Polyclonal anti-thymocyte globulins influence apoptosis in reperfused tissues after ischaemia in a non-human primate model

Reperfusion triggers the expression of inflammatory cytokines and adhesion molecules that increase the rate of apoptosis in the reperfused tissues after ischaemia, thus worsening the outcome of the grafts. Polyclonal anti-thymocyte globulins (pATGs) are able to reduce the number of lymphocytes as well as block adhesion molecules and induce apoptosis in T-lymphocytes through Fas-ligand. The aims of this study were to investigate the influence of pATGs on the prevention of apoptosis of reperfused tissues after ischaemia and to monitor their capability to enhance lymphocyte apoptosis thus decreasing the deleterious effects of ischaemia/reperfusion injury (IRI). Extremities of cynomolgus monkeys (n=8) were flushed via either the femoral or the brachial artery. After 60 min of ischaemia the limbs were reperfused with human blood. ATG was added to the blood in a therapeutic dose 20 min prior to reperfusion of the extremities. Surgically available limbs (n=20) were assigned to the following groups: ATG group (n=10) and control group (without ATG; n=10). DNA fragmentation analysis was performed in situ to detect apoptosis at the single-cell level. Our study shows an increased rate of muscle and connective tissue apoptosis in the control group compared with the ATG-treated group. Cells found in the vascular areas present different rates of apoptosis, with enhanced cellular death of endothelium and connective perivascular areas being observed in the control group. The group treated with ATG shows an increased rate of white blood cell (WBC) apoptosis in vascular and perivascular areas. Previous studies have shown that pATGs are able to induce apoptosis as well as complement-mediated cell death in peripheral T-lymphocytes in vitro. Our results confirm that pATGs not only increase the rate of apoptosis of WBCs in vivo but also have a protective effect on the reperfused tissue. This may alleviate the damage after reperfusion of solid-organ transplantation.     

Detection of abnormality in the electrocardiogram without prior knowledge by using the quantisation error of a self-organising map, tested on the European ischaemia database

Most systems for the automatic detection of abnormalities in the ECG require prior knowledge of normal and abnormal ECG morphology from pre-existing databases. An automated system for abnormality detection has been developed based on learning normal ECG morphology directly from the patient. The quantisation error from a self-organising map ‘learns’ the form of the patient's ECG and detects any change in its morphology. The system does not require prior knowledge of normal and abnormal morphologies. It was tested on 76 records from the European Society of Cardiology database and detected 90.5% of those first abnormalities declared by the database to be ischaemic. The system also responded to abnormalities arising from ECG axis changes and slow baseline drifts and revealed that ischaemic episodes are often followed by long-term changes in ECG morphology.     

Phonological processing and oral language abilities in fourth-grade poor readers

This study investigated the contribution of phonological processing and oral language skills to reading abilities (word attack, word recognition, and comprehension) in 17 fourth graders identified as poor readers. Participants were assessed in the areas of phonological awareness, verbal working memory, and rapid naming, in addition to oral language abilities as predictors of poor reading skills. Results indicated that the strongest predictors of word attack skills were phonological awareness and grammaticality judgment. The combination of phonological awareness, grammaticality judgment, phoneme manipulation, and rapid naming of digits accounted for more than half of the variance in word recognition. Furthermore, the amount of discrepancy between IQ scores and reading achievement did not distinguish groups of poor readers. The results support the importance of metalinguistic skills to support reading ability. Phonological processing and oral language abilities may vary in children with poor reading skills as processing demands change with age and task.

Learning outcomes

As a result of this activity, the reader will be able to: (1) identify phonological processing and oral language skills that are most predictive of specific reading skills in poor readers; (2) describe further evidence of the lack of utility of the discrepancy model to define reading disorders in children.     

Transient urethral obstruction predisposes to ascending pyelonephritis and tubulo-interstitial disease: studies in rats

Chronic tubulo-interstitial disease, an important cause of end-stage renal disease, often results from the combined effects of a disturbed urinary outflow tract and urinary tract infection. Acute unilateral ureteral obstruction in rats rapidly induces foci of medullary necrosis, confined to the region of the papilla and fornices. This injury may provide a nidus for bacterial invasion and may invoke reactive and regenerative changes, ultimately leading to chronic pyelonephritis and tubulo-interstitial nephropathy. To explore this possibility, adult rats underwent renal morphological evaluation 2–7 days following transient 24-h unilateral ureteral obstruction. In some experiments the bladder was inoculated with bacteria (10⁸–10⁹ cfu/ml Escherichia coli in 0.5 ml) after release of ureteral obstruction, with subsequent cultures obtained from the pelvis of both kidneys and from the urinary bladder. Morphologic evaluation of perfusion-fixed kidneys, 2–7 days after the release of 24-h ureteral obstruction disclosed papillary necrosis, urothelial proliferation, marked inner-stripe interstitial expansion, and fibrosis and proximal tubular (S₃) dilatation. The lateral (perihilar region) was predominantly affected, with lesions spreading from the fornices. There was some progression of interstitial fibrosis during the postobstructive time course or following more prolonged ureteral obstruction. By contrast, infection hardly contributed to the tubulointerstitial changes. In rats subjected to infection, cultures were positive in all 15 postobstructive kidneys, as opposed to five contralateral kidneys (P < 0.0001). Viable counts from the postobstructive kidney were also higher than those from the contralateral side (79,000 ± 12,000 vs 2900 ± 1600 cfu/ml, mean ± SEM, P < 0.0001), and were comparable to those obtained from the bladder (77,000 ± 13,000 cfu/ml). We conclude that transient ureteral obstruction predisposes to ascending pyelonephritis and to tubulointerstitial disease. This vulnerability may relate to altered urodynamics and medullary tissue destruction. Received: 28 December 1999 / Accepted: 28 September 2000     

两种人体蠕形螨各期形态结构的比较与动态观察

目的比较两种人体蠕形螨的各期形态结构特征以及活动性。方法采用挤压涂片法和透明胶纸粘贴法获取蠕形螨,在数码显微镜MoticDMB5软件系统下动态观察,然后进行拍摄和测量。结果对两种人体蠕形螨发育过程各个时期的形态特征和活动性进行了动态展示和描述。对比观察发现两种人体蠕形螨发育过程基本相似,均有卵、幼虫(3对足)、若虫(4对足)和成虫4期。由于毛囊蠕形螨若虫期有一次蜕皮,将其又分为前若虫和(后)若虫两期,前若虫较(后)若虫短,基节骨突不清。两种蠕形螨各期形态差异均较大,其活动性除虫卵外,各期均可见足和颚体活动,室温较高时(20℃以上)虫体运动活跃,移动明显。两种蠕形螨成虫末体变异也较大。另外,首次在水镜下拍摄到毛囊蠕形螨雌虫肛道(门)。结论两种人体蠕形螨均分为卵、幼虫、若虫和成虫4期,各期形态结构差异明显,易于鉴别;幼虫、若虫和成虫均具有明显的活动能力。两种人体蠕形螨似有亚种存在。     

Ultrastructure and elemental composition of the stapedius muscle in guinea pig

Summary Muscules stapedius in guinea pig was investigated with regard to morphology and elemental composition. The muscle fibers are multinucleated, contain a high amount of ribosomes, and a centriole is often found adjacent to the cell nucleus. Intramitochondrial inclusion bodies occur adjacent to cristae mitochondriales. Both type I and type II fibres occur, the latter with all three subtypes. Elemental analysis from the myofibrillar area revealed unexpected low concentration of K and high concentrations of Na, P, and Ca.Supported by grants from the Karolinska Institutet (Matti Anniko) and the Muscle Dystrophy Association (USA) (Romuald Wroblewski)     

碘酸钾、碘化钾对小鼠甲状腺形态结构和功能的影响

目的 用接近于流行病现场调查的碘水平复制小鼠动物模型，研究不同碘剂对小鼠甲状腺形态结构和功能的影响。方法 将小鼠按体重随机分为基础饲料组(NG)、适碘酸钾组(NO)、高碘酸钾组(HO)、高碘化钾组(HI)，喂养90d后，测定甲状腺重量、血清甲状腺激索、尿碘水平，在光镜和电镜下观察甲状腺形态结构的变化。结果 100μg／L的水碘即可导致小鼠胶质样甲状腺肿，使甲状腺绝对重量和相对重量增加；与NG组比较，HO组和HI组血清Td、尿碘水平上升，血清B水平无明显变化；HO组尿碘水平高于HI组；NO组与NG组比较，除尿碘水平上升外，其余各项指标无明显变化。结论 当饮水中碘浓度为100μg／L时，碘酸钾与碘化钾均可引起小鼠甲状腺肿大和甲状腺功能改变，两者无明显不同；小鼠对碘酸钾的利用率低于对碘化钾的利用率。     

肝内胆管细胞癌的形态学CT分型及临床意义

目的对肝内胆管细胞癌的形态学CT分型以及临床意义进行评价分析,为今后的临床治疗工作提供可靠的理论依据。方法抽取在2013年1月~2014年6月我院收治的临床确诊肝内胆管细胞癌患者24例,对其CT扫描情况展开回顾性分析,评价形态学CT分型以及临床诊断价值。结果本组24例患者中,包括有肿块型者10例,CT表现为肝内结节状肿瘤,未出现周围胆管扩张现象;管周围浸润型者5例,CT表现为沿着胆管纵轴生长的树枝状肿瘤,合并有周围胆管扩张;肿块合并管周浸润型者7例,CT表现出肝内结节状肿瘤,并且合并有胆管扩张;管内生长型2例,CT表现为单发、多发肿瘤结节位于扩张的胆管内。结论经CT检查可以对肝内胆管细胞癌展开准确的形态学分型,为临床治疗方案的选择提供了可靠的参考依据,临床价值显著,值得关注。     

The 7.5-kb common plasmid is unrelated to the drug susceptibility of Chlamydia trachomatis

Using a new plaque cloning technique, we obtained unique Chlamydia trachomatis strains, which were confirmed to be free of the 7.5-kb common plasmid and glycogen in inclusions. The inclusions in plasmid-free and glycogen-negative strains were characterized by a target-like bull's eye morphology that appeared with the formation of a central translucent area that began to be seen clearly at 30 h postinoculation. The clear zone was composed of gel materials originating from reticulate bodies (RBs) that were abnormally large in size and irregular in shape, although one could not differentiate the aberrant RBs from normal RBs at early stages of development. The in-vitro susceptibility of these strains to various chemotherapeutic antibiotics was tested by comparison with their parent strains possessing the common plasmid. No difference was detected for any of the antibiotics tested, indicating that the 7.5-kb common plasmid is unrelated to the drug susceptibility of C. trachomatis. Received: August 7, 2000 / Accepted: December 11, 2000     

CT重建椎弓根轴线投影点定位研究

目的:建立椎弓根螺钉最佳入钉点,提高椎弓根螺钉内固定术的准确性和安全性。方法:高速螺旋CT共扫描检查40例国人的200个L1~L5脊椎。重建后测量400个椎弓根的入点坐标(x,y),即椎弓根轴线在椎骨后表面的投影点与后正中线的距离(x)及与横突中线的垂直距离(y)。结果:x坐标从L1~L5逐渐增大,男性大于女性(P<0.05);y坐标从L1到L4逐渐下移,在L4与横突中线接近重叠,但L5突然上升,与L2节段水平相当,L1~L5y坐标基本上都在横突中线以上,但每组数据变异较大。就y坐标而言,椎弓根轴线投影点与传统入点比较均有差异。结论:横突中线是椎弓根螺钉置入的重要参照标志,但椎弓根轴线投影点并不在横突中线上,不同个体、节段之间y坐标存在的较大差异是高误置率发生的重要原因。对个体而言,术前常规通过CT测量椎弓根轴线在椎骨后表面的投影点数据对椎弓根螺钉的置入有重要指导意义。