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Grafting of Ring-Opened Cyclopropylamine Thin Films on Silicon (100) Hydride via UV Photoionization

Tung J, Ching JY, Ng YM, Tew LS, Khung YL

ACS Appl Mater Interfaces, 2017 Sep 13;9(36):31083-31094.
PMID: 28832115 DOI: 10.1021/acsami.7b08343

The grafting of cyclopropylamine onto a silicon (100) hydride (Si-H) surface via a ring-opening mechanism using UV photoionization is described here. In brief, radicals generated from the Si-H surface upon UV irradiation were found to behave in classical hydrogen abstraction theory manner by which the distal amine group was first hydrogen abstracted and the radical propagated down to the cyclopropane moiety. This subsequently liberated the strained bonds of the cyclopropane group and initiated the surface grafting process, producing a thin film approximately 10-15 nm in height. Contact angle measurements also showed that such photoionization irradiation had yielded an extremely hydrophilic surface (∼21.3°) and X-ray photoelectron spectroscopy also confirmed the coupling was through the Si-C linkage. However, when the surface underwent high-temperature hydrosilylation (>160 °C), the reaction proceeded predominantly through the nucleophilic NH2 group to form a Si-N linkage to the surface. This rendered the surface hydrophobic and hence suggested that the Si-H homolysis model may not be the main process. To the best of our knowledge, this was the first attempt reported in the literature to use photoionization to directly graft cyclopropylamine onto a silicon surface and in due course generate a highly rich NH-terminated surface that was found to be highly bioactive in promoting cell viability on the basis of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide studies.
A Risk-Scoring System Combined With a Fecal Immunochemical Test Is Effective in Screening High-Risk Subjects for Early Colonoscopy to Detect Advanced Colorectal Neoplasms

Chiu HM, Ching JY, Wu KC, Rerknimitr R, Li J, Wu DC, et al.

Gastroenterology, 2016 Mar;150(3):617-625.e3.
PMID: 26627608 DOI: 10.1053/j.gastro.2015.11.042

BACKGROUND & AIMS: Age, sex, smoking, and family history are risk factors for colorectal cancer in Asia. The Asia-Pacific Colorectal Screening (APCS) scoring system was developed to identify subjects with a high risk for advanced neoplasm (AN). We tested an algorithm that combined APCS scores with fecal immunochemical test (FIT) in colorectal cancer screening.
METHODS: We performed a multicenter prospective study, enrolling asymptomatic individuals older than 40 years old in 12 Asia-Pacific regions from December 2011 to December 2013. APCS scores were calculated for each individual (0-1 = low risk [LR], 2-3 = medium risk [MR], and 4-7 = high risk [HR] for AN). LR and MR subjects were offered FIT and referred for early colonoscopies if FIT results were positive. HR subjects were offered colonoscopies. The proportions of subjects with ANs were determined for each group based on colonoscopy findings; odd ratios for LR and MR subjects were calculated compared to LR individuals. We calculated the sensitivity of the APCS-FIT algorithm in identifying subjects with AN.
RESULTS: A total of 5657 subjects were recruited: 646 subjects (11.4%) were considered LR, 3243 subjects (57.3%) were considered MR, and 1768 subjects (31.3%) were considered HR for AN. The proportions of individuals with an AN in these groups were 1.5%, 5.1%, and 10.9%, respectively. Compared with LR group, MR and HR subjects had a 3.4-fold increase and a 7.8-fold increase in risk for AN, respectively. A total of 70.6% subjects with AN (95% confidence interval: 65.6%-75.1%) and 95.1% subjects with invasive cancers (95% confidence interval: 82.2%-99.2%) were correctly instructed to undergo early colonoscopy examination.
CONCLUSIONS: The APCS scoring system, which is based on age, sex, family history, and smoking, is a useful tool for determining risk for colorectal cancer and advanced adenoma in asymptomatic subjects. Use of the APCS score-based algorithm in triaging subjects for FIT or colonoscopy can substantially reduce colonoscopy workload.
An updated Asia Pacific Consensus Recommendations on colorectal cancer screening

Sung JJ, Ng SC, Chan FK, Chiu HM, Kim HS, Matsuda T, et al.

Gut, 2015 Jan;64(1):121-32.
PMID: 24647008 DOI: 10.1136/gutjnl-2013-306503

OBJECTIVE: Since the publication of the first Asia Pacific Consensus on Colorectal Cancer (CRC) in 2008, there are substantial advancements in the science and experience of implementing CRC screening. The Asia Pacific Working Group aimed to provide an updated set of consensus recommendations.
DESIGN: Members from 14 Asian regions gathered to seek consensus using other national and international guidelines, and recent relevant literature published from 2008 to 2013. A modified Delphi process was adopted to develop the statements.
RESULTS: Age range for CRC screening is defined as 50-75 years. Advancing age, male, family history of CRC, smoking and obesity are confirmed risk factors for CRC and advanced neoplasia. A risk-stratified scoring system is recommended for selecting high-risk patients for colonoscopy. Quantitative faecal immunochemical test (FIT) instead of guaiac-based faecal occult blood test (gFOBT) is preferred for average-risk subjects. Ancillary methods in colonoscopy, with the exception of chromoendoscopy, have not proven to be superior to high-definition white light endoscopy in identifying adenoma. Quality of colonoscopy should be upheld and quality assurance programme should be in place to audit every aspects of CRC screening. Serrated adenoma is recognised as a risk for interval cancer. There is no consensus on the recruitment of trained endoscopy nurses for CRC screening.
CONCLUSIONS: Based on recent data on CRC screening, an updated list of recommendations on CRC screening is prepared. These consensus statements will further enhance the implementation of CRC screening in the Asia Pacific region.
Risk of Colorectal Neoplasia in Individuals With Self-Reported Family History: A Prospective Colonoscopy Study from 16 Asia-Pacific Regions

Wong MC, Ching JY, Chiu HM, Wu KC, Rerknimitr R, Li J, et al.

Am J Gastroenterol, 2016 11;111(11):1621-1629.
PMID: 26977757 DOI: 10.1038/ajg.2016.52

OBJECTIVES: We tested the hypothesis that the risk of colorectal cancer (CRC), advanced colorectal neoplasia (ACN), and colorectal adenoma among screening participants with different first-degree relatives (FDRs) affected by CRC was similar.
METHODS: A multi-center, prospective colonoscopy study involving 16 Asia-Pacific regions was performed from 2008 to 2015. Consecutive self-referred CRC screening participants aged 40-70 years were recruited, and each subject received one direct optical colonoscopy. The prevalence of CRC, ACN, and colorectal adenoma was compared among subjects with different FDRs affected using Pearson's χ2 tests. Binary logistic regression analyses were performed to evaluate the risk of these lesions, controlling for recognized risk factors including age, gender, smoking habits, alcohol drinking, body mass index, and the presence of diabetes mellitus.
RESULTS: Among 11,797 asymptomatic subjects, the prevalence of CRC was 0.6% (none: 0.6%; siblings: 1.1%; mother: 0.5%; father: 1.2%; ≥2 members: 3.1%, P<0.001), that of ACN was 6.5% (none: 6.1%; siblings: 8.3%; mother: 7.7%; father: 8.7%; ≥2 members: 9.3%, P<0.001), and that of colorectal adenoma was 29.3% (none: 28.6%; siblings: 33.5%; mother: 31.8%; father: 31.1%; ≥2 members: 38.1%, P<0.001). In multivariate regression analyses, subjects with at least one FDR affected were significantly more likely to have CRC (adjusted odds ratio (AOR)=2.02-7.89), ACN (AOR=1.55-2.06), and colorectal adenoma (AOR=1.31-1.92) than those without a family history. The risk of CRC (AOR=0.90, 95% confidence interval (CI) 0.34-2.35, P=0.830), ACN (AOR=1.07, 95% CI 0.75-1.52, P=0.714), and colorectal adenoma (AOR=0.96, 95% CI 0.78-1.19, P=0.718) in subjects with either parent affected was similar to that of subjects with their siblings affected.
CONCLUSIONS: The risk of colorectal neoplasia was similar among subjects with different FDRs affected. These findings do not support the need to discriminate proband identity in screening participants with affected FDRs when their risks of colorectal neoplasia were estimated.
Early course of inflammatory bowel disease in a population-based inception cohort study from 8 countries in Asia and Australia

Ng SC, Zeng Z, Niewiadomski O, Tang W, Bell S, Kamm MA, et al.

Gastroenterology, 2016 Jan;150(1):86-95.e3; quiz e13-4.
PMID: 26385074 DOI: 10.1053/j.gastro.2015.09.005

BACKGROUND & AIMS: The incidence of inflammatory bowel disease (IBD) is increasing in Asia, but little is known about disease progression in this region. The Asia-Pacific Crohn's and Colitis Epidemiology Study was initiated in 2011, enrolling subjects from 8 countries in Asia (China, Hong Kong, Indonesia, Sri Lanka, Macau, Malaysia, Singapore, and Thailand) and Australia. We present data from this ongoing study.
METHODS: We collected data on 413 patients diagnosed with IBD (222 with ulcerative colitis [UC], 181 with Crohn's disease [CD], 10 with IBD unclassified; median age, 37 y) from 2011 through 2013. We analyzed the disease course and severity and mortality. Risks for medical and surgical therapies were assessed using Kaplan-Meier analysis.
RESULTS: The cumulative probability that CD would change from inflammatory to stricturing or penetrating disease was 19.6%. The cumulative probabilities for use of immunosuppressants or anti-tumor necrosis factor agents were 58.9% and 12.0% for patients with CD, and 12.7% and 0.9% for patients with UC, respectively. Perianal CD was associated with an increased risk of anti-tumor necrosis factor therapy within 1 year of its diagnosis (hazard ratio, 2.97; 95% confidence interval, 1.09-8.09). The cumulative probabilities for surgery 1 year after diagnosis were 9.1% for patients with CD and 0.9% for patients with UC. Patients with CD and penetrating disease had a 7-fold increase for risk of surgery, compared with patients with inflammatory disease (hazard ratio, 7.67; 95% confidence interval, 3.93-14.96). The overall mortality for patients with IBD was 0.7%.
CONCLUSIONS: In a prospective population-based study, we found that the early course of disease in patients with IBD in Asia was comparable with that of the West. Patients with CD frequently progress to complicated disease and have accelerated use of immunosuppressants. Few patients with early stage UC undergo surgery in Asia. Increasing our understanding of IBD progression in different populations can help optimize therapy and improve outcomes.
KEYWORDS: ACCESS; Natural History; Risk Factor; Treatment
Incidence and phenotype of inflammatory bowel disease based on results from the Asia-pacific Crohn's and colitis epidemiology study

Ng SC, Tang W, Ching JY, Wong M, Chow CM, Hui AJ, et al.

Gastroenterology, 2013 Jul;145(1):158-165.e2.
PMID: 23583432 DOI: 10.1053/j.gastro.2013.04.007

BACKGROUND & AIMS: Inflammatory bowel diseases (IBD) are becoming more common in Asia, but epidemiologic data are lacking. The Asia-Pacific Crohn's and Colitis Epidemiology Study aimed to determine the incidence and phenotype of IBD in 8 countries across Asia and in Australia.
METHODS: We performed a prospective, population-based study of IBD incidence in predefined catchment areas, collecting data for 1 year, starting on April 1, 2011. New cases were ascertained from multiple overlapping sources and entered into a Web-based database. Cases were confirmed using standard criteria. Local endoscopy, pathology, and pharmacy records were searched to ensure completeness of case capture.
RESULTS: We identified 419 new cases of IBD (232 of ulcerative colitis [UC], 166 of Crohn's disease [CD], and 21 IBD-undetermined). The crude annual overall incidence values per 100,000 individuals were 1.37 for IBD in Asia (95% confidence interval: 1.25-1.51; 0.76 for UC, 0.54 for CD, and 0.07 for IBD-undetermined) and 23.67 in Australia (95% confidence interval: 18.46-29.85; 7.33 for UC, 14.00 for CD, and 2.33 for IBD-undetermined). China had the highest incidence of IBD in Asia (3.44 per 100,000 individuals). The ratios of UC to CD were 2.0 in Asia and 0.5 in Australia. Median time from symptom onset to diagnosis was 5.5 months (interquartile range, 1.4-15 months). Complicated CD (stricturing, penetrating, or perianal disease) was more common in Asia than Australia (52% vs 24%; P = .001), and a family history of IBD was less common in Asia (3% vs 17%; P < .001).
CONCLUSIONS: We performed a large-scale population-based study and found that although the incidence of IBD varies throughout Asia, it is still lower than in the West. IBD can be as severe or more severe in Asia than in the West. The emergence of IBD in Asia will result in the need for specific health care resources, and offers a unique opportunity to study etiologic factors in developing nations.