Magnifying narrow-band imaging endoscopy is superior in diagnosis of early gastric cancer

AIM:To evaluate the diagnostic effectiveness of white light endoscopy,magnifying endoscopy(ME),and magnifying narrow-band imaging endoscopy(ME-NBI) in detecting early gastric cancer(EGC).METHODS:From March 2010 to June 2012,a total of 3616 patients received screening for gastric cancer by magnifying endoscopy. There were 3675 focal gastric lesions detected using conventional high definition white light endoscopy(HD-WLE) in four different referentialhospitals that were recruited for further investigation using ME and ME-NBI. The images obtained from HD-WLE,ME,and ME-NBI were reviewed by four experienced endoscopists to evaluate their diagnostic effectiveness for EGC. The diagnosis of cancerous and non-cancerous lesions was conducted by evaluating the microvascular and microsurface patterns using the VS classification system. The final endoscopic diagnosis of each lesion was determined by consultation when a disagreement occurred. We used histopathological results as the gold standard for the diagnosis of EGC.RESULTS:Among the 3675 lesions found,1508 were validated by pathological findings as chronic gastritis,1279 as chronic gastritis with intestinal metaplasia,631 as low-grade neoplasia,and 257 as EGC. The sensitivity,specificity,positive predictive value,negative predictive value,and accuracy of HD-WLE for the diagnosis of EGC were 71.2%,99.1%,85.5%,97.9% and 97.1%,respectively. The results of ME for diagnosing EGC were 81.3%,98.8%,83.3%,98.6% and 97.6%,respectively. The results of ME-NBI for the diagnosis of EGC were 87.2%,98.6%,82.1%,99.0% and 97.8%,respectively. The diagnostic sensitivity and accuracy of paired ME and ME-NBI were significantly better than those of HD-WLE(P < 0.05).CONCLUSION:HD-WLE has a relatively high accuracy for diagnosing EGC and is an effective screening tool. Further investigations of ME and ME-NBI are required to achieve superior accuracy.

Differential gene expression profiling of gastric intraepithelial neoplasia and early-stage adenocarcinoma

AIM:To investigate the differentiated whole genome expression profiling of gastric high-and low-grade intraepithelial neoplasia and early-stage adenocarcinoma.METHODS:Gastric specimens from an upper magnifying chromoendoscopic targeted biopsy were collected from March 2010 to May 2013.Whole genome expression profiling was performed on 19 low-grade intraepithelial neoplasia(LGIN),20 high-grade intraepithelial neoplasia(HGIN),19 early-stage adenocarcinoma(EGC),and 19 chronic gastritis tissue samples using Agilent 4×44K Whole Human Genome microarrays.Differentially expressed genes between different types of lesions were identified using an unpaired t-test and corrected with the Benjamini and Hochberg false discovery rate algorithm.A gene ontology(GO)enrichment analysis was performed using the Gene Spring software GX 12.6.The differentially expressed gene was verified using a real-time TaqManPCR assay with independent tissue samples,including 26 LGIN,15 HGIN,14 EGC,and 20 chronic gastritis.The expression of G0S2 were further validated by immunohistochemical staining(IHC)in 24 LGIN,40 HGIN,30 EGC and 61 chronic gastritis specimens.RESULTS:The gene expression patterns of LGIN and HGIN tissues were distinct.There were 2521 significantly differentially expressed transcripts in HGIN,with951 upregulated and 1570 downregulated.A GO enrichment analysis demonstrated that the most striking overexpressed transcripts in HGIN compared with LGIN were in the category of metabolism,defense response,and nuclear factorκB(NF-κB)cascade.While the vast majority of transcripts had barely altered expression in HGIN and EGC tissues,only 38 transcripts were upregulated in EGC.A GO enrichment analysis revealed that the alterations of the immune response were most prominent in the progression from HGIN to EGC.It is worth noting that,compared with LGIN,289 transcriptswere expressed at higher levels both in HGIN and EGC.A characteristic gene,G0/G1 switch 2(G0S2)was one of the 289 transcripts and related to metabolism,the immune response,and the NF-κB cascade,and its expression was validated in independent samples through real-time TaqManPCR and immunohistochemical staining.In real-time PCR analysis,the expression of G0S2 was elevated both in HGIN and EGC compared with that in LGIN(P<0.01 and P<0.001,respectively).In IHC analysis,G0S2 immunoreactivity was detected in the cytoplasmic of neoplastic cells,but was undetectable in chronic gastritis cells.The G0S2 expression in HGIN was higher than that of LGIN(P=0.012,χ2=6.28)and EGC(P=0.008,χ2=6.94).CONCLUSION:A clear biological distinction between gastric high-and low-grade intraepithelial neoplasia was identified,and provides molecular evidence for clinical application.

Ethnic differences in genetic polymorphism associated with irritable bowel syndrome

Genetic polymorphism is associated with irritable bowel syndrome(IBS)in terms of susceptibility and clinical manifestations.Previous studies have shown that genetic polymorphism might play a key role in the onset and progression of IBS by modulating components of its pathogenesis such as the gut-brain axis,gastrointestinal motility,inflammatory activity,and immune status.Although underlying pathophysiological mechanisms have not been fully clarified,the potential ethnic differences that are present in worldwide genetic studies of IBS deserve attention.This review surveyed numerous studies focusing on IBSassociated single nucleotide polymorphisms,and investigated the ethnic disparities revealed by them.The results demonstrate the need for more attention on ethnic factors in IBS-related genetic studies.Taking ethnic backgrounds into accounts and placing emphasis on disparities potentially ascribed to ethnicity could help lay a solid and generalized foundation for transcultural,multi-ethnic,or secondary analyses in IBS,for example,a meta-analysis.Broader genetic studies considering ethnic factors are greatly needed to obtain a better understanding of the pathophysiological mechanisms of IBS and to improve the prevention,intervention,and treatment of this disease.

Clinical and Laboratory Diagnosis of Intestinal Tuberculosis

Background： Tuberculosis （TB） remains a worldwide problem. Intestinal TB （ITB） constitutes a major public health problem in developing countries and has been associated with significant morbidity and mortality. The aim of this study was to characterize the clinical, radiological, endoscopic, and pathological features of ITB and to define the strategy for establishing the diagnosis. Methods： A retrospective study （from January 2000 to June 2015） was carried out in Peking Union Medical College Hospital and all hospitalized cases were diagnosed as ITB during the study period were included. The relevant clinical information, laboratory results, microbiological, and radiological investigations were recorded. Results： Of the 85 cases, 61 cases （71.8%） were ranged from 20 to 50 years. The ileocecal region was involved in about 83.5% （71/85） of patients. About 41.2% （35/85） of patients had co-existing extra ITB, especially active pulmonary TB. Abdominal pain （82.4%） was the most common presenting symptom followed by weight loss （72.9%） and fever （64.7%）. Both T-cell spot of TB test （T-SPOT.TB） and purified protein derivatives （PPD） tests were performed in 26 patients： 20 （76.9%） positive T-SPOT.TB and 13 （50.0%） positive PPD were detected, with a statistical significant difference （P- 0.046）. Twenty cases （23.5%） were histopathology and/or pathogen confirmed TB; 27 cases （31.8%） were diagnosed by clinical manifestation consistent with ITB and evidence of active extra ITB; 38 cases （44.7%） were diagnosed by good response to diagnostic anti-TB therapy. Conclusions： ITB is difficult to diagnose even with modem medical techniques due to its nonspecific clinical and laboratory features. At present, combination of clinical, endoscopic, radiological, and pathological features continues to be the key to the diagnosis of ITB.