sum of two exponential functions with time constants of 1.36 ms (τ_fast) and 5.73 ms (τ_low). The percentage of contribution of each component to the population was 62% for the fast component representing the normal channels and 38% for the slow component representing the tetramethrin modified channels. The amplitudc of TTX-R single-channel currents was slightly changed from −0.72 ± 0.14 to −0.83 ± 0.07 pA by 10 μM tetramethrin. The open time histogram of TTX-R single-channel currents could be fitted by a single exponential function with a time constant of 1.92 ms. In the presence of 10 μM tetramethrin, the open time histogram could be fitted by the sum of two exponential functions with time constants of 2.07 ms (τ_fast) and 9.75 ms (τ_slow). The percentage of contribution of each component was 15% for the fast, unmodified component and 85% for the slow, modified component. Differential effects of tetramethrin on the open time distribution of single sodium channel currents explains the differential sensitivity of TTX-S and TTX-R sodium channels.     

顺丁烯二酸水溶液的热反应动力学

研究了不同温度、浓度条件下，顺丁烯二酸（顺酸）非催化反应网络，即顺酸可生成反丁烯二酸（反酸）和苹果酸，反酸与苹果酸存在可逆反应。建立了该反应网络的动力学模型。测定了不同反应条件下顺酸、反酸和苹果酸浓度随时间变化的规律，据此，动力学参数进行了估值。     

Onychomycoses due to Microascus cirrosus (syn. M. desmosporus)

Microascus cirrosus is very rarely the aetiological agent of onychomycosis. We report two additional cases of toenail infections caused by this fungus.     

人工心脏起搏器的植换

探讨人工心脏起搏器植换方式选择。方法：起搏器植换２２例，其中，能源耗竭１４例，感知和起搏功能障碍４例，囊袋感染破溃致ＰＭ外露４例。非感染者起搏阈值，〈２．５Ｖ，行原位植换：ＰＴ值〉３．０Ｖ或有感染者，更换全套起搏系统。结果：非感染的１８例中，１０例ＰＴ〈２．５Ｖ，实行原位植换；８例ＰＴ值〉３．０Ｖ和其余４例有感染者，植入新的起搏系统。     

Gemfibrozil in the treatment of hyperlipidemia

An elevated serum cholesterol level is a well known major risk factor for developing atherosclerosis in general, and for coronary heart disease in particular. There are many lipid lowering agents currently available. We used gemfibrozil in twenty hyperlipidemic cases who failed to response to diet control for three months. They were thirteen males and seven females with their ages ranging from thirty to eighty-one year-old. They included ten diabetes, one nephrotic syndrome and nine pure hyperlipidemic patients. All cases received gemfibrozil 600mg twice daily for 4-12 weeks. Gemfibrozil caused an increase in HDL cholesterol. The reductions in serum level of total cholesterol, total cholesterol/HDL cholesterol, and triglyceride were found. Only one case developed mild gastrointestinal side effect. There was no other major side effects.     

Fall prevention exercise program for fall risk factor reduction of the community-dwelling elderly in Korea

A randomized comparison of pre-and post-experimental design was used to examine the effects of a fall prevention exercise program (FPEP) on muscle strength, ankle flexibility, balance, instrumental activities of daily living (IADLs), and depression for the community-dwelling elderly in Korea. Twenty-two subjects were assigned to an experimental group and twenty-three to a control group. The experimental group participated in a 4-day-per week FPEP of 8 weeks duration, twice a week by direct instruction and twice a week with videotaped instruction by the program instructor at each senior center. The eight-week FPEP turned out to be significantly effective in enhancing muscle strength, ankle flexibility and balance, and in reducing depression, after intervention among community-dwelling elderly in Korea. IADLs, however, was not changed by the intervention. Further research with a larger sample and longer follow up period is needed to expand our understanding about the effects of FPEP. Future study is also recommended to differentiate between the effects of FPEP by direct instruction and by videotaped.     

Rat sponge implant model: a new system for evaluating angiogenic gene transfer

Therapeutic angiogenesis, either by protein injection or gene therapy, holds considerable promise for the treatment of coronary and peripheral artery diseases. Given the large number of angiogenic genes available, a simple, well defined, standard system to compare the relative angiogenic efficacy of such genes would be valuable. We have employed a replication-deficient adenovirus vector (complete E1a-, partial E1b- and partial E3-) to deliver the beta-galactosidase (beta-gal, AdLacZ) reporter gene or the human VEGF121 gene (AdGV VEGF121.10) to a rat sponge implant model of angiogenesis. beta-gal staining results reveal a transfection efficiency as high as 60% 24 h after 2x1010 particle units AdLacZ injection. Our results also indicate that a single injection of 2x1010 particle units of AdGVVEGF121.10 in the sponge results in >10, 000 pg VEGF protein expression per milligram of sponge tissue 24 h later. VEGF121 protein concentrations decreased 10-fold within 3 days and 100-fold within 7 days after injection. Significant VEGF121 protein levels were still detectable 14 days after initial virus injection. The high level of gene transfection efficiency was accompanied by enhanced angiogenesis in the sponge, a tissue devoid of any vessels before implantation. Compared to control (AdNull: adenovirus vector without the VEGF gene), AdGVVEGF121.10 induced a 2- to 3-fold up-regulation of angiogenesis at 7 and 14 days post vector injection as determined by both increased capillary number and increased tissue ingrowth. The angiogenic effects of AdGVVEGF121. 10 were dose-related in this model system. These findings demonstrate a dose-related angiogenic response to adenovirus-mediated gene therapy in this model.     

培养细胞整装内质网三维结构的多态性

用高锰酸钾－锇酸固定法制备了５种培养细胞整装内质网标本，并在扫描电镜下对其三维结构进行了观察。观察结果表明内质网是由膜性小管构成的贯穿整个细胞质的管囊网络样膜性区室，并以多种形态深入到细胞伪足及突起中；细胞质中内质网则表现为簇状网络（见于ＧＣＭ３Ｔ３细胞）、多态性多孔扁囊样网络、筛网状网络、条索状网络、大孔条索网状和细孔扁囊样分区网络、不规则管网状和多孔管囊分区网络（见于ＣＶ－１细胞）、细管网络（见于ＣＣＬ１８７和ＣＣＬ２２９细胞）、球囊网络（见于ＣＣＬ１８７和Ａ４３１细胞）和不规则管网状网络（见于Ａ４３１细胞）等。内质网的这种多态性提示它是一种高度可变的结构，其可变性可能与细胞特性、分化程度、细胞功能状态及细胞骨架系统的分布变化等因素有关。