Kinetics and enzyme involvement in the metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in microsomes of rat lung and nasal mucosa.

The rat lung and nasal cavity are two target organs for carcinogenesis by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In order to characterize further the enzymes involved in the bioactivation of NNK, detailed kinetic and inhibitory studies were conducted with rat lung and nasal mucosa microsomes, and the results were compared with previous studies. The enzymes in rat lung microsomes catalyzed the alpha-hydroxylation, pyridine N-oxidation and carbonyl reduction of NNK. The apparent Km for the formation of the NNK-derived keto aldehyde, NNK-N-oxide, the NNK-derived keto alcohol and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol were 28.8, 10.4, 7.0 and 178.1 microM respectively. In rat nasal microsomes, alpha-hydroxylation was the predominant pathway and the rate was approximately 200 times higher than that in lung microsomes. The apparent Kms for keto aldehyde and keto alcohol formation in rat nasal microsomes were 9.6 and 10.1 microM respectively. The cytochrome P450 inhibitors metyrapone and carbon monoxide markedly inhibited the metabolism of NNK in both rat lung and nasal microsomes. In rat lung microsomes, alpha-naphthoflavone and monospecific antibodies against P450s 1A2, 2A1 and 2B1 inhibited the formation of keto aldehyde by 39, 46, 64 and 23% respectively. In rat nasal microsomes, alpha-naphthoflavone and antibodies against P450s 1A2, 2A1 and 3A inhibited the metabolism of NNK by 80, 35, 20 and 14% respectively. The results indicate that cytochromes P450 play a major role in the metabolic activation of NNK in rat lung and nasal microsomes, and that there are tissue-related differences in NNK metabolism.     

预移植在胚胎移植中的意义

目的 :评价预移植在胚胎移植中的作用。　方法 :在超声波引导下胚胎移植 114个周期 ,其中 10 1个周期进行预移植。比较预移植与未预移植周期临床妊娠率和胚胎种植率 ;按预移植与实际胚胎放置深度差值分组 ,并比较两组妊娠率和胚胎种植率。　结果 :预移植周期与未预移植周期临床妊娠率和种植率统计学差异无显著性(5 9.4 1%和 6 1.5 4 % ,35 .81%和 31.4 3% ,P均 >0 .0 5 ) ;按预移植与实际胚胎放置深度差值分组后 ,两组妊娠率和种植率统计学差异也无显著性 (6 1.5 4 %和 5 8.6 7% ,4 0 .79%和 34.0 9% ,P均 >0 .0 5 )。　结论 :在胚胎移植技术中 ,预移植不能准确指引胚胎移植深度     

嗜铬细胞瘤患者围手术期处理的改进

目的：探讨提高嗜铬细胞瘤患者围手术期安全性的措施。方法：对15例嗜铬细胞瘤患者、术前采用选择性α1受体阻滞剂多沙唑嗪控释片(可多华)控制高血压；11例患者采用3D DCEMRA进行肿瘤定位；术中均采用联合高容量血液稀释(AHH)和术中患者自体血回输纠正血容量。结果：除1例持续性高血压患者需联合钙离子拮抗剂和ACEI药物降压外．其余患者血压控制均为满意；根据3D DCEMRA定位选择手术径路者均顺利完成手术；AHH联合术中自体血回输使14例患者避免了异体输血。结论：本文围手术期处理改进．可多华可明显减少药物的不良反应；采用3D DCEMRA进行肿瘤定位，可增加手术安全性；AHH联合术中自体血回输可减少医疗成本和异体输血，以及由此而引起的并发症。     

磁疗及特定电磁波促进小儿肺功能恢复78例

Background: Under magnetic field,magnetic therapy can enhance resistance of biological individual,regulate qi and blood,improve local blood circulation and tissue permeability,promote absorption and removal of exudates,strengthen non specific immunity,activate phagocytosis ability of white cells and hence resist inflammation.TDP affect blood dynamics and thereby improving local blood circulation and metabolism and tissue regeneration,tissue nutrition,enhance immune function,promote tissue and cell metabolism and repair through its thermal effect.     

Effects of thiamine deficiency on hepatic cytochromes P450 and drug-metabolizing enzyme activities

To elucidate the mechanisms by which thiamine deficiency affects hepatic microsomal monooxygenase activities, the effect of thiamine deficiency on two constitutive cytochrome P450 isozymes, P450IIE1 and P450IIC11, was investigated, using weanling male Sprague-Dawley rats. The clinical signs of thiamine deficiency were apparent after feeding a thiamine-deficient diet for 3 weeks. Thiamine deficiency caused an increase in P450IIE1, which was determined by N-nitrosodimethylamine demethylase assay and immunoquantitation of P450IIE1. This increase in the P450IIE1 level was mainly attributed to thiamine deficiency per se but not to dietary restriction. Ketone bodies were not elevated in thiamine-deficient rats, whereas ketone bodies were elevated and may have served as inducing factors in calorically restricted pair-fed animals. Injections of pyruvate or pyrithiamine in addition to thiamine deficiency did not potentiate the induction effect. On the other hand, thiamine deficiency did not affect the level of P450IIC11 during the 3 weeks of feeding the thiamine-deficient diet. In addition, thiamine deficiency increased cytosolic glutathione S-transferase activity but not steroid isomerase activity. The present study demonstrates the specificity of thiamine deficiency per se in the induction of P450IIE1 which does not involve an increase in the ketone body level.     

正常人及大鼠心脏内皮素转换酶的分布

目的:了解正常人和大鼠心脏各部分内皮素转换酶(Endothelin-conveerting en-zyme,ECE)的分布。方法:采用半定量RT-PCR法检测ECE mRNA表达,同时根据外源性的巨内皮素-1转变为内皮素-1的量判定ECE活性。结果:正常人心脏各部位心肌均存在ECE,ECEmRNA表达和活性的分布特点一致:心房显著高于心室,左、右心房间及左、右心室和室间隔间无显著性差异。大鼠的ECE mRNA表达和活性分布规律与人相似。结论:正常人和大鼠心脏各组分均存在ECE,且两者的分布规律相似。     

主动脉阻断期间含氧血持续肺动脉灌注的肺保护研究

目的评估体外循环主动脉阻断期间应用含氧血持续肺动脉灌注对肺功能的保护作用.方法选择杂种上海犬(上海农科院犬养殖厂)12只,体重7～12 kg.随机分成应用含氧血持续肺动脉灌注的实验组和对照组,分别测定体外循环前、结束即刻、结束后1 h的肺功能,体外循环术后2组左、右心房内血白细胞记数以及肺水含量的变化.体外循环转流前、后分别在右肺门处随机切取肺组织(3 cm×3 cm大小)送病理检查.结果术后实验组的肺功能明显改善,左、右心房血白细胞记数差异无显著性,肺水含量与对照组比较差异无显著意义.对照组显示肺泡间质明显水肿,肺泡内大量的中性粒细胞渗出,实验组保留了正常的肺组织结构.结论含氧血持续肺动脉灌注可减轻主动脉阻断期间肺组损伤,保护术后肺功能.     

肩锁钩板治疗不稳定性锁骨外侧段骨折的临床研究

目的：比较肩锁钩板和传统克氏针内固定治疗不稳定性锁骨外侧段骨折的疗效。方法：54例不稳定性锁骨外侧段骨折的患者接受了手术治疗，内固定分别是锁骨钩板或克氏针，根据国外的锁骨外侧段骨折肩部功能评价标准进行6－12个月的术后随访，随访结果运用统计学方法进行分析处理，结果：克氏针内固定组的手术优良率为77．3％，并发症发生率为27．3％，骨折愈合率为81．8％；锁骨钩板内固定组的手术优良率为100％，并发症发生率为3．1％，骨折愈合率100％。两组数据统计学差异有显著性，结论：在不稳定性锁骨外侧段骨折的手术治疗中，锁骨钩板较传统克氏针内固定有较高的手术优良率和骨折愈合率，且并发症的发生率较低，因此，它是一种疗效满意的内固定方法。     

大鼠体外循环模型的建立与应用

由于操作简便、节省人力物力，大鼠体外循环模型的应用愈加广泛。大鼠在小型呼吸机辅助下，应用颈静脉插管入右心房引流血液至贮血瓶，在蠕动移液泵作用下，经膜式氧合器氧合、变温器变温，通过股动脉或尾动脉插管注入动脉系统，建立体外循环回路。有血预充、减少总预充量和维持足够的转流流量是建立大鼠体外循环模型的关键。     

PACS系统中IBM磁带库存储故障维修

介绍了一例PACS系统中磁带库因通信通路问题引起的故障及维修过程。