Meta-analysis: the diagnostic yield of chromoendoscopy for detecting dysplasia in patients with colonic inflammatory bowel disease

BACKGROUND

Dysplasia in inflammatory bowel disease (IBD) is often multifocal and flat. Dye spraying is believed to enhance visualisation of subtle mucosal abnormalities.

AIM

To perform a meta-analysis of the published studies to compare the diagnostic yield of dysplastic lesions in patients with IBD undergoing surveillance colonoscopy between chromoendoscopy and standard white light endoscopy.

METHODS

We searched electronic databases for full journal articles reporting on chromoendoscopy in patients with IBD. Pooled incremental yield of chromoendoscopy over white light endoscopy for dysplasia detection was determined. A fixed effects model was used unless there was significant heterogeneity. Publication bias was assessed using Funnel plots or Egger's test.

RESULTS

Six studies involving 1277 patients provided data on a number of dysplastic lesions detected. The difference in yield of dysplasia between chromoendoscopy and white light endoscopy was 7% (95% CI 3.2-11.3) on a per patient analysis with an NNT of 14.3. The difference in proportion of lesions detected by targeted biopsies was 44% (95% CI 28.6-59.1) and flat lesions was 27% (95% CI 11.2-41.9) in favour of chromoendoscopy.

CONCLUSIONS

Chromoendoscopy is significantly better than white light endoscopy in detecting dysplasia in patients with colonic IBD. This holds true for all dysplastic lesions, proportion of targeted lesions and proportion of flat lesions detected.

Meta-analysis: the diagnostic yield of chromoendoscopy for detecting dysplasia in patients with colonic inflammatory bowel disease

BACKGROUND

Dysplasia in inflammatory bowel disease (IBD) is often multifocal and flat. Dye spraying is believed to enhance visualisation of subtle mucosal abnormalities.

AIM

To perform a meta-analysis of the published studies to compare the diagnostic yield of dysplastic lesions in patients with IBD undergoing surveillance colonoscopy between chromoendoscopy and standard white light endoscopy.

METHODS

We searched electronic databases for full journal articles reporting on chromoendoscopy in patients with IBD. Pooled incremental yield of chromoendoscopy over white light endoscopy for dysplasia detection was determined. A fixed effects model was used unless there was significant heterogeneity. Publication bias was assessed using Funnel plots or Egger's test.

RESULTS

Six studies involving 1277 patients provided data on a number of dysplastic lesions detected. The difference in yield of dysplasia between chromoendoscopy and white light endoscopy was 7% (95% CI 3.2-11.3) on a per patient analysis with an NNT of 14.3. The difference in proportion of lesions detected by targeted biopsies was 44% (95% CI 28.6-59.1) and flat lesions was 27% (95% CI 11.2-41.9) in favour of chromoendoscopy.

CONCLUSIONS

Chromoendoscopy is significantly better than white light endoscopy in detecting dysplasia in patients with colonic IBD. This holds true for all dysplastic lesions, proportion of targeted lesions and proportion of flat lesions detected.

Narrow band imaging for characterization of high grade dysplasia and specialized intestinal metaplasia in Barrett's esophagus: a meta-analysis

BACKGROUND AND STUDY AIM

Narrow band imaging (NBI), a novel endoscopic technique that highlights mucosal surface structures and microvasculature is increasingly advocated as a tool to detect and characterize neoplasia and intestinal metaplasia in patients with Barrett's esophagus. We aimed to assess the diagnostic accuracy of NBI with magnification for the diagnosis of high grade dysplasia (HGD) and specialized intestinal metaplasia (SIM) in patients with Barrett's esophagus.

METHODS

We performed a meta-analysis of studies which compared NBI-based diagnosis of HGD and SIM with histopathology as the gold standard.

RESULTS

Eight studies including 446 patients with 2194 lesions met the inclusion criteria. For diagnosing HGD, the pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) were 0.96 (95 % confidence interval [CI] 0.93-0.99), 0.94 (95 %CI 0.84-1.0), 342.49 (95 %CI 40.49 - 2896.89) and 0.99 (SE 0.01) on a per-lesion analysis with similar results on per-patient analysis.. For the characterization of SIM, the pooled sensitivity, specificity, DOR, and AUC were 0.95 (95 %CI 0.87-1.0), 0.65 (95 %CI 0.52-0.78), 37.53 (95 %CI 6.50-217.62) and 0.88 (SE 0.08) on a per-lesion analysis.

CONCLUSION

NBI with magnification is accurate with high diagnostic precision for diagnosis of HGD in Barrett's esophagus on the basis of irregular mucosal pit patterns and/or irregular microvasculature. NBI has high sensitivity but poor specificity for characterizing SIM.

The seasonal status of chemical parameters in shallow coastal aquifers of Rameswaram Island, India

The study area Rameswaram, a holy island, is famous for the sacred Ramanathaswamy temple, which cements people of the country regardless of their place, residence, or their religion or creed. This coastal tract is experiencing a chronic fresh water shortage, despite a few spring sources. The study area is selected for the characterization of physico-chemical parameters viz., pH, EC, TDS, salinity, TA, TH, CH, MH, chloride, and fluoride for 150 groundwater samples and the impact of pre- and post-monsoons on the groundwater quality is studied. The water quality index advocates the transfer of groundwater quality from unacceptable status in the pre-monsoon into an acceptable status in the post-monsoon. The Langelier saturation index reflects the scaling tendency of groundwater in the study area. The Karl Pearson correlation matrix has approved the maximum influence of calcium and chloride on the total dissolved solids. It is interesting to conclude that the groundwater in the study area has very had nature, especially of non-carbonate type.

Quantification and distribution of heavy metals from small-scale industrial areas of Kanpur city, India

Kanpur city has large number of small-scale industries (SSIs), primarily comprising of textile and leather industries. This study inventorises the presence of heavy metals in the samples collected from Panki and Jajmau Industrial Areas of Kanpur city. The bulk concentration of heavy metals found in solid waste samples was Fe as 1885 and 2340 mg/kg, Mn 173 and 445 mg/kg, Zn 233 and 132 mg/kg, Cu 20 and 28 mg/kg, Cd 1.4 and 1.1mg/kg, Ni 26 and 397 mg/kg, Pb 107 and 19 mg/kg, Cr 1323 and 734 mg/kg, respectively. Heavy metal concentration was also found to be high in soil and road dust samples viz. Ni and Pb were in higher concentration in few samples, whereas Cr was found in higher concentration in all samples than the recommended values of USEPA and specifications for compost quality contained in the Indian Municipal Solid Wastes (Management and Handling) Rules, 2000. The heavy metal pollution so detected is indicative of contamination in ground and surface water and food chain. This raises concerns pertaining to adverse consequences to environment and human health.

A seasonal quality assessment on potability of fresh shallow aquifers along the Rameswaram-Dhanushkodi coastal tract, India

Rameswaram-Dhanushkodi coastal tract lies in the south-east of Rameswaram Island, which stretches about 20 km from the Rameswaram proper and occults several historic values. The objective of the present study is to investigate the water quality parameters viz., pH, electrical conductivity (EC), total dissolved solids (TDS), salinity (SAL), total alkalinity (TA), calcium hardness (CH), magnesium hardness (MH), total hardness (TH), chloride (Cl), and fluoride (F) during summer and winter seasons of the year 2006. The calculated Langelier Saturation Index values confirm the incrusting ability in most of the groundwater samples. The Water Quality Index values show that the potable quality of groundwater is improved from about 32% to 58%, especially in post-winter. The principal component analysis identifies the dominance of CH, TA, and TH with 33% and 44% in summer and winter, respectively. In addition, Cl is also having dominance in winter. The box plots have depicted asympathy in concentrations of F, TDS, and CH during winter, whereas sympathetic relationship in Cl and MH. Unlike in summer, a good correlation of Cl with the other parameters including SAL, EC, TDS, CH, and TH is observed in the winter.

Molecular dynamics investigations on the effect of D amino acid substitution in a triple-helix structure and the stability of collagen

Studies on the structure and stability of peptides and proteins during l-->d configurational change are certainly important for the designing of peptides with new biological activity and protein engineering. The l-->d amino acid (d AA) changes have been observed in aged proteins such as collagen. Hence, in this study, an attempt has been made to explore the effect of the replacement of l amino acid (l AA) in the model collagen-like peptides with d AA and the origin of structural stability (destability) has been traced using the molecular dynamics (MD) method employing the AMBER force field. Our results reveal that the substitution of d AA produces a large local disruption to the triple-helical structure. Formation of a kink (bulge) at the site of substitution is observed from the detailed analysis of MD trajectory. However, this local perturbation of kinked helix changes the direction of the helices and affects the relative orientation of the respective AA residues for helix-helix interaction, enough to affect the overall stability of the model collagen-like peptide. The destabilization energy per d Ala substitution is 7.87 kcal/mol, which is similar to the value for the Gly-->Ala mutation in collagen. Since the Gly-->Ala mutation is involved in genetic disorders such as osteogenesis imperfecta (OI), the l-->d configurational change may produce a similar effect on collagen.