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1.
Med Princ Pract ; 30(4): 331-338, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33049736

RESUMO

OBJECTIVE: It is not known whether patients' ratings of the quality of healthcare services they receive truly correlate with the quality of care from their providers. Understanding this association can potentiate improvement in healthcare delivery. We evaluated the association between patients' ratings of the quality of healthcare services received and uptake of colorectal cancer (CRC) screening. SUBJECTS AND METHODS: We used 2 iterations of the Health Information National Trends Survey (HINTS) of adults in the USA. HINTS 2007 (4,007 respondents; weighted population = 75,397,128) evaluated whether respondents were up to date with CRC screening while HINTS 4 cycle 3 (1,562 respondents; weighted population = 76,628,000) evaluated whether participants had ever received CRC screening in the past. All included respondents from both surveys were at least 50 years of age, had no history of CRC, and had rated the quality of healthcare services that they had received at their healthcare provider's office in the previous 12 months. RESULTS: HINTS 2007 data showed that respondents who rated their healthcare as good or fair/poor were significantly less likely to be up to date with CRC screening compared to those who rated their healthcare as excellent. We found comparable results from analysis of HINTS 4 cycle 3 data with poorer uptake of CRC screening as the healthcare quality ratings of respondents reduced. CONCLUSION: Our study suggests that patients who reported receiving lower quality of healthcare services were less likely to have undergone and be compliant with CRC screening recommendations. It is important to pay close attention to patient feedback surveys in order to improve healthcare delivery.


Assuntos
Colonoscopia/estatística & dados numéricos , Neoplasias Colorretais/diagnóstico , Sangue Oculto , Qualidade da Assistência à Saúde , Idoso , Atenção à Saúde , Detecção Precoce de Câncer , Pesquisas sobre Atenção à Saúde , Humanos , Lactente , Pessoa de Meia-Idade , Percepção , Estados Unidos
2.
Digestion ; 92(2): 60-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26183208

RESUMO

BACKGROUND: It is unclear whether there is a shared pathway in the development of diverticular disease (DD) and potentially neoplastic colorectal lesions since both diseases are found in similar age groups and populations. AIM: To determine the association between DD and colorectal pre-neoplastic lesions in an African-American urban population. METHODS: Data from 1986 patients who underwent colonoscopy at the Howard University Hospital from January 2012 through December 2012 were analyzed for this study. The presence of diverticula and polyps was recorded using colonoscopy reports. Polyps were further classified into adenoma or hyperplastic polyp based on histopathology reports. Multiple logistic regression was done to analyze the association between DD and colonic lesions. RESULTS: Of the 1986 study subjects, 1,119 (56%) were females, 35% had DD and 56% had at least one polyp. There was a higher prevalence of polyps (70 vs. 49%; OR = 2.3; 95% CI: 1.9-2.8) and adenoma (43 vs. 25%; OR = 2.0; 95% CI: 1.7-2.5) in the diverticular vs. non-diverticula patients. Among patients who underwent screening colonoscopy, the presence of diverticulosis was associated with increased odds of associated polyps (OR = 9.9; 95% CI: 5.4-16.8) and adenoma (OR = 5.1; 95% CI: 3.4-7.8). CONCLUSION: Patients with DD are more likely to harbor colorectal lesions. These findings call for more vigilance on the part of endoscopists during colonoscopy in patients known to harbor colonic diverticula.


Assuntos
Adenoma/epidemiologia , Negro ou Afro-Americano/estatística & dados numéricos , Pólipos do Colo/epidemiologia , Diverticulose Cólica/epidemiologia , Lesões Pré-Cancerosas/epidemiologia , Saúde da População Urbana/estatística & dados numéricos , Adenoma/patologia , Idoso , Pólipos do Colo/patologia , Colonoscopia , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Análise Multivariada , Lesões Pré-Cancerosas/patologia , Prevalência , Estudos Retrospectivos , Estados Unidos/epidemiologia
3.
Dig Dis Sci ; 57(4): 905-12, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22350780

RESUMO

BACKGROUND: SEL1L gene product is implicated in the endoplasmic reticulum (ER)-associated protein degradation and Unfolded Protein Response pathways. This gene and associated miRNAs have been indicated as predictive and prognostic markers of pancreatic cancer. AIM: Explore the role of SEL1L in colorectal cancer (CRC) progression. METHODS: SEL1L expression was analysed immunohistochemically in 153 adenomas and 71 CRCs from African American and North Italian patients. The distribution of stained cells was determined by computing median and inter quartile range. The receiver operating characteristics plot was used as discriminate power of SEL1L expression, CRC diagnosis and the effects on patient survival. RESULTS: SEL1L was low in normal mucosa and confined to few scattered cells at the base crypt of the villi and in the foveolar glandular compartment. The highest levels were in Paneth cells within the lysosomes. The enterocytic progenitor cells and mature enterocytes showed less cytoplasmic staining. In CRCs, SEL1L expression significantly correlated with the progression from adenoma to carcinoma (P = 0.0001) being stronger in well-to-moderately differentiated cancers. No correlation was found with other clinicopathological characteristics or ethnicity. CONCLUSIONS: SEL1L expression is a potential CRC tissue biomarker since its expression is significantly higher in adenoma cells with respect to normal mucosa. The levels of expression decrease sensibly in undifferentiated CRC cancers. Interestingly, Paneth cells contain high levels of SEL1L protein that could indicate pre-neoplastic mucosa undergoing neoplastic transformation. Since SEL1L's major function lies within ER stress and active ERAD response, it may identify CRCs with differentiated secretory phenotype and acute cellular stress.


Assuntos
Biomarcadores Tumorais/metabolismo , Transformação Celular Neoplásica , Neoplasias Colorretais/diagnóstico , Proteínas/metabolismo , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adenoma/diagnóstico , Adenoma/metabolismo , Adenoma/patologia , Western Blotting , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Mucosa Intestinal/metabolismo , Masculino , Pessoa de Meia-Idade , Celulas de Paneth/metabolismo , Celulas de Paneth/patologia , Taxa de Sobrevida , Análise Serial de Tecidos , Resposta a Proteínas não Dobradas
4.
Clin Cancer Res ; 15(4): 1155-61, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19190129

RESUMO

PURPOSE: Colorectal cancer develops through genetic, epigenetic, and environmental events that result in uncontrolled cell proliferation. Colorectal cancer incidence and mortality is higher in African Americans (AA) than in the general population. Here, we carried out a molecular analysis of sporadic colorectal cancer tumors from AAs to investigate possible explanations for the observed disparities. EXPERIMENTAL DESIGN: A total of 222 AA colorectal cancer tumors were analyzed for microsatellite instability (MSI) for protein expression of two DNA mismatch repair genes, MLH1 and MSH2, by immunohistochemistry; for the methylation silencing of MLH1, p16, APC, and APC2 promoters by methylation-specific PCR; and for point mutations in two oncogenes, KRAS and BRAF, by sequencing. RESULTS: In our sample, 19.8% of the AAs colorectal cancer tumors were MSI high (MSI-H) and did not associate with any of the clinicopathologic features, except tumor differentiation. Higher levels of inactive DNA mismatch repair proteins MLH1 (41%) and MSH2 (33%) were found by immunohistochemistry. Methylation-specific PCR analysis revealed a high level of methylation for MLH1 (66%), APC (53%), and APC2 (90%), but not for p16 (26%). BRAF mutations were only within the MSI-H tumors, whereas most (64%) of KRAS mutations were found within the non-MSI-H group. CONCLUSIONS: MLH1, MSH2, and BRAF alterations are significantly associated with MSI-H phenotype, unlike APC, APC2 and KRAS alterations. The prominent role of DNA mismatch repair gene suppression in MSI-H and a distinctive role of BRAF and KRAS mutations with respect to MSI status are supported by this study.


Assuntos
Negro ou Afro-Americano/genética , Neoplasias Colorretais/genética , Instabilidade de Microssatélites , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Idoso , Neoplasias Colorretais/patologia , Metilação de DNA , Feminino , Genes APC , Genes p16 , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas p21(ras)
5.
Endosc Int Open ; 8(5): E617-E622, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32355879

RESUMO

Background and study aims Negative experiences with bowel preparation are a barrier to uptake of colonoscopy. The aim of this study was to examine the impact of different flavoring of polyethylene glycol (PEG) laxatives on patient satisfaction with and adequacy of bowel preparation during colonoscopy. Patients and methods This was a single-blind (endoscopist), parallel design, randomized trial (NCT02062112) during which patients scheduled for colonoscopy were assigned to one of three groups: Group 1 (no laxative flavoring, n = 84); Group 2 (flavored entire laxative, n = 90) and Group 3 (tasted PEG with and without flavoring and decided how they want to drink the rest of the laxatives (choice group), n = 82). Patients rated their bowel preparation experience (satisfaction) and endoscopists accessed adequacy of bowel preparation during colonoscopy. Results There were no differences in patient ratings across the groups (1, 2 and 3) in taste of the laxatives ( P  = 0.67), ease of drinking ( P  = 0.53), and overall experience of bowel preparation process ( P  = 0.18). However, higher percentage of patients in the choice group would want the same laxative again if they were going to have a repeat colonoscopy in the future (72.5 % vs 81.3 % vs 88.9 %, P  = 0.04). Surprisingly, adequacy of bowel preparation was highest among patients who drank their PEG unflavored (89.3 % vs 80 % vs 75.5 %, P  = 0.07) and the had highest rates of adenoma detection (40.5 % vs 23.3 vs 39.0, P  = 0.03). Conclusions There were no differences in overall tolerability of bowel preparation by patterns of flavoring of PEG. Those who drank unflavored PEG were less satisfied but had better clinical outcome, suggesting minimum justification effect in bowel preparation process.

6.
Dig Dis Sci ; 54(11): 2484-7, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19757049

RESUMO

BACKGROUND: Average-risk individuals should be offered a screening colonoscopy beginning at 50 years of age. However, there is no clear consensus on an age at which patients should no longer be offered a screening colonoscopy. The purpose of this study was to analyze the outcome of colonoscopy in elderly individuals based on the preprocedure indication. METHODS: A retrospective chart review was performed of all patients who underwent colonoscopy at Howard University Hospital from Jan 1, 2001 to Dec 31, 2005. Patients older than age 75 years were then stratified into two groups: one group classified as average risk for colon cancer and a second group classified as higher risk for finding cancer based on indication. Significant findings from colonoscopy were assigned if the patient was found to have an advanced adenoma, such as villous attributes, high-grade dysplasia, adenoma C1 cm, or cancer. All others findings at colonoscopy were categorized as having nonsignificant findings. RESULTS: During this period, 922 elderly patients (75 years of age or older) underwent colonoscopy. Based on preprocedure indications, 606 patients were considered higher risk and 316 average risk. Among the preprocedure higher-risk patients, 532 had nonsignificant findings include hemorrhoids, diverticulosis, telangiectasias, lipomas, and inflammatory polyps. Among the preprocedure average-risk patients, 286 had nonsignificant findings. From the 110 patients who underwent screening colonoscopy, 99 patients had nonsignificant findings. Malignancy was found in 42 patients: 33 who had higher-risk indications and 9 who had average-risk indications. CONCLUSION: Average-risk patients are less likely to have significant findings, including cancer, on colonoscopy.


Assuntos
Adenoma/diagnóstico , Neoplasias do Colo/diagnóstico , Colonoscopia , Adenoma/epidemiologia , Negro ou Afro-Americano , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Colo/epidemiologia , District of Columbia/epidemiologia , Feminino , Humanos , Masculino , Programas de Rastreamento , Estudos Retrospectivos
7.
Dig Dis Sci ; 54(10): 2109-17, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19057998

RESUMO

Chromatin remodeling and activation of transcription are important aspects of gene regulation, but these often go awry in disease progression, including during colon cancer development. We investigated the status of global histone acetylation (by measuring H3, H4 acetylation of lysine residues, which also occur over large regions of chromatin including coding regions and non-promoter sequences) and expression of histone deacetylase 2 (HDAC2) in colorectal cancer (CRC) tissue microarrays using immunohistochemical staining. Specifically, HDAC2 and the acetylation of histones H4K12 and H3K18 were evaluated in 134 colonic adenomas, 55 moderate to well differentiated carcinomas, and 4 poorly differentiated carcinomas compared to matched normal tissue. In addition, the correlation between expression of these epigenetic biomarkers and various clinicopathological factors including, age, location, and stage of the disease were analyzed. HDAC2 nuclear expression was detected at high levels in 81.9%, 62.1%, and 53.1% of CRC, adenomas, and normal tissue, respectively (P = 0.002). The corresponding nuclear global expression levels in moderate to well differentiated tumors for H4K12 and H3K18 acetylation were increased while these levels were decreased in poorly differentiated tumors (P = 0.02). HDAC2 expression was correlated significantly with progression of adenoma to carcinoma (P = 0.002), with a discriminative power of 0.74, when comparing cancer and non-cancer cases. These results suggest HDAC2 expression is significantly associated with CRC progression.


Assuntos
Adenoma/metabolismo , Carcinoma/metabolismo , Neoplasias do Colo/metabolismo , Histona Desacetilases/análise , Histonas/metabolismo , Acetilação , Adenoma/mortalidade , Adenoma/patologia , Biomarcadores Tumorais/análise , Carcinoma/mortalidade , Carcinoma/patologia , Neoplasias do Colo/mortalidade , Neoplasias do Colo/patologia , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Masculino , Análise em Microsséries , Pessoa de Meia-Idade
8.
Oncotarget ; 10(27): 2607-2624, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-31080553

RESUMO

BACKGROUND: Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the United States. African Americans are disproportionately affected by CRC. Our hypothesis is that driver genes with known and novel mutations have an impact on CRC outcome in this population. Therefore, we investigated the variants' profiles in a panel of 15 CRC genes. PATIENTS & METHODS: Colorectal specimens (n=140) were analyzed by targeted exome sequencing using an Ion Torrent platform. Detected variants were validated in 36 samples by Illumina sequencing. The novel status of the validated variants was determined by comparison to publicly available databases. Annotated using ANNOVAR and in-silico functional analysis of these variants were performed to determine likely pathogenic variants. RESULTS: Overall, 121 known and novel variants were validated: APC (27%), AMER1 (3%), ARID1 (7%), MSH3 (12%), MSH6 (10%), BRAF (4%), KRAS (6%), FBXW7 (4%), PIK3CA (6%), SMAD4 (5%), SOX9 (2%), TCF7L2 (2%), TGFBR2 (5%), TP53 (7%). From these validated variants, 12% were novel in 8 genes (AMER1, APC, ARID1A, BRAF, MSH6, PIK3CA, SMAD4, and TCF7L2). Of the validated variants, 23% were non-synonymous, 14% were stopgains, 24% were synonymous and 39% were intronic variants. CONCLUSION: We here report the specifics of variants' profiles of African Americans with colorectal lesions. Validated variants showed that Tumor Suppressor Genes (TSGs) APC and ARID1 and DNA Mismatch repair (MMR) genes MSH3 and MSH6 are the genes with the highest numbers of validated variants. Oncogenes KRAS and PIK3CA are also altered and likely participate in the increased proliferative potential of the mutated colonic epithelial cells in this population.

9.
Am J Surg Pathol ; 32(2): 275-81, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18223331

RESUMO

Only a few synovial sarcomas arising in the gastrointestinal tract have been reported, most of them are from the esophagus. We report clinical, histopathologic, and immunohistochemical features of 10 gastric synovial sarcomas. These tumors occurred in 4 males and 6 females with mean and median age of 52 years (range, 29 to 68 y). None of the patients had evidence of synovial sarcoma elsewhere. The tumor sizes ranged from 0.8 to 15 cm (mean, 3 cm). Two tumors were large transmural masses of 8 and 15 cm, and 8 were 0.8 to 6 cm, ulcerated cuplike or plaquelike or oval lesions predominantly involving the luminal side. Histologically, 9 tumors were monophasic one also having a poorly differentiated round cell component, and one was biphasic. Microscopic calcifications were present in 2 tumors. At least focal keratin (AE1/AE3 cocktail, keratin 7) and/or epithelial membrane antigen-positivity were detected in all tumors, and there was no CD34 or KIT-immunoreactivity. SYT-SSX fusion transcripts were demonstrated in 7 cases studied by a polymerase chain reaction-based fusion transcript assay. Five patients had a partial gastrectomy, and 5 underwent wedge or segmental resections. Two patients had received chemotherapy after surgery, but none had postoperative radiation. Four patients with plaquelike or cuplike tumors < or =3 cm were alive and well 1, 2, 2, and 18.5 years after surgery. Two patients died of tumor 25 and 29 months after surgery. One of them had a large 8-cm tumor, and another had a 2-cm tumor with a poorly differentiated component. Two patients were alive with recurrences 6 and 48 months after diagnosis. Synovial sarcoma rarely occurs as a gastric primary tumor. It has a variable prognosis depending on tumor size and differentiation, and should be considered in the differential diagnosis of KIT-negative gastric spindle cell neoplasms.


Assuntos
Sarcoma Sinovial/genética , Sarcoma Sinovial/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Adulto , Idoso , Biomarcadores Tumorais/genética , Terapia Combinada , DNA de Neoplasias , Feminino , Gastrectomia , Humanos , Masculino , Pessoa de Meia-Idade , Biologia Molecular , Recidiva Local de Neoplasia , Proteínas de Fusão Oncogênica/análise , Reação em Cadeia da Polimerase , Sarcoma Sinovial/terapia , Neoplasias Gástricas/terapia
10.
Helicobacter ; 13(6): 506-17, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19166416

RESUMO

BACKGROUND AND AIM: Our previous study of Helicobacter pylori-induced apoptosis showed the involvement of Bcl-2 family proteins and cytochrome c release from mitochondria. Here, we examine the release of other factors from mitochondria, such as apoptosis-inducing factor (AIF), and upstream events involving caspase-8 and Bid. METHODS: Human gastric adenocarcinoma (AGS) cells were incubated with a cagA-positive H. pylori strain for 0, 3, 6, and 24 hours and either total protein or cytoplasmic, nuclear, and mitochondrial membrane fractions were collected. RESULTS: Proteins were immunoblotted for AIF, Bid, polyadenosine ribose polymerase (PARP), caspase-8, and beta-catenin. H. pylori activated caspase-8, caused PARP cleavage, and attenuated mitochondrial membrane potential. A time-dependent decrease in beta-catenin protein expression was detected in cytoplasmic and nuclear extracts, coupled with a decrease in beta-actin. An increase in the cytoplasmic pool of AIF was seen as early as 3 hours after H. pylori exposure, and a concomitant increase was seen in nuclear AIF levels up to 6 hours. A band corresponding to full-length Bid was seen in both the cytoplasmic and the nuclear fractions of controls, but not after H. pylori exposure. Active AIF staining was markedly increased in gastric mucosa from infected persons, compared to uninfected controls. CONCLUSION: H. pylori might trigger apoptosis in AGS cells via interaction with death receptors in the plasma membrane, leading to the cleavage of procaspase-8, release of cytochrome c and AIF from mitochondria, and activation of subsequent downstream apoptotic events, as reported previously for chlorophyllin. This is consistent with AIF activation that was found in the gastric mucosa of humans infected with H. pylori. Hence, the balance between apoptosis and proliferation in these cells may be altered in response to injury caused by H. pylori infection, leading to an increased risk of cancer.


Assuntos
Fator de Indução de Apoptose/metabolismo , Apoptose , Células Epiteliais/microbiologia , Helicobacter pylori/fisiologia , Mitocôndrias/metabolismo , Fracionamento Celular , Linhagem Celular Tumoral , Membrana Celular/química , Citoplasma/química , Humanos , Immunoblotting , Membrana Nuclear/química
11.
World J Gastrointest Endosc ; 7(18): 1300-5, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26672497

RESUMO

AIM: To determine compliance to colorectal cancer (CRC) screening guidelines among persons with a family history of any type of cancer and investigate racial differences in screening compliance. METHODS: We used the 2007 Health Information National Trends Survey and identified 1094 (27.4%) respondents (weighted population size = 21959672) without a family history of cancer and 3138 (72.6%) respondents (weighted population size = 58201479) with a family history of cancer who were 50 years and older. We defined compliance with CRC screening as the use of fecal occult blood testing within 1 year, sigmoidoscopy within 5 years, or colonoscopy within 10 years. We compared compliance with CRC screening among those with and without a family member with a history of cancer. RESULTS: Overall, those with a family member with cancer were more likely to be compliant with CRC screening (64.9% vs 55.1%; OR = 1.45; 95%CI: 1.20-1.74). The absolute increase in screening rates associated with family history of cancer was 8.2% among whites. Hispanics had lowest screening rates among those without family history of cancer 41.9% but had highest absolute increase (14.7%) in CRC screening rate when they have a family member with cancer. Blacks had the lowest absolute increase in CRC screening (5.3%) when a family member has a known history of cancer. However, the noted increase in screening rates among blacks and Hispanics when they have a family member with cancer were not higher than whites without a family history of cancer: (54.5% vs 58.7%; OR = 1.16; 95%CI: 0.72-1.88) for blacks and (56.7% vs 58.7%; OR = 1.25; 95%CI: 0.72-2.18) for Hispanics. CONCLUSION: While adults with a family history of any cancer were more likely to be compliant with CRC screening guidelines irrespective of race/ethnicity, blacks and Hispanics with a family history of cancer were less likely to be compliant than whites without a family history. Increased burden from CRC among blacks may be related to poor uptake of screening among high-risk groups.

12.
Am J Physiol Gastrointest Liver Physiol ; 293(1): G19-24, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17395902

RESUMO

Telomeres are repetitive DNA sequences located at the ends of chromosomes. Telomeres are shortened by repeated cell divisions and by oxidative DNA damage, and cells with critically shortened telomeres cannot divide. We hypothesized that chronic gastroesophageal reflux disease (GERD)-induced injury of the esophageal squamous epithelium results in progressive telomeric shortening that eventually might interfere with mucosal healing. To address our hypothesis, we compared telomere length and telomerase activity in biopsy specimens of esophageal squamous epithelium from GERD patients and control patients. Endoscopic biopsies were taken from the esophageal squamous epithelium of 38 patients with GERD [10 long-segment Barrett's esophagus (LSBE), 15 short-segment (SSBE), 13 GERD without Barrett's esophagus] and 16 control patients without GERD. Telomere length was assessed using the terminal restriction fragment assay, and telomerase activity was studied by the PCR-based telomeric repeat amplification protocol assay. Patients with GERD had significantly shorter telomeres in the distal esophagus than controls [8.3 +/- 0.5 vs. 10.9 +/- 1.5 (SE) Kbp, P = 0.043]. Among the patients with GERD, telomere length in the distal esophagus did not differ significantly in those with and without Barrett's esophagus (LSBE 7.9 +/- 0.8, SSBE 8.6 +/- 0.9, GERD without BE 8.7 +/- 1.0 Kbp). No significant differences in telomerase activity in the distal esophagus were noted between patients with GERD and controls (4.0 +/- 0.39 vs. 5.2 +/- 0.53 RIUs). Telomeres in the squamous epithelium of the distal esophagus of patients who have GERD, with and without Barrett's esophagus, are significantly shorter than those of patients without GERD despite similar levels of telomerase activity.


Assuntos
Esôfago de Barrett/genética , Esôfago/ultraestrutura , Refluxo Gastroesofágico/genética , Telômero/ultraestrutura , Adulto , Idoso , Esôfago/enzimologia , Feminino , Fundo Gástrico/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa/fisiologia , Telomerase/metabolismo
13.
Am J Gastroenterol ; 102(10): 2135-46, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17617207

RESUMO

BACKGROUND: Helicobacter pylori infection of the gastric mucosa is strongly associated with gastritis, peptic ulcer disease, and gastric cancer. However, the mechanisms by which H. pylori causes cancer are currently unknown. Binding of epidermal growth factor (EGF) to its receptor (EGFR) may be important in the development of gastric cancer. This interaction accelerates cell proliferation and migration, and triggers epithelial cell signaling. In this study, we investigated the effects of H. pylori on EGFR- and AP-1-mediated signal transduction pathways in the AGS gastric epithelial cell line and gastric tissue from humans. METHODS: Cells were treated with H. pylori and cell death was examined at a variety of time points using cell viability and trypan blue exclusion dye assay. To investigate the effects on EGFR regulation, AGS cells were transfected with a full-length and truncated EGFR luciferase (luc) reporter. Tissue microarray containing 44 samples of gastric biopsies from H. pylori-positive patients was analyzed for protein expression level of EGFR by immunohistochemistry. RESULTS: EGFR promoter activity was increased (twofold) 3 h after treatment with H. pylori commenced. Using a series of EGFR promoter deletion mutants, we identified a region that was crucial for transactivation of the EGFR by H. pylori. To determine whether AP-1 binding was altered, we transfected AGS cells with an AP-1 luciferase construct and then treated them with H. pylori for up to 6 h. We found that AP-1 activity was induced by H. pylori in gastric cells, while electrophoretic mobility shift assays confirmed that binding of AP-1 to the EGFR promoter site was increased following H. pylori treatment. Binding of c-Jun and c-Fos to the EGFR promoter region -1,062/-900 was induced eight- and six fold, respectively, using ChIP assay. Active EGFR staining was markedly increased in gastric mucosa from infected persons, compared to uninfected controls. CONCLUSIONS: We conclude that exposure of gastric cells to H. pylori induces increased production of EGFR through various signal transduction pathways, including those mediated by the EGFR and AP-1. Distinct effects on EGFR activation may specify the subset of AP-1 target genes that are selected, including those involved in proliferation and apoptosis. This is consistent with EGFR activation that was found in the gastric mucosa of humans infected with H. pylori. Hence, the balance between apoptosis and proliferation in these cells may be altered in response to injury caused by H. pylori infection, leading to an increased risk of cancer.


Assuntos
Adenocarcinoma/metabolismo , Receptores ErbB/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori/fisiologia , Neoplasias Gástricas/metabolismo , Fator de Transcrição AP-1/metabolismo , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/fisiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/patologia , Humanos , Transdução de Sinais/fisiologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia
14.
J Immunol ; 174(8): 4688-95, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15814693

RESUMO

Inhibition of LIGHT (a cellular ligand for herpes virus entry mediator and lymphotoxin receptor)/herpes simplex virus entry mediator (HVEM) and LIGHT/lymphotoxin beta receptor (LT beta R) interactions decreases mortality in MHC class I and II disparate graft-vs-host disease (GVHD). The present studies assessed the effects of these interactions on the generation of CD4+ T cell alloresponses in MHC class II-disparate MLC and GVHD. An inhibitor protein of LIGHT and LT alpha beta2 (LT beta R-Ig) and an inhibitor protein of LIGHT (HVEM-Ig) caused similar decreases in alloresponses of control B6 or B6.129S1-IL12rb2(tm1Jm) (B6.IL12R-/-) spleen cells (SpC) in a MHC class II-disparate MLC. GVHD-induced wasting disease in MHC class II-disparate recipients of B6 CD4+ SpC who received either the LT beta R-Ig-encoding adenovirus (LT beta R-Ig Adv; 13.1 +/- 10.9%; n = 10; p = 0.0004) or the HVEM-Ig-encoding adenovirus (HVEM-Ig Adv; 16.4 +/- 9.9%; n = 13; p = 0.0008) was significantly reduced compared with that in recipients of a control adenovirus (30.4 +/- 8.8%; n = 13). Furthermore, gut GVHD histologic scores of recipients of B6 CD4+ SpC who received the LT beta R-Ig Adv (0.8 +/- 0.8; n = 5; p = 0.0007) or the HVEM-Ig Adv (1.4 +/- 0.5; n = 5; p = 0.008) were reduced compared with scores of recipients of a control adenovirus (2.5 +/- 0.75; n = 11). In the intestine, both LT beta R-Ig Adv and HVEM-Ig Adv decreased CD4+ T cells (0.35 +/- 0.4 x 10(6) (n = 6) vs 0.36 +/- 0.02 x 10(6) (n = 9); p = 0.03 and p = 0.007) compared with control adenovirus (0.86 +/- 0.42 x 10(6); n = 9). LIGHT is critical for optimal CD4+ T cell alloresponses in MHC class II-disparate MLC and GVHD.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Doença Enxerto-Hospedeiro/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Interferon gama/biossíntese , Proteínas de Membrana/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Sequência de Bases , Linfócitos T CD4-Positivos/citologia , Proliferação de Células , DNA Recombinante/genética , Feminino , Doença Enxerto-Hospedeiro/etiologia , Interleucina-12/metabolismo , Intestinos/imunologia , Isoantígenos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/imunologia , Membro 14 de Receptores do Fator de Necrose Tumoral , Receptores Virais/genética , Receptores Virais/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Transdução de Sinais , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral
15.
Am J Gastroenterol ; 100(3): 551-9, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15743351

RESUMO

OBJECTIVES: In some patients with gastroesophageal reflux disease (GERD), the reflux-damaged esophageal squamous epithelium heals through the process of intestinal metaplasia (resulting in Barrett's esophagus) rather than through the regeneration of more squamous cells. We hypothesized that squamous epithelium in Barrett's esophagus might have abnormalities in activation of the extracellular-regulated kinases 1 and 2 (ERK1/2) signaling pathway that may facilitate esophageal repair through metaplasia in response to acid-induced injury. METHODS: Endoscopic biopsies were taken from distal esophageal squamous mucosa in patients who had GERD with and without Barrett's esophagus and in controls, before and after esophageal perfusion with 0.1 N HCl acid. Basal ERK1/2 phosphorylation, acid-induced ERK1/2 activity and phosphorylation, and localization of phosphorylated ERK1/2 were determined using immunoblotting, Western blotting, and immunohistochemistry. RESULTS: Compared to patients with Barrett's esophagus, patients with GERD exhibited significantly lower baseline levels of phosphorylated ERK1/2 expression (35 +/- 4%vs 90 +/- 21% control, p= 0.01) Acid exposure significantly increased ERK1/2 activity (346.6 +/- 51.90 to 446.8 +/- 62.44 RIU, p= 0.02) and phosphorylation (3.55 +/- 1.26 to 4.49 +/- 1.25 [ratio phospho/total ERK], p= 0.01) in the squamous mucosa of GERD patients, but not in those with Barrett's esophagus or in controls. CONCLUSIONS: Between patients with Barrett's esophagus and patients with uncomplicated GERD, there are significant differences in baseline levels and in acid-induced activation of ERK1/2 in esophageal squamous epithelium. To our knowledge, this is the first description of a molecular, phenotypic feature that distinguishes the esophageal squamous mucosa of GERD patients with and without Barrett's esophagus.


Assuntos
Esôfago de Barrett/enzimologia , Refluxo Gastroesofágico/enzimologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Adulto , Idoso , Esôfago de Barrett/complicações , Biópsia , Western Blotting , Ativação Enzimática , Feminino , Humanos , Immunoblotting , Imuno-Histoquímica , Masculino , Metaplasia , Pessoa de Meia-Idade , Mucosa/enzimologia , Fosforilação , Transdução de Sinais/fisiologia , Distribuição Tecidual
16.
J Immunol ; 170(10): 5082-8, 2003 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-12734353

RESUMO

Inhibition of TNF/TNFR2 interactions ameliorates intestinal graft-vs-host disease (GVHD) and Th1 cytokine responses induced by transfer of B6 CD4(+) spleen cells into irradiated MHC class II disparate B6.C-H-2(bm12) (bm12) x B6 F(1) recipients. The present studies examined whether these effects of TNF are IL-12 dependent. T cell proliferative responses of B6.129S1-IL-12rb2(tm1Jm) (B6.IL-12R(-/-)) responder spleen cells were found to be comparable to those of control B6 spleen cells. TNF inhibition reduced T cell proliferation and IFN-gamma production in supernatants of MLC using either B6.IL-12R(-/-) or control B6 responder cells. GVHD induced wasting disease in recipients of B6.IL-12R(-/-) CD4(+) spleen cells that received a TNF inhibitor-encoding adenovirus (5.4 +/- 6.5% weight loss (n = 7)) was significantly reduced compared with levels of weight loss observed in recipients that had received a control adenovirus (25.7 +/- 12.2% weight loss (n = 11), p = 0.001). Furthermore, TNF inhibition was associated with a reduction in colonic GVHD scores (p = 0.039) and in the percentage of the splenic CD4(+) T cells that expressed IFN-gamma (16 vs 6%). These findings indicate that TNF promotes CD4(+) T cell alloproliferation, IFN-gamma responses, and intestinal GVHD by IL-12-independent mechanisms.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Doenças do Colo/imunologia , Doença Enxerto-Hospedeiro/imunologia , Interferon gama/biossíntese , Interleucina-12/fisiologia , Fator de Necrose Tumoral alfa/fisiologia , Animais , Transplante de Medula Óssea/imunologia , Transplante de Medula Óssea/patologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/transplante , Células Cultivadas , Doenças do Colo/genética , Doenças do Colo/patologia , Doenças do Colo/prevenção & controle , Regulação para Baixo/genética , Regulação para Baixo/imunologia , Feminino , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/patologia , Doença Enxerto-Hospedeiro/prevenção & controle , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/farmacologia , Interferon gama/antagonistas & inibidores , Interleucina-18/biossíntese , Ativação Linfocitária/genética , Teste de Cultura Mista de Linfócitos/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Receptores de Interleucina/deficiência , Receptores de Interleucina/genética , Receptores de Interleucina/fisiologia , Receptores de Interleucina-12 , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/fisiologia , Proteínas Recombinantes de Fusão/farmacologia , Baço/citologia , Baço/imunologia , Baço/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores
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