Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Clin Radiol ; 73(6): 592.e9-592.e14, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29519499

RESUMO

AIM: To assess the accuracy of simple cardiovascular magnetic resonance imaging (CMR) parameters for first-line analysis of right ventricle (RV) dysfunction in children to identify those who require in-depth analysis and those in whom simple assessment is sufficient. MATERIALS AND METHODS: Sixty paediatric CMR studies were analysed. The following CMR parameters were measured: RV end-diastolic and end-systolic area (4CH EDA and 4CH ESA), fractional area change (FAC), RV diameter in end-diastole (RVD1), tricuspid annular plane systolic excursion (TAPSE), and RV outflow tract diameter in end-diastole (RVOT prox). They were correlated with RV end-diastolic volume (RVEDVI) and RV ejection fraction (RVEF). RESULTS: RVEDVI correlated best with 4CH ESA (r=0.85, <0.001) and EDA (r=0.82, <0.001). For RVEF only a moderate reverse correlation was found for 4CH ESA (-0.56, <0.001), 4CH EDA (-0.49, 0.001) and positive correlation for FAC (0.49, <0.001). There was no correlation between TAPSE and RVEF and only weak between RVD1 and RVEDVI. A 4CH ESA cut-off value of 8.5 cm2/m2 had a very high diagnostic accuracy for predicting an enlarged RV (AUC=0.912, p<0.001, sensitivity 92.3%, specificity 79%) and a cut-off value of 10.5 cm2/m2 was also a good predictor of depressed RV systolic function (AUC=0.873, p<0.001, sensitivity 83%, specificity 89%). CONCLUSION: For routine screening in clinical practice, 4CH ESA seems a reliable and easy method to identify patients with RV dysfunction.


Assuntos
Hipertrofia Ventricular Direita/patologia , Disfunção Ventricular Esquerda/patologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Hipertrofia Ventricular Direita/fisiopatologia , Lactente , Recém-Nascido , Angiografia por Ressonância Magnética , Masculino , Curva ROC , Encaminhamento e Consulta , Estudos Retrospectivos , Sístole , Disfunção Ventricular Esquerda/fisiopatologia
2.
Clin Radiol ; 72(4): 286-292, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28069158

RESUMO

AIM: To investigate changes in myocardial tissue volume during the cardiac cycle to verify the hypothesis of non-compressibility of the myocardium in healthy individuals (HI) as well as in patients with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and aortic stenosis (AS). MATERIALS AND METHODS: The study group included 30 HI, and patients with HCM (n=110), DCM (n=89), and AS (n=78). Left ventricular (LV) function, end-diastolic, and end-systolic volumes were calculated based on cardiac magnetic resonance imaging (CMR) for all participants. RESULTS: End-systolic myocardial volumes were higher than end-diastolic in both controls (91.2±26.6 versus 85.1±24.3 ml, p<0.001) and in all patient groups: HCM (214.3±81.6 versus 176±64.2 ml, p<0.01), DCM (128.4±43.1 versus 115.4±42.9 ml, p<0.001) and AS (155.1±37.1 versus 129.4±34.6 ml, p<0.001). HCM and AS patients had significantly higher systolic volume gain than HI (21.5±8.3 versus 10.6±6.3%, p<0.01 and 18.3±5.7 versus 10.6±6.3% p=0.013, respectively). Conversely, DCM patients had lesser increases in myocardial systolic volume than HCM patients (11.2±4.8% versus 21.5±8.3, p=0.01) and AS patients (11.2±4.8% versus 18.3±5.7, p=0.02). No differences were found in systolic volume gain between AS and HCM patients (p=ns) or between DCM patients and HI (p=ns). CONCLUSION: End-systolic myocardial volume was significantly higher than end-diastolic volume in all subsets of patients. The systolic volume gain was greater in individuals with hypertrophy than in those without.


Assuntos
Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Imageamento por Ressonância Magnética , Miocárdio/patologia , Adulto , Idoso , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Hipertrófica/patologia , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Tamanho do Órgão , Adulto Jovem
3.
Clin Radiol ; 69(7): e1-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24824972

RESUMO

AIM: To assess the relationship between cardiothoracic ratio (CTR) and ventricular and atrial volumes in patients with repaired tetralogy of Fallot (TOF). MATERIALS AND METHODS: Patients with repaired TOF undergoing cardiac magnetic resonance (CMR) and chest radiography within 1 day were included (n = 82; median age: 24.7 years, interquartile range: 21.5-35.9). The CTR was obtained from upright posteroanterior chest roentgenograms. Analyses of CMR images and radiographs were performed in a blinded fashion. RESULTS: There were 35.1% (13/37) of patients with normal CTR (<0.5) who had severe right ventricular (RV) dilatation. There were six patients (13.3%, 6/45) with high CTR with both normal RV and left-ventricular (LV) volumes. CTR did not correlate with either RV or LV volumes but showed a weak correlation with right- and left-atrial volumes (r = 0.43, p = 0.0001; r = 0.27, p = 0.01, respectively). CTR ≥0.5 showed poor ability in the identification of severe RV dilatation (sensitivity: 61.8%, specificity: 50%). The combination of CTR and signs of RV enlargement on lateral radiographs did not improve the diagnostic accuracy of any of those parameters alone. CONCLUSION: CTR in patients with repaired TOF reflected atrial rather than ventricular dilatation. The use of CTR or lateral radiographs in patients with repaired TOF may lead to false conclusions concerning ventricular size.


Assuntos
Complicações Pós-Operatórias/patologia , Tetralogia de Fallot/patologia , Adulto , Análise de Variância , Dilatação Patológica/patologia , Feminino , Átrios do Coração/patologia , Humanos , Angiografia por Ressonância Magnética , Masculino , Tamanho do Órgão/fisiologia , Sensibilidade e Especificidade , Volume Sistólico/fisiologia , Tetralogia de Fallot/fisiopatologia , Tetralogia de Fallot/cirurgia , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
J Microbiol Methods ; 101: 28-32, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24681305

RESUMO

An anaerobic colorimetric assay for quantifying microbial demethylation activity was adapted for aerobic use in studying lignin and lignin-derived compounds. Standard curves of 0-500µM pyrocatechol with and without 0.3% lignin demonstrated the use in either case. This method detects demethylation products up to 500µM without using additional dilutions.


Assuntos
Colorimetria/métodos , Lignina/análise , Lignina/química , Ácido Nitrilotriacético/química , Titânio/química , Absidia/metabolismo , Anaerobiose , Biomassa , Coriolaceae/metabolismo , Resíduos Industriais , Lignina/metabolismo , Metilação , Eliminação de Resíduos
5.
Clin Radiol ; 68(12): 1206-11, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23942263

RESUMO

AIM: To assess changes in ventricular size and function over time in conservatively treated adult patients with repaired tetralogy of Fallot (TOF) and significant pulmonary regurgitation (PR). MATERIALS AND METHODS: Patients with repaired TOF who had undergone more than one cardiac magnetic resonance study were identified. To confine the cause of ventricular size and function deviation to PR, patients with residual ventricular septal defect, more than mild regurgitation at a valve other than the pulmonary valve, and known coronary artery disease were excluded. RESULTS: The final analysis included 27 adults with PR fraction >20%. During a follow-up of mean 2.1 ± 0.8 years, there was no change in right ventricular (RV) end-diastolic volume (EDV; 162.1 ± 27.6 versus 164 ± 29.6 ml/m(2), p = 0.5). Left ventricular (LV) EDV showed a small decrease (85.1 ± 16.2 versus 81.5 ± 14.1 ml/m(2), p = 0.02). The mean PR fraction, PR volume, and peak RV outflow tract gradient did not change. Additionally, both RV ejection fraction (EF) and LVEF remained stable over the follow-up period (48.1 ± 6.5 versus 48.4 ± 6.7%, p = 0.83, and 57.3 ± 5.4 versus 57.2 ± 5.1 %, p = 0.91, respectively). Only two asymptomatic patients (7.4% of the study group) developed symptoms and the remaining did not deteriorate. CONCLUSION: The RVEDV, RVEF, and LVEF remained stable over a mean follow-up of approximately 2 years in the majority of adult patients after TOF repair with significant PR and a wide range of RVEDV.


Assuntos
Ventrículos do Coração/anatomia & histologia , Insuficiência da Valva Pulmonar/cirurgia , Tetralogia de Fallot/cirurgia , Função Ventricular Direita/fisiologia , Pré-Escolar , Feminino , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Insuficiência da Valva Pulmonar/fisiopatologia , Tetralogia de Fallot/fisiopatologia , Fatores de Tempo , Adulto Jovem
7.
Waste Manag ; 29(2): 647-54, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18835150

RESUMO

In recent times, the State of New Jersey (USA) has been making attempts at promoting recycling as an environmentally friendly means of attaining self-sufficiency at waste disposal, and the state has put in place a 50% recycling target for its municipal solid waste stream. While the environmental benefits of recycling are obvious, a recycling program must be cost effective to ensure its long-term sustainability. In this paper, a linear programming model is developed to examine the current state of recycling in selected counties in Northern New Jersey and assess the needs to achieve the state's recycling goal in these areas. The optimum quantities of waste to be sent to the different waste facilities, which include landfills, incinerators, transfer stations, recycling and composting plants, are determined by the model. The study shows that for these counties, the gap between the current waste practices where the recycling rate stands at 32% and the state's goal can be bridged by more efficient utilization of existing facilities and reasonable investment in expanding those for recycling activities.


Assuntos
Participação da Comunidade/estatística & dados numéricos , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/estatística & dados numéricos , Características da Família , Modelos Teóricos , New Jersey , Eliminação de Resíduos/métodos , Software
8.
Eur J Vasc Endovasc Surg ; 30(2): 143-6, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15936960

RESUMO

OBJECTIVE: The aim of our study was to identify risk factors for early restenosis after carotid endarterectomy (CEA). METHODS: Prospective follow-up of 497 primary CEAs was performed at 3, 6, 12 and 24 months by clinical assessment and duplex ultrasound to identify > or = 50% restenosis. RESULTS: Early restenosis occurred in 71 (14.3%) patients. By univariate analysis high carotid clamping time (CCT) (p = 0.002) and absence of shunt use (p = 0.03) were related to early restenosis. High CCT was the only independent predictor of early restenosis in a forward stepwise logistic regression model (OR = 2.25; CI 1.2-4.1; p = 0.008). CONCLUSIONS: Carotid clamping time may be a novel risk factor for early restenosis.


Assuntos
Estenose das Carótidas/etiologia , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estenose das Carótidas/diagnóstico , Constrição , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo , Grau de Desobstrução Vascular
9.
Intensive Care Med ; 28(5): 594-8, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12029408

RESUMO

OBJECTIVE: To evaluate the time-course of two organ failure scores (SOFA and Goris) after surgery for postoperative peritonitis in critically ill patients according to the persistence/nonpersistence of intraabdominal sepsis (IAS). DESIGN: Retrospective study. PATIENTS: Sixty-two consecutive patients (SAPSII = 38+/-14) admitted in the surgical ICU. METHODS: Patients were classified according to the persistence of IAS (IAS+, n=36) confirmed by a second laparotomy or the lack of IAS (IAS-, n=26) assessed by a favorable 30-day evolution without reintervention. Scores were calculated daily from day 0 preoperatively to postoperative day 5. RESULTS: In both groups, SOFA scores were higher on day 1 when compared to day 0 (8.3+/-3.1 vs 6.1+/-3.7 in the IAS+ group and 5.2+/-3.4 vs 2.7+/-2.7 in the IAS- group). In the IAS- patients, the SOFA score displayed a decrease starting on day 2 when compared to day 1 (4.4+/-3.6 vs 5.2+/-3.4, P=0.03). In contrast, in the IAS+ patients, the SOFA score remained unchanged until day 5. The time course of the Goris score was strictly similar to the SOFA scores. CONCLUSION: In critically ill patients with postoperative peritonitis, the postoperative time course of the SOFA and the Goris organ failure scores was different between patients with or without intra-abdominal persistent sepsis. The lack of improvement of one of these scores on postoperative day 2 may suggest persistent intraabdominal sepsis and supports the need for a new surgical exploration.


Assuntos
Insuficiência de Múltiplos Órgãos/diagnóstico , Peritonite/complicações , Sepse/diagnóstico , Análise de Variância , Distribuição de Qui-Quadrado , Estado Terminal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peritonite/etiologia , Peritonite/cirurgia , Complicações Pós-Operatórias , Valor Preditivo dos Testes , Estudos Retrospectivos , Sepse/etiologia , Sepse/cirurgia , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Fatores de Tempo
10.
Anesth Analg ; 91(3): 714-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10960406

RESUMO

UNLABELLED: Recovery from anesthesia might be compromised in obese patients. Because of its pharmacological properties, desflurane might allow rapid postoperative recovery for these patients. We compared postoperative recovery for 36 obese patients randomized to receive either desflurane, propofol, or isoflurane to maintain anesthesia during laparoscopic gastroplasties. Anesthesia was induced with propofol and succinylcholine IV and was maintained with rocuronium, alfentanil, inhaled nitrous oxide, and the study drug. Immediate recovery (i.e., times from the discontinuation of anesthesia to tracheal extubation, eye opening, and the ability to state one's name) was measured. At the time of postanesthesia care unit (PACU) admission, arterial saturation and the ability of patients to move were recorded. In the PACU, intermediate recovery was measured by using sedation and psychometric evaluations, 30, 60, and 120 min postoperatively. Data were compared between groups by using the Kruskal-Wallis and chi(2) tests. Results were reported as means +/- SD. P: < 0.05, compared with desflurane, was considered significant. Immediate recovery occurred faster, and was more consistent, after desflurane than after propofol or isoflurane (times to extubation were 6 +/- 1 min, 13 +/- 8 min [P: < 0.05, compared with desflurane], and 12 +/- 6 min [P: < 0.05, compared with desflurane], respectively). At PACU admission, SpO(2) values were significantly higher and patient mobility was significantly better after desflurane than after isoflurane or propofol. Sedation was significantly less pronounced with desflurane at 30 and 120 min postoperatively. In morbidly obese patients, postoperative immediate and intermediate recoveries are more rapid after desflurane than after propofol or isoflurane anesthesia. This advantage of desflurane persists at least for 2 h after surgery and is associated with both an improvement in patient mobility and a reduced incidence of postoperative desaturation. IMPLICATIONS: In morbidly obese patients, postoperative immediate and intermediate recoveries are more rapid and consistent after desflurane than after propofol or isoflurane anesthesia.


Assuntos
Período de Recuperação da Anestesia , Anestesia por Inalação , Anestesia Intravenosa , Anestésicos Inalatórios , Anestésicos Intravenosos , Isoflurano/análogos & derivados , Obesidade/fisiopatologia , Propofol , Adulto , Desflurano , Feminino , Humanos , Masculino , Dor Pós-Operatória/epidemiologia , Dor Pós-Operatória/psicologia , Náusea e Vômito Pós-Operatórios/epidemiologia , Náusea e Vômito Pós-Operatórios/psicologia , Estudos Prospectivos
11.
J Am Acad Dermatol ; 43(2 Pt 1): 272-4, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10906650

RESUMO

Hyperpigmentation of the skin is often refractory to conventional therapies, but has significant cosmetic implications if located on visible areas. Because laser systems are capable of removing pigment deposits caused by selective photothermolysis, we addressed the issue of whether the Q-switched ruby laser could be a useful alternative in the treatment of nonmelanotic hyperpigmented skin lesions. We report the successful treatment of a patient with hyperpigmentation caused by iatrogenic human herpesvirus 8-associated Kaposi's sarcoma and a patient with hyperpigmentation caused by long-term antimalarial therapy for cutaneous lupus erythematosus. In both patients, clinical lightening of the darkly pigmented lesions was seen after a single treatment, and a significant improvement was observed after 3 laser applications. The patients tolerated the laser therapy well without any short-term side effects and did not experience either scarring or considerable textural skin changes. Histologic examination was performed before and after laser treatment to confirm the reduction of the pigment deposits. Our data indicate that treatment of nonmelanotic skin hyperpigmentation with the Q-switched ruby laser might be a safe and powerful therapeutic method.


Assuntos
Hiperpigmentação/radioterapia , Terapia a Laser , Idoso , Feminino , Humanos , Hiperpigmentação/patologia , Masculino , Pessoa de Meia-Idade
12.
Int J Oncol ; 15(1): 173-8, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10375612

RESUMO

Interleukin-6 (IL-6) is implicated in the in vivo proliferation of malignant plasma cells in multiple myeloma. To define the molecular basis of the IL-6-induced mitogenic response in myeloma cells, we applied STAR (subtractive transcriptional amplification of mRNA), a new differential expression analysis technology, to isolate mRNAs preferentially expressed in IL-6-treated versus untreated cultures of the factor-responsive myeloma cell line U266. From the resulting collection of STAR clones, sequence information was obtained for a total of 72 distinct transcripts. Of these, 29 were found to correspond to known genes, 22 matched expressed sequence tags in public databases and 21 showed no sequence similarity to any existing entries. Among the known genes uncovered in the screen were those encoding proteins that function in cell division, cell signalling and gene/protein expression. Northern blot analysis documented that two transcription factor genes chosen for further study, c-myc promoter-binding protein (MBP-1) and X-box binding protein 1 (XBP-1), were up-regulated in U266 cells about 3-fold relative to the cell cycle-dependent beta-actin gene 12 h after IL-6 treatment. Both genes were also similarly up-regulated by IL-6 in factor-dependent ANBL-6 myeloma cells. These results indicate that MBP-1 and XBP-1 are IL-6 genes in myeloma cells; as such, they may play a role in IL-6-mediated growth control in multiple myeloma.


Assuntos
Proteínas de Ligação a DNA/genética , Interleucina-6/farmacologia , Mieloma Múltiplo/genética , Proteínas de Neoplasias/genética , Fosfopiruvato Hidratase , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor , Sequência de Bases , Biomarcadores Tumorais , Divisão Celular/efeitos dos fármacos , DNA Complementar/genética , Etiquetas de Sequências Expressas , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-6/fisiologia , Dados de Sequência Molecular , Mieloma Múltiplo/patologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , Fatores de Transcrição de Fator Regulador X , Transdução de Sinais/efeitos dos fármacos , Técnica de Subtração , Transfecção , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo , Proteína 1 de Ligação a X-Box
13.
Int J Clin Pract ; 53(1): 19-23, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10344061

RESUMO

The clinical benefits of beta-blockers in heart failure are currently subject to intense debate and are being investigated. The economic impact of beta-blockade, however, has largely remained unexplored. The Cardiac Insufficiency Bisoprolol Study (CIBIS), while failing to show statistically significant reduction in mortality over conventional therapy, demonstrates that the administration of bisoprolol adjuvant to standard therapy leads to a significant reduction in hospital admission. The present study is a cost minimisation analysis based on CIBIS data for the UK and is restricted to direct costs only. The costs of bisoprolol medication and inpatient treatment of heart failure are considered. The 'base case' analysis and the sensitivity analyses carried on all cost driver parameters show that administering bisoprolol to heart failure patients adjuvantly to the standard therapy is at least cost neutral. Additional drug costs incurred by bisoprolol are compensated by the inpatient treatment costs of heart failure avoided. All other non-quantifiable clinical benefits such as improvement of New York Heart Association functional class are positive extras to patients and the National Health Service.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Bisoprolol/uso terapêutico , Baixo Débito Cardíaco/tratamento farmacológico , Adolescente , Antagonistas Adrenérgicos beta/economia , Adulto , Idoso , Bisoprolol/economia , Baixo Débito Cardíaco/economia , Análise Custo-Benefício , Custos de Medicamentos , Feminino , Custos Hospitalares , Humanos , Masculino , Pessoa de Meia-Idade
14.
WMJ ; 97(3): 58-61, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9540452

RESUMO

UNLABELLED: To compare mortality for diabetes and diabetes-related causes in Native American (NA) with total mortality for Wisconsin population by age, and gender. METHODS: Adjusting for age and sex, standardized mortality ratios (SMRs) were calculated for Wisconsin Native Americans for 1986-1995, using the 1990 total Wisconsin population as a reference and death certificate data to count and categorize deaths. RESULTS: Statistically significant high NA SMRs were found for total deaths (SMR = 1.28, p < .005), diabetes (SMR = 2.87, p < .005), heart disease (SMR = 1.16, p < .005), and kidney disease (SMR = 2.72, p < .005). There was substantial concordance in SMRs between men and women. NA SMRs were above 1 for all five year age groups below 75. Comparisons are provided with national data. CONCLUSION: Mortality due to diabetes mellitus, heart disease and kidney disease are higher among Native Americans in Wisconsin for all age groups below 75 and in both genders.


Assuntos
Povo Asiático , Causas de Morte , Diabetes Mellitus/etnologia , Diabetes Mellitus/mortalidade , Angiopatias Diabéticas/etnologia , Angiopatias Diabéticas/mortalidade , Nefropatias Diabéticas/etnologia , Nefropatias Diabéticas/mortalidade , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/etnologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Angiopatias Diabéticas/etiologia , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Distribuição por Sexo , Taxa de Sobrevida , Wisconsin/epidemiologia
15.
Appl Environ Microbiol ; 63(1): 310-3, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8979357

RESUMO

A nucleic acid sequence-based amplification system primarily targeting mRNA from the Listeria monocytogenes hlyA gene was developed. This system enabled the detection of low numbers (< 10 CFU/g) of L. monocytogenes cells inoculated into a variety of dairy and egg products after 48 h of enrichment in modified listeria enrichment broth.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Escherichia coli , Genes Bacterianos , Proteínas Hemolisinas/genética , Listeria monocytogenes/genética , Técnicas de Amplificação de Ácido Nucleico , Sequência de Bases , Primers do DNA/genética , Laticínios/microbiologia , Ovos/microbiologia , Estudos de Avaliação como Assunto , Microbiologia de Alimentos , Listeria monocytogenes/isolamento & purificação , RNA Bacteriano/genética , RNA Mensageiro/genética , Sensibilidade e Especificidade
16.
Protein Expr Purif ; 11(3): 271-8, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9425631

RESUMO

A gene encoding the extracellular domain of the human erythropoietin receptor (EPO-R) was constructed using oligonucleotides, with a view to maintaining preferred codon usage for the Streptomycetes. The gene was subcloned into a multicopy Streptomyces-Escherichia coli shuttle vector, pCAN46 (derived from pIJ680), containing a strong constitutive promoter from the S. fradiae aph gene, a signal peptide coding region derived from the protease B gene of S. griseus, and a transcription terminator sequence also derived from the S. fradiae aph gene. Extracellular expression of authentic EPO-R by S. lividans was demonstrated using SDS-PAGE and Western blot analysis, followed by direct amino terminal sequencing of the purified product. Specific binding of S. lividans-expressed EPO-R to recombinant human glycosylated EPO was demonstrated using BIAcore (surface plasmon resonance) analysis and native gel shift assays.


Assuntos
Genes Sintéticos , Receptores da Eritropoetina/biossíntese , Sequência de Bases , Western Blotting , Clonagem Molecular/métodos , Códon , Eletroforese em Gel de Poliacrilamida , Escherichia coli , Genes Bacterianos , Vetores Genéticos , Glicosilação , Humanos , Cinética , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Sinais Direcionadores de Proteínas , Receptores da Eritropoetina/isolamento & purificação , Receptores da Eritropoetina/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Solubilidade , Streptomyces/genética
17.
Can J Microbiol ; 42(3): 284-8, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8868236

RESUMO

A gene encoding a Streptomyces lividans homologue of the chymotrypsin-like serine protease (SAM-P20) of Streptomyces albogriseolus was isolated using the Streptomyces griseus prtB gene as a hybridization probe. Nucleotide sequence analysis of a representative clone uncovered the possible presence of a sequence of 900 nucleotides encoding 300 amino acids, including a putative "prepro" region of 115 amino acids. Alignment of the predicted amino acid sequence of this putative gene with other members of the family of Streptomyces extracellular chymotrypsin-like proteases indicated a high degree of homology in all cases, especially with the SAM-P20 protease. This gene product has been identified as the second member of a potentially larger family of SAL (SAM-P20-like) proteases in S. lividans 66.


Assuntos
Serina Endopeptidases/genética , Streptomyces/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência , Streptomyces/enzimologia
18.
Appl Microbiol Biotechnol ; 45(1-2): 141-7, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8920189

RESUMO

Amino-terminal degradation has been observed for many of the secreted heterologous proteins produced by S. lividans 66. We, therefore, set out to characterize the relevant proteinases and their genes. A tripeptide chromogenic substrate was used to identify a gene that was shown to encode a secreted protein which removed tripeptides from the amino terminus of extracellular proteins (tripeptidyl aminopeptidase, Tap; Butler et al. 1995). This activity was removed by a homologous gene deletion replacement and the ability of the S. lividans strain to remove N-terminal tripeptides was greatly reduced, but still significant. When the tap-deleted strain was used as a host for the rescreening of a S. lividans 66 genomic DNA library, a number of other genes encoding proteases with aminopeptidase activities were discovered. One clone (P5-4) produced a 45-kDa secreted protein (Ssp), which showed activity against Ala-Pro-Ala-beta-naphthylamide (APA-beta NH-Nap) substrate. Further analysis of the cloned DNA showed an open-reading frame encoding a protein larger than 45 kDa. Direct Edman degradation of the secreted protein confirmed that it was encoded within the cloned DNA and probably processed from a larger precursor. Protein sequence analysis revealed a striking homology to subtilisin BPN' in three regions around the active-site residues suggesting that the protein is a serine protease. As expected, the protease activity was inhibited by phenylmethylsulphonyl fluoride. Mutant strains with most of the ssp gene deleted exhibited reduced activity against APA-beta NH-Nap substrate compared to their non-deleted parental strains.


Assuntos
Endopeptidases/genética , Genes Bacterianos , Streptomyces/enzimologia , Streptomyces/genética , Subtilisinas/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , DNA Bacteriano/genética , Endopeptidases/metabolismo , Deleção de Genes , Biblioteca Genômica , Dados de Sequência Molecular , Oligopeptídeos/química , Mapeamento por Restrição , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Especificidade por Substrato , Subtilisinas/metabolismo
19.
J Bacteriol ; 177(21): 6033-40, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7592364

RESUMO

A strain of Streptomyces lividans 66 deleted for a major tripeptidyl aminopeptidase (Tap) was used as a host to screen an S. lividans genomic library for clones overexpressing activity against the chromogenic substrate Ala-Pro-Ala-beta-naphthylamide. In addition to reisolation of the tap gene, clones representing another locus, slpD, were uncovered. slpD was analyzed by deletion subcloning to localize its functional sequence. Nucleotide sequence determination revealed an open reading frame encoding a 55-kDa protein exhibiting significant amino acid sequence homology to Tap, particularly around the putative active-site serine residue. No secreted protein was observed for strains harboring the slpD clone, but inspection of the predicted protein sequence revealed a putative lipoprotein signal peptide (signal peptidase II type), suggesting a mycelial location for the SlpD proteinase. In an attempt to isolate an endoprotease known to be active against some heterologous proteins, a second clone was isolated by using a longer substrate (t-butyloxycarbonyl [Boc]-APARSPA-beta-naphthylamide) containing a chemical blocking group at the amino terminus to prevent aminopeptidase cleavage. This locus, slpE, appeared to also encode a 55-kDa mycelium-associated (lipoprotein) proteinase, whose predicted protein sequences showed significant amino acid homology to Tap and SlpD, particularly around the putative active-site serine residues. Chromosomal integration and deletion analysis in both the wild-type and Tap-deficient backgrounds appeared to indicate that SlpD was essential for viability and SlpE was required for growth on minimal media.


Assuntos
Proteínas de Bactérias/genética , Endopeptidases/genética , Genes Bacterianos , Lipoproteínas/genética , Streptomyces/genética , Sequência de Aminoácidos , Aminopeptidases , Sequência de Bases , Parede Celular/enzimologia , Cromossomos Bacterianos/genética , Dipeptidil Peptidases e Tripeptidil Peptidases , Endopeptidases/metabolismo , Escherichia coli/genética , Deleção de Genes , Biblioteca Genômica , Lipoproteínas/metabolismo , Dados de Sequência Molecular , Oligopeptídeos/metabolismo , Mapeamento por Restrição , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Streptomyces/enzimologia , Especificidade por Substrato
20.
Appl Environ Microbiol ; 61(8): 3145-50, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7487044

RESUMO

The gene encoding a tripeptidyl aminopeptidase (Tap) from Streptomyces lividans was cloned by using a simple agar plate activity assay. Overexpression of the cloned gene results in the production of a secreted protein which has an apparent subunit molecular weight of 55,000 and is responsible for the major amino-terminal degradative activity in culture broths of S. lividans strains. A DNA sequence analysis revealed a potential protein-encoding region of the size expected to encode the observed protein, which contained a sequence that exhibited significant homology around a putative active site serine residue observed for lipases, esterases, and acyl transferases. Preceding the amino terminus of the secreted protein was a predicted signal peptide of 36 amino acids followed by a tripeptide, which could be autocatalytically removed from a secreted Tap precursor. The transcriptional start site for the gene was mapped by primer extension. Mutant strains of S. lividans lacking detectable Tap activity were able to grow and sporulate normally. Cross-species hybridization experiments showed that DNA homologs of the tap gene are present in most of the Streptomyces strains tested.


Assuntos
Endopeptidases/genética , Genes Bacterianos , Streptomyces/enzimologia , Streptomyces/genética , Sequência de Aminoácidos , Aminopeptidases , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , DNA Bacteriano/genética , Dipeptidil Peptidases e Tripeptidil Peptidases , Dados de Sequência Molecular , Mutação , Plasmídeos/genética , Sinais Direcionadores de Proteínas/genética , Mapeamento por Restrição , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...