Matrix Metalloproteinases 2 and 9 Polymorphism in Patients With Myeloproliferative Diseases: A STROBE-Compliant Observational Study

Chronic myeloproliferative disorders such as polycythemia vera (PV), essential thrombocytosis (ET), and idiopathic myelofibrosis arise from clonal proliferation of neoplastic stem cells in the bone marrow. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have potential to degrade all types of extracellular matrix (ECM) and also play a role in remodeling of the ECM. It is known that MMPs play a role in bone marrow remodeling.The primary goal of our study is to explore the relationship between chronic myeloproliferative diseases and some of MMP gene polymorphisms. The demonstration of a relationship will help to understand whether these polymorphisms may be a potential early diagnosis marker of the diseases.Patients were selected from outpatient clinics of Turgut Ozal University Hospital, Ankara, Turkey, between December 2010 and May 2011. Twenty-eight patients that previously diagnosed and followed-up with PV, 17 with secondary polycythemia (SP), and 12 with ET were enrolled in the study, along with a control group of 22 healthy people.DNA was isolated from peripheral blood. Using polymerase chain reaction–restriction fragment length polymorphism method, MMP2 and MMP9 gene polymorphisms were analyzed with agarose gel electrophoresis. There was a statistically significant difference between the study groups and the control group in terms of Gln279Arg polymorphisms rates of MMP9. The highest MMP9 Gln279Arg polymorphism rate was observed in the ET group. But nobody from the control group had polymorphic MMP9. There was no statistically significant difference between the groups in terms of MMP2-735 C > T polymorphism rates.In conclusion, MMP9 gene Gln279Arg polymorphism was associated with ET, SP, and PV diseases. Hence, we believe that these gene polymorphisms may play a role in the mechanism of bone marrow fibrosis and may be a factor that increases the risk of thrombosis. Illumination of the molecular basis of the relationship between MMP-thrombosis and MMP-fibrosis provides a better understanding of the pathophysiology of PV and ET diseases and will allow new approaches to diagnosis and treatment.     

Estimation of phase signal change in neuronal current MRI for evoke response of tactile detection with realistic somatosensory laminar network model

Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm³. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation.     

Comparison of the anatomic and hearing outcomes of cartilage type 1 tympanoplasty in pediatric and adult patients

European Archives of Oto-Rhino-Laryngology - As a graft material cartilage produces an excellent anatomical result with a low risk of re-perforation. However, there is a controversy among surgeons...     

Melatonin ameliorates amyloid beta‐induced memory deficits,tau hyperphosphorylation and neurodegeneration via PI3/Akt/GSk3β pathway in the mouse hippocampus

Alzheimer's disease (AD) is the most prevalent age‐related neurodegenerative disease, pathologically characterized by the accumulation of amyloid beta (Aβ) aggregation in the brain, and is considered to be the primary cause of cognitive dysfunction. Aβ aggregates lead to synaptic disorder, tau hyperphosphorylation, and neurodegeneration. In this study, the underlying neuroprotective mechanism of melatonin against Aβ_1‐42‐induced neurotoxicity was investigated in the mice hippocampus. Intracerebroventricular (i.c.v.) Aβ_1‐42‐injection triggered memory impairment, synaptic disorder, hyperphosphorylation of tau protein, and neurodegeneration in the mice hippocampus. After 24 hr of Aβ_1‐42 injection, the mice were treated with melatonin (10 mg/kg, intraperitonially) for 3 wks, reversed the Aβ_1‐42‐induced synaptic disorder via increasing the level of presyanptic (Synaptophysin and SNAP‐25) and postsynaptic protein [PSD95, p‐GluR1 (Ser845), SNAP23, and p‐CREB (Ser133)], respectively, and attenuated the Aβ_1‐42‐induced memory impairment. Chronic melatonin treatment attenuated the hyperphosphorylation of tau protein via PI3K/Akt/GSK3β signaling by activating the p‐PI3K, p‐Akt (Ser 473) and p‐GSK3β (Ser9) in the Aβ_1‐42‐treated mice. Furthermore, melatonin decreased Aβ_1‐42‐induced apoptosis through decreasing the overexpression of caspase‐9, caspase‐3, and PARP‐1 level. Additionally, the evaluation of immunohistochemical analysis of caspase‐3, Fluorojade‐B, and Nissl staining indicated that melatonin prevented neurodegeneration in Aβ_1‐42‐treated mice. Our results demonstrated that melatonin has neuroprotective effect against Aβ_1‐42‐induced neurotoxicity through decreasing memory impairment, synaptic disorder, tau hyperphosphorylation, and neurodegeneration via PI3K/Akt/GSK3β signaling in the Aβ_1‐42‐treated mouse model of AD. On the basis of these results, we suggest that melatonin could be an effective, promising, and safe neuroprotective candidate for the treatment of progressive neurodegenerative disorders, such as AD.