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1.
Infection ; 43(1): 95-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25037735

RESUMEN

Acinetobacter baumannii is an emerging nosocomial pathogen primarily in countries with a high prevalence of multidrug resistance. Here we report the detection of a bla OXA23 carbapenemase-producing A. baumannii strain in a German patient with prosthetic hip joint infection following several hip joint surgeries but no history of foreign travel.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Prótesis de Cadera/efectos adversos , Infecciones Relacionadas con Prótesis , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/aislamiento & purificación , Adulto , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple , Humanos , Masculino , Reoperación
2.
Diagn Microbiol Infect Dis ; 93(2): 125-130, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30266398

RESUMEN

Periprosthetic joint infections (PJIs) are a major complication in total joint arthroplasty. Staphylococcus aureus and coagulase-negative staphylococci are known to cause the majority of all PJIs. This study aimed to analyze the eradication rates of S. aureus and S. epidermidis with methicillin susceptibility and methicillin resistance in a 2-stage therapy algorithm. Seventy-four patients with PJI caused by methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRSE), methicillin-susceptible S. aureus (MSSA), and methicillin-susceptible coagulase-negative staphylococci (MSSE) were included, and the outcome was analyzed retrospectively. After a minimal follow-up of 2 years, n = 56 patients (75.7%) were definitively free of infection. The analysis revealed significant differences between the groups, with eradication rates as follows: MSSA (92.6%), MSSE (95.2%), MRSA (80%), and MRSE (54.2%). MRSE showed a significantly lower rate of patients graded as "definitively free of infection" as compared to patients with infections caused by MSSA, MSSE, and MRSA.


Asunto(s)
Resistencia a la Meticilina , Infecciones Relacionadas con Prótesis/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Femenino , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Persona de Mediana Edad , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Infecciones Relacionadas con Prótesis/epidemiología , Estudios Retrospectivos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/epidemiología , Resultado del Tratamiento
3.
J Antimicrob Chemother ; 62(5): 1109-12, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18647743

RESUMEN

OBJECTIVES: False-positive results of the galactomannan (GM) ELISA caused by concurrent administration of piperacillin/tazobactam have been reported in patients with febrile neutropenia. PATIENTS AND METHODS: This prospective study investigated different sampling times in 30 patients receiving piperacillin/tazobactam for febrile neutropenia. RESULTS: Prior to the first piperacillin/tazobactam infusion, a median GM index of 0.2 [interquartile range (IQR) 0.1-0.3] was noted; in two patients (7%) the index was 0.5. Immediately after piperacillin/tazobactam infusion, the median index increased to 0.3 (IQR 0.2-0.4, P = 0.002) leading to 21% (7/30) false-positive results, if > or = 0.5 is assumed as the cut-off level. GM indices before the next piperacillin/tazobactam infusion were not increased (median 0.2, IQR 0.2-0.35, P > 0.05), but 10% (3/30) were still > or = 0.5. With a cut-off level of > 0.7, no false-positive results were noted at any sampling time point. CONCLUSIONS: We conclude that the clinical relevance of false-positive GM results during piperacillin/tazobactam treatment is small if samples are collected prior to infusion and if a cut-off level of > 0.7 is used.


Asunto(s)
Aspergilosis/diagnóstico , Aspergillus/aislamiento & purificación , Mananos/sangre , Ácido Penicilánico/análogos & derivados , Piperacilina/uso terapéutico , Anciano , Antígenos Fúngicos/sangre , Aspergillus/química , Ensayo de Inmunoadsorción Enzimática/métodos , Reacciones Falso Positivas , Galactosa/análogos & derivados , Humanos , Persona de Mediana Edad , Ácido Penicilánico/uso terapéutico , Estudios Prospectivos , Tazobactam
4.
Eur J Med Res ; 13(3): 131-2, 2008 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-18499559

RESUMEN

We describe a clinical case of ARDS in an HIV infected patient. ARDS was associated to a respiratory syncytial virus infection that triggered a suspected Pneumocystis infection that despite missing etiologic proofs was treated with antimycotics. As rather limited information on RSV associated ARDS in HIV patients is available in the current literature, this case is of significant interest.


Asunto(s)
Antifúngicos/uso terapéutico , Infecciones por VIH/complicaciones , Síndrome de Dificultad Respiratoria/complicaciones , Infecciones por Virus Sincitial Respiratorio/complicaciones , Adulto , Diagnóstico Diferencial , Humanos , Masculino , Neumonía por Pneumocystis/diagnóstico , Neumonía por Pneumocystis/tratamiento farmacológico , Síndrome de Dificultad Respiratoria/diagnóstico , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Infecciones por Virus Sincitial Respiratorio/tratamiento farmacológico
5.
J Hosp Infect ; 99(2): 208-217, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29203445

RESUMEN

BACKGROUND: The current increase in nosocomial infections caused by vancomycin-resistant enterococci (VRE) warrants improvement of detection methods and hygiene measures. Knowledge of the local epidemiology is important for monitoring compliance of medical personnel with hygiene measures. AIM: To evaluate semi-automated repetitive element palindromic polymerase chain reaction (rep-PCR) for rapid molecular typing of VRE. METHODS: Primary VRE isolates were collected during an observation period of one year and retrospectively typed by rep-PCR. Molecular typing was performed on isolates from two departments with elevated VRE rates and patients with increased risk for systemic VRE infections. Typing results were correlated with temporal and spatial information on patient moves, VRE laboratory results and multi-locus sequence typing (MLST). FINDINGS: Approximately 70% of VRE isolates within a department could be assigned to similarity clusters. Spread of VRE was limited to the individual departments. There was no evidence for spread of endemic VRE strains within the geographical catchment area of the hospital. Our results demonstrate the utility of rep-PCR typing on a department level. However, a Diversilab® threshold of ≥98% had to be applied to claim similarity, and suspected transmissions needed to be confirmed by vanA/B genotyping and compiled information on spatial and temporal patient contact. MLST verified the findings. CONCLUSION: Spread of predominantly detected vancomycin-resistant Enterococcus faecium was limited to the department level with no evidence for wider dissemination within the hospital. Well-standardized and validated (semi-)automated rep-PCR systems are useful for rapid detection of possible VRE transmission. However, suspected transmissions need to be confirmed by clinical and microbiological parameters.


Asunto(s)
Infección Hospitalaria/epidemiología , Enterococcus faecium/aislamiento & purificación , Infecciones por Bacterias Grampositivas/epidemiología , Epidemiología Molecular/métodos , Tipificación Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Enterococos Resistentes a la Vancomicina/aislamiento & purificación , Infección Hospitalaria/microbiología , Infección Hospitalaria/transmisión , ADN Bacteriano/genética , Enterococcus faecium/clasificación , Enterococcus faecium/genética , Monitoreo Epidemiológico , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/transmisión , Departamentos de Hospitales , Humanos , Epidemiología Molecular/normas , Tipificación Molecular/normas , Reacción en Cadena de la Polimerasa/normas , Secuencias Repetitivas de Ácidos Nucleicos , Estudios Retrospectivos , Análisis Espacio-Temporal , Enterococos Resistentes a la Vancomicina/clasificación , Enterococos Resistentes a la Vancomicina/genética
6.
Leukemia ; 12(9): 1338-43, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9737680

RESUMEN

The efficacy of antifungal prophylaxis with itraconazole capsules and its serum concentrations were evaluated in patients intensively treated for acute leukaemia. A consecutive group of patients without systemic antifungal prophylaxis (January 1993 to August 1994, period 1) was compared with another consecutive group of patients (period 2) who received itraconazole capsules (September 1994 to April 1995 400 mg/day, from May 1995 onwards 600 mg/day). All patients admitted with acute leukaemia and standard or high-dose chemotherapy were included into the study. Clinical endpoint was mortality from proven fungal infection. Seventy-six patients and 148 courses of cytotoxic chemotherapy were analysed in the control group as well as 47 patients and 112 treatment courses in the intervention group. Antifungal prophylaxis led to a significant decrease of mortality from invasive fungal infections (8.8%-0.9%, P = 0.005). The median trough concentration of itraconazole of all measurements was 520 ng/ml (range 230-793) in patients who received 400 mg/day and 760 ng/ml (370-1200) in patients receiving a dosage of 600 mg/day (P = 0.002). These findings suggest that itraconazole is an effective drug for antifungal prophylaxis but also that a considerable number of patients do not reach the desired trough levels (>500 ng/ml) with itraconazole capsules.


Asunto(s)
Antifúngicos/uso terapéutico , Itraconazol/uso terapéutico , Micosis/prevención & control , Neutropenia/complicaciones , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Antifúngicos/sangre , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Monitoreo de Drogas , Femenino , Humanos , Itraconazol/sangre , Leucemia/sangre , Leucemia/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Neutropenia/inducido químicamente , Estudios Prospectivos
7.
Biochem Pharmacol ; 44(2): 309-15, 1992 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-1642645

RESUMEN

The metabolism of testosterone and benzo(a)pyrene (BaP) which is mediated by diverse enzymes was determined in cryopreserved rat liver parenchymal cells and compared with that found in freshly isolated cells. In addition, the activities of single xenobiotic-metabolizing enzymes were measured by using specific substrates. The cytochrome P450 (P450)-mediated total metabolic conversion of testosterone was reduced to 55% in cryopreserved cells. The metabolite profile, i.e. the formation of single metabolites compared with total metabolic conversion, was however unchanged when compared with freshly isolated cells. A concomitant reduction in the activities of the involved P450 isoenzymes can therefore be postulated. The amount of detected phase I-metabolites of BaP was unaffected by the cryopreservation method. The formation of phase II-metabolites and total metabolic conversion of BaP in cryopreserved cells was however reduced to about 50-60%. The reduced glutathione S-transferase and more obviously phenol sulfotransferase activities measured in cryopreserved cells, may explain the impaired conjugation of BaP. The ratio between phase I- and phase II-metabolites was thus changed by cryopreservation. Density separation on Percoll yielded cryopreserved cells with a viability and metabolic capacity not measurably different from freshly isolated cells. To this extent, cryopreserved, Percoll-purified liver parenchymal cells are a useful in vitro system for drug metabolism studies. However due to the extensive loss in cell number during this procedure (recovery = 22% of freshly isolated cells) the application of this system is limited.


Asunto(s)
Benzo(a)pireno/metabolismo , Hígado/enzimología , Testosterona/metabolismo , Animales , Arilsulfotransferasa/metabolismo , Recuento de Células , Criopreservación , Sistema Enzimático del Citocromo P-450/metabolismo , Glutatión Transferasa/metabolismo , Hidroxilación , Hígado/metabolismo , Proteínas/análisis , Ratas , Azul de Tripano
8.
Environ Health Perspect ; 88: 71-6, 1990 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2125561

RESUMEN

The ability of isolated rat liver endothelial and Kupffer cells to activate benzo(a)pyrene (BP), trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene (DDBP), trans-1,2-dihydroxy-1,2-dihydrochrysene (DDCH), and aflatoxin B1 (AFB1) to mutagenic metabolites was assessed by means of a cell-mediated bacterial mutagenicity assay and compared with the ability of parenchymal cells to activate these compounds. Endothelial and Kupffer cells from untreated rats were able to activate AFB1 and DDBP; DDBP was activated even in the absence of an NADPH-generating system. Pretreating the animals with Aroclor 1254 strongly enhanced the mutagenicity of the dihydrodiol, whereas the mutagenicity of AFB1 showed a slight increase. BP and DDCH were only activated by endothelial and Kupffer cells isolated from Aroclor 1254-pretreated rats. Parenchymal cells from untreated animals activated all four carcinogens tested; Aroclor 1254 enhanced the parenchymal cell-mediated mutagenicity of BP and DDCH but did not affect that of DDBP and clearly reduced that of AFB1. The reduced mutagenicity of AFB1 correlates with the decrease in the amount of 2 alpha-hydroxytestosterone formed when testosterone was incubated with parenchymal cell microsomes from Aroclor 1254-pretreated rats (compared with microsomes from untreated animals): the formation of 2 alpha-hydroxytestosterone is specifically catalyzed by cytochrome P-450h, a hemoprotein thought to be involved in the activation of AFB1. These results show that not only rat liver parenchymal cells, but also endothelial and Kupffer cells, activate several carcinogens to mutagenic metabolites.


Asunto(s)
Aflatoxinas/farmacocinética , Hígado/metabolismo , Mutágenos/farmacocinética , Compuestos Policíclicos/farmacocinética , Aflatoxina B1 , Animales , Biotransformación , Endotelio Vascular/citología , Endotelio Vascular/metabolismo , Técnicas In Vitro , Macrófagos del Hígado/metabolismo , Hígado/citología , Masculino , Ratas , Ratas Endogámicas , Testosterona/metabolismo
9.
Rofo ; 167(1): 24-31, 1997 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-9289038

RESUMEN

PURPOSE: This retrospective study was designed to show whether invasive pulmonary aspergillosis, which is often difficult to diagnose by bronchoscopy or serology, can be diagnosed at an early stage by typical radiological findings on conventional radiographs or by CT, specially high resolution CT (HR-CT). PATIENTS AND METHODS: In 19 Patients with 20 disease episodes, 20 thorax radiographs and eight spiral CT examinations were performed and in four cases HR-CT was also available. The earliest pathological findings and the course of the disease were analysed and the results of the various examinations were compared. RESULTS: 90% of chest examinations, including CT and HR-CT, showed the following lesions as part of the earliest changes: round or wedge-shaped opacities or the so-called "halo" sign. CT or HR-CT always demonstrated more lesions than plain chest radiographs; 75% of lesions appeared typical and thereby contributed to the diagnosis. CONCLUSION: The typical radiological findings of round or wedge-shaped opacities and the so-called "halo" sign are additional criteria for the diagnosis of invasive pulmonary aspergillosis. The superiority of CT or HR-CT in the demonstration of pathological changes suggests that these should be used early in the investigation of patients who are specially at risk.


Asunto(s)
Aspergilosis/diagnóstico por imagen , Huésped Inmunocomprometido , Enfermedades Pulmonares Fúngicas/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía Torácica/métodos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos
10.
Eur J Clin Microbiol Infect Dis ; 26(11): 801-6, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17786491

RESUMEN

Piperacillin-Tazobactam (Pip-Taz) is an evidence-based empirical treatment of febrile neutropenia in adolescents and adults. No data are available in pediatric cancer patients <25 months of age. In this retrospective, multicenter data survey, the analysis focuses on safety, tolerance, and efficacy. The daily dose administered was 240 mg/kg given in three equally divided doses. Data on 156 Pip-Taz treatment courses in 69 children <25 months from five pediatric cancer treatment centers (2001-2005) were analyzed. The median duration of treatment with Pip-Taz was 5 days (range, 1-23 days; 1-12 Pip-Taz courses per patient). Pip-Taz was started on the first day of fever in 90% of all courses, in 6% in the first 72 h, and in 4% as second- or third-line agent. Forty-five percent of all patients were neutropenic. In all patients, the outcome was favorable independent whether Pip-Taz was given as monotherapy (42 courses; 27%) or in combination. Overall, Pip-Taz was well tolerated and discontinued due to adverse events in only two patients who experienced non-life-threatening allergic reactions (skin rash and wheezing). The results of this study are preliminary due to the methodological limitations of a retrospective survey. Taking this bias into consideration, Pip-Taz appears to be a safe, and feasible alternative in pediatric cancer patients with febrile neutropenia <25 months of age suggesting that the inclusion of children of all age groups in future prospective controlled studies evaluating Pip-Taz is justified.


Asunto(s)
Infecciones Bacterianas/tratamiento farmacológico , Neoplasias/complicaciones , Fiebre de Origen Desconocido/tratamiento farmacológico , Humanos , Hipersensibilidad , Lactante , Recién Nacido , Neutropenia , Ácido Penicilánico/administración & dosificación , Ácido Penicilánico/efectos adversos , Ácido Penicilánico/análogos & derivados , Ácido Penicilánico/uso terapéutico , Piperacilina/administración & dosificación , Piperacilina/efectos adversos , Piperacilina/uso terapéutico , Combinación Piperacilina y Tazobactam , Estudios Retrospectivos , Resultado del Tratamiento , Privación de Tratamiento
11.
In Vitro Cell Dev Biol ; 27A(11): 858-63, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1748626

RESUMEN

Cytochrome P-450 dependent hydroxylation of testosterone was measured in 7-day-old cultures of primary rat liver parenchymal cells. Determinations were carried out in monocultures of parenchymal cells and co-cultures of parenchymal cells with rat liver nonparenchymal epithelial cells, or mouse embryo fibroblasts. In the monoculture system, testosterone metabolism was drastically reduced and hardly measurable after 7 days in culture. In the co-culture systems, individual P-450 isoenzymes were stabilized on different levels. P-450s p and presumably c were well preserved, P-450 a was reduced but clearly measurable, P-450 h was totally lost whereas P-450s b and e were not measurable after 7 days (the activities of these isoenzymes however were already low in freshly isolated parenchymal cells). The results were independent of the cell line used for co-cultivation and of the method of parenchymal cell isolation, that is whether collagenase or EDTA was used as the agent for dissociating the cells from the liver. The results showed that the co-cultivation of liver parenchymal cells with other nonparenchymal cells significantly improved the differentiated status of the former. In this cell culture system however, not every parameter was equally well stabilized.


Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Isoenzimas/metabolismo , Hígado/citología , Animales , Células Cultivadas , Sistema Enzimático del Citocromo P-450/fisiología , Embrión de Mamíferos/citología , Estabilidad de Enzimas , Fibroblastos/citología , Hidroxilación , Hígado/enzimología , Masculino , Ratones , Ratones Endogámicos C3H , Ratas , Ratas Endogámicas , Testosterona/metabolismo
12.
Antimicrob Agents Chemother ; 39(3): 714-9, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7793878

RESUMEN

Mersacidin is an antibiotic peptide produced by Bacillus sp. strain HIL Y-85,54728 that belongs to the group of lantibiotics. Its activity in vivo against methicillin-resistant Staphylococcus aureus strains compares with that of the glycopeptide antibiotic vancomycin (S. Chatterjee, D. K. Chatterjee, R. H. Jani, J. Blumbach, B. N. Ganguli, N. Klesel, M. Limbert, and G. Seibert, J. Antibiot. 45:839-845, 1992). Incubation of Staphylococcus simulans 22 with mersacidin resulted in the cessation of growth and slow lysis. Biosyntheses of DNA, RNA, and protein were not affected, whereas incorporation of glucose and D-alanine was inhibited and a regular reduction in the level of cell wall thickness was observed. Thus, unlike type A lantibiotics, mersacidin does not form pores in the cytoplasmic membrane but rather inhibits cell wall biosynthesis. Comparison with tunicamycin-treated cells indicated that peptidoglycan rather than teichoic acid metabolism is primarily affected. Mersacidin caused the excretion of a putative cell wall precursor into the culture supernatant. The formation of polymeric peptidoglycan was effectively inhibited in an in vitro assay, probably on the level of transglycosylation. In contrast to vancomycin, the activity of mersacidin was not antagonized by the tripeptide diacetyl-L-Lys-D-Ala-D-Ala, indicating that on the molecular level its mode of action differs from those of glycopeptide antibiotics. These data together with electron microscopy suggest that mersacidin acts on a novel target, which opens new perspectives for the treatment of methicillin-resistant S. aureus.


Asunto(s)
Antibacterianos/farmacología , Bacterias/metabolismo , Péptidos , Peptidoglicano/biosíntesis , Secuencia de Aminoácidos , Bacterias/efectos de los fármacos , Bacterias/ultraestructura , Bacteriocinas , Pared Celular/efectos de los fármacos , Pared Celular/metabolismo , Medios de Cultivo , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Micrococcus luteus/efectos de los fármacos , Micrococcus luteus/metabolismo , Micrococcus luteus/ultraestructura , Microscopía Electrónica , Datos de Secuencia Molecular , Fosfatos/metabolismo , Staphylococcus/efectos de los fármacos , Staphylococcus/metabolismo , Staphylococcus/ultraestructura , Vancomicina/farmacología
13.
Toxicol Appl Pharmacol ; 129(1): 155-62, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7974489

RESUMEN

Oral administration of benzilic acid ester-based acaricide bromopropylate at daily doses of 3, 15, 100, and 300 mg/kg body wt to young adult male Tif:MAGf mice for 14 days caused slightly increased liver weights in the high-dose group. A dose-dependent increase of the microsomal cytochrome P450 content was accompanied by elevated ethoxycoumarin O-deethylase, ethoxyresorufin O-deethylase, pentoxyresorufin O-depentylase, and total testosterone hydroxylase activities. When compared with mice treated in parallel with the model compounds for hepatic xenobiotic metabolizing enzyme induction, phenobarbitone, and 3-methylcholanthrene, the enzyme activity changes observed with bromopropylate largely equalled those expressed in phenobarbitone-treated mice. Immunochemical studies with monoclonal antibodies against rat liver cytochrome P450 isoenzymes of the gene families 1A, 2B, 3A, and 4A confirmed that bromopropylate is a phenobarbitone-type inducer in the mouse liver. Titration of liver microsomal suspensions with bromopropylate yielded Type I substrate binding spectra. The specific amplitude was increased 1.5-fold when microsomes from bromopropylate-treated mice (300 mg/kg body wt) were used instead of control microsomes, indicating the induction of cytochromes P450 catalyzing the oxidative metabolism of the test compound. Single oral administration of 300 mg/kg body wt [14C]bromopropylate to male mice, without or following pretreatment for 14 days with 300 mg/kg body wt unlabeled bromopropylate, gave no indication for DNA binding of the test compound in the liver. This excludes a genotoxic potential via covalent DNA modification. The results suggest that, in analogy to phenobarbitone, bromopropylate acts as a tumor promotor rather than a tumor initiator in the mouse liver.


Asunto(s)
Hidrocarburo de Aril Hidroxilasas , Bencilatos/toxicidad , Sistema Enzimático del Citocromo P-450/metabolismo , ADN/metabolismo , Insecticidas/toxicidad , Hígado/efectos de los fármacos , 7-Alcoxicumarina O-Dealquilasa/metabolismo , Administración Oral , Análisis de Varianza , Animales , Anticuerpos Monoclonales , Especificidad de Anticuerpos , Bencilatos/administración & dosificación , Sitios de Unión/efectos de los fármacos , Unión Competitiva , Fraccionamiento Celular , Citocromo P-450 CYP1A1 , Citocromo P-450 CYP2B1 , Citosol/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Inducción Enzimática/efectos de los fármacos , Immunoblotting , Insecticidas/administración & dosificación , Hígado/enzimología , Hígado/metabolismo , Masculino , Ratones , Microsomas Hepáticos/efectos de los fármacos , Oxidorreductasas/metabolismo , Distribución Aleatoria , Esteroide Hidroxilasas/metabolismo
14.
Plant Physiol ; 102(1): 71-83, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8108506

RESUMEN

A heterologous probe encoding phenylalanine ammonia-lyase (PAL) was used to identify PAL clones in cDNA libraries made with RNA from young leaf tissue of two Populus deltoides x P. trichocarpa F1 hybrid clones. Sequence analysis of a 2.4-kb cDNA confirmed its identity as a full-length PAl clone. The predicted amino acid sequence is conserved in comparison with that of PAL genes from several other plants. Southern blot analysis of popular genomic DNA from parental and hybrid individuals, restriction site polymorphism in PAL cDNA clones, and sequence heterogeneity in the 3' ends of several cDNA clones suggested that PAL is encoded by at least two genes that can be distinguished by HindIII restriction site polymorphisms. Clones containing each type of PAL gene were isolated from a poplar genomic library. Analysis of the segregation of PAL-specific HindIII restriction fragment-length polymorphisms demonstrated the existence of two independently segregating PAL loci, one of which was mapped to a linkage group of the poplar genetic map. Developmentally regulated PAL expression in poplar was analyzed using RNA blots. Highest expression was observed in young stems, apical buds, and young leaves. Expression was lower in older stems and undetectable in mature leaves. Cellular localization of PAL expression by in situ hybridization showed very high levels of expression in subepidermal cells of leaves early during leaf development. In stems and petioles, expression was associated with subepidermal cells and vascular tissues.


Asunto(s)
Genes de Plantas , Fenilanina Amoníaco-Liasa/genética , Plantas/enzimología , Plantas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Regulación de la Expresión Génica , Hibridación Genética , Datos de Secuencia Molecular , Familia de Multigenes , Desarrollo de la Planta , Homología de Secuencia de Aminoácido , Árboles
15.
Biochem Biophys Res Commun ; 160(1): 46-52, 1989 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-2540752

RESUMEN

The phosphorylation of the two major phenobarbital-inducible cytochrome P450 isoenzymes IIB1 and IIB2 was increased in hepatocytes by the action of the membrane permeating cAMP derivatives N6-dibutyryl-cAMP and 8-thiomethyl-cAMP. Under these conditions the dealkylation of 7-pentoxyresorufin, a selective substrate of cytochrome P450IIB1 and P450IIB2 was markedly reduced. 16 beta-Hydroxylation of testosterone which is catalyzed specifically only by cytochrome P450IIB1 and IIB2 was strongly reduced; for 16 alpha-hydroxylation which is also catalyzed by cytochrome P450IIB1 and IIB2 but additionally by 3 further cytochrome P450 isoenzymes, this reduction was less pronounced; for the oxidation of the 17 beta-hydroxyl group which besides cytochromes P450IIB1 and IIB2 is additionally catalyzed not only by other cytochromes P450 but also by 17 beta-hydroxysteroid dehydrogenase there was a clear tendency of reduction which, however, no longer reached statistical significance. Hydroxylation at other positions of testosterone which are catalyzed by other cytochrome P450 isoenzymes were not significantly changed. Hence isoenzyme-selective phosphorylation of cytochrome P450 leads to a corresponding isoenzyme-selective modulation of monooxygenase activity which holds promise to be especially important as a fast regulation of the control of genotoxic metabolites.


Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Isoenzimas/metabolismo , Hígado/enzimología , Oxigenasas de Función Mixta/metabolismo , Procesamiento Proteico-Postraduccional , Animales , AMP Cíclico/farmacología , Hidroxilación , Masculino , Fenobarbital/farmacología , Fosforilación , Ratas , Ratas Endogámicas , Esteroide 16-alfa-Hidroxilasa , Testosterona/metabolismo
16.
Zentralbl Bakteriol ; 284(2-3): 318-28, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8837393

RESUMEN

Mersacidin is a lanthionine-containing peptide antibiotic (lantibiotic), able to inhibit the growth of a number of Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) in a manner similar to, but distinct from, vancomycin. In order to further understand the mode of action of this lantibiotic, Staphylococcus simulans 22 cells were treated either with the antibiotics penicillin, tunicamycin or vancomycin or with mersacidin and then compared with untreated cells after electron microscopic examination. Mersacidin treatment brought about a time-dependent, generalised decrease in the thickness of the bacterial cell wall. In addition, mersacidin treatment caused a roughening of the cell wall surface layer and also reduced the thickness and frequency of formation of dividing cell septa. Reduction of cell wall thickness appears to result from inhibition of new wall biosynthesis combined with cell wall turnover. These features of mersacidin-induced effects on cell morphology confirm that it has a novel mode of action (Brötz, H., G. Bierbaum, A. Markus, E. Molitor, and H.-G. Sahl: Antimicrob. Agents Chemother. 39 [1995] 714-719), probably directed towards a membrane-bound biosynthetic step but not towards a specific penicillin-binding-protein.


Asunto(s)
Alanina/análogos & derivados , Antibacterianos/farmacología , Péptidos , Staphylococcus/efectos de los fármacos , Staphylococcus/ultraestructura , Alanina/farmacología , Bacteriocinas , Penicilinas/farmacología , Sulfuros , Tunicamicina/farmacología , Vancomicina/farmacología
17.
Zentralbl Bakteriol ; 284(2-3): 466-73, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8837405

RESUMEN

65 different clinical specimens from patients suspected of being infected with Mycobacterium tuberculosis were examined by three different diagnostic methods. Two of these methods were the conventional microscopic and cultural examinations. The third, a modern chemotaxonomical method is based upon the detection of tuberculostearic acid by GC-MS analysis using selected ion monitoring (GC-MS/SIM). Comparison of the results of the GC-MS analysis with those of the conventional methods has indicated that tuberculostearic acid analysis can be used for diagnosing tuberculosis under diagnostic routine conditions. The GC-MS method is rapid, usually providing results within 20 hours or less.


Asunto(s)
Cromatografía de Gases y Espectrometría de Masas , Mycobacterium tuberculosis/aislamiento & purificación , Ácidos Esteáricos/análisis , Tuberculosis/microbiología , Humanos , Metanol/farmacología , Mycobacterium tuberculosis/metabolismo , Factores de Tiempo , Tuberculosis/diagnóstico , Tuberculosis/patología
18.
Plant Mol Biol ; 39(4): 657-69, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10350081

RESUMEN

Phenylalanine ammonia-lyase (PAL) catalyzes the first step in phenylpropanoid metabolism and plays a central role in the biosynthesis of phenylpropanoid compounds. We have previously cloned two PAL genes, PALI and PAL2, from a Populus trichocarpa x P. deltoides F1 hybrid. Here, we describe the properties of PALI and PAL2 promoters and their expression patterns in transgenic tobacco and poplar. The promoters were 75% identical in the regions sequenced, and each contained two copies of AC-rich putative cis-acting elements that matched a consensus plant myb transcription factor binding site sequence. In transgenic tobacco, PALI-GUS and PAL2-GUS fusions directed similar patterns of expression in developing primary xylem of leaves, stems, and other organs, and in secondary xylem of stems. Contrary to previously documented patterns of PAL1/2 expression in poplar, no expression of either fusion was detected in epidermal or subepidermal cell layers of young tobacco leaves or stems. In poplar, the PAL2-GUS fusion directed the highest levels of expression in roots and young leaves and stems. In young leaves and stems, high GUS activity was detected in epidermal or subepidermal cells as well as in primary xylem and phloem fibers. GUS activity was low in woody stems, and was weak or absent in developing secondary xylem. The patterns of PAL2-GUS expression in poplar are very similar to those of PAL1/2 mRNA accumulation in poplar. However, the distinct patterns of expression directed by the PAL2 promoter in poplar and tobacco show that PAL2-GUS expression in tobacco does not accurately reflect all aspects of PAL2 expression in poplar.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Fenilanina Amoníaco-Liasa/genética , Regiones Promotoras Genéticas , Árboles/crecimiento & desarrollo , Árboles/genética , Secuencia de Bases , Sitios de Unión , Secuencia Conservada , Regulación del Desarrollo de la Expresión Génica , Genes de Plantas , Isoenzimas/biosíntesis , Isoenzimas/genética , Datos de Secuencia Molecular , Fenilanina Amoníaco-Liasa/biosíntesis , Hojas de la Planta , Tallos de la Planta , Plantas Modificadas Genéticamente , Plantas Tóxicas , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-myb , Mapeo Restrictivo , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico , Nicotiana/genética , Nicotiana/metabolismo , Transactivadores/metabolismo , Factores de Transcripción , Árboles/metabolismo
19.
Mycoses ; 42(5-6): 395-402, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10536431

RESUMEN

Fungal colonization has been associated with an increased rate of invasive fungal infections in neutropenic patients. This study evaluates weekly fungal surveillance cultures from the oropharyngeal and perianal space as well as other suspected sites in 219 courses of myelosuppressive chemotherapy with itraconazole antifungal prophylaxis in 116 neutropenic patients with acute leukaemia. Itraconazole was given from the start of chemotherapy in one of six different dosing regimens. Fungal colonization occurred in 68 (31%) of courses, which was lower than in a historical control group without prophylaxis (53%, P = 0.004). Twenty-six per cent of these 116 isolates had a growth rate of more than 50 colony forming units (CFU) per culture. Candida glabrata (51%), Candida albicans (18%) and Candida krusei (4%) were the most frequently isolated species. Higher median itraconazole trough concentrations were associated with a lower growth rate in the cultures (< or = 50 CFU/culture versus > 50 CFU/culture): 710 (430-1180) ng ml-1 versus 900 (560-1650) ng ml-1 (P = 0.015). The use of itraconazole solution--compared with capsules--led to a reduced growth rate (P = 0.035). In conclusion, compared with historical controls itraconazole antifungal prophylaxis reduces the incidence and the extent of fungal colonization during neutropenia in patients with acute leukaemia.


Asunto(s)
Itraconazol/uso terapéutico , Leucemia/complicaciones , Micosis/prevención & control , Enfermedad Aguda , Canal Anal/microbiología , Antifúngicos/uso terapéutico , Humanos , Leucemia Mieloide/complicaciones , Micosis/complicaciones , Orofaringe/microbiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones
20.
Mycoses ; 42(11-12): 591-600, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10680434

RESUMEN

We have previously shown that a trough concentration of at least 500 ng ml-1 itraconazole is necessary for an effective antifungal prophylaxis in neutropenic patients. Since the bioavailability of itraconazole is reduced in these patients, a satisfactory dosing regimen remains to be defined. In this study, six dosing regimens with itraconazole capsules 400, 600 or 800 mg day-1, itraconazole solution 400 mg day-1 (additional loading dose: 400 mg day-1 solution for 2 days), 800 mg day-1 or 400 mg day-1 (additional loading dose: 800 mg day-1 capsules for 7 days, s/c1200) were compared during 160 courses of myelosuppressive chemotherapy in 123 patients with acute leukaemia. After the first week, patients taking 800 mg day-1 or 400 mg day-1 (s/c1200) itraconazole solution achieved significantly higher trough concentrations (high-performance liquid chromatography) than patients in other groups (P < 0.05) and 87 and 100%, respectively, of these had concentrations > 500 ng ml-1. Contrary to a dose of 400 mg day-1, a dose of 800 mg day-1 itraconazole solution induced severe nausea and vomiting in 46% of the patients. We conclude that 400 mg day-1 itraconazole solution with a loading dose of 800 mg day-1 capsules for 7 days resulted in sufficient trough concentrations from the first week onwards and appears to be suitable for antifungal prophylaxis in neutropenic patients.


Asunto(s)
Antifúngicos/sangre , Itraconazol/sangre , beta-Ciclodextrinas , 2-Hidroxipropil-beta-Ciclodextrina , Administración Oral , Antifúngicos/administración & dosificación , Cápsulas , Ciclodextrinas , Humanos , Itraconazol/administración & dosificación , Micosis/prevención & control , Neutropenia/tratamiento farmacológico , Soluciones
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