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1.
Clin Genet ; 93(4): 880-890, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29240241

RESUMO

Okur-Chung syndrome is a neurodevelopmental condition attributed to germline CSNK2A1 pathogenic missense variants. We present 8 unreported subjects with the above syndrome, who have recognizable dysmorphism, varying degrees of developmental delay and multisystem involvement. Together with 6 previously reported cases, we present a case series of 7 female and 7 male subjects, highlighting the recognizable facial features of the syndrome (microcephaly, hypertelorism, epicanthic fold, ptosis, arched eyebrows, low set ears, ear fold abnormality, broad nasal bridge and round face) as well as frequently occurring clinical features including neurodevelopmental delay (93%), gastrointestinal (57%), musculoskeletal (57%) and immunological (43%) abnormalities. The variants reported in this study are evolutionary conserved and absent in the normal population. We observed that the CSNK2A1 gene is relatively intolerant to missense genetic changes, and most variants are within the protein kinase domain. All except 1 variant reported in this cohort are spatially located on the binding pocket of the holoenzyme. We further provide key recommendations on the management of Okur-Chung syndrome. To conclude, this is the second case series on Okur-Chung syndrome, and an in-depth review of the phenotypic features and genomic findings of the condition with suggestions on clinical management.


Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Transtornos do Neurodesenvolvimento/genética , Adolescente , Caseína Quinase II/química , Caseína Quinase II/genética , Criança , Pré-Escolar , Deficiências do Desenvolvimento/fisiopatologia , Face/fisiopatologia , Feminino , Genótipo , Humanos , Deficiência Intelectual/fisiopatologia , Masculino , Anormalidades Musculoesqueléticas/genética , Anormalidades Musculoesqueléticas/fisiopatologia , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/fisiopatologia , Fenótipo , Conformação Proteica , Dobramento de Proteína , Sequenciamento do Exoma/métodos
2.
Eur J Clin Microbiol Infect Dis ; 36(7): 1231-1241, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28251359

RESUMO

Staphylococcus aureus bacteremia (SAB) causes significant morbidity and mortality. We assessed the disease severity and clinical outcomes of SAB in patients with pre-existing immunosuppression, compared with immunocompetent patients. A retrospective cohort investigation studied consecutive patients with SAB hospitalized across six hospitals in Toronto, Canada from 2007 to 2010. Patients were divided into immunosuppressed (IS) and immunocompetent (IC) cohorts; the IS cohort was subdivided into presence of one and two or more immunosuppressive conditions. Clinical parameters were compared between cohorts and between IS subgroups. A competing risk model compared in-hospital mortality and time to discharge. A total of 907 patients were included, 716 (79%) were IC and 191 (21%) were IS. Within the IS cohort, 111 (58%) had one immunosuppressive condition and 80 (42%) had two or more conditions. The overall in-hospital mortality was 29%, with no differences between groups (IS 32%, IC 28%, p = 0.4211). There were no differences in in-hospital mortality (sub-distribution hazard ratio [sHR] 1.17, 95% confidence interval [CI] 0.88-1.56, p = 0.2827) or time to discharge (sHR 0.94, 95% CI 0.78-1.15, p = 0.5570). Independent mortality predictors for both cohorts included hypotension at 72 h (IS: p < 0.0001, IC: p < 0.0001) and early embolic stroke (IS: p < 0.0001, IC: p = 0.0272). Congestive heart failure was a mortality predictor in the IS cohort (p = 0.0089). Fever within 24 h (p = 0.0092) and early skin and soft tissue infections (p < 0.0001) were survival predictors in the IS cohort. SAB causes significant mortality regardless of pre-existing immune status, but immunosuppressed patients do not have an elevated risk of mortality relative to immunocompetent patients.


Assuntos
Bacteriemia/epidemiologia , Hospedeiro Imunocomprometido , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Bacteriemia/patologia , Canadá/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
4.
Hong Kong Med J ; 23(4): 404-10, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28775221

RESUMO

The implementation of a new clinical service is associated with anxiety and challenges that may prevent smooth and safe execution of the service. Unexpected issues may not be apparent until the actual clinical service commences. We present a novel approach to test the new clinical setting before actual implementation of our endovascular aortic repair service. In-situ simulation at the new clinical location would enable identification of potential process and system issues prior to implementation of the service. After preliminary planning, a simulation test utilising a case scenario with actual simulation of the entire care process was carried out to identify any logistic, equipment, settings or clinical workflow issues, and to trial a contingency plan for a surgical complication. All patient care including anaesthetic, surgical, and nursing procedures and processes were simulated and tested. Overall, 17 vital process and system issues were identified during the simulation as potential clinical concerns. They included difficult patient positioning, draping pattern, unsatisfactory equipment setup, inadequate critical surgical instruments, blood products logistics, and inadequate nursing support during crisis. In-situ simulation provides an innovative method to identify critical deficiencies and unexpected issues before implementation of a new clinical service. Life-threatening and serious practical issues can be identified and corrected before formal service commences. This article describes our experience with the use of simulation in pre-implementation testing of a clinical process or service. We found the method useful and would recommend it to others.


Assuntos
Valva Aórtica/cirurgia , Procedimentos Endovasculares/educação , Implementação de Plano de Saúde/métodos , Avaliação de Processos em Cuidados de Saúde/métodos , Treinamento por Simulação/métodos , Procedimentos Endovasculares/métodos , Hong Kong , Humanos
9.
Public Health ; 127(2): 109-18, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23352122

RESUMO

OBJECTIVES: To investigate the use of tobacco in Vietnam. STUDY DESIGN: Review study. METHODS: Data were collected through a review of tobacco-related literature in Vietnam. Grey literature and web content from agencies such as the World Health Organization and the US Centers for Disease Control and Prevention were consulted. RESULTS: Tobacco smoking is still common in Vietnam, although numerous policies have been issued and implemented over the last two decades. Based on the most recent data (2010), the prevalence of smoking among adults aged >15 years was 23.8%, with a higher percentage among males (47.4%) than females (1.4%). The prevalence of smoking among students aged 13-15 was 3.8% (2007), with a similar gender pattern. The prevalence of exposure to secondhand smoke is of concern, with 73.1% and 55.9% of adults reporting exposure to secondhand smoke at home and at work or other places, respectively. Of the adult respondents, 55.5% believed that smoking may cause lung cancer, stroke and heart disease. Most students (93.4%) and adults (91.6%) had seen anti-smoking media messages. Of the students, 56.4% had seen pro-cigarette advertisements on billboards, 36.9% had seen pro-cigarette advertisements in newspapers or magazines, and 8.2% had been offered free cigarettes by tobacco company representatives. The price of cigarettes decreased by approximately 5% between 1995 and 2006, whereas gross domestic product per capita increased by more than 150%. On average, smokers smoked 13.5 cigarettes per day, and spent US$86 on cigarettes per year. Despite such high levels of tobacco exposure in Vietnam, the total tax on cigarettes remains at 45% of the retail price. Furthermore, only 29.7% of smokers had been advised to quit by a healthcare provider in the past 12 months. CONCLUSION: Strong enforcement and evidence-based regulations which rounded on MPOWER are needed to help protect current smokers and non-smokers from the devastating effects of tobacco.


Assuntos
Regulamentação Governamental , Política de Saúde , Prevenção do Hábito de Fumar , Fumar/legislação & jurisprudência , Adolescente , Adulto , Publicidade/legislação & jurisprudência , Feminino , Educação em Saúde , Humanos , Masculino , Vigilância da População , Fumar/epidemiologia , Impostos , Produtos do Tabaco/economia , Poluição por Fumaça de Tabaco/legislação & jurisprudência , Poluição por Fumaça de Tabaco/prevenção & controle , Abandono do Uso de Tabaco , Vietnã/epidemiologia
10.
Eye (Lond) ; 37(5): 1033-1036, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35840716

RESUMO

INTRODUCTION: Proton beam therapy has been utilised for the treatment of uveal melanoma in the UK for over 30 years, undertaken under a single centre. In the UK, all ocular tumours are treated at one of four centres. We aimed to understand the variation in referral patterns to the UK proton service, capturing all uveal melanoma patients treated with this modality. METHODS: Retrospective analysis of data regarding all patients treated at the Clatterbridge Proton service between January 2004 and December 2014. RESULTS: A total of 1084 patients with uveal melanoma were treated. The mean age was 57 years (range 9-90 years), basal diameter of 11.5 mm (range 2.0-23.4 mm) and tumour thickness of 3.9 mm (range 0.1-15.4 mm). The majority were TNM stage I (39%) or II (36%). The distance to the optic nerve varied from 0 to 24.5 mm with 148 (14%) of patients having ciliary body involvement. There were variations in the phenotypic characteristic of the tumours treated with protons from different centres, with London referring predominantly small tumours at the posterior pole, Glasgow referring large tumours often at the ciliary body and Liverpool sending a mix of these groups. DISCUSSION: In the UK, common indications for the use of proton treatment in uveal melanoma include small tumours in the posterior pole poorly accessible for plaque treatment (adjacent to the disc), tumours at the posterior pole affecting the fovea and large anterior tumours traditionally too large for brachytherapy. This is the first UK-wide audit enabling the capture of all patients treated at the single proton centre.


Assuntos
Braquiterapia , Melanoma , Terapia com Prótons , Neoplasias Uveais , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Prótons , Corpo Ciliar/patologia , Estudos Retrospectivos , Neoplasias Uveais/radioterapia , Neoplasias Uveais/patologia , Melanoma/patologia , Reino Unido
11.
Mod Pathol ; 24(1): 108-16, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20852592

RESUMO

Splenic hamartoma is a rare tumor-like lesion composed of structurally disorganized red pulp elements. It has been hypothesized that two other splenic lesions, cord capillary hemangioma and myoid angioendothelioma, may fall within the spectrum of splenic hamartoma, simply representing morphological variants. In this study, we compared the vascular and stromal composition of cord capillary hemangioma and myoid angioendothelioma with those of classical hamartoma. In addition, we assessed the clonal vs polyclonal nature of the lesions in nine female cases by performing clonality analysis for X-chromosome inactivation at the human androgen receptor locus (HUMARA) on laser-assisted microdissected samples. In 15 of 17 cases, increased reticulin and/or collagen content was observed. The classical hamartoma cases showed a vasculature predominantly composed of CD8+ CD31+ CD34- splenic sinuses, whereas cases of cord capillary hemangioma and myoid angioendothelioma contained many CD8- CD31+ CD34+ cord capillaries, but very little CD8+ vasculature. All cases lacked expression of D2-40 and Epstein Barr virus-encoded RNA. All cases showed a proliferation index of ≤5% by Ki-67. Cases of classical hamartoma lacked significant perisinusoidal expression of collagen IV and low-affinity nerve growth factor receptor. Both markers were variably expressed in the other lesions. Increased CD163-positive histiocytes were found in four cases (three cord capillary hemangiomas and one myoid angioendothelioma). HUMARA analysis was informative in all nine tested cases, of which three cases showed a non-random X-chromosome inactivation pattern, indicating clonality. All three clonal cases were cord capillary hemangiomas. Our study has shown that in spite of considerable morphologic heterogeneity and overlapping features, classical hamartoma and cord capillary hemangioma and myoid angioendothelioma are different in terms of their vascular and stromal composition. Clonality analysis supports a true neoplastic origin for the cord capillary hemangioma. A larger study using additional immunohistochemical and molecular studies is necessary to further evaluate the biological significance of the current findings.


Assuntos
Cromossomos Humanos X , Hamartoma/genética , Hemangioma Capilar/genética , Neoplasias Esplênicas/genética , Inativação do Cromossomo X/genética , Adolescente , Adulto , Idoso , Criança , Células Clonais , Diagnóstico Diferencial , Feminino , Hamartoma/patologia , Hemangioendotelioma/genética , Hemangioendotelioma/patologia , Hemangioma Capilar/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Esplênicas/patologia , Adulto Jovem
12.
East Asian Arch Psychiatry ; 31(1): 9-12, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33753571

RESUMO

OBJECTIVE: To evaluate psychometric properties of the Chinese version of Dementia Quality of Life Measure - Proxy (C-DEMQoL-Proxy). METHODS: Care home residents aged ≥60 years who were diagnosed with dementia or demonstrated impairment in cognition were recruited from four care facilities in Hong Kong. Caregivers of these participants were also invited to participate. The original DEMQoL-Proxy was translated into Chinese (Cantonese) by a trained translator. The forward-translated version was reviewed by an expert panel of six experienced healthcare professionals. Revisions were made based on comments. The instrument was back-translated to English to check whether further changes were necessary. Demographic data (age, sex, type and severity of dementia, and Mini-Mental State Examination [MMSE] score) were collected from medical records of participants with dementia. Caregivers were interviewed by an occupational therapist or personnel supervised by the occupational therapist using the C-DEMQoL-Proxy and the Chinese version of Quality of Life-Alzheimer's Disease-Proxy (C-QoL-AD-Proxy). Acceptability, reliability, and validity of the C-DEMQoL-Proxy were evaluated using standard psychometric methods. RESULTS: 90 individuals (82.2% women) with dementia aged 72 to 102 years were included. Their diagnosis included Alzheimer's disease (23.3%), vascular dementia (15.6%), mixed and other types of dementias (51.1%), and missing (10%). Severity was mild in 12.2%, moderate in 62.2%, and severe in 25.6%. The mean MMSE score was 12.0 ± 4.9. 20% of the caregivers were family members and the rest were professional carers. The C-DEMQoL-Proxy had good acceptability, with no floor or ceiling effects or missing data. It had good internal consistency (Cronbach alpha = 0.91) and test-retest reliability (intraclass correlation coefficients = 0.83). It was mildly correlated with C-QoL-AD-Proxy (r = 0.29, p < 0.01). Age and sex were not correlated with C-DEMQoL-Proxy scores. C-DEMQoL-Proxy scores were not significantly different between dementia types, severity levels, or between those with higher or lower MMSE scores. CONCLUSION: The C-DEMQoL-Proxy is a valid and reliable instrument to assess health-related quality of life in individuals with dementia.


Assuntos
Demência , Qualidade de Vida , Inquéritos e Questionários , Idoso , Idoso de 80 Anos ou mais , Feminino , Hong Kong , Humanos , Masculino , Procurador , Psicometria , Reprodutibilidade dos Testes , Instituições Residenciais , Traduções
13.
Artigo em Inglês | MEDLINE | ID: mdl-20859824

RESUMO

Hexavalent chromium combines with glutathione in chloride intracellular channel carrier to form tetravalent and pentavalent chromium in plasma and organelle membranes. It also combines with NADH/NADPH to form pentavalent chromium in mitochondria. Tetravalent- and pentavalent- chromium (directly and indirectly) mediated DNA double strand breaks activate DNA damage signaling sensors: DNA-dependent-protein-kinase signals p53-dependent intrinsic mitochondrial apoptosis, and ataxia-telangiectasia-mutated and ataxia-telangiectasia-Rad3-related signal cell-arrest for DNA repair. Tetravalent chromium may be the most potent species since it causes DNA breaks and somatic recombination, but not apoptosis. Upon further failure of apoptosis and senescence/DNA-repair, damaged cells may become immortal with loss-of-heterozygosity and genetic plasticity.


Assuntos
Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Cromo/toxicidade , Humanos
14.
Water Sci Technol ; 61(4): 1011-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20182081

RESUMO

We investigated three major parameters in simulating desorption behaviours: the pre-contamination period, dilution by clean water mass (dilution ratio) and the length of the time interval between dilutions, in both batch and stepwise desorption experiments using particles pre-contaminated with a polycyclic aromatic hydrocarbon, naphthalene (NAPH). We found that the dilution ratio plays a major role in batch desorption, whereas the pre-contamination period plays a major role in stepwise desorption (SD). In addition, the diffusion process was found to be the rate-determining step for our study of SD kinetics. Based on the results of our batch experiments, we were able to derive a mathematical expression capable of correlating the SD rate constant with the length of time interval between dilutions. This expression can be applied in numerical modelling of various naturally occurring processes such as the dispersion and dilution of a heavily contaminated water mass in a marine environment due to an oil spill incident.


Assuntos
Sedimentos Geológicos , Naftalenos/isolamento & purificação , Poluentes do Solo/isolamento & purificação , Purificação da Água/métodos , Algoritmos , Simulação por Computador , Cinética , Modelos Estatísticos , Modelos Teóricos , Naftalenos/química , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes do Solo/química , Fatores de Tempo , Movimentos da Água , Poluentes Químicos da Água/isolamento & purificação
15.
AJNR Am J Neuroradiol ; 41(4): 645-649, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32217549

RESUMO

Use of mechanical thrombectomy for stroke has increased since the publication of trials describing outcome improvement when used in the anterior circulation. These results, however, cannot be directly translated to the posterior circulation. While a high NIHSS score has demonstrated an association with poor outcomes in posterior stroke, the NIHSS is weighted toward hemispheric disease, and complex scores potentially delay definitive imaging diagnosis. We performed a retrospective analysis to ascertain whether any rapidly obtainable demographic or clinical and imaging data have a correlation with patient outcome postthrombectomy. Seventy-three cases were audited between September 2010 and October 2017. Presenting with a Glasgow Coma Scale score of >13 meant that the odds of reaching the primary end point of functional independence (defined as a 90-day modified Rankin Scale score of 0-2) were 5.70 times greater; similarly, presenting with a posterior circulation ASPECTS of >9 resulted in the odds of reaching the primary end point being 4.03 times greater. Older age correlated to a lower odds of independence (0.97, p = .04).


Assuntos
Procedimentos Endovasculares/métodos , Escala de Coma de Glasgow , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Resultado do Tratamento , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
16.
Clean Technol Environ Policy ; 22(6): 1359-1370, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32837502

RESUMO

Abstract: The global scientific community has intensified efforts to develop, test, and commercialize pharmaceutical products to deal with the COVID-19 pandemic. Trials for both antivirals and vaccines are in progress; candidates include existing repurposed drugs that were originally developed for other ailments. Once these are shown to be effective, their production will need to be ramped up rapidly to keep pace with the growing demand as the pandemic progresses. It is highly likely that the drugs will be in short supply in the interim, which leaves policymakers and medical personnel with the difficult task of determining how to allocate them. Under such conditions, mathematical models can provide valuable decision support. In particular, useful models can be derived from process integration techniques that deal with tight resource constraints. In this paper, a linear programming model is developed to determine the optimal allocation of COVID-19 drugs that minimizes patient fatalities, taking into account additional hospital capacity constraints. Two hypothetical case studies are solved to illustrate the computational capability of the model, which can generate an allocation plan with outcomes that are superior to simple ad hoc allocation.

17.
J Cell Biol ; 103(4): 1383-98, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2945826

RESUMO

Work from several laboratories has identified a proteoglycan complex secreted by a variety of non-neuronal cells that can promote neurite regeneration when applied to the surface of culture dishes. Using a novel immunization protocol, a monoclonal antibody (INO) was produced that blocks the activity of this outgrowth-promoting factor (Matthew, W. D., and P. H. Patterson, 1983, Cold Spring Harbor Symp. Quant. Biol. 48:625-631). We have used the antibody to analyze the components of the active site and to localize the complex in vivo. INO binding is lost when the complex is dissociated; if its components are selectively reassociated, INO binds only to a complex containing two different molecular weight species. These are likely to be laminin and heparan sulfate proteoglycan, respectively. On frozen sections of adult rat tissues, INO binding is present on the surfaces of glial cells of the peripheral, but not the central, nervous system. INO also binds to the basement membrane surrounding cardiac and skeletal muscle cells, and binding to the latter greatly increases after denervation. In the adrenal gland and kidney, INO selectively reacts with areas rich in basement membranes, staining a subset of structures that are immunoreactive for both laminin and heparan sulfate proteoglycan. In general, the outgrowth-blocking antibody binds to areas known to promote axonal regeneration and is absent from areas known to lack this ability. This suggests that this complex, which is active in culture, may be the physiological substrate supporting nerve regeneration in vivo.


Assuntos
Anticorpos Monoclonais/imunologia , Axônios/fisiologia , Proteoglicanas de Sulfatos de Condroitina/fisiologia , Glicosaminoglicanos/fisiologia , Heparitina Sulfato/fisiologia , Laminina/fisiologia , Regeneração Nervosa , Proteoglicanas/fisiologia , Animais , Axônios/ultraestrutura , Membrana Basal/análise , Sítios de Ligação , Proteoglicanas de Heparan Sulfato , Músculos/análise , Neuroglia/análise , Nervos Periféricos/análise , Ratos
18.
J Cell Biol ; 139(6): 1507-21, 1997 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9396756

RESUMO

Laminins, heterotrimers of alpha, beta, and gamma chains, are prominent constituents of basal laminae (BLs) throughout the body. Previous studies have shown that laminins affect both myogenesis and synaptogenesis in skeletal muscle. Here we have studied the distribution of the 10 known laminin chains in muscle and peripheral nerve, and assayed the ability of several heterotrimers to affect the outgrowth of motor axons. We show that cultured muscle cells express four different alpha chains (alpha1, alpha2, alpha4, and alpha5), and that developing muscles incorporate all four into BLs. The portion of the muscle's BL that occupies the synaptic cleft contains at least three alpha chains and two beta chains, but each is regulated differently. Initially, the alpha2, alpha4, alpha5, and beta1 chains are present both extrasynaptically and synaptically, whereas beta2 is restricted to synaptic BL from its first appearance. As development proceeds, alpha2 remains broadly distributed, whereas alpha4 and alpha5 are lost from extrasynaptic BL and beta1 from synaptic BL. In adults, alpha4 is restricted to primary synaptic clefts whereas alpha5 is present in both primary and secondary clefts. Thus, adult extrasynaptic BL is rich in laminin 2 (alpha2beta1gamma1), and synaptic BL contains laminins 4 (alpha2beta2gamma1), 9 (alpha4beta2gamma1), and 11 (alpha5beta2gamma1). Likewise, in cultured muscle cells, alpha2 and beta1 are broadly distributed but alpha5 and beta2 are concentrated at acetylcholine receptor-rich "hot spots," even in the absence of nerves. The endoneurial and perineurial BLs of peripheral nerve also contain distinct laminin chains: alpha2, beta1, gamma1, and alpha4, alpha5, beta2, gamma1, respectively. Mutation of the laminin alpha2 or beta2 genes in mice not only leads to loss of the respective chains in both nerve and muscle, but also to coordinate loss and compensatory upregulation of other chains. Notably, loss of beta2 from synaptic BL in beta2(-/-) "knockout" mice is accompanied by loss of alpha5, and decreased levels of alpha2 in dystrophic alpha2(dy/dy) mice are accompanied by compensatory retention of alpha4. Finally, we show that motor axons respond in distinct ways to different laminin heterotrimers: they grow freely between laminin 1 (alpha1beta1gamma1) and laminin 2, fail to cross from laminin 4 to laminin 1, and stop upon contacting laminin 11. The ability of laminin 11 to serve as a stop signal for growing axons explains, in part, axonal behaviors observed at developing and regenerating synapses in vivo.


Assuntos
Envelhecimento/fisiologia , Laminina/biossíntese , Músculo Esquelético/fisiologia , Junção Neuromuscular/fisiologia , Neurônios/fisiologia , Nervos Periféricos/fisiologia , Sinapses/fisiologia , Animais , Células Cultivadas , Embrião de Galinha , Meios de Cultivo Condicionados , Desenvolvimento Embrionário e Fetal , Gânglios Parassimpáticos/citologia , Gânglios Parassimpáticos/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Laminina/análise , Laminina/fisiologia , Substâncias Macromoleculares , Camundongos , Camundongos Knockout , Neurônios Motores/fisiologia , Desenvolvimento Muscular , Músculo Esquelético/embriologia , Músculo Esquelético/crescimento & desenvolvimento , Neurônios/citologia , Nervos Periféricos/embriologia , Nervos Periféricos/crescimento & desenvolvimento , Ratos , Células Tumorais Cultivadas
19.
Science ; 188(4185): 273-5, 1975 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-47182

RESUMO

In vitro axonal transport of tritiated protein decreased 40 to 60 percent when neuronal cell bodies were incubated in calcium-free medium, but was not affected when only nerve trunks were exposed to calcium-free conditions. In addition, calcium-45 was transported along axons at a rate similar to that of rapidly transported tritiated protein. These data are interpreted to suggest that calcium ions are involved in the initiation of axonal transport and in the coupling of transported proteins to the transport system.


Assuntos
Transporte Axonal , Axônios/metabolismo , Cálcio/metabolismo , Modelos Neurológicos , Animais , Cálcio/fisiologia , Radioisótopos de Cálcio , Gânglios Espinais/metabolismo , Técnicas In Vitro , Leucina/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Rana catesbeiana , Nervo Isquiático/metabolismo , Medula Espinal/metabolismo , Nervos Espinhais/metabolismo , Trítio
20.
Science ; 264(5166): 1772-5, 1994 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-8209258

RESUMO

Mutations of human Cu,Zn superoxide dismutase (SOD) are found in about 20 percent of patients with familial amyotrophic lateral sclerosis (ALS). Expression of high levels of human SOD containing a substitution of glycine to alanine at position 93--a change that has little effect on enzyme activity--caused motor neuron disease in transgenic mice. The mice became paralyzed in one or more limbs as a result of motor neuron loss from the spinal cord and died by 5 to 6 months of age. The results show that dominant, gain-of-function mutations in SOD contribute to the pathogenesis of familial ALS.


Assuntos
Esclerose Lateral Amiotrófica/genética , Doença dos Neurônios Motores/genética , Superóxido Dismutase/genética , Esclerose Lateral Amiotrófica/enzimologia , Esclerose Lateral Amiotrófica/patologia , Animais , Encéfalo/enzimologia , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Placa Motora/patologia , Doença dos Neurônios Motores/enzimologia , Doença dos Neurônios Motores/patologia , Neurônios Motores/enzimologia , Neurônios Motores/patologia , Músculos/inervação , Músculos/patologia , Mutação , Linhagem , Medula Espinal/patologia , Superóxido Dismutase/metabolismo
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