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1.
Infection ; 41(1): 195-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22753132

RESUMO

PURPOSE: Our aim was to evaluate the expression of Toll-like receptor-4 (TLR-4) and the level of interferon-gamma (IFN-γ) and interleukin-10 (IL-10) in young infants infected by Bordetella pertussis and B. parapertussis. METHODS: Twenty-two infants under the age of 3.5 months with the clinical suspicion of pertussis were enrolled in the study. Nasopharyngeal secretions were obtained for laboratory testing, and blood samples were obtained for flow cytometry and cytokine level analysis. RESULTS: Six infants had positive PCR results for pertussis; the other 16 infants had infections attributable to another causal agent and were used as the control group. The mean fluorescence index, used as a measure of TLR-4 expression by monocytes, was significantly lower in infants with pertussis than in the control group infants (34.32 ± 18.58 vs. 63.14 ± 28, respectively; p = 0.041). The serum IFN-γ level was also significantly lower in infants with pertussis than in the control group patients (0.41 ± 0.58 vs. 1.36 ± 1.87, respectively; p = 0.04). No differences were found in the levels of IL-10. CONCLUSIONS: Based on these results, we suggest that TL4 expression by monocytes and serum INF-γ levels are lower in infants with positive PCR results for pertussis than in infants with a non-pertussis upper respiratory tract infection.


Assuntos
Receptor 4 Toll-Like/metabolismo , Coqueluche/metabolismo , Bordetella parapertussis/genética , Bordetella pertussis/genética , Feminino , Humanos , Lactente , Recém-Nascido , Interferon gama/sangue , Masculino , Monócitos/metabolismo , Receptor 4 Toll-Like/sangue , Coqueluche/sangue , Coqueluche/diagnóstico
2.
Eur J Clin Microbiol Infect Dis ; 31(12): 3323-30, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22825246

RESUMO

Acute bronchiolitis (AB) is caused primarily by respiratory syncytial virus (RSV). Recent laboratory tools have implicated a variety of other pathogens; however, their clinical relevance has not been clearly defined. The purpose of this study was to determine whether the etiological agents of AB affect its course. A multicenter prospective study was performed in previously healthy children <24 months of age who presented with <4 days duration of AB. Subjects were divided into the following groups: "only RSV," "also RSV," "no RSV," and "no pathogen." The clinical severity score on admission as well as the overall severity of disease was assessed. RSV was the most common cause of AB (77.5 %). "Only RSV" or "also RSV" patients had a higher clinical score on admission compared to those with "no RSV," p < 0.001 and p < 0.02, respectively. "Only RSV" and "also RSV" patients had a higher disease severity score when compared to patients with "no RSV," 5.9 ± 1.4 vs. 5.1 ± 1.5, p < 0.001, and 5.6 ± 1.4 vs. 5.1 ± 1.5, p < 0.02, respectively. Disease severity did not vary as a function of transfer to the pediatric intensive care unit (PICU) or duration of supplemental oxygen, yet, "only RSV" was associated with a longer length of stay (LOS) than "no RSV," p < 0.02. "Only RSV"-related AB was associated with a more severe initial clinical presentation and a longer LOS. There appears to be little immediate clinical benefit to diagnosing RSV AB to the individual patient, but the application of these diagnostic methods may have significant cost-saving implications and, thus, deserves consideration by medical professionals and health policy analysts.


Assuntos
Bronquiolite/epidemiologia , Bronquiolite/patologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/patologia , Vírus Sincicial Respiratório Humano/patogenicidade , Bronquiolite/virologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Índice de Gravidade de Doença
4.
Cancer Res ; 36(12): 4657-62, 1976 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-63324

RESUMO

The myelogenous leukemia cell line K-562 with a Ph1+chromosome, derived from a patient with chronic myelogenous leukemia in terminal blastic crisis, is not a bone marrow-derived lymphoblastic cell line, because the cells neither produce immunoglobulins nor possess complement receptors. Since it has been suspected that blasts found in some patients with chronic myelogenous leukemia in blastic crisis might be thymus-derived cells, we have studied several parameters to demonstrate that K-562 cells are not thymus-derived lymphoblasts. The results of this study show: (a) no cross-reactivity of antisera to K-562 cells with normal human thymocytes; (b) lack of cytotoxicity of a specific horse anti-human thymocyte globulin for K-562 cells; (c) failure of the treatment of K-562 cells with bovine thymosin to induce antigenic determinant and erythrocyte rosette receptors on K-562 cells; (d) presence of receptors for the Fc portion of immunoglobulin G; (e) absence of terminal deoxynucleotidyl transferase; and (f) cytotoxicity of monkey antiserum to K-562 cells for malignant thymus-derived cells (Molt-4). However, absorption with Molt-4 cells abolished the cross-reactivity with Molt-4 cells, whereas 60% of the antibody to K-562 cells remained in the immune serum. Studies of DNA polymerase activities revealed that K-562 cells have levels of polymerase alpha and beta, like other proliferating cells, and an RNA-dependent DNA polymerase activity, presumably representing polymerase gamma.


Assuntos
Leucemia Mieloide/imunologia , Linfócitos T/imunologia , Antígenos de Neoplasias , Linhagem Celular , Membrana Celular/imunologia , Aberrações Cromossômicas , Cromossomos Humanos 21-22 e Y , Reações Cruzadas , Testes Imunológicos de Citotoxicidade , DNA Nucleotidiltransferases/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Epitopos , Eritrócitos/imunologia , Humanos , Imunoglobulina G , Leucemia Mieloide/enzimologia , Leucemia Mieloide/genética , Ativação Linfocitária , Linfócitos/enzimologia , Linfócitos/imunologia
5.
Exp Hematol ; 10(8): 698-707, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6183138

RESUMO

The incubation of K-562 leukemia cells with specific goat immunoglobulin resulted in gradual cytolysis in the absence of complement and effector cells. Optimal lysis (100%), reached in 3-4 days, occurred when the concentration of the antibody in the culture medium was about 20 micrograms/ml containing an initial inoculum of 15,000 cells. A lower concentration (10 micrograms/15,000 cells/ml) led to partial cytolysis; the surviving cells, cultured in fresh medium, were still vulnerable to antibody lysis (30 micrograms/ml), thus indicating the lack of an apparent resistant cell population. The amount of free antibody in the culture medium diminished rapidly and very little or none was detectable after 2-3 hours of incubation with K-562 cells. The immune gamma-globulin also inhibited colony formation of K-562 cells in soft agar. The immune gamma-globulin, absorbed extensively with normal blood cells, to pluripotent K-562 cells, cross-reacted with several human malignant hematopoietic cell lines tested. These cells included T-lymphoblasts (JM and MOLT-4), promyelocytes (HL-60), Burkitt's lymphoma cells (RAJI), myeloblasts (KG-1 and KG-1a), and multiple myeloma cells (K-737). The absorption of the immune gamma-globulin with an equal number of cells from each of the cell lines assayed diminished but did not completely remove the antibody responsible for cytolysis of K-562 target cells. Thus, the K-562 leukemia blasts appear to possess common and specific antigens that may be only partially expressed on other committed leukemia cell lines studied. For this reason, the cytolytic activity of the immune gamma-globulin could only be removed by absorption with K-562 cells possessing a complete array of antigens solely present on pluripotential hematopoietic cells.


Assuntos
Anticorpos/imunologia , Citotoxicidade Celular Dependente de Anticorpos , Proteínas do Sistema Complemento/imunologia , Células-Tronco Hematopoéticas/imunologia , Leucemia/imunologia , Linhagem Celular , Relação Dose-Resposta Imunológica , Epitopos , Humanos
6.
J Interferon Cytokine Res ; 18(12): 1045-50, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9877448

RESUMO

Interleukin (IL)-1alpha and IL-1beta are encoded by two separate genes, but both function as comitogens for lymphocyte activation. In this study, we observed K-562 cells to express constitutively mRNA for IL-1alpha, although IL-1alpha was not detected in the growth-conditioned medium (GCM). However, IL-1beta mRNA was not expressed unless the cells had been treated with phorbol myristate acetate (PMA). Both IL-1alpha and IL-1beta were detected in the GCM after the cells had been cultured with PMA, suggesting that IL-1 elaboration required PMA treatment. The K-562 cells treated with PMA differentiated to the myeloblastic stage, as observed by nuclear morphologic properties by electron microscopy. PMA treatment induced de novo expression of CD61 or gpIIIa, a marker associated with megakaryoblasts. These results showed that although K-562 cells constitutively expressed IL-1alpha mRNA, PMA treatment was required for secretion. On the other hand, both the expression and secretion of IL-1beta required treatment with PMA. This study showed that K-562 cells treated with PMA differentiated to the myeloblastic stage and expressed and secreted IL-1alpha and IL-1beta.


Assuntos
Interleucina-1/genética , RNA Mensageiro/biossíntese , Divisão Celular/efeitos dos fármacos , Humanos , Interleucina-1/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Células Tumorais Cultivadas
7.
J Immunol Methods ; 253(1-2): 37-44, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11384667

RESUMO

K-562 cells have the capacity to undergo multi-lineage differentiation, which may be crucial to their ability to serve as target reservoirs for CD56+ large granular lymphocytes (LGL). Conventional techniques using chromium release assays to measure lymphocyte-mediated cytotoxicity suffer from disadvantages, including radioactive contamination and the inability to simultaneously determine K-562 and/or CD56+ lymphocyte phenotypes. We illustrate here a three-color flow cytometric method providing for the simultaneous evaluation of K-562-CD56+ LGL binding, K-562 cell viability, and the status of K-562 cell differentiation. Phorbol 12-myristate 13-acetate (PMA) engenders megakaryocytic differentiation in K-562 cell populations, as measured by presentation of the beta(3) integrin (gpIIIa, CD61), while maintaining a negative expression of MHC-I and MHC-II molecules. Using the auto-fluorescence of K-562 cells, flow cytometry can be used to demonstrate a significant decrease in CD56+ LGL activity against K-562 cells in populations pre-incubated with PMA. The capacity of three-color flow cytometry to measure lymphocyte-target cell binding and cell death kinetics, while simultaneously determining target cell phenotype, permits the specific localization of CD61-expressing K-562 cells to areas inconsistent with CD56+ LGL-mediated patterns of lysis.


Assuntos
Antígeno CD56/análise , Testes Imunológicos de Citotoxicidade/métodos , Citometria de Fluxo/métodos , Células Matadoras Naturais/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Megacariócitos/imunologia , Antígenos CD/análise , Morte Celular , Diferenciação Celular , Cor , Humanos , Integrina beta3 , Células K562 , Células Matadoras Naturais/metabolismo , Cinética , Glicoproteínas da Membrana de Plaquetas/análise , Acetato de Tetradecanoilforbol/farmacologia
8.
Leuk Res ; 10(5): 565-74, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-2940421

RESUMO

The surface antigen profile of 8 sublines of K-562 cells, the original line, and the clone RA6 was determined with a panel of 12 monoclonal antibodies reactive with hematopoietic cell differentiation antigens. Cells from all sublines expressed the precursor hematopoietic antigen reactive with RFB-1, the T-cell antigen reactive with OKT17, the B cell/granulocyte antigen reactive with BA-1, the My-1 antigen, and glycophorin A which reacted with R10. A low percentage of cells in some of the sublines expressed platelet/monocyte glycoprotein I binding AN51, monocyte antigen binding 63D3, and an erythroblast/monocyte/platelet antigen binding 5F1. The use of a panel of K-562 sublines demonstrates that K-562 cells do share several "common" antigens but express a marked diversity and variability of other hematopoietic antigens.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Superfície/análise , Sistema Hematopoético/imunologia , Leucemia/imunologia , Antígenos de Neoplasias/análise , Linhagem Celular , Aberrações Cromossômicas , Citometria de Fluxo , Humanos , Imunoglobulina G/imunologia , Leucemia/genética , Neprilisina
9.
Leuk Res ; 11(4): 359-64, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3470580

RESUMO

K-562 is described as a pluripotent leukemic cell line which expresses a diversity of hematopoietic cell differentiation antigens. With the use of monoclonal antibodies (MoAb), we show that the expression of these antigens is either "modulated", i.e. they are not expressed in early logarithmic growth but are expressed in late logarithmic growth, or "continuous", i.e. they are not affected by proliferation and phase of culture growth. Whether an antigen is modulated or continuously expressed appears to be an inherent property of the subline, since the expression of myeloid antigen binding the MoAb, PM81, was modulated on cells from a clone, whereas, the expression of this antigen was continuous by the parent subline and an independent subline F-1. Continuously expressed antigens appear to be an integral component of the K-562 cell surface matrix, while modulated antigen expression appears to be influenced by culture growth conditions.


Assuntos
Antígenos de Neoplasias/análise , Crise Blástica , Células-Tronco Hematopoéticas/imunologia , Leucemia Mieloide/imunologia , Anticorpos Monoclonais , Linhagem Celular , Células Cultivadas , Humanos , Fatores de Tempo
10.
Leuk Res ; 24(12): 1049-57, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11077119

RESUMO

Highly enriched preparations of human CD3+CD4+ T-lymphocytes were stimulated with mitogen or OKT3 to determine the capacity of K-562 cells to function as accessory cells. Phorbol 12-myristate 13-acetate (PMA)-treated K-562 cells were induced to differentiate along the megakaryocytic lineage and could supplant monocyte-accessory cell function. Intracytoplasmic analysis of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) established that IL-4, and not IFN-gamma, was preferentially produced by the activated lymphocytes. This polarized stimulation is compatible with a type 2 or humoral immune response of purified T cells co-cultured with differentiated K-562 cells in vitro, and may have implications in immunoregulation due to disease progression.


Assuntos
Linfócitos T CD4-Positivos/fisiologia , Células K562/imunologia , Ativação Linfocitária , Células Th2/fisiologia , Complexo CD3 , Citometria de Fluxo , Humanos , Imunofenotipagem , Mitógenos , Acetato de Tetradecanoilforbol , Células Th1
11.
Anticancer Res ; 22(6C): 3853-65, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12553005

RESUMO

Squamous cell carcinoma of the vulva (SCC) accounts for about 4% of all gynaecological malignancies. It has an incidence of about 1.8 per 100,000. However, after the age of 75 the incidence of vulvar carcinoma peaks at approximately 20 per 100,000, making it as common as cervical carcinoma. Benign and pre-malignant vulvar lesions can be broadly divided into non-neoplastic epithelial disorders of the vulva (NNEDV), vulvar intraepithelial neoplasia (VIN) and Paget's disease of the vulva (PDV). NNEDV lesions include lichen sclerosus (LS) and squamous hyperplasia (SH). To date no solid prognostic tools are available to predict which pre-malignant vulvar lesions will progress to SCC. About 4.5% of patients develop SCC following a history of LS and ca. 4% of treated VIN lesions go on to become vulvar SCC. In PDV, 28% of patients have an underlying cancer. Angiogenesis, the development of new blood vessels from existing vasculature, is an essential component of solid tumour growth and metastasis. Several angiogenic factors are expressed by many tumours, suggesting that tumours promote their own vascularisation by activating the host endothelium. This review follows the progress of research in angiogenesis in vulvar disease as assessed by a variety of methods, such as in situ hybridisation (ISH), microvessel density measurements (MVD), immunohistochemically-detected angiogenic growth factor expression, including vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP), and serum concentrations of VEGF. Thus, the potential of angiogenesis as a prognostic and predictive tool for identifying which pre-malignant lesions could progress to SCC is discussed. A relatively high MVD and strong VEGF expression may serve as prognostic indicators of survival in invasive SCC. MVD and VEGF expression are also predictive factors in identifying which VIN lesions are more likely to become invasive. However VEGF is not a predictive marker in cases of LS likely to progress to carcinoma. The expression of PD-ECGF/TP in all types of lesions tested prevents its use as a prognostic tool, unlike VEGF. However, PD-ECGF/TP is involved in PDV pathogenesis, but is not a marker of the malignant progression of PDV. In PDV, VEGF was not expressed even in those cases associated with invasive disease. Serum concentrations of VEGF play a functional role in vulvar carcinogenesis. Although associated with impaired disease-free and overall survival, pre-treatment serum concentrations of VEGF are not an independent predictor of outcome in patients with vulvar cancer. These studies suggest that further angiogenic research will be important in both the therapy and prognosis of malignant and pre-malignant vulvar disease.


Assuntos
Carcinoma de Células Escamosas/irrigação sanguínea , Neovascularização Patológica/patologia , Lesões Pré-Cancerosas/irrigação sanguínea , Neoplasias Vulvares/irrigação sanguínea , Animais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Neovascularização Patológica/metabolismo , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , Neoplasias Vulvares/metabolismo , Neoplasias Vulvares/patologia
12.
Isr J Psychiatry Relat Sci ; 34(3): 235-8, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9334529

RESUMO

A case of psychogenic cough tic is presented to demonstrate the problems and complications that can arise from misdiagnosis of this dramatic and disabling disorder. It can be confused with TS and may be treated more aggressively than is beneficial. A single case with a recurrent course is described with the hypothesis of a possible autoimmune contribution. The combination of organic precipitants and emotional maintaining factors suggests that psychogenic cough tic is a condition that lies between somatization and transient tic disorder.


Assuntos
Tosse/psicologia , Transtornos de Tique/psicologia , Adolescente , Tosse/diagnóstico , Feminino , Humanos
14.
Am J Orthopsychiatry ; 37(4): 661-5, 1967 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6033419
15.
Clin Exp Immunol ; 145(3): 563-70, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16907927

RESUMO

In this study, we compared the rate of spontaneous apoptosis of B cells from umbilical cord blood with adult B cells and assessed the role of Bcl-2, CD5, interleukin (IL)-4 and B cell-activating factor in B cell spontaneous apoptosis. We found that spontaneous apoptosis of cultured B cells, as assessed by utilizing annexin-V binding, was significantly higher in cord blood than in healthy adult individuals (77.5; 95 CI, 73.5-81.5 versus 59.2; 95 CI, 54-64, respectively, P < 0.0001) and further confirmed by 4' 6-diamidino-2-phenylindole, dihydrochloride (DAPI) staining. Whereas the expression of B cell-activating factor from the tumour necrosis factor family (BAFF) receptor mRNA was similar in B cells from adults and cord blood, we detected lower levels of circulating BAFF in the serum of cord blood (0.68 +/- 0.13 ng versus 1.83 +/- 0.54 ng, P = 0.01). The latter may explain, in part, our observation of lower levels of mean fluorescence intensity of Bcl-2 in cord B cells compared with adults (1.6 +/- 0.9 versus 2.85 +/- 1.3, P = 0.033). CD19(+) CD5(+) B cells from cord blood underwent a lower rate of apoptosis in comparison to CD19(+) CD5(-) B cells (25.1 +/- 9.3%versus 58.5 +/- 12.5%, P < 0.0001). This pattern of sensitivity was comparable in adult blood (15 +/- 5.5%versus 22.7 +/- 9.3%, P = 0.01). Nevertheless, the rate of apoptosis was higher in CD19(+) CD5(+) from cord blood compared to CD19(+) CD5(+) from adults (25.1 +/- 9.3%versus 15 +/- 5.5%, P = 0.0013). The addition of rIL-4 (10 u/ml) to cultured cells decreased B cell apoptosis in a similar fashion in both cord and adults blood. This rescue was strengthened when BAFF (100 microg/ml) was further added. Thus, alterations in Bcl-2 or serum BAFF level may explain the increased rate of cord blood B cell apoptosis.


Assuntos
Linfócitos B/citologia , Sangue Fetal/imunologia , Adulto , Análise de Variância , Antígenos CD19/imunologia , Apoptose/efeitos dos fármacos , Fator Ativador de Células B , Linfócitos B/imunologia , Antígenos CD5/imunologia , Células Cultivadas , Citometria de Fluxo , Humanos , Interleucina-4/farmacologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Recombinantes/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
16.
Clin Exp Allergy ; 35(2): 221-5, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15725195

RESUMO

BACKGROUND: Matrix metalloproteinase (MMP)-9 is produced by many inflammatory cells such as macrophages, neutrophils, mast cells, eosinophils and T lymphocytes. Activated T cells are capable, through cell-cell contact, of inducing MMP-9 expression in human mast cells. OBJECTIVE: To investigate the activation status of peripheral CD4+ T cells and the level of MMP-9 in the plasma of patients with chronic urticaria (CU), and whether MMP-9 levels are in association with CU severity. METHODS: Study subjects included 29 patients with CU and 30 healthy control subjects. At the time of assessment, patients were divided into subgroups according to urticarial severity. Plasma levels of total MMP-9 (free pro-MMP-9 and free MMP-9) were determined by ELISA. CD4+ lymphocytes were positively selected with magnetic microbeads. After 48 h of activation, CD4+ T cells were assayed for both nuclear factor-kappa B (NF-kappa B) expression and proliferation. RESULTS: Plasma levels of MMP-9 were found to be significantly higher in 29 CU patients compared with 18 healthy controls (186 +/- 174 vs. 31 +/- 21 ng/mL, P<0.0001). We also found a significant correlation between MMP-9 levels and urticarial severity (r = 0.92, P<0.001). In addition, CD4+ T cells from CU patients expressed higher levels of NF-kappa B than CD4+ T cells from healthy controls (82 +/- 30 vs. 69 +/- 20 optical density, P = 0.007). Finally, as compared with seven healthy individuals, DNA synthesis in CD4+ T cells from seven CU patients was found to be significantly elevated (1000 +/- 240 vs. 751 +/- 166 counts per minute, P = 0.01). CONCLUSION: Increased levels of MMP-9 are found in CU patients, and particularly among those with severe disease. We also demonstrated that CD4+ T cells from such patients are highly activated.


Assuntos
Metaloproteinase 9 da Matriz/sangue , Urticária/enzimologia , Adolescente , Adulto , Biomarcadores/sangue , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Estudos de Casos e Controles , Proliferação de Células , Doença Crônica , Feminino , Humanos , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Urticária/imunologia , Urticária/patologia
17.
Plant Physiol ; 41(10): 1591-600, 1966 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16656445

RESUMO

Both lipase from runner beans and a protease (pronase) initially cause increased intensity dependence of the DCPIP Hill reaction of spinach chloroplasts. This is followed by an increase in the extrapolated zero intensity quantum requirement. Pronase treatment of the chloroplasts causes rapid changes in absorption and ORD spectra, whereas the effect of lipase treatment is much less pronounced. Long treatments of the thylakoids with the lipase and protease cause unique morphological changes within the membrane. These changes are used to assign chemical compositions to some of the structures revealed by freeze-etching.

18.
Plant Physiol ; 47(3): 400-3, 1971 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16657630

RESUMO

The rate of (14)C-leucine and (3)H-uracil incorporation by tobacco cells (Nicotiana tabaccum var. Samsun N.N.) in suspension culture was simultaneously decreased by the addition of kinetin at concentrations above 2.5 x 10(-5)m. Ribosomal RNA was the first RNA species affected by kinetin. The purine derivatives, adenine and N(6)-methyl-aminopurine, which exhibit low cytokinin activity overcame the inhibitory effects of kinetin. However, purine derivatives without cytokinin activity, guanine, N(6,6)-dimethyl-aminopurine, and 2-aminopurine, did not relieve kinetin inhibition.

19.
Plant Physiol ; 56(4): 481-5, 1975 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16659330

RESUMO

The sites of action of several compounds, reported to inhibit CO(2) fixation by chloroplast preparations were located by developing assays in lettuce chloroplasts to test their effect on partial reactions of the carbon cycle and on carbonic anhydrase. The results indicated that: d, l-glyceral-dehyde and 5'-AMP inhibit phosphoribulose kinase or isomerase. 3-Phosphoglyceric acid and 6-phosphogluconate inhibit ribulose diphosphate carboxylase. Azide, Mg(2+), and nitrite inhibit the activity of carbonic anhydrase of lettuce chloroplasts and light-dependent CO(2) fixation by intact chloroplasts with similar sensitivities. None of these inhibited CO(2) fixation in ruptured chloroplasts. It is suggested that the inhibition by azide, nitrite, and magnesium ions of CO(2) fixation by intact chloroplasts is due to their inhibition of the activity of carbonic anhydrase.

20.
Mol Pathol ; 55(6): 348-59, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12456770

RESUMO

Angiogenesis, the development of new blood vessels from the existing vasculature, is an essential component of solid tumour growth and metastasis. Several angiogenic factors are expressed by many tumours, suggesting that tumours promote their own vascularisation by activating the host endothelium. This review will discuss various angiogenic stimulators and inhibitors in epithelian ovarian cancer (EOC), including vascular endothelial growth factor and platelet derived endothelial cell growth factor/thymidine phosphorylase. The analysis of tumour vascularisation by microvessel density will also be discussed and the relevance of these markers of angiogenesis in the prognosis of EOC will be assessed.


Assuntos
Neovascularização Patológica/metabolismo , Neoplasias Ovarianas/irrigação sanguínea , Indutores da Angiogênese/metabolismo , Biomarcadores Tumorais/metabolismo , Fatores de Crescimento Endotelial/metabolismo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Linfocinas/metabolismo , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/patologia , Neoplasias Ovarianas/metabolismo , Prognóstico , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
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