RESUMEN
Allergic contact dermatitis has been established as the most frequent cause of eyelid dermatitis, but it is often misdiagnosed. The purpose of this study was to evaluate the characteristics of patients with eyelid dermatitis who were referred for patch testing. The patients were divided into three subgroups in this retrospective study: patients with only eyelid involvement, patients with involvement of eyelids and other areas, and patients without eyelid involvement. Data was collected on diagnoses, medical history, personal care products and make-up use, occupational dermatitis, and positive allergens. An independent t-test, one-way ANOVA, and chi-squared test were used to analyze the data. A total of 427 patients who referred for patch tests were included in the study. Of these, 139 patients had eyelid dermatitis. Allergic contact dermatitis (ACD) was the most common diagnosis in all three groups referred for patch tests. Use of shaving cream and hair conditioner was significantly higher in patients with only eyelid involvement and nickel sulfate was the most common allergen among them. Patch testing is the gold standard tool in the evaluation of eyelid contact dermatitis, and it is a necessity in the treatment of eyelid dermatitis, for the accurate identification of responsible allergens.
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Alérgenos , Dermatitis Alérgica por Contacto , Enfermedades de los Párpados , Pruebas del Parche , Humanos , Estudios Retrospectivos , Dermatitis Alérgica por Contacto/diagnóstico , Dermatitis Alérgica por Contacto/inmunología , Dermatitis Alérgica por Contacto/etiología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Alérgenos/inmunología , Alérgenos/efectos adversos , Enfermedades de los Párpados/diagnóstico , Enfermedades de los Párpados/inmunología , Enfermedades de los Párpados/etiología , Anciano , Adulto Joven , Níquel/efectos adversos , Níquel/inmunología , Párpados/patología , Cosméticos/efectos adversosRESUMEN
In this descriptive cross-sectional study by census method, the performance of 116 radiographers in the target centers was evaluated in relation to the observance of radiation protection principles with respect to patients, patient companion and radiographers. The data collection tool was a checklist containing 34 principles of radiation protection that were used after confirmation of its continuity and justifiability. The results showed that only in (39.2%) 45 radiographers the observance rate of the principles of radiation protection was acceptable. The highest and lowest levels in which radiographers observed protective principles were observance of protective principles with respect to themselves (60.8%) and protective principles respect of the patient companion (6.3%), respectively. According to the findings, radiation protection principles are not systematically designed, implemented, controlled and monitored by radiographers, and less than half of the radiographers observe the protection principles at the optimal level.
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Protección Radiológica , Humanos , Estudios Transversales , Irán , Encuestas y CuestionariosRESUMEN
BACKGROUND: Gestational diabetes mellitus (GDM) is one of the most common metabolic dysfunction in pregnancy and as overweight and obesity are of the major risk factors. The aim of this study was to determine the effect of Information-Motivation and Behavioral skills (IMB) model-based counseling on preventing GDM in overweight and obese pregnant women. METHODS: This randomized controlled trial study was conducted on 137 pregnant women in two groups; education and counseling IMB model-based for four sessions (n = 70), and antenatal usual care (AUC) (n = 67). This study was conducted on overweight and obese pregnant women, at the 12 to 16 weeks' gestation and recruited from the Prenatal Clinic of Rohani Hospital in north of Iran. Blood glucose was measured before and 8 weeks after the intervention. Descriptive and inferential statistics including mean, frequency, t-test, chi-square and ANCOVA were used. RESULTS: The prevalence of GDM was lower in the intervention group than the control group (10% and 29.9%, respectively, RR = 0.33, CI 95% (0.15- 0.74) p = .004) as well as mean fasting blood glucose (Cohen's d = 0.28, p = .07), and glucose tolerance test at the first and second hour (d = 0.41 and Cohen's d = 0.73, respectively, p < .01). CONCLUSIONS: A lifestyle intervention in early pregnancy by IMB counseling in overweight and obese pregnant women can be effective in decrease GDM.
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Diabetes Gestacional , Sobrepeso , Femenino , Embarazo , Humanos , Irán , Glucemia , Modelo de Habilidades de Información Motivación Comportamiento , Autocuidado , Obesidad/epidemiologíaRESUMEN
BACKGROUND & AIM: Chronic disease is a major concern with an aging population, and arthritis is one of the most prevalent chronic diseases affecting 10% of the population. Self-management can be appropriate to relieve the outcome of osteoarthritis as one of the most suitable approaches in people with chronic diseases. This study aimed to determine the effect of self-management education programs on the outcome of knee osteoarthritis in adult patients. METHODS: Eighty participants were randomized into either control (40) or intervention (40) groups. Initially, demographic data and outcome of knee osteoarthriti datas were collected. The intervention group was then offered a self-management program. After completing the education, the KOOS questionnaire was completed by both groups. The intervention group practiced the self-management program for 8 weeks at their homes. The outcome of knee osteoarthritis in the two groups was then reassessed and compared. RESULTS: There was no significant difference in the total score of the outcome of knee osteoarthritis before the training of the self-management education program (P > 0.05) between the two groups. After implementation of the self-management education program, the two groups demonstrated significant differences in scores for pain, symptoms, activities of daily living, sport and recreation function, and quality of life (P < 0.001). CONCLUSION: Self-management education can improve all outcomes of knee osteoarthritis. Adherence to the proper diet and the use of pain reduction methods along with exercise improve the effects of knee osteoarthritis.
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Osteoartritis de la Rodilla , Automanejo , Actividades Cotidianas , Adulto , Terapia por Ejercicio , Humanos , Calidad de VidaRESUMEN
AIM: The present study investigated the role of redox balance, inflammation, mitochondrial dysfunction, and apoptosis in Tramadol (Tra)-induced testicular toxicity. METHOD: Twenty-four male Wistar rats were randomly divided into either the control group or the groups receiving different doses of Tra (25, 50, and 75 mg/kg/day, i.p.) for 21 successive days. Testicular tissues were collected for oxidative stress, mitochondrial function, sperm assays and histopathological evaluation. Real-time polymerase chain reaction was performed to evaluate the markers of inflammation and apoptosis. RESULTS: Tra caused a significant reduction in the sperm count, motility and morphology, while it caused a marked increase in oxidative stress parameters. In addition, Tra induced testicular mitochondrial dysfunction due to the collapse of mitochondrial membrane potential and mitochondrial swelling. It also led to the significant inhibition of anti-apoptotic Bcl-2 expression, besides a significant increase in pro-apoptotic Bax expression. There was a significant increase in the level of tumour necrosis factor-α, interlukin-1ß and nuclear factor kappa B. Histopathological degenerative changes were observed in the testis after Tra exposure. CONCLUSIONS: The present results suggest that Tra exposure may lead to reproductive toxicity due to the loss of the antioxidant defence system, mitochondrial dysfunction, and activation of inflammatory and apoptotic pathways (Tab. 4, Fig. 5, Ref. 63).
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Apoptosis , Narcóticos , Estrés Oxidativo , Tramadol , Animales , Antioxidantes , Apoptosis/efectos de los fármacos , Humanos , Masculino , Mitocondrias , FN-kappa B , Narcóticos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar , Espermatozoides , Testículo/efectos de los fármacos , Tramadol/toxicidadRESUMEN
AIMS: Vitamin D deficiency is considered as a risk factor in cardiometabolic disorders, including cardiovascular diseases, hypertension and Type 2 diabetes mellitus. We have investigated the effect of vitamin D3 supplementation on glucose homeostasis in healthy overweight and obese women. METHODS: In a double-blind randomized placebo-controlled clinical trial, 77 healthy overweight or obese women (mean age 38 ± 8 years; BMI 29.9 ± 4.2 kg/m(2)) were randomly assigned to the vitamin D3 group (25 µg/day as cholecalciferol tablets) or the placebo group. Selected anthropometric indices, glucose, insulin, HbA(1c) and homeostasis model assessment of insulin resistance at baseline and after 12 weeks were measured. Dietary intakes using 24-h food recall and food frequency questionnaires were assessed. Physical activity was assessed by the International Physical Activity Questionnaire. Adjusted mean differences were calculated using analysis of covariance. Correlation coefficients were calculated by Pearson's analysis. RESULTS: Mean fasting blood glucose concentrations declined in the vitamin D3 and placebo groups (-0.28 ± 0.4 vs. -0.65 ± 0.4 mmol/l, P < 0.001) and the mean percentage of HbA(1c) was decreased (-13 ± 18 vs. -19 ± 17 mmol/l, P = 0.06) in both groups, respectively. Mean 25-hydroxyvitamin D concentrations increased in the vitamin D3 and placebo groups (38.2 ± 32 vs. 4.6 ± 14 nmol/l, P < 0.001), respectively. There was a significant correlation between HbA(1c) and 25-hydroxyvitamin D concentrations (r = -0.271; P = 0.018). CONCLUSIONS: The results indicate that the vitamin D3 supplement of 25 µg/day had no beneficial effect on glycaemic indices in healthy overweight or obese women.
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Glucemia/metabolismo , Colecalciferol/uso terapéutico , Suplementos Dietéticos , Resistencia a la Insulina , Obesidad/dietoterapia , Deficiencia de Vitamina D/dietoterapia , Vitaminas/uso terapéutico , Adulto , Índice de Masa Corporal , Registros de Dieta , Método Doble Ciego , Ingestión de Alimentos , Ejercicio Físico , Femenino , Homeostasis/efectos de los fármacos , Humanos , Masculino , Obesidad/sangre , Obesidad/complicaciones , Encuestas y Cuestionarios , Resultado del Tratamiento , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/complicacionesRESUMEN
The objective was to determine the effects of ground wheat grain (GW) inclusion rate, grinding extent (GE), and their interaction on lactating cow performance. Eight midlactation cows in 3 × 4 m individual boxes were used in a 4 × 4 replicated Latin square design study with 4 21 d periods. GW was fed at either 10% or 20% of diet dry matter (DM), as either finer or coarser particles. DM intake increased and net energy for lactation (NE(L)) intake tended to increase when GW was fed at 10% instead of 20% of diet DM. Milk energy yield, milk solids content and yield, and urine pH were unaffected. Fecal pH tended to increase at 20% versus 10% GW. Total tract apparent NDF, but not DM, digestibility tended to be greater for coarsely than finely GW and tended to be greater at 10% versus 20% GW. GW at 10% versus 20% of diet DM decreased blood BHBA and increased blood concentrations of total proteins and albumin. Data provide novel evidence that both finely and coarsely ground WG can be safely fed up to 20% midlactation cows. Commercial accessibility and cost will determine feeding preference of wheat grain to dairy cows.
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Alimentación Animal , Lactancia , Triticum , Tejido Adiposo , Animales , Bovinos , Industria Lechera , Femenino , LecheRESUMEN
Adaptation of Penicillium simplicissimum with different heavy metals present in a spent hydrocracking catalyst, as well as one-step, two-step, and spent medium bioleaching of the spent catalyst by the adapted fungus, was examined in batch cultures. Adaptation experiments with the single metal ions Ni, Mo, Fe, and W showed that the fungus could tolerate up to 1500 mg/L Ni, 8000 mg/L Mo, 3000 mg/L Fe, and 8000 mg/L W. In the presence of multi-metals, the fungus was able to tolerate up to 300 mg/L Ni, 200 mg/L Mo, 150 mg/L Fe and 2500 mg/L W. A total of 3% (w/v) spent catalyst generally gave the maximum extraction yields in the two-step bioleaching process (100% of W, 100% of Fe, 92.7% of Mo, 66.43% of Ni, and 25% of Al). The main lixiviant in the bioleaching was shown to be gluconic acid. The red pigment produced by the fungus could also possibly act as an agent in Al leaching.
Asunto(s)
Contaminantes Ambientales/aislamiento & purificación , Residuos Industriales/análisis , Penicillium/metabolismo , Tungsteno/aislamiento & purificación , Biodegradación Ambiental/efectos de los fármacos , Biomasa , Catálisis/efectos de los fármacos , Concentración de Iones de Hidrógeno/efectos de los fármacos , Penicillium/efectos de los fármacos , Penicillium/crecimiento & desarrollo , Reciclaje , Tungsteno/toxicidadRESUMEN
A case-control study determined the association of urinary tract infection (UTI) with genital hygiene practices and sexual activity in pregnant women attending prenatal clinics in Babol, Islamic Republic of Iran. A sample of 100 pregnant women with positive urine cultures (cases) were compared with 150 healthy pregnant women matched for age, social, economic and education status and parity (controls). Escherichia coli was the infecting organism in 83% of cases. Factors associated with UTI included sexual intercourse > or = 3 times per week (OR = 5.62), recent UTI (OR = 3.27), not washing genitals precoitus (OR = 2.16), not washing genitals postcoitus (OR = 2.89), not voiding urine postcoitus (OR = 8.62) and washing genitals from back to front (OR = 2.96).
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Coito , Higiene , Complicaciones Infecciosas del Embarazo/etiología , Infecciones Urinarias/etiología , Análisis de Varianza , Baños/estadística & datos numéricos , Estudios de Casos y Controles , Conducta de Ingestión de Líquido , Infecciones por Escherichia coli/etiología , Femenino , Humanos , Irán , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/prevención & control , Medición de Riesgo , Factores de Riesgo , Autocuidado/métodos , Autocuidado/estadística & datos numéricos , Encuestas y Cuestionarios , Infecciones Urinarias/epidemiología , Infecciones Urinarias/prevención & control , MicciónRESUMEN
A case-control study determined the association of urinary tract infection [UTI] with genital hygiene practices and sexual activity in pregnant women attending prenatal clinics in Babol, Islamic Republic of Iran. A sample of 100 pregnant women with positive urine cultures [cases] were compared with 150 healthy pregnant women matched for age, social, economic and education status and parity [controls]. Escherichia coli was the infecting organism in 83% of cases. Factors associated with UTI included sexual intercourse > /= 3 times per week [OR = 5.62], recent UTI [OR = 3.27], not washing genitals precoitus [OR = 2.16], not washing genitals postcoitus [OR = 2.89], not voiding urine postcoitus [OR = 8.62] and washing genitals from back to front [OR = 2.96]
Asunto(s)
Infecciones Urinarias , Higiene , Enfermedades Urogenitales Femeninas y Complicaciones del Embarazo , Conducta Sexual , Estudios de Casos y Controles , Factores de RiesgoRESUMEN
BACKGROUND AND PURPOSE: Protective cardiovascular effects of peroxisome proliferator activated receptor (PPAR)alpha and PPARgamma activators have been demonstrated. If used as vasoprotective agents in high risk vascular patients rather than for their metabolic benefits, these agents could be associated with unwanted side effects. As a proof of concept to support the use of combined low doses of PPARalpha and PPARgamma as vascular protective agents in high risk vascular patients, we tested the hypothesis that combined low doses of PPARalpha (fenofibrate) and PPARgamma (rosiglitazone) activators would provide vascular protective benefits similar to full individual doses of these PPAR agonists. EXPERIMENTAL APPROACH: Male Sprague-Dawley rats infused with Ang II (120 ng kg(-1) min(-1)) were treated with rosiglitazone (1 or 2 mg kg(-1) day(-1)) alone or concomitantly with fenofibrate (30 mg kg(-1) day(-1)) for 7 days. Thereafter, vessels was assessed on a pressurized myograph, while NAD(P)H oxidase activity was determined by lucigenin chemiluminescence. Inflammation was evaluated using ELISA for NFkappaB and Western blotting for adhesion molecules. KEY RESULTS: Ang II-induced blood pressure increase, impaired acetylcholine-induced vasorelaxation, altered vascular structure, and enhanced vascular NAD(P)H oxidase activity and inflammation were significantly reduced by low dose rosiglitazone+fenofibrate. CONCLUSIONS AND IMPLICATIONS: Combined low doses of PPARalpha and PPARgamma activators attenuated development of hypertension, corrected vascular structural abnormalities, improved endothelial function, oxidative stress, and vascular inflammation. These agents used in low-dose combination have synergistic vascular protective effects. The clinical effects of combined low-dose PPARalpha and PPARgamma activators as vascular protective therapy, potentially with reduced side-effects and drug interactions, should be assessed.
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Angiotensina II/farmacología , Vasos Sanguíneos/efectos de los fármacos , Hipertensión/tratamiento farmacológico , PPAR alfa/efectos de los fármacos , PPAR gamma/efectos de los fármacos , Animales , Presión Sanguínea/efectos de los fármacos , Vasos Sanguíneos/patología , Sinergismo Farmacológico , Hipertensión/patología , Masculino , NADPH Oxidasas/sangre , PPAR alfa/fisiología , PPAR gamma/fisiología , Ratas , Ratas Sprague-DawleyRESUMEN
It has been shown that glomerular ANG II receptors are downregulated and protein kinase C (PKC) activity is enhanced in diabetes mellitus. Therefore, we investigated glomerular and preglomerular vascular ANG II receptors and PKC isoform regulation in streptozotocin (STZ)-diabetic rats treated with insulin and/or captopril. Diabetic rats were prepared by injecting STZ (60 mg/kg). Those that developed diabetes after 48 h were treated with low or high doses of insulin, or with a low dose of insulin as well as captopril, and killed 14 days later. Their glomeruli and preglomerular vessels were purified, competitive binding studies were performed by using the ANG II antagonists losartan and PD-123319, and PKC analysis was carried out by Western blotting. Competitive binding studies showed that the AT(1) receptor was the only ANG II receptor detected on both glomeruli and preglomerular vessels of all groups. Preglomerular vascular AT(1) receptor density (B(max)) was significantly upregulated in low insulin-treated STZ rats, whereas glomerular AT(1) B(max) was downregulated. Furthermore, both the captopril- and high insulin-treated groups had less glomerulosclerosis and vascular damage than the low insulin-treated group. PKCalpha, PKCdelta, PKCepsilon, and PKCmu isoforms found in preglomerular vessels were upregulated by captopril and high insulin doses, respectively, whereas no such regulation occurred in glomeruli. We conclude that in STZ-diabetic rats ANG II receptors and PKC isoforms on preglomerular vessels and glomeruli are differentially regulated by treatment with insulin and/or captopril.
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Diabetes Mellitus Experimental/metabolismo , Glomérulos Renales/irrigación sanguínea , Proteína Quinasa C/metabolismo , Receptores de Angiotensina/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Vasos Sanguíneos/enzimología , Vasos Sanguíneos/metabolismo , Captopril/farmacología , Hipoglucemiantes/farmacología , Insulina/farmacología , Isoenzimas/metabolismo , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
We have shown previously that angiotensin II (Ang II) activates the janus-activated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway in vascular smooth muscle cells (VSMCs) and that activation of the JAK/STAT pathway is required for Ang II induction of VSMC proliferation. In the present study, we examined the effects of hyperglycemia (HG) on Ang II-induced JAK/STAT signaling events in cultured VSMCs. HG increases Ang II-induced JAK2 tyrosine phosphorylation and promotes a partial tyrosine phosphorylation of the enzyme under basal conditions. In addition, HG increases both basal and Ang II-induced complex formation of JAK2 with the Ang II AT(1) receptor. The extent of STAT1 and STAT3 tyrosine and serine phosphorylation are also increased under HG conditions. Furthermore, the tyrosine phosphorylation and activities of the SHP-1 and SHP-2 tyrosine phosphatases, enzymes that regulate Ang II-induced JAK2 tyrosine phosphorylation, are altered by HG. SHP-1, which is responsible for JAK2 tyrosine dephosphorylation in VSMC, is completely deactivated in HG, resulting in a prolonged duration of JAK2 phosphorylation under HG conditions. HG also enhances Ang II induction of VSMC proliferation. Taken together, these data suggest that HG augments Ang II induction of VSMC proliferation by increasing signal transduction through the JAK/STAT pathway.
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Angiotensina II/metabolismo , Hiperglucemia/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Músculo Liso Vascular/metabolismo , Transducción de Señal , Animales , División Celular , Células Cultivadas , Glucosa/farmacología , Proteínas Quinasas JNK Activadas por Mitógenos , Masculino , Músculo Liso Vascular/citología , Fosforilación , Ratas , Ratas Sprague-Dawley , Tirosina/metabolismoRESUMEN
It has been shown that glomerular angiotensin II (ANG II) receptors are downregulated and protein kinase C (PKC) is activated under diabetic conditions. We, therefore, investigated ANG II receptor and PKC isoform regulation in glomerular mesangial cells (MCs) under normal and elevated glucose concentrations. MCs were isolated from collagenase-treated rat glomeruli and cultured in medium containing normal or high glucose concentrations (5.5 and 25.0 mM, respectively). Competitive binding experiments were performed using the ANG II antagonists losartan and PD-123319, and PKC analysis was conducted by Western blotting. Competitive binding studies showed that the AT1 receptor was the only ANG II receptor detected on MCs grown to either subconfluence or confluence under either glucose concentration. AT1 receptor density was significantly downregulated in cells grown to confluence in high-glucose medium. Furthermore, elevated glucose concentration enhanced the presence of all MC PKC isoforms. In addition, PKCbeta, PKCgamma and PKCepsilon were translocated only in cells cultured in elevated glucose concentrations following 1-min stimulation by ANG II, whereas PKCalpha, PKCtheta, and PKClambda were translocated by ANG II only in cells grown in normal glucose. Moreover, no changes in the translocation of PKCdelta, PKCiota, PKCzeta, and PKCmu were detected in response to ANG II stimulation under euglycemic conditions. We conclude that MCs grown in high glucose concentration show altered ANG II receptor regulation as well as PKC isoform translocation compared with cells grown in normal glucose concentration.
Asunto(s)
Glucosa/farmacología , Glomérulos Renales/enzimología , Proteína Quinasa C/metabolismo , Receptores de Angiotensina/metabolismo , 1-Sarcosina-8-Isoleucina Angiotensina II/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo/efectos de los fármacos , Isoenzimas/metabolismo , Glomérulos Renales/química , Glomérulos Renales/citología , Masculino , Proteína Quinasa C beta , Proteína Quinasa C-alfa , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1 , Receptor de Angiotensina Tipo 2RESUMEN
Secreted by the heart, more specifically by atrial cardiomyocytes under normal conditions but also by ventricular myocytes during cardiac hypertrophy, natriuretic peptides are now considered important hormones in the control of blood pressure and salt and water excretion. Studies on natriuretic peptide secretagogues and their mechanisms of action have been complicated by hemodynamic changes and contractions to which the atria are constantly subjected. It now appears that atrial stretch through mechano-sensitive ion channels, adrenergic stimulation via alpha 1A-adrenergic receptors, and endothelin via its ETA receptor subtype are major triggering agents of natriuretic peptide release. With several other stimuli, such as angiotensin II and beta-adrenergic agents, modulation of natriuretic peptide release appears to be linked to local generation of prostaglandins. In all cases, intracellular calcium homeostasis, controlled by several ion channels, is considered a key element in the regulation of natriuretic peptide secretion.
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Miocardio/metabolismo , Natriuréticos/metabolismo , Animales , Hemodinámica/fisiología , Humanos , Membranas Intracelulares/fisiología , Transducción de Señal/fisiología , Sistema Vasomotor/fisiologíaRESUMEN
OBJECTIVE: To characterize glomerular and preglomerular vascular angiotensin II receptors during the acute phase of nonrenin-dependent one-kidney, one clip hypertension in rats, using the angiotensin II antagonists losartan and PD 123319, and to investigate their regulation after renin-angiotensin system blockade with either an angiotensin converting enzyme inhibitor, captopril, or an angiotensin II receptor antagonist, TCV-116. MATERIALS AND METHODS: One-kidney, one clip hypertension was produced in male Sprague-Dawley rats by placing a silver clip (internal diameter 0.2 mm) on the left renal artery and removing the contralateral kidney. After 1, 2 or 4 weeks, the rats were killed, and their glomerular and preglomerular vascular membranes were purified. Competitive binding studies were performed using specific angiotensin II antagonists. Similarly, one-kidney, one clip hypertension was allowed to develop for 2 weeks before treatment with captopril or TCV-116 for 2 weeks. RESULTS: Competitive binding studies showed that only the angiotensin II type 1 (AT1) receptor was detected on both glomeruli and preglomerular vessels of all groups. The vascular AT1 receptor density was significantly higher in the 1 and 2 week one-kidney, one clip groups, but the glomerular receptor density was not different in these rats compared with age-matched uninephrectomized controls. The glomerular receptor density was significantly higher in captopril-treated rats and significantly lower in TCV-116-treated rats compared with untreated and control rats, but no significant changes were detected in any groups in vascular AT1 receptor density. CONCLUSIONS: Angiotensin II receptors on preglomerular vessels and glomeruli are differentially regulated during the early phase of hypertension and after renin-angiotensin system blockade. Vascular angiotensin II receptors are upregulated in the early phase of hypertension whereas glomerular angiotensin II receptors are not However, after renin-angiotensin system blockade, glomerular but not vascular angiotensin II receptors were differentially regulated according to the type of blockade.
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Hipertensión Renovascular/metabolismo , Receptores de Angiotensina/metabolismo , Sistema Renina-Angiotensina/efectos de los fármacos , Antagonistas de Receptores de Angiotensina , Animales , Antihipertensivos/farmacología , Modelos Animales de Enfermedad , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Estudios de Seguimiento , Hipertensión Renovascular/tratamiento farmacológico , Hipertensión Renovascular/patología , Imidazoles/farmacología , Glomérulos Renales/irrigación sanguínea , Glomérulos Renales/metabolismo , Masculino , Nefrectomía , Piridinas/farmacología , Ratas , Ratas Sprague-Dawley , Arteria Renal/metabolismo , Arteria Renal/patologíaRESUMEN
The kidney is composed of different complex structures regulating--among others--renal blood flow and glomerular filtration rate. Several vasoactive peptide systems are involved in that regulation, including atrial natriuretic peptides, the renin-angiotensin system, endothelin and their respective receptors. In this review, we will briefly describe the characteristics, location and regulation of these receptors in the rat kidney.
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Factor Natriurético Atrial , Endotelinas , Riñón/metabolismo , Receptores de Péptidos , Sistema Renina-Angiotensina , Animales , RatasRESUMEN
Local renal and plasma renin-angiotensin systems (RAS) both play an important role in blood pressure regulation during the development of two-kidney, one clip Goldblatt hypertension (2K1C) through their vasoactive component, angiotensin II (Ang II). Our goal was to characterize glomerular and preglomerular vascular Ang II receptors during the different stages of development of hypertension in 2K1C rats (2-, 4-, 8-, and 16-weeks postoperative) using Ang II antagonists [Sar1,Ile8]-Ang II, losartan, and PD 123319 and their regulation after angiotensin-converting enzyme (ACE) inhibition by captopril. Competitive binding studies showed that the only Ang II receptor detected on both glomeruli and preglomerular vessels of all groups (2-, 4-, 8-, and 16-week 2K1C rats, control rats, and captopril-treated rats) was the Ang II type 1 receptor (AT1). Vascular AT1 receptor density (Bmax) was significantly lower in only the 16-week 2K1C group, whereas glomerular Bmax was significantly lower in 2K1C rats at 2-, 4-, and 8-weeks. Vascular and glomerular receptor densities were both significantly higher in captopril-treated rats than in nontreated rats. We therefore conclude that in 2K1C rats, Ang II receptors on preglomerular vessels and glomeruli are regulated differentially during the development of hypertension and after ACE inhibition. Our results suggest that glomerular Ang II receptors are regulated by systemic plasma Ang II levels, whereas vascular Ang II receptors are not. However, when renal and systemic RASs are both blocked, these receptors are upregulated but are no longer differentially regulated.
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Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Captopril/farmacología , Hipertensión Renovascular/metabolismo , Riñón/efectos de los fármacos , Riñón/metabolismo , Receptores de Angiotensina/efectos de los fármacos , Receptores de Angiotensina/metabolismo , Animales , Vasos Sanguíneos/metabolismo , Hipertensión Renovascular/patología , Glomérulos Renales/irrigación sanguínea , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Angiotensin-converting enzyme inhibitors (ACE-I) and specific nonpeptide angiotensin II (ANG II) receptor antagonists have been used extensively to treat a variety of cardiovascular disorders in experimental animals and humans. Despite their widespread use, only a limited amount of data has been published regarding the effect that renin-angiotensin system (RAS) blockade may have on ANG II receptors, and very often this information is contradictory. The present study was designed to investigate whether changes in plasma ANG II levels induced by RAS blockade could alter glomerular ANG II receptor characteristics. Captopril was employed as an ACE-I with losartan and TCV-116, two AT1 receptor antagonists of different chemical structure. Two experimental protocols were established. Protocol 1 contained 3 experimental groups: controls (Sprague-Dawley rats, 250-300 g BW), and animals treated with either captopril (0.5 g/l via drinking water) or losartan (10 mg/kg BW p.o.). In protocol 2, the animals were treated as in protocol 1 except that losartan was replaced by TCV-116 (1 mg/kg BW p.o.). At the end of treatment (3 days), all groups were killed by decapitation, blood was collected for plasma renin activity (PRA) measurement, and hearts and kidneys were excised. ANG II receptors were assessed by radioligand binding assays on membrane preparations of purified glomeruli, by displacement of 125I-[Sar1, Ile8]-ANG II with specific nonpeptide antagonists of AT1 (losartan) and AT2 (PD 123319) receptor subtypes. RAS blockade by either ACE-I or AT1 antagonists increased PRA. The binding assays showed that renal glomeruli from treated rats and controls expressed a single population (AT1) of ANG II receptors. The density of glomerular AT1 receptors was not modulated by captopril, but was significantly lower in animals treated with either losartan (Bmax: 854 +/- 169 vs. 379 +/- 79 fmol/mg protein and Kd: 59 +/- 6 vs. 45 +/- 6 nM for controls and losartan, respectively) or TCV-116 (480 +/- 72 vs. 188 +/- 16 fmol/mg protein and Kd: 45 +/- 9 vs. 37 +/- 18 nM for controls and TCV-116, respectively) than in their controls. No changes in receptor affinity (Kd) were detected. Previous membrane "acid-wash" did not modify the results. We conclude that short-term RAS blockade by AT1 antagonists, but not by ACE-I, induces true downregulation of renal glomerular ANG II receptors. No AT2 receptor subtype was detected.
Asunto(s)
Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Glomérulos Renales/efectos de los fármacos , Peptidil-Dipeptidasa A/metabolismo , Receptores de Angiotensina/metabolismo , Angiotensina II/sangre , Angiotensina II/metabolismo , Animales , Unión Competitiva , Compuestos de Bifenilo/farmacología , Captopril/farmacología , Corazón/efectos de los fármacos , Imidazoles/farmacología , Losartán , Masculino , Proteínas de la Membrana/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1 , Receptor de Angiotensina Tipo 2 , Renina/sangre , Renina/metabolismo , Sistema Renina-Angiotensina/efectos de los fármacos , Sistema Renina-Angiotensina/fisiología , Tetrazoles/farmacologíaRESUMEN
A software program has been developed that uses a frame-based expert system for differential diagnosis in neuroradiology. A frame-based expert system is used to store the magnetic resonance (MR) and computed tomographic (CT) imaging characteristics of over 100 known brain disorders in object-like entities. The frames are organized in a hierarchic structure in which lower order frames inherit attributes from higher order frames, with the highest frame containing information that applies to all the other frames. Program execution follows a consultation paradigm with a dynamic database. A decision tree menu provides a user-friendly interface with which to navigate through the network, based on features of the lesion as depicted on MR and CT images. The system can provide a differential diagnosis based on the MR imaging findings alone with information criteria including the signal intensity of the lesion on T1- and T2-weighted images, the location of the lesion, and the presence or absence of mass effect. The differential diagnosis may be further refined by adding CT-related information, including CT attenuation and the presence or absence of calcification and contrast enhancement.