Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Neurology ; 82(2): 174-81, 2014 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-24376275

RESUMEN

OBJECTIVE: To make evidence-based recommendations for screening, diagnosing, and treating psychiatric disorders in individuals with multiple sclerosis (MS). METHODS: We reviewed the literature (1950 to August 2011) and evaluated the available evidence. RESULTS AND RECOMMENDATIONS: Clinicians may consider using the Center for Neurologic Study Emotional Lability Scale to screen for pseudobulbar affect (Level C). Clinicians may consider the Beck Depression Inventory and a 2-question tool to screen for depressive disorders and the General Health Questionnaire to screen for broadly defined emotional disturbances (Level C). Evidence is insufficient to support/refute the use of other screening tools, the possibility that somatic/neurovegetative symptoms affect these tools' accuracy, or the use of diagnostic instruments or clinical evaluation procedures for identifying psychiatric disorders in MS (Level U). Clinicians may consider a telephone-administered cognitive behavioral therapy program for treating depressive symptoms (Level C). Although pharmacologic and nonpharmacologic therapies are widely used to treat depressive and anxiety disorders in individuals with MS, evidence is insufficient to support/refute the use of the antidepressants and individual and group therapies reviewed herein (Level U). For pseudobulbar affect, a combination of dextromethorphan and quinidine may be considered (Level C). Evidence is insufficient to determine the psychiatric effects in individuals with MS of disease-modifying and symptomatic therapies and corticosteroids; risk factors for suicide; and treatment of psychotic disorders (Level U). Research is needed on the effectiveness in individuals with MS of pharmacologic and nonpharmacologic treatments frequently used in the non-MS population.


Asunto(s)
Trastornos Mentales/diagnóstico , Trastornos Mentales/psicología , Esclerosis Múltiple/psicología , Síntomas Afectivos/etiología , Síntomas Afectivos/psicología , Depresión/diagnóstico , Depresión/psicología , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Medicina Basada en la Evidencia , Humanos , Trastornos Mentales/etiología , Trastornos Mentales/terapia , Esclerosis Múltiple/complicaciones , Escalas de Valoración Psiquiátrica , Encuestas y Cuestionarios
2.
Tex Med ; 108(5): e1, 2012 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22714948

RESUMEN

A prevalence study of amyotrophic lateral sclerosis (ALS) was conducted in 3 areas in Texas to enable the state health department to better respond to community concerns regarding the occurrence of ALS and to contribute to national prevalence estimates. The overall ALS point prevalence was lower than previously published US estimates. This study provides ALS prevalence estimates for Texas, including Hispanic populations.


Asunto(s)
Esclerosis Amiotrófica Lateral/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Hispánicos o Latinos/etnología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Texas/epidemiología , Población Blanca/etnología
3.
Expert Rev Neurother ; 11(7): 1077-88, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21539437

RESUMEN

Pseudobulbar affect (PBA) consists of uncontrollable outbursts of laughter or crying inappropriate to the patient's external circumstances and incongruent with the patient's internal emotional state. Recent data suggest disruption of cortico-pontine-cerebellar circuits, reducing the threshold for motor expression of emotion. Disruption of the microcircuitry of the cerebellum itself may likewise impair its ability to act as a gate-control for emotional expression. Current evidence also suggests that serotonergic and glutamatergic neurotransmission play key roles. Although antidepressants have shown benefit, the supportive clinical data have often derived from small numbers of patients and unvalidated measures of PBA severity. Dextromethorphan/quinidine, the first FDA-approved PBA medication, is a novel therapy with antiglutamatergic actions. As life expectancy lengthens and the neurologic settings of PBA become more common, the need for treatment can be expected to increase.


Asunto(s)
Encéfalo/fisiopatología , Parálisis Seudobulbar/etiología , Parálisis Seudobulbar/fisiopatología , Antagonistas Adrenérgicos alfa/uso terapéutico , Encéfalo/efectos de los fármacos , Ensayos Clínicos como Asunto , Llanto/fisiología , Dextrometorfano/uso terapéutico , Antagonistas de Aminoácidos Excitadores/uso terapéutico , Humanos , Risa/fisiología , Parálisis Seudobulbar/tratamiento farmacológico , Quinidina/uso terapéutico , Transmisión Sináptica
4.
Ann Neurol ; 68(5): 693-702, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20839238

RESUMEN

OBJECTIVE: To evaluate dextromethorphan combined with ultra low-dose quinidine (DMq) for treating pseudobulbar affect (PBA) in patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS). METHODS: In a 12-week randomized, double-blind trial, ALS and MS patients with clinically significant PBA (a baseline score ≥13 on the Center for Neurologic Studies-Lability Scale [CNS-LS]) were maintained, twice daily, on placebo, DMq at 30/10mg (DMq-30), or DMq at 20/10mg (DMq-20). RESULTS: In 326 randomized patients (of whom 283, or 86.8%, completed the study), the PBA-episode daily rate was 46.9% (p < 0.0001) lower for DMq-30 than for placebo and 49.0% (p < 0.0001) lower for DMq-20 than for placebo by longitudinal negative binomial regression, the prespecified primary analysis. Mean CNS-LS scores decreased by 8.2 points for DMq-30 and 8.2 for DMq-20, vs 5.7 for placebo (p= 0.0002 and p= 0.0113, respectively). Other endpoints showing statistically significant DMq benefit included, for both dosage levels, the likelihood of PBA remission during the final 14 days and, for the higher dosage, improvement on measures of social functioning and mental health. Both dosages were safe and well tolerated. INTERPRETATION: DMq markedly reduced PBA frequency and severity, decreasing the condition's detrimental impact on a patient's life, with satisfactory safety and high tolerability. The findings expand the clinical evidence that DMq may be an important treatment for patients suffering from the socially debilitating symptoms of PBA.


Asunto(s)
Síntomas Afectivos/tratamiento farmacológico , Dextrometorfano/administración & dosificación , Quinidina/administración & dosificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Esclerosis Amiotrófica Lateral/complicaciones , Dextrometorfano/efectos adversos , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Electrocardiografía/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Oxígeno/sangre , Quinidina/efectos adversos
5.
Prev Chronic Dis ; 7(1): A12, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20040227

RESUMEN

INTRODUCTION: We estimated the prevalence of multiple sclerosis (MS) in 3 large geographic areas in the southern, middle, and northern United States. METHODS: The primary data source was medical records from office visits to private neurologists' practices or to neurology departments in tertiary care facilities during a 3-year period. Additional data sources included patient advocacy groups, nursing homes, and general practitioners. RESULTS: Three-year US age-adjusted prevalence estimates for the study areas varied substantially. The prevalence was lowest (47.2 per 100,000 population) in the Texas study area (33 degrees 30' north latitude), intermediate (86.3 per 100,000 population) in the Missouri study area (39 degrees 07' north latitude), and highest (109.5 per 100,000 population) in the Ohio study area (41 degrees 24' north latitude). The geographic differences remained strong after age-adjustment to the world standard population. The inverse association between UV light exposure and MS prevalence estimates was consistent with this observed latitude gradient. In all 3 areas, MS prevalence was highest among women, people aged 40 to 59 years, and non-Hispanics. CONCLUSION: These results provide necessary prevalence estimates for community cluster investigations and establish baseline estimates for future studies to evaluate temporal trends in disease prevalence.


Asunto(s)
Esclerosis Múltiple/epidemiología , Adulto , Distribución por Edad , Anciano , Femenino , Humanos , Persona de Mediana Edad , Prevalencia , Grupos Raciales , Estados Unidos/epidemiología
6.
Tex Med ; 105(6): e1, 2009 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-19492265

RESUMEN

The Texas Department of State Health Services extended a prevalence study of multiple sclerosis (MS) in a 19-county area in North Texas to include 3 additional years of data and included a new geographic area with a predominantly Hispanic population (El Paso County). Patients in whom MS was diagnosed by a neurologist, who resided in the study areas, and who had an office visit between 1998 and 2003 were included in the study. The 6-year MS prevalence estimate for the North Texas counties was 71.5 per 100,000, and for El Paso County it was 49.4 per 100,000. In both areas, prevalence estimates were higher for females, age groups 40 to 49 and 50 to 59, and for non-Hispanic whites. These estimates provide valuable information about the epidemiology of MS in Texas and allow for a comparison with national estimates. The results also provide much needed prevalence data for the Hispanic population.


Asunto(s)
Hispánicos o Latinos/estadística & datos numéricos , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/epidemiología , Población Blanca/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/etnología , Prevalencia , Factores de Riesgo , Distribución por Sexo , Texas/epidemiología
8.
Semin Neurol ; 29(3): 220-33, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19551599

RESUMEN

Ambulatory prevalence rates for significant depressive syndromes in general neurology clinics are quite high, in the range of 15 to 20% of clinic attendees. These depressive syndromes are a source of considerable morbidity and even mortality for the patients who suffer from them. Depression is a treatable syndrome, but there are not enough psychiatrists to administer all the treatments. Inevitably, many neurologists will become involved with some antidepressant therapies. In this article, I review a series of steps that can be used by neurologists to diagnose and treat the depressive disorders that occur in their practices. The Goldman algorithm for the treatment of depression is also presented as a therapeutic tool for practicing neurologists.


Asunto(s)
Depresión , Enfermedades del Sistema Nervioso/complicaciones , Neurología/métodos , Algoritmos , Depresión/diagnóstico , Depresión/etiología , Depresión/terapia , Humanos , Esclerosis Múltiple/complicaciones , Guías de Práctica Clínica como Asunto , Suicidio/psicología
9.
Endocrinology ; 150(7): 3267-73, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19325001

RESUMEN

Recent studies suggested an involvement of thromboxane A2 in cyclooxygenase-2-dependent inhibition of steroidogenic acute regulatory (StAR) gene expression. The present study further investigated the role of thromboxane A2 receptor in StAR gene expression and steroidogenesis in testicular Leydig cells. The thromboxane A2 receptor was detected in several Leydig cell lines. Blocking thromboxane A2 binding to the receptor using specific antagonist SQ29548 or BM567 resulted in dose-dependent increases in StAR protein and steroid production in MA-10 mouse Leydig cells. The results were confirmed with Leydig cells isolated from rats. StAR promoter activity and StAR mRNA level in the cells were also increased after the treatments, suggesting an involvement of the thromboxane A2 receptor in StAR gene transcription. Furthermore study indicated that blocking the thromboxane A2 receptor reduced dosage sensitive sex reversal-adrenal hypoplasia congenita critical region on the X chromosome, gene 1 protein, a transcriptional repressor of StAR gene expression. Specific binding of the antagonists to the receptors on cellular membrane was demonstrated by binding assays using (3)H-SQ29548 and binding competition between (3)H-SQ29548 and BM567. Whereas SQ29548 enhanced cAMP-induced StAR gene expression, in the absence of cAMP, it was unable to increase StAR protein and steroidogenesis. However, when the receptor was blocked by the antagonist, subthreshold levels of cAMP were able to induce maximal levels of StAR protein expression, suggesting that blocking the thromboxane A2 receptor increase sensitivity of MA-10 cells to cAMP stimulation. Taken together, the results from the present and previous studies suggest an autocrine loop, involving cyclooxygenase-2, thromboxane A synthase, and thromboxane A2 and its receptor, in cyclooxygenase-2-dependent inhibition of StAR gene expression.


Asunto(s)
Células Intersticiales del Testículo/metabolismo , Fosfoproteínas/genética , Receptores de Tromboxano A2 y Prostaglandina H2/fisiología , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes , Línea Celular , Ciclooxigenasa 2/genética , Ácidos Grasos Insaturados , Regulación de la Expresión Génica , Hidrazinas/farmacología , Masculino , Ratones , Ratas , Compuestos de Sulfonilurea/farmacología , Tromboxano A2/genética , Tromboxano A2/fisiología , Tromboxano-A Sintasa/genética , Tromboxano-A Sintasa/fisiología
10.
Open Neuroimag J ; 2: 52-5, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19018315

RESUMEN

An emerging clinical priority for the treatment of Alzheimer's disease (AD) is the implementation of therapies at the earliest stages of disease onset. All AD patients pass through an intermediary stage of the disorder known as Mild Cognitive Impairment (MCI), but not all patients with MCI develop AD. By applying computer based signal processing and pattern recognition techniques to the electroencephalogram (EEG), we were able to classify AD patients versus controls with an accuracy rate of greater than 80%. We were also able to categorize MCI patients into two subgroups: those with EEG Beta power profiles resembling AD patients and those more like controls. We then used this brain-based classification to make predictions regarding those MCI patients most likely to progress to AD versus those who would not. Our classification algorithm correctly predicted the clinical status of 4 out of 6 MCI patients returning for 2 year clinical follow-up. While preliminary in nature, our results suggest that automated pattern recognition techniques applied to the EEG may be a useful clinical tool not only for classification of AD patients versus controls, but also for identifying those MCI patients most likely to progress to AD.

11.
Headache ; 48(10): 1537-9, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18783445

RESUMEN

Night guards are commonly prescribed as a palliative measure for bruxism, temporomandibular joint symptoms, and associated disorders. We describe a patient with a 10- to 12-year history of night guard use with concurrent unilateral side-locked migrainous headaches with autonomic symptoms characteristic of trigeminal autonomic cephalgia. These headaches were refractory to numerous pharmacological interventions. Upon self-initiated cessation of night guard use, there was complete remission of headaches. We believe the headaches were initiated by night guard-initiated irritation of the trigeminal nerve and a trigeminal autonomic reflex resulting in unilateral migrainous headache with autonomic signs.


Asunto(s)
Protectores Bucales/efectos adversos , Cefalalgia Autónoma del Trigémino/etiología , Cefalalgia Autónoma del Trigémino/fisiopatología , Nervio Trigémino/fisiopatología , Disreflexia Autónoma/diagnóstico , Disreflexia Autónoma/etiología , Disreflexia Autónoma/fisiopatología , Sistema Nervioso Autónomo/fisiopatología , Femenino , Lateralidad Funcional/fisiología , Humanos , Persona de Mediana Edad , Reflejo Anormal/fisiología , Bruxismo del Sueño/fisiopatología , Bruxismo del Sueño/terapia , Cefalalgia Autónoma del Trigémino/diagnóstico , Nervio Trigémino/anatomía & histología , Enfermedades del Nervio Trigémino/diagnóstico , Enfermedades del Nervio Trigémino/etiología , Enfermedades del Nervio Trigémino/fisiopatología
12.
Arch Clin Neuropsychol ; 23(5): 603-12, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18639437

RESUMEN

Although initially developed as a brief dementia battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has not yet demonstrated its sensitivity, specificity, and positive and negative predictive powers in detecting cognitive impairment in patients with Alzheimer's disease (AD). Therefore, the current study examined the clinical utility of the RBANS by comparing two age-, education-, and gender-matched groups: patients with AD (n=69) and comparators (n=69). Significant differences (p<0.001) were observed on the RBANS Total score, all 5 Indexes, and all 12 subtests, with patients performing worse than the comparison participants. An optimal balance between sensitivity and specificity on RBANS scores was obtained when cutoffs of one and one and a half standard deviations below the mean of the comparison sample were implemented. Areas under the Receiver Operating Characteristic curves for all RBANS Indexes were impressive though Immediate and Delayed Memory Indexes were excellent (0.96 and 0.98, respectively). Results suggest that RBANS scores yield excellent estimates of diagnostic accuracy and that the RBANS is a useful screening tool in detection of cognitive deficits associated with AD.


Asunto(s)
Enfermedad de Alzheimer/complicaciones , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Pruebas Neuropsicológicas/normas , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Femenino , Humanos , Masculino , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad
13.
J Rural Health ; 24(3): 244-52, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18643801

RESUMEN

CONTEXT: Health-related quality of life (HRQOL) is a multi-dimensional construct including aspects of life quality or function that are affected by physical health and symptoms, psychosocial factors, and psychiatric conditions. HRQOL gives a broader measure of the burden of disease than physical impairment or disability levels. PURPOSE: To identify factors associated with HRQOL among people with multiple sclerosis (MS) utilizing the SF-8 Health Survey. METHODS: Data presented in this study were collected in a survey of 1,518 people with MS living in all 50 states. The survey sample was randomly selected from the database of the National Multiple Sclerosis Society, using ZIP codes to recruit the survey sample. A multiple linear regression model was employed to analyze the survey data, with the Physical Component Summary and the Mental Component Summary of the SF-8 the dependent variables. Independent variables were demographic characteristics, MS-disease characteristics, and health services utilized. FINDINGS: People with MS in rural areas tended to report lower physically related HRQOL. Worsening MS symptoms were associated with reduced physical and mental dimensions of HRQOL. In addition, people with MS who received a diagnosis of depression tended to have reduced physical and mental dimensions of HRQOL. Receiving MS care at an MS clinic was associated with better physically related HRQOL, while having a neurologist as principal care physician was associated with better mental-related HRQOL. CONCLUSION: The challenge is to increase the access that people living with MS in rural areas have to MS-focused specialty care.


Asunto(s)
Estado de Salud , Esclerosis Múltiple/fisiopatología , Calidad de Vida , Población Rural , Población Urbana , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Esclerosis Múltiple/psicología , Estados Unidos
14.
Acad Med ; 83(5): 452-66, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18448899

RESUMEN

PURPOSE: The authors perform a review of the literature pertinent to the question, "What makes a good clinical teacher in medicine?" METHOD: After framing the question, based on discussions of their own experiences with clinical teachers, the authors performed a search of the literature pertinent to the question, "What are the qualities of a good clinical teacher in medicine?" Between July and December, 2006, they reviewed titles from Index Medicus (1909-1966), PubMed (1966 to the present), PubMed Related Articles, and referenced articles. The initial selections were chosen by scanning pre-1966 Index Medicus title lists and post-1966 abstracts. Chosen articles were then read in their entirety, and those which described specific characteristics of clinical teachers were selected for inclusion. Qualitative analysis was used to identify themes. RESULTS: From 4,914 titles, 68 articles were selected for analysis-26 published before 1966, and 42 published after 1966. Four hundred eighty descriptors were identified and grouped into 49 themes, which were clustered into three main categories: physician, teacher, and human characteristics. Echoing the authors' intuitive descriptions, noncognitive characteristics dominated the descriptions and themes. CONCLUSIONS: Excellent clinical teaching, although multifactorial, transcends ordinary teaching and is characterized by inspiring, supporting, actively involving, and communicating with students. Faculty development programs and future research should focus on development of the noncognitive attributes of clinical teachers, as well as the knowledge and skills associated with effective teaching.


Asunto(s)
Educación Médica , Docentes Médicos , Conocimientos, Actitudes y Práctica en Salud , Competencia Profesional , Enseñanza , Humanos , Estados Unidos
15.
J Endocrinol ; 197(2): 315-23, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18434361

RESUMEN

During the aging process of males, testosterone biosynthesis declines in testicular Leydig cells resulting in decreases in various physiological functions. To explore the possibility of delaying the decline using food supplements, we have studied steroidogenic effects of a natural flavonoid, chrysin, in mouse Leydig cells. Chrysin dramatically increased cyclic AMP (cAMP)-induced steroidogenesis in MA-10 mouse Leydig tumor cells. This result was confirmed using Leydig cells isolated from mouse testes. The steroidogenic effect of chrysin is not associated with an increase in expression of the P450 side-chain cleavage enzyme, required for the conversion of cholesterol to pregnenolone. In addition, when 22(R)hydroxylcholesterol was used as a substrate, chrysin induced a non-significant increase in steroid hormone, suggesting that the majority of the observed increase in steroidogenesis was due to the increased supply of substrate cholesterol. These observations were corroborated by showing that chrysin induced a marked increase in the expression of steroidogenic acute regulatory (StAR) protein, the factor that controls mitochondrial cholesterol transfer. Also, chrysin significantly increased StAR promoter activity and StAR mRNA level. Further studies indicated that this compound depressed expression of DAX-1, a repressor in StAR gene transcription. In the absence of cAMP, chrysin did not increase steroidogenesis. However, when a sub-threshold level of cAMP was used, StAR protein and steroid hormone were increased by chrysin to the levels seen with maximal stimulation of cAMP. These results suggest that while chrysin itself is unable to induce StAR gene expression and steroidogenesis, it appears to function by increasing the sensitivity of Leydig cells to cAMP stimulation.


Asunto(s)
Flavonoides/farmacología , Células Intersticiales del Testículo/efectos de los fármacos , Fosfoproteínas/genética , Testosterona/biosíntesis , Animales , Bucladesina/farmacología , Línea Celular Tumoral , Proteínas Quinasas Dependientes de AMP Cíclico/fisiología , Inhibidores de la Ciclooxigenasa 2/farmacología , Receptor Nuclear Huérfano DAX-1 , Proteínas de Unión al ADN/genética , Relación Dosis-Respuesta a Droga , Células Intersticiales del Testículo/metabolismo , Lipooxigenasa/fisiología , Masculino , Ratones , Progesterona/biosíntesis , Receptores de Ácido Retinoico/genética , Proteínas Represoras/genética , Transducción de Señal
16.
Artículo en Inglés | MEDLINE | ID: mdl-19162853

RESUMEN

Using multiple discriminant analysis (MDA) and k-means clustering, coherence features extracted from the EEGs of a group of 56 subjects were analyzed to assess how feasible an automated coherence-based pattern recognition system that detects Alzheimer's disease (AD) would be. Sixteen of the subjects were AD patients, 24 were mild cognitive impairment (MCI) patients while 16 were age-matched controls. With MDA, an overall classification rate (CR) of 84% was obtained for AD vs. MCI vs. Controls classifications. The high CR implies that it is possible to distinguish between the three groups. The coherence features were also statistically analyzed to derive a neural model of AD and MCI, which indicated that patients with AD may have a greater number of damaged cortical fibers than their MCI counterparts, and furthermore, that MCI may be an intermediary step in the development of AD.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/fisiopatología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/fisiopatología , Diagnóstico por Computador/métodos , Electroencefalografía/métodos , Modelos Neurológicos , Anciano , Enfermedad de Alzheimer/complicaciones , Inteligencia Artificial , Análisis por Conglomerados , Trastornos del Conocimiento/etiología , Simulación por Computador , Femenino , Humanos , Masculino , Reconocimiento de Normas Patrones Automatizadas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Endocrinology ; 149(2): 851-7, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18006634

RESUMEN

The cyclooxygenase-2 (COX2)-dependent inhibition of Leydig cell steroidogenesis has been demonstrated. To understand the mechanism for this effect of COX2, the present study examined the role of an enzyme downstream of COX2, namely thromboxane A synthase (TBXAS), in steroidogenesis. Inhibition of TBXAS activity with the inhibitor furegrelate induced a concentration-dependent increase in cAMP-induced steroidogenic acute regulatory (StAR) protein in MA-10 mouse Leydig cells. The increase in StAR protein occurred concomitantly with a significant increase in steroid hormone production. Similar results were obtained in StAR promoter activity assays and RT-PCR analyses of StAR mRNA levels, suggesting that inhibition of TBXAS activity enhanced StAR gene transcription. These observations were corroborated when TBXAS expression was specifically inhibited by RNA interference. Although the RNA interference reduced mRNA levels of TBXAS, it increased StAR mRNA levels, StAR protein, and steroidogenesis. Additional studies indicated that inhibition of TBXAS activity reduced DAX-1 protein, a repressor in StAR gene transcription. In the absence of cAMP, inhibition of TBXAS activity did not induce a significant increase in steroid hormone and StAR protein. However, addition of a low level of cAMP analogs dramatically increased steroidogenesis. Lastly, inhibition of protein kinase A activity essentially abolished the steroidogenic effect of the TBXAS inhibitor. Thus, the results from the present study suggest that a minimal level of protein kinase A activity is required for the steroidogenic effect of the TBXAS inhibitor and that inhibition of TBXAS activity or its expression increase the steroidogenic sensitivity of MA-10 mouse Leydig cells to cAMP stimulation.


Asunto(s)
Células Intersticiales del Testículo/enzimología , Fosfoproteínas/metabolismo , Tromboxano-A Sintasa/metabolismo , Animales , Bucladesina/farmacología , Línea Celular Tumoral , AMP Cíclico/metabolismo , Receptor Nuclear Huérfano DAX-1 , Proteínas de Unión al ADN/genética , Sinergismo Farmacológico , Regulación Enzimológica de la Expresión Génica/fisiología , Tumor de Células de Leydig , Células Intersticiales del Testículo/citología , Masculino , Ratones , Fosfoproteínas/genética , ARN Interferente Pequeño , Esteroides/biosíntesis , Neoplasias Testiculares , Tromboxano A2/farmacología , Tromboxano-A Sintasa/antagonistas & inhibidores , Tromboxano-A Sintasa/genética , Transcripción Genética/fisiología
18.
Neuroepidemiology ; 28(4): 246-52, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17878739

RESUMEN

In response to citizen concerns in 5 small Illinois towns, community-based case-finding determined the prevalence of multiple sclerosis (MS). Potential cases were identified through town meetings, publicity, advocacy groups and local volunteer outreach coordinators. Estimated prevalence based on available medical records for self-identifying individuals for 3 of the 5 communities was high (218-231 per 100,000 population) compared to other studies. Scanning databases in medical offices used in many other studies may miss MS cases; yet tracking medical records is labor-intensive and sometimes restricted by privacy guidelines. MS registries could improve case-finding accuracy and efficiency.


Asunto(s)
Estudios de Casos y Controles , Esclerosis Múltiple/epidemiología , Características de la Residencia , Femenino , Humanos , Masculino , Registros Médicos , Esclerosis Múltiple/diagnóstico , Prevalencia , Sistema de Registros
19.
J Environ Health ; 69(10): 34-8, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17583294

RESUMEN

The authors investigated a cluster of multiple sclerosis (MS) among people who had attended two elementary schools in El Paso, Texas, from 1948 through 1970. The community was concerned about the possibility of childhood exposure to heavy metals from a large nearby smelter because historical environmental and biological sampling data demonstrated the potential for study cohort members to have been exposed to heavy metals during their pre-adolescent years. One cohort had no reported cases of MS. In the second cohort, 22 members self-reported a diagnosis of MS, and 16 of these cases were confirmed as MS by an independent board-certified neurologist. The crude MS prevalence estimate was 411 per 100,000 (95 percent confidence interval [CI] = 197-603), Prevalence estimates from four different populations were used for calculation of standardized morbidity ratios (SMRs). At the extremes, the study cohort represents a deficit of cases (SMR= 0.9; 95 percent CI = 0.51-1.44) or a four-fold excess (SMR = 4.0; 95 percent Cl = 2.29-6.5).


Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Intoxicación por Metales Pesados , Esclerosis Múltiple/epidemiología , Adulto , Anciano , Niño , Análisis por Conglomerados , Estudios de Cohortes , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Cabello/química , Humanos , Masculino , Metalurgia , Metales Pesados/análisis , Persona de Mediana Edad , Esclerosis Múltiple/etiología , Prevalencia , Estudios Retrospectivos , Estudiantes/estadística & datos numéricos , Encuestas y Cuestionarios , Texas/epidemiología
20.
J Environ Health ; 69(10): 41-5, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17583295

RESUMEN

The study reported here determined the prevalence of multiple sclerosis (MS) between January 1, 1998, and December 31, 2000, for a 19-county study area surrounding Lubbock, Texas. The primary data source for case ascertainment was medical records from the offices of neurologists practicing in the study area. The study found that the overall prevalence for the 19-county study area was 42.8 per 100,000 population (95 percent CI = 36.8-49.5). The prevalence estimate for females was 68.6 per 100,000 (95 percent CI = 58.0-80.6), and for males it was 16.6 per 100,000 (95 percent CI = 11.6-23.1). The prevalence estimate for non-Hispanic whites was 56.0 per 100,000 (95 percent CI = 47.1-66.1); the next highest prevalence was among non-Hispanic blacks at 22.1 per 100,000 (95 percent Cl = 8.1-48.1), and Hispanics at 11.2 per 100,000 (95 percent CI = 6.4-18.2). This project generated the first Texas-specific population-based MS prevalence estimates, including prevalence estimates specific to Hispanics and blacks in Texas. The results underscore the need for additional epidemiologic information on the distribution of MS in other areas of Texas and the United States, as well as information on the underlying etiology of the disease.


Asunto(s)
Negro o Afroamericano/estadística & datos numéricos , Hispánicos o Latinos/estadística & datos numéricos , Esclerosis Múltiple/epidemiología , Adulto , Anciano , Femenino , Humanos , Masculino , Registros Médicos/estadística & datos numéricos , Persona de Mediana Edad , Esclerosis Múltiple/etnología , Esclerosis Múltiple/mortalidad , Neurología/estadística & datos numéricos , Prevalencia , Texas/epidemiología , Población Blanca/estadística & datos numéricos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...