Bioactive diterpenes and other constituents of Croton steenkampianus

A new indanone derivative (1) and two new diterpenoids (2 and 3), together with three known flavonoids, have been isolated from an ethanol extract of the leaves of Croton steenkampianus. The structure of 2 was solved by single-crystal X-ray diffraction analysis, whereas those of 1 and 3 were established mainly by 1D and 2D NMR spectroscopic methods. The isolated compounds were tested for their antiplasmodial activity and cytotoxicity. Antiplasmodial assays against chloroquine-susceptible strains (D10 and D6) and the chloroquine-resistant strains (Dd2 and W2) of Plasmodium falciparum showed that compound 2 gave moderate activities at 9.1-15.8 μM, while none of the compounds were cytotoxic against Vero cells.     

Long-term training induces a healthy inflammatory and endocrine emergent biomarker profile in elderly men

The objective of the present study was to investigate the changes in a large panel of emergent geriatric biomarkers in long-term trained elderly men to analyze the effects of long-term exercise on an aged population. We collected blood samples from two groups of male volunteers older than 65 years who maintain a measure of functional independence: one group of sedentary subjects without a history of regular physical activity and the other of subjects who have sustained training, starting during adulthood (mean training time = 49 ± 8 years). We studied morbidity, polypharmacy, cellular and serological inflammatory parameters, and endocrine mediators. After adjusting for confounding factors, we observed reduced medication intake per subject and lower number of diseases per subject with statistical differences nearly significant in the long-term exercise group. We showed that long-term training was associated with lower levels of white blood cell counts, neutrophil counts, interleukin-6, interleukin-10, interleukin-1 receptor antagonist, and soluble TNF receptor-I. Furthermore, we noted an increase in the concentrations of insulin-like growth factor-1 and dehydroepiandrosterone in the long-term training group. We concluded that long-term exercise training from adulthood to old age is clearly associated with a healthy profile of emergent geriatric biomarkers. Long-term training could improve the inflammatory–endocrine imbalance associated with disease, frailty, functional decline, and mortality in elderly men. Our results point to the benefits of prolonged exercise from adulthood to old age.     

Fear of COVID-19 Scale for Hospital Staff in Regional Hospitals in Mexico: a Brief Report

International Journal of Mental Health and Addiction - The presence of COVID-19 has had psychological consequences among health personnel; these include fear, anxiety, and depression. In the...     

Autophagy is required for performance adaptive response to resistance training and exercise-induced adult neurogenesis

Endurance training promotes exercise-induced adaptations in brain, like hippocampal adult neurogenesis and autophagy induction. However, resistance training effect on the autophagy response in the brain has not been much explored. Questions such as whether partial systemic autophagy or the length of training intervention affect this response deserve further attention. Therefore, 8-week-old male wild-type (Wt; n = 36) and systemic autophagy-deficient (atg4b^−/−, KO; n = 36) mice were randomly distributed in three training groups, resistance (R), endurance (E), and control (non-trained), and in two training periods, 2 or 14 weeks. R and E maximal tests were evaluated before and after the training period. Forty-eight hours after the end of training program, cerebral cortex, striatum, hippocampus, and cerebellum were extracted for the analysis of autophagy proteins (LC3B-I, LC3B-II, and p62). Additionally, hippocampal adult neurogenesis was determined by doublecortin-positive cells count (DCX+) in brain sections. Our results show that, in contrast to Wt, KO were unable to improve R after both trainings. Autophagy levels in brain areas may be modified by E training only in cerebral cortex of Wt trained for 14 weeks, and in KO trained for 2 weeks. DCX + in Wt increased in R and E after both periods of training, with R for 14 weeks more effective than E. Interestingly, no changes in DCX + were observed in KO after 2 weeks, being even undetectable after 14 weeks of intervention. Thus, autophagy is crucial for R performance and for exercise-induced adult neurogenesis.     

The Clinical Significance of Posttranslational Modification of Autoantigens

Posttranslational modifications (PTMs) are defined as covalent modifications occurring in a specific protein amino acid in a time- and signal-dependent manner. Under physiological conditions, proteins are posttranslationally modified to carry out a large number of cellular events from cell signaling to DNA replication. However, an absence, deficiency, or excess in PTMs of a given protein can evolve into a target to trigger autoimmunity, since PTMs arise in the periphery and may not occur in the thymus; hence, proteins with PTMs never tolerize developing thymocytes. Consequently, when PTMs arise during cellular responses, such as inflammation, these modified self-antigens can be taken up and processed by the antigen-presenting cells (APCs). Autoreactive T cells, which recognize peptides presented by APCs, can then infiltrate into host tissue where the modified antigen serves to amplify the autoimmune response, eventually leading to autoimmune pathology. Furthermore, a PTM occurring in an amino acid residue can induce changes in the net charge of the protein, leading to conformational modifications in the tertiary and quaternary structure of the protein, especially interaction with human leukocyte antigen (HLA) molecules. Molecular mimicry (MM) was until now the prevailing hypothesis explaining generation of autoimmunity; nevertheless, experimental animal models need inflammation via infection or other immunogens to ensure autoimmunity; MM alone is not sufficient to develop autoimmunity. PTMs could arise as an additive factor to MM, which is required to start an autoimmune response. PTMs have been found to be present in different pathologic conditions such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome, and primary biliary cirrhosis. The aim of the present review is to expose protein posttranslational modifications and the evidence suggesting their role in the generation of autoimmunity.     

No evidence of association of the KLF12 gene with rheumatoid arthritis in Spanish and Dutch cohorts and a meta-analysis of published data

The aim of the present study was to replicate the previously reported association of KLF12 gene polymorphisms with rheumatoid arthritis (RA). Two independent cohorts from Spain (1,360 RA patients and 1,520 controls) and the Netherlands (1,018 RA patients and 1,150 controls) were genotyped for KLF12 rs1887346 and rs9565072 single-nucleotide polymorphisms using a TaqMan 5'-allele discrimination assay. No evidence of association of RA with the minor T allele of rs9565072 (31.82% vs 33.73%; p = 0.14, odds ratios [OR] 0.92 [95% confidence interval (CI) 0.82-1.03]) or the minor A allele of rs1887346 polymorphism (21.60% vs 21.77%; p = 0.88, OR 0.99 [95% CI 0.87-1.13]) was observed in Spanish patients compared with healthy controls. This lack of association was also confirmed in the Dutch cohort: the minor T allele frequency of rs9565072 in Dutch RA patients was 35.34% versus 35.57% in controls; p = 0.87, OR 0.99 (95% CI 0.87-1.12); and the minor A allele frequency of rs1887346 in Dutch RA patients was 27.64% versus 28.17% in controls; p = 0.70, OR 0.97 (95% CI 0.85-1.12). A meta-analysis of published KLF12 gene association with RA revealed a pooled OR of 0.99 (95% CI 0.93-1.04) for rs1887346 and a pooled OR of 0.99 (95% CI 0.95-1.04) for rs9565072. In conclusion, our findings indicate that the KLF12 rs1887346 and rs9565072 polymorphisms do not play a relevant role in RA.