L-精氨酸对随意皮瓣存活影响的临床研究

目的：研究临床随意皮瓣术后,实验组和对照组皮瓣存活情况,一氧化氮（NO）及超氧化物歧化酶（SOD）、丙二醛（MDA）量的变化,探讨和明确L-精氨酸（L-arg）对随意皮瓣的存活有无影响,有何影响？其作用机制是什么等问题.方法：采用随机双盲实验方案,实验组每日给予L-arg15克,对照组每日给予甘氨酸25克,实验共持续7天,在术后24小时拔引流管时取皮瓣组织检测NO、SOD、MDA的含量,术后7天观测两组皮瓣存活长度.结果：实验组术后24小时NO含量高于对照组（P＜0.01）,实验组SOD含量高于对照组（P＜0.01）,而实验组MDA含量低于对照组（P＜0.01）,实验组皮瓣存活比例也明显高于对照组（P＜0.01）.结论：L-arg对随意皮瓣存活有促进作用.其作用机制可能是增加外源性L-arg的量,促进了机体组织中NO的生成,进而使组织中SOD增多,并降低了机体组织中的MDA,改善皮瓣血供,减轻组织缺血,促进了创面愈合,增加了皮瓣存活.以上结果与动物实验一致.     

Monthly Update Oncologic,Endocrine & Metabolic: Prevention of immune dysfunction by dehydroepiandrosterone in ageing,chronic AIDS and leukaemia patients

Serious fungal infections are increasingly common in immunocompromised patients and existing antifungals do not completely satisfy the medical need. The latter have either considerable toxicity, e.g., amphotericin, which is, however, less toxic in lipid formulations, or have limited activity, e.g., azoles. Cell wall acting antifungals are inherently selective and fungicidal; two classes of compounds - nikkomycin Z targeted at chitin synthase, and echinocandin LY 303366 and pneumocandin L-743,872 targeted at α-1,3-glucan synthase - are currently in clinical development.     

芪贞汤对人大肠癌纤维粘连蛋白黏附能力的影响

[目的]探讨扶正解毒活血法中药芪贞汤对人大肠癌高转移细胞株L-10细胞纤维粘连蛋白黏附能力的影响。[方法]通过体外细胞培养法,观察该方对L-10细胞纤粘连蛋白黏附能力的阻碍作用。[结果]芪贞汤对L-10细胞纤维粘连蛋白黏附能力明显抑制,并且显示了芪贞汤高浓度优于低浓度,有明显的浓度依存性;随着时间的推移,其抑制作用在变化,当作用120min时,阻碍作用达到高峰,随后其阻碍作用逐渐减低。[结论]扶正解毒活血法中药芪贞汤对人大肠癌高转移细胞株L-10细胞具有明显的抗纤维粘连蛋白黏附能力的作用,从而提示芪贞汤有可能通过抑制纤维粘连蛋白黏附能力,实现抑制癌的浸润和转移的作用。     

Determination of copper, lead and iron in water and food samples after column solid phase extraction using 1-phenylthiosemicarbazide on Dowex Optipore L-493 resin

A novel solid phase extraction procedure for determination of copper, lead and iron in natural water and food samples has been established in the presented work. 1-Phenylthiosemicarbazide (1-PTSC) as ligand and Dowex Optipore L-493 resin as adsorbent were used in a mini chromatographic column. Various analytical conditions for the quantitative recoveries of analyte ions including pH, amounts of adsorbent, eluent, sample volume, etc. were investigated. The recovery values for analyte ions were higher than 95%. The determination of copper, lead and iron was performed by flame atomic absorption spectrometry. The influences of some alkali, alkali earth and transition metals on the recoveries of analyte ions were investigated. The preconcentration factor was 62.5. The limit of detections of the understudied analytes (k = 3, N = 21) were 0.64 μg L⁻¹ for copper, 0.55 μg L⁻¹ for lead and 0.82 μg L⁻¹ for iron. The relative standard deviation was found to be lower than 6%. The accuracy of the method was confirmed with certified reference material (GBW 07605 Tea). The method was successively applied for the determination of copper, lead and iron in water and some food samples including cheese, bread, baby food, pekmez, honey, milk and red wine after microwave digestion.     

Assessment of naturally occurring covalent and total dimer levels in human IgG1 and IgG2

Antibody dimers, two self-associated monomers, have been detected on both recombinantly expressed and endogenous human IgG proteins. Nearly 10 years ago, Yoo et al. (2003) described low levels of IgG2 covalent dimer, in human serum, but did not quantify the levels. Here we quantify the total and covalent dimer levels of IgG2 and IgG1 in human blood, and study the origin of covalent dimer formation. Low levels (<1%) of total IgG1 and IgG2 dimers were measured in freshly prepared human plasma. Both IgG1 and IgG2 covalent dimers were also found in plasma. Whereas IgG1 covalent dimer levels were significantly reduced by steps intended to eliminate artifacts during sample preparation, IgG2 covalent dimer levels remain stable in such conditions. About 0.4% of IgG2 in plasma was in a covalent dimer form, yet very little (<0.03%) of IgG1 covalent dimer could be considered naturally occurring. IgG2 dimer also formed in vitro under conditions designed to mimic those in blood, suggesting that formation occurs in vivo during circulation. Thus, small amounts of covalent IgG2 dimer do appear to form naturally.     

宫颈上皮内瘤变及早期宫颈癌组织中P16、HPV L-1壳蛋白的表达及与HR-HPV载量相关性研究

目的:探讨宫颈上皮内瘤变(CIN)及早期宫颈癌组织中P16、HPV L-1壳蛋白的表达及与高危型人乳头瘤病毒(HR-HPV)载量的相关性。方法:分别采用免疫组化法和第二代杂交捕获法(hybrid captureⅡ,HC-2)检测26例慢性宫颈炎组织、83例低度鳞状上皮内病变(LSIL)(CINⅠ83例)、109例高度鳞状上皮内病变(HSIL)(CINⅡ49例,CINⅢ60例)、11例早期宫颈鳞癌组织中P16蛋白、HPV L-1壳蛋白的表达及HR-HPV载量,并分析其相关性。结果:1在宫颈癌前病变中随病变级别增高,HR-HPV阳性率增加,差异有统计学意义(P0.01)。各组织学分级中病毒载量分布差异有统计学意义,HSIL(44.95%)及早期宫颈癌组织(63.64%)中皆以低病毒载量(1~100 RLU/CO)为主。从慢性宫颈炎、LSIL、HSIL到早期宫颈癌,P16蛋白阳性表达率分别为11.54%(3/26),55.42%(46/83),85.32%(93/109),100.00%(11/11),差异有统计学意义(P0.01);L-1壳蛋白阳性率分别为15.38%(4/26),28.92%(24/83),14.68%(16/109),0.00%(0/11),差异有统计学意义(P0.05)。2229例宫颈组织中,随HPV载量增加,P16蛋白表达增强;L-1壳蛋白阳性表达率增加,差异有统计学意义(P0.01)。3在慢性宫颈炎组中,P16蛋白阳性表达与HPV载量呈正相关(r=0.491,P0.05)。在LSIL组中,P16蛋白与HPV载量(r=0.459,P0.01)及L1壳蛋白表达(r=0.297,P0.01)皆呈正相关。4在HSIL及早期宫颈癌组中,P16蛋白、L-1壳蛋白表达与HPV载量三者之间无明显相关性(P0.05)。结论:P16、HPV L-1壳蛋白异常表达是宫颈癌前病变发生发展的早期分子事件,对判断CINⅠ有参考价值,可能比HR-HPV载量更具有预测价值。     

Cell-cycle-dependent changes in membrane potential of L-929 cells caused by the effect of hydrogen peroxide

 The changes in membrane potential of L-929 fibroblasts caused by H₂O₂ (10–50 μM) at different phases of the cell cycle were investigated. The membrane potential of cells in G0, early G1, and G2/M responded to H₂O₂ by hyperpolarizing, while cells in late G1/S responded by depolarizing. Quinidine (50 μM), a blocker of Ca²⁺-dependent K⁺ conductance, inhibited the hyperpolarization response of L-929 cells to H₂O₂ in all cases. Measurements of reactive oxygen species (ROS) production by the cells at the same cell cycle phases indicated that the hyperpolarization response of the cells is linked with minimal production of ROS, and that the depolarization response is associated with maximal production of ROS inside the cell. Received: 5 February 1999 / Received after revision and accepted: 3 March 1999     

Effect of cholecystokinin octapeptide antagonists on the extinction of an active avoidance task in the rat

Cholecystokinin octapeptide (CCK-8) has been shown to be involved in memory processes. For example, in the absence of endogenous CCK-8 in the brain, memory processes are imparied. In order to extend the understanding of this relationship, the present study observed the effect of novel potent CCK-8 antagonists, L-364,718 and CR 1409, on active avoidance responding in the rat. These antagonists caused marked impairment in the performance of the learned task when administered intracerebroventricularly immediately after the learning trials. The results suggest that CCK-8 is indispensable for memory processes.