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1.
J Anim Physiol Anim Nutr (Berl) ; 101 Suppl 1: 105-109, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28627062

RESUMEN

Foot pad dermatitis (FPD) is a widespread disease in poultry and important for economic and animal welfare reasons. It is well recognized that using non-starch polysaccharide (NSP)-degrading enzymes can affect excreta/litter quality (not only in terms of moisture content but also regarding water evaporation) at high stocking densities and might help to prevent FPD and further negative effects of NSP. This study aimed to evaluate effects of a carbohydrase complex (CC) in different dietary inclusion rates on performance, digesta viscosity and foot pad health in broilers from 9 to 37 days of life. In total, 240 broilers were divided into 12 floor pens of 20 birds and received one of four different experimental diets. The four wheat- and soyabean meal-based diets only differed in the inclusion rate of CC: 0%, 50%, 100% and 500% of the recommended dose of CC (Endo-1,4-ß-xylanase and Endo-1,3(4)-ß-glucanase; 50 g/t). The addition of CC led to a significant decrease of digesta viscosity in the proximal small intestine, a tendency of improved feed conversion ratio, and significantly favoured FPD-scores (Treatment 2). At the higher tested inclusion rate of CC (500% of recommended dose), the FPD score was worser than in the treatments with 50% and 100% of the recommended enzyme dosage. No improvements among treatments were observed in terms of body weight and dry matter content of excreta and litter at the end of trial. The low positive effects on foot pad health in this study were presumably associated with the low NSP content in the experimental diets (soluble arabinoxylans: 7.38 g/kg as fed). In conclusion, the addition of the evaluated CC reduced digesta viscosity. An improvement of foot pad health could only be seen in the treatment with 50% of the recommended enzyme dosage in the diet.


Asunto(s)
Alimentación Animal/análisis , Pollos , Enfermedades del Pie/veterinaria , Contenido Digestivo/química , Glicósido Hidrolasas/farmacología , Enfermedades de las Aves de Corral/prevención & control , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dermatitis/prevención & control , Dermatitis/veterinaria , Dieta/veterinaria , Suplementos Dietéticos , Endo-1,4-beta Xilanasas , Enfermedades del Pie/prevención & control , Glicósido Hidrolasas/administración & dosificación , Viscosidad
2.
Urologe A ; 56(9): 1129-1138, 2017 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-28646238

RESUMEN

Secondary bladder neck sclerosis represents one of the more frequent complications following endoscopic, open, and other forms of minimally invasive prostate surgery. Therapeutic decisions depend on the type of previous intervention (e.g., radical prostatectomy, TURP, HoLEP, radiotherapy, HIFU) and on associated complications (e.g., incontinence, fistula). Primary treatment in most cases represents an endoscopic bilateral incision. No specific advantages of any type of the applied energy (i.e., mono-/bipolar HF current, cold incision, holmium/thulium YAG laser) could be documented. Adjuvant measures such as injection of corticosteroids or mitomycin C have not been helpful in clinical routine. In case of first recurrence, a transurethral monopolar or bipolar resection can usually be performed. Recently, the ablation of the scared tissue using bipolar vaporization has been recommended providing slightly better long-term results. Thereafter, surgical reconstruction is strongly recommended using an open, laparoscopic, or robot-assisted approach. Depending on the extent of the bladder neck sclerosis and the underlying prostate surgery, a Y-V/T-plasty, urethral reanastomosis, or even a radical prostatectomy with new urethravesical anastomosis should be performed. Stent implantation should be reserved for patients who are not suitable for surgery. The final palliative measure is a cystectomy with urinary diversion or a (continent) cystostomy.


Asunto(s)
Terapia por Láser , Complicaciones Posoperatorias/patología , Prostatectomía , Resección Transuretral de la Próstata , Obstrucción del Cuello de la Vejiga Urinaria/patología , Vejiga Urinaria/cirugía , Humanos , Masculino , Complicaciones Posoperatorias/cirugía , Reoperación , Factores de Riesgo , Esclerosis , Obstrucción del Cuello de la Vejiga Urinaria/cirugía
3.
AIDS Care ; 24(11): 1323-32, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22272693

RESUMEN

This article sets out to investigate the psychiatric and psychosocial risk factors for high risk sexual behaviour in a war-affected population in Eastern Uganda. A cross-sectional survey was carried out in four sub-counties in two districts in Eastern Uganda where 1560 randomly selected respondents (15 years and above) were interviewed. The primary outcome was a derived variable "high risk sexual behaviour" defined as reporting at least one of eight sexual practices that have been associated with HIV transmission in Uganda and which were hypothesised could arise as a consequence of psychiatric disorder or psychosocial problems. Multivariable logistic regression was used to assess factors associated with high risk sexual behaviour in this population. Males were more likely to have at least one "high risk sexual behaviour" than females (11.8% vs. 9.1% in the last year). Sex outside marriage was the most commonly reported high risk sexual behaviour. Among males, the factors independently associated with high risk sexual behaviour were: being married, belonging to non-Catholic/non-Protestant religions, poverty, being a victim of intimate partner violence and having a major depressive disorder (MDD). Among females, the factors that were independently associated with high risk sexual behaviour were: being in the reproductive age groups of 25-34 and 35-44 years, not seeing a close relative killed and having experienced war-related sexual torture. Holistic HIV/AIDS prevention programming in conflict and post-conflict settings should address the psychiatric and psychosocial well-being of these communities as a risk factor for HIV acquisition.


Asunto(s)
Trastorno Depresivo Mayor/epidemiología , Infecciones por VIH/psicología , Conducta Sexual/psicología , Estrés Psicológico/epidemiología , Guerra , Adulto , Estudios Transversales , Femenino , Infecciones por VIH/epidemiología , Infecciones por VIH/transmisión , Humanos , Entrevistas como Asunto , Modelos Logísticos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Asunción de Riesgos , Parejas Sexuales , Factores Socioeconómicos , Uganda/epidemiología , Adulto Joven
4.
Drug Metab Dispos ; 31(11): 1382-90, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14570771

RESUMEN

Assessment of the pharmacokinetics of [14C]2-[3-[3-[(5-ethyl-4'-fluoro-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-2-propylphenoxy-]benzoic acid ([14C]LY293111), an experimental anti-cancer agent, suggested long-lived circulating metabolites in rats. In vivo metabolites of LY293111 were examined in plasma, bile, urine, and feces of Fischer 344 (F344) rats after oral administration of [14C]LY293111. Metabolites were profiled by high-performance liquid chromatography-radiochromatography, and identified by liquid chromatography (LC)/mass spectrometry and LC/NMR. The major in vivo metabolites of LY293111 identified in rats were phenolic (ether), acyl, and bisglucuronides of LY293111. Measurement of radioactivity in rat plasma confirmed that a fraction of LY293111-derived material was irreversibly bound to plasma protein and that this bound fraction increased over time. This was consistent with the observed disparity in half-lives between LY293111 and total radioactivity in rats and monkeys, and is likely due to covalent modification of proteins by the acyl glucuronide. In vitro metabolism of [14C]LY293111 in liver slices from CD-1 mice, F344 rats, rhesus and cynomolgus monkeys, and humans indicates that glucuronidation was the primary metabolic pathway in all species. The acyl glucuronide was the most prevalent radioactive peak (16% of total 14C) produced by F344 rat slices, whereas the ether glucuronide was the major metabolite in all other species (26-36% of total 14C). Several minor hydroxylated metabolites were detected in F344 rat slice extracts but were not observed in other species. The data presented suggest that covalent modification of proteins by LY293111 acyl glucuronide is possible in multiple species, although the relative reactivity of this metabolite appears to be low compared with those known to cause adverse drug reactions.


Asunto(s)
Benzoatos/sangre , Benzoatos/farmacocinética , Animales , Benzoatos/química , Evaluación Preclínica de Medicamentos/métodos , Femenino , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Macaca fascicularis , Macaca mulatta , Masculino , Ratones , Persona de Mediana Edad , Ratas , Ratas Endogámicas F344 , Especificidad de la Especie
5.
Biotech Histochem ; 75(2): 49-53, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10941508

RESUMEN

Molecular cytogenetics, particularly the localization of DNA sequences by in situ hybridization, has increased our understanding about the genomic structure of plants and animals. We demonstrate here the application of an improved nonfluorescent in situ hybridization system detection (DAKO GenPoint system) to plant chromosomes. Using this system, highly repetitive 18S-25S rRNA genes were mapped on Vicia faba chromosomes (2n = 12). The modified method of this horseradish peroxidase based enzymatic detection system gave satisfactory results that are comparable to fluorescent signal detection.


Asunto(s)
Peroxidasa de Rábano Silvestre/metabolismo , Hibridación in Situ/métodos , Mapeo Físico de Cromosoma/métodos , Cromosomas/genética , Sondas de ADN , ADN de Plantas/genética , ADN Ribosómico/genética , Fabaceae/genética , Fluorescencia , Genes de ARNr/genética , Histocitoquímica , Hibridación Fluorescente in Situ , Microscopía Fluorescente , Plantas Medicinales
6.
Arch Neurol ; 57(1): 140, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10634465
7.
Pediatr Res ; 46(4): 455-60, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10509368

RESUMEN

Using 1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI 52466), we tested the hypothesis that alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are important controllers of cerebral O2 supply/consumption balance in newborn piglets during both normoxia and hypoxia. Twenty-seven 2- to 7-day-old piglets were anesthetized with alpha-chloralose and were divided into four groups: 1) normoxia (n = 7), 2) GYKI 52466 (10 mg/kg, n = 7), 3) hypoxia (n = 6), and 4) hypoxia + GYKI 52466 (n = 7). We used [14C]iodoantipyrine to measure regional cerebral blood flow (rCBF) in mL/min/100 g, and we determined O2 extraction by microspectrophotometry, calculating cerebral O2 consumption (VO2) in mL O2/min/100 g in the cortex, hypothalamus, and pons. GYKI 52466 had no effect on regional VO2 or rCBF in normoxic piglets compared with controls. Hypoxia resulted in an increase in local VO2 and rCBF in the cortex and hypothalamus compared with controls: rCBF from 50 +/- 10 to 97 +/- 16 and VO2 from 2.4 +/- 0.5 to 3.7 +/- 0.4 in the cortex, and rCBF from 41 +/- 9 to 99 +/- 17 and VO2 from 2.5 +/- 1 to 3.8 +/- 0.5 in the hypothalamus. GYKI 52466 abolished this hypoxic flow effect in both the cortex (68 +/- 14) and hypothalamus (73 +/- 12). GYKI 52466 also blocked the increased VO2 in the cortex (2.5 +/- 0.4) and hypothalamus (3.0 +/- 0.5) of the hypoxic group. These findings suggest that the AMPA receptor is an important controller of VO2 in the cortex and hypothalamus during hypoxia in this immature porcine model.


Asunto(s)
Encéfalo/metabolismo , Consumo de Oxígeno , Receptores AMPA/antagonistas & inhibidores , Animales , Animales Recién Nacidos , Benzodiazepinas/farmacología , Encéfalo/efectos de los fármacos , Encéfalo/fisiología , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Circulación Cerebrovascular/efectos de los fármacos , Femenino , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Hipoxia Encefálica/metabolismo , Hipoxia Encefálica/fisiopatología , Masculino , Consumo de Oxígeno/efectos de los fármacos , Porcinos
9.
Pharmacology ; 56(1): 37-45, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9467186

RESUMEN

We tested the hypothesis that increased O2 consumption and inotropy after reduction of myocardial cyclic guanosine monophosphate (cGMP) are mediated through L-type calcium channels. Anesthetized, open-chest New Zealand white rabbits were divided into four groups. Hearts were exposed to control vehicle (n = 8); LY83583 (LY, 10(-3) mol/l, guanylate cyclase inhibitor, (n = 9); nifedipine (nif, 10(-4) mol/l, L-type calcium channel blocker, n = 8), or nif+LY (n = 6). Vehicle or compound was applied topically to the epicardium for 15 min. Subepicardial (EPI) blood flow increased (from 213 +/- 22 to 323 +/- 24 ml/ min/100 g) in the presence of LY, as did subendocardial (ENDO) blood flow (from 238 +/- 20 to 333 +/- 38 ml/min/ 100 g). O2 consumption increased in the presence of LY:18.0 +/- 1.0 (EPI) and 17.0 +/- 0.6 (ENDO) ml O2/min/100 g as compared with 9.5 +/- 2.0 (EPI) and 10.6 +/- 2.5 (ENDO) in the control group. The increase in O2 consumption with LY was undiminished in the presence of nif (nif+LY group 21.0 +/- 3.0 ml O2/min/100 g EPI and 22.1 +/- 3.8 ENDO). Nif alone decreased left ventricular dP/dtmax from (2,762 +/- 197 to 2,413 +/- 316 mm Hg/s) and maximal rate of change in wall thickness (dW/dtmax from 13.5 +/- 2.0 to 9.5 +/- 0.8 mm/s), while percent change of wall thickness (from 21.3 +/- 3.3 to 31.3 +/- 7.2) and dW/dtmax (from 13.3 +/- 3.0 to 15.3 +/- 2.3 mm/s) increased in the nif+LY group. Thus, the positive O2 consumption and inotropic effects of decreasing cGMP were undiminished by nif. These results suggest that the cGMP reduction induced increases in O2 consumption and that inotropy may not be mediated through L-type calcium channels.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Cardiotónicos/farmacología , GMP Cíclico/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Aminoquinolinas/farmacología , Animales , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/farmacología , Guanilato Ciclasa/antagonistas & inhibidores , Nifedipino/farmacología , Oxidación-Reducción , Conejos
10.
Am J Bot ; 84(1): 26-33, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11539495

RESUMEN

An obstacle to the study of root architecture is the difficulty of measuring and quantifying the three-dimensional configuration of roots in soil. The objective of this work was to determine if fractal geometry might be useful in estimating the three-dimensional complexity of root architecture from more accessible measurements. A set of results called projection theorems predict that the fractal dimension (FD) of a projection of a root system should be identical to the FD of roots in three-dimensional space (three-dimensional FD). To test this prediction we employed SimRoot, an explicit geometric simulation model of root growth derived from empirical measurements of common bean (Phaseolus vulgaris L.). We computed the three-dimensional FD, FD of horizontal plane intercepts (planar FD), FD of vertical line intercepts (linear FD), and FD of orthogonal projections onto planes (projected FD). Three-dimensional FD was found to differ from corresponding projected FD, suggesting that the analysis of roots grown in a narrow space or excavated and flattened prior to analysis is problematic. A log-linear relationship was found between FD of roots and spatial dimension. This log-linear relationship suggests that the three-dimensional FD of root systems may be accurately estimated from excavations and tracing of root intersections on exposed planes.


Asunto(s)
Simulación por Computador , Fabaceae/crecimiento & desarrollo , Fractales , Modelos Biológicos , Raíces de Plantas/crecimiento & desarrollo , Plantas Medicinales , Gravitropismo/fisiología
11.
J Adolesc Health ; 19(6): 409-15, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8969372

RESUMEN

PURPOSE: With the increase in melanoma incidence, the sun exposure and protective behaviors of adolescents are of great concern. Limited data are available on the prevalence and predictors of risk behavior in adolescents in the southeastern United States. This study examined the levels of sun exposure and variables predictive of sun exposure among adolescents in two Alabama middle schools. METHODS: A total of 509 sixth-graders completed a self-administered survey assessing: (a) their knowledge, attitudes, and beliefs about malignant melanoma; and (b) their sun exposure and sunburns for a specific weekend and for the summer. RESULTS: Levels of sun exposure and frequency of sunburn were high. Regression models determined the predictors of weekend and summer sun exposure, and weekend sunburn. Significant predictors varied by outcome and included gender, perceived importance of a suntan, parent and peer modeling, and sunscreen use. CONCLUSION: Reducing the risk of melanoma will require a three-pronged intervention strategy with efforts directed at adolescents, their parents, and the broader community.


Asunto(s)
Conducta del Adolescente , Conocimientos, Actitudes y Práctica en Salud , Helioterapia/estadística & datos numéricos , Asunción de Riesgos , Quemadura Solar/prevención & control , Adolescente , Distribución de Chi-Cuadrado , Niño , Femenino , Helioterapia/efectos adversos , Humanos , Masculino , Melanoma/prevención & control , Vigilancia de la Población , Ropa de Protección , Análisis de Regresión , Factores de Riesgo , Neoplasias Cutáneas/prevención & control , Sudeste de Estados Unidos , Protectores Solares/administración & dosificación
12.
Int J Psychoanal ; 77 ( Pt 6): 1101-26, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9119579

RESUMEN

Using the example of the analysis of 6-year-old Erna, which extended over more than two years and was the longest treatment conducted by Melanie Klein in her Berlin years, the authors demonstrate the importance of her early child analyses for the development of some of her concepts and hence for a decisive advance in psychoanalysis itself. For this purpose they adduce unpublished original documents found among Klein's papers in London, which include autobiographical material, the text of her Würzburg lecture on her obsessional-neurotic little patient, handwritten session notes, and drawings by Erna herself. Although in the author's view Klein attempted to accommodate her findings within Freud's theoretical framework, her clinical experience of the psychic reality of the relational world of early oedipality eventually called for the introduction of new concepts. The combined parent figure, primary sadism, the paranoid-schizoid position, splitting, the relevance of the death drive to the superego, and later formulations on reparation, envy and gratitude are all shown to be foreshadowed in Klein's account of the treatment of Erna. After some retrospective considerations of Erna's analysis and a fleeting glimpse of Erna as an adult, the authors conclude by emphasising the significance of Klein's emigration to England for the subsequent flowering of her work.


Asunto(s)
Trastornos Neuróticos/psicología , Teoría Psicoanalítica , Terapia Psicoanalítica , Arteterapia , Niño , Contratransferencia , Mecanismos de Defensa , Femenino , Alemania , Historia del Siglo XX , Humanos , Trastornos Neuróticos/historia , Trastornos Neuróticos/terapia , Apego a Objetos , Complejo de Edipo , Desarrollo de la Personalidad , Psicoanálisis/historia , Interpretación Psicoanalítica , Transferencia Psicológica
13.
Eur Spine J ; 1(4): 240-3, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20054925

RESUMEN

In order to monitor changes in postural performance capacity in patients with idiopathic scoliosis after an intensive in-patient Schroth rehabilitation programme lasting several weeks, we undertook electromyographic investigations in 316 patients with a mean age of 20 years (range 8-76 years) and a mean Cobb curvature angle of 38.2 degrees (range 10 degrees-147 degrees). Electromyographic activity was recorded by means of surface electrodes in the thoracic and lumbar region at the level of the apical vertebra, paravertebrally on both sides of the erector spinae muscle during trunk lifting from the prone position. Two hundred and fifty-nine recordings without artefacts were evaluated. Significant reductions in muscle activity of 6.85% in the thoracic convex region (P < 0.05) and of 14.2% (P < 0.001) on the lumbar convex side were found. The activity quotient (convesx/concave) was reduced by 11.99% (P<0.001) in the thoracic region and by 7.91% (P<0.01) in the lumbar region. These findings confirm the improvement of postural performance capacity after an intensive in-patient Schroth rehabilitation programme. As the imbalance of electromyographic activity may be influenced by scoliosis-specific exercises leading to a highly significant reduction of the Cobb angle, it is assumed to be secondary to the development of the scoliotic curve and may not be a primary factor in the aetiology of idiopathic scoliosis.


Asunto(s)
Contracción Muscular/fisiología , Músculo Esquelético/fisiopatología , Escoliosis/rehabilitación , Columna Vertebral/fisiopatología , Adolescente , Adulto , Anciano , Niño , Electromiografía , Terapia por Ejercicio , Femenino , Humanos , Masculino , Masaje , Persona de Mediana Edad , Escoliosis/fisiopatología , Resultado del Tratamiento
14.
J Mol Biol ; 227(4): 1032-42, 1992 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-1433284

RESUMEN

NADH:ubiquinone oxidoreductase, the respiratory chain complex I of mitochondria, is an assembly of some 25 nuclear-encoded and 7 mitochondrially encoded subunits. The complex has an overall L-shaped structure formed by a peripheral arm and an elongated membrane arm. The peripheral arm containing one FMN and at least three iron-sulphur clusters constitutes the NADH dehydrogenase segment of the electron pathway. The membrane arm with at least one iron-sulphur cluster constitutes the ubiquinone reducing segment. We are studying the assembly of the complex in Neurospora crassa. By disrupting the gene of a nuclear-encoded subunit of the membrane arm a mutant was generated that cannot form complex I. The mutant rather pre-assembles the peripheral arm with all redox groups and the ability to catalyse NADH oxidation by artificial electron acceptors. The final assembly of the membrane arm is blocked in the mutant leading to accumulation of complementary assembly intermediates. One intermediate is associated with a protein that is not present in the fully assembled complex I. The results demonstrate that the two arms of complex I are assembled independently on separate pathways, and gave a first insight into the assembly pathway of the membrane arm. It is also shown for the first time that the obligate aerobic fungus N. crassa can grow and respire without an intact complex I. Gene replacement in this fungus is therefore a tool for investigation of this complex.


Asunto(s)
Mitocondrias/enzimología , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Neurospora crassa/metabolismo , Southern Blotting , Western Blotting , Centrifugación por Gradiente de Densidad , Citocromos/metabolismo , Eliminación de Gen , Proteínas Hierro-Azufre/química , Proteínas Hierro-Azufre/metabolismo , Mutagénesis , NAD(P)H Deshidrogenasa (Quinona)/genética , Neurospora crassa/enzimología , Neurospora crassa/genética , Recombinación Genética , Transformación Genética
15.
J Mol Biol ; 221(3): 1027-43, 1991 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-1834851

RESUMEN

Two related forms of the respiratory chain NADH dehydrogenase (NADH:ubiquinone reductase or complex I) are synthesized in the mitochondria of Neurospora crassa. Normally growing cells make a large form that consists of 25 subunits encoded by nuclear DNA and six to seven subunits encoded by mitochondrial DNA. Cells grown in the presence of chloramphenicol, however, make a smaller form comprising only 13 subunits, all encoded by nuclear DNA. When the large enzyme is dissected by chaotropic agents (such as NaBr), all those subunits of the large form that are missing in the small form can be isolated as a distinct, so-called hydrophobic fragment. The small enzyme and the hydrophobic fragment make up, with regard to their redox groups, subunit composition and function, two complementary parts of the large-form NADH dehydrogenase. Averaging of electron microscope images of single particles of the large enzyme was carried out, revealing an unusual L-shaped structure with two domains or "arms" arranged at right angles. The hydrophobic fragment obtained by the NaBr treatment corresponds in size and appearance to one of these arms. A three-dimensional reconstruction from images of negatively stained membrane crystals of the large-form NADH dehydrogenase shows a peripheral domain, protruding from the membrane, with weak unresolved density within the membrane. This peripheral domain was removed by washing the crystals in situ with 2 M-NaBr, exposing a large membrane-buried domain, which was reconstructed in three dimensions. A three-dimensional reconstruction of the small enzyme from negatively stained membrane crystals, also described here, shows only a peripheral domain. These results suggest that the membrane protruding arm of the large form corresponds to the small enzyme, whereas the arm lying within the membrane can be identified as the hydrophobic fragment. The two parts of NADH dehydrogenase that can be defined by the separate genetic origin of (most of) their subunits, their independent assembly, and their distinct contributions to the electron pathway can thus be assigned to the two arms of the L-shaped complex I.


Asunto(s)
Membranas Intracelulares/enzimología , Mitocondrias/enzimología , NADH Deshidrogenasa/ultraestructura , Neurospora crassa/enzimología , Cristalografía , Membranas Intracelulares/ultraestructura , Microscopía Electrónica , Mitocondrias/ultraestructura , NADH Deshidrogenasa/química , NADH Deshidrogenasa/metabolismo , Neurospora crassa/ultraestructura , Conformación Proteica
16.
J Cereb Blood Flow Metab ; 11(5): 829-36, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1874815

RESUMEN

We determined the effects of spreading depression on local cerebral O2 supply, oxygenation, and O2 consumption in the anesthetized rat. Spreading depression was induced by application of 0.5 M KCl to the frontal cortex. Regional cerebral blood flow was determined with [14C]iodoantipyrine and regional O2 extraction was determined microspectrophotometrically. The passage of the spreading depression wave was determined with a multiprobe assembly that recorded NADH redox state (surface fluorometry), extracellular K+ activity, and DC steady potential (surface minielectrodes). As the wave of spreading depression passed, there was an increase in extracellular K+ and a decrease in NADH. Cerebral blood flow was significantly increased (120 +/- 51 ml/min/100 g, mean +/- SD) during the wave as compared with other regions. In the affected cortex, blood flow was not different from that in the contralateral cortex (69 +/- 28 ml/min/100 g) either before or after the wave of spreading depression passed. Arterial and venous O2 saturation were unaffected by the wave and the histogram of O2 saturations of examined veins followed a similar normal distribution in all regions. Oxygen extraction was not altered by the wave of spreading depression. Oxygen consumption was significantly increased during the wave to 7.4 +/- 3.7 ml O2/min/100 g compared with the contralateral cortex (5.1 +/- 2.6 ml/min/100 g) and other regions. It can be concluded that spreading depression caused an increase in cerebral O2 consumption that was adequately matched by an increase in local blood flow. Oxygen delivery was not limited during spreading depression and its effects were quickly over as evidenced by the lack of alteration in oxygenation after the wave of spreading depression passed.


Asunto(s)
Circulación Cerebrovascular , Depresión de Propagación Cortical/fisiología , Consumo de Oxígeno , Animales , Corteza Cerebral/fisiología , Lóbulo Frontal , Masculino , NAD/metabolismo , Potasio/metabolismo , Ratas , Ratas Endogámicas
18.
J Appl Physiol (1985) ; 61(5): 1712-9, 1986 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3781979

RESUMEN

This study was performed to determine whether the brain can increase the number of perfused capillaries and arterioles supplying it regionally during hemorrhage. This was done using a technique to simultaneously determine total and perfused regional arteriolar and capillary morphology. Conscious Long-Evans rats served as unbled controls or were bled 65 mmHg or to 40-45 mmHg and stabilized for 30 min. Regional cerebral blood flow was determined using [14C]iodoantipyrine in half of these animals and fluorescein isothiocyanate-dextran was injected in the other half for determination of perfused cerebral microvascular morphometric indexes. The total microvasculature was labeled postmortem via an alkaline phosphatase stain. Regional cerebral blood flow was significantly increased in animals bled to 65 mmHg. During hemorrhage to 40-45 mmHg, cerebral blood flow was reduced 50% (from 59 +/- 28 to 26 +/- 11 ml X min-1 X 100 g-1, mean +/- SD) with no regional redistribution. For all treatments, total capillary density ranged from 400 to 500 capillaries/mm2, and in controls 47% were perfused. Animals bled to 65 mmHg did not mobilize their unperfused microvascular reserve even though they showed a slight tendency to do so. During hemorrhage to 40-45 mmHg, this percent increased significantly to 57% with the largest increase occurring in the pons. Approximately 51% of arterioles were perfused in controls and this was not different compared with the percent perfused during hemorrhage. Despite the overall lack of mobilization of unperfused arterioles, some regions within the brain significantly mobilized their reserves with severe hemorrhage, e.g., hippocampus (78%), hypothalamus (67%), and medulla (73%).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Encéfalo/irrigación sanguínea , Hemorragia/patología , Animales , Arteriolas/patología , Velocidad del Flujo Sanguíneo , Capilares/patología , Circulación Cerebrovascular , Hipocampo/irrigación sanguínea , Hipotálamo/irrigación sanguínea , Bulbo Raquídeo/irrigación sanguínea , Ratas
19.
Eur J Biochem ; 158(3): 615-21, 1986 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-3015618

RESUMEN

Dimeric ubiquinol:cytochrome c reductase of Neurospora mitochondria was isolated as a protein-Triton complex and free of ubiquinol (Q). The enzyme was incorporated into phosphatidylcholine membranes together with Q. The effects of varying the molar ratio of Q to enzyme on the electron transfer from duroquinol (DHQ2) to the cytochromes c, c1 and b were studied. The rate of electron flow from DQH2 to cytochrome c was 15 times increased by Q and was maximal when one molecule of Q was bound to one enzyme dimer. The apparent Km value for DQH2 of the Q-free enzyme was 5 microM and of the Q-supplemented enzyme 25 microM. The pre-steady-state rate of electron transfer from DQH2 to cytochrome c1 was also 15 times increased by Q and was maximal with one Q molecule bound to one enzyme dimer. This effect of Q was inhibited by antimycin. The pre-steady-state rate of electron transfer from DQH2 to cytochrome b was 5 times decreased when Q was bound to the enzyme and this effect of Q was insensitive to myxothiazol. The H+/2e- stoichiometry with DQH2 as substrate of the Q-supplemented enzyme was 3.6. These results are interpreted in accordance with a Q-cycle mechanism operating in a dimeric cytochrome reductase. Each enzyme monomer catalyses a single electron transfer from the QH2-oxidation centre to the Q-reduction centre and the two monomers cooperate in the reduction of Q to QH2 at one Q-reduction centre. This centre contains two different binding sites for Q. DQH2 does not properly react at the QH2-oxidation centre. DQH2, however, binds to the loose Q-binding site of the Q-reduction centre and reduces the Q bound to the tight Q-binding site of the centre. The QH2 thus formed at the Q-reduction centre serves as electron donor for the QH2-oxidation centre.


Asunto(s)
Mitocondrias/enzimología , Complejos Multienzimáticos/análisis , Neurospora/enzimología , Quinona Reductasas/análisis , Ubiquinona/metabolismo , Transporte Biológico , Grupo Citocromo c/metabolismo , Transporte de Electrón , Complejo III de Transporte de Electrones , Hidroquinonas/metabolismo , Oxidación-Reducción , Protones , Ubiquinona/análisis
20.
Arch Dermatol Res ; 269(2): 189-95, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-7458409

RESUMEN

To investigate the influence of 8-MOP and UVA on the induction of cell-mediated immunity, guinea pigs, sensitized with a single injection of dinitrofluorobenzene (DNFB) in Freund's complete adjuvant (FCA) in all footpads and the nuchal skin, were treated with 8-MOP, UVA, or 8-MOP + UVA on days 0, 2, and 5 and tested with dinitrochlorobenzene (DNCB) on day 14 after sensitization. Two control groups, exposed in a covered condition to the PUVA 4000 lamp, to observe the heat effect, showed a slightly enhanced contact sensitivity in comparison to the only sensitized control group. No altered reactivity was observed after irradiation with longwave UV light alone, whereas a statistically significant enhanced resp. reduced contact sensitivity was obtained after the treatment with 8-MOP alone and the combined action of 8-MOP + UVA, respectively.


Asunto(s)
Dermatitis por Contacto/inmunología , Dinitroclorobenceno/farmacología , Nitrobencenos/farmacología , Terapia PUVA , Fotoquimioterapia , Animales , Dinitrofluorobenceno/farmacología , Cobayas
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