Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Ann Oncol ; 27(4): 706-11, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26658889

RESUMEN

BACKGROUND: Patients with metastatic renal carcinoma (mRCC) treated with first-line pazopanib were not included in the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) prognostic model. SPAZO (NCT02282579) was a nation-wide retrospective observational study designed to assess the effectiveness and validate the IMDC prognostic model in patients treated with first-line pazopanib in clinical practice. PATIENTS AND METHODS: Data of 278 patients, treated with first-line pazopanib for mRCC in 34 centres in Spain, were locally recorded and externally validated. Mean age was 66 years, there were 68.3% male, 93.5% clear-cell type, 74.8% nephrectomized, and 81.3% had ECOG 0-1. Metastatic sites were: lung 70.9%, lymph node 43.9%, bone 26.3%, soft tissue/skin 20.1%, liver 15.1%, CNS 7.2%, adrenal gland 6.5%, pleura/peritoneum 5.8%, pancreas 5%, and kidney 2.2%. After median follow-up of 23 months, 76.4% had discontinued pazopanib (57.2% due to progression), 47.9% had received second-line targeted therapy, and 48.9% had died. RESULTS: According to IMDC prognostic model, 19.4% had favourable risk (FR), 57.2% intermediate risk (IR), and 23.4% poor risk (PR). No unexpected toxicities were recorded. Response rate was 30.3% (FR: 44%, IR: 30% PR: 17.3%). Median progression-free survival (whole population) was 11 months (32 in FR, 11 in IR, 4 in PR). Median and 2-year overall survival (whole population) were 22 months and 48.1%, respectively (FR: not reached and 81.6%, IR: 22 and 48.7%, PR: 7 and 18.8%). These estimations and their 95% confidence intervals are fully consistent with the outcomes predicted by the IMDC prognostic model. CONCLUSION: Our results validate the IMDC model for first-line pazopanib in mRCC and confirm the effectiveness and safety of this treatment.


Asunto(s)
Carcinoma de Células Renales/tratamiento farmacológico , Terapia Molecular Dirigida , Pronóstico , Pirimidinas/administración & dosificación , Sulfonamidas/administración & dosificación , Adulto , Anciano , Carcinoma de Células Renales/patología , Bases de Datos Factuales , Supervivencia sin Enfermedad , Femenino , Humanos , Indazoles , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Pirimidinas/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , España , Sulfonamidas/efectos adversos
2.
Europace ; 15(8): 1210-4, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23478089

RESUMEN

AIMS: The Calgary Syncope Symptom Score (CSSS) has been validated as a simple point score of historical features with high sensitivity and specificity for the diagnosis of vasovagal syncope (VVS) in younger populations without evidence of structural heart disease. Our purpose was to evaluate the performance of the CSSS in an elderly population with suspected VVS. METHODS AND RESULTS: Hundred and eighty patients of ≥60 years of age (mean 73.4 ± 7.8) with suspected clinical diagnosis of VVS were studied. The CSSS (VVS score ≥-2) was calculated in all patients prior to undergoing head-up tilt test (HUT). A standardized HUT protocol with active nitroglycerin phase was used to reproduce syncopal symptoms as gold standard for diagnosis of VVS. Hundred and forty patients had positive HUT response. Eighty-three patients (42.3%) had CSSS ≥-2 suggesting a diagnosis of VVS. The Calgary Syncope Symptom Score sensitivity was 0.51 [95% confidence interval (CI) 0.42-0.59] and specificity 0.73 (95% CI 0.52-0.85) with positive predictive value and negative predictive value of 0.87 (95% CI 0.77-0.93) and 0.30 (95% CI 0.21-0.40), respectively. One hundred (55.6%) patients had previous history of mild cardiovascular disease documented during assessment prior to HUT. In this population sensitivity and specificity was markedly reduced: 0.13 (95% CI 0.05-0.29) and 0.70 (95% CI 0.57-0.80), respectively. CONCLUSION: The CSSS has a lower sensitivity and specificity in an elderly population presenting with syncope compared to previously validated data in young adults, particularly in elderly patients with previous history of mild cardiovascular disease. A modified CSSS may be needed to improve specificity and sensitivity in this population.


Asunto(s)
Nitroglicerina , Índice de Severidad de la Enfermedad , Síncope Vasovagal/diagnóstico , Pruebas de Mesa Inclinada/métodos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ontario/epidemiología , Prevalencia , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y Especificidad , Vasodilatadores
3.
Heliyon ; 8(6): e09744, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35770151

RESUMEN

Nicotine (NIC) and resveratrol (RES) are chemicals in tobacco and wine, respectively, that are widely consumed concurrently worldwide. NIC is an alkaloid known to be toxic, addictive and to produce oxidative stress, while RES is thought of as an antioxidant with putative health benefits. Oxidative stress can induce genotoxic damage, yet few studies have examined whether NIC is genotoxic in vivo. In vitro studies have shown that RES can ameliorate deleterious effects of NIC. However, RES has been reported to have both antioxidant and pro-oxidant effects, and an in vivo study reported that 0.011 mM RES was genotoxic. We used the Drosophila melanogaster wing spot test to determine whether NIC and RES, first individually and then in combination, were genotoxic and/or altered the cell division. We hypothesized that RES would modulate NIC's effects. NIC was genotoxic in the standard (ST) cross in a concentration-independent manner, but not genotoxic in the high bioactivation (HB) cross. RES was not genotoxic in either the ST or HB cross at the concentrations tested. We discovered a complex interaction between NIC and RES. Depending on concentration, RES was protective of NIC's genotoxic damage, RES had no interaction with NIC, or RES had an additive or synergistic effect, increasing NIC's genotoxic damage. Most NIC, RES, and NIC/RES combinations tested altered the cell division in the ST and HB crosses. Because we used the ST and HB crosses, we demonstrated that genotoxicity and cell division alterations were modulated by the xenobiotic metabolism. These results provide evidence of NIC's genotoxicity in vivo at specific concentrations. Moreover, NIC's genotoxicity can be modulated by its interaction with RES in a complex manner, in which their interaction can lead to either increasing NIC's damage or protecting against it.

4.
Neurologia (Engl Ed) ; 36(3): 191-200, 2021 Apr.
Artículo en Inglés, Español | MEDLINE | ID: mdl-29525397

RESUMEN

Parkinson's disease (PD) is characterised by motor alterations, which are commonly treated with L-DOPA. However, long-term L-DOPA use may cause dyskinesia. Although the pathogenic mechanism of L-DOPA-induced dyskinesia is unclear, the condition has been associated with alterations in dopamine receptors, among which D2 receptors (D2R) have received little attention. This study aims to: (i)develop and standardise an experimental model of L-DOPA-induced dyskinesia in rats with hemiparkinsonism; and (ii)evaluate the correlation between D2R expression and presence of abnormal involuntary movements (AIM). We allocated 21 male Wistar rats into 3 groups: intact controls, lesioned rats (with neurotoxin 6-OHDA), and dyskinetic rats (injected with L-DOPA for 19 days). Sensorimotor impairment was assessed with behavioural tests. Dyskinetic rats gradually developed AIMs during the treatment period; front leg AIMs were more severe and locomotor AIMs less severe (P<.05). All AIMs were significantly evident from day 5 and persisted until the last day of injection. D2R density was greater in the striatum and the medial anterior brain of the lesioned and dyskinetic rats than in those of controls. Our results suggest an association between D2R expression and locomotor AIMs. We conclude that RD2 is involved in L-DOPA-induced dyskinesia.


Asunto(s)
Discinesia Inducida por Medicamentos , Enfermedad de Parkinson , Animales , Discinesia Inducida por Medicamentos/etiología , Levodopa/efectos adversos , Masculino , Oxidopamina/toxicidad , Ratas , Ratas Sprague-Dawley , Ratas Wistar
5.
Mol Cell Biol ; 17(11): 6283-93, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9343389

RESUMEN

The dimorphic fungus Yarrowia lipolytica grows to form hyphae either in rich media or in media with GlcNAc as a carbon source. A visual screening, called FIL (filamentation minus), for Y. lipolytica yeast growth mutants has been developed. The FIL screen was used to identify three Y. lipolytica genes that abolish hypha formation in all media assayed. Y. lipolytica HOY1, a gene whose deletion prevents the yeast-hypha transition both in liquid and solid media, was characterized. HOY1 is predicted to encode a 509-amino-acid protein with a homeodomain homologous to that found in the chicken Hox4.8 gene. Analysis of the protein predicts a nuclear location. These observations suggest that Hoy1p may function as a transcriptional regulatory protein. In disrupted strains, reintroduction of HOY1 restored the capacity for hypha formation. Northern blot hybridization revealed the HOY1 transcript to be approximately 1.6 kb. Expression of this gene was detected when Y. lipolytica grew as a budding yeast, but an increase in its expression was observed by 1 h after cells had been induced to form hyphae. The possible functions of HOY1 in hyphal growth and the uses of the FIL screen to identify morphogenetic regulatory genes from heterologous organisms are discussed.


Asunto(s)
Proteínas Fúngicas , Genes Fúngicos , Genes Homeobox , Proteínas de Homeodominio/genética , Saccharomycetales/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Cruzamientos Genéticos , Eliminación de Gen , Expresión Génica , Prueba de Complementación Genética , Proteínas de Homeodominio/biosíntesis , Datos de Secuencia Molecular , Morfogénesis/genética , Mutación , Hibridación de Ácido Nucleico , Proteínas Recombinantes/biosíntesis , Secuencias Reguladoras de Ácidos Nucleicos , Saccharomyces cerevisiae/genética , Saccharomycetales/citología , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Factores de Transcripción/genética
6.
Can J Gastroenterol ; 21(11): 721-6, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18026575

RESUMEN

BACKGROUND: Distension and electrical stimuli in the esophagus alter heart rate variability (HRV) consistent with activation of vagal afferent and efferent pathways. Sham feeding stimulates gastric acid secretion by means of vagal efferent pathways. It is not known, however, whether activation of vagal efferent pathways is organ- or stimulus-specific. OBJECTIVE: To test the hypothesis that sham feeding increases the high frequency (HF) component of HRV, indicating increased neurocardiac vagal activity in association with the known, vagally mediated, increase in gastric acid secretion. METHODS: Continuous electrocardiography recordings were obtained in 12 healthy, semirecumbent subjects during consecutive 45 min baseline, 20 min sham feeding (standard hamburger meal) and 45 min recovery periods. The R-R intervals and beat-to-beat heart rate signal were determined from digitized electrocardiography recordings; power spectra were computed from the heart rate signal to determine sympathetic (low frequency [LF]) and vagal (HF) components of HRV. RESULTS: Heart rate increased during sham feeding (median 70.8 beats/min, 95% CI 66.0 to 77.6; P<0.001), compared with baseline (63.6, 95% CI 60.8 to 70.0) and returned to baseline levels within 45 min. Sham feeding increased the LF to HF area ratio (median: 1.55, 95% C.I 1.28 to 1.77; P<0.021, compared with baseline (1.29, 95% CI 1.05 to 1.46); this increase in LF to HF area ratio was associated with a decrease in the HF component of HRV. CONCLUSIONS: Sham feeding produces a reversible increase in heart rate that is attributable to a decrease in neurocardiac parasympathetic activity despite its known ability to increase vagally mediated gastric acid secretion. These findings suggest that concurrent changes in cardiac and gastric function are modulated independently by vagal efferent fibres and that vagally mediated changes in organ function are stimulus- and organ-specific.


Asunto(s)
Ingestión de Alimentos/fisiología , Frecuencia Cardíaca/fisiología , Corazón/inervación , Sistema Nervioso Parasimpático/fisiología , Nervio Vago/fisiología , Adulto , Vías Eferentes/fisiología , Electrocardiografía , Femenino , Ácido Gástrico/metabolismo , Humanos , Masculino , Especificidad de Órganos , Placebos
7.
FEMS Microbiol Rev ; 25(3): 335-47, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11348688

RESUMEN

Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and plant variants able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms, and probably by plants, include biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux. Some of these systems have been proposed as potential biotechnological tools for the bioremediation of Cr pollution. In this review we summarize the interactions of bacteria, algae, fungi and plants with Cr and its compounds.


Asunto(s)
Cromo/farmacología , Contaminantes Ambientales/toxicidad , Secuencia de Aminoácidos , Bacterias/efectos de los fármacos , Biodegradación Ambiental , Cromo/análisis , Cromo/química , Cromo/farmacocinética , Cromo/toxicidad , Microbiología Ambiental , Contaminantes Ambientales/análisis , Eucariontes/efectos de los fármacos , Hongos/efectos de los fármacos , Datos de Secuencia Molecular , Plantas/efectos de los fármacos
8.
Neurología (Barc., Ed. impr.) ; 36(3): 191-200, abril 2021. ilus, tab, graf
Artículo en Español | IBECS (España) | ID: ibc-219730

RESUMEN

La enfermedad de Parkinson (EP) se caracteriza por una serie de deficiencias motoras que son tratadas comúnmente con L-DOPA; sin embargo, tras un uso crónico se desarrollan disquinesias inducidas por L-DOPA (DIL). Por otra parte, el origen de las DIL no está del todo claro, pero se asocia con alteración en receptores dopaminérgicos, donde los receptores D2 (RD2) han sido poco estudiados. El presente trabajo buscó: 1) desarrollar y estandarizar un modelo experimental de disquinesia con L-DOPA en ratas hemiparkinsonizadas, y 2) evaluar la correlación entre la expresión del RD2 y la manifestación de movimientos involuntarios anormales (MIA). Se utilizaron 21 ratas Wistar macho asignadas a 3 grupos: control intacto, lesionados (con la neurotoxina 6-OHDA) y lesionados disquinéticos (inyectados con L-DOPA durante 19 días). Los reactivos biológicos se sometieron a pruebas comportamentales para evaluar el deterioro sensoriomotor. Los animales del grupo disquinético desarrollaron de forma gradual MIA durante el tratamiento, siendo mayores los MIA de miembro anterior y menores los de tipo locomotor (p < 0,05). Todos los MIA fueron significativamente evidentes a partir del día 5 y se mantuvieron hasta el último día de inyección. Además, se pudo evidenciar incremento en la densidad del RD2 en el estriado y el cerebro anterior medial en los grupos lesionados con respecto al control, así como también una posible asociación entre la expresión del RD2 y MIA de tipo locomotor. Por lo que concluimos que el RD2 está implicado en el fenómeno disquinético generado con la L-DOPA. (AU)


Parkinson's disease (PD) is characterised by motor alterations, which are commonly treated with L-DOPA. However, long-term L-DOPA use may cause dyskinesia. Although the pathogenic mechanism of L-DOPA-induced dyskinesia is unclear, the condition has been associated with alterations in dopamine receptors, among which D2 receptors (D2R) have received little attention. This study aims to: (i) develop and standardise an experimental model of L-DOPA-induced dyskinesia in rats with hemiparkinsonism; and (ii) evaluate the correlation between D2R expression and presence of abnormal involuntary movements (AIM). We allocated 21 male Wistar rats into 3 groups: intact controls, lesioned rats (with neurotoxin 6-OHDA), and dyskinetic rats (injected with L-DOPA for 19 days). Sensorimotor impairment was assessed with behavioural tests. Dyskinetic rats gradually developed AIMs during the treatment period; front leg AIMs were more severe and locomotor AIMs less severe (P < .05). All AIMs were significantly evident from day 5 and persisted until the last day of injection. D2R density was greater in the striatum and the medial anterior brain of the lesioned and dyskinetic rats than in those of controls. Our results suggest an association between D2R expression and locomotor AIMs. We conclude that RD2 is involved in L-DOPA-induced dyskinesia. (AU)


Asunto(s)
Humanos , Animales , Discinesias , Enfermedad de Parkinson , Ratas , Preparaciones Farmacéuticas , Levodopa
9.
Biol Psychol ; 90(3): 179-85, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22504296

RESUMEN

BACKGROUND: Cardiac autonomic dysfunction has been proposed as an important contributing factor to the increased cardiovascular risk observed in major depression (MDD). However, the evidence regarding alterations in heart rate variability (HRV) in otherwise healthy depressed subjects has been inconclusive. METHODS: A case-control study in 50 treatment-naïve young adults with a first MDD episode without comorbid psychiatric disorders and 50 healthy control subjects was conducted. Time- and frequency-domain indexes of HRV were determined at baseline supine and after 5-min of orthostatic stress at 60°. RESULTS: There were no significant differences in the time- or frequency-domain variables of HRV between depressed patients and controls. However, a random-effect ANOVA model showed that during orthostatic stress depressed men had a reduced HRV and decreased parasympathetic activity compared to control subjects, while no differences were found between depressed women and controls. CONCLUSION: These results suggest a sex-dependent relationship between major depression and cardiac autonomic dysfunction and provide one potential explanation for sex differences in the association of depressive symptoms with cardiovascular morbidity.


Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Trastorno Depresivo Mayor/fisiopatología , Corazón/fisiopatología , Análisis de Varianza , Estudios de Casos y Controles , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Electrocardiografía , Femenino , Corazón/inervación , Frecuencia Cardíaca/fisiología , Hispánicos o Latinos , Humanos , Hipotensión Ortostática/fisiopatología , Modelos Lineales , Masculino , Análisis Multivariante , Examen Físico , Escalas de Valoración Psiquiátrica , Caracteres Sexuales , Posición Supina/fisiología , Adulto Joven
10.
Curr Med Chem ; 19(26): 4414-30, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22830343

RESUMEN

The increase in the therapeutic arsenal in the last 20 years, has given rise to changes in treating colorectal cancer (CRC) with only pyrimidines to combine several cytotoxic drugs. However, the present question is to determine the optimal sequence of this combination. This review presents an update of data on chemical and clinical features of chemotherapy used for colorectal cancer and the mechanisms of cellular resistance and potential predictive and prognostic biomarkers, which may contribute to a better selection of a therapeutic strategy.


Asunto(s)
Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Quimioterapia/tendencias , Humanos , Pronóstico
11.
Curr Microbiol ; 52(3): 178-81, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16502289

RESUMEN

Mucor circinelloides transformants prototrophic to leucine and resistant to carboxine (Leu(+) Cbx(r)) have been obtained by treatment of protoplasts with plasmid constructs containing homologous leuA gene and adjacent autonomously replicating sequences (ARS) element combined with the Cbx(r)(carboxine-resistance) gene of Ustilago maydis and ARS sequences from this basidiomycete (plasmid pGG37) or from the 2 mu plasmid of Saccharomyces cerevisiae (plasmid pGG43). The presence in the same plasmid molecule of the M. circinelloides leuA gene and adjacent ARS element together with heterologous ARS elements produced an increase in the transformation frequency of about 65-120%. The presence of autoreplicating plasmid molecules in the transformants was demonstrated by mitotic stability experiments, by Southern analysis, and by the rescue of plasmids from transformed bacterial cells.


Asunto(s)
Replicación del ADN/genética , Farmacorresistencia Fúngica/genética , Técnicas de Transferencia de Gen , Vectores Genéticos/genética , Mucor/genética , Transformación Genética/genética , Carboxina/farmacología , Genes Dominantes , Genes Fúngicos , Leucina/metabolismo , Mucor/efectos de los fármacos , Plásmidos/genética , Ustilago/genética
12.
Mol Genet Genomics ; 274(4): 354-63, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16179992

RESUMEN

NAD-dependent alcohol dehydrogenase (ADH) activity was detected mainly in the cytosol of aerobically cultured mycelium and in anaerobically grown yeast cells of Mucor circinelloides. ADH levels were about 2.5-fold higher in yeast cells than in mycelium; zymogram analysis suggested that the same ADH enzyme is produced in both developmental stages. The enzyme, named ADH1, was purified to homogeneity from yeast cells, using ion-exchange and affinity chromatography. The active ADH1 appears to be a homomeric tetramer of 37,500-kDa subunits. Km values obtained for acetaldehyde, ethanol, NADH and NAD+ indicated that in vivo the enzyme mainly serves to reduce acetaldehyde to ethanol. Amino acid sequences of internal peptides obtained from the purified ADH1 were used to design oligonucleotides that allowed the cloning of the corresponding cDNA by RT-PCR, and the characterization of the genomic DNA sequence. The adh1 ORF is interrupted by two small introns located towards the 5'-end. M. circinelloides adh1 encodes a protein of 348 amino acids, which display moderate to high overall identity to several hypothetical ADH enzymes from the related zygomycete Rhizopus oryzae. adh1 mRNA is expressed at similar levels in aerobic mycelium and anaerobic yeast cells. During exponential growth under aerobic conditions, the level of adh1 transcript was correlated with the glucose concentration in the growth medium.


Asunto(s)
Alcohol Deshidrogenasa/química , Alcohol Deshidrogenasa/genética , Mucor/enzimología , Mucor/genética , Acetaldehído/química , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Southern Blotting , Sistema Libre de Células , Cromatografía de Afinidad , Cromatografía por Intercambio Iónico , Clonación Molecular , Medios de Cultivo/metabolismo , Citosol/metabolismo , ADN/química , ADN Complementario/metabolismo , Electroforesis en Gel de Poliacrilamida , Etanol/química , Fermentación , Proteínas Fúngicas/química , Regulación Fúngica de la Expresión Génica , Biblioteca de Genes , Genes Fúngicos , Intrones , Cinética , Datos de Secuencia Molecular , Peso Molecular , NAD/química , NAD/metabolismo , Sistemas de Lectura Abierta , Péptidos/química , Filogenia , Isoformas de Proteínas , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rhizopus/metabolismo , Especificidad por Sustrato , Factores de Tiempo
13.
Rev Latinoam Microbiol ; 40(1-2): 45-52, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-10932734

RESUMEN

Arsenic resistance determinants from 42 environmental bacterial isolates (32 Gram negative) were analyzed by DNA: DNA hybridization using probes derived from Escherichia coli and Staphylococcus plasmid or chromosomal arsenic resistance (ars) genes. In colony hybridization assays, 11 and 1 Gram negative strains hybridized with the E. coli chromosome and plasmid probes, respectively. No hybridization was detected using a probe containing only the arsA (ATPase) gene from E. coli plasmid or with a Staphylococcus plasmid ars probe. From Southern hybridization tests of some of the positive strains it was concluded that homology to ars chromosomal genes occurred within chromosome regions, except in an E. coli isolate where hybridization occurred in both the chromosome and a 130-kb plasmid. Our results show that DNA sequences homologous to E. coli ars chromosomal genes are commonly present in the chromosomes of environmental arsenic-resistant Gram negative isolates.


Asunto(s)
Arsenicales/farmacología , Bacterias/genética , Proteínas Bacterianas , ADN Bacteriano/genética , Farmacorresistencia Microbiana/genética , Bombas Iónicas , Complejos Multienzimáticos , Factores R/genética , Microbiología del Suelo , Adenosina Trifosfatasas/genética , Arseniatos/farmacología , ATPasas Transportadoras de Arsenitos , Arsenitos/farmacología , Bacterias/efectos de los fármacos , Cromosomas Bacterianos/genética , Escherichia coli/genética , México , Hibridación de Ácido Nucleico , Contaminantes del Suelo/farmacología , Transactivadores/genética
14.
Curr Genet ; 26(2): 166-71, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8001172

RESUMEN

Three allyl-alcohol-resistant mutants were isolated in the dimorphic fungus Mucor rouxii and characterized with regard to their alcohol dehydrogenase (ADH) activity in vitro and in vivo as well as their ability to execute the morphological alternatives of dimorphism under different environmental stimuli, either in the absence or in the presence of oxygen. These studies indicated that fermentation and yeast-cell development are independent events and that ADH activity is essential for growth of the fungus in the absence of oxygen. Heterokaryon construction and analysis indicated that in the three mutant strains the corresponding genetic alterations are recessive nuclear mutations which behave as allelic in complementation tests.


Asunto(s)
Alcohol Deshidrogenasa/metabolismo , Etanol/metabolismo , Mucor/genética , Alcohol Deshidrogenasa/genética , Sistema Libre de Células , Fermentación , Genes Dominantes , Genes Fúngicos , Genes Recesivos , Cinética , Morfogénesis , Mucor/metabolismo , Mucor/fisiología , Mutagénesis , Fenotipo , Especificidad de la Especie , Levaduras
15.
Curr Microbiol ; 33(6): 390-2, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8900106

RESUMEN

We designed PCR primers by comparison of the deduced amino acid sequences of several ornithine decarboxylase (ODC) genes. They were used to amplify fragments homologous to these genes from several dimorphic fungi. These were sequenced and the deduced amino acid sequences were compared with the corresponding regions of ODCs from different sources. Fungal ODCs fell into a compact group, well separated from the ODCs of other taxa. Sequence homology among fungal enzymes corresponded to their taxonomic position. Interesting patterns of amino acid conservation in ODCs from fungi, distinct from other organisms, were detected.


Asunto(s)
Hongos/enzimología , Ornitina Descarboxilasa/química , Secuencia de Aminoácidos , Datos de Secuencia Molecular , Ornitina Descarboxilasa/genética , Reacción en Cadena de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA