米诺环素对压力作用下体外培养视网膜神经细胞凋亡的抑制

目的 观察米诺环素对压力系统作用下大鼠视网膜神经细胞(RNs)的活性及凋亡的影响，探讨其对受损RNs保护的可能机制。 方法 制备大鼠RNs体外加压培养模型，通过细胞形态学观察、四唑盐（MTT）比色法测定细胞活力、吖啶橙/溴化乙锭（AO/EB）染色法检测细胞凋亡率等方法观察不同浓度的米诺环素对上述损伤细胞的保护作用，并用免疫细胞化学法观察iNOS和caspase 3表达的改变。 结果 加压培养后RNs与对照组相比形态改变较明显，细胞活力降低，5393%的细胞发生凋亡。20000 μmol/L的米诺环素治疗组则细胞形态改善，活力显著增高，1729%的细胞发生凋亡；免疫细胞化学法显示细胞内iNOS和caspase-3表达较加压损伤组减少。 结论 一定剂量的米诺环素在体外可有效抑制压力引起的大鼠RNs损伤及凋亡；抑制iNOS和caspase-3的表达可能是其潜在作用机制。     

2例丙肝患者伴发获得性大疱性表皮松解症

作者报道2例确诊的慢性丙肝病毒感染患者合并获得性大疱性表皮松解症（EBA）。两例患者临床上均表现为典型EBA，包括皮肤脆性增加及自发和继发于外伤后发生皮肤水疱，继而以粟丘疹和瘢痕愈合。EBA常常是一种免疫状态改变或低下的疾病。还需进一步研究在这两例患者中和一般情况下丙肝病毒是否诱发EBA。     

Prolonged cardioselective blockade of beta-1 adrenoreceptors in combination with increased diuresis as a method of choice in the treatment of hypertension]

The clinical effects of Tenoric, a long-acting combined drug (atenolol and chlorthalidone in a tablet), were studied in 31 patients with Stages I and II hypertensive disease, by using echocardiography, daily automatic blood pressure monitoring, bicycle ergometry, measurements of plasma renin and aldosterone. The drug was found to be highly clinically effective in labile and sustained hypertension. When given once or twice a day, it makes it possible to reliably monitor blood pressure, improve hemodynamic parameters, as reflected by lower cardiac output and decreased peripheral vascular resistance, reduce the estimated mass of the left myocardium, alleviate a pressor response to exercise and enhance its tolerance, lower plasma renin levels. The side effects of the drug are minimal and include moderate bradycardia. Peripheral vasospasm and systemic weakness were observed in single cases. There were no atherogenic changes in lipid spectrum and disturbed glucose and uric acid metabolism during the drug therapy.     

血清低密度脂蛋白胆固醇直接测定与Friedewald公式计算结果比较

采用聚乙烯硫酸（ＰＶＳ）沉淀法测定血清低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）值，同时应用Ｆｒｉｅｄｅｗａｌｄ公式计算ＬＤＬ－Ｃ含量，并对两法结果进行比较分析，提出当甘油三脂（ＴＧ）＜４．５２ｍｍｏｌ／Ｌ时，Ｆ公式计算法可代替ＰＶＳ法，当ＴＧ＞４．５２ｍｍｏｌ／Ｌ时，不宜用Ｆ公式计算ＬＤＬ－Ｃ的值。     

Dose-Response Characteristics of Spinal Bupivacaine in Volunteers: Clinical Implications for Ambulatory Anesthesia

Background: Small doses of bupivacaine may be a reasonable choice for spinal anesthesia for patients having ambulatory surgery. However, few dose-response data are available to guide the selection of reasonable doses of bupivacaine for different ambulatory procedures.

Methods: Eight volunteers per group were randomized to receive 3.75, 7.5, or 11.25 mg of 0.75% bupivacaine with 8.25% dextrose in a double-blind manner. Sensory block was assessed with pinprick, transcutaneous electrical stimulation equivalent to surgical incision at the ankle, knee, pubis, and umbilicus, and with duration of tolerance to pneumatic thigh tourniquet. Motor block at the quadriceps and gastrocnemius muscles was assessed with isometric force dynamometry. Times until recovery from spinal anesthesia were recorded. Dose-response relationships were determined by linear regressions. Mean (95% confidence intervals) for durations of sensory and motor block per milligram of bupivacaine administered were calculated from linear regressions.

Results: Significant dose-response relationships (P < 0.006) were determined for sensory block, motor block, and time until recovery (R from 0.6 to 0.9). Within the range of doses studied, each additional milligram of bupivacaine was associated with an increase in duration of tolerance to transcutaneous electrical stimulation of 10 (7 to 13) min, an increase in tolerance to tourniquet of 7 (2 to 11) min, an increase in duration of motor block of 8 (5 to 12) min, and an increase in time until recovery of 21 (17 to 25) min.     

The effect of various anaesthetics on the spatial tuning of two major wave peaks in the transient pattern electroretinogram of the cat: evidence for pattern and luminance components

The main PERG component of the transient contrast reversal pattern electroretinogram (PERG) in cats was a negative wave (3.5 microV average, SD 1.7 microV) peaking at about 130 msec (N130) with a spatial resolution above 5.5 c/deg, close to behavioural estimates. The early positivity (P35) was more variable, smaller and had lower spatial resolution. Different anaesthetic protocols affected both the waveform and the amplitude by spatial frequency functions. Responses of urethane anaesthetised cats were like those reported previously for decerebrate cats or cats paralysed and ventilated with N2O/O2/CO2 (75%/24%/1%). P35 was evoked only by coarse stimuli and N130 amplitude decreased linearly as spatial frequency increased. When the luminance response amplitude, predicted from the optical transfer function of the eye, was subtracted, spatial tuning appeared. An anaesthetic mixture of ketamine hydrochloride and xylazine depressed both P35 and N130 at low spatial frequencies while enhancing them at high frequencies. In paralysed animals ventilated with N2O/O2 (67%/33%) P35 was larger and recordable to 1.6 c/deg. Peak times were reduced and the inter-peak time halved. Other anaesthetics depressed the ERGs. These effects suggest that cats are a good model for studying N130 in isolation or its interaction with P35 and that both PERG peaks include luminance and pattern components.