The bioactivation of 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954)--I. Purification and properties of a nitroreductase enzyme from Escherichia coli--a potential enzyme for antibody-directed enzyme prodrug therapy (ADEPT).

A nitroreductase enzyme has been isolated from Escherichia coli B. This enzyme is an FMN-containing flavoprotein with a molecular mass of 24 kDa and requires either NADH or NADPH as a cofactor. Partial protein sequence analysis showed extensive homology with the "classical nitroreductase" of Salmonella typhimurium and a nitroreductase induced in Enterobacter cloacae. In common with the Salmonella enzyme, the E. coli B enzyme is capable of reducing nitrofurazone. The E. coli nitroreductase is also capable of reducing the anti-tumour agent CB1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide], a property shared with the mammalian enzyme DT diaphorase [NAD(P)H dehydrogenase (quinone)] as isolated from Walker cells. The reduction of CB1954 by the E. coli enzyme results in the generation of cytotoxic species. Both enzymes also share the properties of being able to reduce quinones and are both inhibited by dicoumarol. The nitroreductase is a more active enzyme against CB1954 (kcat = 360 min-1) than Walker DT diaphorase (kcat = 4 min-1) and also has a lower Km for NADH (6 vs 75 microM).     

中国健康志愿者单剂静滴甲磺酸加替沙星注射液的药代动力学

目的:研究中国健康成年男性志愿者单剂静滴甲磺酸加替沙星注射液的药代动力学。方法:按药物临床试验管理规范(GCP)指导原则设计试验方案。选择9名受试者分别依次单刘静滴100,200和400mg的甲磺酸加替沙星注射液后,应用HPLC测定血药浓度,采用3P97软件进行数据处理,求出药代动力学参数。结果:受试者分别给药后,药-时曲线符合二房室模型,主要药代动力学参数C_(max)分别为1.10±0.19,2.17±0.33和3.16±0.47mg·L~(-1);t_(1/2)β分别为7.42±1.99,8.41±2.72和8.46±2.83h;AUC_(0-∞)分别为4.45 ±0.71,11.10±1.81和23.03±3.83mg h·L~(-1)。原形药主要经肾排泄,48h尿药累积排泄率分别为(43.08±15.79)％,(51.33±23.69)%和(45.67±18.22)％。结论:9名静滴甲磺酸加替沙星注射液后,药-时曲线符合二房室模型。提示甲磺酸加替沙星在100～400mg剂量内药物体内过程基本呈线性动力学特征而无饱和性,主要排泄途径为肾脏。     

Pediatric utilization of rapamycin for severe cardiac allograft rejection

BACKGROUND: Rapamycin is a new immunosuppressive agent that has been shown to be effective in the treatment of acute cardiac rejection in the adult population. METHODS: This case documents a pediatric patient with ongoing cardiac rejection that did not abate despite treatment with antithymocyte serum (RATS), corticosteroid pulses, and methotrexate in addition to daily prednisone, mycophenolate mofetil, and tacrolimus. RESULTS: Initiation of therapy with rapamycin resulted in a rapid resolution of cardiac rejection and reduction of concomitant immunosuppressive agents and few side effects. CONCLUSIONS: This case illustrated the utilization of rapamycin in a pediatric patient with ongoing acute rejection despite several modifications in treatment.     

原发性乳腺恶性淋巴瘤六例临床分析

目的 分析原发性乳腺恶性淋巴瘤的临床特点,探讨其诊断、分期和治疗方法。方法回顾分析我院自1995～2002年收治的6例原发性乳腺恶性淋巴瘤和1980～2002年国内主要文献报道的279例原发性乳腺恶性淋巴瘤的临床特征、诊断情况和治疗方法,进行对比分析。结果 285例病例均为非霍奇金淋巴瘤(NHL),免疫学检查证实有282例为B细胞源性(98.9％);女性268例,占94.0％;病灶位于右侧163例,占57.2％;Ⅰ期和Ⅱ期的原发性乳腺恶性淋巴瘤占89.8％。经手术、化疗、放疗等综合治疗后,生存期2～206个月,中位生存期最短23个月,最长56个月。结论 原发性乳腺恶性淋巴瘤绝大部分为B细胞源性非霍奇金淋巴瘤(NHL),Ⅰ期、Ⅱ期多见。对于原发性乳腺恶性淋巴瘤,诊断是关键,确诊后经手术、化疗、放疗等综合治疗,可以获得较长的生存期,疗效十分满意。     

Human serum induces apoptosis of xenogenic cardiomyocytes in vivo and in vitro

Abstract: Discordant xenotransplantation is complicated by delayed xenograft rejection (DXR). Previous studies have demonstrated that anti‐apoptotic genes are protective against DXR. This study examines the hypothesis that apoptosis plays a role in human anti‐xenograft responses. C57BL/6 mice and NOD SCID mice were given a single intravenous injection of either a lethal dose (LD, survival < 30 min) or a sublethal dose (SLD) of human serum, and isolated pig and mouse rod‐shaped cardiomyocytes were exposed to human serum in vitro. In situ detection of apoptotic cells in mouse hearts was assessed using a terminal deoxynucleotidyl transferase‐mediated dUTP nicked‐end labeling assay. Mice transfused with human serum had approximately a 10‐fold increased percentage of apoptotic cells after SLD 18 h post‐injection compared with animals given saline, and a fourfold increase over LD. Administration of cobra venom factor (CVF) decomplemented SLD 18 h did not significantly ( P  > 0.05) alter the percentage apoptosis. The addition of 20 mM Gal‐α‐1,3‐Gal to SLD 18 h significantly ( P  < 0.05) reduced percentage apoptosis to levels comparable to saline treated control animals. In vitro using mouse and pig cardiomyocytes demonstrated parallel results as in vivo experiments.
Human serum induces apoptosis of cardiomyocytes in immunocompetent and immunoincompetent mice in vivo, as well as mouse and pig cardiomyocytes in vitro. Further, this apoptotic response can be inhibited by the addition of Gal‐α‐1,3‐Gal without affecting the capacity of the serum to cause HAR. These results demonstrate that a putative human serum factor induces a delayed apoptotic injury of xenograft tissues, and supports the hypothesis that apoptosis may be an important mediator of DXR.     

Adult height in patients with childhood onset atopic dermatitis

Cross sectional studies have reported impaired growth in children with atopic dermatitis. If this growth impairment is irreversible, it would be expected to adversely influence final height attainment. The standing heights and other anthropometric parameters were assessed in 35 adults with onset of atopic dermatitis before 5 years of age and a control group of 35 adults with adult onset contact dermatitis or psoriasis. There was no significant difference in the standing height SD score, mid-parental height SD score, sitting height SD score, subischial leg length SD score, nor body mass index between the atopic dermatitis and control groups. The standing height SD score was not significantly different among: (a) patients with atopic dermatitis affecting less than 50% of their body surface area and those with greater than 50% affected; (b) patients using the four different potency topical corticosteroids; and (c) patients with atopic dermatitis without asthma and those with coexisting asthma. It is concluded that short stature is not a feature of our group of adult patients with onset of atopic dermatitis before 5 years of age, continuing into adulthood, and severe enough to require specialist care. This suggests that if growth impairment occurs in childhood, it is likely to be temporary and reversible.     

Patient-Reported Outcomes Measurement in Radiation Oncology: Interpretation of Individual Scores and Change over Time in Clinical Practice

Tools for measuring patients’ perceived health and quality of life, such as patient-reported outcome measures (PROMs), inform clinical decisions for patients requiring radiation therapy. However, there may be inconsistencies in how patients interpret and respond to PROMs due to cultural, environmental, personal, or experiential factors. Differential item functioning (DIF) and response shift (RS) refer to differences in the meaning of PROMs between patients or over time (respectively). DIF and RS can threaten the accurate interpretation and use of PROMs, potentially resulting in erroneous conclusions about effectiveness, and flawed individual-level clinical decision-making. Given the empirical evidence of DIF and RS, we aim to review clinical implications and solutions for addressing DIF and RS by providing vignettes from collaborative examinations with workshop participants, as well as the literature. By making these methodological concepts accessible and relevant, for practice, clinicians may feel more confident to ask clarifying questions of patients when PROM scores and the contextual patient information do not align. PROM scores need to be interpreted via dialogue with the patient to avoid misinterpretation due to DIF and RS, which could diminish patient–clinician communication and impede shared decision-making. This work is part of an interdisciplinary knowledge translation initiative focused on the interpretation of PROM scores by clinically-oriented audiences.     

Medical career choice: Current status of research literature

This article examines the research evidence supporting relationships between both personal and social factors and the career choices of physicians in training. Although the research literature in this area is limited by a lack of longitudinal studies, a dependence on cross‐sectional designs, and a lack of multivariate investigations, data support relationships in each of the following areas: sociodemographic characteristics of student, student personality and attitudinal variables, institutional characteristics of the medical school, characteristics of the specialty training programs, and information available to students about the various careers. Additionally, this review investigates the stability of career preferences and career choices over time.     

Improving outcomes of the Fontan operation in children with atrial isomerism and heterotaxy syndromes.

BACKGROUND: The historic outcome of the Fontan procedure in children with single ventricle and heterotaxy syndrome has been poor, and in the current era it has been incompletely described. METHODS: From January 1993 through April 2000, 30 patients (age range, 5.3 +/- 3.6 years) had total cavopulmonary connection for single ventricle and isomerism and heterotaxy syndrome. Right atrial isomerism and heterotaxy (n = 19) or left atrial isomerism and heterotaxy (n = 11) were associated with a morphologic right ventricle (n = 26), a common atrioventricular valve (n = 25), pulmonary atresia (n = 9) or stenosis (n = 17), anomalous pulmonary venous drainage (partial, n = 7; total, n = 11; obstructed, n = 4), and interrupted inferior vena cava (n = 13). A previous systemic to pulmonary artery shunt had been performed in 21 patients, and 3 patients had previous pulmonary artery banding. The Fontan procedure was staged in all but 3 patients at a median age of 12 months (range, 3 to 114 months). Before the Fontan procedure, atrial arrhythmia was present in 7 patients (23%). RESULTS: An extracardiac conduit was constructed in 22 patients (median diameter, 20 mm; range, 16 to 27 mm), and a lateral tunnel was constructed in 4 patients. Associated procedures included pulmonary artery augmentation (n = 17), repair of anomalous pulmonary venous drainage (n = 7), and repair of a regurgitant atrioventricular valve (n = 2). The mean cardiopulmonary bypass time was 134 +/- 57 minutes. Cardioplegic cardiac arrest was used in 12 patients for a mean duration of 62 +/- 28 minutes. There were four hospital deaths (13%), three that occurred in children having concomitant repair of anomalous pulmonary venous drainage (previously undetected in one). Thirteen children (41%) developed early postoperative atrial arrhythmias, 11 of the 13 children required temporary pacing. There was one late death. Follow-up (3.4 +/- 2.7 years) was available on 24 of 25 survivors. All but 2 patients were in sinus rhythm. CONCLUSIONS: Early and midterm outcomes after the Fontan procedure in this patient group improved and may be further ameliorated by detecting and repairing associated obstruction to pulmonary venous flow and performing atrioventricular valvuloplasty before the Fontan procedure.