The Significance of Vascular Alterations in Acute and Chronic Rejection for Vascularized Composite Allotransplantation.

Vascularized composite allotransplantation (VCA) has emerged as a useful reconstructive option for patients suffering from major tissue defects and functional deficits. While the technical feasibility has been optimized and more than 130 VCAs have been performed during the last two decades, hurdles such as acute and chronic allograft rejection, graft deterioration, and eventual functional impairment need to be addressed. Recently, chronic graft rejection and progressive failure have been linked to vascular alterations observed in the allografts. Graft vasculopathy (GV) may play a pivotal role in long-term graft deterioration. The understanding of the underlying pathophysiological processes and their initial triggers is of utmost importance in the prevention, attenuation, and therapy of GV. While there are reports on the etiology and development of GV in solid organ transplantation, there are limited data with respect to chronic rejection and GV in the realm of VCA. Nevertheless, recent reports from long-term VCA recipients suggest that GV could truly jeopardize allografts in the follow-up evaluation. Chronic rejection and GV include different entities and might have different pathways in distinct organs. Herein, we reviewed the current literature on vascular changes during both acute and chronic allograft rejection, with a focus on their clinical and translational significance for VCA

mTORC1 Inhibition Protects Human Regulatory T Cells From Granzyme-B-Induced Apoptosis

Regulatory T cells (T-regs) have shown great promise as a means of cellular therapy in a multitude of allo- and auto-immune diseases-due in part to their immunosuppressive potency. Nevertheless, the clinical efficacy of human T-regs in patients has been limited by their poor in vivo homeostasis. To avert apoptosis, T-regs require stable antigenic (CD3 zeta/T-cell-receptor-mediated), co-stimulatory (CD28-driven), and cytokine (IL-2-dependent) signaling. Notably, this sequence of signals supports an activated T-reg phenotype that includes a high expression of granzymes, particularly granzyme B (GrB). Previously, we have shown that aside from the functional effects of GrB in lysing target cells to modulate allo-immunity, GrB can leak out of the intracellular lysosomal granules of host T-regs, initiating pro-apoptotic pathways. Here, we assessed the role of inhibiting mechanistic target of rapamycin complex 1 (mTORC1), a recently favored drug target in the transplant field, in regulating human T-reg apoptosis via GrB. Using ex vivo models of human T-reg culture and a humanized mouse model of human skin allotransplantation, we found that by inhibiting mTORC1 using rapamycin, intracytoplasmic expression and functionality of GrB diminished in host T-regs; lowering human T-reg apoptosis by in part decreasing the phosphorylation of S6K and c-Jun. These findings support the already clinically validated effects of mTORC1 inhibition in patients, most notably their stabilization of T-reg bioactivity and in vivo homeostasis

Association of lipoprotein levels with sleep apnea: role of autonomic dysfunction

Objectives. Although multiple mechanisms, including autonomic dysfunction, seem to link sleep-disordered breathing (SDB) with dyslipidemia in animal studies, the data in clinical studies are limited. The aim of this study was to explore the association of lipoprotein levels with SDB measures in healthy habitual snorers. We supposed that autonomic dysfunction is the linking mechanism

Factors Associated with Non-Attendance at Dental Preventive Care in Slovak High School Students

This study aimed to determine the factors associated with the avoidance of dental preventive care in high school students and their parents in the framework of The Youth and Parents Risk Factor Behavior Survey in Slovakia, the ongoing cross-sectional school-based survey of students and their parents or legal representatives. The data were collected using two separate standardized questionnaires: (i) the questionnaire for students (n = 515) and (ii) the questionnaire for parents (n = 681). The study group included 57 high school students (54.4% males) who did not visit the dentist for preventive care in the previous year. The control group included 458 students (35.8% males) who visited a dentist for preventive care at least once in the previous year. A significantly higher number of males (54.4%), older adolescents, and young adults (21.8%; 20.0%) were not visiting dental preventive care regularly. Incomplete family (56.1%), stressful situations at home (17.5%), and feeling unwell were the factors contributing to the avoidance of dental preventive care. More than 34.5% of adolescents and young adults were not visiting either dental preventive care or pediatric preventive care (adjusted odds ratio (AOR) = 5.14; 95% confidence interval (CI) = 2.40, 10.99). Children of divorced mothers and mothers with household income lower than EUR 900 had significantly higher dental care avoidance in bivariate analysis. A significantly higher percentage of fathers from the exposed group were not visiting dental preventive care regularly (47.8%, p < 0.05). The results of the study can be used as an educational intervention step focusing on the parental influence on adolescent and young adults’ behavior and as a challenge for the improvement of dental preventive care in older adolescents and young adults

LDL and HDL lipoprotein subfractions in multiple sclerosis patients with decreased insulin sensitivity

Objectives. Increased metabolic and cardiovascular morbidity has been reported in multiple sclerosis (MS) patients. Previously, we have found decreased insulin sensitivity and hyperinsulinemia in a group of newly diagnosed MS patients. We hypothesize that these features may be associated with an altered lipid profile and low, intermediate, or high density lipoprotein (LDL, IDL, HDL) subclasses accelerating atherosclerosis and thus contributing to the cardiovascular risk increase in these patients

The Interplay of Dyslipidemia, Oxidative Stress, and Clinical Outcomes in Acute Ischemic Stroke Patients with and without Coronary Artery Disease

We assessed lipid and lipoprotein profiles, along with oxidative stress (OS) parameters, in patients within the crucial 24 h period following an acute ischemic stroke (AIS), comparing those with and without coronary artery disease (CAD). We aimed to correlate these measures with clinical condition scales (NIHSS, mRS) post-AIS. This study included 27 AIS patients without CAD (AIS group) and 37 AIS patients with CAD (CAD-AIS group). Using polyacrylamide gel electrophoresis (Lipoprint system), we determined plasma LDL and HDL subfractions. Spectrophotometric methods were used to assess plasma antioxidant capacity, lipoperoxides, homocysteine (HC) levels, paraoxonase1, and catalase activities. We also measured urine isoprostanes and the activities of antioxidant enzymes (SOD, GPx) with commercial kits. CAD-AIS patients had notably higher HC levels, while there were no significant differences in lipoprotein subfractions and OS parameters between both groups. In the AIS group, mRS scores showed negative correlations with catalase, GPx activities, and total cholesterol. In the CAD-AIS group, atherogenic lipoproteins (IDLC, LDL2, LDL3–7) exhibited a significant positive correlation with mRS. This study underscores the role of dyslipidemia and OS in the development of AIS and CAD. It emphasizes the complex connections between specific biomarkers and post-stroke clinical outcomes. Our results suggest a significant impact of CAD treatment on lipid profile but not on homocysteine levels. The traditional narrative associating high cholesterol as the ultimate risk factor for cardiovascular diseases needs to be challenged, at least with respect to neurological outcomes. These insights may guide more targeted therapeutic approaches

Lipoprotein Subfractions Associated with Endothelial Function in Previously Healthy Subjects with Newly Diagnosed Sleep Apnea—A Pilot Study

Background: Obstructive sleep apnea (OSA) activates several pathophysiological mechanisms which can lead to the development of vascular diseases. Endothelial dysfunction (ED) is an initial step in the development of atherosclerosis. The association between ED and OSA has been described in several studies, even in previously healthy subjects. High-density lipoproteins (HDL) were generally considered to be atheroprotective, and low-density lipoprotein (LDL) to be an atherogenic component of lipoproteins. However, recent findings suggest a pro-atherogenic role of small HDL subfractions (8–10) and LDL subfractions (3–7). This study aimed to evaluate the relationship between endothelial function and lipid subfractions in previously healthy OSA subjects. Material and Methods: We prospectively enrolled 205 subjects with sleep monitoring. Plasma levels of triacylglycerols, total cholesterol, LDL, HDL, and their subfractions were assessed. Endothelial function was determined using peripheral arterial tonometry, and reperfusion hyperemia index (RHI) was assessed. Results: Plasma levels of small and intermediate HDL subfractions have statistically significant pro-atherogenic correlations with endothelial function (p = 0.015 and p = 0.019). In other lipoprotein levels, no other significant correlation was found with RHI. In stepwise multiple linear regression analysis, small HDL (beta = −0.507, p = 0.032) was the only significant contributor in the model predicting RHI. Conclusions: In our studied sample, a pro-atherogenic role of small HDL subfractions in previously healthy subjects with moderate-to-severe OSA was proven

Lipoprotein Subfractions Associated with Endothelial Function in Previously Healthy Subjects with Newly Diagnosed Sleep Apnea—A Pilot Study

Background: Obstructive sleep apnea (OSA) activates several pathophysiological mechanisms which can lead to the development of vascular diseases. Endothelial dysfunction (ED) is an initial step in the development of atherosclerosis. The association between ED and OSA has been described in several studies, even in previously healthy subjects. High-density lipoproteins (HDL) were generally considered to be atheroprotective, and low-density lipoprotein (LDL) to be an atherogenic component of lipoproteins. However, recent findings suggest a pro-atherogenic role of small HDL subfractions (8–10) and LDL subfractions (3–7). This study aimed to evaluate the relationship between endothelial function and lipid subfractions in previously healthy OSA subjects. Material and Methods: We prospectively enrolled 205 subjects with sleep monitoring. Plasma levels of triacylglycerols, total cholesterol, LDL, HDL, and their subfractions were assessed. Endothelial function was determined using peripheral arterial tonometry, and reperfusion hyperemia index (RHI) was assessed. Results: Plasma levels of small and intermediate HDL subfractions have statistically significant pro-atherogenic correlations with endothelial function (p = 0.015 and p = 0.019). In other lipoprotein levels, no other significant correlation was found with RHI. In stepwise multiple linear regression analysis, small HDL (beta = −0.507, p = 0.032) was the only significant contributor in the model predicting RHI. Conclusions: In our studied sample, a pro-atherogenic role of small HDL subfractions in previously healthy subjects with moderate-to-severe OSA was proven