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1.
Phys Chem Chem Phys ; 23(27): 14592-14600, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34164634

RESUMO

Interactions between interior substitutional nitrogen defects and surface unsaturated dangling bonds in synthetic nanodiamonds of ∼25 nm size were explored experimentally and theoretically. The experimental results demonstrate the disappearance of the specific paramagnetism of nitrogen centers in the smallest nanoparticles isolated after processing large micron diamonds in a ball mill, accompanied by the formation of unsaturated surface dangling bonds and internal defects. First principles modelling confirms the vanishing of the magnetic moments related with nitrogen centers even for distances from the surface defects greater than 1 nm. To understand this effect, we consider a bond reconstruction scheme with the formation of several carbon-carbon double bonds in the area between the interior and surface point defects. The scheme is in agreement with the changes in electron density through the distance between the two defects. The developed approach can be used to describe the interactions between various defects in carbon-based systems.

2.
Lupus ; 27(3): 417-427, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28820362

RESUMO

Purpose TAFRO syndrome is a novel disorder manifesting as fever, anasarca, thrombocytopenia, renal insufficiency and organomegaly, and its etiology has not been clarified. The aim of this study was to elucidate similarities and differences between systemic lupus erythematosus (SLE) and TAFRO syndrome. Methods We examined 46 consecutive patients diagnosed with SLE and determined whether they meet the proposed diagnostic criteria for TAFRO syndrome (2015 version). Results Of the 46 patients with SLE, four (8.7%) also met the TAFRO syndrome criteria (TAFRO-like group). All patients in the TAFRO-like group were males, and their mean age was significantly higher than that of the non-TAFRO group (67.5 ± 8.7 vs. 39.3 ± 18.1 years, p = 0.004). C-reactive protein and γ-glutamyl transpeptidase levels were significantly higher, and frequencies of anti-dsDNA and anti-Sm antibodies were significantly lower in the TAFRO-like than non-TAFRO group. Elder cases (onset age ≥ 50 years) met significantly more categories of the diagnostic criteria for TAFRO syndrome than did those with younger cases. Conclusions Several patients with SLE, especially elder cases, showed features similar to those of TAFRO syndrome. Although exclusion of SLE is needed in the diagnostic criteria for TAFRO syndrome, TAFRO syndrome-like SLE should be considered.


Assuntos
Edema/diagnóstico , Febre/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Insuficiência Renal/diagnóstico , Trombocitopenia/diagnóstico , Adulto , Idoso , Feminino , Humanos , Interleucina-6/metabolismo , Japão , Masculino , Pessoa de Meia-Idade , Síndrome , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto Jovem
3.
Clin Radiol ; 72(10): 905.e1-905.e5, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28629605

RESUMO

AIM: To assess detailed computed tomography (CT) findings in patients with the recently described thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly (TAFRO) syndrome, in order to contribute to imaging interpretation in the challenging diagnosis of this disease. MATERIALS AND METHODS: The institutional review board approved this retrospective study and waived the need for informed consent. Eleven patients (six men, five women; mean age, 52.5 years) with confirmed TAFRO syndrome were included in this study. Chest-to-pelvis CT images were analysed for the presence of anasarca, organomegaly, bone lesions, and lung lesions. RESULTS: Anasarca was present in all patients and involved multiple cavities and tissues; pleural effusion and ascites were found in 100% of patients; pericardial effusion in 64%; periportal collar in 91%; gallbladder wall oedema in 78%; subcutaneous oedema in 91%; retroperitoneal oedema in 100%; and mesenteric oedema in 100%. Organomegaly involved multiple organs: hepatomegaly in 73%, splenomegaly in 82%, lymphadenopathy in 100%, and enlarged anterior mediastinum in 64% (solitary, well-circumscribed mass, 0%; infiltrative mass, 0%; non-mass-forming infiltrative lesion, 64%). Bone lesions were present in 91% patients and all bone lesions had ground-glass density with diffuse distribution. None of the patients had any lesions in their lungs. CONCLUSION: The present study revealed that the findings of anasarca, organomegaly, and diffuse bony ground-glass appearance were observed in detail on CT in patients with TAFRO syndrome. A "matted" appearance of the enlarged anterior mediastinum is the characteristic CT finding of TAFRO syndrome, and it is possible to diagnose TAFRO syndrome from the combination of several CT findings.


Assuntos
Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Edema/diagnóstico por imagem , Trombocitopenia/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Hiperplasia do Linfonodo Gigante/patologia , Edema/complicações , Edema/patologia , Feminino , Febre/complicações , Febre/patologia , Fibrose/complicações , Fibrose/diagnóstico por imagem , Fibrose/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Reticulina , Estudos Retrospectivos , Síndrome , Trombocitopenia/complicações , Trombocitopenia/patologia
4.
Br J Neurosurg ; 27(3): 393-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23167667

RESUMO

We report a 61-year-old woman with definite diagnosis of isolated neurosarcoidosis in the medulla oblongata involving the fourth ventricle. We could not recognize neurosarcoidosis as one of the differential diagnoses of the lesion before biopsy because the brainstem lesion location and periventricular lesion configuration were quite unusual.


Assuntos
Encefalopatias/patologia , Doenças do Sistema Nervoso Central/patologia , Quarto Ventrículo/patologia , Bulbo/patologia , Sarcoidose/patologia , Encefalopatias/cirurgia , Doenças do Sistema Nervoso Central/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Fotografação , Cuidados Pós-Operatórios , Sarcoidose/cirurgia
5.
Clin Exp Immunol ; 168(1): 68-74, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22385240

RESUMO

Excessive T helper type 1 (Th1) cell activity has been reported in Behçet's disease (BD). Recently, association of Th17 cells with certain autoimmune diseases was reported, and we thus investigated circulating Th17 cells in BD. CD4(+) CD45RO(-) (naive) T cells were cultured with Th0-, Th1-, Th2- and Th17-related cytokines and antibodies, and their mRNA was studied by real-time polymerase chain reaction (PCR). When naive CD4(+) T cells were cultured with Th1- and Th17-related cytokines, interferon (IFN)-γ mRNA and interleukin (IL)-17 mRNA were up-regulated, respectively, in BD patients. Naive CD4(+) T cells cultured in a Th17 cell-inducing condition expressed IL-23 receptor (IL-23R) mRNA excessively. IL-17 mRNA expression was induced only when naive CD4(+) T cells were cultured in the presence of IL-23. CD4(+) T cells cultured with Th17 cytokines expressed excessive RAR-related orphan receptor C (RORC) mRNA. Using intracellular cytokine staining, we found that CD45RO(+) (memory) CD4(+) T cells producing IL-17 and IFN-γ simultaneously were increased significantly. Memory CD4(+) T cells producing IFN-γ but not IL-17 decreased profoundly in BD patients. CD4(+) T cells producing IL-17 and IFN-γ simultaneously were found in BD skin lesions. Collectively, we found excessive CD4(+) T cells producing IL-17 and IFN-γ (Th1/Th17) cells in patients with BD, and possible involvement of IL-23/IL-23R pathway for the appearance of excessive Th1/Th17 cells.


Assuntos
Síndrome de Behçet/imunologia , Linfócitos T CD4-Positivos/imunologia , Interferon gama/biossíntese , Interleucina-17/metabolismo , Adulto , Síndrome de Behçet/metabolismo , Síndrome de Behçet/patologia , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Feminino , Humanos , Interleucina-17/biossíntese , Interleucina-17/imunologia , Interleucina-23/biossíntese , Interleucina-23/imunologia , Interleucina-23/metabolismo , Antígenos Comuns de Leucócito/genética , Masculino , Pessoa de Meia-Idade , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/biossíntese , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Pele/imunologia , Pele/patologia , Células Th1/imunologia , Células Th1/metabolismo , Células Th17/imunologia
6.
Clin Exp Rheumatol ; 30(3 Suppl 72): S35-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22935165

RESUMO

OBJECTIVES: Behçet's disease (BD) is a multi-systemic inflammatory disease, characterised by recurrent oral aphthosis, genital ulcers, skin lesions and uveitis. We have reported excessive Th1 cell activity in patients with BD. More recently, Th17 cells were suggested to associate with several autoimmune diseases. This study was designed to investigate the role of Th17 related cytokines and signalling molecules in patients with BD. METHODS: We examined mRNA expressions of Th1 and Th17 related cytokines and related signalling molecules in PBMC of 12 patients with BD and 14 normal controls (NC) using quantitative RT-PCR. We studied expressions of the Th17 related cytokines in other four BD patients' skin lesions by immunofluorescence. RESULTS: Major Th17 related cytokines were not detected in unstimulated PBMC in patients with BD. After stimulation, mRNA expressions of TGFß receptor type 1, IL-12 receptor ß2 and suppressor of cytokine signalling protein (SOCS) 1 on PBMC were significantly enhanced in patients with BD, as compared with NC (p<0.05). mRNA expression of RORC, a key transcription factor for Th17 cell differentiation, was comparable between BD and NC. CD4+ T cells infiltrating into BD skin lesion expressed TGFß1 much more than those infiltrating into non-Behçet's disease erythema nodosum. CONCLUSIONS: These findings suggest that TGFß/Smad signalling pathway of T cells is overactive in patients with BD.


Assuntos
Síndrome de Behçet/metabolismo , Transdução de Sinais , Pele/metabolismo , Proteína Smad2/metabolismo , Células Th17/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Adulto , Síndrome de Behçet/genética , Síndrome de Behçet/imunologia , Estudos de Casos e Controles , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Feminino , Imunofluorescência , Regulação da Expressão Gênica , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Fosforilação , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Pele/imunologia , Proteína Smad2/genética , Células Th17/imunologia
7.
Clin Exp Immunol ; 160(3): 420-30, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20345976

RESUMO

This study investigated how CD8(+) T cell subsets respond to allo- and infectious immunity after living donor liver transplantation (LDLT). Early alloimmunity: 56 recipients were classified into three types according to the post-transplant course; type I demonstrated uneventful post-transplant course, type II developed severe sepsis leading to multiple organ dysfunction syndrome or retransplantation and type III with acute rejection. In 23 type I recipients, the interleukin (IL)-12 receptor beta-1 (R beta 1)(+) cells of central memory T cells (Il-12R beta 1(+) T(CM)) were increased above the pretransplant level. In 16 type II recipients, IL-12R beta 1(+) T(CM) was decreased markedly below the pretransplant level on postoperative day (POD) 5. In 17 type III recipients, IL-12R beta 1(+) T(CM) was decreased for a more prolonged period until POD 10. Along with down-regulation of IL-12R beta 1(+) T(CM), the IL-12R beta 1(+) cells of CCR7-negative subsets (CNS) as well as perforin, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha decreased gradually, resulting in the down-regulation of effectors and cytotoxicity. The down-regulation of IL-12R beta 1(+) T(CM) was suggested to be due to the recruitment of alloantigen-primed T cells into the graft, and then their entry into the secondary lymphoid organ, resulting in graft destruction. Infectious immunity: immunocompetent memory T cells with the capacity to enhance effectors and cytotoxicity were generated in response to post-transplant infection along with both up-regulation of the IL-12R beta 1(+) T(CM) and an increase in the CNS showing the highest level of IL-12R beta 1(+) cells. In conclusion, this work demonstrated that the IL-12R beta 1(+) cells of T(CM) and CNS are regulated in a tightly coupled manner and that expression levels of IL-12R beta 1(+) T(CM) play a crucial role in controlling allo- and infectious immunity.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Regulação para Baixo/imunologia , Memória Imunológica/imunologia , Transplante de Fígado/imunologia , Doadores Vivos , Receptores CCR7 , Receptores de Interleucina-12/imunologia , Adulto , Linfócitos T CD8-Positivos/patologia , Feminino , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/patologia , Humanos , Infecções/imunologia , Infecções/metabolismo , Interferon gama/imunologia , Interferon gama/metabolismo , Isoantígenos/imunologia , Isoantígenos/metabolismo , Transplante de Fígado/patologia , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/imunologia , Insuficiência de Múltiplos Órgãos/metabolismo , Insuficiência de Múltiplos Órgãos/patologia , Perforina/imunologia , Perforina/metabolismo , Receptores de Interleucina-12/biossíntese , Estudos Retrospectivos , Sepse/imunologia , Sepse/metabolismo , Sepse/patologia , Fatores de Tempo , Transplante Homólogo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
8.
Neuroscience ; 158(2): 683-92, 2009 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-19017538

RESUMO

Intercellular signaling via cell-surface Notch receptors controls the cell-fate decision in the developing brain. Recent studies have suggested that the response of endogenous neural stem cells to brain injury in adult mammals might be mediated by Notch signaling. Here, we investigated the role of Notch signaling in ischemic damage in the hippocampal CA1 region after transient global ischemia in rats. In the acute phase of ischemia, Notch1-positive cells increased in number in the posterior periventricle, which is the posterior part of the lateral ventricle, after the i.c.v. administration of epidermal growth factor and fibroblast growth factor-2. In addition, Notch signaling was upregulated in the CA1 region 5 days after ischemia. By contrast, the attenuation of Notch signaling caused by the administration of a gamma-secretase inhibitor in the subacute phase (6-12 days after ischemia) amplified the immature migratory neurons 12 days after ischemia, and resulted in an increased number of newly generated neurons in the CA1 after 28 days. Our results suggest that Notch signaling in the CA1 is activated in parallel with the increase of endogenous neural stem cells stimulated by ischemia, and that the attenuation of Notch signaling could induce more efficient differentiation of neural progenitors toward a neuronal lineage.


Assuntos
Células-Tronco Adultas/fisiologia , Diferenciação Celular/fisiologia , Hipocampo/patologia , Hipóxia-Isquemia Encefálica/patologia , Neurônios/fisiologia , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Células-Tronco Adultas/efeitos dos fármacos , Animais , Bromodesoxiuridina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Proteínas do Domínio Duplacortina , Inibidores Enzimáticos/farmacologia , Fator de Crescimento Epidérmico/administração & dosagem , Fator 2 de Crescimento de Fibroblastos/administração & dosagem , Hipóxia-Isquemia Encefálica/terapia , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/efeitos dos fármacos , Neuropeptídeos/metabolismo , Fosfopiruvato Hidratase/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
9.
Cancer Res ; 48(8): 2299-303, 1988 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-3349494

RESUMO

A total of 186 cystectomized specimens were examined by step-sectioning to determine the relation between papillary and nodular transitional cell carcinomas of the urinary bladder. Tumors were classified as papillary (PC), nodular (NC), and carcinoma in situ (CIS) according to their gross and microscopic configurations. These cases, grouped as simple combinations of PC, NC, and CIS, namely, PC, PC + CIS, PC + NC, PC + NC + CIS, NC, NC + CIS, and CIS, were analyzed with respect to (a) the time from the initial symptom to cystectomy, (b) the treatment before cystectomy, (c) the grade, (d) the stage of tumors, (e) the multiplicity of tumors, (f) the presence of papillary structures inside or on the surface of nodular carcinoma, and (g) data on survival after cystectomy. Of the tumors, 17 were classified as CIS and 80 as PC and PC + CIS. Studies on 57 cases suggested an early change from PC to a mixture of PC and NC through papillonodular carcinoma during development, whereas 6 showed late development of NC during repeated recurrence of PC. These courses indicate that some cases of NC developed from PC. On the other hand, 26 cases exhibited direct progression from CIS to NC. Thus nodular invasive carcinomas may develop in two ways: by emergence of a more anaplastic cell population within a preexisting low grade papillary carcinoma; and by de novo development of an invasive nodular carcinoma directly from CIS.


Assuntos
Carcinoma Papilar/patologia , Carcinoma de Células de Transição/patologia , Neoplasias da Bexiga Urinária/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/mortalidade , Carcinoma de Células de Transição/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Bexiga Urinária/cirurgia , Neoplasias da Bexiga Urinária/mortalidade
10.
Cancer Res ; 59(5): 1054-60, 1999 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10070963

RESUMO

The large species difference in the pharmacokinetics/pharmacodynamics of 7-hydroxystaurosporine (UCN-01) can be partially explained by the high affinity binding of UCN-01 to human alpha1-acid glycoprotein (AGP) (Fuse et al, Cancer Res., 58: 3248-3253, 1998). To confirm whether its binding to human AGP actually changes the in vivo pharmacokinetics, we have studied the alteration in its pharmacokinetics after simultaneous administration of human AGP to rats: (a) the protein binding of UCN-01 was evaluated by chasing its dissociation from proteins using dextran-coated charcoal. The UCN-01 remaining 0.1 h after adding dextran-coated charcoal to human plasma or AGP was approximately 80%, although the values for other specimens, except monkey plasma (approximately 20%), were <1%, indicating that the dissociation from human AGP was specifically slower than from other proteins; and (b) the pharmacokinetics of UCN-01 simultaneously administered with human AGP has been determined. The plasma concentrations after i.v. administration of UCN-O1 with equimolar human AGP were much higher than those after administration of UCN-01 alone. The steady-state distribution volume and the systemic clearance were reduced to about 1/100 and 1/200, respectively. Human AGP thus reduced the distribution and elimination of UCN-01 substantially. On the other hand, dog AGP, which has a low binding affinity for UCN-01, did not change the pharmacokinetics of UCN-01 so much. Furthermore, human AGP markedly reduced the hepatic extraction ratio of UCN-01 from 0.510 to 0.0326. Also, human AGP (10 microM) completely inhibited the initial uptake of UCN-01 (1 microM) into isolated rat hepatocytes, whereas the uptake of UCN-01 was unchanged in the presence of human serum albumin (10 microM). In conclusion, the high degree of binding of UCN-01 to human AGP causes a reduction in the distribution and clearance, resulting in high plasma concentrations in humans.


Assuntos
Alcaloides/farmacocinética , Antineoplásicos/farmacocinética , Fígado/metabolismo , Orosomucoide/metabolismo , Alcaloides/administração & dosagem , Alcaloides/sangue , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Células Cultivadas , Cães , Haplorrinos , Humanos , Injeções Intravenosas , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Albumina Sérica/metabolismo , Especificidade da Espécie , Estaurosporina/análogos & derivados
11.
Geobiology ; 14(4): 374-89, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27027643

RESUMO

Many physical and chemical processes control the extent of Fe(III) oxyhydroxide reduction by dissimilatory Fe(III)-reducing bacteria. The surface precipitation of secondary Fe minerals on Fe(III) oxyhydroxides limits the extent of microbial Fe(III) reduction, but this phenomenon has not yet been observed in nature. This paper reports the observation of secondary Fe-mineral (goethite) encrustation on ferrihydrite surface within freshwater sediment up to 10 cm deep. The sediment surface was characterized by the predominance of ferrihydrites with biogenic stalks and sheaths. An Fe(II)-oxidizing bacterium (Gallionellaceae) was detected by 16S rRNA gene analysis at sediment depths of 1 and 2 cm. Fe(2+) concentration in the sediment pore water was relatively higher at 2-4 cm depths. The 16S rRNA genes affiliated with dissimilatory Fe(III)-reducing bacteria were detected at 1, 2, and 4 cm depths. The results of the Fe K-edge extended X-ray absorption fine structure (EXAFS) analysis suggested the presence of goethite and siderite at depths below 3 cm. However, the change in the Fe-mineral composition was restricted to sediment depths between 3 and 4 cm, despite the presence of abundant ferrihydrite at depths below 4 cm. An increase in CH4 concentration was observed at deeper than 6 cm. Stable isotopic analysis of CH4 in the pore water indicated that acetoclastic CH4 occurred at depths below 7 cm. Transmission electron microscope observations suggested the presence of goethite and siderite on stalks and sheaths at depths below 3 cm. Results from conversion electron yield EXAFS analysis suggested that goethite dominated at 10 cm depth, thereby indicating that ferrihydrite was encrusted by goethite at this depth. Moreover, the incomplete reduction of ferrihydrite below depths of 4 cm was not due to the lack of organic carbon, but was possibly due to the surface encrustation of goethite on ferrihydrite.


Assuntos
Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Compostos Férricos/metabolismo , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Compostos de Ferro/química , Minerais/química , Archaea/classificação , Archaea/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Água Doce , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espectroscopia por Absorção de Raios X
12.
Biochim Biophys Acta ; 1244(2-3): 339-44, 1995 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-7599153

RESUMO

We have designed a new type of antisense oligodeoxyribonucleotide. These oligonucleotides are able to form hairpin loop structures at the 3'-ends. The stability to nuclease degradation was observed by incubation of these hairpin oligonucleotides with snake venom phosphodiesterase, DNA polymerase, and fetal bovine serum. Of particular interest is the hairpin antisense oligonucleotide containing 2'-methoxynucleosides with base-pairing in the stem region at the 3'-end, which has increased nuclease resistance.


Assuntos
Composição de Bases , Conformação de Ácido Nucleico , Oligonucleotídeos Antissenso/química , Sequência de Bases , DNA Polimerase I/metabolismo , Estabilidade de Medicamentos , Produtos do Gene rev/genética , HIV-1/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Oligonucleotídeos Antissenso/metabolismo , Fosfodiesterase I , Diester Fosfórico Hidrolases/metabolismo , Ribonuclease H/metabolismo , Produtos do Gene rev do Vírus da Imunodeficiência Humana
13.
Biochim Biophys Acta ; 1489(2-3): 374-82, 1999 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-10673038

RESUMO

We studied the hairpin-loop structure of an RNA fragment (GUUUCGUACAAAC) (R13) with the sequence corresponding to the self-cleavage domain in the precursor of an RNA molecule from bacteriophage T4-infected Escherichia coli cells (p2Sp1 RNA). In order to determine the influence of the hairpin-loop structure on these sequence-specific cleavage reactions, we have synthesized oligoribonucleotides containing hairpin-loop, double-helical stem-loop, and single-stranded RNA structures. The cleavage was affected by the hairpin-loop structure. Furthermore, the helix-stem, which retains the thermodynamically extrastable stem hairpin-loop structures, is also important for the cleavage activity. However, the thermodynamically extrastable helix-stem structure reduced the cleavage activity of the adjacent UA and CA sequences at the helix-stem site. For the cleavage reactions of the RNA cleavage products, the R6 (ACAAAC), R7 (GUUUCGU), and R9 (GUUUCGUAC) mers from the parent RNA, R13 (GUUUCGUACAAAC), a very slight amount of cleavage product (2%) from the RNA 9 was observed, but no reaction occurred for the R6 and R7. We also describe the influences of the sequences (UA and CA) on the cleavage activity.


Assuntos
Conformação de Ácido Nucleico , RNA/metabolismo , Sequência de Bases , Hidrólise , Cinética , Desnaturação de Ácido Nucleico , RNA/química
14.
Biochim Biophys Acta ; 1354(3): 211-8, 1997 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-9427530

RESUMO

The precursor of an RNA molecule from T4-infected E. coli cells (p2Spl RNA) has the capacity to cleave itself at specific positions [UpA (139-140) and CpA (170-171)], within a putative loop and stem structure. This sequence-specific cleavage requires at least a monovalent cation and non-ionic detergents. In order to determine the influence of the pyrimidine and purine bases on these sequence-specific cleavage reactions, we studied the cleavage reactions of hairpin loop RNAs substituted at the cleavage sites with modified pyrimidine- and purine-nucleosides. The cleavage was affected by the 2'-hydroxyl groups and the bases of the pyrimidines, and the 6-amino group of the purine.


Assuntos
Oligorribonucleotídeos/química , Nucleosídeos de Purina/química , Nucleosídeos de Pirimidina/química , Composição de Bases , Sequência de Bases , Sítios de Ligação/genética , Conformação de Ácido Nucleico , Oligorribonucleotídeos/síntese química , Oligorribonucleotídeos/metabolismo , Nucleosídeos de Purina/síntese química , Nucleosídeos de Purina/metabolismo , Nucleosídeos de Pirimidina/síntese química , Nucleosídeos de Pirimidina/metabolismo , RNA Catalítico/química , RNA Catalítico/genética , RNA Catalítico/metabolismo
15.
Biochim Biophys Acta ; 1379(2): 217-23, 1998 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-9528657

RESUMO

Sequence specific RNA cleaving molecules were synthesized by attaching novel polyamine derivatives bearing imidazole and/or primary amine groups to the 5'-end of DNA oligonucleotides as the sequence-recognizing moieties. The actions of the molecules on a half-tRNA(Asp) were investigated. The oligonucleotides directed the nuclease activity (the imidazole and the primary amine are the catalytic groups) of the enzyme to the nucleotides directly adjacent to the complementary target sequence on the substrate RNA. The cleavage reaction shows a bell-shaped pH dependence with a maximum at pH 7.0, indicating the participation of protonated and non-protonated imidazoles residues in the process. The specificity of these hybrid enzymes can be easily altered, and they should prove to be useful tools for probing RNA structures in solution and as potential reactive groups in antisense oligonucleotide derivatives. We also describe the site-specific cleavage of tRNA(Asp) by the cleaving reagents bearing imidazole and/or primary amine groups at the 5'-end of oligodeoxyribonucleotides.


Assuntos
RNA de Transferência de Ácido Aspártico/metabolismo , Aminas/química , Sequência de Bases , Sítios de Ligação , Concentração de Íons de Hidrogênio , Imidazóis/química , Técnicas In Vitro , Indicadores e Reagentes , Cinética , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/genética , Oligodesoxirribonucleotídeos/metabolismo , RNA de Transferência de Ácido Aspártico/química , RNA de Transferência de Ácido Aspártico/genética
16.
Genetics ; 152(4): 1285-97, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10430559

RESUMO

Molecular phylogenetic analysis of naturally occurring archaeal communities in deep-sea hydrothermal vent environments was carried out by PCR-mediated small subunit rRNA gene (SSU rDNA) sequencing. As determined through partial sequencing of rDNA clones amplified with archaea-specific primers, the archaeal populations in deep-sea hydrothermal vent environments showed a great genetic diversity, and most members of these populations appeared to be uncultivated and unidentified organisms. In the phylogenetic analysis, a number of rDNA sequences obtained from deep-sea hydrothermal vents were placed in deep lineages of the crenarchaeotic phylum prior to the divergence of cultivated thermophilic members of the crenarchaeota or between thermophilic members of the euryarchaeota and members of the methanogen-halophile clade. Whole cell in situ hybridization analysis suggested that some microorganisms of novel phylotypes predicted by molecular phylogenetic analysis were likely present in deep-sea hydrothermal vent environments. These findings expand our view of the genetic diversity of archaea in deep-sea hydrothermal vent environments and of the phylogenetic organization of archaea.


Assuntos
Archaea/genética , Adaptação Fisiológica , DNA Arqueal/genética , DNA Ribossômico/genética , Variação Genética , Temperatura Alta , Biologia Marinha , Hibridização de Ácido Nucleico , Filogenia , RNA Arqueal/genética , RNA Ribossômico/genética , Homologia de Sequência do Ácido Nucleico , Microbiologia da Água
17.
Exp Hematol ; 29(6): 709-19, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11378266

RESUMO

OBJECTIVE: To elucidate the mechanism of immunologic escape of leukemia cells and establish an effective anti-leukemia immunotherapy, we attempted to generate dendritic cells from leukemia cells in patients with acute myelogenous leukemia (AML). Using these leukemia-derived dendritic cells, we investigated leukemia cell-associated T-cell anergy. MATERIALS AND METHODS: Leukemia cells of 30 patients with AML were cultured with granulocyte-macrophage colony-stimulating factor, interleukin-4, and tumor necrosis factor-alpha. Cultured leukemia cells were evaluated for antigen-presenting ability by mixed leukocyte culture (MLC). Normal lymphocytes, which were cocultured with leukemia blasts in the first MLC, were cultured with leukemia-derived dendritic cells in the second MLC. RESULTS: In cultures of leukemia cells from 21 of 30 patients examined, cells with stellate morphology and cell fractions with CD1a(+) and/or CD83(+) were present. Autologous MLC using lymphocytes obtained in remission phase as responders as well as allogeneic MLC demonstrated antigen-presenting ability in leukemia-derived dendritic cells. Leukemia cells of FAB-M0, M1, M2, M3, or M6 morphology/phenotype gave rise to dendritic cells as well as leukemia cells of M5. The leukemic origin of dendritic cells was suggested by in situ hybridization. By coculture with CD80(-) leukemia blasts, the response of normal lymphocytes to leukemia-derived dendritic cells cultured from the same individual as that of leukemia blasts was markedly reduced, compared with the lymphocytes cultured with leukemia blasts from a different individual as leukemia blasts. CONCLUSIONS: Escape of leukemia cells from anti-leukemia immunity may be associated with T-cell anergy caused by leukemia blasts. The results of the present study suggest that leukemia-derived dendritic cells can be applied efficiently in anti-leukemia immunotherapy.


Assuntos
Crise Blástica/imunologia , Anergia Clonal/imunologia , Células Dendríticas/imunologia , Leucemia Mieloide Aguda/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Cocultura , Fatores Estimuladores de Colônias/farmacologia , Células Dendríticas/efeitos dos fármacos , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Interleucina-4/farmacologia , Cariotipagem , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Contagem de Leucócitos , Teste de Cultura Mista de Linfócitos , Masculino , Pessoa de Meia-Idade , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologia
18.
Exp Hematol ; 27(5): 826-33, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10340398

RESUMO

Morphophenotypic lineage switches occur in a small percentage of those with acute leukemia, and the underlying mechanisms are not clear. In this study, we attempted to induce a lineage switch in acute myelocytic leukemia (AML) with monosomy 7, whose lineage had switched from acute T-lymphocytic leukemia (T-ALL) during chemotherapy, in severe combined immunodeficient (SCID) mice. Although the transplanted myeloid cells were engrafted in SCID mice without cytokine administration, T-ALL developed in SCID mice treated with recombinant human granulocyte-macrophage colony-stimulating factor or recombinant human interleukin 3. Analysis of the nucleotide sequences of the rearranged T-cell receptor gamma-chain (TCR-gamma) gene revealed that this lineage switch resulted from the selection of the T-lineage subclone in SCID mice, which had expanded at onset. In addition, we found that the T-lineage and myeloid cells belonged to the distinct subclones, which were different in TCR-gamma gene rearrangements, but were derived from a common clone with an identical N-ras gene mutation for both subclones. In in vitro cultures, only the myeloid subclone grew; the T-lineage subclone failed to grow even in the presence of recombinant human granulocyte-macrophage colony-stimulating factor or recombinant human interleukin 3. These results suggested that the initial diagnostic T-lymphoid subclone, whose growth was dependent on these cytokines and the hematopoietic microenvironment, emerged from a bipotential T-lymphoid/myeloid leukemic stem cell, and further genetic event(s) induced the myeloid subclone, which grew independently of these cytokines and the microenvironment.


Assuntos
Linhagem da Célula , Cromossomos Humanos Par 7 , Leucemia Mieloide/patologia , Leucemia-Linfoma de Células T do Adulto/patologia , Monossomia , Doença Aguda , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Sequência de Bases , Pré-Escolar , DNA de Neoplasias , Rearranjo Gênico da Cadeia gama dos Receptores de Antígenos dos Linfócitos T , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Interleucina-3/farmacologia , Cariotipagem , Leucemia Mieloide/genética , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Leucemia-Linfoma de Células T do Adulto/genética , Masculino , Camundongos , Camundongos SCID , Dados de Sequência Molecular , Transplante de Neoplasias , Proteínas Recombinantes/farmacologia , Células Tumorais Cultivadas
19.
Eur J Surg Oncol ; 41(10): 1308-15, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26235238

RESUMO

BACKGROUND: Despite recent improvements in early detection, progress in surgical techniques, and development of chemoradiation therapies, prognosis of esophageal cancer remains poor. The aim of the present study was to assess whether Glasgow Prognostic Score (GPS), an inflammation-based prognostic score, has prognostic value independent of conventional clinicopathological criteria in patients undergoing curative resection for esophageal cancer, even in elderly patients. METHODS: We retrospectively reviewed the database of 141 consecutive patients with histologically verified esophageal squamous cell carcinoma who underwent potentially curative surgery in our institute, between January 2006 and December 2014. GPS and neutrophil lymphocyte ratio (NLR) were calculated. RESULTS: On multivariate analysis, TNM stage (p < 0.0001) and GPS (p = 0.041) were independently associated with worse prognosis in overall patients with esophageal cancer. Multivariate analysis evaluated the prognostic factors in two different patient groups: patients younger than 70 years (non-elderly) and those aged 70 years or more (elderly). Multivariate analysis demonstrated that TNM stage (p = 0.0003) was an only independent risk factor for a worse prognosis among non-elderly group. Meanwhile, multivariate analysis demonstrated that TNM stage (p = 0.001) and GPS (p = 0.043) were the independent risk factor for a worse prognosis among elderly group. CONCLUSION: The present study demonstrated that GPS is associated with prognosis and can be considered as an independent prognostic marker in patients who underwent esophagectomy. Moreover, the GPS has the advantage of being simple to measure, routinely available and well standardized. But the present study failed to confirm the NLR as a significant predictor of survival following resection for esophageal cancer.


Assuntos
Proteína C-Reativa/imunologia , Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagectomia , Neutrófilos/imunologia , Fatores Etários , Idoso , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Colesterol/sangue , Estudos de Coortes , Neoplasias Esofágicas/imunologia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago , Feminino , Humanos , Inflamação , Contagem de Leucócitos , Excisão de Linfonodo , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Albumina Sérica/metabolismo , Toracoscopia
20.
FEBS Lett ; 440(3): 273-6, 1998 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-9872385

RESUMO

Methods for the preparation of an Escherichia coli tRNA mixture lacking one or a few specific tRNA species can be the basis for future applications of cell-free protein synthesis. We demonstrate here that virtually a single tRNA species in a crude E. coli tRNA mixture can be knocked out by an antisense (complementary) oligodeoxyribonucleotide. One out of five oligomers complementary to tRNA(Asp) blocked the aspartylation almost completely, while minimally affecting the aminoacylation with other 13 amino acids tested. This 'knockout' tRNA behaved similarly to the untreated tRNA in a cell-free translation of an mRNA lacking Asp codons.


Assuntos
Escherichia coli/genética , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , RNA Bacteriano/efeitos dos fármacos , RNA de Transferência de Ácido Aspártico/efeitos dos fármacos , Ácido Aspártico/genética , Sistema Livre de Células/efeitos dos fármacos , Códon/genética , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos Antissenso/metabolismo , RNA Bacteriano/genética , RNA Mensageiro/genética , RNA de Transferência de Ácido Aspártico/química , RNA de Transferência de Ácido Aspártico/genética , Ribonuclease H/metabolismo
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