Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Environ Sci Technol ; 58(20): 9000-9012, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38710661

RESUMO

Additive manufacturing (AM) offers a variety of material manufacturing techniques for a wide range of applications across many industries. Most efforts at process optimization and exposure assessment for AM are centered around the manufacturing process. However, identifying the material allocation and potentially harmful exposures in end-of-life (EoL) management is equally crucial to mitigating environmental releases and occupational health impacts within the AM supply chain. This research tracks the allocation and potential releases of AM EoL materials within the US through a material flow analysis. Of the generated AM EoL materials, 58% are incinerated, 33% are landfilled, and 9% are recycled by weight. The generated data set was then used to examine the theoretical occupational hazards during AM EoL material management practices through generic exposure scenario assessment, highlighting the importance of ventilation and personal protective equipment at all stages of AM material management. This research identifies pollution sources, offering policymakers and stakeholders insights to shape pollution prevention and worker safety strategies within the US AM EoL management pathways.


Assuntos
Exposição Ocupacional , Humanos , Reciclagem
2.
J Occup Environ Hyg ; 20(11): 545-562, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37526475

RESUMO

Under the Toxic Substances Control Act (TSCA), the United States Environmental Protection Agency (USEPA) is required to determine whether a new chemical substance poses an unreasonable risk to human health or the environment before the chemical is manufactured in or imported into the United States. This manuscript provides a review of the process used to evaluate the risk associated with a chemical based on the scenarios and models used in the evaluation. Specifically, the Generic Scenarios and Emission Scenario Documents developed by the USEPA were reviewed, along with background documentation prepared by USEPA to identify the core elements of the environmental release and occupational exposure scenarios used to assess the risk of the chemical being evaluated. Additionally, this contribution provides an overview of methods used to model occupational exposures and environmental releases as part of the chemical evaluation process used in other jurisdictions, along with work being performed to improve these models. Finally, the alternative methods to evaluate occupational exposures and environmental releases that may be used as part of the decision-making process regarding a chemical are identified. The contribution provides a path forward for reducing the time required and improving the chemical evaluation of the unreasonable risk determination regarding the manufacture or import of a chemical.


Assuntos
Exposição Ocupacional , Estados Unidos , Humanos , Exposição Ocupacional/prevenção & controle , Medição de Risco/métodos , Fatores de Risco , Exposição Ambiental
3.
J Exp Med ; 220(6)2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36995340

RESUMO

Phagocytosis is a key macrophage function, but how phagocytosis shapes tumor-associated macrophage (TAM) phenotypes and heterogeneity in solid tumors remains unclear. Here, we utilized both syngeneic and novel autochthonous lung tumor models in which neoplastic cells express the fluorophore tdTomato (tdTom) to identify TAMs that have phagocytosed neoplastic cells in vivo. Phagocytic tdTompos TAMs upregulated antigen presentation and anti-inflammatory proteins, but downregulated classic proinflammatory effectors compared to tdTomneg TAMs. Single-cell transcriptomic profiling identified TAM subset-specific and common gene expression changes associated with phagocytosis. We uncover a phagocytic signature that is predominated by oxidative phosphorylation (OXPHOS), ribosomal, and metabolic genes, and this signature correlates with worse clinical outcome in human lung cancer. Expression of OXPHOS proteins, mitochondrial content, and functional utilization of OXPHOS were increased in tdTompos TAMs. tdTompos tumor dendritic cells also display similar metabolic changes. Our identification of phagocytic TAMs as a distinct myeloid cell state links phagocytosis of neoplastic cells in vivo with OXPHOS and tumor-promoting phenotypes.


Assuntos
Neoplasias Pulmonares , Macrófagos , Humanos , Macrófagos/metabolismo , Fagocitose/genética , Neoplasias Pulmonares/patologia , Células Mieloides/metabolismo , Estresse Oxidativo , Microambiente Tumoral
4.
Am Soc Clin Oncol Educ Book ; 42: 1-13, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35658503

RESUMO

Patients with cancer generally have a higher risk of adverse outcomes from COVID-19, with higher age, male sex, poor performance status, cancer type, and uncontrolled malignant disease as the main risk factors. However, the influence of specific cancer therapies varies and raises concerns during the pandemic. In patients undergoing cancer immunotherapy or other immunosuppressive cancer treatments, we summarize the evidence on outcomes from COVID-19; address the safety, immunogenicity, and efficacy of COVID-19 vaccination; and review COVID-19 antiviral therapeutics for the patient with cancer. Despite higher mortality for patients with cancer, treatment with immune checkpoint inhibitors does not seem to increase mortality risk based on observational evidence. Inhibitory therapies directed toward B-cell lineages, including monoclonal antibodies against CD20 and CAR T-cell therapies, are associated with poor outcomes in COVID-19; however, the data are sparse. Regarding vaccination in patients receiving immune checkpoint inhibitors, clinical efficacy comparable to that in the general population can be expected. In patients undergoing B-cell-depleting therapy, immunogenicity and clinical efficacy are curtailed, but vaccination is not futile, which is thought to be due to the cellular response. Vaccine reactogenicity and toxicity in all groups of patients with cancer are comparable to that of the general population. Preexposure prophylaxis with monoclonal antibodies directed against the viral spike may provide passive immunity for those not likely to mount an adequate vaccine response. If infected, prompt treatment with monoclonal antibodies or oral small molecule antivirals is beneficial, though with oral antiviral therapies, care must be taken to avoid drug interactions in patients with cancer.


Assuntos
COVID-19 , Neoplasias , Anticorpos Monoclonais/uso terapêutico , Antivirais/uso terapêutico , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Inibidores de Checkpoint Imunológico , Fatores Imunológicos/uso terapêutico , Imunoterapia , Neoplasias/tratamento farmacológico , SARS-CoV-2 , Vacinação
5.
J Clin Med ; 10(20)2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34682769

RESUMO

PURPOSE: Teenagers and young adults (TYAs; aged 13-24) experience prolonged intervals to cancer diagnosis. Insight into diagnostic intervals in young adults (YAs; aged 25-39) and subgroups at risk for long intervals is lacking. We investigated the diagnostic pathway of YA cancer patients, examined patient and tumor characteristics associated with its length, and compared the patient interval length of our sample with a TYA cohort. METHODS: In this cross-sectional survey YAs diagnosed with cancer in the UK in the past five years completed a questionnaire describing their patient (time from first symptom to first doctor consultation) and healthcare interval (from first consultation until consultation with a cancer specialist), sociodemographic, and clinical characteristics. Associations between characteristics and interval length were examined and compared with previously published data in TYAs. RESULTS: Among 341 YAs the patient interval lasted ≥2 weeks, ≥1 month, and ≥3 months in 60%, 42%, and 21%, respectively, compared to 48%, 27%, and 12% in the TYA group. The healthcare interval lasted ≥2 weeks, ≥1 month, and ≥3 months in 62%, 40%, and 17% of YA patients, respectively. YAs with melanoma or cervical cancer were most likely to experience long intervals, whereas YAs with breast cancer and leukemia were most likely to experience short intervals. CONCLUSIONS: Most YAs were not seen by a cancer specialist within 2 weeks of GP consultation. Interval lengths in YAs were associated with cancer diagnosis. Patient intervals were longer among YAs than among TYAs. Our study highlights long diagnostic pathways among YAs and calls for more awareness among healthcare professionals about malignancies in this age group.

6.
FASEB J ; 35(2): e21331, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33476078

RESUMO

Type 2 immunity plays an essential role in the maintenance of metabolic homeostasis and its disruption during obesity promotes meta-inflammation and insulin resistance. Infection with the helminth parasite Schistosoma mansoni and treatment with its soluble egg antigens (SEA) induce a type 2 immune response in metabolic organs and improve insulin sensitivity and glucose tolerance in obese mice, yet, a causal relationship remains unproven. Here, we investigated the effects and underlying mechanisms of the T2 ribonuclease omega-1 (ω1), one of the major S mansoni immunomodulatory glycoproteins, on metabolic homeostasis. We show that treatment of obese mice with plant-produced recombinant ω1, harboring similar glycan motifs as present on the native molecule, decreased body fat mass, and improved systemic insulin sensitivity and glucose tolerance in a time- and dose-dependent manner. This effect was associated with an increase in white adipose tissue (WAT) type 2 T helper cells, eosinophils, and alternatively activated macrophages, without affecting type 2 innate lymphoid cells. In contrast to SEA, the metabolic effects of ω1 were still observed in obese STAT6-deficient mice with impaired type 2 immunity, indicating that its metabolic effects are independent of the type 2 immune response. Instead, we found that ω1 inhibited food intake, without affecting locomotor activity, WAT thermogenic capacity or whole-body energy expenditure, an effect also occurring in leptin receptor-deficient obese and hyperphagic db/db mice. Altogether, we demonstrate that while the helminth glycoprotein ω1 can induce type 2 immunity, it improves whole-body metabolic homeostasis in obese mice by inhibiting food intake via a STAT6-independent mechanism.


Assuntos
Ingestão de Alimentos , Endorribonucleases/uso terapêutico , Glicoproteínas/uso terapêutico , Proteínas de Helminto/uso terapêutico , Obesidade/tratamento farmacológico , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Células Cultivadas , Endorribonucleases/farmacologia , Glicoproteínas/farmacologia , Proteínas de Helminto/farmacologia , Locomoção , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Schistosoma mansoni/enzimologia , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Termogênese , Nicotiana/genética , Nicotiana/metabolismo
8.
BMC Cancer ; 19(1): 770, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31382912

RESUMO

BACKGROUND: Etoposide (E) at 100 mg/m2 combined with Cisplatin (P) at 20 mg/m2 represents an induction 2-day regimen embedded in our clinical practice for patients with advanced GCT or TN at high risk of early death. We evaluated 24/7 Em-EP administration to a combined GCT-TN cohort at our Emergency Cancer Treatment Centre (ECTC) to determine its efficacy within the acute setting. METHODS: Patients who received Em-EP during a five-year interval were identified from electronic databases at Imperial College Healthcare NHS Trust. Data collected included demographics, treatment details and clinical outcome. RESULTS: Em-EP was administered in the emergency setting to 104 patients, predominantly young adults (median age 35, range 17-71). Half the cases were GCT (n = 52): 22 male (6 seminomas, 13 non-seminomas); 30 female (2 dysgerminomas, 28 non-dysgerminomas). The other 50% were treated for TN (n = 52): 45 gestational (GTN) and 7 non-gestational. Most patients received Em-EP for a new cancer diagnosis (n = 100, 96%), within 24 h (n = 93, 89%) and out-of-hours (n = 74, 70%). Indications for Em-EP included symptomatic disease (n = 66, 63%), high-burden disease, (n = 51, 49%) and organ failure requiring Intensive Care Unit support (n = 9, 9%). Neutropenic sepsis was observed in 5%. Four-week overall survival after Em-EP administration was 98%. CONCLUSIONS: Despite the potentially fatal complications encountered in the acute setting, early mortality with Em-EP is low at our ECTC. Specialist units that treat unwell patients with advanced GCT or TN should consider making Em-EP available 24/7 for emergency administration. Its efficacy within a prospective cohort and in other platinum-sensitive malignancies requires evaluation.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Cisplatino/uso terapêutico , Serviços Médicos de Emergência , Etoposídeo/uso terapêutico , Doença Trofoblástica Gestacional/tratamento farmacológico , Doença Aguda , Adolescente , Adulto , Idoso , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Atenção à Saúde , Etoposídeo/administração & dosagem , Etoposídeo/efeitos adversos , Feminino , Febre/etiologia , Seguimentos , Doença Trofoblástica Gestacional/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Neutropenia/etiologia , Gravidez , Estudos Prospectivos , Estudos Retrospectivos , Sepse/etiologia , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
9.
J Neurol Neurosurg Psychiatry ; 88(7): 575-585, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28501821

RESUMO

OBJECTIVES: To analyse and describe the clinical and genetic spectrum of Charcot-Marie-Tooth disease (CMT) caused by mutations in the neurofilament light polypeptide gene (NEFL). METHODS: Combined analysis of newly identified patients with NEFL-related CMT and all previously reported cases from the literature. RESULTS: Five new unrelated patients with CMT carrying the NEFL mutations P8R and N98S and the novel variant L311P were identified. Combined data from these cases and 62 kindreds from the literature revealed four common mutations (P8R, P22S, N98S and E396K) and three mutational hotspots accounting for 37 (55%) and 50 (75%) kindreds, respectively. Eight patients had de novo mutations. Loss of large-myelinated fibres was a uniform feature in a total of 21 sural nerve biopsies and 'onion bulb' formations and/or thin myelin sheaths were observed in 14 (67%) of them. The neurophysiological phenotype was broad but most patients with E90K and N98S had upper limb motor conduction velocities <38 m/s. Age of onset was ≤3 years in 25 cases. Pyramidal tract signs were described in 13 patients and 7 patients were initially diagnosed with or tested for inherited ataxia. Patients with E90K and N98S frequently presented before age 3 years and developed hearing loss or other neurological features including ataxia and/or cerebellar atrophy on brain MRI. CONCLUSIONS: NEFL-related CMT is clinically and genetically heterogeneous. Based on this study, however, we propose mutational hotspots and relevant clinical-genetic associations that may be helpful in the evaluation of NEFL sequence variants and the differential diagnosis with other forms of CMT.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/patologia , Mutação/genética , Proteínas de Neurofilamentos/genética , Axônios/patologia , Ataxia Cerebelar/genética , Ataxia Cerebelar/patologia , Genótipo , Humanos , Linhagem , Fenótipo , Nervo Sural/patologia
10.
Nat Immunol ; 18(6): 642-653, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28436955

RESUMO

It remains unclear whether activated inflammatory macrophages can adopt features of tissue-resident macrophages, or what mechanisms might mediate such a phenotypic conversion. Here we show that vitamin A is required for the phenotypic conversion of interleukin 4 (IL-4)-activated monocyte-derived F4/80intCD206+PD-L2+MHCII+ macrophages into macrophages with a tissue-resident F4/80hiCD206-PD-L2-MHCII-UCP1+ phenotype in the peritoneal cavity of mice and during the formation of liver granulomas in mice infected with Schistosoma mansoni. The phenotypic conversion of F4/80intCD206+ macrophages into F4/80hiCD206- macrophages was associated with almost complete remodeling of the chromatin landscape, as well as alteration of the transcriptional profiles. Vitamin A-deficient mice infected with S. mansoni had disrupted liver granuloma architecture and increased mortality, which indicates that failure to convert macrophages from the F4/80intCD206+ phenotype to F4/80hiCD206- may lead to dysregulated inflammation during helminth infection.


Assuntos
Granuloma/imunologia , Fígado/imunologia , Macrófagos/imunologia , Esquistossomose mansoni/imunologia , Deficiência de Vitamina A/imunologia , Animais , Antígenos de Diferenciação/metabolismo , Citometria de Fluxo , Antígenos de Histocompatibilidade Classe II/metabolismo , Interleucina-4/imunologia , Lectinas Tipo C/metabolismo , Fígado/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/metabolismo , Receptor de Manose , Lectinas de Ligação a Manose/metabolismo , Camundongos , Cavidade Peritoneal/citologia , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Superfície Celular/metabolismo , Schistosoma mansoni , Esquistossomose mansoni/patologia , Tretinoína/farmacologia , Proteína Desacopladora 1/metabolismo , Vitaminas/farmacologia
11.
J Neurol Sci ; 364: 116-21, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-27084228

RESUMO

BACKGROUND: Hereditary spastic paraplegias (HSPs) are a clinically and genetically heterogeneous group of neurodegenerative diseases with progressive lower limb spasticity and weakness. The aim of this study is to determine the frequency of different SPG mutations in Hungarian patients, and to provide further genotype-phenotype correlations for the known HSP causing genes. METHODS: We carried out genetic testing for 58 probands with clinical characteristics of HSP. For historical reasons, three different approaches were followed in different patients: 1) Sanger sequencing of ATL1 and SPAST genes, 2) whole exome, and 3) targeted panel sequencing by next generation sequencing. RESULTS: Genetic diagnosis was established for 20 probands (34.5%). We detected nine previously unreported mutations with high confidence for pathogenicity. The most frequently affected gene was SPAST with pathogenic or likely pathogenic mutations in 10 probands. The most frequently detected variant in our cohort was the SPG7 p.Leu78*, observed in four probands. Altogether five probands were diagnosed with SPG7. Additional mutations were detected in SPG11, ATL1, NIPA1, and ABCD1. CONCLUSION: This is the first comprehensive genetic epidemiological study of patients with HSP in Hungary. Next generation sequencing improved the yield of genetic diagnostics in this disease group even when the phenotype was atypical. However, considering the frequency of the HSP-causing gene defects, SPG4, the most common form of the disease, should be tested first to be cost effective in this economic region.


Assuntos
Adenosina Trifosfatases/genética , Predisposição Genética para Doença/genética , Metaloendopeptidases/genética , Polimorfismo de Nucleotídeo Único/genética , Paraplegia Espástica Hereditária/genética , Membro 1 da Subfamília D de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , ATPases Associadas a Diversas Atividades Celulares , Adolescente , Adulto , Idade de Início , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Biologia Computacional , Feminino , Proteínas de Ligação ao GTP/genética , Frequência do Gene , Estudos de Associação Genética , Genótipo , Humanos , Hungria , Lactente , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Fenótipo , Proteínas/genética , Paraplegia Espástica Hereditária/epidemiologia , Paraplegia Espástica Hereditária/fisiopatologia , Espastina , Adulto Jovem
12.
Sci Rep ; 6: 23401, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-27021742

RESUMO

A series of 5-(2'-indolyl)thiazoles were synthesized and evaluated for their cytotoxicity against selected human cancer cell lines. The reaction of thioamides 3 with 3-tosyloxypentane-2,4-dione 4 led to in situ formation of 5-acetylthiazole 5 which upon treatment with arylhydrazines 6 in polyphosphoric acid resulted in the formation of 5-(2'-indolyl)thiazoles 2. Among the synthesized 5-(2'-indolyl)thiazoles, compounds 2d-f, and 2h exhibited encouraging anticancer activity and also selectivity towards particular cell lines (IC50 = 10-30 µM). Further studies on the SAR of compound 2e may result in good anticancer activity.


Assuntos
Antineoplásicos/síntese química , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Modelos Químicos , Tiazóis/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células HCT116 , Humanos , Concentração Inibidora 50 , Células MCF-7 , Estrutura Molecular , Relação Estrutura-Atividade , Tiazóis/química , Tiazóis/farmacologia
13.
Case Rep Genet ; 2015: 239167, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25878907

RESUMO

Introduction. The valosin-containing protein (VCP) regulates several distinct cellular processes. Consistent with this, VCP mutations manifest variable clinical phenotypes among and within families and are a diagnostic challenge. Methods. A 60-year-old man who played ice hockey into his 50's was evaluated by electrodiagnostics, muscle biopsy, and molecular genetics. Results. With long-standing pes cavus and toe walking, our patient developed progressive weakness, cramps, memory loss, and paresthesias at age 52. An axonal sensorimotor neuropathy was found upon repeated testing at age 58. Neuropathic histopathology was present in the quadriceps, and exome sequencing revealed the VCP mutation c.290 C>T, p.Gly97Glu. Conclusions. Our patient reflects the clinical heterogeneity of VCP mutations, as his neurological localization is a spectrum between a lower motor neuron disorder and a hereditary axonal peripheral neuropathy such as CMT2. Our case demonstrates a rare manifestation of the c.290 C>T, pGly97Glu VCP mutation.

14.
Brain ; 137(Pt 11): 2897-902, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25125609

RESUMO

Mutations in VCP have been reported to account for a spectrum of phenotypes that include inclusion body myopathy with Paget's disease of the bone and frontotemporal dementia, hereditary spastic paraplegia, and 1-2% of familial amyotrophic lateral sclerosis. We identified a novel VCP mutation (p.Glu185Lys) segregating in an autosomal dominant Charcot-Marie-Tooth disease type 2 family. Functional studies showed that the Glu185Lys variant impaired autophagic function leading to the accumulation of immature autophagosomes. VCP mutations should thus be considered for genetically undefined Charcot-Marie-Tooth disease type 2.


Assuntos
Adenosina Trifosfatases/genética , Proteínas de Ciclo Celular/genética , Doença de Charcot-Marie-Tooth/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Charcot-Marie-Tooth/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Linhagem , Fenótipo , Proteína com Valosina
15.
Neurology ; 82(22): 2007-16, 2014 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-24808017

RESUMO

OBJECTIVE: To identify a novel disease gene in 2 families with autosomal recessive hereditary spastic paraplegia (HSP). METHODS: We used whole-exome sequencing to identify the underlying genetic disease cause in 2 families with apparently autosomal recessive spastic paraplegia. Endogenous expression as well as subcellular localization of wild-type and mutant protein were studied to support the pathogenicity of the identified mutations. RESULTS: In 2 families, we identified compound heterozygous or homozygous mutations in the kinesin gene KIF1C to cause hereditary spastic paraplegia type 58 (SPG58). SPG58 can be complicated by cervical dystonia and cerebellar ataxia. The same mutations in a heterozygous state result in a mild or subclinical phenotype. KIF1C mutations in SPG58 affect the domains involved in adenosine triphosphate hydrolysis and microtubule binding, key functions for this microtubule-based motor protein. CONCLUSIONS: KIF1C is the third kinesin gene involved in the pathogenesis of HSPs and is characterized by a mild dominant and a more severe recessive disease phenotype. The identification of KIF1C as an HSP disease gene further supports the key role of intracellular trafficking processes in the pathogenesis of hereditary axonopathies.


Assuntos
Cinesinas/genética , Mutação/genética , Paraplegia Espástica Hereditária/genética , Adulto , Movimento Celular/genética , Feminino , Alemanha , Heterozigoto , Homozigoto , Humanos , Espaço Intracelular/genética , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Índice de Gravidade de Doença
16.
Brain ; 137(Pt 1): 69-77, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24355708

RESUMO

Boucher-Neuhäuser and Gordon Holmes syndromes are clinical syndromes defined by early-onset ataxia and hypogonadism plus chorioretinal dystrophy (Boucher-Neuhäuser syndrome) or brisk reflexes (Gordon Holmes syndrome). Here we uncover the genetic basis of these two syndromes, demonstrating that both clinically distinct entities are allelic for recessive mutations in the gene PNPLA6. In five of seven Boucher-Neuhäuser syndrome/Gordon Holmes syndrome families, we identified nine rare conserved and damaging mutations by applying whole exome sequencing. Further, by dissecting the complex clinical presentation of Boucher-Neuhäuser syndrome and Gordon Holmes syndrome into its neurological system components, we set out to analyse an additional 538 exomes from families with ataxia (with and without hypogonadism), pure and complex hereditary spastic paraplegia, and Charcot-Marie-Tooth disease type 2. We identified four additional PNPLA6 mutations in spastic ataxia and hereditary spastic paraplegia families, revealing that Boucher-Neuhäuser and Gordon Holmes syndromes in fact represent phenotypic clusters on a spectrum of neurodegenerative diseases caused by mutations in PNPLA6. Structural analysis indicates that the majority of mutations falls in the C-terminal phospholipid esterase domain and likely inhibits the catalytic activity of PNPLA6, which provides the precursor for biosynthesis of the neurotransmitter acetylcholine. Our findings show that PNPLA6 influences a manifold of neuronal systems, from the retina to the cerebellum, upper and lower motor neurons and the neuroendocrine system, with damage of this protein causing an extraordinarily broad continuous spectrum of associated neurodegenerative disease.


Assuntos
Ataxia Cerebelar/genética , Hormônio Liberador de Gonadotropina/deficiência , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Hipogonadismo/genética , Mutação/genética , Fosfolipases/genética , Distrofias Retinianas/genética , Ataxias Espinocerebelares/genética , Adulto , Ataxia/etiologia , Ataxia/genética , Ataxia Cerebelar/fisiopatologia , DNA/genética , Exoma/genética , Família , Feminino , Hormônio Liberador de Gonadotropina/genética , Transtornos Heredodegenerativos do Sistema Nervoso/fisiopatologia , Humanos , Hipogonadismo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Mutação/fisiologia , Distrofias Retinianas/fisiopatologia , Paraplegia Espástica Hereditária/genética , Ataxias Espinocerebelares/fisiopatologia
17.
Nat Rev Clin Oncol ; 10(12): 688-96, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24129347

RESUMO

Several drugs targeting poly(ADP-ribose) polymerase (PARP) enzymes are under development. Responses have been observed in patients with germline mutations in BRCA1 and BRCA2, with further data supporting antitumour activity of PARP inhibitors in sporadic ovarian cancer. Strategies to identify other predictive biomarkers remain under investigation. Iniparib was purported to be a PARP inhibitor that showed promising results in randomized phase II trials in patients with triple-negative breast cancer. Negative results from a phase III study in this disease setting, however, tempered enthusiasm for this agent. Recently, data from in vitro experiments suggest that iniparib is not only structurally distinct from other described PARP inhibitors, but is also a poor inhibitor of PARP activity. In this context, the negative iniparib phase III data might have erroneously promulgated the notion that PARP inhibition is not an effective therapeutic strategy. Here, we scrutinize the development of iniparib from preclinical studies to registration trials, and identify and discuss the pitfalls in the development of anticancer drugs to prevent future late-stage trial failures.


Assuntos
Antineoplásicos/uso terapêutico , Benzamidas/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases , Ensaios Clínicos como Assunto , Feminino , Humanos , Projetos de Pesquisa
18.
J Clin Invest ; 122(2): 538-44, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22232211

RESUMO

Hereditary spastic paraplegias (HSPs) are a group of genetically heterogeneous neurodegenerative conditions. They are characterized by progressive spastic paralysis of the legs as a result of selective, length-dependent degeneration of the axons of the corticospinal tract. Mutations in 3 genes encoding proteins that work together to shape the ER into sheets and tubules - receptor accessory protein 1 (REEP1), atlastin-1 (ATL1), and spastin (SPAST) - have been found to underlie many cases of HSP in Northern Europe and North America. Applying Sanger and exome sequencing, we have now identified 3 mutations in reticulon 2 (RTN2), which encodes a member of the reticulon family of prototypic ER-shaping proteins, in families with spastic paraplegia 12 (SPG12). These autosomal dominant mutations included a complete deletion of RTN2 and a frameshift mutation predicted to produce a highly truncated protein. Wild-type reticulon 2, but not the truncated protein potentially encoded by the frameshift allele, localized to the ER. RTN2 interacted with spastin, and this interaction required a hydrophobic region in spastin that is involved in ER localization and that is predicted to form a curvature-inducing/sensing hairpin loop domain. Our results directly implicate a reticulon protein in axonopathy, show that this protein participates in a network of interactions among HSP proteins involved in ER shaping, and further support the hypothesis that abnormal ER morphogenesis is a pathogenic mechanism in HSP.


Assuntos
Retículo Endoplasmático/ultraestrutura , Proteínas de Membrana/genética , Proteínas Musculares/genética , Mutação , Proteínas do Tecido Nervoso/genética , Paraplegia Espástica Hereditária/genética , Paraplegia Espástica Hereditária/patologia , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Análise Mutacional de DNA , Retículo Endoplasmático/metabolismo , Células HEK293 , Células HeLa , Humanos , Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Paraplegia Espástica Hereditária/fisiopatologia , Espastina
19.
Curr Biol ; 21(8): 692-9, 2011 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-21497086

RESUMO

Geminin is an essential cell-cycle protein that is only present from S phase to early mitosis in metazoan somatic cells. Genetic ablation of geminin in the mouse results in preimplantation embryonic lethality because pluripotent cells fail to form and all cells differentiate to trophoblast. Here we show that geminin is present in G1 phase of mouse pluripotent cells in contrast to somatic cells, where anaphase-promoting complex/cyclosome (APC/C)-mediated proteasomal destruction removes geminin in G1. Silencing geminin directly or by depleting the APC/C inhibitor Emi1 causes loss of stem cell identity and trophoblast differentiation of mouse embryonal carcinoma and embryonic stem cells. Depletion of cyclins A2 or B1 does not induce this effect, even though both of these APC/C substrates are also present during G1 of pluripotent cells. Crucially, geminin antagonizes the chromatin-remodeling protein Brg1 to maintain expression of Oct4, Sox2, and Nanog. Our results define a pluripotency pathway by which suppressed APC/C activity protects geminin from degradation in G1, allowing sustained expression of core pluripotency factors. Collectively, these findings link the cell cycle to the pluripotent state but also raise an unexplained paradox: How is cell-cycle progression possible in pluripotent cells when oscillations of key regulatory proteins are lost?


Assuntos
Proteínas de Ciclo Celular/metabolismo , Fase G1 , Proteínas de Homeodomínio/metabolismo , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Células-Tronco Pluripotentes/citologia , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/metabolismo , Ciclossomo-Complexo Promotor de Anáfase , Animais , Diferenciação Celular , Ciclina A2/metabolismo , Ciclina B1/metabolismo , DNA Helicases/metabolismo , Células-Tronco de Carcinoma Embrionário/citologia , Células-Tronco Embrionárias/citologia , Geminina , Camundongos , Proteína Homeobox Nanog , Complexos Ubiquitina-Proteína Ligase/metabolismo
20.
Laryngoscope ; 116(8): 1434-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16885749

RESUMO

OBJECTIVES: Minichromosome maintenance protein 2 (Mcm-2) is essential for DNA replication and serves as a useful biomarker of cell-cycle state in human tissue samples. Ki-67 is an established proliferation marker. Because Mcm-2 expression has not previously been assessed in thyroid tissue, the aim of this study was to assess the expression of both proteins in a range of thyroid lesions to determine their potential value as preoperative markers of thyroid malignancy. METHODS: Mcm-2 and Ki-67 protein expression were assessed by immunohistochemistry in formalin-fixed, paraffin-embedded thyroid tissues from 128 patients with histologic diagnoses of papillary carcinoma (n = 38), follicular carcinoma (n = 22), follicular adenoma (n = 33), and dominant nodules of multinodular goitre (n = 35). RESULTS: Mcm-2 and Ki-67-labeling indices (LIs) were both higher in follicular and papillary carcinomas than in follicular adenomas or dominant nodules. The Ki-67 LI discriminated better between follicular carcinomas and follicular adenomas (P < .0001) than Mcm-2 (P = .0273). However, the Mcm-2 and Ki-67 LIs overlapped widely between the four histologic groups, and the expression of these proteins was also noted to be heterogenous within these lesions. CONCLUSION: Neither Mcm-2 or Ki-67 can currently be reliably applied as preoperative markers to distinguish benign from malignant thyroid lesions.


Assuntos
Biomarcadores Tumorais/análise , Proteínas de Ciclo Celular/análise , Antígeno Ki-67/análise , Proteínas Nucleares/análise , Neoplasias da Glândula Tireoide/diagnóstico , Adenoma/diagnóstico , Carcinoma Papilar/diagnóstico , Bócio Nodular/diagnóstico , Humanos , Imuno-Histoquímica , Componente 2 do Complexo de Manutenção de Minicromossomo , Glândula Tireoide/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA