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1.
Epidemiol Infect ; 143(1): 1-12, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25023603

RESUMO

General Practitioner consultation rates for influenza-like illness (ILI) are monitored through several geographically distinct schemes in the UK, providing early warning to government and health services of community circulation and intensity of activity each winter. Following on from the 2009 pandemic, there has been a harmonization initiative to allow comparison across the distinct existing surveillance schemes each season. The moving epidemic method (MEM), proposed by the European Centre for Disease Prevention and Control for standardizing reporting of ILI rates, was piloted in 2011/12 and 2012/13 along with the previously proposed UK method of empirical percentiles. The MEM resulted in thresholds that were lower than traditional thresholds but more appropriate as indicators of the start of influenza virus circulation. The intensity of the influenza season assessed with the MEM was similar to that reported through the percentile approach. The MEM pre-epidemic threshold has now been adopted for reporting by each country of the UK. Further work will continue to assess intensity of activity and apply standardized methods to other influenza-related data sources.


Assuntos
Notificação de Doenças/métodos , Monitoramento Epidemiológico , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Atenção Primária à Saúde/métodos , Humanos , Reino Unido/epidemiologia
2.
Child Abuse Negl ; 37(11): 917-25, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23978575

RESUMO

Research has shown that adverse childhood experiences (ACEs) increase the risk of poor health-related outcomes in later life. Less is known about the consequences of ACEs in early adulthood or among diverse samples. Therefore, we investigated the impacts of differential exposure to ACEs on an urban, minority sample of young adults. Health, mental health, and substance use outcomes were examined alone and in aggregate. Potential moderating effects of sex were also explored. Data were derived from the Chicago Longitudinal Study, a panel investigation of individuals who were born in 1979 or 1980. Main-effect analyses were conducted with multivariate logistic and OLS regression. Sex differences were explored with stratified analysis, followed by tests of interaction effects with the full sample. Results confirmed that there was a robust association between ACEs and poor outcomes in early adulthood. Greater levels of adversity were associated with poorer self-rated health and life satisfaction, as well as more frequent depressive symptoms, anxiety, tobacco use, alcohol use, and marijuana use. Cumulative adversity also was associated with cumulative effects across domains. For instance, compared to individuals without an ACE, individuals exposed to multiple ACEs were more likely to have three or more poor outcomes (OR range=2.75-10.15) and four or more poor outcomes (OR range=3.93-15.18). No significant differences between males and females were detected. Given that the consequences of ACEs in early adulthood may lead to later morbidity and mortality, increased investment in programs and policies that prevent ACEs and ameliorate their impacts is warranted.


Assuntos
Sobreviventes Adultos de Maus-Tratos Infantis/psicologia , Nível de Saúde , Transtornos Mentais/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , População Urbana , Adulto , Negro ou Afro-Americano , Chicago/epidemiologia , Estudos de Coortes , Intervalos de Confiança , Feminino , Inquéritos Epidemiológicos , Hispânico ou Latino , Humanos , Masculino , Transtornos Mentais/etnologia , Análise Multivariada , Razão de Chances , Áreas de Pobreza , Fatores Sexuais , Transtornos Relacionados ao Uso de Substâncias/etnologia , Adulto Jovem
4.
Curr Med Chem ; 17(34): 4166-90, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20939817

RESUMO

Excessive stimulation of NMDA receptors is involved in various CNS pathologies such as Parkinson's disease, acute and chronic pain and cerebral ischaemia. The use of NMDA antagonists as therapeutic agents has been restricted as a result of unwanted side effects including hallucinations and loss of co-ordination. NR2B subtype selective antagonists have previously shown a therapeutic effect without causing the side effects of broad spectrum NMDA antagonists. Considerable research has since been devoted to the development of orally bioavailable, selective NR2B antagonists and their applications in various neurological diseases. The improved therapeutic index of these compounds is expected to be the result of the subtype selectivity and cellular location of the NR2B receptors within the CNS. This review describes recent advances in the development of NR2B antagonists as well as their therapeutic applications.


Assuntos
Benzamidinas/síntese química , Benzamidinas/uso terapêutico , Antagonistas de Aminoácidos Excitatórios , Piperidinas/síntese química , Piperidinas/uso terapêutico , Receptores de N-Metil-D-Aspartato , Animais , Isquemia Encefálica/tratamento farmacológico , Química Farmacêutica , Antagonistas de Aminoácidos Excitatórios/síntese química , Antagonistas de Aminoácidos Excitatórios/farmacologia , Humanos , Camundongos , Dor/tratamento farmacológico , Doença de Parkinson/tratamento farmacológico , Ratos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/fisiologia , Relação Estrutura-Atividade
5.
Sci Justice ; 50(3): 150-5, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20709276

RESUMO

Titanium dioxide based powders are regularly used in the development of latent fingerprints on dark surfaces. For analysis of prints on adhesive tapes, the titanium dioxide can be suspended in a surfactant and used in the form of a powder suspension. Commercially available products, whilst having nominally similar composition, show varying levels of effectiveness of print development, with some powders adhering to the background as well as the print. X-ray fluorescence (XRF), analytical transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and laser particle sizing of the fingerprint powders show TiO(2) particles with a surrounding coating, tens of nanometres thick, consisting of Al and Si rich material, with traces of sodium and sulphur. Such aluminosilicates are commonly used as anti-caking agents and to aid adhesion or functionality of some fingerprint powders; however, the morphology, thickness, coverage and composition of the aluminosilicates are the primary differences between the white powder formulations and could be related to variation in the efficacy of print development.


Assuntos
Adesivos , Dermatoglifia , Nanotecnologia , Corantes , Humanos , Microscopia Eletrônica de Transmissão , Pós , Espectrometria por Raios X , Titânio
6.
Res Vet Sci ; 82(3): 409-15, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17092526

RESUMO

This study examines how systemic biomarkers of endothelial function and nitric oxide metabolism are affected by exercise in dogs. Furthermore, breed variation and white-coat effect have been tested by sampling three different dog breeds both in their home and in a clinical setting. Short-term exercise increased plasma nitrate and nitrite (NOx) and von Willebrand factor (vWf). There was significant difference between Pointers and the small dog breeds Cairn Terriers and Cavalier King Charles Spaniels in the general plasma levels of vWf and asymmetric dimethylarginine (ADMA). NOx and vWf were significantly higher when the sample was taken in the laboratory cf. at home, whereas ADMA and L-arginine were significantly lower. In conclusion, both short-term exercise and white-coat effect influence several plasma markers of endothelial function depending also on the breed and gender of the dogs. These findings should be considered in future studies concerning endothelial function in dogs.


Assuntos
Cães/classificação , Cães/fisiologia , Endotélio/fisiologia , Condicionamento Físico Animal/fisiologia , Caracteres Sexuais , Alaska , Animais , Arginina/análogos & derivados , Arginina/sangue , Biomarcadores , Cor , Cães/genética , Inibidores Enzimáticos/sangue , Feminino , Regulação da Expressão Gênica , Cabelo , Masculino , Óxido Nítrico/sangue , Fator de von Willebrand/metabolismo
7.
Exp Dermatol ; 12(2): 126-36, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12702140

RESUMO

The capacity of adult hair follicle dermal cells to participate in new follicle induction and regeneration, and to elicit responses from diverse epithelial partners, demonstrates a level of developmental promiscuity and influence far exceeding that of interfollicular fibroblasts. We have recently suggested that adult follicle dermal cells have extensive stem or progenitor cell activities, including an important role in skin dermal wound healing. Given that up to now tissue engineered skin equivalents have several deficiencies, including the absence of hair follicles, we investigated the capacity of follicle dermal cells to be incorporated into skin wounds; to form hair follicles in wound environments; and to create a hair follicle-derived skin equivalent. In our study, we implanted rat follicle dermal cells labelled with a vital dye into ear and body skin wounds. We found that they were incorporated into the new dermis in a manner similar to skin fibroblasts, but that lower follicle dermal sheath also assimilated into hair follicles. Using different combinations of follicle dermal cells and outer root sheath epithelial cells in punch biopsy wounds, we showed that new hair follicles were formed only with the inclusion of intact dermal papillae. Finally by combining follicle dermal sheath and outer root sheath cells in organotypic chambers, we created a skin equivalent with characteristic dermal and epidermal architecture and a normal basement membrane - the first skin to be produced entirely from hair follicle cells. These data support the hypothesis that follicle dermal cells may be important in wound healing and demonstrate their potential usefulness in human skin equivalents and skin substitutes. While we have made progress towards producing skin equivalents that contain follicles, we suggest that the failure of cultured dermal papilla cells to induce follicle formation in wounds illustrates the complex role the follicle dermis may play in skin. We believe that it demonstrates a genuine dichotomy of activity for follicle cells within skin.


Assuntos
Folículo Piloso/citologia , Folículo Piloso/fisiologia , Cicatrização/fisiologia , Animais , Separação Celular , Sobrevivência Celular , Transplante de Células , Células Cultivadas , Derme/citologia , Derme/fisiologia , Feminino , Folículo Piloso/crescimento & desenvolvimento , Masculino , Ratos , Ratos Endogâmicos , Regeneração/fisiologia
8.
Lancet ; 358(9291): 1445-8, 2001 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-11705511

RESUMO

The dermal sheath that surrounds the outside of the hair follicle contains progenitor cells that maintain and regenerate the dermal papilla, a key component for hair growth. Our contention is that dermal sheath cells have other roles. We believe that they can become wound healing fibroblasts and perform an important function in the repair of skin dermis after injury. The dermal sheath has close developmental and anatomical parallels with follicle outer root sheath, the epithelial component that contains the stem cells responsible for replacing skin epidermis. Dermal sheath cells also have a myofibroblast or wound healing phenotype, and in animals with high follicle densities differences in wound healing are observed in conjunction with changes in the hair growth cycle. Similarly, in human beings there are apparent differences in wound healing responses between hairy and non-hairy body sites. Moreover, clinical and experimental data suggest that the involvement of follicle-derived dermal cells results in qualitatively improved dermal repair. Therefore, in a therapeutic context, hair follicle dermal cells provide an accessible option for the creation of dermal or full skin equivalents that could both improve wound healing and reduce scarring. Indeed, given the inductive properties of adult hair follicle dermal cells, it is reasonable to envisage a tissue engineering approach for the production of a skin equivalent that will grow hair follicles when grafted.


Assuntos
Folículo Piloso/fisiologia , Cicatrização , Animais , Folículo Piloso/anatomia & histologia , Humanos
9.
J Invest Dermatol ; 117(3): 596-604, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11564165

RESUMO

Successful hair follicle organ culture has been established for some time, but hair growth in vitro is limited and generally terminates prematurely in comparison with in vivo. The reasons why growth stops in culture are as yet unknown. In this investigation, adult rat vibrissa follicles for which growth in culture is limited to about 10 d, were maintained in vitro for a minimum of 20 d after the hair shaft stopped growing. The pattern of fiber growth and long-term follicle pathology reflected the initial hair cycle stage at the time of isolation. Furthermore, there was evidence that a group of follicles put into culture when in late anagen were attempting to cycle in vitro. Microscopy showed that, in spite of widespread pathologic changes to the follicle epithelium, dermal cells in the follicle showed remarkable resilience. Their viability was confirmed when primary cell cultures were established from isolated dermal tissue. These cells labeled positively for alpha-smooth muscle actin, an established marker of hair follicle dermal cell phenotype in vitro. Moreover, isolated dermal tissue induced hair growth when implanted into inactivated hair follicles in vivo. These data confirm that the cessation in hair growth is not due to a loss of the inductive capacity in the dermal component. Long-term organ culture may provide opportunities to investigate factors that are expressed or lost during hair growth cessation. In addition it may be possible to develop this method further to obtain a reliable and predictable model of hair follicle cycling in vitro.


Assuntos
Folículo Piloso/citologia , Folículo Piloso/fisiologia , Cabelo/citologia , Cabelo/crescimento & desenvolvimento , Animais , Diferenciação Celular , Divisão Celular , Técnicas de Cultura de Órgãos , Ratos
10.
Exp Dermatol ; 10(4): 229-37, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11493311

RESUMO

A series of experimental bioassays has shown that the dermal papilla of the adult rodent vibrissa hair follicle retains unique inductive properties. In view of the many phenotypic and functional differences between specific hair follicle types, and the growing interest in hair follicle biology and disease, it remains important to establish that the human hair follicle dermal papilla has equivalent capabilities. In this study we tested the ability of human hair follicle papillae to induce hair growth when implanted into transected, athymic mouse vibrissa follicles. The implanted papillae that interacted with mouse follicle epithelium created new fibre-producing follicle end bulbs. The origin of the papillae in the recombinant structures was confirmed using laser capture microdissection and human specific gender determination by PCR. The demonstration that intact adult human dermal papillae can induce hair growth has implications for molecular analysis of basic hair growth mechanisms, particularly since the study involved common epithelial-mesenchymal signalling and recognition properties across species. It also improves the prospects for a cell-based clinical approach to hair follicle disorders.


Assuntos
Folículo Piloso/transplante , Cabelo/crescimento & desenvolvimento , Transplante de Pele , Transplante Heterólogo , Vibrissas/fisiologia , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos Nus
11.
Neuroscience ; 105(3): 761-71, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11516839

RESUMO

Neurons are one of the most polarized cells and often the nerve terminals may be located long distances from the cell body, thus signal transduction in neurons unlike other cells may need to be conducted over large distances. The mitogen-activated protein/extracellular signal-regulated kinases (MAP kinases or ERKs) regulate a diverse array of functions and in neurons, the ERK signalling pathways appear to have an important role in activity-dependent regulation of neuronal function. Using the ligated rat sciatic nerve as an experimental model we previously showed that the ERK1/2, MAP/ERK kinase (MEK1/2) and the p110 catalytic subunit of PI3-kinase are transported in the rat sciatic nerve. We have extended these findings to determine if these proteins are transported in the active state using antibodies that specifically detect the active form of ERK1/2, MEK1/2 and AKT which is activated downstream of PI3-kinase. We show significant accumulation of active ERK1 on the proximal and distal sides of a nerve ligation after 16 h. Active ERK2 also appeared to be accumulating at the ligature, however this did not reach statistical significance. In contrast there was not any significant accumulation of active MEK1/2 or active AKT. A component of both active ERK1 and active ERK2 is present in between the two ligations suggesting they are also present in the surrounding Schwann cells and are activated in response to nerve injury. Taken together our results suggest that a component of the accumulation of active ERK1 on the distal and proximal side of the nerve ligations results from transport in the anterograde and retrograde direction in the rat sciatic nerve.


Assuntos
Transporte Axonal/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Condução Nervosa/fisiologia , Transporte Proteico/fisiologia , Nervo Isquiático/metabolismo , Transdução de Sinais/fisiologia , Animais , Anticorpos/farmacologia , Imuno-Histoquímica , Ligadura , MAP Quinase Quinase 1 , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Compressão Nervosa , Fator de Crescimento Neural/antagonistas & inibidores , Fator de Crescimento Neural/imunologia , Fator de Crescimento Neural/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Ratos Wistar , Nervo Isquiático/citologia , Nervo Isquiático/cirurgia
12.
J Neurosci Res ; 64(6): 575-81, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11398180

RESUMO

Rapsyn is a key molecule involved in the formation of postsynaptic specializations at the neuromuscular junction, in its absence there are both pre- and post-synaptic deficits including failure to cluster acetylcholine receptors. Recently we have documented increases in both nerve-muscle branching and numbers of motoneurons, suggesting alterations in skeletal muscle derived trophic support for motoneurons. The aim of the present study was to evaluate the contribution of target derived trophic factors to increases in motoneuron branching and number, in rapsyn deficient mice that had their postsynaptic specializations disrupted. We have used reverse transcription-polymerase chain reaction and Western blot to document the expression of known trophic factors and their receptors in muscle, during the period of synapse formation in rapsyn deficient mouse embryos. We found that the mRNA levels for ciliary neurotrophic factor (CNTF) was decreased in the rapsyn deficient muscles compared with litter mate controls although those for NGF, BDNF, NT-3 and TGF-beta2 did not differ. We found that both the mRNA and the protein expression for suppressor of cytokine signaling 3 (SOCS3) decreased although janus kinase 2 (JAK2) did not change in the rapsyn deficient muscles compared with litter mate controls. These results suggest that failure to form postsynaptic specializations in rapsyn deficient mice has altered the CNTF cytokine signaling pathway within skeletal muscle, the target for motoneurons. This alteration may in part, account for the increased muscle nerve branching and motoneuron survival seen in rapsyn deficient mice.


Assuntos
Fator Neurotrófico Ciliar/fisiologia , Proteínas Musculares/genética , Proteínas Proto-Oncogênicas , Proteínas Repressoras , Transdução de Sinais/fisiologia , Fatores de Transcrição , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Primers do DNA , Diafragma/inervação , Diafragma/fisiologia , Expressão Gênica/fisiologia , Janus Quinase 2 , Camundongos , Camundongos Knockout , Neurônios Motores/fisiologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Fator de Crescimento Neural/genética , Neurotrofina 3/genética , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/isolamento & purificação , Proteínas/genética , Proteínas/isolamento & purificação , RNA Mensageiro/análise , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina
13.
Am J Vet Res ; 62(6): 912-20, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11400850

RESUMO

OBJECTIVE: To determine nitrogen balance in clinically normal dogs receiving parenteral nutrition solutions. ANIMALS: 8 clinically normal female Beagles. PROCEDURE: Dogs were randomly assigned to receive 4 treatments in random order. Treatment A consisted of IV administration of nonlactated Ringer's solution. Treatments B, C, and D consisted of IV administration of isocaloric parenteral solutions containing 0, 1.36, and 2.04 g of amino acids/kg of body weight/d, respectively, for 7 consecutive days. Urine and feces were collected on days 5, 6, and 7 of each treatment period, and Kjeldahl analysis was used to determine nitrogen balance. RESULTS: Mean nitrogen balance was negative with treatments A and B but was not significantly different from 0 with treatments C and D. Dogs had the lowest nitrogen balance values and lost the most weight while receiving treatment A. Dogs were able to conserve protein and had higher nitrogen balance values when receiving treatment B, compared with treatment A. Dogs lost the least amount of weight while receiving treatment D. Regression analysis indicated that an IV amino acid intake of 2.32 g/kg/d (95% confidence interval, 2.00 to 2.81 g/kg/d), as supplied by the commercial product used in this study, would result in zero nitrogen balance in clinically normal dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that IV amino acid requirement of clinically normal dogs is approximately 2.3 g/kg/d.


Assuntos
Aminoácidos/metabolismo , Cães/metabolismo , Nitrogênio/metabolismo , Nutrição Parenteral/veterinária , Animais , Peso Corporal , Cães/sangue , Cães/fisiologia , Fezes/química , Feminino , Nitrogênio/análise , Nitrogênio/urina , Distribuição Aleatória , Análise de Regressão , Urina/química
14.
JAMA ; 285(18): 2339-46, 2001 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-11343481

RESUMO

CONTEXT: Most studies of the long-term effects of early childhood educational interventions are of demonstration programs rather than large-scale public programs. Previous studies of one of the oldest federally funded preschool programs have reported positive effects on school performance, but effects on educational attainment and crime are unknown. OBJECTIVE: To determine the long-term effectiveness of a federal center-based preschool and school-based intervention program for urban low-income children. DESIGN, SETTING, AND PARTICIPANTS: Fifteen-year follow-up of a nonrandomized, matched-group cohort of 1539 low-income, mostly black children born in 1980 and enrolled in alternative early childhood programs in 25 sites in Chicago, Ill. INTERVENTIONS: The Chicago Child-Parent Center (CPC) Program (n = 989 children) provides comprehensive education, family, and health services and includes half-day preschool at ages 3 to 4 years, half- or full-day kindergarten, and school-age services in linked elementary schools at ages 6 to 9 years. The comparison group (n = 550) consisted of children who participated in alternative early childhood programs (full-day kindergarten): 374 in the preschool comparison group from 5 randomly selected schools plus 2 others that provided full-day kindergarten and additional instructional resources and 176 who attended full-day kindergartens in 6 CPCs without preschool participation. MAIN OUTCOME MEASURES: Rates of high school completion and school dropout by age 20 years, juvenile arrests for violent and nonviolent offenses, and grade retention and special education placement by age 18 years. RESULTS: Relative to the preschool comparison group and adjusted for several covariates, children who participated in the preschool intervention for 1 or 2 years had a higher rate of high school completion (49.7 % vs 38.5%; P =.01); more years of completed education (10.6 vs 10.2; P =.03); and lower rates of juvenile arrest (16.9% vs 25.1%; P =.003), violent arrests (9.0% vs 15.3%; P =.002), and school dropout (46.7% vs 55.0%; P =.047). Both preschool and school-age participation were significantly associated with lower rates of grade retention and special education services. The effects of preschool participation on educational attainment were greater for boys than girls, especially in reducing school dropout rates (P =.03). Relative to less extensive participation, children with extended program participation from preschool through second or third grade also experienced lower rates of grade retention (21.9% vs 32.3%; P =.001) and special education (13.5% vs 20.7%; P =.004). CONCLUSIONS: Participation in an established early childhood intervention for low-income children was associated with better educational and social outcomes up to age 20 years. These findings are among the strongest evidence that established programs administered through public schools can promote children's long-term success.


Assuntos
Crime/estatística & dados numéricos , Intervenção Educacional Precoce , Escolaridade , Adolescente , Chicago/epidemiologia , Criança , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Pobreza
15.
Neuroreport ; 12(4): 725-8, 2001 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-11277572

RESUMO

We have examined the distribution of the neuronal calcium-binding protein, neuronal calcium sensor 1 (NCS-1) in the developing and adult rat retina using subcellular fractionation of the rat retina and immunohistochemistry. NCS-1 immunoreactivity was situated primarily in the ganglion cells, a class of amacrine cells, and in the inner plexiform layer (IPL). During development, NCS-1 protein expression closely followed that of the synaptic vesicle protein, synaptophysin, increasing dramatically in the IPL at postnatal day 3, the time when conventional synapses are formed in the retina. These findings suggest that NCS-1 plays a role in synaptogenesis in the retina and in synaptic transmission at conventional synapses but not ribbon synapses in the adult rat retina.


Assuntos
Proteínas de Ligação ao Cálcio/análise , Neuropeptídeos/análise , Retina/química , Retina/embriologia , Células Ganglionares da Retina/química , Animais , Fracionamento Celular , Feminino , Feto/química , Imunofluorescência , Proteínas do Tecido Nervoso/análise , Proteínas Sensoras de Cálcio Neuronal , Gravidez , Ratos , Ratos Wistar , Retina/citologia , Sinapses/química , Sinapses/fisiologia
16.
Neuroreport ; 12(2): 281-4, 2001 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-11209935

RESUMO

Early endosomal antigen 1 (EEA1) is known to be a marker of early endosomes and in cultured hippocampal neurons it preferentially localizes to the dendritic but not the axonal compartment. We show in cultured dorsal root ganglia and superior cervical ganglia neurons that EEA1 localizes to the cell bodies and the neurites of both sensory and sympathetic neurons. We then show in vivo using a ligated rat sciatic nerve that EEA1 significantly accumulates on the proximal side and not on the distal side of the ligation. This suggests that EEA1 is transported in the anterograde direction in axons either as part of the homeostatic process or to the nerve ligation site in response to nerve injury.


Assuntos
Transporte Axonal/fisiologia , Proteínas de Membrana/metabolismo , Neurônios Aferentes/metabolismo , Nervo Isquiático/citologia , Nervo Isquiático/metabolismo , Animais , Animais Recém-Nascidos , Axônios/química , Axônios/metabolismo , Endossomos/metabolismo , Imunofluorescência , Gânglios Espinais/citologia , Homeostase/fisiologia , Ligadura , Masculino , Proteínas de Membrana/análise , Camundongos , Camundongos Endogâmicos BALB C , Neurônios Aferentes/química , Neurônios Aferentes/ultraestrutura , Ratos , Ratos Wistar , Nervo Isquiático/lesões , Gânglio Cervical Superior/citologia , Proteínas de Transporte Vesicular
17.
Cytometry ; 43(3): 182-8, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11170104

RESUMO

BACKGROUND: Neurons require contact with their target tissue in order to survive and make correct connections. The retrograde axonal transport of neurotrophins occurs after receptor-mediated endocytosis into vesicles at the nerve terminal. However, the mechanism by which the neurotrophin signal is propagated from axon terminal to cell body remains unclear. METHODS: Retrograde axonal transport was examined using the transport of I(125)-labeled neurotrophins from the eye to sympathetic and sensory ganglia. The phenomena was further studied by adding rhodamine-labeled nerve growth factor (NGF) to cultures of dissociated sympathetic ganglia and the movement of organelles followed with the aid of video microscopy. RESULTS: I(125)-labeled neurotrophins were transported from the eye to the sympathetic and sensory ganglia. A 100-fold excess of unlabeled neurotrophin, administered up to 4 h after the labeled material, completely prevented accumulation of labeled neurotrophin in the ganglia. The effect was specific for the labeled neurotrophin as administration of a high concentration of a different neurotrophin failed to inhibit the transport. In dissociated cultures, we found rapid binding of label, to surface membrane receptors, followed by an accumulation of labeled vesicles in the growth cone. Incubation of these cultures with unlabeled NGF led to a rapid loss of label in the growth cones. CONCLUSIONS: These results suggest that there is a pool of internalized neurotrophin, in vesicles in the nerve terminal, which is in rapid equilibrium with the external environment. It is from this pool that a small fraction of the neurotrophin-containing vesicles is targeted for retrograde transport. Potential models for this system are presented.


Assuntos
Terminações Nervosas/fisiologia , Fator de Crescimento Neural/metabolismo , Neurônios/fisiologia , Organelas/fisiologia , Gânglio Cervical Superior/fisiologia , Gânglio Trigeminal/fisiologia , Animais , Transporte Axonal , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Células Cultivadas , Olho , Corantes Fluorescentes , Radioisótopos do Iodo , Masculino , Camundongos , Camundongos Endogâmicos CBA , Microscopia de Vídeo , Modelos Neurológicos , Fatores de Crescimento Neural/metabolismo , Neurônios/citologia , Neurotrofina 3/metabolismo , Receptores de Fator de Crescimento Neural/fisiologia , Rodaminas
19.
J Neurosci Res ; 62(2): 216-24, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11020214

RESUMO

It was recently demonstrated that the yeast homologue of phosphatidylinositol 4-kinasebeta PIK1 is directly associated with frq1, the yeast homologue of mammalian neuronal calcium sensor-1 (NCS-1) (Hendricks et al., [1999] Nat. Cell Biol. 1:234- 241). This was a novel finding and suggests that a calcium binding protein activates and regulates PtdIns 4-kinasebeta. This finding had not been shown in mammalian cells and both PtdIns 4-kinasebeta and NCS-1 have been shown to have important roles in the regulation of exocytotic release associated with neurotransmission. The aims of this study were to determine if PtdIns 4-kinasebeta and NCS-1 directly associate in mammalian neural tissues. We show that the immunostaining pattern for PtdIns 4-kinasebeta and NCS-1 is co-localized throughout the neurites of newborn cultured dorsal root ganglia (DRG) neurons but not in E13 DRG neurons. We then provide biochemical evidence that PtdIns 4-kinasebeta may not be in physical association with NCS-1 in mammalian nervous tissue unlike that previously reported in yeast.


Assuntos
1-Fosfatidilinositol 4-Quinase/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Gânglios Espinais/metabolismo , Neuritos/metabolismo , Neuropeptídeos/metabolismo , Proteínas de Saccharomyces cerevisiae , Animais , Animais Recém-Nascidos , Células Cultivadas , Embrião de Mamíferos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Sensoras de Cálcio Neuronal
20.
Brain Res Brain Res Rev ; 33(2-3): 169-78, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11011064

RESUMO

Neurotrophins are released from target tissues following neural innervation and bind to specific receptors situated on the nerve terminal plasma membrane. The neurotrophin-receptor complex undergoes retrograde axonal transport towards the cell soma, where it signals to the nucleus. This process allows neurotrophins to perform their numerous functions, which include the promotion of neuronal survival and the outgrowth of axons towards certain target tissues. The molecular events controlling each of the components of retrograde axonal transport are beginning to become defined. There is good evidence for the participation of phosphatidylinositol 3-kinase, phosphatidylinositol 4-kinase and the actin cytoskeleton in neurotrophin retrograde axonal transport in vivo. It also appears that the retrograde motor protein dynein mediates the retrograde axonal transport in vivo of neurotrophins such as nerve growth factor. This review discusses the role of the neurotrophin receptors in binding and axonal transport, the endocytic processes required for neurotrophin internalization, the targeting and trafficking of neurotrophins, and the propagation of neurotrophin-induced signals along the axon.


Assuntos
Transporte Axonal/fisiologia , Fatores de Crescimento Neural/metabolismo , Animais , Humanos , Receptores Proteína Tirosina Quinases/metabolismo
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