Cell culture tests for assessing the tolerance of soft tissue to variously modified titanium surfaces

The aim of our research project was to achieve an improvement in the integration of enossal dental implants in the region of peri-implantary soft tissue. Improvement in the adhesion of the gingiva of the surface of enossal implants was to be achieved by modification of the titanium surface. The effect of different modifications on the biocompatibility of the modified titanium surfaces was tested: sulfur dioxide plasma treatment of titanium; acetylene plasma treatment of titanium followed by sulfur dioxide plasma etching; plasma nitration of titanium; replacement of titanium by glycidoxypropyltrimethoxy silane; coating titanium with poly[(ethene-co-vinyl acetate)-graft-vinyl chloride] and coating titanium with fibronectin. Determination of the chemical composition of the surface was carried out using X-ray photospectroscopy. The adsorption of fibronectin at the surface of the titanium was tested using an Enzyme Linked Immunosorbent Assay. In selected in vitro tests with human gingival fibroblasts, cell morphology was assessed using scanning electron microscopy and light microscopy. Cell proliferation and protein synthesis, as well as the activity of mitochondrial dehydrogenases were evaluated. By means of centrifugation and by determining initial cell adhesion, the adhesion of gingival fibroblasts was investigated. According to the kind of modification made to the titanium surfaces, it was possible to observe differences in the cellular behavior of gingiva fibroblasts on the differently modified surfaces of the implants. Coating the titanium using fibronectin produced optimization of cell growth and improvement in the adhesion of gingiva fibroblasts to the implant surface. In contrast, modification of the titanium with poly[(ethene-co-vinyl acetate)-graft-vinyl chloride] generally resulted in a deterioration of the biocompatibility of the surface. A marked correlation between the cellular compatibility of the modified titanium and the surface modification made did not become apparent. One reason for this is the large number of parameters determining the interaction between implant and tissue.     

Chemistry Test Ordering Patterns after Elimination of Predefined Multitest Chemistry Panels in a Children's Hospital

Predefined multitest chemistry panels (PMCPs) have constituted a large proportion of laboratory tests and patient charges, even in pediatric settings, despite the absence of documented clinical utility for PMCPs and the general availability of random access analyzers that do not require predefined test combinations. We eliminated PMCPs in our tertiary children's hospital but placed no other restrictions on ordering, and observed a 32.7% reduction in the number of automated chemistry tests ordered. All 23 tests in the previous PMCPs showed a decline in utilization, >50% for 8 of the tests and 20–50% for 13 others, and this change was sustained throughout an 8-month follow-up period. The total number of orders for one or more tests increased by 8.2%, but the variety of combinations that were ordered increased by 280%. The most substantial changes included a decrease in the number of orders for combinations of >15 tests, and increases in the number of orders for single tests and combinations of 2 to 5 tests. Orders for combinations identical to all of the former PMCPs declined, with the exception of the 4-test electrolyte panel. There was a marked decline in orders for a 7-test panel identical to the recently defined HCFA-AMA Basic Metabolic Panel, and orders for combinations identical to the HCFA-AMA Liver Function and Extended Metabolic panels were vanishingly rare and nonexistent, respectively. The calculated reduction in patient charges was much greater than actual cost savings, but the reduction in total tests and increase in the variety of test combinations suggest that significant savings can be realized if clinicians are encouraged to order only the tests or combinations they need without imposing procedural, financial, and regulatory burdens. Received June 30, 1998; accepted November 16, 1998.     

变量变换及其在营养调查资料分析中的应用

目的：通过对营养调查资料分析中的有关统计方法的比较和对变量变换方法的应用探讨说明在营养调查资料分析中如何正确地应用有关统计方法。方法：利用一项在上海地区开展的大规模女性肺癌病例对照研究资料，先采用直方图、Ｐ－Ｐ图及偏度、峰度检验等方法来说明数据是否符合正态分布。再对参数与非参数统计学检验的方法进行比较。重点讨论了变量变换及其应用，文中采用的变量变换方法为：自然对数变换、平方根变换、Ｂｏｘ－Ｃｏｘ幂指数转换。结果：无论是病例，还是对照人群在膳食营养素的摄入量方面往往都是非正态分布的。而且同一样本数据参数与非参数统计学检验两者的结果并不一致。变量变换后几乎所有的膳食营养素的分布情况都有了不同程度的改善。但转换后真正满足正态分布的数据病例组仅约三分之一，而对照组更低。其余数据要么偏度失正态、要么峰度失正态，或两者同时失正态。在各种变换方法中似以Ｂｏｘ－Ｃｏｘ幂指数转换法较好。结论：应从样本数据本身的性质或特点出发，决定在营养调查资料分析中采用的统计方法；也可考虑利用一些变量变换法对数据进行预处理，然后再进行统计学检验     

A proof-of-concept study to assess the putative dose response to topical corticosteroid in persistent allergic rhinitis using adenosine monophosphate challenge

INTRODUCTION: The aim of this proof-of-concept study was to assess whether nasal adenosine monophosphate (AMP) challenge may be used to quantify dose response to topical fluticasone propionate (FP) in persistent allergic rhinitis (PER). METHODS: Eligible subjects with PER entered a randomized double-blind crossover study of 2 weeks of intranasal FP at 100 microg or 400 microg daily, with a 2-week placebo washout period before each randomized treatment. Measurements after each washout or treatment comprised: peak nasal inspiratory flow (PNIF) response to nasal AMP (the primary outcome), domiciliary PNIF, the mini rhinoconjunctivitis quality of life questionnaire (miniRQLQ), symptom scores, nasal nitric oxide levels and overnight urinary cortisol:creatinine ratios. RESULTS: Thirteen patients completed per protocol. Maximal PNIF response to AMP was attenuated 0.9% (95% confidence interval -7.1 to 9.0, P=NS) by FP 100 microg, and 12.9% (4.8-20.9, P=0.009) by FP 400 microg. The 400-100 microg difference was 12.0% U (2.6-21.3, P=0.049). None of the other outcomes were responsive enough to detect any significant treatment effects. The standardized response means to FP 400 microg were 81% for AMP challenge, 54% for domiciliary PNIF, 53% for miniRQLQ, 24% for symptom scores and 18% for nasal nitric oxide. No adrenal suppression was detected at either dose. CONCLUSION: FP exhibited dose-related suppression of nasal airway hyperresponsiveness to AMP challenge, but without associated detectable adrenal suppression at the higher dose. Moreover, the AMP response demonstrated the highest signal to noise ratio compared with other outcome measures in PER.     

临床试验中评价处理效应的协变量调整问题

临床试验设计和分析中常常包括影响疾病结果的非处理因素，这些因素被统称为协变量。对处理效应的评价，若不合理考虑协变量的影响，常常会导致结论的偏倚乃至错误。因此，在临床试验中要审慎地对待这一问题，在评价处理效应时应该考虑用协变量对其进行适当的调整，以达到处理效应的正确评价。试验设计阶段的协变量调整称为“事先调整”，常用的方法有分层法、动态分配最小化法等。试验分析阶段的协变量调整称为“事后调整”，常用的方法有分层检验法、回归模型法等。通过协变量调整，一方面阐明病人特征在处理组间的不均衡并没有影响到处理效应的正确评价，提高临床试验结果的可信度；另外，协变量调整方法的合理运用还可提高统计效能。本对处理效应评价协变量调整涉及的概念、方法、步骤等进行介绍和探讨，尤其强调了应用中的一些统计学事项。     

高速气流吹袭时人上肢气动力特性

目的研究抬腿和不抬腿两种姿态下有 /无防护时 ,人上肢的气动力特性。方法在FL 2 4风洞中进行 1 /5人椅模型跨超声速风洞试验 ,研究人上肢各部的气动力特性。马赫数M =0 .4～ 2 .0 ,俯仰角α =5°～ 30°,侧滑角 β=0°～ 90°,雷诺数Re =( 0 .93～ 3.1 )× 1 0 6。结果 1 )抬腿对上肢气动特性有明显影响 ,其影响大小与抬腿状态有关 ;2 )侧滑一般使上肢气动载荷明显增加 ,特别是 β =5 0°是试验中上肢载荷比较严重的状态 ;3)所研究的防护装置 ,特别是导流板 ,对上肢的保护作用明显 ;4)提出了人上肢气动力的计算公式。结论 1 )本研究的防护装置 ,特别是导流板 ,对上肢的保护作用明显。 2 )本研究可为研制人上肢高速气流吹袭防护装置和制定相关标准提供可靠依据 ;3)人上肢气动力的计算可使用本文公式。     

Perineal Pad Test in Evaluating Outcome of Treatments for Female Incontinence: A Systematic Review

Our objective was to systematically review clinical studies of incontinence treatments for women that used pad tests to assess outcome, to determine how closely the ICS guidelines had been followed. Our review (Medline 1988–2000, plus referenced studies) identified 75 relevant papers, carrying out pad tests in clinics (n= 53) or patients’ homes (n= 28). Clinic pad tests lasted between 60 seconds and 2 hours, with inconsistent starting bladder volumes, activities carried out, other test details and presentation of results. Home pad tests lasted between 1.5 and 48 hours: the conduct and reporting of these tests were also variable. Only 25 studies used pad tests that were apparently consistent with ICS guidelines. Pad tests are important in identifying urine loss in clinical evaluations; however, we found wide variations in their conduct and reporting. We recommend that the ICS should review the guidelines, and that further research should develop clinically valid pad tests. Authors and journal editors should ensure that pad test details are fully reported.     

丙基硫氧嘧啶改善甲亢患者心脏及内分泌功能的疗效及意义

１３例初诊甲亢患者于应用丙基硫氧嘧啶治疗前、治疗３个月及６个月时超声心动图检测心功能并用放射免疫分析法检测血浆心钠素（ＡＮＰ）、肾素活性（ＰＲＡ）、血管紧张素Ⅱ（ＡｎｇⅡ）及血清甲状腺激素（ＴＴ＿３、ＴＴ＿４）水平。治疗后心率下降（Ｐ＜０．００１），体重增加（Ｐ＜０．００１），心输出量及心指数下降（Ｐ＜０．０５）。各瓣膜区流速减慢（Ｐ＜０．０５），ＴＴ＿３、ＴＴ＿４恢复正常。随高动力性循环状态改善，血浆ＡＮＰ水平明显下降（Ｐ＜０．０１）．ＡｎｇⅡ及ＰＲＡ明显升高（Ｐ＜０．０１及０．００１）。提示丙基硫氧嘧啶能有效改善甲亢患者的心脏功能及内分泌功能。     

镍冶炼烟尘致NIH3T3细胞形态转化作用的实验研究

目的　研究镍冶炼工人接触烟尘的生物学效应。方法　以来自我国两家镍冶炼厂的镍冶炼烟尘为受试物 ,处理小鼠NIH3T3细胞 ,观察细胞吞噬活性、毒性和转化活性 ,预测镍冶炼烟尘的致癌危险性。结果　 (1)两种镍冶炼烟尘均可被NIH3T3细胞吞噬 ,两样品在 10 0 .0 0 0 μg/ml剂量的吞噬率分别为6 9 .0 %、39.0 % ,2 0 0 .0 0 0 μg/ml剂量的吞噬率分别为 78.0 %、4 7.0 % ,差异均有显著性 (P <0 .0 1)。剂量为12 .5 0 0～ 10 0 .0 0 0 μg/ml时 ,两样品的相对克隆形成率分别为 71.1%～ 3.9%和 84 .4 %～9.1%。两种镍冶炼烟尘以克隆形成率表示的细胞毒性与Ni2 O3 接近 ,高于TiO2 ,而低于阳性对照物N 甲基 N’ 硝基 N 亚硝基胍 (MNNG)。 (2 )MNNG、Ni2 O3 和两份镍冶炼烟尘均可诱发NIH3T3细胞发生形态转化 ,两种镍冶炼烟尘在 12 .5 0 0～ 5 0 .0 0 0 μg/ml范围内的转化率分别为 1.9%～ 3.6 %和 0 .9%～ 2 .5 %。 (3)MNNG和镍冶炼烟尘处理的NIH3T3细胞均可与刀豆素A(ConA)发生凝集反应 ,并能在软琼脂培养基中形成集落 ,验证了转化克隆的可靠性。结论　镍冶炼烟尘具有细胞转化活性 ,为镍冶炼烟尘的致癌危险性以及镍冶炼工肺癌的病因学研究提供了新的实验室证据。