Evaluation of the use of computed tomography versus conventional orthogonal X-ray simulation in the treatment of rectal cancer

The aim of this study is to compare and contrast the treatment fields designed using CT versus conventional orthogonal X-ray simulation in the treatment of patients with rectal cancer given preoperative chemotherapy and radiotherapy. Nine patients participated in this study. The coverage of treatment fields, the volume of treatment fields, and the position of the anorectal junction in relation to the inferior border of the obturator foramen as the delineator of the pelvic floor were evaluated in each patient using CT and conventional orthogonal X-ray simulation. The results demonstrated undercoverage of the anterior border of the lateral fields of up to 2.5 cm in seven of nine patients when conventional orthogonal X-ray simulation was compared to CT simulation. In addition, the inferior border of the obturator foramen proved to be a poor delineator of the pelvic floor with the anorectal junction situated up to 2 cm superiorly in seven of nine patients. In conclusion, CT simulation is superior to conventional orthogonal X-ray simulation when designing treatment fields for patients with rectal cancer.     

Assessing diagnosis in heart failure: which features are any use?

We assessed the value of symptoms, past history, medications and signs in the evaluation of patients who might have heart failure secondary to left ventricular systolic dysfunction. An open-access echocardiography service was set up to help identify patients with left ventricular systolic dysfunction who might benefit from treatment with an angiotensin-converting-enzyme inhibitor. History and examination were recorded for each of these patients. The patients were divided into groups according to whether left ventricular systolic function was preserved or not and whether various clinical features were present or not. Of 259 consecutive patients studied, 41 had impairment of left ventricular systolic function as assessed by echocardiography. Past history of myocardial infarction and displaced apex beat were the best single predictors of left ventricular systolic dysfunction as assessed by echocardiography. The combination of past history of myocardial infarction and displaced apex had the best positive predictive value of all. Patients with such clinical features or combinations of clinical features may not need echocardiography, and where access to this resource is limited, it could be reserved for patients without such diagnostic features.      

Low incidence of HTLV infections in random blood donors with indeterminate western blot patterns

Peripheral blood mononuclear cells (PBMCs) were recovered from platelet units of 61 blood donors who were HTLV-I positive and 3 blood donors who were HTLV-I negative on enzyme-linked immunosorbent assay (ELISA). Western blot analyses were performed on the sera and DNA was prepared from the PBMCs and analyzed by the polymerase chain reaction (PCR). Of the 61 repeatably reactive samples, 2 were positive, 26 were negative, and 33 were interpreted as indeterminate on Western blot. HTLV-II sequences were detected by PCR in one of the Western blot-positive samples, as well as in one Western blot-indeterminate sample that showed reactivity to p24 only. HTLV-I sequences were detected in the second Western blot-positive sample. HTLV sequences were not detected in the remaining samples, which suggested that the majority of individuals with indeterminate results on Western blots that used one set of commercially available reagents are not infected with HTLV. It is demonstrated in this study that PCR can be used not only to resolve the infection status of individuals with indeterminate Western blots but also to distinguish between HTLV-I and HTLV-II.     

三七总皂苷对大鼠肾缺血再灌注损伤的保护作用及其线粒体机制

目的:观察三七总皂苷(血栓通注射液的药物成分)对大鼠肾缺血再灌注损伤的保护作用,分析其可能的线粒体机制。方法:实验于2006-01/09在广州医学院病理生理学实验室完成。实验分组:取108只SD雄性大鼠,随机分为假手术组、缺血再灌注模型组、三七总皂苷组,每组36只。实验干预:①假手术组:实验前1h腹腔注射生理盐水,全麻下行右肾摘除,左肾暴露40min后取下。②缺血再灌注模型组:实验前1h腹腔注射生理盐水,全麻下行右肾摘除,左肾动脉夹闭缺血45min后再灌注1h。③三七总皂苷组:实验前1h腹腔注射血栓通注射液70mg/kg,其余方法同缺血再灌注模型组。实验评估:①再灌注后1h取肾组织匀浆检测肾组织超氧化物歧化酶活性、丙二醛含量。②测血浆肌酐、尿素氮、血清降钙素基因相关肽含量。③电镜观察肾组织线粒体超微结构的改变。④检测线粒体细胞色素氧化酶、琥珀酸脱氢酶活性,Ca2 含量。结果:108只大鼠均进入结果分析。①三七总皂苷组肾组织超氧化物歧化酶活性高于缺血再灌注模型组;丙二醛含量低于缺血再灌注模型组。②三七总皂苷组血浆肌酐、尿素氮含量低于缺血再灌注模型组;降钙素基因相关肽水平高于缺血再灌注模型组。③电镜观察三七总皂苷组线粒体结构有明显的改善,嵴数目减少不多,且排列较整齐,没有线粒体崩解的情况。④三七总皂苷组肾组织线粒体中细胞色素氧化酶、琥珀酸脱氢酶活性高于缺血再灌注模型组;Ca2 含量低于缺血再灌注模型组。结论:三七总皂苷对肾缺血再灌注损伤有明显保护作用,其保护作用机制与直接清除自由基,提高琥珀酸脱氢酶、细胞色素氧化酶活性、升高血清降钙素基因相关肽水平,降低钙超载,从而减轻线粒体损伤有关。