A Distinct Pattern of Circulating Amino Acids Characterizes Older Persons with Physical Frailty and Sarcopenia: Results from the BIOSPHERE Study

Physical frailty and sarcopenia (PF&S) are hallmarks of aging that share a common pathogenic background. Perturbations in protein/amino acid metabolism may play a role in the development of PF&S. In this initial report, 68 community-dwellers aged 70 years and older, 38 with PF&S and 30 non-sarcopenic, non-frail controls (nonPF&S), were enrolled as part as the "BIOmarkers associated with Sarcopenia and Physical frailty in EldeRly pErsons" (BIOSPHERE) study. A panel of 37 serum amino acids and derivatives was assayed by UPLC-MS. Partial Least Squares\u207bDiscriminant Analysis (PLS-DA) was used to characterize the amino acid profile of PF&S. The optimal complexity of the PLS-DA model was found to be three latent variables. The proportion of correct classification was 76.6 \ub1 3.9% (75.1 \ub1 4.6% for enrollees with PF&S; 78.5 \ub1 6.0% for nonPF&S). Older adults with PF&S were characterized by higher levels of asparagine, aspartic acid, citrulline, ethanolamine, glutamic acid, sarcosine, and taurine. The profile of nonPF&S participants was defined by higher concentrations of \u3b1-aminobutyric acid and methionine. Distinct profiles of circulating amino acids and derivatives characterize older people with PF&S. The dissection of these patterns may provide novel insights into the role played by protein/amino acid perturbations in the disabling cascade and possible new targets for interventions

Metabolites

An altered amino acid metabolism has been described in frail older adults which may contribute to muscle loss and functional decline associated with frailty. In the present investigation, we compared circulating amino acid profiles of older adults with physical frailty and sarcopenia (PF&S, = 94), frail/pre-frail older adults with type 2 diabetes mellitus (F-T2DM, = 66), and robust non-diabetic controls ( = 40). Partial least squares discriminant analysis (PLS-DA) models were built to define the amino acid signatures associated with the different frailty phenotypes. PLS-DA allowed correct classification of participants with 78.2 ± 1.9% accuracy. Older adults with F-T2DM showed an amino acid profile characterized by higher levels of 3-methylhistidine, alanine, arginine, ethanolamine, and glutamic acid. PF&S and control participants were discriminated based on serum concentrations of aminoadipic acid, aspartate, citrulline, cystine, taurine, and tryptophan. These findings suggest that different types of frailty may be characterized by distinct metabolic perturbations. Amino acid profiling may therefore serve as a valuable tool for frailty biomarker discovery

Operationalizing mild cognitive impairment criteria in small vessel disease: The VMCI-Tuscany Study

Introduction Mild cognitive impairment (MCI) prodromic of vascular dementia is expected to have a multidomain profile. Methods In a sample of cerebral small vessel disease (SVD) patients, we assessed MCI subtypes distributions according to different operationalization of Winblad criteria and compared the neuroimaging features of single versus multidomain MCI. We applied three MCI diagnostic scenarios in which the cutoffs for objective impairment and the number of considered neuropsychological tests varied. Results Passing from a liberal to more conservative diagnostic scenarios, of 153 patients, 5% were no longer classified as MCI, amnestic multidomain frequency decreased, and nonamnestic single domain increased. Considering neuroimaging features, severe medial temporal lobe atrophy was more frequent in multidomain compared with single domain. Discussion Operationalizing MCI criteria changes the relative frequency of MCI subtypes. Nonamnestic single domain MCI may be a previously nonrecognized type of MCI associated with SVD

Marcatori di stress ossidativo in pazienti con epilessia focale farmacoresistente e farmacosensibile

L’epilessia è una delle più diffuse malattie neurologiche e interessa oltre 70 milioni di persone in tutto il mondo. Nonostante ciò, i farmaci antiepilettici attualmente in uso sono efficaci soprattutto nel diminuire la frequenza e la sintomatologia delle crisi ma non hanno alcun effetto sulla prevenzione dell’epilettogenesi. Inoltre, non solo presentano multiple reazioni avverse ma falliscono nel controllo delle crisi nel 30-50% dei pazienti. Per questo motivo, con l’obiettivo di sviluppare trattamenti più performanti, negli ultimi anni sono stati studiati i meccanismi alla base dell’epilettogenesi, tra i quali sembrano avere un ruolo dominante l’infiammazione del SNC e lo stress ossidativo. Si tratta di due fenomeni che compaiono in maniera rapida nell’encefalo danneggiato e che si influenzano e sostengono a vicenda. È stato dimostrato che nei modelli animali sono entrambi coinvolti nell’abbassamento della soglia epilettogena e vari markers biologici sia di stress ossidativo che di neuroinfiammazione risultano elevati nell’encefalo e in periferia sia in modelli animali sia in pazienti con epilessia. Comprendere a fondo il ruolo di stress ossidativo e neuroinfiammazione nell’epilettogenesi potrebbe aprire la strada all’utilizzo di terapie antiossidanti e/o antinfiammatorie, con la speranza che si rivelino una strategia efficace per migliorare la clinica ma soprattutto la prognosi di pazienti con epilessia. Il presente lavoro di tesi concentra l’attenzione sul ruolo dello stress ossidativo, definito come la condizione nella quale viene meno l’equilibrio tra specie antiossidanti e ossidanti, a favore di queste ultime. A tale scopo sono stati analizzati tre marcatori di stress ossidativo, dosabili nel sangue (AOPP, FRAP, tioli), in pazienti con epilessia di tipo focale. Si è poi proceduto al confronto tra pazienti con epilessia e un gruppo di controlli sani e tra soggetti farmacosensibili e farmacoresistenti. Infine, dal momento che l’epilessia del lobo temporale è la forma maggiormente analizzata in tutti i campi, compresi i recenti studi sullo stress ossidativo, è stato operato un ulteriore confronto tra pazienti con epilessia del lobo temporale e pazienti con altri tipi di epilessia focale, in questo caso soprattutto occipitale e frontale

Effect of Early Radial Shock Wave Treatment on Spasticity in Subacute Stroke Patients: A Pilot Study

Background. Spasticity is a complication that can start immediately after stroke. Radial extracorporeal shock wave therapy (rESWT) is a physical therapy tool used to manage chronic spasticity. However, the effect of rESWT's early use to treat spasticity after stroke is still not clearly investigated. The aim of this study is to evaluate the efficacy of rESWT in improving poststroke spasticity of the upper limb in patients with a recent onset of spasticity compared to conventional physiotherapy alone. Methods. 40 stroke patients were randomly assigned to experimental (EG) or control group (CG). Both groups underwent two daily sessions of conventional rehabilitation therapy (CRT) 5 days per week; the EG underwent one rESWT session a week for 4 weeks. The modified Ashworth scale (MAS) tested at the shoulder, elbow, and wrist was used as outcome measure. MAS was evaluated at baseline, after 2 and 4 rESWT session, and one month after the last session (follow-up). Results. No significant differences between groups were found at baseline in terms of age, days from onset of spasticity after stroke, and MAS at each body segment. The sample lost eight drop-out patients. Except for the shoulder MAS values, the EG showed statistically significant lower MAS values already after the second rESWT session compared to CG. This significant difference was maintained until the follow-up. The CG showed a significant increase of wrist spasticity after the second evaluation, while the EG maintained constant MAS values throughout the observational period. The elbow spasticity was significantly higher in the CG at the follow-up evaluation. Conclusion. The rESWT combined with CRT seems to be effective in avoiding the increasing progression of spasticity after stroke

Mapping the amide I absorption in single bacteria and mammalian cells with resonant infrared nanospectroscopy

Infrared (IR) nanospectroscopy performed in conjunction with atomic force microscopy (AFM) is a novel, label-free spectroscopic technique that meets the increasing request for nano-imaging tools with chemical specificity in the field of life sciences. In the novel resonant version of AFM-IR, a mid-IR wavelength-tunable quantum cascade laser illuminates the sample below an AFM tip working in contact mode, and the repetition rate of the mid-IR pulses matches the cantilever mechanical resonance frequency. The AFM-IR signal is the amplitude of the cantilever oscillations driven by the thermal expansion of the sample after absorption of mid-IR radiation. Using purposely nanofabricated polymer samples, here we demonstrate that the AFM-IR signal increases linearly with the sample thickness t for $t;gt$ 50 nm, as expected from the thermal expansion model of the sample volume below the AFM tip. We then show the capability of the apparatus to derive information on the protein distribution in single cells through mapping of the AFM-IR signal related to the amide-I mid-IR absorption band at 1660 cm−1. In Escherichia Coli bacteria we see how the topography changes, observed when the cell hosts a protein over-expression plasmid, are correlated with the amide I signal intensity. In human HeLa cells we obtain evidence that the protein distribution in the cytoplasm and in the nucleus is uneven, with a lateral resolution better than 100 nm

A(1) adenosine receptors in human neutrophils: Direct binding and electron microscope visualization

By occupying specific surface receptors, adenosine and adenosine analogues modulate neutrophil functions; in particular, functional and biochemical studies have shown that Al adenosine receptors modulate chemotaxis in response to chemotactic peptides. Until now, the characteristics of the specific agonist binding and the visualization of A(1) receptors in human neutrophils have not been investigated. In the present study, we used the agonist [H-3] CHA for radioligand binding studies and a CHA-biotin XX probe in order to visualize the A(1) binding sites in human neutrophils, ultrastructurally, by conjugation with colloidal gold-streptavidin. [H-3] CHA bound A(1) adenosine receptors with selectivity and specificity, although with a low binding capacity. Scatchard analysis showed a Kd Value of 1.4 +/- 0.08 nM and a maximum density of binding sites of 7.1 +/- 0.37 fmol/mg of proteins. The good affinity and selectivity of the CHA-biotin XX probe for A(1) adenosine receptors allowed us to visualize them, after conjugation with colloidal gold-streptavidin, as electron-dense gold particles on the neutrophil surface and inside the cell. The internalization of the ligand-receptor complex was followed in a controlled temperature system, and occurred through a receptor-mediated pathway. The kinetics of the intracellular trafficking was fast, taking less than 5 min. These data suggest that the CHA-biotin XX-streptavidin-gold complex is a useful marker for the specific labelling of A(1) binding sites and to follow the intracellular trafficking of these receptors. J. Cell. Biochem.75:235-244, 1999. (C) 1999 Wiley-Liss, Inc

High-fat feeding stimulates endocrine, glucose-dependent insulinotropic polypeptide (GIP)-expressing cell hyperplasia in the duodenum of Wistar rats

AIMS/HYPOTHESIS: Incretins are hormones released by enteroendocrine cells in response to meals, depending upon absorption of nutrients. The present study aimed to elucidate the mechanisms through which a high-fat diet (HFD) induces insulin resistance and insulin hypersecretion by focusing on the effects on enteroendocrine cells, especially those secreting glucose-dependent insulinotropic polypeptide (GIP). METHODS: Forty male Wistar rats, 4 months old, were randomised into two groups; one group received a chow diet and the other one received a purified tripalmitin-based HFD ad libitum. An OGTT was performed every 10 days and histological and immunofluorescence evaluations of the duodenum were obtained at 60 days from the beginning of the diets. Plasma glucose, insulin, GIP and glucagon-like peptide-1 (GLP-1) levels were measured. Immunofluorescence analysis of duodenal sections for pancreatic duodenal homeobox-1 (PDX-1), KI67, GLP-1, GIP and insulin were performed. RESULTS: Compared with chow diet, HFD induced a progressive significant increase of the glucose, insulin and GIP responses to OGTT, whereas GLP-1 circulating levels were reduced over time. After 60 days of HFD, cellular agglomerates of KI67 and PDX-1 positive cells, negative for insulin and GLP-1 but positive for GIP staining, were found inside the duodenal mucosa, and apoptosis was significantly increased. CONCLUSIONS/INTERPRETATION: With the limitation that we could not establish a causal relationship between events, our study shows that HFD stimulates duodenal proliferation of endocrine cells differentiating towards K cells and oversecreting GIP. The progressive increment of GIP levels might represent the stimulus for insulin hypersecretion and insulin resistance