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1.
Plant Dis ; 98(10): 1444, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30703982

RESUMO

Eucalypt rust caused by Puccinia psidii Winter represents a major disease affecting eucalypt production in South America, and is threatening myrtaceous hosts worldwide. In Uruguay, it was first detected infecting Eucalyptus globulus in 2001 (4) and later on E. grandis, Myrrhinium atropurpureum, and Myrcianthes pungens, two myrtaceae hosts native to Uruguay (3). Over the summer 2013, bright orange-yellowish pustules were detected on stock plants of E. dunnii in a nursery located in western Uruguay, province of Paysandú. A severe and explosive epidemic was readily observed. Affected leaves were taken to the laboratory and examined under the microscope. Uredinia and urediniospores were similar with those described previously in Uruguay on other hosts (3,4). Uredioniospores were 18 to 25 × 15 to 21 µm, yellow, unicellular, spherical to elliptical, base truncate, finely and uniformly echinulate with spines up to 1 µm long, with an evident bald patch without spines. To confirm identity of this fungus, genomic DNA was extracted from single-pustule urediniospores, and ITS region was amplified using primers PR1 and PR2 (1) with PCR conditions previously described (3). Forward and reverse sequences from three single pustules were obtained, assembled, and compared with those available in GenBank using BLAST searches. Obtained sequences showed to be identical to those analyzed by Pérez et al. (2011) collected from E. grandis and E. globulus, with no variation found in the analyzed region. A 100% identity was found with isolates UY1374 and UY1375 obtained from E. globulus, and with isolate UY1731 obtained from E. grandis (FJ710805, FJ710806, and FJ710807, respectively). Sequences were deposited in GenBank with accession numbers KM083129, KM083130, and KM083131. Even though this pathogen is known to occur in a wide variety of myrtaceous species, to our knowledge, this is the first natural infection record of P. psidii on E. dunnii in Uruguay and worldwide. This report confirms previous studies that indicated the susceptibility of E. dunnii when inoculated under controlled conditions (2,5). E. dunnii is being widely planted in Uruguay, eastern Argentina, and southern Brazil, with increasing significance to the pulp industry. Although the consequences of this finding have yet to be realized, scouting plantations is essential to estimate the real impact of this pathogen on this tree species. Our study contributes to expand the host range known for this globally important pathogen. References: (1) S. R. H. Langrell et al. Plant Pathol. 57:687, 2008. (2) L. Morin et al. PLoS ONE 7:e35434, 2012. (3) C. A. Pérez et al. Mycol. Progress 10:273, 2011. (4) N. Telechea et al. Plant Pathol. 52:427, 2003. (5) E. A. V. Zauza et al. Australas. Plant Pathol. 39:406, 2010.

2.
J Clin Invest ; 52(6): 1384-93, 1973 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-4703225

RESUMO

The hypothesis that diets high in carbohydrate produce hyperlipidemia in man was tested in new experiments which provided all calories either by the intravenous route or orally. After a base-line general diet, eight healthy men were fed fat-free diets consisting of 80% of the calories from glucose and 20% from an amino acid hydrolysate. The calories were adequate to maintain body weight. The solutions (1 cal/ml) were infused by constant drip over a 24 h period through either a superior vena cava catheter or a nasogastric tube. Each feeding was for 12 days in sequence but assigned in random order. The high CHO diet given orally, as expected, increased the mean base-line serum triglyceride level from 176+/-29 (SE) to 274+/-47. The identical diet given intravenously (i.v.) failed to produce hypertriglyceridemia; triglyceride levels were not significantly changed, 154+/-37, nor were blood glucose levels. Serum insulin levels were higher during the intravenous feeding. In contrast, both i.v. and oral feedings greatly lowered mean serum cholesterol concentration from the base-line value of 220+/-13 mg/100 ml to 135+/-11 and 151+/-13, respectively. However, the serum cholesterol level was significantly lower (P < 0.01) with the intravenous feeding than with the oral feeding. In addition, the fecal excretion of both neutral sterols and bile acids diminished greatly during the period of intravenous feeding. The fecal mass was likewise decreased. The bacterial conversion of cholesterol to conprostanol did not occur with either intravenous or oral feeding, but with both regimens secondary bile acids predominated, as usual, in the bile acid fraction of the stool. These results emphasize the key role of the intestinal mucosa in the etiology of carbohydrate-induced hypertriglyceridemia and as a direct or indirect contributor to plasma triglyceride and cholesterol levels in the absence of dietary lipids. When the gut mucosa was bypassed, carbohydrate-induced hypertriglyceridemia did not occur and both serum triglyceride and serum cholesterol levels decreased greatly at a time when the excretion of steroids in the stool was also reduced.


Assuntos
Ácidos e Sais Biliares/metabolismo , Colesterol/sangue , Carboidratos da Dieta/administração & dosagem , Fezes/metabolismo , Esteróis/metabolismo , Triglicerídeos/sangue , Administração Oral , Glicemia/metabolismo , Ácido Desoxicólico/metabolismo , Humanos , Injeções Intravenosas , Insulina/sangue , Ácido Litocólico/metabolismo , Masculino
3.
Rev. mex. ing. bioméd ; 42(2): 1136, May.-Aug. 2021. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1347763

RESUMO

ABSTRACT This article proposes two methodologies for the detection of lesions in the retina, which may indicate the presence of diabetic retinopathy (DR). Through the use of digital image processing techniques, it is possible to isolate the pixels that correspond to a lesion of RD, to achieve segmenting microaneurysms, the edges of the objects contained in the image are highlighted in order to detect the contours of the objects to select by size those that meet an area of 15 to 25 pixels in the case of 512x512 images and identify the objects as possible microaneurysms, while for the detection of exudates the green channel is selected to contrast the luminous objects in the retinography and from the conversion to gray scale, a histogram is graphed to identify the ideal threshold for the segmentation of the pixels that belong to the exudates at the end of the optical disk previously identified by a specialist. A confusion matrix supervised by an ophthalmologist was created to quantify the results obtained by the two methodologies, obtaining a specificity of 0.94 and a sensitivity of 0.97, values that are outstanding to proceed with the classification stage.


RESUMEN Este artículo propone dos metodologías para la detección de lesiones en la retina, que pueden significar la presencia de retinopatía diabética (RD). Mediante el uso de técnicas de procesamiento de imágenes digitales se logra aislar los pixeles que corresponden a una lesión propia de RD, para lograr segmentar microaneurismas se resaltan los bordes de los objetos contenido en la imagen con la finalidad de detectar los contornos de los objetos para seleccionar por tamaño los que cumplan con un área de 15 a 25 pixeles en el caso de imágenes de 512x512 y se identifiquen los objetos como posibles microaneurismas, mientras que para la detección de exudados se selecciona el canal verde para contrastar los objetos luminosos en la retinografía y a partir de la conversión a escala de grises se grafica un histograma para identificar el umbral idóneo para la segmentación de los pixeles que pertenecen a los exudados al final eliminar el disco óptico previamente identificado por un especialista. Se creó una matriz de confusión supervisada por un oftalmólogo para cuantificar los resultados obtenidos por las dos metodologías obteniendo una especificidad del 0.94 y una sensibilidad del 0.97, unos valores que son sobresalientes para proceder con la etapa de clasificación.

4.
J Clin Virol ; 34 Suppl 2: S61-8, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16461242

RESUMO

BACKGROUND: Transfusion-transmitted infections (TTIs) constitute a major health problem worldwide where routine screening of blood or blood products is improperly done, and where non-medical injecting medications and/or drug use are prevalent. Prevalence and risk factors vary by geographic location and by the specific TTI (including HIV-1, HBV, HCV and HTLV-I). OBJECTIVE: To determine the prevalence and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru. STUDY DESIGN: A cross-sectional multi-center study was conducted across seven major hospitals in Peru from February 2003 to September 2004. Self-reported behavior information (medical procedures, number of sexual partners, and drug use history) was analyzed, along with a review of exposure history from hospital medical records. Prevalences were calculated by TTI for different exposures, along with unadjusted and adjusted odds ratios for infection risk. RESULTS: Overall, 192 (54.7%) of 351 multi-transfused patients were found infected with one or more TTIs. Number of transfusion units, years of transfusion history (6 or more), and number of treatment facilities (2 or more) were associated with HCV infection. Hemodialysis history was a common risk factor associated with HBV, HCV and HTLV-I infection. HIV infection was associated only with total number of transfusion units received. CONCLUSIONS: High prevalences of HBV and HCV infection were found among Peruvian multi-transfused patients and were associated with a past history and number of blood transfusions, as well as with past hemodialysis procedures. TTIs continue to represent a significant public health problem in Peru. Continued vigilant attention to blood safety procedures, including universal screening and health care provider education, is recommended.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Anti-HIV/sangue , Infecções por HIV/epidemiologia , Infecções por HTLV-I/epidemiologia , Anticorpos Anti-Hepatite B/sangue , Hepatite B/epidemiologia , Anticorpos Anti-Hepatite C/sangue , Hepatite C/epidemiologia , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Diálise Renal , Reação Transfusional , Adolescente , Adulto , Estudos Transversais , Transmissão de Doença Infecciosa , Feminino , Infecções por HIV/transmissão , Infecções por HTLV-I/transmissão , Hepatite B/transmissão , Hepatite C/transmissão , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Peru/epidemiologia , Fatores de Risco
5.
Am J Cardiol ; 82(11): 1329-32, 1998 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9856914

RESUMO

This study examines whether there are differences between Mexican Americans and non-Hispanic whites in reported symptoms of acute myocardial infarction (AMI). The symptoms experienced by patients identified in a community-based surveillance program were examined to determine whether between-group differences existed by ethnicity, gender, and diabetic status. Data were available regarding the symptoms of 589 patients, between the ages of 25 and 74 years, who were hospitalized and diagnosed as either having definite or possible AMI in special care units at 1 of 7 hospitals in Corpus Christi, Texas. The most frequently reported symptoms were chest pain (83.2%), chest pressure or discomfort (67.6%), sweating (64.2%), fatigue (62.6%), dyspnea (60.3%), and arm or jaw pain (58.2%). After adjusting for age, diabetes mellitus, and gender, and relative to non-Hispanic whites, Mexican Americans were more likely to report chest pain, upper back pain, and palpitations, and less likely to report arm or jaw pain. Likewise, relative to men, women were more likely to report fatigue, dyspnea, dizziness, upper back pain, palpitations, and cough, and were less likely to report chest pain. Significant differences were also observed when older patients' symptoms were compared with younger patients' symptoms.


Assuntos
Americanos Mexicanos , Infarto do Miocárdio/etnologia , População Branca , Adulto , Idoso , Angiopatias Diabéticas/complicações , Angiopatias Diabéticas/epidemiologia , Angiopatias Diabéticas/etnologia , Feminino , Humanos , Masculino , Americanos Mexicanos/estatística & dados numéricos , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/epidemiologia , Análise de Regressão , População Branca/estatística & dados numéricos
6.
J Thorac Cardiovasc Surg ; 73(1): 139-44, 1977 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-831004

RESUMO

Nine cases of pulmonary monosporosis treated in the Missouri State Chest Hospital over a period of 19 years (1956 to 1975) were reviewed. Nine other cases from the literature are summarized. Ten of these 18 patients underwent resectional operations with two operative deaths, one from respiratory insufficiency and the other from a bronchopleural fistula and massive hemorrhage. The rest of the patients had an uneventful recovery. The indications for resectional surgery are re-established for suitable cases. The underlying disease is the major determinant of the outcome of the surgery. Other modes of treatment are also discussed. Based on the analysis of these 18 cases, a guideline for the management of pulmonary monosporosis is proposed.


Assuntos
Pneumopatias Fúngicas/cirurgia , Micetoma/cirurgia , Idoso , Anfotericina B/uso terapêutico , Feminino , Humanos , Pneumopatias Fúngicas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Micetoma/tratamento farmacológico , Escarro/microbiologia
7.
Fertil Steril ; 76(4): 823-5, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11591421

RESUMO

OBJECTIVE: To determine the effect of repeated freezing and thawing, and storage temperature, on the assay results of commonly measured reproductive hormones, and sex hormone-binding globulin (SHBG) in human serum. DESIGN: Prospective laboratory study. SETTING: Academic medical center. PATIENT(S): Four men and three pregnant women in the third trimester. INTERVENTION(S): Pooled serum from men and pregnant females were frozen at either -20 degrees C or -70 degrees C. Aliquots were then subjected to repeat freeze/thaw cycles, from 1 to 10 times, and assays were performed after the final freeze/thaw cycle. MAIN OUTCOME MEASURE(S): Assay results for eight hormones (FSH, LH, PRL, androstenedione (A), 17alpha-hydroxyprogesterone, P, insulin, and SHBG, as a function of the number of freeze/thaw cycles and storage temperature. RESULT(S): Only SHBG in male serum at -20 degrees C and P in pregnant serum at -70 degrees C showed statistically significant decreases in assay results with repeated freeze/thaw cycles (3.3% and 1.1% per cycle, respectively). All other analytes did not show significant changes as a function of freeze/thaw cycles or storage temperature. CONCLUSION(S): There is no consistent or predictable alteration in the results of SHBG, or the glycoprotein and steroid hormones evaluated, as a function of repeated freeze/thaw or the storage temperature of human serum.


Assuntos
Congelamento , Hormônios/sangue , Reprodução/fisiologia , Preservação de Sangue , Criopreservação , Feminino , Humanos , Masculino , Gravidez , Estudos Prospectivos , Globulina de Ligação a Hormônio Sexual/análise , Temperatura
8.
Health Educ Behav ; 26(5): 714-33, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10533175

RESUMO

To inform intervention development in a multisite randomized community trial, the Rapid Early Action for Coronary Treatment (REACT) project formative research was undertaken for the purpose of investigating the knowledge, beliefs, perceptions, and usual practice of health care professionals. A total of 24 key informant interviews of cardiologists and emergency physicians and 15 focus groups (91 participants) were conducted in five major geographic regions: Northeast, Northwest, Southeast, Southwest, and Midwest. Transcript analyses revealed that clinicians are somewhat unaware of the empirical evidence related to the problem of patient delay, are concerned about the practice constraints they face, and would benefit from concrete suggestions about how to improve patient education and encourage fast action. Findings provide guidance for selection of educational strategies and messages for health providers as well as patients and the public.


Assuntos
Atitude do Pessoal de Saúde , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Infarto do Miocárdio/terapia , Padrões de Prática Médica , Idoso , Cardiologia , Serviço Hospitalar de Emergência , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Enfermagem , Atenção Primária à Saúde , Fatores de Tempo , Estados Unidos
9.
Microsc Res Tech ; 75(3): 285-93, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21823201

RESUMO

In vitro interaction of Entamoeba histolytica trophozoites with fibronectin (FN) induces redistribution of the amoebic fibronectin receptor (ß1EhFNR). Trafficking of beta1 integrins is important for cell adhesion and migration in higher eukaryotes and requires the participation of Rab proteins. In E. histolytica, the machinery involved in integrin trafficking is not completely known. EhRab7 is a 24.5-kDa protein whose alignment with other Rab7 proteins demonstrated that it shared significant homology with Rab7 proteins from other organisms, including humans. Using different types of microscopy (fluorescence and confocal microscopy), it was established that Rab7 and the actin cytoskeleton participated in the mobilization of ß1EhFNR in FN-stimulated trophozoites. ß1EhFNR and Rab7 co-localized only in vesicular structures at 5 min, and at longer time (1 h), both co-localized in both plasma membrane and in vesicular structures; at the same time, Rab7 co-localized with specific actin structures (phagocytic vacuoles). At 5 h the ß1EhFNR, Rab7, and actin co-localized at the plasma membrane, and only ß1EhFNR and Rab7 decorated vesicles of different sizes. Actin and Rab7 co-localized in a cap-like structure at one end of the cell. Fluorescence resonance energy transfer and electron microscopy confirmed the close interaction between ß1EhFNR and Rab7. Moreover, the use of a lysosome-specific marker (LysoTracker) and a Golgi-specific marker (NBD C(6)-ceramide) allowed us to establish that, at some point within the endocytic route, ß1EhFNR and Rab7 co-localized within a lysosome-type organelle, but not a Golgi-like organelle, which indicated that this integrin-like molecule was returned to the plasma membrane via exocytic or secretory vesicles.


Assuntos
Actinas/metabolismo , Citoesqueleto/metabolismo , Entamoeba histolytica/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Integrina alfa5beta1/metabolismo , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Endocitose/fisiologia , Fibronectinas/metabolismo , Transferência Ressonante de Energia de Fluorescência , Humanos , Microscopia Confocal , Microscopia de Fluorescência , Dados de Sequência Molecular , Filogenia , Transporte Proteico/fisiologia , Homologia de Sequência de Aminoácidos , Trofozoítos/metabolismo , proteínas de unión al GTP Rab7
13.
Langmuir ; 24(17): 9820-4, 2008 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-18646871

RESUMO

In the present study, we report a method for preparing a fluorescent thermosensitive hybrid material based on monodisperse, thermosensitive poly( N-isopropyl acrylamide) (PNIPAM) microgels covered with CdTe nanocrystals of 3.2 nm diameter. The CdTe nanocrystals were covalently immobilized on the surface of PNIPAM microgels. The chemical environment around the CdTe nanocrystals was modified by changing the temperature and inducing the microgel volume-phase transition. This change provoked a steep variation in the nanocrystal photoluminescence (PL) intensity in such a way that when the temperature was under the low critical solution temperature (LCST) of the polymer (36 degrees C) the PL of the nanocrystals was strongly quenched, whereas above the LCST the PL intensity was restored.


Assuntos
Compostos de Cádmio/química , Nanopartículas/química , Telúrio/química , Resinas Acrílicas/química , Aminas/química , Cristalização , Géis , Concentração de Íons de Hidrogênio , Íons , Luz , Microquímica/métodos , Fotoquímica/métodos , Polímeros/química , Pontos Quânticos , Temperatura
14.
Nephron ; 22(4-6): 418-22, 1978.
Artigo em Inglês | MEDLINE | ID: mdl-740106

RESUMO

The effects of dialysis on plasma glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were investigated. GOT was measured using Autoanalyzer (SMA) and kinetic (Karmen) methods. Hemodialysis of uremic subjects was associated with a significant increase of GOT (SMA) and GPT (SMA). In contrast, hemodialysis had no effect on GOT (Karmen). However, the SMA method is influenced by substances affecting the blank value. Therefore, the results suggest that the increase in transaminase activities measured by the SMA method are not due to true increases in enzyme activities. Plasma from dialysis patients, obtained prior to hemodialysis, was also dialyzed in vitro. In vitro dialysis of uremic plasma significantly increased GOT (SMA), GOT (Karmen) and GPT vitro dialysis of uremic plasma significantly increased GOT (SMA), OGT (Karmen) and GPT (SMA). The results suggest that an inhibitor of transaminase activity may accumulate in renal failure. In vitro dialysis may remove this inhibitor and thus increase true transaminase activity.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Diálise Renal , Proteínas Sanguíneas/metabolismo , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Humanos , Uremia/sangue , Uremia/terapia
15.
Am J Obstet Gynecol ; 181(3): 596-600, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10486469

RESUMO

OBJECTIVE: We sought to determine the prevalence of 3beta-hydroxysteroid dehydrogenase-deficient nonclassic adrenal hyperplasia among adult hyperandrogenic women with dehydroepiandrosterone sulfate excess. STUDY DESIGN: Thirty consecutive hyperandrogenic women with hirsutism, oligomenorrhea, or both and dehydroepiandrosterone sulfate levels of >8.5 micromol/L and 24 control subjects were studied. Basal sex hormone binding globulin, total and free testosterone, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone, and basal and 60-minute corticotropin-stimulated 17-hydroxypregnenolone and dehydroepiandrosterone were measured, and the increment (change from basal to 60-minute value) was calculated. RESULTS: Twenty-six (87%) and 25 (83%) of the 30 hyperandrogenic patients studied had 60-minute dehydroepiandrosterone and change in 0- to 60-minute dehydroepiandrosterone levels greater than the mean + 2 SD of control subjects, respectively. Six (20%) and 6 (20%) of the 30 hyperandrogenic patients had 60-minute 17-hydroxypregnenolone and 0- to 60-minute change in 17-hydroxypregnenolone levels greater than the mean + 2 SD of control subjects, respectively. However, none of the subjects had either 60-minute 17-hydroxypregnenolone levels or 60-minute dehydroepiandrosterone levels or both associated with the diagnosis of genetically proved 3beta-hydroxysteroid dehydrogenase deficiency (>5-fold of the control mean value). CONCLUSION: 3beta-Hydroxysteroid dehydrogenase-deficient nonclassic adrenal hyperplasia is rare even among adult hyperandrogenic patients with adrenal androgen excess.


Assuntos
3-Hidroxiesteroide Desidrogenases/deficiência , Hiperplasia Suprarrenal Congênita/complicações , Hiperandrogenismo/complicações , 17-alfa-Hidroxiprogesterona/sangue , Adolescente , Hiperplasia Suprarrenal Congênita/sangue , Hiperplasia Suprarrenal Congênita/enzimologia , Hormônio Adrenocorticotrópico , Adulto , Desidroepiandrosterona/sangue , Sulfato de Desidroepiandrosterona/sangue , Feminino , Humanos , Hiperandrogenismo/sangue , Hiperandrogenismo/enzimologia , Cinética , Testosterona/sangue
16.
J Pediatr ; 129(6): 804-8, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8969720

RESUMO

BACKGROUND: We recently demonstrated that the use of an external nasal dilator reduced subjective snoring levels and improved sleep quality. Our study polysomnographically evaluated the effects of this device on the frequency of obstructive airway events during sleep in infants with and without congestion. METHODS: We used a crossover study to monitor 20 infants between the ages of 2 and 4 months (15 infants without congestion and 5 with congestion). Monitoring was conducted during two daytime sleep sessions in a crossover study in which infants slept with or without a cutdown version of an external nasal dilator (Breathe Right Nasal Strips, CNS, Inc., Bloomington, Minn.) in the first session with crossover to the other condition in the second session. A respiratory disturbance index consisting of apneas (pauses in respiration of at least 8 seconds) or hypopneas (decreased airflow resulting in oxygen desaturation of at least 3%) was determined. RESULTS: Babies without congestion showed a greater than 50% reduction in respiratory disturbance index from 3.2 +/- 2.8 to 1.2 +/- 1.2 events per hour (p < 0.005). Congested infants showed a decrease from 6.9 +/- 2.9 to 1.5 +/- 1.6 events per hour (p < 0.05). Babies with the greatest number of events showed the greatest improvement. CONCLUSION: The use of an external nasal dilator reduces the frequency of obstructive respiratory events in infants.


Assuntos
Dilatação/instrumentação , Obstrução Nasal/terapia , Respiração , Sono/fisiologia , Estudos Cross-Over , Dilatação/estatística & dados numéricos , Desenho de Equipamento , Feminino , Humanos , Recém-Nascido , Masculino , Obstrução Nasal/fisiopatologia , Polissonografia/estatística & dados numéricos , Estatísticas não Paramétricas
17.
Arterioscler Thromb Vasc Biol ; 17(11): 2975-81, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9409284

RESUMO

Nitric oxide (NO) and superoxide are both constitutive products of the endothelium. Because NO is readily inactivated by superoxide, the bioactivity of endothelium-derived NO (EDNO) is dependent on local activity of superoxide dismutase (SOD). We examined the effects of chronic inhibition of copper-zinc SOD (CuZnSOD) using a rat model of dietary copper restriction. Male weanling Sprague-Dawley rats were fed a Cu-deficient diet and received either no Cu replacement (Cu-deficient) or Cu in the drinking water (Cu-sufficient). Compared with Cu-sufficient animals, Cu-deficiency was associated with a 68% reduction in CuZnSOD activity and a 58% increase in vascular superoxide as estimated by lucigenin chemiluminescence (both P < .05). Compared with Cu-sufficient animals, arterial relaxation in the thoracic aorta from Cu-deficient animals was 10-fold less sensitive to acetylcholine, a receptor-dependent EDNO agonist, but only 1.5-fold less sensitive to A23187, a receptor-independent EDNO agonist, and only 1.25-fold less sensitive to authentic NO (all P < .05). In contrast, acute inhibition of CuZnSOD with 10 mM diethyldithiocarbamate produced a more uniform reduction in sensitivity to acetylcholine (8-fold), A23187 (10-fold), and NO (4-fold; all P < .001). Cu-deficient animals demonstrated a 2.5-fold increase in plasma-esterified F2-isoprostanes, a stable marker of lipid peroxidation, that correlated inversely with arterial relaxation to acetylcholine (R = -.83; P < .0009) but not A23187 or authentic NO. From these findings, we conclude that chronic inhibition of CuZnSOD inhibits EDNO-mediated arterial relaxation through two mechanisms, one being direct inactivation of NO and the other being lipid peroxidation that preferentially interrupts receptor-mediated stimulation of EDNO.


Assuntos
Cobre/deficiência , Endotélio Vascular/enzimologia , Peroxidação de Lipídeos , Óxido Nítrico/antagonistas & inibidores , Superóxido Dismutase/deficiência , Superóxidos/metabolismo , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiopatologia , Calcimicina/farmacologia , Cálcio/metabolismo , Quelantes/farmacologia , Cobre/administração & dosagem , Ditiocarb/farmacologia , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Ionóforos/farmacologia , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacologia , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/fisiologia , Vasodilatação/efeitos dos fármacos
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