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1.
Appl Immunohistochem Mol Morphol ; 30(4): 291-297, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35384879

RESUMEN

INTRODUCTION: Radicular cysts (RCs) and residual radicular cysts (RRCs) are the sequelae of dental caries and that leads to proliferation of epithelial rests of Malassez in periapical tissues. OBJECTIVES: The aim was to evaluate the relationship between Langerhans cells, macrophages, matrix metalloproteinases (MMP-9, MMP-13), and tumor necrosis factor-alpha (TNF-α) in the capsule and lining epithelium of cystic lesions. MATERIALS AND METHODS: Twenty RCs and 20 RRCs were submitted to immunohistochemical analysis with anti-CD68, anti-CD1a, anti-MMP-9, anti-MMP-13, and anti-TNF-α antibodies. The Mann-Whitney test and the Spearman correlation test were used for analysis of the data (P<0.05). RESULTS: The immunoexpression of MMP-13 and CD68 was significantly higher in RCs when compared with RRCs (P=0.011 and 0.012, respectively). The presence of an intense inflammatory infiltrate was significantly correlated with the immunoexpression of CD68 in RCs (P=0.025). Expression of CD68 showed a significant positive correlation with MMP-13 (P=0.015). A moderate correlation was observed between MMP-9 and MMP-13 (P=0.010). TNF-α expression was more common in RCs (P=0.001). CD1a was more frequently expressed in atrophic epithelium (P=0.041) and was significantly correlated with TNF-α (P=0.014). CONCLUSION: Langerhans cells induce a greater release of TNF-α which, in turn, is responsible for the stimulation of M1 macrophages. Higher immunoexpression of MMP-13 and MMP-9 is observed in the early stages of RCs compared with RRCs. Therefore, the toxins of microorganisms present in highly inflamed RCs are the main factors triggering a proinflammatory immune response and greater cystic expansion in the early stages of these lesions.


Asunto(s)
Caries Dental , Metaloproteinasas de la Matriz , Granuloma Periapical , Quiste Radicular , Caries Dental/patología , Humanos , Células de Langerhans/metabolismo , Macrófagos/metabolismo , Metaloproteinasa 13 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Granuloma Periapical/metabolismo , Granuloma Periapical/patología , Quiste Radicular/metabolismo , Quiste Radicular/patología , Inhibidores del Factor de Necrosis Tumoral , Factor de Necrosis Tumoral alfa
2.
Int J Mol Sci ; 22(18)2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34576130

RESUMEN

Several studies have sought new therapies for obesity and liver diseases. This study investigated the effect of the trypsin inhibitor isolated from tamarind seeds (TTI), nanoencapsulated in chitosan and whey protein isolate (ECW), on the liver health status of the Wistar rats fed with a high glycemic index (HGLI) diet. The nanoformulations without TTI (CW) and ECW were obtained by nanoprecipitation technique, physically and chemically characterized, and then administered to the animals. The adult male Wistar rats (n = 20) were allocated to four groups: HGLI diet + water; standard diet + water; HGLI diet + ECW (12.5 mg/kg); and HGLI diet + CW (10.0 mg/kg), 1 mL per gagave, for ten days. They were evaluated using biochemical and hematological parameters, Fibrosis-4 Index for Liver Fibrosis (FIB-4), AST to Platelet Ratio Index (APRI) scores, and liver morphology. Both nanoparticles presented spherical shape, smooth surface, and nanometric size [120.7 nm (ECW) and 136.4 nm (CW)]. In animals, ECW reduced (p < 0.05) blood glucose (17%), glutamic oxalacetic transaminase (39%), and alkaline phosphatase (24%). Besides, ECW reduced (p < 0.05) APRI and FIB-4 scores and presented a better aspect of hepatic morphology. ECW promoted benefits over a liver injury caused by the HGLI diet.


Asunto(s)
Quitosano/química , Dieta , Índice Glucémico , Hígado/lesiones , Nanopartículas/química , Tamarindus/química , Inhibidores de Tripsina/farmacología , Proteína de Suero de Leche/química , Animales , Glucemia/metabolismo , Ayuno/sangre , Homeostasis , Insulina/sangre , Resistencia a la Insulina , Riñón/fisiopatología , Hígado/efectos de los fármacos , Hígado/patología , Hígado/fisiopatología , Masculino , Nanopartículas/ultraestructura , Ratas Wistar , Valores de Referencia
3.
J Nutr ; 151(11): 3543-3554, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34313768

RESUMEN

BACKGROUND: Human milk oligosaccharides (HMOs) are unconjugated glycans associated with infant health and development. OBJECTIVES: To investigate the associations between HMO concentrations at 1 month and infant development throughout the first year of life. METHODS: A prospective cohort of Brazilian women between 18-40 years of age and their infants was studied from baseline (between 28-35 gestational weeks) and followed at 1 (n = 73), 6 (n = 51), and 12 months (n = 45). A total of 19 HMOs were quantified by HPLC with fluorescence detection. Infant development was evaluated by the Brazilian Ages and Stages Questionnaire. A directed acyclic graph was used to define the minimally sufficient adjustment (gestational age at birth, gestational weight gain, prepregnancy BMI, maternal age, parity, and the mode of breastfeeding at 1 month). Cox regression models with HRs and Benjamini-Hochberg multiple corrections were performed to estimate associations of HMOs with the cumulative risk of inadequate development for 5 developmental domains or for ≥2 developmental domains in all women and in the subset of secretor women (defined as the presence or near absence of 2'-fucosyllactose and lacto-N-fucopentaose I). RESULTS: The multivariate models with multiple corrections revealed an inverse association between lacto-N-tetrose (LNT) and the risk of inadequate development for personal-social skills (0.06; 95% CI: 0.01-0.76) and for ≥2 developmental domains (0.06; 95% CI: 0.01-0.59). The secretor mothers analysis also showed inverse associations with slightly different results for personal-social skills (0.09; 95% CI: 0.02-0.84) and ≥2 developmental domains (0.05; 95% CI: 0.01-0.70). CONCLUSIONS: Higher concentrations of LNT HMOs in Brazilian women are associated with their infants being less likely to be at risk of inadequate development for personal-social skills or for ≥2 developmental domains during the first year of life.


Asunto(s)
Desarrollo Infantil , Leche Humana , Lactancia Materna , Niño , Femenino , Humanos , Lactante , Recién Nacido , Oligosacáridos , Embarazo , Estudios Prospectivos
4.
Obes Facts ; 14(4): 357-369, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34256373

RESUMEN

INTRODUCTION: Obesity has emerged as one of the main public health problems. This condition triggers a series of hormonal and metabolic changes related to a low-grade chronic inflammatory condition. The trypsin inhibitor purified from tamarind (TTIp) seeds is a promising anti-inflammatory molecule, but its safety needs to be evaluated. This study aimed to evaluate TTIp bioactive dose effects on organs involved in its metabolism (liver and pancreas) and affected tissues (small intestine and perirenal adipose tissue) in an obesity model. METHODS: Three groups of adult male Wistar rats were used (n = 5). Two of these groups had diet-induced obesity, and a third group was eutrophic. TTIp was administered by gavage in one of the obese groups for 10 days, while the remaining groups received a vehicle. The chromatographic profile and the inhibition assay corroded the purification of the inhibitor. Physical and behavioral changes, liver enzymes, and stereological and histopathological analyses of tissues were evaluated. RESULTS: TTIp did not cause visible signs of toxicity, nor caused changes in liver enzymes, the liver, and pancreatic tissues. TTIp did not cause changes in the intestinal mucosa, showing improvement in the villi's histopathological characteristics compared to the group of animals with obesity without treatment with TTIp (p = 0.004). The analysis of perirenal adipose tissue showed that the average sectional area of animals with obesity that received TTIp did not differ from the control. There was a difference between the high glycemic load diet group and the group treated with the inhibitor (351.8 ± 55.5) (p = 0.016). In addition, the group that received TTIp had no inflammatory infiltrates. CONCLUSION: Based on histological and stereological analysis, the use of TTIp is potentially safe and anti-inflammatory in the evaluated obesity model and can be investigated as a possible adjuvant in obesity therapy.


Asunto(s)
Tamarindus , Tejido Adiposo , Animales , Antiinflamatorios/uso terapéutico , Dieta Alta en Grasa , Mucosa Intestinal , Obesidad/tratamiento farmacológico , Obesidad/etiología , Ratas , Ratas Wistar
5.
Brain Behav ; 11(3): e02009, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33452751

RESUMEN

INTRODUCTION: Neuroimaging studies have shown callosal abnormalities among maltreated subjects, but little is known about the functional and neurobiological correlates of these supposed developmental alterations. The aim of this study was to investigate childhood maltreatment (CM), neurocognitive functioning, cortisol levels, and corpus callosum (CC) integrity among adolescents. METHODS: One hundred and seven subjects underwent magnetic resonance imaging (MRI) with voxel-based diffusion-tensor imaging (DTI) and the Crossed Finger Localization Test (CFLT). Psychopathology was investigated with the Schedule for Affective Disorders and Schizophrenia (K-SADS-PL); CM was detailed by the Childhood Trauma Questionnaire (CTQ), and salivary cortisol levels were measured by immunoassay. RESULTS: Higher levels of CM were associated with current lower CFLT scores, mainly in the CROSSED condition, involving interhemispheric communication of sensorimotor information (p < .05) and with reduced fractional anisotropy (FA) in the splenium of the CC (p < .01). Deficits in the CFLT were also associated with higher cortisol levels (p < .05). CONCLUSION: The association among CM, neuropsychological abnormalities, callosal microstructure alterations, and cortisol levels suggests an altered pattern of brain interhemispheric connectivity among maltreated adolescents. Further studies are needed to investigate the extent to which these sensorimotor deficits and abnormal cortisol levels may be possible mediators of negative neurodevelopmental trajectories and adult psychopathology.


Asunto(s)
Imagen de Difusión Tensora , Hidrocortisona , Adolescente , Adulto , Anisotropía , Cuerpo Calloso/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética
6.
Clin Oral Investig ; 25(6): 3719-3727, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33226499

RESUMEN

OBJECTIVE: This study investigated the association between periodontitis severity (exposure) and metabolic syndrome (MetS - outcome), using two criteria for diagnosis of the outcome, since this relationship remains unexplored. MATERIALS AND METHODS: A case-control study was conducted with 870 individuals: 408 with first MetS diagnosis (cases) and 462 without MetS (controls). Participants' general information was obtained using a questionnaire and laboratory data was collected from medical records. Periodontitis severity criteria followed the Center for Disease Control and Prevention: none, mild, moderate, and severe. Odds ratios (OR) and 95% confidence intervals (95% CI) were determined by logistic regression analysis. RESULTS: Findings showed a positive association between moderate and severe periodontitis and MetS: ORadjusted = 1.64 (95% CI: 1.01 to 2.68) and ORadjusted = 1.94 (95% CI: 1.19 to 3.16), respectively, after adjustment for age, sex, schooling level, smoking habit, and cardiovascular disease. The adjusted measurements showed that among individuals with moderate or severe periodontitis, the probability of having MetS was around two times greater than among those without periodontitis, and that the chance was greater among participants with severe periodontitis than those with moderate periodontitis. CONCLUSION: An association between the severity of periodontal status and MetS was found, suggesting a possible relationship between the two diseases. CLINICAL RELEVANCE: MetS influences the etiology of cardiovascular diseases, one of the leading causes of mortality worldwide. The findings suggest that the greater the severity of periodontitis, the greater is the association magnitude with MetS. The health professional needs to recognize that the importance of periodontal disease may play in MetS.


Asunto(s)
Síndrome Metabólico , Enfermedades Periodontales , Periodontitis , Estudios de Casos y Controles , Estudios Transversales , Humanos , Síndrome Metabólico/complicaciones , Síndrome Metabólico/epidemiología , Periodontitis/complicaciones , Periodontitis/epidemiología , Fumar
7.
Nutrients ; 11(11)2019 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-31739532

RESUMEN

In vivo studies show the benefits of the trypsin inhibitor isolated from tamarind (Tamarindusindica L.) (TTI) seeds in satiety and obesity. In the present study, TTI nanoencapsulation (ECW) was performed to potentialize the effect of TTI and allow a controlled release in the stomach. The impact on glycemia, insulin, and lipid profile was evaluated in Wistar rats overfed with a high glycemic index diet (HGLI). Characterization of the nanoparticles and in vitro stability in simulated gastrointestinal conditions, monitored by antitrypsin activity and HPLC, was performed. ECW and empty nanoparticles (CW) were administered by gavage, using 12.5 and 10.0 mg/kg, respectively. Both nanoformulations presented a spherical shape and smooth surface, with an average diameter of 117.4 nm (24.1) for ECW and 123.9 nm (11.3) for CW. ECW maintained the antitrypsin activity (95.5%) in the gastric phase, while TTI was completely hydrolyzed. In Wistar rats, the nanoformulations significantly reduced glycemia and HOMA IR, and ECW increased HDL-c compared to CW (p < 0.05).Pancreas histopathology of animals treated with ECW suggested an onset of tissue repair. Thenanoencapsulation provided TTI protection, gradual release in the desired condition, and improvement of biochemical parameters related to carbohydrate metabolism disorders,without compromising insulinemia.


Asunto(s)
Glucemia/metabolismo , HDL-Colesterol/sangre , Hiperglucemia/prevención & control , Insulina/sangre , Nanopartículas , Tamarindus/química , Inhibidores de Tripsina/administración & dosificación , Animales , Quitosano , Preparaciones de Acción Retardada , Dieta , Ayuno , Índice Glucémico , Hidrólisis , Hiperglucemia/sangre , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Resistencia a la Insulina , Masculino , Páncreas/efectos de los fármacos , Páncreas/patología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Ratas Wistar , Semillas , Tripsina/metabolismo , Inhibidores de Tripsina/farmacología , Inhibidores de Tripsina/uso terapéutico , Proteína de Suero de Leche
8.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 41(2): 101-111, Mar.-Apr. 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-990827

RESUMEN

Objective: To compare results of positron emission tomography (PET) with carbon-11-labeled Pittsburgh compound B (11C-PIB) obtained with cerebellar or global brain uptake for voxel intensity normalization, describe the cortical sites with highest tracer uptake in subjects with mild Alzheimer's disease (AD), and explore possible group differences in 11C-PIB binding to white matter. Methods: 11C-PIB PET scans were acquired from subjects with AD (n=17) and healthy elderly controls (n=19). Voxel-based analysis was performed with statistical parametric mapping (SPM). Results: Cerebellar normalization showed higher 11C-PIB uptake in the AD group relative to controls throughout the cerebral cortex, involving the lateral temporal, orbitofrontal, and superior parietal cortices. With global uptake normalization, greatest cortical binding was detected in the orbitofrontal cortex; decreased 11C-PIB uptake in white matter was found in the posterior hippocampal region, corpus callosum, pons, and internal capsule. Conclusion: The present case-control voxelwise 11C-PIB PET comparison highlighted the regional distribution of amyloid deposition in the cerebral cortex of mildly demented AD patients. Tracer uptake was highest in the orbitofrontal cortex. Decreased 11C-PIB uptake in white-matter regions in this patient population may be a marker of white-matter damage in AD.


Asunto(s)
Humanos , Masculino , Femenino , Anciano , Anciano de 80 o más Años , Radioisótopos de Carbono , Corteza Cerebral/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Enfermedad de Alzheimer/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen , Índice de Severidad de la Enfermedad , Estudios de Casos y Controles
9.
Braz J Psychiatry ; 41(2): 101-111, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30540022

RESUMEN

OBJECTIVE: To compare results of positron emission tomography (PET) with carbon-11-labeled Pittsburgh compound B (11C-PIB) obtained with cerebellar or global brain uptake for voxel intensity normalization, describe the cortical sites with highest tracer uptake in subjects with mild Alzheimer's disease (AD), and explore possible group differences in 11C-PIB binding to white matter. METHODS: 11C-PIB PET scans were acquired from subjects with AD (n=17) and healthy elderly controls (n=19). Voxel-based analysis was performed with statistical parametric mapping (SPM). RESULTS: Cerebellar normalization showed higher 11C-PIB uptake in the AD group relative to controls throughout the cerebral cortex, involving the lateral temporal, orbitofrontal, and superior parietal cortices. With global uptake normalization, greatest cortical binding was detected in the orbitofrontal cortex; decreased 11C-PIB uptake in white matter was found in the posterior hippocampal region, corpus callosum, pons, and internal capsule. CONCLUSION: The present case-control voxelwise 11C-PIB PET comparison highlighted the regional distribution of amyloid deposition in the cerebral cortex of mildly demented AD patients. Tracer uptake was highest in the orbitofrontal cortex. Decreased 11C-PIB uptake in white-matter regions in this patient population may be a marker of white-matter damage in AD.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Radioisótopos de Carbono , Corteza Cerebral/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Sustancia Blanca/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Índice de Severidad de la Enfermedad
10.
Nat Commun ; 8(1): 1258, 2017 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-29097735

RESUMEN

AMPK is a conserved serine/threonine kinase whose activity maintains cellular energy homeostasis. Eukaryotic AMPK exists as αßγ complexes, whose regulatory γ subunit confers energy sensor function by binding adenine nucleotides. Humans bearing activating mutations in the γ2 subunit exhibit a phenotype including unexplained slowing of heart rate (bradycardia). Here, we show that γ2 AMPK activation downregulates fundamental sinoatrial cell pacemaker mechanisms to lower heart rate, including sarcolemmal hyperpolarization-activated current (I f) and ryanodine receptor-derived diastolic local subsarcolemmal Ca2+ release. In contrast, loss of γ2 AMPK induces a reciprocal phenotype of increased heart rate, and prevents the adaptive intrinsic bradycardia of endurance training. Our results reveal that in mammals, for which heart rate is a key determinant of cardiac energy demand, AMPK functions in an organ-specific manner to maintain cardiac energy homeostasis and determines cardiac physiological adaptation to exercise by modulating intrinsic sinoatrial cell behavior.


Asunto(s)
Proteínas Quinasas Activadas por AMP/genética , Bradicardia/genética , Calcio/metabolismo , Frecuencia Cardíaca/genética , Sarcolema/metabolismo , Nodo Sinoatrial/metabolismo , Adulto , Animales , Bradicardia/metabolismo , Electrocardiografía Ambulatoria , Ejercicio Físico , Corazón/diagnóstico por imagen , Humanos , Imagen por Resonancia Cinemagnética , Espectroscopía de Resonancia Magnética , Ratones , Microscopía Electrónica de Transmisión , Mutación , Miocardio/metabolismo , Miocardio/patología , Miocardio/ultraestructura , Condicionamiento Físico Animal , Resistencia Física , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Nodo Sinoatrial/patología
11.
Front Psychol ; 8: 57, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28184203

RESUMEN

Cardiovascular risk (CVR) factors may be associated with poor cognitive functioning in elderlies and impairments in brain structure. Using MRI and voxel-based morphometry (VBM), we assessed regional white matter (WM) volumes in a population-based sample of individuals aged 65-75 years (n = 156), subdivided in three CVR subgroups using the Framingham Risk Score. Cognition was assessed using the Short Cognitive Performance Test. In high-risk subjects, we detected significantly reduced WM volume in the right juxtacortical dorsolateral prefrontal region compared to both low and intermediate CVR subgroups. Findings remained significant after accounting for the presence of the APOEε4 allele. Inhibitory control performance was negatively related to right prefrontal WM volume, proportionally to the degree of CVR. Significantly reduced deep parietal WM was also detected bilaterally in the high CVR subgroup. This is the first large study documenting the topography of CVR-related WM brain volume deficits. The significant association regarding poor response inhibition indicates that prefrontal WM deficits related to CVR are clinically meaningful, since inhibitory control is known to rely on prefrontal integrity.

12.
Molecules ; 17(3): 2616-27, 2012 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-22391597

RESUMEN

Nevirapine (NVP) is an anti-HIV drug associated with severe hepatotoxicity and skin rashes, which raises concerns about its chronic administration. There is increasing evidence that metabolic activation to reactive electrophiles capable of reacting with bionucleophiles is likely to be involved in the initiation of these toxic responses. Phase I NVP metabolism involves oxidation of the 4-methyl substituent and the formation of phenolic derivatives that are conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid species prone to react with bionucleophiles. The covalent adducts thus formed might be at the genesis of toxic responses. As part of a program aimed at evaluating the possible contribution of quinoid derivatives of Phase I phenolic NVP metabolites to the toxic responses elicited by the parent drug, we have investigated the oxidation of 2-hydroxy-NVP with dipotassium nitroso-disulfonate (Frémy's salt), mimicking the one-electron oxidation involved in enzyme-mediated metabolic oxidations. We report herein the isolation and full structural characterization of a 1H-pyrrole-2,5-dione derivative as a major product, stemming from an unusual pyridine ring contraction.


Asunto(s)
Nevirapina/análogos & derivados , Nevirapina/química , Fenoles/química , Cristalografía por Rayos X , Hidrólisis , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Modelos Químicos , Conformación Molecular , Estructura Molecular , Compuestos Nitrosos/química , Oxidantes/química , Oxidación-Reducción
13.
Org Biomol Chem ; 9(22): 7822-35, 2011 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-21969039

RESUMEN

Nevirapine (11-cyclopropyl-5,11-dihydro-4-methyl-6H-dipyrido[3,2-b:2',3'-e][1,4]diazepin-6-one, NVP) is a non-nucleoside HIV-1 reverse transcriptase inhibitor used to prevent mother-to-child transmission of the virus. However, severe hepatotoxicity and serious adverse cutaneous effects have raised concerns about the safety of NVP administration. NVP metabolism yields several phenol-type derivatives conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid species that could react with bionucleophiles. The covalent adducts thus formed might be at the genesis of toxic responses. As an initial step to test this hypothesis, we synthesized the phenolic metabolite, 2-hydroxy-NVP, and investigated its oxidation in vitro. Using potassium nitrosodisulfonate and sodium periodate as model oxidants, we obtained evidence for fast generation of an electrophilic quinone-imine, which readily underwent hydrolytic conversion to fully characterized spiro derivatives, 1'-cyclopropyl-4-methyl-1H,1'H-spiro[pyridine-2,2'-pyrido[2,3-d]pyrimidine]-3,4',6(3'H)-trione in aqueous media and 1'-cyclopropyl-4-methyl-1'H,2H-spiro[pyridine-3,2'-pyrido[2,3-d]pyrimidine]-2,4',6(1H,3'H)-trione in non-aqueous media. The spiro compound generated in aqueous solution underwent subsequent hydrolytic degradation of the NVP ring system, whereas the one formed in non-aqueous media was stable to hydrolysis. The product profile observed with the chemical oxidants in aqueous solution was replicated using lactoperoxidase-mediated oxidation of 2-hydroxy-NVP. These observations suggest that metabolic activation of NVP, via Phase I oxidation to 2-hydroxy-NVP and subsequent generation of a quinone-imine, could occur in vivo and play a role in NVP-induced toxicity.


Asunto(s)
Fármacos Anti-VIH/efectos adversos , Infecciones por VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , Nevirapina/efectos adversos , Fenoles/metabolismo , Quinonas/metabolismo , Inhibidores de la Transcriptasa Inversa/efectos adversos , Fármacos Anti-VIH/uso terapéutico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Femenino , Infecciones por VIH/virología , Transcriptasa Inversa del VIH/antagonistas & inhibidores , VIH-1/enzimología , Humanos , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Nevirapina/análogos & derivados , Nevirapina/uso terapéutico , Oxidantes/química , Oxidación-Reducción , Ácido Peryódico/química , Fenoles/química , Embarazo , Piridinas/química , Quinonas/química , Inhibidores de la Transcriptasa Inversa/uso terapéutico , Soluciones , Agua
14.
Chem Res Toxicol ; 21(7): 1443-56, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18597499

RESUMEN

Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor used against the human immunodeficiency virus type 1 (HIV-1), mostly to prevent mother-to-child HIV transmission in developing countries. One of the limitations of nevirapine use is severe hepatotoxicity, which raises concerns about its administration, particularly in the perinatal and pediatric settings. Nevirapine metabolism involves oxidation of the 4-methyl substituent to 12-hydroxy-NVP and the formation of phenolic derivatives. Further metabolism of 12-hydroxy-NVP by phase II esterification may produce electrophilic derivatives capable of reacting with DNA to yield covalent adducts, which could potentially be involved in the initiation of mutagenic and carcinogenic events. In the present study, we have investigated the reactivity of the synthetic model electrophile, 12-mesyloxy-NVP, toward 2'-deoxynucleosides and DNA. Parallel synthetic studies were conducted with 12-bromo-NVP and 3',5'- O-bis( tert-butyldimethylsilyl)-2'-deoxynucleosides, using palladium(0) catalysis. Multiple adducts from deoxyguanosine, deoxyadenosine, and deoxycytidine were isolated in the reactions with 12-mesyloxy-NVP and characterized by NMR and MS. The adduct structures consistently involved binding through C12 of NVP and N7 or N9 of deoxyguanosine; N1, N3, or N9 of deoxyadenosine; and N3 of deoxycytidine. Reactions conducted under palladium(0) catalysis yielded adducts through O (6) and N1 of deoxyguanosine, N1 of deoxyadenosine, and N3 of deoxycytidine. At least seven deoxynucleoside-NVP adducts were present in DNA reacted with 12-mesyloxy-NVP and enzymatically hydrolyzed. Four of these adducts were identified as 12-(deoxyadenosin-N1-yl)nevirapine, 12-(deoxycytidin-N3-yl)nevirapine, 12-(deoxyguanosin- O(6)-yl)nevirapine, and 12-(deoxyadenosin- N(6)-yl)nevirapine. One depurinating adduct, 12-(guanin-N7-yl)nevirapine, was identified in the thermal neutral DNA hydrolysate. If formed in vivo, some of these adducts would have considerable mutagenic potential. Our results thus suggest that NVP metabolism to 12-hydroxy-NVP may be a factor in NVP hepatocarcinogenicity.


Asunto(s)
Fármacos Anti-VIH/metabolismo , Aductos de ADN/metabolismo , Nevirapina/metabolismo , Inhibidores de la Transcriptasa Inversa/metabolismo , Animales , Fármacos Anti-VIH/química , ADN/química , ADN/metabolismo , Aductos de ADN/síntesis química , Desoxiadenosinas/química , Desoxiadenosinas/metabolismo , Desoxicitidina/química , Desoxicitidina/metabolismo , Desoxiguanosina/química , Desoxiguanosina/metabolismo , Espectrometría de Masas , Nevirapina/análogos & derivados , Nevirapina/química , Inhibidores de la Transcriptasa Inversa/química
15.
Med Sci Monit ; 8(9): PI70-7, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12218955

RESUMEN

BACKGROUND: The purpose of this phase I study was to evaluate the toxicity profile, dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and plasma pharmacokinetics of oral etoposide, and to recommend a safe fractionated dose for phase II trials in pediatric patients with refractory solid tumors. MATERIAL/METHODS: All patients had tumors no longer amenable to established forms of treatment. The initial dose of etoposide was 20 mg/m(2) TID for 14 days every 21 days (dose-level I). Etoposide plasma pharmacokinetics were studied on day 1 of treatment and determined by HPLC. RESULTS: Seventeen children were enrolled, 13 of whom were included in the pharmacokinetic study, for a total of 64 courses. Nine patients were included at dose-level I; grade 2-3 leucopenia was observed in 5. The dose was then raised to 25 mg/m(2) (dose-level II) in another 8 patients; grade 3-4 leucopenia was observed in 4. This dose-level was therefore considered the MTD. The DLT was neutropenia. In patients at dose-level I and II the maximum plasma etoposide concentration was 2.97 and 8.59 mg/ml, respectively. Drug levels > 1 microg/ml were maintained for about 6.3 hours following drug administration at both dose-levels. Partial response was observed in 1 patient and 4 patients showed stable disease. CONCLUSIONS: Prolonged oral etoposide was well tolerated by our patients. Considering the MTD, and the fact that the patients included at dose-level I achieved an adequate (>1 microg/ml) plasma concentration of etoposide for a sufficient time, this dose level was recommended for phase II studies in pediatric malignancies.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/farmacocinética , Etopósido/administración & dosificación , Etopósido/farmacocinética , Neoplasias/tratamiento farmacológico , Administración Oral , Adolescente , Área Bajo la Curva , Niño , Preescolar , Femenino , Humanos , Masculino , Factores de Tiempo , Resultado del Tratamiento
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