An analysis of reimbursement for outpatient medical care in an urban hospital emergency department.

The investigators examined the demographic and clinical factors associated with the collection experience in a series of 786 patients who were treated in an urban hospital emergency department (ED) but not admitted to the hospital. They found that 57% of the total net charge of $150,489 had been paid within 180 days. This rate can be compared with an average inpatient collection rate of 85% at 180 days. Seven factors were found to account for the collection rate variation, making up 38.4% of the total variation. Age, gender, primary diagnosis, season of visit, time of arrival, and residence were not found to be main contributors. Insufficient collection rates may be an indication that EDs increasingly are becoming a financial risk to hospitals. The hospital's collection experience will become more important as an indicator of financial risk if the costs of operating EDs continue to escalate and collection rates do not improve. Both the costs of providing a service and the amount of the charge actually collected are valid concerns to those operating EDs.     

Markers of HIV infection in the Concorde trial. Concorde Co-ordinating Committee

The Concorde trial compared immediate (Imm) with deferred (Def) AZT monotherapy in asymptomatic HIV-positive participants. Haematological and immunological markers and weight were measured throughout, and correlated with clinical endpoints. Markers associated with disease progression (CD4 lymphocyte count and percentage, platelets, p24 antigen and beta 2 microglobulin favoured Imm: those associated with toxicity (haemoglobin, neutrophils and white cell count) favoured Def. CD8 and total lymphocyte count did not differ significantly between groups. In multivariate analysis, the combination of baseline CD4, p24 antigen and beta 2m was the best baseline predictor of disease. Including change in CD4 and beta 2m at 12 weeks, or changes over follow- up in these markers significantly improved the fit. Markers were also incorporated into the definition of 'clinical' endpoints. Hazard ratio estimates from end-points that included CD4 < 50 and CD4 < 25 were closest to those for AIDS or death alone, but added very few extra events. Use of other landmark CD4 counts (100 or greater) or relative decreases in counts (25% or more) increased the number of events, but overestimated the effect of immediate AZT. Although AZT had a beneficial effect on the surrogate markers of efficacy evaluated, these changes did not predict clinical outcome, nor could the markers be usefully incorporated into an endpoint definition.      

脑源性神经生长因子促进成年大鼠脑海马神经干细胞定向分化的浓度选择

目的：探讨培养基中表皮生长因子与血清两者浓度一定的条件下，不同浓度的脑源性神经生长因子对成年大鼠脑海马神经干细胞向神经元分化的影响。 方法：实验于2007—08在中国医科大学神经解剖研究室完成。①材料：清洁级雄性成年SD大鼠1只，由中国医科大学实验动物部提供，实验过程中对动物的处置符合动物伦理学标准。实验过程中应用的表皮生长因子、脑源性神经生长因子均由R＆D公司提供：（多实验方法：无菌条件下分离大鼠脑海马组织，剪碎后胰蛋白酶消化，过滤、离心、弃上清，加入含2％B27、20μg／L表皮生长因子、20μg／L碱性成纤维生长因子的DMEM／F12无血清条件培养基体外培养神经干细胞，传至第4代时利用有限稀释法进行单克隆培养，100倍镜下克隆球直径约为200μm时制备单细胞悬液，稀释后滴加于96孔板内，设立两组，全量新鲜培养基组加入刚配置未使用过的DMEM／F12无血清培养基100μL，半量条件培养基组加入上述曾用于神经干细胞培养且含有其代谢产物的1／2DMEM／F12无血清培养基100斗L。（劲实验评估：观察神经干细胞的单克隆培养增殖情况。对克隆球行巢蛋白、神经元特异性烯醇化酶、胶质原纤维酸性蛋白免疫细胞化学染色。按培养基中脑源性神经生长因子终浓度的不同将所培养细胞设立0，50，100，150，200μg／L组，各组均加入20μg／L表皮生长因子和体积分数为0．1的胎牛血清，1周后行神经元特异性烯醇化酶免疫细胞化学染色，检测神经干细胞向神经元分化情况。 结果：①神经干细胞单克隆培养结果：单克隆培养开始时神经干细胞增殖缓慢，半量条件培养基组细胞增殖速度快于全量新鲜培养基组，随着细胞数的增多，两组细胞增殖速度也相应加快，分别在培养后第12天、第15天形成直径为200μm的克隆球。②神经干细胞免疫细胞化学染色结果：单克隆培养后克隆球表达巢蛋白，诱导分化后神经元特异性烯醇化酶、胶质原纤维酸性蛋白均呈阳性表达：③各组神经干细胞分化为神经元的比例：与0μg／L脑源性神经生长因子组比较，50，100μg／L脑源性神经生长因子组的神经干细胞分化为神经元比例均明显增高（t=2．502～5．025，P〈0．05）；而浓度为150，200μg／L时均无明显变化（t=0．420～1．857，P〉0．05）。 结论：向含有B27、表皮生长因子、碱·性成纤维生长因子的DMEM／F12条件培养基中加入20μg／L表皮生长因子和体积分数为0．1胎牛血清的情况下，脑源性神经生长因子促使神经干细胞向神经元分化的较佳浓度为50μg／L。     

瘢痕疙瘩发病机制的研究动态

目的:总结瘢痕疙瘩在分子遗传学和生物化学方面的发病机制,为临床诊断和治疗提供可靠的依据。资料来源:应用计算机检索Pubmed1980-01/2006-10相关瘢痕疙瘩发病机制方面的文献,检索词“keloids”,限定文献语言种类为English。同时计算机检索中国期刊网1980-01/2006-10相关瘢痕疙瘩发病机制方面的文献,检索词“瘢痕疙瘩”,限定文献语言种类为中文。资料选择:对资料进行初审,选取包括瘢痕疙瘩发病机制的文献,开始查找全文。纳入标准:与瘢痕疙瘩和瘢痕疙瘩成纤维细胞相关的分子生物学研究。排除标准:相关的综述文献。资料提炼:共检索到681篇关于瘢痕疙瘩发病机制的文献,最终纳入33篇符合标准的文献。资料综合:瘢痕疙瘩有着过度生长、侵犯邻近组织、手术切除后极易复发、治疗效果不佳等特点,成为当今医学界面临的一个重大难题。瘢痕疙瘩发病机制迄今未明,本文从遗传机制、成纤维细胞功能、生物活性因子和胶原代谢等方面综述了近几年来对瘢痕疙瘩病因研究的最新进展,发现利用基因检测技术成为探求病因的一个重要手段和发展趋势,也为未来基因治疗提供了可靠的实验室依据。结论:越来越多的研究在瘢痕疙瘩相关致病基因位点的定位和克隆方面展开,这不但能够查找出发病原因,还可以为易感人群的早期预防提供方向,为瘢痕疙瘩的基因治疗奠定一定的基础。     

Long-term use of antecubital veins for plasma exchange. The Canadian Cooperative Multiple Sclerosis Study Group

True or sham plasma exchange was done weekly for 20 weeks in patients in two of the randomization groups in a prospective, blind clinical trial of experimental treatments for multiple sclerosis. Because patients could be randomized to receive sham plasma exchange and placebo medications, it was decided when the trial was designed that the use of fistulae, arteriovenous shunts, venous cutdowns, or other aggressive forms of venous access would not be permitted for any patient. Accordingly, patients judged to have inadequate superficial antecubital veins were ineligible for the trial. To date, only 13 (4.4%) of 294 patients considered for entry into the trial have been rejected on these grounds. In only 4 of the 93 patients undergoing exchange was it necessary to discontinue plasma exchange because of inadequate venous access. In 79.3 percent of the 1207 exchanges done in these patients, there were no problems of any kind with venous access. In 5.4 percent of these 1207 exchanges, it was necessary to terminate the procedure prematurely because of difficulties with patients' veins. Thus, the great majority of patients free of serious systemic illness (other than chronic progressive multiple sclerosis) can undergo weekly plasma exchange for up to 20 weeks using superficial antecubital veins without the need to resort to more invasive methods of venous access.     

The process and outcomes of a multimethod needs assessment at a homeless shelter.

Many factors contribute to homelessness, including extreme poverty, extended periods of unemployment, shortages of low-income housing, deinstitutionalization, and substance abuse. As a result, the needs of people who are homeless are broad and complex. This needs assessment used literature reviews, review of local documents and reports, participant observation, locus groups, and reflective journals to guide the development of an occupational performance skills program at one homeless shelter in south Florida. Through these methods, the role of occupational therapy was extended beyond direct service to include program and resource development, staff education, advocacy, and staff-resident mediation. The findings of the needs assessment and the actions taken as a result of this work point to the huge potential for occupational therapists and students to work together with staff and residents of homeless shelters.     

Differences in teniposide disposition and pharmacodynamics in patients with newly diagnosed and relapsed acute lymphocytic leukemia.

Teniposide, a widely used investigational anticancer drug, is extensively bound to plasma proteins (greater than 95%). The present study evaluated the clearance and pharmacodynamics of total and unbound teniposide in patients with acute lymphocytic leukemia who were either in first complete remission or who had relapsed and achieved a subsequent complete remission. When compared to values of patients in first remission, the mean total systemic clearance of teniposide in relapsed patients was significantly lower at the time remission reinduction therapy was initiated, but increased to values greater than first remission patients after a subsequent remission was achieved. However, the mean clearance of unbound teniposide (ml/min/m2) was 3-fold lower in relapsed patients during reinduction therapy (1224 vs. 4261, P less than .0001), and improved but remained low after these patients achieved a subsequent remission (1965, P = .025). Changes in plasma protein binding accounted for the increase in total clearance when unbound clearance decreased. Continuous therapy with L-asparaginase was the major treatment difference in those patients with hypoalbuminemia and lower clearance of unbound teniposide. In 15 evaluable patients in complete remission, there was a statistically significant (P = .039) linear correlation between the percentage decrease in white blood cell count and the systemic exposure (AUC) to unbound teniposide, with higher exposure associated with a greater decrease in white blood cell count. There was not a significant correlation between the percent decrease in white blood cell count and the dosage given or the systemic exposure to total teniposide.(ABSTRACT TRUNCATED AT 250 WORDS)     

乙交酯-丙交酯共聚物-细胞复合体移植治疗脊髓损伤

目的:观察神经干细胞、许旺细胞和组织工程支架材料乙交酯-丙交酯共聚物于大鼠髓内共移植后的生物相容性,及其对大鼠损伤脊髓形态和功能的修复作用。方法:实验于2005-05/2006-09在首都医科大学附属北京市神经外科研究所损伤修复实验室完成。①实验材料:健康成年雌性Wistar大鼠36只,随机数字表法分为单纯支架组、神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组,12只/组。乙交酯-丙交酯共聚物由中科院化学研究所医用高分子材料中心提供。②实验方法:各组大鼠均建立脊髓T9半横断损伤模型。神经干细胞 许旺细胞 支架复合体组取2×1010L-1的许旺细胞、神经干细胞各10μL接种于乙交酯-丙交酯共聚物支架内,神经干细胞 支架复合体组取2×1010L-1的神经干细胞10μL接种于乙交酯-丙交酯共聚物支架内,单纯支架组取10μLDMEM培养液置于乙交酯-丙交酯共聚物支架内,于脊髓缺损处分别植入对应的复合物。③实验评估:应用电镜观察乙交酯-丙交酯共聚物支架的降解及轴突的再生状况;应用BBB评分和电生理技术检测大鼠脊髓功能性的恢复情况。结果:36只Wistar大鼠均进入结果分析。①行为学观察结果:移植术后4,12周,神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组大鼠的后肢运动功能BBB评分均好于单纯支架组(P<0.01),其中神经干细胞 许旺细胞 支架复合体组尤为明显。②神经电生理检查结果:在脊髓半横断损伤后即刻,所有动物的体感诱发电位和运动诱发电位波幅都明显减低甚至消失。移植术后4周,神经干细胞 支架复合体组、神经干细胞 许旺细胞 支架复合体组大鼠的体感诱发电位和运动诱发电位波幅均有所恢复;至移植术后12周恢复明显。单纯支架组移植术后4,12周体感诱发电位和运动诱发电位波幅无明显变化。③电镜观察结果:扫描电镜下,随着时间的延长各组植入的乙交酯-丙交酯共聚物逐渐降解。透射电镜下,各组植入材料正中横断面可见新生的无髓及有髓神经纤维,至12周时神经干细胞 许旺细胞 支架复合体组最明显。结论:乙交酯-丙交酯共聚物在大鼠损伤的脊髓内具有良好的生物相容性;其与神经干细胞、许旺细胞共移植能够明显促进脊髓半横断损伤大鼠的脊髓轴突再生,并改善肢体的运动功能。     

人工耳蜗植入术后声场主观测听阈值与产生听觉最小电流值的关联分析

目的:观察人工耳蜗植入术后产生听觉的最小电流值(T值)和声场主观测听阈值的变化趋势,分析可能存在的对应关系。方法:于2001-01/2004-12选择解放军第四军医大学西京医院全军耳鼻咽喉专科中心收治的接受人工耳蜗植入者20例,年龄3～6岁,无耳蜗畸形,植入后电极阻抗测试完全正常。植入者在开机后的3,6,12个月3个时间点调机和声场测听。人工耳蜗调试采用澳大利亚Cochlear公司提供的调试软件R126 V2.1,采用游戏行为测听法确定T值。对开机后3,6,12个月的声场主观测听阈值与人工耳蜗调试中T值的变化进行分析。结果:声场测听阈值在开机12个月中呈逐渐降低趋势,开机12个月时声场测听的听力水平较3个月和6个月有明显提高(P<0.05)。植入者术后12个月声场主观测听(啭音)听阈为15～35dB nHL,听力水平较术前有明显提高。20例植入者T值在开机12个月后降到144～158mA,明显低于6个月和3个月的水平(P<0.05)。结论:开机后12个月内产生听觉的最小电流值和声场测听阈值都呈逐渐下降趋势。植入者在熟悉适应了电声信号后,可以在刺激电流强度下降的同时获得更好的听力水平。     

广东地区散发克罗恩病患者β防御素2启动子区基因突变检测

目的:对广东地区散发克罗恩病患者β防御素2启动子区基因突变进行筛查,探讨该基因在克罗恩病发病中的作用。方法:克罗恩病组为2002-01/2006-10于南方医院消化科确诊的克罗恩病患者45例,对照组为门诊健康志愿者50例。签定知情同意书后分别取静脉血5mL,提取基因组DNA,并根据设计好的引物序列及PCR反应条件进行目的片段的扩增,阴性对照使用蒸馏水代替DNA。扩增成功的目的基因片段用DNA纯化试剂盒进行纯化,并由上海英俊公司完成测序工作。利用DNAMAN软件将患者测序结果与正常对照结果进行比对,并与基因库数据对照(http://www.ncbi.nlm.nih.gov/BLAST/),SPSS13.0进行统计学分析。并根据结果分析其与克罗恩病患者病变特点的相关性。结果:①纳入的45例克罗恩病患者与50例健康志愿者在性别和年龄上无统计学意义,并全部进入实验分析。②45例克罗恩病患者中有4例在β防御素2启动子区第-233(G→C)位发现基因突变,密码子由AGG变成AGC,编码氨基酸由精氨酸变成丝氨酸,而50例对照组未发现此改变,二者比较具有统计学意义(χ2=4.34,P<0.05)。③4例突变的患者病变均位于小肠(χ2=10.81,P<0.01)且病情较重。结论:在克罗恩患者中存在着β防御素2启动子区基因突变携带者,与患者发病年龄、病变部位、病变程度明显相关,有必要对其功能进行进一步探讨。