Four nonisotopic immunoassays of free thyroxin evaluated

We evaluated four new nonisotopic immunoassays of free thyroxin (FT4)--Amerlite FT4 (Amersham International), Magic Lite FT4 (Ciba Corning Diagnostics), Stratus FT4 (Dade--Baxter Travenol), and FT4 Enzelsa (Compagnie ORIS Industrie)--by comparison with two FT4 radioimmunoassays: Amerlex and Sclavo. Inter- and intra-assay coefficients of variation were less than 10% in the working range and there was no significant interaction between the tracer conjugate and albumin. All methods except Enzelsa gave results equivalent to those obtained with the Sclavo chromatographic technique. In a population consisting of 325 euthyroid subjects and 111 hyperthyroid and 61 hypothyroid patients without any treatment, we observed slight overlaps between the hyperthyroid and euthyroid populations and diagnostic sensitivities were approximately 0.95 and 0.80 for hyperthyroidism and hypothyroidism. In specific populations (69 patients with chronic renal failure, 20 patients in intensive-care, 17 patients treated with heparin, and 27 pregnant women), results were quantitatively similar to those obtained by the Sclavo assay. We conclude that these nonisotopic methods are a valid alternative to current radioisotopic commercial methods.     

Vitamin D and multiple sclerosis. A prospective survey of patients of Poitou-Charentes area

Introduction

Recent reports demonstrate the implication of vitamin D in multiple sclerosis (MS).

Methods

In a multicentric regional study (Poitou-Charentes area) during the first trimester 2010, we measured the 25-OH vitamin D serum level in 170 consecutive MS patients, and in 170 controls matched for age (± 4 years), sex and date of blood sample analysis. We searched for correlations between 25-OH vitamin D serum levels and the MS form, the disability (EDSS), the relapse rate during the previous year and the presence and number of enhancing lesions on T1-weighted MRI dating less than 12 months in relapsing MS.

Results

Hypovitaminosis D was very frequent in MS patients and 25-OH vitamin D serum level was significantly lower (14,5 ± 9,2 mcg/mL) in MS patients than in the control group (16,7 ± 9,6 mcg/mL). This serum level was inversely correlated with the degree of disability measured with EDSS score and was lower in secondary progressive (RR-SP) and primary progressive (PP) MS than in relapsing MS (RR). No correlation was found between 25-OH vit D serum level and relapse rate during the previous year in RR MS and the presence and number of enhancing lesions on T1-weighted MRI dating from less than 12 months.

Conclusion

25-OH vit D serum level is very low in MS, mainly in RR-SP and PP MS and is correlated with disability. This suggests MS patients should be screened for vitamin D deficiency and given supplementation systematically when hypovitaminosis D is discovered.     

核因子κBp65特异性小干涉核糖核酸抑制肿瘤坏死因子α诱导大鼠关节滑膜细胞中一氧化氮合酶2和环氧合酶2的表达

目的:利用核因子κBp65特异性小干涉核糖核酸抑制肿瘤坏死因子α诱导的关节滑膜细胞中一氧化氮合酶2和环氧合酶2的表达,探讨基因治疗类风湿性关节炎的新方法。方法:实验于2005-03/2006-03在北京大学医学部中心实验室(国家级)完成。①实验材料:清洁级健康近交系SD大鼠10只;一氧化氮合酶2,环氧合酶2,3-磷酸甘油醛脱氢酶引物(由北京奥科生物公司合成);肿瘤坏死因子α(Sigma公司);核因子κBp65特异性小干涉核糖核酸和转染条件由北京大学运动医学研究所陈连旭博士提供。②实验干预:切取大鼠髋关节和膝关节的滑膜体外培养滑膜细胞。利用脂质体siPORTTMLipid将核因子κBp65特异性小干涉核糖核酸转染滑膜细胞,再加入肿瘤坏死因子α刺激。阴性对照为任意编码的小干涉核糖核酸,阳性对照为针对3-磷酸甘油醛脱氢酶的小干涉核糖核酸。③实验评估:提取滑膜细胞中的核蛋白,利用电泳迁移率试验检测核因子κB的活性;提取滑膜细胞的核糖核酸和总蛋白,利用反转录聚合酶链反应和蛋白质免疫印记法从信使核糖核酸和蛋白质两水平检测一氧化氮合酶2和环氧合酶2的表达。结果:①肿瘤坏死因子α和核因子κBp65特异性小干涉核糖核酸对核因子κB转录活性的影响:与正常滑膜细胞相比,肿瘤坏死因子α可以显著提高核因子κB的结合能力,而事先转染小干涉核糖核酸48h,再用肿瘤坏死因子α刺激,核因子κB的结合能力又显著降低。②核因子κBp65特异性小干涉核糖核酸对核因子κB下游因子的影响:在培养的滑膜细胞中,肿瘤坏死因子α可以显著增加一氧化氮合酶2和环氧合酶2的表达;在转染小干涉核糖核酸抑制核因子κBp65的表达后再用肿瘤坏死因子α刺激,一氧化氮合酶2和环氧合酶2的表达被抑制。结论:①核因子κBp65特异性小干涉核糖核酸可降低肿瘤坏死因子α诱导的滑膜细胞中核因子κB的转录活性,抑制其下游因子一氧化氮合酶2和环氧合酶2的表达。②核因子κBp65特异性小干涉核糖核酸可用于基因治疗类风湿性关节炎的试验研究。     

Reduction of atherosclerosis in cholesterol-fed rabbits and decrease of expressions of intracellular adhesion molecule-1 and vascular endothelial growth factor in foam cells by a water-soluble fraction of Polygonum multiflorum

Polygonum multiflorum stilbeneglycoside （PMS） is a water-soluble fraction of Polygonum multiflorum Thunb. , one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White （NZW） rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS （25, 50, or 100 mg/kg）. Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule （ICAM）-1 protein and the vascular endothelial growth factor （VEGF） protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells.     

Mediastinal lymph node metastases from bronchogenic carcinoma: detection with MR imaging and CT

Magnetic resonance (MR) imaging and computed tomography (CT) were compared in a prospective study of 48 patients for the detection of metastatic mediastinal lymphadenopathy from bronchogenic carcinoma. The images were interpreted by three experienced radiologists using a five-point rating scale, enabling receiver operating characteristic (ROC) analysis. Imaging results were evaluated against "truth" data based on analysis of surgical specimens from mediastinoscopy and thoracotomy. All MR images were cardiac gated to reduce cardiac motion artifacts in the mediastinum. MR and CT both performed well, as indicated by similar areas under the ROC curves of 0.779 +/- 0.039 for MR imaging and 0.781 +/- 0.038 for CT scanning. No strong correlation between nodal size and metastatic involvement could be found for either MR or CT results. As long as nodal size remains the sole criterion in the detection of metastatic mediastinal lymphadenopathy, MR imaging is unlikely to enable better interpretations than CT scanning.     

A serologic study of red cells and sera from 18 Rh:32,-46 (RN/RN) persons

The red cells (RBCs) and sera from 18 RN/RN persons were studied. The study confirmed the Rh type D+C+E-c-e+Cw-, which is characterized by an increased expression of the D antigen; a markedly decreased expression of the C and e antigens; the presence of a low-incidence antigen, Rh32; and the absence of a high-incidence antigen, Rh46, which is associated with an epitope recognized by a murine monoclonal antibody (MR432). Other Rh antigens of low and high incidence were investigated, and the presence of Rh17 and Rh44 on the RBCs was confirmed. Three persons exposed to Rh:46 cells by pregnancy or transfusion (or both) had anti-Rh46. This antibody gave positive reactions with all RBCs of common and rare Rh phenotype except Rhnull, and those of D--, D.., DCw-, and RN homozygotes. This antibody is considered to be of clinical significance in case of transfusion or pregnancy.     

“It ain't over … till it's over!” Risk-mitigation strategies for patients with gastrointestinal diseases in the aftermath of the COVID-19 pandemic

The available COVID-19 literature has focused on specific disease manifestations, infection control, and delivery or prioritization of services for specific patient groups in the setting of the acute COVID-19 pandemic. Local health systems aim to contain the COVID-19 pandemic and hospitals and health-care providers rush to provide the capacity for a surge of COVID-19 patients. However, the short, medium-term, and long-term outcomes of patients with gastrointestinal (GI) diseases without COVID-19 will be affected by the ability to develop locally adapted strategies to meet their service needs in the COVID-19 setting. To mitigate risks for patients with GI diseases, it is useful to differentiate three phases: (i) the acute phase, (ii) the adaptation phase, and (iii) the consolidation phase. During the acute phase, service delivery for patients with GI disease will be curtailed to meet competing health-care needs of COVID-19 patients. During the adaptation phase, GI services are calibrated towards a “new normal,” and the consolidation phase is characterized by rapid introduction and ongoing refinement of services. Proactive planning with engagement of relevant stakeholders including consumer representatives is required to be prepared for a variety of scenarios that are dictated by thus far undefined long-term economic and societal impacts of the pandemic. Because substantial changes to the delivery of services are likely to occur, it is important that these changes are embedded into quality and research frameworks to ensure that data are generated that support evidence-based decision-making during the adaptation and consolidation phases.     

uPA纤溶途径与肝纤维化

细胞外基质(extracellular matrix,ECM)过度沉积是肝纤维化的特征性表现,纤溶系统尤其是尿激酶型纤溶酶原激活剂(urokinase- plasminogen activator,uPA)所介导的纤溶途径与肝纤维化关系密切,其主要成分包括纤溶酶原、纤溶酶、纤溶酶原激活剂及其抑制剂．uPA纤溶途径位于ECM降解酶系的顶端,肝纤维化时通过uPA-纤溶酶-基质金属蛋白酶(matrix metalloproteinases,MMPs)-ECM级联机制下调ECM降解,促进ECM在肝内沉积,而且可能在肝星状细胞(hepatic stellate cell,HSC)增殖、迁移以及肝细胞再生等过程中起到重要作用．