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1.
J Appl Microbiol ; 126(3): 864-871, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30520218

RESUMEN

AIMS: We developed a new rapid and reliable method for identifying bacteria using a combination of Fourier transform infrared (FT-IR) spectroscopy of bacterial genomic DNA and multivariate analysis. METHODS AND RESULTS: FT-IR spectra of genomic DNA from four type strains of Pseudomonas spp., three type strains of Escherichia spp. and two type strains of Bacillus spp. were analysed in the 4000-400 cm-1 region. Spectral differences were found in the frequency regions of N-H stretching (amide I), C=O stretching vibrations (amide II) and PO2 - ionized asymmetric and symmetric stretching. Partial least squares discriminant analysis of the FT-IR spectra showed that the microbial strains could be discriminated by hierarchical clustering analysis. CONCLUSIONS: FT-IR spectral analysis of bacterial genomic DNA has potential for the rapid identification of bacteria at the genus and species levels. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reports a new bacterial identification method using multivariate analysis of FT-IR spectra of bacterial genomic DNA.


Asunto(s)
Bacterias , Técnicas de Tipificación Bacteriana/métodos , ADN Bacteriano , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Bacterias/clasificación , Bacterias/genética , ADN Bacteriano/análisis , ADN Bacteriano/química , ADN Bacteriano/genética
2.
Geophys Res Lett ; 45(2): 1133-1140, 2018 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-29503484

RESUMEN

Bretherton et al. (2004) used the Special Sensor Microwave Imager (SSM/I) version 5 product to derive an exponential curve that describes the relationship between precipitation and column relative humidity (CRH) over the tropical oceans. The curve, which features a precipitation pickup at a CRH of about 0.75 and a rapid increase of precipitation with CRH after the pickup, has been widely used in the studies of the tropical atmosphere. This study re-examines the moisture-precipitation relationship by using the version 7 SSM/I data, in which several biases in the previous version are corrected, and evaluates the relationship in the Coupled Model Intercomparison Project phase 5 (CMIP5) models. In the revised exponential curve derived using the updated satellite data, the precipitation pick-up occurs at a higher CRH (~0.8), and precipitation increases more slowly with CRH than in the previous curve. In most CMIP5 models, the precipitation pickup is too early due to the common model bias of overestimated (underestimated) precipitation in the dry (wet) regime.

3.
J Neurosurg ; 61(6): 1100-6, 1984 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6502239

RESUMEN

A combined anterior and lateral approach to the anterior cervical spinal canal with fusion was performed on five patients with cervical dumbbell-shaped tumors. The procedure consists of anterior discectomy and ipsilateral uncectomy, and removal of the posterolateral corners and posterior transverse ridges of the upper and lower vertebral bodies at the level of the tumor. In the case of a large tumor in the spinal canal, additional removal of a limited segment from the lateral part of the vertebral body was performed. The bone defect was filled with a T-shaped iliac bone graft. Two vertebral bodies were fused in each case. The highest level of the operation was C-2 and the lowest was T-1. The authors believe that any cervical dumbbell-shaped tumor below the C-2 level can be removed via an anterolateral approach as long as no more than three levels of the spine are involved.


Asunto(s)
Meningioma/cirugía , Neurilemoma/cirugía , Neoplasias de la Médula Espinal/cirugía , Neoplasias de la Columna Vertebral/cirugía , Adulto , Vértebras Cervicales , Femenino , Humanos , Masculino , Persona de Mediana Edad
4.
Laryngoscope ; 107(4): 466-71, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9111375

RESUMEN

The vast majority of cerebellopontine angle (CPA) tumors are extraaxial masses arising from either the eighth nerve (acoustic neuroma) or meninges (meningioma). Rarely, a tumor that arises from the brain parenchyma may protrude laterally to present with a clinical and radiographic picture simulating that of the much more common extraaxial lesions. Three individuals with CPA lesions that ultimately proved at operation to be exophytic brain tumors (pontine medulloblastoma, cerebellar astrocytoma, and fourth ventricular ependymoma) are described. The clinical manifestations of these lesions, although not entirely typical, fell well within the possible range of presentation of benign tumors primary to the CPA. In two of these cases the tumor actually penetrated into the internal auditory canal. As the optimal management strategy for treating parenchymal tumors differs substantially from that for extraaxial lesions, it is essential that the surgeon have a preoperative awareness of the lesion's nature before embarking on a surgical endeavor. Critical to arriving at the correct diagnosis is the close examination of preoperative imaging studies. The clinician should be alerted to the possibility that a CPA tumor is of intraaxial origin when the preoperative magnetic resonance imaging scan shows 1) blurring of the margin between the tumor and brainstem or cerebellum; 2) a degree of peritumoral hyperintensity on T2-weighted scans disproportionate to the size of the extraaxial mass; and 3) dilation of the lateral recess of the fourth ventricle.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Neoplasias Cerebelosas/diagnóstico , Ángulo Pontocerebeloso , Anciano , Diagnóstico Diferencial , Ependimoma/diagnóstico , Femenino , Glioblastoma/diagnóstico , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Meduloblastoma/diagnóstico
5.
JPEN J Parenter Enteral Nutr ; 16(5): 413-8, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1433773

RESUMEN

Glutathione (GSH) is a potent endogenous antioxidant that protects major organs from oxidant injury. However, present nutrition regimens may inadequately support tissue stores of this tripeptide during critical illness. To determine whether GSH reserves can be enhanced in vivo with intravenous (IV) supplements, rats underwent central venous catheterization, were given chow and water ad libitum during a 2-day recovery period, and were then randomized to receive one of three treatments as an IV bolus: (1) dextrose, (2) glutathione (GSH), or (3) glutathione monoethyl ester. GSH monoethyl ester is transported into cells more easily than is GSH. Tissue and plasma samples were analyzed for GSH at 2 and 4 hours after drug administration. Liver, renal, and ileal mucosal GSH were significantly increased in the GSH-monoethyl ester rats compared with dextrose-treated animals. In addition, plasma GSH was dramatically increased after monoester injection. In contrast, GSH administration depressed liver GSH stores and did not significantly affect GSH concentration in the other organs analyzed. Plasma GSH concentration was elevated 2 hours after GSH administration. We conclude that: (1) the monoethyl ester of glutathione can be used in vivo to enhance tissue and plasma GSH concentration and (2) IV GSH administration does not significantly increase tissue GSH levels and may paradoxically depress hepatic GSH in normal rats. Because the malnourished and critically ill are likely to have depleted GSH stores, nutrition strategies that include the provision of GSH monoester may lend additional support to those organs that are at risk for injury from oxygen free radicals during catabolic states.


Asunto(s)
Glutatión/análogos & derivados , Glutatión/farmacología , Animales , Antioxidantes , Cateterismo Venoso Central , Glucosa/administración & dosificación , Glucosa/farmacología , Glutatión/administración & dosificación , Glutatión/análisis , Humanos , Íleon/química , Inyecciones Intravenosas , Riñón/química , Hígado/química , Ratas , Ratas Wistar
6.
Arch Otolaryngol Head Neck Surg ; 122(11): 1240-9, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8906061

RESUMEN

Although neurofibromatosis (NF) became widely recognized as a pathologic entity in the late 19th century, only relatively recently has a clear distinction been made between its generalized form and the central variety. The latter form is typified by bilateral acoustic neuromas (ANs), which may be accompanied by other intracranial tumors, in particular, meningiomas. Up until almost the current era, confusion regarding the protean manifestations of the 2 types of NF existed in the minds of clinicians and in the literature. In 1987, a consensus panel of the National Institutes of Health differentiated the clinical manifestations associated with classic von Recklinghausen syndrome from those of the predominantly intracranial subtype and they were subsequently deemed NF type 1 (NF-1) and NF type 2 (NF-2), respectively. During the last few years, the genetic flaws that underlie these 2 syndromes have been elucidated, revealing that their origins lie in defects on separate chromosomes. The early literature on the subject included repeated descriptions of patients with manifestations typical of NF-2. The investigators, however, considered the intracranial lesions to be merely 1 facet of the generalized form of the disease. A few prescient individuals, however, demonstrated an appreciation for the distinguishing characteristics between these superficially similar, yet quite different, syndromes. The goals of this article are to trace the evolution of the concept of NF-2 as a distinct clinical entity from NF-1 and to assess the early awareness of and attitudes toward bilateral ANs, familial ANs, and ANs associated with other intracranial tumors.


Asunto(s)
Neurofibromatosis 2/historia , Europa (Continente) , Historia del Siglo XVI , Historia del Siglo XVII , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia Antigua , Historia Medieval , Humanos , Masculino , Neurofibromatosis 1/historia , Neuroma/clasificación , Neuroma/historia , Neuroma Acústico/historia
7.
Plast Reconstr Surg ; 105(3): 1129-35; discussion 1136-9, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10724275

RESUMEN

The objective of this study was to determine whether brow elevation occurs as a result of paralysis of brow depressors after botulinum toxin A injection. The study's design was a prospective case series with pretreatment and posttreatment outcome evaluation with statistical analysis at a university-based division of facial plastic surgery private clinic. Twenty-two patients of a consecutive sample desiring a cosmetic enhancement underwent injection of botulinum toxin A directed to brow depressors. Injections consisted of 7 to 10 units of botulinum toxin A (Botox, Allergan, Irvine, Calif.) into selected brow depressor muscle (lateral orbicularis oculi) bilaterally. No patients withdrew for adverse effects. All patients were evaluated 2 weeks after treatment. The outcomes were measured by change in brow elevation along vertical axis extending from both midpupil and lateral canthus to the caudal row of brow hairs with eyes at neutral gaze and the head at Frankfort plane. Preintervention and postintervention brow height was measured by the primary clinical investigator. The average brow elevation from the midpupil observed after selected injection of brow depressors with botulinum toxin A was 1.02 mm (p = 0.038). The average brow elevation from the lateral canthus observed after selected injection of brow depressors with botulinum toxin A was 4.83 mm (p<0.0001). Significant temporal brow elevation occurs as the result of paralysis of brow depressors by using botulinum toxin A injection. This procedure may be considered an alternative to surgical brow elevation.


Asunto(s)
Toxinas Botulínicas/administración & dosificación , Ritidoplastia/métodos , Blefaroplastia , Femenino , Humanos , Inyecciones , Masculino , Órbita , Estudios Prospectivos
12.
J Clin Gastroenterol ; 33(1): 53-5, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11418792

RESUMEN

We report the first case in the English literature of an intramural duodenal hematoma presenting as a complication of Helicobacter pylori-induced peptic ulcer disease. Intramural duodenal hematomas have been previously described in patients-usually in the setting of blunt trauma, postendoscopic biopsy, gastrostomy placement, and hemostatic therapy and in patients with a coagulopathy or bleeding diathesis-but not as a presentation of peptic ulcer disease. It is important to recognize this complication, as surgical management may benefit patients with a duodenal hematoma.


Asunto(s)
Enfermedades Duodenales/etiología , Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Hematoma/etiología , Úlcera Péptica Hemorrágica/etiología , Úlcera Péptica/complicaciones , Biopsia , Diagnóstico Diferencial , Enfermedades Duodenales/patología , Duodeno/patología , Mucosa Gástrica/patología , Obstrucción de la Salida Gástrica/etiología , Obstrucción de la Salida Gástrica/patología , Infecciones por Helicobacter/patología , Hematoma/patología , Humanos , Masculino , Persona de Mediana Edad , Úlcera Péptica/patología , Úlcera Péptica Hemorrágica/patología
13.
J Gastroenterol Hepatol ; 15(11): 1282-6, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11129222

RESUMEN

BACKGROUND/METHODS: To investigate the prevalence and clinical significance of hepatitis C virus (HCV) infection and its relationship with the development of hepatocellular carcinoma (HCC), 162 consecutive alcoholic patients with cirrhosis were studied. Alcohol intake and parenteral risk factors were investigated by interview using a questionnaire. All patients had consumed at least 80 g alcohol/day for at least the past 5 years. Sera were tested for anti-HCV using a third-generation enzyme immunoassay (EIA), hepatitis B s antigen (HBsAg), anti-HBs, anti-HBc and anti-HIV. Serum HCV-RNA was detected by a one-tube reverse transcription-polymerase chain reaction (RT-PCR) method. Patients were classified into three groups accroding to the presence or absence of viral markers: (i) cases without anti-HCV or HBsAg (group A); (ii) cases with HBsAg only (group B); and (iii) cases with anti-HCV only (group C). Demographic and clinical findings were compared among the three groups. RESULTS: Anti-HCV was present in 17 cases (10.5%) and HBsAg was present in 47 cases (29%). No patient had both anti-HCV and HBsAg. Group C subjects were the oldest, but the duration of drinking in this group was similar to that of group A. There was no significant difference in the daily alcohol intake among the three groups. Previous surgical operations and tattooing were more frequent in group C. Only one patient in group C was an intravenous drug user. The combined rate of HCC was significantly higher in groups B and C than in groups A (34, 23.5 and 6.1%, respectively). Laboratory data showed a higher platelet count, higher albumin level, lower bilirubin level and lower aspartate aminotransferase/alanine aminotransferase ratio in group C patients than in the other two groups. Hepatitis C virus RNA was detected in 14 of 85 cases tested (16.5%), in 11 of 12 cases (91.7%) with anti-HCV and in three of 73 cases (4.1%) without anti-HCV. CONCLUSIONS: Hepatitis C virus infection is frequent in alcoholic patients with cirrhosis in Korea. Hepatitis C virus, as well as hepatitis B virus, infection may have a synergistic effect on the development of HCC in alcoholic patients.


Asunto(s)
Carcinoma Hepatocelular/complicaciones , Hepatitis C/complicaciones , Cirrosis Hepática Alcohólica/complicaciones , Neoplasias Hepáticas/complicaciones , Adulto , Anciano , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/virología , Femenino , Hepacivirus/genética , Hepacivirus/inmunología , Anticuerpos Antihepatitis/sangre , Hepatitis B/complicaciones , Hepatitis B/diagnóstico , Hepatitis B/epidemiología , Hepatitis C/diagnóstico , Hepatitis C/epidemiología , Humanos , Corea (Geográfico)/epidemiología , Cirrosis Hepática Alcohólica/epidemiología , Cirrosis Hepática Alcohólica/virología , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/virología , Masculino , Persona de Mediana Edad , Prevalencia , ARN Viral/sangre
14.
Facial Plast Surg ; 16(1): 23-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11802342

RESUMEN

The deep nasolabial fold and other facial furrows and wrinkles have challenged the facial plastic surgeon. A variety of techniques have been used in the past to correct these troublesome defects. Advances in the last five years in new materials and design have created a subcutaneous implant that has excellent properties. This article reviews the development and use of Softform facial implant.


Asunto(s)
Materiales Biocompatibles , Politetrafluoroetileno , Ritidoplastia , Materiales Biocompatibles/química , Materiales Biocompatibles/historia , Procedimientos Quirúrgicos Dermatologicos , Historia del Siglo XX , Humanos , Inyecciones Subcutáneas , Labio/cirugía , Nariz/cirugía , Politetrafluoroetileno/química , Politetrafluoroetileno/historia , Ritidoplastia/efectos adversos , Ritidoplastia/historia , Ritidoplastia/métodos , Ritidoplastia/tendencias , Envejecimiento de la Piel , Propiedades de Superficie
15.
Head Neck ; 21(8): 772-5, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10562692

RESUMEN

BACKGROUND: The most common neoplasm of the parotid gland is the pleomorphic adenoma. The familial occurrence of such tumors arising within the parotid gland is rare, with only 3 previous reports in the literature. Bilateral synchronous pleomorphic adenomas of the parotid gland are also uncommon. We report 2 siblings with pleomorphic adenomas of the parotid gland, 1 of whom had bilateral synchronous mixed tumors. Patients and Methods Chromosomal analysis of tumor cells from the sibling with bilateral adenomas revealed the translocation t(3;12)(p21;q15). Chromosome 12q breakpoints have previously been identified in a wide variety of solid tumors including pleomorphic adenomas of the parotid gland. CONCLUSIONS: We discuss bilateral mixed tumors, familial parotid tumors, and the potential for a genetic predisposition for the recurrence of such parotid tumors, as suggested by characteristic chromosomal translocations associated with mixed tumors.


Asunto(s)
Adenoma Pleomórfico/genética , Neoplasias de la Parótida/genética , Adenoma Pleomórfico/diagnóstico , Adenoma Pleomórfico/patología , Adenoma Pleomórfico/cirugía , Cromosomas Humanos Par 12 , Femenino , Predisposición Genética a la Enfermedad , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Recurrencia Local de Neoplasia/genética , Neoplasias de la Parótida/diagnóstico , Neoplasias de la Parótida/patología , Neoplasias de la Parótida/cirugía , Translocación Genética
16.
Facial Plast Surg ; 14(2): 145-50, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-11816204

RESUMEN

The basic principles of successful total nasal reconstruction include providing a sufficient amount of tissue coverage, creating an adequate structural framework, and fashioning a viable inner lining. Relative uniformity of opinion exists regarding sources for tissue coverage and nasal lining. A variety of options exists, however, regarding the type of material used for nasal framework. Alloplastic metals, such as vitallium or titanium mesh, combined with autogenous soft tissue coverage, are reliable alternatives for use in total nasal reconstruction.


Asunto(s)
Rinoplastia/métodos , Cartílago/trasplante , Frente/cirugía , Humanos , Mucosa Nasal/cirugía , Mucosa Nasal/trasplante , Tabique Nasal/cirugía , Trasplante de Piel , Colgajos Quirúrgicos , Mallas Quirúrgicas , Expansión de Tejido
17.
Biochemistry ; 29(11): 2802-7, 1990 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-2161256

RESUMEN

Superoxide dismutase (SOD) is an enzyme that detoxifies superoxide (O2.-), a potentially toxic oxygen-derived species. Attempts to increase intracellular concentrations of SOD by direct application are complicated because SOD, being a relatively large molecule, does not readily cross cell membranes. We have identified a set of stable nitroxides that possess SOD-like activity, have the advantage of being low molecular weight, membrane permeable, and metal independent, and at pH 7.0 have reaction rate constants with O2.- ranging from 1.1 x 10(3) to 1.3 x 10(6) M-1 s-1. These SOD mimics protect mammalian cells from damage induced by hypoxanthine/xanthine oxidase and H2O2, although they exhibit no catalase-like activity. In addition, the nitroxide SOD mimics rapidly oxidize DNA-FeII and thus may interrupt the Fenton reaction and prevent formation of deleterious OH radicals and/or higher oxidation states of metal ions. Whether by SOD-like activity and/or interception of an electron from redox-active metal ions they protect cells from oxidative stress and may have use in basic and applied biological studies.


Asunto(s)
Superóxido Dismutasa , Animales , Células Cultivadas , Fenómenos Químicos , Química , Cricetinae , Grupo Citocromo c/metabolismo , ADN/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Compuestos Ferrosos/metabolismo , Óxidos de Nitrógeno/metabolismo , Oxazoles , Oxidación-Reducción , Superóxido Dismutasa/genética
18.
Neurochirurgia (Stuttg) ; 32(6): 180-3, 1989 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2594133

RESUMEN

Intraventricular or epidural injection of morphine through implantable infusion devices was used for severe pain in 50 patients with advanced cancer, arachnoiditis, or spinal injury. Intraventricular catheter was inserted for injection of morphine in 21 patients, 29 were treated through epidural infusion. For the evaluation of results the multimodal evoked potential (MEP) has been obtained before and after each treatment. 80% of the patients experienced good results. No significant side effects have been noted in patients with either epidural or intraventricular injection of morphine. These may be excellent methods for pain control in well selected patients.


Asunto(s)
Analgesia Epidural/instrumentación , Catéteres de Permanencia , Inyecciones Intraventriculares/instrumentación , Morfina/administración & dosificación , Neoplasias/fisiopatología , Dolor Intratable/tratamiento farmacológico , Adulto , Anciano , Relación Dosis-Respuesta a Droga , Electroencefalografía/efectos de los fármacos , Potenciales Evocados/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor
19.
Ann Rheum Dis ; 61(6): 547-50, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12006332

RESUMEN

OBJECTIVE: To determine the causes of acute abdominal pain in systemic lupus erythematosus (SLE) and to compare the clinical and laboratory data, especially antiphospholipid antibodies and the SLE Disease Activity Index (SLEDAI), between lupus enteritis (gastrointestinal vasculitis) and acute abdominal pain without lupus enteritis in patients with SLE. METHODS: A retrospective study was carried out for all patients admitted with SLE from 1993 to March 2001. The SLEDAI and laboratory data were collected at the time of diagnosis of SLE and at the time of acute abdominal pain. Lupus enteritis (gastrointestinal vasculitis) was diagnosed by clinical investigation and abdominal computed tomographic findings. RESULTS: Chart review identified 175 patients (20 male, 155 female) who had been admitted with SLE. Of these patients, 38 (22%) presented with acute abdominal pain. Lupus enteritis was the most common cause of acute abdominal pain. Patients were divided into three groups: group 1: lupus enteritis (n=17), group 2: acute abdominal pain without lupus enteritis (n=21), and group 3: SLE without acute abdominal pain (n=137). There was no difference in age and sex among the three groups. Antiphospholipid, anti-RNP, anti-Sm, anti-Ro, and anti-La antibodies did not differ among the three groups. There was no difference in the SLEDAI at the time of diagnosis and at the time of acute abdominal pain between groups 1 and 2. Complement, erythrocyte sedimentation rate, C reactive protein, and anti-dsDNA measured at the time of acute abdominal pain did not differ between groups 1 and 2. A drop in the white blood cell count at the time of abdominal pain was more prominent in group 1 than group 2. In lupus enteritis, the jejunum and ileum were the sites most commonly affected. Rectal involvement was rare. Even though four patients relapsed, all the patients with lupus enteritis, including those who relapsed, responded well to corticosteroid. CONCLUSION: Lupus enteritis is the most common cause of acute abdominal pain in SLE. All patients with lupus enteritis responded well to a high dose of a corticosteroid without surgical intervention. The SLEDAI and laboratory data, except leucopenia, do not correlate with the occurrence of lupus enteritis.


Asunto(s)
Dolor Abdominal/etiología , Enteritis/complicaciones , Lupus Eritematoso Sistémico/complicaciones , Dolor Abdominal/inmunología , Enfermedad Aguda , Adulto , Anticuerpos Antifosfolípidos/análisis , Enteritis/inmunología , Femenino , Humanos , Lupus Eritematoso Sistémico/inmunología , Masculino , Estudios Retrospectivos
20.
Arch Biochem Biophys ; 289(1): 62-70, 1991 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-1654848

RESUMEN

Stable nitroxide radicals have been previously shown to function as superoxide dismutase (SOD)2 mimics and to protect mammalian cells against superoxide and hydrogen peroxide-mediated oxidative stress. These unique characteristics suggested that nitroxides, such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), might protect mammalian cells against ionizing radiation. Treating Chinese hamster cells under aerobic conditions with 5, 10, 50, and 100 mM Tempol 10 min prior to X-rays resulted in radiation protection factors of 1.25, 1.30, 2.1, and 2.5, respectively. However, the reduced form of Tempol afforded no protection. Tempol treatment under hypoxic conditions did not provide radioprotection. Aerobic X-ray protection by Tempol could not be attributed to the induction of intracellular hypoxia, increase in intracellular glutathione, or induction of intracellular SOD mRNA. Tempol thus represents a new class of non-thiol-containing radiation protectors, which may be useful in elucidating the mechanism(s) of radiation-induced cellular damage and may have broad applications in protecting against oxidative stress.


Asunto(s)
Supervivencia Celular/efectos de la radiación , Óxidos N-Cíclicos/farmacología , Oxígeno/farmacología , Protectores contra Radiación/farmacología , Animales , Northern Blotting , Línea Celular , Membrana Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Cricetinae , Óxidos N-Cíclicos/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Expresión Génica/efectos de los fármacos , Glutatión/metabolismo , Oxígeno/metabolismo , ARN Mensajero/metabolismo , Marcadores de Spin , Superóxido Dismutasa/genética
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