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2.
Schmerz ; 30(3): 218-26, 2016 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-27221745

RESUMEN

On behalf of the Medical/Psychological Pain Associations, Pain Patients Alliance and the Professional Association of Pain Physicians and Psychologists, the Joint Commission of Professional Societies and Organizations for Quality in Pain Medicine, working in close collaboration with the respective presidents, has developed verifiable structural and process-related criteria for the classification of medical and psychological pain treatment facilities in Germany. Based on the established system of graded care in Germany and on existing qualifications, these criteria also argue for the introduction of a basic qualification in pain medicine. In addition to the first-ever comprehensive description of psychological pain facilities, the criteria presented can be used to classify five different levels of pain facilities, from basic pain management facilities, to specialized institutions, to the Centre for Interdisciplinary Pain Medicine. The recommendations offer binding and verifiable criteria for quality assurance in pain medicine and improved pain treatment.


Asunto(s)
Dolor Crónico/clasificación , Dolor Crónico/terapia , Programas Nacionales de Salud/clasificación , Programas Nacionales de Salud/organización & administración , Clínicas de Dolor/clasificación , Clínicas de Dolor/organización & administración , Manejo del Dolor/clasificación , Garantía de la Calidad de Atención de Salud/clasificación , Garantía de la Calidad de Atención de Salud/organización & administración , Alemania , Humanos , Comunicación Interdisciplinaria , Colaboración Intersectorial
3.
J Antimicrob Chemother ; 71(1): 213-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26433782

RESUMEN

OBJECTIVES: The aim of this study was to evaluate the susceptibilities of Clostridium difficile isolates to cadazolid, a novel antibiotic for the treatment of C. difficile infection. METHODS: Ribotyping and susceptibilities were determined for C. difficile isolates from a multicentre, double-blind, Phase 2 study of oral cadazolid in patients with C. difficile infection (NCT01222702, ClinicalTrials.gov; EudraCT 2010-020941-29, European Clinical Trials Database). Patients were randomized to receive 250, 500 or 1000 mg of cadazolid twice daily or 125 mg of vancomycin four times daily, for 10 days. MICs of cadazolid, vancomycin, fidaxomicin, linezolid and moxifloxacin were determined at baseline for all patients and post-baseline for patients with clinical failure or recurrence, using the agar dilution method. RESULTS: Seventy-eight of 84 patients had an evaluable toxigenic C. difficile isolate at baseline. The most frequent PCR ribotype was 027 (15.4%). Cadazolid MICs for baseline isolates (including epidemic strain 027) ranged from 0.06 to 0.25 mg/L. Baseline cadazolid MICs were similar to those of fidaxomicin and lower than those of vancomycin, linezolid and moxifloxacin. For each clinical outcome group (clinical cure, clinical failure, sustained clinical response and clinical failure or recurrence), the baseline cadazolid MIC range was 0.06-0.25 mg/L. Mean (min-max) cadazolid faecal concentration (µg/g) on day 5 was 884 (101-2710), 1706 (204-4230) and 3226 (1481-12 600) for the doses 250, 500 and 1000 mg, respectively. CONCLUSIONS: For all cadazolid doses, the faecal concentration was in excess of several thousand-fold the MIC90 for C. difficile. The MIC of cadazolid for all C. difficile isolates, including epidemic strains, was low and in the same narrow range regardless of treatment outcome.


Asunto(s)
Antibacterianos/administración & dosificación , Clostridioides difficile/efectos de los fármacos , Infecciones por Clostridium/tratamiento farmacológico , Infecciones por Clostridium/microbiología , Oxazolidinonas/administración & dosificación , Vancomicina/administración & dosificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Clostridioides difficile/clasificación , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Método Doble Ciego , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Oxazolidinonas/farmacología , Ribotipificación , Vancomicina/farmacología , Adulto Joven
4.
PLoS One ; 10(12): e0145235, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26678612

RESUMEN

In stem cell cultures from adult human tissue, undesirable contamination with fibroblasts is frequently present. The presence of fibroblasts obscures the actual number of stem cells and may result in extracellular matrix production after transplantation. Identification of fibroblasts is difficult because of the lack of specific fibroblast markers. In our laboratory, we isolate and expand neural-crest-derived stem cells from human hair follicle bulges and investigate their potential to differentiate into neural cells. To establish cellular identities, we perform immunohistochemistry with antibodies specific for glial and neuronal markers, and use fibroblasts as negative control. We frequently observe that human adult dermal fibroblasts also express some glial and neuronal markers. In this study, we have sought to determine whether our observations represent actual expression of these markers or result from cross-reactivity. Immunohistochemistry was performed on human adult dermal fibroblasts using acknowledged glial and neuronal antibodies followed by verification of the data using RT-qPCR. Human adult dermal fibroblasts showed expression of the glia-specific markers SOX9, glial fibrillary acidic protein and EGR2 (KROX20) as well as for the neuron-specific marker class III ß-tubulin, both at the protein and mRNA level. Furthermore, human adult dermal fibroblasts showed false-positive immunostaining for S100ß and GAP43 and to a lower extent for OCT6. Our results indicate that immunophenotyping as a tool to determine cellular identity is not as reliable as generally assumed, especially since human adult dermal fibroblasts may be mistaken for neural cells, indicating that the ultimate proof of glial or neuronal identity can only be provided by their functionality.


Asunto(s)
Fibroblastos/metabolismo , Neuroglía/metabolismo , Neuronas/metabolismo , Cultivo Primario de Células/métodos , Animales , Biomarcadores/metabolismo , Células Cultivadas , Proteína 2 de la Respuesta de Crecimiento Precoz/genética , Proteína 2 de la Respuesta de Crecimiento Precoz/metabolismo , Fibroblastos/citología , Proteína GAP-43/genética , Proteína GAP-43/metabolismo , Humanos , Inmunohistoquímica , Ratones , Neuroglía/citología , Neuronas/citología , Proteínas de Transporte de Catión Orgánico/genética , Proteínas de Transporte de Catión Orgánico/metabolismo , Proteínas S100/genética , Proteínas S100/metabolismo , Factor de Transcripción SOX9/genética , Factor de Transcripción SOX9/metabolismo
5.
Histochem Cell Biol ; 144(1): 87-91, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25724811

RESUMEN

Class III ß-tubulin (TUBB3)-positive cells from the hair follicle bulge are thought to be neuronal cells derived from a local neural crest stem cell. However, TUBB3 has recently been shown to be expressed in the melanocytic lineage. To evaluate the neural-crest-associated immunophenotype of TUBB3-positive cells from hair follicle bulge explants, we dissected hair follicle bulges out from mouse whisker pads and cultured for 1 month and assessed outgrowing cells by means of immunocytochemistry using the biomarkers TUBB3, nestin, NGFR, SOX9, TYRP1 and laminin. Large amounts of TUBB3-positive cells could be cultured that co-expressed nestin, NGFR, SOX9 and, to a lesser degree, TYRP1, matching a melanoglial phenotype. In addition, a small population of TUBB3-negative but laminin-positive cells was found, which presumably are of glial origin. It can be concluded that cells of melanoglial origin can easily be obtained from hair follicle bulge explants. These cells may be of use in experimental animal or human disease and wound healing models. Notably, the TUBB3-positive cells are of melanoglial rather than neuronal origin.


Asunto(s)
Folículo Piloso/citología , Neuroglía/citología , Tubulina (Proteína)/análisis , Animales , Células Cultivadas , Inmunofenotipificación , Ratones , Ratones Endogámicos C57BL , Nestina/análisis , Cresta Neural/citología , Neuroglía/química , Vibrisas
6.
J Antimicrob Chemother ; 69(3): 697-705, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24128668

RESUMEN

OBJECTIVES: We investigated the in vitro activity of cadazolid against 100 Clostridium difficile isolates and its efficacy in a simulated human gut model of C. difficile infection (CDI). METHODS: MICs of cadazolid, metronidazole, vancomycin, moxifloxacin and linezolid were determined using agar incorporation for 100 C. difficile isolates, including 30 epidemic strains (ribotypes 027, 106 and 001) with reduced metronidazole susceptibility, 2 linezolid-resistant isolates and 2 moxifloxacin-resistant isolates. We evaluated the efficacy of two cadazolid dosing regimens (250 versus 750 mg/L twice daily for 7 days) to treat simulated CDI. Microflora populations, C. difficile total viable counts and spores, cytotoxin titres, possible emergence of cadazolid, linezolid or quinolone resistance, and antimicrobial concentrations were monitored throughout. RESULTS: Cadazolid was active against all (including linezolid- and moxifloxacin-resistant) C. difficile strains (MIC90 0.125, range 0.03-0.25 mg/L). The cadazolid geometric mean MIC was 152-fold, 16-fold, 9-fold and 7-fold lower than those of moxifloxacin, linezolid, metronidazole and vancomycin, respectively. Both cadazolid dosing regimens rapidly reduced C. difficile viable counts and cytotoxin with no evidence of recurrence. Cadazolid levels persisted at 50-100-fold supra-MIC for 14 days post-dosing. Cadazolid inhibition of enumerated gut microflora was limited, with the exception of bifidobacteria; Bacteroides fragilis group and Lactobacillus spp. counts were unaffected. There was no evidence for selection of strains resistant to cadazolid, quinolones or linezolid. CONCLUSIONS: Cadazolid activity was greater than other tested antimicrobials against 100 C. difficile strains. Cadazolid effectively treated simulated CDI in a gut model, with limited impact on the enumerated gut microflora and no signs of recurrence or emergence of resistance within the experimental timeframe.


Asunto(s)
Clostridioides difficile/efectos de los fármacos , Infecciones por Clostridium/tratamiento farmacológico , Tracto Gastrointestinal/microbiología , Oxazolidinonas/farmacología , Oxazolidinonas/uso terapéutico , Carga Bacteriana , Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Modelos Teóricos , Resultado del Tratamiento
7.
Orthopade ; 42(10): 854-7, 2013 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-24081393

RESUMEN

Most patients who attend orthopedic trauma surgery practices present with pain of the musculoskeletal system which can significantly affect the quality of life. For most patients the reason for the pain is quite obvious and can be easily addressed; however, for other patients the mechanism responsible for the pain remains unclear. In these patients it is mandatory to have well founded knowledge about the origin of the pain, possible pathways of pain sensitization and chronification in order to ask the right questions during (pain) anamnesis and to perform an adequate clinical functional examination. This is the foundation to offer an effective treatment to patients or when necessary to initiate further diagnostic investigations in order to avoid pain chronification or to direct patients to a multimodal interdisciplinary approach when the pain is already chronic.


Asunto(s)
Artralgia/clasificación , Artralgia/diagnóstico , Dolor Musculoesquelético/clasificación , Dolor Musculoesquelético/diagnóstico , Dimensión del Dolor/métodos , Examen Físico/métodos , Humanos
8.
Orthopade ; 42(10): 834-41, 2013 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-24048264

RESUMEN

Manual medicine (MM) is a manual medical technique to identify and treat reversible dysfunction especially of the musculoskeletal system. The origins of MM were derived from empirical observations but MM is nowadays based on anatomy, biomechanics and neurophysiology. Besides special training in palpation according to precise topographic anatomic knowledge, the diagnostics of segmental or articular dysfunction are also based on knowledge about afferent convergence of multiceptive neurons located in proprioceptive and nociceptive layers of the brain stem and spinal cord. This leads to activation of motor and sympathetic reactions with the consequence of segmental or regional dysfunction. Manual therapy aims to eliminate noci-afferents as well as to activate inhibitory receptive fields. This can be achieved either by a single high velocity manipulative impulse or by slow-soft rhythmic repetitive mobilization. The special medical education and training in MM is outlined in relation to the Bologna postgraduate concept. As MM is basically used in relation to the musculoskeletal system it should definitely be incorporated into the specialization for orthopedics and traumatology and become part of the examination. In outpatient medicine an orthopedic and trauma surgeon without MM expertise will be inferior to a general practitioner with this expertise.


Asunto(s)
Atención Ambulatoria/métodos , Artropatías/diagnóstico , Artropatías/rehabilitación , Manipulaciones Musculoesqueléticas/métodos , Medicina Basada en la Evidencia , Humanos
9.
Schmerz ; 22(5): 594-603, 2008 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-18604567

RESUMEN

Analgesic therapy is not without risk. However, the risk of most analgesic interventions is minor compared to the risk of the inadequate treatment of pain and insufficient treatment may lead to chronic pain.A correct diagnosis should be the basis of any specific treatment of pain disorders. Only a diagnosis which implicates a multi-disciplinary assessment and which considers both the pathoanatomical, functional and biopsychosocial dysfunctions can lead to an adequate therapeutic intervention. Furthermore, therapeutic planning should include the personal needs of the patient and should have realistic aims.Pharmacological treatment is guided by the WHO pain ladder. The risks of the relevant substance groups must be considered. NSAIDs (non-steroidal anti-inflammatory drugs) which are included in all steps of the WHO pain ladder carry specific risks for the gastrointestinal, cardiovascular and renal systems and are contraindicated in many patients in need of analgesic therapy, e.g. in many elderly patients. Opioids which are recommended at steps 2 and 3 of the WHO pain ladder have less organ toxicity but they are still used reluctantly. Coanalgetics, especially antidepressants bear specific risks and the discussion on suicide rates under antidepressant medication is ongoing.Invasive methods such as the intrathecal application of analgesics are valuable procedures if the indication is correct and the treating physician has sufficient experience. Pain therapy is essential and the risks of the procedures are manageable. Considering the current knowledge on the mechanisms of pain sensitisation, the lack of adequate pain control can lead to chronic pain with severe consequences for the patient.


Asunto(s)
Analgésicos/efectos adversos , Dolor/tratamiento farmacológico , Analgesia Epidural/efectos adversos , Analgésicos/uso terapéutico , Antidepresivos/efectos adversos , Antidepresivos/uso terapéutico , Enfermedad Crónica , Terapia Combinada , Interacciones Farmacológicas , Quimioterapia Combinada , Humanos , Bombas de Infusión , Dolor/psicología , Grupo de Atención al Paciente , Medición de Riesgo
10.
Orthopade ; 36(1): 41-8, 2007 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-17205323

RESUMEN

The bases for peripheral pain syndromes of the musculoskeletal system, which are common and often difficult to treat, involve complex neurophysiologic changes. They are generally very troublesome for the patient and result in long-term disability and absence from work and sport activities. As all levels of the pain perception system are involved, evaluation has to take place at the peripheral, spinal and central nervous system levels. Treatment requires a concept including all affected structures. If this is not the case, an inefficient series of monotherapies often results, which increases the risk of pain chronification in these patients similar to the situation found for low back pain. The biomechanical-functional aspect is of great importance for the lower extremities. This point of view, which is familiar to the orthopedist, reveals a clear connection between pain and disturbed function, permitting a clear concept for a successful therapy.


Asunto(s)
Enfermedades Musculoesqueléticas/diagnóstico , Enfermedades Musculoesqueléticas/terapia , Manejo del Dolor , Dolor/diagnóstico , Enfermedades del Sistema Nervioso Periférico/diagnóstico , Enfermedades del Sistema Nervioso Periférico/terapia , Humanos , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina , Síndrome
11.
J Med Chem ; 44(12): 1847-52, 2001 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-11384231

RESUMEN

Potent, selective, and structurally new inhibitors of the Fe(II) enzyme Escherichia coli peptide deformylase (PDF) were obtained by rational optimization of the weakly binding screening hit (5-chloro-2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-acetic acid hydrazide (1). Three-dimensional structural information, gathered from Ni-PDF complexed with 1, suggested the preparation of two series of related hydroxamic acid analogues, 2-(2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-N-hydroxy-acetamides (A) and 2-(2,2-dioxo-1,4-dihydro-2H-2lambda(6)-benzo[1,2,6]thiadiazin-3-yl)-N-hydroxy-acetamides (B), among which potent PDF inhibitors (37, 42, and 48) were identified. Moreover, two selected compounds, one from each series, 36 and 41, showed good selectivity for PDF over several endoproteases including matrix metalloproteases. However, these compounds showed only weak antibacterial activity.


Asunto(s)
Amidohidrolasas , Aminopeptidasas/antagonistas & inhibidores , Antibacterianos/síntesis química , Escherichia coli/enzimología , Ácidos Hidroxámicos/síntesis química , Inhibidores de Proteasas/síntesis química , Quinazolinas/síntesis química , Tiadiazinas/síntesis química , Aminopeptidasas/química , Antibacterianos/química , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/aislamiento & purificación , Sitios de Unión , Cristalografía por Rayos X , Diseño de Fármacos , Humanos , Enlace de Hidrógeno , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Conformación Molecular , Inhibidores de Proteasas/química , Inhibidores de Proteasas/farmacología , Quinazolinas/química , Quinazolinas/farmacología , Tiadiazinas/química , Tiadiazinas/farmacología
12.
Antimicrob Agents Chemother ; 45(4): 1058-64, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11257016

RESUMEN

New inhibitors of peptide deformylase (PDF) which are very potent against the isolated enzyme and show a certain degree of antibacterial activity have recently been synthesized by our group. Several lines of experimental evidence indicate that these inhibitors indeed interfere with the target enzyme in the bacterial cell. (i) The inhibition of Escherichia coli growth could be counteracted by overexpression of PDF from different organisms, including E. coli, Streptococcus pneumoniae, and Haemophilus influenzae. Conversely, reduced expression of PDF in S. pneumoniae resulted in an increased susceptibility to the inhibitors. (ii) Proteome analysis on two-dimensional gels revealed a shift for many proteins towards lower pI in the presence of PDF inhibitors, as would be expected if the proteins still carry their N-formyl-Met terminus. (iii) PDF inhibitors show no antimicrobial activity against E. coli under conditions that make growth independent of formylation and deformylation. The antibacterial activity in E. coli was characterized as bacteriostatic. Furthermore, the development of resistance in E. coli was observed to occur with high frequency (10(-7)). Resistant mutants show a reduced growth rate, and DNA sequence analysis revealed mutations in their formyl transferase gene. Taking all these aspects into account, we conclude that PDF may not be an optimal target for broad-spectrum antibacterial agents.


Asunto(s)
Amidohidrolasas , Aminopeptidasas/antagonistas & inhibidores , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Aminopeptidasas/genética , Aminopeptidasas/metabolismo , Antiinfecciosos Urinarios/farmacología , Proteínas Bacterianas/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Antagonismo de Drogas , Escherichia coli/enzimología , Escherichia coli/genética , Genes Bacterianos , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/metabolismo , Mutagénesis Insercional , Mutación , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo , Transformación Bacteriana , Trimetoprim/farmacología
13.
J Med Chem ; 43(12): 2324-31, 2000 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-10882358

RESUMEN

Low-molecular-weight beta-sulfonyl- and beta-sulfinylhydroxamic acid derivatives have been synthesized and found to be potent inhibitors of Escherichia coli peptide deformylase (PDF). Most of the compounds synthesized and tested displayed antibacterial activities that cover several pathogens found in respiratory tract infections, including Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The potential of these compounds as antibacterial agents is discussed with respect to selectivity, intracellular concentrations in bacteria, and potential for resistance development.


Asunto(s)
Amidohidrolasas , Aminopeptidasas/antagonistas & inhibidores , Antibacterianos/síntesis química , Inhibidores Enzimáticos/síntesis química , Ácidos Hidroxámicos/síntesis química , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacología , Chlamydophila pneumoniae/efectos de los fármacos , Cristalografía por Rayos X , Farmacorresistencia Microbiana , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/metabolismo , Haemophilus influenzae/efectos de los fármacos , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/metabolismo , Ácidos Hidroxámicos/farmacología , Modelos Moleculares , Moraxella catarrhalis/efectos de los fármacos , Mycoplasma pneumoniae/efectos de los fármacos , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/química , Inhibidores de Proteasas/metabolismo , Inhibidores de Proteasas/farmacología , Infecciones del Sistema Respiratorio/microbiología , Estereoisomerismo , Relación Estructura-Actividad
15.
J Mol Biol ; 266(1): 23-30, 1997 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-9054967

RESUMEN

A single amino acid substitution, Phe98 to Tyr98, in dihydrofolate reductase (DHFR) is the molecular origin of trimethoprim (TMP) resistance in Staphylococcus aureus. This active site amino acid substitution was found in all S. aureus TMP-resistant clinical isolates tested. In order to explore the structural role of Tyr98 in TMP-resistance the ternary complexes of the chromosomal S. aureus DHFR (SaDHFR) with methotrexate (MTX) and TMP in the presence of nicotinamide adenine dinucleotide phosphate (NADPH) as well as that of mutant Phe98Tyr DHFR SaDHFR(F98Y) ternary folate-NADPH complex have been determined by X-ray crystallography. Critical evidence concerning the resistance mechanism has also been provided by NMR spectral analyses of 15N-labelled TMP in the ternary complexes of both wild-type and mutant enzyme. These studies show that the mutation results in loss of a hydrogen bond between the 4-amino group of TMP and the carbonyl oxygen of Leu5. This mechanism of resistance is predominant in both transferable plasmid-encoded and non-transferable chromosomally encoded resistance. Knowledge of the resistance mechanism at a molecular level could help in the design of antibacterials active against multi-resistant Staphylococcus aureus (MRSA), one of todays most serious problems in clinical infectology.


Asunto(s)
Fenilalanina , Conformación Proteica , Staphylococcus aureus/enzimología , Tetrahidrofolato Deshidrogenasa/química , Tetrahidrofolato Deshidrogenasa/genética , Resistencia al Trimetoprim , Sitios de Unión , Cromosomas Bacterianos , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Conformación Molecular , NADP/química , NADP/metabolismo , Mutación Puntual , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Tetrahidrofolato Deshidrogenasa/metabolismo , Trimetoprim/química , Trimetoprim/metabolismo , Tirosina
16.
Antimicrob Agents Chemother ; 40(6): 1376-81, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8726004

RESUMEN

Epiroprim (EPM; Ro 11-8958) is a new selective inhibitor of microbial dihydrofolate reductase. EPM displayed excellent activity against staphylococci, enterococci, pneumococci, and streptococci which was considerably better than that of trimethoprim (TMP). EPM was also active against TMP-resistant strains, although the MICs were still relatively high. Its combination with dapsone (DDS) was synergistic and showed as in vitro activity superior to that of the TMP combination with sulfamethoxazole (SMZ). The EPM-DDS (ratio, 1:19) combination inhibited more than 90% of all important gram-positive pathogens at a concentration of 2 + 38 micrograms/ml. Only a few highly TMP-resistant staphylococci and enterococci were not inhibited. EPM was also more active than TMP against Moraxella catarrhalis, Neisseria meningitidis, and Bacteroides spp., but it was less active than TMP against all other gram-negative bacteria tested. Atypical mycobacteria were poorly susceptible to EPM, but the combination with DDS was synergistic and active at concentrations most probably achievable in biological fluids (MICs from 0.25 +/- 4.75 to 4 + 76 micrograms/ml). EPM and the EPM-DDS combination were also highly active against experimental staphylococcal infections in a mouse septicemia model. The combination EPM-DDS has previously been shown to exhibit activity in Pneumocystis carinii and Toxoplasma models and, as shown in the present study, also shows good activity against a broad range of bacteria including many strains resistant to TMP and TMP-SMZ.


Asunto(s)
Dapsona/farmacología , Antagonistas del Ácido Fólico/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Trimetoprim/análogos & derivados , Animales , Combinación de Medicamentos , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Sepsis/tratamiento farmacológico , Trimetoprim/farmacología
17.
J Bacteriol ; 175(4): 1075-80, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8432701

RESUMEN

The mechanism of transport of the xenobiotic 4-toluene sulfonate (TS) in Comamonas testosteroni T-2 was investigated. Rapid uptake of TS was observed only in cells grown with TS or 4-methylbenzoate as a carbon and energy source. Initial uptake rates under aerobic conditions showed substrate saturation kinetics, with an apparent affinity constant (Kt) of 88 microM and a maximal velocity (Vmax) of 26.5 nmol/min/mg of protein. Uptake of TS was inhibited completely by uncouplers and only marginally by ATPase inhibitors and the phosphate analogs arsenate and vanadate. TS uptake was also studied under anaerobic conditions, which prevented intracellular TS metabolism. TS was accumulated under anaerobic conditions in TS-grown cells upon imposition of an artificial transmembrane pH gradient (delta pH, inside alkaline). Uptake of TS was inhibited by structurally related methylated and chlorinated benzenesulfonates and benzoates. The results provide evidence that the first step in the degradation of TS by C. testosteroni T-2 is uptake by an inducible secondary proton symport system.


Asunto(s)
Bacterias Gramnegativas/metabolismo , Compuestos de Tosilo/metabolismo , Aerobiosis , Anaerobiosis , Bencenosulfonatos , Unión Competitiva , Transporte Biológico , Permeabilidad de la Membrana Celular , Especificidad por Sustrato
18.
J Bacteriol ; 173(12): 3741-8, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2050632

RESUMEN

Comamonas testosteroni T-2 synthesizes an inducible enzyme system that oxygenates 4-toluene sulfontate (TS) to 4-sulfobenzyl alcohol when grown in TS-salts medium. We purified this TS methyl-monooxygenase system (TSMOS) and found it to consist of two components. A monomeric, iron-sulfur flavoprotein (component B), which has been shown to act as a reductase in the 4-sulfobenzoate dioxygenase system of this organism (H. H. Locher, T. Leisinger, and A. M. Cook, Biochem. J. 274:833-842, 1991), carried electrons from NADH to component M, an oxygenase. This oxygenase had the UV-visible spectral characteristics of an iron-sulfur protein. Mrs of about 152,000 for the native oxygenase and of 43,000 under denaturing conditions indicated a homotri- or homotetrameric enzyme, whose N-terminal amino acids and amino acid composition were determined. The activity of the purified enzyme was enhanced about fivefold by the addition of Fe2+. In the presence of O2 and NADH, components B and M together catalyzed the stoichiometric transformation of TS or p-toluate to the corresponding alcohol. The reaction was confirmed as oxygenation of the methyl group by observation of an oxygen atom from 18O2 in carboxybenzyl alcohol. The substrate range of TSMOS included carboxylated analogs of TS (p- and m-toluates and 4-ethylbenzoate), whereas p-xylene, toluene, and p-cresol were not substrates. TSMOS also catalyzed demethylation; 4-methoxybenzoate was transformed to 4-hydroxybenzoate and formaldehyde.


Asunto(s)
Oxigenasas/aislamiento & purificación , Pseudomonas/enzimología , Aminoácidos/análisis , Bencenosulfonatos , Cromatografía por Intercambio Iónico , Electroforesis en Gel de Poliacrilamida , Inducción Enzimática , Oxigenasas/biosíntesis , Oxigenasas/química , Oxigenasas/metabolismo , Espectrofotometría Ultravioleta , Compuestos de Tosilo/metabolismo
19.
Biochem J ; 274 ( Pt 3): 833-42, 1991 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-2012609

RESUMEN

Cell-free extracts of Comamonas testosteroni T-2 grown in toluene-p-sulphonate/salts medium catalyse the conversion of p-sulphobenzoate (PSB) into protocatechuate and sulphite by an NADH-requiring and Fe2(+)-activated dioxygenase. Anion-exchange chromatography of extracts yielded red (A) and yellow (B) protein fractions, both of which were necessary for dioxygenative activity. Further purification of each fraction by hydrophobic interaction chromatography and gel filtration led to two homogeneous protein components (A and B), which together converted 1 mol each of PSB, O2 and NADH into 1 mol each of protocatechuate, sulphite and, presumably, NAD+. The system was named 4-sulphobenzoate 3,4-dioxygenase (PSB dioxygenase system). Monomeric component B (Mr 36,000) was determined to be a reductase that contained 1 mol of FMN and about 2 mol each of iron and inorganic sulphur per mol. This component transferred electrons from NADH to the oxygenase component (A) or to, e.g., cytochrome c. Homodimeric component A (subunit Mr 50,000) of the PSB dioxygenase system contained one [2Fe-2S] centre per subunit and its u.v.-visible-absorption spectrum corresponded to a Rieske-type iron-sulphur centre. The requirement for activation by iron was interpreted as partial loss of mononuclear iron during purification of component A. Component A could be reduced by dithionite or by NADH plus catalytic amounts of component B. The PSB dioxygenase system displayed a narrow substrate range: none of 18 sulphonated or non-sulphonated analogues of PSB showed significant substrate-dependent O2 uptake. The physical properties of the PSB dioxygenase system resemble those of other bacterial multi-component dioxygenase, especially phthalate dioxygenase. However, it differs from most characterized systems in its overall reaction; the product is a vicinal diphenol, and not a dihydrodiol.


Asunto(s)
Dioxigenasas , Oxigenasas/aislamiento & purificación , Pseudomonas/enzimología , Aminoácidos/análisis , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Flavinas/análisis , Oxigenasas/química , Espectrofotometría Ultravioleta , Especificidad por Sustrato
20.
J Gen Microbiol ; 135(7): 1969-78, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2614395

RESUMEN

Pseudomonas (Comamonas) testosteroni T-2 completely converted p-toluenesulphonic acid (TS) or p-sulphobenzoic acid (PSB) to cell material, CO2 and sulphate, with growth yields of about 5 g protein (mol C)-1. PSB and sulphite were excreted as transient intermediates during growth in TS-salts medium. All reactions of a catabolic pathway involving sidechain oxidation and cleavage of the sulphonate moiety as sulphite were measurable in the soluble portion of cell extracts. Degradation of TS and PSB was inducible and apparently involved at least two regulons. TS was converted to p-sulphobenzyl alcohol in a reaction requiring NAD(P)H and 1 mol O2 (mol TS)-1. This alcohol was in an equilibrium (in the presence of NAD+) with p-sulphobenzaldehyde, which was converted to PSB in an NAD(P)+-dependent reaction. PSB was desulphonated to protocatechuic acid in a reaction requiring NAD(P)H and 1 mol O2 (mol PSB)-1. Experiments with 18 O2 confirmed involvement of a dioxygenase, because both atoms of this molecular oxygen were recovered in protocatechuate. Protocatechuate was converted to 2-hydroxy-4-carboxymuconate semialdehyde by a 4.5-dioxygenase.


Asunto(s)
Bencenosulfonatos/metabolismo , Pseudomonas/metabolismo , Biodegradación Ambiental , Sistema Libre de Células , Oxidación-Reducción , Pseudomonas/crecimiento & desarrollo
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