Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Dis Colon Rectum ; 58(8): 743-52, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26163953

RESUMO

BACKGROUND: Modern chemotherapy aims to improve long-term survival for selected patients with peritoneal carcinomatosis. Publications suggest promising results, but the spread of these new aggressive treatment strategies in the general population is not well known. OBJECTIVE: The aim of this study was to draw a picture of epidemiology, management, and survival in synchronous and metachronous peritoneal carcinomatosis from colorectal cancer. DESIGN: The cumulative risk of metachronous peritoneal carcinomatosis was estimated in patients resected for cure. Net survival rates were calculated for synchronous and metachronous peritoneal carcinomatosis. SETTINGS: The study was conducted with the use of the Burgundy Digestive Cancer Registry. PATIENTS: Overall, 9174 primary colorectal cancers registered between 1976 and 2011 by the population-based digestive cancer registry were considered. RESULTS: In total, 7% of patients were diagnosed with synchronous peritoneal carcinomatosis. The 5-year cumulative risk of metachronous peritoneal carcinomatosis was 6%, and the stage of the colorectal cancer at diagnosis was the major risk factor. Other independent risk factors were mucinous adenocarcinoma, ulceroinfiltrating tumors, and diagnosis after obstruction or perforation. The proportion of patients resected for cure was 11% and 9% for synchronous and metachronous peritoneal carcinomatosis, and 3-year overall net survival was 8% and 5%. The corresponding rates after resection for cure were 21% and 17%. There was a dramatic increase in the proportion of patients receiving systemic chemotherapy: from 11% before 1997 to 48% in 2011 for synchronous peritoneal carcinomatosis and from 3% to 38% for metachronous peritoneal carcinomatosis. LIMITATIONS: This is a retrospective observational population-based study. CONCLUSION: Peritoneal carcinomatosis complicating colorectal cancer is a major reason for treatment failure. This study identified patients at a high risk of developing peritoneal carcinomatosis who may benefit from specific surveillance. New therapeutic modalities are also needed to improve the prognosis.


Assuntos
Adenocarcinoma Mucinoso/epidemiologia , Antineoplásicos/uso terapêutico , Neoplasias Colorretais/epidemiologia , Neoplasias Peritoneais/epidemiologia , Peritônio/cirurgia , Sistema de Registros , Adenocarcinoma/epidemiologia , Adenocarcinoma/secundário , Adenocarcinoma/terapia , Adenocarcinoma Mucinoso/secundário , Adenocarcinoma Mucinoso/terapia , Idoso , Carcinoma/epidemiologia , Carcinoma/secundário , Carcinoma/terapia , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Procedimentos Cirúrgicos de Citorredução , Feminino , França/epidemiologia , Humanos , Masculino , Neoplasias Peritoneais/secundário , Neoplasias Peritoneais/terapia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
2.
J Virol ; 86(1): 584-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22013034

RESUMO

A deletion of ∼20 amino acids in the stalk of neuraminidase is frequently observed upon transmission of influenza A viruses from waterfowl to domestic poultry. A pair of recombinant H7N1 viruses bearing either a short- or long-stalk neuraminidase was genetically engineered. Inoculation of the long-stalk-neuraminidase virus resulted in a higher cloacal excretion in ducks and led conversely to lower-level oropharyngeal excretion in chickens, associated with a higher-level local immune response and better survival. Therefore, a short-stalk neuraminidase is a determinant of viral adaptation and virulence in chickens but is detrimental to virus replication and shedding in ducks.


Assuntos
Vírus da Influenza A Subtipo H7N1/enzimologia , Vírus da Influenza A Subtipo H7N1/fisiologia , Influenza Aviária/virologia , Neuraminidase/química , Proteínas Virais/química , Eliminação de Partículas Virais , Animais , Galinhas , Patos , Vírus da Influenza A Subtipo H7N1/genética , Neuraminidase/genética , Neuraminidase/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Replicação Viral
3.
Phys Rev E Stat Nonlin Soft Matter Phys ; 81(3 Pt 2): 036323, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20365870

RESUMO

A reduced model to decrease the number of degrees of freedom of the discretized Navier-Stokes equations to a small set that nevertheless captures the essential dynamics of the flow is proposed. The Rayleigh-Bénard convection problem in a cylinder of aspect ratio one where the lower and upper disks, maintained at hot and cold temperatures, respectively, rotate at equal and opposite angular velocities has been chosen to test the technique. The nonlinear dynamics is rich and complex when the temperature difference between disks and their angular velocity is varied. Representatives states--stationary, periodic near sinusoidal, and near heteroclinic--are presented. In each case, the reduced model is compared with temporal integration, and we show that 41 degrees of freedom are sufficient to reproduce the signal. We discuss the strengths and weaknesses of the algorithm by which we build our reduced model.

4.
J Virol ; 84(2): 940-52, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19889765

RESUMO

A deletion of about 20 amino acids in the stalk of the neuraminidase (NA) is frequently detected upon transmission of influenza A viruses from waterfowl to domestic poultry. Using reverse genetics, a recombinant virus derived from a wild duck influenza virus isolate, A/Mallard/Marquenterre/Z237/83 (MZ), and an NA stalk deletion variant (MZ-delNA) were produced. Compared to the wild type, the MZ-delNA virus showed a moderate growth advantage on avian cultured cells. In 4-week-old chickens inoculated intratracheally with the MZ-delNA virus, viral replication in the lungs, liver, and kidneys was enhanced and interstitial pneumonia lesions were more severe than with the wild-type virus. The MZ-delNA-inoculated chickens showed significantly increased levels of mRNAs encoding interleukin-6 (IL-6), transforming growth factor-beta4 (TGF-beta4), and CCL5 in the lungs and a higher frequency of apoptotic cells in the liver than did their MZ-inoculated counterparts. Molecular mechanisms possibly underlying the growth advantage of the MZ-delNA virus were explored. The measured enzymatic activities toward a small substrate were similar for the wild-type and deleted NA, but the MZ-delNA virus eluted from chicken erythrocytes at reduced rates. Pseudoviral particles expressing the MZ hemagglutinin in combination with the MZ-NA or MZ-delNA protein were produced from avian cultured cells with similar efficiencies, suggesting that the deletion in the NA stalk does not enhance the release of progeny virions and probably affects an earlier step of the viral cycle. Overall, our data indicate that a shortened NA stalk is a strong determinant of adaptation and virulence of waterfowl influenza viruses in chickens.


Assuntos
Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Aviária/virologia , Neuraminidase/genética , Doenças das Aves Domésticas/virologia , Deleção de Sequência , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , Patos , Engenharia Genética , Humanos , Vírus da Influenza A Subtipo H1N1/enzimologia , Vírus da Influenza A Subtipo H1N1/genética , Influenza Aviária/transmissão , Dados de Sequência Molecular , Neuraminidase/química , Doenças das Aves Domésticas/patologia , Proteínas Virais/química , Virulência
5.
Arch Virol ; 150(3): 507-19, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15592893

RESUMO

The effects of the very virulent RB-1B strain of Marek's disease virus (MDV) and turkey herpesvirus (HVT), a vaccinal strain, on abundance of IFN mRNA in the blood were investigated. MDV and HVT infection did not change the circulating level of IFN-gamma mRNA 1 and 7 days p.i., but they increased IFN-alpha mRNA levels slightly in genetically susceptible (to tumour development) B(13)/B(13) chickens. The total number of circulating leukocytes was unchanged and increase in message was accompanied by an increase in circulating CD8alpha(+) and MHC Class II(+) cells. On the contrary, both viruses slightly increased IFN-gamma transcripts and decreased IFN-alpha transcripts in genetically resistant B(21)/B(21) chickens. Further, oncogenic MDV was able to block the response to inactivated Newcastle disease virus, a potent inducer of IFN, in both chicken lines. The inhibiting effect on transcription was present for both IFN at days 1 and 7 p.i. in susceptible B(13)/B(13) chickens, but only at day 7 p.i. in resistant B(21)/B(21) chickens. By contrast, non-oncogenic HVT did not interfere with induction of either message at one day p.i. and MDV had a more suppressive effect than HVT on IFN gene transcription 7 days p.i. in B(21)/B(21) chickens. Thus, the strong ability of MDV to block induction of IFN gene transcription detected in the blood as soon as one day after infection in susceptible chickens, as opposed to resistant chickens, not only causes immunosuppression but also may be related to the virus's oncogenicity.


Assuntos
Herpesvirus Meleagrídeo 1/imunologia , Interferon-alfa/sangue , Interferon gama/sangue , Mardivirus/imunologia , Doença de Marek/imunologia , Animais , Antígenos CD8 , Galinhas , Suscetibilidade a Doenças , Genes MHC da Classe II , Interferon-alfa/genética , Interferon gama/genética , Contagem de Leucócitos , Mardivirus/genética , RNA Mensageiro/sangue , RNA Viral/análise , Fatores de Tempo , Transcrição Gênica
6.
Avian Dis ; 48(3): 617-24, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15529984

RESUMO

A reproducible and original method for the preparation of chicken intestine epithelial cells from 18-day-old embryos for long-term culture was obtained by using a mechanical isolation procedure, as opposed to previous isolation methods using relatively high concentrations of trypsin, collagenase, or EDTA. Chicken intestine epithelial cells typically expressed keratin and chicken E-cadherin, in contrast to chicken embryo fibroblasts, and they increased cell surface MHC II after activation with crude IFN-gamma containing supernatants, obtained from chicken spleen cells stimulated with concanavalin A or transformed by reticuloendotheliosis virus. Eimeria tenella was shown to be able to develop until the schizont stage after 46 hr of culture in these chicken intestinal epithelial cells, but it was not able to develop further. However, activation with IFN-gamma containing supernatants resulted in strong inhibition of parasite replication, as shown by incorporation of [3H]uracil. Thus, chicken enterocytes, which are the specific target of Eimeria development in vivo, could be considered as potential local effector cells involved in the protective response against this parasite.


Assuntos
Técnicas de Cultura de Células/métodos , Eimeria tenella/efeitos dos fármacos , Enterócitos/parasitologia , Interferon gama/farmacologia , Animais , Caderinas/metabolismo , Embrião de Galinha , Eimeria tenella/fisiologia , Enterócitos/metabolismo , Citometria de Fluxo , Genes MHC da Classe II/genética , Queratinas/metabolismo , Trítio , Uracila
7.
Phys Rev E Stat Nonlin Soft Matter Phys ; 70(6 Pt 2): 066311, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15697506

RESUMO

The spatiotemporal instability of the buoyancy-driven flow adjacent to a vertically heated wall, which is immersed in thermally stratified medium, is studied theoretically and numerically. The temperature gradients ratio between the wall and the ambient fluid is shown to lead to rich scenario of absolute-convective instability transitions. The direct numerical simulations consistent with the theoretical prediction are presented. The supercritical steady state, found in previous simulations of the natural convection in vertically heated square cavity, is explained in terms of the convective instability, and the nonlinear effect on the convectively unstable waves is discussed as well.

8.
Vet Parasitol ; 110(3-4): 181-95, 2003 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-12482647

RESUMO

Primary infection with Eimeria intestinalis confers very effective immunity against further infections in rabbits. This study was designed to determine the onset of the immune response in primary-infected rabbits and to characterise the immune status of protected rabbits. Variations in kinetics of CD4+ and CD8+ T-cell subpopulations were followed after primary infection at the intestinal sites of penetration (duodenum) and development (ileum), in mesenteric lymph nodes (MLN) and in the spleen. The response against the parasite was measured by specific lymphocyte proliferation in the spleen and MLN and by determining specific IgG titres in serum. The mucosal immune response was strong after primary infection and was characterised by (i) transient increase in the percentages of intestinal CD4+ lymphocytes and MLN CD8+ lymphocytes 14 days PI and (ii) strong increase in the percentages of intestinal CD8+ lymphocytes from 14 days PI persisting throughout further infections. Extensive infiltration of the lamina propria with CD8+ lymphocytes was observed 14 days PI. The specific proliferative response started between 7 and 14 days PI in MLN but remained undetectable in spleens for up to 21 days, in contrast to "immunised" rabbits. The fact that systemic immune responses were low after primary infection, in contrast to indicators of mucosal immune responsiveness, suggests that protection of rabbits against E. intestinalis infection is due to an effective mucosal immune response, and that systemic responses that increase after successive infections are only reflections of repeated encounters with parasite antigens.


Assuntos
Eimeria/imunologia , Sistema Imunitário/imunologia , Intestinos/imunologia , Ativação Linfocitária , Coelhos/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Coccidiose/imunologia , Feminino , Imunoglobulina G/sangue , Masculino , Tamanho do Órgão , Organismos Livres de Patógenos Específicos , Baço/imunologia
10.
Virology ; 277(1): 58-65, 2000 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-11062036

RESUMO

The purpose of this study was to determine to what extent nitric oxide (NO) may play a role in the antiviral-mediated effect of chicken IFN-gamma against the Marek's disease virus (MDV) RB-1B. NO-generating compounds S-nitroso-N-acetylpenicillamine (SNAP) and 3-morpholino-sydononimine (SIN-1) strongly inhibited RB-1B replication in chicken embryo fibroblasts (85%) in a dose-dependent manner. The addition of superoxide dismutase (SOD) did not alter the inhibitory effect of SIN-1, which is also known to generate superoxide anions. IFN-gamma-stimulated embryo fibroblasts almost totally suppressed viral replication and were high NO producers. Nevertheless, addition of N(G)-monomethyl-l-arginine (l-NMMA), a competitive inhibitor of NO synthase, inhibited NO production without preventing the dramatic viral suppression. IFN-gamma-stimulated chicken bone-marrow macrophages were good NO producers and demonstrated a specific cell dose-related inhibiting effect on RB-1B replication in bystander fibroblasts (around 60% at 10(6) macrophages). Adding l-NMMA together with oxygen scavengers such as SOD or d-mannitol restored viral replication almost completely. In conclusion, NO alone is a powerful inhibitor of MDV replication in chicken fibroblasts. Nevertheless, NO is not responsible for the direct inhibitory effect of the IFN-gamma treatment of fibroblasts and is only partially involved in the inhibitory effect of IFN-gamma-stimulated macrophages, which is also mediated by reactive oxygen intermediates.


Assuntos
Herpesvirus Galináceo 2/fisiologia , Interferon gama/fisiologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/fisiologia , Replicação Viral/efeitos dos fármacos , Animais , Células da Medula Óssea/citologia , Células COS , Células Cultivadas , Embrião de Galinha , Galinhas , Chlorocebus aethiops , Técnicas de Cocultura , Fibroblastos , Herpesvirus Galináceo 2/efeitos dos fármacos , Macrófagos/fisiologia , Macrófagos/virologia , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Penicilamina/análogos & derivados , Penicilamina/farmacologia , S-Nitroso-N-Acetilpenicilamina , Superóxido Dismutase/farmacologia , Superóxidos/metabolismo , Replicação Viral/fisiologia , ômega-N-Metilarginina/farmacologia
11.
Vet Parasitol ; 92(1): 37-49, 2000 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-10936544

RESUMO

We have previously shown that activation of primary cultures of chicken bone-marrow macrophages and embryo fibroblasts with supernatants of concanavaline A-stimulated or reticuloendotheliosis virus (REV)-transformed chicken spleen cells as source of IFN-gamma significantly decreases Eimeria tenella growth in vitro. In the present study, we used various chicken cell lines, HD11 macrophages and DU24 fibroblasts, both virally transformed, CHCC-OU2 fibroblasts and LMH hepatic epithelial cells, both chemically transformed, to replicate E. tenella in vitro. We confirmed the previous results by showing that HD11 macrophages pre-treated for 24h with recombinant chicken IFN-gamma (either produced in E. coli or by transfected COS cells), at doses ranging from 1000 to 10U/ml, drastically inhibited E. tenella replication as measured by [3H] uracil uptake after a further 70h of culture, as when treated with REV supernatant. Likewise the fibroblast and epithelial cell lines exhibited significant inhibitory activity on E. tenella replication after pre-treatment with recombinant chicken IFN-gamma, but were less sensitive (1000-100U/ml) than when treated with REV supernatant. Recombinant chicken IFN-alpha pre-treatment of all cell lines had no inhibitory effect on parasite development.


Assuntos
Coccidiose/veterinária , Eimeria tenella/fisiologia , Interferon gama/fisiologia , Macrófagos/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Linhagem Celular , Galinhas , Coccidiose/imunologia , Células Epiteliais/imunologia , Fibroblastos/imunologia
12.
Int J Immunopharmacol ; 22(5): 365-72, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10708884

RESUMO

Acemannan (ACM 1), a beta-(1,4) -acetylated mannan isolated from Aloe vera, can be used as an effective adjuvant in vaccination against some avian viral diseases. Our results demonstrate a quick and lasting in vivo priming effect of ACM 1 on macrophage response after intramuscular inoculation in chickens (500 microg per 2-month-old bird). In response to IFN-gamma in vitro, monocytes from ACM 1-treated chickens exhibited a strong enhancement of NO production from 3 to 9 days p.i., but a weaker effect on MHC II cell surface antigen expression on day 3 p.i. A stimulating effect of ACM 1 treatment was also observed on spontaneous and inducible NO production for splenocytes only on day 3 p.i. By that time, splenocytes exhibited a strong higher capacity to proliferate in response to the T cell-mitogen PHA. At the same time, the in vivo capacity to produce NO, measured by the (NO(-)(2)+NO(-)(3)) serum level after intravenous LPS injection, increased greatly from 3 to 9 days p.i. In conclusion, ACM 1 was able efficiently and durably to increase the activation capacity of macrophages from the systemic immune compartment (in particular from the blood and spleen after an intramuscular injection) in chickens, especially for NO production. These findings provide a better understanding of the adjuvant activity of ACM 1 for viral and tumoral diseases.


Assuntos
Adjuvantes Imunológicos/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Mananas/farmacologia , Animais , Galinhas , Antígenos de Histocompatibilidade Classe I/análise , Antígenos de Histocompatibilidade Classe II/análise , Ativação Linfocitária/efeitos dos fármacos , Monócitos/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico/sangue
13.
Vet Immunol Immunopathol ; 70(1-2): 135-41, 1999 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10507294

RESUMO

Cholera toxin (CT) is a well-known mucosal adjuvant in mammals, but it does not give conclusive results in chickens. Cells from the chicken immune system may be insensitive to CT activity. Our results showed that intravenously administered CT had strong immunomodulatory effects on chicken antigen-specific T- and B-cell immune responses. Seven and eight days post-inoculation (p.i.), chickens immunized with KLH and CT exhibited a faster and higher specific proliferative response in the spleen after in vitro restimulation than chickens immunized with KLH alone. At the same time, the specific antibody response in serum was significantly higher, with a strong IgG enhancement and a peak of IgA in chickens immunized with KLH and CT. The anti-KLH splenic antibody response in vitro involved a significant increase in specific IgG and IgA isotypes when CT was used as adjuvant. In conclusion, as in mammals, systemic CT demonstrated strong adjuvant properties in chickens enhancing T-cell priming in vivo and, thus, leading to increased specific antibody production, including IgA.


Assuntos
Adjuvantes Imunológicos , Galinhas/imunologia , Toxina da Cólera/imunologia , Animais , Células Cultivadas , Ensaio de Imunoadsorção Enzimática/veterinária , Hemocianinas/imunologia , Imunoglobulina A/imunologia , Switching de Imunoglobulina , Ativação Linfocitária
14.
Avian Dis ; 43(1): 65-74, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10216761

RESUMO

Pretreatment of chicken bone marrow macrophages and embryo fibroblasts with supernatants containing chicken interferon gamma (IFN-gamma) for 24 hr prior to inoculation inhibited intracellular Eimeria tenella replication, measured by [3H] uracil incorporation. The supernatants (Sns) were obtained from culture of lymphoblastoid cells transformed by a reticuloendotheliosis virus (REV) and chicken splenocytes stimulated with concanavalin A (Con A). The mechanisms of the E. tenella growth inhibitory activity induced by Sn REV and Sn Con A in chicken macrophages and fibroblasts were studied. Addition of oxygen scavengers (superoxide dismutase, D-mannitol, DABCO, benzoic acid, L-histidine hydrochloride) was able to overcome the inhibition of E. tenella replication after pretreatment with Sn REV or Sn Con A in macrophage cultures but not in fibroblast cultures. Nitric oxide (NO) synthesis was induced in macrophage culture treated with Sn REV or Sn Con A but not in fibroblast culture. Addition of NG monomethyl-L-arginine, an NO synthase inhibitor together with the supernatants was also able to overcome inhibition of E. tenella replication in macrophage culture. On the other hand, addition of L-tryptophan to Sn REV- or Sn Con A-treated fibroblasts was able to reverse the inhibitory effect on E. tenella replication. In conclusion, production of inorganic NO or toxic oxygen intermediates may be involved in the E. tenella growth inhibitory activity of chicken macrophages pretreated with supernatants containing an IFN-gamma activity, and cellular tryptophan depletion may be involved for chicken fibroblasts, thus matching the mechanisms of the IFN-gamma-induced growth inhibitory activity for protozoans in mammals.


Assuntos
Coccidiose/veterinária , Concanavalina A/farmacologia , Eimeria tenella/crescimento & desenvolvimento , Fibroblastos/parasitologia , Interferon gama/fisiologia , Macrófagos/parasitologia , Doenças das Aves Domésticas/parasitologia , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Ácido Benzoico/metabolismo , Transformação Celular Viral , Células Cultivadas , Galinhas , Inibidores Enzimáticos/farmacologia , Histidina/metabolismo , Manitol/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/antagonistas & inibidores , Piperazinas/metabolismo , Vírus da Reticuloendoteliose Aviária , Baço/efeitos dos fármacos , Baço/virologia , Superóxido Dismutase/metabolismo , Triptofano/farmacologia
15.
Blood ; 93(9): 2898-906, 1999 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10216084

RESUMO

The fibrinogen receptor GPIIb-IIIa integrin is known to be expressed on cells of the megakaryocytic lineage, but its presence on hematopoietic progenitors has been a controversial issue. To resolve this ambiguity unequivocally, we performed clonogenic assays and intrathymic cell-transfer experiments in congenic animals. As the ontogeny of the avian hematopoietic system is well documented, we used this experimental model to trace GPIIb-IIIa expression during embryogenesis. Consequently, we now report that the GPIIb-IIIa integrin is expressed as early as embryonic day 3.5 (E3.5) to 4 in intraaortic hematopoietic clusters, the first site of intraembryonic hematopoietic progenitor emergence, and later in E6 paraaortic foci. Myeloid and erythroid progenitors were also detected within the GPIIb-IIIa+ CD45(+) population isolated from the E3.5 to 4 aortic area, while in embryonic and adult bone marrow, myeloid, erythroid, and T-cell progenitors were present in the GPIIb-IIIa+ c-kit+ population. Furthermore, we also provide the first evidence, that GPIIb-IIIa+ bone marrow cells can differentiate into T cells. Hence, GPIIb-IIIa can be used as a marker for multilineage hematopoietic progenitors, permitting identification of early intraembryonic sites of hematopoiesis, as well as the isolation of embryonic and adult hematopoietic progenitors.


Assuntos
Plaquetas/citologia , Células da Medula Óssea/citologia , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Hematopoéticas/fisiologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/genética , Animais , Aorta/embriologia , Plaquetas/fisiologia , Medula Óssea/embriologia , Células da Medula Óssea/fisiologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Galinha , Galinhas , Ensaio de Unidades Formadoras de Colônias , Eritrócitos/citologia , Eritrócitos/fisiologia , Granulócitos/citologia , Granulócitos/fisiologia , Células-Tronco Hematopoéticas/citologia , Megacariócitos/citologia , Megacariócitos/fisiologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/biossíntese , Proteínas Recombinantes/farmacologia , Fator de Células-Tronco/farmacologia , Linfócitos T/citologia , Linfócitos T/fisiologia
16.
Vaccine ; 17(11-12): 1516-24, 1999 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-10195788

RESUMO

We investigated the adjuvant effect of cholera toxin (CT) on the intestinal and systemic immune systems of chickens. The CT was given orally, mixed with a non-replicating antigen, a recombinant Eimeria protein, IPEI, or with a replicating one, Eimeria tenella parasite. There were increases in the specific IgA and IgG responses to the recombinant protein IPEI, with a significant anti-1PE1 IgG response in the duodenum (p < 0.05) and caecum (p < 0.05) 4 weeks after immunization and a specific IgA (p < 0.05) response in the duodenum after 3 weeks. A transient anti-1PE1 IgG (p < 0.05) response was detected in the serum 1 week post-injection and an IgA response (p < 0.05) at 2 weeks. CT given with the replicative parasite caused no change in the intestinal and systemic immune responses with 1 or 3 immunizations although a specific antiparasitic in vitro proliferation of the spleen cells from infected chickens was observed. Nevertheless, 0.05 mg CT given per os to chickens was strongly immunogenic in both experiments. A strong serum IgG (p < 0.01) response was detected as soon as 1 week after the end of the immunization protocol with 1PE1 and 2 weeks after infection with E. tenella. Strong anti-CT IgG responses were also detected by the second week post-immunization in the duodenum and caeca (p < 0.01). Hence, CT can be used as a mucosal adjuvant in chickens to improve the intestinal immune response.


Assuntos
Adjuvantes Imunológicos , Anticorpos Antiprotozoários/biossíntese , Toxina da Cólera/imunologia , Coccidiose/imunologia , Coccidiose/veterinária , Eimeria tenella/imunologia , Vacinas Protozoárias , Administração Oral , Animais , Galinhas , Toxina da Cólera/administração & dosagem , Ensaio de Imunoadsorção Enzimática/veterinária , Imunidade Celular , Imunidade nas Mucosas , Imunoglobulina A/biossíntese , Imunoglobulina G/biossíntese , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/imunologia
17.
Avian Dis ; 42(2): 239-47, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9645314

RESUMO

Pretreatment of chicken macrophages or fibroblasts with supernatants from concanavalin A-stimulated spleen cells or from the virus-transformed cell line reticuloendotheliovirus as source of interferon gamma (IFN-gamma) slows down subsequent sporozoite replication in the cells. To identify the presence of IFN-gamma, we combined four typical activities of IFN-gamma: inhibition of cytopathic effect of vesicular stomatitis virus on IFN-gamma-treated fibroblasts, cytostatic activity of IFN-gamma-activated macrophages, induction of major histocompatibility complex II antigen expression on IFN-gamma-activated fibroblasts and macrophages, and induction of nitrite production in macrophages. We have shown that chicken fibroblasts and macrophages possess a microbiostatic capacity once they are able to prevent the otherwise unchecked intracellular replication of Eimeria tenella following activation with culture supernatants identified as containing a strong IFN-gamma activity.


Assuntos
Eimeria tenella/imunologia , Fibroblastos/imunologia , Interferon gama/imunologia , Macrófagos/imunologia , Animais , Linhagem Celular Transformada , Células Cultivadas , Embrião de Galinha , Galinhas , Eimeria tenella/crescimento & desenvolvimento , Fibroblastos/parasitologia , Citometria de Fluxo/veterinária , Antígenos de Histocompatibilidade Classe II/biossíntese , Interferon gama/análise , Macrófagos/parasitologia , Nitritos/metabolismo , Organismos Livres de Patógenos Específicos
18.
Int J Parasitol ; 27(7): 803-9, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9279583

RESUMO

The development and appearance of antibody was studied in the intestine and serum from histocompatible GB1 chickens orally infected with oocysts of Eimeria acervulina (restricted to the duodenum) or Eimeria tenella (restricted to the caeca). The local immune response was measured as the specific antibody levels in the supernatants of intestinal fragments (duodenum and caecum) maintained in culture for 16 h at 41 degrees C, 5% CO2, 95% air. Specific IgM was detected 1 week after E. acervulina infection, and the specific IgA and IgG contents of the duodenum and caecum were significantly elevated (P < 0.001) after 2 weeks. The intestinal specific IgG content was raised. E. tenella infection resulted in specific IgA only in the parasitized area during the second week post-infection (P < 0.05). Specific IgM and IgG were both detected in the duodenum and caecum, respectively, 1 and 2 weeks p.i. Production of parasite-specific immunoglobulins was always significantly higher in the parasitized than in the unparasitized areas (caeca for E. acervulina, duodenum for E. tenella). This ex vivo culture assay of intestinal fragments used to measure the mucosal immune response of intestinal areas showed a significant production of specific IgA and IgM. In addition, high levels of IgG were also measured. The role of this specific IgG in Eimeria infection remains to be determined.


Assuntos
Galinhas/imunologia , Coccidiose/veterinária , Eimeria/imunologia , Imunoglobulinas/biossíntese , Mucosa Intestinal/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Ceco/imunologia , Coccidiose/imunologia , Duodeno/imunologia , Eimeria tenella/imunologia , Imunidade nas Mucosas , Imunoglobulina A/biossíntese , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/veterinária , Cinética
19.
Cell Immunol ; 168(2): 302-6, 1996 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8640879

RESUMO

The tetrapeptide AcSer-Asp-Lys-Pro (AcSDKP) is a physiological negative regulator of hematopoiesis in mammals. It acts by blocking the cell cycle entry of quiescent stem cells and progenitors. In the present study we report that AcSDKP blocks the proliferation of human as well as chicken lymphocytes. It inhibits by 25 to 40% the polyclonal mitogen- (phytohemagglutinin (PHA), pokeweed mitogen (PWM), or concanavalin A) or mixed lymphocyte reaction-induced proliferation of chicken lymphocytes. A comparable degree of inhibition was observed in human whole blood cultures stimulated by "T" (PHA) or "T and B" (PWM) mitogens. Our results obtained on two phylogenetically distant species show that AcSDKP reduces the lymphocyte proliferation probably by blocking or retarding entry into the cell cycle as previously demonstrated for hematopoietic progenitors and hepatocytes. Therefore, this endogenous, non-species-specific tetrapeptide may be involved in the regulation of immune response.


Assuntos
Ciclo Celular/efeitos dos fármacos , Galinhas/imunologia , Ativação Linfocitária/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Oligopeptídeos/farmacologia , Animais , Bolsa de Fabricius/citologia , Concanavalina A/farmacologia , Depressão Química , Relação Dose-Resposta a Droga , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Teste de Cultura Mista de Linfócitos , Linfócitos/citologia , Fito-Hemaglutininas/farmacologia , Mitógenos de Phytolacca americana/farmacologia , Fase S/efeitos dos fármacos , Especificidade da Espécie , Baço/citologia
20.
Exp Cell Res ; 223(1): 112-6, 1996 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-8635482

RESUMO

The tetrapeptide AcSer-Asp-Lys-Pro (AcSDKP), a physiological negative regulator of cell proliferation, inhibits the progression of normal quiescent cell to the S phase of the cycle, while it is inactive in the proliferation of permanent cell lines and of freshly isolated leukemic cells. It protects normal hematopoietic stem cells and progenitors from the toxic effects of anticancer drugs. We studied the effects of AcSDKP on the S phase entry of mouse and chicken continuous cell lines MS-K, 3T3, MDCC-PA9, and MDCC-MSB1 lines when they are cultured under these defined conditions. They show that AcSDKP acts on cells previously partially synchronized by culture under conditions of low serum concentrations or serum starvation. Our results demonstrate that AcSDKP reduces the proliferation of these cell of continuous cell lines as it does on hepatocytes or hematopoietic cells in vivo or on freshly isolated cells in vitro, by blocking or retarding their entry into S phase from early G1.


Assuntos
Divisão Celular/efeitos dos fármacos , Inibidores do Crescimento/farmacologia , Oligopeptídeos/farmacologia , Fase S/efeitos dos fármacos , Animais , Sangue , Linhagem Celular , Galinhas , Meios de Cultura , Camundongos , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...