大鼠移植胰腺冷缺血再灌注后细胞凋亡的变化

目的　探讨移植胰腺冷缺血再灌注后胰腺细胞凋亡的变化过程。方法　 6 5只SD大鼠随机分成 7组 :假手术组 ,冷缺血 2h组 ,冷缺血 2h再灌注 1、3、6、9、12h组。通过HE染色后光镜及电镜观察各组的胰腺组织的病理变化 ;采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)检测凋亡细胞的分布及计数。结果　胰腺移植后早期即可观察到细胞凋亡的典型改变 ,胰腺冷缺血再灌注后发生凋亡的高峰期为再灌注后 3h[AI为 (9.4 6± 2 .91) % ,P <0 .0 1) ,再灌注 6h较 3小时细胞凋亡有所减少 [AI为 (5 .74± 1.6 6 ) % ,P <0 .0 1],再灌注 9h及 12h细胞凋亡进一步减少 [AI分别为 (3.6 0± 1.6 4 ) %及 (3.2 6± 1.35 ) % ,P <0 .0 5 ]。结论　细胞凋亡是胰腺移植后的早期事件 ,移植胰腺冷缺血再灌注后早期主要的死亡方式是凋亡 ;移植胰腺冷缺血再灌注后的凋亡高峰发生在再灌注后 3h。     

~99m锝-葡聚糖淋巴系统显像剂研制及其初步临床应用

作者采用沉淀法对药用葡聚糖进行分级纯化,通过家兔实验筛选出合乎淋巴系统定向要求分子量(105000)的葡聚糖,并制成一步标记法的亚锡葡聚糖药盒,4℃贮存8个月,标记率大于95％。~(99)m锝-葡聚糖的体内外稳定性均佳。家兔研究表明:(1)淋巴结内聚集量最高,其他非靶器(除肝脏、肾脏外)均处于极低水平;(2)显像速度快、图像清晰,既显示淋巴结又显示淋巴管;(3)注射部位清除速度快,6.5h清除95％。安全试验表明:~(99)m锝-葡聚糖是一种毒性极低、非常安全的药物。临床试用100余例,均获满意图像,检查全过程1h内完成,检查结果与诊断基本相符,故~(99)m锝-葡聚糖是目前临床上比较理想的淋巴系统显像剂,可进一步推广应用。     

Inhibitory effects of benzoate on chiral inversion and clearance of N(G)-nitro-arginine in conscious rats.

N(G)-nitro-arginine (NNA) is known to exhibit stereoselective pharmacokinetics in which N(G)-nitro-d-arginine (d-NNA) has a faster clearance rate than N(G)-nitro-l-arginine (l-NNA) in anesthetized rats, and d-NNA undergoes unidirectional chiral inversion. It was postulated that chiral inversion of d-NNA was performed in a two-step pathway by d-amino acid oxidase (DAAO) followed by an unidentified transaminase. Such chiral inversion contributes (at least partially) to the pharmacokinetic stereoselectivity of NNA. This study used the selective inhibitor of DAAO, sodium benzoate, to test the above hypothesis. An i.v. bolus injection of d-NNA (32 mg/kg) and l-NNA (16 mg/kg) in conscious rats exhibited biphasic disposition with different pharmacokinetic parameters in a stereospecific manner (approximately 5-10-fold differences). Unidirectional chiral inversion of d-NNA but not l-NNA was found from these animals. In addition to its similar inhibitory effects on the d-NNA conversion and DAAO activity in kidney homogenates, sodium benzoate completely blocked chiral inversion of d-NNA and led to a smaller stereospecific difference, reflected by a nearly 50% reduction of d-NNA clearance and a 2-fold increase in t(1/2) and area under the curve of d-NNA in benzoate-pretreated rats. The results suggest that DAAO plays an essential role in chiral inversion of d-NNA and chiral inversion contributes mostly to the pharmacokinetic stereospecificity of NNA.     

备劳特联合爱喘乐雾化吸入治疗儿童哮喘急性发作的疗效观察

目的 :观察氧雾化吸入备劳特和爱喘乐治疗儿童哮喘急性发作的疗效。方法 :选择 15 8例哮喘急性发作患儿作为研究对象 ,分为观察组和对照组。观察组采用氧驱动雾化吸入备劳特和爱喘乐 ;对照组静脉滴注氨茶碱和地塞米松。结果 :观察组显效率 87.3% (96 /110 ) ,总有效率 99.1% (10 9/110 ) ,临床治愈率 94 .5 % (10 4 /110 ) ;对照组显效率 2 2 .9% (11/48) ,总有效率 6 0 .4 % (2 9/48) ,临床治愈率 5 4 .2 % (2 6 /48)。观察组显效率、总有效率及临床治愈率皆显著高于对照组 ,差异有高度统计意义 (P <0 .0 1)。观察组治疗后心率较治疗前明显下降 ,差异有统计意义(P <0 .0 5 )。结论 :采用氧驱动雾化吸入备劳特和爱喘乐能快速、有效地控制哮喘发作。     

Glutamate acts at NMDA receptors on fresh bovine and on cultured human retinal pigment epithelial cells to trigger release of ATP

Efficient vesicle membrane recycling at presynaptic terminals is pivotal for preventing depletion and maintaining high firing rates in neuronal networks. We used a new approach, based on the combination of spectrally different optical probes, to investigate how stimulation determines the fate of synaptic vesicles after endocytosis. We found that in the small central synapses of rat hippocampal neurones low frequency stimulation (40 action potentials at 2 Hz) targets vesicles preferentially to vesicle pools that were kinetically faster. Vesicles taken up during endocytosis triggered by high frequency stimulation (400 action potentials, 20 Hz) were also placed in the back of the release queue. We performed a spatial analysis of the recycled vesicles in living hippocampal boutons using two spectrally different FM-dyes (FM1-43 and FM5-95). By using these consecutively, vesicles endocytosed by either stimulation protocol were labelled with a different colour. This revealed that the kinetic arrangement was also reflected in the spatial organization of vesicles within the bouton. Next, we identified the postsynaptic site of the active zone by transfecting the neurones with postsynaptic density protein PSD-95-CFP. The data from these triple colour experiments suggest that retrieval after low frequency stimulation keeps vesicles in a more confined region closer to the active zone as identified by PSD-95-CFP expression at the postsynaptic site.     

Nerve growth factor and tyrosine kinase A in human salivary adenoid cystic carcinoma: expression patterns and effects on in vitro invasive behavior.

PURPOSE: Perineural invasion is a frequent occurrence in salivary adenoid cystic carcinoma (ACC) and may prevent complete surgical resection. Studies have indicated that nerve growth factor (NGF) and its high-affinity receptor tyrosine kinase A (TrkA) may play a role in perineural invasion in several malignancies in which perineural invasion is observed. The present study was conducted to investigate the expression of NGF and TrkA in salivary ACC and to examine the effects of NGF on adhesion, migration and invasion capacities of a salivary ACC cell line (SACC-83) in vitro. PATIENTS AND METHODS: Expression of NGF and TrkA was explored using immunohistochemistry in paraffin-embedded tissues of 32 cases of salivary ACC. The effects of NGF on in vitro adhesion, migration, and invasion capacities of the SACC-83 cell line were examined using an MTT assay and a modified Boyden chamber assay respectively. RESULTS: In ACC specimens, 31 (96.9%) and 32 (100%) tumors showed immunoreactivity for NGF and TrkA respectively. Significant correlations were found between NGF/TrkA expression levels and perineural invasion (P < .05). In cell adhesion assay, the percent adherences of SACC-83 cells co-cultured with 25 ng/ml NGF at 1.5 hours and 5, 25 ng/ml NGF at 6 hours were significantly higher than that co-cultured with 0 ng/ml NGF (P < .05). However, high concentration of NGF (500 ng/ml) resulted in a significant inhibition of invasion (P < .05). CONCLUSION: Overexpression of NGF and TrkA in human salivary ACC tissues may constitute a reason for perineural invasion in salivary ACC.     

清胆汤治疗慢性胆囊炎52例

近3年来，笔者自拟清胆汤治疗慢性胆囊炎52例收到较好效果，现报告如下。     

三种卷烟的成分及其对健康的影响

本文分析了我国高、中、低三种卷烟的成分、致突变性和对人体健康的影响。结果表明,高焦油卷烟含焦油、BaP 和重金属元素均高于中、低焦油的卷烟,其焦油有致突变作用。吸烟者吸三种卷烟后能引起气道阻力。血中COHb%和尿中柯的宁等指标明显升高。吸烟者吸烟时可使其被动吸烟者的COHb%浓度均达有害程度。     

Brain natriuretic peptide enhances the endothelium-independent cAMP and vasorelaxant responses of calcitonin gene-related peptide in rat aorta

Calcitonin gene-related peptide (CGRP) causes vasorelaxation in rat aorta involving endothelium/nitric oxide (NO)-dependent elevations of both cAMP and cGMP levels. When endothelium is removed, preincubation with exogenous NO uncovers and potentiates direct (endothelium-independent) cAMP elevations and vasorelaxations caused by CGRP. This enhancing effect of NO potentially involves elevation of cGMP and inhibition of Type III (cGMPinhibitable) phosphodiesterase, causing accumulation of cAMP. However, NO may have other actions. The aim of the present study was to determine if brain natriuretic peptide (BNP), which elevates cGMP levels independent of NO, could enhance cAMP accumulations and vasorelaxations induced by CGRP in rat aortic rings denuded of endothelium. When added separately, neither CGRP (100 nM) nor BNP (10 nM) altered cAMP levels. When added in combination, CGRP (100 nM) and BNP (10 nM) significantly elevated cAMP levels (from control of 0.95 ± 0.08 to 1.53 ± 0.09 pmol/mg protein) at 2 min. BNP (10 nM) elevated cGMP levels 10-fold at 2 min and this response was not altered by co-administration of CGRP (100 nM).Pretreatment with BNP at concentrations as low as 1 nM in endothelium-denuded aortic rings greatly enhanced the direct vasorelaxant effects of CGRP (100 nM) (from control of 0% to 57.6 ± 6.8% relaxation of phenylephrineprecontractions). Our findings indicate that BNP enhances direct (endothelium-independent) cAMP elevations and vasorelaxations caused by CGRP in rat aorta, thus supporting the concept that cGMP inhibits cAMP metabolism and enhances CGRP-induced responses in aortic smooth muscle cells.