Search

Introduction: This study explored the ability of plasma amyloid beta (Aβ)42/Aβ40 to identify brain amyloid deposition in cognitively unimpaired (CU) individuals., Methods: Plasma Aβ was quantified with an antibody-free high-performance liquid chromatography tandem mass spectrometry method from Araclon Biotech (ABtest-MS) in a subset of 731 CU individuals from the screening visit of the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) Study, to assess associations of Aβ42/Aβ40 with Aβ positron emission tomography (PET)., Results: A model including Aβ42/Aβ40, age, apolipoprotein E ε4, and recruitment site identified Aβ PET status with an area under the curve of 0.88 and an overall accuracy of 81%. A plasma-based pre-screening step could save up to 42% of the total number of Aβ PET scans., Discussion: ABtest-MS accurately identified brain amyloid deposition in a population of CU individuals, supporting its implementation in AD secondary prevention trials to reduce recruitment time and costs. Although a certain degree of heterogeneity is inherent to large and multicentric trials, ABtest-MS could be more robust to pre-analytical bias compared to other immunoprecipitation mass spectrometry methods., Highlights: Plasma amyloid beta (Aβ)42/Aβ40 accurately identified brain Aβ deposition in cognitively unimpaired individuals from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) Study.The inclusion of the recruitment site in the predictive models has a non-negligible effect.A plasma biomarker-based model could reduce recruitment costs in Alzheimer's disease secondary prevention trials.Antibody-free liquid chromatography mass spectrometry methods may be more robust to pre-analytical variability than other platforms., Competing Interests: J.A.A., M.P.L., L.S., S.C., and J.T. are full‐time employees at Araclon Biotech‐Grifols. M.E.S. is a statistical consultant at Caebi. R.A.R. and S.A.L. have no conflicts of interest relevant to this study. Author disclosures are available in the supporting information., (© 2023 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals, LLC on behalf of Alzheimer's Association.)

Background: Accessible and cost-effective diagnostic tools are urgently needed to accurately quantify blood biomarkers to support early diagnosis of Alzheimer's disease (AD). In this study, we investigated the ability of plasma amyloid-beta (Aβ)42/Aβ40 ratio measured by an antibody-free mass-spectrometric (MS) method, ABtest-MS, to detect early pathological changes of AD., Methods: This cohort study included data from the baseline and 2-year follow-up visits from the Fundació ACE Healthy Brain Initiative (FACEHBI) study. Plasma Aβ42/Aβ40 was measured with ABtest-MS and compared to 18 F-Florbetaben PET as the reference standard (cutoff for early amyloid deposition of 13.5 centiloids). Cross-validation was performed in an independent DPUK-Korean cohort. Additionally, associations of plasma Aβ42/Aβ40 with episodic memory performance and brain atrophy were assessed., Results: The FACEHBI cohort at baseline included 200 healthy individuals with subjective cognitive decline (SCD), of which 36 (18%) were Aβ-PET positive. Plasma Aβ42/Aβ40 levels were significantly lower in Aβ-PET positive individuals (median [interquartile range, IQR], 0.215 [0.203-0.236]) versus Aβ-PET negative subjects (median [IQR], 0.261 [0.244-0.279]) (P < .001). Plasma Aβ42/Aβ40 was significantly correlated with Aβ-PET levels (rho = -0.390; P < .001) and identified Aβ-PET status with an area under the receiver operating characteristic curve (AUC) of 0.87 (95% confidence interval [CI], 0.80-0.93). A cutoff for the Aβ42/Aβ40 ratio of 0.241 (maximum Youden index) yielded a sensitivity of 86.1% and a specificity of 80.5%. These findings were cross-validated in an independent DPUK-Korean cohort (AUC 0.86 [95% CI 0.77-0.95]). Lower plasma Aβ42/Aβ40 ratio was associated with worse episodic memory performance and increased brain atrophy. Plasma Aβ42/Aβ40 at baseline predicted clinical conversion to mild cognitive impairment and longitudinal changes in amyloid deposition and brain atrophy at 2-year follow-up., Conclusions: This study suggests that plasma Aβ42/Aβ40, as determined by this MS-based assay, has potential value as an accurate and cost-effective tool to identify individuals in the earliest stages of AD, supporting its implementation in clinical trials, preventative strategies and clinical practice., (© 2023. The Author(s).)

Intravenous immunoglobulin (IVIg) is used as treatment for several autoimmune and inflammatory conditions, but its specific mechanisms are not fully understood. Herein, we aimed to evaluate, using systems biology and artificial intelligence techniques, the differences in the pathophysiological pathways of autoimmune and inflammatory conditions that show diverse responses to IVIg treatment. We also intended to determine the targets of IVIg involved in the best treatment response of the evaluated diseases. Our selection and classification of diseases was based on a previously published systematic review, and we performed the disease characterization through manual curation of the literature. Furthermore, we undertook the mechanistic evaluation with artificial neural networks and pathway enrichment analyses. A set of 26 diseases was selected, classified, and compared. Our results indicated that diseases clearly benefiting from IVIg treatment were mainly characterized by deregulated processes in B cells and the complement system. Indeed, our results show that proteins related to B-cell and complement system pathways, which are targeted by IVIg, are involved in the clinical response. In addition, targets related to other immune processes may also play an important role in the IVIg response, supporting its wide range of actions through several mechanisms. Although B-cell responses and complement system have a key role in diseases benefiting from IVIg, protein targets involved in such processes are not necessarily the same in those diseases. Therefore, IVIg appeared to have a pleiotropic effect that may involve the collaborative participation of several proteins. This broad spectrum of targets and 'non-specificity' of IVIg could be key to its efficacy in very different diseases., Competing Interests: EC-G, SC, and JT are full time employees at Grifols. CS-V and HB are full time employees at Anaxomics Biotech. TS was a full time-employee at Anaxomics Biotech at the time of the study. SK has received fees for lectures and reviewing research proposals from CSL-Behring and Grifols. The authors declare that this study received funding from Grifols (including medical writing assistance, and the article processing fees). The funder participated in the original idea, writing of this article and decision to submit it for publication, but was not involved in the study design, collection, analysis and interpretation of data., (Copyright © 2022 Segú-Vergés, Caño, Calderón-Gómez, Bartra, Sardon, Kaveri and Terencio.)

Tissue-specific regulation of LPL has been widely studied in rats. Previous studies reported that in vivo administration of adrenaline and acute stress cause an increase in plasma LPL activity coinciding with a decrease in white adipose tissue (WAT) LPL activity. We studied the speed of LPL activity changes during 30 min of stress by immobilization (IMMO) in rats. A first experimental approach in permanently cannulated rats permitted sequential blood sampling in the same animal during IMMO and the obtaining of hemodynamic parameters. In a second experimental approach, animals were euthanized at different times after the start of IMMO to determine LPL activity in tissues. Stress was characterized by rises in blood pressure, heart rate, plasma corticosterone, and available circulating energy substrates. Five min after the start of IMMO, LPL activity fell in retroperitoneal WAT and increased in plasma. These data show the quickest LPL activity change ever described in response to a physiological situation. The speed and simultaneity of these changes suggest that the release from endothelium to the bloodstream may constitute a fast nonexplored mechanism of tissue LPL activity regulation, involved in the lipid energy-substrate redistribution between tissues needed to prepare the "fight-or-flight" response.

In this work we describe the synthesis and biological evaluation of the tacrine-1,4-dihydropyridine (DHP) hybrids (3-11). These multipotent molecules are the result of the juxtaposition of an acetylcholinesterase inhibitor (AChEI) such as tacrine (1) and a 1,4-DHP such as nimodipine (2). Compounds 3-11 are very selective and potent AChEIs and show an excellent neuroprotective profile and a moderate Ca2+ channel blockade effect. Consequently, these molecules are new potential drugs for the treatment of Alzheimer's disease.

Among the known non-benzodiazepine hypnotic drugs, Zolpidem (1a), Indiplon (2a) and Zaleplon (2b) have shown high affinity and selectivity for the alpha(1) subunit of the GABA-A receptor. Our group has performed pharmacophoric and ADMET-prediction studies to evaluate a virtual library of new molecules based on privileged structures. Among these, we have synthesized a library of N-substituted indoles and a library of N-substituted benzimidazoles. Afterwards, in vitro screening and in vivo spontaneous motor activity in mice has revealed molecules with good in vitro affinities for the alpha(1) receptor and potent in vivo induction of sedation.

Among the known non-benzodiazepinic hypnotic drugs acting on the alpha1 subunit of the GABA-A receptor, Zolpidem, Zaleplon and Indiplon have showed high affinity and selectivity. Following a design methodology including pharmacophoric requirements and ADME-predicted properties, we have synthesized a library of 3-amino-4,5-dihydro-1H-pyrazolo[3,4-b]pyridin-6(7H)-ones and their N1-alkyl derivatives as new scaffolds for designing non-benzodiazepine BZ receptor ligands.

We report an assay for the determination of the activity of 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase, the enzyme which catalyzes the fourth reaction step of the 2-C-methyl-D-erythritol 4-phosphate pathway for the synthesis of isoprenoids, which is based on the spectrophotometrical determination of adenosine 5'-diphosphate using pyruvate kinase and L-lactate dehydrogenase as auxiliary enzymes. This method can be adapted to microtiter plates, can be automated, and because of its simplicity and speed can be useful for the functional characterization of the enzyme and for the screening of inhibitors with potential antibiotic or antimalarial action.

Peripheral blood mononuclear cells from 97 predominantly lepromatous leprosy patients and 11 control subjects were tested in a lymphoproliferative assay for response to Mycobacterium leprae (whole and sonicated), and sonicated M. vaccae, M. tuberculosis, and M. scrofulaceum, in the presence and absence of three types of interleukin 2 (IL-2) (crude, purified, and recombinant). IL-2 enhanced the response to sonicated M. tuberculosis and M. leprae organisms more often in patients than in control subjects, but not significantly so and only in a minority of patients. This effect was significantly more common (though still only found in a minority of 46%) using M. leprae organisms as antigen, than when using sonicates of M. leprae (19%) or M. vaccae (19%). However it was nearly as frequent using sonicated M. tuberculosis, or M. scrofulaceum. Thus in only nine patients was the effect specific to M. leprae. Enhancement by IL-2 could not be related to the type of IL-2 used, the dose of antigen, or the amount of endogenous IL-2 released by the cells tested. Similarly it was not related to the extent to which IL-2 caused increased background proliferation in control wells, which occurred to an equal extent using cells from control subjects, nor was it related to the extent of antigen-driven proliferation. The data have also been analysed in relation to duration of disease (50 years to a few weeks) and ethnic origin. No correlations have been revealed. Thus enhancement by IL-2 of the lymphoproliferative response to mycobacterial antigens does occur using cells from lepromatous leprosy patients, but it is found in a minority of patients, it is not specific to M. leprae, and can occur with cells from normal donors.