Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Clin. transl. oncol. (Print) ; 23(5): 922-930, mayo 2021. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-221232

RESUMO

Soft-tissue sarcomas constitute an uncommon and heterogeneous group of tumors of mesenchymal origin. Diagnosis, treatment, and management should be performed by an expert multidisciplinary team. MRI/CT of the primary tumor and biopsy is mandatory before any treatment. Wide surgical resection with tumor-free tissue margin is the mainstay for localized disease. Radiotherapy is indicated in large, deep, high-grade tumors, or after marginal resection not suitable for re-excision. Perioperative chemotherapy should be discussed for high-risk sarcomas of the extremities and trunk-wall. In the case of oligometastatic disease, patients should be considered for local therapies. First-line treatment with anthracyclines (or in combination with ifosfamide) is the treatment of choice. Other drugs have shown activity in second-line therapy and in specific histological subtypes but options are limited and thus, a clinical trial should always be discussed (AU)


Assuntos
Humanos , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/terapia , Sarcoma/terapia , Sarcoma/diagnóstico , Tomografia Computadorizada por Raios X , Imageamento por Ressonância Magnética , Sociedades Médicas , Biópsia , Espanha
2.
Clin Transl Oncol ; 23(5): 922-930, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33405052

RESUMO

Soft-tissue sarcomas constitute an uncommon and heterogeneous group of tumors of mesenchymal origin. Diagnosis, treatment, and management should be performed by an expert multidisciplinary team. MRI/CT of the primary tumor and biopsy is mandatory before any treatment. Wide surgical resection with tumor-free tissue margin is the mainstay for localized disease. Radiotherapy is indicated in large, deep, high-grade tumors, or after marginal resection not suitable for re-excision. Perioperative chemotherapy should be discussed for high-risk sarcomas of the extremities and trunk-wall. In the case of oligometastatic disease, patients should be considered for local therapies. First-line treatment with anthracyclines (or in combination with ifosfamide) is the treatment of choice. Other drugs have shown activity in second-line therapy and in specific histological subtypes but options are limited and thus, a clinical trial should always be discussed.


Assuntos
Sarcoma/diagnóstico , Sarcoma/terapia , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/terapia , Antraciclinas/uso terapêutico , Antineoplásicos/uso terapêutico , Lista de Checagem , Quimioterapia Adjuvante/métodos , Dermatofibrossarcoma/terapia , Feminino , Fibromatose Agressiva/genética , Fibromatose Agressiva/terapia , Humanos , Imageamento por Ressonância Magnética , Masculino , Oncologia , Terapia Neoadjuvante/métodos , Radioterapia/métodos , Neoplasias Retroperitoneais/terapia , Sarcoma/diagnóstico por imagem , Sarcoma/patologia , Sociedades Médicas , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/patologia , Tumores Fibrosos Solitários/tratamento farmacológico , Espanha , Tomografia Computadorizada por Raios X , Neoplasias Uterinas/terapia
3.
Clin Transl Oncol ; 22(4): 555-562, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31256362

RESUMO

PURPOSE: There is limited evidence on the efficacy and safety of anti-programmed cell death protein 1 (PD-1)-/anti-programmed death-ligand 1 (PD-L1)-based immunotherapy in the elderly, particularly those aged over 75 years. METHODS/PATIENTS: The clinical response and toxicity profile of anti-PD-1-/anti-PD-L1-based immunotherapy in patients aged over 75 years were assessed in this retrospective observational study conducted in the Medical Oncology Service of a tertiary level hospital. The associations among clinical responses, adverse events, and geriatric syndromes were evaluated. RESULTS: In total, 20 patients aged between 75 and 94 years were evaluated. Pembrolizumab and nivolumab were the most commonly used drugs. A clinical benefit (stable disease, partial response or complete response) was documented in 13 patients (65%). This proportion was 80% in patients aged between 75 and 79 years, and 50% in those aged over 79 years (p = 0.236). The adverse events were similar to those reported in younger patients. At least one clinical adverse event (cAE) and one laboratory adverse event (lAE) was reported in 75% and 55% of patients, respectively. Polypharmacy was observed for all patients and multi-morbidity in 95%. Patients without gait disorders showed more responses to immunotherapy. The number of lAEs was significantly associated with the number of commonly prescribed drugs (slope = 0.218, p = 0.010), the Eastern Cooperative Oncology Group score, and the number of cAEs. CONCLUSIONS: The elderly can obtain benefits from anti-PD-1-/anti-PD-L1-based immunotherapy. The toxicity profile was similar to that reported in younger counterparts.


Assuntos
Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Imunoterapia/efeitos adversos , Masculino , Neoplasias/mortalidade , Estudos Retrospectivos
4.
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
5.
Med. intensiva (Madr., Ed. impr.) ; 40(8): 491-498, nov. 2016. graf, tab
Artigo em Espanhol | IBECS | ID: ibc-157223

RESUMO

OBJETIVO PRIMARIO: Conocer la variabilidad interobservador de los parámetros ecocardiográficos transtorácicos que evalúan la función sistólica del ventrículo derecho en sujetos en el postoperatorio temprano de cirugía cardiaca. Objetivo secundario: Evaluar la factibilidad en la medición de estos parámetros ecocardiográficos. DISEÑO: Piloto, transversal, doble ciego. Mayo de 2011 a febrero de 2013. Ámbito: Unidad de Cuidados Intensivos Posquirúrgicos Cardiovasculares, Instituto Nacional de Cardiología «Ignacio Chávez», Ciudad de México (México). PACIENTES: Muestreo no probabilístico, consecutivo, se estudiaron 56 pacientes postoperados de cirugía cardiaca. Intervención: Entre 6 a 8 h después de la intervención de cirugía cardiaca se obtuvieron los parámetros ecocardiográficos. La segunda medición se realizó a posteriori, de forma cegada. Variables de interés: Excursión sistólica del plano valvular tricuspídeo (TAPSE), velocidad sistólica pico del anillo tricuspídeo medida por Doppler tisular (VSPAT), diámetros y fracción de acortamiento del tracto de salida del ventrículo derecho. La variabilidad interobservador y su magnitud se obtuvieron con el procedimiento de Bland-Altman y el coeficiente de correlación intraclase (intervalo de confianza del 95%). RESULTADOS: El TAPSE y la VSPAT se pudieron estudiar por ambos observadores en 48 (92%) de los sujetos. El promedio del TAPSE fue 11,68±4,53mm con valor mínimo-máximo de 4 a 27mm. Se encontró disfunción sistólica del ventrículo derecho en 41 (85%) y TAPSE normal en 7 (15%) pacientes. La diferencia media y sus límites de acuerdo del TAPSE fueron -0,917±2,95 (-6,821; 4,988), y su magnitud de 0,725 (0,552; 0,837). Los valores de VSPAT fueron -0,001± 0,015 (-0,031; 0,030) con magnitud de 0,825 (0,708; 0,898) respectivas. CONCLUSIONES: Fue posible estimar el TAPSE y la VSPAT por parte de ambos observadores en el 92% de los sujetos. Estos índices ecocardiográficos tuvieron la menor variabilidad interobservador en sujetos postoperados de cirugía cardiaca


PRIMARY OBJECTIVE: To know the variability of transthoracic echocardiographic parameters that assess right ventricular systolic function by analyzing interobserver agreement in the early postoperative period of cardiovascular surgery. Secondary objective: To assess the feasibility of these echocardiographic measurements. Design: A cross-sectional study, double-blind pilot study was carried out from May 2011 to February 2013. Setting: Cardiovascular postoperative critical care at the National Institute of Cardiology ‘Ignacio Chávez’, Mexico City, Mexico. Patients: Consecutive, non-probabilistic sampling. Fifty-six patients were studied in the postoperative period of cardiac surgery. Intervention: The first echocardiographic parameters were obtained between 6-8hours after cardiac surgery, followed by blinded second measurements. Main variables: Tricuspid annular plane systolic excursion (TAPSE), tricuspid annular peak systolic velocity on tissue Doppler imaging (VSPAT), diameters and right ventricular outflow area, tract fractional shortening. The agreement was analyzed by the Bland-Altman method, and its magnitude was assessed by the intraclass correlation coefficient (95% confidence interval). Results: Both observers evaluated TAPSE and VSPAT in 48 patients (92%). The average TAPSE was 11.68±4.53mm (range 4-27mm). Right ventricular systolic dysfunction was observed in 41 cases (85%) and normal TAPSE in 7 patients (15%). The average difference and its limits according to TAPSE were -0.917±2.95 (-6.821, 4.988), with a magnitude of 0.725 (0.552, 0.837); the tricuspid annular peak systolic velocity on tissue Doppler imaging was -0.001±0.015 (-0.031, 0.030), and its magnitude 0.825 (0.708, 0.898), respectively. Conclusions: VSPAT and TAPSE were estimated by both observers in 92% of the patients, these parameters exhibiting the lowest interobserver variability


Assuntos
Humanos , Função Ventricular Direita/fisiologia , Sístole/fisiologia , Procedimentos Cirúrgicos Cardíacos/estatística & dados numéricos , Ecocardiografia Doppler/métodos , Período Pós-Operatório , Cardiopatias/cirurgia , Estudo Observacional , Valva Tricúspide
6.
Med Intensiva ; 40(8): 491-498, 2016 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27198648

RESUMO

PRIMARY OBJECTIVE: To know the variability of transthoracic echocardiographic parameters that assess right ventricular systolic function by analyzing interobserver agreement in the early postoperative period of cardiovascular surgery. SECONDARY OBJECTIVE: To assess the feasibility of these echocardiographic measurements. DESIGN: A cross-sectional study, double-blind pilot study was carried out from May 2011 to February 2013. SETTING: Cardiovascular postoperative critical care at the National Institute of Cardiology "Ignacio Chávez", Mexico City, Mexico. PATIENTS: Consecutive, non-probabilistic sampling. Fifty-six patients were studied in the postoperative period of cardiac surgery. INTERVENTION: The first echocardiographic parameters were obtained between 6-8hours after cardiac surgery, followed by blinded second measurements. MAIN VARIABLES: Tricuspid annular plane systolic excursion (TAPSE), tricuspid annular peak systolic velocity on tissue Doppler imaging (VSPAT), diameters and right ventricular outflow area, tract fractional shortening. The agreement was analyzed by the Bland-Altman method, and its magnitude was assessed by the intraclass correlation coefficient (95% confidence interval). RESULTS: Both observers evaluated TAPSE and VSPAT in 48 patients (92%). The average TAPSE was 11.68±4.53mm (range 4-27mm). Right ventricular systolic dysfunction was observed in 41 cases (85%) and normal TAPSE in 7 patients (15%). The average difference and its limits according to TAPSE were -0.917±2.95 (-6.821, 4.988), with a magnitude of 0.725 (0.552, 0.837); the tricuspid annular peak systolic velocity on tissue Doppler imaging was -0.001±0.015 (-0.031, 0.030), and its magnitude 0.825 (0.708, 0.898), respectively. CONCLUSIONS: VSPAT and TAPSE were estimated by both observers in 92% of the patients, these parameters exhibiting the lowest interobserver variability.


Assuntos
Ecocardiografia , Disfunção Ventricular Direita/diagnóstico , Estudos Transversais , Método Duplo-Cego , Humanos , Variações Dependentes do Observador , Projetos Piloto , Valva Tricúspide
7.
Rev. Soc. Esp. Dolor ; 22(2): 73-79, mar.-abr. 2015. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-136056

RESUMO

La heterogeneidad de los pacientes con osteoporosis hace necesaria una aproximación individualizada para conseguir un equilibrio entre los beneficios y limitaciones de los tratamientos disponibles. La indicación de este se realiza en función del riesgo absoluto de fractura por fragilidad. En los pacientes con un bajo riesgo de fractura son suficientes las medidas higiénicas, prevención de caídas y mantener una ingesta adecuada de calcio y vitamina D. En los pacientes con un riesgo moderado se debe individualizar la necesidad de tratamiento farmacológico e iniciar el tratamiento en aquellos con alto riesgo de fractura. Los fármacos más utilizados son los bifosfonatos, inhibidores de la reabsorción ósea, también se utilizan fármacos osteoanabólicos como la hormona teriparatida, y anticuerpos monoclonales como el denosumab. En los pacientes cuyo dolor no se controla de manera satisfactoria se ha de valorar la indicación de tratamientos mínimamente invasivos como bloqueos espinales, vertebroplastia o cifoplastia (AU)


The heterogeneity of patients with osteoporotic vertebral compression necessitates a tailored approach of balancing the benefits and limitations of available treatments. The indication for treatment is made based on the absolute risk of fragility fracture. In patients with a low risk of fracture are sufficient hygienic measures, preventing falls and maintaining an adequate intake of calcium and vitamin D. In patients with a moderate risk should be individualized drug treatment need and initiate treatment in those at high risk of fracture. The most commonly used drugs are bisphosphonates, inhibitors of bone resorption, also used as hormone teriparatide, osteoanabolic drug and monoclonal antibodies such as denosumab. In patients whose pain is not controlled can satisfactorily assessed the indication for minimally invasive treatments like vertebroplasty, kyphoplasty or spinal blocks (AU)


Assuntos
Humanos , Osteoporose/tratamento farmacológico , Dor Crônica/tratamento farmacológico , Manejo da Dor/métodos , Fraturas da Coluna Vertebral/prevenção & controle , Clínicas de Dor/organização & administração , Difosfonatos/uso terapêutico , Teriparatida/uso terapêutico , Vertebroplastia , Cifoplastia , Fraturas da Coluna Vertebral/cirurgia
8.
Rev. Soc. Esp. Dolor ; 21(6): 328-337, nov.-dic. 2014. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-131154

RESUMO

La osteoporosis (OP) se define como una enfermedad esquelética caracterizada por una resistencia ósea disminuida que predispone a un aumento en el riesgo de fracturas. En Europa se producen 2,7 millones de fracturas por fragilidad, tanto en hombres como mujeres, con un coste directo de 36 billones de euros. Estas fracturas se asocian con un incremento en la morbilidad y mortalidad. El riesgo de fractura osteoporótica viene determinado por la presencia de uno o más factores de riesgo y el descenso de la densidad mineral ósea (DMO) valorado mediante la técnica Dual Energy X-ray absortiometry (DEXA), densitometría. La indicación de tratamiento se realiza en función del riesgo absoluto de fractura por fragilidad. En los pacientes con un bajo riesgo de fractura son suficientes las medidas higiénicas, prevención de caídas y mantener una ingesta adecuada de calcio y vitamina D. En los pacientes con un riesgo moderado se debe individualizar la necesidad de tratamiento farmacológico e iniciar el tratamiento en aquellos con alto riesgo de fractura. Los fármacos más utilizados son los bifosfonatos, inhibidores de la reabsorción ósea, también se utilizan fármacos osteoanabólicos como la hormona teriparatida y anticuerpos monoclonales como el denosumab (AU)


Osteoporosis (OP) is defined as a skeletal disorder characterized by decreased bone strength, which predisposes to an increase in fracture risk. In Europe produced 2.7 million fragility fractures in both men and women with a direct cost of 36 billion euros. These fractures are associated with increased morbidity and mortality. The risk of osteoporotic fracture is determined by the presence of one or more risk factors and decreased bone mineral density (BMD) assessed by Dual Energy technique absortiometry X-ray (DEXA) densitometry. The indication for treatment is made based on the absolute risk of fragility fracture. In patients with a low risk of fracture are sufficient hygienic measures, preventing falls and maintaining an adequate intake of calcium and vitamin D. In patients with a moderate risk should be individualized drug treatment need and initiate treatment in those at high risk of fracture. The most commonly used drugs are bisphosphonates, inhibitors of bone resorption, also used as hormone teriparatide, osteoanabolic drug and monoclonal antibodies such as denosumab (AU)


Assuntos
Humanos , Masculino , Feminino , Osteoporose/tratamento farmacológico , Difosfonatos/uso terapêutico , Vertebroplastia/instrumentação , Vertebroplastia/métodos , Clínicas de Dor/organização & administração , Clínicas de Dor , Dor Aguda/tratamento farmacológico , Manejo da Dor/métodos , Indicadores de Morbimortalidade , Acidentes por Quedas/prevenção & controle , Acidentes por Quedas/estatística & dados numéricos , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/reabilitação , Densitometria/métodos , Fatores de Risco , Densidade Óssea , Razão de Chances , Calcitonina/uso terapêutico
9.
J Biotechnol ; 186: 21-9, 2014 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-24975573

RESUMO

The Streptomyces clavuligerus cephamycin C gene cluster has been subcloned in a SuperCos-derived cosmid and introduced in Streptomyces flavogriseus ATCC 33331, Streptomyces coelicolor M1146 and Streptomyces albus J1074. The exconjugant strains were supplemented with an additional copy of the S. clavuligerus cephamycin regulatory activator gene, ccaRC, expressed from the constitutive Pfur promoter. Only S. flavogriseus-derived exconjugants produced a compound active against Escherichia coli ESS22-31 that was characterized by HPLC-MS as cephamycin C. The presence of an additional ccaR copy resulted in about 40-fold increase in cephamycin C production. Optimal heterologous cephamycin C production was in the order of 9% in relation to that of S. clavuligerus ATCC 27064. RT-qPCR studies indicated that ccaRC expression in S. flavogriseus::[SCos-CF] was 7% of that in S. clavuligerus and increased to 47% when supplemented with a copy of Pfur-ccaR. The effect on cephamycin biosynthesis gene expression was thus improved but not in an uniform manner for every gene. In heterologous strains, integration of the cephamycin cluster results in a ccaR-independent increased resistance to penicillin, cephalosporin and cefoxitin, what corresponds well to the strong expression of the pcbR and pbpA genes in S. flavogriseus-derived strains.


Assuntos
Antibacterianos/metabolismo , Cefamicinas/metabolismo , Família Multigênica/genética , Streptomyces/genética , Streptomyces/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Cefamicinas/farmacologia , Clonagem Molecular , DNA Recombinante , Técnicas de Transferência de Genes , Testes de Sensibilidade Microbiana
10.
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
11.
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
12.
Appl Microbiol Biotechnol ; 97(21): 9451-63, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23974366

RESUMO

Clusters for clavulanic acid (CA) biosynthesis are present in the actinomycetes Streptomyces flavogriseus ATCC 33331 and Saccharomonospora viridis DSM 43017. These clusters, which are silent, contain blocks of conserved genes in the same order as those of the Streptomyces clavuligerus CA cluster but assembled in a different organization. S. flavogriseus was grown in nine different media, but clavulanic acid production was undetectable using bioassays or by high-performance liquid chromatography analyses. Reverse-transcriptase polymerase chain reaction (RT-PCR) of S. flavogriseus CA biosynthesis genes showed that the regulatory genes ccaR and claR and some biosynthetic genes were expressed whereas expression of cyp, orf12, orf13, and oppA2 was undetectable. The ccaR gene of S. clavuligerus was unable to switch on CA production in S. flavogriseus::[Pfur-ccaR C], but insertion of a cosmid carrying the S. clavuligerus CA cluster (not including the ccaR gene) conferred clavulanic acid production on S. flavogriseus::[SCos-CA] particularly in TBO and YEME media; these results suggests that some of the S. flavogriseus CA genes are inactive. The known heptameric sequences recognized by CcaR in S. clavuligerus are poorly or not conserved in S. flavogriseus. Quantitative RT-PCR analysis of the CA gene clusters of S. clavuligerus and S. flavogriseus showed that the average expression value of the expressed genes in the former strain was in the order of 1.68-fold higher than in the later. The absence of CA production by S. flavogriseus can be traced to the lack of expression of the essential genes cyp, orf12, orf13, orf14, and oppA2. Heterologous expression of S. clavuligerus CA gene cluster in S. flavogriseus::[SCos-CA] was 11- to 14-fold lower than in the parental strain, suggesting that the genetic background of the host strain is important for optimal production of CA in Streptomyces.


Assuntos
Vias Biossintéticas/genética , Ácido Clavulânico/metabolismo , Regulação Bacteriana da Expressão Gênica , Streptomyces/genética , Streptomyces/metabolismo , Perfilação da Expressão Gênica , Família Multigênica , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
J Biotechnol ; 163(1): 69-76, 2013 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-23147422

RESUMO

Expression of the holomycin biosynthesis genes (hlm) has been studied in the wild type strain Streptomyces clavuligerus ATCC 27064 and holomycin overproducer mutants. RT-PCR transcription analysis of S. clavuligerus oppA2::aph showed a higher transcription of the hlmA, B, C, D, E, F, G, H, I and hlmL genes, a slightly lower expression for hlmK and no significant differences for the transcription of the two putative regulatory genes, hlmM and hlmJ, in relation to the wild type strain. Accordingly, protein spots corresponding to HlmD, HlmF and HlmG, which were barely detectable in the wild type strain, were present in high amounts in the holomycin overproducer S. clavuligerus oppA2::aph proteome. Transcription start point analysis of the hlm genes revealed that the annotated sequences in the databases for several hlm genes were incorrect. The hlm cluster was introduced into Streptomyces coelicolor M1154 and holomycin production by S. coelicolor M1154 [pVR-hol1] was validated by bioassays and confirmed by HPLC analysis and mass spectrometry. Heterologous holomycin production by the S. coelicolor transformant is 500-fold lower than in S. clavuligerus oppA2::aph. The transformant S. coelicolor M1154 [pVR-hol1] shows holomycin sensitivity to 100 µg/ml, similar to that of the parental S. coelicolor M1154 strain, suggesting that heterologous expression in S. coelicolor might be toxic due to the lack of an holomycin resistance gene in this host strain.


Assuntos
Perfilação da Expressão Gênica/métodos , Lactamas/metabolismo , Família Multigênica , Streptomyces/genética , Streptomyces/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Mutação , Proteômica/métodos , Transcriptoma
14.
Mol Microbiol ; 81(4): 968-81, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21696462

RESUMO

RT-PCR analysis of the genes in the clavulanic acid cluster revealed three transcriptional polycistronic units that comprised the ceaS2-bls2-pah2-cas2, cyp-fd-orf12-orf13 and oppA2-orf16 genes, whereas oat2, car, oppA1, claR, orf14, gcaS and pbpA were expressed as monocistronic transcripts. Quantitative RT-PCR of Streptomyces clavuligerus ATCC 27064 and the mutant S. clavuligerus ccaR::aph showed that, in the mutant, there was a 1000- to 10,000-fold lower transcript level for the ceaS2 to cas2 polycistronic transcript that encoded CeaS2, the first enzyme of the clavulanic acid pathway that commits arginine to clavulanic acid biosynthesis. Smaller decreases in expression were observed in the ccaR mutant for other genes in the cluster. Two-dimensional electrophoresis and MALDI-TOF analysis confirmed the absence in the mutant strain of proteins CeaS2, Bls2, Pah2 and Car that are required for clavulanic acid biosynthesis, and CefF and IPNS that are required for cephamycin biosynthesis. Gel shift electrophoresis using recombinant r-CcaR protein showed that it bound to the ceaS2 and claR promoter regions in the clavulanic acid cluster, and to the lat, cefF, cefD-cmcI and ccaR promoter regions in the cephamycin C gene cluster. Footprinting experiments indicated that triple heptameric conserved sequences were protected by r-CcaR, and allowed identification of heptameric sequences as CcaR binding sites.


Assuntos
DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Streptomyces/genética , Streptomyces/metabolismo , Transativadores/metabolismo , Sítios de Ligação , Vias Biossintéticas/genética , Cefamicinas/biossíntese , Ácido Clavulânico/biossíntese , Pegada de DNA , Eletroforese em Gel Bidimensional , Ensaio de Desvio de Mobilidade Eletroforética , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Mutagênese Insercional , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
17.
An Med Interna ; 25(3): 131-3, 2008 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-18560681

RESUMO

We report a case of 78-year old man who presented with symptoms of adrenal insufficiency. The computed tomography (CT) scan showed the presence of bilateral adrenal masses. A CT-scan guided needle biopsy revealed diffuse large- B cell lymphoma. The absence of pathological findings in clinical, bone marrow and CT scan examinations supported the diagnosis of primary non-Hodgkin Lymphoma of the adrenal glands. The patient was treated with four cycles of R-CHOP chemotherapy with Rituximab, liposomal Doxorubicin, Cyclophosphamide, Vincristine and Prednisolone. At the end of fourth cycle there was radiological improvement but the chemotherapy was stopped because of IV grade toxicity. He completed treatment with radiotherapy of right adrenal mass. Few days after finishing radiation therapy the patient died due to a disseminated infection. No progressive disease was founded.


Assuntos
Neoplasias das Glândulas Suprarrenais/complicações , Insuficiência Adrenal/etiologia , Linfoma Difuso de Grandes Células B/complicações , Idoso , Humanos , Masculino
18.
An. med. interna (Madr., 1983) ; 25(3): 131-133, mar. 2008. ilus
Artigo em Es | IBECS | ID: ibc-65195

RESUMO

Presentamos el caso de un varón de 78 años que ingresa por un cuadro de debut de insuficiencia suprarrenal. Se realizó un estudio TC que mostró masas suprarrenales bilaterales de hasta 10 cm. Se completó estudio con biopsia percutanea de masa suprarrenal y biopsia de médula ósea, siendo diagnosticado de Linfoma no Hodgkin B difuso de células grandes primario suprarrenal con afectación suprarrenal bilateral. El paciente fue tratado con quimioterapia según esquema R-CHOP (Rituximab, Ciclofosfamida, Doxorrubicina liposomal, Vincristina y Prednisona).Tras 4 ciclos de quimioterapia se objetivo una respuesta parcial radiológica. Se suspendió la quimioterapia por toxicidad grado IV, completándose el tratamiento con RT sobre masa suprarrenal derecha. El paciente falleció por cuadro séptico pocos días después de finalizar la radioterapia, sin objetivarse progresión de la enfermedad


We report a case of 78-year old man who presented with symptoms of adrenal insufficiency. The computed tomography (CT) scan showed the presence of bilateral adrenal masses. A CT-scan guided needle biopsy revealed diffuse large- B cell lymphoma. The absence of pathological findings in clinical bone marrow and CT scan examinations supported the diagnosis of Lymphoma of the adrenal glands.The patient was treated with four cycles of R-CHOP chemotherapy with Rituximab, liposomal Doxorubicin, Cyclophosphamide, Vincristine and Prednisolone. At the end of fourth cycle there was radiological improvement but the chemotherapy was stopped because of IV grade toxicity. He completed treatment with radiotherapy of right adrenal mass. Few days after finishing radiation therapy the pacient died due to a disseminated infection. No progressive disease was founded


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Adenoma Adrenocortical/complicações , Adenoma Adrenocortical/diagnóstico , Choque Séptico/complicações , Linfoma não Hodgkin/complicações , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/radioterapia , Biópsia/métodos , Doença de Addison/complicações , Quimioterapia Combinada , Diagnóstico Diferencial , Carcinoma Adrenocortical/complicações , Insuficiência Renal/complicações , Ciclofosfamida/uso terapêutico , Vincristina/uso terapêutico , Prednisona/uso terapêutico , Linfoma não Hodgkin/patologia , Choque Séptico/mortalidade , Doença de Addison/tratamento farmacológico , Dor Abdominal/diagnóstico , Dor Abdominal/etiologia
19.
Clin Transl Oncol ; 9(5): 332-4, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17525045

RESUMO

Gestational trophoblastic disease consists of a pathological spectrum of entities from molar pregnancies, which are premalignant conditions, to malignant invasive choriocarcinoma. Serum Beta-human chorionic gonadotropin (hCG) levels are essential both in the diagnosis and in the follow-up. There are high rates of complete responses and long-term survivors, because of the excellent chemosensitivity of these tumours. After initial management, an increased level of Beta-hCG indicates persistent disease. However, in the absence of evidence of persistent disease, false-positive Beta-hCG values may be considered. We present here the case of a woman with a metastatic choriocarcinoma in complete response after chemotherapy, who developed later persistent false-positive values of Beta-hCG in the follow-up. Causes of false-positive Beta-hCG determinations are revised.


Assuntos
Gonadotropina Coriônica Humana Subunidade beta/sangue , Doença Trofoblástica Gestacional/sangue , Adulto , Reações Falso-Positivas , Feminino , Seguimentos , Humanos , Gravidez
20.
Clin. transl. oncol. (Print) ; 9(5): 332-334, mayo 2007.
Artigo em Inglês | IBECS | ID: ibc-123315

RESUMO

Gestational trophoblastic disease consists of a pathological spectrum of entities from molar pregnancies, which are premalignant conditions, to malignant invasive choriocarcinoma. Serum Beta-human chorionic gonadotropin (hCG) levels are essential both in the diagnosis and in the follow-up. There are high rates of complete responses and long-term survivors, because of the excellent chemosensitivity of these tumours. After initial management, an increased level of Beta-hCG indicates persistent disease. However, in the absence of evidence of persistent disease, false-positive Beta-hCG values may be considered. We present here the case of a woman with a metastatic choriocarcinoma in complete response after chemotherapy, who developed later persistent false-positive values of Beta-hCG in the follow-up. Causes of false-positive Beta-hCG determinations are revised (AU)


No disponble


Assuntos
Humanos , Feminino , Gravidez , Adulto , Gonadotropina Coriônica Humana Subunidade beta/sangue , Doença Trofoblástica Gestacional/sangue , Complicações na Gravidez/sangue , Reações Falso-Positivas , Seguimentos , Doença Trofoblástica Gestacional/complicações , Doença Trofoblástica Gestacional/diagnóstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...