Successful control of vancomycin-resistant Enterococcus faecium nosocomial outbreak in a teaching hospital in China

In 2008, a vancomycin-resistant enterococci outbreak occurred across 2 intensive care units in our hospital. This outbreak prompted us to implement intensified control measures. We describe the molecular epidemiology of the outbreak, as well as the intervention strategies that resulted in successful control of the outbreak.     

Dysregulated in vitro hematopoiesis, radiosensitivity, proliferation, and osteoblastogenesis with marrow from SAMP6 mice

The senescence accelerated-prone mouse variant 6 (SAMP6) shows normal growth followed by rapid aging, development of osteopenia, and shortened lifespan, compared with control R1 mice. Because oxidative stress is a fundamental mechanism of tissue aging, we tested whether cellular parameters that are associated with oxidative stress are impaired with marrow from SAMP6 mice. We compared in vitro hematopoiesis, irradiation sensitivity, proliferative potential, and osteoblastogenesis with marrow cells from SAMP6 and R1 mice. Marrow cells from SAMP6 mice showed shortened in vitro hematopoiesis; their stromal cells showed greater radiation sensitivity and decreased proliferation. Consistent with those properties, there was constitutive upregulation of transforming growth factor-β(1), an inhibitor of hematopoiesis, and of cell cycle inhibitory genes, p16(INK4A) and p19(ARF). Paradoxically, there was constitutive expression of osteoblast genes in stromal cells from SAMP6 mice, but in vitro matrix mineralization was impaired. These studies and data included in other reports indicate that impaired proliferation of osteoblast progenitors in SAMP6 marrow may be a major factor contributing to accelerated loss of bone mass. In sum, marrow from SAMP6 mice had diminished capacity for long-term hematopoiesis, increased radiosensitivity, and reduced proliferative capacity.     

Quantitative assessment of left ventricular systolic function in patients with coronary heart disease by velocity vector imaging

Objective: To assess the left ventricular (LV) longitudinal systolic function and asynchrony in patients with coronary atherosclerotic heart disease (CAD) by syngo velocity vector imaging (VVI). Methods: Twenty‐eight control subjects and 79 patients with CAD were examined, including 28 patients with myocardial infarction, 26 patients with coronary lumen stenosis <50%, and 25 patients with myocardial ischemia. According to the results of coronary arteriography and electrocardiogram (ECG), the myocardial segments of the LV of CAD patients were divided into four groups: ischemic, infarcted, nonischemic, and normal. Dynamic imaging was performed on all subjects. The systolic peak strain (Smax), systolic strain rate (SRmax), time to peak strain (PTs), and time to peak strain rate (PTsr) in every cardiac cycle were measured. Results: A total of 1,253 out of 1,712 (96.5%) segments were successfully analyzed with VVI. Smax and SRmax of the ischemic and infarcted segments were impaired in CAD patients. Optimal sensitivity and specificity were obtained with strain and strain rate cutoffs of ?14.08% and ?0.83 s^?1, respectively, for detecting ischemic segments and ?6.65% and ?0.38 s^?1, respectively, for detecting infarcted segments. The PTs and PTsr were significantly longer in the ischemic and infarcted segments compared to those of the control group. Conclusions: Utilizing VVI, the longitudinal strain, strain rate, and peak time in CAD patients are easy to obtain and reproducible. Strain and strain rate cutoff values of abnormal myocardium are valuable for detecting ischemia and infarction. The PTs and PTsr values possibly estimate myocardium asynchrony in CAD patients. (Echocardiography 2012;29:340‐345)     

急性外伤性颅内血肿开颅血肿清除术后迟发血肿相关因素分析

目的 分析颅内血肿开颅血肿清除术患者的临床特征及术后出现迟发血肿的危险因素.方法 以我院2009-03-2013-03收治的68例急性外伤性颅内血肿开颅手术治疗患者为研究对象,根据是否发生迟发血肿进行分组,采用Logistic回归模型分析术后迟发血肿危险因素.结果 多因素Logistic回归分析结果显示血浆凝血酶时间、手术时机、颅骨骨折为发生迟发血肿的危险因素.结论 急性外伤性颅内血肿患者多伴有重型颅脑损伤和颅内占位,术后迟发血肿一般发生于术后12 h内,以脑内血肿、硬膜外血肿、硬膜下血肿为常见,血浆凝血酶时间延长、手术时机短、合并颅骨骨折为高危因素,应引起高度关注.     

A Near Infra-Red Study of Blood Oxygenation Changes Resulting From High and Low Frequency Repetitive Transcranial Magnetic Stimulation

High and low frequency repetitive transcranial magnetic stimulation (rTMS) are both used to treat major depressive disorder(MDD). However, the physiological mechanisms underlying the therapeutic benefit and the effect of the stimulation frequency are unclear. Twelve healthy participants received 1Hz, 2Hz, and 5Hz active rTMS. Twenty 5 second trains were delivered at left dorsolateral prefrontal cortex at 110% of resting motor threshold with a 25 second inter-train interval. Blood oxygenation (HbO) was significantly reduced following the 1Hz trains compared to the HbO increases observed in both the 2Hz and 5Hz conditions. There was no significant inter-hemispheric difference in response. These results suggest that short trains of high and low frequency rTMS delivered to prefrontal cortex evoke a differential HbO response and provide additional evidence that high frequency trains result in increased neural activity. The findings may provide further explanation for the improved symptoms observed in MDD patients treated with high frequency rTMS.