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1.
Percept Mot Skills ; 96(3 Pt 1): 1005-12, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12831282

RESUMEN

24 young (4 mo.) and 24 old (8 mo.) male Wistar rats were exposed for 30 min. on two consecutive days to either a sham-field or to a frequency-modulated magnetic field applied through a pair of solenoids (spatially heterogeneous strength) or a Helmholtz coil (spatially homogeneous strength). The maximum field strength was about 2 microTesla. The rats exposed to the spatially heterogeneous magnetic field but not the homogeneous magnetic field exhibited strong analgesia to thermal stimuli applied to the footpads immediately after the treatment and 30 min. later. The effect accommodated 38% of the variance in the latency to respond to the thermal stimuli. These results suggest that the practice by many researchers in bioelectromagnetism to design coils to generate maximum spatial homogeneity of intensities within the exposure volume when applying complex weak magnetic fields may actually diminish any biological effects.


Asunto(s)
Analgesia/instrumentación , Magnetismo/instrumentación , Manejo del Dolor , Animales , Masculino , Distribución Aleatoria , Ratas , Ratas Wistar , Factores de Tiempo
2.
J Neurosurg Anesthesiol ; 14(4): 304-8, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12357088

RESUMEN

Elevated body temperature increases mortality and worsens outcome in acute stroke patients. In animal models of stroke, even slight hypothermia was shown to be neuroprotective. Pharmacological treatment alone (paracetamol, metamizol) usually fails to lower core body temperature below 37 degrees C. The purpose of this study was to establish the feasibility and safety of continuous body surface cooling towards low normothermic temperatures in noncomatose, nonventilated stroke unit patients. Eighteen acute stroke patients (15 ischemic infarcts, 3 hemorrhages) with baseline body core temperatures >37.0 degrees C (taken in the urinary bladder) were laid on a water-perfused cooling mattress and received pethidine and dihydroergotoxine in order to avoid shivering and peripheral vasoconstriction. The target range for core body temperature was between 36 and 37 degrees C for 24 hours. None of the patients was treated with antipyretic drugs during the cooling period. Median baseline National Institutes of Health Stroke Scale score (NIHSSS) was 15.5 (8-24). Three patients had core temperatures >38 degrees C. A temperature in the target range could be reached within 3.3 hours (median) and maintained in all but two patients. Major procedure-related adverse events were vomiting (n = 2), drop in mean arterial blood pressure >20% (n = 2), pneumonia (n = 2), and a rise in central venous pressure >20 cm H2O (n = 3) totaling 9 events in 8 of 18 patients (44%). No patient died within the first week; mortality after three months was 12%. Continuous body core temperature reduction of 1-2 degrees C may safely be attained by a cooling mattress in nonventilated stroke unit patients. Critically high temperature values can be avoided. The neuroprotective potential of this method has to be assessed in a controlled trial.


Asunto(s)
Temperatura Corporal/fisiología , Hipertermia Inducida , Accidente Cerebrovascular/terapia , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Análisis de los Gases de la Sangre , Presión Sanguínea/fisiología , Proteína C-Reactiva , Estudios de Factibilidad , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Hipertermia Inducida/efectos adversos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Estudios Prospectivos , Accidente Cerebrovascular/fisiopatología , Resultado del Tratamiento
3.
Neuroscience ; 112(3): 665-76, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12074908

RESUMEN

In adults and children, head trauma can have long-term neuropathological and functional consequences. The thalamus is a major site of remote neurodegeneration after cortical damage in adult humans and experimental animals, but less is known about thalamic responses to cortical injury in the immature brain. This study introduces an in vivo model of axotomy/target deprivation-induced neuronal apoptosis in the dorsal lateral geniculate nucleus of the thalamus produced by unilateral ablation of the occipital cortex in the immature mouse. We specifically examined whether occipital cortex ablation in the immature brain causes apoptotic death of projection neurons in the dorsal lateral geniculate nucleus. After unilateral occipital cortex aspiration, 10-day-old C57BL/6 mice were recovered for up to 28 days. Fluorogold-prelabeled thalamocortical projection neurons were apoptotic at 36-48 h after ablation. The structural progression of apoptosis in the immature lateral geniculate nucleus reveals typical chromatolytic morphology by 18-24 h, followed by cytoplasmic shrinkage and chromatin condensation characteristic of end-stage apoptosis after 36-48 h. Electron microscopy confirmed the presence of apoptosis. This study shows internucleosomal DNA fragmentation and expression of cleaved caspase-3 occurs rapidly, being noted first at 18 h, well before the peak of apoptotic cell death occurring at 36 h after cortical damage in the immature brain. From these data we suggest that axotomy/target deprivation-induced cell death in the immature brain may: (1) differ from that previously reported in adult mice with respect to the time required for progression to cell death; (2) be mediated by caspase-3 activation.


Asunto(s)
Animales Recién Nacidos/fisiología , Apoptosis , Lesiones Encefálicas/fisiopatología , Neuronas/fisiología , Lóbulo Occipital/lesiones , Tálamo/fisiopatología , Animales , Lesiones Encefálicas/patología , Caspasa 3 , Caspasas/química , Caspasas/metabolismo , Fragmentación del ADN , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Degeneración Nerviosa/fisiopatología , Nucleosomas/fisiología , Lóbulo Occipital/ultraestructura , Transmisión Sináptica , Factores de Tiempo
4.
Dev Neurosci ; 23(3): 186-91, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11598318

RESUMEN

We studied neuronal cell body, axonal, and terminal degeneration in brains from 7-day-old rat pups recovered for 0, 1.5, 3, 6, 24, 48, 72 h, and 6 days following hypoxia-ischemia and identified proteins involved in the delayed neurodegeneration in the thalamus. We found that injury is biphasic with initial necrosis in the ipsilateral forebrain by 3 h following hypoxia-ischemia, in contrast to more delayed and apoptotic-like injury in the ventral-basal thalamus, brainstem, and other remote non-forebrain regions. Prior to the appearance of large numbers of apoptotic profiles in the ventral-basal thalamus, expression of Fas death receptor protein, activated forms of caspase 8 and caspase 3, and pro-apoptotic Bcl-2 proteins are increased. This manuscript combines our data on hypoxic-ischemic injury in the developing brain and presents evidence for at least two forms of neurodegeneration, namely, acute necrosis in the forebrain and delayed neurodegeneration in the thalamus, which is death-receptor-mediated programmed cell death.


Asunto(s)
Apoptosis , Hipoxia-Isquemia Encefálica/patología , Degeneración Nerviosa/patología , Proteínas Proto-Oncogénicas c-bcl-2 , Tálamo/patología , Animales , Caspasas/análisis , Corteza Cerebral/citología , Complejo IV de Transporte de Electrones/análisis , Mitocondrias/metabolismo , Vías Nerviosas , Neuronas/química , Neuronas/enzimología , Neuronas/patología , Proteínas Proto-Oncogénicas/análisis , Ratas , Tálamo/crecimiento & desarrollo , Proteína X Asociada a bcl-2 , Receptor fas/análisis
5.
J Comp Neurol ; 433(3): 299-311, 2001 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-11298357

RESUMEN

The mechanisms of injury-induced apoptosis of neurons within the CNS are not understood. We used a model of cortical injury in rat and mouse to induce retrograde neuronal apoptosis in thalamus. In this animal model, unilateral ablation of the occipital cortex causes unequivocal apoptosis of corticopetal projection neurons in the dorsal lateral geniculate nucleus (LGN) by 7 days postlesion. We tested the hypothesis that p53 and Bax regulate this retrograde neuronal apoptosis. We found, by using immunocytochemistry, that p53 accumulates in nuclei of neurons destined to undergo apoptosis. By immunoblotting, p53 levels increase ( approximately 150% of control) in nuclear-enriched fractions of the ipsilateral LGN by 5 days after occipital cortex ablation. p53 is functionally activated in nuclear fractions of the ipsilateral LGN at 5 days postlesion, as shown by DNA binding assay (approximately fourfold increase) and by immunodetection of phosphorylated p53. The levels of procaspase-3 increase at 4 days postlesion, and caspase-3 is activated prominently at 5 days postlesion. To identify whether neuronal apoptosis in the adult brain is dependent on p53 and Bax, cortical ablations were done on p53 and bax null mice. Neuronal apoptosis in the dorsal LGN is significantly attenuated (approximately 34%) in p53(-/-) mice. In lesioned p53(+/+) mice, Bax immunostaining is enhanced in the ipsilateral dorsal LGN and Bax immunoreactivity accumulates at perinuclear locations in dorsal LGN neurons. The enhancement and redistribution of Bax immunostaining is attenuated in lesioned p53(-/-) mice. Neuronal apoptosis in the dorsal LGN is blocked completely in bax(-/-) mice. We conclude that neuronal apoptosis in the adult thalamus after cortical injury requires Bax and is modulated by p53.


Asunto(s)
Apoptosis , Lesiones Encefálicas/fisiopatología , Cuerpos Geniculados/fisiopatología , Neuronas/fisiología , Proteínas Proto-Oncogénicas c-bcl-2 , Proteínas Proto-Oncogénicas/fisiología , Proteína p53 Supresora de Tumor/fisiología , Animales , Caspasa 3 , Caspasas/metabolismo , Núcleo Celular/metabolismo , ADN/metabolismo , Activación Enzimática , Genes Supresores de Tumor/fisiología , Genes p53/fisiología , Cuerpos Geniculados/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Lóbulo Occipital/lesiones , Ratas , Ratas Sprague-Dawley , Tálamo/patología , Tálamo/fisiopatología , Proteína X Asociada a bcl-2
6.
J Neurosci ; 21(6): 1931-8, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11245678

RESUMEN

Brain injury in newborns can cause deficits in motor and sensory function. In most models of neonatal brain injury, thalamic damage often occurs. Using the Rice-Vannucci model of neonatal hypoxic-ischemic brain injury, we have shown that neuronal degeneration in somatosensory thalamus is delayed in onset ( approximately 24 hr) compared with cortical and striatal injury and exhibits prominent structural features of apoptosis. In the present study, we examined whether cell death in the thalamus has molecular features of apoptosis. Fas death receptor protein expression increased rapidly after neonatal hypoxia-ischemia, in concert with cleavage of procaspase 8 to its active form. Concurrently, the levels of Bax in mitochondrial-enriched cell fractions increase, and cytochrome c accumulates in the soluble fraction. Mitochondria accumulate in a perinuclear distribution by 6 hr after hypoxia-ischemia. Cytochrome oxidase subunit 1 protein levels also increase at 6 hr after hypoxia-ischemia. Increased levels of Fas death receptor, Bax, and cytochrome c, activation of caspase 8, and abnormalities in mitochondria in the thalamus significantly precede the activation of caspase 3 and the appearance of neuronal apoptosis at 24 hr. We conclude that the delayed neurodegeneration in neonatal rat ventral basal thalamus after hypoxic-ischemic injury is apoptosis mediated by death receptor activation.


Asunto(s)
Apoptosis , Hipoxia-Isquemia Encefálica/patología , Proteínas Proto-Oncogénicas c-bcl-2 , Tálamo/patología , Animales , Animales Recién Nacidos , Caspasa 3 , Caspasa 8 , Caspasa 9 , Caspasas/metabolismo , Grupo Citocromo c/metabolismo , Citocromos c1/metabolismo , Humanos , Hipoxia-Isquemia Encefálica/metabolismo , Immunoblotting , Células Jurkat/metabolismo , Células Jurkat/patología , Mitocondrias/metabolismo , Neuronas/metabolismo , Neuronas/patología , Proteínas Proto-Oncogénicas/metabolismo , Ratas , Tálamo/metabolismo , Factores de Tiempo , Proteína X Asociada a bcl-2 , Receptor fas/biosíntesis
7.
Ann Hum Biol ; 27(5): 453-65, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11023116

RESUMEN

Ireland's unique and well-documented history provides insight into the formation and origins of population subdivisions. Of particular interest, is the controversial ethnogenesis of an itinerant population of Ireland: the Travellers. The objectives of this study were: (1) to determine the genetic affinity of the Travellers to the general Irish population based on gene frequency data, subdivided by county, and (2) to explore the relationship between subpopulations of Ireland, given its turbulent history. The gene frequencies of standard genetic markers collected from populations residing in counties of Ireland and the Travellers were calculated and analysed using several multivariate methods. First, a relationship (R) matrix was used to ascertain the scaled variance covariance matrix of population similarity. Second, mean per locus heterozygosity (H) was regressed on distance of the region from the gene frequency centroid (r(ii)). The results of this study include: (1) the confirmation of Crawford's (1975, in Biosocial Interrelations in Population Adaptations, E. S. Watts et al. (eds), pp. 93-103) conclusions concerning the origins and genetic affinity of the Travellers; (2) based on several multivariate analyses, the major influence on population structure was unique historical events; and (3) Relethford and Crawford's (1995, American Journal of Physical Anthropology, 96, 25-38) hypothesis concerning the distinctiveness of the midland counties was verified by this study.


Asunto(s)
Genética de Población , Viaje , Emigración e Inmigración/historia , Frecuencia de los Genes , Heterocigoto , Historia del Siglo XV , Historia del Siglo XVI , Historia del Siglo XVII , Historia del Siglo XX , Historia Antigua , Historia Medieval , Humanos , Irlanda , Análisis Multivariante
8.
J Neurosci ; 20(21): 7994-8004, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11050120

RESUMEN

Birth asphyxia can cause moderate to severe brain injury. It is unclear to what degree apoptotic or necrotic mechanisms of cell death account for damage after neonatal hypoxia-ischemia (HI). In a 7-d-old rat HI model, we determined the contributions of apoptosis and necrosis to neuronal injury in adjacent Nissl-stained, hematoxylin and eosin-stained, and terminal deoxynucleotidyl transferase-mediated UTP nick end-labeled sections. We found an apoptotic-necrotic continuum in the morphology of injured neurons in all regions examined. Eosinophilic necrotic neurons, typical in adult models, were rarely observed in neonatal HI. Electron microscopic analysis showed "classic" apoptotic and necrotic neurons and "hybrid" cells with intermediate characteristics. The time course of apoptotic injury varied regionally. In CA3, dentate gyrus, medial habenula, and laterodorsal thalamus, the density of apoptotic cells was highest at 24-72 hr after HI and then declined. In contrast, densities remained elevated from 12 hr to 7 d after HI in most cortical areas and in the basal ganglia. Temporal and regional patterns of neuronal death were compared with expression of caspase-3, a cysteine protease involved in the execution phase of apoptosis. Immunocytochemical and Western blot analyses showed increased caspase-3 expression in damaged hemispheres 24 hr to 7 d after HI. A p17 peptide fragment, which results from the proteolytic activation of the caspase-3 precursor, was detected in hippocampus, thalamus, and striatum but not in cerebral cortex. The continued expression of activated caspase-3 and the persistence of cells with an apoptotic morphology for days after HI suggests a prolonged role for apoptosis in neonatal hypoxic ischemic brain injury.


Asunto(s)
Apoptosis , Hipoxia-Isquemia Encefálica/patología , Enfermedades Neurodegenerativas/patología , Animales , Animales Recién Nacidos , Caspasa 3 , Caspasas/metabolismo , Corteza Cerebral/enzimología , Corteza Cerebral/patología , Cuerpo Estriado/enzimología , Cuerpo Estriado/patología , Giro Dentado/enzimología , Giro Dentado/patología , Modelos Animales de Enfermedad , Hipocampo/enzimología , Hipocampo/patología , Hipoxia-Isquemia Encefálica/complicaciones , Hipoxia-Isquemia Encefálica/enzimología , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Necrosis , Enfermedades Neurodegenerativas/enzimología , Enfermedades Neurodegenerativas/etiología , Neuronas/metabolismo , Neuronas/ultraestructura , Ratas , Tálamo/enzimología , Tálamo/patología
9.
Br J Nutr ; 84(5): 689-96, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11177182

RESUMEN

Portal appearance of short-chain fatty acids (SCFA) produced from fermentation of three different resistant starch (RS) sources (raw potato starch, high-amylose maize starch and retrograded high-amylose maize starch) was investigated in pigs. The catheterization technique coupled with determination of portal blood flow was used to estimate SCFA uptake by the colonic mucosa. Our hypothesis was that these three RS were not equivalent butyrate providers for the colonic mucosa and that butyrate uptake would therefore be different after in vivo fermentation of each starch. The starches induced different patterns of appearance of SCFA in the portal blood; raw potato starch was the only RS source to show a significant appearance of butyrate in the portal blood. Thus, uptake of butyrate by the colonic mucosa apparently differed between starches. This finding suggests that butyrate uptake does not only depend on the flow of butyrate appearing in the lumen. Indeed, for unexplained reasons, utilization of butyrate by the colonic mucosa appeared to be less efficient when the butyrate was produced from fermentation of potato starch than when it was produced from fermentation of the other RS sources.


Asunto(s)
Amilosa/farmacología , Butiratos/metabolismo , Colon/metabolismo , Ácidos Grasos Volátiles/metabolismo , Almidón/farmacología , Animales , Butiratos/sangre , Cateterismo , Neoplasias del Colon/prevención & control , Ácidos Grasos Volátiles/sangre , Femenino , Absorción Intestinal/fisiología , Mucosa Intestinal/metabolismo , Sistema Porta/fisiología , Solanum tuberosum , Almidón/administración & dosificación , Porcinos
10.
Stroke ; 29(4): 824-9, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9550518

RESUMEN

BACKGROUND AND PURPOSE: We previously showed that treatment with a competitive N-methyl-D-aspartate (NMDA) receptor antagonist GPI-3000 (GPI) improved short-term physiological recovery after incomplete global cerebral ischemia complicated by dense acidosis. We tested the hypothesis that GPI administered after resuscitation from cardiac arrest would improve a more long-term recovery as measured by neurobehavioral assessment and neuropathology 4 days after resuscitation. METHODS: Anesthetized dogs were subjected to 7 minutes of cardiac arrest followed by vest cardiopulmonary resuscitation. Neurobehavioral outcomes were scored daily on a score ranging from 0 (normal) to 500 (worst). On the fourth day, the animals were killed, and neuropathology was evaluated in a blinded manner in the hippocampus and the neocortex by hematoxylin and eosin staining and by determination of percentage of injured neurons. Three groups of animals were treated in a randomized, blinded protocol with either saline (SAL), low-dose GPI (5 mg/kg followed by 1 mg/kg per hour for 2 hours), or high-dose GPI (25 mg/kg, followed by 5 mg/kg per hour for 2 hours). RESULTS: The mortality rate was higher in animals receiving GPI than in saline-treated control animals (4 of 15 deaths in SAL, 6 of 15 in the low-dose GPI group, and 9 of 18 in the high-dose GPI group). Neurobehavioral scores were depressed in GPI-treated animals compared with saline-treated control animals in a dose-dependent manner, with 96-hour scores of essentially normal (9+/-2) in saline-treated animals compared with those animals with significant impairment (181+/-47) treated with high-dose GPI. Neuropathological damage in the neocortex was most severe in GPI-treated animals, with the percentage of injured neurons dependent on the dose: 8.3%+/-2.7% SAL, 13.2%+/-6.4% low-dose GPI, and 39.4%+/-10.1%, high-dose GPI. CA1 neuronal damage was severe regardless of treatment. CONCLUSIONS: Contrary to results seen in experimental global and focal cerebral ischemia, in which NMDA receptor antagonism may improve responses to injury, receptor antagonism with GPI does not improve brain outcome after cardiac arrest and resuscitation in the dog. Behavioral and histological outcomes both were worsened by GPI treatment at two doses, and mortality was higher relative to saline control treatment. We speculate that systemic drug effects, as well as potential neurotoxicity of the drug under ischemic conditions, may be responsible for the deleterious outcomes observed in our cardiac arrest model.


Asunto(s)
Aminoácidos/uso terapéutico , Isquemia Encefálica/etiología , Antagonistas de Aminoácidos Excitadores/uso terapéutico , Paro Cardíaco/tratamiento farmacológico , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Animales , Conducta Animal/efectos de los fármacos , Unión Competitiva , Reanimación Cardiopulmonar , Perros , Paro Cardíaco/complicaciones , Paro Cardíaco/fisiopatología , Distribución Aleatoria , Resultado del Tratamiento
11.
Cancer Epidemiol Biomarkers Prev ; 5(3): 217-22, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8833622

RESUMEN

In 1982 we started a series of pilot studies to examine the feasibility of dietary intervention with a low-fat, high-carbohydrate diet in women with extensive mammographic densities. The purpose of the present paper is to examine the long-term effects of participation in these studies by assessing nutrient intake and other variables several years after active participation had stopped. Two hundred sixteen women were eligible for the follow-up study and were invited to attend and interview with a dietician. Data were collected by food frequency questionnaire from 157 subjects (73%), and blood was obtained from 115 subjects. Total energy intake was slightly lower in the intervention group. Total fat and percent energy from fat were significantly lower in the intervention group. The intake of all types of fat (saturated fat, linoleic acid, and oleic acid) and dietary cholesterol was lower in the in the intervention group; however, the polyunsaturated/saturated fat ratio did not differ between the groups. Total cholesterol and apoprotein B levels were lower in the intervention group compared to the control group. Follicle-stimulating hormone was 29% higher in postmenopausal members of the intervention group than in controls, but there was no difference in levels of estradiol. A total of 19 women enrolled in pilot studies had developed breast cancer, 5.7 times the number expected, confirming that the selection of women with extensive mammographic densities does identify a high-risk group. These data suggest that even quite short periods of intensive dietary counselling may have prolonged effects on diet, and that once subjects have adopted new dietary habits, the habits may persist even in the absence of continued counselling.


Asunto(s)
Neoplasias de la Mama/prevención & control , Dieta con Restricción de Grasas , Carbohidratos de la Dieta/administración & dosificación , Adulto , Anciano , Apolipoproteínas B/administración & dosificación , Mama/patología , Neoplasias de la Mama/dietoterapia , Colesterol en la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Ingestión de Energía , Estradiol/sangre , Ácidos Grasos Insaturados/administración & dosificación , Estudios de Factibilidad , Conducta Alimentaria , Femenino , Hormona Folículo Estimulante/sangre , Estudios de Seguimiento , Humanos , Ácido Linoleico , Ácidos Linoleicos/administración & dosificación , Estudios Longitudinales , Mamografía , Persona de Mediana Edad , Evaluación Nutricional , Ácido Oléico/administración & dosificación , Proyectos Piloto , Posmenopausia
12.
J Comp Neurol ; 353(4): 539-52, 1995 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-7759614

RESUMEN

To determine the distributions of glutamate receptors throughout the macaque hypothalamus, we utilized highly specific antipeptide antibodies to visualize alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subunits (GluR1, GluR2 and GluR3 [designated as GluR2/3], and GluR4); kainate receptor subunits (GluR6 and GluR7, [designated as GluR6/7]), and a metabotropic receptor (mGluR1 alpha). The results indicate that these glutamate receptors are distributed differentially throughout the monkey hypothalamus. alpha-Amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors are the dominant non-N-methyl-D-aspartate glutamate receptors within the monkey hypothalamus, and the GluR2 subunit is most abundant. GluR1-immunoreactive neurons and neuropil are observed predominantly in the tuberal and mammillary nuclei. GluR2/3-immunoreactive neurons and neuropil have a broader distribution within preoptic, anterior, tuberal, and caudal regions. Separate (but partially overlapping) distributions of GluR1- and GluR2/3-immunoreactive neurons were found, suggesting that the GluR1, GluR2, and/or GluR3 subunits may be coexpressed in subsets of hypothalamic neurons. In contrast, GluR4 immunoreactivity was expressed minimally within monkey hypothalamus. GluR6/7 immunoreactivity was enriched selectively within the suprachiasmatic nucleus. mGluR1 alpha immunoreactivity was present in the mammillary complex. The localization of non-N-methyl-D-aspartate glutamate receptor subunits to neurons throughout the macaque hypothalamus provides further evidence for the glutamatergic regulation of neuroendocrine, autonomic, and limbic circuits. Differential distributions of glutamate receptor subunits may increase the dynamic range of the effects of presynaptic glutamate, allowing for the regulation of several distinct functions subserved by hypothalamic neurons.


Asunto(s)
Hipotálamo/química , Macaca fascicularis/metabolismo , Receptores de Glutamato/análisis , Secuencia de Aminoácidos , Animales , Inmunohistoquímica , Datos de Secuencia Molecular , Área Preóptica/química , Prosencéfalo/química
13.
N Engl J Med ; 326(22): 1464-8, 1992 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-1349424

RESUMEN

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a chronic degenerative neurologic disorder characterized by the death of motor neurons in the cerebral cortex and spinal cord. Recent studies have suggested that the metabolism of glutamate, a potentially neurotoxic amino acid, is abnormal in patients with ALS. We hypothesized that the high-affinity glutamate transporter is the site of the defect. METHODS: We measured high-affinity, sodium-dependent glutamate transport in synaptosomes from neural tissue obtained from 13 patients with ALS, 17 patients with no neurologic disease, and 27 patients with other neuro-degenerative diseases (Alzheimer's disease in 15 patients and Huntington's disease in 12 patients). The groups were comparable with respect to age and the interval between death and autopsy. Synaptosomes were prepared from spinal cord, motor cortex, sensory cortex, visual cortex, striatum, and hippocampus. We also measured sodium-dependent transport of gamma-aminobutyric acid and phenylalanine in the synaptosomal preparations. RESULTS: In patients with ALS, there was a marked decrease in the maximal velocity of transport for high-affinity glutamate uptake in synaptosomes from spinal cord (-59 percent, P less than 0.001), motor cortex (-70 percent, P less than 0.001), and somatosensory cortex (-39 percent, P less than 0.05), but not in those from visual cortex, striatum, or hippocampus. The affinity of the transporter for glutamate was not altered. No abnormalities in glutamate transport were found in synaptosomes from patients with other chronic neurodegenerative disorders. The transport of gamma-aminobutyric acid and phenylalanine was normal in patients with ALS. CONCLUSIONS: ALS is associated with a defect in high-affinity glutamate transport that has disease, region, and chemical specificity. Defects in the clearance of extracellular glutamate because of a faulty transporter could lead to neurotoxic levels of extracellular glutamate and thus be pathogenic in ALS.


Asunto(s)
Esclerosis Amiotrófica Lateral/metabolismo , Encéfalo/metabolismo , Glutamatos/metabolismo , Médula Espinal/metabolismo , Anciano , Enfermedad de Alzheimer/metabolismo , Transporte Biológico , Femenino , Ácido Glutámico , Humanos , Enfermedad de Huntington/metabolismo , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Corteza Motora/metabolismo , Fenilalanina/metabolismo , Corteza Somatosensorial/metabolismo , Sinaptosomas/química , Corteza Visual/metabolismo , Ácido gamma-Aminobutírico/metabolismo
14.
J Am Coll Nutr ; 11(2): 172-6, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1578094

RESUMEN

Renewed interest in the antihistamine action of ascorbic acid has emerged with the recently recognized immunosuppressive role of histamine. We examined the antihistamine effect of acute and chronic vitamin C (VC) administration and its effect on neutrophil chemotaxis in healthy men and women. In the chronic study, 10 subjects ingested a placebo during weeks 1, 2, 5 and 6, and 2 g/day of VC during weeks 3 and 4. Fasting blood samples were collected after the initial 2-week period (baseline) and at the end of weeks 4 and 6. Plasma ascorbate rose significantly following VC administration compared to baseline and withdrawal values. Neutrophil chemotaxis rose 19% (NS) during VC administration, and fell 30% after VC withdrawal, but these changes were not correlated to plasma ascorbate levels (r = 0.01). Chemotaxis was inversely correlated to blood histamine (r = -0.32, p = 0.045), and, compared to baseline and withdrawal values, histamine levels were depressed 38% following VC supplementation. Blood histamine and neutrophil chemotaxis did not change 4 hours following a single 2 g dose of ascorbic acid, although plasma ascorbate rose 150%. These data indicate that VC may indirectly enhance chemotaxis by detoxifying histamine in vivo.


Asunto(s)
Ácido Ascórbico/farmacología , Quimiotaxis de Leucocito/efectos de los fármacos , Antagonistas de los Receptores Histamínicos/farmacología , Histamina/sangre , Adulto , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/sangre , Femenino , Antagonistas de los Receptores Histamínicos/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología
15.
J Comp Neurol ; 309(4): 445-85, 1991 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-1918444

RESUMEN

The cytoarchitecture and distributions of seven neuropeptides were examined in the the bed nucleus of the stria terminalis (BST), substantia innominata (SI), and central and medial nuclei of the amygdala of human and monkey to determine whether neurons of these regions form an anatomical continuum in primate brain. The BST and centromedial amygdala have common cyto- and chemo-architectonic characteristics, and these regions are components of a distinct neuronal complex. This neuronal continuum extends dorsally, with the stria terminalis, from the BST and merges with the amygdala; it extends ventrally from the BST through the SI to the centromedial amygdala. The cytoarchitectonics of the BST-amygdala complex are heterogeneous and compartmental. The BST is parcellated broadly into anterior, lateral, medial, ventral, supracapsular, and sublenticular divisions. The central and medial nuclei of the amygdala are also parcellated into several subdivisions. Neurons of central and medial nuclei of the amygdala are similar to neurons in the lateral and medial divisions of the BST, respectively. Neurons in the SI form cellular bridges between the BST and amygdala. The BST, SI, and amygdala share several neuropeptide transmitters, and patterns of peptide immunoreactivity parallel cytological findings. Specific chemoarchitectonic zones were delineated by perikaryal, peridendritic/perisomatic, axonal, and terminal immunoreactivities. The results of this investigation demonstrate that there is a neuronal continuity between the BST and amygdala and that the BST-amygdala complex is prominent and discretely compartmental in forebrains of human and monkey.


Asunto(s)
Amígdala del Cerebelo/anatomía & histología , Hipotálamo/anatomía & histología , Primates/anatomía & histología , Amígdala del Cerebelo/citología , Amígdala del Cerebelo/metabolismo , Animales , Chlorocebus aethiops , Femenino , Histocitoquímica , Humanos , Hipotálamo/citología , Hipotálamo/metabolismo , Inmunohistoquímica , Macaca mulatta , Masculino , Vías Nerviosas/anatomía & histología , Vías Nerviosas/citología , Vías Nerviosas/metabolismo , Neuropéptidos/metabolismo , Papio , Primates/metabolismo
16.
J Neurol Sci ; 86(2-3): 159-69, 1988 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2464666

RESUMEN

Neuronal nucleic acid responses were examined within the rat thalamic ventrobasal nuclear complex (VBC) and nucleus reticularis (NR) following single intraperitoneal injections of the central muscarinic-cholinergic (M2) receptor agonist oxotremorine (0.1, 0.7, or 1.0 mg/kg). After stoichiometric azure B and Feulgen staining of brain sections, scanning-integrating cytophotometry was used to quantify azure B-ribonucleic acid (RNA) content, Feulgen-DNA levels, and changes in the susceptibility of chromatin to Feulgen acid hydrolysis (F-DNA yield) of neurons on an individual basis. Changes in neuronal nucleolar volume were also determined histometrically. Within the VBC, oxotremorine produced marked dose-dependent elevations in neuronal RNA content and nucleolar volume with increased F-DNA yield (chromatin activation) in a proportion of VBC neurons. In contrast, within the NR, oxotremorine elicited reductions in RNA levels, F-DNA yield and nucleolar volume. The data demonstrate that oxotremorine-induced central muscarinic receptor stimulation is associated with metabolic correlates of thalamic VBC neuroexcitation and NR neuron depression. The overall study lends further credence to the hypothesis that muscarinic-cholinergic mechanisms are operative within the mammalian thalamus.


Asunto(s)
Cromatina/ultraestructura , Neuronas/citología , Oxotremorina/farmacología , ARN/metabolismo , Tálamo/citología , Animales , Cromatina/efectos de los fármacos , Masculino , Neuronas/efectos de los fármacos , ARN/efectos de los fármacos , Ratas , Ratas Endogámicas , Receptores Colinérgicos/efectos de los fármacos , Valores de Referencia , Coloración y Etiquetado , Tálamo/efectos de los fármacos
17.
Health Phys ; 43(3): 363-75, 1982 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6293999

RESUMEN

Radiation parameters associated with the open pit mining of a small (10,000 tonnes), but high grade (2%) uranium deposit at Nabarlek, N.T., have been investigated in detail. External radiation levels, radon emanation rates and radon daughter levels were measured systematically during the development of the mine, and are correlated with ore grade, properties of the host rock and atmospheric conditions. Significant radon daughter concentrations were observed only under stable atmospheric conditions, usually during the might and were invariably associated with thermal inversions. The mean cumulative exposure to radon daughters was estimated from the measured levels to be 0.065 Working Level Months for employees working in the pit for the entire four and a half months of mining. The mean cumulative external gamma ray exposure for the same employee group was measured using thermoluminescent dosimeters to be 2.3 mSv (230 mrem). For most other employees, however, exposures were much lower. Data on long lived radionuclides in dust and on particle size distribution are also presented.


Asunto(s)
Contaminación Radiactiva del Aire/análisis , Polvo , Minería , Uranio , Partículas alfa , Australia , Bismuto/análisis , Rayos gamma , Plomo/análisis , Tamaño de la Partícula , Polonio/análisis , Dosis de Radiación , Radón/análisis , Hijas del Radón
18.
J Am Diet Assoc ; 76(4): 343-6, 1980 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7391466

RESUMEN

Forty-five grossly obese patients (averaging 64.1 kg. above ideal body weight) were treated as in-patients with a modified protein-sparing fast. Twenty-seven of these patients had diabetes, sixteen of them requiring insulin. In-patient treatment with PSMF ranged from three days to two years. The dietary regimen provided 1.2 gm. protein per kilogram ideal body weight, with no added fat or carbohydrates; this generally amounted to 270 to 430 gm. meat, distributed in three meals (about 500 to 800 kcal per day). Generous vitamin and mineral supplements were provided. Concomitant psychotherapy was also part of the treatment. Before discharge, the patients had lost from 0.45 to 93.2 kg., depending on compliance, length of hospitalization, and amount of exercise. After discharge, compliance fell, despite provision of group therapy with a psychologist and bi-weekly appointments with the physician and dietitian. The more committed patients who attended group therapy regularly have been more successful in continuing to lose weight.


Asunto(s)
Peso Corporal , Proteínas en la Dieta/administración & dosificación , Ayuno , Adulto , Dieta Reductora , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Psicoterapia de Grupo
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