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1.
Sci Total Environ ; 859(Pt 1): 160132, 2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36400291

RESUMEN

The present study employed data collected during the Mycosands survey to investigate the environmental factors influencing yeasts and molds distribution along European shores applying a species distribution modelling approach. Occurrence data were compared to climatic datasets (temperature, precipitation, and solar radiation), soil datasets (chemical and physical properties), and water datasets (temperature, salinity, and chlorophyll-a concentration) downloaded from web databases. Analyses were performed by MaxEnt software. Results suggested a different probability of distribution of yeasts and molds along European shores. Yeasts seem to tolerate low temperatures better during winter than molds and this reflects a higher suitability for the Northern European coasts. This difference is more evident considering suitability in waters. Both distributions of molds and yeasts are influenced by basic soil pH, probably because acidic soils are more favorable to bacterial growth. Soils with high nitrogen concentrations are not suitable for fungal growth, which, in contrast, are optimal for plant growth, favored by this environment. Finally, molds show affinity with soil rich in nickel and yeasts with soils rich in cadmium resulting in a distribution mainly at the mouths of European rivers or lagoons, where these metals accumulate in river sediments.


Asunto(s)
Ríos , Contaminantes del Suelo , Ríos/química , Suelo/química , Cadmio/análisis , Contaminantes del Suelo/análisis , Metales/análisis , Levaduras , Monitoreo del Ambiente
2.
Sci Total Environ ; 781: 146598, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-33812107

RESUMEN

The goal of most studies published on sand contaminants is to gather and discuss knowledge to avoid faecal contamination of water by run-offs and tide-retractions. Other life forms in the sand, however, are seldom studied but always pointed out as relevant. The Mycosands initiative was created to generate data on fungi in beach sands and waters, of both coastal and freshwater inland bathing sites. A team of medical mycologists and water quality specialists explored the sand culturable mycobiota of 91 bathing sites, and water of 67 of these, spanning from the Atlantic to the Eastern Mediterranean coasts, including the Italian lakes and the Adriatic, Baltic, and Black Seas. Sydney (Australia) was also included in the study. Thirteen countries took part in the initiative. The present study considered several fungal parameters (all fungi, several species of the genus Aspergillus and Candida and the genera themselves, plus other yeasts, allergenic fungi, dematiaceous fungi and dermatophytes). The study considered four variables that the team expected would influence the results of the analytical parameters, such as coast or inland location, urban and non-urban sites, period of the year, geographical proximity and type of sediment. The genera most frequently found were Aspergillus spp., Candida spp., Fusarium spp. and Cryptococcus spp. both in sand and in water. A site-blind median was found to be 89 Colony-Forming Units (CFU) of fungi per gram of sand in coastal and inland freshwaters, with variability between 0 and 6400 CFU/g. For freshwater sites, that number was 201.7 CFU/g (0, 6400 CFU/g (p = 0.01)) and for coastal sites was 76.7 CFU/g (0, 3497.5 CFU/g). For coastal waters and all waters, the median was 0 CFU/ml (0, 1592 CFU/ml) and for freshwaters 6.7 (0, 310.0) CFU/ml (p < 0.001). The results advocate that beaches should be monitored for fungi for safer use and better management.


Asunto(s)
Playas , Arena , Australia , Mar Negro , Hongos , Humanos , Italia , Microbiología del Agua
3.
Acta Oncol ; 57(6): 807-812, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29265948

RESUMEN

BACKGROUND: Biliary tract cancer (BTC) is an uncommon cancer with an unfavorable prognosis. Since 2010, the standard of care for patients with unresectable BTC is palliative treatment with gemcitabine plus cisplatin, based on the landmark phase III ABC-02 trial. This current study aims to evaluate the efficacy and safety of gemcitabine and cisplatin in patients with unresectable cholangiocarcinoma and gallbladder cancer in daily practice that meet the criteria for the ABC-02 trial in comparison to patients who did not. METHODS: Patients diagnosed with unresectable BTC between 2010 and 2015 with an indication for gemcitabine and cisplatin were included. We divided these patients into three groups: (I) patients who received chemotherapy and met the criteria of the ABC-02 trial, (II) patients who received chemotherapy and did not meet these criteria and (III) patients who had an indication for chemotherapy, but received best supportive care without chemotherapy. Primary outcome was overall survival (OS) and secondary outcome was progression-free survival (PFS). RESULTS: We collected data of 208 patients, of which 138 (66.3%) patients received first line chemotherapy with gemcitabine and cisplatin. Median OS of 69 patients in group I, 63 patients in group II and 65 patients in group III was 9.6 months (95%CI = 6.7-12.5), 9.5 months (95%CI = 7.7-11.3) and 7.6 months (95%CI = 5.0-10.2), respectively. Median PFS was 6.0 months (95%CI = 4.4-7.6) in group I and 5.1 months (95%CI = 3.7-6.5) in group II. Toxicity and number of dose reductions (p = .974) were comparable between the two chemotherapy groups. CONCLUSION: First-line gemcitabine and cisplatin is an effective and safe treatment for patients with unresectable BTC who do not meet the eligibility criteria for the ABC-02 trial. Median OS, PFS and treatment side effects were comparable between the patients who received chemotherapy (group I vs. group II).


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Sistema Biliar/tratamiento farmacológico , Colangiocarcinoma/tratamiento farmacológico , Neoplasias de la Vesícula Biliar/tratamiento farmacológico , Cuidados Paliativos/métodos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias del Sistema Biliar/mortalidad , Colangiocarcinoma/mortalidad , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Desoxicitidina/análogos & derivados , Supervivencia sin Enfermedad , Femenino , Neoplasias de la Vesícula Biliar/mortalidad , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Gemcitabina
5.
Water Res ; 47(18): 6921-8, 2013 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-23871256

RESUMEN

The State of California has mandated the preparation of a guidance document on the application of fecal source identification methods for recreational water quality management. California contains the fifth highest population of cattle in the United States, making the inclusion of cow-associated methods a logical choice. Because the performance of these methods has been shown to change based on geography and/or local animal feeding practices, laboratory comparisons are needed to determine which assays are best suited for implementation. We describe the performance characterization of two end-point PCR assays (CF128 and CF193) and five real-time quantitative PCR (qPCR) assays (Rum2Bac, BacR, BacCow, CowM2, and CowM3) reported to be associated with either ruminant or cattle feces. Each assay was tested against a blinded set of 38 reference challenge filters (19 duplicate samples) containing fecal pollution from 12 different sources suspected to impact water quality. The abundance of each host-associated genetic marker was measured for qPCR-based assays in both target and non-target animals and compared to quantities of total DNA mass, wet mass of fecal material, as well as Bacteroidales, and enterococci determined by 16S rRNA qPCR and culture-based approaches (enterococci only). Ruminant- and cow-associated genetic markers were detected in all filters containing a cattle fecal source. However, some assays cross-reacted with non-target pollution sources. A large amount of variability was evident across laboratories when protocols were not fixed suggesting that protocol standardization will be necessary for widespread implementation. Finally, performance metrics indicate that the cattle-associated CowM2 qPCR method combined with either the BacR or Rum2Bac ruminant-associated methods are most suitable for implementation.


Asunto(s)
Bacterias/clasificación , Monitoreo del Ambiente/métodos , Reacción en Cadena de la Polimerasa/métodos , Rumiantes/microbiología , Microbiología del Agua , Contaminación del Agua/análisis , Animales , Bacterias/genética , Bacterias/aislamiento & purificación , California , Bovinos/microbiología , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Heces/microbiología , Marcadores Genéticos , ARN Ribosómico 16S/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos
8.
Equine Vet J ; 39(5): 470-8, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17910275

RESUMEN

Infection with Rhodococcus (Corynebacterium) equi is a well-recognised condition in foals that represents a consistent and serious risk worldwide. The condition manifests itself primarily as one of pulmonary abscessation and bronchitis, hence the terminology of 'rattles' derived from its most obvious clinical sign, frequently terminal when first identified. This review addresses the clinical manifestation, bacteriology and pathogenesis of the condition together with recent developments providing knowledge of the organism in terms of virulence, epidemiology, transmission and immune responses. Enhanced understanding of R. equi virulence mechanisms and biology derived from the recently available genome sequence may facilitate the rational development of a vaccine and the improvement of farm management practices used to control R. equi on stud farms in the future. Reliance on vaccines alone, in the absence of management strategies to control the on-farm challenge is likely to be disappointing.


Asunto(s)
Infecciones por Actinomycetales/veterinaria , Enfermedades de los Caballos/diagnóstico , Enfermedades de los Caballos/microbiología , Rhodococcus equi/patogenicidad , Infecciones por Actinomycetales/diagnóstico , Infecciones por Actinomycetales/microbiología , Infecciones por Actinomycetales/transmisión , Animales , Animales Recién Nacidos , Vacunas Bacterianas , Enfermedades de los Caballos/prevención & control , Enfermedades de los Caballos/transmisión , Caballos , Rhodococcus equi/genética , Factores de Riesgo , Virulencia
9.
Microb Ecol ; 47(1): 68-79, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15259271

RESUMEN

The phenotypic and genetic characteristics of 14 strains of the purple nonsulfur bacterium Rhodopseudomonas palustris were studied to assess diversity within this species. While all strains had certain phenotypic characteristics in common, including the ability to metabolize benzoate and degrade 2- and 3-chlorobenzoate, there were also significant differences among the strains such as the rate of growth in media containing benzoate as a carbon source. Genetic characterization of the strains revealed there were three divergent lineages in the species. Based on 16S rRNA gene sequences, the 14 strains could be grouped into three distinct clusters (A, B, and C), and this clustering was congruent with that based on gene sequences of form II ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Although BOX-PCR genomic DNA fingerprints of all 14 strains exhibited differences, analysis of the fingerprint images and UPGMA/product-moment analysis of similarities showed there were three groupings that were entirely consistent with clusters based on other characteristics of the strains. Thus, regardless of the method of analysis used, strains in groups A and B consistently clustered together and were separate from those of group C. These results suggest that strains in groups A-B and C represent phylogenetically related clones that have diverged from one another. This indicates that at least three lineages of Rhodopseudomonas palustris exist among the strains included in this study, and that each may be particularly well adapted to a distinct ecological niche.


Asunto(s)
Variación Genética , Fenotipo , Filogenia , Rhodopseudomonas/genética , Secuencia de Bases , Southern Blotting , Clorobenzoatos/metabolismo , Análisis por Conglomerados , Coenzima A Ligasas/genética , Dermatoglifia del ADN , Cartilla de ADN , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Rhodopseudomonas/metabolismo , Análisis de Secuencia de ADN , Especificidad de la Especie
10.
Vet Microbiol ; 94(2): 143-58, 2003 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-12781482

RESUMEN

Preliminary analysis of a partial (30% coverage) genome sequence of Rhodococcus equi has revealed a number of important features. The most notable was the extent of the homology of genes identified with those of Mycobacterium tuberculosis. The similarities in the proportion of genes devoted to fatty acid degradation and to lipid biosynthesis was a striking but not surprising finding given the relatedness of these organisms and their success as intracellular pathogens. The rapid recent improvement in understanding of virulence in M. tuberculosis and other pathogenic mycobacteria has identified a large number of genes of putative or proven importance in virulence, homologs of many of which were also identified in R. equi. Although R. equi appears to have currently unique genes, and has important differences, its similarity to M. tuberculosis supports the need to understand the basis of virulence in this organism. The partial genome sequence will be a resource for workers interested in R. equi until such time as a full genome sequence has been characterized.


Asunto(s)
ADN Bacteriano/química , Genoma Bacteriano , Rhodococcus equi/genética , Aerobiosis/genética , Aminoácidos/metabolismo , Anaerobiosis/genética , Animales , Secuencia de Bases , Carbono/metabolismo , Farmacorresistencia Bacteriana/genética , Metabolismo Energético/genética , Enzimas/genética , Ácidos Grasos/metabolismo , Caballos , Humanos , Huésped Inmunocomprometido , Lípidos/biosíntesis , Mycobacterium tuberculosis/enzimología , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Rhodococcus equi/enzimología , Rhodococcus equi/patogenicidad , Análisis de Secuencia de ADN/veterinaria , Homología de Secuencia de Ácido Nucleico , Virulencia/genética
11.
FEMS Microbiol Lett ; 205(2): 243-6, 2001 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-11750810

RESUMEN

The identification of virulence factors in Rhodococcus equi has been severely hampered by the lack of a method for in vivo random insertion mutagenesis. This study reports the use of transposomes to generate random insertions of a gene conferring kanamycin resistance into the genome of R. equi ATCC 33701. Southern hybridisation using the kanamycin resistance gene as probe showed that insertion of transposome is random. This was confirmed following nucleotide sequence analysis of the junction between the transposome and chromosomal DNA. The presence of a 9 bp duplication of the target sequence showed that random integration of the transposome was due to a bona fide Tn5 transposition event.


Asunto(s)
Rhodococcus equi/genética , Genoma Bacteriano , Resistencia a la Kanamicina/genética , Datos de Secuencia Molecular , Mutagénesis Insercional , Transposasas/genética
12.
J Bacteriol ; 183(24): 7285-94, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11717288

RESUMEN

A transposon mutant of Rhodobacter capsulatus, strain Mal7, that was incapable of photoautotrophic and chemoautotrophic growth and could not grow photoheterotrophically in the absence of an exogenous electron acceptor was isolated. The phenotype of strain Mal7 suggested that the mutation was in some gene(s) not previously shown to be involved in CO(2) fixation control. The site of transposition in strain Mal7 was identified and shown to be in the gene nuoF, which encodes one of the 14 subunits for NADH ubiquinone-oxidoreductase, or complex I. To confirm the role of complex I and nuoF for CO(2)-dependent growth, a site-directed nuoF mutant was constructed (strain SBC1) in wild-type strain SB1003. The complex I-deficient strains Mal7 and SBC1 exhibited identical phenotypes, and the pattern of CO(2) fixation control through the Calvin-Benson-Bassham pathway was the same for both strains. It addition, it was shown that electron transport through complex I led to differential control of the two major cbb operons of this organism. Complex I was further shown to be linked to the control of nitrogen metabolism during anaerobic photosynthetic growth of R. capsulatus.


Asunto(s)
Proteínas Hierro-Azufre , NADH NADPH Oxidorreductasas/metabolismo , Rhodobacter capsulatus/fisiología , Dióxido de Carbono/metabolismo , Complejo I de Transporte de Electrón , Homeostasis , Mutagénesis Insercional , Mutación , NADH NADPH Oxidorreductasas/genética , Nitrógeno/metabolismo , Nitrogenasa/metabolismo , Oxidación-Reducción , Oxidorreductasas/metabolismo , Vía de Pentosa Fosfato , Fotosíntesis
13.
Clin Chem ; 47(10): 1811-20, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11568091

RESUMEN

BACKGROUND: Profiling of the plasma indoles tryptophan, 5-hydroxytryptophan (5-HTP), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) is useful in the diagnosis and follow-up of patients with carcinoid tumors. We describe an automated method for the profiling of these indoles in protein-containing matrices as well as the plasma indole concentrations in healthy controls and patients with carcinoid tumors. METHODS: Plasma, cerebrospinal fluid, and tissue homogenates were prepurified by automated on-line solid-phase extraction (SPE) in Hysphere Resin SH SPE cartridges containing strong hydrophobic polystyrene resin. Analytes were eluted from the SPE cartridge by column switching. Subsequent separation and detection were performed by reversed-phase HPLC combined with fluorometric detection in a total cycle time of 20 min. We obtained samples from 14 healthy controls and 17 patients with metastasized midgut carcinoid tumors for plasma indole analysis. In the patient group, urinary excretion of 5-HIAA and serotonin was compared with concentrations of plasma indoles. RESULTS: Within- and between-series CVs for indoles in platelet-rich plasma were 0.6-6.2% and 3.7-12%, respectively. Results for platelet-rich plasma serotonin compared favorably with those obtained by single-component analysis. Plasma 5-HIAA, but not 5-HTP was detectable in 8 of 17 patients with carcinoid tumors. In the patient group, platelet-rich plasma total tryptophan correlated negatively with platelet-rich plasma serotonin (P = 0.021; r = -0.56), urinary 5-HIAA (P = 0.003; r = -0.68), and urinary serotonin (P <0.0001; r = -0.80). CONCLUSIONS: The present chromatographic approach reduces analytical variation and time needed for analysis and gives more detailed information about metabolic deviations in indole metabolism than do manual, single-component analyses.


Asunto(s)
Tumor Carcinoide/sangre , Indoles/sangre , Neoplasias Intestinales/sangre , Triptófano/sangre , 5-Hidroxitriptófano/análisis , 5-Hidroxitriptófano/sangre , Adulto , Anciano , Autoanálisis , Tumor Carcinoide/química , Líquido Cefalorraquídeo/química , Preescolar , Cromatografía Líquida de Alta Presión , Femenino , Humanos , Ácido Hidroxiindolacético/análisis , Ácido Hidroxiindolacético/sangre , Indoles/análisis , Neoplasias Intestinales/química , Masculino , Persona de Mediana Edad , Control de Calidad , Reproducibilidad de los Resultados , Serotonina/análisis , Serotonina/sangre , Espectrometría de Fluorescencia , Triptófano/análisis , Orina/química
14.
J Nucl Med ; 41(11): 1793-800, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11079485

RESUMEN

UNLABELLED: Carcinoid tumors can produce serotonin (5-hydroxytryptamine) and catecholamines from the precursors tryptophan and tyrosine. Our aim was to evaluate the tyrosine analog L-3-[123I]iodo-alpha-methyltyrosine (IMT) in the detection and the determination of biochemical activity of these tumors in comparison with 111In-labeled [diethylenetriaminepentaacetic acid (DTPA)-D-Phe1]-octreotide (111In-octreotide) scintigraphy. METHODS: SPECT and planar whole-body imaging were performed 15 min after administration of 300 MBq IMT in 22 patients with metastatic carcinoid tumors. The number of lesions detected was compared with the number detected by 111In-octreotide scintigraphy. The size and intensity of uptake of all lesions were graded using a simple scoring system, yielding a total body uptake score for both tracers. These scores were compared (nonparametric correlation) with biochemical markers of serotonin and catecholamine metabolism. RESULTS: IMT SPECT detected only 63 of 145 lesions detected by 111In-octreotide imaging (43%). IMT SPECT performance was best in the liver (60% detection rate). Both IMT uptake and 111In-octreotide uptake scores correlated with markers of serotonin metabolism (respective values for urinary 5-hydroxyindoleacetic acid: r = 0.67 and 0.48, P < 0.001 and 0.05; for urinary serotonin: r = 0.56 and 0.40, P = 0.002 and 0.05; and for platelet serotonin: r = 0.57 and 0.45, P < 0.01 and 0.05). No correlation with adrenaline or noradrenaline metabolites was found. However, IMT uptake, but not 111In-octreotide uptake, correlated with dopamine metabolite excretion (homovanillic acid: r = 0.60, P < 0.05; and dopamine relative sum: r = 0.61, P < 0.05). IMT uptake was higher in patients with increased dopamine metabolite excretion (P = 0.05). CONCLUSION: IMT uptake can be demonstrated in carcinoid lesions, but the method detected only 43% of carcinoid lesions that were positive on 111In-octreotide scintigraphy. Uptake of both tracers is related to the serotonin secretory activity. However, IMT uptake, but not 111In-octreotide uptake, was related to tumor dopamine metabolism. These findings may be of interest in the metabolic targeting of carcinoids.


Asunto(s)
Tumor Carcinoide/diagnóstico por imagen , Catecolaminas/metabolismo , Radioisótopos de Indio , Radioisótopos de Yodo , Metiltirosinas , Octreótido/análogos & derivados , Serotonina/metabolismo , Adulto , Anciano , Tumor Carcinoide/metabolismo , Tumor Carcinoide/secundario , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cintigrafía
15.
Clin Chem ; 46(10): 1588-96, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11017936

RESUMEN

BACKGROUND: We evaluated the discriminating capacity of the indole markers urinary 5-hydroxyindoleacetic acid (5-HIAA), urinary serotonin, and platelet serotonin in the diagnosis of carcinoid tumors. METHODS: Indole markers were measured in 688 patients with suspected carcinoid disease. The initial values of indole markers from patients in whom a carcinoid tumor was confirmed during follow-up (n = 98) were used for ROC analysis. Two groups served as reference populations. The first consisted of 45 healthy individuals ("healthy controls"). The second was a random sample of 40 patients, drawn from the 590 (688 minus 98) patients with carcinoid-like symptoms but without a carcinoid tumor ("clinically suspected patients"). RESULTS: ROC curve analysis showed platelet serotonin to have the highest discriminating capacity, especially in foregut carcinoids. Cutoff values for platelet serotonin obtained from ROC analysis with healthy controls as reference group (5.4 nmol/10(9) platelets) gave a sensitivity of 74%, specificity of 91%, positive predictive value of 63%, and negative predictive value of 95% when applied to the initial 688 patients. Using the cutoff value with the clinically suspected patients as the reference group (9.3 nmol/10(9) platelets) gave a sensitivity of 63%, specificity of 99%, positive predictive value of 89%, and negative predictive value of 93%. Indole markers were increased in 169 (25%) of 688 patients. In 76 (45%) of these 169 patients, a carcinoid tumor was present. Slight increases of markers were associated with non-carcinoid neuroendocrine tumors, non-neuroendocrine tumors, and disturbed bowel motility. CONCLUSIONS: ROC curve analysis shows that platelet serotonin is the most discriminating indole marker for the diagnosis of carcinoid tumors. Platelet serotonin especially improves the diagnosis of carcinoids producing small amounts of serotonin.


Asunto(s)
Biomarcadores de Tumor/análisis , Tumor Carcinoide/diagnóstico , Ácido Hidroxiindolacético/análisis , Serotonina/análisis , Adulto , Anciano , Anciano de 80 o más Años , Plaquetas/metabolismo , Cromatografía Líquida de Alta Presión , Femenino , Humanos , Ácido Hidroxiindolacético/orina , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos , Serotonina/sangre , Serotonina/orina
16.
FEMS Microbiol Lett ; 191(1): 1-5, 2000 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-11004391

RESUMEN

This paper reports the presence of an ideR gene, which encodes an iron-dependent regulatory protein, in Rhodococcus erythropolis and in the intracellular pathogen Rhodococcus equi. The ideR gene of the latter encoded a protein of 230 amino acids with a molecular mass of 25619. The alpha-helices forming the helix-turn-helix motif of the R. equi protein were identical to those of the DtxR protein of Corynebacterium diphtheriae, which is an IdeR homologue. This indicates that the two proteins bind to the same DNA binding site. This was confirmed following expression of IdeR in Escherichia coli, which showed that the IdeR protein could repress transcription of the tox promoter of C. diphtheriae in an iron dependent manner. An open reading frame specifying a 283-amino acid polypeptide similar to galE encoding UDP-galactose 4-epimerase was present downstream of the ideR gene.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación Bacteriana de la Expresión Génica , Hierro/metabolismo , Rhodococcus equi/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Secuencia de Bases , Clonación Molecular , Proteínas de Unión al ADN/química , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Genes Bacterianos , Datos de Secuencia Molecular , Rhodococcus equi/genética , Rhodococcus equi/crecimiento & desarrollo , Alineación de Secuencia , Análisis de Secuencia de ADN
17.
J Bacteriol ; 182(16): 4637-9, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10913100

RESUMEN

The levels of reduced and oxidized nicotinamide adenine dinucleotides were determined in Xanthobacter flavus during a transition from heterotrophic to autotrophic growth. Excess reducing equivalents are rapidly dissipated following induction of the Calvin cycle, indicating that the Calvin cycle serves as a sink for excess reducing equivalents. The physiological data support the conclusion previously derived from molecular studies in that expression of the Calvin cycle genes is controlled by the intracellular concentration of NADPH.


Asunto(s)
NADP/metabolismo , NAD/metabolismo , Xanthobacter/metabolismo , Formiato Deshidrogenasas/metabolismo , Cinética , Oxidación-Reducción , Fosfoglicerato Quinasa/metabolismo , Ribulosa-Bifosfato Carboxilasa/metabolismo , Ciclo del Sustrato , Xanthobacter/crecimiento & desarrollo
19.
Int J Syst Bacteriol ; 49 Pt 3: 1039-44, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10425761

RESUMEN

The phylogenetic positions of two strains of fermentative bacteria that had been isolated from the highest positive tubes inoculated with serial dilutions of estuarine mud in agar media with either glutamate or aspartate as substrate were determined by comparative sequence analysis of their 16S rRNA genes. The strain isolated with glutamate (glu 65) utilized several substrates, including a number of amino acids but no sugars. The degradation of certain substrates was enhanced by or dependent upon co-cultivation with a hydrogen-utilizing partner. In earlier work this strain was assigned to the new genus and species Acidaminobacter hydrogenoformans. On the basis of its 16S rRNA gene sequence Acidaminobacter hydrogenoformans has now been identified as a member of cluster XI of the Clostridium subphylum with Clostridium halophilum as its closest relative. The aspartate-fermenting strain asp 66T was a Gram-negative, rather aerotolerant anaerobe which utilized a wide range of substrates in a propionic fermentation and had the ability to fix molecular nitrogen. Strain asp 66T was shown to be a new member of the beta-subclass of the Proteobacteria with Azoarcus sp. strain 6a3 and Rhodocyclus tenuis as its closest relatives. It is described as Propionibacter pelophilus gen. nov., sp. nov., with the type strain asp 66T (= DSM 12018T).


Asunto(s)
Sedimentos Geológicos/microbiología , Bacterias Gramnegativas/clasificación , Bacterias Grampositivas/clasificación , Filogenia , Propionatos/metabolismo , Anaerobiosis , ADN Bacteriano/química , ADN Bacteriano/genética , Genes de ARNr , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Gramnegativas/metabolismo , Bacterias Grampositivas/genética , Bacterias Grampositivas/aislamiento & purificación , Bacterias Grampositivas/metabolismo , Datos de Secuencia Molecular , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
20.
Oncol Rep ; 5(1): 5-21, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9458286

RESUMEN

The role of biochemical markers of bone metabolism in the diagnosis and monitoring of bone metastases in solid tumors is reviewed. Emphasis is on the recently developed markers, which may provide a more accurate quantitation of bone metabolism. In metastatic bone disease, bone formation and resorption become uncoupled processes, leading to predominantly osteoblastic or osteolytic metastases. In osteolytic metastases, bone resorption is enhanced without appropriate acceleration of bone formation. In osteolytic metastases the resorption markers are indicated for the detection of bone metastases. Urinary pyridinium cross-links and serum collagen telopeptides are sensitive and specific markers of bone resorption. These markers, can often identify bone metastases before visualization by imaging techniques. When osteolytic lesions are responding to treatment the physiologic coupling between bone resorption and formation is partly restored. An increase in formation markers, bone specific isoenzyme of alkaline phosphatase (BSAP), osteocalcin (OC) and carboxyterminal propeptide of collagen type I (PICP), will then closely reflect restoration of coupling. In osteoblastic metastases, bone formation markers can accurately indicate early and advanced bone involvement. Bone resorption markers are less sensitive in these osteoblastic lesions. The collagen telopeptides however, are resorption markers with the ability to detect early bone metastases. Osteoblastic lesions responding to therapy are indicated by declining values of formation as well as resorption markers. The precise role of the recently developed markers of bone metabolism in early diagnosis and monitoring of bone metastases needs further evaluation in longitudinal studies. Since the delicate derangements in bone metabolism may be obscured in mixed patient groups, these studies should address uniform patient groups with respect to the primary tumor type.


Asunto(s)
Neoplasias Óseas/metabolismo , Neoplasias Óseas/secundario , Huesos/metabolismo , Neoplasias/patología , Biomarcadores , Neoplasias Óseas/patología , Resorción Ósea , Huesos/patología , Colágeno/metabolismo , Humanos , Neoplasias/metabolismo , Osteoblastos/metabolismo , Osteoblastos/patología , Osteólisis
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