The value of the QRS scoring system in assessing regional and global left ventricular ejection fraction early after myocardial infarction

In 71 patients with a myocardial infarction (MI) (anterior in27, inferior in 44 patients) global (GEF) and regional (REF)left ventricular ejection fractions were determined by radionuclideventriculography and estimated from a 12 lead electrocardiogram(ECG), using Selvester's QRS score, during the early phase ofa MI (15 to 21 days following MI). Global ejection fractionsdetermined by radionuclide ventriculography and from ECG usingPalmeri's method were: for all M140.8 ± 12.6% vs 39.6± 11.4%; in the group of anterior M132.0 ± 10.0%vs 30.0 ± 9.7% and in the group of inferior MI 48.9±12.0%vs 45.1 ± 8.2%. A good correlation was found betweenglobal ejection fractions determined by radionuclide ventriculographyand ECG, as well as between radionuclide GEF and ECG score.A weaker correlation was found between radionuclide GEF andenzymes among all MIs and in the group of anterior MI, whilein the group of inferior MI this correlation was insignificant.The analysis of REF determined by radionuclide ventriculographyand ECG showed the greatest abnormalities in the infarct region,but in the group of anterior MI, dysfunction was present inthe whole left ventricle. The comparison of infarct-relatedREF derived from radionuclide ventriculography, with the QRSscore showed a significantly higher correlation than the comparisonwith enzymes. ECG estimation of REF from a modified Palmeri'sequation showed a better correlation with radionuclide REF thandid GEF derived from the standard Palmeri's equation: anteriorMI; r = 0.90 vs r = 0.82, inferior MI; r = 0.84 vs r = 0.69,respectively. Our results underline the value of relativelysimple ECG methods for the assessment of left ventricular globalfunction, and new possibilities for the estimation of regionalfunction in patients with myocardial infarction.     

Enhanced oxidative stress and increased mitochondrial mass during Efavirenz-induced apoptosis in human hepatic cells

BACKGROUND AND PURPOSE

Efavirenz (EFV) is widely used in the treatment of HIV-1 infection. Though highly efficient, there is growing concern about EFV-related side effects, the molecular basis of which remains elusive.

EXPERIMENTAL APPROACH

In vitro studies were performed to address the effect of clinically relevant concentrations of EFV (10, 25 and 50 µM) on human hepatic cells.

KEY RESULTS

Cellular proliferation and viability were reduced in a concentration-dependent manner. Analyses of the cell cycle and several cell death parameters (chromatin condensation, phosphatidylserine exteriorization, mitochondrial proapoptotic protein translocation and caspase activation) revealed that EFV triggered apoptosis via the intrinsic pathway. In addition, EFV directly affected mitochondrial function in a reversible manner, inducing a decrease in mitochondrial membrane potential and an increase in mitochondrial superoxide production, followed by a reduction in cellular glutathione content. The rapidity of these actions rules out any involvement of mitochondrial DNA replication, which, until now, was thought to be the main mechanism of mitochondrial toxicity of antiretroviral drugs. Importantly, we also observed an increase in mitochondrial mass, manifested as an elevated cardiolipin content and enhanced expression of mitochondrial proteins, which was not paralleled by an increase in the mtDNA/nuclear DNA copy number ratio. The toxic effect of EFV was partially reversed by antioxidant pretreatment, which suggests ROS generation is involved in this effect.

CONCLUSION AND IMPLICATIONS

Clinically relevant concentrations of EFV were shown to be mitotoxic in human hepatic cells in vitro, which may be pertinent to the understanding of the hepatotoxicity associated with this drug.     

Generation of a panel of antibodies against proteins encoded on human chromosome 21

Background  

Down syndrome (DS) is caused by trisomy of all or part of chromosome 21. To further understanding of DS we are working with a mouse model, the Tc1 mouse, which carries most of human chromosome 21 in addition to the normal mouse chromosome complement. This mouse is a model for human DS and recapitulates many of the features of the human syndrome such as specific heart defects, and cerebellar neuronal loss. The Tc1 mouse is mosaic for the human chromosome such that not all cells in the model carry it. Thus to help our investigations we aimed to develop a method to identify cells that carry human chromosome 21 in the Tc1 mouse. To this end, we have generated a panel of antibodies raised against proteins encoded by genes on human chromosome 21 that are known to be expressed in the adult brain of Tc1 mice     

Solitary epidermolytic acanthoma: a clinical and histopathological study

Background Epidermolytic acanthoma (EA) is an uncommon cutaneous entity that typically presents as a solitary lesion, or, less commonly, as multiple or disseminated discrete lesions. It usually appears at or after middle‐age, and has been reported in various locations including the face, trunk, extremities and genitalia. Histopathologically, EA shows epidermolytic hyperkeratosis (EHK) involving either the entire thickness of the epidermis or just the granular and upper spinous layers. Objective and methods To describe the clinical and microscopic features of EA, we retrospectively reviewed all cases diagnosed as EA at the Skin Pathology Laboratory at Boston University between 1999 and 2009. Results Solitary EA is more common in men (65%) and usually presents as a hyperkeratotic papule on the trunk (45%) or extremities (25%). Histopathologically, all cases of solitary EA showed the classical features of hyperkeratosis, acanthosis and EHK. Three architectural patterns were observed on scanning magnification: papillomatous (55%), cup‐shaped (40%) and acanthotic (15%). Additional common features encountered included focal parakeratosis (85%), and a sparse to mild superficial perivascular lymphocytic infiltrate (90%). Conclusion This large case series of solitary EA reviews the clinical features of this entity and describes several new histological variants.     

生物玻璃和生物胶原膜联合应用于即刻义齿种植

目的：建立即刻种植动物模型,观察生物玻璃和生物胶原膜在即刻种植中引导骨组织再生、促进骨愈合效果. 方法：实验方法：取成年家犬12只,随机编号后分为4个组,在全麻下分别拔除双侧下颌第一双尖牙,制备近中拔牙窝并即刻植入种植体.前3个组分别应用生物玻璃填塞种植体与拔牙窝骨壁之间的间隙,或在种植床上方覆盖生物胶原膜,并尝试两种方法的联合应用,空白组不采用特殊处理.②观察指标：术后观察记录种植床愈合情况.术后4,8,12周分批处死动物并取其下颌骨标本,采用大体观察、X射线、普通光镜组织学方法和扫描电镜方法观察其在种植床中引起的骨组织再生变化过程和骨结合率,统计比较各种方法的成功率. 结果：①即刻种植成功率：总体成功率为95.8%,其中应用生物玻璃填塞种植体周围间隙可以诱导骨组织再生,其成功率均为100%,在种植床上方覆盖生物胶原膜者成功率为91.7%.②诱导骨组织再生作用：单用生物玻璃或两种方法联合应用诱导骨再生效果均较快,8周时表现骨质沉积量明显较多,其成骨呈多中心性,12周时可以诱导再生成熟的骨组织,并使种植体达到骨结合;应用生物胶原膜成骨呈向心性,成骨速度稍慢,12周时可以引导再生成熟的骨组织,并使种植体达到骨结合;空白组12周时在种植体的上部仍有较大部分软组织存在. 结论：在即刻种植中应用生物玻璃和生物胶原膜均可以诱导骨组织再生,促进骨愈合,获得较高的种植成功率;两者联合应用的成骨效果较单独应用生物胶原膜好.     

新型缩氨基硫脲衍生物——氨基巯三唑Schiff碱的合成与抗菌活性

设计合成了新型缩氨基硫脲衍生物4-氨基-3-(呋喃-2)-5-巯基-1,2,4-三唑及其十种不同醛的Schiff碱衍生物,并进行了抑菌实验。结果表明:Schiff碱化合物结构中的甲亚胺基是该类化合物的活性功能基。苯环上更换不同的取代基对其活性有一定的影响,其中化合物4-(5-硝基亚糠基氨基)-3-(呋喃-2)-5-巯基-1,2,4-三唑(Ik)抗菌活性最高且抗菌谱最广;化合物4-亚水杨基氨基-3-(呋喃-2)-5-巯基-1,2,4-三唑(Ib)具有较强的抑霉活性。