Search

Melatonin ( N -acetyl-5-methoxytryptamine) is an indoleamine secreted by the pineal gland during the dark phase of the photoperiod. Its main function is the synchronization of different body rhythms with the dark-light cycle. Research on melatonin has significantly advanced since its discovery and we now know that it has considerable significance in various physiological processes, including immunity, aging, and reproduction. Moreover, in recent years evidence of the pharmacological possibilities of melatonin has increased. Indoleamine, on the other hand, has antidepressant-like effects in rodents, which may be mediated by the activation of calcium-calmodulin-dependent kinase II (CaMKII) and are also related to the regulation of neuroplasticity processes, including neurogenesis, synaptic maintenance, and long-term potentiation. Remarkably, patients with major depression show decreased levels of circulating melatonin in plasma. This review presents evidence of the antidepressant-like effects of melatonin in preclinical models and the participation of CaMKII in these actions. CaMKII's role in cognition and memory processes, which are altered in depressive states, are part of the review, and the effects of melatonin in these processes are also reviewed. Furthermore, participation of CaMKII on structural and synaptic plasticity and the effects of melatonin are also described. Finally, the advantages of using melatonin in combination with other antidepressants such as ketamine for neuroplasticity are described. Evidence supports that CaMKII is activated by melatonin and downstream melatonin receptors and may be the common effector in the synergistic effects of melatonin with other antidepressants. SIGNIFICANCE STATEMENT: This review compiled evidence supporting that melatonin causes antidepressant-like effects in mice through calmodulin kinase II stimulation of downstream melatonin receptors as well as the participation of this enzyme in neuroplasticity, memory, and cognition. Finally, we describe evidence about the effectiveness of antidepressant-like effects of melatonin in combination with ketamine., (Copyright © 2024 by The Author(s).)

Introduction and Objectives: Myocardial infarction (MI) incidence and case fatality trends are highly informative but relatively untested at the population level. The objective of this work was to estimate MI incidence and case fatality in the Girona population aged 35-74 years, and to determine their 30-year trends (1990-2019)., Methods: The REGICOR (Girona Heart Registry) monitored MI incidence and case fatality rates from 1990 to 2008. For the period 2008 to 2019, we linked discharges from Girona hospitals (n=4 974 977) and mortality registry (n=70 405) during this period. Our linkage algorithm selected key MI diagnostic codes and removed duplicates. Estimates from the linkage algorithm and the REGICOR registry were compared using chi-square tests for overlapping years (2008-2009). We estimated the annual percent change (APC) of standardized MI incidence and 28-day case fatality, and analyzed their trends using joinpoint regression., Results: MI incidence and case fatality estimates were similar in the linkage algorithm and the REGICOR registry. We observed significant decreasing trends in the incidence of MI. The trend was APC, -0.96% (95% confidence interval (95%CI), -1.4 to -0.53) in women from 1990 to 2019 and -4.2% (95%CI, -5.5 to -3.0) in men from 1994 to 2019. The largest decrease in case fatality was -3.8% (95%CI, -5.1 to -2.5) from 1995 to 2003 in women and -2.4% (95%CI, -2.9 to -1.9) from 1995 to 2004 in men, mainly due to prehospital case fatality declines: -1.8% (95%CI, -2.6 to -1.1) in men and -3.2% (95%CI, -4.6 to -1.8) in women., Conclusions: In Girona, MI incidence and case fatality decreased between 1990 and 2019. The incidence showed a slow but continuous decrease while case fatality only stabilized in the last decade, particularly in women., (Copyright © 2023. Published by Elsevier España, S.L.U.)

Fasciola hepatica, a worldwide distributed helminth, has a robust immunoregulatory effect in the host, increasing the susceptibility to secondary infections. Foot and mouth disease (FMD) is a highly contagious acute vesicular viral disease effectively controlled by vaccination in endemic regions. Despite the evidence of immunoregulatory effects, the impact of fasciolosis on the immune response induced by FMD vaccination in cattle has never been assessed. Our objective was to evaluate whether the infection by F. hepatica in cattle influences the long-term immunity elicited by the currently used commercial FMD-inactivated vaccines. Aberdeen Angus steers negative for F. hepatica were vaccinated twice against FMD virus (FMDV) during the first 6 months of age using a commercial oil vaccine formulated with A24/Cruzeiro and O1/Campos strains. When maternal antibodies against F. hepatica were weaned (18--20 months of age) animals were divided into groups of 12 and infected or mock-infected with 500 metacercariae/animal. Individual serum samples were collected at 0-, 28-, 59-, 87- and 157-days post-infection (dpi). Indirect ELISAs were used to detect A24/Cruzeiro specific bovine IgG and IgG subtypes. The total IgG antibody levels and avidity against FMDV did not show significant differences between all the groups. The commercial vaccine induced higher IgG2 than IgG1 titers in vaccinated animals. Anti-FMDV IgG1 levels significantly decreased in the infected group at 28 dpi. In addition, the avidity of IgG1 FMDV-specific antibodies at day 28 in the infected group was reduced compared to the control. These results show that F. hepatica infection modified anamnestic responses against FMDV, reducing serum IgG1 titers and avidity. To our knowledge, this is the first report of immune-regulation of F. hepatica altering the immune response of FMD vaccines, one of the most globally used animal vaccines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Here we report the stepwise synthesis of new nanographenes (NGs) and polycyclic aromatic hydrocarbons (PAHs) obtained via Scholl ring fusion applied at aromatic homologation compounds, which are obtained through one-step Ni-catalysed C sp2 -F functionalization. The latter are rapidly accessed valid precursors for the Scholl reaction, and screening of experimental conditions allowed us to describe for the first time furanol-bearing PAHs. Mechanistic insights are obtained by DFT to rationalize the formation of the furanol PAHs under moderately acidic conditions. All PAHs and NGs synthesized show moderate/weak fluorescent properties, and all PAHs crystallized show some degree of curvature and are obtained as racemic mixtures. Enantiomeric separation by chiral HPLC of one furanol-bearing PAH allowed the study of their chiroptical CD properties., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)