Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 94
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
EMBO J ; 40(14): e105712, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34057742

RESUMO

During development, neural progenitors are in proliferative and immature states; however, the molecular machinery that cooperatively controls both states remains elusive. Here, we report that cyclin D1 (CCND1) directly regulates both proliferative and immature states of cerebellar granule cell progenitors (GCPs). CCND1 not only accelerates cell cycle but also upregulates ATOH1 protein, an essential transcription factor that maintains GCPs in an immature state. In cooperation with CDK4, CCND1 directly phosphorylates S309 of ATOH1, which inhibits additional phosphorylation at S328 and consequently prevents S328 phosphorylation-dependent ATOH1 degradation. Additionally, PROX1 downregulates Ccnd1 expression by histone deacetylation of Ccnd1 promoter in GCPs, leading to cell cycle exit and differentiation. Moreover, WNT signaling upregulates PROX1 expression in GCPs. These findings suggest that WNT-PROX1-CCND1-ATOH1 signaling cascade cooperatively controls proliferative and immature states of GCPs. We revealed that the expression and phosphorylation levels of these molecules dynamically change during cerebellar development, which are suggested to determine appropriate differentiation rates from GCPs to GCs at distinct developmental stages. This study contributes to understanding the regulatory mechanism of GCPs as well as neural progenitors.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cerebelo/crescimento & desenvolvimento , Cerebelo/metabolismo , Ciclina D1/metabolismo , Grânulos Citoplasmáticos/metabolismo , Fosforilação/fisiologia , Células-Tronco/metabolismo , Animais , Ciclo Celular/genética , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Proteínas Hedgehog/metabolismo , Camundongos , Neurogênese/fisiologia , Transdução de Sinais/fisiologia , Fatores de Transcrição
2.
Cell ; 139(1): 161-74, 2009 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-19804761

RESUMO

GABAergic interneurons are key elements in neural coding, but the mechanisms that assemble inhibitory circuits remain unclear. In the spinal cord, the transfer of sensory signals to motor neurons is filtered by GABAergic interneurons that act presynaptically to inhibit sensory transmitter release and postsynaptically to inhibit motor neuron excitability. We show here that the connectivity and synaptic differentiation of GABAergic interneurons that mediate presynaptic inhibition is directed by their sensory targets. In the absence of sensory terminals these GABAergic neurons shun other available targets, fail to undergo presynaptic differentiation, and withdraw axons from the ventral spinal cord. A sensory-specific source of brain derived neurotrophic factor induces synaptic expression of the GABA synthetic enzyme GAD65--a defining biochemical feature of this set of interneurons. The organization of a GABAergic circuit that mediates presynaptic inhibition in the mammalian CNS is therefore controlled by a stringent program of sensory recognition and signaling.


Assuntos
Interneurônios/fisiologia , Medula Espinal/fisiologia , Ácido gama-Aminobutírico/fisiologia , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Glutamato Descarboxilase , Camundongos , Neurônios Motores/fisiologia , Terminações Pré-Sinápticas , Propriocepção , Células Receptoras Sensoriais/fisiologia , Medula Espinal/citologia
4.
BMC Cancer ; 22(1): 119, 2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35093003

RESUMO

BACKGROUND: Borderline resectable pancreatic cancer (BRPC) is a category of pancreatic cancer that is anatomically widely spread, and curative resection is uncommon with upfront surgery. Intensity-modulated radiation therapy (IMRT) is a form of radiation therapy that delivers precise radiation to a tumor while minimizing the dose to surrounding normal tissues. Here, we conducted a phase 2 study to estimate the curability and efficacy of neoadjuvant chemoradiotherapy using IMRT (NACIMRT) for patients with BRPC with arterial abutment (BRPC-A). METHODS: A total of 49 BRPC-A patients were enrolled in this study and were treated at our hospital according to the study protocol between June 2013 and March 2021. The primary endpoint was microscopically margin-negative resection (R0) rates and we subsequently analyzed safety, histological effect of the treatment as well as survivals among patients with NACIMRT. RESULTS: Twenty-nine patients (59.2%) received pancreatectomy after NACIMRT. The R0 rate in resection patients was 93.1% and that in the whole cohort was 55.1%. No mortality was encountered. Local therapeutic effects as assessed by Evans classification showed good therapeutic effect (Grade 1, 3.4%; Grade 2a, 31.0%; Grade 2b, 48.3%; Grade 3, 3.4%; Grade 4, 3.4%). Median disease-free survival was 15.5 months. Median overall survival in the whole cohort was 35.1 months. The only independent prognostic pre-NACIMRT factor identified was serum carbohydrate antigen 19-9 (CA19-9) > 400 U/ml before NACIMRT. CONCLUSIONS: NACIMRT showed preferable outcome without significant operative morbidity for BRPC-A patients. NACIMRT contributes to good local tumor control, but a high initial serum CA19-9 implies poor prognosis even after neoadjuvant treatment. TRIAL REGISTRATION: UMIN-CTR Clinical Trial: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000011776 Registration number: UMIN000010113. Date of first registration: 01/03/2013.


Assuntos
Terapia Neoadjuvante , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/terapia , Radioterapia de Intensidade Modulada , Idoso , Antígenos Glicosídicos Associados a Tumores/sangue , Artérias , Feminino , Humanos , Masculino , Margens de Excisão , Pessoa de Meia-Idade , Pancreatectomia , Estudos Prospectivos , Resultado do Tratamento
5.
Scand J Gastroenterol ; 55(4): 479-484, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32223573

RESUMO

Background: In the treatment of metastatic pancreatic neuroendocrine tumors (PanNETs), surgical resection is the first choice if curative resection is expected. However, most patients develop recurrence after resection of liver metastasis. Because one of the benefits of resection is to gain a tumor-free period for the patients, it is important to identify which patients achieve longer recurrence-free survival (RFS) by resection. In this study, the clinicopathological factors associated with RFS after resection of metastatic PanNETs in the liver were evaluated to identify the patient group that is suitable for resection.Methods: Consecutively diagnosed patients with PanNET liver metastasis with resection at our hospital from January 2000 to July 2019 were evaluated. A total of 26 metastatic PanNET patients with primary liver resections were evaluated. The median follow-up time was 48.3 months.Results: There were 18 NET recurrences of the total 26 resections, with a median RFS of 17.9 months. Independent risk factors for short RFS were a high Ki67 index (p = .009) and the number of resected tumors (p = .045). When the cut-off value for the Ki67 index was 5.0% and that for the number of resected tumors was 6, Ki67 > 5.0% tumors had shorter RFS (4.9 months vs. 38.2 months p = .006), and patients with tumors > = 7 tumors had shorter RFS (4.7 months vs. 27.5 months p = .001).Conclusions: These findings indicate that good candidates for resection of metastatic tumors of PanNETs could be patients with low Ki67 tumors and a small number of metastatic tumors.


Assuntos
Antígeno Ki-67/metabolismo , Neoplasias Hepáticas/secundário , Recidiva Local de Neoplasia/mortalidade , Tumores Neuroendócrinos/mortalidade , Neoplasias Pancreáticas/mortalidade , Adulto , Idoso , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/patologia , Tumores Neuroendócrinos/cirurgia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Fatores de Risco , Taxa de Sobrevida
6.
Surg Today ; 49(7): 593-600, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30838442

RESUMO

BACKGROUND: We evaluated the clinicopathological factors associated with lymph node metastasis in patients with non-functioning pancreatic neuroendocrine neoplasms (PanNENs), focusing on the risk factors and range of lymph node metastasis for tumors ≤ 2 cm in diameter. METHODS: The subjects of this study were patients with PanNENs consecutively diagnosed at our hospital between January, 2000 and June, 2018. We analyzed 69 patients who underwent R0 resection of a non-functioning sporadic PanNEN with no distant metastasis, as well as 43 patients with tumors ≤ 20 mm in radiological diameter. RESULTS: Nineteen patients (27.5%), including 7 (16.3%) with a small PanNEN, had lymph node metastasis. A large radiological diameter, a high Ki67 index, and cyst formation correlated significantly with positive lymph node metastasis. In patients with tumors ≤ 20 mm in diameter, a high Ki67 index correlated significantly with lymph node metastasis. When we set the cut-off Ki67 index as 3.3%, 2 of 43 patients had lymph node metastasis. Tumors in the uncinate process readily metastasized to the region around the superior mesenteric artery. CONCLUSIONS: These findings suggest that a high Ki67 index indicates a risk of lymph node metastasis for tumors ≤ 20 mm in diameter and that lymphadenectomy should be performed in the region spatially adjacent to the primary tumor.


Assuntos
Biomarcadores Tumorais/análise , Antígeno Ki-67/análise , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Excisão de Linfonodo , Metástase Linfática , Masculino , Artéria Mesentérica Superior/patologia , Pessoa de Meia-Idade , Tumores Neuroendócrinos/cirurgia , Neoplasias Pancreáticas/cirurgia , Valor Preditivo dos Testes , Tomografia Computadorizada por Raios X
7.
Ann Surg Oncol ; 25(2): 528-534, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29164413

RESUMO

BACKGROUND: The primary site of a neuroendocrine neoplasms (NEN) around the head of the pancreas is sometimes difficult to assess before resection, and the characteristics of the primary site around this region have not been elucidated for recurrence after curative resection. In this study, the clinicopathologic characteristics of pancreatic NEN (PanNEN) and duodenal NEN (DuNEN) were evaluated, and the risk factors as well as the recurrence types after resection were investigated. METHODS: Consecutively diagnosed NEN patients at the authors' hospital from January 2000 to July 2016 were evaluated in this study. For 117 PanNEN patients and 31 non-ampullary DuNEN patients, R0 resection was achieved. The median follow-up period was 8.1 years. RESULTS: In this study, 27 PanNEN patients (23.1%) had recurrences, with a median disease-free survival (DFS) of 133 months, whereas 11 DuNEN patients (35.5%) had recurrences, with a median DFS of 156 months. The PanNEN patients tended to have primary recurrence in the liver (85.2%), followed by lymph nodes (11.1%). The independent risk factors for short DFS were lymph node metastasis at resection (p = 0.001) and microvascular invasion (p = 0.048). In contrast, the DuNEN patients were likely to have lymph node metastasis (81.8%). The independent risk factors for short DFS were lymph node metastasis at resection (p = 0.003) and large diameter (p = 0.013). CONCLUSIONS: Most initial recurrences of PanNEN occurred in the liver, whereas those of DuNEN appeared in lymph nodes, suggesting that proper diagnosis of the primary site and appropriate imaging methods for surveillance after resection are necessary.


Assuntos
Neoplasias Duodenais/cirurgia , Recidiva Local de Neoplasia/diagnóstico , Tumores Neuroendócrinos/cirurgia , Pancreatectomia/mortalidade , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Neoplasias Duodenais/patologia , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia/mortalidade , Tumores Neuroendócrinos/secundário , Neoplasias Pancreáticas/patologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
8.
Pancreatology ; 17(3): 484-489, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28336225

RESUMO

BACKGROUND/OBJECTIVES: Pancreatic fistulas are one of the most frequent morbidities after pancreaticoduodenectomy. Several reports have suggested a relationship between bacterial infections and postoperative pancreatic fistulas, although details of the mechanisms involved in hemorrhage in association with the fistulas have not been elucidated. This study retrospectively examined the relationship between positive drainage culture and hemorrhage associated with pancreatic fistulas after pancreaticoduodenectomy. METHODS: From January 2012 to December 2015, 142 consecutive patients underwent pancreaticoduodenectomy at our institution. We retrospectively reviewed the patients' demographic data, perioperative laboratory data, and drainage culture results. RESULTS: Twenty-four (17%) patients had clinically relevant postoperative pancreatic fistulas, whereas thirty-four (24%) patients experienced positive drainage culture. Multivariable analysis revealed that positive drainage culture was independently associated with clinically relevant postoperative pancreatic fistulas (odds ratio, 18.1; 95% confidence interval, 5.5-72.2; P < 0.001). Additionally, the prevalence of Candida albicans in the lavage of eight patients significantly correlated with hemorrhage associated with pancreatic fistulas (odds ratio, 43.5; 95% confidence interval, 6.2-513.3; P < 0.001). Seventy-five percent (6/8) of these patients suffered potentially lethal hemorrhagic complications and needed intervention. CONCLUSIONS: A positive abdominal drainage culture is associated with the development of pancreatic fistulas. Moreover, the presence of Candida albicans in drainage fluid may be a risk factor for hemorrhagic complications.


Assuntos
Candida albicans , Candidíase/complicações , Hemorragia/etiologia , Fístula Pancreática/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Candidíase/microbiologia , Feminino , Hemorragia/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fístula Pancreática/microbiologia , Pancreaticoduodenectomia/efeitos adversos , Complicações Pós-Operatórias/microbiologia , Prevalência , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
9.
Genes Cells ; 20(6): 500-11, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25919081

RESUMO

Notch signaling has been shown to contribute to murine pancreatic development at various stages. Delta-like 1 (Dll1) or Jagged1 (Jag1) are the Notch ligands that solely function to trigger this signaling during the pancreatic bud stage (~e9.5) or after birth, respectively. However, it has not been elucidated whether these Notch ligands are required at the later stage (e10.5-18.5) when the particular pancreas structures form. Here, we detected the dual expression of Dll1 and Jag1 in the epithelium after e10.5, which was restricted to the ductal cell lineage, including centroacinar cells expressing Sox9, CD133 and Hes1 but not the ductal cell markers Hnf1ß and DBA, at e18.5. To evaluate the significance of the Notch ligands during this period, we established double-floxed mice of Dll1 and Jag1 genes with Ptf1a-Cre knock-in allele and examined the effects on development. The abrogation of both ligands but not a single one led to the loss of centroacinar cells, which was due to the decrease in cell proliferation and the increase in cell death, as well as to the reduction of Sox9. These results suggested that Dll1 and Jag1 function redundantly and are necessary to maintain the centroacinar cells as an environmental niche in the developing pancreas.


Assuntos
Células Acinares/metabolismo , Pâncreas/metabolismo , Receptor Notch1/metabolismo , Células Acinares/citologia , Animais , Apoptose , Proteínas de Ligação ao Cálcio/metabolismo , Proliferação de Células , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Jagged-1 , Ligantes , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Pâncreas/citologia , Pâncreas/crescimento & desenvolvimento , Fatores de Transcrição SOX9/metabolismo , Proteínas Serrate-Jagged
10.
Surg Today ; 46(11): 1282-9, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26860274

RESUMO

PURPOSES: In the surgical treatment of pancreatic cancer, margin-negative status is one of the most important determinants of survival. We conducted this study to explore surgical margin status as well as other factors affecting the survival of borderline-resectable pancreatic cancer (BRPC) patients who received neoadjuvant chemotherapy with gemcitabine and S-1. METHODS: Eighteen BRPC patients were prospectively treated with concurrent gemcitabine and S-1 neoadjuvant chemotherapy (NAC+) and 15 of these patients underwent resection. We evaluated the safety and efficacy of this treatment regimen by comparing the outcomes of these patients with those of 19 BRPC patients who did not receive neoadjuvant chemotherapy (NAC-) during the same period. RESULTS: Fifteen (83 %) of the NAC+ patients underwent pancreatectomy. The remaining three patients (17 %) had regional tumor progression or liver metastasis. Of the 15 NAC+ patients who underwent resection, 3 (20 %) had margin-positive status, whereas 9 of the 19 (43 %) NAC- patients had margin-positive status (p = 0.002). However, disease-free survival and overall survival were similar in the two groups (MST 21.7 vs. 21.1 months). NAC+ patients with tumors smaller than 30 mm had favorable overall survival (MST 43.9 vs. 23.1 months, p = 0.0321). Most recurrences developed at distant sites rather than locally in both groups. CONCLUSIONS: In the neoadjuvant setting, gemcitabine and S-1 improved the negative surgical margin rate in BRPC patients, but it did not improve survival. Thus, neoadjuvant chemotherapy should be given to BRPC patients at an earlier stage.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Neoadjuvante , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Adjuvante , Terapia Combinada , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Ácido Oxônico/administração & dosagem , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Taxa de Sobrevida , Tegafur/administração & dosagem , Resultado do Tratamento , Gencitabina
11.
J Neurosci ; 34(14): 4786-800, 2014 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-24695699

RESUMO

In the cerebellum, the bHLH transcription factors Ptf1a and Atoh1 are expressed in distinct neuroepithelial regions, the ventricular zone (VZ) and the rhombic lip (RL), and are required for producing GABAergic and glutamatergic neurons, respectively. However, it is unclear whether Ptf1a or Atoh1 is sufficient for specifying GABAergic or glutamatergic neuronal fates. To test this, we generated two novel knock-in mouse lines, Ptf1a(Atoh1) and Atoh1(Ptf1a), that are designed to express Atoh1 and Ptf1a ectopically in the VZ and RL, respectively. In Ptf1a(Atoh1) embryos, ectopically Atoh1-expressing VZ cells produced glutamatergic neurons, including granule cells and deep cerebellar nuclei neurons. Correspondingly, in Atoh1(Ptf1a) animals, ectopically Ptf1a-expressing RL cells produced GABAergic populations, such as Purkinje cells and GABAergic interneurons. Consistent results were also obtained from in utero electroporation of Ptf1a or Atoh1 into embryonic cerebella, suggesting that Ptf1a and Atoh1 are essential and sufficient for GABAergic versus glutamatergic specification in the neuroepithelium. Furthermore, birthdating analyses with BrdU in the knock-in mice or with electroporation studies showed that ectopically produced fate-changed neuronal types were generated at temporal schedules closely simulating those of the wild-type RL and VZ, suggesting that the VZ and RL share common temporal information. Observations of knock-in brains as well as electroporated brains revealed that Ptf1a and Atoh1 mutually negatively regulate their expression, probably contributing to formation of non-overlapping neuroepithelial domains. These findings suggest that Ptf1a and Atoh1 specify spatial identities of cerebellar neuron progenitors in the neuroepithelium, leading to appropriate production of GABAergic and glutamatergic neurons, respectively.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cerebelo/citologia , Ácido Glutâmico/metabolismo , Células-Tronco Neurais/fisiologia , Neurônios/metabolismo , Fatores de Transcrição/metabolismo , Ácido gama-Aminobutírico/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular/genética , Cerebelo/embriologia , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento/genética , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Fatores de Transcrição/genética
12.
Nihon Rinsho ; 73(12): 2129-33, 2015 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-26666164

RESUMO

The functional cells or tissues derived from human induced pluripotent stem cells (iPSCs) make it possible to overcome with the insufficiency of cell sources for regenerative medicine, to investigate the precise mechanism of human organogenesis and disease, and to develop the new drugs. Especially for type 1 diabetes, making mature pancreatic beta cells from human iPSCs might have a good opportunity of regenerative medicine. However, so far in vitro, producing the fully maturated pancreatic beta cells is not achieved. Here we review the previous reports and discuss the possibility and validity of our strategy for making mature pancreatic beta cell with three-dimensional culture of pancreatic organoid derived from human iPSCs.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Pâncreas/citologia , Trifosfato de Adenosina/metabolismo , Animais , Diferenciação Celular , Humanos , Pâncreas/metabolismo , Medicina Regenerativa/métodos
13.
J Neurosci ; 33(44): 17326-34, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-24174665

RESUMO

Ca(2+)-dependent activator protein for secretion 1 (CAPS1) plays a regulatory role in the dense-core vesicle (DCV) exocytosis pathway, but its functions at the cellular and synaptic levels in the brain are essentially unknown because of neonatal death soon after birth in Caps1 knock-out mice. To clarify the functions of the protein in the brain, we generated two conditional knock-out (cKO) mouse lines: 1) one lacking Caps1 in the forebrain; and 2) the other lacking Caps1 in the cerebellum. Both cKO mouse lines were born normally and grew to adulthood, although they showed subcellular and synaptic abnormalities. Forebrain-specific Caps1 cKO mice showed reduced immunoreactivity for the DCV marker secretogranin II (SgII) and the trans-Golgi network (TGN) marker syntaxin 6, a reduced number of presynaptic DCVs, and dilated trans-Golgi cisternae in the CA3 region. Cerebellum-specific Caps1 cKO mice had decreased immunoreactivity for SgII and brain-derived neurotrophic factor (BDNF) along the climbing fibers. At climbing fiber-Purkinje cell synapses, the number of DCVs was markedly lower and the number of synaptic vesicles was also reduced. Correspondingly, the mean amplitude of EPSCs was decreased, whereas paired-pulse depression was significantly increased. Our results suggest that loss of CAPS1 disrupts the TGN-DCV pathway, which possibly impairs synaptic transmission by reducing the presynaptic release probability.


Assuntos
Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio/deficiência , Complexo de Golgi/metabolismo , Proteínas do Tecido Nervoso/deficiência , Terminações Pré-Sinápticas/metabolismo , Vesículas Secretórias/metabolismo , Animais , Encéfalo/ultraestrutura , Complexo de Golgi/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Terminações Pré-Sinápticas/ultraestrutura , Probabilidade , Transporte Proteico/genética , Vesículas Secretórias/ultraestrutura
14.
Strahlenther Onkol ; 190(5): 485-90, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24599344

RESUMO

BACKGROUND AND PURPOSE: To evaluate the treatment outcomes of radiotherapy and prognostic factors for recurrent pancreatic cancer. PATIENTS AND METHODS: The study comprised 30 patients who developed a locoregional recurrence of primarily resected pancreatic cancer and received radiotherapy between 2000 and 2013 with a median dose of 54 Gy (range, 39-60 Gy). Concurrent chemotherapy included gemcitabine for 18 patients and S-1 for seven patients. The treatment outcomes and prognostic factors were retrospectively analyzed. RESULTS: The median follow-up after radiotherapy was 14.6 months. The 1-year overall survival, local control, and progression-free survival rates were 69%, 67%, and 32%, respectively. The median overall survival and progression-free survival rates were 15.9 and 6.9 months, respectively. Tumor marker reduction and ≥ 50% reduction were observed in 18 and two patients, respectively. Of the seven patients who exhibited pain symptoms, four and two patients were partly and completely relieved, respectively. Late grade 3 ileus and gastroduodenal bleeding were observed in one patient each. Among the clinicopathological factors evaluated, only a disease-free interval of greater than 18.9 months exhibited a significant association with improved overall survival (p = 0.017). CONCLUSIONS: Radiotherapy for isolated locally recurrent pancreatic cancer resulted in encouraging local control, overall survival, and palliative effects with mild toxicity, particularly in patients with a prolonged disease-free interval. This treatment strategy should be prospectively evaluated.


Assuntos
Quimiorradioterapia Adjuvante , Recidiva Local de Neoplasia/radioterapia , Pancreatectomia , Neoplasias Pancreáticas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Intervalo Livre de Doença , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Oxônico/administração & dosagem , Medição da Dor , Cuidados Paliativos/métodos , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Prognóstico , Dosagem Radioterapêutica , Tegafur/administração & dosagem , Gencitabina
15.
Nat Commun ; 15(1): 458, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302444

RESUMO

In the central nervous system, astrocytes enable appropriate synapse function through glutamate clearance from the synaptic cleft; however, it remains unclear how astrocytic glutamate transporters function at peri-synaptic contact. Here, we report that Down syndrome cell adhesion molecule (DSCAM) in Purkinje cells controls synapse formation and function in the developing cerebellum. Dscam-mutant mice show defects in CF synapse translocation as is observed in loss of function mutations in the astrocytic glutamate transporter GLAST expressed in Bergmann glia. These mice show impaired glutamate clearance and the delocalization of GLAST away from the cleft of parallel fibre (PF) synapse. GLAST complexes with the extracellular domain of DSCAM. Riluzole, as an activator of GLAST-mediated uptake, rescues the proximal impairment in CF synapse formation in Purkinje cell-selective Dscam-deficient mice. DSCAM is required for motor learning, but not gross motor coordination. In conclusion, the intercellular association of synaptic and astrocyte proteins is important for synapse formation and function in neural transmission.


Assuntos
Neuroglia , Neurônios , Animais , Camundongos , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Cerebelo/metabolismo , Ácido Glutâmico/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Células de Purkinje/metabolismo , Sinapses/metabolismo
16.
Nat Genet ; 32(1): 128-34, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12185368

RESUMO

Pancreas development begins with the formation of buds at specific sites in the embryonic foregut endoderm. We used recombination-based lineage tracing in vivo to show that Ptf1a (also known as PTF1-p48) is expressed at these early stages in the progenitors of pancreatic ducts, exocrine and endocrine cells, rather than being an exocrine-specific gene as previously described. Moreover, inactivation of Ptf1a switches the character of pancreatic progenitors such that their progeny proliferate in and adopt the normal fates of duodenal epithelium, including its stem-cell compartment. Consistent with the proposal that Ptf1a supports the specification of precursors of all three pancreatic cell types, transgene-based expression of Pdx1, a gene essential to pancreas formation, from Ptf1a cis-regulatory sequences restores pancreas tissue to Pdx1-null mice that otherwise lack mature exocrine and endocrine cells because of an early arrest in organogenesis. These experiments provide evidence that Ptf1a expression is specifically connected to the acquisition of pancreatic fate by undifferentiated foregut endoderm.


Assuntos
Duodeno/embriologia , Regulação da Expressão Gênica , Proteínas de Homeodomínio , Pâncreas/embriologia , Fatores de Transcrição/fisiologia , Animais , Animais Geneticamente Modificados , Diferenciação Celular , Linhagem da Célula , Duodeno/citologia , Camundongos , Pâncreas/citologia , Transativadores/metabolismo
17.
Cancer Med ; 12(18): 18611-18621, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37649318

RESUMO

BACKGROUND: Resectable pancreatic cancer (RPC) is potentially resectable on admission, and the impact of neoadjuvant therapy on these tumors is controversial. Moreover, the safety and efficacy of neoadjuvant chemoradiotherapy with moderately hypofractionated intensity-modulated radiation therapy (NACIMRT) for RPC have not been studied. Here, we conducted a phase II study to evaluate the safety and efficacy of hypofractionated NACIMRT for RPC. METHODS: A total of 54 RPC patients were enrolled and treated according to the study protocol. We used moderately hypofractionated (45 Gy in 15 fractions) IMRT with gemcitabine to shorten the duration of radiotherapy and reduce gastrointestinal toxicity. The primary endpoint was overall survival (OS), and we subsequently analyzed the microscopically margin-negative resection (R0) rate, disease-free survival (DFS), and histologic effects and safety of NACIMRT. RESULTS: Median OS for the cohort was 40.0 months. Forty-two patients (77.8%) underwent pancreatectomy after NACIMRT. Median DFS was 20.3 months. The R0 resection rate was 95.2% (40/42) per protocol and 85.2% (46/54) for the cohort. There were no intervention-related deaths during the study period. Local treatment response, as assessed by the CAP classification, showed no residual tumor in 4.8% of patients. Overall, 23.9% of patients experienced CTCAE grade 3 or 4 during NACIMRT. Adjuvant therapy was initiated in 88% of patients undergoing resection. Postoperative complications grade ≥3b on the Clavien-Dindo scale occurred in 4.8% of patients. CA19-9 level at enrollment was an independent prognostic factor for OS and DFS. CONCLUSIONS: This is the first prospective study of hypofractionated IMRT as neoadjuvant therapy for RPC. Hypofractionated NACIMRT for RPC could be safely introduced with a high induction rate of adjuvant chemotherapy, with an overall survival of 40.0 months.

18.
Dev Biol ; 354(1): 44-54, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21443869

RESUMO

During brain development, neurons and glias are generated from neural stem cells and more limited intermediate neural progenitors (INPs). Numerous studies have revealed the mechanisms of development of neural stem cells. However, the signaling pathways that govern the development of INPs are largely unknown. The cerebellum is suitable for examining this issue because cerebellar cortical inhibitory neurons such as basket and stellate cells are derived from small Pax2(+) interneuronal progenitors. Here, we show that Sox2(-)/Pax2(+) and Sox2(+)/Pax2(-) progenitors, 2 types of interneuronal progenitors of basket and stellate cells, exist in the cerebellar white matter (WM) and that the former arise from the latter during the first postnatal week. Moreover, RBP-J promotes the neurogenesis of stellate and basket cells by converting Sox2(+)/Pax2(-) interneuronal progenitors to more mature Sox2(-)/Pax2(+) interneuronal progenitors. This study shows a novel RBP-J function that promotes INP differentiation.


Assuntos
Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/metabolismo , Células-Tronco Neurais/metabolismo , Neurogênese , Neurônios/metabolismo , Animais , Apoptose/genética , Cerebelo/citologia , Cerebelo/metabolismo , Feminino , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Imuno-Histoquímica , Hibridização In Situ , Interneurônios/citologia , Interneurônios/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Neurônios/citologia , Fator de Transcrição PAX2/genética , Fator de Transcrição PAX2/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Transdução de Sinais
19.
Cancer Cell ; 4(6): 437-50, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14706336

RESUMO

To evaluate the role of oncogenic RAS mutations in pancreatic tumorigenesis, we directed endogenous expression of KRAS(G12D) to progenitor cells of the mouse pancreas. We find that physiological levels of Kras(G12D) induce ductal lesions that recapitulate the full spectrum of human pancreatic intraepithelial neoplasias (PanINs), putative precursors to invasive pancreatic cancer. The PanINs are highly proliferative, show evidence of histological progression, and activate signaling pathways normally quiescent in ductal epithelium, suggesting potential therapeutic and chemopreventive targets for the cognate human condition. At low frequency, these lesions also progress spontaneously to invasive and metastatic adenocarcinomas, establishing PanINs as definitive precursors to the invasive disease. Finally, mice with PanINs have an identifiable serum proteomic signature, suggesting a means of detecting the preinvasive state in patients.


Assuntos
Carcinoma Ductal Pancreático/genética , Genes ras/fisiologia , Mutação , Neoplasias Pancreáticas/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Carcinoma Ductal Pancreático/metabolismo , Ciclo-Oxigenase 2 , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica , Isoenzimas/metabolismo , Metaloproteinase 7 da Matriz/metabolismo , Proteínas de Membrana , Camundongos , Metástase Neoplásica , Estadiamento de Neoplasias , Pâncreas/metabolismo , Pâncreas/patologia , Neoplasias Pancreáticas/metabolismo , Prostaglandina-Endoperóxido Sintases/metabolismo , Fatores de Transcrição HES-1
20.
Surg Today ; 42(5): 441-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22173649

RESUMO

PURPOSE: Delayed gastric emptying (DGE) is a leading cause of complication after pylorus-preserving pancreaticoduodenectomy (PPPD). Its incidence has been reported to range from 5 to 57%. We describe a modified reconstruction method, which resulted in a low rate of DGE. METHODS: Between April 2003 and March 2008, we performed PPPD and reconstruction using an antecolic method in 118 consecutive patients. After PPPD, reconstruction was done using conventional Child procedure in 12 patients (PPPD group) and with the following modifications in the remaining 106 patients (PPPDR group): duodenojejunostomy was performed using the straight method and the jejunum was anastomosed with a 30° counterclockwise twist. We evaluated the incidence of DGE based on the grading system defined by the International Study Group of Pancreatic Surgery (ISGPS). RESULTS: The PPPDR group had a lower incidence of DGE than the PPPD group (PPPD), occurring in 7 patients (7%) versus 4 patients (33%), respectively. However, the overall morbidity rates and postoperative hospital stays of the two groups did not differ significantly. CONCLUSIONS: Straight stomach reconstruction with a twisted anastomosis could reduce the incidence of DGE after PPPD reconstruction.


Assuntos
Gastrectomia/métodos , Esvaziamento Gástrico , Gastroparesia/epidemiologia , Gastroparesia/prevenção & controle , Jejuno/diagnóstico por imagem , Pancreaticoduodenectomia/métodos , Estômago/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica/métodos , Feminino , Gastrectomia/efeitos adversos , Gastrectomia/estatística & dados numéricos , Humanos , Incidência , Jejuno/cirurgia , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/efeitos adversos , Pancreaticoduodenectomia/estatística & dados numéricos , Piloro/cirurgia , Radiografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA