Thrombosis at venous insertion sites after inferior vena caval filter placement

Color Doppler flow imaging or compression ultrasound (US) was used to prospectively determine frequency of thrombosis at 54 venous insertion sites (47 in common femoral veins, seven in right internal jugular veins) after percutaneous placement of Greenfield filters for interruption of the inferior vena cava. Fifty-one filters were successfully placed in 51 patients with a dilator set or a balloon angioplasty catheter. Nine focal thrombi were detected in the common femoral vein (19%) and one in the right internal jugular vein (14%). Use of dilators induced eight thrombi (24%), compared with two (10%) from balloon catheters. The left common femoral vein had a high frequency of thrombosis, regardless of dilation technique (five of nine). Of nine patients with acute common femoral vein thrombosis, four became symptomatic within 10 days after the procedure. Patients may remain asymptomatic or have delayed symptoms; thus, US is valuable for determining patients at risk of thrombosis of the common femoral vein.     

Density of tuberculin skin reaction and its association with tuberculosis infection as defined by dual tuberculin testing.

OBJECTIVE: To determine whether the density of tuberculin skin reactions is associated with tuberculosis infection. METHODS: In a national tuberculin survey in Tanzania, 1983-1987, all eligible children in a random sub-sample of schools underwent dual tuberculin skin testing with PPD-RT23 and PPD-scrofulaceum. The density of reactions to RT23 was classified as proposed by Palmer. A larger reaction to PPD-scrofulaceum than to PPD-RT23 is suggestive of infection with environmental mycobacteria. Tuberculosis infection was defined based on dual skin test results applying a range of possible definitions. RESULTS: A total of 10,782 children aged 5-14 years and without BCG scar were included in the analysis. Large skin reactions to RT23 were generally firmer than small ones. After taking the size of the skin reaction to RT23 into account, its density was not associated with the size of the skin reaction against PPD-scrofulaceum. In particular, the density of reactions in the range 6-11 mm was not associated with tuberculosis infection according to any of the definitions used. CONCLUSION: This study suggests that the density of reaction was not associated with tuberculosis infection in Tanzanian school children after taking the size of the induration into account.     

Infusible platelet membrane microvesicles: a potential transfusion substitute for platelets

BACKGROUND: Several substitutes for intact, viable platelets have been used for transfusion, both to people and in animal models, with varied success. Infusible platelet membrane (IPM) is prepared from human platelets. IPM retains the glycoprotein (GP)lb receptor and has platelet factor 3 activity (procoagulant activity). However, factor V, serotonin, a cytoplasmic marker enzyme (purine nucleotide phosphorylase), GPIIb/IIIa complex, and HLA class I and II antigens are all absent in IPM. STUDY DESIGN AND METHODS: IPM is prepared from outdated platelets. The platelets were disrupted by freezing and thawing; they were washed and heated to inactivate possible viral contaminants, and then the sonicated membrane microvesicle fraction was separated and lyophilized. The hemostatic activity of IPM was measured by its ability to reduce the prolonged bleeding time in thrombocytopenic rabbits. RESULTS: Administration of IPM at a dose of 2 mg per kg results in a substantial reduction in the bleeding time. In a series of 23 experiments, a median preinjection bleeding time of 15 minutes was reduced to 6 minutes within 4 hours after IPM administration. Administration of IPM did show a mild enhancement in the thrombogenicity index, as measured in the Wessler rabbit model. This enhancement is, however, not significant, as a thrombogenicity index value of up to 0.6 is clinically acceptable. CONCLUSION: IPM may have clinical potential as a substitute for platelets in the treatment of bleeding due to thrombocytopenia.     

下坡运动对大鼠骨骼肌肌浆网功能的影响

目的：观测研究下坡(离心)运动对大鼠骨骼肌肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放在量与时程上的影响。此外,测定离子载体的刺激作用,即测定在含与不含(Ca2+离子载体)A23187时Ca2+-ATP酶活性的比值,用以评定囊泡的完整性。方法：成年雄性SD大鼠随机分为对照与离心运动组, 离心运动的大鼠分别于运动后即刻, 4, 24, 48, 72 和144h后取样 (n=7). 离心运动方式采用90min持续跑台下坡运动(-16°;15m/min)。取大鼠红股肌制备组织匀浆, 测定肌浆网Ca2+-ATP酶活性,Ca2+摄取与释放。结果：与对照组[19.25±1.38 nmol ·min-1·(mg protein)-1]相比, 肌浆网Ca2+摄取分别于运动后即刻和4h下降了29% and 36% (P<0.05), 24h依然降低(P<0.05). 肌浆网Ca2+释放与对照组[31.06±2.36 nmol·min-1·(mg protein)-1] 相比,也分别于运动后即刻和4h下降了37% and 39% (P<0.05), 24h持续降低(P<0.05). 用含离子载体测定的肌浆网Ca2+-ATP酶活性运动后4h降低了31%(P<0.05), 并于运动后24h仍然降低 (P<0.05)。运动后, 含与不含A23187时测定的Ca2+-ATP酶活性的比值未见显著性改变, 表明该运动没有明显改变肌浆网膜的完整性。结论：一次性低强度，长时间下坡运动导致肌浆网功能长时间降低, 运动后恢复期两天尚未完全恢复, 亦可构成离心运动诱导的骨骼肌某些功能降低的基础。提示这些变化可能产生于离心收缩时肌节长度不匀一性所造成的张力应激。     

体外制成复合软质再生颅骨修复材料填充犬颅骨缺损

目的:目前颅骨修补材料有很多种,但都为异源性无机骨替代物,并且应用该方法又要给患者再次行开颅手术,实验拟开展新型颅骨再生材料的研究。方法:实验于2006-05/11在解放军第一五七医院动物中心及中山大学附属第三医院动物实验室完成。①实验动物:30只犬随机分为实验组20只,对照组10只。②实验方法:应用纳米级羟基磷灰石为支架和成骨细胞培养,加入脱矿的犬类骨基质为载体的重组人类骨形成蛋白2,制成复合软质再生颅骨。实验组犬在右侧颅骨缺损中填补藻酸钙凝胶、成骨细胞、纳米级骨粉的复合材料,左侧颅骨缺损中填补藻酸钙凝胶、成骨细胞、纳米级骨粉和重组人类骨形成蛋白2的复合材料。对照组犬在右侧为单纯颅骨缺损,左侧颅骨缺损中填补藻酸钙凝胶、成骨细胞、纳米级骨粉和重组人类骨形成蛋白2复合材料。实验过程中对动物处置符合动物伦理学标准。③实验评估:手术后1,2,3,6个月X射线片检查颅骨缺损修复情况,对再生的颅骨组织标本进行茜素红S染色,观察成骨能力及再生材料骨膜组织细胞体外培养情况。结果:实验动物均进入结果分析。术后1个月,成骨活跃,骨端新生骨小梁基本覆盖骨断端,缺损区可见较多新生骨小梁形成,骨端新生骨小梁向缺损区长入;术后2个月可见较多散在骨岛形成;术后3个月可见成熟骨,并有髓腔形成,缺损区大量新骨形成。而各对照组骨断端处有散在骨岛,或被增生的纤维结缔组织占据,可见大量纤维组织及毛细血管长入,植入的基质材料基本被吸收,无新骨生成。结论:应用纳米级羟基磷灰石为支架和成骨细胞培养,加入脱矿骨基质为载体的重组人类骨形成蛋白2,制成的复合软质再生颅骨能自身代谢并逐渐骨化,形成新的颅骨。     

Use of risk stratification to target therapies in patients with recent onset arthritis; design of a prospective randomized multicenter controlled trial

Background  

Early and intensive treatment is important to inducing remission and preventing joint damage in patients with rheumatoid arthritis. While intensive combination therapy (Disease Modifying Anti-rheumatic Drugs and/or biologicals) is the most effective, rheumatologists in daily clinical practice prefer to start with monotherapy methotrexate and bridging corticosteroids. Intensive treatment should be started as soon as the first symptoms manifest, but at this early stage, ACR criteria may not be fulfilled, and there is a danger of over-treatment. We will therefore determine which induction therapy is most effective in the very early stage of persistent arthritis. To overcome over-treatment and under-treatment, the intensity of induction therapy will be based on a prediction model that predicts patients' propensity for persistent arthritis.     

Simvastatin protects against cholestasis-induced liver injury

Background:

Bile duct obstruction is associated with hepatic accumulation of leukocytes and liver injury. The aim of this study was to evaluate the effect of simvastatin on cholestasis-induced liver inflammation and tissue damage.

Experimental approach:

C57BL/6 mice were treated with simvastatin (0.02 and 0.2 mg·kg⁻¹) and vehicle before and after undergoing bile duct ligation (BDL) for 12 h. Leukocyte recruitment and microvascular perfusion in the liver were analysed using intravital fluorescence microscopy. CXC chemokines in the liver were determined by enzyme-linked immunosorbent assay. Liver damage was monitored by measuring serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Hepatic levels of myeloperoxidase (MPO) were also determined.

Key results:

Administration of 0.2 mg·kg⁻¹ simvastatin decreased ALT and AST by 87% and 83%, respectively, in BDL mice. This dose of simvastatin reduced hepatic formation of CXC chemokines by 37–82% and restored sinusoidal perfusion in cholestatic animals. Moreover, BDL-induced leukocyte adhesion in sinusoids and postsinusoidal venules, as well as MPO levels in the liver, was significantly reduced by simvastatin. Notably, administration of 0.2 mg·kg⁻¹ simvastatin 2 h after BDL induction also decreased cholestatic liver injury and inflammation.

Conclusions and implications:

These findings show that simvastatin protects against BDL-induced liver injury. The hepatoprotective effect of simvastatin is mediated, at least in part, by reduced formation of CXC chemokines and leukocyte recruitment. Thus, our novel data suggest that the use of statins may be an effective strategy to protect against the hepatic injury associated with obstructive jaundice.     

Mycobacterium tuberculosis Genotype and Case Notification Rates, Rural Vietnam, 2003�C2006

Tuberculosis case notification rates (CNRs) for young adults in Vietnam are increasing. To determine whether this finding could reflect emergence of Mycobacterium tuberculosis Beijing genotype, we studied all new sputum smear–positive pulmonary tuberculosis patients registered for treatment in 3 rural districts in Vietnam during 2003–2006. Beijing strain infections were more frequent in younger patients (15–24 years of age, 53%) than in older patients (31%; p<0.001). The increase in CNRs for youngest patients was larger for disease caused by the Beijing genotype than by other genotypes, but the difference was not significant. For patients 15–24 years of age, 85% of fluctuations in CNRs between years was caused by fluctuations in Beijing genotype infections compared with 53% and 23% in the groups 25–64 and >65 years of age, respectively (p<0.001). These findings suggest that young adults may be responsible for introducing Beijing strains into rural Vietnam.