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1.
J Affect Disord ; 351: 971-976, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38346649

RESUMEN

BACKGROUND: Suicidal ideation is a major concern in clinical practice. Yet, little is known about prevalence rates of suicidal ideation in patients undergoing outpatient psychotherapeutic treatment. Therefore, the aim of the current study is to assess the prevalence of suicidal ideation in a large sample of psychotherapy outpatients in Germany. The data analyzed in this study is taken from the KODAP-project on the coordination of data collection and analysis at German university-based research and training outpatient clinics for psychotherapy. METHODS: A total of N = 10,357 adult outpatients (64.4 % female; age: M(SD) = 35.94 (13.54), range: 18-92 years of age) starting cognitive-behavioral therapy at one of 27 outpatient clinics in Germany were included in the current study. Prevalence of suicidal ideation was assessed with the Suicide Item (Item 9) of the Beck-Depression Inventory II. RESULTS: Suicidal ideation was reported by 36.7 % (n = 3795) of the participants. Borderline Personality Disorder, Posttraumatic Stress Disorder, and recurrent Major Depression were the diagnoses most strongly associated with the presence and severity of suicidal ideation. LIMITATION: Suicide ideation was assessed only with the respective item of the Beck Depression Inventory II. CONCLUSION: Suicidal ideation is very common among adult patients who start psychotherapy in Germany. A well-founded knowledge of risk assessment in suicidal patients and suicide-specific treatment options is therefore highly relevant.


Asunto(s)
Trastorno Depresivo Mayor , Ideación Suicida , Adulto , Humanos , Femenino , Masculino , Pacientes Ambulatorios , Prevalencia , Trastorno Depresivo Mayor/epidemiología , Trastorno Depresivo Mayor/terapia , Trastorno Depresivo Mayor/diagnóstico , Psicoterapia , Factores de Riesgo
2.
Ophthalmologe ; 118(10): 995-1003, 2021 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-33893529

RESUMEN

The indications for orbital tumor surgery are an incisional biopsy to confirm the diagnosis or in malignant operable tumors a complete excision or a debulking to avoid complications in large invasively infiltrating tumors. In the case of benign tumors, the indications for surgery depend mostly on the clinical symptoms and cosmetic esthetic disfigurement. In the present article the preoperative examinations as well as surgical access approaches to different orbital regions, endoscopic procedures and methods of intraoperative navigation are presented. Magnetic resonance imaging is the instrument of choice, whereby in many cases computed tomography (CT) adds further information. Depending on the indications, diffusion-weighted sequences, CT angiography and digital subtraction angiography (DSA, catheter angiography) are added to the preoperative diagnostics. For space-occupying lesions located anterior to the bulbar equator, an anterior orbitotomy can be performed transconjunctivally or transpalpebrally. A lateral orbitotomy is used to reach lateral, laterocranial, and lateroinferior orbital segments, whereas transcranial approaches are suitable for processes located far posterior and for those with retro-orbital intracranial extension as well as for processes in the optic foramen/superior orbital fissure. The indications for an endonasal access approach are processes medial to the bulb or optic nerve and up to the orbital apex. A transantral access can be chosen for caudal, mediolateral, and medioinferior space-occupying lesions. Modern orbital surgery is complemented by endoscopic procedures and intraoperative navigation. Orbital tumors belong to the interdisciplinary relevant diseases. Therefore, an optimal management takes place at specialized multidisciplinary centers.


Asunto(s)
Neoplasias Orbitales , Biopsia , Endoscopía , Humanos , Órbita/diagnóstico por imagen , Órbita/cirugía , Neoplasias Orbitales/diagnóstico por imagen , Neoplasias Orbitales/cirugía , Tomografía Computarizada por Rayos X
3.
Clin Oral Investig ; 25(10): 5823-5831, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33774714

RESUMEN

OBJECTIVES: For many years, tumor development has been viewed as a cell-autonomous process; however, today we know that the tumor microenvironment (TME) and especially cancer-associated fibroblasts (CAFs) significantly contribute to tumor progression. Caveolin-1 (Cav-1) is a scaffolding protein which is involved in several cancer-associated processes as important component of the caveolae. Our goal was to shed light on the expression of the two different isoforms of Cav-1 in normal fibroblasts (NFs) and CAFs of patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Fibroblasts from normal mucosa and CAFs were isolated and propagated in vitro. Gene expression of the different Cav-1 isoforms was assessed via quantitative real-time PCR (qPCR) and supplemented by protein expression analysis. RESULTS: We could show that the Cav-1ß isoform is more highly expressed in NFs and CAFs compared to Cav-1α. Furthermore, the different Cav-1 isoforms tended to be differently expressed in different tumor stages. However, this trend could not be seen consistently, which is in line with the ambiguous role of Cav-1 in tumor progression described in literature. Western blotting furthermore revealed that NFs and CAFs might differ in the oligomerization profile of the Cav-1 protein. CONCLUSION: These differences in expression of Cav-1 between NFs and CAFs of patients with OSCC confirm that the protein might play a role in tumor progression and is of interest for further analyses. CLINICAL RELEVANCE: Our findings support a possible role of the two isoforms of Cav-1 in the malignant transformation of OSCC.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Caveolina 1 , Línea Celular Tumoral , Fibroblastos , Humanos , Isoformas de Proteínas , Carcinoma de Células Escamosas de Cabeza y Cuello , Microambiente Tumoral
5.
J Bacteriol ; 199(20)2017 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-28784814

RESUMEN

Anaerobic phenylalanine (Phe) degradation in the betaproteobacterium Aromatoleum aromaticum involves transamination and decarboxylation to phenylacetaldehyde, followed by oxidation to phenylacetate. The latter reaction is catalyzed simultaneously by two enzymes, a highly specific phenylacetaldehyde dehydrogenase (PDH) and a rather unspecific tungsten-dependent aldehyde oxidoreductase (AOR). Attempting to establish increased synthesis of AOR, we constructed a mutant lacking the gene for PDH. This mutant still grew on phenylalanine, exhibiting increased AOR activities on medium containing tungstate. In the absence of tungstate, the mutant showed initially severe growth deficiency, but it resumed growth on Phe after longer incubation times. Moreover, the growth rates of the mutant increased during several reinoculation cycles on either tungstate-proficient or -deficient media, reaching the same values as recorded in wild-type strains. We confirmed AOR as the major alternative enzyme serving Phe degradation under tungstate-supplied conditions and identified and characterized the alternative NAD-dependent aldehyde dehydrogenase AldB taking over the function under tungstate-deficient conditions. Sequence analysis of the respective genes from adapted cultures under either growth condition revealed a mutation in the upstream region of the aor operon and a mutation within the coding region of aldB, which are likely involved in the observed adaptation of the deletion mutant to regain fast growth on Phe.IMPORTANCE The betaproteobacterium Aromatoleum aromaticum degrades many aromatic compounds under denitrifying conditions. One of the steps of phenylalanine degradation is catalyzed by two simultaneously induced enzymes, a NAD(P)-dependent phenylacetaldehyde dehydrogenase and a W-containing aldehyde oxidoreductase. We report here that the latter fully complements a constructed deletion mutant lacking the gene for phenylacetaldehyde dehydrogenase and is overproduced after several reinoculations. Moreover, an alternative NAD-dependent dehydrogenase is recruited to resume growth in tungstate-free medium, which does not allow the production of aldehyde oxidoreductase. This alternative enzyme is overproduced and seems to have acquired a point mutation in the active center. Our research illustrates the flexibility of environmentally important bacteria in adapting their metabolic pathways to new challenges within only a few generations.

6.
Environ Mol Mutagen ; 58(3): 172-177, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28370324

RESUMEN

Cold atmospheric argon plasma is recognized as a new contact free approach for the decrease of bacterial load on chronic wounds in patients. So far very limited data are available on its toxicity and mutagenicity on eukaryotic cells. Thus, the toxic/mutagenic potential of cold atmospheric argon plasma using the MicroPlaSter ß® , which has been used efficiently in humans treating chronic and acute wounds, was investigated using the XTT assay in keratinocytes and fibroblasts and the HGPRT (hypoxanthine guanine phosphoribosyl transferase) assay with V79 Chinese hamster cells. The tested clinical parameter of a 2 min cold atmospheric argon plasma treatment revealed no relevant toxicity on keratinocytes (viability: 76% ± 0.17%) and on fibroblasts (viability: 81.8 ± 0.10) after 72 hr as compared to the untreated controls. No mutagenicity was detected in the HGPRT assay with V79 cells even after repetitive CAP treatments of 2-10 min every 24 hr for up to 5 days. In contrast, UV-C irradiation of V79 cells, used as a positive control in the HGPRT test, led to DNA damage and mutagenic effects. Our findings indicate that cold atmospheric plasma using the MicroPlaSter ß® shows negligible effects on keratinocytes and fibroblasts but no mutagenic potential in the HGPRT assay, indicating a new contact free safe technology. Environ. Mol. Mutagen. 58:172-177, 2017. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Argón/toxicidad , Fibroblastos/efectos de los fármacos , Queratinocitos/efectos de los fármacos , Mutágenos/toxicidad , Gases em Plasma/toxicidad , Animales , Supervivencia Celular/efectos de los fármacos , Cricetinae , Fibroblastos/patología , Humanos , Hipoxantina Fosforribosiltransferasa/genética , Queratinocitos/patología , Pruebas de Mutagenicidad , Cultivo Primario de Células
7.
Appl Microbiol Biotechnol ; 99(12): 5055-69, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25549618

RESUMEN

Enzyme-catalyzed enantioselective reductions of ketones and keto esters have become popular for the production of homochiral building blocks which are valuable synthons for the preparation of biologically active compounds at industrial scale. Among many kinds of biocatalysts, dehydrogenases/reductases from various microorganisms have been used to prepare optically pure enantiomers from carbonyl compounds. (S)-1-phenylethanol dehydrogenase (PEDH) was found in the denitrifying bacterium Aromatoleum aromaticum (strain EbN1) and belongs to the short-chain dehydrogenase/reductase family. It catalyzes the stereospecific oxidation of (S)-1-phenylethanol to acetophenone during anaerobic ethylbenzene mineralization, but also the reverse reaction, i.e., NADH-dependent enantioselective reduction of acetophenone to (S)-1-phenylethanol. In this work, we present the application of PEDH for asymmetric reduction of 42 prochiral ketones and 11 ß-keto esters to enantiopure secondary alcohols. The high enantioselectivity of the reaction is explained by docking experiments and analysis of the interaction and binding energies of the theoretical enzyme-substrate complexes leading to the respective (S)- or (R)-alcohols. The conversions were carried out in a batch reactor using Escherichia coli cells with heterologously produced PEDH as whole-cell catalysts and isopropanol as reaction solvent and cosubstrate for NADH recovery. Ketones were converted to the respective secondary alcohols with excellent enantiomeric excesses and high productivities. Moreover, the progress of product formation was studied for nine para-substituted acetophenone derivatives and described by neural network models, which allow to predict reactor behavior and provides insight on enzyme reactivity. Finally, equilibrium constants for conversion of these substrates were derived from the progress curves of the reactions. The obtained values matched very well with theoretical predictions.


Asunto(s)
Proteínas Bacterianas/metabolismo , Ésteres/metabolismo , Cetonas/metabolismo , Oxidorreductasas/metabolismo , Rhodocyclaceae/enzimología , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Catálisis , Desnitrificación , Cetonas/química , Cinética , Oxidación-Reducción , Oxidorreductasas/química , Oxidorreductasas/genética , Rhodocyclaceae/química , Rhodocyclaceae/genética , Estereoisomerismo , Especificidad por Sustrato
8.
J Biotechnol ; 192 Pt B: 400-9, 2014 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-24998764

RESUMEN

The molybdenum/iron-sulfur/heme protein ethylbenzene dehydrogenase (EbDH) was successfully applied to catalyze enantiospecific hydroxylation of alkylaromatic and alkylheterocyclic compounds. The optimization of the synthetic procedure involves use of the enzyme in a crude purification state that saves significant preparation effort and is more stable than purified EbDH without exhibiting unwanted side reactions. Moreover, immobilization of the enzyme on a crystalline cellulose support and changes in reaction conditions were introduced in order to increase the amounts of product formed (anaerobic atmosphere, electrochemical electron acceptor recycling or utilization of ferricyanide as alternative electron acceptor in high concentrations). We report here on an extension of effective enzyme activity from 4h to more than 10 days and final product yields of up to 0.4-0.5g/l, which represent a decent starting point for further optimization. Therefore, we expect that the hydrocarbon-hydroxylation capabilities of EbDH may be developed into a new process of industrial production of chiral alcohols.


Asunto(s)
Alcoholes/química , Alcoholes/metabolismo , Enzimas Inmovilizadas/metabolismo , Ingeniería Metabólica/métodos , Oxidorreductasas/metabolismo , Enzimas Inmovilizadas/química , Ferricianuros , Hidroxilación , Molibdeno , Oxidorreductasas/química , Rhodocyclaceae/enzimología , Estereoisomerismo , Especificidad por Sustrato
9.
FEBS Lett ; 509(3): 345-9, 2001 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-11749953

RESUMEN

CoA-transferases are found in organisms from all lines of descent. Most of these enzymes belong to two well-known enzyme families, but recent work on unusual biochemical pathways of anaerobic bacteria has revealed the existence of a third family of CoA-transferases. The members of this enzyme family differ in sequence and reaction mechanism from CoA-transferases of the other families. Currently known enzymes of the new family are a formyl-CoA: oxalate CoA-transferase, a succinyl-CoA: (R)-benzylsuccinate CoA-transferase, an (E)-cinnamoyl-CoA: (R)-phenyllactate CoA-transferase, and a butyrobetainyl-CoA: (R)-carnitine CoA-transferase. In addition, a large number of proteins of unknown or differently annotated function from Bacteria, Archaea and Eukarya apparently belong to this enzyme family. Properties and reaction mechanisms of the CoA-transferases of family III are described and compared to those of the previously known CoA-transferases.


Asunto(s)
Bacterias Anaerobias/enzimología , Coenzima A Transferasas/clasificación , Coenzima A Transferasas/metabolismo , Proteínas Bacterianas/clasificación , Proteínas Bacterianas/metabolismo , Unión Competitiva , Coenzima A Transferasas/química , Cinética , Especificidad por Sustrato , Tioléster Hidrolasas/clasificación , Tioléster Hidrolasas/metabolismo
10.
Arch Microbiol ; 176(1-2): 129-35, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11479712

RESUMEN

The initial steps in the anaerobic oxidation of the aromatic hydrocarbon ethylbenzene by denitrifying bacteria are two sequential dehydrogenation reactions of ethylbenzene to (S)-1-phenylethanol and further to acetophenone. The enzyme catalysing the second oxidation step, (S)-1-phenylethanol dehydrogenase, was analysed in the denitrifying bacterium Azoarcus sp. strain EbN1. An NAD+-dependent 1-phenylethanol dehydrogenase for each of the enantiomers of 1-phenylethanol was identified in this bacterium; the two enzymes were induced under different growth conditions. (S)-1-phenylethanol dehydrogenase from ethylbenzene-grown cells was purified and biochemically characterised. The enzyme is a typical secondary alcohol dehydrogenase and consists of two subunits of 25.5 kDa. The enantioselective enzyme catalyses the oxidation of (S)-1-phenylethanol or the reduction of acetophenone and is inhibited by high concentrations of (R)-1-phenylethanol. The enzyme exhibits low apparent K(m) values for (S)-1-phenylethanol and acetophenone and is rather substrate-specific, using only a few chemically similar secondary alcohols, such as 1-phenylpropanol and isopropanol.


Asunto(s)
Azoarcus/enzimología , Derivados del Benceno/metabolismo , Oxidorreductasas/metabolismo , 2-Propanol/metabolismo , Secuencia de Aminoácidos , Anaerobiosis , Azoarcus/crecimiento & desarrollo , Azoarcus/metabolismo , Catálisis , Isoenzimas/antagonistas & inhibidores , Isoenzimas/aislamiento & purificación , Isoenzimas/metabolismo , Cinética , Datos de Secuencia Molecular , Peso Molecular , Oxidorreductasas/antagonistas & inhibidores , Oxidorreductasas/química , Oxidorreductasas/aislamiento & purificación , Propanoles/metabolismo , Subunidades de Proteína , Alineación de Secuencia , Especificidad por Sustrato
11.
J Bacteriol ; 183(14): 4288-95, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11418570

RESUMEN

Anaerobic microbial toluene catabolism is initiated by addition of fumarate to the methyl group of toluene, yielding (R)-benzylsuccinate as first intermediate, which is further metabolized via beta-oxidation to benzoyl-coenzyme A (CoA) and succinyl-CoA. A specific succinyl-CoA:(R)-benzylsuccinate CoA-transferase activating (R)-benzylsuccinate to the CoA-thioester was purified and characterized from Thauera aromatica. The enzyme is fully reversible and forms exclusively the 2-(R)-benzylsuccinyl-CoA isomer. Only some close chemical analogs of the substrates are accepted by the enzyme: succinate was partially replaced by maleate or methylsuccinate, and (R)-benzylsuccinate was replaced by methylsuccinate, benzylmalonate, or phenylsuccinate. In contrast to all other known CoA-transferases, the enzyme consists of two subunits of similar amino acid sequences and similar sizes (44 and 45 kDa) in an alpha(2)beta(2) conformation. Identity of the subunits with the products of the previously identified toluene-induced bbsEF genes was confirmed by determination of the exact masses via electrospray-mass spectrometry. The deduced amino acid sequences resemble those of only two other characterized CoA-transferases, oxalyl-CoA:formate CoA-transferase and (E)-cinnamoyl-CoA:(R)-phenyllactate CoA-transferase, which represent a new family of CoA-transferases. As suggested by kinetic analysis, the reaction mechanism of enzymes of this family apparently involves formation of a ternary complex between the enzyme and the two substrates.


Asunto(s)
Acilcoenzima A/metabolismo , Coenzima A Transferasas/metabolismo , Succinatos/metabolismo , Thauera/enzimología , Tolueno/metabolismo , Anaerobiosis , Catálisis , Coenzima A Transferasas/antagonistas & inhibidores , Coenzima A Transferasas/aislamiento & purificación , Oxígeno/metabolismo
12.
J Biol Chem ; 276(24): 21381-6, 2001 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-11294876

RESUMEN

The initial enzyme of ethylbenzene metabolism in denitrifying Azoarcus strain EbN1, ethylbenzene dehydrogenase, was purified and characterized. The soluble periplasmic enzyme is the first known enzyme oxidizing a nonactivated hydrocarbon without molecular oxygen as cosubstrate. It is a novel molybdenum/iron-sulfur/heme protein of 155 kDa, which consists of three subunits (96, 43, and 23 kDa) in an alphabetagamma structure. The N-terminal amino acid sequence of the alpha subunit is similar to that of other molybdenum proteins such as selenate reductase from the related species Thauera selenatis. Ethylbenzene dehydrogenase is unique in that it oxidizes the hydrocarbon ethylbenzene, a compound without functional groups, to (S)-1-phenylethanol. Formation of the product was evident by coupling to an enantiomer-specific (S)-1-phenylethanol dehydrogenase from the same organism. The apparent K(m) of the enzyme for ethylbenzene is very low at <2 microm. Oxygen does not affect ethylbenzene dehydrogenase activity in extracts but inactivates the purified enzyme, if the heme b cofactor is in the reduced state. A variant of ethylbenzene dehydrogenase exhibiting significant activity also with the homolog n-propylbenzene was detected in a related Azoarcus strain (PbN1).


Asunto(s)
Azoarcus/enzimología , Molibdeno/análisis , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Azoarcus/crecimiento & desarrollo , Cromatografía , Cromatografía por Intercambio Iónico , Citoplasma/enzimología , Hemoproteínas/química , Hemoproteínas/aislamiento & purificación , Hemoproteínas/metabolismo , Proteínas Hierro-Azufre/química , Proteínas Hierro-Azufre/aislamiento & purificación , Proteínas Hierro-Azufre/metabolismo , Cinética , Peso Molecular , Oxidorreductasas/aislamiento & purificación , Espectrofotometría , Especificidad por Sustrato
13.
J Bacteriol ; 182(2): 272-7, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10629170

RESUMEN

The pathway of anaerobic toluene oxidation to benzoyl coenzyme A (benzoyl-CoA) consists of an initial reaction catalyzed by benzylsuccinate synthase, a glycyl radical enzyme adding the methyl group of toluene to the double bond of a fumarate cosubstrate, and a subsequent beta-oxidation pathway of benzylsuccinate. Benzylsuccinate synthase has been studied in some detail, whereas the enzymes participating in beta oxidation of benzylsuccinate are unknown. We have investigated these enzymes by analyzing substrate-induced proteins in toluene-grown cells. Toluene-induced proteins were identified and N-terminally sequenced. Nine of these proteins are encoded by an 8.5-kb operon consisting of bbs (beta-oxidation of benzylsuccinate) genes whose products are apparently involved in the beta-oxidation pathway of benzylsuccinate. Two of the genes, bbsE and bbsF, code for the subunits of a succinyl-CoA:benzylsuccinate CoA-transferase whose activity was previously detected in toluene-grown Thauera aromatica. The bbsG gene codes for a specific benzylsuccinyl-CoA dehydrogenase, as confirmed by overexpression of the gene in Escherichia coli and detection of enzyme activity. The further enzymes of the pathway are probably encoded by bbsH (enoyl-CoA hydratase), bbsCD (3-hydroxyacyl-CoA dehydrogenase), and bbsB (3-oxoacyl-CoA thiolase). The operon contains two additional genes, bbsA and bbsI, for which no obvious function could be derived. The bbs operon is expressed only in toluene-grown cells and is regulated at the transcriptional level. Promoter mapping revealed a transcription start site upstream of the bbsA gene. This represents the first known promoter site in Thauera spp.


Asunto(s)
Proteínas Bacterianas , Modelos Químicos , Operón , Oxidorreductasas/genética , Succinatos/metabolismo , Thauera/genética , Thauera/metabolismo , Tolueno/metabolismo , Acetil-CoA C-Aciltransferasa/genética , Secuencia de Aminoácidos , Anaerobiosis , Secuencia de Bases , Clonación Molecular , Enoil-CoA Hidratasa/genética , Datos de Secuencia Molecular
14.
Arch Microbiol ; 172(4): 204-12, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10525736

RESUMEN

The capacity of anoxygenic phototrophic bacteria to utilize aromatic hydrocarbons was investigated in enrichment cultures with toluene. When mineral medium with toluene (provided in an inert carrier phase) was inoculated with activated sludge and incubated under infrared illumination (> 750 nm), a red-to-brownish culture developed. Agar dilution series indicated the dominance of two types of phototrophic bacteria. One type formed red colonies, had rod-shaped cells with budding division, and grew on benzoate but not on toluene. The other type formed yellow-to-brown colonies, had oval cells, and utilized toluene and benzoate. One strain of the latter type, ToP1, was studied in detail. Sequence analysis of the 16S rRNA gene and DNA-DNA hybridization indicated an affiliation of strain ToP1 with the species Blastochloris sulfoviridis, a member of the alpha-subclass of Proteobacteria. However, the type strain (DSM 729) of Blc. sulfoviridis grew neither on toluene nor on benzoate. Light-dependent consumption of toluene in the presence of carbon dioxide and formation of cell mass by strain ToP1 were demonstrated in quantitative growth experiments. Strain ToP1 is the first phototrophic bacterium shown to utilize an aromatic hydrocarbon. In the supernatant of toluene-grown cultures and in cell-free extracts incubated with toluene and fumarate, the formation of benzylsuccinate was detected. These findings indicate that the phototrophic bacterium activates toluene anaerobically by the same mechanism that has been reported for denitrifying and sulfate-reducing bacteria. The natural abundance of phototrophic bacteria with the capacity for toluene utilization was examined in freshwater habitats. Counting series revealed that up to around 1% (1.8 x 10(5) cells per gram dry mass of sample) of the photoheterotrophic population cultivable with acetate grew on toluene.

15.
FEMS Microbiol Lett ; 166(1): 35-41, 1998 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-9741082

RESUMEN

The genes for a two-component regulatory system of the denitrifying toluene-degrading bacterium Thauera aromatica were identified immediately upstream of the genes for benzylsuccinate synthase (bssDCAB), the first enzyme involved in anaerobic toluene metabolism. The genes apparently encode the regulators of toluene catabolic enzymes and were therefore termed tdiSR (for toluene degradation including sensor and regulator). The tdiR gene product was overproduced in Escherichia coli and assayed for binding to a DNA fragment containing the 5' region of the bss operon. We observed specific DNA binding with cell extracts containing overproduced TdiR, but not with control extracts. The tdiSR genes are almost identical to two genes of Thauera strain T1, which have not been assigned a function so far. In addition, the derived gene products share similarity with regulators of toluene and styrene catabolic pathways in aerobic Pseudomonas species, and with the tutCB gene products of Thauera strain T1. The latter have previously been implicated in regulating anaerobic toluene metabolism. Our data suggest that toluene catabolism under aerobic and anaerobic conditions is regulated by similar, but distinct two-component systems.


Asunto(s)
Bacterias Gramnegativas/metabolismo , Tolueno/metabolismo , Aerobiosis , Anaerobiosis , Sitios de Unión/genética , Biodegradación Ambiental , Liasas de Carbono-Carbono/genética , Liasas de Carbono-Carbono/metabolismo , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Bacterias Gramnegativas/genética , Operón , Pseudomonas/genética , Pseudomonas/metabolismo , Mapeo Restrictivo , Especificidad de la Especie , Estireno , Estirenos/metabolismo
16.
Arch Microbiol ; 170(2): 120-31, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9683649

RESUMEN

Differential induction of enzymes involved in anaerobic metabolism of aromatic substrates was studied in the denitrifying bacterium Thauera aromatica. This metabolism is divided into (1) peripheral reactions transforming the aromatic growth substrates to the common intermediate benzoyl-CoA, (2) the central benzoyl-CoA pathway comprising ring-reduction of benzoyl-CoA and subsequent beta-oxidation to 3-hydroxypimelyl-CoA, and (3) the pathway of beta-oxidation of 3-hydroxypimelyl-CoA to three acetyl-CoA and CO2. Regulation was studied by three methods. 1. Determination of protein patterns of cells grown on different substrates. This revealed several strongly substrate-induced polypeptides that were missing in cells grown on benzoate or other intermediates of the respective metabolic pathways. 2. Measurement of activities of known enzymes involved in this metabolism in cells grown on different substrates. The enzyme pattern found is consistent with the regulatory pattern deduced from simultaneous adaptation of cells to utilisation of other aromatic substrates. 3. Immunological detection of catabolic enzymes in cells grown on different substrates. Benzoate-CoA ligase and 4-hydroxybenzoate-CoA ligase were detected only in cells yielding the respective enzyme activity. However, presence of the subunits of benzoyl-CoA reductase and 4-hydroxybenzoyl-CoA reductase was also recorded in some cell batches lacking enzyme activity. This possibly indicates an additional level of regulation on protein level for these two reductases.


Asunto(s)
Bacterias/enzimología , Hidrocarburos Aromáticos/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Acilcoenzima A/metabolismo , Anaerobiosis/fisiología , Proteínas Bacterianas/análisis , Benzoatos/metabolismo , Coenzima A/metabolismo , Coenzima A Ligasas/metabolismo , Electroforesis en Gel Bidimensional , Inducción Enzimática/efectos de los fármacos , Oxidorreductasas/metabolismo , Fenoles/metabolismo , Fenilacetatos/metabolismo , Fenilalanina/metabolismo , Tolueno
17.
Aktuelle Radiol ; 8(3): 135-7, 1998 May.
Artículo en Alemán | MEDLINE | ID: mdl-9645251

RESUMEN

We report on a 33-year-old man with symptomatic heterotopic suprarenal splenic tissue. Heterotopic splenic tissue can often be found after posttraumatic splenectomy. It is a result of autotransplantation induced by trauma (splenosis). Additionally it can grow during embryogenic development. Such an accessory spleen is found in 10-44% of all autopsies. In this case report the patient was treated by resection due to increasing flank pain and suspected neoplasm.


Asunto(s)
Enfermedades de las Glándulas Suprarrenales/diagnóstico por imagen , Coristoma/diagnóstico por imagen , Complicaciones Posoperatorias/diagnóstico por imagen , Bazo , Esplenectomía , Esplenosis/diagnóstico por imagen , Enfermedades de las Glándulas Suprarrenales/patología , Enfermedades de las Glándulas Suprarrenales/cirugía , Glándulas Suprarrenales/diagnóstico por imagen , Glándulas Suprarrenales/patología , Adulto , Coristoma/patología , Coristoma/cirugía , Humanos , Masculino , Complicaciones Posoperatorias/patología , Complicaciones Posoperatorias/cirugía , Reoperación , Esplenosis/patología , Esplenosis/cirugía , Tomografía Computarizada por Rayos X
18.
Mol Microbiol ; 28(3): 615-28, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9632263

RESUMEN

Toluene is anoxically degraded to CO2 by the denitrifying bacterium Thauera aromatica. The initial reaction in this pathway is the addition of fumarate to the methyl group of toluene, yielding benzylsuccinate as the first intermediate. We purified the enzyme catalysing this reaction, benzylsuccinate synthase (EC 4.1.99-), and studied its properties. The enzyme was highly oxygen sensitive and contained a redox-active flavin cofactor, but no iron centres. The native molecular mass was 220 kDa; four subunits of 94 (alpha), 90 (alpha'), 12 (beta) and 10 kDa (gamma) were detected on sodium dodecyl sulphate (SDS) gels. The N-terminal sequences of the alpha- and alpha'-subunits were identical, suggesting a C-terminal degradation of half of the alpha-subunits to give the alpha'-subunit. The composition of native enzyme therefore appears to be alpha2beta2gamma2. A 5 kb segment of DNA containing the genes for the three subunits of benzylsuccinate synthase was cloned and sequenced. The masses of the predicted gene products correlated exactly with those of the subunits, as determined by electrospray mass spectrometry. Analysis of the derived amino acid sequences revealed that the large subunit of the enzyme shares homology to glycyl radical enzymes, particularly near the predicted radical site. The highest similarity was observed with pyruvate formate lyases and related proteins. The radical-containing subunit of benzylsuccinate synthase is oxygenolytically cleaved at the site of the glycyl radical, producing the alpha'-subunit. The predicted cleavage site was verified using electrospray mass spectrometry. In addition, a gene coding for an activating protein catalysing glycyl radical formation was found. The four genes for benzylsuccinate synthase and the activating enzyme are organized as a single operon; their transcription is induced by toluene. Synthesis of the predicted gene products was achieved in Escherichia coli in a T7-promotor/polymerase system.


Asunto(s)
Proteínas Bacterianas , Liasas de Carbono-Carbono/metabolismo , Bacilos Gramnegativos Anaerobios Facultativos/enzimología , Tolueno/metabolismo , Secuencia de Aminoácidos , Anaerobiosis , Northern Blotting , Liasas de Carbono-Carbono/química , Liasas de Carbono-Carbono/genética , Liasas de Carbono-Carbono/aislamiento & purificación , Clonación Molecular , Enzimas/química , Enzimas/genética , Genes Bacterianos , Bacilos Gramnegativos Anaerobios Facultativos/genética , Datos de Secuencia Molecular , Peso Molecular , Sistemas de Lectura Abierta , Operón , Mapeo Restrictivo , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
19.
Aktuelle Radiol ; 8(2): 71-5, 1998 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-9592580

RESUMEN

PURPOSE: To evaluate the effect of angiography on patient management and mortality in patients with GIB of unknown origin. MATERIAL AND METHODS: 88 angiographies were performed in 74 patients with GIB of unknown origin (18 upper gastrointestinal tract [GIT]), 35 lower GIT. 21 unknown localisation) and were evaluated retrospectively in regard to the influence on patient management and clinical outcome. RESULTS: After unsuccessful endoscopic diagnosis, angiography shows a sensitivity of 60% in the acute phase of GIB. Once the GIB had stopped the sensitivity was 14%. Following angiographic localisation, patients were more commonly treated surgically (71% vs. 44.5%) and subsequently had a lower rate of persistent or recurring bleeding (15% vs. 37.5%) as well as a lower event related mortality (10.5% vs. 25%). Patients with angiographic localisation of the bleeding site had a better outcome than patients with unsuccessful bleeding localisation, with regard to both surgical (85% vs. 62.5%) and conservative (100% vs. 85%) treatment. CONCLUSION: Angiographic localisation should be attempted in all cases of unknown GI-bleeding after endoscopic methods have been unsuccessful or ambiguous, because such a procedure has a positive effect on patient management and outcome. Moreover, angiography also offers therapeutic options.


Asunto(s)
Angiografía , Sistema Digestivo/irrigación sanguínea , Hemorragia Gastrointestinal/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Sistema Digestivo/diagnóstico por imagen , Endoscopía , Femenino , Hemorragia Gastrointestinal/mortalidad , Hemorragia Gastrointestinal/terapia , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia
20.
Aktuelle Radiol ; 8(2): 101-3, 1998 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-9592586

RESUMEN

Although retroperitoneal hemorrhage is a rather seldom complication of Behçet's syndrome it is in no way unusual. Younger patients in particular those from the eastern Mediterranean or east Asian regions in whom a retroperitoneal hemorrhage or an aneurysm in the aorto-iliaco-femoral flow region has be diagnosed must be considered for the differential diagnosis of Behçet's syndrome. The consequences for the surgeon are resection deep into healthy tissue and in general an appropriately close follow-up with strict avoidance of arterial angiography.


Asunto(s)
Aneurisma de la Aorta Abdominal/etiología , Rotura de la Aorta/etiología , Síndrome de Behçet/complicaciones , Espacio Retroperitoneal/irrigación sanguínea , Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Rotura de la Aorta/diagnóstico por imagen , Síndrome de Behçet/diagnóstico por imagen , Hemorragia/diagnóstico por imagen , Hemorragia/etiología , Humanos , Espacio Retroperitoneal/diagnóstico por imagen , Tomografía Computarizada por Rayos X
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