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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 4138-4141, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30441266

RESUMO

Endoscopic image diagnosis assisted by machine learning is useful for reducing misdetection and interobserver variability. Although many results have been reported, few effective methods are available to automatically detect early gastric cancer. Early gastric cancer have poor morphological features, which implies that automatic detection methods can be extremely difficult to construct. In this study, we proposed a convolutional neural network-based automatic detection scheme to assist the diagnosis of early gastric cancer in endoscopic images. We performed transfer learning using two classes (cancer and normal) of image datasets that have detailed texture information on lesions derived from a small number of annotated images. The accuracy of our trained network was 87.6%, and the sensitivity and specificity were well balanced, which is important for future practical use. We also succeeded in presenting a candidate region of early gastric cancer as a heat map of unknown images. The detection accuracy was 82.8%. This means that our proposed scheme may offer substantial assistance to endoscopists in decision making.


Assuntos
Neoplasias Gástricas , Automação , Detecção Precoce de Câncer , Gastroscopia , Humanos , Aprendizado de Máquina , Redes Neurais de Computação , Sensibilidade e Especificidade , Neoplasias Gástricas/diagnóstico
2.
Bone Marrow Transplant ; 45(5): 912-8, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19802024

RESUMO

Chronic GVHD (cGVHD) of the liver is an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-SCT). It is characterized by the destruction of bile duct epithelium followed by progressive cholestasis, which resembles primary biliary cirrhosis (PBC) clinically and histologically. Bezafibrate (BF) is a widely used agent for hyperlipidemia that is also effective in ursodeoxycholic acid (UDCA)-resistant PBC patients. The putative mechanism in cholestasis is that BF upregulates the expression of phosphatidylcholine flippase on bile canaliculi, facilitates phospholipid output into bile and relieves bile duct damage caused by hydrophobic bile salts. Therefore, the effects of BF in patients with cGVHD of the liver were investigated. Of 87 patients with cGVHD who survived more than 100 days after SCT, 8 were given BF to treat liver cGVHD because of a poor therapeutic response to UDCA and immunosuppressants. The serum alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase (gamma-GTP) levels decreased significantly within 1 month after initiation of BF therapy compared with those before BF therapy in all patients (ALP, 964.9.0+/-306.9 to 597.8+/-102.5 IU/l, P=0.012; gamma-GTP, 528.8+/-299.0 to 269.0+/-119.9 IU/l, P=0.012). BF was effective in patients with liver cGVHD, including UDCA-resistant patients. BF could be a novel therapeutic option for liver cGVHD that helps to preserve normal immunity with the antileukemic effect of cGVHD.


Assuntos
Bezafibrato/uso terapêutico , Doença Enxerto-Hospedeiro/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hepatopatias/terapia , Adulto , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/complicações , Doença Enxerto-Hospedeiro/diagnóstico , Humanos , Hepatopatias/complicações , Hepatopatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Homólogo
3.
Br J Cancer ; 101(6): 967-72, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19638983

RESUMO

BACKGROUND: Stat3 is a member of the Janus-activated kinase/STAT signalling pathway. It normally resides in the cytoplasm and can be activated through phosphorylation. Activated Stat3 (p-Stat3) translocates to the nucleus to activate the transcription of several molecules involved in cell survival and proliferation. The constitutive activation of Stat3 has been shown in various types of malignancies, and its expression has been reported to indicate a poor prognosis. However, the correlation between the constitutive activation of Stat3 and the prognosis of cervical cancer patients has not been reported. METHODS: The immunohistochemical analysis of p-Stat3 expression was performed on tissues from 125 cervical squamous-cell carcinoma patients who underwent extended hysterectomy and pelvic lymphadenectomy, and the association of p-Stat3 expression with several clinicopathological factors and survival was investigated. RESULTS: Positive p-Stat3 expression was observed in 71 of 125 (56.8%) cases and was significantly correlated with lymph node metastasis, lymph vascular space invasion, and large tumour diameter (>4 cm) by Fisher's exact test. Kaplan-Meier survival analysis showed that p-Stat3 expression was statistically indicative of a poor prognosis for overall survival (P=0.006) and disease-free survival (P=0.010) by log-rank test. CONCLUSION: These data showed that p-Stat3 expression in cervical cancer acts as a predictor of poor prognosis.


Assuntos
Carcinoma de Células Escamosas/mortalidade , Fator de Transcrição STAT3/análise , Neoplasias do Colo do Útero/mortalidade , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/patologia , Colo do Útero/química , Feminino , Humanos , Interleucina-6/fisiologia , Metástase Linfática , Fosforilação , Prognóstico , Taxa de Sobrevida , Neoplasias do Colo do Útero/química , Neoplasias do Colo do Útero/patologia , Fator A de Crescimento do Endotélio Vascular/análise , Proteína bcl-X/análise
4.
Anat Histol Embryol ; 38(3): 214-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19469767

RESUMO

The structure of the equine ovary is different from that of other mammals in its extremely large size, the presence of ovarian fossa and the inverted location of its cortex and medulla. A three-dimensional internal structure microscopy (3D-ISM), which consists of a computer-controlled slicer, a CCD camera, a laser disc recorder and a PC, is very useful for the observation of the internal structures in equine ovaries. In addition, the three-dimensional images of follicles and corpus luteum (CL) reconstructed by the segmentation technique can clarify the spatial arrangement in the equine ovary. In this study, to understand the changes in the ovarian internal structures of the mare during the oestrous cycle, the size and numbers of follicles and luteal structures were analysed by 3D-ISM in addition to the concentrations of progesterone (P(4)) and oestradiol-17beta. As a result, many small follicles (<10 mm in diameter) were detected. It was recognized that the luteal structures were distinguished into three types, such as the corpus haemorragicum (CH), which is formed by blood elements at the cavity after ovulation, CL and corpus albican (CA). There were some CHs and CL in the group, which had the concentration of P(4) > 1 ng/ml. CHs were also observed in the group, which had low level of P(4) (P(4) < 1 ng/ml). CAs were found regardless of the P(4) level. In conclusion, 3D-ISM enabled the internal observation of the ovarian structures in detail, and estimation of the stage of the ovarian cycle with complementary physiological information. The findings by 3D-ISM provide basic information for clinical applications.


Assuntos
Corpo Lúteo/ultraestrutura , Estro/fisiologia , Cavalos/anatomia & histologia , Folículo Ovariano/ultraestrutura , Animais , Corpo Lúteo/anatomia & histologia , Estradiol/sangue , Estro/sangue , Feminino , Cavalos/sangue , Cavalos/fisiologia , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/veterinária , Microscopia/instrumentação , Microscopia/métodos , Microscopia/veterinária , Folículo Ovariano/anatomia & histologia , Progesterona/sangue , Gravação de Videodisco
5.
Am J Transplant ; 9(4): 844-52, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19344470

RESUMO

Simultaneous heart-kidney transplantation (SHK) remains uncommon in the US. We examined outcomes of SHK compared to heart transplant alone (HTA) and deceased donor kidney transplant (DDKT). Data from OPTN/UNOS heart and kidney data bases were used to identify 16,710 HTA, 263 SHK transplants and 68,833 DDK transplants between 1998 and 2007. Outcomes included patient survival (PS), acute cardiac and renal rejection and renal graft survival (rGS). The adjusted risk of death was 44% lower with SHK compared to HTA. Over half of SHK were performed in cases where pretransplant dialysis was not initiated. In these cases, there was no significant difference in the risk of death between SHK and HTA (HR 1.01; 95% CI 0.67-1.50). Recipients of SHK had worse 1-year rGS and PS and had a higher relative risk of overall renal graft loss compared to DDKT recipients. One-year rates of cardiac (14.5%) and renal (6.5%) rejection were lower in SHK compared to HTA and DDKT, respectively. Recipients of SHK had a lower adjusted risk of death compared to HTA recipients, particularly in patients who required pretransplant dialysis. These data suggest that SHK should be considered in heart transplant candidates with renal failure requiring dialysis, whereas the utility of SHK in cases of renal failure not requiring dialysis warrants further study.


Assuntos
Transplante de Coração/estatística & dados numéricos , Transplante de Rim/estatística & dados numéricos , Adolescente , Adulto , Idoso , Cadáver , Feminino , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto , Transplante de Coração/mortalidade , Humanos , Transplante de Rim/mortalidade , Doadores Vivos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Reoperação/mortalidade , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Análise de Sobrevida , Doadores de Tecidos/estatística & dados numéricos , Resultado do Tratamento , Estados Unidos/epidemiologia , Adulto Jovem
7.
Blood ; 98(7): 2193-9, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11568007

RESUMO

HV(MNE) is a novel Epstein-Barr (EBV)-like virus isolated from a Macaca nemestrina with CD8(+) T-cell mycosis fungoides-cutaneous T-cell lymphoma. Here it is demonstrated that intravenous inoculation of irradiated HV(MNE)-infected T cells or cell-free virus from the J94356(PBMC) cell line in New Zealand White rabbits results in seroconversion to the viral capsid antigen (VCA) of EBV; all animals that seroconverted to VCA developed malignant lymphoma within months of inoculation. In contrast, control rabbits, inoculated with heat-inactivated culture supernatants from the same cell line, failed to seroconvert to VCA and did not develop disease. Disseminated lymphoma cells of mixed origin were detected in most vital organs, including the spleen, liver, lungs, kidneys, and heart of the affected rabbits. Neoplastic infiltrates were also observed in lymph nodes, thymus, skin, and subcutaneous tissues. HV(MNE) DNA and EBV-like RNA expression was demonstrated in the lymphomatous organs and in 2 transformed T-cell lines, one established from the lymph node and the other from the blood of the 2 lymphomatous animals. Analysis of one of these T-cell lines demonstrated the persistence of HV(MNE) DNA, expression of an LMP1-like protein, and acquisition of interleukin-2 independence, and constitutive activation of the Jak/STAT pathway. Thus, HV(MNE) in rabbits provides a valuable animal model for human T-cell lymphoma whereby genetic determinants for T-cell transformation by this EBV-like animal virus can be studied.


Assuntos
Infecções por Herpesviridae/patologia , Lymphocryptovirus , Linfoma/virologia , Macaca nemestrina/virologia , Proteínas do Leite , Infecções Tumorais por Vírus/patologia , Animais , Antígenos Virais/sangue , Capsídeo/imunologia , DNA Viral/análise , Proteínas de Ligação a DNA/metabolismo , Infecções por Herpesviridae/virologia , Herpesvirus Humano 4 , Humanos , Lymphocryptovirus/genética , Lymphocryptovirus/crescimento & desenvolvimento , Linfoma/etiologia , Linfoma Cutâneo de Células T/patologia , Linfoma Cutâneo de Células T/virologia , RNA Viral/análise , Coelhos , Fator de Transcrição STAT5 , Linfócitos T/metabolismo , Linfócitos T/patologia , Linfócitos T/virologia , Transativadores/metabolismo , Células Tumorais Cultivadas/transplante , Células Tumorais Cultivadas/virologia , Infecções Tumorais por Vírus/virologia , Proteínas da Matriz Viral/metabolismo
8.
Biomaterials ; 22(9): 875-81, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11311005

RESUMO

Apatite formation on implants is important in achieving a direct bonding to bone tissue. We recently showed that titanium metal chemically treated with a hydrogen peroxide solution containing tantalum chloride has the ability to form a hydroxyapatite layer in simulated body fluid which had inorganic ion composition similar to human blood plasma. In this study, a pure titanium cylinder (4.0 mm in diameter, 20.0 mm in length) treated with this method was implanted into a hole (4.2 mm in diameter) in a rabbit's tibia. After implantation for predetermined periods up to 16 weeks, the specimens were extracted with bone tissue, and were examined by push-out test to evaluate the shearing force between the implant and bone tissue. The results were compared with those of non-treated pure titanium. Eight weeks after surgery, the shearing force of the treated titanium implanted in the 4.2 mm-hole was significantly higher than that of non-treated titanium, although the surface roughness was not changed after the treatment. Scanning electron microscopic (SEM) observation and energy-dispersive X-ray (EDX) microanalysis showed that the bone comes very close to the surface of the treated titanium. Moreover, the shearing force was higher for the implanted sample in the 4.0 mm-hole than that in the 4.2 mm-hole. Thus, it is confirmed that the treatment with hydrogen peroxide solution containing tantalum chloride provides higher bonding ability on titanium implants in vivo.


Assuntos
Materiais Biocompatíveis , Osso e Ossos , Cloretos/química , Peróxido de Hidrogênio/química , Tantálio/química , Titânio , Animais , Microscopia Eletrônica de Varredura , Coelhos , Titânio/química
9.
Transplantation ; 70(7): 1055-9, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11045642

RESUMO

BACKGROUND: Historically, panel reactive antibody (PRA) analysis to detect HLA antibodies has been performed using cell-based complement-dependent cytotoxicity (CDC) techniques. Recently, a flow cytometric procedure (FlowPRA) was introduced as an alternative approach to detect HLA antibodies. The flow methodology, using a solid phase matrix to which soluble HLA class I or class II antigens are attached is significantly more sensitive than CDC assays. However, the clinical relevance of antibodies detected exclusively by FlowPRAhas not been established. In this study of cardiac allograft recipients, FlowPRA was performed on pretransplant sera with no detectable PRA activity as assessed by CDC assays. FlowPRA antibody activity was then correlated with clinical outcome. METHODS: PRA analysis by anti-human globulin enhanced (AHG) CDC and FlowPRA was performed on sera corresponding to final cross-match specimens from 219 cardiac allograft recipients. In addition, sera collected 3-6 months posttransplant from 91 patients were evaluated. The presence or absence of antibodies was correlated with episodes of rejection and patient survival. A rejection episode was considered to have occurred based on treatment with antirejection medication and/or histology. RESULTS: By CDC, 12 patients (5.5%) had pretransplant PRA >10%. In contrast, 72 patients (32.9%) had pretransplant anti-HLA antibodies detectable by FlowPRA (34 patients with only class I antibodies; 7 patients with only class II antibodies; 31 patients with both class I and class II antibodies). A highly significant association (P<0.001) was observed between pretransplant HLA antibodies detected by FlowPRA and episodes of rejection that occurred during the first posttransplant year. Fifteen patients died within the first year posttransplant. Of nine retrospective flow cytometric cross-matches that were performed, two were in recipients who had no pretransplant antibodies detectable by FlowPRA. Both of these cross-matches were negative. In contrast, five of seven cross-matches were positive among recipients who had FlowPRA detectable pretransplant antibodies. Posttransplant serum specimens from 91 patients were also assessed for antibodies by FlowPRA. Among this group, 58 patients had FlowPRA antibodies and there was a trend (although not statistically significant) for a biopsy documented episode of rejection to have occurred among patients with these antibodies. CONCLUSIONS: Collectively, our data suggest that pre- and posttransplant HLA antibodies detectable by FlowPRA and not AHG-CDC identify cardiac allograft recipients at risk for rejection. Furthermore, a positive donor reactive flow cytometric cross-match is significantly associated with graft loss. Thus, we believe that detection and identification of HLA-specific antibodies can be used to stratify patients into high and low risk categories. An important observation of this study is that in the majority of donor:recipient pairs, pretransplant HLA antibodies were not directed against donor antigens. We speculate that these non-donor-directed antibodies are surrogate markers that correspond to previous T cell activation. Thus, the rejection episodes that occur in these patients are in response to donor-derived MHC peptides that share cryptic determinants with the HLA antigens that initially sensitized the patient.


Assuntos
Antígenos HLA/imunologia , Transplante de Coração/imunologia , Anticorpos/análise , Especificidade de Anticorpos , Citotoxicidade Imunológica , Citometria de Fluxo , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/terapia , Humanos , Sensibilidade e Especificidade , Transplante Homólogo
10.
J Biol Chem ; 275(49): 38912-20, 2000 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-10986284

RESUMO

Angiostatin, a potent endogenous inhibitor of angiogenesis, is generated by cancer-mediated proteolysis of plasminogen. The culture medium of human prostate carcinoma cells, when incubated with plasminogen at a variety of pH values, generated angiostatic peptides and miniplasminogen. The enzyme(s) responsible for this reaction was purified and identified as procathepsin D. The purified procathepsin D, as well as cathepsin D, generated two angiostatic peptides having the same NH(2)-terminal amino acid sequences and comprising kringles 1-4 of plasminogen in the pH range of 3.0-6.8, most strongly at pH 4.0 in vitro. This reaction required the concomitant conversion of procathepsin D to catalytically active pseudocathepsin D. The conversion of pseudocathepsin D to the mature cathepsin D was not observed by the prolonged incubation. The affinity-purified angiostatic peptides inhibited angiogenesis both in vitro and in vivo. Importantly, procathepsin D secreted by human breast carcinoma cells showed a significantly lower angiostatin-generating activity than that by human prostate carcinoma cells. Since deglycosylated procathepsin D from both prostate and breast carcinoma cells exhibited a similar low angiostatin-generating activity, this discrepancy appeared to be attributed to the difference in carbohydrate structures of procathepsin D molecules between the two cell types. The seminal vesicle fluid from patients with prostate carcinoma contained the mature cathepsin D and procathepsin D, but not pseudocathepsin D, suggesting that pseudocathepsin D is not a normal intermediate of procathepsin D processing in vivo. The present study provides evidence for the first time that cathepsin D secreted by human prostate carcinoma cells is responsible for angiostatin generation, thereby causing the prevention of tumor growth and angiogenesis-dependent growth of metastases.


Assuntos
Catepsina D/metabolismo , Fragmentos de Peptídeos/metabolismo , Plasminogênio/metabolismo , Neoplasias da Próstata/enzimologia , Serina Endopeptidases/metabolismo , Angiostatinas , Antineoplásicos/farmacocinética , Neoplasias da Mama , Feminino , Humanos , Concentração de Íons de Hidrogênio , Cinética , Masculino , Modelos Moleculares , Plasminogênio/química , Inibidores de Proteases/farmacologia , Estrutura Secundária de Proteína , Serina Endopeptidases/isolamento & purificação , Células Tumorais Cultivadas
11.
Blood ; 96(1): 275-81, 2000 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-10891462

RESUMO

Human T lymphotropic virus type I (HTLV-I) is the etiological agent of adult T-cell lymphocytic leukemia (ATLL), whereas HTLV-II has not been associated with hematopoietic malignancies. The control of apoptotic pathways has emerged as a critical step in the development of many cancer types. As a result, the underlying mechanism of long-term survival of HTLV-I and HTLV-II was studied in infected T cells in vitro and in ex vivo ATLL samples. Results indicate that HTLV-I- and HTLV-II-infected T cells in vitro express high levels of the antiapoptotic protein Bcl compared with other human leukemic T cell lines or uninfected peripheral blood mononuclear cells. The levels of proapoptotic proteins Bax, BAD, and Bak were not significantly altered. HTLV-I and HTLV-II viral transactivators, Tax1 and Tax2, are known to increase expression of cellular genes. These proteins were tested for increased transcription from the human Bcl2 and Bcl-X(L) promoters. Whereas no effect was observed on the Bcl2 promoter, both Tax1 and Tax2 increased transcription of the Bcl-X(L) promoter in T cells, although Tax1 appeared to be more efficient than Tax2. The biological significance of these observations was validated by the finding of an increased expression of Bcl-X(L) in ex vivo ATLL cells, especially from patients unresponsive to various chemotherapy regimens. Altogether, these data suggest that overexpression of Bcl-X(L )in vivo( )may be in part responsible for the resistance of ATLL cells to chemotherapy. In addition, inefficient activation of the Bcl-X(L) promoter by Tax2 may result in a shorter survival time of HTLV-II-infected cells in vivo and a diminished risk of leukemia development.


Assuntos
Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Vírus Linfotrópico T Tipo 2 Humano/fisiologia , Leucemia-Linfoma de Células T do Adulto/sangue , Proteínas Proto-Oncogênicas c-bcl-2/genética , Linfócitos T/fisiologia , Linfócitos T/virologia , Adulto , Linhagem Celular Transformada , Produtos do Gene tax/genética , Genes bcl-2 , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 2 Humano/genética , Humanos , Células Jurkat , Leucemia-Linfoma de Células T do Adulto/imunologia , Contagem de Leucócitos , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-bcl-2/sangue , Proteínas Recombinantes/biossíntese , Valores de Referência , Linfócitos T/imunologia , Ativação Transcricional , Transfecção , Células Tumorais Cultivadas , Proteína bcl-X
12.
Blood ; 95(12): 3939-44, 2000 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-10845931

RESUMO

Human T-cell lymphotropic virus type I (HTLV-I) transforms T cells in vitro, and the viral transactivator Tax functionally impairs the tumor suppressor p53 protein, which is also stabilized in HTLV-I-infected T cells. Thus, the functional impairment of p53 is essential to maintain the viral-induced proliferation of CD4+ mature T cells. However, in the CD4+ leukemic cells of patients with adult T-cell leukemia/lymphoma (ATLL), the viral transactivator does not appear to be expressed, and p53 mutations have been found only in a fraction of patients. We sought to investigate whether p53 function is impaired, in ex vivo samples from patients with ATLL, in the absence of genetic mutations. Here we demonstrate that the p53 protein is stabilized also in ex vivo ATLL samples (10 of 10 studied) and that at least in 2 patients p53 stabilization was not associated with genetic mutation. Furthermore, the assessment of p53 function after ionizing radiation of ATLL cells indicated an abnormal induction of the p53-responsive genes GADD45 and p21(WAF1) in 7 of 7 patients. In 2 of 2 patients, p53 regulation of cell-cycle progression appeared to be impaired as well. Because p53 is part of a regulatory loop that also involves MDM2 and p14(ARF), the status of the latter proteins was also assessed in cultured or fresh ATLL cells. The p97 MDM2 protein was not detected by Western blot analysis in established HTLV-I-infected T-cell lines or ex vivo ATLL cell lysates. However, the MDM2 protein could be easily detected after treatment of cells with the specific proteasome inhibitor lactacystin, suggesting a normal regulation of the p53-MDM2 regulating loop. Similarly, p14(ARF) did not appear to be aberrantly expressed in ex vivo ATLL cells nor in any of the established HTLV-I-infected T-cell lines studied. Thus, p53 stabilization in HTLV-I infection occurs in the absence of genetic mutation and alteration of the physiologic degradation pathway of p53. (Blood. 2000;95:3939-3944)


Assuntos
Genes p53 , Leucemia-Linfoma de Células T do Adulto/genética , Linfócitos/imunologia , Proteínas Nucleares , Proteínas/genética , Proteínas Proto-Oncogênicas/genética , Proteína Supressora de Tumor p53/metabolismo , Adulto , Ciclo Celular/fisiologia , Ciclo Celular/efeitos da radiação , Linhagem Celular , Células Cultivadas , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Humanos , Linfócitos/efeitos dos fármacos , Proteínas de Neoplasias/genética , Proteínas/análise , Proteínas Proto-Oncogênicas/análise , Proteínas Proto-Oncogênicas c-mdm2 , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Transfecção , Proteína Supressora de Tumor p14ARF , Proteína Supressora de Tumor p53/análise
13.
AIDS Res Hum Retroviruses ; 16(8): 709-13, 2000 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-10826477

RESUMO

The stoichiometry of the p16INK4A and p15INK4B proteins bound to the cyclin D-CDK4/6 complex regulates the entry of cells into the G1 phase of the cell cycle. Thus, their level of expression is essential in maintaining regulated cell growth. In several tumors, deletion of these genes has been reported and, more recently, promoter methylation has been suggested as an alternative mechanism to decrease the expression of these cell cycle inhibitor proteins. Here, we studied the methylation status and the integrity of the p16INK4A and p15INK4B genes in 8 chronically HTLV-I-infected T cell lines and in ex vivo cells from 14 ATLL patients. Deletion of the locus carrying both genes was not found in the HTLV-I-infected T cell lines but was found in seven of eight acute ATLL cases and in none of the PBMCs from the chronic cases or the affected lymph nodes of the lymphoma type. In contrast, partial or complete methylation of one or both genes was found only in chronically HTLV-I T cells. Thus, HTLV-I infection targets the p16INK4A and p15INK4B loci both in vitro and in vivo, although the mechanisms may differ.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/genética , Deleção de Genes , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Leucemia-Linfoma de Células T do Adulto/genética , Regiões Promotoras Genéticas , Linfócitos T/virologia , Linhagem Celular Transformada/fisiologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Humanos , Metilação , Células Tumorais Cultivadas
14.
Blood ; 94(6): 2090-101, 1999 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10477739

RESUMO

Epstein-Barr virus (EBV) infection of humans has been associated with the development of lymphoid malignancies mainly of B-cell lineage, although occasionally T-cell lymphomas have been reported. We describe here the characterization of a novel EBV-like virus (HV(MNE)) isolated from a simian T-cell lymphotropic virus type I/II (STLV-I/II) seronegative pigtailed macaque (Macaca nemestrina) with a cutaneous T-cell lymphoma. Immunohistochemistry studies on the skin lesions demonstrated that the infiltrating cells were of the CD3(+)/CD8(+) phenotype. Two primary transformed CD8(+) T-cell lines were obtained from cultures of peripheral blood mononuclear cells (PBMC) and skin, and, with time, both cell lines became interleukin-2-independent and acquired the constitutive activation of STAT proteins. Polymerase chain reaction analysis of the DNA from the cell lines and tissues from the lymphomatous animal demonstrated the presence of a 536-bp DNA fragment that was 90% identical to EBV polymerase gene sequences, whereas the same DNA was consistently negative for STLV-I/II sequences. Electron microscopy performed on both cell lines, after sodium butyrate treatment, showed the presence of a herpes-like virus that was designated HV(MNE) according to the existing nomenclature. In situ hybridization studies using EBV Epstein-Barr viral-encoded RNA probes showed viral RNA expression in both CD8(+) T-cell lines as well as in the infiltrating CD8(+) T cells of skin-tissue biopsies. Phylogenetic analysis of a 465-bp fragment from the polymerase gene of HV(MNE) placed this virus within the Lymphocryptovirus genus and demonstrated that HV(MNE) is a distinct virus, clearly related to human EBV and other EBV-like herpesviruses found in nonhuman primates.


Assuntos
Herpesvirus Humano 4/classificação , Lymphocryptovirus/classificação , Lymphocryptovirus/isolamento & purificação , Macaca nemestrina/virologia , Micose Fungoide/veterinária , Filogenia , Doenças dos Primatas/virologia , Neoplasias Cutâneas/veterinária , Linfócitos T/imunologia , Animais , Sequência de Bases , Linhagem Celular Transformada , DNA Viral/química , DNA Viral/genética , Herpesvirus Humano 4/genética , Humanos , Lymphocryptovirus/genética , Dados de Sequência Molecular , Micose Fungoide/imunologia , Micose Fungoide/patologia , Micose Fungoide/virologia , Reação em Cadeia da Polimerase , Doenças dos Primatas/imunologia , Doenças dos Primatas/patologia , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Pele/imunologia , Pele/patologia , Pele/virologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/virologia
15.
J Virol ; 73(8): 6460-7, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10400740

RESUMO

The HTLV-1 singly spliced open reading frame I protein, p12(I), is highly unstable and appears to be necessary for persistent infection in rabbits. Here we demonstrate that p12(I) forms dimers through two putative leucine zipper domains and that its stability is augmented by specific proteasome inhibitors. p12(I) is ubiquitylated, and mutations of its unique carboxy-terminus lysine residue to an arginine greatly enhance its stability. Interestingly, analysis of 53 independent HTLV-1 strains revealed that the natural p12(I) alleles found in ex vivo samples of tropical spastic paraparesis-HTLV-1-associated myelopathy patients contain a Lys at position 88 in some cases, whereas arginine is consistently found at position 88 in HTLV-1 strains from all adult T-cell leukemia-lymphoma (ATLL) cases and healthy carriers studied. This apparent segregation of different alleles in tropical spastic paraparesis-HTLV-associated myelopathy and ATLL or healthy carriers may be relevant in vivo, since p12(I) binds the interleukin-2 receptor beta and gammac chains, raising the possibility that the two natural alleles might affect differently the regulation of these molecules.


Assuntos
Alelos , Substituição de Aminoácidos , Arginina/genética , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Zíper de Leucina , Leucemia-Linfoma de Células T do Adulto/virologia , Lisina/genética , Proteínas Oncogênicas Virais/genética , Paraparesia Espástica Tropical/virologia , Fatores de Transcrição , Adulto , Sequência de Aminoácidos , Arginina/metabolismo , Arginina/fisiologia , Sítios de Ligação , Portador Sadio , Cisteína Endopeptidases/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Lisina/metabolismo , Lisina/fisiologia , Dados de Sequência Molecular , Complexos Multienzimáticos/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Proteínas Oncogênicas Virais/fisiologia , Complexo de Endopeptidases do Proteassoma , Ubiquitinas , Proteínas Virais Reguladoras e Acessórias
16.
Leukemia ; 11 Suppl 3: 67-9, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9209301

RESUMO

Adult T cell leukemia (ATL) is an aggressive neoplasm of mature helper T cell, which is etiologically linked with human T-lymphotropic virus type 1 (HTLV-I). We studied HTLV-I provirus in 61 cases of ATL with Southern blot analyses and long PCR. These methods detected defective virus in 34 cases (56%). Furthermore, it found two types of defective virus. The first type (type 1) defective virus had both LTRs, but lacked internal sequences, such as gag and pol. Type 1 defective virus was seen in 50% of all defective virus. The second form (type 2) of defective virus had only one LTR, and 5'-LTR was preferentially deleted. This type of defective virus could be more frequently detected in aggressive types of ATL (16/44 cases) than chronic type (1/17 cases). This defective virus might be associated with clinical subtype.


Assuntos
Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Leucemia de Células T/classificação , Leucemia de Células T/virologia , Provírus/isolamento & purificação , Adulto , Southern Blotting/métodos , Vírus Defeituosos/isolamento & purificação , Genes gag , Genes pol , Vírus Linfotrópico T Tipo 1 Humano/classificação , Vírus Linfotrópico T Tipo 1 Humano/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Sequências Repetitivas de Ácido Nucleico , Linfócitos T Auxiliares-Indutores
18.
Proc Natl Acad Sci U S A ; 94(25): 13897-902, 1997 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-9391124

RESUMO

Human T cell leukemia/lymphotropic virus type I (HTLV-I) induces adult T cell leukemia/lymphoma (ATLL). The mechanism of HTLV-I oncogenesis in T cells remains partly elusive. In vitro, HTLV-I induces ligand-independent transformation of human CD4+ T cells, an event that correlates with acquisition of constitutive phosphorylation of Janus kinases (JAK) and signal transducers and activators of transcription (STAT) proteins. However, it is unclear whether the in vitro model of HTLV-I transformation has relevance to viral leukemogenesis in vivo. Here we tested the status of JAK/STAT phosphorylation and DNA-binding activity of STAT proteins in cell extracts of uncultured leukemic cells from 12 patients with ATLL by either DNA-binding assays, using DNA oligonucleotides specific for STAT-1 and STAT-3, STAT-5 and STAT-6 or, more directly, by immunoprecipitation and immunoblotting with anti-phosphotyrosine antibody for JAK and STAT proteins. Leukemic cells from 8 of 12 patients studied displayed constitutive DNA-binding activity of one or more STAT proteins, and the constitutive activation of the JAK/STAT pathway was found to persist over time in the 2 patients followed longitudinally. Furthermore, an association between JAK3 and STAT-1, STAT-3, and STAT-5 activation and cell-cycle progression was demonstrated by both propidium iodide staining and bromodeoxyuridine incorporation in cells of four patients tested. These results imply that JAK/STAT activation is associated with replication of leukemic cells and that therapeutic approaches aimed at JAK/STAT inhibition may be considered to halt neoplastic growth.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Leucemia-Linfoma de Células T do Adulto/metabolismo , Leucemia-Linfoma de Células T do Adulto/patologia , Proteínas do Leite , Proteínas Tirosina Quinases/metabolismo , Transativadores/metabolismo , Adulto , Sequência de Bases , Divisão Celular , Sondas de DNA/genética , Ativação Enzimática , Vírus Linfotrópico T Tipo 1 Humano/patogenicidade , Humanos , Janus Quinase 3 , Leucemia-Linfoma de Células T do Adulto/genética , Fator de Transcrição STAT1 , Fator de Transcrição STAT3 , Fator de Transcrição STAT5 , Fatores de Tempo
19.
Plast Reconstr Surg ; 97(3): 577-86, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8596789

RESUMO

We examined the effects of dorsal root ganglion isografts on the denervation process of skeletal muscle. A segment of sciatic nerve was removed from each of 25 inbred Wistar-Kyoto rats. Fifteen were set aside as controls. In the remaining 10 rats, isogeneic cervical dorsal root ganglia were grafted to the severed distal stump of the common peroneal nerve. Between day 72 and day 286 postoperatively, both controls and recipients were killed after twitch and tetanic tension recording of the extensor digitorum longus was performed. The wet muscle weight and the twitch and tetanic tensions of the denervated extensor digitorum longus in the graft group were significantly greater than those in the control group. The mean area of the denervated tibialis anterior muscle fibers in the graft group also was significantly larger than that in the control group. In electron and light microscopic images, nerve cells along the periphery of each dorsal root ganglion were found surviving with regenerating axons throughout the experimental period. Numerous myelinated axons were observed in the common peroneal nerve of the graft group, and there were significantly more axonal branches in the extensor digitorum longus of the graft group than in the extensor digitorum longus of the control group. Thus sensory nerve fibers from the grafted dorsal root ganglia had certain beneficial effects to slow the denervation process, presumably secreting trophic factors into the denervated muscle. Clinically, we have transferred avulsed dorsal root ganglia in cases of total brachial plexus avulsion directly into denervated skeletal muscle. This procedure, accompanied by nerve crossing procedures, will probably keep denervated skeletal muscle in a better condition until regenerating motor axons from the repair site reach their target muscle.


Assuntos
Gânglios Espinais/transplante , Denervação Muscular , Músculo Esquelético/inervação , Animais , Gânglios Espinais/anatomia & histologia , Humanos , Tono Muscular , Músculo Esquelético/fisiologia , Músculo Esquelético/cirurgia , Nervo Fibular/cirurgia , Ratos , Ratos Endogâmicos WKY , Nervo Isquiático/cirurgia , Fatores de Tempo , Transplante Isogênico
20.
Leukemia ; 10(2): 333-7, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8637243

RESUMO

Adult T cell leukemia (ATL), a neoplasm of mature helper T lymphocytes is etiologically associated with human T lymphotropic virus type-I (HTLV-I). ATL cells infiltrate various organs, the lung, skin, central nervous system, gastrointestinal tract, and bone, causing various clinical manifestations. Two unusual cases of ATL, in which lytic bone lesion was the primary site of ATL, are described. One patient had multiple lytic lesions in bones without any involvement of other organs, and the other patient had a bone lesion in the right radius, which disappeared after chemotherapy. In both cases, monoclonal integration of HTLV-I provirus was demonstrated in the genomic DNA from each bone lesion. Although their clinical courses and pathological findings were different, ATL in both patients began as a bone lesion, showing that primary lymphoma of bone can be manifested in ATL cases.


Assuntos
Neoplasias Ósseas/virologia , Osso e Ossos/virologia , DNA Viral/genética , Leucemia de Células T/virologia , Provírus/isolamento & purificação , Integração Viral , Adulto , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Feminino , Infecções por HTLV-I/diagnóstico por imagem , Infecções por HTLV-I/patologia , Infecções por HTLV-I/virologia , Humanos , Leucemia de Células T/diagnóstico por imagem , Leucemia de Células T/patologia , Masculino , Osteólise/diagnóstico por imagem , Osteólise/etiologia , Osteólise/patologia , Reação em Cadeia da Polimerase , Provírus/genética , Radiografia
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