There is accumulating evidence that soluble amyloid-beta (Abeta) oligomers, rather than amyloid fibrils, are the principal pathogenic species in Alzheimer disease (AD). Here, we have developed a novel enzyme-linked immunosorbent assay (ELISA) specific for high-molecular-weight (HMW) Abeta oligomers. Analysis of Abeta oligomers derived from synthetic Abeta 1-42, by size-exclusion chromatography (SEC), revealed that our ELISA specifically detected HMW Abeta oligomers of 40-200 kDa. Using this ELISA, we detected significantly higher (P<0.0001) signals in cerebrospinal fluid (CSF) samples from 25 patients with AD or mild cognitive impairment (MCI), compared to 25 age-matched controls. As a test for discriminating between the AD/MCI and control groups, the area under the curve in receiver operating characteristic analysis for the CSF HMW Abeta oligomers was greater than that for CSF Abeta x-42. Furthermore, the CSF levels of HMW Abeta oligomers showed a negative correlation with Mini-Mental State Examination scores in the AD/MCI group. We conclude that the CSF HMW Abeta oligomers detected by our ELISA could be useful as a diagnostic marker for AD, and also as a potential surrogate marker for disease severity. Our results support the idea that soluble HMW Abeta oligomers play a critical role in the pathogenesis and progression of AD.

BackgroundThere is still a substantial unmet need for less invasive and lower-cost blood-based biomarkers to detect brain Alzheimer’s disease (AD) pathology. This study is aimed to determine whether quantification of plasma tau phosphorylated at threonine 181 (p-tau181) is informative in the diagnosis of AD.MethodsWe have developed a novel ultrasensitive immunoassay to quantify plasma p-tau181, and measured the levels of plasma p-tau181 in three cohorts.ResultsIn the first cohort composed of 20 AD patients and 15 age-matched controls, the plasma levels of p-tau181 were significantly higher in the AD patients than those in the controls (0.171 ± 0.166 pg/ml in AD versus 0.0405 ± 0.0756 pg/ml in controls, p = 0.0039). The percentage of the subjects whose levels of plasma p-tau181 exceeded the cut-off value (0.0921 pg/ml) was significantly higher in the AD group compared with the control group (60% in AD versus 16.7% in controls, p = 0.0090). In the second cohort composed of 20 patients with Down syndrome (DS) and 22 age-matched controls, the plasma concentrations of p-tau181 were significantly higher in the DS group (0.767 ± 1.26 pg/ml in DS versus 0.0415 ± 0.0710 pg/ml in controls, p = 0.0313). There was a significant correlation between the plasma levels of p-tau181 and age in the DS group (R2 = 0.4451, p = 0.0013). All of the DS individuals showing an extremely high concentration of plasma p-tau181 (> 1.0 pg/ml) were older than the age of 40. In the third cohort composed of 8 AD patients and 3 patients with other neurological diseases, the levels of plasma p-tau181 significantly correlated with those of CSF p-tau181 (R2 = 0.4525, p = 0.023).ConclusionsWe report for the first time quantitative data on the plasma levels of p-tau181 in controls and patients with AD and DS, and these data suggest that the plasma p-tau181 is a promising blood biomarker for brain AD pathology. This exploratory pilot study warrants further large-scale and well-controlled studies to validate the usefulness of plasma p-tau181 as an urgently needed surrogate marker for the diagnosis and disease progression of AD.Electronic supplementary materialThe online version of this article (doi:10.1186/s13024-017-0206-8) contains supplementary material, which is available to authorized users.

OBJECTIVE-Mesenchymal stem cells (MSCs) have been reported to secrete various cytokines that exhibit angiogenic and neurosupportive effects. This study was conducted to investigate the effects of MSC transplantation on diabetic polyneuropathy (DPN) in rats.RESEARCH DESIGN AND METHODS-MSCs were isolated from bone marrow of adult rats and transplanted into hind limb skeletal muscles of rats with an 8-week duration of streptozotocin (STZ)-induced diabetes or age-matched normal rats by unilateral intramuscular injection. Four weeks after transplantation, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) productions in transplanted sites, current perception threshold, nerve conduction velocity (NCV), sciatic nerve blood flow (SNBF), capillary number-to-muscle fiber ratio in soleus muscles, and sural nerve morphometry were evaluated.RESULTS-VEGF and bFGF mRNA expression were significantly increased in MSC-injected thigh muscles of STZ-induced diabetic rats. Furthermore, colocalization of MSCs with VEGF and bFGF in the transplanted sites was confirmed. STZ-induced diabetic rats showed hypoalgesia, delayed NCV, decreased SNBF, and decreased capillary number-to-muscle fiber ratio in soleus muscles, which were all ameliorated by MSC transplantation. Sural nerve morphometry showed decreased axonal circularity in STZ-induced diabetic rats, which was normalized by MSC transplantation. D iabetic polyneuropathy (DPN) is the most common complication of diabetes. It is estimated that ϳ20 -30% of diabetic patients are affected by symptomatic DPN (1). Generally, DPN develops symmetrically in a length-dependent fashion, with dying back or dropout of the longest nerve fibers; both myelinated and unmyelinated, large and small are affected. Diabetic patients suffer from various symptoms of DPN, such as spontaneous pain, hyperalgesia, and diminished sensation (2). It has been shown that tight glycemic control is effective in slowing the progression of DPN but cannot completely prevent it (3). Therefore, additional therapeutic strategies are required. CONCLUSIONS-TheseNeural cell degeneration and decreased nerve blood flow (NBF) have been recognized as pathophysiologically characteristic features of DPN (4). Therefore, therapeutic agents that could act as both neurotrophic and angiogenic factors would be useful for the treatment of DPN even at an advanced stage. We previously demonstrated that local administration of basic fibroblast growth factor (bFGF) by intramusclar injection with crosslinked gelatin hydrogel improved the impaired nerve functions of streptozotocin (STZ)-induced diabetic rats, including amelioration of decreased NBF, hypoalgesia, and the delayed motor nerve conduction velocity (MNCV) on the treated side of sciatictibial nerves and that these effects were maintained for at least 30 days (5). Schratzberger et al. (6) showed that vascular endothelial growth factor (VEGF) gene transfer significantly increased the NCV and NBF as well as the vascular densities in muscle and peripheral nerv...

Background: Supported by compelling genetic data regarding early-onset familial Alzheimer disease (AD), the amyloid ␤-peptide (A␤)-centric theory holds that A␤ is involved in the pathogenesis of sporadic AD. Mutations in the amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) genes lead to increased A␤ levels before symptoms arise.Objectives: To evaluate the pattern of Pittsburgh Compound B (PiB) retention in subjects with different autosomal dominant mutations associated with familial AD vs that in healthy age-matched control subjects and subjects with probable sporadic AD, to correlate A␤ burden as measured by PiB with available clinical and cognitive data, and to compare the regional brain patterns of PiB retention and fluorodeoxyglucose F 18 (FDG) uptake.Design: Correlation analysis of positron emission tomography (PET) imaging studies.Setting: Academic research.Participants: Seven PSEN1 mutation carriers and 1 APP mutation carrier underwent PiB and FDG PET imaging. Amyloid ␤-peptide burden and FDG uptake were established using standardized uptake values normalized to pons.Main Outcome Measure: Primary outcomes were PET results, which were compared with those of a wellcharacterized cohort of 30 healthy control subjects and 30 subjects with probable sporadic AD.

We present a case of a 32-year-old diabetic woman with Prader–Willi syndrome who developed severe ketoacidosis caused by a sodium-glucose cotransporter 2 (SGLT2) inhibitor, a novel class of antihyperglycemic agents, during a strict low-carbohydrate diet. At admission, a serum glucose level of 191 mg/dL was relatively low, though laboratory evaluations showed severe ketoacidosis. This is the first report of ketoacidosis caused by a SGLT2 inhibitor. It is necessary to not only pay attention when using a SGLT2 inhibitor in patients following a low-carbohydrate diet, but also to start a low-carbohydrate diet in patients treated with a SGLT2 inhibitor because of a high risk for developing ketoacidosis.