Total cavopulmonary anastomosis using atrial septal flap: technique and early results

Introduction The Fontan procedure has undergone many modifications to avoid atrial arrhythmias and thrombus formation. We used patient’s interatrial septum as a flap to direct the inferior venacaval blood to the superior venacava. Methods Seventeen patients, aged 1 to 17 years, underwent modified total cavopulmonary anastomosis. Interatrial septum was used to create the inner half of the atrial tunnel, outer half being formed by right atrial free wall. Post-operatively, all patients underwent echocardiography. Seven patients underwent 24 hour ambulatory Holter monitoring and 6 patients underwent cardiac catheterization and cineangiography. Results There was one early death due to low cardiac output. One patient had transient supraventricular arrhythmia. Two patients had singnificant pleural effusion. Holter Monitoring reveled sinus rhythm in all 7 patients studied. Follow up ranged from 18 to 60 months and patients were evaluated as they came for follow up. Long term follow up is currently being compiled. There was one late death from a non-cardiac cause. The remaining patients were in New York Heart Association (NYHA) Class I or II. All patients were in sinus rhythm. Echocardiography and cineangiography revealed absence of obstruction or leak. Conclusions Total cavopulmonary anastomosis using autogenous atrial septum is a useful modification for classical cavopulmonary anastomosis and provides good early results.     

急性心肌梗死后CD34+干细胞自体动员的意义

目的:已有理论提出急性心肌梗死后骨髓和外周血中的CD34 干细胞具有自身动员的潜能,观察这一潜能的变化特征及其对心肌梗死组织再生能力的影响。方法:实验于2004-09/2005-02在阜外心血管病医院完成。①实验动物:雄性SD大鼠40只,随机数字表法分为心肌梗死组、假手术组,20只/组。②实验方法:心肌梗死组大鼠采用冠状动脉结扎法建立心肌梗死模型。心电图ST段抬高或有室性心律出现,前壁心肌呈苍白色为造模成功。假手术组仅作开胸手术,前降支不予结扎。③实验评估:于心肌梗死后3,7,14,28d,流式细胞仪检测骨髓和外周血中CD34 干细胞的含量。用免疫组化方法检测梗死心肌组织中的Ki67细胞和毛细血管数量。结果:①外周血及骨髓CD34 干细胞含量的变化:心肌梗死组外周血中的CD34 干细胞数量于造模后3d开始上升,7d后明显高于假手术组(P<0.01),至14,28d时逐渐回落至假手术组水平(P>0.05)。心肌梗死组骨髓中的CD34 干细胞数量于造模后各时间点始终无明显变化(P>0.05)。②组织学评定:心肌梗死组梗死区Ki67细胞和毛细血管数量于造模后3d开始增多,7d时明显多于非梗死区(P<0.05);至14,28d梗死区Ki67细胞数量明显少于造模后7d(P<0.05),毛细血管数量的减少不明显(P>0.05)。免疫组化染色显示少数Ki67细胞分化为血管内皮细胞,未见向心肌细胞分化。③相关性分析:梗死区Ki67细胞、毛细血管数量于造模后7d与外周血中CD34 干细胞数量呈显著正相关(r=0.913,P=0.021;r=0.887,P=0.035)。结论:机体CD34 干细胞的自体动员、增殖反应的潜能随急性心肌梗死时间的延长而逐渐减弱,自体动员的干细胞功能尚不足以达到修复梗死心肌组织的效果。     

Evaluation of Helicobacter pylori infection and other risk factors in patients with benign peptic ulcer disease

ObjectiveTo assess and compare the risk factors in patients with benign gastric and duodenal ulcers and to correlate the prevalence of Helicobacter pylori (H. pylori) infection in benign peptic ulcer disease.MethodsA total of 30 consecutive patients with peptic ulcer disease were included in this study after upper gastrointestinal endoscopy. Their clinical profile and endoscopic findings were noted. Antral biopsies were subjected to histopathological examination and urease test for detection of H. pylori. Results were correlated. The study was cleared by the Institute Research Council and the Ethics committee.ResultsThe male: female ratio was 11:4. Overall, H. pylori infection was prevalent in 93.3% of the patients. Patients who took spicy food had a significantly higher rate of H. pylori positivity (P=0.04). Smoking, alcohol intake and NSAIDs did not affect H. pylori status in patients. There was no significant association between the site of the ulcer and H. pylori infection.ConclusionsBased on our observations we conclude that prevalence of H. pylori infection is similar in duodenal and gastric ulcers and intake of spicy food is a significant risk factor.     

Screening for ‘window‐period’ acute HIV infection among pregnant women in rural South Africa

Objectives

The aim of this study was to evaluate the HIV‐1 RNA pooled nucleic acid amplification testing (NAAT) strategy to screen pregnant women in the ‘window period’ of acute HIV infection (AHI) in rural South Africa.

Methods

In 2007 and 2008, 750 consecutive pregnant women on their first antenatal care visit to a primary health care clinic were tested anonymously for HIV infection. HIV‐1 RNA pooled NAAT was performed on HIV antibody‐negative samples. All positive pools were tested individually and positive samples were classified as incident cases to calculate HIV incidence.

Results

The overall HIV prevalence was 37.3% [95% confidence interval (CI) 34.3–41.3]. Of the 467 HIV antibody‐negative samples, four (0.9%) were HIV‐1 RNA‐positive. The mean viral load in the four samples was 386 260 HIV‐1 RNA copies/mL (range 64 200–1 228 130). The HIV incidence was 11.2% per year (95% CI 0.3–22.1) and all women with AHI were ≤21 years of age.

Conclusions

Identifying AHI in pregnancy is important for health interventions to reduce perinatal and heterosexual transmission of HIV, and to estimate HIV incidence for epidemiological surveillance.     

Molecular basis of altered red blood cell membrane properties in Southeast Asian ovalocytosis: role of the mutant band 3 protein in band 3 oligomerization and retention by the membrane skeleton

Southeast Asian ovalocytosis (SAO) is an asymptomatic trait characterized by rigid, poorly deformable red cells that resist invasion by several strains of malaria parasites. The underlying molecular genetic defect involves simple heterozygous state for a mutant band 3 protein, which contains a deletion of amino acids 400 through 408, linked with a Lys 56-to-Glu substitution (band 3-Memphis polymorphism). To elucidate the contribution of the mutant SAO band 3 protein to increased SAO red blood cell (RBC) rigidity, we examined the participation of the mutant SAO band 3 protein in increased band 3 attachment to the skeleton and band 3 oligomerization. We found first that SAO RBC skeletons retained more band 3 than normal cells and that this increased retention preferentially involved the mutant SAO band 3 protein. Second, SAO RBCs contained a higher percentage of band 3 oligomer-ankyrin complexes than normal cells, and these oligomers were preferentially enriched by the mutant SAO protein. At the ultrastructural level, the increased oligomer formation of SAO RBCs was reflected by stacking of band 3-containing intramembrane particles (IMP) into longitudinal strands. The IMP stacking was not reversed by treating SAO RBCs in alkaline pH (pH 11), which is known to weaken ankyrin-band 3 interactions, or by removing the cytoplasmic domain of band 3 from SAO membranes with trypsin. Finally, we found that band 3 protein in intact SAO RBCs exhibited a markedly decreased rotational mobility, presumably reflecting the increased oligomerization and the membrane skeletal association of the SAO band 3 protein. We propose that the mutant SAO band 3 has an increased propensity to form oligomers, which appear as longitudinal strands of IMP and exhibit increased association with membrane skeleton. This band 3 oligomerization underlies the increase in membrane rigidity by precluding membrane skeletal extension, which is necessary for membrane deformation.     

Engraftment of bone marrow cells into normal unprepared hosts: effects of 5-fluorouracil and cell cycle status

Bone marrow from animals treated with 5-fluorouracil (5FU) competes equally with normal marrow when assessed in vivo in an irradiated mouse, but shows markedly defective engraftment when transplanted into noncytoablated hosts. Using Southern Blot analysis and a Y-chromosome specific probe, we determined the level of engraftment of male donor cells in the bone marrow, spleen, and thymus of unprepared female hosts. We have confirmed the defective engraftment of marrow harvested 6 days after 5FU (FU-6) and transplanted into unprepared hosts and shown that this defect is transient; by 35 days after 5FU (FU-35), engraftment has returned to levels seen with normal marrow. FU-6 marrow represents an actively cycling population of stem cells, and we hypothesize that the cycle status of the stem cell may relate to its capacity to engraft in the nonirradiated host. Accordingly, we have evaluated the cycle status of engrafting normal and FU-6 marrow into normal hosts using an in vivo hydroxyurea technique. We have shown that those cells engrafting from normal marrow and over 70% of the cells engrafting from FU-6 marrow were quiescent, demonstrating no killing with hydroxyurea. We have also used fluorescent in situ hybridization (FISH) analysis with a Y-chromosome probe and demonstrated that normal and post-5FU engraftment patterns in peripheral blood were similar to those seen in bone marrow, spleen, and thymus. Altogether these data indicate that cells engrafting in normal, unprepared hosts are dormant, and the defect that occurs after 5FU is concomitant with the induction of these cells to transit the cell cycle.     

对QT离散度实质的探讨

为探讨ＱＴ离散度（ＱＴｄ）的真实意义，观察１３９例急性心肌梗死（ＡＭＩ，ＡＭＩ组）及１０９例正常人（对照组）的最长ＱＴ间期（ＱＴｍａｘ）、校正ＱＴｍａｘ（ＱＴｃｍａｘ）及ＱＴｄ的变化。结果：①ＡＭＩ组的ＱＴｍａｘ、ＱＴｃｍａｘ和ＱＴｄ均显著高于对照组（分别为４２２．６０±３０．５１ｍｓｖｓ３８２．４６±２３．４０ｍｓ、４６０．２１±２８．９６ｍｓｖｓ３８８．５１±２０．１５ｍｓ、５９．８０±２８．４０ｍｓｖｓ３９．４３±１２．２１ｍｓ，Ｐ均＜０．００１）。②ＡＭＩ组中发生严重室性心律失常（ＶＡ）患者（１１４例）的ＱＴｍａｘ、ＱＴｃｍａｘ、ＱＴｄ与无ＶＡ的患者（２５例）相比，均有显著差异（分别为４４８．５８±３３．４０ｍｓｖｓ４１６．１０±３５．３０ｍｓ、４８１．４３±３５．１７ｍｓｖｓ４３９．６０±２７．１０ｍｓ、６６．９０±２０．７２ｍｓｖｓ４８．３２±２３．６１ｍｓ，Ｐ均＜０．００１）。认为ＡＭＩ时ＱＴｄ系Ｔ向量环在不同导联上的“投影”差异所引起的，其异常的本质是ＱＴ间期延长     

Purified murine hematopoietic stem cells function longer on nonirradiated W41/Wv than on +/+ irradiated stroma

Mouse bone marrow (BM) was separated into low-density, lineage- negative, wheat germ agglutinin-positive (WGA+), Rhodamine-123 bright (Rhbright) or dim (Rhdim) cells to obtain populations that were highly enriched for committed progenitors (Rhbright cells) or for more primitive stem cells (Rhdim). When 2,500 Rhbright or Rhdim cells were seeded onto 6-week-old irradiated (20 Gy) long-term BM cultures (LTBMC), the nonadherent cell production from Rhbright cells was transient and ended after 5 weeks. Production from Rhdim cells did not begin until week 3, peaked at week 5, and ended at week 8, when the irradiated stroma seemed to fail. Termination of cell production from Rhdim cells did not occur in nonirradiated LTBMC from W41/Wv mice. During peak nonadherent cell production, 25% to 30% of the cells in the nonirradiated LTBMC from W41/Wv mice had donor cell markers. Two approaches were tested to try to enhance the proportion or number of donor cells. Addition of Origen-HGF at the time of seeding Rhdim cells caused a nonspecific increase in both host and donor cell production, but a specific increase in production of donor cells was obtained by seeding the cultures at 2 weeks rather than 6 weeks. Limiting dilution of Rhdim cells gave the same frequency of wells producing cells on both irradiated +/+ and nonirradiated W41/Wv or W/Wv cultures.     

继续医学教育活动的有效性

继续医学教育的目的是通过向医生提供最新的医学知识和技能,使医生在其整个职业生涯中,一直保持较高的医疗水平.但目前还没有充足的证据能证明继续医学教育活动的有效性,以及在继续医学教育活动中哪些教育方法和技术能最有效地传播和记忆医学知识.为了全面、系统地评估继续医学教育活动的有效性,以及了解不同的教育手段对医生知识、态度、技能、临床表现和临床效果的作用.美国约翰·霍普金斯大学医学院、美国医疗保健研究与质量管理署和美国胸科医师学会的专家共同进行了一项系统回顾性研究.