Inhibition of glucuronidation of benzo(a)pyrene phenols by long-chain fatty acids

Long-chain fatty acids inhibit glucuronidation of benzo(a)pyrene phenols in perfused liver; therefore, this study was designed to investigate interactions of fatty acids with beta-glucuronidase, glucuronosyl transferase, and energy supply. In beta-glucuronidase-deficient C3H/He mice, infusion of oleate (250 microM) increased the release of free benzo(a)pyrene phenols from 14 to 33 nmol/g/h and decreased release of glucuronides into the perfusate from 25 to 17 nmol/g/h. Rates of accumulation of glucuronides in the liver were also diminished from 11 to 4 nmol/g/h after infusion of oleate (250 microM). Fatty acids did not affect the release of benzo(a)pyrene metabolites into bile, and the ratio of free phenol to glucuronide production was increased from 0.57 to 1.30. A similar trend was observed in livers from DBA/2 mice that have beta-glucuronidase. Rates of hydrolysis of benzo(a)pyrene-O-glucuronide were not altered in isolated microsomes by addition of oleoyl coenzyme A (CoA) or octanoyl CoA (10- approximately 100 microM). Thus, we conclude that fatty acids do not alter glucuronidation by acting on beta-glucuronidase. The concentration of cofactors (UDP-glucuronic acid, UDP-glucose, and adenine nucleotides) involved in hepatic conjugation was not altered by infusion of concentrations of oleate (300 microM) that inhibited glucuronidation in perfused livers. When oleate concentrations were increased to 600 microM, UDP-glucuronic acid and UDP-glucose decreased 44 and 49%, respectively, and the ATP:ADP ratio declined concomitantly. Oleoyl CoA inhibited UDP-glucuronosyl transferase noncompetitively (half-maximal inhibition, 10 microM) in microsomes with 3-hydroxy-benzo(a)pyrene or p-nitrophenol as substrate. In contrast, octanoyl CoA was a very poor inhibitor of transferase activity. Inhibition of the transferase by oleoyl CoA was increased markedly by treatment with detergents (Triton X-100), i.e., half-inhibition of glucuronosyl transferase was obtained with about 2 microM oleoyl CoA. Inhibition of UDP-glucuronosyl transferase by oleoyl CoA was also increased in a dose-dependent manner by albumin, possibly due to increasing access of the CoA derivative to the enzyme. Collectively, these data indicate that fatty acids diminish glucuronidation via the formation of acyl CoA compounds that inhibit UDP-glucuronosyl transferase noncompetitively.     

大豆总皂甙对培养心肌细胞自发性搏动与动作电位的影响

培养Wistar大鼠乳鼠的心室肌细胞,向培养基中分别加入浓度为1.56μg/ml至50μg/ml的大豆皂甙,可使心肌细胞群落的自发性搏动呈剂量依赖性抑制。洗脱大豆皂甙或向培养基中再加入10μg/ml肾上腺素均能使自发性搏动恢复。向培养基中加入大豆皂甙5μg/ml使心肌细胞动作电位的波幅、波宽、超射、最大舒张电位、阈电位、最大除极速度等各电参数立即减小。Ca~(2+)80μg/ml能使动作电位的抑制逆转。上述结果表明大豆皂甙对培养的鼠心肌细胞具有钙通道阻滞用。     

电镜和荧光显微技术在细胞凋亡研究中的应用

目的：探讨荧光显微技术在检测细胞凋亡中的作用。方法：应用拓扑异构酶Ⅱ抑制剂VP-16及化学毒物叠氮钠分别诱导HL-60细胞凋亡和死亡，用透射电镜和经Hoechst 33258染色的荧光显微镜对凋亡及死亡动态观察和定量分析。结果：HL-60细胞在VP16处理后，荧光显微镜下可见核浓缩、染色质凝集、核碎裂等凋亡特征；而叠氮钠诱导的细胞死亡则出现核溶解、核染色质弥散，但无上述改变；两者电镜的观察与荧光显微镜的改变一致；凋亡细胞及坏死细胞荧光显微镜下呈不同的形态特征。对处理的不同时间点细胞的荧光显微镜观察发现：处理后4h核形态开始变化，有核浓缩的细胞比例在处理8h达高峰，然后下降，核碎裂细胞的比例在24h达高峰，约占80％，表明核浓缩发生在核碎裂之前。结论：荧光显微镜技术可明确观察判断细胞凋亡及坏死，并可进行动态及定量分析，是良好的凋亡检测方法。     

心电图短P-R间期观测研究

目的：探讨和鉴别心电图短Ｐ－Ｒ间期的产生原因，为临床诊断、治疗提供依据。方法：检测１１５例受检者的常规导联心电图（ＲＬＥＣＧ）、头胸导联心电图（ＨＣＥＣＧ）、食管导联心电图（ＥＬＥＣＧ），对其中５５例临床可疑心律失常和ＲＬＥＣＧ示短Ｐ－Ｒ间期者行食管心房调搏电生理检查。结果：①Ｐ波出现率和振幅均值比较ＥＬＥＣＧ＞ＨＣＥＣＧ＞ＲＬＥＣＧ（Ｐ＜０．０１），出现率分别为１００％、９５％、９１％。②ＨＣＥＣＧＰ－Ｒ段均值（Ｐ＜０．０１）及变异系数＜ＲＬＥＣＧ。③ＲＬＥＣＧ波幅低、图形多变是产生心电图短Ｐ－Ｒ间期的主要原因。结论：作为无创伤性检查方法，ＨＣＥＣＧ和ＥＬＥＣＧ可以对短Ｐ－Ｒ间期者进行初步筛选，而经食管心房调搏能检测ＥＣＧ短Ｐ－Ｒ间期的电生理特性，对鉴别诊断有肯定价值。     

泌尿生殖道炎症患者沙眼衣原体感染的临床研究

目的　探讨在泌尿生殖道有炎症表现的情况下沙眼衣原体 (CT)感染的状况。方法　采用C -C快速法。结果　CT在泌尿生殖道炎症时的阳性率显著高于无炎症表现者 (P <0 .0 5) ;男性在有无炎症表现情况下的CT阳性率差异有显著性 (P <0 .0 5) ,而女性差异无显著性 (P >0 .0 5) ;2 1～ 50岁为高发年龄段。结论　CT感染症状隐匿 ,临床无症状者也应注意CT的检测 ,尤其是女性和高危人群。     

白术茯苓汤及其配伍对脾虚大鼠胃肠激素的影响

目的：探讨益气健脾方剂治疗脾虚证的配伍规律。方法：采用苦寒泻下法复制大鼠脾虚模型，运用放射免疫分析法（RIA）检测白术茯苓汤及其与补气药。行气药及除湿药的不同配伍对脾虚大鼠胃泌素（GAS）、胃动素（MTL）及血管活性肠肽（VIP）的含量影响。结果：与正常对照组比较，脾虚模型大鼠GAS、MTL降低（P＜0．01），VIP升高（P＜0．01）；与自然恢复组比较，各治疗组以上部分或全部指标均有不同程度的改善，其中，以综合配伍组改善作用最优。结论：白术茯苓汤的脾虚大鼠胃肠激素的紊乱的某些指标，有一定的改善作用，综合配合组以上指标的改善，优于白术茯苓汤组及其余各配伍组，说明中医关于复方配伍的理论与实践，有其科学价值。     

感染患者血清可溶性细胞间粘附分子含量的变化及其对脑梗死的影响

目的：探讨感染合并脑梗死患者血清可溶性细胞间粘附分子（sICAM-1)的变化及临床意义。方法：采用双抗体（ELISA）法测定50例感染合并脑梗死患者血清中sICAM-1的含量，并与30例脑梗死患者和30例健康人对照。结果：感染合并脑梗死患者急性期血清sICAM-1的水平明显高于对照组。结论：感染合并脑梗死时sICAM-1的表达明显升高，sICAM-1水平的增高加重了脑梗死的发生发展。     

腮腺导管癌的临床病理特征分析--附1例报告及文献复习

目的:结合文献探讨腮腺导管癌的临床病理特征。方法:报道1例腮腺导管癌，就本病的临床生物学特征、病理、治疗及预后进行总结分析。结果:经手术及放疗后3个月复查，出现同侧颈部淋巴结转移。结论:腮腺导管癌是一类恶性度很高的恶性肿瘤，诊断主要依靠术后病理学及免疫组织化学检查，以局部广泛切除加颈廓清术为主，术后给予放疗。     

改良静脉输液排气法

为缩短静脉输液排气时间，提高一次排气成功率，对传统排气方法进行了改进，效果良好。现介绍如下。