大黄素对大鼠原位肝移植术后急性排斥反应的干预

目的:目前国外已有少量报道证实中药大黄素具有极强的免疫抑制效应。实验拟进一步验证大黄素对同种异体大鼠肝移植术后早期急性排斥反应的干预效果。方法:实验于2004-01/2005-02在西安交通大学第一附属医院肝胆外科实验室完成。制备SD→Wistar大鼠全血供肝移植模型(n=80),按随机数字表法分为4组,每组20只。模型对照组、大黄素组、环孢素A组及环孢素A 大黄素组分别腹腔注射给予9g/L生理盐水、1.5mg/(kg·d)大黄素、3mg/(kg·d)环孢素A及3mg/(kg·d)环孢素 1.5mg/(kg·d)大黄素。术后观察大鼠一般情况,并于第7天各组分别处死10只大鼠,取肝脏标本及血清,观察移植肝组织排斥反应强度、Fractalkine(Fkn)阳性表达情况及大鼠血清中白蛋白含量及谷丙转氨酶活性,余受体继续应用药物干预直至死亡,记录其生存时间。结果:各组受体手术成功数量分别为模型对照组17只、大黄素组18只、环孢素A组18只、环孢素A 大黄素组18只。①与模型对照组相比,各用药组大鼠术后存活时间明显延长(P<0.05),以环孢素A 大黄素组存活时间最长。②与模型对照组相比,各用药组大鼠术后第7天移植肝排斥反应强度明显降低(P<0.05),血清中白蛋白含量明显升高,而谷丙转氨酶活性明显降低(P均<0.05),肝组织中Fkn表达阳性率明显降低(P<0.05),以环孢素A 大黄素组表现最为显著。结论:大黄素具有抑制同种异体大鼠肝移植急性排斥反应发生、发展的作用,与环孢素A联用具有协同作用。     

The mediating role of health professionals' recommendation in the uptake of colorectal cancer testing among older Chinese adults

The purpose of this study is to examine the mediating effect of health professionals' recommendations on the relationship between the characteristics of older Chinese adults and the use of colorectal cancer testing. This was a cross‐sectional population‐based telephone survey. A total of 2004 Chinese adults aged 50 or above were recruited between 2 and 28 May 2007 to complete an anonymous telephone survey. The survey covered demographics, perceived health status and susceptibility to cancer, utilization of complementary medicine, family history of cancer, and cancer screening behaviour. The uptake of flexible sigmoidoscopy/colonoscopy was 12%, of which only 3.4% had been recommended by health professionals. The effects of gender, a history of serious disease, perceptions related to health status and visiting doctor regularly on the flexible sigmoidoscopy/colonoscopy uptake were mediated by a health professional's recommendation. A health professional's recommendation can be a catalyst for the decision of undergoing a colorectal cancer screening test in older adult people, in particular for those who are more health‐conscious. As health professionals can play a crucial role in the development of successful population‐based colorectal cancer screening program, efforts should be made to facilitate them in making recommendations for colorectal cancer screening to targeted high‐risk group.     

Intrathecal methotrexate overdose

We report two cases of intrathecal methotrexate overdose. A 3-y-old girl with acute lymphoblastic leukaemia and a 4-y-old boy with Burkitt's lymphoma were to receive an intrathecal injection of methotrexate after completion of intravenous methotrexate infusion. Instead of 12.5 mg, they both received a dose of 125 mg. Both children developed generalized convulsion 3 h after the overdose, but afterwards recovered completely. Intravenous folinic acid and dexamethasone rescue were employed, but no attempt was made to exchange the cerebrospinal fluid. In addition to the staffs failure to check the drug label carefully, the marked resemblance of the two dose preparations of methotrexate (50 mg/5 ml and 500 mg/5 ml) may have been contributory.     

Discrepancy between computed tomography coronary angiography and selective coronary angiography in the pre‐stenting assessment of coronary lesion length

We aimed to compare the lesion length measured on computed tomography coronary angiography (CT‐CA) with the selective coronary angiography (SCA) lesion length measured on quantitative coronary angiography (QCA). Compared with SCA, CT‐CA has the advantage of showing the lumen and the atherosclerotic plaque in the arterial wall. This prospective observational study involved 44 coronary lesions. Computed tomography coronary angiography was carried out with an electrocardiogram‐gated 16‐slice CT before percutaneous coronary intervention. A cardiologist and a radiologist measured CT lesion lengths in consensus, whereas an interventional cardiologist carried out QCA to obtain SCA lesion lengths independently. The median difference of (CT lesion length − SCA lesion length) was 9.84 mm (95%CI: [7.26, 13.34]). The median difference of (stent length − SCA lesion length) was 7.68 mm (95%CI: [6.29, 9.26]); the median difference of (stent length − CT length) was −2.63 mm (95%CI: [−5.80, 0.05]). The mean ratio of stent length to SCA lesion length was 2.07 (95%CI: [1.83, 2.30]). The mean ratio of stent length to CT‐CA lesion length was 0.97 (95%CI: [0.83, 1.11]). In the subgroup of drug‐eluting stents (17 lesions), the median difference of (stent length − SCA lesion length) was 9.76 mm (95%CI: [6.59, 13.28]); the median difference of (stent length − CT length) was −5.2 mm (95%CI: [−11, 0.5]). The mean ratio of stent length to CT‐CA lesion length was 0.93 (95%CI: [0.68, 1.17]). Computed tomography lesion length was substantially longer than SCA lesion length measured by QCA. Routine practice of choosing stent length based on QCA may underestimate the actual length of target lesion. This may lead to incomplete coverage of the target lesion, particularly when drug‐eluting stents are used.     

Diagnostic accuracy of 16‐slice CT coronary angiography in the evaluation of coronary artery disease

Multislice CT coronary angiography (CT‐CA) has emerged as a potential imaging method for coronary artery disease. This study aimed to ascertain the accuracy of 16‐slice CT in the diagnosis of significant coronary stenosis (≥50% reduction of lumen diameter). This mixed retrospective/prospective observational study compared 95 paired 16‐slice CT‐CA and fluoroscopic coronary angiography (FCA) sets. A cardiologist and a radiologist blinded to the FCA findings evaluated CT‐CA images independently by visual estimation. Disagreement between these reporters was arbitrated by a third CT reporter (a cardiologist). A separate cardiologist blinded to CT‐CA findings assessed FCA by visual estimation. Of 1161 coronary segments assessable on FCA, 1103 segments (95%) were assessable on CT‐CA. The CT‐CA correctly diagnosed 147/180 segments with significant stenoses (sensitivity = 82%) and correctly identified 874/923 coronary segments without significant stenoses (specificity = 95%). The positive and negative predictive values of CT‐CA in the diagnosis of coronary segment with significant stenosis were 75 and 96%, respectively. On patient‐based analysis, CT‐CA correctly identified all 68 studies with at least one vessel with significant stenosis (sensitivity = 100%; specificity = 83%). The positive and negative predictive values of CT‐CA in identifying patients with significant coronary stenosis were 94 and 100%, respectively. The 16‐slice CT‐CA showed moderately good sensitivity but very high specificity and negative predictive value in the diagnosis of significant coronary stenosis. The CT‐CA would appear to be a useful ‘rule‐out’ test for patients with low‐risk profile for ischaemic heart disease.     

Exchanging dual‐lumen central venous catheters: How I do it

The management of a blocked long‐term central venous catheter has traditionally been removal and re‐siting, even when device failure is not associated with venous thrombosis or sepsis. It is not possible to ‘railroad’ a split dual‐lumen central venous catheter down a long tortuous s.c. tunnel. Our exchange technique was designed to salvage the tunnel and venous access site in a long‐term catheter that has had uncomplicated primary device failure. In this technique we divide the dual‐lumen catheter and secure the venous access site and the s.c. tunnel with separate peel‐away sheaths. The new catheter is then introduced in the conventional manner through the two peel‐away sheaths, which are then removed. The key advantage of the technique is that it preserves one of the few central venous access sites available. This article describes exchange of an internal jugular catheter, but the same technique is applicable to subclavian catheters.