Mitochondrial-targeted plastoquinone derivatives. Effect on senescence and acute age-related pathologies

Plastoquinone, a very effective electron carrier and antioxidant of chloroplasts, was conjugated with decyltriphenylphosphonium to obtain a cation easily penetrating through membranes. This cation, called SkQ1, is specifically targeted to mitochondria by electrophoresis in the electric field formed by the mitochondrial respiratory chain. The respiratory chain also regenerates reduced SkQ1H(2) from its oxidized form that appears as a result of the antioxidant activity of SkQ1H(2). SkQ1H(2) prevents oxidation of cardiolipin, a mitochondrial phospholipid that is especially sensitive to attack by reactive oxygen species (ROS). In cell cultures, SkQ1 and its analog plastoquinonyl decylrhodamine 19 (SkQR1) arrest H(2)O(2)-induced apoptosis. When tested in vivo, SkQs (i) prolong the lifespan of fungi, crustaceans, insects, fish, and mice, (ii) suppress appearance of a large number of traits typical for age-related senescence (cataract, retinopathies, achromotrichia, osteoporosis, lordokyphosis, decline of the immune system, myeloid shift of blood cells, activation of apoptosis, induction of β-galactosidase, phosphorylation of H2AX histones, etc.) and (iii) lower tissue damage and save the lives of young animals after treatments resulting in kidney ischemia, rhabdomyolysis, heart attack, arrhythmia, and stroke. We suggest that the SkQs reduce mitochondrial ROS and, as a consequence, inhibit mitochondria-mediated apoptosis, an obligatory step of execution of programs responsible for both senescence and fast "biochemical suicide" of an organism after a severe metabolic crisis.     

Systemic and skin toxicity in Cercopithecus aethiops sabaeus monkeys treated during 26 weeks with a high intravenous dose of the anti- epidermal growth factor receptor monoclonal antibody Nimotuzumab

Nimotuzumab (h-R3) is a humanized anti-epidermal growth factor receptor monoclonal antibody (mAb) registered for treating head and neck tumours. The present study was designed to evaluate the systemic and skin toxicity of chronic intravenous administration of the h-R3 in a relevant species demonstrated by comparing the h-R3 binding affinity constants (Kd) in microsomal placental fractions from Homo sapiens and Cercopithecus aethiops monkeys using an EGF-Receptor radioligand competition assay. The Kd obtained for Nimotuzumab were 9.1 x 10(-8) M for monkeys and 4.5 x 10(-8) M for humans. Monkeys (n = 18) were distributed into 3 groups with 3 animals of each sex in each group. Group I received saline; group II received 2.85 mg/kg of h-R3; and group III received 28.57 mg/kg of the h-R3, which represent 1 and 10 times the human dose, and they were weekly intravenously treated during 26 weeks. During the study there were no deaths. Electroneurophysiological, sanguine chemistry and haematological results did not evidence alterations. Areas of haematomas, probably related with the administration procedure, were observed at the administration zones of all animals. The electrocardiography study showed at the end of the study a slight increase in the cardiac frequency of four treated animals without other signs. Unexpectedly, skin biopsies and a detailed clinical inspection of the animals did not detect the presence of cutaneous rash or any other skin toxicity sign reported for the majority of the anti-EGF-R monoclonal antibodies. It is concluded that doses up to 28.5 mg/kg of h-R3, intravenously administered during 26 weeks to Cercopithecus aethiops monkeys, do not produce considerable toxic effects.     

What do we know about the epidemiology of avoidant/restrictive food intake disorder in children and adolescents? A systematic review of the literature

Background

Avoidant/restrictive food intake disorder (ARFID) was a new diagnosis in DSM-5. This systematic review explores what is known to date about the epidemiology of ARFID in children and adolescents.

Method

Embase, Medline and PsycInfo were used to identify studies meeting inclusion criteria. PRISMA guidelines were followed.

Results

Thirty studies met inclusion criteria, with most coming from specialised eating disorder services where prevalence rates were 5%–22.5%. Three studies from specialist feeding clinics showed the highest prevalence rates, ranging from 32% to 64%. Studies from non-clinical samples reported ARFID prevalence estimates ranging from 0.3% to 15.5%. One study, using national surveillance methodology, reported the incidence of ARFID in children and adolescents reaching clinical care to be 2.02 per 100,000 patients. Psychiatric comorbidity was common, especially anxiety disorders (9.1%–72%) and autism spectrum disorder (8.2%–54.75%).

Conclusion

The current literature on the epidemiology of ARFID in children and adolescents is limited. Studies are heterogeneous with regard to setting and sample characteristics, with a wide range of prevalence estimates. Further studies, especially using surveillance methodology, will help to better understand the nature of this disorder and estimate clinical service needs.