Functional Recovery Caused by Human Adipose Tissue Mesenchymal Stem Cell-Derived Extracellular Vesicles Administered 24 h after Stroke in Rats.

Ischemic stroke is a major cause of death and disability, intensely demanding innovative and accessible therapeutic strategies. Approaches presenting a prolonged period for therapeutic intervention and new treatment administration routes are promising tools for stroke treatment. Here, we evaluated the potential neuroprotective properties of nasally administered human adipose tissue mesenchymal stem cell (hAT-MSC)-derived extracellular vesicles (EVs) obtained from healthy individuals who underwent liposuction. After a single intranasal EV (200 µg/kg) administered 24 h after a focal permanent ischemic stroke in rats, a higher number of EVs, improvement of the blood-brain barrier, and re-stabilization of vascularization were observed in the recoverable peri-infarct zone, as well as a significant decrease in infarct volume. In addition, EV treatment recovered long-term motor (front paws symmetry) and behavioral impairment (short- and long-term memory and anxiety-like behavior) induced by ischemic stroke. In line with these findings, our work highlights hAT-MSC-derived EVs as a promising therapeutic strategy for stroke.

Pharmacokinetics study of mazindol in plasma, oral fluid, and urine of volunteers.

PURPOSE: There are no pharmacokinetics studies in oral fluid reported in the literature, as well as there are no data on correlation of drug levels in plasma, urine, and oral fluid in order to propose alternative matrices to monitor the use of mazindol by drivers. The present work aimed to study, preliminarily, mazindol's pharmacokinetics in plasma and oral fluid, as well as investigate the correlation of drug levels in urine, plasma, and oral fluid. METHOD: Blood, urine, and oral fluid samples from seven healthy male volunteers were collected at 0, 1, 2, 4, 5, 6, 8, 10, and 24 h after administration of tablets of 2 mg mazindol and analyzed by a previously validated method by LC-MS with liquid-liquid extraction. Levels of the drug found were higher in plasma when compared with oral fluid and higher in urine in relation to plasma. The study of the mazindol's pharmacokinetics showed that the most suitable model to describe the variation of the concentration over time is the compartment open model with absorption and elimination following the first-order kinetics, and confirming literature data, drug is metabolized, being the major metabolite detected, but not quantified. CONCLUSION: It was not found a good correlation between the concentrations of mazindol in urine and plasma, but between plasma and oral fluid, there was a good correlation, suggesting this as an alternative matrix to plasma. However, studies involving more subjects are needed.

Comparing tau status determined via plasma pTau181, pTau231 and [18F]MK6240 tau-PET.

BACKGROUND: Tau in Alzheimer's disease (AD) is assessed via cerebrospinal fluid (CSF) and Positron emission tomography (PET). Novel methods to detect phosphorylated tau (pTau) in blood have been recently developed. We aim to investigate agreement of tau status as determined by [18F]MK6240 tau-PET, plasma pTau181 and pTau231. METHODS: We assessed cognitively unimpaired young, cognitively unimpaired, mild cognitive impairment and AD individuals with [18F]MK6240, plasma pTau181, pTau 231, [18F]AZD4694 amyloid-PET and MRI. A subset underwent CSF assessment. We conducted ROC curves to obtain cut-off values for plasma pTau epitopes. Individuals were categorized as positive or negative in all biomarkers. We then compared the distribution among concordant and discordant groups in relation to diagnosis, Aß status, APOEε4 status, [18F]AZD4694 global SUVR, hippocampal volume and CSF pTau181. FINDINGS: The threshold for positivity was 15.085 pg/mL for plasma pTau181 and 17.652 pg/mL for plasma pTau231. Most individuals had concordant statuses, however, 18% of plasma181/PET, 26% of plasma231/PET and 25% of the pTau231/pTau181 were discordant. Positivity to at least one biomarker was often accompanied by diagnosis of cognitive impairment, Aß positivity, APOEε4 carriership, higher levels of [18F]AZD4694 global SUVR, hippocampal atrophy and CSF pTau181. INTERPRETATION: Plasma pTau181, pTau231 and [18F]MK6240 seem to reflect different stages of tau progression. Plasma biomarkers can be useful in the context of diagnostic information and clinical trials, to evaluate the disease stage. Moreover, they seem to confidently evaluate tau-PET positivity. FUNDING: Moreover, this study was supported by Weston Brain Institute, Canadian Institute of Health Research and Fonds de Recherche du Québec.

Rapid size-exclusion high performance liquid chromatography method for the quality control of amyloid-ß oligomers.

Amyloid-ß (Aß) dysmetabolism is thought to be the main trigger for neurodegenerative events in Alzheimer's disease (AD). In particular, soluble Aß oligomers (AßOs) are proposed as key mediators of synaptic and cognitive dysfunction in AD. Over the past few decades, AßOs prepared from synthetic Aß have been widely applied in vitro and in vivo, the so-called chemical models of AD, uncovering their multiple neurotoxic mechanisms. However, the lack of a reliable quality control (QC) for synthetic AßOs may reflect poor experimental reproducibility. In keeping with this, we optimized and validated a rapid and reproducible SECHPLC method using fluorescence detection for the QC of synthetic AßOs. Our analytical method offers an unprecedent alternative to improve the reproducibility of AD chemical models.

Validation and application of a liquid chromatography-electrospray ionization mass spectrometric method for determination of mazindol in human plasma and urine.

INTRODUCTION: Even after removal of some stimulants, like fenproporex, amfepramone and mazindol, from Brazilian market, the use of these substances is still high, especially by drivers. Mazindol is the second most used anorectic agent in the world acting as an indirect sympathomimetic agonist, having stimulatory action on central nervous system. Plasma is a good matrix to monitor since it reflects the psychomotor effects of these drugs, but unlike urine has an invasive collection; drug levels and detection time are quite low. METHOD: The method involved a liquid-liquid extraction of the samples and a LC-MS analysis was fully validated. Method was used to analyze samples of urine and plasma collected from health volunteers in a period of 24h. Metabolite of mazindol was synthesized using alkaline conditions. RESULTS: After validation the method proved to be adequate to analyze samples collected from health volunteers. Method was linear in the concentration range of 0.1-10ng/mL (r=0.9982) for plasma and 5-50ng/mL (r=0.9973) for urine. DISCUSSION: Analysis of the samples showed that mazindol can be detected after 1h of administration and that concentration levels in urine were always higher than in plasma. Mazindol metabolite was detected only in urine.