Auditory cortex hypoperfusion: a metabolic hallmark in Beta Thalassemia

Abstract Background Sensorineural hearing loss in beta-thalassemia is common and it is generally associated with iron chelation therapy. However, data are scarce, especially on adult populations, and a possible involvement of the central auditory areas has not been investigated yet. We performed a multicenter cross-sectional audiological and single-center 3Tesla brain perfusion MRI study enrolling 77 transfusion-dependent/non transfusion-dependent adult patients and 56 healthy controls. Pure tone audiometry, demographics, clinical/laboratory and cognitive functioning data were recorded. Results Half of patients (52%) presented with high-frequency hearing deficit, with overt hypoacusia (Pure Tone Average (PTA) > 25 dB) in 35%, irrespective of iron chelation or clinical phenotype. Bilateral voxel clusters of significant relative hypoperfusion were found in the auditory cortex of beta-thalassemia patients, regardless of clinical phenotype. In controls and transfusion-dependent (but not in non-transfusion-dependent) patients, the relative auditory cortex perfusion values increased linearly with age (p < 0.04). Relative auditory cortex perfusion values showed a significant U-shaped correlation with PTA values among hearing loss patients, and a linear correlation with the full scale intelligence quotient (right side p = 0.01, left side p = 0.02) with its domain related to communication skills (right side p = 0.04, left side p = 0.07) in controls but not in beta-thalassemia patients. Audiometric test results did not correlate to cognitive test scores in any subgroup. Conclusions In conclusion, primary auditory cortex perfusion changes are a metabolic hallmark of adult beta-thalassemia, thus suggesting complex remodeling of the hearing function, that occurs regardless of chelation therapy and before clinically manifest hearing loss. The cognitive impact of perfusion changes is intriguing but requires further investigations

A systematic review of workplace disclosure and accommodation requests among youth and young adults with disabilities

This is an Accepted Manuscript of an article published by Taylor& Francis in Disability and Rehabilitation August 10th 2017,available online: http://www.tandfonline.com/10.1080/09638288.2017.1363824Purpose: The objective of this systematic review is to critically appraise the literature on disability disclosure and workplace accommodations for youth and young adults with disabilities. Methods: Systematic searches of nine international databases identified 27 studies meeting our inclusion criteria. These studies were analyzed with respect to the characteristics of the participants, methodology, results of the studies and the quality of the evidence. Results: Among the 27 studies, 18,419 participants (aged 14–33, mean 23.9 years) were represented across seven countries. Barriers to disability disclosure and requests for workplace accommodations were found at the individual (i.e., disability type, severity, poor self-concept, and advocacy skills), employment (i.e., type of industry, and working conditions, lack of supports), and societal levels (i.e., stigma/discrimination). Facilitators of disability disclosure included individual factors (i.e., knowledge of supports and workplace rights, self-advocacy skills), employment (i.e., training/supports, effective communication with employers, realizing the benefits of accommodations), and societal factors (i.e., positive attitudes toward people with disabilities). There was little consensus on the processes and timing of how disability should be discussed in the workplace among youth with disabilities. Conclusions: Our findings highlight the complexities of disability disclosure for youth with disabilities. More studies are needed to explore issues of workplace disclosure and accommodations for young people to improve disclosure strategies and the process of providing appropriate accommodations.Ontario Ministry of Advanced Education and Skills Development Ontario Ministry of Research and Innovation10.13039/501100003400 This study was funded by the Ontario Ministry of Advanced Education and Skills Development. The first author is supported by a career award from the Ontario Ministry of Research and Innovation

N-Valproyl-L-Phenylalanine as New Potential Antiepileptic Drug: Synthesis, Characterization and In Vitro Studies on Stability, Toxicity and Anticonvulsant Efficacy

Valproic acid (VPA) is considered first-line treatment for primarily generalized idiopathic seizures such as absence, generalized tonic-clonic and myoclonic seizures. Among major antiepileptic drugs, VPA is also considered effective in childhood epilepsies and infantile spasms. Due to its broad activity, VPA acts as a mood stabilizer in bipolar disorder and it is useful in migraine prophylaxis. Despite its long-standing usage, severe reactions to VPA, such as liver toxicity and teratogenicity, are reported. To circumvent side effects due to structural characteristics of VPA, we synthesized in good yield a new VPA-aminoacid conjugate, the N-valproyl-L-Phenylalanine, and characterized by FT-IR, MS, 13C and 1H- NMR analyses. The Log DpH7.4 value (0.19) indicated that new molecule was potentially able to cross biological membranes. The resistance to chemical and enzymatic hydrolysis of N-valproyl-L-phenylalanine was also assessed. All trials suggested that the compound, at the pH conditions of the entire gastro-intestinal tract, remained unmodified. Furthermore, the new compound did not undergo enzymatic cleavage both in plasma and in cerebral medium up to 24 h. The toxicity assay on primary cultures of astrocytes indicated that the synthetized conjugate was less toxic than both free VPA and L-Phenylalanine. In this paper, the anticonvulsant activity of the new compound against epileptic burst discharges evoked in vitro in rat hippocampal slices was also evaluated. These preliminary results underline that N-valproyl-L-phenylalanine as new potential antiepileptic agent could represent a good candidate to further investigations

Enzymatic and Biological Characterization of Novel Sirtuin Modulators against Cancer

Sirtuins, a family of nicotinamide adenine dinucleotide (NAD+)-dependent lysine deacetylases, are promising targets for anticancer treatment. Recently, we characterized a novel pan-sirtuin (SIRT) inhibitor, MC2494, displaying antiproliferative effects and able to induce death pathways in several human cancer cell lines and decrease tumor growth in vivo. Based on the chemical scaffold of MC2494, and by applying a structure&ndash;activity relationship approach, we developed a small library of derivative compounds and extensively analyzed their enzymatic action at cellular level as well as their ability to induce cell death. We also investigated the effect of MC2494 on regulation of cell cycle progression in different cancer cell lines. Our investigations indicated that chemical substitutions applied to MC2494 scaffold did not confer higher efficacy in terms of biological activity and SIRT1 inhibition, but carbethoxy-containing derivatives showed higher SIRT2 specificity. The carbethoxy derivative of MC2494 and its 2-methyl analog displayed the strongest enzymatic activity. Applied chemical modifications improved the enzymatic selectivity of these SIRT inhibitors. Additionally, the observed activity of MC2494 via cell cycle and apoptotic regulation and inhibition of cell migration supports the potential role of SIRTs as targets in tumorigenesis and makes SIRT-targeting molecules good candidates for novel pharmacological approaches in personalized medicine