RESUMO
BACKGROUND: Treatment of complex anal fistulas remains difficult. However, treatment with stem cells has had an encouraging success rate when applied to complex perianal fistulas. We systematically reviewed the current evidence through meta-analysis. METHODS: We performed an electronic literature search on PubMed, Embase, and the Cochrane Library and identified studies (published between January 1946 and August 2017) that used stem cells to treat patients with complex perianal fistula. Each paper was evaluated for treatment success rate, target patients, types of stem cells used, number of cells used, and criteria for complete healing. Potential publication bias was assessed via visual inspection of a funnel plot and Orwin's fail-safe N. Out of 171 papers, 16 were included in the meta-analysis. RESULTS: The overall healing rate of stem cell injection therapy for patients with complex perianal fistulas was 62.8% (95% CI 53.5-71.2, I2 = 54.05%), whereas those for patients with Crohn's perianal fistulas alone and complex anal fistulas not associated with Crohn's disease were 64.1% and 61.5% (p = 0.840), respectively. Healing rates for autologous and allogenic stem cell treatment were 69.4% and 50.7% (p = 0.020), respectively. Four comparative studies out of 16 studies were analyzed separately. Stem cell therapy increased the healing rate compared to the control groups (OR 0.379, 95% CI 0.152-0.947). CONCLUSIONS: Stem cell therapy is a good treatment option for complex perianal fistulas, which cannot be healed by conventional operative procedures. However, further research for additional supportive evidence, such as a large-scale randomized controlled trial, is required.
Assuntos
Fístula Cutânea/cirurgia , Fístula Retal/cirurgia , Transplante de Células-Tronco , Humanos , Resultado do TratamentoRESUMO
INTRODUCTION: Recombinant Newcastle Disease virus (rNDV) vectored vaccines are safe mucosal applicable vaccines with intrinsic immune-modulatory properties for the induction of efficient immunity. Like all viral vectored vaccines repeated inoculation via mucosal routes invariably results to immunity against viral vaccine vectors. To obviate immunity against viral vaccine vectors and improve the ability of rNDV vectored vaccines in inducing T cell immunity in murine air way we have directed dendritic cell targeted HIV-1 gag protein (DEC-Gag) vaccine; for the induction of helper CD4+ T cells to a Recombinant Newcastle disease virus expressing codon optimized HIV-1 Gag P55 (rNDV-L-Gag) vaccine. METHODS: We do so through successive administration of anti-DEC205-gagP24 protein plus polyICLC (DEC-Gag) vaccine and rNDV-L-Gag. First strong gag specific helper CD4+ T cells are induced in mice by selected targeting of anti-DEC205-gagP24 protein vaccine to dendritic cells (DC) in situ together with polyICLC as adjuvant. This targeting helped T cell immunity develop to a subsequent rNDV-L-Gag vaccine and improved both systemic and mucosal gag specific immunity. RESULTS: This sequential DEC-Gag vaccine prime followed by an rNDV-L-gag boost results to improved viral vectored immunization in murine airway, including mobilization of protective CD8+ T cells to a pathogenic virus infection site. CONCLUSION: Thus, complementary prime boost vaccination, in which prime and boost favor distinct types of T cell immunity, improves viral vectored immunization, including mobilization of protective CD8+ T cells to a pathogenic virus infection site such as the murine airway.
Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Proteína do Núcleo p24 do HIV/imunologia , Imunização Secundária , Vírus da Doença de Newcastle/imunologia , Vacinas contra a AIDS/genética , Animais , Células CHO , Cricetulus , Proteína do Núcleo p24 do HIV/genética , Humanos , Camundongos , Vírus da Doença de Newcastle/genéticaRESUMO
Yersinia pestis is a Gram-negative bacterium that causes plague. After Y. pestis overcomes the skin barrier, it encounters antigen-presenting cells (APCs), such as Langerhans and dendritic cells. They transport the bacteria from the skin to the lymph nodes. However, the molecular mechanisms involved in bacterial transmission are unclear. Langerhans cells (LCs) express Langerin (CD207), a calcium-dependent (C-type) lectin. Furthermore, Y. pestis possesses exposed core oligosaccharides. In this study, we show that Y. pestis invades LCs and Langerin-expressing transfectants. However, when the bacterial core oligosaccharides are shielded or truncated, Y. pestis propensity to invade Langerhans and Langerin-expressing cells decreases. Moreover, the interaction of Y. pestis with Langerin-expressing transfectants is inhibited by purified Langerin, a DC-SIGN (DC-specific intercellular adhesion molecule 3 grabbing nonintegrin)-like molecule, an anti-CD207 antibody, purified core oligosaccharides and several oligosaccharides. Furthermore, covering core oligosaccharides reduces the mortality associated with murine infection by adversely affecting the transmission of Y. pestis to lymph nodes. These results demonstrate that direct interaction of core oligosaccharides with Langerin facilitates the invasion of LCs by Y. pestis. Therefore, Langerin-mediated binding of Y. pestis to APCs may promote its dissemination and infection.
Assuntos
Células Apresentadoras de Antígenos/imunologia , Antígenos CD/imunologia , Lectinas Tipo C/imunologia , Lectinas de Ligação a Manose/imunologia , Fagocitose/imunologia , Yersinia pestis/imunologia , Animais , Células Apresentadoras de Antígenos/microbiologia , Antígenos CD/metabolismo , Aderência Bacteriana/imunologia , Células CHO , Células Cultivadas , Cricetinae , Cricetulus , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Citometria de Fluxo , Interações Hospedeiro-Patógeno/imunologia , Humanos , Células de Langerhans/imunologia , Células de Langerhans/metabolismo , Lectinas Tipo C/metabolismo , Lectinas de Ligação a Manose/metabolismo , Camundongos , Antígenos O/imunologia , Antígenos O/metabolismo , Peste/imunologia , Peste/microbiologia , Ligação Proteica/imunologia , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Análise de Sobrevida , Yersinia pestis/metabolismo , Yersinia pestis/fisiologiaRESUMO
Protein vaccines, if rendered immunogenic, would facilitate vaccine development against HIV and other pathogens. We compared in nonhuman primates (NHPs) immune responses to HIV Gag p24 within 3G9 antibody to DEC205 ("DEC-HIV Gag p24"), an uptake receptor on dendritic cells, to nontargeted protein, with or without poly ICLC, a synthetic double stranded RNA, as adjuvant. Priming s.c. with 60 µg of both HIV Gag p24 vaccines elicited potent CD4(+) T cells secreting IL-2, IFN-γ, and TNF-α, which also proliferated. The responses increased with each of three immunizations and recognized multiple Gag peptides. DEC-HIV Gag p24 showed better cross-priming for CD8(+) T cells, whereas the avidity of anti-Gag antibodies was â¼10-fold higher with nontargeted Gag 24 protein. For both protein vaccines, poly ICLC was essential for T- and B-cell immunity. To determine whether adaptive responses could be further enhanced, animals were boosted with New York vaccinia virus (NYVAC)-HIV Gag/Pol/Nef. Gag-specific CD4(+) and CD8(+) T-cell responses increased markedly after priming with both protein vaccines and poly ICLC. These data reveal qualitative differences in antibody and T-cell responses to DEC-HIV Gag p24 and Gag p24 protein and show that prime boost with protein and adjuvant followed by NYVAC elicits potent cellular immunity.
Assuntos
Vacinas contra a AIDS/imunologia , Adjuvantes Imunológicos/farmacologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proteína do Núcleo p24 do HIV/imunologia , RNA de Cadeia Dupla/farmacologia , Vaccinia virus/imunologia , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/farmacologia , Animais , Linfócitos B/imunologia , Citocinas/imunologia , Feminino , Anticorpos Anti-HIV/imunologia , Proteína do Núcleo p24 do HIV/farmacologia , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/genética , Imunidade Celular/imunologia , Macaca mulatta , Masculino , RNA de Cadeia Dupla/imunologia , Vaccinia virus/genéticaRESUMO
Bacteriophages are bacterial viruses with unique characteristics that make them excellent surrogates for mammalian pathogenic viruses in environmental studies. Simple and reliable methodologies for isolation, detection, characterization and enumeration of somatic and F-specific bacteriophage are available in the literature. Limited information or methods are available for producing high-titer purified phage suspensions for studying microbial transport and survival in natural and engineered environments. This deficiency arises because most research on the production of high-titer phage suspensions was completed over half a century ago and more recent advances on these methods have not been compiled in a single publication. We present a review of the available methods and new data on the propagation, concentration and purification of two bacteriophage host systems (somatic PRD1/Salmonella thyphimurium and F-specific PR772/Escherichia coli) that are commonly utilized in laboratory and field-scale assessments of subsurface microbial transport and survival. The focus of the present study is to recommend the approach(es) that will ensure maximum bacteriophage yields while optimizing suspension purification (i.e. avoiding modification of surface charge of the phage capsids and/or inadvertent introduction of dissolved organic matter to the study system).
Assuntos
Bacteriófago PRD1/isolamento & purificação , Monitoramento Ambiental/métodos , Bacteriófago PRD1/química , Bacteriófago PRD1/crescimento & desenvolvimento , Carbono/análise , Contagem de Colônia Microbiana , Cinética , Tamanho da Partícula , Poluentes da Água/análiseRESUMO
OBJECTIVE: Data concerning faecal incontinence (FI) in men are lacking. The aim of this study was to evaluate the historical aetiology and contrast aetiologies in younger and older men suffering from FI. METHOD: After institutional review board approval, a retrospective chart review was undertaken of all patients with FI seen between 1999 and 2005. The data of male patients was further analysed to assess the impact of age and historical aetiology on FI. RESULTS: A total of 404 males were included, 203 patients were <70 years of age (group A) and 201 patients were >or=70 years of age (group B). The most common prior diagnosis in group A was perianal sepsis in 23 (11.3%) patients and symptomatic haemorrhoids in 20 (9.9%) patients; in group B it was prostate cancer in 57 (28.4%) patients, symptomatic haemorrhoids in 31 (15.4%) patients and neurological diseases in 18 (9%) patients. The most common prior procedure in group A was restorative proctectomy/proctocolectomy in 32 (15.8%) patients, fistulotomy or haemorrhoidectomy in 21 (10.3%) and 19 (9.4%) patients respectively. In group B, radiation therapy for prostate cancer was utilized in 48 (23.9%) patients and haemorrhoidectomy in 29 (14.4%) patients. Comparing group A and group B relative to diagnosis - perianal sepsis, perineal trauma, congenital disorders, HIV infection and anal cancer were more common in group A, whereas prostate cancer, neurological diseases and colon cancer were significantly more common in group B. CONCLUSION: Prostate cancer, symptomatic haemorrhoids, perianal sepsis, rectal cancer and a history of restorative rectal resection were common associations with FI in men. The aetiologies for FI in men vary with age.
Assuntos
Incontinência Fecal/etiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Criança , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
We propose a biochemical mechanism for the negative role of Notch signaling on p53 transactivation function. Expression of the intracellular domain of human Notch1 (Notch1-IC) inhibits the expression of p53-responsive genes p21, mdm2, and bax in HCT116 p53(-/-) cells. Furthermore, Notch1-IC expression inhibits the phosphorylation of ectopically expressed p53 in HCT116 p53(-/-) cells as well as the phosphorylation of endogenous p53 in UV-treated HCT116 p53(+/+) cells. Transcriptional downregulation of p53-responsive genes by Notch1-IC was confirmed both by chromatin immunoprecipitation assay and Northern blot analysis. We found the intracellular interaction between Notch1-IC and p53 in HCT116 p53(+/+) cells and suggest that activated Notch1 interaction with p53 is an important cellular event for the inhibition of p53-dependent transactivation. The N-terminal fragment of Notch1-IC, which can interacts with p53, inhibits p53 phosphorylation and represses p53 transactivation. In addition, Notch signaling downregulated p53-dependent apoptosis induced by UV irradiation.
Assuntos
Receptor Notch1/metabolismo , Ativação Transcricional/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Apoptose/efeitos da radiação , DNA/metabolismo , Regulação para Baixo/efeitos da radiação , Células HCT116 , Humanos , Fosforilação/efeitos da radiação , Ligação Proteica/efeitos da radiação , Receptor Notch1/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais/efeitos da radiação , Transcrição Gênica/efeitos da radiação , Ativação Transcricional/efeitos da radiação , Proteína Supressora de Tumor p53/biossíntese , Raios UltravioletaRESUMO
A mushroom extract, Agaricus blazei Murill Kyowa (ABMK), has been reported to possess antimutagenic and antitumor effects. Here, we investigate the beneficial effects of ABMK consumption on immunological status and qualities of life in cancer patients undergoing chemotherapy. One hundred cervical, ovarian, and endometrial cancer patients were treated either with carboplatin (300 mg / m(2)) plus VP16 (etoposide, 100 mg / m(2)) or with carboplatin (300 mg / m(2)) plus taxol (175 mg / m(2)) every 3 weeks for at least three cycles with or without oral consumption of ABMK. We observed that natural killer cell activity was significantly higher in ABMK-treated group (ANOVA, n = 39, P < 0.002) as compared with nontreated placebo group (n = 61). However, no significant difference in lymphokine-activated killer and monocyte activities was observed in a manner similar to the count of specific immune cell populations between ABMK-treated and nontreated groups. However, chemotherapy-associated side effects such as appetite, alopecia, emotional stability, and general weakness were all improved by ABMK treatment. Taken together, this suggests that ABMK treatment might be beneficial for gynecological cancer patients undergoing chemotherapy.
Assuntos
Agaricus , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias dos Genitais Femininos/tratamento farmacológico , Fitoterapia/métodos , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carboplatina/administração & dosagem , Carboplatina/efeitos adversos , Etoposídeo/administração & dosagem , Etoposídeo/efeitos adversos , Feminino , Humanos , Imunidade/efeitos dos fármacos , Células Matadoras Naturais/efeitos dos fármacos , Pessoa de Meia-Idade , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Extratos Vegetais/uso terapêutico , Qualidade de Vida , Resultado do TratamentoRESUMO
To determine the best molecular method for diagnosing leprosy, two sets of Mycobacterium leprae-specific primers were compared. Fresh biopsies and slit skin smear samples were obtained from 67 leprosy patients and examined by touchdown (TD) PCR using primers amplifying either a 129-bp fragment of the RLEP repetitive sequence or a 360-bp fragment of the 18-kDa protein gene of M. leprae. Seventeen of 30 (56.7%) biopsy specimens and four of 37 (10.8%) slit skin smear specimens were positive using the primer for the 18-kDa protein gene, whereas 24 of 30 (80%) biopsy and 27 of 37 (73%) slit skin smear samples showed detectable PCR products in the RLEP repetitive sequence. Twenty-one of 31 cases (67.7%) with a bacterial index of zero were PCR positive for the primer RLEP repetitive sequence. These results demonstrate that detection of M. leprae using PCR with primers to a RLEP sequence is more sensitive and specific than PCR with the 18-kDa protein gene primers and also slit smears with acid fast staining. PCR of RLEP repetitive sequences is therefore a useful means of detecting M. leprae DNA even when it is present at very low levels.
Assuntos
Proteínas de Bactérias/genética , Hanseníase/diagnóstico , Mycobacterium leprae/genética , Reação em Cadeia da Polimerase/métodos , Anticorpos Antibacterianos/sangue , Primers do DNA , Humanos , Hanseníase/microbiologia , Mycobacterium leprae/isolamento & purificação , Sequências Repetitivas de Ácido Nucleico , Pele/microbiologiaRESUMO
To determine the best molecular method for diagnosing leprosy, two sets of Mycobacterium leprae-specific primers were compared. Fresh biopsies and slit skin smear samples were obtained from 67 leprosy patients and examined by touchdown (TD) PCR using primers amplifying either a 129-bp fragment of the RLEP repetitive sequence or a 360-bp fragment of the 18-kDa protein gene of M. leprae. Seventeen of 30 (56.7 per cent) biopsy specimens and four of 37 (10.8 per cent) slit skin smear specimens were positive using the primer for the 18-kDa protein gene, whereas 24 of 30 (80 per cent) biopsy and 27 of 37 (73 per cent) slit skin smear samples showed detectable PCR products in the RLEP repetitive sequence. Twenty-one of 31 cases (67.7 per cent) with a bacterial index of zero were PCR positive for the primer RLEP repetitive sequence. These results demonstrate that detection of M. leprae using PCR with primers to a RLEP sequence is more sensitive and specific than PCR with the 18-kDa protein gene primers and also slit smears with acid fast staining. PCR of RLEP repetitive sequences is therefore a useful means of detecting M. leprae DNA even when it is present at very low levels.
Assuntos
Humanos , Anticorpos Antibacterianos/sangue , Hanseníase/diagnóstico , Hanseníase/microbiologia , Mycobacterium leprae/genética , Mycobacterium leprae/isolamento & purificação , Pele/microbiologia , Primers do DNA , Proteínas de Bactérias/genética , Reação em Cadeia da Polimerase/métodos , Sequências Repetitivas de Ácido NucleicoRESUMO
Although there is no genetic diversity in isolates of Mycobacterium leprae, the variance of tandem repeats in the rpoT gene was recently demonstrated. We have typed clinical isolates of M. leprae in Korea using difference of the tandem repeats in the rpoT gene. Among 69 patients, 65 Korean isolates (94.2%) demonstrated four copies of the 6 bp tandem repeat (GACATC) in the rpoT gene, and incidences of three copies were found in only two Koreans and two foreigners (2.9%, respectively).
Assuntos
DNA Bacteriano/análise , Hanseníase/epidemiologia , Mycobacterium leprae/classificação , Mycobacterium leprae/genética , Sequência de Bases , Feminino , Genótipo , Humanos , Incidência , Coreia (Geográfico)/epidemiologia , Hanseníase/genética , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Probabilidade , Sensibilidade e Especificidade , Sequências de Repetição em TandemRESUMO
Toll-like receptor 2 (TLR2) is critical in the immune response to mycobacterial infections and the mutations in the TLR2 have been shown to confer the susceptibility to severe infection with mycobacteria. To define this, we screened the intracellular domain of TLR2 in 131 subjects. Groups of 45 lepromatous and 41 tuberculoid leprosy (TT) patients and 45 controls were investigated. Ten subjects among the lepromatous leprosy (LL) patients had a band variant detected by single-stranded conformational polymorphism. DNA sequencing detected a C to T substitution at nucleotide 2029 from the start codon of the TLR2. The mutation would substitute Arg to Trp at amino acid residue 677, one of the conserved regions of TLR2. In our results, the mutation was involved in only LL, not TT and control. Thus, we suggest that the mutation in the intracellular domain of TLR2 has a role in susceptibility to LL.
Assuntos
Proteínas de Drosophila , Hanseníase Virchowiana/genética , Glicoproteínas de Membrana/genética , Mutação , Mycobacterium leprae , Receptores de Superfície Celular/genética , Sequência de Aminoácidos , Predisposição Genética para Doença , Humanos , Hanseníase Virchowiana/sangue , Hanseníase Virchowiana/imunologia , Hanseníase Tuberculoide/sangue , Hanseníase Tuberculoide/genética , Hanseníase Tuberculoide/imunologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Glicoproteínas de Membrana/química , Dados de Sequência Molecular , Polimorfismo Conformacional de Fita Simples , Receptores de Superfície Celular/química , Alinhamento de Sequência , Transdução de Sinais , Receptor 2 Toll-Like , Receptores Toll-LikeAssuntos
Dapsona/uso terapêutico , Hansenostáticos/uso terapêutico , Hanseníase/tratamento farmacológico , Mutação/genética , Mycobacterium leprae/genética , Adulto , Idoso , Animais , Di-Hidropteroato Sintase/genética , Resistência Microbiana a Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium leprae/efeitos dos fármacos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNARESUMO
OBJECTIVES: Man-made vitreous fibers (MMVFs) can induce cytotoxicity in a way similar to that of other particles, including silica and asbestos fibers. However, as yet the mechanism of MMVF-induced cytotoxicity is still not clear. This report aims to clarify the mechanism of MMVF-induced cytotoxicity in the alveolar macrophage (AM). In this mechanism, an attempt to prove the involvement of the adenosine triphosphate (ATP) generation system and the polyinosinic acid-inhibitable scavenger receptors was made. METHODS: Several parameters were observed for cytotoxicity, such as cell viability, the release of lactic dehydrogenase (LDH) and ATP levels in rat AM's that were treated with refractory ceramic fibers (RF2) and rock wool (RW1). A specially designed ATP generation system was used to determine the effect of MMVF on ATP generation. A scavenger receptor ligand was applied to evaluate the relationship between scavenger receptors and MMVF-induced ATP depletion. RESULTS: A 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that both RF2 and RW1 caused a decrease in cell viability and this decrease was concentration-dependent. RF2 and RW1 increased the release of LDH with increasing fiber concentration. From these parameters, RF2 was shown to exhibit greater cytotoxicity than did RW1. Both fibers decreased the intracellular ATP content and this decrease was concentration-dependent. The decrease was more pronounced in RW1 than in RF2 at all fiber concentrations. These fibers suppressed succinate-triggered oxygen consumption. Polyinosinic acid, a ligand of the scavenger receptor, inhibited the MMVF-induced decrease in ATP concentration. CONCLUSION: These results suggest that RF2 and RW1 can induce cytotoxicity and ATP depletion in the AM through the polyinosinic acid-inhibitable scavenger receptor. ATP depletion was the important factor in MMVF cytotoxicity, especially by RW1.
Assuntos
Sobrevivência Celular/efeitos dos fármacos , Cerâmica/toxicidade , Macrófagos Alveolares/efeitos dos fármacos , Proteínas de Membrana , Fibras Minerais/toxicidade , Receptores de Lipoproteínas , Trifosfato de Adenosina/metabolismo , Animais , L-Lactato Desidrogenase/metabolismo , Macrófagos Alveolares/citologia , Macrófagos Alveolares/enzimologia , Macrófagos Alveolares/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Receptores Imunológicos/metabolismo , Receptores Depuradores , Receptores Depuradores Classe BRESUMO
The genetic diversity and related global distribution of 51 Mycobacterium leprae isolates were studied. Isolates were obtained from leprosy patients from 12 geographically distinct regions of the world and two were obtained from nonhuman sources. Polymerase chain reaction (PCR) followed by DNA sequencing was performed targeting the rpoT gene of M. leprae. Isolates were classified into two groups based on the number of tandem repeats composed of 6 base pairs in the rpoT gene. Isolates from Japan (except Okinawa) and Korea belonged to one group, while those from Southeast Asian countries, Brazil, Haiti and Okinawa in Japan belonged to a second genotype. M. leprae obtained from two nonhuman sources (an armadillo and a mangabey monkey) revealed the latter genotype. These results demonstrate the genetic diversity of M. leprae and the related genotype-specific distribution in the world.
Assuntos
Proteínas de Bactérias , Técnicas de Tipagem Bacteriana , Hanseníase/microbiologia , Mycobacterium leprae/classificação , Mycobacterium leprae/genética , Fator sigma/genética , Genes Bacterianos , Variação Genética , Genoma Bacteriano , Genótipo , Geografia , Humanos , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
6-(1-azidoalkyl)-DMNQ derivatives compared to 2-(1-azidoalkyl)-DMNQ isomers, exhibited higher cytotoxic activity against L1210 mouse leukemia cells and stronger inhibition of DNA topoisomerase-I (TOPO-I), suggesting involvement of steric hindrance. However, similar antitumor activity against mice bearing S-180 cell was shown by 2- and 6-(1-azidoalkyl)-DMNQ derivatives.
Assuntos
Antineoplásicos/síntese química , Azidas/síntese química , Inibidores Enzimáticos/síntese química , Naftoquinonas/síntese química , Inibidores da Topoisomerase I , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Azidas/química , Azidas/farmacologia , Cromatografia em Camada Fina , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Leucemia L1210/patologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Naftoquinonas/química , Naftoquinonas/farmacologia , Transplante de Neoplasias , Sarcoma Experimental/tratamento farmacológico , Sarcoma Experimental/patologia , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Exposure to silica has been associated with progressive pulmonary inflammation and fibrosis. While the fibroblasts play an important role in the pathogenesis of silicosis, the direct interaction between silica and fibroblasts is poorly understood. We observed that silica particles stimulated intracellular ROS generation in Rat2 fibroblast, evidenced by DCFH oxidation. Silica-induced DCFH oxidation was inhibited by catalase and DPI, a flavoenzyme inhibitor. Additionally, the time course of elevation of the intracellular ROS was paralleled by the increases of MEK and ERK phosphorylation. Silica-induced ERK phosphorylation was also effectively attenuated by catalase and DPI. However, SOD enhanced the silica-induced ERK phosphorylation, indicating a role for H(2)O(2) in ERK activation. Furthermore, ERK and MEK phosphorylation are reproduced by H(2)O(2) treatment. Taken together, these results demonstrate that silica stimulates ROS production via flavoenzyme-dependent mechanism in Rat2 fibroblasts and the H(2)O(2), in turn, serves as a signal transduction element in activating MEK-ERK pathway.
Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Dióxido de Silício/farmacologia , Animais , Catalase/farmacologia , Linhagem Celular , Ativação Enzimática , Inibidores Enzimáticos/farmacocinética , Fibroblastos , Peróxido de Hidrogênio/metabolismo , Oniocompostos/farmacocinética , Oxirredução , Fosforilação , Ratos , Transdução de Sinais/efeitos dos fármacosRESUMO
For the differentiation and identification of mycobacterial species, the rpoB gene, encoding the beta subunit of RNA polymerase, was investigated. rpoB DNAs (342 bp) were amplified from 44 reference strains of mycobacteria and clinical isolates (107 strains) by PCR. The nucleotide sequences were directly determined (306 bp) and aligned by using the multiple alignment algorithm in the MegAlign package (DNASTAR) and the MEGA program. A phylogenetic tree was constructed by the neighbor-joining method. Comparative sequence analysis of rpoB DNAs provided the basis for species differentiation within the genus Mycobacterium. Slowly and rapidly growing groups of mycobacteria were clearly separated, and each mycobacterial species was differentiated as a distinct entity in the phylogenetic tree. Pathogenic Mycobacterium kansasii was easily differentiated from nonpathogenic M. gastri; this differentiation cannot be achieved by using 16S rRNA gene (rDNA) sequences. By being grouped into species-specific clusters with low-level sequence divergence among strains of the same species, all of the clinical isolates could be easily identified. These results suggest that comparative sequence analysis of amplified rpoB DNAs can be used efficiently to identify clinical isolates of mycobacteria in parallel with traditional culture methods and as a supplement to 16S rDNA gene analysis. Furthermore, in the case of M. tuberculosis, rifampin resistance can be simultaneously determined.