Partial obstruction of the inferior vena cava after surgery for left atrial myxoma

We present a case of iatrogenic partial obstruction of the inferior vena cava after removal of a left atrial myxoma. The closure occurred subsequent to repair of a discontinuity between the right atrium and inferior vena cava caused by excessive traction on frail tissues.     

Optimizing fat oxidation through exercise in severely obese Caucasian adolescents

OBJECTIVE: To measure the contribution of substrate oxidation to energy expenditure during cycling at different workloads and to identify the exercise intensity that elicits the maximum fat oxidation rate in groups of severely obese or nonobese Caucasian adolescents. DESIGN: A total of 30 severely obese subjects (mean body mass index, BMI = 34.7 kg/m2; fat-mass = 39.9%) and 30 nonobese sedentary adolescents (mean BMI = 22.7 kg/m2; fat-mass = 21.8%) aged 14-16 years, participated in this study. Body composition was assessed by bioelectrical impedance. Peak oxygen uptake (VO2peak) and maximal fat oxidation rate were determined with indirect calorimetry by using a graded exercise test on an electromagnetically braked cycle ergometer. RESULTS: Predicted VO2max were expressed in absolute (l/min) and relative (ml/kg FFM/min) values, and maximal work rates were not significantly different between obese and nonobese adolescents, but were significantly higher in boys than in girls. No significant differences in fat oxidation rates were found in obese and nonobese sedentary adolescents during the graded exercise test. Maximal fat oxidation was observed at an exercise intensity corresponding to (mean +/- SD) 41 +/- 3%VO2max or 58 +/- 3% HRmax. At this exercise intensity, fat oxidation rates were higher in boys than in girls (0.32 +/- 0.02 g/min vs. 0.25 +/- 0.02 g/min, P < 0.001). CONCLUSIONS: Severely obese and sedentary nonobese adolescents reached maximal fat oxidation rates at 41%VO2max, which corresponds to 58% HRmax. At this exercise intensity, fat oxidation rates were higher in boys than in girls probably due to higher VO2max and absolute workload during the exercise steps for boys compared with those for girls.     

Joint Drug Purchases and Drug Preparation Risk Behaviors Among Puerto Rican Injection Drug Users

In the process of preparing jointly purchased drugs, injection drug users (IDUs) may share drug preparation materials and use a single syringe to distribute injectable drugs. The aim of this study was to examine the association of joint drug purchasing with drug preparation risk behaviors among Puerto Rican IDUs. The study sample comprised 555 IDUs from New York City and 297 from Puerto Rico. IDUs reported pooling money for 12% of the injection episodes in New York, and for 14% of the injection episodes in Puerto Rico. In both study sites, all correlation coefficients between frequency of pooling money and drug preparation behaviors were .30 or larger. After controlling for sociodemographics, drugs injected, and injection frequency, pooling money was significantly associated to all four drug preparation behaviors in both study sites. HIV prevention interventions need to be cognizant of the joint purchasing of drugs and its relationship to drug preparation risk behaviors.     

Gender Differences in HIV Risk Behaviors Among Puerto Rican Drug Injectors by Awareness of HIV Seropositive Status

This study examined HIV injection- and sex-related risk behaviors among Puerto Rican drug injectors by gender, separately for those who were aware of being HIV positive and those who believed they were seronegative or were unaware of their serostatus. The participants (N = 873: 561 in New York; 312 in Puerto Rico) were recruited from January 1998 to July 1999 in the two sites by street outreach workers. Of the participants, 81% were males and 19% self-reported that they were previously told that they had been infected with HIV. Significant gender differences existed in injection and sexual risk behaviors in bivariate analyses. The factors related to HIV risk behaviors between males and females differed after controlling for the impacts of other variables in multivariate analyses. Self-efficacy for risk behaviors was significantly related to all of the HIV risk behaviors. Components of HIV prevention programs should include enhancing self-efficacy for reducing risk behaviors.     

Dynamic electrocardiographic changes after aborted sudden death in a patient with Brugada syndrome and rate-dependent right bundle branch block

A 37-year-old man with Brugada syndrome and dynamic changes of the ST-segment morphology observed after an episode of aborted sudden death is described. On admission, after 3 syncopal episodes during nighttime, his electrocardiogram showed right bundle branch block (RBBB) with a J-point elevation of 0.6 mV in lead V 2 . Changes observed in the following days included a diminished J-point elevation and intermittent "saddle-back" type of morphology. During a previous 2-year follow-up, intermittent, complete, acceleration-dependent RBBB was documented. Right ventricular intracavitary tracings showed an RS pattern with a broad S wave in the unipolar electrogram; the time of onset of intrinsic deflection in this electrogram was 60 milliseconds. To our knowledge, this is the first report of an intracavitary demonstration of complete RBBB in Brugada syndrome.     

Workforce projections for emergency medicine in Puerto Rico: a five-year follow-up of an evident demand

In this study, two mathematical equations were used to calculate and establish the actual Emergency Medicine workforce needed in Puerto Rico (PR) and project the time frame to meet the actual demand. 1) Supply equals the number of existing Emergency Physicians (EPs) plus residency-trained graduates in EM per year minus the annual attrition rate (3%); and 2) Demand equals six (6) full time equivalent positions per Emergency Department (ED) times the total number of EDs in PR. Under both scenarios tested, the significant EP shortage in PR will continue until 2044. The actual calculated shortage is 287 EPs. There is an actual significant shortage in the Puerto Rico EP workforce. It will take a long time to make leaders understand the positive impact of having residency-trained EPs in every ED, on quality patient care and the whole health care system.     

凋亡抑制基因survivin反义寡核苷酸联合bcl-2反义寡核苷酸诱导肺癌细胞株凋亡的实验观察

目的：探讨凋亡：抑制基因survivin反义寡核苷酸单用或联用bcl-2反义寡核苷酸对肺癌细胞株的作用，探讨其在抗癌方面的作用。方法：①实验于2002-08／2003-04在蚌埠医学院免疫学实验室完成。将对数生长期NCI—H446细胞分为6组：空白对照组，脂质体10mg／L组（仅加空脂质体），NSODN 500nmol／L组（该3组均为对照组），survivin反义寡核苷酸500nmol／L组，bcl-2反义寡核苷酸5μmol／L，survivin反义寡核苷酸500nmol／L＋bcl-2反义寡核苷酸5μmol／L组（分别在脂质体介导下转染不同寡核苷酸，48h后收取细胞进行以下检测）。②在脂质体介导下，以survivin的反义寡核苷酸作用于肺癌细胞株NCI-H446和SPC—A1，于72h用反转录聚合酶链反应检测survivin mRNA表达。凋亡指数：（静止期／DNA合成前期）占整个细胞周期的百分比；增殖指数=（DNA复制期＋合成后期／有丝分裂期）占整个细胞周期的百分比。②survivin反义寡核苷酸单独或联合bcl-2反义寡核苷酸作用NCI—H446后，用四甲基偶氮唑盐法检测细胞生长抑制率并计算两药相互作用指数，锥虫蓝拒染实验检测细胞死亡率。（3）计量资料差异性比较采用方差分析和q检验。结果：①两种肺癌细胞株皆表达survivin基因。survivin反义寡核苷酸作用细胞株后，出现生长抑制和细胞凋亡，细胞survivin mRNA明显下调，反义寡核苷酸500nmol／L作用72h后NCI—H446和SPC—A1细胞survivin mRNA抑制率分别达62．72％和67．43％。②四甲基偶氮唑盐法检测结果显示，survivin反义寡核苷酸和bcl-2反义寡核苷酸单独应用对NCI—H446细胞均有生长抑制作用；联合应用survivin反义寡核苷酸和bcl-2反义寡核苷酸的细胞生长抑制率为64．9％，优于单独应用（单用bcl-2反义寡核苷酸为34．2％）（P〈0．01），两药相互作用指数为0．708。锥虫蓝拒染实验显示，survivin反义寡核苷酸500nmol／L＋bcl-2反义寡核苷酸5μmol／L组细胞死亡率为62．1％，高于两药单用时的31．4％和41．4％。流式细胞仪检测凋亡显示，与各对照组相比，survivin反义寡核苷酸和bcl-2反义寡核苷酸均可诱导细胞凋亡，凋亡率分别为43．6％和30．7％，两者联用凋亡率提高到58．6％（p〈0．01）。结论：①survivin反义寡核苷酸能抑制肺癌细胞株survivin基因表达，并诱导细胞凋亡和抑制生长。②survivin反义寡核苷酸联合bcl-2反义寡核苷酸具有显著协同抗癌作用。     

Echocardiographic images in mitral valve repair by "edge to edge" technique.

The "edge to edge" or "double orifice" technique is a new surgical option of mitral repair when functional valve insufficiency is present, due to ischemic or dilated cardiomyopathy. This technique is not frequently used and radically changes mitral anatomy and hemodynamic. Therefore, echocardiographic examination is completely different and implies good experience to evaluate postoperative valve function. For these reasons we present a case report of a patient who underwent this repair and was evaluated in the follow up by standard transthoracic echocardiography: the anatomical and functional assessment that was satisfactory compared with transesophageal examination is documented.