RESUMEN
STUDY DESIGN: Blinded review of selected and un-selected computed tomographic myelograms. OBJECTIVE: To determine whether shape of the vertebral body endplate margins is a risk factor for the development of symptomatic lumbar disc herniations. The law of LaPlace for a fluid-filled tube suggests that anular tension could be related to endplate shape and a propensity for disc herniation. SUMMARY OF BACKGROUND DATA: It was hypothesized that the law of Laplace could apply to the lumbar spine because of to the cylindrical shape of the lumbar disc and its high water content in nonelderly individuals. It was further hypothesized that differences in the radius of the curvature could place stresses on the anulus that would make posterior disc herniations more likely with "rounder" endplates. METHODS: Ninety-seven contrast computed tomography scans were reviewed at transitional L4-L5 and L5-S1 in patients under 60 years of age, without previous spine surgery and without spondylolisthesis. Determinations of disc herniations and measurements of endplates were performed by blinded observers. A ratio of these measurements was used to determine the relative circularity of the endplate. Height, weight, body mass index, and disc endplate size and shape were related to the presence of disc herniation. RESULTS: By multiple logistic regression, only endplate shape was strongly related to disc herniations. Endplate area was a less significant factor in men. CONCLUSIONS: The shape of the vertebral body margin at the endplate is an important factor contributing to the development of disc herniations at L4-L5 and L5-S1.
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Desplazamiento del Disco Intervertebral/patología , Disco Intervertebral/patología , Vértebras Lumbares/patología , Sacro/patología , Femenino , Humanos , Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Mielografía , Sacro/diagnóstico por imagen , Método Simple Ciego , Tomografía Computarizada por Rayos XRESUMEN
The authors investigated the use of gamma knife surgery (GKS) in the treatment of central neurocytoma, a usually benign primary brain tumor of the lateral and third ventricles. Four patients with subtotally resected or recurrent central neurocytomas were retrospectively studied. The prescription isodose was 9 to 13 Gy to the 30 to 50% peripheral isodose line. Pre- and postoperative magnetic resonance (MR) images were compared to determine the volume reduction following GKS. Follow-up review included annual MR imaging and clinical evaluation by a neurosurgeon. Follow-up periods ranged from 12 to 99 months. Marked reduction in tumor size was seen in all four patients; the decrease in tumor volume for each was 48%, 72%, 81%, and 77%, respectively, at the last follow-up review. None of the four patients required additional treatment and none experienced a decline in neurological function during the follow-up period. No complications have been noted in any of these patients to date. Even though there have been few observations and follow-up time has been limited, because of the consistency of the response and the lack of observed side effects, GKS may be the treatment of choice for subtotally resected and recurrent central neurocytomas.
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Neoplasias del Ventrículo Cerebral/cirugía , Neurocitoma/cirugía , Radiocirugia , Adulto , Neoplasias del Ventrículo Cerebral/patología , Ventrículos Cerebrales/patología , Ventrículos Cerebrales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Neurocitoma/patología , Examen Neurológico , Estudios RetrospectivosRESUMEN
STUDY DESIGN: Combined prospective human cohort and prospective controlled animal model. OBJECTIVES: To determine whether free glutamate is available in herniated disc material in concentrations sufficient to diffuse to glutamate receptors and affect the activity of neurons in the dorsal root ganglion that may transmit pain information. SUMMARY OF BACKGROUND DATA: The severity of lumbar radicular pain cannot be fully explained by physical pressure on nerve roots or ganglions. In experimental models, inflammatory processes are relatively modest under conditions of disc herniation. The hypothesis for the current study was that the proteoglycan link and core proteins, which contain high fractions of acidic amino acids, may be a source of glutamate when enzymatically degraded in an environment without glutamate reuptake systems. Glutamate would be free to diffuse to the dorsal root ganglion to affect glutamate receptors. METHODS: Disc material was harvested during surgery from herniated and nonherniated portions in patients undergoing elective lumbar disc surgery and subjected to immunohistochemistry and high-performance liquid chromatography for assessment of the presence of extracellular disc matrix glutamate. Miniosmotic pumps with differing concentrations of radiolabeled glutamate based on human data were implanted in the rat epidural space for 72 hours and dorsal root ganglion (DRG) in the region were harvested. RESULTS: Densitometry of disc matrix demonstrated immunohistochemical evidence for significant extracellular glutamate (P < 0.002). High performance liquid chromatography showed significant concentrations of glutamate in disc material and significantly more in herniated than in nonherniated disc material (P < 0.05). Significant radiolabeling of the dorsal root ganglion after epidural glutamate infusion was found at concentrations two orders of magnitude below measured disc glutamate levels. Autoradiography demonstrated radiolabeling of adjacent DRG. CONCLUSIONS: Glutamate originating from degenerated disc proteoglycan may diffuse to the dorsal root ganglion and effect glutamate receptors. Consideration may be given to treating disc radiculopathy with epidural glutamate receptor antagonists.
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Ganglios Espinales/fisiopatología , Ácido Glutámico/metabolismo , Disco Intervertebral/química , Dolor de la Región Lumbar/metabolismo , Vértebras Lumbares , Neuronas/metabolismo , Transducción de Señal/efectos de los fármacos , Adulto , Animales , Autorradiografía , Cromatografía Líquida de Alta Presión , Implantes de Medicamentos , Antagonistas de Aminoácidos Excitadores/administración & dosificación , Antagonistas de Aminoácidos Excitadores/uso terapéutico , Ganglios Espinales/efectos de los fármacos , Ácido Glutámico/administración & dosificación , Ácido Glutámico/aislamiento & purificación , Humanos , Inyecciones Epidurales , Disco Intervertebral/metabolismo , Desplazamiento del Disco Intervertebral/complicaciones , Desplazamiento del Disco Intervertebral/metabolismo , Desplazamiento del Disco Intervertebral/cirugía , Dolor de la Región Lumbar/tratamiento farmacológico , Dolor de la Región Lumbar/etiología , Masculino , Persona de Mediana Edad , Neuronas/efectos de los fármacos , Estudios Prospectivos , Radiculopatía/complicaciones , Radiculopatía/tratamiento farmacológico , Radiculopatía/metabolismo , Ratas , Receptores de Glutamato/metabolismo , Transducción de Señal/fisiologíaAsunto(s)
Trastornos de la Conducta Infantil/diagnóstico , Servicios de Salud Mental/normas , Escalas de Valoración Psiquiátrica , Niño , Servicios de Salud del Niño/normas , Protección a la Infancia , Toma de Decisiones , Humanos , Psicometría , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estados UnidosRESUMEN
Interference with growth factor-receptor interactions may have particular relevance in efforts to intervene clinically in both autocrine and paracrine aspects of malignancy. Suramin is a synthetic anticancer agent that works, in part, by blocking the binding of growth factors to their receptors. While initial clinical trials have been encouraging, its use in clinical applications is associated with significant toxicities. Suradista is a novel sulfonated distamycin derivative that is also effective at complexing and inactivating growth factors and cytokines while remaining relatively nontoxic. The goal of this study was to compare the antineoplastic properties of suramin and Suradista. To achieve this, the effects of these compounds on growth factor induced mitogenesis in normal mouse fibroblasts and human umbilical vein endothelial cells were examined, as well as their ability to inhibit the growth of NIH/3T3 cells that had been transformed by the introduction of a fibroblast growth factor (FGF) 1 coding region (residues 1-154) fused to the signal peptide of the hst/KS3 gene (sp-hst/KS3:FGF1-154). In each case, Suradista was more effective than suramin in inhibiting mitogenesis in normal cells, as well as the growth of the transformed cells. Furthermore, Suradista was also shown to be as effective as suramin at inhibiting the growth of sp-hst/KS3:FGF1-154-transformed NIH/3T3 xenografts grown in athymic nude mice when given at only 50% the dosage used for suramin (50 mg/kg for Suradista versus 100 mg/kg for suramin). In summary, these results indicate that novel compounds acting like suramin may be developed as effective antineoplastic agents and may also prove to be of clinical benefit.
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Antineoplásicos/farmacología , Distamicinas/farmacología , Inhibidores de Crecimiento/farmacología , Células 3T3/efectos de los fármacos , Animales , Antineoplásicos/química , Línea Celular Transformada/efectos de los fármacos , Línea Celular Transformada/patología , Células Cultivadas , Citocinas/antagonistas & inhibidores , ADN/biosíntesis , Distamicinas/química , Endotelio Vascular/efectos de los fármacos , Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Factores de Crecimiento de Fibroblastos/farmacología , Humanos , Ratones , Ratones Desnudos , Mitosis/efectos de los fármacos , Mitosis/genética , Trasplante de Neoplasias , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Suramina/farmacología , Transfección , Venas UmbilicalesRESUMEN
A multiinstitutional study was conducted to evaluate the technique, dose-selection parameters, and results of gamma knife stereotactic radiosurgery in the management of trigeminal neuralgia. Fifty patients at five centers underwent radio-surgery performed with a single 4-mm isocenter targeted at the nerve root entry zone. Thirty-two patients had undergone prior surgery, and the mean number of procedures that had been performed was 2.8 (range 1-7). The target dose of the radiosurgery used in the current study varied from 60 to 90 Gy. The median follow-up period after radiosurgery was 18 months (range 11-36 months). Twenty-nine patients (58%) responded with excellent control (pain free), 18 (36%) obtained good control (50%-90% relief), and three (6%) experienced treatment failure. The median time to pain relief was 1 month (range 1 day-6.7 months). Responses remained consistent for up to 3 years postradiosurgery in all cases except three (6%) in which the patients had pain recurrence at 5, 7, and 10 months. At 2 years, 54% of patients were pain free and 88% had 50% to 100% relief. A maximum radiosurgical dose of 70 Gy or greater was associated with a significantly greater chance of complete pain relief (72% vs. 9%, p = 0.0003). Three patients (6%) developed increased facial paresthesia after radiosurgery, which resolved totally in one case and improved in another. No patient developed other deficits or deafferentation pain. The proximal trigeminal nerve and root entry zone, which is well defined on magnetic resonance imaging, is an appropriate anatomical target for radiosurgery. Radiosurgery using the gamma unit is an additional effective surgical approach for the management of medically or surgically refractory trigeminal neuralgia. A longer-term follow-up review is warranted.
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Radiocirugia , Neuralgia del Trigémino/cirugía , Adulto , Anciano , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
Meningiomas arise from the arachnoidal cells surrounding the brain and are one of the most common tumors of the central nervous system. These tumors are known to be hormonally modulated and may occur in association with breast carcinoma. Overexpression of the erbB-2 oncogene product and mutation of the tumor suppressor p53 gene are considered causal driving forces in the pathogenesis of adenocarcinomas of the breast. To determine whether abnormal expression of these genes also plays a role in the pathogenesis of meningiomas, we analyzed the expression of the erbB-2 and p53 proteins in 17 atypical and 35 typical meningioma tissue specimens by immunohistochemistry. The staining intensity was assigned a relative value of 0 to 5+, where 5+ denoted confluent immunoreactivity, 4+ to 1+ denoted varying degrees of focal positivity, and 0 denoted no evidence of staining. Levels of p53 and erbB-2 immunohistochemical staining were then correlated with tumor histology. For p53 immunoreactivity, typical meningiomas had a median staining score of 1.0, compared to 4.0 for atypical meningiomas (P < 0.0001, Mann-Whitney U test). For erbB-2 immunoreactivity, typical meningiomas had a median staining score of 5.0 compared to 1.0 for atypical meningiomas (P < 0.0001, Mann-Whitney U test). The inverse relationship between levels of erbB-2 and p53 immunoreactivity was found to be statistically significant (P < 0.0001, ANOVA). Expression of the erbB-2 protein was not associated with gene amplification or the presence of activating mutation in the transmembrane region of the protein. These findings may improve our understanding of the molecular events that occur in the neoplastic transformation of meningothelial cells. The patterns of erB-2 and p53 immunoreactivity may prove to be useful markers with which to identify potentially more malignant meningiomas.
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Neoplasias Meníngeas/química , Meningioma/química , Proteínas de Neoplasias/análisis , Receptor ErbB-2/análisis , Proteína p53 Supresora de Tumor/análisis , Secuencia de Bases , Neoplasias de la Mama/química , Estudios de Evaluación como Asunto , Genes erbB-2 , Humanos , Inmunohistoquímica , Neoplasias Meníngeas/patología , Meningioma/patología , Datos de Secuencia MolecularRESUMEN
Communities throughout the nation are attempting to develop comprehensive systems of community-based, interagency care for children and youth with emotional or behavioral disorders and their families. Needs assessment has been identified as a key component of these initiatives. A needs assessment provides system planners with the data needed to make informed decisions with regard to improving the current system of care. In this first of a two-article series, an overview is presented of a model needs assessment designed for implementation by an interagency coalition interested in developing a comprehensive system of community-based services for children and youth with emotional or behavioral disorders and their families. Major components of the model include foundations for needs assessment, data collection, and data utilization.
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Servicios de Salud del Adolescente/normas , Servicios de Salud del Niño/normas , Servicios Comunitarios de Salud Mental/normas , Salud de la Familia , Necesidades y Demandas de Servicios de Salud/organización & administración , Modelos Organizacionales , Adolescente , Servicios de Salud del Adolescente/organización & administración , Niño , Trastornos de la Conducta Infantil/epidemiología , Trastornos de la Conducta Infantil/terapia , Servicios de Salud del Niño/organización & administración , Planificación en Salud Comunitaria/organización & administración , Servicios Comunitarios de Salud Mental/organización & administración , Estudios Transversales , Humanos , Illinois/epidemiología , Estudios Longitudinales , Desarrollo de Programa , Estados Unidos/epidemiologíaRESUMEN
In a previous article, rationale and procedures were presented for a model needs assessment of community-based services for children and youth with emotional and behavioral disorders and their families. In this article, the authors describe initial needs assessment planning activities, examine the implementation of the proposed model, provide a general overview of the results, and review how the community that conducted the assessment used the information to identify system development priorities and action plans. Quantitative data are provided on the population demographics and parent and direct services provider surveys. Qualitative data are presented on the semistructured interviews with key stakeholders and direct service providers.
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Servicios de Salud del Adolescente/normas , Servicios de Salud del Niño/normas , Servicios Comunitarios de Salud Mental/normas , Salud de la Familia , Necesidades y Demandas de Servicios de Salud/organización & administración , Adolescente , Servicios de Salud del Adolescente/organización & administración , Adulto , Niño , Trastornos de la Conducta Infantil/epidemiología , Trastornos de la Conducta Infantil/terapia , Servicios de Salud del Niño/organización & administración , Preescolar , Planificación en Salud Comunitaria/organización & administración , Servicios Comunitarios de Salud Mental/organización & administración , Femenino , Humanos , Illinois/epidemiología , Masculino , Desarrollo de Programa , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
Both federal and state governments have mandates to collect, analyze, and disseminate health care information. The federal government is the single largest payer for health care and health services research. Its agencies, the Healthcare Finance Administration (HCFA) and the Agency for Healthcare Policy Research (AHCPR) play a major role in shaping information strategies for all health care stakeholders. State governments are among those stakeholders and are fertile grounds for experimentation, change, and learning. Building effective federal-state partnerships and public-private partnerships can help foster innovation in health data collection and analysis, as well as identify new strategies for information dissemination.
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Agencias Gubernamentales , Servicios de Información/organización & administración , Evaluación de Resultado en la Atención de Salud/normas , Gestión de la Calidad Total/normas , Recolección de Datos/métodos , Difusión de Innovaciones , Servicios de Información/normas , Reproducibilidad de los Resultados , Estados UnidosRESUMEN
BACKGROUND AND PURPOSE: Free radical scavengers enhance neuronal survival in some models of transient forebrain ischemia. Recent experiments have suggested that N-acetylcysteine prevents cellular injury after a reperfusion injury. No information is available regarding the neuroprotective potential of the free radical scavenger N-acetylcysteine after transient forebrain ischemia. In this study we evaluated the potential of N-acetylcysteine to improve hippocampal neuronal survival after transient forebrain ischemia in the rat. METHODS: In series A and B, ventilated, paralyzed, normothermic rats had 10 minutes of transient forebrain ischemia induced by bilateral carotid occlusion with hypotension induced by blood withdrawal (mean arterial blood pressure, 45 mm Hg). In series A, animals were administered N-acetylcysteine (163 mg/kg) 30 minutes and 5 minutes before transient forebrain ischemia. In series B, N-acetylcysteine (326 mg/kg) was administered 15 minutes after transient forebrain ischemia. In series C, N-acetylcysteine (326 mg/kg) was administered 15 minutes after transient forebrain ischemia in animals with a mean arterial blood pressure of 30 mm Hg during transient forebrain ischemia. All series had normal control, sham, and vehicle treatment groups. In all series, the rats were allowed to recover and were killed at 7 days after ischemia. The effect of forebrain ischemia was assessed by evaluating the number of viable neurons at bregma sections -3.3, -3.8, and -4.3 of the CA1 region of the hippocampus. RESULTS: The results demonstrated no physiological difference among the various treatment groups. There were no differences in the number of viable neurons between the transient forebrain ischemia with no treatment group and the vehicle (saline)-treated transient forebrain ischemic groups. Animals pretreated with N-acetylcysteine (mean number of neurons, 84 +/- 6) had a significant increase (P < .05) in neuronal survival compared with vehicle-treated animals (mean number of neurons, 43 +/- 4). Animals posttreated with N-acetylcysteine (mean number of neurons, 89 +/- 9) had a significant increase in neuronal survival compared with vehicle-treated animals (mean number of neurons, 7 +/- 1). However, N-acetylcysteine protection was only partial at 45 mm Hg and did not improve neuronal survival (mean number of neurons, 22 +/- 3) in animals with a more severe ischemic insult (mean arterial blood pressure, 30 mm Hg during transient forebrain ischemia) compared with vehicle-treated animals (mean number of neurons, 10 +/- 1). CONCLUSIONS: N-Acetylcysteine partially improved neuronal survival when administered before or after ischemia following transient cerebral ischemia (mean arterial blood pressure, 45 mm Hg) but not with a more severe ischemic insult of 10 minutes of transient cerebral ischemia with a mean arterial blood pressure of 30 mm Hg.
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Acetilcisteína/farmacología , Depuradores de Radicales Libres/farmacología , Hipocampo/efectos de los fármacos , Ataque Isquémico Transitorio/fisiopatología , Animales , Supervivencia Celular/efectos de los fármacos , Hipocampo/citología , Masculino , Neuronas/citología , Neuronas/efectos de los fármacos , Prosencéfalo , Ratas , Ratas Sprague-DawleyRESUMEN
The effect of peripherally administered angiotensin II (AII) on blood flow to choroid plexuses was examined in pentobarbital-anesthetized rats. The indicator fractionation method with 123I- or 125I-N-isopropyl-p-iodoamphetamine as the marker was employed to measure blood flow. Basal blood flow to choroid plexus of the lateral cerebral ventricle (LVCP) (3.19 +/- 0.23 ml g-1 min-1) was lower than that to choroid plexuses of the third (3VCP) and fourth (4VCP) ventricles (3.90 +/- 0.38 and 3.95 +/- 0.36 ml g-1 min-1, respectively). The effect of AII on choroidal blood flow varied depending on peptide dose and anatomical location of the choroidal tissue. AII infused intravenously at rates of 30 and 50 ng kg-1 min-1 decreased blood flow to both LVCP and 4VCP by 12-20%. Both lower (10 ng kg-1 min-1) and higher (100 and 300 ng kg-1 min-1) AII doses did not alter blood flow to LVCP and 4VCP. Blood flow to the 3VCP was not affected by any dose of the peptide used. In comparison, blood flow to cerebral cortex increased by 33% during intravenous AII infusion at a rate of 300 ng kg-1 min-1. The choroidal blood flow-lowering effect of moderate AII doses was abolished by both AT1 (losartan) and AT2 (PD 123319) receptor subtype antagonists (3 mg kg-1 i.v.). To determine whether the hemodynamic changes observed in choroid plexuses with moderate AII doses influence CSF formation, the ventriculocisternal perfusion was performed in rats (under the experimental conditions described) with Blue Dextran 2000 as the indicator.(ABSTRACT TRUNCATED AT 250 WORDS)
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Angiotensina II/farmacología , Líquido Cefalorraquídeo/fisiología , Plexo Coroideo/irrigación sanguínea , Plexo Coroideo/fisiología , Angiotensina II/administración & dosificación , Angiotensina II/antagonistas & inhibidores , Animales , Compuestos de Bifenilo/farmacología , Velocidad del Flujo Sanguíneo , Presión Sanguínea/efectos de los fármacos , Corteza Cerebral/irrigación sanguínea , Plexo Coroideo/efectos de los fármacos , Imidazoles/farmacología , Infusiones Intravenosas , Losartán , Masculino , Ratas , Ratas Sprague-Dawley , Tetrazoles/farmacologíaRESUMEN
The wild-type p53 gene is thought to play a critical role in tumor suppression and has been shown to reverse the transformed phenotype of tumor cells in vitro. Mutational inactivation of this aspect of p53 activity occurs frequently in many human neoplasms, including astrocytomas, and is thought to represent a critical step in tumor progression. We have found previously that the presence of p53 immunoreactivity was significantly associated with malignant astrocytomas arising in younger patients, although occurring infrequently in tumors in older patients. Given that young age is the most consistent clinical factor predictive of longer survival in patients with astrocytomas, this suggested that p53 protein accumulation might be a molecular predictor of enhanced survival. To test this hypothesis, we retrospectively studied the association of p53 overexpression with survival in 149 patients with astrocytomas, using univariate and multivariate analysis to determine its value in predicting survival. Although our analysis reaffirmed the strong association between young age and increased survival, we were unable to demonstrate any difference in survival between patients with Grade III and IV tumors with p53 immunoreactivity compared with those without. Presumably, once a tumor has progressed to high grade, the relative importance of p53 status as a predictor of survival is low, probably because of the large number of accumulated genetic alterations associated with malignant tumors. In contrast, the presence of p53 overexpression in Grade II astrocytomas seemed from survival curves to indicate shorter survival compared with patients who had no p53 immunoreactivity. However, this variable did not quite reach statistical significance (P = 0.08) as an independent predictive variable in multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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Astrocitoma/genética , Glioblastoma/genética , Neoplasias Supratentoriales/genética , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Astrocitoma/mortalidad , Astrocitoma/cirugía , Encéfalo/patología , Terapia Combinada , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Regulación Neoplásica de la Expresión Génica/fisiología , Glioblastoma/mortalidad , Glioblastoma/cirugía , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Supratentoriales/mortalidad , Neoplasias Supratentoriales/cirugía , Tasa de SupervivenciaRESUMEN
Homework is a key area of concern in our nation's public schools, as well as a central element of collaboration between home and school. The purpose of the current study was to survey the policies of a national sample of school districts concerning homework. Specific foci of the survey included whether a homework policy had been instituted, if modifications were made in the policy for students with disabilities, the types of homework, the length and frequency of assignments given, and specific communication mechanisms between home and school. A total of 550 surveys were mailed, with a response rate of 48.5%. The results indicated that only 35.2% of school divisions did have a policy on homework, with 64.4% of those policies including modifications for students with disabilities. Findings in terms of frequency and amount of homework assigned, as well as home-school communication mechanisms, are highlighted. The results are discussed within the context of policy development and instructional implications.
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Política Organizacional , Instituciones Académicas , Carga de Trabajo , Recolección de Datos , Humanos , Discapacidades para el Aprendizaje , Estudiantes , Estados UnidosRESUMEN
The purpose of this study was to survey the homework practices of general education teachers who teach students with disabilities. A national sample of 441 elementary, middle, and senior high teachers were asked about their homework practices, including their use of adaptations for students with disabilities. The results highlight homework practices and adaptations that are used frequently and perceived by teachers as helpful for students with disabilities. Also discussed are the differences in practices and adaptations across elementary, middle, and high school teachers, as well as the instructional implications of the identified homework practices for students with disabilities and their general education teachers.
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Instituciones Académicas , Enseñanza , Carga de Trabajo , Educación Especial , Humanos , Discapacidades para el Aprendizaje , Integración Escolar , Padres , Recursos HumanosRESUMEN
The effect of central administration of angiotensin II (AII) on cerebrospinal fluid (CSF) formation was studied in pentobarbital-anesthetized, artificially-ventilated rats. CSF production was measured by the ventriculocisternal perfusion method with Blue Dextran 2000 as the indicator. Baseline value of CSF production was 3.35 +/- 0.08 microliters/min. Intracerebroventricular (i.c.v.) infusion of AII at rates of 0.5 and 5 pg/min significantly lowered (P < 0.01) CSF formation by 23% and 16%, respectively. In comparison, high peptide doses (50 and 500 pg/min) did not alter this parameter. The inhibitory effect of low AII doses on CSF formation was blocked by the i.c.v. AT1 receptor subtype antagonists, losartan and SK&F 108566 (2.4 and 2.7 ng/min, respectively), but not by the AT2 receptor subtype-specific agent, PD 123319 (3.8 ng/min). Peptide AII antagonists, [Sar1,Ile8]AII (5 ng/min), which binds to both AT1 and AT2 receptors, had a similar effect to those of AT1-specific blockers. It is concluded that AII, by controlling CSF formation, may influence the water and electrolyte balance in the brain.
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Angiotensina II/farmacología , Líquido Cefalorraquídeo/efectos de los fármacos , Receptores de Angiotensina/metabolismo , Antagonistas de Receptores de Angiotensina , Animales , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: By early 1994, 38 states had invested in data collection, analysis, and dissemination on the use, cost, effectiveness, and performance of hospitals. States use these data to control costs, encourage prudent purchasing, monitor effectiveness and outcomes of health care, guide health policy, and promote informed decision making. Experience in several states suggests that public release of hospital-specific data influences hospital performance. ISSUES: The value of state data organizations' databases to address issues of quality and accountability can be strengthened by ensuring the stability and growth of statewide health information systems, supporting research on information dissemination techniques, and promoting comparisons among hospitals. CONCLUSIONS: Information to measure provider performance must be placed in the public domain--to help ensure prudent and cost-effective health care purchasing and to give providers comparable information for improvement of care. State-level health databases are an essential component of the information infrastructure needed to support health reform.