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1.
Ann Cardiol Angeiol (Paris) ; 68(1): 39-48, 2019 Feb.
Artigo em Francês | MEDLINE | ID: mdl-30683484

RESUMO

OBJECTIVES: To study the use, efficiency and wishes for a "medicalization" of the electronic cigarette (EC) for smoking cessation in secondary prevention of acute coronary syndrome (ACS). PATIENTS AND METHOD: Prospective epidemiological study with inclusion of smoker patients hospitalized from 1st June 2015 to 31st March 2016 at the St Quentin Hospital (Picardy, France) for an ACS (except unstable angina), interviewed 1 year after their ACS, excluding patients over 75 years or with personal history of ACS. RESULTS: Eighty-one patients were included. 59 questionnaires (73%) were returned and analyzed. The average age was 53.3 years. There were 45 men (76.3%) and 14 women (23.7%). 11 patients (18.6%) had used the EC at least once before their ACS and 11 (18.6%) had used it after. That was the second most used smoking cessation method after the nicotine patches. One year after their SCA, 39 patients (66.1%) had stopped smoking: 63.6% (7/11) of EC users after the ACS against 66.7% (32/48) of non-users (P=0.848). After multivariate analysis, only cessation without help was associated with ceasing (P=0.013). CE users were significantly younger, were smoking more before their ACS, and had started smoking earlier. 50% of CE users would have appreciated to be better informed by their general practitioner and 53.3% expressed themselves in favor of a sale in pharmacies. CONCLUSION: EC is the second most common means of smoking cessation after an ACS. Further comparative studies are essential to know more about its efficiency and safety.


Assuntos
Síndrome Coronariana Aguda/prevenção & controle , Sistemas Eletrônicos de Liberação de Nicotina/estatística & dados numéricos , Prevenção Secundária , Abandono do Hábito de Fumar/métodos , Abandono do Hábito de Fumar/estatística & dados numéricos , Síndrome Coronariana Aguda/epidemiologia , Feminino , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários
2.
J Appl Microbiol ; 124(2): 559-571, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29222941

RESUMO

AIM: The spoilage potential of 28 bacterial strains isolated from spoiled raw yellowfin tuna was evaluated. METHODS AND RESULTS: Bacterial species were inoculated in irradiated tuna matrix. Chemical changes, bacterial growth and sensory quality were monitored during aerobic storage at 8°C. Pseudomonas spp., Enterobacter spp. and Escherichia hermanii had no spoiling effect. Brochothrix thermosphacta and Carnobacterium divergens/maltaromaticum developed moderate unpleasant odours. Hafnia paralvei and Serratia spp. released strong off-odours (pyrrolidine, sulphur/cabbage). No bacterial group (except H. paralvei) combined with Pseudomonas spp. deteriorated the sensory quality of tuna. When C. divergens/maltaromaticum was associated with H. paralvei or B. thermosphacta, the odour is close to the naturally contaminated tuna stored on the same conditions. The pH, total volatile basic nitrogen (TVBN) and trimethylamine (TMA) were not correlated with the spoilage. CONCLUSIONS: The bacterial species had a different impact on the sensory quality of the fish. The bacterial interactions lead to an enhancement or an inhibition of the spoilage potential and the bacterial growth. SIGNIFICANCE AND IMPACT OF STUDY: The specific spoilage organism (SSO) appears to be an association of lactic acid bacteria (LAB) with Enterobacteriaceae or B. thermosphacta. Pseudomonas, often dominant at the sensory rejection time, is not a good quality indicator.


Assuntos
Bactérias/isolamento & purificação , Peixes/microbiologia , Atum/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Humanos , Odorantes/análise , Paladar
3.
Biomed Mater Eng ; 28(s1): S65-S74, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28372279

RESUMO

Endothelial Colony Forming Cells (ECFCs) are obtained in culture from Circulating Endothelial Progenitor Cells. They display all characteristics of endothelial cells and they display stem cells features. Cord blood-derived ECFCs (CB-ECFCs) have a high clonogenic and proliferative potentials, and exhibit vascular repair capabilities useful for the treatment of ischemic diseases. However, the link between immaturity and functional properties of CB-ECFCs is still poorly defined. We showed that these cells have a high clonogenic potential and are capable to be efficiently reprogrammed into induced pluripotent stem cells. Moreover, we analyzed the expression of a broad panel of genes involved in embryonic stem cell properties. We define a novel stem cell transcriptional signature for CB-ECFCs fora better characterization and stratification according to their stem cell profile. We then improved the yield of CB-ECFC production for obtaining cells more functional in fewer passages. We used Glycosaminoglycans (GAG), components from the extracellular matrix which potentiate heparin binding growth factor activities. GAG mimetics were designed, having the capacity to increase the yield of ECFC during the isolation process, to increase the number of colonies, improve adhesion, proliferation, migration and self-renewal. GAG mimetics have thus great interest for vascular regeneration in combination with ECFC. Our results show that CB-ECFC are immature cells harboring specific functions such as formation of colonies, proliferation and formation of vascular structures in vitro and in vivo.


Assuntos
Células Endoteliais/citologia , Sangue Fetal/citologia , Neovascularização Fisiológica , Células-Tronco/citologia , Adesão Celular , Técnicas de Cultura de Células/métodos , Diferenciação Celular , Movimento Celular , Proliferação de Células , Separação Celular , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Glicosaminoglicanos/química , Glicosaminoglicanos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco/metabolismo
4.
Eur Cell Mater ; 30: 51-68, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26337540

RESUMO

Critical limb ischaemia often leads to amputation of the limb and potential mortality. Moreover, there are still significant problems with current therapeutic treatments, according to poor revascularisation of degenerated tissue probably due to modifications within the microenvironment. This study is focused on the changes of structure and bioactivity of glycosaminoglycans (GAGs), especially heparan sulphate (HS) and chondroitin sulphate (CS) in rat Extensor Digitorum Longus (EDL) muscle after ischaemia. Male Wistar rats were subjected to ischaemic-injury by ligation of the neurovascular trunk accompanying EDL-tendon. After 4, 8, 15, 21, 60 and 90 d, the rats were sacrificed and the muscles were collected and submitted to histological, biochemical and gene expression assays. We demonstrated that ischaemia induced modification of expression of enzymes involved in GAG biosynthesis which correlated with significant changes in HS and CS structural features such as size and sulphation pattern. These major structural changes are associated to modifications of GAG abilities to bind growth factors and to modulate cell activity. Moreover, a CS hallmark of injury is maintained as well after the regeneration process. Finally, we showed the relevance of the role of this glycanic matrix remodelling, since a GAG mimetic treatment accelerated muscle repair after ischaemia.


Assuntos
Sulfatos de Condroitina/metabolismo , Glicosaminoglicanos/metabolismo , Isquemia/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Regeneração/fisiologia , Animais , Células Cultivadas , Progressão da Doença , Expressão Gênica/fisiologia , Isquemia/patologia , Masculino , Ratos Wistar
5.
IEEE Trans Vis Comput Graph ; 18(12): 2639-48, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26357173

RESUMO

A discourse parser is a natural language processing system which can represent the organization of a document based on a rhetorical structure tree-one of the key data structures enabling applications such as text summarization, question answering and dialogue generation. Computational linguistics researchers currently rely on manually exploring and comparing the discourse structures to get intuitions for improving parsing algorithms. In this paper, we present DAViewer, an interactive visualization system for assisting computational linguistics researchers to explore, compare, evaluate and annotate the results of discourse parsers. An iterative user-centered design process with domain experts was conducted in the development of DAViewer. We report the results of an informal formative study of the system to better understand how the proposed visualization and interaction techniques are used in the real research environment.

6.
Br J Cancer ; 104(11): 1670-4, 2011 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-21540859

RESUMO

BACKGROUND: Patients receiving cytotoxic therapy for solid tumours are at risk of severe influenza. However, few data are available regarding the immunogenical efficacy of influenza vaccine in these patients. METHODS: In this prospective study, 25 patients with breast (n=13) or prostate (n=12) cancer received a trivalent inactivated influenza vaccine along with docetaxel (Taxotere) administration. The influenza virus type A and B antibody titres were measured using haemagglutinin inhibition (Garten et al, 2009) before and 21 days after the vaccination. Seroconversion rate was defined as the percentage of patients with an increase in the serum titres ≥ 4 after vaccination. RESULTS: Median age was 65 years (range: 33-87 years); 52% were females. Seroconversion rates were low: 28% (95% CI: 23.1-33.3) for H1N1, 8% (95% CI: 7.7-8.3) for H3N2 and 16% (95% CI: 7.7-25) for the B strain. The geometric mean titres ratios were 2.16 (H1N1), 1.3 (H3N2) and 1.58 (B). No serious adverse event (AE) related to the vaccine was reported. All the reported AE were from mild-to-moderate intensity. CONCLUSION: In the patients receiving docetaxel for solid tumours, influenza vaccine triggers an immune response in only one third. Strategies using more immunogenic influenza vaccines must be evaluated in such patients.


Assuntos
Anticorpos Antivirais/biossíntese , Antineoplásicos/uso terapêutico , Vacinas contra Influenza/imunologia , Taxoides/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Docetaxel , Feminino , Hemaglutinação por Vírus , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/efeitos adversos , Betainfluenzavirus/imunologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Taxoides/administração & dosagem
7.
Lett Appl Microbiol ; 50(4): 357-61, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20132434

RESUMO

AIMS: To investigate the antimicrobial spectrum of Lactococcus piscium CNCM I-4031 and its protective effect in cooked and peeled shrimp against Brochothrix thermosphacta. METHODS AND RESULTS: Sixteen pathogenic and spoiling bacteria were inhibited in Elliker, but not in shrimp juice agar plates. In shrimp packed under modified atmosphere and stored at 8 degrees C, B. thermosphacta (10(3) CFU g(-1)) was inhibited by 4.1 log CFU g(-1) when co-inoculated with L. piscium (10(6) CFU g(-1)). Brochothrix thermosphacta spoiled the product after 11 days, with the emission of strong butter/caramel off-odours. In co-culture with L. piscium, sensory shelf-life was extended by at least 10 days. The inhibition was partially explained by a drop in pH from 6.6 to 5.6. The physicochemical composition of shrimp and shrimp juice was established to identify the inhibition mechanisms involved. CONCLUSION: Lactococcus piscium CNCM I-4031 has a wide antimicrobial spectrum. The strain inhibits B. thermosphacta in shrimp and significantly prolongs sensory shelf-life. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactococcus piscium CNCM I-4031 is shown to be a promising agent for improving shrimp quality and may be tested against pathogens and in other food matrices. Knowledge of the physicochemical composition of shrimp and shrimp juice will allow the development of a chemically defined model medium for determining the inhibition mechanisms involved.


Assuntos
Bactérias/crescimento & desenvolvimento , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Lactococcus/crescimento & desenvolvimento , Frutos do Mar/microbiologia , Antibiose , Técnicas de Cocultura , Meios de Cultura , Manipulação de Alimentos , Frutos do Mar/análise
8.
Mol Psychiatry ; 15(7): 748-55, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19125158

RESUMO

Bipolar disorder (BD) is one of the most common and persistent psychiatric disorders. Early-onset BD has been shown to be the most severe and familial form. We recently carried out a whole-genome linkage analysis on sibpairs affected by early-onset BD and showed that the 20p12 region was more frequently shared in our families than expected by chance. The synaptosomal-associated protein SNAP25 is a presynaptic plasma membrane protein essential for the triggering of vesicular fusion and neurotransmitter release, and for which abnormal protein levels have been reported in postmortem studies of bipolar patients. We hypothesised that variations in the gene encoding SNAP25, located on chromosome 20p12, might influence the susceptibility to early-onset BD. We screened SNAP25 for mutations and performed a case-control association study in 197 patients with early-onset BD, 202 patients with late-onset BD and 136 unaffected subjects. In addition, we analysed the expression level of the two SNAP25 isoforms in 60 brains. We showed that one variant, located in the promoter region, was associated with early-onset BD but not with the late-onset subgroup. In addition, individuals homozygous for this variant showed a significant higher SNAP25b expression level in prefrontal cortex. These results show that variations in SNAP25, associated with an increased gene expression level in prefrontal cortex, might predispose to early-onset BD. Further analyses of this gene, as well as analysis of genes encoding for the SNAP25 protein partners, are required to understand the impact of such molecular mechanisms in BD.


Assuntos
Transtorno Bipolar/genética , Regulação da Expressão Gênica , Estudos de Associação Genética/métodos , Polimorfismo de Nucleotídeo Único , Córtex Pré-Frontal/metabolismo , Regiões Promotoras Genéticas/genética , Proteína 25 Associada a Sinaptossoma/genética , Adulto , Idade de Início , Transtorno Bipolar/diagnóstico , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isoformas de Proteínas/biossíntese , Proteína 25 Associada a Sinaptossoma/biossíntese
9.
Mol Psychiatry ; 13(1): 90-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17505466

RESUMO

Melatonin is produced in the dark by the pineal gland and is a key regulator of circadian and seasonal rhythms. A low melatonin level has been reported in individuals with autism spectrum disorders (ASD), but the underlying cause of this deficit was unknown. The ASMT gene, encoding the last enzyme of melatonin synthesis, is located on the pseudo-autosomal region 1 of the sex chromosomes, deleted in several individuals with ASD. In this study, we sequenced all ASMT exons and promoters in individuals with ASD (n=250) and compared the allelic frequencies with controls (n=255). Non-conservative variations of ASMT were identified, including a splicing mutation present in two families with ASD, but not in controls. Two polymorphisms located in the promoter (rs4446909 and rs5989681) were more frequent in ASD compared to controls (P=0.0006) and were associated with a dramatic decrease in ASMT transcripts in blood cell lines (P=2 x 10(-10)). Biochemical analyses performed on blood platelets and/or cultured cells revealed a highly significant decrease in ASMT activity (P=2 x 10(-12)) and melatonin level (P=3 x 10(-11)) in individuals with ASD. These results indicate that a low melatonin level, caused by a primary deficit in ASMT activity, is a risk factor for ASD. They also support ASMT as a susceptibility gene for ASD and highlight the crucial role of melatonin in human cognition and behavior.


Assuntos
Acetilserotonina O-Metiltransferasa/genética , Transtorno Autístico/genética , Melatonina/biossíntese , Acetilserotonina O-Metiltransferasa/metabolismo , Adolescente , Adulto , Transtorno Autístico/enzimologia , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Análise por Pareamento , Melatonina/metabolismo , Pessoa de Meia-Idade , Linhagem , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Valores de Referência
10.
Am J Med Genet B Neuropsychiatr Genet ; 141B(5): 504-12, 2006 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-16741933

RESUMO

Abnormal dopaminergic function in the prefrontal cortex (PFC) may be a key factor in the etiopathogeny of schizophrenia and bipolar disorder. Both schizophrenic and bipolar subjects have executive functions (EF) deficits, thought to reflect abnormal PFC function. The main inactivation pathways for dopamine in the PFC are enzymatic cleavage by the Carboxy-O-Methyl-Transferase (COMT) and reuptake by the nor-epinephrine transporter (NET). Our aim in this study was to replicate previous studies that investigated influence of the COMT genotype on EF in schizophrenic subjects, their relatives and controls and extend their scope by including bipolar patients, and their relatives and by exploring NET gene polymorphisms influence on executive performances. We investigated one functional polymorphism of the COMT gene and two polymorphisms of the NET gene. EF were assessed by means of the Trail Making Test (TMT) and the Wisconsin Card Sorting Test (WCST). We assessed the effect of each of the three genotypes on EF for the whole sample (N = 318) and separately in schizophrenic (N = 66), bipolar (N = 94) and healthy subjects (i.e., relatives and controls N = 158). Separate analyses were performed because of the presence, in patients samples, of potentially confounding factors, especially medication. Genotype had no significant effect on the cognitive measures in any of the analyses (for the two EF measures, the three polymorphisms, and the four groups). In our sample we found no evidence in favor of a major effect of COMT or NET polymorphisms on the two tests of EF.


Assuntos
Transtorno Bipolar/genética , Catecol O-Metiltransferase/genética , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/genética , Polimorfismo Genético , Esquizofrenia/genética , Adulto , Transtorno Bipolar/fisiopatologia , Transtorno Bipolar/psicologia , Família , Saúde da Família , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico
11.
J. physiol. biochem ; 61(3): 469-480, jul.-sept. 2005. ilus, tab
Artigo em En | IBECS | ID: ibc-045365

RESUMO

Recent characterization of the whole saliva proteome led to contradictory picturesconcerning the complexity of its proteome. In this work, 110 proteins wereanalysed by mass spectrometry allowing the identification of 10 accessions previouslynot detected on protein two-dimensional maps, including myosin heavy chain(fast skeletal muscle, IIA and IIB), phosphatidylethanolamine binding protein,secretory actin-binding protein precursor and triosephosphate isomerase. Furthercomparison with available data demonstrated simultaneously a low diversity interms of variety of accessions and a high complexity in terms of number of proteinspots identifying the same accession, the two thirds of identified spots correspondingto amylases, cystatins and immunoglobulins. This diversity may be of interest inthe development of non invasive diagnostic tool for several disease (AU)


No dipsonible


Assuntos
Humanos , Proteoma/análise , Saliva , Proteômica/métodos , Amilases/isolamento & purificação , Cistatinas/isolamento & purificação , Imunoglobulinas/isolamento & purificação , Cadeias Pesadas de Miosina/isolamento & purificação , Proteínas dos Microfilamentos/isolamento & purificação , Espectrometria de Massas
12.
Hum Reprod ; 20(12): 3452-8, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16096325

RESUMO

BACKGROUND: Alpha6beta1 integrin has been proposed to act as a sperm receptor on the mouse oocyte by interacting with spermatozoon fertilin beta. We investigated, in humans, whether oocyte integrins could act similarly in gamete fusion, using a cyclic peptide containing the putative disintegrin-binding domain of human fertilin beta [cyclic FEE (cFEE)] and RGD peptide. METHODS: Zona-free eggs were inseminated in the absence or presence of peptides. To maintain the membrane protein pattern, the zona pellucida was removed by microdissection. Immunofluorescence and confocal microscopy were used to detect integrin subunits on the oocyte. RESULTS: Unexpectedly, cFEE alone increased human gamete fusion by 94% instead of inhibiting fertilization. Furthermore, cFEE together with RGD potentiated the RGD-induced inhibition of fertilization in a dose-dependent manner. The data suggested the hypothesis of integrin cross-talk, further supported by the co-localization of alpha6beta1 and alphavbeta3 integrins, the putative receptors of cFEE and RGD peptides, respectively. CONCLUSIONS: RGD-sensitive and -insensitive integrins may be associated in a multimolecular complex working as a sperm receptor on the human oocyte membrane. Supplementation of human IVF culture medium with cFEE peptide might improve fertilization rates in ART.


Assuntos
Fertilização in vitro/métodos , Fertilização/efeitos dos fármacos , Células Germinativas/efeitos dos fármacos , Oligopeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Proteínas ADAM/metabolismo , Animais , Biotinilação , Membrana Celular/metabolismo , Fertilinas , Humanos , Integrina alfa6beta1/metabolismo , Integrina alfaVbeta3/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Camundongos , Microscopia Confocal , Microscopia de Fluorescência , Oligopeptídeos/química , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Peptídeos/química , Estrutura Terciária de Proteína , Sêmen/metabolismo , Injeções de Esperma Intracitoplásmicas/métodos , Interações Espermatozoide-Óvulo/efeitos dos fármacos , Espermatozoides/metabolismo
13.
J Physiol Biochem ; 61(3): 469-80, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16440601

RESUMO

Recent characterization of the whole saliva proteome led to contradictory pictures concerning the complexity of its proteome. In this work, 110 proteins were analysed by mass spectrometry allowing the identification of 10 accessions previously not detected on protein two-dimensional maps, including myosin heavy chain (fast skeletal muscle, IIA and IIB), phosphatidylethanolamine binding protein, secretory actin-binding protein precursor and triosephosphate isomerase. Further comparison with available data demonstrated simultaneously a low diversity in terms of variety of accessions and a high complexity in terms of number of protein spots identifying the same accession, the two thirds of identified spots corresponding to amylases, cystatins and immunoglobulins. This diversity may be of interest in the development of non invasive diagnostic tool for several disease.


Assuntos
Proteoma , Saliva/química , Proteínas e Peptídeos Salivares/análise , Bases de Dados de Proteínas , Eletroforese em Gel Bidimensional , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Nahrung ; 46(2): 58-63, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12017991

RESUMO

Glycation by the Maillard reaction is an ubiquitous reaction of condensation of a reducing sugar with amino groups of proteins, which products could improve the functional and/or biological properties for food and non-food uses. It can induce structural modifications in proteins, modifying their properties. The aim of this work was to investigate the association behavior and the conformational changes of beta-lactoglobulin (BLG) after its glycation by the Maillard reaction with several alimentary sugars (arabinose, galactose, glucose, lactose, rhamnose and ribose). Protein samples were heated in the presence or in the absence (heated control) of different sugars during 3 days at 60 degrees C. Glycation induced oligomerization of BLG monomers. Depending on the reactivity of the sugar, the population of produced oligomers showed smaller or greater heterogeneity in molecular masses. Analysis of modified BLG by circular dichroism and by its susceptibility to pepsinolysis showed that the conditions of heating used did not significantly alter the conformation of BLG. Heating of BLG in presence of sugars induced only minor structural modification, when using the less reactive sugars such as lactose and rhamnose. It was, however, at the origin of major three-dimensional destructuring in the case of the more reactive sugars such as arabinose and ribose. Pepsinolysis of glycated BLG did not affect about 62 and 35% of the protein molecules modified with lactose or rhamnose, and arabinose or ribose, respectively. The increase of susceptibility of glycated BLG to pepsinolysis could be related to the alteration of the conformation of the protein when glycation was performed with highly reactive sugars, as observed by circular dichroism and calorimetry analysis.


Assuntos
Carboidratos/química , Lactoglobulinas/química , Reação de Maillard , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Eletroforese em Gel de Poliacrilamida , Glicosilação , Temperatura Alta , Hidrólise , Conformação Proteica , Relação Estrutura-Atividade
15.
J Bacteriol ; 183(22): 6551-7, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11673424

RESUMO

Rhodococcus ruber (formerly Gordonia terrae) IFP 2001 is one of a few bacterial strains able to degrade ethyl tert-butyl ether (ETBE), which is a major pollutant from gasoline. This strain was found to undergo a spontaneous 14.3-kbp chromosomal deletion, which results in the loss of the ability to degrade ETBE. Sequence analysis of the region corresponding to the deletion revealed the presence of a gene cluster, ethABCD, encoding a ferredoxin reductase, a cytochrome P-450, a ferredoxin, and a 10-kDa protein of unknown function, respectively. The EthB and EthD proteins could be easily detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and were induced by ETBE in the wild-type strain. Upstream of ethABCD lies ethR, which codes for a putative positive transcriptional regulator of the AraC/XylS family. Transformation of the ETBE-negative mutant by a plasmid carrying the ethRABCD genes restored the ability to degrade ETBE. Complementation was abolished if the plasmid carried ethRABC only. The eth genes are located in a DNA fragment flanked by two identical direct repeats of 5.6 kbp. The ETBE-negative mutants carry a single copy of this 5.6-kbp repeat, suggesting that the 14.3-kbp chromosomal deletion resulted from a recombination between the two identical sequences. The 5.6-kbp repeat is a class II transposon carrying a TnpA transposase, a truncated form of the recombinase TnpR, and a terminal inverted repeat of 38 bp. The truncated TnpR is encoded by an IS3-interrupted tnpR gene.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Etil-Éteres/metabolismo , Genes Bacterianos , Família Multigênica , Rhodococcus/genética , Clonagem Molecular , Ferredoxinas/genética , Deleção de Genes , Dados de Sequência Molecular , Oxirredutases/genética , Rhodococcus/metabolismo
16.
J Agric Food Chem ; 49(10): 5031-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11600062

RESUMO

The Maillard reaction occurs during many industrial and domestic thermal treatments of foods. It is widely used because of its role in creating colors, flavors, textures, and other functional properties in foodstuffs. Proteins glycated without the use of conventional chemical reagents have improved technofunctional properties such as heat stability, emulsifying, and foaming properties. The present study was carried out to determine the extent to which this reaction can convey antioxidant, antimicrobial, or cytotoxic activities to beta-lactoglobulin (BLG) and to its tryptic and peptic hydrolysates. BLG was modified with six different sugars in solution at 60 degrees C. Antiradical properties were estimated using a radical scavenging activity test. Antimicrobial activities against different bacterial strains were studied with a diffusion disk method. Cytotoxic tests were performed using two cell lines and the 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) rapid colorimetric assay. Glycation induced a radical scavenging activity to BLG, the intensity of which depended on the sugar used for modification. Proteins modified with ribose and arabinose showed the highest radical scavenging activities depicted by about 80 and 60% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) absorption decrease at 515 nm. No antimicrobial effect of any glycated form of BLG against Escherichia coli, Bacillus subtilis, Listeria innocua, and Streptococcus mutans was observed. The MTT test showed no enhancement of cytotoxicity by modified proteins and peptides against COS-7 and HL-60 cells. Thus, glycated proteins could be used in formulated food as functional ingredients with a radical scavenging activity able to delay deterioration due to oxidation. This use could be even more advisable considering the lack of toxicity to eukaryotic and prokaryotic cell cultures demonstrated in this work.


Assuntos
Bactérias/efeitos dos fármacos , Bepridil/análogos & derivados , Morte Celular/efeitos dos fármacos , Sequestradores de Radicais Livres , Lactoglobulinas/química , Lactoglobulinas/farmacologia , Reação de Maillard , Picratos , Animais , Bactérias/crescimento & desenvolvimento , Bepridil/química , Compostos de Bifenilo , Células COS/efeitos dos fármacos , Glicosilação , Células HL-60/efeitos dos fármacos , Temperatura Alta , Humanos , Hidrólise , Pepsina A/metabolismo , Relação Estrutura-Atividade , Tripsina/metabolismo
17.
Inorg Chem ; 40(18): 4762-74, 2001 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-11511227

RESUMO

The use of lanthanide triple-decker sandwich molecules containing porphyrins and phthalocyanines in molecular information storage applications requires the ability to attach monomeric triple deckers or arrays of triple deckers to electroactive surfaces. Such applications are limited by existing methods for preparing triple deckers. The reaction of a lanthanide porphyrin half-sandwich complex ((Por)M(acac)) with a dilithium phthalocyanine (PcLi2) in refluxing 1,2,4-trichlorobenzene (bp 214 degrees C) affords a mixture of triple deckers of composition (Pc)M(Pc)M(Por), (Por)M(Pc)M(Por), and (Pc)M(Por)M(Pc). We have investigated more directed methods for preparing triple deckers of a given type with distinct metals in each layer. Application of the method of Weiss, which employs reaction of a (Por)M(acac) species with a lanthanide double decker in refluxing 1,2,4-trichlorobenzene, afforded the desired triple decker in some cases but a mixture of triple deckers in others. The approach we developed employs in situ formation of the lanthanide reagent EuCl[N(SiMe3)2]2 or CeI[N(SiMe3)2]2, which upon reaction with a porphyrin affords the half-sandwich complex (Por)EuX or (Por)CeX' (X = Cl, N(SiMe3)2; X' = I, N(SiMe3)2). Subsequent reaction with PcLi2 gives the double decker (Por)M(Pc). The (Por(1))EuX half-sandwich complex gave the desired triple decker upon reaction with (Pc)Eu(Pc) but little of the desired product upon reaction with (Por(2))Eu(Pc). The (Por(1))CeX' half-sandwich complex reacted with europium double deckers (e.g., (tBPc)Eu(Por(2)), (tBPc)2Eu) to give the triple deckers (Por(1))Ce(tBPc)Eu(Por(2)) and (Por(1))Ce(tBPc)Eu(tBPc) in a rational manner (tB = tetra-tert-butyl). The reactions yielding the half-sandwich, double-decker, and triple-decker complexes were performed in refluxing bis(2-methoxyethyl) ether (bp 162 degrees C). The porphyrins incorporated in the various triple deckers include meso-tetrapentylporphyrin, meso-tetra-p-tolylporphyrin, octaethylporphyrin, and meso-tetraarylporphyrins bearing iodo, ethynyl, or iodo and ethynyl substituents. The triple deckers bearing iodo and/or ethynyl substituents constitute useful building blocks for information storage applications.

18.
J Appl Microbiol ; 90(4): 578-87, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11309070

RESUMO

AIMS: The aim of the study was to assess the relationships between the remaining shelf-life (RSL) of cold-smoked salmon and various microbiological and physico-chemical parameters, using a multivariate data analysis in the form of stepwise forward multiple regression. METHODS AND RESULTS: Thirteen batches of French cold-smoked salmon were analysed weekly during vacuum-packed storage at 5 degrees C for their lipid, water, salt, phenol, pH, total volatile basic nitrogen (TVBN) and trimethylamine contents, total psychrotrophic count, lactic acid bacteria, lactobacilli, B. thermosphacta, Enterobacteriaceae and yeast counts. At the sensory rejection time, the flora was dominated by lactobacilli, lactobacilli/Enterobacteriaceae or Carnobacteria/B. thermosphacta. Shelf-life was very variable (1->6 weeks) and was related to the initial Enterobacteriaceae load (P < 0.05), depending on hygienic conditions in the smokehouse. High correlations existed between the RSL and lactobacilli count (P < 0.01), yeast count (P < 0.05) and TVBN concentration (P < 0.01). A polynomial fitting the RSL as a function of those three factors was proposed (R(2) = 0.80). Assuming that lactobacilli count could not exceed 109 cfu g-1, a minimum of 36 mg-N 100 g-1 was necessary for a product to be rejected, with a yeast count of 104 cfu g-1. CONCLUSION: Estimation of cold-smoked salmon quality is possible by measuring three parameters: lactobacilli and yeast counts and TVBN concentration. SIGNIFICANCE AND IMPACT OF THE STUDY: The technical content is important for the smoked salmon industry and for development of quality standards for cold-smoked salmon.


Assuntos
Produtos Pesqueiros/microbiologia , Microbiologia de Alimentos , Conservação de Alimentos , Temperatura Baixa , Contagem de Colônia Microbiana , Conservação de Alimentos/métodos , Conservação de Alimentos/normas , Concentração de Íons de Hidrogênio , Controle de Qualidade , Análise de Regressão , Salmão/microbiologia , Fumaça
19.
Hum Mutat ; 16(2): 143-56, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10923036

RESUMO

We have collated the results of cystic fibrosis (CF) mutation analysis conducted in 19 laboratories in France. We have analyzed 7, 420 CF alleles, demonstrating a total of 310 different mutations including 24 not reported previously, accounting for 93.56% of CF genes. The most common were F508del (67.18%; range 61-80), G542X (2.86%; range 1-6.7%), N1303K (2.10%; range 0.75-4.6%), and 1717-1G>A (1.31%; range 0-2.8%). Only 11 mutations had relative frequencies >0. 4%, 140 mutations were found on a small number of CF alleles (from 29 to two), and 154 were unique. These data show a clear geographical and/or ethnic variation in the distribution of the most common CF mutations. This spectrum of CF mutations, the largest ever reported in one country, has generated 481 different genotypes. We also investigated a cohort of 800 French men with congenital bilateral absence of the vas deferens (CBAVD) and identified a total of 137 different CFTR mutations. Screening for the most common CF defects in addition to assessment for IVS8-5T allowed us to detect two mutations in 47.63% and one in 24.63% of CBAVD patients. In a subset of 327 CBAVD men who were more extensively investigated through the scanning of coding/flanking sequences, 516 of 654 (78. 90%) alleles were identified, with 15.90% and 70.95% of patients carrying one or two mutations, respectively, and only 13.15% without any detectable CFTR abnormality. The distribution of genotypes, classified according to the expected effect of their mutations on CFTR protein, clearly differed between both populations. CF patients had two severe mutations (87.77%) or one severe and one mild/variable mutation (11.33%), whereas CBAVD men had either a severe and a mild/variable (87.89%) or two mild/variable (11.57%) mutations.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/epidemiologia , Fibrose Cística/genética , Mutação/genética , Ducto Deferente/anormalidades , Adulto , Alelos , Deleção Cromossômica , Mutação da Fase de Leitura/genética , França/epidemiologia , Frequência do Gene , Genótipo , Humanos , Infertilidade Masculina/epidemiologia , Infertilidade Masculina/genética , Masculino , Pessoa de Meia-Idade , Mutagênese Insercional/genética , Mutação de Sentido Incorreto/genética , Polimorfismo Genético/genética
20.
J Food Prot ; 63(4): 502-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10772216

RESUMO

The simultaneous effect of salt and smoke on the natural flora of cold-smoked salmon was studied during 5 weeks of vacuum storage at 5 degrees C. The quadratic polynomial, as a function of factors, was used to express total viable count (TVC), total lactic acid bacteria, lactobacilli numerated on Rogosa agar, H2S-producing bacteria, and yeasts at different sampling times. TVC and total lactic acid bacteria were mainly inhibited by the salt concentration (5% wt/wt) in the meat and to a lesser extent by the phenol content. Inhibition was linearly proportional to salt and smoke content (the higher the concentration, the greater the inhibition). No synergistic effect on inhibition was observed between the two factors. In our working conditions, the TVC French standard (<10(6) CFU g(-1)) was maintained during 4 weeks of storage at 5 degrees C, with a minimum concentration of 2.4% (wt/wt) of salt in meat and smoking treatment corresponding to 0.6 mg 100 g(-1) of phenol. When the salt level was higher than 3%, the TVC standard was maintained, regardless of phenol level. A negative interaction between the two factors was found for H2S-producing bacteria and a positive one for yeasts.


Assuntos
Produtos Pesqueiros/microbiologia , Microbiologia de Alimentos , Conservação de Alimentos , Animais , Temperatura Baixa , Salmão , Fumaça , Cloreto de Sódio , Vácuo
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