266 resultados para CTC


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Effects of dips in 10 and 50 ppm Chlortetracycline solution on the storage-life of sardines in ice have been studied. 5 ppm-CTC-ice in conjunction with dip in 10 ppm CTC-solution has also been tried. CTC-treatment considerably reduced bacterial number and gave a better appearance to the fish. The high fat content in sardines resulted in rapid development of rancidity. CTC has been found to have no control on the development of rancidity. Hence, CTC treatment of sardines is found to be of limited advantage in extending the storage-life of the fish in ice.

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The native flora of oil sardine and mackerel consisting of Pseudomonas spp; Moraxella spp., Acinetobacter spp. and Vibrio spp. underwent significant changes during ice storage. At the time of spoilage, Pseudomonas spp. were predominant. CTC treatment significantly reduced the Pseudomonas spp. in the initial stages of storage; but later Pseudomonas spp. reasserted and constituted the bulk of the spoilage flora. In prawn, the native flora was comprised of Pseudomonas spp., Acinetobacter spp., Moraxella spp. and Vibrio spp. At the time of spoilage a heterogeneous flora, consisting of Pseudomonas spp; Moraxella spp. and Acinetobacter spp. predominated. CTC treatment significantly changed the flora of prawns. During spoilage, Pseudomonas predominated in CTC treated prawns.

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钙调素拮抗剂W_7和FPZ均可抑制葛仙米藻殖段的分化。利用FPZ作为荧光染色剂发现 ,经过钙调素拮抗剂处理的藻体有较低的钙调素分布。在达到一定浓度后 ,金属离子螯合剂EGTA也抑制藻殖段分化。金霉素 (CTC)荧光显示 ,经EGTA处理的藻细胞其膜钙分布大大减少。但实验表明 ,藻殖段得以正常分化却是多种金属离子共同参与的结果。一氧化氮 (NO)可以大大降低葛仙米藻殖段的分化率 ,一氧化氮合成酶 (NOS)的抑制剂NNA也可以抑制藻殖段的分化。外源地加入氧自由基抑制了藻殖段的分化 ,但是氧自由基的清除物过氧

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Relationship between biology and environment is always the theme of ecology. Transect is becoming one of the important methods in studies on relationship between global change and terrestrial ecosystems, especially for analysis of its driving factors. Inner Mongolia Grassland is the most important in China Grassland Transect brought forward by Yu GR. In this study, changes in grassland community biomass along gradients of weather conditions in Inner Mongolia was researched by the method of transect. Methods of regression about biomass were also compared. The transect was set from Eerguna county to Alashan county (38° 07' 35" ~50° 12' 20" N, 101° 55' 25" -120° 20' 46" E) in Inner Mongolia, China. The sample sites were mainly chosen along the gradient of grassland type, meadow steppe-* typical steppe-*desert steppe-*steppification desert-^desert. The study was carried out when grassland community biomass got the peak in August or September, 2003 and 2004. And data of 49 sample sites was gotten, which included biomass, mean annual temperature, annual precipitation, accumulated temperature above zero, annual hours of sunshine and other statistical and descriptive data. The aboveground biomass was harvested, and the belowground biomass was obtained by coring (30 cm deep). Then all the biomass samples were dried within (80 + 5) °C in oven and weighted. The conclusion is as follows: 1) From the northeast to the southwest in Inner Mongolia, along the gradient of grassland type, meadow steppe-*typical steppe-*desert steppe-*steppification desert-* desert, the cover degree of vegetation community reduces. 2) By unitary regression analysis, biomass is negatively correlated with mean annual temperature, s^CTC accumulated temperature, ^10°C accumulated temperature and annual hours of sunshine, among which mean annual temperature is crucial, and positively with mean annual precipitation and mean annual relative humidity, and the correlation coefficient between biomass and mean annual relative humidity is higher. Altitude doesn't act on it evidently. Result of multiple regression analysis indicates that as the primary restrictive factor, precipitation affects biomass through complicated way on large scale, and its impaction is certainly important. Along the gradient of grassland type, total biomass reduces. The proportion of aboveground biomass to total biomass reduces and then increases after desert steppe. The trend of below ground biomass's proportion to total biomass is adverse to that of aboveground biomass. 3) Precipitation is not always the only driving factor along the transect for below-/aboveground biomass ratio of different vegetation type composed by different species, and distribution of temperature and precipitation is more important, which is much different among climatic regions, so that the trend of below-/aboveground biomass ratio along the grassland transect may change much through the circumscription of semiarid region and arid region. 4) Among reproductive allocation of aboveground biomass, only the proportion of stem in total biomass notably correlates to the given parameters. Stem/leaf biomass ratio decreases when longitude and latitude increase, caloric variables decrease, and variables about water increase from desert to meadow steppe. The change trends are good modeled by logarithm or binomial equations. 5) 0'-10 cm belowground biomass highly correlates to environmental parameters, whose proportion to total biomass changes most distinctly and increases along the gradient from the west to the east. The deeper belowground biomass responses to the environmental change on the adverse trend but not so sensitively as the surface layer. Because the change value of 0~10 cm belowground biomass is always more than that of below 10 cm along the gradient, the deference between them is balanced by aboveground biomass's change by the resource allocation equilibrium hypothesis.

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抗生素是广泛应用于人类和动物疾病治疗的药物,近年来在养殖业中抗生素更是常常作为动物催长剂。这些抗生素会通过人畜排泄物、药品的丢弃、污水排放、农业废物堆积等途径进入到环境中。环境中抗生素的残留会导致细菌耐药性的产生、微生态平衡的破坏,以及对生态环境和人类难以预知的影响。抗生素污染是近十年来才在国际上引起注意的新型环境问题,目前研究非常薄弱,要深入认识抗生素的环境影响特征就迫切需要对抗生素在环境中的迁移、归宿等地球化学行为进行针对性的研究。本文研究了贵阳城市污水、南明河及乌江渡水库中氯霉素(CAP)、土霉素(OTC)、四环素(TC)和金霉素(CTC)的环境地球化学特征,包括抗生素的分布、迁移特征及影响因素,并分析了贵阳市动物源性食品中抗生素的残留特征,探讨了环境因素对抗生素稳定性及吸附/解吸的影响,以期了解抗生素在环境中的降解、迁移等环境行为的特征,并据此评价抗生素的环境影响特点,为认识抗生素的污染特点、发展相应的控制、治理措施提供科学依据。主要内容包括: 1. 对环境样品中CAP和TCs的前处理过程和检测方法进行了优化。对水样的前处理采用固相萃取的方法,对土壤和沉积物的前处理采用EDTA-McIlvaine振荡萃取、SAX-HLB净化富集的方法;选择HPLC-UV作为分析的手段,对样品中的4种抗生素进行了检测,各化合物得到了很好的分离,该方法简便、快捷、重现性好。 2. 证实了抗生素在城市污水中的普遍存在。贵阳城市污水中以CAP的污染最为突出,其含量明显高于广州地区的城市污水;污水中四环素类药物(TCs)的含量和大多数欧美国家及地区城市污水中TCs的含量相当。这一结果证明,污水中抗生素的污染非常严重,对地表水环境形成严重的威胁。污水中抗生素的来源包括:人服用抗生素药物以及食用含有抗生素残留的食品之后的排泄物;食品中残留的抗生素随剩余食品的丢弃而进入污水。污水中抗生素的含量都具有明显的季节变化规律,冬春季含量明显高于夏秋季,我们认为这与各季节用水量和疾病特点有关。污水中抗生素的大量存在说明:1)抗生素存在滥用的现象,特别是CAP可能存在严重的违法使用,这一现象应当重视;2)污水中的抗生素会威胁水环境质量,应加强处理和控制技术。 3. 证明了城市河流受到多种来源的抗生素影响,其中城市污水是最重要的源,而且抗生素在河流中呈现一定的持久性。南明河上游河段中抗生素的来源包括郊区城镇污水、养鱼场、制药厂污水排放及地表垃圾。城市污水是抗生素的一大排放源,受其影响,排污口下游的河段受到的抗生素污染尤为严重,此外还有来自下游郊区城镇和农业污水的影响。对南明河中抗生素的来源及行为特点的剖析表明:1)抗生素在南明河的水和沉积物中具有不同的分布特征:河水中以CAP的污染最为严重,各水样中CAP的含量基本都高于TCs;而大部分沉积物中TCs的含量都高于CAP。CAP和TCs在水-沉积物之间的分布特征表明,它们在水环境中的地球化学行为明显受到吸附/解吸特点的影响,CAP的亲水性强,而TCs的亲粒性强。2)虽然在养殖业中已禁止使用CAP,但河水和污水中CAP的大量存在,这一结果揭露了CAP仍然存在大量违法使用的事实。3)河水中抗生素含量的季节差异明显,冬春季抗生素的含量高于夏秋季,其原因主要是夏秋季河水流量大,对河水中抗生素的稀释作用强。沉积物中抗生素的含量没有明显的季节变化规律,各季节抗生素的平均含量差异较小。4)受污水影响,各季节排污口下游的南明河水受到的抗生素污染尤为严重,污水口上下游之间的含量差异明显。沉积物在冬季受城市污水的影响大,在排污口下游的抗生素的含量明显高于上游,而春、夏、秋季受污水影响不明显。这可能是因为在春、夏和秋季其它污染源的影响较大,因此污水的影响强度减弱。夏季上游沉积物中CAP的含量甚至高于下游,原因一方面是因为夏季城市污水中抗生素含量低,对南明河的影响减小,另一方面可能因为夏季雨水多、水量大,将上游的地表垃圾以及积累在小河沟中的垃圾冲刷到南明河中,而这些工业及生活垃圾通常是抗生素的一大来源。 抗生素在河流中呈现了一定的持久性,在20 km的范围内水和沉积物显示了明显的污染水平,可能会对水生生态以及流域的环境造成一定的影响。此外,贵阳市南明河两岸的农田通常是用河水进行灌溉的,从而可能使抗生素的污染危及到食物链,对人体的健康有潜在的威胁。 4. 由于食品(如鱼肉、猪肉等)中残留的抗生素是污水中抗生素的重要来源,因此我们研究了养殖业(水产养殖区)中抗生素的环境行为特点,还研究了常见动物源性食品中抗生素的残留特点。对养鱼区的研究表明,养鱼饲料中含有大量的抗生素,是养鱼区水环境中抗生素的来源。由于饲料的颗粒大,且河水流速快,因此饲料中的抗生素不会对水体造成很大的影响,但是在网箱区的沉积物中形成了高含量的残留,除此以外,在乌江渡主航道的河心沉积物中抗生素的含量也相当可观。这说明该区水产养殖的抗生素主要影响沉积物,且相应的污染不是局部的,而会影响到整个养鱼区。从沉积物中抗生素平均含量的季节差异来看,各季TCs的用药量可能不同,秋季的用量可能最大,而其它季节用量相当;CAP在每个季节的用量可能相当。尽管分析的饲料中CAP的含量高于TCs,但在各季节乌江渡水库主航道沉积物中TCs的含量几乎都远高于CAP,这是由于TCs比CAP更易存在于沉积物中。乌江渡水库上下游主航道沉积物中抗生素的含量差异日益减小,说明了乌江渡水库的污染已日益严重。这些抗生素虽然暂时被固定在了沉积物中,活性相对较小,但是在外界条件的影响下,它们的吸附/解吸作用是可以改变的。因此,乌江渡沉积物中高含量的抗生素残留对水生生态环境具有潜在的威胁。 对贵阳市动物源性食品(鱼肉、猪肉和牛奶)中抗生素的残留特征的分析表明,这些食品中普遍残留有高含量的抗生素,被人食用后,其中的抗生素也会被人体摄入,一部分抗生素会随着人的排泄物而进入到污水中,并最终进入环境中;另一部分抗生素会积蓄在人体中,到一定浓度后就会对人体造成伤害。鲩鱼、鲫鱼、鲤鱼、鳙鱼和鲢鱼中CAP、OTC、TC和CTC的平均含量范围分别在57.1~365.5 µg/kg、37.0~60.7µg/kg、34.3~72.4 µg/kg和22.3~68.0 µg/kg之间。秋季的长吻鲍、团头鲂、鲈鱼、长江洄鱼、对虾、黄鳝、泥鳅和猪肉中CAP、OTC、TC和CTC的平均含量分别为88.1 µg/kg、76.8 µg/kg、343.7 µg/kg和34.2 µg/kg;牛奶中的含量分别为4.2 µg/L、1.6 µg/L和2.5 µg/L和22.0 µg/L。 5. 确定了抗生素的稳定性、吸附/解吸作用与各因素的关系,据此可以探讨环境中抗生素的行为特点及机理,并为环境中抗生素的污染防治提供依据。在短时的加热中,TCs发生了部分降解,而CAP却几乎没有发生分解,说明烹饪过程中的加热不能去除食品中的抗生素,这些抗生素则会进入到人体和污水中。当pH在2~8之间时,TCs的性质较稳定;CAP在pH=1~10的范围内性质都比较稳定。地表和地下水体的pH一般为7左右,说明了水环境中TCs受pH的影响小,而CAP几乎不受影响。在6个月的时间内,TCs在3种介质中都发生了不同程度的降解,但仍有大部分残留;CAP几乎没有发生明显的降解,这说明CAP和TCs的污染具有一定的持久性。TCs的吸附/解吸受颗粒物粒径的影响大,粒径越小,吸附越强;CAP不受影响。这证明了在环境中CAP更易以水溶态的形式存在,而TCs更易吸附在沉积物中。颗粒物中CaCO3含量越高,TC和CTC的吸附越强,证明CaCO3可以用来增强TC、CTC的吸附,这为环境中抗生素的治理提供了一条思路。

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Este trabalho do tipo exploratório, bibliográfico e descritivo tem como objetivo oferecer subsídios técnicos para processos que visam à obtenção da matéria-prima couro bovino de alta qualidade, além de difundir procedimentos, leis e recomendações técnicas das Boas Práticas Agropecuárias Bovinos de Corte. Esta publicação foi elaborada com base em informações diretas e simples, voltada para todos os elos da cadeia produtiva do couro, tais como: pecuaristas; transportadores; frigoríficos e curtumes.

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No município de Guaíra, SP identificou-se a necessidade de realizar uma pesquisa interdisciplinar para avaliar o efeito das práticas de manejo em sistemas de produção. Dessa forma, em áreas irrigadas de agricultores desse município e do município de Suzano, SP, foi realizado um estudo metodológico, comparando-se dois tratamentos: um sistema de manejo alternativo (SA) e outro convencional(SC), utilizado pelo produtor, em sistema de preparo convencional do solo (PC) ou em sistema de plantio direto (PD), tendo a mata nativa(M) como um sistema referência auto-sustentável. Para avaliação, foram selecionados diversos parâmetros: físicos e químicos (compactação do solo, velocidade de infiltração básica da água, agregação de partículas do solo, pH, V%, CTC e teor de matéria orgânica), biológicos/bioquímicos (incidência de patógenos e pragas, grupos de microrganismos, atividade enzimática da desidrogenase, polissacarídeos e biomassa microbiana e de produtividade). Após três anos de aplicação dessa metodologia em Guaíra, os resultados mostraram que o PD reduziu em 50% a incidência de patógenos produtores de escleródios (Sclerotium rolfsii e Sclerotinia sclerotiorum). Também, melhoria das propriedades físicas e químicas do solo, verificadas pela maior quantidade de matéria orgânica incorporada, maior atividade microbiana e agregação de partículas do solo avaliadas pela quantificação de polissacarídeos, desidrogenase e biomassa em C e, por conseguinte, menor incidência dos patógenos. A análise dos custos de produção realizado de 1994- 97, ainda apresentaram vantagens do SC em relação ao SA em Guaíra, diferentemente de Suzano, que, após 6 anos, já mantém um sistema de produção equilibrado. No controle biológico, a bactéria Bacillus subtilis proporcionou uma redução de 50% de Fusarium solani, agente da podridão radicular do feijoeiro, um aumento de emergência de 20% em relação ao controle químico.

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A utilização do lodo de esgoto para fins agrícolas e florestais tem se apresentado como a alternativa mais adequada para a sua disposição final, tanto do ponto de vista ambiental quanto do agronômico, principalmente em processos de recuperação de áreas degradadas, pois transforma um rejeito em importante insumo agrícola. Este trabalho apresentou como objetivo principal verificar a viabilidade da aplicação do lodo produzido pela Estação de Tratamento de Esgoto do Aeroporto Internacional do Rio de Janeiro (ETAR-APOIO) no processo de revegetação de uma área degradada, denominada Jazida do Itacolomi, situada na área patrimonial do Aeroporto Internacional do Rio de Janeiro. Foram introduzidas duas espécies vegetais Mimosa caesalpiniifolia (Sabiá) e Mimosa bimucronata (Maricá) na área experimental, adubadas com doses de lodo de esgoto equivalentes a 0,00; 2,85; 5,70; 11,40 e 22,80 t ha-1. Alterações na fertilidade do solo foram avaliadas através das seguintes variáveis: valor pH, teor de matéria orgânica, capacidade de troca catiônica (CTC) e disponibilidade de macro e micronutrientes. O comportamento das espécies vegetais mediante às doses de lodo de esgoto foi avaliado através de medições da altura e do diâmetro das copas das mudas. Os resultados obtidos indicaram que o processo de revegetação empregado na recuperação de áreas degradadas pode tornar-se uma alternativa viável para a disposição final do lodo de esgoto. Observou-se também que a adição do lodo de esgoto ao solo aumentou consideravelmente os teores de matéria orgânica, nitrogênio, fósforo e cálcio, bem como a CTC e em menor extensão os teores de magnésio e potássio, em contrapartida houve pouca alteração no pH do solo. Não foi observado efeito depressivo, causado por qualquer dose de lodo, sobre o desenvolvimento de Mimosa caesalpiniifolia e Mimosa bimucronata.

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O objetivo deste trabalho foi mostrar, através de um mapeamento, a distribuição aproximada da fertilidade dos solos (pH, P, K, Ca, Mg, Ca + Mg, Al, H + Al, SB, CTC efetiva, m% e V%) no Estado do Amazonas, para que, futuramente, seja utilizado para um provável zoneamento agrícola do Estado.

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One hundred and sixteen women with measurable metastatic breast cancer participated in a randomised phase II study of single agent liposomal pegylated doxorubicin (Caelyx) given either as a 60 mg/m2 every 6 weeks (ARM A) or 50 mg/m2 every 4 weeks (ARM B) schedule. Patients were over 65 years of age or, if younger, had refused or been unsuitable for standard anthracyclines. The aims of the study were to evaluate toxicity and dose delivery with the two schedules and obtain further information on the response rate of liposomal pegylated doxorubicin as a single agent in anthracycline nai ve advanced breast cancer. Twenty-six patients had received prior adjuvant chemotherapy (including an anthracycline in 10). Sixteen had received non-anthracycline-based first-line chemotherapy for advanced disease. One hundred and eleven patients were evaluable for toxicity and 106 for response. The delivered dose intensity (DI) was 9.8 mg/m2 (95% CI, 7.2-10.4) with 37 (69%) achieving a DI of >90% on ARM A and 11.9 mg/m2 (95% CI, 7.5-12.8) with 37 (65%) achieving a DI of >90% on ARM B. The adverse event profiles of the two schedules were distinctly different. Mucositis was more common with the every 6 weeks regimen (35% CTC grade 3/4 in ARM A, 14% in ARM B) but palmar plantar erythrodysesthesia (PPE) was more frequent with the every 4 weeks regimen (2% CTC grade 3/4 in ARM A, 16% in ARM B). Confirmed objective partial responses by RECIST criteria were seen with both schedules; 15/51 (29%) on ARM A and 17/56 (31%) on ARM B. Liposomal pegylated doxorubicin showed significant activity in advanced breast cancer with a generally favourable side-effect profile. The high frequency of stomatitis seen with 6 weekly treatment makes this the less preferred of the two schedules tested.

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PURPOSE: The association of continuous infusion 5-fluorouracil, epirubicin (50 mg/m2 q 3 weeks) and a platinum compound (cisplatin or carboplatin) was found to be very active in patients with either locally advanced/inflammatory (LA/I) [1, 2] or large operable (LO) breast cancer (BC) [3]. The same rate of activity in terms of response rate (RR) and response duration was observed in LA/I BC patients when cisplatin was replaced by cyclophosphamide [4]. The dose of epirubicin was either 50 mg/m2 [ 1, 2, 3] or 60 mg/m2/cycle [4]. The main objective of this study was to determine the maximum tolerated dose (MTD) of epirubicin when given in combination with fixed doses of cyclophosphamide and infusional 5-fluorouracil (CEF-infu) as neoadjuvant therapy in patients with LO or LA/I BC for a maximum of 6 cycles. PATIENTS AND METHODS: Eligible patients had LO or LA/I BC, a performance status 0-1, adequate organ function and were <65 years old. Cyclophosphamide was administered at the dose of 400 mg/m2 day 1 and 8, q 4 weeks and infusional 5-fluorouracil 200 mg/m2/day was given day 1-28, q 4 weeks. Epirubicin was escalated from 30 to 45 and to 60 mg/m2 day 1 and 8; dose escalation was permitted if 0/3 or 1/6 patients experienced dose limiting toxicity (DLT) during the first 2 cycles of therapy. DLT for epirubicin was defined as febrile neutropenia, grade 4 neutropenia lasting for >7 days, grade 4 thrombocytopenia, or any non-haematological toxicity of CTC grade > or =3, excluding alopecia and plantar-palmar erythrodysesthesia (this toxicity was attributable to infusional 5-fluorouracil and was not considered a DLT of epirubicin). RESULTS: A total of 21 patients, median age 44 years (range 29-63) have been treated. 107 courses have been delivered, with a median number of 5 cycles per patient (range 4-6). DLTs on cycles I and 2 on level 1, 2, 3: grade 3 (G3) mucositis occurred in 1/10 patients treated at the third dose level. An interim analysis showed that G3 PPE occurred in 5/16 pts treated with the 28-day infusional 5-FU schedule at the 3 dose levels. The protocol was subsequently amended to limit the duration of infusional 5-fluorouracil infusion from 4 to 3 weeks. No G3 PPE was detected in 5 patients treated with this new schedule. CONCLUSIONS: This study establishes that epirubicin 60mg/m2 day 1 and 8, cyclophosphamide 400mg/m2 day 1 and 8 and infusional 5-fluorouracil 200 mg/m2/day day 1-21. q 4 weeks is the recommended dose level. Given the encouraging activity of this regimen (15/21 clinical responses) we have replaced infusional 5-fluorouracil by oral capecitabine in a recently activated study.

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Cystic fibrosis (CF) patients may suffer increased morbidity and mortality through colonisation, allergy and invasive infection from fungi. The black yeast, Exophiala dermatitidis (synonym Wangiella dermatitidis) has been found with increasing frequency in sputum specimens of CF patients, with reported isolation rates ranging from 1.1 to 15.7%. At present, no diagnostic PCR exists to aid with the clinical laboratory detection and identification of this organism. A novel species-specific PCR-based assay was developed for the detection of E. dermatitidis, based on employment of rDNA operons and interspacer (ITS) regions between these rDNA operons. Two novel primers, (designated ExdF & ExdR) were designed in silico with the aid of computer-aided alignment software and with the alignment of multiple species of Exophiala, as well as with other commonly described yeasts and filamentous fungi within CF sputum, including Candida. Aspergillus and Scedosporium. An amplicon of approximately 455 by was generated, spanning the partial ITS I region - the complete 5.8S rDNA region - partial ITS2 region, employing ExdF (forward primer [16-mer], 5'-CCG CCT ATT CAG GTC C-3' and ExdR (reverse primer [16-mer], 5'-TCT CTC CCA CTC CCG C-3', was employed and optimised on extracted genomic DNA from a well characterised culture of E. dermatitidis, as well as with high quality genomic DNA template from a further 16 unrelated fungi, including Candida albicans, C. dubliniensis, C. parapsilosis, C. glabrata, Scedosporium apiospermum, Penicillium sp., Aspergillus fumigatus, Aspergillus versicolor, Pichia guilliermondii, Rhodotorula sp., Trichosporon sp., Aureobasidium pullulans, Fusarium sp., Mucor hiemalis, Bionectria ochroleuca, Gibberella pulicaris. Results demonstrated that only DNA from E. dermatitidis gave an amplification product of the expected sire, whilst none of the other fungi were amplifiable. Subsequent employment of this primer pair detected this yeast from mycological cultures from 2/50 (4%) adult CF patients. These two patients were the only patients who were previously shown to have a cultural history of E. dermatitidis from their sputum. E. dermatitidis is a slow-growing fungus, which usually takes up to two weeks to culture in the microbiology laboratory and therefore is slow to detect conventionally, with the risk of bacterial overgrowth from common co-habiting pan- and multiresistant bacterial pathogens from sputum. namely Pseudomonas aeruginosa and Burkholderia cepacia complex organisms, hence this species-specific PCR assay may help detect this organism from CF sputum more specifically and rapidly. Overall, employment of this novel assay nay help in the understanding of the occurrence. aetiology and epidemiology of E. dermatitidis, as an emerging fungal agent in patients with CF. (C) 2008 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

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As a result of the stressful conditions in aquaculture facilities there is a high risk of bacterial infections among cultured fish. Chlortetracycline (CTC) is one of the antimicrobials used to solve this problem. It is a broad spectrum antibacterial active against a wide range of Gram-positive and Gram-negative bacteria. Numerous analytical methods for screening, identifying, and quantifying CTC in animal products have been developed over the years. An alternative and advantageous method should rely on expeditious and efficient procedures providing highly specific and sensitive measurements in food samples. Ion-selective electrodes (ISEs) could meet these criteria. The only ISE reported in literature for this purpose used traditional electro-active materials. A selectivity enhancement could however be achieved after improving the analyte recognition by molecularly imprinted polymers (MIPs). Several MIP particles were synthesized and used as electro-active materials. ISEs based in methacrylic acid monomers showed the best analytical performance according to slope (62.5 and 68.6 mV/decade) and detection limit (4.1 × 10−5 and 5.5 × 10−5 mol L−1). The electrodes displayed good selectivity. The ISEs are not affected by pH changes ranging from 2.5 to 13. The sensors were successfully applied to the analysis of serum, urine and fish samples.

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Les protéines sont les macromolécules les plus polyvalentes de la cellule. Elles jouent un rôle fondamental dans la majorité des processus biologiques à travers la formation de complexes multi-protéiques. Durant la transcription, une multitude de facteurs sont impliquées dans le contrôle de l’activité des complexes ARN polymérases. Notre laboratoire s’est intéressé au réseau d’interaction de la machinerie de transcription des ARN polymérases nucléaires, dans le but de mieux comprendre leurs mécanismes de régulation. Pour ce faire, une procédure protéomique comprenant la purification de complexes protéiques par affinité couplée à la spectrométrie de masse et à l’analyse bioinformatique a été développée. La méthode de purification TAP (Tandem Affinity Purification) a été adaptée pour permettre la purification de complexes protéiques solubles assemblés in vivo à partir de cellules humaines. L’objectif de mon projet de maîtrise était de purifier le complexe de l’ARN Pol I ainsi que de poursuivre l’expansion du réseau d’interactions protéine-protéine de la machinerie de transcription de l’ARN Pol II humaine. À l’aide des protéines POLR1E, TWISTNB, POLR2E, PFDN4, MBD2, XPA, CAND1 et PDCD5 étiquetées (TAP-tag) exprimées dans des lignées cellulaires ECR-293, plusieurs complexes protéiques solubles ont été purifiés et analysés par spectrométrie de masse. Les interactions protéiques ont été triées et validées bioinformatiquement pour donner en final une liste d’interactions ayant un haut degré de confiance à partir de laquelle des réseaux d’interactions protéine-protéine ont été créés. Le réseau créé au cours de ce projet connecte plusieurs composantes de la machinerie transcriptionnelle tels que les ARN Pol I, II et III, les complexes RPAP3/R2TP/prefoldin-like, TRiC/CCT, Mi-2/NuRD et des facteurs de transcription et de réparation de l’ADN. Ce type d’analyse nous a permis d’identifier et de caractériser de nouveaux régulateurs de la machinerie de transcription de l’ARN Pol I et II et de mieux comprendre son fonctionnement.