Adenoma incidence decreases u nder the efect of polypectomy

MM： To investigate whether, under the influence of pol ypectomy, the incidence of adenoma decreases with age.METHODS： Consecutive patients with colonic adenomas identified at index colonoscopy were retrospectively selected if they had undergone three or more complete colonoscopies, at least 24 mo apart. Patients who had any first-degree relative with colorectal cancer were excluded. Data regarding number of adenomas at each colonoscopy, their location, size and histological classification were recorded. The monthly incidence density of adenomas after the index examination was estimated for the study population, by using the person-years method. Baseline adenomas were excluded from incidence calculations but their characteristics were correlated with recurrence at follow-up, using the X^42 test.RESULTS： One hundred and fifty-six patients were included （109 male, mean age at index colonoscopy 56.8 ± 10.3 years）, with follow-up that ranged from 48 to 232 mo. No significant correlations were observed between the number, the presence of villous component, or the size of adenomas at index colonoscopy and the presence of adenomas at subsequent colonoscopies （P = 0.49, 0.12 and 0.78, respectively）. The incidence of colonic adenomas was observed to decay from 1.4% person-months at the beginning of the study to values close to 0%, at 12 years after index colonoscopy.CONCLUSION： Our results suggest the sporadic formation of adenomas occurs within a discrete period and that, when these adenomas are removed, all neoplasia-prone clones may be extinguished.

How Growth Ability of Multidrug-Resistant Escherichia coli Is Affected by Abiotic Stress Factors

The ability of multidrug-resistant Escherichia coli to adapt and grow in a wide range of different environmental conditions may be crucial to the global spread of antimicrobial resistance. The aim of this study was to evaluate the survival ability of 54 multidrug-resistant E. coli strains, isolated from three different biotopes (clinical setting, gull intestine, river water) when subjected to variations in pH (from 3 to 11) and salinity (from 0.5% to 6% of NaCl) and to nutrient deprivation. The growth of each isolate as well as of a reference strain was assessed during 168 h in every varying condition. Slight variations in the growth ability under some abiotic stress factors were recorded among the isolates from the different biotopes. Multidrug-resistant isolates from gull feces were found to be the more tolerant to environmental abiotic changes, while isolates from river water were the less tolerant. In addition, it was notorious that the carriage of antimicrobial resistance has a clear fitness cost in comparison with the susceptible (reference) strain, highlighting the necessity of reducing the selective pressure exerted by antibiotics. This study underlines the ecological hardness of multidrug-resistant E. coli isolates with a consequent ability to reach and colonize new host and environments.

Impaired T-cell differentiation in diabetic foot ulceration

Foot ulceration is one of the most debilitating complications associated with diabetes,but its cause remains poorly understood.Several studies have been undertaken to understand healing kinetics or find possible therapies to enhance healing.However,few studies have been directed at understanding the immunological alterations that could influence wound healing in diabetes.In this study,we analysed the T-cell receptor(TCR)repertoire diversity in TCR-αβ^(+)T cells.We also analysed the distribution and phenotype of T cells obtained from the peripheral blood of healthy controls and diabetic individuals with or without foot ulcers.Our results showed that diabetic individuals,especially those with foot ulcers,have a significantly lower naive T-cell number and a poorer TCR-Vβrepertoire diversity.We also showed that the reduced TCR-Vβrepertoire diversity in diabetic individuals was mainly owing to the accumulation of effector T cells,the major source of tumour necrosis factor-αproduction,which was even more pronounced in patients with acute foot ulceration.Moreover,the expression of several inflammatory chemokine receptors was significantly reduced in diabetic patients.In conclusion,effector T-cell accumulation and TCR repertoire diversity reduction appear to precede the development of foot ulcers.This finding may open new immunological therapeutic possibilities and provide a new prognostic tool in diabetic wound care.

Imbalance in T-cell differentiation as a biomarker of chronic diabetic foot ulceration

Diabetes is a growing epidemic due to the systematic increase in overweight and obesity,and chronic diabetic foot ulcers(DFUs)are the most debilitating and costly complication of diabetes.Prevention is still essential for DFU care,but early detection is limited because we do not have a good DFU biomarker.Here,we report the preliminary results of a large longitudinal study to test the effectiveness of the use of T-cell phenotype and TCR repertoire diversity as DFU biomarkers.Our results show that the ratio of effector/naïve T-cells and the number of TCR expansions are valuable biomarkers of DFU prognosis.