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1.
J R Army Med Corps ; 165(1): 41-44, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29666201

RESUMO

Blast injuries are often caused by more than one mechanism, do not occur in isolation, and typically elicit a secondary multi-system response. Research efforts often do not separate blast injuries caused by blast waves from those caused by blunt force trauma and other mechanisms. 15 experts from nine different NATO nations developed in the HFM Research Task Group (RTG; HFM-234 (RTG)) 'Environmental Toxicology of Blast Exposures: Injury Metrics, Modelling, Methods and Standards' Guidelines for Conducting Epidemiological Studies of Blast Injury. This paper describes these guidelines, which are intended to provide blast injury researchers and clinicians with a basic set of recommendations for blast injury epidemiological study design and data collection that need to be considered and described when conducting prospective longitudinal studies of blast injury.


Assuntos
Traumatismos por Explosões/epidemiologia , Projetos de Pesquisa Epidemiológica , Estudos Epidemiológicos , Guias como Assunto , Humanos
4.
J R Army Med Corps ; 165(1): 38-40, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29643122

RESUMO

Blast injury is a very complex phenomenon and frequently results in multiple injuries. One method to investigate the consequences of blast injuries is with the use of living systems (animal models). The use of animals allows the examination and evaluation of injury mechanisms in a more controlled manner, allowing variables such as primary or secondary blast injury for example, to be isolated and manipulated as required. To ensure a degree of standardisation across the blast research community a set of guidelines which helps researchers navigate challenges of modelling blast injuries in animals is required. This paper describes the guidelines for Using Animal Models in Blast Injury Research developed by the NATO Health Factors and Medicine (HFM) Research Task Group 234.


Assuntos
Pesquisa Biomédica/normas , Traumatismos por Explosões , Modelos Animais de Doenças , Animais , Guias como Assunto , Projetos de Pesquisa
5.
J Mater Chem B ; 5(34): 7109-7117, 2017 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32263901

RESUMO

The present work involves the design of a multifunctional system based on gold nanoshells (AuNSs) decorated with lanthanide-based upconversion nanoparticles (UCNPs) intended as an optical heater and a temperature probe at the nanoscale. The synthesis of NaGdF4 UCNPs doped with ions Yb3+:Er3+ was performed via thermal decomposition of lanthanide fluoride precursors at high temperatures (>300 °C) in the presence of a coordinating ligand (oleic acid). UCNPs were synthesized at three different temperatures (310, 315 and 320 °C) and characterized in terms of morphological, structural and emission properties. In view of the intended biological applications, the surface of hydrophobic oleate-capped UCNPs was modified using a silica coating to achieve sufficient water dispersibility, through a modified Stöber process using a reverse micro-emulsion method. Monodisperse NaGdF4:Yb3+:Er3+ upconversion nanocrystals (∼25 nm dia.) were obtained in cubic (at 310, 315 °C) and hexagonal (at 320 °C) phases. The UCNPs in the hexagonal phase were shown to be more suitable as temperature sensors, due to their lower red-to-green emission ratios and higher thermal sensitivities. The emission spectrum of NaGdF4:Yb3+:Er3+ (oleate- or silica-coated) UCNPs was recorded at different temperatures in the vicinity of the physiological range (20-70 °C) and presented suitable properties for application as temperature sensors, such as excellent linearity (r2 > 0.99) and sensitivity (>3 × 10-3 K-1). The heating capacity of AuNSs@UCNPs was verified by monitoring the Er3+ emission, showing their potential for application as a hyperthermia agent controlled using a nanothermometer function.

6.
J Leukoc Biol ; 69(5): 815-24, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11358991

RESUMO

Recent studies indicate that nitric oxide (NO) or related compounds may regulate the production of interleukin (IL)-8, a potent proinflammatory chemokine. Here we report that peroxynitrite (ONOO(-)) formed by a reaction of NO with superoxide mediates IL-8 gene expression and IL-8 production in IL-1beta- and TNF-alpha-stimulated human leukocytes in whole blood. The NO synthase inhibitors aminoguanidine and N(G)-nitro-L-arginine methyl ester blocked nuclear accumulation of activator protein-1 (AP-1) and nuclear factor (NF)-kappaB in both polymorphonuclear (PMN) and mononuclear leukocytes and inhibited IL-8 mRNA expression and IL-8 release by approximately 90% in response to IL-1beta and TNF-alpha. Enhanced ONOO(-) formation was detected in granulocytes, monocytes, and lymphocytes after challenge with IL-1beta or TNF-alpha. The addition of ONOO(-) (0.2-80 microM) to whole blood increased nuclear accumulation of AP-1 and NF-kappaB in PMN and mononuclear leukocytes and augmented IL-8 mRNA expression and IL-8 production in a concentration-dependent fashion. Pyrrolidine dithiocarbamate, an inhibitor of NF-kappaB activation, attenuated approximately 70% of IL-8 release evoked by IL-1beta, TNF-alpha, or ONOO(-). These results indicate that ONOO(-) formation may underlie the action of cytokines towards IL-8 gene expression in human leukocytes.


Assuntos
Interleucina-8/biossíntese , Leucócitos Mononucleares/metabolismo , NF-kappa B/metabolismo , Nitratos/metabolismo , Fator de Transcrição AP-1/metabolismo , Antioxidantes/farmacologia , Núcleo Celular/metabolismo , Células Cultivadas , Expressão Gênica/efeitos dos fármacos , Guanidinas/farmacologia , Humanos , Interleucina-1/farmacologia , Interleucina-8/genética , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Pirrolidinas , RNA Mensageiro , Tiocarbamatos/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
8.
Tissue Antigens ; 57(4): 390-3, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11380956

RESUMO

Three novel DRB3* alleles were identified using CANTYPE reverse hybridization assay. The initial unusual hybridization patterns of DRB3-specific polymerase chain reaction (PCR)-amplified DNA from each subject were confirmed by cloning and sequencing analysis. DRB3*0106 allele is identical to DRB3*0101 except for a single nucleotide substitution (CTG-->GTG) changing codon 38 from Leu to Val. This polymorphism is commonly found in DRB3*03 alleles. Compared with DRB3*0202, DRB3*02022 contains a single silent nucleotide substitution (AAT-->AAC, both encoding for Asn) at codon 77. This polymorphism is also present in DRB3*0204 allele. The new DRB3*0107 allele has a sequence unique to DRB3 alleles. From codon 5 to codon 36 the sequence is identical to that of DRB3*0101 allele. From codon 37 to codon 87 the sequence of DRB1*0107 allele is identical to that of DRB3*0202. This sequence would thus explain the CANTYPE(R) DRB3-specific unusual pattern of reactions. The new DRB3*0107 could have arisen from a gene conversion between DRB3*0101 and DRB3*0202 alleles, but the DRB3*0106 and the DRB3*02022 may have been generated by a point mutation event. The DRB3*0107 allele was identified in a Caucasoid individual. The ethnic origin of the subjects carrying the other two alleles are unknown. The three alleles presented here were only identified once, in a total population of 49,000.


Assuntos
Alelos , Antígenos HLA-DR/genética , Sequência de Bases , Transplante de Medula Óssea/imunologia , Éxons/genética , Éxons/imunologia , Cadeias HLA-DRB3 , Humanos , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Reação em Cadeia da Polimerase
9.
FASEB J ; 14(3): 572-80, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10698973

RESUMO

Antiflammin-1 and antiflammin-2 are nonapeptides corresponding to the region of highest similarity between glucocorticoid-inducible proteins lipocortin-1 and uteroglobin. We have studied whether antiflammins could affect expression of adhesion molecules on human leukocytes and coronary artery endothelial cells (HCAEC) and binding of neutrophils (PMNs) to HCAEC. Although neither antiflammin-1 nor antiflammin-2 affected expression of adhesion molecules on resting PMNs, monocytes, and lymphocytes in whole blood, they attenuated changes in L-selectin and CD11/CD18 expression evoked by platelet-activating factor or interleukin-8 with IC(50) values of 4-20 micromol/l. The maximum inhibition was similar to those seen with human recombinant lipocortin-1 (100 microgram/ml). Unlike dexamethasone (100 nmol/l), the antiflammins had little effect on LPS-stimulated expression of E-selectin and ICAM-1 on HCAEC. Consistently, culture of HCAEC with dexamethasone, but not with antiflammins, decreased PMN binding to endothelial cells. Preincubation of PMNs with antiflammins markedly decreased their adhesion to LPS-activated HCAEC. Inhibition of adhesion was additive with function blocking anti-E-selectin and anti-L-selectin antibodies, but was not additive with anti-CD18 antibody. These results show that antiflammins inhibit PMN adhesion to HCAEC by attenuating activation-induced up-regulation of CD11/CD18 expression on leukocytes, and suggest that antiflammins may represent a novel therapeutic approach in blocking leukocyte trafficking in host defense and inflammation.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Adesão Celular/efeitos dos fármacos , Selectina E/genética , Endotélio Vascular/fisiologia , Molécula 1 de Adesão Intercelular/genética , Leucócitos/fisiologia , Neutrófilos/fisiologia , Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/farmacologia , Uteroglobina/farmacologia , Adulto , Anexina A1/farmacologia , Antígenos CD18/genética , Adesão Celular/fisiologia , Células Cultivadas , Vasos Coronários , Endotélio Vascular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Humanos , Técnicas In Vitro , Cinética , Leucócitos/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Linfócitos/fisiologia , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/fisiologia , Neutrófilos/efeitos dos fármacos , Fator de Ativação de Plaquetas/farmacologia
10.
Tissue Antigens ; 52(3): 294-9, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9802612

RESUMO

Four novel HLA Class II alleles were identified using CANTYPE reverse hybridization assay. The initial unusual SSO hybridization patterns were confirmed by cloning and sequencing analysis. DRB3*0208 allele is identical to DRB3*0202 except for three nucleotide substitutions (GAT-->AGC) changing codon 57 from Asp to Ser. This polymorphism has so far been undetected in DRB3 alleles. DRB1*15023 differs from DRB1*15021 by a single silent nucleotide substitution (AAC-->AAT, both encoding for Asn) at codon 33. This polymorphism has not, until now, been identified in DRB alleles. Compared with DQB1*03011, the novel DQB1*03012 contains a single silent nucleotide substitution (GCA-->GCG, both encoding for Ala) at codon 38. Finally, DQB1*0614 allele is identical to DQB1*0603 except for a single nucleotide substitution (TAC-->TTC), changing codon 9 from Tyr to Phe. Polymorphisms observed here in the DQB1*03012 and DQB1*0614 alleles are present in several of the known DQB1 alleles. DRB3*0208, DQB1*03012 and DQB1*0614 may have arisen from gene conversion, but the DRB1*15023 most likely was generated by a point mutation event. DQB1*0614 was detected in three related subjects, while each of the other three new alleles has only been detected once.


Assuntos
Alelos , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Sequência de Bases , Clonagem Molecular , Feminino , Cadeias beta de HLA-DQ , Cadeias HLA-DRB3 , Antígenos de Histocompatibilidade Classe II/genética , Teste de Histocompatibilidade , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Alinhamento de Sequência , Análise de Sequência de DNA
11.
Tissue Antigens ; 51(6): 658-62, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9694360

RESUMO

Three novel HLA class II alleles (DRB1*1333, DRB1*0426, DRB5*0109) are described here. The 3 novel alleles were initially detected as previously unidentified SSO hybridization patterns using the CANTYPE reverse hybridization assay. Sequences were determined by cloning/sequencing. DRB1*1333 is identical to DRB1*1303 except for a single nucleotide substitution (ACC-->AAC), changing codon 77 from Thr to Asn. This polymorphism is typical for DRB1*03 alleles. DRB1*0426 is identical to DRB1*0401 except for a single nucleotide substitution (GCC-->ACC) at codon 58, changing the encoded Ala to Thr. DRB5*0109 is identical to DRB5*0101, except for a single nucleotide substitution (GAC-->AAC), changing codon 70 from Asp to Asn. Both latter polymorphisms were so far undetected in DRB alleles. DRB1*1333 could have arisen from a gene conversion event, but DRB1*0426 and DRB5*0109 most likely were generated by point mutation events. For all 3 alleles, the sequence was confirmed by the original hybridization pattern (DRB1*1333) or by hybridization to a newly designed probe (DRB1*0426 and DRB5*0109). Ethnic backgrounds were Lebanese for DRB1*1333 and Caucasian for DRB1*0426 and DRB5*0109.


Assuntos
Alelos , Antígenos HLA-DR/genética , Sequência de Bases , DNA , Cadeias HLA-DRB1 , Cadeias HLA-DRB5 , Humanos , Dados de Sequência Molecular
13.
Tissue Antigens ; 51(5): 577-81, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9672161

RESUMO

We report here the identification of four novel DRB alleles using a reverse hybridization (CANTYPE) assay. Molecular cloning and sequencing confirmed the initial unusual hybridization patterns. All four new alleles were detected during routine HLA typing for the Canadian Unrelated Bone Marrow Donor Registry. DRB1*0703 is identical to DRB1*0701 except for a single nucleotide substitution (AGA-->AGT), changing codon 29 from Arg to Ser, a so far undetected DRB polymorphism. DRB1*0817 differs from DRB1*0801 by a single nucleotide substitution (TAC-->TTC), changing codon 47 from Tyr to Phe. This polymorphism has not, until now, been identified in DRB1*08 alleles. Compared with DRB3*0301, DRB3*0302 contains a single nucleotide substitution (TAC-->CAC) at codon 30, changing the encoded Tyr to His. This polymorphism is typical for DRB3*02 alleles. DRB3*01014 is identical to DRB3*0101 except for a single silent nucleotide substitution (GGG-->GGA) at codon 84. This polymorphism has previously only been described for the DRB1*15012 allele. DRB1*0817, DRB3*0302 and DRB3*01014 may have arisen from gene conversion, but DRB1*0703 most likely was generated by a point mutation event. The DRB3*0302 allele was detected in two unrelated subjects, while the other three have each only been detected once.


Assuntos
Alelos , Antígenos HLA-DR/genética , Sequência de Bases , DNA Complementar , Antígenos HLA-DR/classificação , Cadeias HLA-DRB1 , Cadeias HLA-DRB3 , Humanos , Dados de Sequência Molecular
14.
J Natl Cancer Inst ; 88(16): 1136-45, 1996 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-8757193

RESUMO

BACKGROUND: The development of immunotoxins has been hampered by difficulties, particularly in solid tumors, of finding appropriate target antigens and of linking sufficiently potent toxins. PURPOSE: We evaluated the tissue specificity of an immunotoxin, N901-blocked ricin (N901-bR), and assessed its potential for eliminating neural cell adhesion molecule (NCAM)-positive tumor cells in conditions appropriate for in vitro purging, prior to autologous stem cell transplantation, and its potential for myelosuppression. N901-bR consists of a monoclonal antibody (MAb), N901, directed against CD56, an antigen of the family of NCAMs, covalently linked to blocked ricin as the cytotoxic effector moiety. METHODS: The tissue specificity of the N901 MAb and the N901-bR immunotoxin was tested against a wide array of human tumor tissues and normal human tissues by immunohistochemical staining. The cytotoxic activity of N901-bR was tested against both small-cell lung cancer (SCLC) cells and neuroblastoma cells, either alone or among normal bone marrow mononuclear cells, and the efficacy of this treatment to specifically eliminate these cells was evaluated in a limiting dilution assay. In addition, normal bone marrow mononuclear cells were incubated with N901-bR, and the toxic effects of the immunotoxin on normal hematopoietic progenitors was evaluated. RESULTS: N901 and N901-bR exhibited specificity for several neoplasms of neuroectodermal origin, including SCLC and neuroblastoma. Staining of normal tissues was essentially limited to various neuroendocrine cells, cardiac muscle cells, and cells in peripheral nerve tissue. We observed a time- and dose-dependent elimination of tumor cells in vitro, with three logs (i.e., > 99.9%) of malignant cells being killed following only 5 hours of exposure to 10 nM N901-bR. Unconjugated N901 MAb specifically blocked the elimination of NCAM-positive cells by N901-bR, whereas neither an isotype-matched control MAb nor galactose (the ligand of native ricin) had any effect on the activity of the immunotoxin, confirming the specificity of its cytotoxic activity. Importantly, N901-bR used under optimal conditions for in vitro tumor cell depletion was not toxic to hematopoietic precursors. CONCLUSIONS: N901-bR has the properties required to target CD56, an antigen present not only on cells from a large number of cancers of neuroendocrine origin, but also on some important normal tissues. In addition, treatment with this immunotoxin results in the highly effective and specific elimination of neuroblastoma and SCLC cells and does not affect normal hematopoietic progenitors. IMPLICATIONS: N901-bR may have clinical utility for purging of neuroblastoma cells and SCLC cells before autologous stem cell transplantation. Further toxicology studies are warranted to assess the potential of N901-bR for in vivo administration.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Carcinoma de Células Pequenas/imunologia , Imunotoxinas/uso terapêutico , Neoplasias Pulmonares/imunologia , Moléculas de Adesão de Célula Nervosa/imunologia , Neuroblastoma/tratamento farmacológico , Ricina/análogos & derivados , Purging da Medula Óssea/métodos , Relação Dose-Resposta a Droga , Células-Tronco Hematopoéticas , Humanos , Imunoconjugados , Imuno-Histoquímica , Imunofenotipagem , Especificidade de Órgãos , Ricina/uso terapêutico , Fatores de Tempo
15.
J Toxicol Environ Health ; 47(5): 465-78, 1996 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-8614016

RESUMO

Groups of 7 Wistar rats each received a single intratracheal instillation of either saline (control), UICC chrysotile B asbestos (5 mg), or very short 4T30 chrysotile asbestos fibers (5 mg). Five animals in each group were killed at 1, 3, and 6 wk posttreatment and analyzed by bronchoalveolar lavage (BAL) for BAL cell populations and cytokine production in conjunction with histopathological assessment of lung tissue. Chrysotile B and short 4T30 chrysotile fibers induced chronic inflammatory reactions characterized by alveolar macrophage (AM) accumulation that resulted, respectively, in lung fibrosis and resolving granuloma. Alveolar macrophages (AM) obtained from rats treated with UICC chrysotile B and short 4T30 chrysotile produced enhanced levels of interleukin-1 (IL-1) and interleukin-6 (IL-6), both spontaneously and in response to lipopolysaccharide (LPS). A different pattern of response was observed for tumor necrosis factor-alpha (TNF-alpha). Fibrogenic chrysotile B caused biphasic changes characterized by significant inhibition of LPS-induced TNF-alpha release by AM 1 and 3 wk after treatment, followed by stimulation of spontaneous and LPS-induced TNF-alpha at 6 wk. In contrast, no significant change in spontaneous and LPS-induced TNF-alpha release was seen with AM from animals with resolving granuloma (4T30 group). Thus, modulation of AM-derived TNF-alpha was correlated under these conditions with the fibrogenic potential of asbestos dusts. These data support a role for TNF-alpha in fibrosis and suggest that TNF-alpha may represent a useful marker of lung damage induced by fibrogenic dusts.


Assuntos
Asbestos Serpentinas/toxicidade , Citocinas/metabolismo , Poeira/efeitos adversos , Macrófagos Alveolares/metabolismo , Animais , Asbestos Serpentinas/administração & dosagem , Lavagem Broncoalveolar , Células Cultivadas , Interleucina-1/metabolismo , Interleucina-1/farmacologia , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Intubação Intratraqueal , Lipopolissacarídeos/farmacologia , Masculino , Fibras Minerais/toxicidade , Fibrose Pulmonar/etiologia , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
16.
Mediators Inflamm ; 5(1): 37-42, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-18475695

RESUMO

Activation of alveolar macrophages (AM) for tumour necrosis factor production is suppressed initially during the inflammatory response to fibrogenic dusts. We investigated the mechanisms involved in TNF suppression, notably the role of other AM-derived mediators including prostaglandin E(2) (PGE(2)), transforming growth factor-beta(1) (TGF-beta(1)), and interleukin 6 (IL-6). The action of PGE(2) and TGF-beta(1), on AM was different. At physiologically relevant doses (25-300 pg/ml), PGE(2) did not cause significant inhibition of Hpopolysaccharide (Lps)-induced TNF release by AM in vitro but stimulated IL-6 (up to six fold), an inhibitor of AM-derived TNT. In contrast, TGF-beta(1) (0.5-50 ng/ml) inhibited both LPS-induced TNT and IL-6 release by 50% but had no effect on PGE(2) production by AM. To determine the respective contribution of these different inhibitors in TNF suppression, AM from rats exposed to fibrogenic asbestos for weeks were treated with neutralizing antibody against TGF-beta(1) or indomethacin, an inhibitor of PGE(2) synthesis. Treatment of rat AM with anti-TGF-beta(1) but not indomethacin, abrogated the observed TNT suppression. These results suggest that an autocrine, TGF-beta(1)-dependent mechanism is involved in the down-regulation of TNF production by rat AM from animals with lung fibrosis.

19.
J Immunol ; 152(10): 5092-9, 1994 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-8176225

RESUMO

Human monocytes constitutively express the platelet-activating factor receptor (hPAF-R). In this report, we have investigated the modulation of hPAF-R by IFN-gamma. Treatment of monocytes with IFN-gamma caused a time- and concentration-dependent accumulation of hPAF-R mRNA. In contrast, IFN-alpha was inactive. The effect of IFN-gamma was rapid, evident by 1 h of stimulation and reaching a maximum after 2 h. The high level of hPAF-R mRNA was maintained for at least 24 h. Flow cytometry analysis revealed that monocytes treated with IFN-gamma had a two- to sixfold increase in PAF receptor expression at the cell surface, when compared with untreated cells. The increase in hPAF-R expression was associated with an augmented response of IFN-gamma-treated cells to PAF in terms of cytosolic calcium ([Ca2+]i) variations. The IFN-gamma-dependent accumulation of hPAF-R mRNA was not due to the stabilization of hPAF-R mRNA, as shown by unchanged hPAF-R mRNA t1/2. Pretreatment of monocytes with actinomycin D, however, completely abrogated the effect of IFN-gamma, suggesting a transcriptional regulation. Moreover, the up-regulation of hPAF-R mRNA by IFN-gamma was independent of de novo protein synthesis since cycloheximide, an inhibitor of protein synthesis, did not affect this up-regulation. These studies are the first report showing that IFN-gamma regulates hPAF-R gene expression in human monocytes, by a mechanism suggesting transcriptional regulation. This may represent a prototypic example of regulation by lymphocyte-derived cytokines of lipid mediator receptors in myeloid cells, thus adding a novel element in the interrelationship between immune and inflammatory responses.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Interferon gama/farmacologia , Monócitos/efeitos dos fármacos , Glicoproteínas da Membrana de Plaquetas/efeitos dos fármacos , Receptores de Superfície Celular , Receptores Acoplados a Proteínas G , Sequência de Bases , Humanos , Dados de Sequência Molecular , Monócitos/metabolismo , Glicoproteínas da Membrana de Plaquetas/análise , Glicoproteínas da Membrana de Plaquetas/genética , RNA Mensageiro/análise , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima
20.
J Leukoc Biol ; 53(3): 279-86, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8454952

RESUMO

Bronchoalveolar lavage (BAL) cells were isolated from rats 1, 3, and 6 weeks after a single intratracheal instillation of saline, UICC chrysotile asbestos (5 mg), or silica (5 mg). In asbestos-exposed rats, the pulmonary response was characterized by a significant increase in the number of alveolar macrophages (AMs) and the appearance of fibrotic lesions within 1 week. By contrast, mixed macrophage and neutrophil accumulations were observed in the silica group without evidence of fibrosis. Tumor necrosis factor-alpha (TNF-alpha) production by lipopolysaccharide (LPS)-stimulated BAL cells from asbestos-treated rats was significantly lower than controls 1 and 3 weeks after exposure. However, by 6 weeks higher levels of TNF-alpha production were noticeable in this group. Decreases in LPS-induced TNF-alpha production were also observed with BAL cells from silica-treated animals at all time points studied. Lower levels of TNF-alpha were not related to decreased BAL cell viability or the presence of a significant proportion of neutrophils in the silica group. Furthermore, biphasic changes in TNF-alpha production seen in the asbestos group were correlated with concomitant decreases (3 weeks) and increases (6 weeks) in levels of TNF-alpha mRNA in AMs. These data indicate that lower levels of TNF-alpha resulted from inhibition at the gene expression level and provide evidence for bidirectional modulation of TNF-alpha production by AMs during inflammatory reactions.


Assuntos
Amianto/efeitos adversos , Macrófagos Alveolares/metabolismo , Fibrose Pulmonar/etiologia , Fibrose Pulmonar/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/citologia , Sobrevivência Celular , Regulação para Baixo , Regulação da Expressão Gênica , Masculino , Neutrófilos/fisiologia , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/genética , Regulação para Cima
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