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1.
Eur J Clin Nutr ; 69(11): 1233-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26130298

RESUMO

BACKGROUND/OBJECTIVES: In Australia, the Australian Bureau of Statistics discontinued collection of apparent consumption data for refined sugars in 1998/1999. The objectives of this study were to update this data series to determine whether it is a reliable data series that reflects consumption of refined sugars, defined as sucrose in the forms of refined or raw sugar or liquified sugars manufactured for human consumption. SUBJECTS/METHODS: The study used the same methodology as that used by the Australian Bureau of Statistics to derive a refined sugars consumption estimate each year until the collection was discontinued. Sales by Australian refiners, refined sugars imports and the net balance of refined sugars contained in foods imported into, and exported from, Australia were used to calculate total refined sugars use for each year up to 2011. Per capita consumption figures were then derived. RESULTS: During the period 1938-2011, apparent consumption of refined sugars in Australia fell 13.1% from 48.3 to 42.0 kg per head (R(2)=0.74). Between the 1950s and the 1970s, apparent consumption was relatively stable at about 50 kg per person. In the shorter period 1970-2011, refined sugars consumption fell 16.5% from 50.3 to 42.0 kg per head, though greater variability was evident (R(2)=0.53). An alternative data set showed greater volatility with no trend up or down. CONCLUSIONS: The limited variability of the extended apparent consumption series and its consistency with recent national dietary survey data and sugar-sweetened beverage sales data indicate that it is a reliable data set that reflects declining intake of refined sugars in Australia.


Assuntos
Dieta , Sacarose Alimentar/administração & dosagem , Comportamento Alimentar , Austrália , Bebidas , Comércio , Humanos , Obesidade/etiologia , Edulcorantes/administração & dosagem
3.
Genes Brain Behav ; 7(5): 587-98, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18363852

RESUMO

Inbred strains of mice differ in their susceptibility to excitotoxin-induced cell death, but the genetic basis of individual variation in differential susceptibility is unknown. Previously, we identified a highly significant quantitative trait locus (QTL) on chromosome 18 that influenced susceptibility to kainic acid-induced cell death (Sicd1). Comparison of susceptibility to seizure-induced cell death between reciprocal congenic lines for Sicd1 and parental background mice indicates that genes influencing this trait were captured in both strains. Two positional gene candidates, Galr1 and Mbp, map to 55 cM, where the Sicd1 QTL had been previously mapped. Thus, this study was undertaken to determine if Galr1 and/or Mbp could be considered as candidate genes. Genomic sequence comparison of these two functional candidate genes from the C57BL/6J (resistant at Sicd1) and the FVB/NJ (susceptible at Sicd1) strains showed no single-nucleotide polymorphisms. However, expression studies confirmed that Galr1 shows significant differential expression in the congenic and parental inbred strains. Galr1 expression was downregulated in the hippocampus of C57BL/6J mice and FVB.B6-Sicd1 congenic mice when compared with FVB/NJ or B6.FVB-Sicd1 congenic mice. A survey of Galr1 expression among other inbred strains showed a significant effect such that 'susceptible' strains showed a reduction in Galr1 expression as compared with 'resistant' strains. In contrast, no differences in Mbp expression were observed. In summary, these results suggest that differential expression of Galr1 may contribute to the differences in susceptibility to seizure-induced cell death between cell death-resistant and cell death-susceptible strains.


Assuntos
Morte Celular/genética , Epilepsia/genética , Epilepsia/patologia , Predisposição Genética para Doença/genética , Receptor Tipo 1 de Galanina/genética , Animais , Sequência de Bases , Epilepsia/induzido quimicamente , Agonistas de Aminoácidos Excitatórios/toxicidade , Variação Genética , Genômica , Haplótipos , Hipocampo/patologia , Hipocampo/fisiologia , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Proteína Básica da Mielina , Proteínas do Tecido Nervoso/genética , Neurotoxinas/toxicidade , Fenótipo , Polimorfismo de Nucleotídeo Único , Especificidade da Espécie , Fatores de Transcrição/genética
4.
Neuroscience ; 146(2): 784-91, 2007 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-17331653

RESUMO

Motor cortex lesions in rats partially denervate the striatum, producing behavioral deficits and inducing reactive neuroplasticity. Plastic responses include changes in growth-associated protein marker expression and anatomical restructuring. Corticostriatal plasticity is dependent on dopamine at the striatal target, where D1 receptor signaling reinforces behaviorally relevant neural activity. To determine whether striatal dopamine D1 receptor signaling is important for the growth-associated protein responses and behavioral recovery that follow unilateral motor cortex aspiration, the dopamine D1 receptor antagonist SCH23390 was intrastriatally infused in cortically lesioned animals. After a cortical aspiration lesion in Long Evans rats, the growth-associated proteins SCG10 and GAP-43 were upregulated in the cortex contralateral to the lesion at 30 days post-lesion. However, continuous unilateral intrastriatal infusion of SCH23390 prevented this aspiration-induced upregulation. Furthermore, lesioned rats demonstrated spontaneous sensorimotor improvement, in terms of limb-use symmetry, about 1 month post-lesion. This improvement was prevented with chronic intrastriatal SCH23390 infusion. The D1 receptor influence may be important to normalize corticostriatal activity (and observable behavior), either in a long-term manner or temporarily until other more permanent means of synaptic regulation, such as sprouting or synaptogenesis, may be implemented.


Assuntos
Benzazepinas/farmacologia , Lesões Encefálicas/patologia , Antagonistas de Dopamina/farmacologia , Córtex Motor/patologia , Plasticidade Neuronal/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Lesões Encefálicas/fisiopatologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/fisiopatologia , Dopamina/metabolismo , Proteína GAP-43/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Masculino , Proteínas de Membrana/metabolismo , Plasticidade Neuronal/fisiologia , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Long-Evans , Fatores de Tempo
5.
Neuroscience ; 135(4): 1231-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16165289

RESUMO

Investigation of the elements underlying synapse replacement after brain injury is essential for predicting the neural compensation that can be achieved after various types of damage. The growth-associated proteins superior cervical ganglion-10 and growth-associated protein-43 have previously been linked with structural changes in the corticostriatal system in response to unilateral deafferentation. To examine the regulation of this response, unilateral cortical aspiration lesion was carried out in combination with ipsilateral 6-hydroxydopamine lesion of the substantia nigra, and the time course of the contralateral cortical molecular response was followed. Unilateral cortical aspiration lesion in rats corresponds with an upregulation of superior cervical ganglion-10 mRNA at 3 and 10 days post-lesion, and protein, sustained from three to at least 27 days following lesion. With the addition of substantia nigra lesion, the response shifts to an upregulation of growth-associated protein-43 mRNA at 3 and 10 days post-lesion, and protein after 10 days. Nigral lesion alone does not alter contralateral expression of either gene. Likewise, motor function assessment using the rotorod test revealed no significant long-term deficits in animals that sustained only nigrostriatal damage, but cortical lesion was associated with a temporary deficit which was sustained when nigrostriatal input was also removed. Growth-associated protein-43 and superior cervical ganglion-10, two presynaptic genes that are postulated to play roles in lesion-induced sprouting, are differentially upregulated in corticostriatal neurons after cortical versus combined cortical/nigral lesions. The shift in contralateral gene response from superior cervical ganglion-10 to growth-associated protein-43 upregulation and associated behavioral deficit following combined cortical and nigral denervation suggest that nigrostriatal afferents regulate cortical lesion-induced gene expression and ultimate functional outcome.


Assuntos
Lesões Encefálicas/metabolismo , Córtex Cerebral/metabolismo , Proteína GAP-43/biossíntese , Fatores de Crescimento Neural/biossíntese , Substância Negra/metabolismo , Animais , Western Blotting , Lesões Encefálicas/fisiopatologia , Proteínas de Transporte , Córtex Cerebral/lesões , Lateralidade Funcional , Expressão Gênica , Hibridização In Situ , Masculino , Proteínas de Membrana , Proteínas dos Microtúbulos , Atividade Motora/fisiologia , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos F344 , Substância Negra/lesões , Regulação para Cima
6.
Exp Neurol ; 165(1): 191-206, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10964498

RESUMO

Ultrastructural changes within the ipsilateral dorsolateral striatum were investigated 1 month following a unilateral ablation of the rat frontal cortex (CTX), removing corticostriatal input, or injection of the neurotoxin, 6-hydroxydopamine (6-OHDA), into the substantia nigra pars compacta, removing nigrostriatal input. In addition, a combined ipsilateral cortical and 6-OHDA lesion (CTX/6-OHDA) was carried out. We find that following a CTX, 6-OHDA, or CTX/6-OHDA lesion, there was a significant decrease in the density of striatal nerve terminal glutamate immunoreactivity compared to the control group. There was also a significant increase in all three lesion groups in the mean percentage of asymmetrical synapses associated with a perforated postsynaptic density. There was a large increase within the CTX/6-OHDA-lesioned group and a smaller but still significant increase in the CTX-lesioned group in the percentage of terminals or boutons with multiple synaptic contacts (i.e., multiple synaptic boutons, MSBs), compared to either the 6-OHDA or the control group. There was no change in any of these measurements within the contralateral striatum. There was a significant decrease in the number of apomorphine-induced contralateral rotations in the CTX/6-OHDA versus the 6-OHDA-lesioned group. Animals receiving just the single CTX or 6-OHDA lesion recovered in motor function compared to the control group as measured by the Rotorod test, while the CTX/6-ODA-lesioned group recovered to less than 50% of the control level. The data suggest that following a CTX and/or 6-OHDA lesion, there is an increase in striatal glutamatergic function. The large increase in the percentage of MSBs in the combined lesion group suggests that dopamine or other factors released by the dopamine terminals assist in regulating synapse formation.


Assuntos
Encefalopatias/patologia , Corpo Estriado/patologia , Ácido Glutâmico/metabolismo , Substância Negra/patologia , Sinapses/ultraestrutura , Animais , Encefalopatias/metabolismo , Corpo Estriado/metabolismo , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Atividade Motora , Vias Neurais/metabolismo , Vias Neurais/patologia , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Ratos Endogâmicos F344 , Substância Negra/metabolismo , Sinapses/metabolismo
7.
Neuroscience ; 90(4): 1349-60, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10338302

RESUMO

Synapse replacement after brain injury has been widely documented by anatomical studies in various parts of both the developing and adult nervous system. However, the molecular events that define the specificity of the empirically derived rules of reactive synaptogenesis in different regions of the adult brain remain unclear. In this study we examined the differential regulation of the lesion-induced response of the two growth-associated proteins, superior cervical ganglia-10 and growth-associated protein-43, after unilateral cortex ablation, and determined a hierarchical order for the lesion response from remaining afferent projection neurons originating from the contralateral cortex, ipsilateral thalamus and substantia nigra. We report that in response to unilateral cortex ablation both messenger RNA, by northern blot, and protein, by western blot, for superior cervical ganglia-10 but not growth-associated protein-43 was increased in the homologous area of the contralateral cortex but not the ipsilateral thalamus or substantia nigra. In addition, the specificity of the superior cervical ganglia-10 response, assessed by combined in situ hybridization and retrograde FluoroGold labeling of striatal afferent neurons, found that superior cervical ganglia-10 messenger RNA was increased prominently in layer V pyramidal neurons of the contralateral corticostriatal pathway but was unchanged in afferent projection neurons from the thalamus and substantia nigra. Furthermore, the increase in both superior cervical ganglia-10 messenger RNA and protein seen at three days postlesion in contralateral corticostriatal neurons coincides in time with the initiation of neurite outgrowth in the deafferented striatum by contralateral corticostriatal axons described in our previous ultrastructural study. However, if cortical input to the striatum was removed bilaterally the lesion-induced response for superior cervical ganglia-10 messenger RNA shifted secondarily to thalamostriatal neurons in the ipsilateral thalamus. These data provide evidence that superior cervical ganglia-10 and growth-associated protein-43 are differentially regulated in neurons of the contralateral corticostriatal pathway in response to unilateral cortex ablation and suggests that superior cervical ganglia-10 plays a role in the regulation of neurite outgrowth in the adult striatum after brain injury. However, the specific role that superior cervical ganglia-10 may play in reactive synaptogenesis remains unclear. In addition, our data suggest that a hierarchical order exists for the reinnervation of deafferented striatal neurons after unilateral cortex ablation with preference given to homologous axons from the contralateral cortex.


Assuntos
Lesões Encefálicas/metabolismo , Córtex Cerebral/fisiologia , Dominância Cerebral/fisiologia , Proteína GAP-43/metabolismo , Fatores de Crescimento Neural/metabolismo , Estilbamidinas , Animais , Northern Blotting , Proteínas de Transporte , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Corantes Fluorescentes/farmacocinética , Proteína GAP-43/genética , Hibridização In Situ , Masculino , Proteínas de Membrana , Proteínas dos Microtúbulos , Fatores de Crescimento Neural/genética , Neurônios/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos F344 , Substância Negra/citologia , Substância Negra/metabolismo , Tálamo/citologia , Tálamo/metabolismo , Fatores de Tempo , Distribuição Tecidual/fisiologia
8.
Neurosci Lett ; 242(2): 69-72, 1998 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-9533396

RESUMO

Synaptic replacement in rat striatum following a unilateral cortical lesion was investigated using electron microscopy and the anterograde tracer, biotinylated dextrin amine (BDA). In the deafferented striatum evidence of axon sprouting and synapse replacement was seen at 20 days after the lesion and most newly-formed axon terminals were labeled with BDA injected previously into the contralateral cortex. In addition, BDA-labeled fibers from the contralateral cortex formed multiple asymmetric axospinous synapses with deafferented striatal neurons, a morphological feature rarely seen in unlesioned rats. These data suggest that in response to a unilateral cortex lesion axons from the contralateral cortex sprout and reinnervated the deafferented striatal neurons and that reinnervation by 'like' afferents maybe crucial for the establishment of functional recovery after the unilateral cortex lesion.


Assuntos
Axônios/fisiologia , Corpo Estriado/citologia , Interneurônios/ultraestrutura , Plasticidade Neuronal/fisiologia , Fatores Etários , Animais , Axônios/ultraestrutura , Biotina/análogos & derivados , Tamanho Celular , Córtex Cerebral/citologia , Dendritos/fisiologia , Dendritos/ultraestrutura , Dextranos , Corantes Fluorescentes , Lateralidade Funcional/fisiologia , Interneurônios/citologia , Interneurônios/fisiologia , Masculino , Microscopia Eletrônica , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Ratos Endogâmicos F344
9.
Neuroscience ; 82(1): 7-19, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9483499

RESUMO

The VGF gene encodes a neuronal secretory-peptide precursor that is rapidly induced by neurotrophic growth factors and by depolarization in vitro. VGF expression in the animal peaks during critical periods in the developing peripheral and central nervous systems. To gain insight into the possible functions and regulation of VGF in vivo, we have used in situ hybridization to examine the regulation of VGF messenger RNA by experimental manipulations, and have found it to be regulated in the CNS by paradigms that affect electrical activity and by lesion. Inhibition of retinal electrical activity during the critical period of visual development rapidly repressed VGF messenger RNA in the dorsal lateral geniculate nucleus of the thalamus. In the adult, kainate-induced seizures transiently induced VGF messenger RNA in neurons of the dentate gyrus, hippocampus, and cerebral cortex within hours. Cortical lesion strongly induced VGF messenger RNA in ipsilateral cortex within hours, and strongly repressed expression in ipsilateral striatum. Ten days postlesion there was a delayed induction of VGF messenger RNA in a portion of deafferented striatum where compensatory cortical sprouting has been detected. Expression of the neuronal secretory-peptide precursor VGF is therefore modulated in vivo by monocular deprivation, seizure, and cortical lesion, paradigms which lead to neurotrophin induction, synaptic remodeling and axonal sprouting.


Assuntos
Sistema Nervoso Central/lesões , Sistema Nervoso Central/fisiologia , Córtex Cerebral/patologia , Neurônios/fisiologia , Biossíntese de Proteínas , Proteínas , RNA Mensageiro/biossíntese , Convulsões/patologia , Animais , Sistema Nervoso Central/metabolismo , Antagonistas de Aminoácidos Excitatórios , Olho , Corpos Geniculados/metabolismo , Corpos Geniculados/fisiologia , Processamento de Imagem Assistida por Computador , Hibridização In Situ , Injeções , Ácido Caínico/administração & dosagem , Ácido Caínico/toxicidade , Masculino , Neurônios/metabolismo , Neuropeptídeos , Sondas RNA , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-Dawley , Convulsões/induzido quimicamente , Tetrodotoxina/administração & dosagem , Tetrodotoxina/toxicidade
10.
Soc Work Health Care ; 26(3): 1-18, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9456471

RESUMO

This study identified and measured the predictive value of specific indicators of consumers' overall perception of a hospital-based social work service. A review of the health and social work literature revealed a number of distinct "components" which predict overall satisfaction with the service a patient receives. A questionnaire evaluating client perceptions of each component was developed and administered to 83 randomly selected respondents. The study also gathered information about perceptions of patients/families regarding the reason for social work involvement and the corresponding outcome measured on a goal attainment scale. Findings were positive concerning the value of social work. The results suggest that the "components" of satisfaction that were tested were relevant as they were positively and significantly associated with patients' overall rating of the social work service. Implications for practice are discussed.


Assuntos
Avaliação de Resultados em Cuidados de Saúde , Satisfação do Paciente , Serviço Hospitalar de Assistência Social/normas , Adolescente , Adulto , Criança , Pré-Escolar , Competência Clínica/normas , Continuidade da Assistência ao Paciente/normas , Família/psicologia , Acessibilidade aos Serviços de Saúde/normas , Hospitais Pediátricos , Humanos , Lactente , Recém-Nascido , Valor Preditivo dos Testes , Relações Profissional-Paciente , Inquéritos e Questionários
11.
Exp Neurol ; 149(1): 87-96, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9454618

RESUMO

This study evaluates the time course of expression of three astrocytic mRNAs, glial fibrillary acidic protein (GFAP), apolipoprotein E (ApoE), and clusterin, in the rat striatum (ST) following a unilateral lesion of either the cortex (CX) or the substantia nigra (SN), using Northern blot and in situ hybridization analyses. We found that while there was a time-dependent increase in astrocytic GFAP mRNA in the deafferented ST following both the CX and the SN lesions, the time course of the response was different between the two lesion paradigms. Specifically, the increase in GFAP mRNA in striatal astrocytes after the SN lesion was rapid and transient returning to control levels by 10 days postlesion, while the response was long lasting and remained increased until at least 27 days after the CX lesion. In addition, the mRNA response for both ApoE and clusterin was differentially regulated in response to the two lesions. Specifically, both clusterin and ApoE mRNAs were rapidly increased in the ST following the CX lesion while both mRNAs remained unchanged following the SN lesion. Data from this study extend information derived from previous investigations on the multifunctional role of astrocytes in the response to brain injury. Specifically, our data support the notion that while the time course of the GFAP response in striatal astrocytes may vary between lesion paradigms, the upregulation of GFAP is part of a generalized response of reactive astrocytes to diverse brain injuries. By comparison, upregulation of the mRNAs for the lipoproteins clusterin and ApoE are lesion specific and may play a role in the transport of recycled myelin lipids from dying axons to actively growing axons and dendrites in reactive synaptogenesis.


Assuntos
Astrócitos/metabolismo , Córtex Cerebral/patologia , Corpo Estriado/metabolismo , Chaperonas Moleculares , RNA Mensageiro/metabolismo , Substância Negra/patologia , Animais , Apolipoproteínas E/genética , Clusterina , Proteína Glial Fibrilar Ácida/genética , Glicoproteínas/genética , Masculino , Ratos , Ratos Endogâmicos F344
12.
Exp Neurol ; 147(2): 287-98, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9344554

RESUMO

Golgi-Cox method and morphometric analyses were used to study the plasticity of striatal medium spiny I neurons in 6-month-old C57BL/6N mice after unilateral or bilateral lesion of the cerebral cortex or combined lesions of the ipsilateral cerebral cortex and intralaminar thalamus. In adult mouse, unilateral lesions of the cerebral cortex did not result in a net gain or loss of linear dendritic length in a randomly selected population of striatal medium spiny I neurons. In addition, there was a well-defined time course of striatal spine loss and replacement occurring after a unilateral cortical lesion. By day 3 postlesion the average 20-microm dendritic segment had lost 30% of the unlesioned control spine value, reached its nadir, lost 45.5%, at 10 days postlesion, and recovered to 80% of unlesioned control levels by 20 days postlesion. The recovery of spines was blocked by a secondary lesion on the contralateral cortex but not on the ipsilateral intralaminar thalamus. These data suggest that striatal medium spiny I neurons of adult mice have a remarkable capacity for plasticity and reactive synaptogenesis following a decortication. The recovery of spine density is primarily induced by axonal sprouting of survival homologous afferent fibers from the contralateral cortex.


Assuntos
Córtex Cerebral/lesões , Corpo Estriado/patologia , Dendritos/ultraestrutura , Regeneração Nervosa , Plasticidade Neuronal , Neurônios/fisiologia , Tálamo/lesões , Animais , Tamanho Celular , Denervação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sinapses/ultraestrutura
13.
Synapse ; 27(1): 57-68, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9268065

RESUMO

Aging disrupts the expression of synaptic plasticity in many central nervous system (CNS) structures including the striatum. We found age differences in paired-pulse plasticity to persist at excitatory striatal synapses following block of gamma aminobutyric acid (GABA)A and GABA(B) receptors, a property that was independent of the number of afferents activated. High Mg2+/low Ca2+ artificial cerebral spinal fluid (ACSF) reduced release probability and consequently the size of the evoked excitatory post-synaptic potential (EPSP). High Mg2+/low Ca2+ ACSF also increased the expression of paired-pulse facilitation and eliminated the age difference seen previously in normal ACSF. These data suggest that age differences in paired-pulse plasticity reflect an alteration in release probability at excitatory striatal synapses. In support of this hypothesis, we found age differences in another presynaptic form of plasticity referred to as synaptic augmentation. Examination of the synaptic depression that developed during the conditioning tetanus also revealed an age-related increase in synaptic depression. These data indicate that age-related changes in facilitation may be due in part to a reduction in the readily releasable pool of synaptic vesicles. Dendritic structure (spine density and dendritic length) was correlated with short-term synaptic plasticity, but these relationships depended upon the variance associated with age (hierarchical regression). Post-hoc within-age group regressions demonstrated relationship between spine density and paired-pulse plasticity. No other age-specific correlations were found. These findings imply an age-dependent association between altered dendritic morphology and changes in synaptic plasticity.


Assuntos
Envelhecimento/fisiologia , Corpo Estriado/fisiologia , Plasticidade Neuronal/fisiologia , Terminações Pré-Sinápticas/fisiologia , Sinapses/fisiologia , Animais , Masculino , Ratos , Ratos Endogâmicos F344 , Fatores de Tempo
14.
Neuroreport ; 8(17): 3691-5, 1997 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9427352

RESUMO

Stathmin (p19) is developmentally regulated as a neural-enriched phosphoprotein associated with neurite outgrowth and synaptic formation during cell proliferation and differentiation, and remains highly abundant in adult rat brain. Whether stathmin is involved in injury-induced reactive synaptogenesis in adult rat was examined in this study. Following unilateral cortical lesion, a significant increase in stathmin mRNA expression was found in the cells of contralateral homotypic cortex and in the subventricular zone of the lateral ventricle. This increase coincided in time with the corticostriatal axon sprouting and synaptic remodeling previously found in denervated striatum. Our data suggest that stathmin plays an important role in regulation of reactive synaptogenesis in adult brain.


Assuntos
Lesões Encefálicas/metabolismo , Encéfalo/metabolismo , Proteínas dos Microtúbulos , Fosfoproteínas/biossíntese , Sinapses/fisiologia , Transcrição Gênica , Animais , Encéfalo/patologia , Lesões Encefálicas/patologia , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Ventrículos Cerebrais/metabolismo , Ventrículos Cerebrais/patologia , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Lateralidade Funcional , Regulação da Expressão Gênica , Masculino , RNA Mensageiro/biossíntese , Ratos , Ratos Endogâmicos F344 , Estatmina , Fatores de Tempo
15.
J Neurochem ; 67(5): 2164-71, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8863527

RESUMO

This study analyzed the effects of acute systemic treatment with buthionine sulfoximine (BSO), a synthesis inhibitor of the antioxidant reduced glutathione (GSH), on dopaminergic neurons of the murine nigrostriatal pathway. Part 1 of the study established a dose-response curve and the temporal pattern of GSH loss and recovery in the substantia nigra and striatum following acute BSO treatment. Part 2 of the study determined the effect of acute BSO treatment on the morphology and biochemistry of nigrostriatal neurons. We found that decreases in GSH levels had profound morphological effects, including decreased catecholamine fluorescence per cell, increased levels of lipid peroxidation and lipofuscin accumulation, and increased numbers of dystrophic axons in dopaminergic neurons of the nigrostriatal pathway. However, no measurable effects were observed in biochemical levels of either dopamine or its metabolites. These changes mimic those that have been reported to occur in the nigrostriatal system of rodents with advancing age. Our data suggest that reduction of GSH via BSO treatment results in the same types of nigrostriatal degenerative effects that occur during the aging process and consequently is a good model system for examining the role of GSH in protecting this area of the brain against the harmful effects of age-related oxidative stress.


Assuntos
Envelhecimento/fisiologia , Butionina Sulfoximina/farmacologia , Corpo Estriado/metabolismo , Dopamina/metabolismo , Glutationa/metabolismo , Neurônios/metabolismo , Substância Negra/metabolismo , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Antioxidantes , Corpo Estriado/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Glutationa/antagonistas & inibidores , Ácido Homovanílico/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Neurônios/efeitos dos fármacos , Substância Negra/crescimento & desenvolvimento , Tirosina 3-Mono-Oxigenase/metabolismo
16.
J Neurophysiol ; 76(4): 2353-63, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8899609

RESUMO

1. The influence of age on striatal neuron Ca2+ physiology was studied through an analysis of intracellularly recorded Ca(2+)-mediated plateau potentials. In vitro brain slices from young and aged rats were treated with the K+ channel blocker tetraethylammonium (30 mM) to facilitate the expression of plateau potentials. A sample of neurons was also filled with biocytin and post hoc correlations were performed between morphology and physiology. 2. Testing of sampling parameters in neurons from young rats revealed that tetrodotoxin did not affect the amplitude or duration of plateau potentials. The membrane potential induced during plateau testing and the rate of plateau potential generation, however, had to be held constant because these variables affected plateau potential duration. 3. A significant age-related decrease was found in the duration of Ca(2+)-mediated plateau potentials that could not be explained by alterations in the activation or inactivation properties of the plateau potential. Investigation into relationships between cell morphology and plateau potential duration revealed a number of correlations. Soma size and dendritic length were correlated with plateau potential duration, independent of age (hierarchical regression), and an age-related decrease in dendritic length but not in soma size was found. Spine density and plateau potential duration were also correlated, but the significance depended on the variance associated with age. These data indicate that the extent of somadendritic membrane (including spines) affects plateau potential duration in striatal neurons and that dendrite and spine loss in aged animals may contribute to age-related decreases in plateau potential duration. 4. The response to replacement of Ca2+ with Ba2+ was age dependent, with Ba2+ causing a greater increase in the duration of plateau potentials in young neurons. These data rule out an increase in Ca(2+)-mediated inactivation of Ca2+ channels as a primary cause for the shortening of plateau potentials in aged neurons. Our morphological findings suggest that dendritic regression in aged neurons may have reduced the number of Ca2+ channels participating in plateau potential generation, but other mechanisms related to changes in the type of Ca2+ channel expressed and possible differences in their inactivation kinetics may also contribute to the age-related change in plateau potential duration.


Assuntos
Envelhecimento/fisiologia , Cálcio/fisiologia , Corpo Estriado/fisiologia , Neurônios/fisiologia , Análise de Variância , Animais , Bário/farmacologia , Tamanho Celular , Corpo Estriado/citologia , Dendritos/ultraestrutura , Potenciais Evocados/efeitos dos fármacos , Técnicas In Vitro , Masculino , Neurônios/ultraestrutura , Ratos , Ratos Endogâmicos F344 , Análise de Regressão , Tetraetilamônio , Compostos de Tetraetilamônio/farmacologia
17.
Exp Neurol ; 141(1): 145-53, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8797677

RESUMO

This study examined the time course of dendritic reorganization of dentate granule neurons of the hippocampus following the loss of input from both the fimbria fornix (FF) and the entorhinal cortex (EC). We used the Golgi-Cox stain to assess the morphology of dentate granule neurons at six postlesion time points (4, 8, 14, 30, 45, and 60 days) and dendritic measures included total dendritic length, number of segments, number of branch points, and spine density. We found that as early as 4 days postlesion, total dendritic length and number of segments were significantly decreased with the greatest change occurring in the distal parts of the dendritic arbor located in the outer molecular layer of the dentate gyrus. Dendritic measures related to segment number and dendritic length returned to 70% of intact values by 30 days postlesion and were not significantly different from unlesioned rats at 45 and 60 days postlesion. In contrast, the recovery of spine density was transient. Spine density in the outer molecular layer of the dentate gyrus decreased by 60% at 4 days postlesion and returned to 87% of intact values by 30 days postlesion. However, there was a second loss of dendritic spines along the distal portion of the dendrite between 30 and 60 days postlesion. These data provide evidence that the ability of granule neurons to recover a dendritic morphology similar to that of unlesioned rats is impaired following the combined EC/FF lesion and that the "secondary loss" of dendritic spine density on granule neurons may significantly limit the chances of the hippocampus reforming a synaptic circuitry that could lead to functional recovery after the EC/FF lesion.


Assuntos
Dendritos/fisiologia , Giro Denteado/fisiologia , Córtex Entorrinal/fisiologia , Hipocampo/fisiologia , Plasticidade Neuronal , Neurônios/fisiologia , Animais , Denervação , Giro Denteado/citologia , Hipocampo/citologia , Hipocampo/ultraestrutura , Masculino , Ratos , Ratos Endogâmicos F344
18.
Brain Res Mol Brain Res ; 40(1): 79-96, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8840016

RESUMO

The receptor protein tyrosine phosphatase (RPTP) zeta/beta and a major isoform, phosphacan, a chondroitin sulfate proteoglycan that contains the RPTP zeta/beta extracellular domain but not the transmembrane and intracellular phosphatase domains, are expressed abundantly in the nervous system, primarily by astroglia. Because of similarities in the expression patterns of RPTP zeta/beta and the receptor tyrosine kinase TrkB, we investigated whether RNAs encoding these proteins were co-localized during development, which would suggest that these molecules might functionally interact in vivo. By in-situ hybridization, we noted extensive areas of overlap in the expression of trkB and RPTP zeta/beta mRNAs in the developing peripheral and central nervous systems. Analysis with a probe specific for the catalytic TrkB isoform suggested that RPTP zeta/beta and non-catalytic trkB mRNAs were co-expressed in particular regions of the nervous system while the catalytic trkB and RPTP zeta/beta transcripts were also, but to a lesser extent. RPTP zeta/beta and phosphacan expression were extremely similar, differing particularly in the level of expression in the ventricular and subventricular zones, hippocampus, and ependyma. Furthermore, both RPTP zeta/beta and phosphacan mRNAs were found in several subsets of neurons as well as astrocytes. Following CNS injury, we observed robust induction of RPTP zeta/beta mRNA in areas of axonal sprouting, and of both RPTP zeta/beta and phosphacan mRNAs in areas of glial scarring, implying that the encoded proteins and the cell adhesion molecules and extracellular matrix proteins to which they bind may contribute to recovery from injury and perhaps regulation of axonal regrowth in the nervous system.


Assuntos
Lesões Encefálicas/metabolismo , Encéfalo/metabolismo , Proteoglicanas de Sulfatos de Condroitina/biossíntese , Desenvolvimento Embrionário e Fetal , Regulação da Expressão Gênica no Desenvolvimento , Proteínas do Tecido Nervoso/biossíntese , Proteínas Tirosina Fosfatases/biossíntese , Receptores de Fator de Crescimento Neural/biossíntese , Células de Schwann/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Animais , Encéfalo/embriologia , Linhagem Celular , Células Cultivadas , Sequência Conservada , Primers do DNA , Glioma , Masculino , Dados de Sequência Molecular , RNA Mensageiro/biossíntese , Ratos , Ratos Endogâmicos F344 , Receptor do Fator Neutrófico Ciliar , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores
19.
J Occup Rehabil ; 6(1): 5-16, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24234807

RESUMO

Cost factors were examined in 157 patients with work- related spine injuries who were referred to a second opinion program between 1985 and 1991. The independent medical examination (IME) included a history, physical examination, and review of imaging and other studies. Data on demographic variables, litigation, work, injury history, physical examination, and imaging studies were recorded. A standard measure of psychological status (Low Back Pain Symptom Check List) was filled out. The instrument uses pain language as a clinical marker of psychological disturbance linked to a range of conflictual issues such as suppressed anger, burdensome feeling of inferiority, damaged self- esteem, role confusion, abnormal mentation, fear of responsibility or intimacy, gender issues, sexual concerns, disturbing arousal, and the like. Since it relies exclusively on pain language for diagnosis, it does not identify the specific nature of the psychological conflict. Data on treatment, final resolution, and cost were obtained from computerized files of the insurance company. The total cost incurred was $6,551,139. This averaged to $41,727 per case. More expensive cases were associated with a surgical intervention, psychological disturbance, litigation, motor weakness, and positive radiographs. These five variables accounted for 48% of the cost variance. Surgery accounted for 19.9% of the variance and contained the most expensive cases ($68,310 vs. $31,423). Psychological disturbance was detected in 27% of the sample and accounted for 10.5% of the cost variance. Litigation was present in 72% of the cases and accounted for 9.1% of the cost variance. Motor strength and radiographs taken together accounted for 8.4% of the variance. The usefulness of this information was explored from an actuarial and medical perspective.

20.
J Bone Joint Surg Am ; 77(12): 1814-8, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8550648

RESUMO

The results of postoperative epidural administration of saline solution (a placebo), morphine, methylprednisolone, and a combination of morphine and methylprednisolone for the reduction of pain after an operation for spinal stenosis or a herniated intervertebral disc were compared in a prospective, randomized blinded study. Epidural administration of morphine and methylprednisolone--either alone or in combination--significantly reduced the need for analgesia after an operation for spinal stenosis (p < 0.05) but not after an operation for a herniated intervertebral disc. Morphine and methylprednisolone did not have an addictive effect on the reduction of pain. Itching was significantly more common in the patients who had received morphine than in those who had received the placebo (p = 0.04). Although urinary retention was more frequent after the use of morphine than after the use of the placebo, the difference was not significant with the size of the sample that was analyzed (p = 0.25).


Assuntos
Analgésicos Opioides/administração & dosagem , Deslocamento do Disco Intervertebral/cirurgia , Metilprednisolona/administração & dosagem , Morfina/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Estenose Espinal/cirurgia , Adulto , Idoso , Analgesia Epidural , Analgesia Controlada pelo Paciente , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Método Simples-Cego
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