Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 662
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Phys Rev Lett ; 124(10): 102501, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32216444

RESUMO

Interaction cross sections for ^{42-51}Ca on a carbon target at 280 MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N=28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N=28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare ^{48}Ca core in Ca isotopes beyond N=28.

2.
Pharmazie ; 73(6): 315-317, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29880082

RESUMO

Angelica keiskei Koidzumi (Ashitaba) is a large perennial herb that is native to the Pacific coast of Japan, and it has recently become popular as herbal medicine, dietary supplement and health food in Asian countries. The structures of various constituents isolated from Ashitaba such as chalcones, flavanones and coumarins have been precisely characterized, and many of them have bioactivities. A recent study clarified that Angelica keiskei exerts actions that lead to the prevention of thrombosis. Here, we introduce the possibility that ingesting Ashitaba could help to prevent thrombotic diseases.


Assuntos
Angelica/química , Fibrinolíticos/farmacologia , Extratos Vegetais/farmacologia , Animais , Fibrinolíticos/isolamento & purificação , Humanos , Japão , Trombose/prevenção & controle
3.
Pharmazie ; 71(11): 651-654, 2016 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29441970

RESUMO

Angelica keiskei Koidzumi (Ashitaba) is a traditional folk medicine that is also regarded in Japan as a health food with potential antithrombotic properties. The ability of the major chalcones, xanthoangelol (XA) and 4-hydroxyderricin (4-HD) extracted from Ashitaba roots to inhibit platelet aggregation activity in vitro was recently determined. However, the anti-platelet activities of Ashitaba chalcones in vivo have remained unclear. The present study examines the anti-platelet effects of Ashitaba exudate and its constituent chalcones using mouse tail-bleeding models that reflect platelet aggregation in vivo. Ashitaba exudate and the major chalcone subtype XA, suppressed the lipopolysaccharide (LPS)-induced shortening of mouse tail bleeding. However, trace amounts of other Ashitaba chalcone subtypes including xanthoangelols B (XB), D (XD), E (XE) and F (XF) did not affect tail bleeding. These results suggest that the major chalcone subtype in Ashitaba, XA, has anti-platelet-activities in vivo.


Assuntos
Angelica/química , Chalconas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Animais , Chalconas/química , Hemorragia/tratamento farmacológico , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Raízes de Plantas/química , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/química
4.
Phys Rev Lett ; 112(3): 036602, 2014 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-24484156

RESUMO

We demonstrate spin injection into superconducting Nb by employing a spin absorption technique in lateral spin valve structures. Spin currents flowing in a nonmagnetic Cu channel are preferably absorbed into Nb due to its strong spin-orbit interaction, the amount of which dramatically changes below or above the superconducting critical temperature (TC). The charge imbalance effect observed in the Cu/Nb interface ensures that superconducting Nb absorbs pure spin currents even below TC. Our analyses based on the density of states calculated using the Usadel equation can well reproduce the experimental results, implying that the strong spin-orbit interaction of Nb is still effective for the spin absorption even below TC. Most importantly, our method allows us to determine the intrinsic spin relaxation time in the superconducting Nb, which reaches more than 4 times greater than that in the normal state.

6.
J Appl Microbiol ; 112(6): 1193-206, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22404232

RESUMO

AIM: To isolate and characterize lactic acid bacteria (LAB) and determine whether they could potentially be used as heavy metal (cadmium and lead) absorbing probiotics. METHODS AND RESULTS: The study used 53 environmental (mud and sludge) samples to isolate cadmium- and lead-resistant LAB, by following spared plate technique. A total of 255 cadmium- and lead-resistant LAB were isolated from these samples. The survival of 26 of the LAB was found after passing through sequential probiotic characterizations. These 26 probiotic LAB exhibited remarkable variations in their metal-resistant and metal-removal abilities. Of 26, seven (Cd54-2, Cd61-7, Cd69-12, Cd70-13, Pb82-8, Pb96-19 and Cd109-16) and four (Pb71-1, Pb73-2, Pb85-9 and Pb96-19) strains displayed relatively elevated cadmium- and lead-removal efficiencies from water, respectively, compare with that of the remaining strains. Strains Cd70-13 and Pb71-1 showed the highest cadmium (25%) and lead (59%) removal capacity from MRS (De Man, Rogosa and Sharpe) culture medium, respectively, amongst the selected strains and showed a good adhesive ability on fish mucus. A phylogenetic analysis of their 16S rDNA sequences revealed that the strains Cd70-13 and Pb71-1 belong to Lactobacillus reuteri. CONCLUSION: Excellent probiotic, metal sorption and adhesive characteristics of newly identified Lact. reuteri strains Cd70-13 and Pb71-1 were isolated, which indicated their high potential abilities to survive in the intestinal milieu and to uptake the tested metals from the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first study that has aimed to isolate, characterize and identify metal-resistant LAB strains that have potential to be a probiotic candidate for food and in vivo challenge studies in the intestinal milieu of fish for the uptake and control of heavy metal bioaccumulation.


Assuntos
Cádmio/toxicidade , Peixes , Lactobacillus/classificação , Chumbo/toxicidade , Probióticos , Alimentos Marinhos , Animais , Meios de Cultura , Humanos , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Masculino , Filogenia , Alimentos Marinhos/microbiologia , Alimentos Marinhos/toxicidade
7.
J Exp Med ; 168(5): 1553-62, 1988 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-2460577

RESUMO

Previous studies have revealed that the reticulum cell sarcoma (RCS) of SJL/J (H-2s, IE-) mice express an "IE-like" stimulatory tumor-associated antigen, the expression of which is requisite for stimulating host T cells necessary for tumor growth. Herein, we present evidence that the predominant T cells raised in the syngeneic response to both spontaneous and transplantable RCS tumors are of the V beta 17a TCR clonotype. The V beta 17a+ clonotype of T cells has been shown to interact with IE allogeneic specificities. We demonstrate that all four characterized RCS-specific T cell hybridomas stained positively for the anti-V beta 17a mAb, KJ23a. Additionally, KJ23a, when added to cocultures of the T cell hybridomas and RCS tumors, inhibited the release of IL-2 by the hybridomas. Further, KJ23a was shown to markedly inhibit the proliferation of SJL/J T cells when cocultured with either spontaneous or transplantable RCS tumor cells. When analyzed by flow cytometry, the T cell blast population raised in response to both spontaneous and transplantable RCS were greater than 80% KJ23a+. These T cells were brightly stained by the anti-CD4 mAb, Gk1.5, and, therefore, represent class II-responsive T cells. In corroboration of the in vitro data, T cells derived from mesenteric lymph nodes of RCS tumor-bearing mice had likewise undergone a similar expansion of V beta 17a+, CD4+ T cells. Together, these results indicate that KJ23a+ T cells play an important and predominant role in the response of SJL/J mice to spontaneous RCS tumors and provide further suggestive evidence that the stimulatory antigen(s) on the RCS tumor is IE or an "IE-like" molecule. Significantly, the important role V beta 17a+ T cells play in the response to RCS suggests a potential therapeutic role for KJ23a mAb in the intervention and prevention of RCS tumors in SJL/J mice.


Assuntos
Linfoma não Hodgkin/imunologia , Receptores de Antígenos de Linfócitos T/fisiologia , Linfócitos T/fisiologia , Animais , Linfócitos T CD4-Positivos/imunologia , Epitopos , Citometria de Fluxo , Hibridomas/fisiologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos , Transplante de Neoplasias , Receptores de Antígenos de Linfócitos T alfa-beta
8.
Artigo em Inglês | MEDLINE | ID: mdl-19842407

RESUMO

The medical records of Japanese patients with measles, age 15 to 39 years old, were analyzed for febrile period in 200 patients and maximum body temperature in 211 patients. The febrile periods by age group were as follows: 7.7 +/- 1.4 days, 7.8 +/- 1.7 days, 8.1 +/- 1.7 days, 8.1 +/- 2.4 days and 7.5 +/- 1.4 days in 15-19, 20-24, 25-29, 30-34 and 35-39 year-olds, respectively. No significant differences in febrile periods were identified among the different age groups. A maximum body temperature over 40 degrees C was seen in 61, 58, 59, 50 and 33% of the 15-19, 20-24, 25-29, 30-34 and 35-39 year-olds, respectively. The results of our study indicate age is not a determining factor for febrile period, but maximum body temperature may be lower in older than in younger patients with measles.


Assuntos
Febre/etiologia , Sarampo/complicações , Adolescente , Adulto , Fatores Etários , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto Jovem
9.
J Orthop Surg (Hong Kong) ; 17(1): 116-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19398808

RESUMO

We present a 36-year-old man with a severe pes equinus deformity of the ankle and an intractable ulcer over the Achilles tendon after a 4th-degree burn. He underwent a one-stage reconstructive surgical procedure using an anteromedial thigh flap with its vascularised fascia. After lengthening of the Achilles tendon and posterior release of the ankle, the anteromedial thigh fasciocutaneous flap was transferred. The ischaemic Achilles tendon was wrapped with the vascularised femoral fascia for vascularisation and reinforcement. The skin defect was covered with the skin paddle of the combined flap. There were no postoperative complications. At the 3-year follow up, the range of movement of the ankle was almost normal. The patient was able to walk and climb stairs without support, and the ulcer was cured.


Assuntos
Tendão do Calcâneo/cirurgia , Queimaduras/complicações , Pé Equino/etiologia , Pé Equino/cirurgia , Adulto , Queimaduras/patologia , Pé Equino/fisiopatologia , Humanos , Masculino , Amplitude de Movimento Articular , Retalhos Cirúrgicos
10.
Leukemia ; 32(3): 626-632, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28914260

RESUMO

High-dose methotrexate (Hd-MTX) therapy has recently been applied to the treatment of adult acute lymphoblastic leukemia (ALL) based on pediatric protocols; however, its effectiveness for adult ALL has not yet been confirmed in a rigorous manner. We herein conducted a randomized phase III trial comparing Hd-MTX therapy with intermediate-dose (Id)-MTX therapy. This study was registered at UMIN-CTR (ID: C000000063). Philadelphia chromosome (Ph)-negative ALL patients aged between 25 and 64 years of age were enrolled. Patients who achieved complete remission (CR) were randomly assigned to receive therapy containing Hd-MTX (3 g/m2) or Id-MTX (0.5 g/m2). A total of 360 patients were enrolled. The CR rate was 86%. A total of 115 and 114 patients were assigned to the Hd-MTX and Id-MTX groups, respectively. The estimated 5-year disease-free survival rate of the Hd-MTX group was 58%, which was significantly better than that of the Id-MTX group at 32% (P=0.0218). The frequencies of severe adverse events were not significantly different. We herein demonstrated the effectiveness and safety of Hd-MTX therapy for adult Ph-negative ALL. Our results provide a strong rationale for protocols containing Hd-MTX therapy being applied to the treatment of adult ALL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Biomarcadores Tumorais , Esquema de Medicação , Feminino , Humanos , Masculino , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Mutação , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Indução de Remissão , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
11.
Mol Biol Cell ; 12(5): 1421-30, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11359932

RESUMO

The Rab3 small G protein family consists of four members, Rab3A, -3B, -3C, and -3D. Of these members, Rab3A regulates Ca(2+)-dependent neurotransmitter release. These small G proteins are activated by Rab3 GDP/GTP exchange protein (Rab3 GEP). To determine the function of Rab3 GEP during neurotransmitter release, we have knocked out Rab3 GEP in mice. Rab3 GEP-/- mice developed normally but died immediately after birth. Embryos at E18.5 showed no evoked action potentials of the diaphragm and gastrocnemius muscles in response to electrical stimulation of the phrenic and sciatic nerves, respectively. In contrast, axonal conduction of the spinal cord and the phrenic nerve was not impaired. Total numbers of synaptic vesicles, especially those docked at the presynaptic plasma membrane, were reduced at the neuromuscular junction approximately 10-fold compared with controls, whereas postsynaptic structures and functions appeared normal. Thus, Rab3 GEP is essential for neurotransmitter release and probably for formation and trafficking of the synaptic vesicles.


Assuntos
Proteínas de Ligação ao Cálcio , Embrião de Mamíferos/fisiologia , Junção Neuromuscular/metabolismo , Junção Neuromuscular/ultraestrutura , Vesículas Sinápticas/metabolismo , Proteínas rab3 de Ligação ao GTP/metabolismo , Potenciais de Ação/fisiologia , Animais , Eletromiografia , Desenvolvimento Embrionário e Fetal , Feminino , Marcação de Genes , Pulmão/patologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Neurofilamentos/metabolismo , Receptores Colinérgicos/metabolismo , Sinaptotagminas
12.
Artigo em Inglês | MEDLINE | ID: mdl-18041311

RESUMO

The plasma levels of D-dimer can be used as a marker of fibrin formation and degradation. Plasma D-dimer levels in the febrile phase of 6 patients with typhoid fever and in the afebrile convalescent phase of 4 of them were measured. D-dimer levels were high in the febrile phase of all 6 patients and within normal range in the afebrile convalescent phase of all 4 patients. Our results indicate that thrombus formation and fibrinolysis may occur in the febrile phase of patients with typhoid fever.


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Febre Tifoide/sangue , Adolescente , Adulto , Feminino , Febre/sangue , Fibrina/metabolismo , Humanos , Masculino , Trombose/sangue
13.
Blood Cancer J ; 7(4): e559, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28452984

RESUMO

Although tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of chronic myeloid leukemia (CML), the ability of TKIs to eradicate CML remains uncertain and patients must continue TKI therapy for indefinite periods. In this study, we performed whole-exome sequencing to identify somatic mutations in 24 patients with newly diagnosed chronic phase CML who were registered in the JALSG CML212 study. We identified 191 somatic mutations other than the BCR-ABL1 fusion gene (median 8, range 1-17). Age, hemoglobin concentration and white blood cell counts were correlated with the number of mutations. Patients with mutations ⩾6 showed higher rate of achieving major molecular response than those<6 (P=0.0381). Mutations in epigenetic regulator, ASXL1, TET2, TET3, KDM1A and MSH6 were found in 25% of patients. TET2 or TET3, AKT1 and RUNX1 were mutated in one patient each. ASXL1 was mutated within exon 12 in three cases. Mutated genes were significantly enriched with cell signaling and cell division pathways. Furthermore, DNA copy number analysis showed that 2 of 24 patients had uniparental disomy of chromosome 1p or 3q, which disappeared major molecular response was achieved. These mutations may play significant roles in CML pathogenesis in addition to the strong driver mutation BCR-ABL1.


Assuntos
Proteínas de Ligação a DNA/genética , Dioxigenases/genética , Histona Desmetilases/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Fatores Etários , Variações do Número de Cópias de DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Epigênese Genética/genética , Feminino , Proteínas de Fusão bcr-abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Contagem de Leucócitos , Masculino , Mutação , Inibidores de Proteínas Quinases/administração & dosagem , Transdução de Sinais , Sequenciamento do Exoma
14.
Leukemia ; 19(8): 1306-11, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15920495

RESUMO

Acute promyelocytic leukemia (APL) cells express a considerable level of CD33, which is a target of gemtuzumab ozogamicin (GO), and a significantly lower level of P-glycoprotein (P-gp). In this study, we examined whether GO was effective on all-trans retinoic acid (ATRA)- or arsenic trioxide (ATO)-resistant APL cells. Cells used were an APL cell line in which P-gp was undetectable (NB4), ATRA-resistant NB4 (NB4/RA), NB4 and NB4/RA that had been transfected with MDR-1 cDNA (NB4/MDR and NB4/RA/MDR, respectively), ATO-resistant NB4 (NB4/As) and blast cells from eight patients with clinically ATRA-resistant APL including two patients with ATRA- and ATO-resistant APL. The efficacy of GO was analyzed by (3)H-thymidine incorporation, the dye exclusion test and cell cycle distribution. GO suppressed the growth of NB4, NB4/RA and NB4/As cells in a dose-dependent manner. GO increased the percentage of hypodiploid cells significantly in NB4, NB4/RA and NB4/As cells, and by a limited degree in NB4/MDR and NB4/RA/MDR cells. Similar results were obtained using blast cells from the patients with APL. GO is effective against ATRA- or ATO-resistant APL cells that do not express P-gp, and the mechanism of resistance to GO is not related to the mechanism of resistance to ATRA or ATO in APL cells. Leukemia (2005) 19, 1306-1311. doi:10.1038/sj.leu.2403807; published online 26 May 2005.


Assuntos
Aminoglicosídeos/farmacologia , Anticorpos Monoclonais/farmacologia , Resistencia a Medicamentos Antineoplásicos , Leucemia Promielocítica Aguda/patologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/análise , Anticorpos Monoclonais Humanizados , Trióxido de Arsênio , Arsenicais/farmacologia , Ciclo Celular , Proliferação de Células/efeitos dos fármacos , Gemtuzumab , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Óxidos/farmacologia , Resultado do Tratamento , Tretinoína/farmacologia , Células Tumorais Cultivadas
15.
Artigo em Inglês | MEDLINE | ID: mdl-16771228

RESUMO

We report a case of Weil's disease manifesting elevation of plasma D-dimer in the acute phase. Later, in the convalescent phase after treatment, the plasma levels of D-dimer returned to normal. Plasma D-dimer can be used as a marker of fibrin formation and degradation. Based on our observations, we conjecture that fibrin formation and fibrinolysis may occur in the acute phase of Weil's disease.


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Doença de Weil/sangue , Doença Aguda , Adulto , Biomarcadores/sangue , Humanos , Masculino
16.
Cancer Res ; 57(18): 3910-3, 1997 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-9307270

RESUMO

The effects of an acidic condition (pH 6.5) on WAF1 gene expression and p53 accumulation was investigated in human glioblastoma cells with different p53 statuses. WAF1 and p53 accumulation after treatment in acidic conditions was observed in A-172 cells carrying the wild-type p53 gene but not in T98G cells carrying the mutant p53 gene. Northern blot analysis showed that WAF1 gene activation by acidic conditions only occurred in A-172 cells. Consistent with this, activation of the binding of p53 to its specific DNA sequence by acidic stress was detected by gel mobility shift assay using p53 consensus sequence as a probe. Moreover, the increased WAF1 protein and mRNA levels that were due to acidic treatment returned to normal levels upon the return of the cells to neutral conditions, 6 h after the cells had been cultured in acidic conditions for 6 or 12 h. These findings suggest that WAF1 gene activation is inducible by acidic conditions in human glioblastoma cells, which is probably due to activation of the p53-dependent signal transduction pathway.


Assuntos
Ciclinas/genética , Glioblastoma/genética , Proteína Supressora de Tumor p53/fisiologia , Inibidor de Quinase Dependente de Ciclina p21 , DNA de Neoplasias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , RNA Mensageiro/genética , RNA Neoplásico/genética , Transdução de Sinais , Ativação Transcricional , Células Tumorais Cultivadas , Regulação para Cima
17.
Cancer Res ; 50(24): 8028-33, 1990 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-2123745

RESUMO

The first demonstration of cytokine expression in T-cell lymphoma by immunohistochemical methods is reported. Lymph node biopsy specimens were obtained from 18 patients with peripheral T-cell lymphoma. Interleukin 4 (IL-4) and gamma-interferon were each detected in 7 lymph nodes. Lymph node specimens diagnosed as angioimmunoblastic T-cell lymphoma and angiocentric lymphoma having distinctive histopathological features expressed IL-4 more frequently than other T-cell lymphomas, and all 7 patients expressing IL-4 had hypergammaglobulinemia. Lymph nodes with gamma-interferon expression showed an increase in histiocytes and/or epithelioid cells. Thus, IL-4 may play an important role in the development of hypergammaglobulinemia as well as in the growth and histopathogenesis of T-cell lymphoma, and gamma-interferon may be responsible for the development of Lennert's lesion.


Assuntos
Interferon gama/análise , Interleucina-4/análise , Linfonodos/patologia , Linfoma de Células T/patologia , Anticorpos , Anticorpos Monoclonais , Antígenos CD/análise , Antígenos de Diferenciação de Linfócitos T/análise , Antígenos CD4/análise , Antígenos CD8 , Citocinas/análise , Feminino , Humanos , Imuno-Histoquímica , Interferon gama/genética , Interleucina-4/genética , Linfonodos/imunologia , Linfoma de Células T/imunologia , Masculino , RNA Mensageiro/análise , RNA Mensageiro/genética
18.
Cancer Res ; 47(2): 523-6, 1987 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-3539324

RESUMO

Spontaneous reticulum cell sarcoma (RCS) tumor induction occurs in 90% of SJL/J mice of 8-13 months of age. Tumor induction and growth has been shown to be under the influence of both H-2 and non-H-2 genes as well as the presence of an intact host T-cell system. We postulated that cellular oncogenes may play a role in the induction, growth, and characteristics of RCS. DNA-mediated gene transfer protocols were adopted to investigate the presence of transforming genes in DNA from RCS of SJL/J mice. High molecular weight DNA was isolated from these tumors as well as from brains and livers of control tumor-free SJL/J mice and transfected into NIH-3T3 mouse and F2408 rat fibroblast cell lines. Foci of transformed cells with a peculiar round morphology were scored in both rat and mouse cultures given tumor DNA, but not in those receiving DNA from normal tissues. DNA from first-cycle transformants was transfected in further cycles of transfection, giving rise to foci with similar morphological appearances and growth properties. These experiments suggest that a transforming gene, present in RCS spontaneous tumors, is involved in the malignant conversion of the transfected normal fibroblasts. The implication of these results with respect to the induction and growth properties of RCS is discussed.


Assuntos
DNA de Neoplasias/genética , Linfoma não Hodgkin/genética , Oncogenes , Animais , Feminino , Camundongos , Camundongos Endogâmicos , Transcrição Gênica , Transfecção
19.
Cancer Res ; 59(13): 3239-44, 1999 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-10397271

RESUMO

Nitric oxide is known to be a multifunctional physiological substance. Recently, it was suggested that nitric oxide is involved in p53-dependent response to many kinds of stress, such as heat shock and changes in cellular metabolism. To verify this hypothesis, we examined the effect of nitric oxide produced endogenously by heat-shocked cells on nonstressed cells using a human glioblastoma cell line, A-172, and its mutant p53 (mp53) transfectant (A-172/mp53). The accumulation of inducible nitric oxide synthase was caused by heat treatment of the mtp53 cells but not of the wild-type p53 (wtp53) cells. The accumulation of heat shock protein 72 (hsp72) and p53 was observed in nontreated mtp53 cells cocultivated with heated mp53 cells, and the accumulation of these proteins was suppressed by the addition of a specific inducible nitric oxide synthase inhibitor, aminoguanidine, to the medium. Furthermore, the accumulation of these proteins was observed in the wtp53 cells after exposure to the conditioned medium by preculture of the heated mp53 cells, and the accumulation was completely blocked by the addition of a specific nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide, to the medium. In addition, the accumulation of hsp72 and p53 in the wtp53 cells was induced by the administration of an nitric oxide-generating agent, S-nitroso-N-acetylpenicillamine, to the medium. Finally, the thermosensitivity of the wtp53 cells was reduced in the conditioned medium by preculture of the heated mp53 cells as compared with conventional fresh growth medium. Our finding of the accumulation of hsp72 and p53 in nitric oxide-recipient cells cocultivated with heated nitric oxide-donor cells provides the first evidence for an intercellular signal transduction pathway via nitric oxide as intermediate without cell-to-cell interactions such as gap junctions.


Assuntos
Genes p53 , Óxido Nítrico/fisiologia , Transdução de Sinais/fisiologia , Benzoatos/farmacologia , Neoplasias Encefálicas , Divisão Celular , Técnicas de Cocultura , Glioblastoma , Guanidinas/farmacologia , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/biossíntese , Proteínas de Choque Térmico/genética , Temperatura Alta , Humanos , Hipertermia Induzida , Imidazóis/farmacologia , Cinética , Mutagênese , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II , Penicilamina/análogos & derivados , Penicilamina/farmacologia , S-Nitroso-N-Acetilpenicilamina , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/biossíntese
20.
Mon Not R Astron Soc ; 457(4): 4089-4113, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32848283

RESUMO

We present a statistical analysis of the first four seasons from a "second-generation" microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg2 of the Galactic bulge by the OGLE, MOA, and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12% of the events showed a deviation from single-lens microlensing, and for ~1/3 of those the anomaly is likely caused by a planetary companion. For each of the 224 events we have performed numerical ray-tracing simulations to calculate the detection efficiency of possible companions as a function of companion-to-host mass ratio and separation. Accounting for the detection efficiency, we find that 55 - 22 + 34 % of microlensed stars host a snowline planet. Moreover, we find that Neptunes-mass planets are ~ 10 times more common than Jupiter-mass planets. The companion-to-host mass ratio distribution shows a deficit at q ~ 10-2, separating the distribution into two companion populations, analogous to the stellar-companion and planet populations, seen in radial-velocity surveys around solar-like stars. Our survey, however, which probes mainly lower-mass stars, suggests a minimum in the distribution in the super-Jupiter mass range, and a relatively high occurrence of brown-dwarf companions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA