Surgical versus non-surgical endodontic re-treatment for periradicular lesions

Background : Though success rates of endodontic initial treatment have been improving over the years, persistence of periapical disease is far from being a rare condition. The most common therapeutical options for the re‐treatment of teeth with periapical pathosis are non‐surgical orthograde treatment and surgical treatment. Selection between alternative treatments should be based on assessment of respective benefits (mainly healing) and risks from studies consistent with a high level of evidence. Objectives : To test the null hypothesis of no difference in outcome between surgical and non‐surgical therapy for endodontic re‐treatment of periradicular lesions. Search strategy : The Cochrane Oral Health Group Trials Register, CENTRAL, MEDLINE and EMBASE were searched with appropriate search strategies. Handsearching included eight dental journals. The bibliographies of relevant clinical trials and relevant articles were checked for identifying studies outside the handsearched journals. Seven manufacturers of instruments in the field of endodontics or endodontic surgery or both, as well as the authors of the identified randomized controlled trials (RCTs) were contacted in order to identify unpublished or ongoing RCTs. No language restriction was placed. The last electronic search was conducted on 3rd April 2007. Selection criteria : All RCTs about re‐treatment of teeth with periapical pathosis in which both surgical and non‐surgical approaches were used and having a follow up of at least 1 year were considered for the analysis. Data collection and analysis : A quality assessment of the included RCTs was carried out and the authors were contacted for missing information. We independently extracted the data in duplicate. We followed the Cochrane Oral Health Group's statistical guidelines. Main results : Three RCTs were identified, two of them reporting different data from the same clinical study. The risk of bias was judged as moderate for one study and high for the other one. One hundred and twenty‐six cases were followed up for at least 1 year, and 82 had a follow up of 4 years. At the 1‐year follow up the success rate for surgical treatment was slightly better than non‐surgical (risk ratio (RR) 1.13; 95% confidence interval (CI) 0.98 to 1.30). When the follow up was extended to 4 years (only one RCT made it) the outcome for the two procedures became similar. Authors' conclusions : The finding that healing rates can be higher for cases treated surgically as compared to those treated non‐surgically, at least in the short term, is based on two RCTs only. A single RCT reported that in the medium to long term healing rates for the two procedures are very similar. There is currently scarce evidence for a sound decision making process among alternative treatments for the re‐treatment of a periradicular pathosis. More well‐designed RCTs should be performed with follow up of at least 4 years, and with a consistent sample size, to detect a true difference in the long term between the outcomes of the two alternative treatments, if any exist.     

血管紧张素原基因5’端启动子区A-20C和A-6G单核苷酸多态性与蒙古族人群原发性高血压的相关性

目的:分析血管紧张素原基因启动子区A-20C和A-6G单核苷酸多态性与蒙古族人群原发性高血压的相关性。方法:实验于2005-08/2006-01在北京华大实验室完成。选取对象均为生活在内蒙古乌拉特后旗的蒙古族牧民,三代血亲内无其他民族。采用基因测序技术对内蒙古蒙古族人群中107例原发性高血压患者和108例正常对照者进行A-20C和A-6G基因分型,观察高血压组和正常对照组不同基因型的分布和等位基因频率的差异。结果:①两组受试者在性别、年龄及吸烟、饮酒、体质量指数和临床化验检查指标有较好的匹配(P均>0.05)。②两组血管紧张素原基因A-20C位点AA,AC,CC基因型频率比较差异无显著性意义(高血压组分别为0.51,0.29,0.20;正常对照组分别为0.49,0.28,0.23,χ2=0.395,P=0.529)。A,C等位基因频率比较差异无显著性意义(高血压组分别为0.65,0.35;正常对照组分别为0.63,0.37,χ2=0.015,P=0.904)。③两组血管紧张素原基因A-6G位点AA,AG,GG基因型频率比较差异无显著性意义(高血压组分别为0.50,0.33,0.17;正常对照组分别为0.55,0.34,0.11,χ2=1.924,P=0.165)。A,G等位基因频率比较差异无显著性意义(高血压组分别为0.66,0.34;正常对照组分别为0.72,0.28,χ2=1.728,P=0.189)。④高血压组协同存在血管紧张素原基因A-20C基因型CC时,血管紧张素原基因A-6G基因型GG频率稍高于正常对照组,但差异无显著性意义(χ2=2.395,P=0.122,OR=7.52,95%CI0.014～1.250),高血压组G等位基因明显高于正常对照组(分别为0.37,0.22,χ2=4.658,P=0.034),携带该等位基因的蒙古族人群发生原发性高血压的相对危险度升高(OR=2.80,95%CI1.087～7.271)。结论:血管紧张素原基因A-20C和A-6G单核苷酸多态性与蒙古族人群原发性高血压相关,并可能具有协同作用。     

Respiratory support withdrawal in intensive care units: families,physicians and nurses views on two hypothetical clinical scenarios

Introduction  

Evidence suggests that dying patients' physical and emotional suffering is inadequately treated in intensive care units. Although there are recommendations regarding decisions to forgo life-sustaining therapy, deciding on withdrawal of life support is difficult, and it is also difficult to decide who should participate in this decision.     

Normalization of enhanced hepatic gluconeogenesis by the antiglucocorticoid RU 38486 in acutely uraemic rats

Hepatic amino acid uptake, urea and glucose production are increased in acute uraemia. It has been shown that this metabolic pattern is mediated by glucocorticoids. Accordingly, the administration of the antiglucocorticoid RU 38486 to acutely uraemic rats resulted in a reduction of serum urea-N and glucose levels. To clarify whether this effect is due to a reduction in hepatic gluconeogenesis we examined the effect of the antiglucocorticoid RU 38486 on urea and glucose formation in isolated hepatocytes from sham-operated (SHAM) and bilaterally nephrectomized (BNX) rats receiving RU 38486 or the vehicle only. Hepatic glucose production in BNX rats was considerably increased from Na-pyruvate (+79%), alanine (+174%), glutamine (+158%), and serine (+87%) compared with SHAM animals. Concomitantly, hepatic urea formation was also enhanced from amino acid substrates in acutely uraemic rats. When uraemic animals were treated with RU 38486, glucose production from amino acids and Na-pyruvate was reduced to the range of SHAM animals or even lower. This effect could not be demonstrated in SHAM-operated controls. A comparable decrement in hepatic urea production was observed in BNX rats treated with the antiglucocorticoid. Thus, glucocorticoids appear to play a key role in the abnormal hepatic urea and glucose production of acutely uraemic rats.     

Nationwide survey of home transfusion practices

BACKGROUND: Limited information exists on home transfusion practices. STUDY DESIGN AND METHODS: In 1995, a survey requesting data for 1994 was sent to 1273 American Association of Blood Banks (AABB) institutional members and 113 non-AABB home health care agencies that provide out-of-hospital transfusions. RESULTS: Of 943 respondents, 102 provide blood to a home transfusion program, 37 provide blood and run a home transfusion program, and 13 run a home transfusion program only, for a total of 152 (16%) with some involvement in home blood transfusions. Most of the 50 respondents with a home transfusion program are licensed by their state and accredited by the Joint Commission on Accreditation of Healthcare Organizations. All respondents have written policies for home transfusion, and 90 percent require a signed informed-consent document before initiating transfusions in the home. Most have policies requiring that there be a second adult and a telephone in the home, that the home be deemed safe for transfusion, that the patient's physician be readily available, and that the patient have had prior transfusions. The most common component issued by the blood providers was red cells, followed by platelets. White cell-reduced components were always provided by 36 percent of respondents. The most common patient diagnosis was cancer. Home transfusions were provided primarily by registered nurses. Only 14 percent of respondents indicated that the medical director of the blood bank is responsible for approving a patient for home transfusion. A posttransfusion visit is performed by 46 percent of respondents. CONCLUSION: Although most facilities have policies for the administration of home transfusions, there remains marked heterogeneity among blood providers and transfusionists regarding home transfusion practices.     

The influence of age on the pharmacokinetics of the antiepileptic agent oxcarbazepine

The disposition of oxcarbazepine was studied in 12 young and 12 elderly healthy male and 12 young and 12 elderly healthy female volunteers, with emphasis on the influence of age. Oxcarbazepine was administered as a single dose of either 300 mg (men) or 600 mg (women), followed by multiple-dose (300 mg) administration twice a day for 7 days (men) or 6 days (women). Semilogarithmic plasma concentration-time curves showed an increasing decline at decreasing concentrations. Accumulation of the pharmacologically active metabolite monohydroxycarbamazepine was found to be more than one would anticipate on the basis of linear and unchanged pharmacokinetics. Saturation did not seem to occur at the level of renal excretion. No apparent differences between male and female volunteers were observed. A significant higher maximum concentration, higher area under the curve parameters, and a lower elimination rate constant were observed in the elderly. These observations are in line with a smaller renal clearance of monohydroxycarbamazepine in the elderly group. In a clinical situation, these age-related differences are not likely to have important implications. In general, treatment with oxcarbazepine was well tolerated.     

重庆居民与流动人口结核病就诊及诊断的延迟因素：隐蔽性调查分析

目的:调查重庆居民及流动人口结核病就诊及诊断延迟情况,探索在其过程中存在的问题,分析问题产生的原因。方法:在重庆市主城区按照经济发展水平的不同选取了两个区Y和J,采用方便抽样的方法在Y区抽取了一家综合性医院的呼吸科门诊R,在J区抽取了一家综合性医院的一般基层门诊P,于2005-10-10/14和2005-10-17/21,采用隐蔽性观察法对门诊情况进行了观察,主要观察医生和患者的相关语言、行为,了解结核病就诊及诊断延迟情况。实验得到了利物浦大学热带医学院伦理委员会的许可,并通过了重庆市卫生局的批准。资料分析采用主题框架分析法。结果:重庆居民和流动人口都存在结核病就诊延迟的情况,主要与患者的经济状况、健康意识和社会支持等因素有关;医院在结核病的诊断方面具备基本的技术和条件,诊断延迟则主要与医务人员对结核病的意识和责任心有关;另外患者自身在诊疗过程中的中途退出现象不容忽视,也是导致延迟的一个重要因素。结论:一方面综合医院缺乏对结核病患者的管理措施和意识,对结核患者重治轻管,另一方面特殊人群的患者卫生保健支付能力差,缺乏相关结核病防控知识,应依据目前的形势对相关领域进行政策倾斜和调控,积极开展对人群行之有效的健康教育。     

Platelet-derived growth factor promotes polymorphonuclear leukocyte activation

The platelet-derived growth factor (PDGF) has several well defined important biologic activities. Platelet-derived growth factor is the major mitogen in human serum for cells of mesenchymal origins; it is a potent chemoattractant protein for human monocytes, neutrophils, fibroblasts, and smooth muscle cells; and has been implicated in transformation by simian sarcoma virus and perhaps in transformation by other agents as well. In this article, PDGF has been shown to stimulate activation of human peripheral blood neutrophils defined by loss of membrane associated calcium as reflected by loss of chlortetracycline fluorescence, release of superoxide anion and specific granule enzymes, and enhanced neutrophil adherence and aggregation. These responses occurred in a dose-dependent fashion at concentrations of PDGF between 10 ng/mL (0.4 nmol/L) and 40 ng/mL (1.5 nmol/L) and were comparable to effects obtained with optimal concentrations of fMLP and C5a. Degranulation induced by PDGF was selective for secondary (specific) granules and not primary (azurophil) granules. Platelet-derived growth factor thus is ideally suited for a pivotal role in attracting inflammatory cells locally and initiating neutrophil activation at sites of blood vessel injury. Platelet-derived growth factor or a closely related protein also may play an important role in attracting and activating neutrophils in association with inflammatory tumors.