Maize NDC80 is a constitutive feature of the central kinetochore

In yeast and animals, Nuclear Division Cycle 80 (NDC80) is an important kinetochore protein that binds to microtubules and mediates chromosome movement. Its localization pattern is unusual, since it is generally not viewed as either an inner (centromeric chromatin) or outer (regulatory) component of the kinetochore. Here we report the characterization of NDC80 in a higher plant. By taking advantage of the large meiotic kinetochores of maize, we were able to show that NDC80 localizes outside of the constitutive kinetochore protein CENP-C. Further, a detailed analysis of mitosis indicates that NDC80 is stably present on kinetochores throughout the cell cycle. The quantity of NDC80 positively correlates with measured quantities of DNA and CENP-C, suggesting that NDC80 rapidly associates with DNA following replication and is stably maintained at centromeres during cell division. The data suggest that in plants NDC80 is on par with ‘foundation’ kinetochore proteins such as CENH3 and CENP-C.     

Global gene expression and the role of sigma factors in Neisseria gonorrhoeae in interactions with epithelial cells

Like many bacterial pathogens, Neisseria gonorrhoeae must adapt to environmental changes in order to successfully colonize and proliferate in a new host. Modulation of gene expression in response to environmental signals is an efficient mechanism used by bacteria to achieve this goal. Using DNA microarrays and a tissue culture model for gonococcal infection, we examined global changes in gene expression in N. gonorrhoeae in response to adherence to host cells. Among those genes induced upon adherence to human epithelial cells in culture was rpoH, which encodes a homolog of the heat shock sigma factor, sigma(32) (RpoH), as well as genes of the RpoH regulon, groEL and groES. Attempts to construct an rpoH null mutant in N. gonorrhoeae were unsuccessful, suggesting that RpoH is essential for viability of N. gonorrhoeae. The extracytoplasmic sigma factor, RpoE (sigma(E)), while known to regulate rpoH in other bacteria, was found not to be necessary for the up-regulation of rpoH in gonococci upon adherence to host cells. To examine the role of RpoH in host cell interactions, an N. gonorrhoeae strain conditionally expressing rpoH was constructed. The results of our experiments showed that while induction of rpoH expression is not necessary for adherence of gonococci to epithelial cells, it is important for the subsequent invasion step, as gonococci depleted for rpoH invade cells two- to threefold less efficiently than a wild-type strain. Taken together, these results indicate that sigma(32), but not sigma(E), is important for the response of gonococci in the initial steps of an infection.     

白细胞介素1刺激破骨细胞性骨吸收作用的实验研究

目的：了解白细胞介素1β（IL－1β）在破骨细胞性骨吸收中的刺激作用及其相应的作用机制。方法：分别将新生大鼠破骨细胞单独以及和成骨细胞联合接种于预置象牙片的培养板中。24h后培养液中加入不同浓度的IL－1β。继续培养48h,然后取出象牙片,超声处理后行甲苯胺蓝染色,光镜下观察骨吸收陷窝的数目并计算其部面积。结果：IL－1β能够明显增加坡骨细胞和成骨细胞联合培养组象牙片上吸收陷窝的数目和面前,且刺激作用呈剂量依赖性,但对单独培养的破骨细胞无明显刺激作用。结论：IL－1β的刺激骨吸收作用由成骨细胞所介导,而非直接作用于破骨细胞。     

小儿再发性腹痛的病因学分析

目的 分析小儿再发性腹痛的病因以及相关的因素为临床选择辅助检查及诊断提供依据或参考。方法 268例再发性腹痛患儿选人调查对象,对其进行病因学调查,调查内容包括年龄、性别、季节、诱因、部位等8个因素,进行分析。选择相关的辅助检查确定病因。结果 有52例有器质性疾病(19．4％),以慢性胃炎居首位。与发作有关的因素有季节、年龄、情绪反应。结论 小儿再发性腹痛绝大多数属于功能性疾病,只有少数由器质性原因引起,但仍应引起足够重视,谨慎的选择辅助检查,避免漏诊。     

人工机械瓣膜替换术后早期并发症分析

1987年1月至2000年4月,共施行人工机械瓣膜替换手术700例,其中二尖瓣替换术398例,主动脉瓣替换术81例,二尖瓣和主动脉瓣替换术213例,三尖瓣替换术8例.158例患者术中和术后早期发生并发症,发生率为22.6%,死亡44例,死亡率6.3%.死亡原因主要为低心排出量综合征、严重感染和心律失常等.     

p16、p15蛋白在小儿急性淋巴细胞白血病的表达及临床相关性研究

目的：探讨p16、p15蛋白在急性淋巴细胞白血病（ALL）发病中的意义。方法：对23例ALL细胞进行间接免疫荧光染色,用流式细胞仪检测细胞的荧光强度,间接反映p16、p15蛋白水平。结果：23例ALL患儿p16蛋白阴性10例,p15蛋白阴性8例,p16、p15蛋白均阴性6例。3例T－ALL中p16、p15蛋白皆阴性2例,13例Non T-ALL中,p16蛋白阴性6例,p15蛋白阴性5例。高白细胞组的p16、p15蛋白表达阳性率低于非高白细胞组,差异有显著意义（P＜0．05）,HR－ALL组p16、p15蛋白阳性表达低于SR－ALL组,差异有显著意义（P＜0．05）。结论：p16、p15蛋白参与了部分急性淋巴细胞白血病的发病,p15、p15蛋白阴性的患者可能预后不良。     

Is a Titanium Implant for Total Knee Arthroplasty Better? A Randomized Controlled Study

BackgroundLighter weight and lower modulus are potential advantages of titanium (Ti) implants over cobalt chrome (CoCr) implants in total knee arthroplasty (TKA). This study was conducted to determine whether Ti implants in TKA resulted in better clinical outcomes and radiologic results.MethodsOne hundred and eight patients (216 knees) with knee arthritis warranting bilateral primary TKA were randomly allocated to undergo Ti rotating-platform TKA in one knee and CoCr rotating-platform TKA in the contralateral knee. The mean follow-up period was 5.3 years (range, 1-7 years). The weight of Ti implants was one-third lighter than that of CoCr implants (133.9 g vs 390.1 g, P < .01). Clinical outcomes were evaluated using clinical scores, patient preferences (lightness, comfort, naturalness, and satisfaction), gait analysis (kinetic and kinematic data), range of motion, and degree of pain. Radiologic results were evaluated based on the radiolucent line (RLL), degree of medial tibial bone loss, and loosening as seen on X-ray.ResultsNo significant differences were observed in clinical scores or patient preference. Regarding implant weight, approximately 70% of patients did not perceive the Ti implant as lighter. No significant differences were observed in gait analysis, range of motion, or degree of pain. The RLL was seen in 9% of the Ti implant group and 19% of the CoCr implant group.ConclusionThe lighter Ti implant did not show any clinical benefit over CoCr implants. The lightness of the Ti implant is not sufficient to matter or be noticeable. However, the Ti implant showed lower rate of RLL than the CoCr implant.Level of Evidencelevel I, randomized controlled trial.     

Estrogen and estrogen receptors in kidney diseases

Acute kidney injury (AKI) and chronic kidney disease (CKD) are posing great threats to global health within this century. Studies have suggested that estrogen and estrogen receptors (ERs) play important roles in many physiological processes in the kidney. For instance, they are crucial in maintaining mitochondrial homeostasis and modulating endothelin-1 (ET-1) system in the kidney. Estrogen takes part in the kidney repair and regeneration via its receptors. Estrogen also participates in the regulation of phosphorus homeostasis via its receptors in the proximal tubule. The ERα polymorphisms have been associated with the susceptibilities and outcomes of several renal diseases. As a consequence, the altered or dysregulated estrogen/ERs signaling pathways may contribute to a variety of kidney diseases, including various causes-induced AKI, diabetic kidney disease (DKD), lupus nephritis (LN), IgA nephropathy (IgAN), CKD complications, etc. Experimental and clinical studies have shown that targeting estrogen/ERs signaling pathways might have protective effects against certain renal disorders. However, many unsolved problems still exist in knowledge regarding the roles of estrogen and ERs in distinct kidney diseases. Further research is needed to shed light on this area and to enable the discovery of pathway-specific therapies for kidney diseases.     

Interphotoreceptor Retinol-Binding Protein Ameliorates Diabetes-Induced Retinal Dysfunction and Neurodegeneration Through Rhodopsin

Patients with diabetes often experience visual defects before any retinal pathologies are detected. The molecular mechanism for the visual defects in early diabetes has not been elucidated. Our previous study reported that in early diabetic retinopathy (DR), rhodopsin levels were reduced due to impaired 11-cis-retinal regeneration. Interphotoreceptor retinol-binding protein (IRBP) is a visual cycle protein and important for 11-cis-retinal generation. IRBP levels are decreased in the vitreous and retina of DR patients and animal models. To determine the role of IRBP downregulation in the visual defects in early DR, we induced diabetes in transgenic mice overexpressing IRBP in the retina. IRBP overexpression prevented diabetes-induced decline of retinal function. Furthermore, IRBP overexpression also prevented decreases of rhodopsin levels and 11-cis-retinal generation in diabetic mice. Diabetic IRBP transgenic mice also showed ameliorated retinal oxidative stress, inflammation, apoptosis, and retinal degeneration compared with diabetic wild-type mice. These findings suggest that diabetes-induced IRBP downregulation impairs the regeneration of 11-cis-retinal and rhodopsin, leading to retinal dysfunction in early DR. Furthermore, increased 11-cis-retinal–free opsin constitutively activates the phototransduction pathway, leading to increased oxidative stress and retinal neurodegeneration. Therefore, restored IRBP expression in the diabetic retina may confer a protective effect against retinal degeneration in DR.     

Donor Choriocarcinoma Transmission From Solid Organ Transplantation: A Case Report

Transplantation of any organ has some inherent risk of disease transmission, such as infection and malignancy. The present study aims to describe 2 cases of choriocarcinoma transmission after kidney and liver transplantation originating from the same patient. The donor was a 17-year-old woman who died of cerebral hemorrhage. Both organ recipients died of metastatic choriocarcinoma few months after the transplantation, within days after starting chemotherapy. Retrospective hCG (human chorionic gonadotropin hormone) analysis in donor's blood stored at the time of donation had a result of 9324 mIU/mL. Despite its rarity, clinicians should be aware of the risk of transplant-related choriocarcinoma from female donors in childbearing age. In some cases, hCG dosage should be performed before donation.