Pancreatic stellate cells in the islets as a novel target to preserve the pancreatic β‐cell mass and function

There are numerous lines of clinical evidence that inhibition of the renin–angiotensin system (RAS) can prevent and delay the development of diabetes. Also, the role of RAS in the pathogenesis of diabetes, including insulin resistance and β‐cell dysfunction, has been extensively investigated. Nevertheless, this role had not yet been fully shown. A variety of possible protective mechanisms for RAS blockers in the regulation of glucose homeostasis have been suggested. However, the direct effect on pancreatic islet fibrosis has only recently been spotlighted. Various degrees of islet fibrosis are often observed in the islets of patients with type 2 diabetes mellitus, which can be associated with a decrease in β‐cell mass and function in these patients. Pancreatic stellate cells are thought to be deeply involved in this islet fibrosis. In this process, the activation of RAS in islets is shown to transform quiescent pancreatic stellate cells into the activated form, stimulates their proliferation and consequently leads to islet fibrotic destruction. In this article, we introduce existing clinical and experimental evidence for diabetes prevention through inhibition of RAS, and review the responsible local RAS signaling pathways in pancreatic stellate cells. Finally, we propose possible targets for the prevention of islet fibrosis.     

Pleural Effusion after Hepatic Radiofrequency Ablation with Artificial Ascites: Clinical Spectrum and Significance

PurposeTo retrospectively investigate incidence, clinical outcome, and risk factors of iatrogenic pleural effusion in patients with hepatic tumors undergoing radiofrequency (RF) ablation using artificial ascites (AA).Materials and MethodsPatients (N = 163) who underwent RF ablation using AA were classified into pleural effusion and non–pleural effusion groups according to the presence of pleural effusion on immediate follow-up CT and chest radiograph after RF ablation. The pleural effusion group included asymptomatic and symptomatic subgroups. The incidence and subsequent clinical outcomes of patients developing pleural effusion after RF ablation were evaluated.ResultsOverall, 96 patients (58.9%) developed pleural effusion, which resolved in 4.4 d ± 3.1. Hospital length of stay in the pleural effusion group was longer than the non-pleural effusion group (6.5 d ± 2.6 vs 5.7 d ± 2.8, P < .01). The pleural effusion group had longer AA infusion time (P = .01), larger infused AA volume (P < .01), and longer ablation time (P < .01) than the non-pleural effusion group. Eighteen patients (18.8%) developed symptomatic pleural effusion and had a larger infused AA volume than asymptomatic patients with pleural effusion (P < .01). Pleural effusion duration and hospital length stay were also longer in the symptomatic pleural effusion subgroup than in the asymptomatic subgroup (P < .01). Infused AA volume was the only independent prognostic factor of pleural effusion duration in multivariate analysis (P = .038).ConclusionsPleural effusion frequently occurs after RF ablation using AA. Although generally considered negligible, pleural effusion could be a clinical problem and prolong hospitalization. Therefore, operators should be careful not to infuse too much AA when performing RF ablation.     

Sleep disorders are distinctively associated with exercise intolerance and sedentary behavior in children with cystic fibrosis

ObjectiveTo evaluate the presence of sleep disorders and its associations with exercise capacity and daily physical activity levels among children and adolescents with CF.MethodsChildren age 6–18 years with a diagnosis of CF were recruited. Information regarding sociodemographic profile, pulmonary function and nutritional status were collected. Sleep disorders (polysomnography), exercise capacity (modified shuttle test - MST) and daily physical activity levels (questionnaire and five days accelerometer use) were evaluated.ResultsThirty-one patients, median age of 9.6 years and forced expiratory volume in 1 s (FEV₁) of 68.1 ± 24.4%, were included. Obstructive sleep apnea syndrome (OSAS) was present in 32.3% and nocturnal hypoxemia in 29%. The MST distance correlated with the mean peripheral oxyhemoglobin saturation (SpO₂) during sleep (r = 0.40) and the percent of total sleep time with SpO₂<90% (r = −0.49). The final MST SpO₂ correlated with the occurrence of OSAS (r = −0.48) and mean nocturnal SpO₂ (r = 0.45). Sedentary activities, as measured by accelerometry, correlated with sleep architecture, including the percent of stage II (r = 0.60) and rapid eye movement (REM) stage sleep (r = −0.37). Patients with OSAS and nocturnal hypoxemia presented lower values (p < 0.05) of distance and final SpO₂ in the MST. Nocturnal hypoxemia was the main variable to influence exercise capacity (r² = 0.521).ConclusionSleep disorders are distinctively related with exercise capacity and daily physical activity levels, as nocturnal hypoxemia is associated with exercise intolerance and sleep architecture disorders are associated with sedentary physical activity levels.     

Heterogeneity in the linear shiny white structures in melanomas seen with polarized light according to histopathological association: Cross-sectional observational study in 118 cutaneous melanomas

Polarized dermoscopy enables visualization of linear shiny white structures in melanomas, thought to be due to the existence of fibrosis in the dermis. Our objective was to establish the existence of two types of linear shiny white structures and assess their association with different histological structures. We performed a cross-sectional study including all non-acral, non-facial melanomas from our hospital with linear shiny white structures. The outcome variable was the type of linear shiny white structures: shiny white streaks and white strands. We evaluated their association with explanatory variables that may affect the reflectance of melanomas and Breslow index. We used χ² statistics and also calculated the sensitivity and specificity of each linear shiny white structure to predict those variables. We detected linear shiny white structures in 118 melanomas. Regarding shiny white streaks, we only found a statistically significant positive relationship with fibrosis in the papillary dermis. Regarding white strands, we found statistically significant and positive relationships with hyperkeratosis, Breslow index of 0.8 mm or more and acanthosis. Sensitivity and specificity study revealed that the presence of shiny white streaks was the most sensitive (81.7%) and specific (72.3%) for fibrosis in the papillary dermis, and presence of white strands was the most sensitive (91.1%) and specific (85.7%) for hyperkeratosis.