Intracellular Ca2+ suppressed a transient potassium current in hippocampal neurons

The effects of intracellular Ca2+ (Ca2+i) on K+ currents in hippocampal cells were examined using acutely isolated cells obtained from adult guinea pigs. Whole-cell voltage-clamp recordings were carried out in a configuration that allowed a continuous perfusion of the intracellular medium. Recording media were made to block inward currents and allowed selective activation of K(+)-dependent outward currents. Voltage-dependent outward currents consisted of an initial rapidly decaying component followed by a sustained component. The time constant of decay of the transient current was about 25 msec, and previous studies (Numann et al., 1987) showed that the kinetic and pharmacological properties of this current closely resembled the A current recorded in invertebrate neurons (Connor and Stevens, 1971; Thompson, 1982). Intracellular perfusion of hippocampal cells with a solution containing elevated Ca2+ (about 4.5 x 10(-4) M) elicited outward currents at the holding potential (-45 to -55 mV) and produced changes in voltage-dependent K+ currents. The transient outward current (IA) activated by depolarization was suppressed with increases in Ca2+i. Delayed, sustained K+ currents were greatly potentiated. Data also showed that, among the 3 effects elicited by Ca2+i, suppression of IA was most sensitive to Ca2+i elevation. Previous results (Numann et al., 1987) showed that IA had a lower threshold (about -45 mV) than sustained currents (about -40 mV). By using low levels of depolarization (-40 mV), IA can be selectively activated, and the suppressive effect of Ca2+i on IA was confirmed on the kinetically isolated IA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Persistent reversal of diabetes by transplantation of fetal pig proislets into nude mice

Facing the limited availability of human adult and fetal pancreases, fetal pig proislets (pancreatic islet precursors) were investigated in view of several inherent advantages. Six litters of fetuses of mean +/- SE gestational age 75 +/- 3 days were obtained from commercially available farm pigs. Pancreatic tissue was gently digested with collagenase, then a 10-day culture was performed. During culture, fetal proislets showed no insulin response to glucose alone but a significant response to glucose plus theophylline. The insulin content per microgram of DNA in the cultured proislets continuously increased. Histological examination by immunoperoxidase staining showed that, apart from single insulin- and glucagon-positive cells, there were no discrete islets in the pancreatic tissue and the cultured proislets. Diabetes was induced with streptozocin (STZ) in eight nude mice 3-4 wk after proislet transplantation and in another eight nude mice without transplantation. During the initial week, blood glucose levels of mice in both groups increased rapidly. The mean +/- SE peak value of blood glucose levels in the transplanted group was 20.4 +/- 2.0 mM and was 20.1 +/- 1.3 mM in the group without transplantation. Simultaneously, body weight decreased from 29.5 +/- 0.7 to 21.5 +/- 0.9 g and from 27.9 +/- 0.7 to 19 +/- 1 g in the groups, respectively. Afterward, blood glucose levels of mice in the transplanted group gradually decreased, and normoglycemia was achieved in all mice within 50 +/- 13 days after injection of STZ, i.e., 74 +/- 13 days after transplantation. The group without transplantation persistently maintained blood glucose levels greater than 16.7 mM.(ABSTRACT TRUNCATED AT 250 WORDS)     

保留肾单位手术治疗早期小肾癌21例临床分析

OBJECTIVE: To evaluate the clinical effects of nephron-sparing surgery in patients with early-stage small renal cell carcinoma. METHODS: Nephron-sparing surgery was performed in 21 patients with renal cell carcinoma including 1 with solitary kidney, 3 with unilateral tumor and contralateral renal compromise, and 17 with unilateral tumor and normal contralateral kidney. The diameter of the tumors ranged from 1.5 to 6.0 cm, with a mean of 2.8 cm. The tumor diameter in 17 patients with normal contralateral kidney was less than 4 cm (mean 2.5 cm) and the average diameter in 4 patients with contralateral renal compromise was 4.2 cm. Sixteen cases were in stage T(1), 4 in stage T(2), and 1 in stage T(3). Of the 21 patients, 4 underwent tumor enucleation, 10 polar nephrectomy and 7 wedge resection. RESULTS: All patients were followed up for an average of 40.8 months (7 to 66 months). One patient suffered a right lung and mediastinum metastasis 3 years after the surgery later and 1 with chronic glomerulonephritis required dialysis 27 months after the operation. No surgical complication or local recurrence were found in other patients. CONCLUSION: As a safe and effective therapy for early-stage small renal cell carcinoma, nephron-sparing surgery can be considered as the gold-standard therapy for patients with lesions less than 4 cm in T(1) and T(2) stages of localized unilateral tumor with normal contralateral kidney.     

外伤性延迟性脾破裂的诊断和治疗（附21例报告）

目的探讨外伤性延迟性脾破裂的发病规律、临床特点、诊断和治疗方法。方法结合国内外资料及本组病例进行回顾性分析。结果明确诊断16例，误诊为肝破裂2例，宫外孕破裂2例，脾肿瘤1例。21例均手术治疗，行脾切除14例，其中保留副脾2例；脾切除加自体脾组织网膜内移植术3例；脾缝合修补术3例；脾部分切除术1例。死亡1例，原因有就诊晚、失血性休克。结论本病由于腹腔内出血与受伤时间间隔长，容易误诊。诊断除依靠病史、临床表现外，应及时进行腹腔穿刺、B超及CT检查。治疗以脾切除为主，可根据病情、脾破裂的程度以及是否有合并伤等情况采取保脾手术。     

从产业组织学角度看中国医疗广告

随着医疗卫生体制改革的全面推行,医疗行业竞争日趋激烈,众多医院采取不同的策略组合以提高其核心竞争力,而广告正是其主要的营销策略之一.本文在对医疗广告特性、类别、作用进行分析的基础上,从产业组织学角度阐述了医疗广告与医疗市场结构、市场效益的关系,提出了中国医疗广告的发展趋势.     

Controlled release of lidocaine hydrochloride from the surfactant-doped hybrid xerogels.

We investigate the controlled release of lidocaine hydrochloride from the doped silica-based xerogels. In the xerogel preparation, tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), and propyltriethoxysilane (PTES) are used as precursors, and a nonionic surfactant Igepal CO 720 is used as a dopant. The experimental results suggest that the release of lidocaine hydrochloride can be easily controlled by partially substituting TEOS with the organosilanes, and/or by adding the dopant. Adding the organosilane precursors lowers the release of both the drug and the surfactant in the order of TEOS, MTES/TEOS, and PTES/TEOS xerogels. The release from the PTES/TEOS xerogels is much lower than that from the other xerogels. The release of lidocaine hydrochloride is obviously suppressed by the addition of Igepal CO 720, while the release of Igepal CO 720 is slightly promoted by the addition of the drug. The overall release process is found to be diffusion-controlled, and the release behaviors can be well explained by considering the effects of the textual properties of the xerogels and the interactions among the drug, the surfactant, and the xerogel matrices.     

对加强药品配送机构监督管理的思考

国家食品药品监督管理局在《关于全面开展加强农村药品监督网络建设促进农村药品供应网络建设工作的指导意见》中明确指出：“为配合药品配送、连锁进县到乡，各省（区、市）食品药品监督部门可以进行建立区域性药品配送站的研究和指导。在进行研究和探索过程中，鼓励将基层的药品批发企业改组成区域性药品配送站”。     

岗前标准预防教育对减少护生针刺伤的效果观察

岗前培训有助于提高护士技能[1]。医务人员由于职业原因引起可能致命感染(乙型肝炎、丙型肝炎、艾滋病),感染者多数为护士或临床实验工作者,暴露方式主要为暴露于病人的血液,多为针刺伤[2]。而实习护士自我防护意识不足,操作生疏,发生针刺伤比率大,约40.3%[3]。标准防护主张医护人员要严格执行消毒隔离制度和操作规程,充分利用各种屏障防护用具和设备,减少各种危险行为,最大限度地保护医护人员和病人安全。我院从2001年7月起对实习护生进行上岗前标准防护知识及操作培训,现报道如下。1材料与方法1.1研究对象2001年7月—2003年5月,来我院进行…