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1.
Knee Surg Sports Traumatol Arthrosc ; 30(11): 3626-3633, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35434767

RESUMEN

PURPOSE: Glenohumeral joint injuries frequently result in shoulder instability. However, the biomechanical effect of cartilage loss on shoulder stability remains unknown. The aim of the current study was to investigate biomechanically the effect of two severity stages of cartilage loss in different dislocation directions on shoulder stability. METHODS: Joint dislocation was provoked in 11 human cadaveric glenoids for 7 different directions between 3 o'clock (anterior) and 9 o'clock (posterior). Shoulder stability ratio (SSR) and concavity gradient were assessed in three states: intact, 3 mm and 6 mm simulated cartilage loss. The influence of cartilage loss on SSR and concavity gradient was statistically evaluated. RESULTS: Both SSR and concavity gradient decreased significantly between intact state and 6 mm cartilage loss in every dislocation direction (p ≤ 0.038), except concavity gradient in 4 o'clock direction. Thereby, anterior-inferior dislocation directions were associated with the highest decrease in both SSR and concavity gradient of up to 59.0% and 49.4%, respectively, being significantly bigger for SSR compared with all other dislocation directions (p ≤ 0.040). Correlations between concavity gradient and SSR for pooled dislocation directions were significant in each separate specimen's state (p < 0.001). CONCLUSION: From a biomechanical perspective, articular cartilage of the glenoid contributes significantly to the concavity gradient, correlating strongly with the associated loss in glenohumeral joint stability. The biggest effect of cartilage loss is observed in the most frequently occurring anterior-inferior dislocation directions, suggesting that surgical interventions to restore cartilage's surface and concavity should be considered for recurrent shoulder dislocations in presence of cartilage loss.


Asunto(s)
Cartílago Articular , Luxaciones Articulares , Inestabilidad de la Articulación , Luxación del Hombro , Articulación del Hombro , Cadáver , Cartílago Articular/cirugía , Humanos , Inestabilidad de la Articulación/cirugía , Hombro , Luxación del Hombro/cirugía , Articulación del Hombro/cirugía
2.
Sensors (Basel) ; 21(6)2021 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-33799914

RESUMEN

Detecting and monitoring air-polluting gases such as carbon monoxide (CO), nitrogen oxides (NOx), and sulfur oxides (SOx) are critical, as these gases are toxic and harm the ecosystem and the human health. Therefore, it is necessary to design high-performance gas sensors for toxic gas detection. In this sense, graphene-based materials are promising for use as toxic gas sensors. In addition to experimental investigations, first-principle methods have enabled graphene-based sensor design to progress by leaps and bounds. This review presents a detailed analysis of graphene-based toxic gas sensors by using first-principle methods. The modifications made to graphene, such as decorated, defective, and doped to improve the detection of NOx, SOx, and CO toxic gases are revised and analyzed. In general, graphene decorated with transition metals, defective graphene, and doped graphene have a higher sensibility toward the toxic gases than pristine graphene. This review shows the relevance of using first-principle studies for the design of novel and efficient toxic gas sensors. The theoretical results obtained to date can greatly help experimental groups to design novel and efficient graphene-based toxic gas sensors.

3.
J Nematol ; 52: 1-8, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32726069

RESUMEN

Phyllophaga spp. are a complex of edaphic insect pests that are present in the corn crops (Zea mays) in México, which are usually controlled with increasing dosages of broad-spectrum chemical insecticides. Several entomopathogenic nematode species can produce acceptable control levels of these larvae. However, the synergistic interaction between fungi and entomopathogenic nematodes (EPN) could improve the control of this insect. This study investigates the mortality of larvae of Phyllophaga vetula by the effect of the separate or combined application of the fungus Metarhizium anisopliae M1cog strain (Ma) and the nematodes Steinernema carpocapsae All strain (Sc) or Steinernema glaseri NJ-43 strain (Sg). In laboratory, dosages of 1 × 106 or 1 × 108 spores/larva and 250 infective juveniles were applied on medium or large size P. vetula larvae contained in vials with sterilized agricultural soil as the assay arena. The separate application of Ma did not kill any larvae, but Sg and Sc killed 40 and 80% of the larvae, respectively. However, the Ma and Sc combination had an important antagonistic interaction that decreased the mortality to 40%, but the combination Ma and Sg had a slight additive interaction that increased the mortality to 47%. The most determining factor in larvae mortality was the nematode used, with Sg as the species with best performance in 6 of the 12 treatments evaluated and with a maximum effectivity of 80% on medium-size larvae if combined with a low dosage of Ma. The combined application of an entomopathogenic fungus and EPN showed no consistent effects on the mortality percentage of P. vetula, mostly because the fungus was not isolated from Phyllophaga larvae.Phyllophaga spp. are a complex of edaphic insect pests that are present in the corn crops (Zea mays) in México, which are usually controlled with increasing dosages of broad-spectrum chemical insecticides. Several entomopathogenic nematode species can produce acceptable control levels of these larvae. However, the synergistic interaction between fungi and entomopathogenic nematodes (EPN) could improve the control of this insect. This study investigates the mortality of larvae of Phyllophaga vetula by the effect of the separate or combined application of the fungus Metarhizium anisopliae M1cog strain (Ma) and the nematodes Steinernema carpocapsae All strain (Sc) or Steinernema glaseri NJ-43 strain (Sg). In laboratory, dosages of 1 × 106 or 1 × 108 spores/larva and 250 infective juveniles were applied on medium or large size P. vetula larvae contained in vials with sterilized agricultural soil as the assay arena. The separate application of Ma did not kill any larvae, but Sg and Sc killed 40 and 80% of the larvae, respectively. However, the Ma and Sc combination had an important antagonistic interaction that decreased the mortality to 40%, but the combination Ma and Sg had a slight additive interaction that increased the mortality to 47%. The most determining factor in larvae mortality was the nematode used, with Sg as the species with best performance in 6 of the 12 treatments evaluated and with a maximum effectivity of 80% on medium-size larvae if combined with a low dosage of Ma. The combined application of an entomopathogenic fungus and EPN showed no consistent effects on the mortality percentage of P. vetula, mostly because the fungus was not isolated from Phyllophaga larvae.

4.
Sci Rep ; 14(1): 22207, 2024 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-39333563

RESUMEN

The cultivation of grapevines has spanned millennia, leading to thousands of varieties through exchanges, mutations, and crosses between genotypes, as well probably as gene flow from wild populations. These varieties are typically categorized by regional origin and primary use, either for wine production or fruit consumption. France, within the Western European group, hosts many of the world's renowned wine grape varieties. However, the historical development of cultivated grapevines in France and in the world remains poorly understood. This study applies morphometry on 19,377 charred and waterlogged archaeological grape pips to investigate the evolutionary history of grapevine in France over the last 10,000 years. The study compares seed outlines and lengths, corrected for taphonomic distortions, with a reference collection of 80 wild and 466 modern domestic grapevine accessions. Findings reveal a shift from wild grapevine exploitation to the expansion of domestic varieties around 600-500 BCE, coinciding with Mediterranean cultural influences and the introduction of eastern grape types. The identification of the East-Table group, a group of varieties of eastern origin for fruit consumption, indicates that grapes were also grown for food, especially in Mediterranean regions and near urban areas, alongside wine production. Early French viticulture featured a notable presence of Western European wine-type grapevines. The abundance of pips with wild-like morphology suggests early cultivation involved plants at an initial domestication stage and gene flow between introduced and wild grapevines. As viticulture spread northward, wild and Eastern morphotypes declined, leading to the dominance of Western European wine types in inner France during the Middle Ages.


Asunto(s)
Semillas , Vitis , Vitis/genética , Vitis/anatomía & histología , Francia , Semillas/genética , Semillas/anatomía & histología , Vino , Evolución Biológica , Flujo Génico
5.
J Autism Dev Disord ; 49(1): 165-172, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30043355

RESUMEN

The purpose of the present study was to compare body composition and physical activity level between children and adults with Autism Spectrum Disorders (ASD). A sample of 78 children, adolescents and adults participated in the study. Anthropometrics and physical activity, using GT1M accelerometer, were assessed. Overweight and obesity prevalence was higher in men vs. male children (p < 0.001) and in men vs. women (p = 0.035). Children recorded more moderate to vigorous physical activity (p = 0.040) than adults. Normal-weight children and adolescents combined as one age group, accomplished more moderate to vigorous physical activity, steps and less sedentary time compared to their overweight and obese counterparts during the weekend. Obesity status may negatively affect physical activity level in ASD individuals.


Asunto(s)
Trastorno del Espectro Autista/psicología , Ejercicio Físico/fisiología , Ejercicio Físico/psicología , Obesidad/psicología , Conducta Sedentaria , Adolescente , Adulto , Antropometría/métodos , Trastorno del Espectro Autista/epidemiología , Trastorno del Espectro Autista/fisiopatología , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Obesidad/fisiopatología , Sobrepeso/epidemiología , Sobrepeso/fisiopatología , Sobrepeso/psicología , Proyectos Piloto , Adulto Joven
7.
Science ; 362(6419): 1177-1182, 2018 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-30442762

RESUMEN

The leucine zipper-like transcriptional regulator 1 (LZTR1) protein, an adaptor for cullin 3 (CUL3) ubiquitin ligase complex, is implicated in human disease, yet its mechanism of action remains unknown. We found that Lztr1 haploinsufficiency in mice recapitulates Noonan syndrome phenotypes, whereas LZTR1 loss in Schwann cells drives dedifferentiation and proliferation. By trapping LZTR1 complexes from intact mammalian cells, we identified the guanosine triphosphatase RAS as a substrate for the LZTR1-CUL3 complex. Ubiquitome analysis showed that loss of Lztr1 abrogated Ras ubiquitination at lysine-170. LZTR1-mediated ubiquitination inhibited RAS signaling by attenuating its association with the membrane. Disease-associated LZTR1 mutations disrupted either LZTR1-CUL3 complex formation or its interaction with RAS proteins. RAS regulation by LZTR1-mediated ubiquitination provides an explanation for the role of LZTR1 in human disease.


Asunto(s)
Síndrome de Noonan/genética , Factores de Transcripción/genética , Ubiquitinación/genética , Proteínas ras/metabolismo , Animales , Desdiferenciación Celular , Proliferación Celular , Proteínas Cullin/metabolismo , Modelos Animales de Enfermedad , Femenino , Células HEK293 , Haploinsuficiencia , Células HeLa , Humanos , Masculino , Ratones Mutantes , Mutación , Células de Schwann/citología , Células de Schwann/metabolismo
8.
Nat Commun ; 9(1): 4836, 2018 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-30446730

RESUMEN

A central paradigm in conservation biology is that population bottlenecks reduce genetic diversity and population viability. In an era of biodiversity loss and climate change, understanding the determinants and consequences of bottlenecks is therefore an important challenge. However, as most studies focus on single species, the multitude of potential drivers and the consequences of bottlenecks remain elusive. Here, we combined genetic data from over 11,000 individuals of 30 pinniped species with demographic, ecological and life history data to evaluate the consequences of commercial exploitation by 18th and 19th century sealers. We show that around one third of these species exhibit strong signatures of recent population declines. Bottleneck strength is associated with breeding habitat and mating system variation, and together with global abundance explains much of the variation in genetic diversity across species. Overall, bottleneck intensity is unrelated to IUCN status, although the three most heavily bottlenecked species are endangered. Our study reveals an unforeseen interplay between human exploitation, animal biology, demographic declines and genetic diversity.


Asunto(s)
Caniformia/genética , Variación Genética , Modelos Estadísticos , Animales , Caniformia/clasificación , Conservación de los Recursos Naturales , Ecosistema , Técnicas de Genotipaje , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Repeticiones de Microsatélite , Dinámica Poblacional/historia
9.
Arch Esp Urol ; 69(8): 553-564, 2016 Oct.
Artículo en Español | MEDLINE | ID: mdl-27725331

RESUMEN

One of the main wishes in the field of urinary catheters and stents is to arm them with biodegradable characteristics because we consider a failure of these devices the need for retrieval, the forgotten catheter syndrome as well as the adverse effects permanent devices cause after fulfilling their aim. The efforts focused in new designs, coatings and biomaterials aim to increase the biocompatibility of theses internal devices. Lately, there have been correct advances to answer the main challenges regarding biodegradable ureteral devices. Thus, modulation of the rate of degradation has been achieved thanks to new biomaterials and the use of copolymers that enable to choose the time of permanence as it is programmed with conventional double J catheters. Biocompatibility has improved with the use of new polymers that adapt better to the urine. Finally, one of the main problems is elimination of degraded fragments and experimentally it has be demonstrated that new designs elicit controlled degradation, from distal to proximal; using stranding and combination of copolymers degradation may be caused by dilution, reducing fragmentation to the last stages of life of the prosthesis. Moreover, it has been demonstrated that biodegradable catheters potentially may cause less urinary tract infection, less encrustation and predictably they will diminish catheter morbidity, since their degradation process reduces adverse effects. Regarding the development of biodegradable urethral stents, it is necessary to find biomaterials that enable maintaining their biomechanical properties in the long term, keeping open the urethral lumen both in patients with BPH and urethral stenosis. Modulation of the time of degradation of the prosthesis has been achieved, but the appearance of urothelial hyperplasia is still a constant in the initial phases after implantation. The development of drug eluting stents, anti-proliferative or anti-inflammatory, as well as biodegradable stents biocoated is a field from which it is expected the arrival of the solution of theses adverse effects. Therefore, many features need to be improved to obtain biodegradable stents, but over the last years some turning points have been accomplished thanks to the advances in Bioengineering, allowing to foresee safe and effective solutions in the nearest future.


Asunto(s)
Implantes Absorbibles , Stents , Catéteres Urinarios , Diseño de Equipo , Humanos
10.
Talanta ; 29(6): 521-4, 1982 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18963178

RESUMEN

A platinum electrode, a Radelkis OP-C-7111D graphite electrode and a laboratory-prepared silicone-rubber-based membrane graphite electrode were used in potentiometric titrations of reducing substances with bromine in acetic acid. In determinations of hydroquinone, 2-methylhydroquinone, 2-chlorohydroquinone and ascorbic acid, the Radelkis electrode showed the greatest sensitivity. The advantage of the laboratory-prepared membrane graphite electrode lay in its rapid attainment of stable potential values. Titrations were improved by addition of potassium acetate to the solutions analysed. The effects of water and acetic anhydride on the results were also investigated.

11.
Environ Pollut ; 114(2): 265-74, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11504349

RESUMEN

Blubber of free-ranging common dolphins (Delphinus delphis) from the northwestern coast of Spain (Atlantic), sampled in 1984 and 1996, and of common dolphins entangled in fishing nets in the southwestern Mediterranean, sampled during 1992 1994, was analysed for organochlorine pollutants. In the Atlantic, concentration of all pollutants was significantly higher in males than in females. The overall tPCB/tDDT ratio in this area was 3.35, which indicates a predominance of industrial inputs over those associated with agriculture. Individuals sampled in 1996 showed significantly lower DDT concentrations but a higher ppDDE/tDDT ratio than those sampled in 1984, which reflects the aging of the environmental load. In the same period, tPCB concentration remained constant and, as a consequence, the tPCB/tDDT ratio more than doubled. In the Mediterranean, the reduced sample size of adult individuals precluded proper statistical investigation of sex-related variation. The overall tPCB/tDDT ratio was 1.12, suggesting a higher contribution of pollutants of agricultural origin. Individuals had significantly higher levels of all DDT forms and a higher ppDDE/tDDT ratio than their counterparts from the Atlantic, but similar PCB concentrations. However, the relative frequency of the different congeners in relation to the total PCB load was different in the two areas. This indicates that the two populations do not mix, at least in the short- or medium-term. Organochlorine levels in both areas are at the mid to low end of the range of concentrations detected in other common dolphin populations and in that of other Delphinidae species from the same region. Although the impact of the organochlorine concentrations on the common dolphin populations surveyed cannot be assessed, it is considered unlikely that they have played a significant role in the decline that the species has suffered in recent decades in the western Mediterranean.


Asunto(s)
DDT/farmacocinética , Delfines/fisiología , Contaminantes Ambientales/farmacocinética , Insecticidas/farmacocinética , Bifenilos Policlorados/farmacocinética , Contaminantes Químicos del Agua/farmacocinética , Tejido Adiposo/química , Animales , DDT/análisis , Recolección de Datos , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Femenino , Insecticidas/análisis , Masculino , Mar Mediterráneo , Movimiento , Bifenilos Policlorados/análisis , Dinámica Poblacional , Factores Sexuales , España , Contaminantes Químicos del Agua/análisis
12.
Chemosphere ; 54(5): 669-77, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14599513

RESUMEN

Blubber and skin samples from 63 spotted dolphins (Stenella attenuata) (18 males, 40 females and 5 of unknown sex) were collected by biopsy techniques in the waters of the Coiba archipelago. Blubber was analyzed for organochlorine compounds and skin for gender determination. Mean levels of HCB (hexachlorobenzene), tPCB (polychlorinated biphenyls) and tDDT (dichlorodiphenyltrichloroethane) were 0.064, 2.30 and 6.4 mgkg(-1), respectively. These levels are low and are not considered to represent a threat to the S. attenuata population. No significant differences either in concentrations of HCB, tPCB and tDDT or in PCB profiles were observed between males and females. The ratio tDDT/tPCB was 2.69, indicating predominantly agrarian versus industrial activities in the area. The ratio ppDDE/tDDT was 0.83, a high figure that suggests both a local reduction of DDT inputs and a high rate of DDT degradation. Significant quantitative and qualitative differences were observed between two schools, suggesting intra-population heterogeneity in organochlorine exposure possibly due to demographic segregation.


Asunto(s)
Adipocitos/química , Delfines/metabolismo , Exposición a Riesgos Ambientales , Hidrocarburos Clorados , Insecticidas/análisis , Piel/química , Contaminantes Químicos del Agua/análisis , Animales , Femenino , Masculino , Panamá , Dinámica Poblacional
13.
Transplant Proc ; 42(8): 2841-4, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20970545

RESUMEN

OBJECTIVES: The optimal use of kidneys from small pediatric cadaveric donors remains controversial. The aim of this study was to analyze short-term graft and patient survivals of en bloc kidney transplantations compared with single cadaveric adult donor kidney transplantations. PATIENTS AND METHODS: We compared the 1-year evolution of 14 adult recipients of en bloc pediatric kidney donors (EBKT) of median age 13.5±14.5 months (range=3 days to 48 months) with 182 recipients of ideal adult cadaveric donors (ADT) showing a median age of 30±21 years (range=14-45 years). RESULTS: Besides the different age and weight of the donors, EBKT recipients were more commonly women (P=.05) and received thymoglobulin induction treatment (P=.00). Delayed graft function was higher in EBKT (46.2% vs 22.2%, P=.05), with no differences in the incidences of acute rejection episodes. Mean serum creatinine values at 3, 6, and 12 months after transplantation were 1.1±0.3, 1.1±0.2, and 1.0±0.2 mg/dL in the EBKT group, compared with 1.3±0.5 (P=.16), 1.3±0.5 (P=.02), and 1.3±0.6 (P<.01) in the ADT group. Vascular allograft complications were more frequent among EBKT. Graft survival rate at 1 year was 92% in both groups, with no differences in patient survival (100% in EBKT vs 92% in ADT; P=.49). CONCLUSIONS: EBKT from small pediatric donors show excellent graft function and 1-year survival and should be considered for transplantation into adults.


Asunto(s)
Neoplasias Renales , Adulto , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad
14.
Rev. int. med. cienc. act. fis. deporte ; 15(57): 165-180, mar. 2015. tab
Artículo en Español | IBECS (España) | ID: ibc-137805

RESUMEN

El objetivo del estudio fue medir y correlacionar la práctica de actividad física y con el Índice de Ruffier (IR) en adolescentes. A un total de 884 alumnos (edad=16,4±0,8 años) se les midió la actividad física con la Versión modificada del Assessment of Physical Activity Level Questionnaire (APALQ) y se evaluó la capacidad de adaptación al esfuerzo mediante el Test Ruffier. La media del Índice de Ruffier fue 11,1±4,6 y el Índice de actividad física (IAF) 13,8±4,4. Las relaciones entre IAF y el IR, y entre horas de ocio sedentario e IR resultaron ser significativas aunque débiles (r=-0,31; p=0,000). En el IR los chicos presentaron valores superiores (t= -8,78; p= 0,000) a las chicas. También destinan más tiempo a la práctica de AF y estas diferencias fueron significativas en AF reglada y no reglada y en participación en competición (p=0,000), mientras que las chicas destinan más tiempo a actividades sedentarias como leer y estudiar (p=0,000). Es necesario promover la práctica de actividades físico-deportivas, especialmente entre las chicas (AU)


The aim of the study was to assess and correlate physical activity practice and fitness level in adolescents. A total of 884 students (age=16,4±0,8 years) answered the modified version of the 'Assessment of Physical Activity Level Questionnaire (APALQ)' and aerobic capacity was assessed through the Ruffier Test. The mean Ruffier Index (IR) was 11,1±4,6 and the mean Physical Activity Index (IAF) was 13,8±4,4. The relationship between IAF and IR, and between sedentary activities in leisure time and IR, was significant (r=-0,31; p=0,000). although weak. Boys showed higher physical fitness values (t= -8,78; p= 0,000) and spent more time practicing physical activity. These differences were significant for both regulated and not regulated physical activity and for participation in competition (p=0.000). Girls spent more time in sedentary activities like reading and studying (p=0.000). It is necessary to promote physical activity and sport practice, especially among girls (AU)


Asunto(s)
Adolescente , Femenino , Humanos , Masculino , Actividades Recreativas , Actividad Motora , Deportes/estadística & datos numéricos , Ejercicio Físico , Conducta Sedentaria , Acondicionamiento Físico Humano/estadística & datos numéricos , Conducta del Adolescente
15.
Talanta ; 52(6): 959-70, 2000 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-18968056

RESUMEN

A historical review of the development of manganese(IV) chemistry and its application in analytical chemistry is presented. A brief presentation of the presence and importance of manganese(IV) in other areas of chemistry is also given.

16.
J Hered ; 95(4): 291-300, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15247308

RESUMEN

Genetic variability is an important component in the ability of populations to adapt in the face of environmental change. Here we report the first description of nuclear genetic variability in the only remaining sizable colony of the Mediterranean monk seal (Monachus monachus), located at Cap Blanc (Western Sahara, Mauritania), whose estimated size during the study period (1994-May 1997) was about 320 individuals. We tested 42 microsatellite loci isolated from five pinniped species in a sample of 52 pups. Three loci failed to give any product, and of the remaining 39, only 15 were polymorphic, with a maximum of 3 alleles detected. Three loci appeared to be X-linked. No departures from Hardy-Weinberg equilibrium were detected and no genetic structure was found between the two nursing caves currently occupied by the seals. Several analytical methods show that, as a consequence of a severe bottleneck, the population has suffered a decrease in genetic variability over the last few centuries.


Asunto(s)
Variación Genética , Genética de Población , Phocidae/genética , Animales , Efecto Fundador , Frecuencia de los Genes , Heterocigoto , Mar Mediterráneo , Repeticiones de Microsatélite/genética
17.
J Biol Chem ; 273(36): 23388-97, 1998 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-9722574

RESUMEN

We studied the effects of nitric oxide (NO) on the control of excess cellular heme and release of catalytically active iron. Endothelial cells (ECs) exposed to hemin followed by a NO donor have a ferritin content that is 16% that of cells exposed to hemin alone. Hemin-treated ECs experience a 3.5-fold rise in non-heme, catalytic iron 2 h later, but a hemin rechallenge 20 h later results in only a 24% increase. The addition of a NO donor after the first hemin exposure prevents this adaptive response, presumably due to effects on ferritin synthesis. NO donors were found to reduce iron release from hemin, while hemin accumulated in cells. A NO donor, in a dose-dependent fashion, inhibited heme oxygenase activity, measured by bilirubin production. Using low temperature EPR spectroscopy, heme oxygenase inhibition correlated with nitrosylation of free heme in microsomes. Nitrosylation of cellular heme prevented iron release, for while there was heme oxygenase-dependent release of iron in cells incubated with hemin for 24 h, the addition of a NO donor blocked iron release. This indicates that NO readily nitrosylates intracellular free heme and prevents its degradation by heme oxygenase. Nitrosylation of heme was found to reduce sensitization of cells to oxidative injury.


Asunto(s)
Endotelio Vascular/efectos de los fármacos , Hemo Oxigenasa (Desciclizante)/metabolismo , Hemo/metabolismo , Hierro/metabolismo , Óxido Nítrico/farmacología , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Adaptación Fisiológica , Supervivencia Celular , Citosol/enzimología , Interacciones Farmacológicas , Espectroscopía de Resonancia por Spin del Electrón , Ferritinas/metabolismo , Hemina/farmacología , Humanos , Peróxido de Hidrógeno/farmacología , Hígado/enzimología , Modelos Biológicos , Estrés Oxidativo , Oxidorreductasas/análisis , Espermina/farmacología
18.
Br Med J ; 2(6202): 1437, 1979 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-519496
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