01:16
A high serum level of homocysteine, known as hyperhomocystenemia (HHcy) is associated with vascular dysfunction such as altered angiogenesis and increased membrane permeability. Epidemiological studies have found associations between HHcy and Alzheimer’s disease (AD) progression that eventually leads to vascular dementia (VaD).
VaD is the second most common cause of dementia in people older than 65, the first being AD. VaD affects the quality of life for those suffering by drastically decreasing their cognitive function. VaD, a cerebrovascular disease, generally occurs due to cerebral ischemic events from either decreased perfusion or hemorrhagic lesions. HHcy is associated with the hallmarks of dementia such as tau phosphorylation, Aβ aggregation, neurofibrillary tangle (NFT) formation, neuroinflammation, and neurodegeneration. Previous reports also suggest HHcy may promote AD like pathology by more than one mechanism, including cerebral microangiopathy, endothelial dysfunction, oxidative stress, neurotoxicity and apoptosis. Despite the corelations presented above, the question still exists – does homocysteine have a causal connection to AD? In this review, we highlight the role of HHcy in relation to AD by discussing its neurovascular effects and amelioration with dietary supplements. Moreover, we consider the studies using animal models to unravel the connection of Hcy to AD.
05:00
This article aims to introduce and demonstrate the application of the standardization and decomposition analysis (SDA) method to gauge differences in HIV prevalence rates among injection drug users (IDUs) across regions (Northeast, South, Midwest, and West) in the U.S.
Using the SDA, the regional HIV prevalence rates were standardized and a rate difference between regions was decomposed into component effects, such as the “real” rate difference, and component effects attributed to differences in specific compositions of confounding factors. A total of 9,824 injection drug users (IDUs) retrieved from the national database of the National Institute on Drug Abuse’s Cooperative Agreement for AIDS Community-Based Outreach/Intervention Research Program (COOP) projects constitute the sample for the study. A computer program DECOMP was used to implement the multi-population SDA.
Neurite outgrowth is an important morphological phenotype of neuronal cells that correlates with their function and cell health, yet there are limited methods available for measuring this phenomenon. Current approaches to measuring neurite outgrowth are laborious and time-consuming, relying largely upon immunocytochemical staining of neuronal markers (e.g., beta-III tubulin or MAP2) followed by manual or automated microscopy for image acquisition and analysis. Here we report the development of a quick and simple dual-color fluorescent dye-based staining method that allows for the simultaneous measurement of neuronal cell health and relative neurite outgrowth from the same sample.
An orangered fluorescent dye that stains cell membrane surfaces is used as an indirect reporter of changes in relative neurite outgrowth due to alterations in the number or length of membrane projections emanating from neuronal cell bodies. Cell viability is assessed simultaneously via the use of a cell-permeant dye that is converted by intracellular esterase activity from a non-fluorescent substrate to a green-fluorescent product. Using Neuroscreen-1 cells (a PC-12 subclone), primary rat cortex neurons, and human induced pluripotent stem cell (iPSC)-derived neurons, we demonstrate that this multiplex assay allows for rapid visualization and unbiased, quantitative plate reader analysis of neuronal cell health and neurite outgrowth.
02:23
The glass molding process (GMP) can press glass perform into a shape of finished lens under high pressure and temperature conditions, and it is easy to achieve mass production. So, it has emerged as a promising alternative way to produce complex shapes lens. It is well known that viscoelastic is one important properties of glass at high temperature. In this study, A 4-pair generalized maxwell model was used to express viscoelastic of glass, and model parameters were obtained by fitting the relaxation curve obtained from experiment.
The finite element models were established by MSC.MARC, the correctness of the FEM models and its used model parameters were verified by the cylindrical compression experiments. Finally, the simulations of glass lens forming stage were performed under different conditions. Stresses distribution were predicted by FEM, it was found that the maximum stress at the edge of lens, which make lens rupture easily at this zone. It was also discovered that the molding temperature is higher, the less stress, and the molding velocity is higher, the higher stress.
02:02
The recreational use of androgenic anabolic steroids (AAS) has been associated with a range of health and psychological problems in the past, but very little research has considered what impact AAS might have upon cognition and memory. The present study aimed to identify whether the recreational use of AAS is linked to deficits in everyday retrospective memory (RM) and everyday prospective memory (PM). We assessed self-reports of RM and PM in 25 regular AAS users and 28 Non-Users (all were males, regular gym users and aged between 18-30 years) using the Prospective and Retrospective Memory Questionnaire.
A Recreational Drug Use Questionnaire was used to measure AAS use and alcohol use. The Hospital Anxiety and Depression Scale measuredtwo dimensions of mood (anxiety and depression). The results revealed thatrecreational AAS users reported significantly more everyday RM lapses (AAS Mean = 2.41 vs Non-Users Mean = 1.66; p<0.001)and significantly more everyday PM lapses (AAS Mean = 2.79 vs Non-User Mean = 1.84; p<0.001) than the Non-User group. These findings were not attributable to other substance use or mood variations. This is the first study to demonstrate everyday memory deficits associated with AAS use and it is suggested that such deficits be added to the growing list of health and cognitive problems associated with AAS use.
