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1.
Adicciones ; 0(0): 1805, 2023 Mar 15.
Artículo en Inglés, Español | MEDLINE | ID: mdl-36975069

RESUMEN

Cannabis is the most widely consumed illegal drug in Spain, with consumption concentrated mainly in adolescence and early adulthood. The objectives were to estimate the prevalence of cannabis use, cannabis use disorder (CUD) and dependent use in the Galician population aged 16 years and over, and to characterize cannabis users and cannabis dependent users. Data are from two cross-sectional studies from the Risk Behavior Information System conducted in 2017 (n = 7,841) and 2018 (n = 7,853). The Cannabis Abuse Screening Test (CAST) was used to identify users with CUD and/or dependent use. Prevalences were estimated and regression models were fitted to identify variables associated with cannabis use and dependent use. In 2017-2018, 2.7% (95% CI: 2.5-3.0) of the Galician population aged 16 years and over consumed cannabis at the time of the survey, with this prevalence being 9% in the 16-24 years age group. Prevalence decreased with age and was higher in males in all age groups. The prevalence of CUD in users was 69.5% (95% CI 61.1-78.1) and of dependent use it was 49.2% (95% CI 46.6-53.9). Tobacco use was the major determinant of being a cannabis user [OR = 19.8 (95% CI 13.8-28.4)] and daily cannabis use of being a dependent user [OR = 5.5 (95% CI 3.2-9.5)]. Cannabis use among the Galician population is high, especially among young people aged 16-24 years, who show the highest probability of dependent use. Prevention measures should be aimed especially at the younger population aged 16 years to curb its use and the development of consequences such as CUD and dependent use.


El cannabis es la droga ilegal más consumida en España con un consumo que se concentra principalmente en la adolescencia y primeros años de la edad adulta. Los objetivos de este estudio fueron estimar la prevalencia de consumo de cannabis, de trastorno por consumo de cannabis (CUD) y de consumo dependiente (CD) en la población gallega ≥16 años y caracterizar a los consumidores y a los consumidores dependientes. Los datos proceden de dos estudios transversales del Sistema de Información sobre Conductas de Riesgo realizados en 2017 (n = 7.841) y 2018 (n = 7.853). Se utilizó el test de adicción al cannabis (CAST) para identificar a los consumidores con CUD y/o CD. Se estimaron prevalencias y se ajustaron modelos de regresión para identificar variables asociadas al consumo y CD de cannabis.  El 2,7% (IC 95%: 2,5-3,0) de la población gallega ≥16 años consumía cannabis en el momento de la encuesta (2017-2018), siendo esta prevalencia del 9% en el grupo de 16-24 años. La prevalencia disminuye con la edad y es superior en hombres en todos los grupos etarios. La prevalencia de CUD en los consumidores fue del 69,5% (IC 95% 61,1-78,1) y de CD del 49,2% (IC 95% 44,6 -53,9). Consumir tabaco es el mayor determinante para ser consumidor de cannabis [OR = 19,8 (IC 95% 13,8-28,4)] y consumir diariamente cannabis para ser consumidor dependiente [OR = 5,5 (IC 95% 3,2-9,5)]. El consumo de cannabis entre la población gallega es bajo, aunque entre los jóvenes de 16-24 años, que son los que muestran más probabilidad de CD, la prevalencia es elevada. Las medidas de prevención deben dirigirse especialmente a la población más joven de 16 años para frenar su consumo y el desarrollo de consecuencias como el CUD y el CD.

2.
Sci Rep ; 10(1): 2138, 2020 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-32034174

RESUMEN

The allele ε4 of the apolipoprotein E gene (APOE ε4) is the major genetic risk factor for non-dominantly inherited Alzheimer's Disease (AD). Current techniques for APOE ε4 carriers identification show good accuracy but have several disadvantages that limit its implementation in a clinical laboratory. These include the need for sample preprocessing, poor automation, low throughput, requirement of additional equipment, and high cost. We followed ISO 13485 guidelines to validate the e4Risk test, a new latex-enhanced immunoturbidimetric blood assay for apolipoprotein E4 (ApoE4) determination in human plasma samples. The test showed high performance in terms of lot to lot variability, precision, interferences, reagents stability, prozone, and detectability. Furthermore, diagnostic accuracy is almost equal (99%) to the gold standard, APOE ε4 genotyping by polymerase chain reaction (PCR). Furthermore, we demonstrated that the e4Risk test can be adapted to any clinical chemistry analyzer, including the high throughput analyzers present in most hospitals and clinical laboratories. The e4Risk test versatility, low cost, and easiness provides an excellent solution for APOE ε4 carriers identification using the same blood sample drawn for biochemical diagnostic work-up of AD patients, which can have important advantages for patient stratification in clinical trials, preventative strategies for AD, and clinical assessment of risk for brain amyloidosis.


Asunto(s)
Apolipoproteína E4/sangre , Autoanálisis/métodos , Adolescente , Adulto , Alelos , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/sangre , Péptidos beta-Amiloides/metabolismo , Apolipoproteína E4/metabolismo , Encéfalo/metabolismo , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/sangre , Fragmentos de Péptidos/metabolismo , Plasma/metabolismo , Adulto Joven
3.
Arq. bras. cardiol ; 99(4): 886-891, out. 2012. graf, tab
Artículo en Portugués | LILACS | ID: lil-654257

RESUMEN

FUNDAMENTO: O transplante cardíaco continua sendo o tratamento de escolha para a insuficiência cardíaca refratária ao tratamento otimizado. Dois métodos diagnósticos apresentam elevada sensibilidade no diagnóstico de episódios de rejeição ao enxerto e Doença Vascular do Enxerto (DVE), causas importantes de mortalidade no pós-transplante. OBJETIVO: Avaliar a relação entre os resultados do ultrassom intracoronariano (USIV) e os laudos das biópsias endomiocárdicas (BX) no seguimento de pacientes submetidos a transplante cardíaco em um serviço de referência brasileiro. MÉTODOS: Foi realizado um ensaio epidemiológico retrospectivo observacional, com pacientes submetidos a transplante cardíaco ortotópico, no período de 2000 a 2009. Foram analisados os prontuários desses pacientes e os resultados dos USIV e BX realizados rotineiramente no seguimento clínico pós-transplante e terapêutica em uso. RESULTADOS: Dos 77 pacientes analisados, 63,63% são do sexo masculino, nas faixas etárias de 22 a 69 anos. Quanto aos resultados dos USIV, 33,96% foram classificados em Stanford classe I, e 32,08%, como Stanford IV. Dos 143 laudos das biópsias, 51,08% tiveram resultado 1R, 3R em 0,69% dos laudos, e 14,48% apresentaram a descrição de efeito Quilty. Todos usaram antiproliferativos, 80,51% usaram inibidores da calcineurina e 19,48% usaram inibidores do sinal de proliferação (ISP). CONCLUSÃO: A avaliação dos pacientes pós-transplante cardíaco por meio do USIV incorpora informações detalhadas para o diagnóstico precoce e sensível da DVE, que são complementadas pelas informações histológicas fornecidas pelas BX, estabelecendo uma possível relação causal entre a DVE e os episódios de rejeição humoral.


BACKGROUND: Cardiac transplantation continues to be the treatment of choice for heart failure refractory to optimized treatment. Two methods have high sensitivity for diagnosing allograft rejection episodes and cardiac allograft vasculopathy (CAV), important causes of mortality after transplantation. OBJECTIVE: To assess the relationship between intravascular ultrasound (IVUS) results and endomyocardial biopsy (BX) reports in the follow-up of patients undergoing cardiac transplantation in a Brazilian reference service. METHODS: A retrospective epidemiological observational study was carried out with patients undergoing orthotopic cardiac transplantation from 2000 to 2009. The study assessed the medical records of those patients and the results of the IVUS and BX routinely performed in the clinical post-transplant follow-up, as well as the therapy used. RESULTS: Of the 77 patients assessed, 63.63% were males, their ages ranging from 22 to 69 years. Regarding the IVUS results, 33.96% of the patients were classified as Stanford class I, and 32.08%, as Stanford class IV. Of the 143 BX reports, 51.08% were 1R, and 0.69%, 3R. The Quilty effect was described in 14.48% of the BX reports. All patients used antiproliferative agents, 80.51% used calcineurin inhibitors, and 19.48% used proliferation signal inhibitors. CONCLUSION: The assessment of cardiac transplant patients by use of IVUS provides detailed information for the early and sensitive diagnosis of CAV, which is complemented by histological data derived from BX, establishing a possible causal relationship between CAV and humoral rejection episodes.


Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Enfermedad de la Arteria Coronaria/patología , Rechazo de Injerto/patología , Trasplante de Corazón/patología , Distribución por Edad , Biopsia , Brasil , Enfermedad de la Arteria Coronaria , Rechazo de Injerto , Trasplante de Corazón , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Trasplante Homólogo/patología
4.
Arq Bras Cardiol ; 99(4): 886-91, 2012 Oct.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-22948241

RESUMEN

BACKGROUND: Cardiac transplantation continues to be the treatment of choice for heart failure refractory to optimized treatment. Two methods have high sensitivity for diagnosing allograft rejection episodes and cardiac allograft vasculopathy (CAV), important causes of mortality after transplantation. OBJECTIVE: To assess the relationship between intravascular ultrasound (IVUS) results and endomyocardial biopsy (BX) reports in the follow-up of patients undergoing cardiac transplantation in a Brazilian reference service. METHODS: A retrospective epidemiological observational study was carried out with patients undergoing orthotopic cardiac transplantation from 2000 to 2009. The study assessed the medical records of those patients and the results of the IVUS and BX routinely performed in the clinical post-transplant follow-up, as well as the therapy used. RESULTS: Of the 77 patients assessed, 63.63% were males, their ages ranging from 22 to 69 years. Regarding the IVUS results, 33.96% of the patients were classified as Stanford class I, and 32.08%, as Stanford class IV. Of the 143 BX reports, 51.08% were 1R, and 0.69%, 3R. The Quilty effect was described in 14.48% of the BX reports. All patients used antiproliferative agents, 80.51% used calcineurin inhibitors, and 19.48% used proliferation signal inhibitors. CONCLUSION: The assessment of cardiac transplant patients by use of IVUS provides detailed information for the early and sensitive diagnosis of CAV, which is complemented by histological data derived from BX, establishing a possible causal relationship between CAV and humoral rejection episodes.


Asunto(s)
Enfermedad de la Arteria Coronaria/patología , Rechazo de Injerto/patología , Trasplante de Corazón/patología , Adulto , Distribución por Edad , Anciano , Biopsia , Brasil , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Femenino , Rechazo de Injerto/diagnóstico por imagen , Trasplante de Corazón/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Trasplante Homólogo/patología , Ultrasonografía , Adulto Joven
5.
Horm Res Paediatr ; 73(1): 49-60, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20190540

RESUMEN

BACKGROUND: Aromatase inhibition has been proposed as a potential approach for growth enhancement in children with short stature, but detailed animal studies are lacking. AIM: To assess the effect and potential adverse effects of aromatase inhibition on growth in female rats. METHODS: Prepubertal Wistar rats received intramuscular injections with placebo or the aromatase inhibitor exemestane at a dose of 10, 30 or 100 mg/kg/week (E10, E30, E100) for 3 weeks. A control group was ovariectomized (OVX). Weight and length gain, tibia and femur length, growth plate width, organ weights, insulin-like growth factor I (IGF-I) levels, and histology of the ovaries, uterus and brain were analyzed. X-ray microtomography of femora was performed. RESULTS: E100 significantly increased weight gain and growth plate width, but less prominently than OVX. Trabecular number and thickness were decreased in E100 and OVX in the metaphysis and epiphysis. E100 significantly decreased ovarian weight and multiple cysts were seen upon histological evaluation. No significant effects were found on IGF-I levels and brain morphology in E100. E10 and E30 had no effects on growth. CONCLUSION: A high dose of exemestane marginally increases axial and appendicular growth in female rats, at the expense of osteopenia and polycystic ovaries.


Asunto(s)
Androstadienos/farmacología , Densidad Ósea/efectos de los fármacos , Crecimiento y Desarrollo/efectos de los fármacos , Quistes Ováricos/inducido químicamente , Maduración Sexual/efectos de los fármacos , Androstadienos/administración & dosificación , Animales , Inhibidores de la Aromatasa/administración & dosificación , Inhibidores de la Aromatasa/farmacología , Evaluación Preclínica de Medicamentos , Femenino , Inyecciones Intramusculares , Quistes Ováricos/fisiopatología , Placebos , Control de Calidad , Ratas , Ratas Wistar , Maduración Sexual/fisiología , Regulación hacia Arriba/efectos de los fármacos , Microtomografía por Rayos X
7.
Glia ; 55(14): 1426-36, 2007 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-17674368

RESUMEN

Translocator protein (18 kDa) (TSPO), previously known as peripheral-type benzodiazepine receptor, is a critical component of the mitochondrial permeability transition pore. Brain inflammation results in the induction of the expression of TSPO in glial cells and some TSPO ligands decrease reactive gliosis after brain injury. However, since some TSPO ligands are neuroprotective, their effects on reactive gliosis may be the consequence of a reduced neurodegeneration. To assess whether TSPO ligands can modulate reactive gliosis in absence of neuronal death, we have tested their effects on the inflammatory response induced in the hippocampus of male rats by the intracerebroventricular infusion of lipopolysaccharide (LPS). LPS treatment did not induce neuronal death, assessed by Fluoro jade-B staining, but increased the number of cells immunoreactive for vimentin and MHC-II, used as markers of reactive astrocytes and reactive microglia, respectively. Furthermore, LPS produced an increase in the number of proliferating microglia. The TSPO ligand PK11195 reduced the number of MHC-II immunoreactive cells and the proliferation of microglia in LPS treated rats. In contrast, another TSPO ligand, Ro5-4864, did not significantly affect the response of microglia to LPS. Neither PK11195 nor Ro5-4864 affected the LPS-mediated increase in the number of vimentin-immunoreactive astrocytes at the time point studied, although PK11195 reduced vimentin immunoreactivity. These findings identify TSPO as a potential target for controlling neural inflammation, showing that the TSPO ligand PK11195 may reduce microglia activation by a mechanism that is independent of the regulation of neuronal survival.


Asunto(s)
Encefalitis/tratamiento farmacológico , Encefalitis/metabolismo , Gliosis/tratamiento farmacológico , Gliosis/metabolismo , Receptores de GABA-A/metabolismo , Animales , Antineoplásicos/farmacología , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Benzodiazepinonas/farmacología , Biomarcadores , Muerte Celular/efectos de los fármacos , Muerte Celular/fisiología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Encefalitis/fisiopatología , Fluoresceínas , Gliosis/fisiopatología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/fisiopatología , Antígenos de Histocompatibilidad Clase II/análisis , Antígenos de Histocompatibilidad Clase II/metabolismo , Inyecciones Intraventriculares , Isoquinolinas/farmacología , Ligandos , Lipopolisacáridos , Masculino , Microglía/efectos de los fármacos , Microglía/metabolismo , Compuestos Orgánicos , Ratas , Ratas Wistar , Receptores de GABA/metabolismo , Receptores de GABA-A/efectos de los fármacos , Vimentina/análisis , Vimentina/metabolismo
8.
Eur J Neurosci ; 25(10): 3039-46, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17561817

RESUMEN

Previous studies have shown that the neuroprotective hormone, testosterone, administered immediately after neural injury, reduces reactive astrogliosis. In this study we have assessed the effect of early and late therapy with testosterone or its metabolites, oestradiol and dihydrotestosterone, on reactive astroglia and reactive microglia after a stab wound brain injury in orchidectomized Wistar rats. Animals received daily s.c. injections of testosterone, oestradiol or dihydrotestosterone on days 0-2 or on days 5-7 after injury. The number of vimentin immunoreactive astrocytes and the volume fraction of major histocompatibility complex-II (MHC-II) immunoreactive microglia were estimated in the hippocampus in the lateral border of the wound. Both early and delayed administration of testosterone or oestradiol, but not dihydrotestosterone, resulted in a significant decrease in the number of vimentin-immunoreactive astrocytes. The volume fraction of MHC-II immunoreactive microglia was significantly decreased in the animals that received testosterone or oestradiol in both early and delayed treatments and in animals that received early dihydrotestosterone administration. Thus, both early and delayed administration of testosterone reduces reactive astroglia and reactive microglia and these effects may be at least in part mediated by oestradiol, while dihydrotestosterone may mediate part of the early effects of testosterone on reactive microglia. In conclusion, testosterone controls reactive gliosis and its metabolites, oestradiol and dihydrotestosterone, may be involved in this hormonal effect. The regulation of gliosis may be part of the neuroprotective mechanism of testosterone.


Asunto(s)
Astrocitos/efectos de los fármacos , Lesiones Encefálicas/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Gliosis/tratamiento farmacológico , Microglía/efectos de los fármacos , Testosterona/farmacología , Animales , Astrocitos/metabolismo , Biomarcadores/metabolismo , Encéfalo/metabolismo , Encéfalo/fisiopatología , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/fisiopatología , Dihidrotestosterona/farmacología , Dihidrotestosterona/uso terapéutico , Esquema de Medicación , Estradiol/farmacología , Estradiol/uso terapéutico , Gliosis/fisiopatología , Gliosis/prevención & control , Antígenos de Histocompatibilidad Clase II/metabolismo , Inmunohistoquímica , Masculino , Microglía/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Ratas , Ratas Wistar , Testosterona/uso terapéutico , Vimentina/metabolismo
9.
J Peripher Nerv Syst ; 11(2): 111-8, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16787508

RESUMEN

Data obtained in our and other laboratories have indicated that progesterone (P) and its derivatives, dihydroprogesterone (DHP) and tetrahydroprogesterone (THP), stimulate the expression of two myelin proteins of the peripheral nervous system (PNS) [i.e., glycoprotein zero (P0) and peripheral myelin protein 22 (PMP22)]. We have now considered the effects of P and its derivatives on these and other myelin proteins [i.e., myelin-associated glycoprotein (MAG) and myelin and lymphocyte protein (MAL)] in sex-specific cultures of rat Schwann cells. Gene expression of myelin proteins was assessed by RNase protection assay. Treatment with P or DHP induced a stimulatory effect on P0 mRNA levels in male but not in female Schwann cells. In contrast, treatment with THP increased gene expression of P0 exclusively in female Schwann cells. A similar sex-difference was also evident for other myelin proteins. Indeed, PMP22 expression was stimulated by treatment with P in male cultures, whereas THP induced an increase of mRNA levels in female cultures. Moreover, MAG was stimulated by THP treatment in male cultures only, whereas MAL expression was unaffected by neuroactive steroid treatment in both male and female cultures. In conclusion, the present observations indicate that the effects of neuroactive steroids on myelin proteins are sexually dimorphic. This finding might represent an important background for sex-specific therapies of acquired and inherited peripheral neuropathies.


Asunto(s)
20-alfa-Dihidroprogesterona/farmacología , Expresión Génica/efectos de los fármacos , Proteínas de la Mielina/metabolismo , Progesterona/farmacología , Células de Schwann/efectos de los fármacos , Caracteres Sexuales , Análisis de Varianza , Animales , Animales Recién Nacidos , Northern Blotting/métodos , Western Blotting/métodos , Células Cultivadas , Femenino , Inmunohistoquímica/métodos , Masculino , Proteína P0 de la Mielina/genética , Proteína P0 de la Mielina/metabolismo , Proteínas de la Mielina/clasificación , Proteínas de la Mielina/genética , Glicoproteína Asociada a Mielina/genética , Glicoproteína Asociada a Mielina/metabolismo , ARN Mensajero/metabolismo , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Células de Schwann/metabolismo
10.
Neurosci Lett ; 402(1-2): 150-3, 2006 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-16626861

RESUMEN

The effect of the neuroactive steroids progesterone, dihydroprogesterone and tetrahydroprogesterone on myelin abnormalities induced by diabetes was studied in the sciatic nerve of adult male rats treated with streptozotocin. Streptozotocin increased blood glucose levels and decreased body weight gain, parameters not affected by steroids. Streptozotocin increased the number of fibers with myelin infoldings in the axoplasm, 8 months after the treatment. Chronic treatment for 1 month with progesterone and dihydroprogesterone resulted in a significant reduction in the number of fibers with myelin infoldings to control levels. Treatment with tetrahydroprogesterone did not significantly affect this myelin alteration. These results suggest that neuroactive steroids such as progesterone and dihydroprogesterone may represent therapeutic alternatives to counteract peripheral myelin alterations induced by diabetes.


Asunto(s)
20-alfa-Dihidroprogesterona/farmacología , Diabetes Mellitus Experimental/patología , Vaina de Mielina/metabolismo , Enfermedades del Sistema Nervioso Periférico/patología , Progesterona/farmacología , Análisis de Varianza , Animales , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Experimental/complicaciones , Masculino , Microscopía Electrónica de Rastreo/métodos , Vaina de Mielina/ultraestructura , Fibras Nerviosas Mielínicas/efectos de los fármacos , Fibras Nerviosas Mielínicas/patología , Enfermedades del Sistema Nervioso Periférico/etiología , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
11.
Neuroreport ; 16(14): 1599-603, 2005 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-16148753

RESUMEN

Gonadal or exogenous estradiol is neuroprotective in multiple experimental paradigms. The role exerted by endogenous extragonadal estradiol synthesis in neuroprotection, however, is poorly understood. Here we show that a dose of kainic acid (3 mg/kg body weight) that does not produce detectable neuronal damage in control male and female gonadectomized rats induces a significant loss of hippocampal hilar neurons after the systemic inhibition of aromatase, the enzyme involved in estradiol biosynthesis from androgens. Extragonadal aromatase inhibition exerts a similar neuronal loss in both male and female rats (26% and 30% reduction in the number of hilar neurons, respectively). These findings indicate that extragonadal estradiol exerts a neuroprotective effect in both sexes, which prevents neuronal loss as a consequence of mild neurodegenerative signals.


Asunto(s)
Estradiol/metabolismo , Hipocampo/efectos de los fármacos , Ácido Kaínico/toxicidad , Neurotoxinas/toxicidad , Animales , Castración/métodos , Recuento de Células/métodos , Muerte Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Estradiol/biosíntesis , Antagonistas de Estrógenos/farmacología , Fadrozol/farmacología , Femenino , Hipocampo/patología , Inmunohistoquímica/métodos , Masculino , Neuropéptido Y/metabolismo , Ratas , Ratas Wistar , Caracteres Sexuales
12.
Exp Gerontol ; 39(11-12): 1623-31, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15582278

RESUMEN

Sex steroids exert pleiotropic effects in the nervous system, preserving neural function and promoting neuronal survival. Therefore, the age-related decrease in sex steroids may have a negative impact on neural function. Progesterone, testosterone and estradiol prevent neuronal loss in the central nervous system in different experimental animal models of neurodegeneration. Furthermore, progesterone and its reduced derivatives dihydroprogesterone and tetrahydroprogesterone reduce aging-associated morphological abnormalities of myelin and aging-associated myelin fiber loss in rat peripheral nerves. However, the results from hormone replacement studies in humans are thus far inconclusive. A possible alternative to hormonal replacement therapy is to increase local steroidogenesis by neural tissues, which express enzymes for steroid synthesis and metabolism. Proteins involved in the intramitochondrial trafficking of cholesterol, the first step in steroidogenesis, such as the peripheral-type benzodiazepine receptor and the steroidogenic acute regulatory protein, are up-regulated in the nervous system after injury. Furthermore, steroidogenic acute regulatory protein expression is increased in the brain of 24-month-old rats compared with young adult rats. This suggests that brain steroidogenesis may be modified in adaptation to neurodegenerative conditions and to the brain aging process. Furthermore, recent studies have shown that local formation of estradiol in the brain, by the enzyme aromatase, is neuroprotective. Therefore, steroidogenic acute regulatory protein, peripheral-type benzodiazepine receptor and aromatase are attractive pharmacological targets to promote neuroprotection in the aged brain.


Asunto(s)
Envejecimiento/fisiología , Encéfalo/fisiología , Hormonas Esteroides Gonadales/fisiología , Anciano , Animales , Aromatasa/metabolismo , Encéfalo/metabolismo , Femenino , Terapia de Reemplazo de Hormonas , Humanos , Masculino , Modelos Animales , Enfermedades Neurodegenerativas/metabolismo , Fosfoproteínas/metabolismo , Progesterona/metabolismo , Ratas , Receptores de GABA-A/metabolismo
13.
Prog Neurobiol ; 71(1): 31-41, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-14611865

RESUMEN

Estradiol, in addition to its participation in neuroendocrine regulation and sexual behavior, has neuroprotective properties. Different types of brain injury induce the expression of the enzyme aromatase in reactive astroglia. This enzyme catalyzes the conversion of testosterone and other C19 steroids to estradiol. Genetic or pharmacological inhibition of brain aromatase results in marked neurodegeneration after different forms of mild neurodegenerative stimuli that do not compromise neuronal survival under control conditions. Furthermore, aromatase mediates neuroprotective effects of precursors of estradiol such as pregnenolone, dehydroepiandrosterone (DHEA) and testosterone. These findings strongly suggest that local formation of estradiol in the brain is neuroprotective and that the induction of aromatase and the consecutive increase in the local production of estradiol are part of the program triggered by the neural tissue to cope with neurodegenerative insults. Aromatase may thus represent an important pharmacological target for therapies conducted to prevent aging-associated neurodegenerative disorders.


Asunto(s)
Aromatasa/fisiología , Encéfalo/enzimología , Encéfalo/patología , Degeneración Nerviosa/prevención & control , Fármacos Neuroprotectores , Animales , Estradiol/metabolismo , Femenino , Humanos , Masculino
14.
Neurobiol Aging ; 24(6): 853-60, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12927767

RESUMEN

Previous studies indicate that steroid hormones may be protective for Schwann cells and promote the expression of myelin proteins in the sciatic nerve of adult rats. In this study, we have evaluated the effect of progesterone (P), dihydroprogesterone (DHP), tetrahydroprogesterone (THP), testosterone (T), dihydrotestosterone (DHT) and 5alpha-androstan-3alpha, 17beta-diol (3alpha-diol) on the morphological alterations of myelinated fibers in the sciatic nerve of 22-24-month-old male rats. The sciatic nerves of untreated old male rats, showed a general disorganization and a significant reduction in the density of myelinated fibers, compared to nerves from 3-month-old male rats. The effect of aging was particularly evident in myelinated fibers of small caliber (<5 microm in diameter). In addition, the sciatic nerves of old rats showed a significant increase in the number of fibers with myelin infoldings in the axoplasm and in the number of fibers with irregular shapes. Treatments of old rats with P, DHP and THP resulted in a significant increase in the number of myelinated fibers of small caliber, a significant reduction in the frequency of myelin abnormalities and a significant increase in the g ratio of small myelinated fibers. Furthermore, P treatment significantly reduced the frequency of myelinated fibers with irregular shapes. In contrast, treatments with T, DHT or 3alpha-diol did not significantly affect any of the morphological parameters examined. In conclusion, our data indicate that P, and its derivatives DHP and THP, are able to reduce aging-associated morphological abnormalities of myelin and aging-associated myelin fiber loss in the sciatic nerve. These data suggest that P, DHP and THP may represent useful therapeutic alternatives to maintain peripheral nerve integrity in aged animals.


Asunto(s)
Envejecimiento/fisiología , Hormonas Esteroides Gonadales/metabolismo , Fibras Nerviosas Mielínicas/fisiología , Nervio Ciático/anatomía & histología , Nervio Ciático/fisiología , 20-alfa-Dihidroprogesterona/metabolismo , Androstano-3,17-diol/metabolismo , Animales , Dihidrotestosterona/metabolismo , Masculino , Degeneración Nerviosa/metabolismo , Progesterona/metabolismo , Ratas , Ratas Sprague-Dawley , Testosterona/metabolismo
15.
J Comp Neurol ; 450(3): 256-71, 2002 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-12209854

RESUMEN

Estrogens and androgens can protect neurons from death caused by injury to the central nervous system. Astrocytes and microglia are major players in events triggered by neural lesions. To determine whether glia are direct targets of estrogens or androgens after neural insults, steroid receptor expression in glial cells was assessed in two different lesion models. An excitotoxic injury to the hippocampus or a stab wound to the parietal cortex and hippocampus was performed in male rats, and the resultant expression of steroid receptors in glial cells was assessed using double-label immunohistochemistry. Both lesions induced the expression of estrogen receptors (ERs) and androgen receptors (ARs) in glial cells. ERalpha was expressed in astrocytes immunoreactive (ERalpha-ir) for glial fibrillary acidic protein or vimentin. AR immunoreactivity colocalized with microglial markers, such as Griffonia simplicifolia lectin-1 or OX-6. The time course of ER and AR expression in glia was studied in the stab wound model. ERalpha-ir astrocytes and AR-ir microglia were observed 3 days after lesion. The number of ERalpha-ir and AR-ir glial cells reached a maximum 7 days after lesion and returned to low levels by 28 days postinjury. The studies of ERbeta expression in glia were inconclusive; different results were obtained with different antibodies. In sum, these results suggest that reactive astrocytes and reactive microglia are a direct target for estrogens and androgens, respectively.


Asunto(s)
Lesiones Encefálicas/metabolismo , Degeneración Nerviosa/metabolismo , Regeneración Nerviosa/fisiología , Neuroglía/metabolismo , Lectinas de Plantas , Ratas Wistar/crecimiento & desarrollo , Receptores Androgénicos/metabolismo , Receptores de Estrógenos/metabolismo , Animales , Astrocitos/citología , Astrocitos/metabolismo , Encéfalo/metabolismo , Encéfalo/patología , Encéfalo/fisiopatología , Lesiones Encefálicas/patología , Lesiones Encefálicas/fisiopatología , Modelos Animales de Enfermedad , Receptor alfa de Estrógeno , Receptor beta de Estrógeno , Proteína Ácida Fibrilar de la Glía/metabolismo , Gliosis/metabolismo , Gliosis/patología , Gliosis/fisiopatología , Inmunohistoquímica , Ácido Kaínico , Lectinas/metabolismo , Masculino , Microglía/citología , Microglía/metabolismo , Degeneración Nerviosa/patología , Degeneración Nerviosa/fisiopatología , Ratas , Ratas Wistar/lesiones , Ratas Wistar/metabolismo , Vimentina/metabolismo
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