Neurovascular unit dysfunction with blood-brain barrier hyperpermeability contributes to major depressive disorder: a review of clinical and experimental evidence

About one-third of people with major depressive disorder (MDD) fail at least two antidepressant drug trials at 1 year. Together with clinical and experimental evidence indicating that the pathophysiology of MDD is multifactorial, this observation underscores the importance of elucidating mechanisms beyond monoaminergic dysregulation that can contribute to the genesis and persistence of MDD. Oxidative stress and neuroinflammation are mechanistically linked to the presence of neurovascular dysfunction with blood-brain barrier (BBB) hyperpermeability in selected neurological disorders, such as stroke, epilepsy, multiple sclerosis, traumatic brain injury, and Alzheimer’s disease. In contrast to other major psychiatric disorders, MDD is frequently comorbid with such neurological disorders and constitutes an independent risk factor for morbidity and mortality in disorders characterized by vascular endothelial dysfunction (cardiovascular disease and diabetes mellitus). Oxidative stress and neuroinflammation are implicated in the neurobiology of MDD. More recent evidence links neurovascular dysfunction with BBB hyperpermeability to MDD without neurological comorbidity. We review this emerging literature and present a theoretical integration between these abnormalities to those involving oxidative stress and neuroinflammation in MDD. We discuss our hypothesis that alterations in endothelial nitric oxide levels and endothelial nitric oxide synthase uncoupling are central mechanistic links in this regard. Understanding the contribution of neurovascular dysfunction with BBB hyperpermeability to the pathophysiology of MDD may help to identify novel therapeutic and preventative approaches

Co2+ substituted Mg–Cu–Zn ferrite: Evaluation of structural, magnetic, and electromagnetic properties

Abstract We report the synthesis of Co2+ substituted Mg–Cu–Zn ferrite via citrate gel combustion process and thereby its structural, transport, and magnetic properties for the use in electromagnetic energy absorption application. The polycrystalline ferrite system is investigated by interplay of stoichiometric composition with Mg0.25–x Co x Cu0.25Zn0.5Fe2O4 (0 ⩽ x ⩽ 0.25). Structural investigations using X-ray diffraction (XRD) and selected area electron diffraction (SAED) reveal the formation of spinel structure with linear growth of lattice constant due to Co2+ substitution. The microstructural analysis (TEM and SEM) depicts the dense microstructure with the average grain size of 0.42–1.25 μm. The elemental analysis (EDS) confirms the elemental composition of the as-prepared ferrite with respect to the initial concentrations of the synthetic composition used. The observed variations in initial permeability (μ i) and magnetic moment (n B) are explained based on deviation in saturation magnetization (M s), anisotropy constant (K 1), density values, and exchange interaction. The temperature dependence of DC resistivity confirms the semiconducting behavior of the as-prepared ferrite material, with an increase in the DC resistivity by an incorporation of cobalt. Furthermore, the effects of adding Co2+ on the Curie temperature, frequency dependent dielectric properties of the ferrite material are also discussed

Cloning, characterization and paper pulp applications of a newly isolated DyP type peroxidase from Rhodococcus sp. T1

WOS: 000462022300057PubMed: 30474775A newly identified ligninolytic Rhodococcus strain (Rhodococcus sp. T1) was isolated from forestry wastes (Trabzon/Turkey). The DyP type peroxidase of Rhodococcus sp. T1 (DyPT1) was cloned, characterized and paper treated for industrial applications. Molecular weight of the protein was about 38kDa. The kinetic parameters were 0.94mM and 1417.53 mu mol/min/mg for Km and Vmax, respectively. The enzyme was active at the temperature range of 25-65 degrees C and optimum temperature was 35 degrees C, enzyme was stable up to 6 days at room temperature. Optimum pH of the DyPT1 was 4.0 and it was stable between pH 4.0-6.0 up to 8 days at room temperature. Effects of some metal ions, Hemin, and some chemical agents on DyPT1 were determined. Hemin has implemented protective effects on the stability and the activity of the enzyme in long time periods when added into growing medium. DyPT1 was applied to eucalyptus kraft pulp for analyzing the bleaching efficiency, physical and optical tests of the manufuctared paper were carried out. Application of lignin peroxidase to kraft pulp caused a decrease of 5.2 units for kappa number and an increase from 52.05 to 64.18% in the delignification rate.Karadeniz Technical University Research Foundation [FBA-2015-5182]This study was financially supported by Karadeniz Technical University Research Foundation (Project No: FBA-2015-5182)