Platelet adhesion to collagen type IV under flow conditions

Collagen type IV is a sheet-forming collagen and a major constituent of the vessel wall. To find out which conditions are important for platelet adhesion to collagen type IV, we performed perfusion studies with anticoagulated blood in parallel plate perfusion chambers. The role of divalent cations was investigated by using plasmas with variable concentrations of Mg2+ and Ca2+ ions. When Mg2+ concentration was decreased from 2.00 mmol/L to 0.25 mmol/L at a fixed Ca2+ concentration of 1.25 mmol/L, platelet coverage on the collagen type IV surface decreased from 22.8% +/- 1.8% (n = 4) to 4.6% +/- 0.6% (n = 4) at a shear rate of 1,600 s-1. Also, platelet aggregate formation on collagen type IV was strongly impaired. A monoclonal antibody against the glycoprotein (Gp) Ib receptor and von Willebrand factor (vWF)- depleted plasma reduced the platelet coverage to collagen type IV to, respectively, 10% and 45% of the control value. Electron microscopy showed that vWF was only present between platelets and between the platelet and the collagen type IV surface, but did not bind elsewhere to collagen type IV. These data indicate that collagen type IV is a reactive collagen for platelets. Differences in physiologic plasma magnesium concentrations may in part explain the differences in platelet reactivity to collagen type IV between individuals, and perhaps contribute to differences in the risk for thrombosis.     

16层螺旋CT血管造影对冠状动脉狭窄的评价

目的:分析16层螺旋CT血管造影(MSCTA)无创性评价冠状动脉(冠脉)狭窄的价值.方法:80例临床初诊疑为冠心病,既往无冠脉成形术和搭桥术史的患者,行冠脉16层MSCTA后(其中9例在CT扫描前心率超过80次/min的患者应用了β受体阻滞剂),回顾性重建心电门控轴位图像,并分别采用容积成像、多平面重建、曲面重建、最大密度投影等后处理方法,对所有冠脉及其分支进行重建,统计可供临床评价的、管径≥1.5 mm的冠脉段,以选择性冠脉造影(SCA)为标准,对比分析MSCTA诊断冠脉显著性狭窄(管腔平均直径缩小>50%)的准确性.结果:94%(989/1056)的冠脉节段和94%(290/310)的冠脉主支可供评价,(6%)67/1056段不能评价的主要原因分别为:心脏运动伪影39段,致密钙化20段和管腔显影不良8段.除外不能评价的冠脉,按节段和主支分类,与SCA相比,MSCTA诊断冠脉显著性狭窄的差异无统计学意义,其敏感性、特异性、阳性和阴性预期值分别为93%、99%、87%、99%和95%、98%、91%及99%.结论:在患者心率<80次/min时,16层MSCTA即可获得较好的图像质量用于评价冠脉并判断其狭窄程度,是一种值得临床医生信赖的检查冠脉有无狭窄的无创伤性方法.     

Stem cell factor and interleukin-7 synergize to enhance early myelopoiesis in vitro

Interleukin-7 (IL-7) has been shown to be a critical factor in murine lymphoid development. It stimulates pre-B cells to divide in the absence of stroma cells and it is an important growth regulator of immature and mature T cells. IL-7 has been shown to synergize with stem cell factor (SCF) to provide a potent growth stimulus for pre-B cells. However, the combined effects of IL-7 and SCF on murine primitive hematopoietic cells in vitro have not been established. In the present study, the effects of recombinant rat (rr) SCF and recombinant human (rh) IL-7 on primitive murine bone marrow progenitors (Lin-Sca1+) were investigated in single-cell cloning experiments. rhIL-7 alone had no proliferative effect on Lin-Sca1+ cells, but in a dose-dependent manner directly enhanced rrSCF-induced colony formation, with an average increase in colony numbers of 2.7-fold. Interestingly, the cells formed in response to SCF and IL-7 were predominantly mature granulocytes. Thus, SCF and IL-7 synergize to stimulate early myelopoiesis in vitro.     

On the nature of personal narratives of high quality

This investigation explores the discourse devices associated with high-quality personal narratives. The study examined normative characteristics of 11 high-quality personal narratives of a frightening experience identified (from a larger set of 72 narratives) for their effectiveness in engaging the audience. Lay ratings and an ethnographic interview with seven of the excellent storytellers further characterized the stories and validated their selection. Narratives of both African Americans and Caucasians were represented, and were similar in nature. The excellent narratives were longer, conveyed more fearful topics, and were more dramatic than average narratives. Drama was achieved through direct speech, prosodic shifts, voice changes, inclusion of multiple characters, repetition, and syntactic and semantic parallelism. Illustrative narrative excerpts are provided. This study illustrates the potential in pairing holistic and analytical approaches to narrative analysis.     

cIMPACT‐NOW update 6: new entity and diagnostic principle recommendations of the cIMPACT‐Utrecht meeting on future CNS tumor classification and grading

cIMPACT‐NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) was established to evaluate and make practical recommendations on recent advances in the field of CNS tumor classification, particularly in light of the rapid progress in molecular insights into these neoplasms. For Round 2 of its deliberations, cIMPACT‐NOW Working Committee 3 was reconstituted and convened in Utrecht, The Netherlands, for a meeting designed to review putative new CNS tumor types in advance of any future World Health Organization meeting on CNS tumor classification. In preparatory activities for the meeting and at the actual meeting, a list of possible entities was assembled and each type and subtype debated. Working Committee 3 recommended that a substantial number of newly recognized types and subtypes should be considered for inclusion in future CNS tumor classifications. In addition, the group endorsed a number of principles—relating to classification categories, approaches to classification, nomenclature, and grading—that the group hopes will also inform the future classification of CNS neoplasms.     

Noninvasive Detection of Coronary Artery Stenosis Using 16-slice Spiral CT：a Comparison with Selective X-ray Coronary Angiography

Multislice spiral CT(MSCT)has recently e-volved as a modalityfor non-invasive coronaryi ma-ging.16-slice MSCT allows excellent distal coro-nary coverage with higer temporal and spatial reso-lution.It can be usedto detect stenosis of coronaryartery with a diameter≥1.5cm[1,2].We investi-gated a group of coronary MSCT angiography(MSCTA)results,with those of selective X-raycoronary angiography(SCA)serving as the refer-ence standard.1MATERIALS AND METHODS1.1PatientsBetween July20…     

Nutritional and genetic contributions to serum cholesterol concentration in a children's follow-up study

In the Finnish multicentre study of cardiovascular risk in young Finns in 1980, 1983 and 1986, 2429, 2052 and 1841 9 to 18-year-old children and adolescents participated. In 1980, subjects of eastern origin living in the west had, despite their western diet, higher serum cholesterol concentrations than subjects both residing in and originating from the west. In males, eastern origin increased the eastlwest difference in serum cholesterol concentrations. Between 1980 and 1986 the mean serum total cholesterol of the study cohorts decreased by 5.5% and simultaneously the east/west differences in serum cholesterol concentrations disappeared in boys. The study suggests that genetic background is a separate factor determining serum total cholesterol level, but with declining serum cholesterol concentrations the effect of the genetic factor does not become manifest.     

中国和英国精神科医生对儿童多动行为症状的评估比较

目的 :比较不同文化背景的精神专科医生在评估多动症儿童各种症状表现时的一致程度 ,探讨文化对儿童多动症诊断可能产生的影响。方法 :使用单独或集体行为观察清单 ,让两地的精神科医生对儿童多动症的各种表现进行症状评估 ;所有的评估者均观察同一录像带上患儿的行为表现 ;对其评定结果进行统计和比较。结果 :儿童独自活动观察量表的 12项中有 11项症状条目评定结果类似 ,有 3项英国医生的评分高于中国医生 ,有 9项中国医生评分高于英国医生 ,其中 1项具有显著性差异。结论 :对行为表现和症状认知的文化差异可能使流行病学的研究出现不同的结果 ,即使使用统一的诊断标准和症状评分量表作为诊断工具 ,不同文化背景的国家 ,儿童多动症的患病率仍然可不一致     

Colorectal liver metastases: Current management and future perspectives

The liver is the commonest site of metastatic disease for patients with colorectal cancer, with at least 25% developing colorectal liver metastases (CRLM) during the course of their illness. The management of CRLM has evolved into a complex field requiring input from experienced members of a multi-disciplinary team involving radiology (cross sectional, nuclear medicine and interventional), Oncology, Liver surgery, Colorectal surgery, and Histopathology. Patient management is based on assessment of sophisticated clinical, radiological and biomarker information. Despite incomplete evidence in this very heterogeneous patient group, maximising resection of CRLM using all available techniques remains a key objective and provides the best chance of long-term survival and cure. To this end, liver resection is maximised by the use of downsizing chemotherapy, optimisation of liver remnant by portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy, and combining resection with ablation, in the context of improvements in the functional assessment of the future remnant liver. Liver resection may safely be carried out laparoscopically or open, and synchronously with, or before, colorectal surgery in selected patients. For unresectable patients, treatment options including systemic chemotherapy, targeted biological agents, intra-arterial infusion or bead delivered chemotherapy, tumour ablation, stereotactic radiotherapy, and selective internal radiotherapy contribute to improve survival and may convert initially unresectable patients to operability. Currently evolving areas include biomarker characterisation of tumours, the development of novel systemic agents targeting specific oncogenic pathways, and the potential re-emergence of radical surgical options such as liver transplantation.     

重组人BAFF112-285的制备及活性分析

目的 制备具有功能活性的重组人TNF家族的B细胞激活因子(B cell activating factor belonging to the TNF family,BAFF)胞外区112—285氨基酸残基段(rhBAFF112—285)，为BAFF的深人研究奠定基础。方法 提取人HL-60细胞总RNA，经RT—PCR扩增编码人BAFF胞外区112—285氨基酸残基(BAFF112—285)的cDNA，行序列测定后，构建于原核表达载体pQE—80L并转化大肠杆菌DH5α，经IPTG诱导表达rhBAFF112—285，Ni^2 —NTA层析纯化，进而经^3H—TdR掺人实验检测其免疫学活性。结果 RT—PC双扩增得到了525bp的DNA片段，序列分析与GenBank中报道的编码人BAFF112—285的cDNA序列一致，该胞外区片段在大肠杆菌中获得了高效表达，表达水平达细菌总蛋白的45．7％，经纯化后纯度可达98．4％，活性检测证实其能明显刺激外周血淋巴细胞活化。结论 利用大肠杆菌可高效表达rhBAFF112—285，所获纯化产物具有生物学活性，所获结果为进一步研究创造了条件。