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)     

Therapy of human cervical carcinoma with monoclonal antibody-Pseudomonas exotoxin conjugates.

Pseudomonas exotoxin A (PE) linked to the F(ab')2 fragment of 1H10, a murine monoclonal antibody recognizing a carbohydrate epitope of a glycoconjugate expressed on the surface of human cervical carcinoma tumor cells, was evaluated for in vitro and in vivo activity. PE can kill cells by ADP-ribosylating elongation factor 2 thus inhibiting protein synthesis. Disulfide- as well as thioether-linked immunotoxins (1H10-PE) killed cervical carcinoma cells in vitro and were 20-160 times more inhibitory to target than to control cells. Cell killing was antibody mediated as demonstrated by the reduction of 1H10-PE growth inhibition to target CaSki cells by free 1H10 F(ab')2. In addition, a control antibody immunotoxin was nontoxic to CaSki cells. Thioether-linked 1H10-PE administered either i.v. or i.p. suppressed the growth of established solid s.c. cervical carcinoma tumors xenografted in nude mice for over 30 days. Treatment with antibody alone or a control immunotoxin had no significant effect on tumor growth. Administration of immunotoxin i.p. was associated with less toxicity than administration i.v., but i.v. injections were more effective at suppressing the growth of established solid tumors.     

Ischemic rat brain extracts induce human marrow stromal cell growth factor production

Intravenous administration of human bone marrow stromal cells (hMSCs) after middle cerebral artery occlusion (MCAo) in rats provides functional benefit. We tested the hypothesis that these functional benefits are derived in part from hMSC production of growth and trophic factors. Quantitative sandwich enzyme‐linked immunosorbent assay (ELISA) of hMSCs cultured with normal and MCAo brain extracts were performed. hMSCs cultured in supernatant derived from ischemic brain extracts increased production of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). These neurotrophins and angiogenic growth factors increased in a post‐ischemia time‐dependent manner. The hMSC capacity to increase expression of growth and trophic factors may be the key to the benefit provided by transplanted hMSCs in the ischemic brain.     

烹调油烟致大小鼠肺癌的实验研究

[目的]了解烹调油烟（cooking oil fumes，COF）的动物致癌性。[方法]采用动式染毒法给Balb／c小鼠（雌雄各半）吸入COF浓度为9．09、20．65、38．85mg／m^3，染毒1次／1～2d，30min／次，共150次，计8个月；SD大鼠（雌雄各半）吸入COF浓度为6、88、15．06、35．33mg／m^3，染毒1次／2d，30min／次，共191次，计12．5个月。分别制备COF慢性中毒动物模型；两实验均设空白对照组，吸入与实验组相同温度的清洁空气。[结果]COF诱发Balb／c小鼠实验组肺癌总发生率为18、95％（29／153），低、中、高浓度组肺癌发生率分别为15．09％、20、00％和22．00％，与对照组差异均有显著性。但低、中、高三组间差异无显著性（P〉0．05）；COF诱发SD大鼠肺癌总发生率为9、10％（9／99），低、中、高浓度组肺癌发生率分别为6．45％、8．57％、12．12％，高浓度组肺癌发生率高于对照组（P〈0．05）。各性别组间肺癌发生率的差别无显著性（P〉0．05）。[结论]COF可以诱导Balb／c小鼠和SD大鼠肺癌，诱发的肺癌主要为肺腺癌（小鼠28／29，大鼠7／9），余为小细胞肺癌。     

善存片联合健脾理气中药预防肿瘤患者化疗所致口腔溃疡的临床观察

目的观察在全身化疗前应用善存片联合健脾理气中药对肿瘤患者口腔溃疡的预防作用。方法将66例肿瘤患者随机分配为治疗组和对照组，每组33例。在全身静脉化疗前3天开始，治疗组每天口服善存片1片及健脾理气中药1剂，对照组服用维生素B：治疗，两组服药化疗后10天为1个疗程。每周期化疗结束后统计口腔溃疡的发生率，共4周期。结果治疗组口腔溃疡的发生率显著降低（P〈0．01）。结论善存片联合健脾理气中药可有效预防及治疗肿瘤患者化疗所致的口腔溃疡。     

成人成骨细胞与珊瑚羟基磷灰石的体外生物相容性

目的：研究成人骨髓成骨细胞与珊瑚羟基磷灰石（carolline hydroxyapatite,CHA)在体外培养条件下的生物相容性。方法：抽取健康成人骨髓组织，置于含体积分数为10％胎牛血清的DMEM培养基中培养，传代后改用含地塞米松、β-甘油磷酸钠和维生素C的条件培养基培养，分为CHA复合细胞组和单纯细胞组，不同时间用倒置相关显微镜，HE染色光镜及扫描电镜观察，MTT法进行细胞增殖测定，并进行细胞微量蛋白含量和碱性磷酸酶的定量检测，结果：成人骨髓成骨细胞体外培养时复合或不复合CHA均生长良好，表现出典型成骨细胞的形态特征和生物学特性，CHA利于细胞的贴附，生长与增殖，并对细胞的功能无不良影响，结论：CHA是较理想的骨组织工程支架材料，成骨细胞复合CHA用于骨缺损的修复，具有广阔的临床应用前景。     

VEGF在膀胱移行细胞癌中的表达及意义

目的：探讨膀胱移行细胞癌中血管内皮生长因子（VEGF）的表达及其与临床病理指标的关系。方法：应用免疫组化方法对40例膀胱移行细胞癌及15例正常膀胱组织中VEGF进行检测。结果：正常膀胱移行上皮均为阴性表达；膀胱移行细胞癌中VEGF阳性表达24例，表达率为60％（24／40），明显高于正常膀胱组织（P＜0.01），其中VEGF表达阳性率随膀胱癌病理分级、临床分期上升而升高，表达强度也随之增强（P＜0.01）。结论：VEGF表达对膀胱移行细胞癌生物学行为有重要影响，VEGF有可能可作为判断膀胱癌生物学行为、转移潜能及预后指标。     

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.     

刘昌国教授治疗高位复杂性肛瘘经验谈

刘昌国教授，曾任新疆医科大学附属中医医院肛肠科主任，从事肛肠疾患临床研究逾四十余年，第二批名老中医学术继承专家，对于肛肠科疑难病治疗颇具心得，疗效卓越。今撷取其一加以整理记录，以飨同道。高位复杂性肛瘘是肛肠科的一种疑难病，指瘘道越过外括约肌深部以上，有两个以上外口，手术操作复杂，术中容易损伤肛门括约肌，造成肛门功能障碍，同时，术后也容易复发。自2004年2月至今，从师刘昌国老师，共诊治高位复杂性肛瘘患者12例，现分析如下：     

赤芍总苷对沙土鼠全脑缺血再灌注损伤的保护作用

OBJECTIVE: To study the protective effects of the total paeony glycoside (TPG) against global cerebral ischemia-reperfusion injury in gerbils. METHODS: Gerbils models of global cerebral ischemia-reperfusion injury were prepared by bilateral common carotid artery ligation for 12 min followed by 24-hour reperfusion. The effects of TGP on brain edema index, superoxide dismatase (SOD) activity and malonaldehyde (MDA) concentration of the cerebral tissue homogenate and pathology of the brain were examined 24 h after model establishment. RESULTS: Compared with the model group, TPG at the doses of 200 and 400 mg/kg could significantly relieve brain edema, enhance SOD activity and lower MDA concentration in the gerbils. Pathological examination showed that the gerbils with TPG treatment had milder injury of the cells in the hippocampal CA1 region. CONCLUSIONS: TPG has obvious protective effects against global cerebral ischemia-reperfusion injury.