987 resultados para BCR
Resumo:
O sistema estuarino das Ilhas de Tinharé-Boipeba está inserido na região do Baixo Sul baiano (Bahia Brasil), costa nordeste brasileira, e conectam-se com o oceano através de três saídas principais, Morro de São Paulo, Boipeba e Barra dos Carvalhos. Informações relacionadas à presença de metais no sedimento são quase inexistentes para a região. Nestes estuários foram coletadas 40 amostras de sedimento, onde analisou-se a concentração de metais (Al, Cu, Fe, Mn, Pb e Zn) através da extração com água-régia, segundo o protocolo do material de referência BCR-701 (RAURET et al., 2001). Baixas concentrações de metais foram registradas nas proximidades das saídas para o mar e no Canal de Garapuá e Rio Grande. Altas concentrações, porém praticamente dentro dos valores de referência na CONAMA 344/04, foram registradas no Rio Una, na maior parte do Rio Cairu, Rio das Almas, em quase todas as estações, no braço leste do Rio Cairu e na porção intermediária do Rio dos Patos. As concentrações dos metais (mg.kg1) apresentaram valores entre os seguintes intervalos, Al (3,57 x 104 a 3,19 x 102), Cu (1,02 x 102 a 0,35), Fe (4,33 x 104 a 2,05 x 102), Mn (1,44 x 103 a 2,73), Pb (6,67 x 101 a 2,66) e Zn (5,08 x 102 a 3,18). Através da análise estatística ACP (Análise dos Componentes Principais) e dos gráficos de correlação entre a granulometria do sedimento (areia, silte e argila) e os metais, observou-se maiores concentrações de metais com o aumento do percentual de silte e diminuição do percentual de areia. Também se identificou uma forte correlação entre a ocorrência do fósforo e a presença de metais. Acredita-se que a principal espécie química em questão seja o fosfato (PO43 ou P2O5) que é uma base dura, onde a ligação com os metais se dá pelo oxigênio, sendo o caráter iônico relevante. Não foi identificada uma correlação entre a presença de metais e a argila, fato atribuído ao baixo teor dessa granulometria para todas as amostras do estudo e a composição da argila desses estuários
Resumo:
A toxicidade dos metais em ambientes aquáticos está relacionada à sua biodisponibilidade e esta, por sua vez, pode ser influenciada por diversos fatores. As características do sedimento fazem dele um importante compartimento para avaliação do nível de contaminação no ambiente aquático. A presente pesquisa teve por objetivo quantificar e avaliar a biodisponibilidade de metais em sedimentos da baía da Ribeira. Nessa região, encontram-se os bairros mais populosos de Angra dos Reis RJ. Essa baía está localizada na parte nordeste da baía da Ilha Grande, que consiste de um espaço pesqueiro, turístico e de importante valor econômico e industrial. Foram coletados 12 sedimentos na baía da Ribeira e determinados os teores dos metais Al, Cu, Cd , Cr, Fe, Mn, Ni, Pb e Zn, através da extração com água régia (protocolo BCR-701), e o potencial de toxicidade dos metais Cd, Cu, Ni, Pb e Zn pelo método de extração dos sulfetos voláteis em meio ácido e quantificação dos metais extraídos simultaneamente (em inglês Acid Volatile Sulfide and Simultaneously Extracted Metal, AVS/SEM). Também foram efetuadas medidas de pH, potencial redox (Eh), carbono orgânico, fósforo total e granulometria. Através desses dados, foi possível estudar correlações entre essas variáveis. As concentrações de cada metal são similares nas diferentes localizações dos sedimentos e não apresentam significativas diferenças com relação a estudos reportados para a área, com exceção do Pb que apresentou a mais alta concentração já reportada. Os valores de SEM/AVS (entre 0,02 e 0,2) menores que 1, indicam que há quantidade de sulfetos suficiente para o aprisionamento dos metais investigados. As correlações obtidas através da Análise dos Componentes Principais demonstram relação direta entre as concentrações da maioria dos metais extraídos por água-régia (Ni, Fe, Cr, Cu, Zn); entre os metais Mn, Pb, Al e o fósforo total; entre os teores de matéria orgânica, carbono orgânico total, fósforo total com as frações finas de silte e argila com o Eh. Os resultados sugerem que a região não sofre influência significativa de fontes antrópicas em relação a metais e que, segundo o AVS/SEM, esses se encontram pouco disponíveis para o ambiente e, portanto, apresentam baixo potencial tóxico
Resumo:
A contaminação do solo no município de Santo Amaro (BA) por metais tóxicos provocada pelas atividades da empresa Plumbum Mineração tem gerado impactos sobre a saúde ambiental e humana. O objetivo da presente pesquisa foi avaliar a viabilidade da remediação deste solo contaminado por chumbo e cádmio, utilizando diferentes fontes de fosfatos e fitorremediação com o capim vetiver [Vetiveria zizanioides (L.)]. O estudo foi realizado em colunas de PVC onde amostras de solo foram colocadas com a aplicação de fosfato dihidrogênio de potássio (KH2PO4) (T1); fertilizante fosfato natural reativo (FNR) (T2) e; uma mistura do KH2PO4 e de fertilizante FNR (T3). Amostras de solo contaminado sem tratamento (T0) foram utilizadas como controle. Após 60, 120 e 180 dias, alíquotas do solo foram retiradas das colunas para análises. Ao final de cada período, mudas de capim vetiver [(Vetiveria zizanioides (L.)] foram plantadas em vasos com as amostras de solo: T0, T1, T2 e T3 em triplicata. Para a determinação das concentrações de chumbo e cádmio no solo e tecidos vegetais foi utilizado o ICP-OES. A partir das análises física e química constatou-se que o solo possui textura argilosa e capacidade de troca catiônica (CTC) elevadas. As extrações com solução de ácido dietilenotriaminopentaacético (DTPA) e Toxicity Characteristic Leaching Procedure (TCLP) mostraram que o tratamento T1 seguido do T3 foram os mais eficientes na imobilização de Pb e Cd. Entretanto, todos os tratamentos resultaram em concentrações de metais ainda disponíveis no solo que excediam os limites estabelecidos pela USEPA, sendo o solo, portanto, considerado tóxico mesmo após o tratamento. Com base nas concentrações de metais extraídos através da extração sequencial pelo método BCR após a remediação e a fitorremediação do solo, foi verificado que todos os três tratamentos com fosfatos foram eficientes em imobilizar o Pb e Cd nas formas menos solúveis, porém, o Cd permaneceu mais solúvel e com maior mobilidade do que o Pb. Os ensaios de letalidade utilizando minhoca Eisenia andrei mostraram que a mortalidade observada no solo após 60 dias de tratamento foi significativamente reduzida após 120 e 180 dias de tratamento. A perda de biomassa pelas minhocas também foi reduzida de acordo com o tempo de tratamento. O teste de germinação com alfaces (Lactuca sativa L.) indicou que as amostras de solo tratadas continuam bastante tóxicas, apesar da disponibilidade reduzida do Pb e do Cd como visto nos resultados da extração por TCLP e por BCR. A avaliação de risco ecológico potencial indicou que os tratamentos do solo com fosfatos associado à fitorremediação reduziram a mobilidade do Pb, principalmente nos tratamentos T1 e T3. Para o Cd o risco ecológico potencial aumenta consideravelmente quando comparado com o Pb demonstrando que esse elemento, apesar dos tratamentos com fosfatos mais a fitorremediação continua móvel. O tratamento com KH2PO4 (T1) foi o mais eficiente na redução da mobilidade, disponibilidade e da toxicidade dos metais, seguido pelo T3 e T2 para o Pb e o T3 seguido pelo T1 e T2 para o Cd.
Resumo:
Kanyakumari district belonging to the high rainfall zone has resource advantages for composite fish culture in the leased-in village tanks. There are more than 400 fish farmers operating in leased-in tanks following composite fish culture under the FFDA programme. To estimate the economic feasibility and financial viability of the enterprise, the present study was taken up. 38 fish farmers selected from the district provided the necessary information like capital investment, costs and return and constraints. The data collected were analysed and a farm nearest to the average farm situation was taken as the representative farm. Investment criteria like PayBack Period (PBP), Simple Rate of Returns (SRR), Net Present Value (NPV) and Benefit Cost Ratio (BCR) were estimated taking into account a period of 10 years, the period for which the village tanks are leased-out to fish farmers under the FFDA programme. The analysis indicated the profitability of composite fish culture in village tanks in the district and the results are discussed with recommendations.
Resumo:
An experiment was conducted to understand the culture feasibility of sliver barb
(Barbodes gonionotus) and GIFT (Genetically Improved Farmed Tilapia) with shrimp
(Penaeus monodon). There were three different treatment (T) combinations: (T1) shrimp
(10,000/ha) and silver barb (10,000/ha), (T2) shrimp (10,000/ha) and GIFT (10,000/ha),
and (T3) shrimp (10,000/ha). Shrimp, after 120 days of culture, attained an average weight
of 23.77g in T1, followed by T3 (23.70g). The highest average weight was recorded in T2
(24.93g). The specific growth rate (SGR) of shrimp was 6.9%, 6.94% and 6.9% for T1 T2
and T3, respectively. The SGR for the B. gonionotus and GIFT was 2.56% and 4.26%,
respectively. The final weight of silver barb was 69.75g and that of GIFT was 161.83g.
Survival of shrimp was higher (65.50%) in T2, followed by T3 (59.97%) and T1 (57.03%).
Survival rate of silver barb (58.10%) was lower compared to that of GIFT (78.43%).
Sporadic and scanty mortality of silver barb with a symptom of blind-red-protruded eye,
swollen belly and body lesion was observed. Production of shrimp was higher of 284.05
kg/ha in monoculture, followed 162.47 kg/ha in concurrent culture with silver barb and
136.77 kg/ha culture with GIFT. In spite of similar stocking density of B. gonionotus and
GIFT in T1 and T2, respectively, the production of GIFT was higher (1272.95 kg/ha)
than that of silver barb ( 402.72kg/ha). Survival, final weight and production rates of
shrimp among the treatments were found insignificant while total production of
shrimp/fish was found to vary significantly (P
Resumo:
本论文分为两部分:1. 综述部分(第一章和第二章),介绍了我国包头地区稀土工业区钍污染概况,对稀土工业生产造成的放射性生态环境污染进行了分析和归纳;评述了土壤和沉积物中放射性核素污染生态物理化学研究和进展;说明了本研究课题的背景、意义和技术路线。2. 实验部分(第三章至第六章),包括以下几方面内容:土壤样品和高铁矿渣样品中钍的分析方法的建立;对土壤和矿渣样品中钍的形态进行定量分析,考察了土壤性质对土壤中钍形态分布的影响;模拟自然环境,研究钍在土壤-植物系统之间的迁移积累和钍形态的植物可利用性;土壤样品对钍的吸附-解吸行为及其影响因素。 我国包头稀土工业在稀土矿浮选和稀土精矿湿法冶炼过程中产生了大量含放射性钍的废渣、废水和粉尘,对当地生态环境造成严重的破坏和放射性污染。 采用合适内标,ICP-MS法对样品中钍分析,考察了基体干扰、记忆效应和质谱干扰,比较了不同的样品消解方法对钍测定的影响,并用标准土壤样品和标准加入法对方法的准确性进行了评价。分别采用Tessier、BCR和Martínez-Aguirre形态萃取方法对土壤和样品中钍的形态进行分析,通过对总量的回收率和萃取剂选择性比较,选择了Martínez-Aguirre连续萃取法定量样品中钍的形态,并对其进行了优化和评价。考察了土壤性质影响着钍的形态分布。 通过盆栽实验,考察了小麦对根际土壤中钍形态分布以及的在不同生长期对钍的吸收影响。利用相应的材料人工模拟了土壤中钍的形态,对模拟的钍各形态的植物可利用性和植物吸收贡献指数进行评估分析。利用不同的磷酸盐对土壤进行培养处理,考察了磷酸盐的加入对土壤中钍的生物可利用性影响。 实验了土壤样品对钍的吸附-解吸过程,通过吸附容量、分配系数和吸附百分比等参数考察土壤对钍吸附能力,并考察了被土壤吸附钍的解吸行为。通过吸附机理的分析,土壤对钍的吸附作用主要是通过Th(IV)的表面水解吸附模式进行。根据实验结果,土壤样品对溶液中钍的吸附热力学可以用Freundlich方程式来描述,吸附的动力学过程可用Elovich方程描述,并对吸附方式和吸附过程进行论述。实验发现,吸附-解吸条件、土壤性质、外源稀土元素和施肥等对土壤吸附钍有一定影响。
Resumo:
采用0.05mol.L-1的EDTA作为萃取剂,在一定的萃取条件下,对2种尾矿土壤中重金属进行土壤柱萃取实验,并采用优化的BCR(European Community Bureau of Reference)连续萃取方案对萃取前后的Pb、Zn、Cu和Cd进行形态分析.研究EDTA对4种金属的萃取效率及萃取前后的形态变化特征.结果表明,EDTA能有效的从土壤中萃取该4种金属,萃取效率依次为:Cd>Zn>Cu>Pb;金属的4种形态均能被EDTA萃取;在浅层土壤中,EDTA对酸可提态的金属的萃取效果尤为显著;在深层土壤中,酸可提取态、氧化物结合态、有机结合态和残余态4种形态的金属萃取效果,随着土壤柱深度的增加而降低.
Resumo:
Sequential extraction procedures were widely applied for speciation of radioactive elements. In this study, the sequential extraction procedure developed by Martinez-Aguirre was employed for quantification of different chemical forms of thorium in the soil. The total amount of thorium in contaminated soil was much higher by four-fold than the local background value. The soil properties affect the amount of thoriurn and distribution of fractions in contaminated soil. Results showed that the proportion of thorium in soils from Baotou was found as the residual fraction (F5 + F6) > absorbed fraction (F3), coprecipitated fraction (F4) > carbonates fraction (172) and exchangeable fraction (F1) that could be available to plants. The recovery, calculated by ratio of the sum of the six fractions to the pseudo-total content of thorium, was in the range from 96% to 110%. A comparison was carried out between the sequential extraction and the single extraction to evaluate the selectivity of the extractants. It was found that the amount of thorium of absorbed fraction (H) was higher in the single extraction than that estimated in the sequential extraction, possibly duo to transform of the labile form. While for non-residual fraction analysis, the single extraction scheme was a desirable alternative to the sequential extraction procedure.
Resumo:
随着城市化进程的快速推进,大量蔬菜等食物由农村向城市输送,因此促进了城郊结合部蔬菜基地的发展。然而,城市化发展却导致越来越严重的城市和城郊土壤和大气污染,加上现代化生产中化肥和农用化学品的大量使用等,使得重金属在菜园土中大量积累,并可能通过食物链进入人体,威胁人类身体健康。因此,对重金属在土壤-蔬菜体系间迁移的生物地球化学行为的研究是我们了解和防治蔬菜重金属污染、促进绿色作物生产和保护人类健康的关键。 本文选择世界典型喀斯特地区的贵阳市市郊的菜园土-蔬菜体系为主要研究对象,通过系统地对土壤、主要蔬菜和大气沉降物质的元素分析以及铅同位素分析,对研究区域菜园土的主要理化性质、土壤(以及剖面)和蔬菜样品中重金属Cu、Pb、Zn和Cd的含量变化、菜园土以及土壤剖面重金属的形态分布等特征进行了研究。利用微量元素地球化学以及同位素地球化学理论,并结合土壤学研究理论和方法探讨了重金属在菜园土(石灰土和黄壤)和蔬菜体系间的赋存形态、重金属元素的来源、迁移与转化规律及其中的主要控制因素。 主要研究结果认为:贵阳市郊菜园土重金属元素含量变化与土壤母质显著相关,黄壤类型菜园土处于中度污染水平,石灰土类型菜园土处于轻度污染水平。菜园土中重金属形态以残余态为主,其次为有机结合态,再次为铁锰氧化物结合态和酸可提取态。土壤剖面中,菜园土表层大多数重金属含量高于背景剖面,其余各层吻合度较高。土壤剖面中重金属的形态分布仍以残余态为主,菜园土剖面上各元素的生物可利用态即酸可提取态、氧化物结合态和有机结合态则均要高于背景剖面,Pb和Zn主要受到有机结合态的影响,而Cd则三种形态的含量均高于背景剖面,种种迹象表明人为活动增加了菜园土重金属的活性和生物有效性,且以有机结合态的改变最为显著。 蔬菜中红薯可食部位的各项重金属富集系数均大于其他蔬菜,最容易受到土壤中重金属的影响;在土壤-蔬菜体系中,重金属元素含量的分布总体特征为菜园土>根>茎叶>果实,体系内元素的迁移在土壤/蔬菜根界面上最为关键,起着控制作用,此界面上各元素的迁移系数顺序为Cd>>Cu,Zn>Pb,大多数重金属元素在黄壤类型的菜园土中的迁移系数要小于石灰土类型的;在土壤-红薯和土壤-辣椒体系中,Cd的迁移系数随土壤pH的增加而降低,而其余元素的迁移系数则随土壤pH的增加而增加;土壤主成分与土壤理化性质对重金属形态分布有显著影响,但BCR连续提取法得到的土壤中重金属元素的各生物可利用态的含量与蔬菜根部的含量相关性不大;覆膜种植方式使土壤pH由4.5降低到3.8,并改变了其它物化参数,从而影响重金属的形态分布及其在蔬菜体内的含量分布特征,极可能增加农业系统中重金属的环境风险;铅稳定同位素分析表明,土壤中的铅主要来自于母岩的风化,蔬菜中放射成因铅明显略低于菜园土,菜园土和蔬菜中铅同位素组成在208Pb/206Pb对207Pb/206Pb的分布图上呈直线分布(在菜园土-蔬菜体系中,土壤样品、蔬菜不同部位的样品、以及雨水样品的铅同位素组成的分布也形成了极好的直线),显示明显的两端元混合体系;根据各端元物质铅同位素组成计算,土壤铅对蔬菜根部、茎叶的贡献值由71.8%~77.7%降低到16.0%~45.4%之间,大气铅的贡献则沿根向茎叶和果实逐渐增加,研究结果显示大气污染对蔬菜重金属Pb的贡献不可忽视。
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矿山环境重金属污染及其生态效应研究是环境地球化学研究的热点问题之一,其中水环境生态系统中的沉积物重金属污染由于可能影响流域水环境安全而备受关注。贵州矿产资源丰富,其开采利用过程中的重金属元素污染十分严重,尤其是Tl、As和Hg的污染备受关注。本研究选择黔西南滥木厂铊矿化区为研究对象,通过分析该地区河流沉积物中铊、砷、汞等重金属元素的环境地球化学分布特征,对重金属污染状况进行评价,并探讨其对环境的生态危害,得到以下几点认识: 1. 滥木厂铊矿化区河流沉积物中重金属Tl、Hg、As和Cd的含量相对很高。其中,Tl、Hg和As在矿山影响区河流沉积物中平均含量分别为23.3 mg/kg、46.8 mg/kg 和97.3 mg/kg,比页岩平均含量高几十倍至上百倍,而矿山未影响区及对照区河流沉积物中含量都相对较低。Cd在矿渣以及清水河矿山影响区、矿山未影响区和对照区河流沉积物中的平均含量都相对较高,分别为0.97 mg/kg、1.31 mg/kg、1.17 mg/kg和1.21 mg/kg,约为页岩平均含量的2~5倍,且变化不明显。重金属环境地球化学分析表明,Tl、Hg和As为同源污染物质,主要来自矿山硫化物的风化淋漓;Cd的高含量与矿山联系不明显,可能是由于地域上的Cd异常所致。Cu、Cr、Zn和Pb的含量都相对较低,只略高于页岩平均含量。 2. 地质累积指数(Igeo)和潜在生态危害系数(RI)分析评价结果显示,滥木厂清水河沉积物主要受到Hg、Tl、As以及Cd的污染。受矿山影响的河流沉积物中Hg和Tl的污染很严重,具有很强的潜在生态危害;As和Cd次之;Zn、Cu、Cr和Pb的污染不明显,潜在生态危害很小。 3. 沉积物中重金属各形态分级提取分析(BCR)表明,受矿山影响的滥木厂清水河沉积物及剖面沉积物中:不但总Tl含量很高,有效态Tl含量也高,平均分别为6.0 mg/kg 和5.9 mg/kg,对环境的生态危害很大;Hg虽然总含量非常高,但其酸可提取态含量都低于仪器的检测下限,可还原态含量也不高,平均分别只为0.46 mg/kg 和1.53 mg/kg,主要集中在不易释放的可氧化态和非常稳定的残余态,对环境的生态危害一般;As的总含量较高,但有效态平均含量只为6.51 mg/kg和1.58 mg/kg,对环境的生态危害较小;Cd的总含量也相对较高,有效态平均含量也分别达0.55 mg/kg和0.52 mg/kg,对环境的危害可能较大;Cr、Cu、Zn及Pb的总含量和有效态含量都较低,对环境的生态危害较小。 4. 滥木厂铊矿化区河流沉积物中Tl、Hg和Cd的重金属污染的生态危害性主要表现为Tl、Hg和Cd对食物链的直接或间接污染。Tl和Cd易在农作物中富集,Hg甲基化后也可以在农作物中富集,其人体健康危害性较大。
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Acute myeloid leukaemia (AML) is the most common form of acute leukaemia in adults. Its treatment has remained largely unchanged for the past 30 years. Chronic myeloid leukaemia (CML) represents a tremendous success story in the era of targeted therapy but significant challenges remain including the development of drug resistance and disease persistence due to presence of CML stem cells. The Aurora family of kinases is essential for cell cycle regulation and their aberrant expression in cancer prompted the development of small molecules that selectively inhibit their activity. Chapter 2 of this thesis outlines the efficacy and mechanism of action of alisertib, a novel inhibitor of Aurora A kinase, in preclinical models of CML. Alisertib possessed equipotent activity against CML cells expressing unmutated and mutated forms of BCR-ABL. Notably, this agent retained high activity against the T315I and E255K BCR-ABL mutations, which confer the greatest degree of resistance to standard CML therapy. Chapter 3 explores the activity of alisertib in preclinical models of AML. Alisertib disrupted cell viability, diminished clonogenic survival, induced expression of the forkhead box O3 (FOXO3a) targets p27 and BCL-2 interacting mediator (BIM), and triggered apoptosis. A link between Aurora A expression and sensitivity to ara-C was established. Chapter 4 outlines the role of the proto-oncogene serine/threonine-protein (PIM) kinases in resistance to ara-C in AML. We report that the novel small molecule PIM kinase inhibitor SGI-1776 disrupted cell viability and induced apoptosis in AML. We establish a link between ara-C resistance and PIM over-expression. Finally, chapter 5 explores how the preclinical work outlined in this thesis may be translated into clinical studies that may lead to novel therapeutic approaches for patients with refractory myeloid leukaemia.
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We studied the cells from three selected patients with Ph-chromosome-negative chronic myeloid leukemia (CML) by Southern blotting, polymerase chain reaction, and in situ hybridization of informative probes to metaphase chromosomes. All three patients had rearrangement of M-BCR sequences in the BCR gene and expression of one or other of the mRNA species characteristic of Ph-positive CML. Leukemic metaphases studied after trypsin-Giemsa banding were indistinguishable from normal. The ABL probe localized both to chromosome 9 and 22 in each case. A probe containing 3' M-BCR sequences localized only to chromosome 22, and not to chromosome 9 as would be expected in Ph-positive CML. Two new probes that recognize different polymorphic regions distal to the ABL gene on chromosome 9 in normal subjects localized exclusively to chromosome 9 in two patients and to both chromosomes 9 and 22 in one patient. These results show that Ph-negative CML with BCR rearrangement is associated with insertion of a variable quantity of chromosome 9 derived material into chromosome 22q11; there is no evidence for reciprocal translocation of material from chromosome 22 to chromosome 9.
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Anti-neutrophil cytoplasmic antibodies (ANCA) are diagnostic markers for systemic vasculitis. They are classically I detected by an indirect immunofluorescence test using normal donor neutrophils as substrate. This assay lacks antigenic specificity and is not quantitative. The 'EC/BCR Project for ANCA Assay Standardization' is an international collaboration study with the aim to develop and standardize solid phase assays for ANCA detection. In this part of the study the isolation and characterization of proteinase-3 and myeloperoxidase, the two main target molecules for ANCA, and the development and standardization of ELISAs with these antigens are described. Six laboratories successfully isolated purified proteinase-3 preparations that could be used. Three of these preparations, together with one myeloperoxidase preparation, were subsequently used for ANCA testing by ELISA. The ELISA technique was standardized in two rounds of testing in the 14 participating laboratories. The coefficient of variation of these new assays decreased from values of approx. 50% in the first round to approx. 20% in the second round. We conclude that purified proteinase-3 and myeloperoxidase can be used in standardized ELISAs for ANCA detection. Whether such procedures offer advantages over the IIF test will be determined in a prospective clinical study.
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OBJECTIVE: To investigate the effect of statin use after radical prostatectomy (RP) on biochemical recurrence (BCR) in patients with prostate cancer who never received statins before RP. PATIENTS AND METHODS: We conducted a retrospective analysis of 1146 RP patients within the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Multivariable Cox proportional hazards analyses were used to examine differences in risk of BCR between post-RP statin users vs nonusers. To account for varying start dates and duration of statin use during follow-up, post-RP statin use was treated as a time-dependent variable. In a secondary analysis, models were stratified by race to examine the association of post-RP statin use with BCR among black and non-black men. RESULTS: After adjusting for clinical and pathological characteristics, post-RP statin use was significantly associated with 36% reduced risk of BCR (hazard ratio [HR] 0.64, 95% confidence interval [CI] 0.47-0.87; P = 0.004). Post-RP statin use remained associated with reduced risk of BCR after adjusting for preoperative serum cholesterol levels. In secondary analysis, after stratification by race, this protective association was significant in non-black (HR 0.49, 95% CI 0.32-0.75; P = 0.001) but not black men (HR 0.82, 95% CI 0.53-1.28; P = 0.384). CONCLUSION: In this retrospective cohort of men undergoing RP, post-RP statin use was significantly associated with reduced risk of BCR. Whether the association between post-RP statin use and BCR differs by race requires further study. Given these findings, coupled with other studies suggesting that statins may reduce risk of advanced prostate cancer, randomised controlled trials are warranted to formally test the hypothesis that statins slow prostate cancer progression.
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Approximately 45,000 individuals are hospitalized annually for burn treatment. Rehabilitation after hospitalization can offer a significant improvement in functional outcomes. Very little is known nationally about rehabilitation for burns, and practices may vary substantially depending on the region based on observed Medicare post-hospitalization spending amounts. This study was designed to measure variation in rehabilitation utilization by state of hospitalization for patients hospitalized with burn injury. This retrospective cohort study used nationally collected data over a 10-year period (2001 to 2010), from the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SIDs). Patients hospitalized for burn injury (n = 57,968) were identified by ICD-9-CM codes and were examined to see specifically if they were discharged immediately to inpatient rehabilitation after hospitalization (primary endpoint). Both unadjusted and adjusted likelihoods were calculated for each state taking into account the effects of age, insurance status, hospitalization at a burn center, and extent of burn injury by TBSA. The relative risk of discharge to inpatient rehabilitation varied by as much as 6-fold among different states. Higher TBSA, having health insurance, higher age, and burn center hospitalization all increased the likelihood of discharge to inpatient rehabilitation following acute care hospitalization. There was significant variation between states in inpatient rehabilitation utilization after adjusting for variables known to affect each outcome. Future efforts should be focused on identifying the cause of this state-to-state variation, its relationship to patient outcome, and standardizing treatment across the United States.