Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
1.
J Endocrinol Invest ; 47(3): 729-738, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37603268

RESUMO

PURPOSE: Hip fracture is a public health problem worldwide. Traditional prognostic models do not include blood biomarkers, such as those obtained by proteomics. This study aimed to investigate the relationships between serum inflammatory biomarkers and frailty in older adults with hip fracture as well as adverse outcomes at one and three months after discharge. METHODS: A total of 45 patients aged 75 or older who were admitted for hip fracture were recruited. At admission, a Comprehensive Geriatric Assessment (CGA) was conducted, which included a frailty assessment using the Clinical Frailty Scale (CFS). Blood samples were collected before surgery. Participants were followed up at one and three months after discharge. The levels of 45 cytokines were analyzed using a high-throughput proteomic approach. Binary logistic regression was used to determine independent associations with outcomes, such as functional recovery, polypharmacy, hospital readmission, and mortality. RESULTS: The results showed that IL-7 (OR 0.66 95% CI 0.46-0.94, p = 0.022) and CXCL-12 (OR 0.97 95% CI 0.95-0.99, p = 0.011) were associated with better functional recovery at three months after discharge, while CXCL-8 (OR 1.07 95% CI 1.01-1.14, p = 0.019) was associated with an increased risk of readmission. CONCLUSIONS: These findings suggest that immunology biomarkers may represent useful predictors of clinical outcomes in hip fracture patients.


Assuntos
Fragilidade , Fraturas do Quadril , Humanos , Idoso , Fragilidade/diagnóstico , Proteômica , Fraturas do Quadril/cirurgia , Biomarcadores , Hospitalização
2.
Eur Phys J C Part Fields ; 83(4): 336, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37128509

RESUMO

We compute next-to-next-to-leading order (NNLO) QCD corrections to neutral vector boson production in association with a charm jet at the LHC. This process is studied in the forward kinematics at s = 13  TeV, which may provide valuable constraints on the intrinsic charm component of the proton. A comparison is performed between fixed order and NLO predictions matched to a parton shower showing mutual compatibility within the respective uncertainties. NNLO corrections typically lead to a reduction of theoretical uncertainties by a factor of two and the perturbative convergence is further improved through the introduction of a theory-inspired constraint on the transverse momentum of the vector boson plus jet system. A comparison between these predictions with data will require an alignment of a flavour-tagging procedure in theory and experiment that is infrared and collinear safe.

3.
Ann Diagn Pathol ; 61: 152056, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36371890

RESUMO

Calcifying aponeurotic fibroma (CAF) is a very rare benign entity that principally affects the volar fascia, tendons, and aponeuroses of the hands and feet with a peak incidence of between 5 and 15 years, although there have been cases found for a wide age range and at various anatomical sites. We present ten CAF cases; consisting of eight children and two adults. CAF occurred in the extremities in nine of the cases and in the chest wall in one case. CAF ultrasound and radiological findings are nonspecific but may help orientate diagnosis. Magnetic resonance imaging should be performed when there are doubtful cases, when occurring in nontypical sites, and when there are cases of nontypical clinical presentation. Histologically, all cases showed two components, a fibromatosis-like component and a nodular component. Chondroid areas were present in five cases. Calcifications were observed in nine cases. ERG immunostaining showed the same patterns in all the cases; diffuse positivity in pericalcified areas, and patchy positivity in areas away from calcifications. CAF has distinctive histopathological features which should aid in the differential diagnoses with other entities.


Assuntos
Calcinose , Fibroma Ossificante , Fibroma , Neoplasias de Tecidos Moles , Criança , Adulto , Humanos , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/cirurgia , Fibroma Ossificante/diagnóstico por imagem , Fibroma/diagnóstico por imagem , Fibroma/cirurgia , Calcinose/diagnóstico por imagem , Calcinose/patologia
4.
Semergen ; 48(8): 101817, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-36155990

RESUMO

OBJECTIVE: The main aim of this study is to determine the prevalence of PRMD (playing-related musculoskeletal disorders) in adults exposed to it due to their profession, in the area of Osuna. DESIGN: It is a cross-sectional study. Site: the study is based on data collected in the local community of musicians (music schools, conservatories and music bands from the region). PARTICIPANTS: 264 individuals older than 18 years old have participated. INTERVENTIONS: semi-structured interviews were conducted. MAIN MEASUREMENTS: the main variables considered were: presence of pain or discomfort related to musical practice, socio-demographic variables defining the sample (age, gender, profession), variables characterizing the musical trajectory of the participant (instrument, number of years playing, number of hours of practice per week), perception of pain, area of pain, interference with their mood, among others. RESULTS: 76% of the musicians had experienced PRMD in some occasion, being more frequent among women (p = 0,009; IC 95%), string musicians (p= 0,041; IC 95%) and among those doing less physical activity (p = 0,000006; IC 95%). CONCLUSIONS: Studying the prevalence of playing-related pain was of great interest, given the potential interventions that could be applied in Primary and Community medical care.


Assuntos
Doenças Musculoesqueléticas , Música , Doenças Profissionais , Adulto , Humanos , Feminino , Adolescente , Prevalência , Estudos Transversais , Doenças Profissionais/epidemiologia , Doenças Musculoesqueléticas/epidemiologia , Dor/epidemiologia , Dor/etiologia
5.
J Nutr Health Aging ; 26(8): 778-785, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35934822

RESUMO

OBJECTIVES: To investigate concerns surrounding the benefits of antiresorptive drugs in older adults, a systematic review was carried out to evaluate the efficacy of these treatments in the prevention of osteoporotic hip fractures in older adults. DESIGN: a systematic review and meta-analysis of randomized clinical trials. SETTING AND PARTICIPANTS: older adults ≥65 years with osteoporosis, with or without a previous fragility fracture. Studies with cancer-related and corticosteroid-induced osteoporosis, participants <65 years and no reported hip fracture were not included. METHODS: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ISI Web of Science and Scopus databases were searched. The primary outcome was hip fracture, and subgroup analysis (≥75 years, with different drug types and secondary prevention) and sensitivity analysis was carried out using a GRADE evaluation. Secondary outcomes were any type of fractures, vertebral fracture, bone markers and adverse events. The risk of bias was assessment with the Cochrane risk of bias tool. RESULTS: A total of 12 randomised controlled trials (RCTs) qualified for this meta-analysis, with 36,196 participants. Antiresorptive drugs have a statistically significant effect on the prevention of hip fracture (RR=0.70; 95%CI 0.60 to 0.81), but with a moderate GRADE quality of evidence and a high number needed to treat (NNT) of 186. For other outcomes, there is a statistically significant effect, but with a low to moderate quality of evidence. Antiresorptives showed no reduction in the risk of hip fracture in people ≥75 years. The results for different drug types, secondary prevention and sensitivity analysis are similar to the main analyses and have the same concerns. CONCLUSIONS: Antiresorptive drugs have a statistically significant effect on preventing hip fracture but with a moderate quality (unclear/high risk of bias) and high NNT (186). This small benefit disappears in those ≥75 years, but increases in secondary prevention. More RCTs in very old osteoporotic adults are needed.


Assuntos
Conservadores da Densidade Óssea , Fraturas do Quadril , Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Idoso , Conservadores da Densidade Óssea/efeitos adversos , Fraturas do Quadril/tratamento farmacológico , Fraturas do Quadril/etiologia , Fraturas do Quadril/prevenção & controle , Humanos , Osteoporose/complicações , Osteoporose/tratamento farmacológico , Osteoporose/prevenção & controle , Fraturas por Osteoporose/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Fraturas da Coluna Vertebral/tratamento farmacológico
7.
Front Microbiol ; 12: 589401, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34267731

RESUMO

Service-Learning is an educational methodology that allows student learning while addressing community needs. A program in microbiology and infectious diseases was implemented in Universidad Complutense de Madrid, Spain. University lecturers, clinical microbiologists, doctorate students, and undergraduates from several Bachelor Degrees and courses worked in an interdisciplinary team along with social institutions that attend disadvantaged persons. Using commercial movies that deal with infectious diseases, the students learn clinical microbiology, prepare divulgation materials, visit social centers to accompany, and help others to know about illnesses and prevention. The program was developed through two academic years and involved 58 voluntary students, 13 teachers and tutors, and 4 social entities as community partners. Postsurvey evaluation of the program revealed a highly satisfactory achievement of goals: acquiring scientific and personal competencies by university students, including critical analysis and science diffusion, solving problems or collaborative team working, and contributing, together with the tutors, to the social responsibility of the university.

9.
Appl Environ Microbiol ; 84(22)2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30194098

RESUMO

The oppA2 gene encodes an oligopeptide-binding protein similar to the periplasmic substrate-binding proteins of the ABC transport systems. However, oppA2 is an orphan gene, not included in an ABC operon. This gene is located in the clavulanic acid (CA) gene cluster of Streptomyces clavuligerus and is essential for CA production. A transcriptomic study of the oppA2-null mutant S. clavuligerus ΔoppA2::aac showed changes in the expression levels of 233 genes from those in the parental strain. These include genes for ABC transport systems, secreted proteins, peptidases, and proteases. Expression of the clavulanic acid, clavam, and cephamycin C biosynthesis gene clusters was not significantly affected in the oppA2 deletion mutant. The genes for holomycin biosynthesis were upregulated 2-fold on average, and the level of upregulation increased to 43-fold in a double mutant lacking oppA2 and the pSCL4 plasmid. Strains in which oppA2 was mutated secreted into the culture the compound N-acetylglycyl-clavaminic acid (AGCA), a putative intermediate of CA biosynthesis. A culture broth containing AGCA, or AGCA purified by liquid chromatography-mass spectrometry (LC-MS), was added to the cultures of various non-CA-producing mutants. Mutants blocked in the early steps of the pathway restored CA production, whereas mutants altered in late steps did not, establishing that AGCA is a late intermediate of the biosynthetic pathway, which is released from the cells when the oligopeptide-binding protein OppA2 is not available.IMPORTANCE The oppa2 gene encodes an oligopeptide permease essential for the production of clavulanic acid. A transcriptomic analysis of S. clavuligerus ΔoppA2::aac in comparison to the parental strain S. clavuligerus ATCC 27064 is reported. The lack of OppA2 results in different expression of 233 genes, including genes for proteases and genes for transport systems. The expression of the clavulanic acid genes in the oppA2 mutant is not significantly affected, but the genes for holomycin biosynthesis are strongly upregulated, in agreement with the higher holomycin production by this strain. The oppA2-mutant is known to release N-acetylglycyl-clavaminic acid to the broth. Cosynthesis assays using non-clavulanic acid-producing mutants showed that the addition of pure N-acetylglycyl-clavaminic acid to mutants in which clavulanic acid formation was blocked resulted in the recovery of clavulanic acid production, but only in mutants blocked in the early steps of the pathway. This suggests that N-acetylglycyl-clavaminic acid is a previously unknown late intermediate of the clavulanic acid pathway.


Assuntos
Proteínas de Bactérias/genética , Ácido Clavulânico/biossíntese , Proteínas de Membrana Transportadoras/genética , Deleção de Sequência , Streptomyces/enzimologia , Streptomyces/metabolismo , Transcrição Gênica , Proteínas de Bactérias/metabolismo , Ácido Clavulânico/química , Ácidos Clavulânicos/metabolismo , Regulação Bacteriana da Expressão Gênica , Proteínas de Membrana Transportadoras/metabolismo , Família Multigênica , Óperon , Streptomyces/genética
10.
Eye (Lond) ; 30(3): 438-46, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26634709

RESUMO

PURPOSE: The main objective of this study is to describe the prevalence, degree and risk of corneal involvement, and visual impact in a pediatric population with blepharokeratoconjunctivitis (BKC). METHODS: Retrospective, observational, case-control study. Clinical records of patients ≤16 years old with BKC seen between 2006 and 2012 were reviewed. The prevalence and relative risk of corneal involvement was evaluated between patients with and without corneal affection through a univariate and multivariate analysis with logistic regression. Visual acuity at presentation and at last follow-up visit was also analyzed. RESULTS: One hundred and fourteen children with BKC, with a male-to-female ratio of 1 : 1 and a mean age at diagnosis of 9.13 years. The mean follow-up time was 26.4 (±25) months. Corneal involvement was present in 39.5% of patients, varying from superficial punctate keratitis to perforation. Corneal changes were not seen in children under 4 years old. The risk of corneal affection was greater in patients with photophobia, hordeolum, female gender and asymmetric disease (OR of 2.69, 11.6, 2.35 and 2.77, respectively). The mean best-corrected visual acuity at presentation was 0.20 (corneal affected group), compared to 0.11 (unaffected group; P=0.02). CONCLUSIONS: Our study showed an older age at time of diagnosis and a worse visual outcome in patients with BKC and corneal disease compared with previous reports. Early diagnosis and detection of risk factors for corneal involvement, as well as adequate treatment, is mandatory to prevent serious long-term visual repercussions in children with BKC.


Assuntos
Blefarite/epidemiologia , Doenças da Córnea/epidemiologia , Ceratoconjuntivite/epidemiologia , Acuidade Visual/fisiologia , Blefarite/fisiopatologia , Estudos de Casos e Controles , Criança , Doença Crônica , Doenças da Córnea/fisiopatologia , Diagnóstico Precoce , Feminino , Seguimentos , Humanos , Ceratoconjuntivite/fisiopatologia , Masculino , México/epidemiologia , Prevalência , Estudos Retrospectivos , Fatores de Risco
11.
Artigo em Inglês | MEDLINE | ID: mdl-26451151

RESUMO

Amphipterygium adstringens is a plant widely used in Mexican traditional medicine for its known anti-inflammatory and antiulcer properties. In this work, we evaluated the in vitro antimicrobial and antiproliferative activities of the methanolic extract of A. adstringens against oral pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Candida albicans, and Candida dubliniensis, using microdilution (MIC) and agar diffusion methods (MBC), and the antiproliferative activity evaluating total growth inhibition (TGI) by staining the protein content with sulforhodamine B (SRB), using nine human cancer cell lines. Crude extract (CE) of A. adstringens showed some degree of activity against one or more of the strains with a MIC from 0.125 mg/mL to 63 mg/mL and MBC from 1.6 to 6.3 mg/mL and cytotoxic activity, particularly against NCI-ADR/RES, an ovarian cell line expressing multiple resistance drugs phenotype. The CE is a complex mixture of possible multitarget metabolites that could be responsible for both antimicrobial and antiproliferative activities, and further investigation is required to elucidate the identity of active compounds. Nevertheless the CE itself is useful in the development of new antimicrobial treatment based on natural products to prevent oral diseases and as alternative natural source for cancer treatment and prevention.

12.
Gene Ther ; 22(7): 596-601, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25994521

RESUMO

Oncolytic adenoviruses can promote immune responses against tumors by expressing and/or displaying tumor-associated antigens. However, the strong immunodominance of viral antigens mask responses against tumor epitopes. In addition, defects in major histocompatibility complex class I antigen presentation pathway such as the downregulation of the transporter-associated with antigen processing (TAP) are frequently associated with immune evasion of tumor cells. To promote the immunogenicity of exogenous epitopes in the context of an oncolytic adenovirus, we have taken advantage of the ER localization of the viral protein E3-19K. We have inserted tumor-associated epitopes after the N-terminal signal sequence for membrane insertion of this protein and flanked them with linkers cleavable by the protease furin to facilitate their TAP-independent presentation. This strategy allowed an enhanced presentation of the exogenous epitopes in TAP-deficient tumor cells in vitro and the generation of higher specific immune responses in vivo that were able to significantly control tumor growth.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas E3 de Adenovirus/genética , Adenovírus Humanos/genética , Epitopos/genética , Mutagênese Insercional , Neoplasias/terapia , Vírus Oncolíticos/genética , Adenovírus Humanos/metabolismo , Animais , Apresentação de Antígeno , Linhagem Celular Tumoral , Feminino , Células HEK293 , Humanos , Camundongos Endogâmicos C57BL
13.
Cancer Gene Ther ; 21(2): 68-73, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24434571

RESUMO

Adenovirus (Ad) i-leader protein is a small protein of unknown function. The C-terminus truncation of the i-leader protein increases Ad release from infected cells and cytotoxicity. In the current study, we use the i-leader truncation to enhance the potency of an oncolytic Ad. In vitro, an i-leader truncated oncolytic Ad is released faster to the supernatant of infected cells, generates larger plaques, and is more cytotoxic in both human and Syrian hamster cell lines. In mice bearing human tumor xenografts, the i-leader truncation enhances oncolytic efficacy. However, in a Syrian hamster pancreatic tumor model, which is immunocompetent and less permissive to human Ad, antitumor efficacy is only observed when the i-leader truncated oncolytic Ad, but not the non-truncated version, is combined with gemcitabine. This synergistic effect observed in the Syrian hamster model was not seen in vitro or in immunodeficient mice bearing the same pancreatic hamster tumors, suggesting a role of the immune system in this synergism. These results highlight the interest of the i-leader C-terminus truncation because it enhances the antitumor potency of an oncolytic Ad and provides synergistic effects with gemcitabine in the presence of an immune competent system.


Assuntos
Adenoviridae/genética , Adenoviridae/fisiologia , Desoxicitidina/análogos & derivados , Neoplasias/genética , Terapia Viral Oncolítica/métodos , Sinais Direcionadores de Proteínas/genética , Liberação de Vírus/fisiologia , Adenoviridae/patogenicidade , Animais , Linhagem Celular Tumoral , Cricetinae , Primers do DNA/genética , Desoxicitidina/farmacologia , Fluorescência , Células HEK293 , Humanos , Imuno-Histoquímica , Mesocricetus , Camundongos , Mutação de Sentido Incorreto , Neoplasias/tratamento farmacológico , Estatísticas não Paramétricas , Liberação de Vírus/efeitos dos fármacos , Gencitabina
14.
Microb Biotechnol ; 7(3): 221-31, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24450885

RESUMO

Streptomyces clavuligerus ATCC 27064 and S. clavuligerus ΔccaR::tsr cultures were grown in asparagine-starch medium, and samples were taken in the exponential and stationary growth phases. Transcriptomic analysis showed that the expression of 186 genes was altered in the ccaR-deleted mutant. These genes belong to the cephamycin C gene cluster, clavulanic acid gene cluster, clavams, holomycin, differentiation, carbon, nitrogen, amino acids or phosphate metabolism and energy production. All the clavulanic acid biosynthesis genes showed Mc values in the order of -4.23. The blip gene-encoding a ß-lactamase inhibitory protein was also controlled by the cephamycin C-clavulanic acid cluster regulator (Mc -2.54). The expression of the cephamycin C biosynthesis genes was greatly reduced in the mutant (Mc values up to -7.1), while the genes involved in putative ß-lactam resistance were less affected (Mc average -0.88). Genes for holomycin biosynthesis were upregulated. In addition, the lack of clavulanic acid and cephamycin production negatively affected the expression of genes for the clavulanic acid precursor arginine and of miscellaneous genes involved in nitrogen metabolism (amtB, glnB, glnA3, glnA2, glnA1). The transcriptomic results were validated by quantative reverse transcription polymerase chain reaction and luciferase assay of luxAB-coupled promoters. Transcriptomic analysis of the homologous genes of S. coelicolor validated the results obtained for S. clavuligerus primary metabolism genes.


Assuntos
Vias Biossintéticas/genética , Cefamicinas/metabolismo , Ácido Clavulânico/metabolismo , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Streptomyces/metabolismo , Fatores de Transcrição/genética , Meios de Cultura/química , Deleção de Genes , Perfilação da Expressão Gênica , Genes Reporter , Luciferases/análise , Luciferases/genética , Reação em Cadeia da Polimerase em Tempo Real , Streptomyces/genética , Streptomyces/crescimento & desenvolvimento
15.
Appl Microbiol Biotechnol ; 98(5): 2183-95, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24305736

RESUMO

A large part (21%) of the wild-type Streptomyces clavuligerus genome is located in a 1.8-Mb megaplasmid that greatly influences secondary metabolites biosynthesis even if the secondary metabolites are chromosomally encoded. The megaplasmid copy number may change depending on the nutritional and environmental conditions. The S. clavuligerus oppA2::aph mutant described by Lorenzana et al. (2004) does not form aerial mycelium, spores, and clavulanic acid, but overproduces holomycin. Transcriptomic studies, polymerase chain reactions (PCR), qPCR, and RT-qPCR analysis showed that S. clavuligerus oppA2::aph has a drastically reduced number of copies (about 25,000-fold lower than the parental strain) of plasmids pSCL1 (10.5 kb), pSCL2 (149.4 kb), and the megaplasmid pSCL4 (1.8 Mb). To clarify the role of the linear plasmids and the function of OppA2 in S. clavuligerus oppA2::aph we constructed oppA2 mutants which contained: (1) a normal copy number of the linear plasmids, (2) completely lack of the linear plasmids, and (3) a parA-parB pSCL4 mutant that resulted in lack of pSCL4. In addition, a strain with a functional oppA2 gene was constructed lacking the megaplasmid pSCL4. The results confirmed that the oppA2 gene is essential for clavulanic acid production, independently of the presence or absence of linear plasmids, but oppA2 has little relevance on differentiation. We demonstrated that the lack of sporulation of S. clavuligerus oppA2::aph is due to the absence of linear plasmids (particularly pSCL4) and the holomycin overproduction is largely due to the lack of pSCL4 and is stimulated by the oppA2 mutation.


Assuntos
Genoma Bacteriano , Plasmídeos , Metabolismo Secundário , Esporos Bacterianos/crescimento & desenvolvimento , Streptomyces/crescimento & desenvolvimento , Streptomyces/metabolismo , Ácido Clavulânico/metabolismo , Mutação , Deleção de Sequência , Esporos Bacterianos/genética , Streptomyces/genética
18.
An Pediatr (Barc) ; 68(5): 432-8, 2008 May.
Artigo em Espanhol | MEDLINE | ID: mdl-18447986

RESUMO

OBJECTIVES: To examine the etiology, clinical, analytical and evolutionary characteristics of gastroenteritis in the pediatric population in the Emergency Department of Dr. Peset University Hospital in Health Care Area 10 in Valencia, Spain, over a 1-year period (2005). PATIENTS AND METHODS: Children < 15 years of age with acute diarrhea were prospectively enrolled in the Emergency Department. Data were collected through information sheets. Their stools were examined for diarrheagenic bacteria and viruses (rotavirus and adenovirus). RESULTS: 794 episodes of gastroenteritis were recorded. The incidence of rotavirus was 22 %, adenovirus 8 %, Campylobacter jejuni 7 % and Salmonella spp. 4 %. Socioeconomic characteristics were not helpful in differentiating disease due to specific enteropathogens. Ninety per cent cases caused by viruses only affected children under three years of age. Rotavirus gastroenteritis had a marked seasonal pattern (90 % cases in December-February). Among infants < or = 6 months of age rotavirus was less frequent as cause of diarrhea in breast-fed infants than in bottle-fed. Macroscopic blood in stools was reported almost exclusively among patients with a bacterial infection. In 96 % of all cases of diarrhea there was no dehydration, in 2 % it was mild, in 2 % moderate and none severe. Ten of the seventeen cases (59 %) of moderate dehydration were caused by rotavirus. Six percent of all children were hospitalised. CONCLUSIONS: Rotavirus was significantly more associated with the need for intravenous fluid therapy and hospitalisation than episodes negative for rotavirus. Rotavirus accounted for 3 % of hospitalisations in infants aged 1 month-2 years.


Assuntos
Infecções por Campylobacter/complicações , Serviços Médicos de Emergência/estatística & dados numéricos , Gastroenterite/microbiologia , Gastroenterite/reabilitação , Hospitais Urbanos/estatística & dados numéricos , Infecções por Rotavirus/complicações , Infecções por Salmonella/complicações , Doença Aguda , Área Programática de Saúde , Pré-Escolar , Feminino , Gastroenterite/virologia , Humanos , Lactente , Masculino , Espanha/epidemiologia
20.
J Bacteriol ; 186(19): 6501-7, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15375131

RESUMO

The oat2 gene, located in the clavulanic acid gene cluster in Streptomyces clavuligerus, is similar to argJ, which encodes N-acetylornithine:glutamic acid acetyltransferase activity. Purified proteins obtained by expression in Escherichia coli of the argJ and oat2 genes of S. clavuligerus posses N-acetyltransferase activity. The kinetics and substrate specificities of both proteins are very similar. Deletion of the oat2 gene did not affect the total N-acetylornithine transferase activity and slightly reduced the formation of clavulanic acid under standard culture conditions. However, the oat2 mutant produced more clavulanic acid than the parental strain in cultures supplemented with high levels (above 1 mM) of arginine. The purified S. clavuligerus ArgR protein bound the arginine box in the oat2 promoter, and the expression of oat2 was higher in mutants with a disruption in argR (arginine-deregulated), confirming that the Arg boxes of oat2 are functional in vivo. Our results suggest that the Oat2 protein or one of its reaction products has a regulatory role that modulates clavulanic acid biosynthesis in response to high arginine concentrations.


Assuntos
Acetiltransferases/fisiologia , Arginina/farmacologia , Proteínas de Bactérias/fisiologia , Ácido Clavulânico/biossíntese , Streptomyces/enzimologia , Cinética , Peso Molecular , Especificidade por Substrato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA