Atherosclerosis, which is the most common chronic disease of the coronary artery, constitutes a vascular pathology induced by inflammation and plaque accumulation within arterial vessel walls. Both DNA methylation and histone modifications are epigenetic changes relevant for atherosclerosis. Recent studies have shown that the DNA methylation and histone modification systems are closely interrelated and mechanically dependent on each other. Herein, we explore the functional linkage between these systems, with a particular emphasis on several recent findings suggesting that histone acetylation can help in targeting DNA methylation and that DNA methylation may control gene expression during atherosclerosis.
Oxidative stress has been implicated as critical pathogenic factors contributing to the etiology of diabetic retinopathy and other retinal diseases. This study investigated antioxidative effect of ascorbic acid and astaxanthin on ARPE-19 cells within an oxidative stress model induced by common biological sources of reactive oxygen species (ROS). Hydrogen peroxide (H2O2) at concentrations of 0.1–0.8 mM and 20–100 mJ/cm2 of ultraviolet B (UVB) were treated to ARPE-19 cells. Cell viability and intracellular ROS level changes were measured. With the sublethal and lethal dose of each inducers, 0–750 μM of ascorbic acid and 0–40 μM of astaxanthin were treated to examine antioxidative effect on the model. Ascorbic acid at concentrations of 500 and 750 μM increased the cell viability not only in the UVB model but also in the H2O2 model, but 20 and 40 μM of astaxanthin only did so in the UVB model. The combination of ascorbic acid and astaxanthin showed better antioxidative effect compared to each drug alone, suggesting a synergistic effect.
Tumor necrosis (TN) can lower responsiveness to chemotherapy and confer basic resistance to anti-cancer therapy. We investigated the association of TN with poor clinical features and outcome in diffuse large B cell lymphoma (DLBCL). We examined the presence or absence of TN in 476 DLBCL patients of who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy. Eighty-nine (18.7 %) patients had TN at diagnosis. Patients with TN had a progression-free survival (PFS) and overall survival (OS) of 39.3 and 46.7 %, whereas patients without TN had a PFS and OS of 73.4 and 82.6 %. Adverse clinical factors of poor Eastern Cooperative Oncology Group performance status ≥ grade 2 (p = 0.005), elevated lactate dehydrogenase ratio >1 (p < 0.001), advanced Ann Arbor stage (p = 0.002), and bulky disease (p = 0.026) were more prevalent in the TN group than the non-TN group. Cox regression model analysis revealed TN as an independent prognostic factor for PFS and OS in DLBCL (PFS, hazard ratio [HR] = 1.967, 95 % confidence interval [CI] = 1.399-2.765, p < 0.001; OS, HR = 2.445, 95 % CI = 1.689-3.640, p < 0.001). The results indicate that TN could reflect adverse clinical features and worse prognosis in DLBCL patients receiving R-CHOP therapy.
Purpose
Vitreous vitamin C, as an anti-oxidant, is responsible for regulating oxygen tension and oxidative stress in the eye. Oxidative stress and retinal ischemia are implicated in the development of proliferative diabetic retinopathy (PDR). In this study, we aimed to determine whether vitreous level of vitamin C is compromised in patients with PDR and to investigate the association of diabetic macular ischemia and vitamin C.
Methods
This prospective study enrolled forty patients who underwent pars plana vitrectomy for the treatment of PDR (PDR group, n = 20) and idiopathic epiretinal membrane (control group, n = 20). Serum, aqueous humor, and the vitreous were collected for the analysis of vitamin C level by HPLC. Diabetic macular ischemia (DMI) in PDR group was evaluated with fluorescein angiography (FA).
Results
PDR patients (60.4 ± 2.1 y) were younger than non-diabetic control patients (67.4 ± 1.2 y). Serum, aqueous, and vitreous levels of vitamin C in PDR were 38.7%, 22.5%, and 11.1% of non-diabetic control group, respectively. All PDR patients had DMI (grade 1: 25%, grade 2: 30%, grade 3: 30%, grade 4: 15%). DMI grade was inversely correlated with the level of vitreous vitamin C (r = -0.546, P = 0.019), not with HbA1C, serum, or aqueous vitamin C level. In addition, the level of vitreous vitamin C (4.5 ± 2.6 μg/ml) in high DMI group (Gr 3 &4) was lower than that (31.0 ± 9.1 μg/ml) in low DMI group (Gr 1&2) (
P
= 0.015).
Conclusions
Vitreous level of vitamin C in PDR patients showed a tenfold decrease, which was associated with the degree of macular ischemia. This suggests that vitreous vitamin C depletion may cause macula ischemia in PDR patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.