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1.
HIV Med ; 14(8): 463-71, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23506263

RESUMEN

OBJECTIVES: HIV-infected patients are commonly prescribed several medications and are thus at risk for drug interactions that may result in QTc prolongation. We sought (1) to identify the frequency of electrocardiogram (ECG) monitoring (2), to determine the prevalence of drug interactions involving QTc-prolonging medications, and (3) to quantify the prevalence of QTc prolongation. METHODS: A cross-sectional study was conducted among HIV-infected adults. Demographics, medications, drug interactions and comorbidities were abstracted from patients' medical records. Abnormal QTc interval was defined per the UK Committee for Proprietary Medicinal Products. Clinical characteristics were compared among ECG recipients and nonrecipients. Among ECG recipients, the prevalence and predictors of QTc prolongation were assessed. RESULTS: Among the 454 patients included in the study, 80.8% were prescribed a medication associated with QTc prolongation and 39% had drug interactions expected to increase QTc prolongation risk. There were 138 patients (30.3%) who received ECG testing. Receipt of ECG monitoring was associated with increasing age, diabetes, increasing total number of medications and gastroesophageal reflux disease. Among ECG recipients, the prevalence of abnormal QTc interval was 27.5%. Chronic kidney disease [prevalence ratio (PR) 3.47; 95% confidence interval (CI) 1.37-8.83; P = 0.009], hepatitis C virus coinfection (PR 2.26; 95% CI 0.97-5.27; P = 0.06) and hypertension (PR 2.11; 95% CI 0.93-4.81; P = 0.07) were independently associated with an abnormal QTc interval. CONCLUSIONS: A low frequency of ECG testing was observed, despite a high use of medications associated with QTc prolongation. The risk of abnormal QTc interval was highest among patients with chronic kidney disease, hypertension and hepatitis C virus coinfection.


Asunto(s)
Interacciones Farmacológicas/fisiología , Electrocardiografía/estadística & datos numéricos , Síndrome de QT Prolongado/inducido químicamente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios Transversales , Diabetes Mellitus Tipo 2 , Femenino , Reflujo Gastroesofágico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/fisiopatología , Hepacivirus , Humanos , Hipertensión , Síndrome de QT Prolongado/epidemiología , Masculino , Persona de Mediana Edad , Insuficiencia Renal Crónica , Factores de Riesgo , Torsades de Pointes/epidemiología , Adulto Joven
2.
Lett Appl Microbiol ; 49(6): 775-83, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19843215

RESUMEN

AIMS: To compare responses of a soil bacterium to Cu and Cd. METHODS AND RESULTS: In minimal medium, Cd caused a dose-dependent growth stasis of logarithmic phase cells of Pseudomonas putida, strain KT2440, whereas Cu did not compromise growth up to 10 mg l(-1). Proteomics showed changes in accumulation of both membrane and soluble proteins by 6 h of treatment; increased Krebs cycle enzymes were apparent. Transcript analysis showed Cd- and Cu-induced different genes. Cd-induced genes encoding the transcriptional regulator CzrR2; an outer membrane protein associated with lipopolysaccharide stability, H1; two oxidative stress protective proteins and the P-type ATPase, CadA2, associated with Cd(2+) efflux. The genes most responsive to Cu encoded the regulator CopR1 and the outer membrane resistance protein regulated by CopR1, CopB1; a putative porin, PorD and the Cu-binding protein, PacZ or CopZ, and CopA2. CONCLUSIONS: These findings support that a soil pseudomonad restricts internalization of the metals by using different sets of binding proteins and efflux pumps. Activation of mechanisms to protect against oxidative stress also was evident especially with Cd exposure. SIGNIFICANCE AND IMPACT OF THE STUDY: The differential cellular responses to Cd and Cu suggest that risk assessment for Cd and Cu should be different.


Asunto(s)
Cadmio/metabolismo , Cobre/metabolismo , Pseudomonas putida/crecimiento & desarrollo , Microbiología del Suelo , Proteínas Bacterianas/metabolismo , Electroforesis en Gel Bidimensional , Regulación Bacteriana de la Expresión Génica , Estrés Oxidativo , Proteoma/metabolismo , Pseudomonas putida/genética , Pseudomonas putida/metabolismo , ARN Bacteriano/genética , ARN Bacteriano/metabolismo
3.
J Antimicrob Chemother ; 62(5): 1138-41, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18694905

RESUMEN

BACKGROUND: Recent evidence suggests that vancomycin demonstrates reduced activity against methicillin-resistant Staphylococcus aureus (MRSA) infections when vancomycin MIC values are at the high end of the susceptibility range (> or = 1.5 mg/L). However, scant research exists on factors predictive of high vancomycin MICs (> or = 1.5 mg/L) among MRSA bacteraemic patients. Empirical therapy decisions would greatly benefit from such information. OBJECTIVES: To identify the parameters predictive of high vancomycin MICs (> or = 1.5 mg/L) among MRSA bacteraemic patients and to develop an evidence-based clinical prediction tool. METHODS: This observational cohort study included adult patients with MRSA bloodstream infections between January 2005 and May 2007. Demographics, co-morbid conditions, and microbiology and antibiotic exposure data were collected. Vancomycin MICs were determined by Etest. Stepwise logistic regression was used to identify independent predictors of high vancomycin MICs. RESULTS: Of the 105 patients who met the inclusion criteria, 77 patients (73.3%) exhibited a high vancomycin MIC (> or = 1.5 mg/L). In the bivariate analysis, prior vancomycin exposure within 30 days of index culture collection [15 patients (19.5%) versus 1 patient (3.6%), P = 0.05] and residence in an intensive care unit (ICU) at the onset of infection [27 patients (35.1%) versus 3 patients (10.7%), P = 0.02] were both significantly associated with a high vancomycin MIC value and both were independent predictors of high MICs in the logistic regression. CONCLUSIONS: Patients with MRSA bloodstream infections in the ICU or with a history of vancomycin exposure should be considered at high risk of infection with strains for which vancomycin MICs are elevated. Appropriate and aggressive empirical therapy is required for these patients.


Asunto(s)
Bacteriemia/microbiología , Resistencia a la Meticilina , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Vancomicina , Adulto , Anciano , Bacteriemia/epidemiología , Estudios de Cohortes , Cuidados Críticos , Femenino , Humanos , Modelos Logísticos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Factores de Riesgo , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificación , Vancomicina/uso terapéutico
4.
Theriogenology ; 70(3): 463-8, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18550159

RESUMEN

This manuscript is a review of current protocols, advantages, and disadvantages of breeding mares with frozen-thawed equine semen. Issues affecting pregnancy rates are discussed, including proper mare selection, induction of ovulation, insemination dose, timing of insemination (single-dose versus multiple-dose insemination), methods of insemination (transrectal-guided deep-horn versus hysteroscopic insemination), and post-insemination mare management procedures. In a retrospective analysis of breeding records, a single-dose of frozen-thawed semen was inseminated within 6h post-ovulation; the pregnancy rate (14-16 days after AI) was 67 of 149 (45%). These results were comparable to those previously achieved under commercial conditions, as well as previous studies using multiple doses of frozen-thawed semen per estrous cycle. In conclusion, these data provided evidence that, with appropriate breeding management, an acceptable pregnancy rate can be achieved in mares with a single-dose of frozen-thawed semen (per-cycle) inseminated within 6h after ovulation.


Asunto(s)
Caballos/fisiología , Preservación de Semen/métodos , Semen/fisiología , Animales , Congelación , Masculino , Espermatozoides/citología , Espermatozoides/fisiología
5.
Emerg Med J ; 25(8): 492-7, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18660397

RESUMEN

OBJECTIVES: To describe the presenting characteristics and risk stratification of patients presenting to the emergency department with chest pain who have a normal initial troponin level followed by a raised troponin level within 12 h (evolving myocardial infarction (EMI)). METHODS: Data from the Internet Tracking Registry for Acute Coronary Syndromes (i*trACS), a registry of patients presenting with undifferentiated chest pain, were used. This analysis included patients without ST segment elevation with at least two troponin assay results < or = 12 h apart. Patients were stratified into three groups: EMI (initial troponin assay negative, second troponin assay positive), non-ST elevation myocardial infarction (NSTEMI) (initial troponin assay positive) and no MI (all troponin assays negative). RESULTS: Of 4136 eligible patients, 5% had EMI, 8% had NSTEMI and 87% had no MI. Patients with EMI were more similar to those with NSTEMI than those with no MI with respect to demographic characteristics, presentation, admission patterns and revascularisation. The initial ECG in patients with EMI was most commonly non-diagnostic (51%), but physicians' initial impressions commonly reflected MI, unstable angina or high-risk chest pain (76%). This risk assessment was followed by a high rate of critical care admissions (32%) and revascularisation (percutaneous coronary intervention 17%) among patients with EMI. CONCLUSION: Patients with EMI appear similar at presentation to those with NSTEMI. Patients with EMI are perceived as being at high risk, evidenced by similar diagnostic impressions, admission practices and revascularisation rates to patients with NSTEMI.


Asunto(s)
Angina de Pecho/etiología , Infarto del Miocardio/diagnóstico , Adolescente , Adulto , Factores de Edad , Electrocardiografía , Servicio de Urgencia en Hospital/estadística & datos numéricos , Tratamiento de Urgencia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Medición de Riesgo , Factores Sexuales , Troponina/metabolismo
6.
J Environ Qual ; 36(5): 1260-5, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17636286

RESUMEN

To determine whether the soil Mycobacterium isolate KMS would mineralize pyrene under rhizosphere conditions, a microcosm system was established to collect radioactive carbon dioxide released from the labeled polycyclic aromatic hydrocarbon. Microcosms were designed as sealed, flow-through systems that allowed the growth of plants. Experiments were conducted to evaluate mineralization of 14C-labeled pyrene in a sand amended with the polycyclic aromatic hydrocarbons degrading Mycobacterium isolate KMS, barley plants, or barley plants with roots colonized by isolate KMS. Mineralization was quantified by collecting the 14CO2 produced from 14C-labeled pyrene at intervals during the 10-d incubation period. Roots and foliar tissues were examined for 14C incorporation. Mass balances for microcosms were determined through combustion of sand samples and collection and quantification of 14CO2 evolved from radiolabeled pyrene. No pyrene mineralization was observed in the sterile control systems. Greater release of 14CO2 was observed in the system with barley colonized by KMS than in microcosms containing just the bacterium inoculum or sterile barley plants. These findings suggest that phytostimulation of polycyclic aromatic hydrocarbons mineralization could be applied in remediation schemes.


Asunto(s)
Hordeum/microbiología , Mycobacterium/metabolismo , Pirenos/química , Biodegradación Ambiental , Dióxido de Carbono/análisis , Raíces de Plantas/microbiología , Hidrocarburos Policíclicos Aromáticos/química , Hidrocarburos Policíclicos Aromáticos/metabolismo , Pirenos/metabolismo , Contaminantes del Suelo , Factores de Tiempo
7.
J Vet Intern Med ; 30(4): 1338-43, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27296082

RESUMEN

BACKGROUND: Despite the paucity of data available, stall-side serum amyloid (SAA) assays are commonly used to make diagnostic and treatment decisions in foals with bronchopneumonia. HYPOTHESIS: Measurement of SAA concentrations can accurately differentiate pneumonic from healthy foals. ANIMALS: Fifty-four pneumonic foals between 3 weeks and 5 months of age were compared to 44 healthy controls. In addition, 47 foals on a farm endemic for R. equi infections were studied. METHODS: Serum samples were collected from pneumonic foals at hospital admission. Foals were categorized as having pneumonia caused by R. equi or by other microorganisms based on culture of a tracheobronchial aspirate. In addition, serum samples were obtained at 2-week intervals from foals born at a farm endemic for R. equi. SAA concentrations were measured by a point-of-care assay. Diagnostic performance of SAA was assessed by use of receiver operating characteristic curves. RESULTS: Concentrations of SAA in foals with bronchopneumonia were significantly (P < 0.001) higher than those of healthy foals, but 15 of 54 pneumonic foals (28%) had SAA concentrations <5 µg/mL. There was no correlation between SAA concentrations and radiographic score in foals with R. equi pneumonia. The ability of SAA to predict development of R. equi pneumonia at the endemic farm was limited with a sensitivity of 64% and a specificity of 77%. CONCLUSION AND CLINICAL IMPORTANCE: Overall, SAA concentrations are significantly higher in pneumonic than in healthy foals. However, performance of SAA in detecting pneumonic foals is limited by the high proportion of false-positive and false-negative results.


Asunto(s)
Infecciones Bacterianas/veterinaria , Bronconeumonía/veterinaria , Enfermedades de los Caballos/sangre , Sistemas de Atención de Punto , Proteína Amiloide A Sérica/metabolismo , Animales , Infecciones Bacterianas/sangre , Infecciones Bacterianas/diagnóstico , Bronconeumonía/sangre , Bronconeumonía/diagnóstico , Estudios de Casos y Controles , Caballos , Sensibilidad y Especificidad
8.
Arch Intern Med ; 161(13): 1653-9, 2001 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-11434798

RESUMEN

BACKGROUND: Although hypoglycemia is the most common complication of intensive diabetes therapy, there is little information about risk factors for hypoglycemia in patients with type 2 diabetes mellitus. OBJECTIVE: To determine the prevalence and predisposing factors for hypoglycemia in patients with type 2 diabetes. METHODS: Retrospective, cross-sectional analysis set in an outpatient specialty diabetes clinic. We included those patients who had baseline and follow-up visits from April 1 through October 31, 1999. Hypoglycemia was defined as typical symptoms relieved by eating, and/or blood glucose level of less than 60 mg/dL (<3.3 mmol/L). Univariate and multivariate logistic regression were used to determine the contributions to hypoglycemia of age, sex, diabetes duration, body mass index (calculated as weight in kilograms divided by the square of height in meters), fasting plasma glucose level, glycosylated hemoglobin (HbA(1c)) level, type of therapy, and previous episodes at the follow-up visit. RESULTS: We studied 1055 patients. Prevalence of hypoglycemic symptoms was 12% (9/76) for patients treated with diet alone, 16% (56/346) for those using oral agents alone, and 30% (193/633) for those using any insulin (P<.001). Severe hypoglycemia occurred in only 5 patients (0.5%), all using insulin. Multiple logistic regression analysis demonstrated that insulin therapy, lower HbA(1c) level at follow-up, younger age, and report of hypoglycemia at the baseline visit were independently associated with increased prevalence of hypoglycemia. There were no significant predictors of severe hypoglycemia. CONCLUSIONS: Mild hypoglycemia is common in patients with type 2 diabetes undergoing aggressive diabetes management, but severe hypoglycemia is rare. Concerns about hypoglycemia should not deter efforts to achieve tight glycemic control in most patients with type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/terapia , Dieta para Diabéticos , Hipoglucemia/etiología , Hipoglucemiantes/efectos adversos , Glucemia , Índice de Masa Corporal , Estudios Transversales , Femenino , Georgia/epidemiología , Hemoglobina Glucada , Humanos , Hipoglucemia/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Factores de Riesgo
9.
Arch Intern Med ; 161(10): 1295-300, 2001 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-11371257

RESUMEN

BACKGROUND: It is commonly believed that good glycemic control is hard to achieve in patients with diabetes mellitus and concurrent chronic illnesses. OBJECTIVE: To determine the impact of comorbidity on glycemic control at presentation and subsequent follow-up in patients with type 2 diabetes. METHODS: We studied 654 consecutive patients who presented to a diabetes clinic in 1997. Comorbidity was rated using the Chronic Disease Score (CDS) index, which is a validated, weighted score that takes into account the patient's age, sex, and classes of medications. Univariate and multivariate linear regressions were used to determine the contribution of age, body mass index (calculated as weight in kilograms divided by the square of height in meters), diabetes duration, type of therapy, and CDS to initial hemoglobin A(1c) (HbA(1c)) level. A similar analysis was performed for the 169 patients with follow-up HbA(1c) levels 6 months after presentation. RESULTS: Patients were 90% African American, and 66% female, with average age of 53 years. Average diabetes duration was 5 years; body mass index, 33; HbA(1c) level, 8.8%; and CDS, 1121 (range, 232-7953). At presentation, patients with higher CDSs tended to be older and to have a lower HbA(1c) level, but multivariate linear regression showed that receiving pharmacological therapy, younger age, and having a lower C-peptide level were the only significant contributors to HbA(1c) level. In the 169 follow-up patients, presenting characteristics were not significantly different from those of the full cohort: average initial HbA(1c) level was 8.8%; CDS, 1073. Their HbA(1c) level at 6 months averaged 7.5% and the CDS had no significant impact on their follow-up HbA(1c) level. CONCLUSION: Comorbidity does not appear to limit achievement of good glycemic control in patients with type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Hemoglobina Glucada/análisis , Hipoglucemiantes/uso terapéutico , Distribución por Edad , Glucemia/análisis , Enfermedades Cardiovasculares/epidemiología , Enfermedad Crónica , Comorbilidad , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/metabolismo , Angiopatías Diabéticas/epidemiología , Neuropatías Diabéticas/epidemiología , Femenino , Estudios de Seguimiento , Enfermedades Gastrointestinales/epidemiología , Humanos , Infecciones/epidemiología , Modelos Lineales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Obesidad/epidemiología , Prevalencia , Medición de Riesgo , Sensibilidad y Especificidad , Distribución por Sexo , Estadísticas no Paramétricas
10.
Diabetes Care ; 23(4): 444-8, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10857932

RESUMEN

OBJECTIVE: To determine whether American Diabetes Association (ADA) guidelines can be met in the context of routine endocrinology practice. RESEARCH DESIGN AND METHODS: Charts were reviewed for a group of patients who were examined in 1998, followed for > or = 1 year, and had two or more visits during that year. Process measures and metabolic outcomes were studied for patients with type 2 diabetes, and glycemic control was assessed for patients with type 1 diabetes. RESULTS: A total of 121 patients with type 2 diabetes had a mean age of 63 years, a mean BMI of 31 kg/m2, and a mean duration of diabetes of 12 years. Many had comorbidities or complications: 80% had hypertension, 64% had hyperlipidemia, 78% had neuropathy, 22% had retinopathy, and 21% had albuminuria. Management of type 2 diabetic patients was complex: 38% used oral hypoglycemic agents alone (54% of these were using two or more agents), 31% used oral hypoglycemic agents and insulin, and 26% used insulin alone; 42% of patients taking insulin therapy injected insulin three or more times per day. Within 12 months, 74% of patients had dilated eye examinations, 70% had lipid profiles, and 55% had urine albumin screening. Of the patients, 87% had a foot examination at their last visit. Blood pressure levels averaged 133/72 mmHg, cholesterol levels averaged 4.63 mmol/l, triglyceride levels averaged 1.99 mmol/l, HDL cholesterol levels averaged 1.24 mmol/l, and LDL cholesterol levels averaged 2.61 mmol/l. Random blood glucose levels averaged 8.0 mmol/l, and HbAlc levels averaged 6.9 +/- 0.1%. A total of 87% of patients had HbAlc levels < or = 8.0%. A total of 30 patients with type 1 diabetes had mean age of 44 years, a mean BMI of 26 kg/m2, and a mean duration of diabetes of 20 years. All type 1 diabetic patients used insulin and averaged 3.4 injections a day; their average HbAlc level was 7.1 +/- 0.2%, and 80% had HbAlc levels < or = 8.0%. CONCLUSIONS: Although endocrinologists must manage patients with multifaceted problems, complex treatment regimens yield glycemic control levels comparable with the Diabetes Control and Complications Trial and allow ADA guidelines to be met in a routine practice setting.


Asunto(s)
Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus/terapia , Endocrinología/normas , Servicio Ambulatorio en Hospital/normas , Agencias Voluntarias de Salud , Análisis de Varianza , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Georgia , Hemoglobina Glucada/análisis , Hospitales Universitarios , Humanos , Hipoglucemiantes/uso terapéutico , Registros Médicos , Guías de Práctica Clínica como Asunto , Garantía de la Calidad de Atención de Salud , Control de Calidad , Estados Unidos
11.
Endocrinology ; 137(8): 3437-46, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8754772

RESUMEN

Direct transcriptional inhibition of the gene that encodes ovine FSH beta-subunit (oFSH beta) by 17 beta-estradiol (E2) has been previously demonstrated by our laboratory. To determine which cis-acting elements in the 5'-flanking region of this gene may be involved in E2 regulation, DNA constructs containing deletions of the 5'-end of the oFSH beta gene were fused to a luciferase reporter and tested in transient transfection assays. These oFSH beta-luciferase constructs and the human E2 receptor expression vector (HEO) were transfected into primary cultures of ovine pituitary cells and subsequently tested with E2. Expression of the largest oFSH beta-luciferase construct (-4741 to +759 of oFSH beta) was inhibited 50% by 20 nM E2. Repression was dependent upon cotransfection of estrogen receptor (HEO) and was E2 dose dependent, with an apparent ED50 similar to that of the positive control consensus estrogen-responsive element construct, ERETk-LUC (ED50 = 50 pM). Deletion studies indicated that sequences between- 105 and -84 bp are necessary for this repression. In addition, a synthetic nucleotide containing oFSH beta sequences from - 105 to -72 could direct E2-dependent repression of a heterologous thymidine kinase promoter that drives luciferase expression. Additional experiments showed that no tissue-specific elements were required for either basal expression or E2-directed transcriptional repression. Although there are no consensus DNA response elements for the estrogen receptor between -105 and +759 of the oFSH beta gene, cotransfection of a mutant E2 receptor lacking the DNA-binding domain (HE-11) failed to mediate E2-dependent inhibition. Gel retardation studies, using the oligonucleotide-containing oFSH beta sequences from -105 to -72, indicated no evidence of direct binding of the estrogen receptor to DNA from -105 to -72. The studies presented here indicate that transcriptional repression of the oFSH beta gene by E2 may be directed in vivo by 5'-flanking sequences between -105 and -72 of the oFSH beta gene. Furthermore, the data suggest that inhibition is mediated via E2 receptor-protein interactions with basal transcription factors that may bind to the -105/-72 DNA directly.


Asunto(s)
Estradiol/farmacología , Hormona Folículo Estimulante/genética , Transcripción Genética/efectos de los fármacos , Animales , Secuencia de Bases , Unión Competitiva , Bovinos/genética , ADN/metabolismo , Femenino , Hormona Folículo Estimulante/farmacología , Humanos , Sistemas de Información , Datos de Secuencia Molecular , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/farmacología , Regiones Promotoras Genéticas/efectos de los fármacos , Receptores de Estradiol/metabolismo , Ovinos , Porcinos/genética
12.
Gene ; 239(1): 129-35, 1999 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-10571042

RESUMEN

Genes from Pseudomonas putida (Pp), sodA, encoding manganese-superoxide dismutase (MnSOD) and, sodB, iron-superoxide dismutase (FeSOD) were cloned by hybridization with digoxigenin (dig)-labeled PCR products generated from Pp genomic DNA. The sodB gene had a 594 bp open reading frame (ORF), corresponding to 198 amino acids (aa), and a transcript of 880 bases. The sodA gene contained a 609 bp ORF encoding 203 aa and was transcribed as part of a polycistronic operon, consisting of orfY-fumC-orfX-sodA. Pp sodA or sodB genes both restored aerobic growth, growth on paraquat, and growth on minimal medium to an Escherichia coli (Ec) mutant deficient in SOD activity. Paraquat treatment did not enhance mRNA transcription of the sod genes or increase SOD activity in Pp. The Pp sodB gene was highly expressed throughout logarithmic-(log) growth phase and stationary-phase cells grown in medium supplemented with FeCl3, but was down-regulated in iron-deficient conditions, such as in stationary-phase or generated by 2,2'-dipyridyl (DP) treatment. This is the first evidence that iron regulates expression of the sodB gene at the transcriptional level. In contrast, iron-deficient conditions, or addition of MnCl2 to the growth medium, induced transcripts (2.4 kb and 1.2 kb) from the sodA operon. Our results reveal an intricate role of iron in the transcriptional regulation of both Pp sodA and sodB genes.


Asunto(s)
Hierro/farmacología , Pseudomonas putida/genética , Superóxido Dismutasa/genética , División Celular/efectos de los fármacos , Clonación Molecular , Medios de Cultivo/farmacología , ADN Bacteriano/química , ADN Bacteriano/genética , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Prueba de Complementación Genética , Isoenzimas/genética , Datos de Secuencia Molecular , Mutación , Paraquat/farmacología , Pseudomonas putida/citología , Pseudomonas putida/enzimología , Análisis de Secuencia de ADN , Transcripción Genética/efectos de los fármacos
13.
Gene ; 199(1-2): 219-24, 1997 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-9358059

RESUMEN

The catA gene, encoding the major CatA from a root-colonizing isolate Pseudomonas putida (Pp), was cloned by complementation into a catalase (Cat)-deficient Escherichia coli (Ec) strain UM2. The ORF for catA consisted of 479 aa with a higher degree of identity with typical Cat from eukaryotes than prokaryotes. Chromosomal homologous exchange with a mutant gene bearing an insertion of a luxAB-npt cassette into the SfiI site of catA generated a CatA-deficient Pp isolate. This mutant and another mutant, J1M, derived by EMS mutagenesis, were highly sensitive to hydrogen peroxide. CatA activity and resistance to hydrogen peroxide were restored in both mutants by catA. Adjacent to the 3' end of catA was a potential ORF of 462 nt that had high identitity with other bfr genes that encode iron-storage proteins. Northern analysis of the bfr gene from Pp revealed a transcript of approximately 500 nt. CatA and bfr probes hybridized to the same size restriction fragments in genomic DNAs from other root-colonizing and plant pathogenic pseudomonads. Thus, the genes for an iron-storage protein and the heme-containing Cat appear to be conserved in adjacent loci in certain pseudomonads.


Asunto(s)
Proteínas Bacterianas , Catalasa/genética , Grupo Citocromo b/genética , Ferritinas/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Pseudomonas putida/genética , Secuencia de Aminoácidos , Secuencia de Bases , Catalasa/metabolismo , Clonación Molecular , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Genes Bacterianos/genética , Prueba de Complementación Genética , Peróxido de Hidrógeno/farmacología , Datos de Secuencia Molecular , Mutagénesis Insercional , Raíces de Plantas/microbiología , Pseudomonas/genética , Pseudomonas putida/enzimología , ARN Bacteriano/análisis , ARN Mensajero/análisis , Mapeo Restrictivo , Análisis de Secuencia de ADN
14.
Gene ; 247(1-2): 199-207, 2000 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-10773460

RESUMEN

The root-colonizing pseudomonad Pseudomonas putida (Pp) appears to produce two subunits, alpha and beta, of the iron-binding protein, bacterioferritin. A gene encoding the alpha-bacterioferritin subunit was located adjacent to the major catalase in Pp. The deduced protein sequence of the Pp bfralpha gene had a very high identity with other alpha-subunits, possessing conserved amino acids responsible for ferroxidase activity. The gene also lacked a deduced methionine at residue 52, associated with heme binding in beta-subunits. An antibody generated toward the Escherichia coli (E. coli) multifunctional single subunit bacterioferritin recognized two proteins in the Pp extract, a 22 kDa protein likely to be a beta-subunit and, to a lesser extent, a 23 kDa band. The 23 kDa band was absent in a Pp mutant in which the bfralpha gene was disrupted. Loss of alpha-bacterioferritin stimulated production of fluorescent siderophore. Growth on media and on root surfaces was not impaired by deletion of the alpha-bacterioferritin. Transcription of bfralpha was independent of the catalase gene and was dependent on iron. The transcript levels from bfralpha decreased in iron deficiency experienced during stationary-phase or upon treatment during growth with an iron chelator.


Asunto(s)
Ferritinas/genética , Pseudomonas putida/genética , Proteínas Bacterianas/genética , División Celular/efectos de los fármacos , División Celular/genética , Fabaceae/microbiología , Expresión Génica , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Hierro/farmacología , Luciferasas/genética , Luciferasas/metabolismo , Mutagénesis , Raíces de Plantas/microbiología , Plantas Medicinales , Pseudomonas putida/efectos de los fármacos , Pseudomonas putida/crecimiento & desarrollo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sideróforos/metabolismo , Transcripción Genética/efectos de los fármacos
15.
Gene ; 76(1): 1-9, 1989 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-2568315

RESUMEN

gamma-Glutamyl transpeptidase (GGT) is a glutathione-metabolizing enzyme that has been extensively studied in relation to hepatocarcinogenesis. Using a cDNA for rat kidney GGT as a probe, we have isolated a full-length cDNA for human GGT from a hepatoma cell-line library. Nucleotide sequence analysis of the clone revealed a 2326-bp insert that includes a 5'-untranslated region of 487 nucleotides (nt), an open reading frame (ORF) of 1707 nt, and a 3'-untranslated region of 132 nt. The ORF encodes a protein with an amino acid sequence that is highly similar to that of the rat GGT precursor peptide, with an overall identity of 79%. The cDNA clone was used to probe Northern blots of hepatoma and kidney RNA from both human and rat. In both species, the GGT mRNA is longer in hepatoma than in kidney. In addition, the human mRNAs were longer than their counterparts in the rat. None of three human hepatocellular carcinomas examined showed a marked elevation in GGT mRNA levels relative to surrounding liver tissue.


Asunto(s)
Carcinoma Hepatocelular/enzimología , ADN/aislamiento & purificación , Riñón/enzimología , Neoplasias Hepáticas/enzimología , ARN Mensajero/aislamiento & purificación , gamma-Glutamiltransferasa/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Southern Blotting , Células Cultivadas , ADN/genética , Sondas de ADN , Humanos , Hígado/citología , Hígado/enzimología , Datos de Secuencia Molecular , ARN Mensajero/genética , Ratas , Mapeo Restrictivo
16.
Mayo Clin Proc ; 71(8): 757-62, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8691896

RESUMEN

OBJECTIVE: To determine the quantitative effects of a corrective rearfoot orthotic device on the vertical, anteroposterior, and mediolateral ground reaction forces (GRFs) during ambulation. DESIGN: We conducted a prospective, randomized, single-blinded study of 25 subjects during ambulation with and without a rearfoot orthotic device. MATERIAL AND METHODS: Thirteen men and 12 women were enrolled in the study; the inclusion criteria included asymptomatic pes planus (5 to 10 degrees of calcaneal eversion). Each subject walked across a standard force plate in 10 trials without an orthotic device. The force plate was used to quantify the effect of a semirigid functional rearfoot orthotic device on GRFs and the center of pressure versus a standard shoe with no device. The observer was blinded, trials were completed in random order, and the paired t test was used for statistical analysis. RESULTS: No evidence suggested the presence of a significant difference in mediolateral GRFs and in the center of pressure exerted at 10%, 20%, 50%, and 80% of stance phase with and without the orthotic device. Significant reductions were noted in vertical GRFs per newton of body weight exerted at 10% (P = 0.0009) and 20% (P = 0.0383) of stance phase and in anteroposterior GRFs exerted at 10% (P = 0.0009) and 50% (P = 0.0033) of stance phase when ambulation was compared with and without the orthotic device. CONCLUSION: These results indicate that a rearfoot orthotic device reduces vertical and anteroposterior GRFs in the early stages of the stance phase during the gait cycle. We found no evidence to suggest a significant difference at any of the percent stance phases when comparisons were made of mediolateral GRFs exerted with and without the orthotic device. These data are contrary to current hypotheses about use of orthotic devices, and further studies would be helpful to reproduce these findings and to determine whether these changes are related to clinical improvement in symptomatic pes planus.


Asunto(s)
Pie Plano/fisiopatología , Pie/fisiología , Aparatos Ortopédicos , Caminata/fisiología , Adolescente , Adulto , Femenino , Pie Plano/rehabilitación , Humanos , Masculino , Estudios Prospectivos , Soporte de Peso/fisiología
17.
DNA Cell Biol ; 10(8): 593-601, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1930694

RESUMEN

Follicle-stimulating hormone (FSH), the primary stimulus for egg and sperm maturation in mammals, is an alpha/beta heterodimer. Each subunit is encoded by a single-copy gene in the human, bovine, and rat genomes. Transcription of both subunits is inhibited by estradiol and progesterone in ovine pituitary cultures. We report the sequence of one ovine FSH-beta gene (-1,527 to +3,664) that is expressed in vivo and the identification of a novel, second ovine FSH-beta-like sequence. Digestion of ovine genomic DNA with Bgl II yielded two fragments of 10 kb and 15 kb that hybridized to a bovine FSH-beta cDNA. The 10-kb fragment contained 6 kb of 5'-flanking region and all but about 200 bp of the 3' terminus of the ovine FSH-beta gene. This FSH-beta gene encodes a protein that differs from the published ovine protein sequence only at the carboxy terminus (Arg-109Glu-110[STOP codon] instead of Glu-109Arg-110[Glx-111]) and at positions 49 (Ala instead of Thr) and 88 (Arg instead of Ser). This gene is organized similarly to the human, bovine, porcine, and rat FSH-beta genes, and its coding sequence is nearly identical (99.5%) to a reported ovine FSH-beta cDNA. Expression of the FSH-beta gene on the 10-kb fragment in vivo was determined by analysis of wether mRNA using the polymerase chain reaction. A 95-bp sequence of the 15-kb fragment was 87% homologous to the corresponding coding region of the 10-kb fragment. This comparison suggested that the 15-kb fragment contains either an FSH-beta-like sequence or a pseudogene. Several potential steroid response elements were found by sequence analysis of the 5'-flanking region of the FSH-beta gene on the 10-kb fragment. A mechanism by which these elements may act is suggested.


Asunto(s)
Hormona Folículo Estimulante/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Southern Blotting , Bovinos , Células Cultivadas , ADN/genética , Datos de Secuencia Molecular , Adenohipófisis/citología , Regiones Promotoras Genéticas , Seudogenes , ARN Mensajero/genética , Secuencias Reguladoras de Ácidos Nucleicos , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico , Ovinos , Transcripción Genética
18.
Photochem Photobiol ; 74(5): 734-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11723803

RESUMEN

The entomopathogenic hyphomycete Metarhizium anisopliae has been used in programs of agricultural pest and disease vector control in several countries. Exposure to simulated solar radiation for a few hours can completely inactivate the conidia of the fungus. In the present study we determined the effect of exposures to full-spectrum sunlight and to solar ultraviolet A radiation at 320-400 nm (UVA) on the conidial culturability and germination of three M. anisopliae strains. The exposures were performed in July and August 2000 in Logan, UT. The strains showed wide variation in tolerance when exposed to full-spectrum sunlight as well as to UVA sunlight. Four-hour exposures to full-spectrum sunlight reduced the relative culturability by approximately 30% for strain ARSEF 324 and by 100% for strains ARSEF 23 and 2575. The relative UV sensitivity of the two more sensitive strains was different under solar UV from that under ultraviolet B radiation at 280-320 nm (UVB) in the laboratory. Four-hour exposures to solar UVA reduced the relative culturability by 10% for strain ARSEF 324, 40% for strain ARSEF 23 and 60% for strain ARSEF 2575. Exposures to both full-spectrum sunlight and UVA sunlight delayed the germination of the surviving conidia of all three strains. These results, in addition to confirming the deleterious effects of UVB, clearly demonstrate the negative effects of UVA sunlight on the survival and germination of M. anisopliae conidia under natural conditions. The negative effects of UVA in sunlight also emphasize that the biological spectral weighting functions for this fungus must not neglect the UVA wavelengths.


Asunto(s)
Hongos Mitospóricos/efectos de la radiación , Luz Solar , Rayos Ultravioleta , Relación Dosis-Respuesta en la Radiación , Hongos Mitospóricos/crecimiento & desarrollo , Factores de Tiempo
19.
Mutat Res ; 237(2): 75-81, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2164149

RESUMEN

We studied the repair of a plasmid vector containing the chloramphenicol acetyltransferase (CAT) gene by treating the plasmid with UV light and then transfecting this plasmid into fibroblasts from human fetal lung (in vitro aging) and into primary cultured fibroblasts from rat lung and skin. This methodology allows us to examine the repair of specific transcribed DNA sequences. There was no age-related change in the repair of UV damage in these cells. Rat embryo fibroblasts at different passages transfected with the plasmid also revealed no significant alteration in UV repair as a function of passage number.


Asunto(s)
Envejecimiento/genética , Daño del ADN , Reparación del ADN/fisiología , Transcripción Genética/genética , Animales , Línea Celular , Cloranfenicol O-Acetiltransferasa/genética , Vectores Genéticos , Humanos , Regiones Promotoras Genéticas , Ratas , Ratas Endogámicas , Virus 40 de los Simios/genética , Transfección , Rayos Ultravioleta
20.
Mutat Res ; 237(1): 37-43, 1990 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2320038

RESUMEN

DNA fingerprinting can be utilized to examine a large number of autosomal loci throughout the human genome. Alterations in banding patterns observed on DNA fingerprint analyses reflect DNA alterations ranging from single base changes to complex chromosomal rearrangements. In this report, we describe the application of this technique to prostatic adenocarcinoma (CAP) and benign prostatic hyperplasia (BPH). The majority of CAP cases (12 of 14) displayed alterations in at least 1 of the approximately 30 resolvable bands obtained by fingerprint analyses when compared with DNA obtained from peripheral white blood cells. Unexpectedly, 5 of the 12 cases of BPH examined revealed at least 1 identifiable band alteration in the prostatic tissue. These findings demonstrate the usefulness of fingerprint analyses in the examination of cancer-associated genetic alterations. They also suggest the presence of observable genetic alterations in BPH.


Asunto(s)
Adenocarcinoma/genética , ADN de Neoplasias/genética , Próstata/patología , Neoplasias de la Próstata/genética , Southern Blotting , Sondas de ADN , Humanos , Hiperplasia , Masculino , Mapeo Nucleótido
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