Towards a new paradigm of microscopic colitis: Incomplete and variant forms

Microscopic colitis(MC) is a chronic inflammatory bowel disease that has emerged in the last three decades as a leading cause of chronic watery diarrhoea. MC classically includes two main subtypes: lymphocytic colitis(LC) and collagenous colitis(CC). Other types of histopathological changes in the colonic mucosa have been described in patients with chronic diarrhoea, without fulfilling the conventional histopathological criteria for MC diagnosis. Whereas those unclassified alterations remained orphan for a long time, the use of the term incomplete MC(MCi) is nowadays universally accepted. However, it is still unresolved whether CC, LC and MCi should be considered as one clinical entity or if they represent three related conditions. In contrast to classical MC, the real epidemiological impact of MCi remains unknown, because only few epidemiological studies and case reports have been described. MCi presents clinical characteristics indistinguishable from complete MC with a good response to budesonide and cholestiramine. Although a number of medical treatments have been assayed in MC patients, currently, there is no causal treatment approach for MC and MCi, and only empirical strategies have been performed. Further studies are needed in order to identify their etiopathogenic mechanisms, and to better classify and treat MC.

What is the optimal level of vitamin D in non-dialysis chronic kidney disease population?

AIM To evaluate thresholds for serum 25(OH)D concentrations in relation to death, kidney progression and hospitalization in non-dialysis chronic kidney disease(CKD) population.METHODS Four hundred and seventy non-dialysis 3-5 stage CKD patients participating in OSERCE-2 study, a prospective, multicenter, cohort study, were prospectively evaluated and categorized into 3 groups according to 25(OH)D levels at enrollment(less than 20 ng/mL, between 20 and 29 ng/mL, and at or above 30 ng/mL), considering 25(OH)D between 20 and 29 ng/mL as reference group. Association between 25(OH)D levels and death(primary outcome), and time to first hospitalization and renal progression(secondary outcomes) over a 3-year followup, were assessed by Kaplan-Meier survival curves and Cox-proportional hazard models. To identify 25(OH)D levels at highest risk for outcomes, receiver operating characteristic(ROC) curves were performed.RESULTS Over 29 ± 12 mo of follow-up, 46(10%) patients dead, 156(33%) showed kidney progression, and 126(27%) were hospitalized. After multivariate adjustment, 25(OH)D < 20 ng/mL was an independent predictor of all-cause mortality(HR = 2.33; 95%CI: 1.10-4.91; P = 0.027) and kidney progression(HR = 2.46; 95%CI: 1.63-3.71; P < 0.001), whereas the group with 25(OH)D at or above 30 ng/mL did not have a different hazard for outcomes from the reference group. Hospitalization outcomes were predicted by 25(OH) levels(HR = 0.98; 95%CI: 0.96-1.00; P = 0.027) in the unadjusted Cox proportional hazards model, but not after multivariate adjusting. ROC curves identified 25(OH)D levels at highest risk for death, kidney progression, and hospitalization, at 17.4 ng/mL [area under the curve(AUC) = 0.60; 95%CI: 0.685-0.69; P = 0.027], 18.6 ng/mL(AUC = 0.65; 95%CI: 0.60-0.71; P < 0.001), and 19.0 ng/m L(AUC = 0.56; 95%CI: 0.50-0.62; P = 0.048), respectively.CONCLUSION25(OH)D < 20 ng/mL was an independent predictor of death and progression in patients with stage 3-5 CKD, with no additional benefits when patients reached the levels at or above 30 ng/m L suggested as optimal by CKD guidelines.

A comprehensive study on IoT privacy and security challenges with focus on spectrum sharing in Next-Generation networks(5G/6G/beyond)

The emergence of the Internet of Things(IoT)has triggered a massive digital transformation across numerous sectors.This transformation requires efficient wireless communication and connectivity,which depend on the optimal utilization of the available spectrum resource.Given the limited availability of spectrum resources,spectrum sharing has emerged as a favored solution to empower IoT deployment and connectivity,so adequate planning of the spectrum resource utilization is thus essential to pave the way for the next generation of IoT applications,including 5G and beyond.This article presents a comprehensive study of prevalent wireless technologies employed in the field of the spectrum,with a primary focus on spectrum-sharing solutions,including shared spectrum.It highlights the associated security and privacy concerns when the IoT devices access the shared spectrum.This survey examines the benefits and drawbacks of various spectrum-sharing technologies and their solutions for various IoT applications.Lastly,it identifies future IoT obstacles and suggests potential research directions to address them.