Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
1.
Rhinology ; 57(3): 190-199, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30609424

RESUMO

BACKGROUND: While bacterial associations with chronic rhinosinusitis (CRS) are increasingly well described, fewer studies have examined the fungal component of the sinonasal microbiota. Here we present a study of the sinonasal mycobiota in a cohort of 144 patients (106 patients with CRS and 38 controls). METHODOLOGY: Fungal communities were characterised by analysis of mucosal swab samples of the left and right middle meatuses via ITS2 marker amplicon sequencing on the Illumina MiSeq platform. Fungal associations with previously published bacterial community and inflammatory cytokine and cell data for this cohort (collected at the same intra-operative time point) were also investigated. RESULTS: Malassezia spp. were ubiquitous and often highly predominant. Season of sampling explained more of the variability in the data than any of the clinical parameters. The predominant Malassezia sp. was distinct in patients with cystic fibrosis compared to those without. However, distinctions in the mycobiota were not evident between any other patient groupings assessed, and few fungal-bacterial or fungal-inflammatory associations were observed. CONCLUSIONS: This study confirms the prominent place of Malassezia spp. within the upper respiratory tract. Overall, few distinctions between patient groups were evident, and these data lend further support to the hypothesis that fungal community types may have no direct causative association with idiopathic CRS. Additional studies incorporating a broader array of inflammatory markers are required to assess whether these ubiquitous fungi nonetheless play an exacerbating role in some sensitive individuals.


Assuntos
Microbiota , Rinite , Sinusite , Bactérias , Estudos de Casos e Controles , Doença Crônica , Humanos , Malassezia/isolamento & purificação , Rinite/microbiologia , Sinusite/microbiologia
2.
Rhinology ; 55(1): 59-69, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28025987

RESUMO

BACKGROUND: The sino-nasal disease chronic rhinosinusitis (CRS) is primarily an inflammatory condition that manifests in several ways. However, the aetiology of this complex disease is poorly understood. The aim of this study was to explore the association between toll-like receptor (TLR) activation, host immune response and sino-nasal mucus in healthy and diseased patients. METHODS: The activation of TLR2/1 and TLR4 by sino-nasal mucus from 26 CRS patients and 10 healthy controls was measured. In addition, 7 inflammatory cytokines, bacterial community composition and bacterial abundance within the sino-nasal mucus were measured using molecular and diagnostic tools. RESULTS: TLR activity was observed in 9/36 samples, including 2 healthy controls. There was a strong, positive correlation between members of the Gammaproteobacteria (Haemophilus, Enterobacter, Pseudomonas) and TLR2/1 and TLR4 activity. Bacterial abundance and cytokine (tumour necrosis factor) abundance were also positively correlated with TLR activity. CONCLUSIONS: These findings suggest that a small proportion (20-30%) of individuals in each sub-group are more predisposed to TLR activity, which may be related to bacterial composition, diversity and abundance in the sinuses.


Assuntos
Muco/imunologia , Mucosa Nasal/imunologia , Rinite/imunologia , Sinusite/imunologia , Receptor 4 Toll-Like/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Fibrose Cística/complicações , Fibrose Cística/imunologia , Fibrose Cística/microbiologia , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Muco/microbiologia , Mucosa Nasal/microbiologia , Pólipos Nasais/complicações , Pólipos Nasais/imunologia , Pólipos Nasais/microbiologia , Rinite/complicações , Rinite/microbiologia , Sinusite/complicações , Sinusite/microbiologia , Adulto Jovem
3.
Diabet Med ; 25(9): 1083-9, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18937676

RESUMO

AIMS: To determine whether the recording of diabetes-related health indicators has increased and differences diminished between age, gender and deprivation groups, following the introduction of the new General Medical Services contract (nGMS), an incentive- and target-based contract for UK family physicians. METHODS: A serial cross-sectional study set in 310 primary care practices in Scotland serving a population of 1.5 million registered patients, focussing on diabetic patients. Data were taken immediately before the introduction of the nGMS and after it had been in place for 1 year. RESULTS: One year after the introduction of the nGMS contract, there was a 54.2% relative increase in the number of patients electronically recorded as having diabetes. In addition, measurement of the quality indicators glycated haemoglobin (HbA(1c)), blood pressure, serum creatinine and cholesterol significantly increased (P < 0.05). Women were less likely than men to have HbA(1c)[odds ratio (OR) 0.85, 95% confidence intervals (CI) 0.80-0.91], serum creatinine (OR 0.90, 95% CI 0.84-0.96) and cholesterol recorded (OR 0.83, 95% CI 0.77-0.90) or achieve HbA(1c) (

Assuntos
Diabetes Mellitus/economia , Programas Nacionais de Saúde/economia , Planos de Incentivos Médicos/economia , Padrões de Prática Médica/economia , Garantia da Qualidade dos Cuidados de Saúde/economia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doença Crônica/terapia , Estudos Transversais , Diabetes Mellitus/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde/normas , Padrões de Prática Médica/normas , Garantia da Qualidade dos Cuidados de Saúde/normas , Escócia , Fatores Sexuais , Fatores Socioeconômicos , Reino Unido , Adulto Jovem
4.
Infect Immun ; 69(10): 6156-64, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11553555

RESUMO

Bacterial DNA and its synthetic immunostimulatory oligodeoxynucleotide analogs (ISS-ODN) activate innate immunity and promote Th1 and cytotoxic T-lymphocyte immune responses. Based on these activities, we investigated whether ISS-ODN could modify the course of Mycobacterium avium infection. M. avium growth in vitro was significantly inhibited by ISS-ODN treatment of human and mouse macrophages, and M. avium growth in vivo was similarly inhibited in C57BL/6 mice treated with ISS-ODN. This protective effect of ISS-ODN was largely independent of tumor necrosis factor alpha (TNF-alpha), interleukin 12 (IL-12), nitric oxide, NADPH oxidase, alpha/beta interferon (IFN-alpha/beta), and IFN-gamma. In contrast, we found that the induction of indoleamine 2,3-dioxygenase (IDO) was required for the antimycobacterial effect of ISS-ODN. To evaluate the potential for synergism between ISS-ODN and other antimycobacterial agents, treatment with a combination of ISS-ODN and clarithromycin (CLA) was tested in vitro and in vivo. ISS-ODN significantly enhanced the therapeutic effect of CLA in both human and mouse macrophages and in C57BL/6 mice. This study newly identifies IDO as being involved in the antimicrobial activity of ISS-ODN and suggests the usefulness of ISS-ODN when used in combination with conventional chemotherapy for microbial infections.


Assuntos
Adjuvantes Imunológicos , Oligodesoxirribonucleotídeos/imunologia , Tionucleotídeos/imunologia , Triptofano Oxigenase/imunologia , Tuberculose/imunologia , Animais , Antibacterianos/uso terapêutico , Células Cultivadas , Claritromicina/farmacologia , DNA/imunologia , DNA/uso terapêutico , Modelos Animais de Doenças , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase , Interferon-alfa/imunologia , Interferon beta/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos , Camundongos Knockout , Monócitos/citologia , Monócitos/imunologia , Monócitos/microbiologia , Mycobacterium avium/crescimento & desenvolvimento , Mycobacterium avium/imunologia , NADPH Oxidases/imunologia , Óxido Nítrico Sintase/imunologia , Óxido Nítrico Sintase Tipo II , Oligodesoxirribonucleotídeos/uso terapêutico , Linfócitos T/imunologia , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia , Fator de Necrose Tumoral alfa/imunologia
5.
Cancer Gene Ther ; 8(1): 63-72, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11219495

RESUMO

Recent studies have shown that gene therapy with type I interferon (IFN) in an adenovirus vector is a powerful tool to suppress the growth of human tumors transplanted in immune-deficient mice. However, in these studies the host immune-mediated effects, which may be important in mediating the long-term control of tumor growth by these cytokines, was not studied. In this paper, we evaluate the antitumor efficacy of different adenoviral vectors containing mouse IFN-alpha genes (i.e., a first-generation replication-defective vector containing IFN-alpha1 and two different second-generation vectors containing IFN-alpha2) in immunocompetent DBA/2 mice transplanted with highly metastatic Friend leukemic cells resistant in vitro to type I IFN. We found that injection of all the different adenovirus vectors containing mouse IFN-alpha( genes resulted in a marked antitumor response in mice transplanted either subcutaneously or intravenously with IFN-resistant Friend leukemic cells compared to tumor-bearing animals inoculated with a control vector. Tumor growth inhibition after injection of IFN-adenovirus vectors was associated with a prolonged presence of high IFN levels in the sera of the injected mice. Suppression of metastatic tumor growth was also observed after a single injection of the IFN--adenovirus recombinant vectors, whereas a comparable antitumor response generally required several injections of high doses of IFN. Altogether, these results demonstrate that IFN--adenoviral vectors can efficiently inhibit metastatic tumor growth by host-mediated mechanisms and suggest that adenovirus-mediated IFN-alpha gene therapy may represent an attractive alternative to the conventional clinical use of this cytokine, which generally requires multiple injections of high IFN doses for a prolonged period of time.


Assuntos
Adenoviridae/genética , Interferon-alfa/genética , Leucemia Experimental/terapia , Animais , Vírus da Leucemia Murina de Friend , Terapia Genética , Vetores Genéticos , Injeções Intraperitoneais , Injeções Intravenosas , Interferon-alfa/sangue , Interferon-alfa/metabolismo , Óperon Lac/fisiologia , Leucemia Experimental/imunologia , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos DBA , Camundongos Nus , Metástase Neoplásica , Transplante de Neoplasias , Análise de Sobrevida , Transfecção , Células Tumorais Cultivadas
6.
J Interferon Cytokine Res ; 21(12): 1011-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11798458

RESUMO

Cytokine production has been implicated in the antiviral response to interferon-alpha (IFN-alpha) in hepatitis C and in the development of IFN-alpha-related side effects. We characterized acute changes in serum cytokine levels following administration of a single dose of consensus IFN (IFN-con1) and during continuous treatment of chronic hepatitis C patients. Serum samples were collected at baseline, at multiple times early after IFN administration, and weekly thereafter. Viral RNA titers were assessed by RT-PCR, and viral kinetics were followed. ELISA assays were used to measure IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-16. Serum cytokine levels were low at baseline. IL-6 was detected in patients with hepatitis C but not in healthy control subjects by either ELISA or RT-PCR, indicating that low levels of circulating IL-6 were associated with hepatitis C infection. None of the cytokines measured increased significantly after IFN administration except for IL-6. IL-6 levels rose rapidly, peaked at 6-15 h in a dose-dependent manner, and returned to baseline by 48 h in both patients receiving a single dose of IFN and those receiving continuous treatment. This was confirmed by RT-PCR. Pretreatment IL-6 levels were directly correlated with area under the curve (AUC) for IL-6 during the 24 h after IFN dosing (r = 0.611, p = 0.007). Viral titers decreased within 24-48 h after a single dose of IFN-con1. Changes in hepatitis C RNA titers were not significantly associated with pretreatment IL-6 levels or with changes in IL-6 levels. In conclusion, (1) baseline serum cytokine levels, except for IL-6, were low or within the normal range in patients with hepatitis C, (2) IL-6 levels were detected in some patients with hepatitis C before treatment but not in healthy controls, (3) IL-6 levels increased acutely after a single dose of IFN-alpha, and IL-6 induction was related to baseline IL-6 level, and (4) changes in IL-6 levels did not correlate with the early virologic response to IFN.


Assuntos
Antivirais/uso terapêutico , Hepatite C/tratamento farmacológico , Hepatite C/imunologia , Interferon Tipo I/uso terapêutico , Interleucina-6/sangue , Citocinas/sangue , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C/virologia , Humanos , Interferon-alfa , Interleucina-6/genética , Cinética , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , RNA Viral/análise , Proteínas Recombinantes
7.
J Interferon Cytokine Res ; 20(7): 623-32, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10926204

RESUMO

We have previously reported the isolation of mutant cell lines from the human carcinoma line ME180 that are resistant to the antiproliferative effect of interferon-gamma (IFN-gamma). These cell lines were defective in the induction of indoleamine 2,3-dioxygenase (IDO), a key enzyme of tryptophan catabolism. One of these cell lines, 3B6A, was chosen for further study. This cell line was also defective in the ability of IFN-gamma to protect against vesicular stomatitis virus (VSV) infection. However it maintained a normal antiviral response to IFN-alpha. A promoter-chloramphenicol acetyltransferase (CAT) construct containing the promoter region of IDO, which includes IFN-gamma activation site (GAS), IFN-stimulated response element-1 (ISRE-1), and ISRE-2 regions, was not expressed in 3B6A in the presence of IFN-gamma, indicating that the defect was likely to be in either Stat1 or IFN regulatory factor-1 (IRF-1), transcription factors known to bind to these cis-acting sequences. The induction of other IFN-gamma-inducible genes, such as tryptophanyl-tRNA synthetase (hWRS), was also affected. Electrophoretic mobility shift assays (EMSA) comparing nuclear extracts from parental and mutant cells indicated that Stat1 from the mutant did not bind to GAS sequences. However, Western blot analysis indicated that Stat1 protein was present. This IDO-negative phenotype can be reversed by transfection with a Stat1 expression vector. DNA sequencing of the Stat1 cDNA from wild-type and 3B6A cells indicated that an amino acid change occurred in the Stat1 protein of the mutant at W573, a tryptophan conserved in all known Stat proteins. We hypothesize that a change in this region of the Stat protein affects the response to IFN-gamma but not to IFN-alpha.


Assuntos
Proteínas de Ligação a DNA/genética , Interferon-alfa/farmacologia , Interferon gama/farmacologia , Transativadores/genética , Triptofano Oxigenase/genética , Vírus da Estomatite Vesicular Indiana/fisiologia , Cloranfenicol O-Acetiltransferase/genética , Proteínas de Ligação a DNA/metabolismo , Resistência a Múltiplos Medicamentos , Feminino , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase , Interferon alfa-2 , Mutação , Regiões Promotoras Genéticas , Proteínas Recombinantes/biossíntese , Fator de Transcrição STAT1 , Transativadores/metabolismo , Transfecção , Triptofano Oxigenase/deficiência , Células Tumorais Cultivadas , Neoplasias do Colo do Útero
8.
J Immunol ; 164(7): 3596-9, 2000 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-10725715

RESUMO

Dendritic cells (DCs) play a key role in the activation and regulation of B and T lymphocytes. Production of indoleamine 2, 3-dioxygenase (IDO) by macrophages has recently been described to result in inhibition of T cell proliferation through tryptophan degradation. Since DCs can be derived from monocytes, we sought to determine whether DCs could produce IDO which could potentially regulate T cell proliferation. Northern blot analysis of RNA from cultured monocyte-derived human DC revealed that IDO mRNA was induced upon activation with CD40 ligand and IFN-gamma. IDO produced from activated DCs was functionally active and capable of metabolizing tryptophan to kynurenine. Activated T cells were also capable of inducing IDO production by DCs, which was inhibited by a neutralizing Ab against IFN-gamma. DC production of IDO resulted in inhibition of T cell proliferation, which could be prevented using the IDO inhibitor 1-methyl-dl -tryptophan. These results suggest that activation of DCs induces the production of functional IDO, which causes depletion of tryptophan and subsequent inhibition of T cell proliferation. This may represent a potential mechanism for DCs to regulate the immune response.


Assuntos
Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Tolerância Imunológica , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Triptofano Oxigenase/biossíntese , Ligante de CD40 , Comunicação Celular/imunologia , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Técnicas de Cocultura , Combinação de Medicamentos , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase , Interferon gama/farmacologia , Cinurenina/isolamento & purificação , Cinurenina/metabolismo , Ligantes , Lipopolissacarídeos/farmacologia , Glicoproteínas de Membrana/farmacologia , RNA Mensageiro/biossíntese , Triptofano/metabolismo , Triptofano Oxigenase/genética , Triptofano Oxigenase/fisiologia , Células Tumorais Cultivadas
9.
J Interferon Cytokine Res ; 20(2): 133-42, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10714548

RESUMO

IFN-gamma treatment of the human carcinoma cell line ME180 causes cell death due to induction of indoleamine 2,3-dioxygenase (IDO) and resulting starvation for tryptophan. A mutant cell line 3B6A derived from ME180 was resistant to IFN-gamma because of loss of IDO activity. Cotransfecting an IDO promoter-chloramphenicol acetyl transferase (CAT) construct with IFN regulatory factor-1 (IRF-1) resulted in induction of CAT activity in both ME180 and 3B6A cells even in the absence of IFN-gamma. This induction was reduced by cotransfection with IRF-2. However, IRF-1 was not able to restore IDO activity, suggesting a possible repressor site outside the IDO promoter region. Stat1alpha (p91) restored both CAT and IDO activities in 3B6A cells following IFN-gamma treatment. 3B6A cells doubly treated with IFN-gamma and IFN-alpha or IFN-beta restored IDO activity, although neither cytokine on its own could induce IDO. Western blot analysis showed that both constitutive expression and induction of Stat1alpha by IFN-gamma were reduced in 3B6A cells, and double treatment of IFN-gamma with IFN-alpha or IFN-beta restored the expression level of Statla. Electrophoretic mobility shift assays indicated that Stat1 binds to the IFN-gamma-activated sequence (GAS) region in the IDO promoter in ME180 cells following IFN-gamma treatment. Our results indicated that the defect in 3B6A cells was reduced expression of Stat1alpha and that IRF-1, NF-kappaB, and PKR were all involved to some extent in the induction of IDO following IFN-gamma treatment.


Assuntos
Interferon gama/farmacologia , Proteínas Repressoras , Fatores de Transcrição/metabolismo , Triptofano Oxigenase/biossíntese , Sequência de Bases , Sítios de Ligação/genética , Cloranfenicol O-Acetiltransferase/biossíntese , Cloranfenicol O-Acetiltransferase/genética , DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Indução Enzimática/efeitos dos fármacos , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase , Fator Regulador 1 de Interferon , Fator Regulador 2 de Interferon , Interferon Tipo I/farmacologia , Fator Gênico 3 Estimulado por Interferon , NF-kappa B/genética , NF-kappa B/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes , Fatores de Transcrição/genética , Transfecção , Triptofano Oxigenase/genética , Células Tumorais Cultivadas , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo
10.
J Gen Virol ; 81(Pt 3): 695-700, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10675406

RESUMO

The effects of interferon (IFN)-alpha, IFN-beta and IFN-gamma on human papillomavirus (HPV) oncogene expression were studied in various cervical carcinoma cell lines containing integrated copies of either HPV type 16 or HPV type 18. The levels of E6 and E7 transcripts were examined 6 h and 30 h after treatment with IFN. In HeLa cells, all three classes of IFNs effected a decrease in the level of HPV-18 E6 and E7 transcripts. On the other hand, none of the IFNs altered the level of these transcripts in C-4II cells. Only IFN-gamma decreased the level of HPV-16 E6 and E7 transcripts in CaSki and HPK1A cells, while IFN-gamma actually increased the level of these transcripts in SiHa cells. This differential IFN regulation of HPV expression in various cervical cancer cell lines may account for the contradictory clinical results observed after treatment of cervical cancer with IFN.


Assuntos
Genes Virais/efeitos dos fármacos , Interferons/farmacologia , Oncogenes/efeitos dos fármacos , Papillomaviridae/efeitos dos fármacos , Papillomaviridae/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Interferon Tipo I/farmacologia , Interferon alfa-2 , Interferon-alfa/farmacologia , Interferon gama/farmacologia , Proteínas Recombinantes , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/virologia
11.
J Interferon Cytokine Res ; 18(5): 337-44, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9620361

RESUMO

A number of novel genes activated by type I interferons (IFNs) were identified by differential display. Of five induced genes examined, four were of unknown function. However, one gene sequence was identical to the human spermidine/spermine N1-acetyltransferase, the rate-limiting enzyme in polyamine catabolism. This enzyme was induced by type I IFNs in a series of hematopoietic cell lines, including Daudi, HL-60, HPBMa, and Wil-2. No induction above constitutive levels occurred in a cell line of epithelial (ME180) or liver (HepG2) origin following treatment with type I IFN. Spermidine/spermine N1-acetyltransferase was not induced by IFN-gamma in Daudi or ME180 cells. That induction occurred not only at the level of transcription but also at the enzyme level was confirmed by direct enzyme assays. As the levels of polyamines are related to cell viability, we propose that induction of this enzyme by IFN may be directly related to the anti-proliferative response to type I IFNs.


Assuntos
Acetiltransferases/biossíntese , Regulação Enzimológica da Expressão Gênica/fisiologia , Células-Tronco Hematopoéticas/metabolismo , Interferon Tipo I/farmacologia , Espermidina/metabolismo , Espermina/metabolismo , Sequência de Bases , Northern Blotting , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patologia , Linhagem Celular , Indução Enzimática , Humanos , Dados de Sequência Molecular , Células Tumorais Cultivadas
12.
Biochim Biophys Acta ; 1341(2): 173-82, 1997 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-9357956

RESUMO

Adenine phosphoribosyltransferase (APRT) from Saccharomyces cerevisiae was purified approximately 1500-fold. The enzyme catalyzes the Mg-dependent condensation of adenine and 5-phosphoribosylpyrophosphate (PRPP) to yield AMP. The purification procedure included anion exchange chromatography, chromatofocusing and gel filtration. Elution of the enzyme from the chromatofocusing column indicated a pI value of 4.7. The molecular mass for the native enzyme was 50 kDa; however, upon electrophoresis under denaturing conditions two bands of apparent molecular mass of 29 and 20 kDa were observed. We have previously reported the presence of two separate coding sequences for APRT, APT1 and APT2 in S. cerevisiae. The appearance of two bands under denaturing conditions suggests that, unlike other APRTs, this enzyme could form heterodimers. This may be the basis for substrate specificity differences between this enzyme and other APRTs. Substrate kinetics and product inhibition patterns are consistent with a ping-pong mechanism. The Km for adenine and PRPP were 6 microM and 15 microM, respectively and the Vmax was 15 micromol/min. These kinetic constants are comparable to the constants of APRT from other organisms.


Assuntos
Adenina Fosforribosiltransferase/isolamento & purificação , Adenina Fosforribosiltransferase/metabolismo , Saccharomyces cerevisiae/enzimologia , Adenina/metabolismo , Adenina/farmacologia , Adenina Fosforribosiltransferase/química , Monofosfato de Adenosina/biossíntese , Sequência de Aminoácidos , Cátions/farmacologia , Cromatografia , Dimerização , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática/efeitos dos fármacos , Ponto Isoelétrico , Cinética , Dados de Sequência Molecular , Peso Molecular , Fosforribosil Pirofosfato/metabolismo , Fosforribosil Pirofosfato/farmacologia , Conformação Proteica , Desnaturação Proteica , Alinhamento de Sequência , Análise de Sequência , Temperatura
13.
J Interferon Cytokine Res ; 16(9): 751-6, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8887061

RESUMO

Indoleamine 2'3 dioxygenase (INDO), the rate-limiting enzyme in the catabolism of the essential amino acid L-tryptophan, is induced in many cell lines following interferon gamma (IFN-gamma) treatment. The induction of this enzyme has been associated with the antiparasitic and cytotoxic activities of human IFN-gamma. DNA analysis coupled to morphologic studies indicated that ME180 cells underwent apoptosis within 48 h of treatment with IFN-gamma. We hypothesized that apoptosis results from L-tryptophan starvation following INDO induction. This was confirmed by the prevention of apoptosis on adding back tryptophan to IFN-gamma-treated cells and the induction of apoptosis by removing tryptophan from the medium in the absence of IFN-gamma.


Assuntos
Apoptose/efeitos dos fármacos , Interferon gama/farmacologia , Triptofano Oxigenase/biossíntese , Triptofano/deficiência , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Indução Enzimática , Humanos , Interferon gama/antagonistas & inibidores , Necrose , Triptofano/farmacologia , Células Tumorais Cultivadas
14.
J Biol Chem ; 271(32): 19140-5, 1996 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-8702590

RESUMO

Indoleamine 2,3-dioxygenase (INDO) is the rate-limiting enzyme in the catabolism of the essential amino acid L-tryptophan. It is induced strongly in many cell lines following interferon-gamma treatment. We report the cloning and characterization of the full-length human INDO promoter. This promoter is 1,245 base pairs long and includes two interferon-stimulated response elements (ISRE) separated by an approximately 1-kilobase sequence. The presence of these two ISREs is critical for maximum INDO promoter activity (50-fold induction). When the ISREs are present in two separate fragments cloned upstream of the chloramphenicol acetyltransferase (CAT) reporter vector, the INDO promoter activity drops significantly (7-fold induction). 5' end deletions of the wild type promoter sequence indicate that removal of the ISRE (ISRE1) at position -1126 reduces the induction level to approximately 25-fold. This activity does not change appreciably when the promoter is deleted down to position -241. Furthermore, site-directed mutagenesis of ISRE1 also decreases the promoter activity in a similar way. When ISRE1 is kept intact, deletion of the second ISRE (ISRE2) at position -111 leads to only 11-fold induction of the promoter. A similar result is obtained when substitution mutations are introduced in ISRE2. Deletion of a 748-base pair sequence between the two ISREs only shows a slight decrease in the INDO promoter activity. These data indicate that the two ISRE sequences are required for the full transcriptional induction of the interferon-gamma-inducible human INDO gene. INDO activity is not induced in the hepatic cell line HepG2. An analysis of INDO-CAT activity in this cell line indicated that the lack of INDO activity was at the transcriptional level and could reflect either the presence of a repressor or lack of a transcription factor. This lack of induction could be correlated with a truncated or unstable IRF-1. However, the levels of IRF-2, JAK2, and STAT 91 were similar in both ME180 and HepG2 cells.


Assuntos
Regulação Enzimológica da Expressão Gênica/genética , Interferon gama/farmacologia , Triptofano Oxigenase/genética , Sequência de Bases , Cloranfenicol O-Acetiltransferase/genética , Clonagem Molecular , DNA Complementar , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Deleção de Sequência , Células Tumorais Cultivadas
15.
J Interferon Cytokine Res ; 16(7): 489-99, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8836913

RESUMO

Consensus interferon (Infergen) is a wholly synthetic type I interferon (IFN), developed by scanning several interferon-alpha nonallelic subtypes and assigning the most frequently observed amino acid in each position, resulting in a consensus sequence. The antiviral, antiproliferative, NK cell activation activity, cytokine induction, and interferon-stimulated gene-induction activity of consensus interferon has been compared with naturally occurring type I interferons. In all of these comparisons, consensus interferon had a higher activity when compared, on a mass basis, with IFN-alpha 2a and IFN-alpha 2b, although the activity was the same for all of these parameters on an antiviral unit basis. That a synthetic type I interferon could have higher activities than naturally occurring molecules is surprising and may be a result of the higher affinity for the array of type I interferon receptors demonstrated for consensus interferon when compared with IFN-alpha. In contrast, consensus interferon was shown to be an inferior inducer of IL-1 beta when compared with IFN-alpha. These results may reflect differential binding to multiple accessory proteins interacting with a type I interferon receptor. These unique biologic properties may lead to a favorable clinical benefit for consensus interferon when compared with the naturally occurring recombinant molecules. Ongoing clinical trials will ascertain whether consensus interferon can be used in a wide array of disease situations, such as chronic viral infections and certain malignancies.


Assuntos
Antineoplásicos/farmacologia , Antivirais/farmacologia , Sequência Consenso , Interferon Tipo I/farmacologia , Sequência de Aminoácidos , Animais , Antineoplásicos/química , Antivirais/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Interferon alfa-2 , Interferon-alfa , Dados de Sequência Molecular , Neoplasias Experimentais/terapia , Proteínas Recombinantes , Homologia de Sequência de Aminoácidos
16.
Proc Natl Acad Sci U S A ; 93(9): 4513-8, 1996 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-8633100

RESUMO

Treatment of a human breast cancer cell line (MDA-MB-435) in nude mice with a recombinant adenovirus containing the human interferon (IFN) consensus gene, IFN-con1 (ad5/IFN), resulted in tumor regression in 100% of the animals. Tumor regression occurred when virus was injected either within 24 hr of tumor cell implantation or with established tumors. However, regression of the tumor was also observed in controls in which either the wild-type virus or a recombinant virus containing the luciferase gene was used, although tumor growth was not completely suppressed. Tumor regression was accompanied by a decrease in p53 expression. Two other tumors, the human myelogenous leukemic cell line K562 and the hamster melanoma tumor RPMI 1846, also responded to treatment but only with ad5/IFN. In the case of K562 tumors, there was complete regression of the tumor, and tumors derived from RPMI 1846 showed partial regression. We propose that the complete regression of the breast cancer with the recombinant virus ad5/IFN was the result of two events: viral oncolysis in which tumor cells are being selectively lysed by the replication-competent virus and the enhanced effect of expression of the IFN-con1 gene. K562 and RPMI 1846 tumors regressed only as a result of IFN gene therapy. This was confirmed by in vitro analysis. Our results indicate that a combination of viral oncolysis with a virus of low pathogenicity, itself resistant to the effects of IFN and IFN gene therapy, might be a fruitful approach to the treatment of a variety of different tumors, in particular breast cancers.


Assuntos
Adenovírus Humanos/genética , Neoplasias da Mama/terapia , Terapia Genética , Vetores Genéticos , Interferons/biossíntese , Melanoma/terapia , Animais , Neoplasias da Mama/patologia , Divisão Celular , Linhagem Celular , Cricetinae , Feminino , Humanos , Imuno-Histoquímica , Interferons/genética , Rim , Cinética , Leucemia Mieloide/terapia , Luciferases/biossíntese , Melanoma/patologia , Mesocricetus , Camundongos , Camundongos Nus , Transplante Heterólogo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/biossíntese
17.
Cancer Gene Ther ; 3(1): 31-8, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8785709

RESUMO

Adeno-associated virus (AAV) vectors were constructed containing both a synthetic type I interferon gene, (IFN-con1) and the bacterial neomycin-resistant gene. Recombinant virions were used to infect a number of human tumor cell lines, including 293, Hela, K562, and Eskol (a hairy cell leukemia-like cell), and geneticin-resistant cells were selected. All IFN-con1-transduced cell lines produced low levels of IFN-con1 and grew at the same rate as nontransduced cell lines. Although these cell lines were resistant to IFN in vitro, when injected into nude mice, 293, K562, and Eskol cells failed to form tumors up to 3 months after the initial inoculum, although mice receiving nontransduced cells developed tumors within 7 to 10 days. Transduced Hela cells grew much slower in vivo and formed much smaller tumors than did the parental cells. When equal numbers of transduced and nontransduced cells were injected into nude mice, tumors initially developed slowly and then completely regressed. Treatment of an established Eskol tumor (histologically a malignant immunoblastic lymphoma) with AAV/IFN-con1-transduced 293 cells resulted in tumor regression, whereas treatment of Eskol tumors with IFN-con1 resulted in a small decrease in tumor size. These results indicate that the human IFN-con1 gene in a viral vector can be used successfully in the treatment of tumors both directly and by tumor-targeted gene therapy.


Assuntos
Divisão Celular , Dependovirus/genética , Terapia Genética/métodos , Interferon Tipo I/genética , Neoplasias Experimentais/terapia , Animais , Células Clonais , Dependovirus/metabolismo , Feminino , Técnicas de Transferência de Genes , Vetores Genéticos , Humanos , Interferon Tipo I/farmacologia , Camundongos , Camundongos Nus , Neoplasias Experimentais/patologia , Células Tumorais Cultivadas , Zinco/farmacologia
19.
Cytokines Mol Ther ; 1(4): 289-300, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9384682

RESUMO

Type I interferons have potent antiproliferative activity both in vitro and in vivo, and their tumor suppressor activity has been suggested. A series of eukaryotic vectors containing a synthetic human consensus type I interferon gene (IFN-con1) under the control of different promoters (cytomegalovirus early promoter, murine metallothionein promoter and the Rous sarcoma virus LTR) were constructed and stably transfected into type I IFN-deficient myelogenous leukemic K562 cells. Constitutive expression of IFNcon1 reverted the malignant phenotype, as indicated by loss of tumorgenicity in nude mice. When stably transformed cells were mixed with parental tumor cells, there was retardation of tumor growth. Constitutive expression of IFNcon1 reverted the malignant phenotype in vitro, as indicated by growth inhibition in culture, and reduction in colony formation on soft agar. Furthermore, IFNcon1 gene expression resulted in elevated erythroid differentiation, growth arrest in S phase and induced apoptosis. Thus the presence of an active IFNcon1 gene overcomes the oncogenic potential of K562 by coordinated modulation of cell proliferation, differentiation and programmed cell death, and it acts as a tumor suppressor in vivo.


Assuntos
Interferon Tipo I/biossíntese , Animais , Apoptose , Sequência de Bases , Ciclo Celular , Diferenciação Celular , Divisão Celular , Cromossomos Humanos Par 9 , Deleção de Genes , Células HeLa , Humanos , Interferon Tipo I/deficiência , Interferon Tipo I/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Metalotioneína/genética , Camundongos , Dados de Sequência Molecular , Família Multigênica , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/biossíntese , Fase S , Transfecção , Células Tumorais Cultivadas
20.
Health Bull (Edinb) ; 53(5): 253-9, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7490195

RESUMO

OBJECTIVE: To identify how computerised practices using Gpass software (General Practice Administration System for Scotland), currently implement the new health promotion regulations. DESIGN: Postal questionnaire to all Gpass practices in Scotland. Data were gathered on types and methods of recording health promotion data, Read code selection, health education given and intended methods of data analysis. Questionnaire results were compared with data from an Electronic Questionnaire analysing actual data recorded on practice computers. RESULTS: Overall response rate: 64.6%, 94.8% of the responding practices have been approved for health promotion band three. Most practices (94.5%) use their computer for data collection, 63.6% of practices use a manual data capture form and 28.8% use computer data capture methods. Methods of collecting patient data and selection of Read codes for computer data entry are variable. Most practices use one method of data collection; a significant minority use multiple methods or more than one Read code to record the same item. The recording of health promotion on computer has increased greatly since the introduction of the new regulations: the current levels of recording are alcohol history (26.3%), blood pressure reading (57.6%), smoking (35.4%), exercise (7.1%), weight (21.4%) and height (16.4%). Most practices (94.3%) intend using Gpass for data analysis. CONCLUSION: Methods of collecting and recording health promotion data differ greatly between practices, with variable standardisation of health promotion codes and differing use of appropriate elements of the Gpass software.


Assuntos
Promoção da Saúde/tendências , Automação de Escritório , Software , Adulto , Idoso , Coleta de Dados , Medicina de Família e Comunidade/estatística & dados numéricos , Feminino , Implementação de Plano de Saúde , Humanos , Estilo de Vida , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , Escócia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA