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Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected. Serum/plasma samples were tested for IgG aPS/PT at Inova Diagnostics (Inova) using two ELISA kits. A replication study (five centres, five countries) was carried out afterwards. Results In the initial study ( n = 247), a moderate agreement between the IgG aPS/PT Inova and MBL ELISA kits was observed ( k = 0.598). IgG aPS/PT were more prevalent in APS patients (51%) than in those without (9%), OR 10.8, 95% CI (4.0-29.3), p < 0.0001. Sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 91%, 5.9 and 0.5, respectively. In the replication study ( n = 214), a moderate/substantial agreement between the IgG aPS/PT results obtained with both ELISA kits was observed ( k = 0.630). IgG aPS/PT were more prevalent in APS patients (47%) than in those without (12%), OR 6.4, 95% CI (2.6-16), p < 0.0001. Sensitivity, specificity, LR + and LR- for APS diagnosis were 47%, 88%, 3.9 and 0.6, respectively. Conclusions IgG aPS/PT detection is an easily performed laboratory parameter that might contribute to a better and more complete identification of patients with APS.
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Anticorpos Antifosfolipídeos/sangue , Síndrome Antifosfolipídica/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Fosfatidilserinas/imunologia , Complicações na Gravidez/diagnóstico , Trombose/diagnóstico , Adolescente , Adulto , Idoso , Síndrome Antifosfolipídica/sangue , Estudos Transversais , Feminino , Humanos , Cooperação Internacional , Masculino , Pessoa de Meia-Idade , Gravidez , Complicações na Gravidez/sangue , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto JovemRESUMO
BACKGROUND: To improve the diagnostic accuracy for hepatic tumors on the liver surface, we investigated the usefulness of an indocyanine green-photodynamic eye (ICG-PDE) system by comparison with Sonazoid intraoperative ultrasonography (IOUS) in 117 patients. Hepatic segmentation by ICG-PDE was also evaluated. METHODS: ICG was administered preoperatively for functional testing and images of the tumor were observed during hepatectomy using a PDE camera. ICG was injected into portal veins to determine hepatic segmentation. RESULTS: Accurate diagnosis of liver tumors was achieved with ICG-PDE in 75% of patients, lower than with IOUS (94%). False-positive and false-negative diagnosis rates for ICG-PDE were 24% and 9%, respectively. New small HCCs were detected in 3 patients. The ICG fluorescent pattern in tumors was strong staining in 41%, weak staining in 13%, rim staining in 20% and no staining in 26%. Hepatocellular carcinoma predominantly showed strong staining (61%), while rim staining predominated in cholangiocellular carcinoma (60%) and liver metastasis (55%). Hepatic segmental staining was performed in 28 patients, proving successful in 89%. CONCLUSION: ICG-PDE is a useful tool for detecting the precise tumor location at the liver surface, identifying new small tumors, and determining liver segmentation for liver resection.
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Neoplasias dos Ductos Biliares/diagnóstico , Ductos Biliares Intra-Hepáticos , Carcinoma Hepatocelular/diagnóstico , Colangiocarcinoma/diagnóstico , Neoplasias Colorretais/patologia , Corantes Fluorescentes , Neoplasias da Vesícula Biliar/patologia , Verde de Indocianina , Neoplasias Hepáticas/diagnóstico , Tumores Neuroendócrinos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/cirurgia , Carcinoma Hepatocelular/cirurgia , Colangiocarcinoma/secundário , Colangiocarcinoma/cirurgia , Meios de Contraste , Reações Falso-Negativas , Reações Falso-Positivas , Estudos de Viabilidade , Feminino , Compostos Férricos , Hepatectomia/métodos , Humanos , Cuidados Intraoperatórios , Ferro , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Óxidos , UltrassonografiaRESUMO
BACKGROUND: Prognostic influences of hepatic transection by an anterior approach using the liver hanging maneuver (LHM) has not been fully clarified. METHODS: We examined 233 patients who underwent major hepatectomy with the LHM (n = 75; hepatocellular carcinoma (HCC) in 35, colorectal liver metastasis (CLM) in 10, intrahepatic cholangiocarcinoma (ICC) in 14 and perihilar bile duct carcinoma (BDC) in 16) or without it (n = 158; HCC in 78, CLM in 21, ICC in 31 and BDC in 28). RESULTS: In HCC patients, cancer-positive margin rate, blood loss, transection time and prevalence of posthepatectomy ascites in the LHM group were significantly lower than those in the non-LHM group (p < 0.05). In CLM, transection time in the LHM group was significantly lower than that in the non-LHM group (p < 0.05). In BDC patients, amount of blood loss, transection time and prevalence of ascites in the LHM group were significantly lower than those in the non-LHM group (p < 0.05). In CLM patients, tumor recurrence rate in the non-LHM group was significantly higher than that in the LHM group and disease-free survival in the LHM group was significantly better than that in the non-LHM group in CLM patients and, however, this difference was not observed in a large CLM exceeding 5 cm. However, significant differences of posthepatectomy disease-free and overall survivals were not observed in HCC, ICC and BDC patients. CONCLUSIONS: Although advantages of LHM improving surgical records in major anatomical liver resections were clarified, oncological advantages in the long-term survival of LHM was still uncertain in the hepatobiliary malignancies.
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Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos , Carcinoma Hepatocelular/cirurgia , Colangiocarcinoma/cirurgia , Neoplasias Colorretais/patologia , Hepatectomia/métodos , Neoplasias Hepáticas/cirurgia , Idoso , Ascite/complicações , Neoplasias dos Ductos Biliares/complicações , Perda Sanguínea Cirúrgica , Carcinoma Hepatocelular/complicações , Colangiocarcinoma/complicações , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasia Residual , Duração da Cirurgia , Prognóstico , Resultado do TratamentoRESUMO
Hepatitis C virus (HCV) infects and associates with B cells, leading to abnormal B-cell activation and development of lymphoproliferative and autoimmune disorders. This immune perturbation may in turn be associated with the resistance of HCV against the host immune system. The objective of this study was to analyse the effects of HCV infection of B cells on the efficacy of interferon (IFN)-based therapy. The study enrolled 102 patients with chronic hepatitis C who were treated with pegylated IFN plus ribavirin. HCV RNA titres in B cells were compared in patients with rapid viral responder (RVR) vs non-RVR, sustained viral responder (SVR) vs non-SVR and null viral responder (NVR) vs VR. The levels of HCV RNA in B cells were significantly higher in non-RVR, non-SVR and NVR groups. Association between the therapy outcome and the positive B-cell HCV RNA was also investigated in relation to other known viral and host factors. Multivariable analyses showed that the positive B-cell HCV RNA and the minor single-nucleotide polymorphism near the IL28B gene (rs8099917) were independent factors associated with NVR in patients infected with HCV genotype 1. When these two factors were combined, the sensitivity, specificity, positive and negative predictive values for NVR were 92.3%, 98.2%, 92.3% and 98.2%, respectively. Genotype 1 and the presence of one or no mutations in the IFN-sensitivity determining region were associated with higher levels of B-cell HCV RNA. B-cell-tropic HCV appears to have an IFN-resistant phenotype. B-cell HCV RNA positivity is a predictive factor for resistance to IFN-based therapy.
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Antivirais/administração & dosagem , Linfócitos B/virologia , Farmacorresistência Viral , Hepacivirus/efeitos dos fármacos , Hepacivirus/fisiologia , Interferons/administração & dosagem , Tropismo Viral , Adulto , Idoso , Feminino , Genótipo , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Humanos , Interleucinas/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , RNA Viral/análise , RNA Viral/genética , Ribavirina/administração & dosagem , Resultado do TratamentoRESUMO
Minimal change nephrotic syndrome (MCNS) usually is considered to have a good renal prognosis, but the frequency of relapses is a therapeutic challenge to physicians. The treatment of patients with multiple relapses remains a matter of controversy, because few controlled studies are available. We report the case of a 25-year-old man who experienced relapses of MCNS. Single-dose rituximab therapy (total dose 500 mg) was given during the fourth relapse. Complete remission occurred 10 days later, when no CD19/20-positive B cells were detected in the blood. This the first report of efficacy of single-dose rituximab therapy to treat multi-relapsing MCNS in an adult patient.
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Anticorpos Monoclonais/administração & dosagem , Fatores Imunológicos/administração & dosagem , Nefrose Lipoide/tratamento farmacológico , Adulto , Anticorpos Monoclonais Murinos , Humanos , Masculino , Recidiva , Rituximab , Resultado do TratamentoRESUMO
The mass of air breathed by a human per day is equivalent to 10-times the mass of food consumed in that time. However, fundamental safety measures for atmospheric bacterial control have not yet been implemented. The purpose of our research is to develop a cell wall Iytic filter using a cell wall Iytic enzyme, which can inactivate the bacteria in air that cause infectious diseases by decomposing their cell envelope. In this study, the use of Iytic enzyme mixture was suggested, including glycosidase, protease and lipase. The performance of the Iytic enzyme mixture was evaluated using lysozyme, a typical Iytic enzyme, as a control. The substrate that we used was Micrococcus luteus, a gram-positive bacteria. The experimental results showed that the use of the Iytic enzyme mixture exhibited a Iytic rate per hour that was 13 - 39% greater than the control. Furthermore, although there are some different phases during bacterium multiplication, the Iytic rate per hour improved for all of the phases when the Iytic enzyme mixture was used.
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AIMS: To evaluate a new delivery system of 5-fluorouracil (5-FU) using 5-fluorocytosine (5-FC) as a prodrug and cytosine deaminase induced in vitro and in vivo. METHODS: Fibroblastic cells from rabbit Tenon's capsule were cultured. The cells were exposed to 5-FU and 5-FC with or without cytosine deaminase induced by recombinant adenovirus. In the in vitro study, cell proliferation and DNA synthesis were assessed by MTS, BrdU assay. The effect of 5-FC removal after the treatment of 5-FC and cytosine deaminase induction was also assayed. In the in vivo study cells with or without cytosine deaminase induction were transplanted into the subconjunctival space of mice, followed by eye drops of 1000 microg/ml of 5-FC three times a day. The mice were sacrificed at days 1, 5, and 10, then the cells transplanted were evaluated. RESULTS: Cell proliferation was inhibited by exposure to 5-FU in a dose dependent manner; however, up to 1000 microg/ml of 5-FC did not affect cell proliferation. Cell proliferation was inhibited by exposure to 5-FC in a time dependent manner with induction of cytosine deaminase following infection of recombinant adenovirus. When 5-FC was removed 3 or 6 days after the treatment, the cells grew again. The effect was reproduced in the in vivo model of subconjunctival cellular proliferation although 5-FC was administrated as eye drops. There were no cases with corneal erosion. CONCLUSION: Cell proliferation was inhibited by co-exposure of 5-FC and cytosine deaminase. This new delivery system may merit controlled delivery of 5-FU after filtering surgery.
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Antimetabólitos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Fluoruracila/administração & dosagem , Nucleosídeo Desaminases , Pró-Fármacos/administração & dosagem , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Citosina Desaminase , DNA/biossíntese , Fibroblastos/efeitos dos fármacos , Flucitosina/administração & dosagem , CoelhosRESUMO
Although the immunopathogenesis of primary biliary cirrhosis (PBC) remains unknown, familial clustering of patients with PBC suggests an important role for genetic factors. In addition, recent data support the thesis that the mucosal immune response against intraluminal pathogens may be involved with the onset of PBC. Mannose-binding lectin (MBL) is a key factor in innate mucosal defenses and has several key single nucleotide polymorphisms (SNPs). To study whether MBL gene SNPs are associated with susceptibility to PBC, we studied 65 patients with PBC and 218 controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence specific priming-polymerase chain reaction (SSP-PCR) to examine four polymorphic loci: two (H/L and X/Y) within the promoter region and the other two (P/Q and A/B) within exon-1. We also analyzed serum MBL concentrations. Interestingly, the prevalence of haplotype HYPA, leading to hyper-production of MBL, as well as HYPA/HYPA genotype were significantly increased in PBC compared to controls (0.53 vs. 0.44, P=0.031; 33.9%vs. 17.0%, P=0.003, respectively). Furthermore, individuals homozygous for HYPA had a significantly increased risk for PBC (odds ratio (OR)=2.51, 95% confidence interval (CI)=1.34-4.66). Our results demonstrate that the MBL genotype can be significantly associated with increased risk for PBC, and further, that increased production of MBL plays a critical role in immunopathogenesis.
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Proteínas de Transporte/genética , Predisposição Genética para Doença/genética , Lectinas/genética , Cirrose Hepática Biliar/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas de Transporte/sangue , Estudos de Casos e Controles , Colectinas , Feminino , Frequência do Gene/genética , Genótipo , Haplótipos/genética , Humanos , Lectinas/sangue , Cirrose Hepática Biliar/imunologia , Masculino , Pessoa de Meia-IdadeAssuntos
Nutrição Enteral , Falência Renal Crônica/terapia , Nutrição Parenteral , Aminoácidos Essenciais/administração & dosagem , Eletrólitos/administração & dosagem , Ingestão de Energia , Nutrição Enteral/métodos , Alimentos Formulados , Humanos , Lipídeos/administração & dosagem , Nutrição Parenteral/métodosRESUMO
Hematopoietic fate maps in the developing mouse embryo remain imprecise. Definitive, adult-type hematopoiesis first appears in the fetal liver, then progresses to the spleen and bone marrow. Clonogenic common lymphoid progenitors and clonogenic common myeloid progenitors (CMPs) in adult mouse bone marrow that give rise to all lymphoid and myeloid lineages, respectively, have recently been identified. Here it is shown that myelopoiesis in the fetal liver similarly proceeds through a CMP equivalent. Fetal liver CMPs give rise to megakaryocyte-erythrocyte-restricted progenitors (MEPs) and granulocyte-monocyte-restricted progenitors (GMPs) that can also be prospectively isolated by cell surface phenotype. MEPs and GMPs generate mutually exclusive cell types in clonogenic colony assays and in transplantation experiments, suggesting that the lineage restriction observed within each progenitor subset is absolute under normal conditions. Purified progenitor populations were used to analyze expression profiles of various hematopoiesis-related genes. Expression patterns closely matched those of the adult counterpart populations. These results suggest that adult hematopoietic hierarchies are determined early in the development of the definitive immune system and suggest that the molecular mechanisms underlying cell fate decisions within the myeloerythroid lineages are conserved from embryo to adult. (Blood. 2001;98:627-635)
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Leucopoese/fisiologia , Fígado/embriologia , Células Progenitoras Mieloides/fisiologia , Fatores Etários , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Células da Medula Óssea/fisiologia , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Linhagem da Célula/fisiologia , Separação Celular , Células Precursoras Eritroides/citologia , Células Precursoras Eritroides/metabolismo , Células Precursoras Eritroides/fisiologia , Feto/citologia , Hematopoese/fisiologia , Fígado/citologia , Camundongos , Camundongos Endogâmicos C57BL , Células Progenitoras Mieloides/citologia , Células Progenitoras Mieloides/metabolismo , RNA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologiaRESUMO
A 67-year-old woman was admitted to our hospital because of lymphadenopathy and lymphocytosis. Monoclonal integration of HTLV-I provirus DNA was detected, and a diagnosis of adult T-cell leukemia (ATL) was made. Flow cytometry revealed that the ATL cells expressed CD20 as well as T-cell-associated antigens, and expression of CD20 mRNA was also demonstrated. A novel T-cell subpopulation expressing CD20 molecules has recently been identified. This is the first report of CD20-positive ATL, suggesting that HTLV-I can infect and transform CD20-positive T cells.
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Antígenos CD20/análise , Antígenos de Neoplasias/análise , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Leucemia-Linfoma de Células T do Adulto/virologia , Células-Tronco Neoplásicas/química , Subpopulações de Linfócitos T/química , Idoso , Southern Blotting , Transformação Celular Viral , Feminino , Citometria de Fluxo , Rearranjo Gênico do Linfócito B , Humanos , Imunofenotipagem , Leucemia-Linfoma de Células T do Adulto/metabolismo , Células-Tronco Neoplásicas/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Subpopulações de Linfócitos T/virologiaRESUMO
Human telomerase reverse transcriptase (hTERT) is considered a potential target for cancer immunotherapy because it is preferentially expressed in malignant cells. hTERT-derived peptides carrying motifs for HLA-A24 (HLA-A*2402), the most common allele among Japanese and also frequently present in persons of European descent, were examined for their capacity to elicit antileukemia cytotoxic T lymphocytes (CTLs). Two of the 5 peptides tested, VYAETKHFL and VYGFVRACL, appeared capable of generating hTERT peptide-specific and HLA-A24-restricted CTLs. The CD8(+) CTL clones specific for these hTERT peptides exerted cytotoxicity against leukemia cells in an HLA-A24-restricted manner. This cytotoxicity was inhibited by the addition of hTERT peptide-loaded autologous cells, suggesting that hTERT is naturally processed in leukemia cells and that hTERT-derived peptides are expressed on these cells and are recognized by CTLs in the context of HLA-A24. Taken together with the currently identified HLA-A2-restricted CTL epitopes derived from hTERT, identification of new CTL epitopes presented by HLA-A24 increases the feasibility of immunotherapy for leukemia using hTERT-derived peptides.
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Antígenos HLA-A/imunologia , Leucemia/imunologia , RNA , Linfócitos T Citotóxicos/imunologia , Telomerase/imunologia , Linhagem Celular , Citotoxicidade Imunológica , Proteínas de Ligação a DNA , Antígeno HLA-A24 , Humanos , Fragmentos de Peptídeos/imunologiaAssuntos
Malformações Arteriovenosas/complicações , Descolamento Retiniano/etiologia , Vasos Retinianos/patologia , Malformações Arteriovenosas/diagnóstico , Exsudatos e Transudatos , Angiofluoresceinografia , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Remissão Espontânea , Descolamento Retiniano/fisiopatologia , Transtornos da Visão/etiologia , Acuidade VisualRESUMO
PURPOSE: To report that optical coherence tomography as early as 24 hours after macular hole surgery shows anatomic configuration of the closed macular holes. METHOD: In a prospective study, seven eyes of seven consecutive patients with stage 3 or 4 idiopathic macular hole underwent surgery. Optical coherence tomography was performed preoperatively and at 24, 48, and 72 hours after the surgery. RESULTS: Optical coherence tomography images could be obtained on four out of the seven eyes at 24 hours after surgery. These images showed anatomic configuration of the closed macular holes. Surgical success was confirmed in all of the eyes when the gas was completely absorbed. CONCLUSION: Optical coherence tomography revealed anatomic configuration of surgically closed macular holes within 24 hours after successful surgery.
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Técnicas de Diagnóstico Oftalmológico , Perfurações Retinianas/diagnóstico , Perfurações Retinianas/cirurgia , Vitrectomia , Idoso , Membrana Epirretiniana/cirurgia , Feminino , Humanos , Interferometria , Implante de Lente Intraocular , Masculino , Pessoa de Meia-Idade , Facoemulsificação , Som , Hexafluoreto de Enxofre/administração & dosagem , Fatores de Tempo , Tomografia/métodos , Acuidade VisualRESUMO
Cancer-associated retinopathy (CAR) is a rare form of retinal degeneration and also one of the paraneoplastic neurologic disorders. Sera of CAR patients usually contain high titers of antibodies against retinal proteins, and CAR is believed to be an autoimmune disease. Using serum from a CAR patient as a molecular probe, a homologue of the polypyrimidine tract-binding protein (PTB) was isolated from a cDNA library of rat neonatal retina. This homologue, named PTB-like protein (PTBLP), encodes a 532 amino acid residue protein and has 73.5 and 68.8% homology with PTB and with a regulator of differentiation 1, respectively. Functional domains in the PTB, such as nuclear localization signals and four RNA recognition motifs (RRMs), were highly conserved. The expression of PTBLP mRNA was observed in the retina and brain but not in liver, kidney, spleen, or lung. The expression of PTBLP protein in rat retina was distributed in most of the cells in the ganglion cell layer and some cells in the inner nuclear layer. The PTBLP protein was localized in the nuclei of these cells. These results suggest that PTBLP is a new member of the PTB gene family and a neuron-specific homologue.
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Proteínas do Olho , Lipoproteínas , Proteínas do Tecido Nervoso , Proteínas de Ligação a RNA/genética , Ribonucleoproteínas/genética , Sequência de Aminoácidos , Animais , Antígenos de Neoplasias/imunologia , Sequência de Bases , Sítios de Ligação , Biomarcadores Tumorais/imunologia , Proteínas de Ligação ao Cálcio/imunologia , Clonagem Molecular , Feminino , Biblioteca Gênica , Hipocalcina , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteína de Ligação a Regiões Ricas em Polipirimidinas , Proteínas de Ligação a RNA/imunologia , Ratos , Recoverina , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonucleoproteínas/imunologiaRESUMO
At temperatures below 2.1 K, long-lived gaseous Rb atoms in glass cells have been generated with a simple method: irradiating the cells, containing 4He gas and Rb metal, with a cw laser. The obtained atomic Rb density ( approximately 10(8) cm(-3)) decreases with a 1/e time constant of about 10 s at 1.85 K. We have performed optical pumping of the Rb atoms and measured the longitudinal electronic spin relaxation time at 1.85 K as well. For processes (such as Rb-He collisions) which do not remove the atomic Rb from the vapor, this relaxation time is found to be about 60+/-15 s.
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A 72-year-old woman was admitted because of a subcutaneous hip tumor. A biopsy specimen of the tumor showed a mixture of medium-sized and large lymphocytes infiltrating the subcutaneous fat tissue with a lobular panniculitis-like pattern--a histologic feature of subcutaneous panniculitic T-cell lymphoma (SPTCL). May-Grünwald-Giemsa-stained cytospin slides of freshly isolated neoplastic cell explants showed that the cells had the characteristics of large granular lymphocytes. Immunophenotypic analysis showed that the cells expressed CD56--a natural killer-associated antigen--as well as the cytotoxic T-cell phenotype CD3+ CD4- CD8+. Southern blot analysis revealed rearrangement bands of the TCR-beta chain gene. Chromosome analysis showed complex abnormalities including t(1;6) (q11; p21). The present case may shed some light on the origin and pathogenesis of SPTCL.
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Aberrações Cromossômicas , Transtornos Cromossômicos , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 6 , Linfoma Cutâneo de Células T/genética , Paniculite/patologia , Neoplasias Cutâneas/genética , Idoso , Feminino , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T , Humanos , Linfócitos/patologia , Linfoma Cutâneo de Células T/patologia , Neoplasias Cutâneas/patologiaRESUMO
Stromal cell-derived factor-1 (SDF-1) is a chemokine produced by bone marrow stromal cells which plays an important role in B-lymphopoiesis and the homing of hematopoietic stem cells to the bone marrow. In the present study, we investigated the role of SDF-1 and its receptor, CXCR4, in the chemotactic interaction between non-Hodgkin B-lymphoma cells and lymph node stromal cells. SDF-1 mRNA was abundantly expressed in stromal cells isolated from the lymph nodes of patients with malignant lymphoma. All B-lymphoma cells freshly isolated from these patients and most laboratory B-lymphoma cell lines, including follicular, diffuse large, and Burkitt's lymphoma cells, expressed surface CXCR4 and migrated in the presence of recombinant human SDF-1alpha. Chemotaxis assays revealed that CXCR4-positive (but not CXCR4-negative) B-lymphoma cells migrated towards lymph node stromal cells, and this migration was almost completely inhibited by the addition of anti-CXCR4 monoclonal antibody to the lymphoma cells or of anti-SDF-1 neutralizing antibody to the culture supernatant of the stromal cells. Down-regulation of surface CXCR4 was detected in B-lymphoma cells which migrated towards the stromal cells but not in those which showed no migratory response. In addition, contact between the lymphoma cells and the stromal cells resulted in down-regulation of surface CXCR4 on the lymphoma cells. These data strongly suggest that SDF-1/CXCR4 is the main chemokine system involved in the chemotactic interaction between B-lymphoma cells and lymph node stromal cells.
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Quimiocinas CXC/biossíntese , Linfonodos/citologia , Linfoma de Células B/patologia , Células Estromais/citologia , Anticorpos Monoclonais/farmacologia , Movimento Celular/efeitos dos fármacos , Quimiocina CXCL12 , Fatores Quimiotáticos/fisiologia , Quimiotaxia/efeitos dos fármacos , Quimiotaxia/fisiologia , Regulação para Baixo , Humanos , Receptores CXCR4/imunologia , Receptores CXCR4/fisiologia , Proteínas Recombinantes/farmacologiaRESUMO
Ribonuclease LE (RNase LE) from cultured tomato (Lycopersicon esculentum) cells is a member of the RNase T(2) family showing broad base specificity. The crystal structure of RNase LE has been determined at 1.65 A resolution. The structure consists of seven alpha-helices and seven beta-strands, belonging to an alpha+beta type structure. Comparison of the structure of RNase LE with that of RNase Rh, a microbial RNase belonging to the RNase T(2) family, reveals that while the overall folding topologies are similar to each other, major insertions and deletions are found at the N-terminal regions. The structural comparison, an amino acid sequence alignment of the RNase T(2) enzymes, and comparison of the disulfide-bonding pattern of these enzymes show that the structure of RNase LE shown here is the basic framework of the animal/plant subfamily of RNase T(2) enzymes (including a self-incompatibility protein called S-RNase), and the structure of RNase Rh is that of the fungal subfamily of RNase T(2) enzymes (including RNase T(2)). Subsequently, we superposed the active-site of the RNase LE with that of RNase Rh and found that (1) His39, Trp42, His92, Glu93, Lys96, and His97 of RNase LE coincided exactly with His46, Trp49, His104, Glu105, Lys108, and His109, respectively, of RNase Rh, and (2) two conserved water molecules were found at the putative P(1) sites of both enzymes. These facts suggest that plant RNase LE has a very similar hydrolysis mechanism to that of fungal RNase Rh, and almost all the RNase T(2) enzymes widely distributed in various species share a common catalytic mechanism. A cluster of hydrophobic residues was found on the active-site face of the RNase LE molecule and two large hydrophobic pockets exist. These hydrophobic pockets appear to be base binding sites mainly by hydrophobic interactions and are responsible for the base non-specificity of RNase LE.