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1.
BMC Nurs ; 20(1): 91, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34098937

RESUMO

BACKGROUND: The conventional written tests and professional assessment have limitation in fair judgement of clinical competence. Because the examiners may not have total objectivity and may lack standardization throughout the assessment process. We sought to design a valid method of competence assessment in medical and nursing specialties. This work was aimed to develop an Objective Structured Clinical Exam (OSCE) to evaluate novice nursing practitioners' clinical competency, work stress, professional confidence, and career satisfaction. METHODS: A Quasi-experimental study (pre-post). Fifty-five novice nursing practitioners received the OSCE three-months following their graduation, which consisted of four stations: history taking, physical examination, problem-directed management, interpersonal communication, and the required techniques of related procedures. The examiners had to complete an assessment checklist, and the participants had to complete a pre-post questionnaire (modified from a Nursing Competency Questionnaire, a Stress scale, and Satisfaction with Learning scale). RESULTS: Among the novice nursing practitioners, 41 of them (74.5 %) passed the exam with a mean score of 61.38 ± 8.34. There was a significantly higher passing rate among nurses who were working in medical-surgical wards (85.7 %) and the intensive care unit-emergency department (77.8 %) compared to novice nursing practitioners working in other units. All the novice nursing practitioners at Station A had poor performance in assessing patients with a fever. OSCE performance was more associated with educational attainment and work unit, rather than the gender. Finally, the participants showed statistically significant increases in their clinical competency, confidence in their professional competence, satisfaction with the clinical practice, and decreased work stress after the OSCE. CONCLUSIONS: We found that the OSCE process had a positive educational effect, in providing a meaningful and accurate assessment of the competence of novice nursing practitioners. An appropriate OSCE program is vital for novice nursing practitioners, educators, and administrators. The effective application of OSCEs can help novice nursing practitioners gain confidence in their clinical skills.

2.
Commun Biol ; 4(1): 595, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34011962

RESUMO

CD28 is required for T cell activation as well as the generation of CD4+Foxp3+ Treg. It is unclear, however, how CD28 costimulation affects the development of CD8+ T cell suppressive function. Here, by use of Hepa1.6.gp33 in vitro killing assay and B16.gp33 tumor mouse model we demonstrate that CD28 engagement during TCR ligation prevents CD8+ T cells from becoming suppressive. Interestingly, our results showed that ectonucleotidase CD73 expression on CD8+ T cells is upregulated in the absence of CD28 costimulation. In both murine and human tumor-bearing hosts, CD73 is upregulated on CD28-CD8+ T cells that infiltrate the solid tumor. UPLC-MS/MS analysis revealed that CD8+ T cells activation without CD28 costimulation produces elevated levels of adenosine and that CD73 mediates its production. Adenosine receptor antagonists block CD73-mediated suppression. Our data support the notion that CD28 costimulation inhibits CD73 upregulation and thereby prevents CD8+ T cells from becoming suppressive. This study uncovers a previously unidentified role for CD28 costimulation in CD8+ T cell activation and suggests that the CD28 costimulatory pathway can be a potential target for cancer immunotherapy.


Assuntos
5'-Nucleotidase/metabolismo , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/imunologia , Ativação Linfocitária/imunologia , Melanoma Experimental/imunologia , 5'-Nucleotidase/genética , Animais , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
3.
Artigo em Inglês | MEDLINE | ID: mdl-32079613

RESUMO

OBJECTIVE: Metabolic syndrome (MetS) gains more attention due to high prevalence of obesity, diabetes and hypertension among adults. Although obesity, diabetes and hypertension can certainly compromise health-related quality of life (HRQoL), the correlations of sociodemographic factors, quality of life and MetS remains unclear. This study aims to investigate the association between HRQoL and MetS in an Asian community of the sociodemographic characteristics. RESEARCH DESIGN AND METHODS: We performed a cross-sectional study by recruiting 2588 Taiwanese patients aged ≥30 years between August 2015 and August 2017. Sociodemographic data and anthropometric variables were obtained from medical records and physical examination. Meanwhile, HRQoL was assessed by 36-Item Short-Form Health Survey questionnaires. RESULTS: The overall prevalence of MetS was 32.8%. Multivariate analysis revealed that age ≥65 years (OR=1.987, p<0.001), body mass index (BMI) ≥24 kg/m2 (OR=7.958, p<0.001), low educational level (OR=1.429, p=0.014), bad self-perceived health status (OR=1.315, p=0.01), and betel nut usage (OR=1.457, p=0.048) were associated with the development of MetS. For patients with MetS, the physical and mental health domains of HRQoL are negatively correlated with abdominal obesity and hypertension, respectively. CONCLUSIONS: Adult MetS in Taiwan was associated with certain sociodemographic factors including older age, high BMI, low educational level, bad self-perceived health status, and betel nut use. Abdominal obesity and hypertension was correlated with HRQoL in patients with MetS.


Assuntos
Hipertensão/epidemiologia , Síndrome Metabólica/epidemiologia , Obesidade Abdominal/epidemiologia , Qualidade de Vida , Adulto , Idoso , Areca/efeitos adversos , Índice de Massa Corporal , Comorbidade , Estudos Transversais , Feminino , Nível de Saúde , Inquéritos Epidemiológicos , Humanos , Masculino , Saúde Mental , Síndrome Metabólica/etiologia , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Taiwan/epidemiologia
4.
Asia Pac J Public Health ; 31(1): 30-38, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30525917

RESUMO

Differences in sociodemographic variables, health beliefs, and a healthy lifestyle all contribute to the varied prevalence of metabolic syndrome (MetS). We investigated the associations among MetS-related risk factors and performed a cross-sectional study, recruiting 1741 Taiwanese residents aged ≥30 years, between August 2014 and August 2015. Data were obtained on sociodemographic factors, health beliefs, and health-promoting lifestyle profiles using questionnaires. Multivariate analysis revealed that age ≥65 years (odds ratio [OR] = 2.17), low educational level (OR = 1.46), body mass index ≥24 kg/m2 (OR = 9.00), more health responsibility (OR = 1.08), and less exercise (OR = 0.924) were independent risk factors for MetS development. A correlation existed between health beliefs and health-promoting lifestyle profiles, suggesting that the establishment of an effective health-promoting program should consider participants' health beliefs.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Estilo de Vida Saudável , Síndrome Metabólica/epidemiologia , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e Questionários , Taiwan/epidemiologia
5.
PLoS One ; 9(11): e109961, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25390652

RESUMO

Emerging evidences have shown that diabetes mellitus not only raises risk but also heightens mortality rate of cancer. It is not clear, however, whether antitumor CD8+ cytotoxic T lymphocyte (CTL) response is down-modulated in diabetic hosts. We investigated the impact of hyperglycemia on CTLs' acquisition of tumor-killing capability by utilizing streptozotocin-induced diabetic (STZ-diabetic) mice. Murine diabetes was induced by intraperitoneal injection of STZ (200 mg/kg) in C57BL/6 mice, 2C-T cell receptor (TCR) transgenic and P14-TCR transgenic mice. The study found that, despite harboring intact proliferative capacity measured with CFSE labeling and MTT assay, STZ-diabetic CD8+ CTLs displayed impaired effector functions. After stimulation, STZ-diabetic CD8+ CTLs produced less perforin and TNFα assessed by intracellular staining, as well as expressed less CD103 protein. Furthermore, adoptive transfer of STZ-diabetic P14 CD8+ effector cells showed an insufficient recruitment to the B16.gp33 melanoma and inadequate production of perforin, granzyme B and TNFα determined by immunohistochemistry in the tumor milieu. As a result, STZ-diabetic CD8+ effector cells were neither able to eliminate tumor nor to improve survival of tumor-bearing mice. Taken together, our data suggest that CD8+ CTLs are crippled to infiltrate into tumors and thus fail to acquire tumor-killing capability in STZ-diabetic hosts.


Assuntos
Linfócitos T CD8-Positivos/citologia , Diabetes Mellitus Experimental/imunologia , Linfócitos do Interstício Tumoral/citologia , Linfócitos T Citotóxicos/citologia , Transferência Adotiva , Animais , Antígenos CD/metabolismo , Diferenciação Celular , Proliferação de Células , Citocinas/metabolismo , Hiperglicemia/imunologia , Cadeias alfa de Integrinas/metabolismo , Masculino , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/metabolismo , Estreptozocina/química
6.
BMJ Open ; 3(10): e003989, 2013 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-24176798

RESUMO

OBJECTIVE: Highly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions. DESIGN: Cross-sectional design. SETTING: Hospital-based and community-based screening settings. PARTICIPANTS: A hospital-based deviation cohort of 3172 participants to evaluate test performance and a community-based validation cohort of 3621 to verify the findings. INTERVENTIONS: Three types of stool tests with bidirectional endoscopy as the reference standard. OUTCOMES: Sensitivity, specificity and positive and negative likelihood ratios. RESULTS: For detecting upper gastrointestinal lesions in cases with negative immunochemical tests, the sensitivity, specificity, and positive and negative likelihood ratios of the guaiac-based and H pylori antigen tests were 16.3% (95% CI 13.3% to 19.8%), 90.1% (88.9% to 91.2%), 1.64 (1.31 to 2.07), and 0.93 (0.89 to 0.97), respectively, and 52.5% (48.1% to 56.9%), 80.6% (79.0% to 82.1%), 2.71 (2.41 to 3.04) and 0.59 (0.54 to 0.65), respectively. For detecting upper gastrointestinal lesions in cases with normal colonoscopy, the results of the guaiac-based and H pylori antigen tests were 17.9% (14.8% to 21.5%), 90.1% (88.9% to 91.2%), 1.81 (1.45 to 2.26) and 0.91 (0.87 to 0.95), respectively, and 53.1% (48.6% to 57.4%), 80.7% (79.1% to 82.2%), 2.75 (2.45 to 3.08) and 0.58 (0.53 to 0.64), respectively. Within the community, positive predictive values of the immunochemical and H pylori antigen tests were 36.0% (26.0% to 46.0%) and 31.9% (28.3% to 35.5%), respectively, for detecting lower and upper gastrointestinal lesions, which were similar to expected values. CONCLUSIONS: The H pylori stool antigen test is more accurate than the guaiac-based test in the screening of upper gastrointestinal lesions in a population with high prevalence of H pylori infection and upper gastrointestinal lesions. It is applicable to add the H pylori antigen test to the immunochemical test for pan detection. TRIAL REGISTRATION: NCT01341197 (ClinicalTrial.gov).

7.
PLoS One ; 4(11): e7766, 2009 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-19901991

RESUMO

Stimulating naïve CD8+ T cells with specific antigens and costimulatory signals is insufficient to induce optimal clonal expansion and effector functions. In this study, we show that the activation and differentiation of CD8+ T cells require IL-2 provided by activated CD4+ T cells at the initial priming stage within 0-2.5 hours after stimulation. This critical IL-2 signal from CD4+ cells is mediated through the IL-2Rbetagamma of CD8+ cells, which is independent of IL-2Ralpha. The activation of IL-2 signaling advances the restriction point of the cell cycle, and thereby expedites the entry of antigen-stimulated CD8+ T-cell into the S phase. Besides promoting cell proliferation, IL-2 stimulation increases the amount of IFNgamma and granzyme B produced by CD8+ T cells. Furthermore, IL-2 at priming enhances the ability of P14 effector cells generated by antigen activation to eradicate B16.gp33 tumors in vivo. Therefore, our studies demonstrate that a full CD8+ T-cell response is elicited by a critical temporal function of IL-2 released from CD4+ T cells, providing mechanistic insights into the regulation of CD8+ T cell activation and differentiation.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Interleucina-2/metabolismo , Animais , Colorimetria/métodos , Interferon gama/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Fase S , Transdução de Sinais , Baço/citologia , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia , Fatores de Tempo
8.
J Formos Med Assoc ; 108(1): 53-60, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19181608

RESUMO

BACKGROUND/PURPOSE: Although evidence suggests that gastroesophageal reflux disease (GERD) may interrupt sleep, the effects of symptomatic and endoscopically diagnosed GERD remain elusive because the patient population is heterogeneous. Accordingly, we designed a cross-sectional study to assess their association. METHODS: Consecutive participants in a routine health examination were enrolled. Definition and severity of erosive esophagitis were assessed using the Los Angeles classification system. Demographic data, reflux symptoms, sleep quality and duration, exercise amount, alcohol consumption, and smoking habits were recorded. Factors affecting sleep quality and sleep duration were revealed by a polytomous logistic regression analysis. RESULTS: A total of 3663 participants were recruited. Subjects with reflux symptoms, female gender, higher body mass index, and regular use of hypnotics had poorer sleep quality. Exercise was associated with better sleep quality. Either symptomatically or endoscopically, GERD did not disturb sleep duration. Among the 3158 asymptomatic patients, those with erosive esophagitis were more likely to have poor sleep quality. The risk increased with the severity of erosive changes (p = 0.03). CONCLUSION: The present study highlights the adverse effect of gastroesophageal reflux on sleep, even in the absence of reflux symptoms. This finding has therapeutic implications in patients with silent erosive disease, and future trials are warranted.


Assuntos
Esofagite/classificação , Transtornos do Sono-Vigília/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , China/epidemiologia , Estudos Transversais , Esofagite/complicações , Esofagite/patologia , Esofagoscopia/efeitos adversos , Feminino , Refluxo Gastroesofágico/complicações , Refluxo Gastroesofágico/epidemiologia , Refluxo Gastroesofágico/patologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Polissonografia/efeitos adversos , Fatores de Risco , Transtornos do Sono-Vigília/fisiopatologia , Inquéritos e Questionários , Resultado do Tratamento
9.
Proteomics Clin Appl ; 2(4): 619-34, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21136859

RESUMO

Helicobacter pylori was reported to be an important risk factor for the carcinogenesis of gastric cancer. Here, we used a proteomic approach to find differentially expressed proteins between the normal and tumor tissue of gastric cancer patients infected with H. pylori. In our results, we found annexin A4 was over-expressed in patients infected with H. pylori and was found in tumor cells, and over-expressed in gastric cancer SCM-1 cells after H. pylori infection. Ca(2+ ) can be induced by H. pylori and interact with annexin A4 Ca(2+) binding site to block the calmodulin-activated chloride conductance activation; therefore, it produces a new environment that benefits the malignant existence of H. pylori and raises the risk for gastric cancer. We also found interleuken-8 (IL-8) expression levels were increased in H. pylori infected SCM-1 cells. Combined with previous reports and our results, we summarize that the over-expression of annexin A4 in SCM-1 cells with H. pylori infection may subsequently induce IL-8 which can further cause tumor angiogenesis. In this paper, we show that annexin A4 is a potential novel molecular marker for gastric cancer with H. pylori infection, and our results may provide a new insight in the development of new anti-cancer drugs.

10.
Helicobacter ; 11(5): 451-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16961808

RESUMO

BACKGROUND: Increasing evidence has shown that Helicobacter pylori CagA protein translocation into gastric epithelial cells plays an important role in the development of gastric inflammation and malignancy. Translocated CagA undergoes tyrosine phosphorylation in gastric adenocarcinoma cell line cells, and CagA involves disruption of cellular apical-junction complex in Madin-Darby canine kidney cells. METHODS: To elucidate whether these events take place in normal human gastric epithelium, we infected human primary gastric epithelial cells with H. pylori. RESULTS: Our results demonstrate that CagA protein was translocated into primary gastric epithelial cells and tyrosine phosphorylated. The translocated CagA induces cytoskeletal rearrangement and the disruption of tight junctions in primary gastric epithelial cells. CONCLUSIONS: This study provides direct evidence of the modulation of gastric epithelial cells by CagA protein translocation, and advances our understanding of the pathogenesis of H. pylori infection.


Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Células Epiteliais/microbiologia , Mucosa Gástrica/microbiologia , Helicobacter pylori/metabolismo , Células 3T3 , Animais , Linhagem Celular Tumoral , Células Cultivadas , Cães , Infecções por Helicobacter/microbiologia , Humanos , Camundongos , Fosforilação , Transporte Proteico , Junções Íntimas/metabolismo
11.
J Gastroenterol Hepatol ; 21(10): 1575-80, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16928219

RESUMO

BACKGROUND: Factors determining post-colonoscopy abdominal pain remain poorly understood. Accordingly, a prospective study was conducted to reveal the key determinants. METHODS: One thousand consecutive and asymptomatic patients (569 men, 431 women; mean age 51 years, range 19-84 years) undergoing total colonoscopy were evaluated to assess their abdominal pain. Their demographic data, psychological profiles (determined on the Brief Symptom Rating Scale and Maudsley Personality Inventory), and endoscopic findings were treated as independent variables in polytomous logistic regression in which pain severities were treated as outcome variables. Factors affecting the duration of pain were evaluated on multivariate linear regression. RESULTS: Colonoscopy duration (s; odds ratio [OR]: 1.001, 95% confidence interval [CI]: 1-1.002, P<0.01) and female sex (OR: 1.368, 95%CI: 1.02-1.853, P=0.03) were significantly associated with abdominal pain, but age, body mass index, psychological traits, conscious sedation, use of i.v. hyoscine butylbromide, and colonic preparation were not. Duration of the colonoscopy was longer in female than male subjects (P=0.04). On stepwise linear regression, irritable bowel syndrome (regression coefficient: 27.47, 95%CI: 6.99-47.67, P<0.01) and conscious sedation (regression coefficient: -22.17, 95%CI: -42.52 to -1.42, P = 0.036) were the best predictors of prolonged pain in 485 patients who had pain. CONCLUSIONS: Female sex and duration of colonoscopy increased the likelihood of post-procedural abdominal pain. Conscious sedation temporarily suppressed the pain but had no effect on its occurrence. Irritable bowel syndrome may have prolonged the discomfort.


Assuntos
Dor Abdominal/diagnóstico , Colonoscopia/efeitos adversos , Neoplasias Colorretais/diagnóstico , Programas de Rastreamento/métodos , Dor Abdominal/epidemiologia , Dor Abdominal/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Razão de Chances , Medição da Dor , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários
12.
J Gastroenterol Hepatol ; 21(5): 798-804, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16704526

RESUMO

BACKGROUND: Associations between psychological and endoscopic profiles are not clearly validated among the heterogeneous patients with gastroesophageal reflux disease (GERD). The purpose of the present paper was therefore to identify any associations by means of cross-sectional study. METHODS: Consecutive participants in a health screening program were enrolled. Definition and severity of erosive esophagitis were assessed with Los Angeles classification. Frequency and severity of psychological symptoms were measured with a 30-item Brief Symptom Rating Scale (BSRS) and personality traits with a short form of the Maudsley Personality Inventory (MPI). Statistic analyses were performed based on the presence of GERD symptoms or endoscopic esophagitis. RESULTS: A total of 4600 participants were recruited. There were 1331 subjects (29%) with manifestations suggesting GERD, including non-erosive reflux disease (NERD) in 488 (10.6%), symptomatic erosive esophagitis (SEE) in 164 (3.6%), and asymptomatic erosive esophagitis (AEE) in 679 (14.8%). The BSRS parameters were significantly higher in symptomatic subjects (i.e. NERD and SEE subjects; P < 0.001); neuroticism scores were also higher (P < 0.001), but extroversion scores (P < 0.001) were lower than those of asymptomatic subjects. Following logistic regression analysis, independent risk factors for GERD symptoms were female gender (odds ratio [OR]: 1.596; 95% confidence interval [CI]: 1.303-1.955) and higher neuroticism scores (OR: 1.046; 95%CI: 1.032-1.06). For erosive esophagitis, independent risk factors were male gender (OR: 2.943; 95%CI: 2.359-3.671) and higher body mass index scores (OR: 1.098; 95%CI: 1.069-1.127). CONCLUSIONS: Psychological characteristics predict likelihood of GERD symptoms but not structural state of esophagus. Male gender and obesity are risk factors for erosive esophagitis; whereas female gender and neuroticism are more likely to be associated with GERD symptoms.


Assuntos
Endoscopia Gastrointestinal , Refluxo Gastroesofágico/patologia , Refluxo Gastroesofágico/psicologia , Programas de Rastreamento , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
13.
Gastrointest Endosc ; 61(4): 547-53, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15812407

RESUMO

BACKGROUND: The goal of this study was to determine the frequency of colorectal neoplasia in an asymptomatic Taiwanese population and the topographic distribution of lesions relative to age and gender. METHODS: Colonoscopy was performed in 1846 consecutive asymptomatic adults undergoing a health evaluation in 2003. Neoplastic lesions were considered advanced if they exceeded 10 mm in size, had a villous component, or contained moderately or severely dysplastic tissue or invasive cancer. Lesions at and proximal to the splenic flexure were considered proximal in location; those distal to the splenic flexure were classified as distal in location. RESULTS: Of 1741 (94.3%) patients (1041 men, 700 women; mean 52.5 years) enrolled, 1708 (98.1%) underwent total colonoscopy. Of these patients, 263 (15.4%) had colorectal neoplasia; 51 (3.0%) had advanced lesions. A total of 331 lesions were detected; 125 (37.8%) were proximal in location. Two thirds of patients with proximal advanced lesions (66.7%, 10/15) had no distal lesion. The proportion of patients with proximal or proximal plus distal lesions increased with age ( p = 0.027). CONCLUSIONS: Colonoscopy is an effective primary screening modality for colorectal neoplasia in asymptomatic Chinese patients. Many lesions would be missed, especially in the elderly, if only sigmoidoscopy was used for initial screening.


Assuntos
Neoplasias do Colo/epidemiologia , Neoplasias do Colo/patologia , Neoplasias Retais/epidemiologia , Neoplasias Retais/patologia , Adulto , Distribuição por Idade , Idoso , Colonoscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Prospectivos , Distribuição por Sexo , Taiwan/epidemiologia
14.
Helicobacter ; 8(3): 235-43, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12752736

RESUMO

BACKGROUND: Tyrosine phosphorylation of Helicobacter pylori cytotoxin-associated protein of in gastric epithelial cells is reported. The goals of this study are first to examine the occurrence of CagA tyrosine phosphorylation in H. pylori strains isolated from patients with gastric adenocarcinoma and gastritis, and second to clarify the relationship between the diversity of tyrosine phosphorylation motifs and the presence of CagA tyrosine phosphorylation. METHODS: Fifty-eight clinical isolates of H. pylori from patients with gastric adenocarcinoma (29 cases) and gastritis (29 cases) were studied for CagA tyrosine phosphorylation by Western blotting. Sequence diversity of tyrosine phosphorylation motifs was analysed among positive- or negative-CagA tyrosine phosphorylation isolates. RESULTS: Positive CagA tyrosine phosphorylation was found in 93.1% (27 of 29) of strains from gastric adenocarcinoma patients and 51.7% (15 of 29) of strains from gastritis patients (p < 0.001). Intact motifs were found in H. pylori isolates with CagA tyrosine phosphorylation. Of the 16 negative CagA tyrosine phosphorylation isolates, intact tyrosine phosphorylation motifs were found in 15 isolates. CONCLUSIONS: CagA tyrosine phosphorylation, which is significantly greater in strains from gastric adenocarcinoma patients, may play a role in gastric carcinogenesis, and could be a better marker of more virulent strains than the cag pathogenicity island in Asia, where the cag pathogenicity island is present in nearly all H. pylori strains. Sequence diversity of tyrosine phosphorylation motifs on CagA was not related to the presence of tyrosine phosphorylation. The absence of tyrosine phosphorylation motif might result in negative tyrosine phosphorylation phenotypes, but such motifs are not the sole factors associated with CagA tyrosine phosphorylation.


Assuntos
Adenocarcinoma/metabolismo , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/microbiologia , Sequência de Aminoácidos , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Células Cultivadas , DNA Bacteriano/genética , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Variação Genética , Infecções por Helicobacter/complicações , Helicobacter pylori/genética , Humanos , Dados de Sequência Molecular , Fosforilação , Estômago/citologia , Neoplasias Gástricas/microbiologia , Tirosina/metabolismo
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