Systematic evaluation of variability in ChIP-chip experiments using predefined DNA targets

The most widely used method for detecting genome-wide protein-DNA interactions is chromatin immunoprecipitation on tiling microarrays, commonly known as ChIP-chip. Here, we conducted the first objective analysis of tiling array platforms, amplification procedures, and signal detection algorithms in a simulated ChIP-chip experiment. Mixtures of human genomic DNA and "spike-ins" comprised of nearly 100 human sequences at various concentrations were hybridized to four tiling array platforms by eight independent groups. Blind to the number of spike-ins, their locations, and the range of concentrations, each group made predictions of the spike-in locations. We found that microarray platform choice is not the primary determinant of overall performance. In fact, variation in performance between labs, protocols, and algorithms within the same array platform was greater than the variation in performance between array platforms. However, each array platform had unique performance characteristics that varied with tiling resolution and the number of replicates, which have implications for cost versus detection power. Long oligonucleotide arrays were slightly more sensitive at detecting very low enrichment. On all platforms, simple sequence repeats and genome redundancy tended to result in false positives. LM-PCR and WGA, the most popular sample amplification techniques, reproduced relative enrichment levels with high fidelity. Performance among signal detection algorithms was heavily dependent on array platform. The spike-in DNA samples and the data presented here provide a stable benchmark against which future ChIP platforms, protocol improvements, and analysis methods can be evaluated.     

Shoulder joint: arthrographic CT and long-term follow-up, with surgical correlation

One hundred two computed tomographic (CT) arthrograms of the shoulder were retrospectively reviewed and compared with conventional double-contrast arthrograms from 101 patients (24 females and 77 males aged 9-70 years). One- to 4-year follow-up was obtained in 84 patients, 40 of whom underwent open-shoulder surgery or arthroscopy. Morphology of the normal portions of each labrum was categorized according to length, width, and tip shape. Correlation between morphology and age was weak, but abnormal labra were more common in younger patients. Conventional radiography was more accurate for detecting bony glenoid margin fractures, but CT was more accurate for detecting Hill-Sach fractures. CT was also more reliable than conventional arthrography in the detection of rotator cuff tears. Hence, few if any conventional radiographs are necessary between contrast material injection and CT imaging. A reduction in the number of images obtained will result in decreased radiation dose, less cost, and shorter examination time without loss of diagnostic accuracy.     

脑血管病急性期MMP-9、IL-6和IL-10水平变化的研究

目的：探讨基质金属蛋白酶‐9（MMP‐9）、白细胞介素‐6（IL‐6）和白细胞介素‐10（IL‐10）与脑动脉粥样硬化斑块不稳定性以及脑梗死的关系。方法选择急性脑血管病患者56例,其中反复短暂性脑缺血发作（TIA）16例,急性脑梗死40例。对照组为21例健康体检者。所有缺血性脑血管病患者均经头CT血管造影（CTA）检查或颈部血管超声证实存在不稳定斑块,且发病机制考虑与不稳定斑块破裂有关。采用ELISA方法检测各组血清MMP‐9、IL‐6和IL‐10水平并进行比较。结果急性脑梗死组患者血清中MMP‐9、IL‐10水平分别为（137.10±69.38）ng/mL和（39.16±32.82）pg/mL,TIA组患者血清中MMP‐9、IL‐10水平分别为（119.79±65.54）ng/mL和（33.00±21.36）pg/mL,均明显高于对照组〔分别为（65.42±36.81）ng/mL和（19.83±12.16）pg/mL〕;脑梗死组患者血清MMP‐9及IL‐10水平均高于TIA组（均P＜0.05）。各组间IL‐6水平差异无统计学意义（均P＞0.05）。结论MMP‐9和IL‐10水平升高可能与动脉粥样硬化不稳定斑块破裂以及脑梗死灶形成有关。     

Effects of Perinatal Stress and Maternal Traumatic Stress on the Cortisol Regulation of Preterm Infants

Preterm infants experience intense stress during the perinatal period because they endure painful and intense medical procedures. Repeated activation of the hypothalamic–pituitary–adrenal (HPA) axis during this period may have long‐term effects on subsequent cortisol regulation. A premature delivery may also be intensely stressful for the parents, and they may develop symptoms of posttraumatic stress disorder (PTSD). Usable saliva samples were collected (4 times per day over 2 days, in the morning at awakening, at midday, in the afternoon, and in the evening before going to bed) to assess the diurnal cortisol regulation from 46 preterm infants when the infants were 12 months of corrected age (～ 14 months after birth). Mothers reported their level of PTSD symptoms. The results showed an interaction between perinatal stress and maternal traumatic stress on the diurnal cortisol slope of preterm infants (R² = .32). This suggests that the HPA axis of preterm infants exposed to high perinatal stress may be more sensitive to subsequent environmental stress.     

3D DESS磁共振序列诊断神经根型颈椎病临床价值

目的：探讨3D双回波稳态进动（dual echo steady state ,DESS）磁共振序列在显示椎管内臂丛神经的形态解剖学信息的情况,以及在显示突出椎间盘与椎管内臂丛神经的关系的临床应用价值。方法对35例有颈肩痛和上肢麻痛等颈丛和臂丛神经根受压症状,临床高度怀疑神经根型颈椎病患者行颈椎M RI常规序列（矢状位 T1 WI ,T2 WI ,横轴位T2WI）和3D DESS序列,3D DESS序列的所有图像均采用3D最大信号强度投影（MIP）与曲面重组等后处理,由2位高级职称M RI影像诊断医师通过对重建后图像所显示的臂丛神经椎管内神经根的形态、长度以及突出椎间盘与椎管内臂丛神经的关系的影像表现,评价3D DESS序列在神经根型颈椎病影像诊断中的临床应用价值。结果3D DESS序列重建图像和常规MRI T2WI序列图像对臂丛神经椎管内神经前根的显示率分别为94．3％（33／35）和88．6％（31／35）,对臂丛神经椎管内神经后根的显示率分别为94．3％（33／35）和80％（28／35）,3D DESS序列明显优于常规层厚 T2 WI图像,差异有显著性意义（P ＜0．05）;在臂丛神经椎管内神经前后根完整性的显示方面,两者间差异无统计学意义（P ＞0.05）。结论3D DESS序列经重建后的图像,可提供更多的椎管内臂丛神经的形态解剖学信息,能清晰显示突出椎间盘对神经根的压迫情况,为临床治疗提供明确依据。     

A longitudinal immunologic evaluation of hemophiliac patients

Over an average span of one year, we performed a prospective clinical and immunologic evaluation of 30 patients with hemophilia. No patient developed life-threatening opportunistic infection or malignancy; however, the immunologic abnormalities and lymphadenopathy initially present in nine patients (lymphadenopathy group) persisted. In addition, five patients, representing 24% of the initial group without lymphadenopathy, developed generalized lymphadenopathy (converter group). One episode of idiopathic thrombocytopenia (ITP) and one episode of staphylococcal sepsis occurred in this "converter" group; one episode of ITP also occurred in the lymphadenopathy group. Sixteen patients remained asymptomatic. At the time of the follow-up evaluation, those differences in mononuclear cell (MNC) percentages and numbers noted initially among the three hemophiliac groups were no longer present. Natural killer cell function alone or in the presence of biologic response modifiers was not different among hemophiliac and control groups. Before developing lymphadenopathy, the converter group of patients had significantly better lymphocyte mitogenic function than did the other two groups of patients with hemophilia. However, lymphocyte mitogenic responses of all groups of patients with hemophilia significantly deteriorated over the course of the study. The abnormal mitogenic responses noted in these patients was explained in part by higher levels of spontaneous suppressor cell activity in mononuclear cell preparations from patients with hemophilia. We conclude that long-term immunologic studies of this patient population requires both quantitative and qualitative evaluations. Our data show that patients with hemophilia have progressive dysfunction of cell- mediated immunity.     

Pressure erosions of bone in rheumatoid arthritis: a subject review

Pressure, or compressive, erosions of bone in various locations in patients with rheumatoid arthritis are described. Possible pathophysiologic mechanisms that account for the appearance and distribution of these erosions include osteopenia, soft-tissue laxity, soft-tissue pressure on bone, bone pressure on bone, and muscular forces.     

肥胖与青少年多囊卵巢综合征

多囊卵巢综合征（PCOS）是育龄妇女常见生殖内分泌疾病。近年发现,随着儿童肥胖患病率增加,青少年PCOS发病率也逐年提高。肥胖可通过增加外周循环胰岛素水平影响PCOS发病机制,PCOS患者高雄激素血症也会增加内脏脂肪沉积。肥胖会增加与PCOS相关的代谢和心血管方面的并发症的患病风险,如胰岛素抵抗（IR）、高脂血症、高血压以及临床症状不明显的动脉粥样硬化等。早期识别青春期PCOS,有利于及时纠正、阻断其内分泌紊乱,防止近期及远期并发症发生。     

Breast specimen radiography: evaluation of a compression device

The irregular shape and uneven tissue thickness of excised breast specimens makes radiographic evaluation difficult, especially when calcifications are not present. Xeroradiographs before and after compression of 20 separate excised breast specimens were compared, and 17 of the same specimens were compared after compression combined with immersion in water. Specimen compression improved visibility of the lesion on average in 88% of cases, and visibility was equal in 12%. Combined compression/immersion further improved visibility of the lesion on average in 37% of cases. More significantly, evaluation of the compressed specimen led to a change in interpretation of the radiographs in 45% of cases. Compression of the specimen in specimen radiography is recommended in all cases in which pre-biopsy localization is performed.