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1.
Braz J Med Biol Res ; 52(3): e8251, 2019 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-30810625

RESUMEN

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1ß) tissue levels, and positive immunostaining for TNF-α, IL-1ß, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.


Asunto(s)
Amifostina/uso terapéutico , Fluorouracilo/efectos adversos , Inflamación/prevención & control , Sustancias Protectoras/uso terapéutico , Estomatitis/prevención & control , Xerostomía/prevención & control , Animales , Cricetinae , Modelos Animales de Enfermedad , Inflamación/inducido químicamente , Inflamación/patología , Masculino , Estomatitis/inducido químicamente , Estomatitis/patología , Xerostomía/inducido químicamente , Xerostomía/patología
2.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;52(3): e8251, 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-984035

RESUMEN

Oral mucositis (OM) is a common and dose-limiting side effect of cancer treatment, including 5-fluorouracil (5-FU) and radiotherapy. The efficacy of the therapeutic measures to prevent OM is limited and disease prevention is not fully observable. Amifostine is a cytoprotective agent with a described anti-inflammatory potential. It is clinically used to reduce radiotherapy and chemotherapy-associated xerostomia. This study investigated the protective effect of amifostine on an experimental model of OM. Hamsters were divided into six groups: saline control group (5 mL/kg), mechanical trauma (scratches) of the right cheek pouch; 5-FU (60 and 40 mg/kg, ip, respectively, administered on days 1 and 2); amifostine (12.5, 25, or 50 mg/kg) + 5-FU + scratches. Salivation rate was assessed and the animals were euthanized on day 10 for the analysis of macroscopic and microscopic injury by scores. Tissue samples were harvested for the measurement of neutrophil infiltration and detection of inflammatory markers by ELISA and immunohistochemistry. 5-FU induced pronounced hyposalivation, which was prevented by amifostine (P<0.05). In addition, 5-FU injection caused pronounced tissue injury accompanied by increased neutrophil accumulation, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) tissue levels, and positive immunostaining for TNF-α, IL-1β, and inducible nitric oxide synthase (iNOS). Interestingly, amifostine prevented the inflammatory reaction and consequently improved macroscopic and microscopic damage (P<0.05 vs 5-FU group). Amifostine reduced inflammation and protected against 5-FU-associated oral mucositis and hyposalivation.


Asunto(s)
Animales , Masculino , Estomatitis/prevención & control , Xerostomía/prevención & control , Amifostina/uso terapéutico , Sustancias Protectoras/uso terapéutico , Fluorouracilo/efectos adversos , Inflamación/prevención & control , Estomatitis/inducido químicamente , Estomatitis/patología , Xerostomía/inducido químicamente , Xerostomía/patología , Cricetinae , Modelos Animales de Enfermedad , Inflamación/inducido químicamente , Inflamación/patología
3.
Artículo en Inglés | MEDLINE | ID: mdl-30502827

RESUMEN

OBJECTIVES: The present study was aimed to find the larvicidal activity of petroleum ether, chloroform, acetone and methanolic extracts of Dichanthium foveolatum (Del.) Roberty, Leptochloa uniflora Hochst, Pancratium triflorum Roxb and Molineria trichocarpa (Wight) N.P.Balakr against Culex quinquefasciatus. METHODS: The larvicidal potential of selected plant extracts were determined against 4th instar larvae of C. quinquefasciatus with various concentrations viz., 50, 100, 150, 200 and 250 mg/ml. The mortality counts were made after 24 h of incubation and LC50 values were calculated. RESULTS: Chloroform extracts of studied plants were showed highest larvicidal activity with remarkable irritant against the larva of C. quinquefasciatus. Highest larvicidal activity was observed in the chloroform extract of D. foveolatum against the larva of C. quinquefasciatus with LC50 = 277.03 mg/ml. The larvicidal activity of the studied plants as follows chloroform extract of D. foveolatum (LC50 = 277.03 mg/ml) >L. uniflora (LC50 = 300.56 mg/ml) >M. trichocarpa (LC50 = 306.60 mg/ml) >P. triflorum (LC50 318.42 mg/ml). The larvicidal potential of P. triflorum was as follows Chloroform > acetone > methanol > petroleum ether. The larvicidal activities of L. uniflora and M. trichocarpa were as follows Chloroform > petroleum ether > acetone > methanol respectively. The larvicidal potentials of D. foveolatum was as follows Chloroform > methanol > acetone > petroleum ether. CONCLUSION: The chloroform extract of D. foveolatum find use as broad-spectrum larvicidal agent in the near future. It is hoped that more work would be undertaken to evaluate the utility of these plant extracts for field applications considering the promising leads given by the present study.


Asunto(s)
Culex , Insecticidas , Extractos Vegetales/farmacología , Plantas Medicinales/química , Animales , Filariasis , Concentración 50 Inhibidora , Larva , Hojas de la Planta/química
4.
Neural Netw ; 75: 141-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26775132

RESUMEN

Magnetic sensors are largely used in several engineering areas. Among them, magnetic sensors based on the Giant Magnetoimpedance (GMI) effect are a new family of magnetic sensing devices that have a huge potential for applications involving measurements of ultra-weak magnetic fields. The sensitivity of magnetometers is directly associated with the sensitivity of their sensing elements. The GMI effect is characterized by a large variation of the impedance (magnitude and phase) of a ferromagnetic sample, when subjected to a magnetic field. Recent studies have shown that phase-based GMI magnetometers have the potential to increase the sensitivity by about 100 times. The sensitivity of GMI samples depends on several parameters, such as sample length, external magnetic field, DC level and frequency of the excitation current. However, this dependency is yet to be sufficiently well-modeled in quantitative terms. So, the search for the set of parameters that optimizes the samples sensitivity is usually empirical and very time consuming. This paper deals with this problem by proposing a new neuro-genetic system aimed at maximizing the impedance phase sensitivity of GMI samples. A Multi-Layer Perceptron (MLP) Neural Network is used to model the impedance phase and a Genetic Algorithm uses the information provided by the neural network to determine which set of parameters maximizes the impedance phase sensitivity. The results obtained with a data set composed of four different GMI sample lengths demonstrate that the neuro-genetic system is able to correctly and automatically determine the set of conditioning parameters responsible for maximizing their phase sensitivities.


Asunto(s)
Fenómenos Magnéticos , Modelos Genéticos , Redes Neurales de la Computación , Algoritmos , Impedancia Eléctrica , Magnetometría/métodos
5.
J Clin Pharm Ther ; 40(1): 41-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25346459

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: Use of cisplatin can induce type I hypersensitivity reactions that may also be linked to the quality of the drug utilized. We observed cases of hypersensitivity that appeared to be associated with the brand of cisplatin used. The aim of this study was to compare two different brands of cisplatin in relation to type I hypersensitivity reactions. METHODS: Brand A was used in a tertiary care teaching hospital until 2012, and use of brand B started from January 2013, when the first hypersensitivity cases were observed. Patients were categorized based on symptom. Cisplatin of both brands was analysed by high-performance liquid chromatography (HPLC) and high-resolution electrospray ionization mass spectrometry (ESI-(+)-MS) and characterized according to US Pharmacopeia. RESULTS AND DISCUSSION: There were no cases of hypersensitivity associated with the use of cisplatin brand A, whereas four of 127 outpatients that used cisplatin brand B were affected. The two brands were in accordance with the US Pharmacopeia parameters, and there was no significant difference in the total platinum levels between the two brands when analysed by HPLC. However, high-resolution ESI-(+)-MS analyses show that brand B contains approximately 2.7 times more hydrolysed cisplatin than brand A. WHAT IS NEW AND CONCLUSION: The increase in the hydrolysed form of cisplatin found in brand B may be the cause of the hypersensitivity reaction observed in a subset of patients. We present the first study of the quality of drugs by high-resolution ESI-(+)-MS. Drug regulatory agencies and manufacturers should consider including measurement of hydrolysed cisplatin as a quality criterion for cisplatin formulations.


Asunto(s)
Cisplatino/efectos adversos , Cisplatino/química , Composición de Medicamentos/métodos , Hipersensibilidad a las Drogas/etiología , Platino (Metal)/química , Antineoplásicos/efectos adversos , Antineoplásicos/química , Química Farmacéutica/métodos , Cromatografía Líquida de Alta Presión/métodos , Hipersensibilidad a las Drogas/prevención & control , Femenino , Humanos , Masculino , Persona de Mediana Edad , Espectrometría de Masa por Ionización de Electrospray/métodos
6.
Rev Sci Instrum ; 85(8): 084708, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25173296

RESUMEN

Recently, our research group at PUC-Rio discovered that magnetic transducers based on the impedance phase characteristics of GMI sensors have the potential to multiply by one hundred the sensitivity values when compared to magnitude-based GMI transducers. Those GMI sensors can be employed in the measurement of ultra-weak magnetic fields, which intensities are even lower than the environmental magnetic noise. A traditional solution for cancelling the electromagnetic noise and interference makes use of gradiometric configurations, but the performance is strongly tied to the homogeneity of the sensing elements. This paper presents a new method that uses electronic circuits to modify the equivalent impedance of the GMI samples, aiming at homogenizing their phase characteristics and, consequently, improving the performance of gradiometric configurations based on GMI samples. It is also shown a performance comparison between this new method and another homogenization method previously developed.

7.
Braz J Med Biol Res ; 40(3): 323-31, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17334529

RESUMEN

The metabolic effects of carbohydrate supplementation in mice have not been extensively studied. In rats, glucose- and fructose-rich diets induce hypertriacylglycerolemia. In the present study, we compared the metabolic responses to two monosaccharide supplementations in two murine models. Adult male Wistar rats (N = 80) and C57BL/6 mice (N = 60), after 3 weeks on a standardized diet, were submitted to dietary supplementation by gavage with glucose (G) or fructose (F) solutions (500 g/L), 8 g/kg body weight for 21 days. Glycemia was significantly higher in rats after fructose treatment (F: 7.9 vs 9.3 mM) and in mice (G: 6.5 vs 10 and F: 6.6 vs 8.9 mM) after both carbohydrate treatments. Triacylglycerolemia increased significantly 1.5 times in rats after G or F supplementation. Total cholesterol did not change with G treatment in rats, but did decrease after F supplementation (1.5 vs 1.4 mM, P < 0.05). Both supplementations in rats induced insulin resistance, as suggested by the higher Homeostasis Model Assessment Index. In contrast, mice showed significant decreases in triacylglycerol (G: 1.8 vs 1.4 and F: 1.9 vs 1.4 mM, P < 0.01) and total cholesterol levels (G and F: 2.7 vs 2.5 mM, P < 0.05) after both monosaccharide supplementations. Wistar rats and C57BL/6 mice, although belonging to the same family (Muridae), presented opposite responses to glucose and fructose supplementation regarding serum triacylglycerol, free fatty acids, and insulin levels after monosaccharide treatment. Thus, while Wistar rats developed features of plurimetabolic syndrome, C57BL/6 mice presented changes in serum biochemical profile considered to be healthier for the cardiovascular system.


Asunto(s)
Carbohidratos de la Dieta/efectos adversos , Fructosa/administración & dosificación , Glucosa/administración & dosificación , Hipertrigliceridemia/etiología , Resistencia a la Insulina , Animales , Colesterol/sangre , Suplementos Dietéticos/efectos adversos , Modelos Animales de Enfermedad , Fructosa/efectos adversos , Glucosa/efectos adversos , Hipertrigliceridemia/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratas , Ratas Wistar , Triglicéridos/sangre
8.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;40(3): 323-331, Mar. 2007. tab, graf
Artículo en Inglés | LILACS | ID: lil-441760

RESUMEN

The metabolic effects of carbohydrate supplementation in mice have not been extensively studied. In rats, glucose- and fructose-rich diets induce hypertriacylglycerolemia. In the present study, we compared the metabolic responses to two monosaccharide supplementations in two murine models. Adult male Wistar rats (N = 80) and C57BL/6 mice (N = 60), after 3 weeks on a standardized diet, were submitted to dietary supplementation by gavage with glucose (G) or fructose (F) solutions (500 g/L), 8 g/kg body weight for 21 days. Glycemia was significantly higher in rats after fructose treatment (F: 7.9 vs 9.3 mM) and in mice (G: 6.5 vs 10 and F: 6.6 vs 8.9 mM) after both carbohydrate treatments. Triacylglycerolemia increased significantly 1.5 times in rats after G or F supplementation. Total cholesterol did not change with G treatment in rats, but did decrease after F supplementation (1.5 vs 1.4 mM, P < 0.05). Both supplementations in rats induced insulin resistance, as suggested by the higher Homeostasis Model Assessment Index. In contrast, mice showed significant decreases in triacylglycerol (G: 1.8 vs 1.4 and F: 1.9 vs 1.4 mM, P < 0.01) and total cholesterol levels (G and F: 2.7 vs 2.5 mM, P < 0.05) after both monosaccharide supplementations. Wistar rats and C57BL/6 mice, although belonging to the same family (Muridae), presented opposite responses to glucose and fructose supplementation regarding serum triacylglycerol, free fatty acids, and insulin levels after monosaccharide treatment. Thus, while Wistar rats developed features of plurimetabolic syndrome, C57BL/6 mice presented changes in serum biochemical profile considered to be healthier for the cardiovascular system.


Asunto(s)
Animales , Masculino , Ratones , Ratas , Carbohidratos de la Dieta/efectos adversos , Fructosa/administración & dosificación , Glucosa/administración & dosificación , Hipertrigliceridemia/etiología , Resistencia a la Insulina , Colesterol/sangre , Modelos Animales de Enfermedad , Suplementos Dietéticos/efectos adversos , Fructosa/efectos adversos , Glucosa/efectos adversos , Hipertrigliceridemia/metabolismo , Ratas Wistar , Triglicéridos/sangre
9.
Rev Neurol ; 41(6): 349-53, 2005.
Artículo en Español | MEDLINE | ID: mdl-16163656

RESUMEN

INTRODUCTION: Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare disease, inherited as autosomal-recessive trait, with variable clinical presentation including severe hypoglycaemia, cardiomyopathy, sudden infant death, progressive liver failure, 'Reye like' syndrome, neuromyopathy, muscle weakness and rhabdomyolysis. CASE REPORT: We report a 3 years old male patient admitted to our emergency department with vomiting, hypotonia and prostration, after a common respiratory infection. The presence of hypoketotic hypoglycaemia and elevated liver enzymes in the admission motivated a metabolic study. We found an abnormal low lactate/pyruvate ratio, decreased serum carnitine and dicarboxylic aciduria leading to the diagnosis of a fatty acid oxidation disorder (LCHADD). The molecular study of HADHA gene revealed homozygosity for the G1528C mutation in the patient DNA, and heterozygosity in both parents. CONCLUSIONS: The diagnosis of a fatty acid oxidation disorder must be considered in the presence of vomiting associated with excessive prostration specially if there is hypoketotic hypoglycaemia or familiar sudden infant death history. Physicians should be aware about these conditions and for the importance of measuring both glycaemia and ketone bodies during the evaluation of high risk situations.


Asunto(s)
3-Hidroxiacil-CoA Deshidrogenasas/deficiencia , Hipoglucemia , Cetosis , Errores Innatos del Metabolismo Lipídico , 3-Hidroxiacil-CoA Deshidrogenasas/genética , Preescolar , Análisis Mutacional de ADN , Ácidos Grasos/metabolismo , Humanos , Hipoglucemia/diagnóstico , Hipoglucemia/etiología , Hipoglucemia/fisiopatología , Cetosis/diagnóstico , Cetosis/etiología , Cetosis/genética , Cetosis/fisiopatología , Errores Innatos del Metabolismo Lipídico/complicaciones , Errores Innatos del Metabolismo Lipídico/diagnóstico , Errores Innatos del Metabolismo Lipídico/genética , Errores Innatos del Metabolismo Lipídico/fisiopatología , 3-Hidroxiacil-CoA Deshidrogenasa de Cadena Larga , Masculino , Proteína Trifuncional Mitocondrial , Subunidad alfa de la Proteína Trifuncional Mitocondrial , Complejos Multienzimáticos/genética , Complejos Multienzimáticos/metabolismo , Oxidación-Reducción , Síndrome
10.
Gen Dent ; 48(1): 100-2, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11199543

RESUMEN

Dental anomalies are an important issue and dentists should be able to manage these conditions. Often, treatment is not necessary; however, some abnormalities may affect the esthetics or function of teeth and can lead to other problems. This case report presents an unusual case of alteration in shape affecting the left lower canine in a 34-year-old woman.


Asunto(s)
Diente Canino/anomalías , Corona del Diente/anomalías , Adulto , Diente Canino/cirugía , Femenino , Humanos , Mandíbula , Anomalías Dentarias/patología , Anomalías Dentarias/cirugía , Corona del Diente/cirugía
11.
IEEE Trans Biomed Eng ; 39(8): 818-24, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1505995

RESUMEN

We discuss the use of magnetocardiography to detect reentry currents in cardiac flutter and fibrillation. The magnetic field produced by induced atrial flutter was measured in isolated rabbit hearts. A moving dipole model is proposed to treat the experimental data and to locate the reentry path.


Asunto(s)
Fibrilación Atrial/diagnóstico , Aleteo Atrial/diagnóstico , Simulación por Computador , Magnetismo , Animales , Estudios de Evaluación como Asunto , Conejos
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