RESUMO
The American College of Surgeons (ACS), founded in 1913, is the one of the oldest surgical professional organizations in the United States. Originally founded to foster surgical professional excellence and collaboration among surgeons in North America, the ACS has now expanded to over 80,000 members worldwide with programs delivering a rich portfolio of professional services in the domains of surgical education, clinical surgery and global surgery, surgical quality and leadership, surgical research, member services. ACS international programs initially focused on international professional exchange and hosting of young surgeons from around the world in US based surgical centers to develop scholarly and clinical collaborations. Over the last 20 years, with the founding of the ACS-Operation Giving Back (OGB) Program, the ACS has broadened its international perspective to support surgical care in emerging nations and to develop collaborative programs with host institutions in emerging nations to support surgical care capacity growth through on site partnerships, and educational and policy initiatives. To that end, in recent years, OGB has developed global surgical programs in the COSECSA region of sub-Saharan Africa creating opportunities to participate in Global Surgical Training Hubs. After developing a pilot hub project in Hawassa, Ethiopia, OGB is now in the process of scaling up two additional sites. In this manuscript, we will describe ACS's rich history of activities promoting international surgical collaboration and scholarship and discuss the process of creating the global surgical training hub model in Hawassa.
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Cirurgia Geral , Cirurgiões , Humanos , Estados UnidosRESUMO
Neurofibromatosis type 1 (NF1) has long been considered a well-defined, recognizable monogenic disorder, with neurofibromas constituting a pathognomonic sign. This dogma has been challenged by recent descriptions of patients with enlarged nerves or paraspinal tumors, suggesting that neurogenic tumors and hypertrophic neuropathy may be a complication of Noonan syndrome with multiple lentigines (NSML) or RASopathy phenotype. We describe a 15-year-old boy, whose mother previously received clinical diagnosis of NF1 due to presence of bilateral cervical and lumbar spinal lesions resembling plexiform neurofibromas and features suggestive of NS. NF1 molecular analysis was negative in the mother. The boy presented with Noonan features, multiple lentigines and pectus excavatum. Next-generation sequencing analysis of all RASopathy genes identified p.Ser548Arg missense mutation in SOS1 in the boy, confirmed in his mother. Brain and spinal magnetic resonance imaging scans were negative in the boy. No heart involvement or deafness was observed in proband or mother. This is the first report of a SOS1 mutation associated with hypertrophic neuropathy resembling plexiform neurofibromas, a rare complication in Noonan phenotypes with mutations in RASopathy genes. Our results highlight the overlap between RASopathies, suggesting that NF1 diagnostic criteria need rethinking. Genetic analysis of RASopathy genes should be considered when diagnosis is uncertain.
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Mutação de Sentido Incorreto , Neurofibromatose 1/genética , Síndrome de Noonan/genética , Proteína SOS1/genética , Nervos Espinhais/metabolismo , Adolescente , Adulto , Saúde da Família , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mães , Neurofibromatose 1/patologia , Síndrome de Noonan/patologia , Fenótipo , Nervos Espinhais/patologiaRESUMO
We recently described a complex multisystem syndrome in which mild-moderate myopia segregated as an independent trait. A plethora of genes has been related to sporadic and familial myopia. More recently, in Chinese patients severe myopia (MYP25, OMIM:617238) has been linked to mutations in P4HA2 gene. Seven family members complaining of reduced distance vision especially at dusk underwent complete ophthalmological examination. Whole-exome sequencing was performed to identify the gene responsible for myopia in the pedigree. Moderate myopia was diagnosed in the family which was associated to the novel missense variant c.1147A > G p.(Lys383Glu) in the prolyl 4-hydroxylase,alpha-polypeptide 2 (P4HA2) gene, which catalyzes the formation of 4-hydroxyproline residues in the collagen strands. In vitro studies demonstrated P4HA2 mRNA and protein reduced expression level as well as decreased collagen hydroxylation and deposition in mutated fibroblast primary cultures compared to healthy cell lines. This study suggests that P4HA2 mutations may lead to myopic axial elongation of eyeball as a consequence of quantitative and structural alterations of collagen. This is the first confirmatory study which associates a novel dominant missense variant in P4HA2 with myopia in Caucasian patients. Further studies in larger cohorts are advisable to fully clarify genotype-phenotype correlations.
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Colágeno/genética , Hidroxilação/genética , Miopia/genética , Prolil Hidroxilases/genética , Adolescente , Adulto , Criança , China/epidemiologia , Colágeno/metabolismo , Exoma/genética , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Miopia/epidemiologia , Miopia/patologia , Linhagem , Fenótipo , Adulto JovemRESUMO
INTRODUCTION: In 2021, in Argentina there were 3,639 deaths by suicide, equivalent to one death every three hours. Evidence indicates that brief suicide preventive interventions in emergency services, such as the Safety Planning Intervention (SPI), effectively reduce future suicidal ideation and attempts in both adults and adolescents. OBJECTIVE: To evaluate the perception of self-efficacy, and the feasibility and usefulness of a training in SPI in early career mental health professionals. METHOD: Sixty-nine early career mental health professionals from Buenos Aires participated in a 3-hour SPI training. Through an online survey, measurements were taken in three times: before and after the training and 8-10 weeks after the training. RESULTS: All participants completed the pre- and post-training measures, and 43 of them completed the follow-up survey. Post-training measures showed an increase in self-efficacy, maintaining the effect at 8-10 weeks. The SPI was found useful and feasible to be implemented in clinical care. More than half of the participants reported having used the SPI during follow-up. CONCLUSION: Results suggest that training in SPI is associated with an increased perception of self-efficacy of early career mental health professionals; this is maintained after 2 months post-training. In addition, the intervention is perceived as feasible, acceptable and useful for professionals in training.
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Carbon doping is studied in MgB2 pellets during one-step synthesis by solid-state reaction, employing both undoped and carbon-doped boron with and without the addition of nano-SiC. The phase formation during the synthesis as a function of time was followed using powder X-ray diffraction and Rietveld refinement. The superconducting properties were characterized with a magnetometer to investigate doping-induced changes. Mg(B1-xCx)2 is obtained with nano-precipitates and different compositions depending on the synthesis temperature. It is found that the addition of nano-SiC prevents the phase formation at low temperature (700°C). Nevertheless, the best superconducting properties are obtained for the sample treated at 900°C using simultaneously C and SiC, with a critical current density of 105â Aâ cm-2 at 3â T and 20â K, named the 900-20-C-nanoSiC sample.
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Neurodegenerative diseases (NDs) and brain tumors are severe, disabling, and incurable disorders that represent a critical problem regarding human suffering and the economic burden on the healthcare system. Because of the lack of effective therapies to treat NDs and brain tumors, the challenge for physicians is to discover new drugs to improve their patients' quality of life. In addition to risk factors such as genetics and environmental influences, increased cellular oxidative stress has been reported as one of the potential common etiologies in both disorders. Given their antioxidant and anti-inflammatory potential, dietary polyphenols are considered to be one of the most bioactive natural agents in chronic disease prevention and treatment. Despite the protective activity of polyphenols, their inefficient delivery systems and poor bioavailability strongly limit their use in medicine and functional food. A potential solution lies in polymeric nanoparticle-based polyphenol delivery systems that are able to enhance their absorption across the gastrointestinal tract, improve their bioavailability, and transport them to target organs. In the present manuscript, we provide an overview of the primary polyphenols used for ND and brain tumor prevention and treatment by focusing on recent findings, the principal factors limiting their application in clinical practice, and a promising delivery strategy to improve their bioavailability.
Assuntos
Neoplasias Encefálicas/prevenção & controle , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/administração & dosagem , Doenças Neurodegenerativas/prevenção & controle , Compostos Fitoquímicos/administração & dosagem , Polifenóis/administração & dosagem , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/metabolismo , Neoplasias Encefálicas/metabolismo , Ensaios Clínicos como Assunto/métodos , Humanos , Nanopartículas/química , Nanopartículas/metabolismo , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Compostos Fitoquímicos/química , Compostos Fitoquímicos/metabolismo , Polifenóis/química , Polifenóis/metabolismoRESUMO
OBJECTIVES: To investigate a possible association between isolated white matter lesions suggestive of demyelinating disease in magnetic resonance imaging (MRI) and patent foramen ovale (PFO) evidence in migraine patients, with or without aura. MATERIALS: 31 migraine patients, 28 females and 3 males, with MRI evidence of white matter lesions suggestive of demyelinating disease according to the Barkhof Criteria. All patients underwent further diagnostics including lumbar puncture, autoimmunity panel and cardiological evaluation to detect the presence of PFO. The mean duration of follow-up was 3.46â¯years and MIPAV software was used to analyze MRI imaging. RESULTS: 14 of the 31 patients (45%) had PFO. A significant association was found between PFO and migraine with visual aura (pâ¯<â¯0.001). No difference in lesion number, volume or area between patients with and without PFO was found, but the distribution was mainly occipital (pâ¯<â¯0.001) in patients with PFO. The follow-up showed a stationary lesion load in all PFO patients; no infratentorial or spinal cord lesion and no enhancement or corpus callosum lesion was ever detected. At the end of follow-up four patients developed multiple sclerosis: younger age at first MRI and oligoclonal bands were associated risk factors. CONCLUSIONS: Migraine is often one of the main symptoms leading to MRI, and in many cases white matter lesions of unspecific significance are discovered, thus placing demyelinating diseases in the differential diagnosis. Our study underlines the potential pathogenetic role of PFO in generating white matter lesions in migraine patients (45%), particularly those with visual aura and occipital lesions. For this reason, we affirm that PFO represents a cardinal point in the differential diagnosis of suspected demyelinating disease.
Assuntos
Doenças Desmielinizantes/diagnóstico , Forame Oval Patente/diagnóstico , Enxaqueca com Aura/diagnóstico , Adulto , Encéfalo/diagnóstico por imagem , Doenças Desmielinizantes/complicações , Diagnóstico Diferencial , Feminino , Seguimentos , Forame Oval Patente/complicações , Coração/diagnóstico por imagem , Humanos , Masculino , Enxaqueca com Aura/complicações , Enxaqueca sem Aura/complicações , Enxaqueca sem Aura/diagnóstico , Bandas Oligoclonais/líquido cefalorraquidiano , Estudos Retrospectivos , Medula Espinal/diagnóstico por imagemRESUMO
Marrow stromal stem cells (MSCs) are stem-like cells that are currently being tested for their potential use in cell therapy for a number of human diseases. MSCs can differentiate into both mesenchymal and nonmesenchymal lineages. In fact, in addition to bone, cartilage and fat, it has been demonstrated that MSCs are capable of differentiating into neurons and astrocytes. RB and RB2/p130 genes are involved in the differentiation of several systems. For this reason, we evaluated the role of RB and RB2/p130 in the differentiation and apoptosis of MSCs under experimental conditions that allow for MSC differentiation toward the neuron-like phenotype. To this end, we ectopically expressed either RB or RB2/p130 and monitored proliferation, differentiation and apoptosis in rat primary MSC cultures induced to differentiate toward the neuron-like phenotype. Both RB and RB2/P130 decreased cell proliferation rate. In pRb-overexpressing cells, the arrest of cell growth was also observed in the presence of the HDAC-inhibitor TSA, suggesting that its antiproliferative activity does not rely upon the HDAC pathway, while the addition of TSA to pRb2/p130-overexpressing cells relieved growth inhibition. TUNEL reactions and studies on the expression of genes belonging to the Bcl-2 family showed that while RB protected differentiating MSCs from apoptosis, RB2/p130 induced an increase of apoptosis compared to controls. The effects of both RB and RB2/p130 on programmed cell death appeared to be HDAC- independent. Molecular analysis of neural differentiation markers and immunocytochemistry revealed that RB2/p130 contributes mainly to the induction of generic neural properties and RB triggers cholinergic differentiation. Moreover, the differentiation potentials of RB2/p130 and RB appear to rely, at least in part, on the activity of HDACs.
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Diferenciação Celular/fisiologia , Células-Tronco Mesenquimais/fisiologia , Neurônios/citologia , Proteínas/fisiologia , Proteína do Retinoblastoma/fisiologia , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Adenoviridae/genética , Animais , Apoptose/fisiologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Morte Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p27 , Proteínas de Ligação a DNA/genética , Fatores de Transcrição E2F , Inibidores Enzimáticos/farmacologia , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Vetores Genéticos/genética , Inibidores de Histona Desacetilases , Histona Desacetilases/fisiologia , Ácidos Hidroxâmicos/farmacologia , Imuno-Histoquímica , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Neurofilamentos/metabolismo , Neurônios/metabolismo , Proteínas/genética , Proteínas/metabolismo , Ratos , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Proteína p130 Retinoblastoma-Like , Fatores de Transcrição/genética , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismoRESUMO
Recent studies suggest a close relationship between cell metabolism and apoptosis. We have evaluated changes in lipid metabolism on permeabilized hepatocytes treated with truncated Bid (tBid) in the presence of caspase inhibitors and exogenous cytochrome c. The measurement of beta-oxidation flux by labeled palmitate demonstrates that tBid inhibits beta-oxidation, thereby resulting in the accumulation of palmitoyl-coenzyme A (CoA) and depletion of acetyl-carnitine and acylcarnitines, which is pathognomonic for inhibition of carnitine palmitoyltransferase-1 (CPT-1). We also show that tBid decreases CPT-1 activity by a mechanism independent of both malonyl-CoA, the key inhibitory molecule of CPT-1, and Bak and/or Bax, but dependent on cardiolipin decrease. Overexpression of Bcl-2, which is able to interact with CPT-1, counteracts the effects exerted by tBid on beta-oxidation. The unexpected role of tBid in the regulation of lipid beta-oxidation suggests a model in which tBid-induced metabolic decline leads to the accumulation of toxic lipid metabolites such as palmitoyl-CoA, which might become participants in the apoptotic pathway.
Assuntos
Carnitina O-Palmitoiltransferase/antagonistas & inibidores , Proteínas de Transporte/farmacologia , Ácidos Graxos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Cardiolipinas/metabolismo , Carnitina O-Palmitoiltransferase/metabolismo , Proteínas de Transporte/metabolismo , Inibidores de Caspase , Caspases/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Células Cultivadas , Citocromos c/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Malonil Coenzima A/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Proteínas de Membrana/genética , Mitocôndrias Hepáticas/genética , Oxirredução/efeitos dos fármacos , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2RESUMO
We studied the distribution and cellular localization of Na(+)-coupled neutral amino acid transporter 2, a member of the system A family of amino acid transporters, in the rat and human cerebral cortex using immunocytochemical methods. Na(+)-coupled neutral amino acid transporter 2-positive neurons were pyramidal and non-pyramidal, and Na(+)-coupled neutral amino acid transporter 2/GABA double-labeling studies revealed that Na(+)-coupled neutral amino acid transporter 2 was highly expressed by GABAergic neurons. Double-labeling studies with the synaptophysin indicated that rare axon terminals express Na(+)-coupled neutral amino acid transporter 2. Na(+)-coupled neutral amino acid transporter 2-immunoreactivity was also found in astrocytes, leptomeninges, ependymal cells and choroid plexus. Electron microscopy showed robust Na(+)-coupled neutral amino acid transporter 2-immunoreactivity in the somato-dendritic compartment of neurons and in glial processes, but, as in the case of double-labeling studies, failed to reveal Na(+)-coupled neutral amino acid transporter 2-immunoreactivity in terminals. To rule out the possibility that the absence of Na(+)-coupled neutral amino acid transporter 1- and Na(+)-coupled neutral amino acid transporter 2-positive terminals was due to insufficient antigen detection, we evaluated Na(+)-coupled neutral amino acid transporter 1/synaptophysin and Na(+)-coupled neutral amino acid transporter 2/synaptophysin coexpression using non-standard immunocytochemical procedures and found that Na(+)-coupled neutral amino acid transporter 1 and Na(+)-coupled neutral amino acid transporter 2+ terminals were rare in all conditions. These findings indicate that Na(+)-coupled neutral amino acid transporter 1 and Na(+)-coupled neutral amino acid transporter 2 are virtually absent in cortical terminals, and suggest that they do not contribute significantly to replenishing the Glu and GABA transmitter pools through the glutamate-glutamine cycle. The strong expression of Na(+)-coupled neutral amino acid transporter 2 in the somato-dendritic compartment and in non-neuronal elements that are integral parts of the blood-brain and brain-cerebrospinal fluid barrier suggests that Na(+)-coupled neutral amino acid transporter 2 plays a role in regulating the levels of Gln and other amino acids in the metabolic compartment of cortical neurons.
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Sistema A de Transporte de Aminoácidos/metabolismo , Córtex Cerebral/citologia , Neurônios/metabolismo , Animais , Western Blotting/métodos , Proteínas de Ligação ao Cálcio/metabolismo , Córtex Cerebral/metabolismo , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Imuno-Histoquímica/métodos , Masculino , Proteínas de Membrana/metabolismo , Microscopia Eletrônica de Transmissão/métodos , Pessoa de Meia-Idade , Proteínas Musculares/metabolismo , Neurônios/ultraestrutura , Fosfopiruvato Hidratase/metabolismo , Ratos , Ratos Sprague-Dawley , Ácido gama-Aminobutírico/metabolismoRESUMO
The crucial role of glutamate receptors of the N-methyl-D-aspartate (NMDA) type in many fundamental cortical functions has been firmly established, as has its involvement in several neuropsychiatric diseases, but until recently, very little was known of the anatomical localization of NMDA receptors in the cerebral cortex of mammals. The recent application of molecular biological techniques to the study of NMDA receptors has allowed the production of specific tools, the use of which has much increased our understanding of the localization of NMDA receptors in the cerebral cortex. In particular, immunocytochemical studies on the distribution of cortical NMDA receptors have: 1. Demonstrated the preferential localization of NMDA receptors in dendritic spines, in line with previous work; 2. Disclosed a thus far unknown fraction of presynaptic NMDA receptors on both excitatory and inhibitory axon terminals: and 3. Shown that cortical astrocytes express NMDA receptors. These studies indicate that the effects of cortical NMDA receptor activation are not caused exclusively by the opening of NMDA channels on neuronal postsynaptic membranes, as previously assumed, and that the activation of presynaptic and glial NMDA receptors can contribute significantly to these effects.
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Córtex Cerebral/química , Neuroglia/química , Neurônios/química , Receptores de N-Metil-D-Aspartato/análise , Adulto , Animais , Córtex Cerebral/citologia , Humanos , MamíferosRESUMO
Neuronal and glial high-affinity Na+/Cl(-)-dependent plasma membrane gamma-aminobutyric acid (GABA) transporters (GATs) contribute to regulating neuronal function. We investigated in the cerebral cortex and neighboring regions of adult rats the distribution and cellular localization of the GABA transporter GAT-2 by immunocytochemistry with affinity-purified polyclonal antibodies that react monospecifically with a protein of 82 kDa. Conventional and confocal laser-scanning light microscopic studies revealed intense GAT-2 immunoreactivity (ir) in the leptomeninges, choroid plexus, and ependyma. Weak GAT-2 immunoreactivity also was observed in the cortical parenchyma, where it was localized to puncta of different sizes scattered throughout the radial extension of the neocortex and to few cell bodies. In sections double-labeled with GAT-2 and glial fibrillary acidic protein (GFAP) antibodies, some GAT-2-positive profiles also were GFAP positive. Ultrastructural studies showed GAT-2 immunoreactivity mostly in patches of varying sizes scattered in the cytoplasm of neuronal and nonneuronal elements: GAT-2-positive neuronal elements included perikarya, dendrites, and axon terminals forming both symmetric and asymmetric synapses; nonneuronal elements expressing GAT-2 were cells forming the pia and arachnoid mater; astrocytic processes, including glia limitans and perivascular end feet; ependymal cells; and epithelial cells of the choroid plexuses. The widespread cellular expression of GAT-2 suggests that it may have several functional roles in the overall regulation of GABA levels in the brain.
Assuntos
Proteínas de Transporte/análise , Proteínas de Membrana Transportadoras , Neuroglia/química , Neurônios/química , Córtex Somatossensorial/química , Ácido gama-Aminobutírico/metabolismo , Animais , Anticorpos , Axônios/química , Axônios/metabolismo , Axônios/ultraestrutura , Transporte Biológico/fisiologia , Western Blotting , Proteínas de Transporte/imunologia , Proteínas de Transporte/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Dendritos/química , Dendritos/metabolismo , Dendritos/ultraestrutura , Células Epiteliais/química , Células Epiteliais/metabolismo , Proteínas da Membrana Plasmática de Transporte de GABA , Proteína Glial Fibrilar Ácida/análise , Proteína Glial Fibrilar Ácida/imunologia , Meninges/química , Meninges/citologia , Meninges/metabolismo , Microscopia Confocal , Microscopia Eletrônica , Inibição Neural/fisiologia , Neuroglia/metabolismo , Neuroglia/ultraestrutura , Neurônios/metabolismo , Neurônios/ultraestrutura , Ratos , Ratos Endogâmicos , Córtex Somatossensorial/citologia , Córtex Somatossensorial/metabolismo , Sinapses/química , Sinapses/metabolismoRESUMO
High-affinity gamma-aminobutyric (GABA) plasma membrane transporters (GATs) influence the action of GABA, the main inhibitory neurotransmitter in the human cerebral cortex. In this study, the cellular expression of GAT-1, the main cortical GABA transporter, was investigated in the human cerebral cortex by using immunocytochemistry with affinity-purified polyclonal antibodies directed to the C-terminus of rat GAT-1. In temporal and prefrontal association cortex (Brodmann's areas 21 and 46) and in cingulofrontal transition cortex (area 32), specific GAT-1 immunoreactivity (ir) was localized to numerous puncta and fibers in all cortical layers. GAT-1+ puncta were distributed homogeneously in all cortical layers, although they were slightly more numerous in layers II-IV, and appeared to have a preferential relationship to the somata and proximal dendrites of unlabeled pyramidal cells, even though, in many cases, they were also observed around nonpyramidal cells. Electron microscopic observations showed that GAT-1+ puncta were axon terminals that formed exclusively symmetric synapses. In addition, some distal astrocytic processes also contained immunoreaction product. Analysis of the patterns of GAT-1 labeling in temporal and prefrontal association areas (21 and 46), in cingulofrontal transition areas (32), and in somatic sensory and motor areas (1 and 4) of the monkey cortex revealed that its distribution varies according to the type of cortex examined and indicated that the distribution of GAT-1 is similar in anatomically corresponding areas of different species. The present study demonstrates that, in the human homotypical cortex, GAT-1 is expressed by both inhibitory axon terminals and astrocytic processes. This localization of GAT-1 is compatible with a major role for this transporter in GABA uptake at GABAergic synapses and suggests that GAT-1 may contribute to determining GABA levels in the extracellular space.
Assuntos
Proteínas de Transporte/biossíntese , Córtex Cerebral/metabolismo , Proteínas de Membrana/biossíntese , Proteínas de Membrana Transportadoras , Neuroglia/metabolismo , Neurônios/metabolismo , Transportadores de Ânions Orgânicos , Ácido gama-Aminobutírico/metabolismo , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Proteínas de Transporte/análise , Membrana Celular/metabolismo , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/citologia , Lobo Frontal/citologia , Lobo Frontal/metabolismo , Proteínas da Membrana Plasmática de Transporte de GABA , Humanos , Imuno-Histoquímica , Macaca mulatta , Proteínas de Membrana/análise , Fibras Nervosas/metabolismo , Fibras Nervosas/ultraestrutura , Neuroglia/citologia , Neurônios/citologia , Ratos , Especificidade da Espécie , Lobo Temporal/citologia , Lobo Temporal/metabolismoRESUMO
Imunocytochemical techniques were used to determine whether agonist-induced activation of mu-opioid receptors alters the number and distribution of mu-opioid receptor-positive cells in the rat cerebral cortex. In untreated rats, mu-opioid receptor immunoreactivity was localized to neuronal perikarya and dendrites and to neuropilar punctate structures. mu-Opioid receptor-positive neurons were mostly in layers II and III and exhibited a bipolar or bitufted morphology. In rats treated with the mu-opioid receptor agonist etorphine (0.1mg/kg intraperitoneally) and perfused after different survival periods, there was an enhancement of immunostaining for mu-opioid receptors observed at 15min, reaching a maximum at 60min, and which returned to normal at 480min. Etorphine-induced effects included an increase in the intensity of cellular and neuropil staining; statistical analysis showed that the number of mu-opioid receptor-positive cells in etorphine-treated groups was significantly higher than in controls or saline-treated rats. In animals that received both etorphine and the mu-opioid receptor antagonist naloxone, the pattern of mu-opioid receptors immunoreactivity was similar to that of untreated animals. This study shows that the number of mu-opioid receptor-positive cells is significantly increased following etorphine treatment and suggests that agonist treatment may be exploited to increased immunostaining of mu-opioid receptors and also of other G-protein coupled receptors.
Assuntos
Córtex Cerebral/metabolismo , Etorfina/farmacologia , Entorpecentes/farmacologia , Neurônios/metabolismo , Receptores Opioides mu/metabolismo , Animais , Córtex Cerebral/efeitos dos fármacos , Técnicas Imunológicas , Neurônios/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Valores de ReferênciaRESUMO
The cellular localization of the vesicular glutamate transporter 1, VGLUT1, was studied in the rat cerebral cortex with immunocytochemical techniques. VGLUT1 immunoreactivity (ir) was localized to punctate structures dispersed in the neuropil of all cortical layers as well as around the profile of somata and proximal dendritic segments of virtually all pyramidal neurons. Using a correlative light and electron microscopic method, we found that VGLUT1 ir is expressed in axon terminals forming synapses exclusively with dendritic shafts and spines. Perisomatic VGLUT1-positive terminals never formed synapses with the pyramidal cell bodies to which they were in apposition, but formed asymmetric synapses with adjacent neuropilar dendritic elements. The high probability of a close spatial relationship between glutamatergic and GABAergic terminals in perisomatic regions suggests that spilled-out glutamate may act on inhibitory axon terminals innervating the soma of cortical pyramidal neurons.
Assuntos
Proteínas de Transporte/metabolismo , Glutamina/metabolismo , Proteínas de Membrana Transportadoras , Terminações Pré-Sinápticas/metabolismo , Células Piramidais/metabolismo , Proteínas de Transporte Vesicular , Animais , Proteínas de Transporte/ultraestrutura , Feminino , Immunoblotting , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Neocórtex/metabolismo , Neocórtex/ultraestrutura , Neurópilo/metabolismo , Neurópilo/ultraestrutura , Terminações Pré-Sinápticas/ultraestrutura , Células Piramidais/ultraestrutura , Ratos , Ratos Sprague-Dawley , Proteína Vesicular 1 de Transporte de GlutamatoRESUMO
We report on two clinically, neurologically normal relatives of a boy affected by adrenoleukodystrophy (ALD); they were found repeatedly to have the biochemical defect of an ALD hemizygote. The assay consisted in the determination of very-long-chain fatty acids in lyophilized and reconstituted plasma. While no evidence of neurologic disease (leukodystrophy or myeloneuropathy) was present in these hemizygotes, adrenocortical insufficiency provoking compensatory high ACTH release was found in both. These findings should be taken into consideration when counseling families in which cases with clinically expressed ALD are represented in several generations.
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Adrenoleucodistrofia/genética , Esclerose Cerebral Difusa de Schilder/genética , Adrenoleucodistrofia/sangue , Adrenoleucodistrofia/diagnóstico , Adrenoleucodistrofia/fisiopatologia , Adrenoleucodistrofia/terapia , Dietoterapia , Ácidos Graxos/sangue , Genótipo , Humanos , Microcorpos/fisiopatologia , Linhagem , FenótipoRESUMO
We used electron microscopic immunocytochemistry with antibodies against NR1 and NR2A and B subunits to study the distribution of N-methyl-D-aspartate (NMDA) receptors in presynaptic axon terminals in the rat cerebral cortex. In all sections examined, NR1 and NR2A/B immunoreactivities were observed in axon terminals: NR1- and NR2A/B-positive axon terminals made both symmetrical and asymmetrical synapses on unlabelled dendritic profiles. Combined pre- and postembedding studies showed that all NR1 and NR2A/B-positive axon terminals making symmetrical synapses were gamma-aminobutyric acid (GABA)-positive. These observations show that both auto- and hetero- NMDA receptors do exist in the cerebral cortex, and indicate that part of the effects of NMDA receptor activation might be determined by modulating glutamate and GABA release.
Assuntos
Axônios/ultraestrutura , Córtex Cerebral/ultraestrutura , Terminações Pré-Sinápticas/ultraestrutura , Receptores de N-Metil-D-Aspartato/ultraestrutura , Animais , Imuno-Histoquímica , Microscopia Eletrônica , Ratos , Ratos Sprague-DawleyRESUMO
The immunosuppressor effects of the widely distributed neuropeptide somatostatin were examined on purified peripheral blood human monocytes. Somatostatin, at concentrations thought to be physiologic (10(-10)-10(-7) M), regulated monocyte/macrophage responses to (LPS) stimulation, as reflected by interleukin production. In particular, somatostatin had direct inhibitory effects on TNF-alpha, IL-1 beta, and IL-6 secretion by LPS-activated monocytes, while the decrease on IL-8 synthesis was modulated mainly by the action of somatostatin on TNF-alpha and IL-1 beta. In fact, the addition of these two inflammatory cytokines to the monocyte culture medium was able to induce IL-8 expression, as demonstrated by mRNA analysis, also in presence of the neuropeptide. Although somatostatin affected IL-8 production in an indirect way, it suppressed directly the chemotactic response of neutrophils to IL-8. Finally, somatostatin downregulation of monocyte activation was confirmed by the decrease of HLA-DR expression on cell plasma membranes (52% versus 33%). Our results confirm that somatostatin exerts preferential effects on the suppression of immunoreactions by modulating cytokine production and activity.
Assuntos
Citocinas/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Somatostatina/farmacologia , Células Cultivadas , Antígenos HLA-DR/biossíntese , Humanos , Terapia de Imunossupressão , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Interleucina-8/biossíntese , Leucócitos Mononucleares/imunologia , Lipopolissacarídeos/farmacologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The cellular localization of acetylcholinesterase (AChE) was investigated at the electron microscope (E.M.) in a neuroblastoma and neuroblastoma x glioma hybrid line, which differ for their ability to establish synaptic contacts. Only cells of the latter line show association of AChE to the plasmamembrane, while in the former the activity is mainly intracellular. Sucrose sedimentation analysis of AChE molecular forms has shown no significant differences in the distribution of the two forms, G2 and G4, between the two cell lines. On the contrary a marked difference is observed in the ability of the cell to release the enzyme in the culture medium. In fact the cells lacking AChE on their surface release in the medium a much higher proportion of their enzyme, than the cells showing AChE association to their plamamembrane. The possible role of two alternative fates for AChE, secretion or membrane insertion, in determining the observed differences of enzyme localization is discussed.
Assuntos
Acetilcolinesterase/metabolismo , Células Tumorais Cultivadas/enzimologia , Linhagem Celular , Citosol/metabolismo , Glioma , Histocitoquímica , Proteínas de Membrana/metabolismo , Microscopia Eletrônica , Conformação Molecular , Neuroblastoma , Células Tumorais Cultivadas/ultraestruturaRESUMO
Phosphorus nuclear magnetic resonance spectroscopy is a non-invasive method used to study muscle bioenergetics in vivo. A new case of Mc Ardle's disease (myophosphorylase deficiency) is reported here. In a context of metabolic myopathy this method can provide a diagnosis of glycogenosis. The spectra obtained at exercise and during recovery determine the degree of enzyme deficiency with satisfactory precision.