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1.
Rev Sci Instrum ; 85(10): 104905, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25362442

RESUMO

In nuclear fusion devices, such as Tore Supra, the plasma facing components (PFC) are in carbon. Such components are exposed to very high heat flux and the surface temperature measurement is mandatory for the safety of the device and also for efficient plasma scenario development. Besides this measurement is essential to evaluate these heat fluxes for a better knowledge of the physics of plasma-wall interaction, it is also required to monitor the fatigue of PFCs. Infrared system (IR) is used to manage to measure surface temperature in real time. For carbon PFCs, the emissivity is high and known (ɛ ∼ 0.8), therefore the contribution of the reflected flux from environment and collected by the IR cameras can be neglected. However, the future tokamaks such as WEST and ITER will be equipped with PFCs in metal (W and Be/W, respectively) with low and variable emissivities (ɛ ∼ 0.1-0.4). Consequently, the reflected flux will contribute significantly in the collected flux by IR camera. The modulated active pyrometry, using a bicolor camera, proposed in this paper allows a 2D surface temperature measurement independently of the reflected fluxes and the emissivity. Experimental results with Tungsten sample are reported and compared with simultaneous measurement performed with classical pyrometry (monochromatic and bichromatic) with and without reflective flux demonstrating the efficiency of this method for surface temperature measurement independently of the reflected flux and the emissivity.

2.
Rev Sci Instrum ; 83(10): 10D727, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23130796

RESUMO

The new JET ITER-like wall (made of beryllium and tungsten) is more fragile than the former carbon fiber composite wall and requires active protection to prevent excessive heat loads on the plasma facing components (PFC). Analog CCD cameras operating in the near infrared wavelength are used to measure surface temperature of the PFCs. Region of interest (ROI) analysis is performed in real time and the maximum temperature measured in each ROI is sent to the vessel thermal map. The protection of the ITER-like wall system started in October 2011 and has already successfully led to a safe landing of the plasma when hot spots were observed on the Be main chamber PFCs. Divertor protection is more of a challenge due to dust deposits that often generate false hot spots. In this contribution we describe the camera, data capture and real time processing systems. We discuss the calibration strategy for the temperature measurements with cross validation with thermal IR cameras and bi-color pyrometers. Most importantly, we demonstrate that a protection system based on CCD cameras can work and show examples of hot spot detections that stop the plasma pulse. The limits of such a design and the associated constraints on the operations are also presented.

3.
Rev Sci Instrum ; 81(10): 10E113, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21033978

RESUMO

During operation of present fusion devices, the plasma facing components (PFCs) are exposed to high heat fluxes. Understanding and preventing overheating of these components during long pulse discharges is a crucial safety issue for future devices like ITER. Infrared digital cameras interfaced with complex optical systems have become a routine diagnostic to measure surface temperatures in many magnetic fusion devices. Due to the complexity of the observed scenes and the large amount of data produced, the use of high computational performance hardware for real-time image processing is then mandatory to avoid PFC damages. At Tore Supra, we have recently made a major upgrade of our real-time infrared image acquisition and processing board by the use of a new field programmable gate array (FPGA) optimized for image processing. This paper describes the new possibilities offered by this board in terms of image calibration and image interpretation (abnormal thermal events detection) compared to the previous system.

4.
Breast ; 13(5): 369-75, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15454191

RESUMO

From 1981 to 1995, 1755 patients aged 70 years or over who had nonmetastatic unilateral breast carcinoma received curative local or regional treatment in our institute. Median follow-up was 8 years. The median age of these patients was 75 years (range: 70-94), and 86% were under 81 years of age. Tumors were classed as T3-4 in 24% of them; 18% had N1b/N2 tumors, and in 12% grade 3 disease was present. Only 19% were both ER and PR negative. The S phase fraction was <5% in 79% of patients. In 1046 patients (60%) modified radical mastectomy was performed, while 20% underwent lumpectomy and in 20% radiotherapy was the only treatment administered. Adjuvant endocrine therapy was given in 463 (26%) cases, and only 3% of patients received chemotherapy. The median overall survival time was 121 months. The overall cancer-related death rate was 49%. The 10-year disease-free survival (DFS) rate was 64%, and the 10-year local relapse rate was 14%. Prognostic factors determined on univariate analysis were tumor size, clinical nodal status (ER and PR), and grade. No significant difference in outcome was observed between mastectomy and conservative treatment. Parameters for which correlations with DFS were found on multivariate analysis were clinical nodal status (P < 0.0001), tumor size (P < 0.0001), ER (P < 0.0001), and PR (P = 0.04). Breast cancer in elderly women is frequently hormone-dependent (81%) with a low proliferation index. Prognostic factors are the same as in younger postmenopausal patients. More than 50% of these patients died from a cause other than their breast cancer.


Assuntos
Neoplasias da Mama/terapia , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Terapia Combinada , Feminino , Humanos , Mastectomia/métodos , Estadiamento de Neoplasias , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
5.
Eur J Cancer ; 40(3): 336-41, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14746850

RESUMO

The aim of this study was to determine whether the metastatic potential of breast cancer could be related to phenotypic characteristics of the tumour. Therefore, we compared the metastatic patterns of invasive lobular (ILC) and ductal (IDC) carcinomas. In ILC, we also analysed this pattern according to the histological subtype of the primary and the E-cadherin (EC) expression level. Metastatic ILC cases (n=96) were retrospectively analysed and classified into classical, alveolar, solid, tubulo-lobular, signet ring cells or pleomorphic subtypes. Anatomical distribution of metastases was detailed for every patient and compared with that registered for IDC (n=2749). Immunostaining of EC (HECD1 antibody) was performed in 82 cases. Histologically, 78 of the 96 cases (81%) corresponded to classical ILC. The pleomorphic subtype was observed in 14 cases (15%), a rate that was higher than that expected. Others corresponded to alveolar (2 cases), signet ring cell (1 case) and solid (1 case) subtypes. EC was undetectable in 72/82 cases (88%). The rate of multiple metastases was higher in ILC (25.0%) than in IDC (15.8%) (P=0.016). Metastases were found more frequently in ILC than in IDC in the bone (P=0.02) and/or in various other sites (peritoneum, ovary, digestive tract, skin em leader ) (P<0.001). In ILC, no significant link was found between the localisation(s) of metastases, the histological subtype and the EC status in the primary. In conclusion, in breast carcinomas, the frequency of multiple metastasis was found to be higher in ILC than IDC. This fact may be related to the phenotypic trait of discohesive small cells which characterises ILC. EC loss, observed in most cases of ILC, may result in alterations in cell-cell adhesion and a preferential growth at metastatic sites. A high rate of pleomorphic tumours was observed in the group of metastatic ILC, but the pattern of metastatic site(s) was not related to the histological subtype of the primary.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/secundário , Carcinoma Lobular/secundário , Fenótipo , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Carcinoma Lobular/genética , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade
6.
Eur J Cancer ; 39(8): 1089-96, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12736108

RESUMO

The aim of this retrospective study was to assess predictive factors for clinical response to preoperative chemotherapy and prognostic factors for survival. From 1981 to 1992, 936 patients with T2-T3, N0-N1 breast cancer who received 2-6 months (median 4) of preoperative chemotherapy were selected from the Institute Curie database. Preoperative treatment was followed by surgery and/or radiotherapy. Median follow-up was 8.5 years (range 7-211 months). The objective response rate before surgery and/or radiotherapy was 58.3%. In stepwise multivariate analysis (Cox model), favourable prognostic factors for survival were the absence of pathological axillary lymph node involvement (Relative Risk (RR) 1.54; P=0.0004), low histological tumour grade (RR=1.54; P=0.0017), clinical response to preoperative chemotherapy (RR=1.45, P=0.0013), positive progesterone receptor (PR) status (RR=1.56; P=0.0001), smaller tumour size (RR=1.37; P=0.005) and lack of clinical lymph node involvement (RR=1.42; P=0.007). The association of clinical tumour response with survival is independent of the baseline characteristics of the tumour. Clinical response could be used as a surrogate marker for evaluation of the efficacy of neoadjuvant chemotherapy before assessment of the pathological response.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Idoso , Análise de Variância , Neoplasias da Mama/cirurgia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
7.
J Clin Microbiol ; 39(5): 1738-45, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11325983

RESUMO

Operons of the afa family are expressed by pathogenic Escherichia coli strains associated with intestinal and extraintestinal infections in humans and animals. The recently demonstrated heterogeneity of these operons (L. Lalioui, M. Jouve, P. Gounon, and C. Le Bouguénec, Infect. Immun. 67:5048-5059, 1999) was used to develop a new PCR assay for detecting all the operons of the afa family with a single genetic tool. This PCR approach was validated by investigating three collections of human E. coli isolates originating from the stools of infants with diarrhea (88 strains), the urine of patients with pyelonephritis (97 strains), and the blood of cancer patients (115 strains). The results obtained with this single test and those previously obtained with several PCR assays were closely correlated. The AfaE adhesins encoded by the afa operons are variable, particularly with respect to the primary sequence encoded by the afaE gene. The receptor binding specificities have not been determined for all of these adhesins; some recognize the Dr blood group antigen (Afa/Dr(+) adhesins) on the human decay-accelerating factor (DAF) as a receptor, and others (Afa/Dr(-) adhesins) do not. Thus, the afa operons detected in this study were characterized by subtyping the afaE gene using specific PCRs. In addition, the DAF-binding capacities of as-yet-uncharacterized AfaE adhesins were tested by various cellular approaches. The afaE8 subtype (Afa/Dr(-) adhesin) was found to predominate in afa-positive isolates from sepsis patients (75%); it was frequent in afa-positive pyelonephritis E. coli (55.5%) and absent from diarrhea-associated strains. In contrast, Afa/Dr(+) strains (regardless of the afaE subtype) were associated with both diarrhea (100%) and extraintestinal infections (44 and 25% in afa-positive pyelonephritis and sepsis strains, respectively). These data suggest that there is an association between the subtype of AfaE adhesin and the physiological site of the infection caused by afa-positive strains.


Assuntos
Adesinas de Escherichia coli/genética , Adesinas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Reação em Cadeia da Polimerase/métodos , Adulto , Animais , Antígenos de Grupos Sanguíneos/metabolismo , Antígenos CD55/metabolismo , Criança , Infecções por Escherichia coli/microbiologia , Células HeLa , Humanos , Lactente , Recém-Nascido , Enteropatias/microbiologia , Oligonucleotídeos/análise , Óperon
8.
Ann Oncol ; 12(2): 231-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11300330

RESUMO

BACKGROUND: In cancer patients, correlation between response to chemotherapy and gain in survival remains debated. We addressed this question in a multivariate analysis evaluating response to chemotherapy as a factor influencing survival of patients with metastatic breast cancer. PATIENTS AND METHODS: From 1977 to 1992, 1430 patients included in eight consecutive prospective trials of anthracycline-based first-line chemotherapy in metastatic breast cancer, were available for assessment. Median follow-up was 155 months. RESULTS: Median survival from the date of randomisation was 24 months. Objective response rate was 63.6%. A complete response (CR) was achieved in 17% (249 patients). In a stepwise forward progression analysis objective response was the first independent prognostic factor for survival. Median survival time was 43 months for complete responders (CR), 29 months for partial responders (PR), 18 months for stable disease (SD), 5 months for progressive disease (PD). The probability of survival at 5 and 10 years was 35% and 15% for CR's and decreased to 18% and 6% for PR's. The timing of best response (at 4 or 8 months) was not related to outcome. CONCLUSIONS: Response to an anthracycline-based chemotherapy is a major independent prognostic factor in metastatic breast cancer. The use of this factor to investigate new drugs seems to be pertinent. The good prognosis of complete responders justifies further evaluation of new treatment strategies for this patient population.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Adulto , Biomarcadores Tumorais/análise , Neoplasias da Mama/secundário , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Estudos Prospectivos , Terapia de Salvação , Taxa de Sobrevida , Resultado do Tratamento
9.
Cancer ; 91(6): 1079-89, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11267952

RESUMO

BACKGROUND: The objective of the current study was to analyze the impact of adjuvant chemotherapy in comparison with other prognostic parameters on the outcome of a series of patients with breast carcinoma at time of metastatic recurrence. METHODS: Data from 1430 patients accrued in 8 prospective trials of anthracycline-based first-line chemotherapy conducted at the Institut Curie between 1977 and 1992 were reviewed. RESULTS: Patients who had not received adjuvant chemotherapy had better response rates (66%) than pretreated patients (56%; P < 0.0001). Median overall survival rates after metastatic recurrence were 26 months compared with 19 months, respectively (P < 0.0001). Local and regional recurrences as well as the number of organ sites involved with metastatic disease were reduced in patients who had received adjuvant chemotherapy. In a multivariate analysis, the following parameters if present at the initiation of treatment were associated with poor outcome: elevated lactico dehydrogenase (LDH), low Karnofsky index, short disease free interval, more than two involved sites, liver involvement, and prior adjuvant chemotherapy. This adverse prognostic effect of prior adjuvant chemotherapy was independent of the type of drugs and of the duration of the treatment and was present even in the subgroup patients with prolonged disease free intervals longer than 48 months. CONCLUSIONS: Adjuvant chemotherapy adversely affects overall response rates and overall survival rates in patients with metastatic breast carcinoma treated with first-line anthracycline based chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carcinoma/tratamento farmacológico , Quimioterapia Adjuvante , Adulto , Idoso , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma/patologia , Carcinoma/cirurgia , Intervalo Livre de Doença , Feminino , Nível de Saúde , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
10.
Eur J Cancer ; 36(18): 2301-12, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11094303

RESUMO

Since response to chemotherapy is a major determinant of survival in metastatic breast cancer, the purpose of our study was to analyse the predictive factors of response. 1426 patients enrolled into eight consecutive randomised trials of anthracycline-based first-line chemotherapy in metastatic breast cancer, between 1977 and 1992, were analysed. A forward stepwise logistic regression analysis was used. The objective response rate (ORR) to chemotherapy in the total population was 63.6% (95% confidence interval (CI): 61.5-67.7). The complete response rate was 17.5%. Multivariate analysis defined adjuvant chemotherapy, lactate dehydrogenase (LDH), Karnofsky index (KI), and pleural and lung metastases to be the five main variables correlated with ORR. A predictive score was calculated using the coefficient of these five variables, The score was established as follows: -1.32+0.54 (if prior adjuvant chemotherapy) +0.80 (low KI) +0.75 (raised LDH) +0.49 (lung metastases) +0.51 (pleural metastases). A low score (less than -0.78) was associated with an ORR greater than 70.0%, representing 41.2% of our population. An intermediate score (between -0.78 and 0) was associated with an ORR of 50 to 70%, representing 37.5% of our population and a positive score was associated with an ORR of less than 50%, representing 21.3% of our population. This score can be used to predict objective response rates to first-line anthracycline-based chemotherapy. This method now needs to be evaluated prospectively in phase II trials. Identification of various risk groups may also be useful for interpretation and design of clinical trials.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Análise Multivariada , Metástase Neoplásica , Recidiva Local de Neoplasia , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Sobrevida
11.
Br J Cancer ; 83(11): 1480-7, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11076657

RESUMO

Neoadjuvant chemotherapy is able to reduce the size of the majority of breast tumours and down-stage axillary-node status. The aim of this study was to assess the prognostic value of persistent node involvement after neoadjuvant chemotherapy. A total of 488 patients with T2-T3, N0-N1 breast cancer treated by neoadjuvant chemotherapy followed by tumour excision and axillary lymph-node dissection between 1981 and 1992 were selected from the Institut Curie database. Median follow-up was 7 years. Overall objective response rate before local treatment was 52% and breast tumour size was reduced in 83% of patients. No pathologic nodal involvement was observed in 46. 5% of patients. Patients with > or = eight positive nodes had a very poor median disease-free survival of only 20 months. Their 10-year disease-free survival rate was 7%, while the 10-year disease-free survival rate for patients with no node involvement was 64%. Median survival for patients with > or = eight nodes positive was 48 months and the 10-year survival rate was 26% (P < 0.0001). On multivariate analysis, outcome was strongly correlated with pathological nodal status, tumour grade, hormonal receptor status and clinical response of the tumour. In conclusion, patients with extensive nodal involvement after neoadjuvant chemotherapy have a very poor outcome. Second-line treatment should be considered in this population.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linfonodos/patologia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Axila , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Ductal de Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Epirubicina/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Humanos , Excisão de Linfonodo , Linfonodos/cirurgia , Metástase Linfática , Pessoa de Meia-Idade , Análise Multivariada , Terapia Neoadjuvante , Estadiamento de Neoplasias , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Taxa de Sobrevida , Tiotepa/administração & dosagem , Resultado do Tratamento
12.
FEBS Lett ; 479(3): 111-7, 2000 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-10981717

RESUMO

The afimbrial adhesive sheath, encoded by the afa-3 gene cluster, is composed of two proteins with different roles in bacterium-HeLa cell interactions. AfaE is required for adhesion and AfaD for internalization. In this study, we found that the AfaD invasin was structurally and functionally conserved among human afa-expressing strains, independently of AfaE subtype and clinical origin of the Escherichia coli isolate. The AggB protein from enteroaggregative E. coli was also found to be an AfaD-related invasin. These data suggest that AfaD is the prototype of a family of invasins encoded by adhesion-associated operons in pathogenic E. coli.


Assuntos
Adesinas Bacterianas , Adesinas de Escherichia coli/química , Proteínas de Bactérias/química , Infecções por Escherichia coli/microbiologia , Escherichia coli/metabolismo , Enteropatias/microbiologia , Adesinas de Escherichia coli/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/metabolismo , Células CHO , Adesão Celular , Sequência Conservada , Cricetinae , Primers do DNA/metabolismo , Escherichia coli/genética , Escherichia coli/patogenicidade , Teste de Complementação Genética , Células HeLa , Humanos , Microscopia Eletrônica , Dados de Sequência Molecular , Família Multigênica , Mutagênese , Plasmídeos/metabolismo , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Infecções Urinárias/microbiologia
13.
Microsc Res Tech ; 49(4): 383-93, 2000 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10820522

RESUMO

In the versatile single species of Escherichia coli, the diarrheagenic group displays a remarkable array of virulence traits. These comprise microbial attachment, production of secretory endotoxins or cell-destroying cytotoxins, direct epithelial cell invasion, and localized effacement of the epithelium. The knowledge of how enteric E. coli induce disease has become increasingly important in the world, because of new pathogen emergence, increasing threats of drug resistance, and growing awareness of their importance in malnutrition and diarrhea. Numerous research programs have demonstrated various mechanisms of pathogenesis. We point out how some pathogens are able to develop intercourse with their host through subversion of its cytoskeleton and signaling processes without toxin secretion or heavy invasiveness. In that domain, the cellular biology of infected cells owes fundamental data to the electron microscopic approach. Combined with advances in microbiology and molecular biology, this approach may provide answers to many unanswered questions.


Assuntos
Diarreia/microbiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/patogenicidade , Escherichia coli/ultraestrutura , Animais , Aderência Bacteriana , Bovinos , Cães , Humanos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/ultraestrutura , Microscopia Eletrônica , Virulência
14.
Microbes Infect ; 2(4): 359-65, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10817637

RESUMO

We used a recent scanning electron microscope equipped with field emission gun and highly sensitive detectors to develop a fast and simple protocol for double immunogold staining using 10- and 15-nm gold particles. We used this approach to analyse the afimbrial adhesive sheath produced by pathogenic Escherichia coli interacting with the surface of epithelial cells. We demonstrated that AfaE adhesin and AfaD invasin were exposed at the bacterial surface during the interaction. This method could be easily and widely extended to the study of the early invasion process of many bacterial and viral pathogens, by immunocytochemical probing.


Assuntos
Adesinas de Escherichia coli/análise , Escherichia coli/patogenicidade , Escherichia coli/metabolismo , Escherichia coli/ultraestrutura , Células HeLa , Humanos , Imuno-Histoquímica , Microscopia Eletrônica de Varredura
15.
Infect Immun ; 67(10): 5048-59, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10496877

RESUMO

The afa gene clusters, which encode proteins involved in adhesion to epithelial cells, from Escherichia coli strains associated with urinary and intestinal infections in humans have been characterized. Pathogenic isolates of bovine and porcine origin that possess afa-related sequences have recently been described. We report in this work the cloning and characterization of the afa-7 and afa-8 gene clusters from bovine isolates. Hybridization and sequencing experiments revealed that despite similarity in genetic organization, the afa-7 and afa-8 genes, and the well-characterized afa-3 operon expressed by human-pathogenic isolates, correspond to three different members of the afa family of gene clusters. However, like the afa-3 gene cluster, both the afa-7 and afa-8 gene clusters were found to encode an afimbrial adhesin (AfaE) and an invasin (AfaD). The AfaD peptides encoded by the three gene clusters were only 45% identical, but functional complementation experiments indicated that they belong to the same family of invasins. Hemagglutination and adhesion assays demonstrated that the AfaE-VII and AfaE-VIII adhesins bind to different receptors and that these receptors are not the human decay-accelerating factor recognized to be the receptor of all previously described AfaE adhesins. The AfaE-VIII adhesin is very similar to the M agglutinin of human-uropathogenic strains. We used PCR assays to screen 25 bovine strains for afaD and afaE genes of either the afa-7 or afa-8 gene cluster. The afa-8 gene cluster was highly prevalent in bovine isolates previously reported to carry afa-related sequences (23 of 24 strains), particularly in strains producing cytotoxic necrotizing factors (16 of 16 strains). The location of the afa-8 gene cluster on the plasmids or chromosome of these isolates suggests that it could be carried by a mobile element, facilitating its dissemination among bovine-pathogenic E. coli strains.


Assuntos
Adesinas de Escherichia coli/genética , Doenças dos Bovinos/etiologia , Diarreia/veterinária , Escherichia coli/genética , Genes Bacterianos , Família Multigênica , Sepse/veterinária , Animais , Aderência Bacteriana , Bovinos , Clonagem Molecular , Diarreia/etiologia , Escherichia coli/patogenicidade , Plasmídeos , Sepse/etiologia
16.
J Clin Microbiol ; 37(9): 2829-33, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10449460

RESUMO

In a follow-up study, enterotoxigenic Escherichia coli (ETEC) infections in 145 children from two communities located in northeastern Argentina were monitored for 2 years. The occurrence of diarrhea was monitored by weekly household visits. Of 730 fecal specimens collected, 137 (19%) corresponded to diarrheal episodes. ETEC was isolated from a significantly higher proportion of symptomatic (18.3%) than asymptomatic (13.3%) children (P = 0.04541). Individuals of up to 24 months of age were found to have a higher risk of developing ETEC diarrhea than older children (odds ratio [OR], 3.872; P = 0.00021). When the toxin profiles were considered, only heat stable enterotoxin (ST)-producing ETEC was directly associated with diarrhea (P = 0.00035). Fifty-five percent of the ETEC isolated from symptomatic children and 19% of the ETEC isolated from asymptomatic children expressed one of the colonization factors (CFs) investigated, i.e., CF antigen I (CFA/I), CFA/II, CFA/III, and CFA/IV; coli surface antigens CS7 and CS17; and putative CFs PCFO159, PCFO166, and PCFO20, indicating a clear association between diarrhea and ETEC strains that carry these factors (P = 0.0000034). The most frequently identified CFs were CFA/IV (16%), CFA/I (10%), and CS17 (9%). CFs were mostly associated with ETEC strains that produce ST and both heat-labile enterotoxin and ST. Logistic regression analysis, applied to remove confounding effects, revealed that the expression of CFs was associated with illness independently of the toxin type (OR, 4.81; P = 0.0003). When each CF was considered separately, CS17 was the only factor independently associated with illness (OR, 16.6; P = 0.0151). Most CFs (the exception was CFA/IV) fell within a limited array of serotypes, while the CF-negative isolates belonged to many different O:H types. These results demonstrate that some CFs are risk factors for the development of ETEC diarrhea.


Assuntos
Infecções por Escherichia coli/microbiologia , Proteínas de Fímbrias , Proteínas de Bactérias/análise , Pré-Escolar , Estudos de Coortes , Diarreia/etiologia , Enterotoxinas/análise , Escherichia coli/classificação , Escherichia coli/patogenicidade , Feminino , Humanos , Lactente , Recém-Nascido , Intestinos/microbiologia , Masculino , Estudos Prospectivos , Sorotipagem
17.
Eur J Cancer ; 35(3): 392-7, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10448288

RESUMO

The aim of this analysis was to assess how the clinical response to chemotherapy corresponded to long-term prognosis in patients of less than 35 years of age. A retrospective analysis was made of response and survival data of 609 premenopausal patients who had been treated by four cycles of neoadjuvant chemotherapy followed by surgery and/or radiotherapy. Patients were stratified into three age groups (group 1, < or = 35 years; group 2, 35-40 years; group 3, > or = 41 years). Objective and complete clinical response rates were significantly higher in the youngest patients (below 35 yrs: P = 0.005 and P = 0.001, respectively) in stark contrast to a particularly poor outcome of this subpopulation. Five-year local recurrence rates were 31% in the youngest patients, compared with 26% and 16% in groups 2 and 3, respectively (P = 0.0007). Group 1 patients also had significantly higher 5-year metastatic relapse rates (41% versus 35% and 28%; P = 0.007) and 5-year survival figures were 70%, 82% and 84% for groups 1, 2 and 3 respectively (P = 0.002). Finally, stratification by age and by response revealed that, whilst the outcome of the youngest patients was highly dependent on their response to primary chemotherapy, complete responders showed disease-free survival rates at 5 years that were lower than these of older patients, whatever their response. Despite a seemingly better control of the primary tumour by chemotherapy, the patients in the youngest age group remained at a high risk for local and metastatic relapse. This apparent paradox may be in part attributable to rapid disease progression of micrometastatic tumour subpopulations that are refractory to chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Fatores Etários , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Quimioterapia Adjuvante , Feminino , Humanos , Recidiva Local de Neoplasia , Análise de Regressão , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
18.
Br J Cancer ; 77(9): 1474-9, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9652764

RESUMO

Infusional 5-fluorouracil in advanced breast cancer has been associated with improved clinical response rates when compared with conventional bolus therapy. As a first line of chemotherapy in proven metastatic breast carcinoma, 258 women were randomly assigned to receive FAC consisting of 5-fluorouracil (F) 600 mg m(-2) intravenously (i.v.) over 1 h on days 1, 2 and 3, doxorubicin (A) 50 mg m(-2) i.v. bolus on day 1 and cyclophosphamide (C), 400 mg m(-2) i.v. bolus on days 1, 2 and 3 or 'FULON' consisting of 5-fluorouracil 250 mg m(-2) day(-1) continuously infused from day 1 to day 22, doxorubicin 15 mg m(-2) i.v. bolus on days 1, 8, 15 and 22 and cyclophosphamide 300 mg m(-2) i.v. bolus on days 1, 8, 15 and 22. Chemotherapy courses were administered 4-weekly for the bolus regimen and 6-weekly for FULON. Pretreatment characteristics were identical between the two groups. Response rates were 54% in the FAC arm and 53% in the FULON arm. Time to progression was 14 months in the FAC arm and 12 months in the FULON arm. Differences were not statistically significant. Median overall survival duration for all patients was 22 months. Haematological toxicity was more severe in the bolus-treated group (P = 0.05), as were nausea and vomiting (P < or = 0.01). We conclude that the two regimens appeared equally effective but have different toxicities.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carcinoma/tratamento farmacológico , Adulto , Idoso , Neoplasias da Mama/patologia , Carcinoma/secundário , Ciclofosfamida/administração & dosagem , Método Duplo-Cego , Doxorrubicina/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Humanos , Neoplasias Hepáticas/secundário , Pessoa de Meia-Idade , Taxa de Sobrevida
19.
Recent Results Cancer Res ; 152: 217-26, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9928560

RESUMO

Chemotherapy dose intensification in breast tumours is being evaluated in many multicentre trials, its indication being based on a clinical response in high-risk patients, thus selecting for tumours with rapid proliferation and low resistance. However, results from randomized trials are still pending. Clinical and pathological responses to therapy are valuable surrogate endpoints following primary chemotherapy. They will make it possible to distinguish at an early stage between patients who still retain an apoptotic response to chemotherapy and those patients whose disease will progress rapidly due to resistance mechanisms. For practical purposes, patients at risk and capable of responding represent the population of choice for primary systemic chemotherapy. Thus, by investigating mechanisms of response and resistance during the first courses of treatment we may target chemotherapy at those patients likely to benefit most from this treatment. A number of immunotherapy and vaccination trials are being conducted in many different centres. There is a lot of anecdotal evidence that cancer vaccines could help patients, but little yet in the way of solid, reproducible clinical data. Best responses to clinical testing would ideally be expected in early-stage disease because there is less tumour bulk and the patient's immune system is still able to respond. Patients with early breast cancer who are at high risk of recurrence and who have failed to respond to primary chemotherapy might be given the option of participating in adjuvant vaccination trials following the completion of local therapy.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Feminino , Humanos , Invasividade Neoplásica , Prognóstico , Resultado do Tratamento
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