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1.
Malays J Pathol ; 45(2): 195-204, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37658529

RESUMO

INTRODUCTION: Extracellular vesicles (exosome-like vesicles) are small membrane vesicles ranging from 20-200nm in size that are released by various cells into the extracellular space. These extracellular vesicles play a major role in cell-to-cell communication and contain materials, such as proteins, mRNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). The effect of exosomes derived from an invasive colon cancer cell line on angiogenesis is unclear. Hence, the aim of this study is to investigate the effect of exosomes derived from an invasive colon cancer cell line on angiogenesis of endothelial cells. MATERIALS AND METHODS: In the present study, the exosomes from the cell culture supernatants of an invasive colon cancer cell line SW480-7 were characterised. The effect on tube formation and expression of angiogenic genes in a microvascular endothelial cell, telomerase-immortalised microvascular endothelial cell (TIME) was examined after co-cultured with exosomes secreted from SW480-7. RESULTS: Zetasizer result showed average diameter of exosomes derived from SW480-7 was 246.2 nm and morphological analysis showed the size of majority of exosomes were less than 200 nm. Results showed that exosomes derived from SW480-7 increased tube formation and up-regulated FGFR3 mRNA expression in TIME. CONCLUSION: Our findings suggest that exosomes derived from SW480-7 increased tube formation and up-regulated expression of FGFR3 mRNA in TIME.

2.
Malays J Pathol ; 44(2): 187-201, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36043582

RESUMO

BACKGROUND: Worldwide, diabetic kidney disease (DKD) remains the leading cause of chronic kidney disease (CKD) and its successor, the end stage renal disease, both of which constitute major morbidity and mortality concerns. CONTENT: The residual risk of disease progression remains despite the advert of newer therapeutic modalities and current biomarkers. Meanwhile, microRNAs (miRNAs) are small non-coding RNAs, which regulate gene expression post-translationally by binding to specific mRNAs. Circulating miRNAs are increasingly recognised as novel biomarker or therapeutic targets, owing to their unique characteristics, such as their resilience to degradation by endogenous RNases, multiple downstream targets, involvement in biological processes, some degree of tissue specificity, relatively easy access and quantification. Unlike proteins, there are far less miRNAs and mature miRNAs are highly stable, structurally less complex without post-translational modification with high degree of conservation across species. Aberrant expression of miRNAs has been established in both in vitro and in vivo models of DKD. An up-to-date compilation of previous studies involving selected circulating miRNAs in blood and urine samples of DKD patients is discussed herein. SUMMARY: This review highlights the unmet clinical challenges and dysregulation of miRNAs in the pathogenesis of DKD.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , MicroRNAs , Insuficiência Renal Crônica , Biomarcadores , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Progressão da Doença , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo
3.
Malays J Pathol ; 44(1): 67-74, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35484888

RESUMO

INTRODUCTION: Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cancer in Malaysia. Despite advanced therapies, many cases of recurrence and resistance have been reported. Aberrant DNA methylation of HER3 has been implicated in carcinogenesis of CRC mainly through the regulation of gene expression. Hence, the objective of this study was to determine the status of HER3 DNA methylation and its effects on gene expression in CRC. MATERIALS AND METHODS: Fifty-nine of archival formalin-fixed, paraffin-embedded CRC cases with the adjacent normal colon tissues were retrieved. Manual micro-dissection was performed prior to RNA and DNA extraction. HER3 gene expression and DNA methylation status was evaluated by qPCR and methylation-specific PCR (MSP) techniques respectively. RESULTS: Upregulation of HER3 mRNA was found in CRC tissue compared to its adjacent normal colon tissue (8.04-fold). Of 59 CRC samples, 8.5% were methylated and 91.5% were unmethylated (hypomethylation). In the adjacent normal colon tissues, methylated and unmethylated tissue were observed in 6.8%and 93.2% respectively. DNA methylation of HER3 showed a significant association with tumour differentiation and tumour location. CONCLUSION: This study showed upregulation and hypomethylation of the HER3 gene in CRC cases. Epigenetic alterations were also found in the adjacent normal colon tissues. Thus, upregulation and hypomethylation of HER3 may play a key role in carcinogenesis of CRC. Hypomethylation of CpG islands might be associated with early steps during carcinogenesis. The findings of this biomarker serve a powerful approach to improve the current diagnostic and therapeutic measures.


Assuntos
Adenocarcinoma , Neoplasias Colorretais , Adenocarcinoma/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinogênese , Neoplasias Colorretais/patologia , Metilação de DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Humanos
4.
Curr Oncol ; 23(Suppl 1): S42-51, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26985145

RESUMO

BACKGROUND: Research has demonstrated that increases in palliative homecare nursing are associated with a reduction in the rate of subsequent hospitalizations. However, little evidence is available about the cost-savings potential of palliative nursing when accounting for both increased nursing costs and potentially reduced hospital costs. METHODS: Our retrospective cohort study included cancer decedents from British Columbia, Ontario, and Nova Scotia who received any palliative nursing in the last 6 months of life. A Poisson regression analysis was used to determine the association of increased nursing costs (in 2-week blocks) on the relative average hospital costs in the subsequent 2-week block and on the overall total cost (hospital costs plus nursing costs in the preceding 2-week block). RESULTS: The cohort included 58,022 cancer decedents. Results of the analysis for the last month of life showed an association between increased nursing costs and decreased relative hospital costs in comparisons with a reference group (>0 to 1 hour nursing in the block): the maximum decrease was 55% for Ontario, 31% for British Columbia, and 38% for Nova Scotia. Also, increased nursing costs in the last month were almost always associated with lower total costs in comparison with the reference. For example, cost savings per person-block ranged from $376 (>10 nursing hours) to $1,124 (>4 to 6 nursing hours) in British Columbia. CONCLUSIONS: In the last month of life, increased palliative nursing costs (compared with costs for >0 to 1 hour of nursing in the block) were associated with lower relative hospital costs and a lower total cost in a subsequent block. Our research suggests a cost-savings potential associated with increased community-based palliative nursing.

5.
J Appl Microbiol ; 118(5): 1180-90, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25688886

RESUMO

AIMS: This study investigates the antagonistic effects of the probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 against vulvovaginal candidiasis (VVC)-causing Candida glabrata. METHODS AND RESULTS: Growth inhibitory activities of Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains against C. glabrata were demonstrated using a spot overlay assay and a plate-based microtitre assay. In addition, these probiotic lactobacilli strains also exhibited potent candidacidal activity against C. glabrata, as demonstrated by a LIVE/DEAD yeast viability assay performed using confocal laser scanning microscopy. The metabolic activities of all C. glabrata strains were completely shut down in response to the challenges by the probiotic lactobacilli strains. In addition, both probiotic lactobacilli strains exhibited strong autoaggregation and coaggregation phenotypes in the presence of C. glabrata, which indicate that these lactobacilli strains may exert their probiotic effects through the formation of aggregates and, thus the consequent prevention of colonization by C. glabrata. CONCLUSIONS: Probiotic Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains exhibited potent antagonistic activities against all of the tested C. glabrata strains. These lactobacilli exhibited antifungal effects, including those attributed to their aggregation abilities, and their presence caused the cessation of growth and eventual cell death of C. glabrata. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to report on the antagonistic effects of these probiotic lactobacilli strains against the non-Candida albicans Candida (NCAC) species C. glabrata.


Assuntos
Antibiose , Candida glabrata/crescimento & desenvolvimento , Candidíase Vulvovaginal/microbiologia , Lacticaseibacillus rhamnosus/fisiologia , Limosilactobacillus reuteri/fisiologia , Probióticos/administração & dosagem , Candida glabrata/efeitos dos fármacos , Feminino , Humanos
6.
Support Care Cancer ; 23(10): 3025-32, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25711657

RESUMO

BACKGROUND: In 2007, the provincial cancer agency in Ontario, Canada initiated a wide-scale program to screen for symptoms in the cancer population using the Edmonton Symptom Assessment Scale (ESAS). The purpose of this study is to evaluate the impact of screening with ESAS on emergency department (ED) visit rates in women with breast cancer receiving adjuvant chemotherapy. PATIENTS AND METHODS: This retrospective cohort study used linked administrative health care data from across the province of Ontario, Canada. The cohort included all women aged ≥18 who were diagnosed with stage I-III breast cancer between January 2007 and December 2009 and received adjuvant chemotherapy within 6 months of diagnosis. Using an adjusted recurrent event model, we examined the association of screening with ESAS at a clinic visit on the ED visit rate. RESULTS: The relative rate of ED visits was 0.57 when prior ESAS screening occurred compared to when it did not. The relative rate of ED visits was 0.83 when the prior number of ESAS screens was modeled as a continuous variable. Alternatively stated, the rate of ED visits was 43 % lower among patients previously screened with ESAS compared to those not previously screened. For each additional prior ESAS assessment, there was a 17 % decreased rate of ED visits. CONCLUSIONS: Our results demonstrate that screening with ESAS is associated with decreased ED visits. To our knowledge, this is the first report on the effectiveness of routinely documenting a patient reported outcome on ED visits, in a real-world setting.


Assuntos
Assistência Ambulatorial/tendências , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Adjuvante , Estudos de Coortes , Detecção Precoce de Câncer , Serviço Hospitalar de Emergência , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Avaliação de Sintomas , Adulto Jovem
7.
Curr Oncol ; 22(5): 341-55, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26628867

RESUMO

BACKGROUND: The quality of data comparing care at the end of life (eol) in cancer patients across Canada is poor. This project used identical cohorts and definitions to evaluate quality indicators for eol care in British Columbia, Alberta, Ontario, and Nova Scotia. METHODS: This retrospective cohort study of cancer decedents during fiscal years 2004-2009 used administrative health care data to examine health service quality indicators commonly used and previously identified as important to quality eol care: emergency department use, hospitalizations, intensive care unit admissions, chemotherapy, physician house calls, and home care visits near the eol, as well as death in hospital. Crude and standardized rates were calculated. In each province, two separate multivariable logistic regression models examined factors associated with receiving aggressive or supportive care. RESULTS: Overall, among the identified 200,285 cancer patients who died of their disease, 54% died in a hospital, with British Columbia having the lowest standardized rate of such deaths (50.2%). Emergency department use at eol ranged from 30.7% in Nova Scotia to 47.9% in Ontario. Of all patients, 8.7% received aggressive care (similar across all provinces), and 46.3% received supportive care (range: 41.2% in Nova Scotia to 61.8% in British Columbia). Lower neighbourhood income was consistently associated with a decreased likelihood of supportive care receipt. INTERPRETATION: We successfully used administrative health care data from four Canadian provinces to create identical cohorts with commonly defined indicators. This work is an important step toward maturing the field of eol care in Canada. Future work in this arena would be facilitated by national-level data-sharing arrangements.

8.
Clin Oncol (R Coll Radiol) ; 35(2): e182-e188, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36535850

RESUMO

AIMS: To assess the risk of cardiac toxicity following radical radiotherapy in advanced lung cancer patients. MATERIALS AND METHODS: Patients with a diagnosis of stage III non-small cell lung cancer (NSCLC) receiving chemoradiotherapy were extracted from a population-based cohort in Ontario, Canada. The primary outcome of cardiac toxicity, defined as cardiac events or congestive heart failure, was assessed at 1 and 5 years following chemoradiotherapy. Secondary outcomes included overall survival, survival in relationship to post-treatment cardiac events and the effect of radiotherapy technique on cardiac toxicity. RESULTS: In total, 2031 NSCLC patients were included. The cumulative incidence of cardiac toxicity at 5 years was 20.3% (18.4-22.3). The median survival was 13.7 months in NSCLC patients who had a cardiac event post-chemoradiotherapy compared with 23.4 months in those who did not (P = 0.012). There was a trend towards increased cumulative cardiac toxicity (hazard ratio 3.37, P = 0.14) with three-dimensional conformal radiotherapy compared with intensity-modulated or volumetric arc radiotherapy techniques. CONCLUSION: The risk of cardiac events and congestive heart failure 5 years after radical thoracic radiotherapy appears high and survival is inferior at 1 year in those patients who experience a cardiac event post-treatment. More conformal radiotherapy techniques may help reduce cardiac toxicity. Further studies should investigate adaptive treatment planning and close monitoring and intervention in this high-risk group after chemoradiotherapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Insuficiência Cardíaca , Neoplasias Pulmonares , Radioterapia de Intensidade Modulada , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Estudos de Coortes , Cardiotoxicidade/etiologia , Radioterapia de Intensidade Modulada/métodos , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Morbidade , Insuficiência Cardíaca/etiologia , Ontário/epidemiologia , Estudos Retrospectivos , Estadiamento de Neoplasias
9.
Eur J Clin Microbiol Infect Dis ; 31(1): 21-31, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21544694

RESUMO

The ubiquitous Candida spp. is an opportunistic fungal pathogen which, despite treatment with antifungal drugs, can cause fatal bloodstream infections (BSIs) in immunocompromised and immunodeficient persons. Thus far, several major C. albicans virulence factors have been relatively well studied, including morphology switching and secreted degradative enzymes. However, the exact mechanism of Candida pathogenesis and the host response to invasion are still not well elucidated. The relatively recent discovery of the quorum-sensing molecule farnesol and the existence of quorum sensing as a basic regulatory phenomenon of the C. albicans population behavior has revolutionized Candida research. Through population density regulation, the quorum-sensing mechanism also controls the cellular morphology of a C. albicans population in response to environmental factors, thereby, effectively placing morphology switching downstream of quorum sensing. Thus, the quorum-sensing phenomenon has been hailed as the 'missing piece' of the pathogenicity puzzle. Here, we review what is known about Candida spp. as the etiological agents of invasive candidiasis and address our current understanding of the quorum-sensing phenomenon in relation to virulence in the host.


Assuntos
Candida/patogenicidade , Candidíase Invasiva/microbiologia , Percepção de Quorum , Animais , Biofilmes , Candida/citologia , Candida/enzimologia , Candida/fisiologia , Farneseno Álcool/metabolismo , Humanos , Fatores de Virulência/metabolismo
10.
Med J Malaysia ; 65(3): 209-14, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21939170

RESUMO

We have previously shown that mesenchymal stem cells (MSC) inhibit tumour cell proliferation, thus promising a novel therapy for treating cancers. In this study, MSC were generated from human bone marrow samples and characterised based on standard immunophenotyping. When MSC were co-cultured with BV173 and Jurkat tumour cells, the proliferation of tumour cells were profoundly inhibited in a dose dependent manner mainly via cell to cell contact interaction. Further cell cycle analysis reveals that MSC arrest tumour cell proliferation in G0/G1 phase of cell cycle thus preventing the entry of tumour cells into S phase of cell cycle.


Assuntos
Ciclo Celular , Proliferação de Células , Células-Tronco Mesenquimais/fisiologia , Humanos , Imunofenotipagem , Células Jurkat/citologia , Células-Tronco Mesenquimais/metabolismo
11.
Curr Oncol ; 27(1): e1-e8, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32218662

RESUMO

Background: Pancreatic cancer (pcc) is one of the most lethal types of cancer, and surgery remains the optimal treatment modality for patients with resectable tumours. The objective of the present study was to examine and compare trends in the survival rate based on treatment modality in patients with pcc. Methods: This population-based retrospective analysis included all patients with known-stage pcc in Ontario between 2007 and 2015. Flexible parametric models were used to conduct the survival analysis. Survival rates were calculated based on treatment modality, while adjusting for patient- and tumour-specific covariates. Results: The study included 6437 patients. We found no noticeable improvement in survival for patients with stage iii or iv tumours; however, for stage i disease, the 1-, 2-, and 5-year survival rates increased over time to 81% from 51%, to 71% from 35%, and to 61% from 22% respectively. Most improvements were seen for surgical modalities, with 2-year survivals increasing to 89% from 65% for distal pancreatectomy (dp) without radiation (rt) or chemotherapy (ctx), to 65% from 37% for dp plus rt or ctx, to 60% from 44% for Whipple-only, and to 50% from 36% for Whipple plus rt or ctx. Lastly, 5-year survival improved to 81% from 52% for dp only, to 41% from 12% for dp plus rt or ctx, to 49% from 25% for Whipple-only, and to 26% from 12% for Whipple plus rt or ctx. Conclusions: Most cases of pcc continue to be diagnosed at a late stage, with poor short-term and long-term prognoses. After adjustment for patient age, sex, and year of diagnosis, the survival for stage i tumours and for surgical modalities increased over time. Further research is needed to identify the reasons for improvement in survival during the study period.


Assuntos
Neoplasias Pancreáticas/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Estudos Retrospectivos , Análise de Sobrevida , Neoplasias Pancreáticas
12.
Clin Exp Immunol ; 155(3): 412-22, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19220831

RESUMO

The pathological significance of the mechanisms of tumour immune-evasion and/or immunosuppression, such as loss of T cell signalling and increase in regulatory T cells (T(regs)), has not been well established in the nasopharyngeal carcinoma (NPC) microenvironment. To evaluate the T(reg) immunophenotypes in tumour-infiltrating lymphocytes (TILs), we performed a double-enzymatic immunostaining for detection of forkhead box P3 (FoxP3) and other markers including CD4, CD8, and CD25 on 64 NPC and 36 non-malignant nasopharyngeal (NP) paraffin-embedded tissues. Expression of CD3 zeta and CD3 epsilon was also determined. The prevalence of CD4(+)FoxP3(+) cells in CD4(+) T cells and the ratio of FoxP3(+)/CD8(+) were increased significantly in NPC compared with those in NP tissues (P < 0.001 and P = 0.025 respectively). Moreover, the ratio of FoxP3(+)/CD25(+)FoxP3(-) in NPC was significantly lower than that in NP tissues (P = 0.005), suggesting an imbalance favouring activated phenotype of T cells in NPC. A significant negative correlation between the abundance of FoxP3(+) and CD25(+)FoxP3(-) cells (P < 0.001) was also identified. When histological types of NPC were considered, a lower ratio of FoxP3(+)/CD25(+)FoxP3(-) was found in non-keratinizing and undifferentiated carcinomas. Increased CD4(+)FoxP3(+)/CD4(+) proportion and FoxP3(+)/CD8(+) ratio were associated with keratinizing squamous cell carcinoma. A reduced expression of CD3 zeta in TILs was found in 20.6% of the NPC tissues but none of the NP tissues. These data provide evidence for the imbalances of T(reg) and effector T cell phenotypes and down-regulation of signal-transducing molecules in TILs, supporting their role in suppression of immune response and immune evasion of NPC.


Assuntos
Carcinoma/imunologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias Nasofaríngeas/imunologia , Linfócitos T Reguladores/imunologia , Biomarcadores/análise , Complexo CD3/análise , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/imunologia , Feminino , Fatores de Transcrição Forkhead/análise , Humanos , Imuno-Histoquímica , Subunidade alfa de Receptor de Interleucina-2/análise , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Nasofaringe/imunologia , Estatísticas não Paramétricas
13.
Sci Rep ; 9(1): 15053, 2019 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-31636311

RESUMO

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease largely caused by cigarette smoking (CS) and is characterized by lung inflammation and airflow limitation that is not fully reversible. Approximately 50% of people with COPD die of a cardiovascular comorbidity and current pharmacological strategies provide little benefit. Therefore, drugs that target the lung and the cardiovascular system concurrently may be an advantageous therapeutic strategy. The aim of this study was to see whether losartan, an angiotensin-II AT1a receptor antagonist widely used to treat hypertension associated with cardiovascular disease, protects against CS-induced lung inflammation in mice. Male BALB/c mice were exposed to CS for 8 weeks and treated with either losartan (30 mg/kg) or vehicle daily. Mice were euthanized and bronchoalveolar lavage fluid (BALF) inflammation, and whole lung cytokine, chemokine and protease mRNA expression assessed. CS caused significant increases in BALF total cells, macrophages, neutrophils and whole lung IL-6, TNF-α, CXCL-1, IL-17A and MMP12 mRNA expression compared to sham-exposed mice. However, losartan only reduced CS-induced increases in IL-6 mRNA expression. Angiotensin-II receptor expression was reduced in lung tissue from CS-exposed mice. In conclusion, losartan did not inhibit CS-induced BALF cellularity despite reducing whole lung IL-6 mRNA and Ang-II receptor expression.


Assuntos
Fumar Cigarros/efeitos adversos , Losartan/farmacologia , Pneumonia/etiologia , Animais , Líquido da Lavagem Broncoalveolar , Quimiocinas/genética , Quimiocinas/metabolismo , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Camundongos Endogâmicos BALB C , Tamanho do Órgão/efeitos dos fármacos , Pneumonia/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
14.
Med J Malaysia ; 63 Suppl A: 77-8, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19024992

RESUMO

The immune modulatory properties of mesenchymal stem cell (MSC) had brought a new insight in cell-based neotherapy. However, recent works of MSC are focused exclusively on bone marrow-derived MSC. We evaluated the immunogenicity of cord blood-derived MSC (CB-MSC) on T lymphocytes. Human peripheral blood mononuclear cells (PBMC) were prepared by density gradient separation and culture with the presence or absence of CB-MSC. PBMC were collected for activation analysis by flow cytometry at 24-, 48-, and 72- hours. The results showed that, CB-MSC does not stimulate nor inhibit T lymphocyte activation.


Assuntos
Medula Óssea/imunologia , Sangue Fetal/imunologia , Imunogenética , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/imunologia , Transplante de Células-Tronco de Sangue Periférico , Linfócitos T/citologia , Antígenos CD , Antígenos de Diferenciação de Linfócitos T , Técnicas de Cultura de Células , Citometria de Fluxo , Humanos , Subunidade alfa de Receptor de Interleucina-2 , Lectinas Tipo C
15.
Cancer Res ; 61(21): 7770-6, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11691791

RESUMO

The clinical utility of antineoplastic agents is limited by the development of drug resistance by tumors. Mitomycin C (MC) is a bacterial product that must be enzymatically reduced to exert anticancer activity. We have demonstrated that expression of the bacterial MC resistance-associated (MCRA) protein in Chinese hamster ovary (CHO) cells confers profound resistance to this antibiotic under aerobic conditions, but not under hypoxia. MCRA produces resistance to MC by redox cycling of the activated hydroquinone intermediate back to the prodrug form. A CHO cell line developed by stepwise exposure to increasing concentrations of MC likewise expressed high level resistance to MC in air, but not under hypoxia. The overexpression of DT-diaphorase and NADPH:cytochrome c (P-450) reductase, two enzymes known to activate MC, restored sensitivity to MC in both MCRA-transfected and drug-selected cell lines. The level of sensitization was proportional to the quantity of enzyme activity expressed, supporting the concept that the levels of these two activating enzymes are important for sensitivity to MC. The findings of resistance to MC in air but not under hypoxic conditions and of restoration of sensitivity to MC by increasing levels of DT-diaphorase activity, properties not adequately explained by other resistance mechanisms (i.e., decreases in MC activation, repair of DNA lesions, and/or drug efflux), support the hypothesis that a functional mammalian homologue of MCRA may be involved in producing resistance to MC.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Mitomicina/farmacologia , NAD(P)H Desidrogenase (Quinona)/biossíntese , NADPH-Ferri-Hemoproteína Redutase/biossíntese , Oxirredutases , Animais , Antibióticos Antineoplásicos/farmacocinética , Proteínas de Bactérias/genética , Biotransformação , Células CHO/efeitos dos fármacos , Células CHO/enzimologia , Hipóxia Celular/fisiologia , Cricetinae , Resistencia a Medicamentos Antineoplásicos , Mitomicina/farmacocinética , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , NADPH-Ferri-Hemoproteína Redutase/genética , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Oxigênio/metabolismo , Transfecção
16.
Sci Rep ; 6: 20983, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26877172

RESUMO

Influenza A virus (IAV) infections are a common cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Oxidative stress is increased in COPD, IAV-induced lung inflammation and AECOPD. Therefore, we investigated whether targeting oxidative stress with the Nox2 oxidase inhibitors and ROS scavengers, apocynin and ebselen could ameliorate lung inflammation in a mouse model of AECOPD. Male BALB/c mice were exposed to cigarette smoke (CS) generated from 9 cigarettes per day for 4 days. On day 5, mice were infected with 1 × 10(4.5) PFUs of the IAV Mem71 (H3N1). BALF inflammation, viral titers, superoxide production and whole lung cytokine, chemokine and protease mRNA expression were assessed 3 and 7 days post infection. IAV infection resulted in a greater increase in BALF inflammation in mice that had been exposed to CS compared to non-smoking mice. This increase in BALF inflammation in CS-exposed mice caused by IAV infection was associated with elevated gene expression of pro-inflammatory cytokines, chemokines and proteases, compared to CS alone mice. Apocynin and ebselen significantly reduced the exacerbated BALF inflammation and pro-inflammatory cytokine, chemokine and protease expression caused by IAV infection in CS mice. Targeting oxidative stress using apocynin and ebselen reduces IAV-induced lung inflammation in CS-exposed mice and may be therapeutically exploited to alleviate AECOPD.


Assuntos
Acetofenonas/administração & dosagem , Azóis/administração & dosagem , Compostos Organosselênicos/administração & dosagem , Pneumonia/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Animais , Modelos Animais de Doenças , Humanos , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza A/patogenicidade , Isoindóis , Masculino , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Pneumonia/patologia , Pneumonia/virologia , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/virologia , Fumaça/efeitos adversos , Fumar/efeitos adversos , Nicotiana/efeitos adversos
17.
Biochim Biophys Acta ; 1010(2): 160-5, 1989 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-2643438

RESUMO

Previous experiments have shown that cultured human fibroblasts possess a cell-surface proteinase (the growth-related proteinase; GRP) which is essential to cell proliferation. In the present work, proteinase inhibition in defined and complex serum-free media and in pre-conditioned normal medium, still resulted in a corresponding inhibition of cell proliferation. Proteinase inhibition also blocked the action of a range of peptide growth factors and of a phorbol ester. Elevated extracellular calcium concentrations were still mitogenic in the presence of proteinase inhibitors. Proteinase inhibition did not affect the mobilisation of intracellular calcium, nor the metabolism of inositol phosphate derivatives in response to a mitogenic stimulus.


Assuntos
Fibroblastos/citologia , Peptídeo Hidrolases/metabolismo , Cálcio/metabolismo , Divisão Celular/efeitos dos fármacos , Membrana Celular/enzimologia , Células Cultivadas , Meios de Cultura , Fibroblastos/efeitos dos fármacos , Fibroblastos/enzimologia , Substâncias de Crescimento/farmacologia , Humanos , Fosfatos de Inositol/metabolismo , Cinética , alfa 1-Antitripsina/farmacologia
18.
Sci Transl Med ; 7(269): 269ra3, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25568071

RESUMO

New chemotherapeutic agents are urgently required to combat the global spread of multidrug-resistant tuberculosis (MDR-TB). The mycobacterial enoyl reductase InhA is one of the few clinically validated targets in tuberculosis drug discovery. We report the identification of a new class of direct InhA inhibitors, the 4-hydroxy-2-pyridones, using phenotypic high-throughput whole-cell screening. This class of orally active compounds showed potent bactericidal activity against common isoniazid-resistant TB clinical isolates. Biophysical studies revealed that 4-hydroxy-2-pyridones bound specifically to InhA in an NADH (reduced form of nicotinamide adenine dinucleotide)-dependent manner and blocked the enoyl substrate-binding pocket. The lead compound NITD-916 directly blocked InhA in a dose-dependent manner and showed in vivo efficacy in acute and established mouse models of Mycobacterium tuberculosis infection. Collectively, our structural and biochemical data open up new avenues for rational structure-guided optimization of the 4-hydroxy-2-pyridone class of compounds for the treatment of MDR-TB.


Assuntos
Antituberculosos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , Oxirredutases/antagonistas & inibidores , Animais , Antituberculosos/química , Proteínas de Bactérias/metabolismo , Fenômenos Biofísicos/efeitos dos fármacos , Cristalografia por Raios X , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Inibidores Enzimáticos/química , Camundongos Endogâmicos BALB C , Modelos Moleculares , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Oxirredutases/metabolismo , Piridinas/química , Piridinas/farmacologia , Reprodutibilidade dos Testes , Análise de Sequência de DNA , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia
19.
Gene ; 176(1-2): 273-4, 1996 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-8918267

RESUMO

The nucleotide (nt) sequence encoding the bovine homologue of interleukin-5 (boIL-5) was determined. Total cDNA generated from stimulated bovine peripheral blood lymphocytes was used to amplify the boIL-5 gene using primers based on the 5' and 3' untranslated regions of the ovine IL-5 cDNA sequence. The boIL-5 coding sequence is 405 bp long, coding for a 15.2 kDa precursor protein of 134 amino acids (aa). Cleavage of a putative signal peptide of 19 aa yields a mature form of 13.1 kDa. Comparisons at the nt level revealed 96%, 81%, 74% and 73% identity with the ovine, human, mouse and rat IL-5 sequences, respectively, and 97%, 66%, 59% and 58% aa identity, respectively.


Assuntos
Interleucina-5/genética , Análise de Sequência de DNA , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , DNA Complementar , Humanos , Dados de Sequência Molecular
20.
Gene ; 124(2): 291-3, 1993 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-8444353

RESUMO

We have cloned a cDNA containing the complete coding sequence of ovine(ov) interleukin 4 (IL4) by the polymerase chain reaction using primers based on the 5' and 3' untranslated regions of the human IL4 gene. RNA was isolated from phorbol myristate acetate- and calcium ionphore A23187-stimulated mesenteric lymph node cells. The ovIL4 cDNA is 535 bp in length and contains an open reading frame of 408 nucleotides (nt) coding for a 15.1-kDa IL4 precursor of 135 amino acids (aa). Cleavage of the putative signal peptide of 22 aa yields the mature form of 13.2 kDa. Analysis of the mature aa sequence shows two potential N-linked glycosylation sites and six Cys residues. Ovine and bovine IL4 are shorter than human, mouse and rat IL4, because of a 51-nt deletion in the coding region. Comparison of the predicted aa sequence shows that ovIL4 shares 92, 57, 37 and 42% identity with the bovine, human, mouse and rat IL4s, respectively.


Assuntos
Interleucina-4/genética , Ovinos/genética , Animais , Sequência de Bases , Clonagem Molecular , DNA , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
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