Monte Carlo and phantom study in the brain edema models

Because the brain edema has a crucial impact on morbidity and mortality,it is important to develop a noninvasive method to monitor the process of the brain edema effectively.When the brain edema occurs,the optical properties of the brain will change.The goal of this study is to access the feasibility and reliability of using noninvasive near-infrared spectroscopy(NIRS)monitoring method to measure the brain edema.Specifically,three models,including the water content changes in the cerebrospinal fuid(CSF),gray matter and white matter,were explored.Moreover,these models were numerically simulated by the Monte Carlo studies.Then,the phantom experiments were performed to investigate the light intensity which was measured at different detecting radius on the tissue surface.The results indicated that the light intensity correlated well with the conditions of the brain edema and the detecting radius.Briefly,at the detect ing radius of 3.0 cm and 4.0 cm,the light intensity has a high response to the change of tissue parameters and optical properties.Thus,it is possible to monitor the brain edema noninvasively by NIRS method and the light intensity is a reliable and simple parameter to assess the brain edema.

Dense core vesicle markers in CSF and cortical tissues of patients with Alzheimer’s disease

Background:New fuid biomarkers for Alzheimer’s disease(AD)that reveal synaptic and neural network dysfunc‑tions are needed for clinical practice and therapeutic trial design.Dense core vesicle(DCV)cargos are promising cerebrospinal fuid(CSF)indicators of synaptic failure in AD patients.However,their value as biomarkers has not yet been determined.Methods:Immunoassays were performed to analyze the secretory proteins prohormone convertases PC1/3 and PC2,carboxypeptidase E(CPE),secretogranins SgIII and SgII,and Cystatin C in the cerebral cortex(n=45,provided by Bellvitge University Hospital)and CSF samples(n=66,provided by The Sant Pau Initiative on Neurodegeneration cohort)from AD patients(n=56)and age-matched controls(n=55).Results:In AD tissues,most DCV proteins were aberrantly accumulated in dystrophic neurites and activated astro‑cytes,whereas PC1/3,PC2 and CPE were also specifcally accumulated in hippocampal granulovacuolar degeneration bodies.AD individuals displayed an overall decline of secretory proteins in the CSF.Interestingly,in AD patients,the CSF levels of prohormone convertases strongly correlated inversely with those of neurodegeneration markers and directly with cognitive impairment status.Conclusions:These results demonstrate marked alterations of neuronal-specifc prohormone convertases in CSF and cortical tissues of AD patients.The neuronal DCV cargos are biomarker candidates for synaptic dysfunction and neurodegeneration in AD.