HIV Knowledge, Risk Behaviors, and Testing Among Chinese-, Korean-, and Vietnamese-American Women.

The relationship between HIV knowledge and testing behavior is poorly understood among young Chinese-, Korean-, and Vietnamese-American women. This study assesses: (1) levels of HIV/AIDS knowledge, (2) lifetime and annual prevalence of HIV testing, and (3) whether higher levels of HIV knowledge were associated with increased likelihood of testing after controlling for HIV risk behaviors. Fifty-one percent reported lifetime HIV testing (n=117); among those tested, 53% were tested within the past year. A significant and positive association between scores on the HIV Knowledge Questionnaire (HIV KQ-45) and HIV testing was identified. This association was no longer statistically significant after controlling for sexual risk behaviors. Participants were most knowledgeable about HIV symptoms (88.6%) and least knowledgeable about treatment options (56.8%). Future studies should further characterize cultural factors affecting these women's sexual practices, as well develop culturally adapted HIV educational interventions to increase HIV knowledge and testing rates.

Morbidity and mortality in Danio rerio and Pimephales promelas exposed to antilipidemic drug mixtures (fibrates and statins) during embryogenesis: Comprehensive assessment via ante and post mortem endpoints.

Antilipidemic drugs are routinely detected in effluent and surface waters downstream of wastewater treatment plants. A mixture exposure study with nine environmentally relevant antilipidemic drugs was performed with zebrafish (Danio rerio, ZF) and fathead minnow (Pimephales promelas, FHM) embryos to investigate the effects on sensitive embryologic stages. Zebrafish embryos were exposed nominally to: (a) 0.005 µM, (b) 0.05 µM, or (c) 0.5 µM of each drug in the mixture. Fathead minnow embryos were exposed nominally to: (a) 0.0005 µM, (b) 0.005 µM, or (c) 0.05 µM of each drug in the mixture. Several of the individual drug concentrations were within ranges previously found in the environment. Multiple metrics demonstrate that (a) exposure of ZF and FHM embryos to antilipidemic drugs during embryonic development results in lethal and sublethal effects, (b) ZF were more sensitive than FHM based on median lethal concentration (LC50 0.02 µM and 0.05 µM, respectively), but FHM exhibited more severe abnormal sublethal morphologies than zebrafish embryos, and (c) the sublethal effects differed between the two species. This model identified novel specific endpoints for assessing sensitive, sublethal effects of pharmaceuticals in the environment. Abnormal myofiber birefringence pattern, hemorrhage, and heart rate are not included in standard evaluations but each of these metrics demonstrated a dose-dependent response in this study. Results demonstrate risk to fish development with potential repercussions at the population level, especially if environmental concentrations increase.

I have heard about it for the first time from you! Implementation of tobacco control law by police personnel in India.

Setting and Objetives: Police personnel, alongside other key stakeholders, are responsible for implementing the Cigarettes and Other Tobacco Products Act (COTPA) in India. This study aimed to assess knowledge and attitudes about COTPA among police personnel and explore enablers and barriers in implementing it. Design: This convergent parallel mixed-methods study used a self-administered questionnaire (quantitative) and key informant interviews (qualitative). Of 300 police personnel across all eight police stations in Daman, 155 participated. Quantitative data were analysed using descriptive statistics and the χ2 test. Qualitative data from in-depth interviews of six key informants from all coordinating departments were analysed thematically. Results: Overall, 63.2% of responders were aware of any tobacco control law in India, and only 12.9% were trained in its implementation. One person had conducted inspections for COTPA compliance in the last 12 months. The majority (78.1%) of the police personnel, and significantly more tobacco non-users than users (81.2% vs. 52.9%, P = 0.016), felt that enforcing anti-tobacco regulations is one of their most important functions. Perceived benefits of the act and formal authority to act were the two main enablers of COTPA implementation. Lack of awareness and coordination, competing priorities, concentration of authority with higher-ranking officials and evasion of the law by retailers and the public hampered effective implementation of the law. Conclusion: Knowledge about the COTPA was average and implementation poor. Sensitisation and training of implementers, systematic transparent reporting and creating awareness among public are recommended for effective implementation.

Contexte et objectifs : Le personnel de la police, en collaboration avec d'autres partenaires clés, est responsable de la mise en œuvre de la Loi cigarettes et autres produits dérivés du tabac (COTPA) en Inde. Cette étude a eu pour but d'évaluer les connaissances et l'attitude au sein du personnel de la police en ce qui concerne la COTPA et a exploré les facilitateurs et les entraves à sa mise en œuvre.Schéma : Cette étude convergente parallèle à méthodes mixtes s'est basée sur un questionnaire auto-administré (méthode quantitative) et sur des entretiens avec des informateurs clés (méthode qualitative). Sur 300 personnels de police dans les huit stations de police de Daman, 155 ont participé. Les données quantitatives ont été analysées grâce à des statistiques descriptives et au test du χ2. Les données qualitatives émanant des entretiens approfondis avec six informateurs clés de tous les services de coordination ont été analysées de manière thématique.Résultats : Au total, 63,2% des participants étaient au courant de l'existence d'une loi de lutte contre le tabac en Inde, et seulement 12,9% ont été formés à sa mise en œuvre. Un seul avait réalisé des inspections relatives au respect de la COTPA au cours des 12 derniers mois. La majorité (78,1%) du personnel de police, et significativement plus de non-utilisateurs que d' utilisateurs de tabac (81,2% contre 52,9%, P = 0,016), estimaient que mettre en œuvre la loi anti-tabac était l'une de leurs fonctions importantes. Les bénéfices perçus de cette loi et le pouvoir officiel ont été les deux principaux facilitateurs de la mise en œuvre de la COTPA. Le manque de sensibilisation et de coordination, les priorités concurrentes, la concentration de l'autorité au sein des supérieurs et l'évasion de la loi par les revendeurs et le public a entravé une véritable mise en œuvre de la loi.Conclusion : La connaissance de la loi a été moyenne et sa mise en œuvre médiocre. La sensibilisation et la formation des responsables de la mise en œuvre, des rapports systématiques transparents et la sensibilisation du public sont recommandés pour une mise en œuvre efficace.

Marco de Referencia y Objetivos: El personal policial, junto con otros interesados directos, tienen a su cargo la ejecución de la COPTA (del inglés, Cigarettes and Other Tobacco Products Act, por ley sobre el consumo de cigarrillos y otros productos del tabaco) en la India. En el presente estudio se evaluaron los conocimientos y las actitudes de los miembros de la policía con respecto a la COPTA y se exploraron los factores facilitadores y los obstáculos a su aplicación.Método: Fue este un estudio de métodos mixtos convergentes y paralelos que utilizó cuestionarios rellenados por el encuestado (cuantitativos) y entrevistas a informantes clave (cualitativos). De los 300 oficiales de policía de las ocho estaciones de Daman, 155 participaron en la encuesta. Los datos cuantitativos se analizaron mediante métodos estadísticos descriptivos y la prueba del χ2. Los datos cualitativos de las entrevistas exhaustivas de seis informantes clave de todos los departamentos coordinadores se analizaron temáticamente.Resultados: En general, el 63,2% estaba al corriente de una ley de control del tabaco en la India, y solo el 12,9% había recibido capacitación relacionada con su aplicación. Solo un funcionario había realizado inspecciones sobre la conformidad con la COTPA en los últimos 12 meses. La mayor parte del personal de policía (78,1%), y una mayor proporción de no consumidores de tabaco (81,2% contra 52,9%; P = 0,016), consideraba que la aplicación de la reglamentación antitabaco constituía una de sus funciones importantes. Los dos principales factores facilitadores de la aplicación de la COPTA fueron la percepción de los beneficios de la ley y la autoridad oficial para actuar. El desconocimiento y la falta de coordinación, las prioridades concurrentes, la concentración de la autoridad en los funcionarios superiores y la evasión de la ley por parte de los comerciantes al por menor y de la población obstaculizan la aplicación eficaz de la ley.Conclusión: Se observó un conocimiento insuficiente y una escasa aplicación de la COTPA. Con miras a lograr una aplicación eficaz, se recomienda sensibilizar y capacitar al personal encargado de aplicar la ley, practicar una notificación sistemática transparente y trabajar por la concienciación de la población.

Esophageal distensibility measurement: impact on clinical management and procedure length.

Luminal distensibility measurement has demonstrated relevance to various disease processes, though its effects on clinical decision-making have been less well understood. This study aims to characterize the clinical impact of impedance planimetry measurement as well as the learning curve associated with its use in the esophagus. A single provider performed distensibility measurement in conjunction with upper endoscopy for a variety of clinical indications with the functional lumen imaging probe (FLIP) over a period of 21 months. Procedural data were prospectively collected and, along with medical records, retrospectively reviewed. Seventy-three procedures (70 patients) underwent esophageal distensibility measurement over the timeline of this study. The most common procedural indications were known or suspected achalasia (32.9%), dysphagia with connective tissue disease (13.7%), eosinophilic esophagitis (12.3%), and dysphagia with prior fundoplication (9.6%). FLIP results independently led to a change in management in 29 (39.7%) cases and supported a change in management in an additional 15 (20.5%) cases. The most common change in management was a new or amended therapeutic procedure (79.5%). Procedural time added by distensibility measurement was greater among earlier cases than among later cases. The median time added overall was 5 minutes and 46 seconds. Procedural time added varied significantly by procedural indication, but changes in management did not. Distensibility measurement added meaningful diagnostic information that impacted therapeutic decision-making in the majority of cases in which it was performed. Procedural time added by this modality is typically modest and decreases with experience.

The effectiveness of computed tomography-guided biopsy for the diagnosis of spondylodiscitis: an analysis of variables affecting the outcome.

OBJECTIVE: To analyze: (i) the effectiveness of CT-guided biopsy for the diagnosis of suspected spinal infections (spondylodiscitis); (ii) identify common causative microorganisms and assess factors that could affect the diagnostic yield. PATIENTS AND METHODS: Forty-five patients undergoing CT-guided biopsy for suspected spinal infection between November 2012 and October 2014 were analyzed. The time from presentation to diagnosis, administration of antibiotics before biopsy, blood culture results, admission C-reactive protein (CRP)/white cell count, presence of fever or neurological deficits, and soft tissue collections on MRI were analyzed. Multivariable logistic regression was performed to determine variables independently associated with a positive biopsy. RESULTS: Eleven (24.4%) patients had positive blood cultures. The first biopsy was positive in 19 (42.2%) patients. Thirty-eight (84.4%) patients had a single biopsy, while seven (15.5%) patients underwent repeat biopsy with a positive yield in one (14.2%) patient. Overall, causative microorganisms were identified in 26 (57.8%) cases. Admission CRP was significantly associated with isolating the causative pathogen from CT-guided biopsy (p<0.001). A soft tissue collection on MRI was associated with identification of a microorganism in blood cultures (p=0.001). CRP was the only independent variable associated with a positive yield on CT-guided biopsy (p=0.007, OR 1.042) and was more likely in patients with CRP>50 (p<0.001). Administration of empirical antibiotics before biopsy did not affect the yield (p=0.572). CONCLUSIONS: A high CRP was a strong predictor of isolation of the causative organism. Repeat CT-guided biopsy was found to have limited value with a low positive yield (14.2%) in our study.

What is the clinical significance of esophagogastric junction outflow obstruction? evaluation of 60 patients at a tertiary referral center.

BACKGROUND: Esophagogastric junction (EGJ) outflow obstruction (EGJOO) is characterized by impaired EGJ relaxation with intact or weak peristalsis. Our aims were to evaluate: (i) prevalence, (ii) yield of fluoroscopy, endoscopy, and endoscopic ultrasound (EUS), (iii) outcomes, and (iv) whether this data differed based on quantitative EGJ relaxation. METHODS: Studies that met criteria for EGJOO were identified. Demographics, encounters, endoscopy, radiology, treatment decisions, and outcomes were extracted. KEY RESULTS: Sixty studies were identified. Dysphagia was the most common symptom. Forty patients underwent barium esophagram (BE): normal (11), hiatal hernia (20), spasm/dysmotility (17), EGJ narrowing (10), compression (2), Schatzki's ring (5), malrotation (1), gastric volvulus (1), mass (1). Esophagogastroduodenoscopy (EGD) was performed in 41 patients: normal (19), hiatal hernia (13), Schatzki's ring (6), esophagitis (3), esophageal candidiasis (3), mass (1). EUS was performed in 20 patients and was frequently normal. Twenty-two patients underwent intervention. While transient improvement was noted in the majority, persistent improvement was seen in only one of nine patients (dilatation), four of six patients (botulinum toxin), and three patients who underwent per-oral endoscopic myotomy. No patients treated with medical therapy alone had improvement in dysphagia. There was no difference in symptoms or outcomes based on quantitative EGJ relaxation. CONCLUSIONS & INFERENCES: The manometric criterion EGJOO defines a heterogeneous clinical group. While BE, EGD, and EUS all provide complementary information, a significant percentage of these studies will be normal. For patients with dysphagia, outcome may depend on EGJ disruption. There were no differences in symptoms our outcomes based on quantitative EGJ relaxation.

Differential expression of hENT1 and hENT2 in colon cancer cell lines.

Human equilibrative nucleoside transporters (hENT) 1 and 2, encoded by SLC29A1 and SLC29A2, permit the bidirectional passage of nucleoside analogues into cells and may correlate with clinical responses to chemotherapy in patients with colorectal cancer (CRC). The purpose of this study was to evaluate the expression profiles of SLC29A1 and SLC29A2 in human cancer cell lines. Using quantitative real-time polymerase chain reaction, we comprehensively profiled the transcription levels of SLC29A1 and SLC29A2 in 16 colon cancer cell lines. We validated the ubiquitous and heterogeneous distribution of SLC29A1 and SLC29A2 in human colon cancer cell lines and demonstrated that SLC29A1 was highly expressed in 25% of metastatic cell lines (Colo201 and Colo205) and 62.5% of primary cell lines (Caco2, Colo320, HCT116, RKO, and SW48). For the first time, we showed that both SLC29A1 and SLC29A2 were expressed at lower levels in colon cancer cell lines originating from metastatic sites than from primary sites. These findings indicate that most patients with metastatic CRC (mCRC) may have low hENT1 expression, and treatment with nucleoside analogues may be inefficient. However, some patients still show high hENT1 expression and have a high probability of benefiting from these drugs. Therefore, evaluating transporter expression profiles and different drug responses between primary and metastatic tumors in patients with mCRC is important. Further assessment of the association between hENTs and drug-based treatment of mCRC is required to elucidate the mechanisms of chemotherapy resistance.

Prognostic value of CpG island methylator phenotype among colorectal cancer patients: a systematic review and meta-analysis.

BACKGROUND: Divergent findings regarding the prognostic value of CpG island methylator phenotype (CIMP) in colorectal cancer (CRC) patients exist in current literature. We aim to review data from published studies in order to examine the association between CIMP and CRC prognosis. MATERIALS AND METHODS: A comprehensive search for studies reporting disease-free survival (DFS), overall survival (OS), or cancer-specific mortality of CRC patients stratified by CIMP is carried out. Study findings are summarized descriptively and quantitatively, using adjusted hazard ratios (HRs) as summary statistics. RESULTS: Thirty-three studies reporting survival in 10 635 patients are included for review. Nineteen studies provide data suitable for meta-analysis. The definition of CIMP regarding gene panel, marker threshold, and laboratory method varies across studies. Pooled analysis shows that CIMP is significantly associated with shorter DFS (pooled HR estimate 1.45; 95% confidence interval (CI) 1.07-1.97, Q = 3.95, I(2) = 0%) and OS (pooled HR estimate 1.43; 95% CI 1.18-1.73, Q = 4.03, I(2) = 0%) among CRC patients irrespective of microsatellite instability (MSI) status. Subgroup analysis of microsatellite stable (MSS) CRC patients also shows significant association between shorter OS (pooled HR estimate 1.37; 95% CI 1.12-1.68, Q = 4.45, I(2) = 33%) and CIMP. Seven studies have explored CIMP's value as a predictive factor on stage II and III CRC patient's DFS after receiving adjuvant 5-fluorouracil (5-FU) therapy: of these, four studies showed that adjuvant chemotherapy conferred a DFS benefit among CIMP(+) patients, one concluded to the contrary, and two found no significant correlation. Insufficient data was present for statistical synthesis of CIMP's predictive value among CRC patients receiving adjuvant 5-FU therapy. CONCLUSION: CIMP is independently associated with significantly worse prognosis in CRC patients. However, CIMP's value as a predictive factor in assessing whether adjuvant 5-FU therapy will confer additional survival benefit to CRC patients remained to be determined through future prospective randomized studies.

Lip prints: The barcode of skeletal malocclusion.

INTRODUCTION: In orthodontics, apart from essential diagnostic aids, there are so many soft tissue analyses in which lips are major part of concern. However, lip prints have never been used in orthodontics as diagnostic aid or forensic tool. Therefore, this study was designed to explore the possible association of lip prints with skeletal malocclusion. MATERIALS AND METHODS: A sample of 114 subjects in the age group of 18-30 years, from North Indian adult population were selected on the basis of skeletal class I, class II and class III malocclusion, each comprising of 38 subjects with equal number of males and females. Lip prints of all the individuals were recorded and digital soft copies of lateral cephalograms were taken. Lip prints were compared between different skeletal malocclusions. RESULTS: It was found that branched lip pattern was most common in North Indian adult population with no sexual dimorphism. The Z-test for proportion showed that the prevalence of vertical lip pattern was significantly higher in subjects having skeletal class III malocclusion. CONCLUSION: A definite co-relation of vertical lip patterns with skeletal class III malocclusion was revealed.

Modified Intraoral Repositioning Appliance in Complete Bilateral Cleft Lip and Palate.

OBJECTIVE: The purpose of the modified repositioning appliance was to overcome the shortcoming of existing design for repositioning protruded premaxilla in a child with bilateral cleft lip and palate. METHODS: The basic principles of design were similar to Latham's appliance but the surgical pinning of premaxillary segment was avoided and instead acrylic splint was prepared. CONCLUSIONS: This technique avoids any invasive procedure, is useful to reposition protruded premaxillary segment in bilateral cleft lip and palate cases specifically in child who reports late with deciduous dentition.

Olanzapine-induced hyperglycaemic coma and neuroleptic malignant syndrome: case report and review of literature.

Although the relationship between antipsychotic medication, particularly second-generation antipsychotics (SGAs), and metabolic disturbance is increasingly accepted, there is an important, but little recognised, potential interaction between this and the other important serious adverse effect of neuroleptic malignant syndrome (NMS). We report a case of a 35-year old female who developed new onset type II diabetes mellitus with hyperosmolar hyperglycaemic coma and acute renal failure following treatment with a SGA for a first manic episode. The history is strongly suggestive of concurrent NMS. This case raises important questions about non-ketotic, hyperosmolar diabetic coma with antipsychotics, the possible association between hyperglycaemia and hyperthermia, and the direction of causality in this, the recognition of either syndrome when they co-exist and management issues in such patients. These questions are considered in the context of currently available literature.

Long-term function after restorative proctocolectomy.

PURPOSE: Early functional outcome after restorative proctocolectomy and formation of an ileoanal pouch is known to be good, but there are minimal data on the long-term function of the pouch. The aim of this study was to look at the long-term functional outcome in patients who had undergone restorative proctocolectomy and formation of an ileoanal pouch. METHODS: A total of 151 consecutive patients (96 males, 55 females) who underwent ileoanal pouch surgery between April 1983 and May 1993 were identified. Functional outcomes from the previous 12 months were appraised by a standardized questionnaire. RESULTS: The median age at surgery was 31 years (range, 6-63 years), with a median follow-up of 142 months (range, 100-221 months). Eighteen patients have had their pouches excised, with another patient being defunctioned. Therefore 19 patients (13 percent) had suffered pouch failure. Altogether, 115 patients were available for follow-up, and 98 patients (85 percent) returned questionnaires. The median pouch-emptying frequency was five times (range, 1-17) during the day and one time (range, 0-6) at night. A total of 74 percent of patients had perfect continence during the day. Most of the patients had no life-style restrictions related to the pouch, and 98 percent of patients would recommend a pouch to others. CONCLUSIONS: Long-term functional outcome after ileoanal pouch surgery is good in most patients. For patients requiring proctocolectomy, ileoanal pouch surgery can now be recommended as an excellent long-term option.

Hydrophobic residues Phe552, Phe554, Ile562, Leu566, and Ile574 are required for oligomerization of anthrax protective antigen.

Anthrax protective antigen (PA) plays a central role in facilitating the entry of active toxin components, namely, lethal factor and edema factor, into the cells. PA is also the main immunogen of both human and veterinary vaccine against anthrax. During host cell intoxication, protective antigen binds to the receptors on cell surface, gets proteolytically activated, oligomerizes to form a heptamer and binds to lethal factor or edema factor. The complex, formed by binding of lethal factor or edema factor to oligomerized PA, is internalized by receptor-mediated endocytosis. Acidification of the endosome results in the insertion of the heptamer into the membrane, thereby forming a pore through which lethal factor or edema factor can translocate into the cytosol. In this study we have identified hydrophobic residues, Phe552, Phe554, Ile562, Leu566, and Ile574, which are required for oligomerization of anthrax protective antigen. Mutation of these conserved residues to alanine impaired the oligomerization of protective antigen. Consequently, these mutants became nontoxic in combination with lethal factor and edema factor. Therapeutic importance of these mutants and their potential as vaccine candidates is discussed.

Purification of anthrax edema factor from Escherichia coli and identification of residues required for binding to anthrax protective antigen.

The structural gene for anthrax edema factor (EF) was expressed in Escherichia coli under the control of a powerful T5 promoter to yield the 89-kDa recombinant protein that reacted with anti-EF antibodies. Recombinant EF was purified to homogeneity by a two-step procedure involving metal chelate affinity chromatography and cation-exchange chromatography. From 1 liter of culture, 2.5 mg of biologically active EF was easily purified. This is the first report of purification of anthrax EF from E. coli. EF purified from E. coli was biologically and functionally as active as its Bacillus anthracis counterpart. The recombinant protein could compete with lethal factor for binding to protective antigen. Sequence analysis revealed a stretch of seven amino acids, Val Tyr Tyr Glu Ile Gly Lys, present both in EF (residues 136 to 142) and lethal factor (residues 147 to 153). To investigate the role of these seven residues in binding to protective antigen, the residues were individually mutated to alanine in EF. Mutations in residues Tyr137, Tyr138, Ile140, and Lys142 of EF specifically blocked its interaction with anthrax protective antigen. The adenylate cyclase activity of the mutants remained unaffected. The results suggested that residues Tyr137, Tyr138, Ile140, and Lys142 are required for binding of EF to anthrax protective antigen, which facilitates its entry into susceptible cells.

Rapid purification of recombinant anthrax-protective antigen under nondenaturing conditions.

Anthrax-protective antigen is the central moiety of the anthrax toxin complex that mediates the entry of the other two toxin components, lethal factor and edema factor into the cells. It is also the main immunogen of the cell-free vaccine against anthrax. However, in addition to PA, the vaccine contains trace amounts of other culture-derived proteins that contribute to the side effects of the vaccine like pain, edema, erythrema, etc. Thus there is a need to develop high-resolution purification methods to purify PA to homogeneity. In this study we have presented a purification strategy for rapid purification of recombinant protective antigen under nondenaturing conditions, which ensures that not only biological activity but also the conformational integrity of immunological epitopes is well-preserved. The protein was purified to homogeneity in a two-step purification procedure that takes just 6 h for completion. Three milligrams of recombinant protective antigen obtained from 1-liter culture was comparable to B. anthracis protective antigen in terms of functional and biological activity. Moreover, the immunogenicity elicited by the purified protein in mice was also studied. The studies reported here are part of continuing research that aims to provide a safe and efficacious alternative to the current vaccine against anthrax.

Accelerated age-related CpG island methylation in ulcerative colitis.

CpG island hypermethylation is a mechanism of gene silencing that can be usurped by neoplastic cells to inactivate undesirable genes. In the colon, hypermethylation often starts in normal mucosa as a function of age and is markedly increased in cancer. To test the hypothesis that subjects at increased risk of colon cancer have higher levels of methylation in their nonneoplastic mucosa, we studied methylation patterns of five genes in the normal and dysplastic mucosa of patients with ulcerative colitis (UC), a condition associated with a marked increased risk of colon cancer. One gene (Mlh1) was unmethylated in all tissues examined. All four remaining genes had low but detectable levels of methylation in the epithelium of UC patients without evidence of dysplasia, and this methylation was not different from non-UC controls. By contrast, all four genes were highly methylated in dysplastic epithelium from high-grade dysplasia (HGD)/cancer patients with UC; methylation in HGD versus controls averaged 40.0% versus 7.4% (P = 0.00003) for ER, 44.0% versus 3.0% (P < 0.00003) for MYOD, 9.4% versus 2.4% (P = 0.03) for p16 exon 1, and 57.5% versus 30.6% (P = 0.01) for CSPG2. Importantly, three of the four genes were also highly methylated in the normal appearing (nondysplastic) epithelium from these same HGD/cancer patients, indicating that methylation precedes dysplasia and is widespread in these patients. Compared with controls, methylation averaged 20.1% versus 7.2% (P = 0.07) for ER, 18.4% versus 3.0% (P < 0.008) for MYOD, and 7.9% versus 2.4% (P = 0.007) for p16 exon 1. These results are consistent with the hypothesis that age-related methylation marks (and may lead to) the field defect that reflects acquired predisposition to colorectal neoplasia. Furthermore, the data suggest that chronic inflammation is associated with high levels of methylation, perhaps as a result of increased cell turnover, and that UC can be viewed as resulting in premature aging of colorectal epithelial cells.

Aging, methylation and cancer.

Alterations in methylation are widespread in cancers. DNA methylation of promoter-associated CpG islands is an alternate mechanism to mutation in silencing gene function, and affects tumor-suppressor genes such as p16 and RBI, growth and differentiation controlling genes such as ER and many others. Evidence is now accumulating that some of these methylation changes may initiate in subpopulations of normal cells as a function of age and progressively increase during carcinogenesis. Age-related methylation appears to be widespread and is one of the earliest changes marking the risk for neoplasia. In colon cancer, we have shown a pattern of age-related methylation for several genes, including ER, IGF2, N33 and MyoD, which progresses to full methylation in adenomas and neoplasms. Hypermethylation of these genes is associated with gene silencing. Age-related methylation involves at least 50% of the genes which are hypermethylated in colon cancer, and we propose that such age-related methylation may partly account for the fact that most cancers occur as a function of old age. Age-related methylation, then, may be a fundamental mark of the field defect in patients with neoplasia. The causes of age-related methylation are still unknown at this point, but evidence points to an interplay between local predisposing factors in DNA (methylation centers), levels of gene expression and environmental exposure. The concept that age-related methylation is a predisposing factor for neoplasia implies that it may serve as a diagnostic risk marker in cancer, and as a novel target for chemoprevention. Studies in animal models support this hypothesis and should lead to novel approaches to risk-assessment and chemoprevention in humans.

Distinct genetic profiles in colorectal tumors with or without the CpG island methylator phenotype.

Colorectal cancers (CRCs) are characterized by multiple genetic (mutations) and epigenetic (CpG island methylation) alterations, but it is not known whether these evolve independently through stochastic processes. We have recently described a novel pathway termed CpG island methylator phenotype (CIMP) in CRC, which is characterized by the simultaneous methylation of multiple CpG islands, including several known genes, such as p16, hMLH1, and THBS1. We have now studied mutations in K-RAS, p53, DPC4, and TGFbetaRII in a panel of colorectal tumors with or without CIMP. We find that CIMP defines two groups of tumors with significantly different genetic lesions: frequent K-RAS mutations were found in CIMP(+) CRCs (28/41, 68%) compared with CIMP(-) cases (14/47, 30%, P = 0.0005). By contrast, p53 mutations were found in 24% (10/41) of CIMP(+) CRCs vs. 60% (30/46) of CIMP(-) cases (P = 0.002). Both of these differences were independent of microsatellite instability. These interactions between CIMP, K-RAS mutations, and p53 mutations were preserved in colorectal adenomas, suggesting that they occur early in carcinogenesis. The distinct combinations of epigenetic and genetic alterations in each group suggest that activation of oncogenes and inactivation of tumor suppressor genes is related to the underlying mechanism of generating molecular diversity in cancer, rather than simply accumulate stochastically during cancer development.