Effectiveness of Resistance Exercise on Cognitive Function in Animal Models of Alzheimer Disease: A Systematic Review and Meta-Analysis.

AIM: Alzheimer's disease (AD) is among common cause of dementia. Complementary therapies, such as resistance exercise (RE), have been proposed as an alternative for the treatment of AD. We performed a systematic review and meta-analysis to investigate the effects of RE on the cognitive function of AD animal models and their physiological mechanisms. METHODS: This review was submitted to PROSPERO (CRD42019131266) and was done according to PRISMA checklist. Four databases were used in the search: MEDLINE/PUBMED, SCOPUS, Web of Science and Google Scholar. We used SYRCLE and CAMAREDES to assess the risk of bias and methodological quality. We calculated the standardized mean difference using 95% confidence intervals and considered the random effects model and p < 0.05 to determine significance. KEY FINDINGS: A total of 1,807 studies were founded, and after the selection process, only 11 studies were included in this review and 8 studies were included for meta-analysis. Four studies applied RE before AD induction, 7 studies applied RE after AD induction or in the AD condition. All studies included 550 adult and older animals weighing 25-280g. Our analysis revealed that RE had a positive effect on memory in AD animal models but did not show a significant impact on anxiety. CONCLUSION: RE performed four or six weeks, more than three days a week, had a significant protective effect on memory. The included studies had a high risk of bias and moderate methodological quality. Therefore, RE can be a potential strategy for preventing cognitive decline in animal models.

Osmotic regulators in cowpea beans plants under water deficiency.

Cowpea is a leguminous plant belonging to the fabaceae family cultivated in the North and Northeast regions of Brazil, with productive potential. Among the abiotic factors, water deficiency is one of the main environmental limitations that influence agricultural production in the world. The objective of this work was to study the relative water content and osmoregulators of cowpea plants subjected to water stress. The experiment was carried out in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA, Belém, PA), cowpea plants BR-17 Gurguéia Vigna unguiculata (L.) Walp were used. The experimental design was completely randomized (DIC) in a 2 × 2 factorial scheme, two water conditions (control and water deficit) and two times of stress (four and six days of water suspension), with 7 replications, totaling 28 experimental units. The water deficit affected plants, causing a reduction in relative water content (69.98%), starch (12.84% in leaves and 23.48% in roots) and carbohydrates (84.34%), and an increase in glycine-betaine, sucrose (114.11% in leaves and 18.71% in roots) and proline (358.86%) at time 2. The relative water content was negatively affected by water conditions, with a decrease in relation to the interaction of the aerial part and the root system. Therefore, greater metabolic responses were noted in plants that were subjected to stress treatment at time 2 (6 days).

Back on top: Resuspended by dredging and other environmental disturbances, organochlorine compounds may affect the health of a dolphin population in a tropical estuary, Sepetiba Bay.

Organochlorine compounds (OCs) are persistent organic pollutants linked to damaging the immune and endocrine systems, leading to a greater susceptibility to infectious diseases at high concentrations. Sepetiba Bay, in the Southeastern Brazilian coast, historically presents anthropogenic activities and environmental contamination that could negatively impact resident populations. In this context, this study aimed to investigate the temporal trends in the accumulation of organochlorine compounds over a 12-year database in the Guiana dolphins' (Sotalia guianensis) resident population from Sepetiba Bay, including individuals collected before, during, and after an unusual mortality event triggered by morbillivirus (n = 85). The influence of biological parameters was also evaluated. The OCs concentrations in the blubber ranged from 0.98 to 739 µg/g of ΣPCB; 0.08-130 µg/g of ΣDDT; <0.002-4.56 µg/g of mirex; <0.002-1.84 µg/g of ΣHCH and <0.001-0.16 µg/g of HCB in lipid weight. Increased temporal trends were found for OCs in Guiana dolphins coinciding with periods of large events of dredging in the region. In this way, our findings suggest that the constant high OCs concentrations throughout the years in this Guiana dolphin population are a result of the constant environmental disturbance in the area, such as dredging. These elevated OCs levels, e.g., ΣPCB concentrations found above the known thresholds, may impair the response of the immune system during outbreak periods, which could lead the population to a progressive decline.

Study of autonomic modulation by non-linear analysis of heart rate variability in different age groups and analysis of health status, disease and risk of death in dogs.

The symbolic analysis of heart rate variability (biomarker of cardiac autonomic homeostasis) is a nonlinear and effective tool for pattern extraction and classification in a series analysis, which implies the transformation of an original time series into symbols, represented by numbers. Autonomic heart rate control is influenced by different factors, and better indicators of heart rate variability are found in healthy young individuals than in older and sicker individuals. The aim of this study was to compare the indicators of heart rate variability among healthy dogs in different age groups and in health status using the nonlinear method of symbolic analysis to evaluate the diagnostic accuracy of this method for the risk of death in dogs. An increase in cardiac sympathetic modulation was observed in puppies and dogs at risk of death, which was evidenced by a marked increase of 0 V% (without variation - associated with sympathetic modulation) and a decrease in patterns of 2 V% (two variations - associated with parasympathetic modulation), while the opposite was observed in young adult dogs with increased parasympathetic modulation. Elderly dogs showed a gradual decrease in parasympathetic activity, which tended to worsen with loss of health. It is concluded that the variables of symbolic analysis may be useful to evaluate autonomic modulation in dogs and assist in the differentiation between health states, advanced disease and death throughout the life cycle and have been shown to be indices with high specificity, sensitivity and diagnostic accuracy to help identify dogs at risk of death.

Neuroinflammation Biomarkers in the AT(N) Framework Across the Alzheimer's Disease Continuum.

In the past years, neuroinflammation has been widely investigated in Alzheimer's disease (AD). Evidence from animal, in vivo and post-mortem studies has shown that inflammatory changes are a common feature of the disease, apparently happening in response to amyloid-beta and tau accumulation. Progress in imaging and fluid biomarkers now allows for identifying surrogate markers of neuroinflammation in living individuals, which may offer unprecedented opportunities to better understand AD pathogenesis and progression. In this context, inflammatory mediators and glial proteins (mainly derived from microglial cells and astrocytes) seem to be the most promising biomarkers. Here, we discuss the biological basis of neuroinflammation in AD, revise the proposed neuroinflammation biomarkers, describe what we have learned from anti-inflammatory drug trials, and critically discuss the potential addition of these biomarkers in the AT(N) framework.

Boron nitride nanotube peapods at ultrasonic velocity impacts: a fully atomistic molecular dynamics investigation.

Boron nitride nanotube peapods (BNNT-peapod) are composed of linear chains of C60molecules encapsulated inside BNNTs, they were first synthesized in 2003. In this work, we investigated the mechanical response and fracture dynamics of BNNT-peapods under ultrasonic velocity impacts (from 1 km s-1up to 6 km s-1) against a solid target. We carried out fully atomistic reactive molecular dynamics simulations using a reactive force field. We have considered the case of horizontal and vertical shootings. Depending on the velocity values, we observed tube bending, tube fracture, and C60ejection. Furthermore, the nanotube unzips for horizontal impacts at certain speeds, forming bi-layer nanoribbons 'incrusted' with C60molecules. The methodology used here is applicable to other nanostructures. We hope it motivates other theoretical investigations on the behavior of nanostructures at ultrasonic velocity impacts and aid in interpreting future experimental results. It should be stressed that similar experiments and simulations were carried out on carbon nanotubes trying to obtain nanodiamonds. The present study expands these investigations to include BNNT.

[Repair of Double-Stranded DNA Breaks Generated by CRISPR-Cas9 in Pseudomonas putida KT2440].

Pseudomonas putida KT2440 is a metabolically versatile bacterium with considerable promise as a chassis strain for production and degradation of complex organic compounds. Unlike most bacteria, P. putida KT2440 encodes the Ku and LigD proteins involved in Non-Homologous End Joining (NHEJ). This pathway of repair of double-strand breaks (DSBs) in DNA has an intrinsic mutagenic potential that could be exploited in combination with currently available genome editing tools that generate programmable DSBs. Here, we investigated the effect of removal or overproduction of NHEJ-associated P. putida KT2440 enzymes on mutations generated upon repair of Cas9-mediated DSBs with the double purpose of characterizing the NHEJ pathway and investigating how it functionally interacts with the current gold standard tool for gene editing. The results of our work shed light on non-templated mechanisms of DSB repair in P. putida KT2440, an information that will serve as foundation to expand the gene engineering toolbox for this important microorganism.

Combined Bleaching Technique Versus At-home Bleaching-A Single-blind Randomized Controlled Trial.

OBJECTIVE: To compare the efficacy, color stability, and tooth sensitivity (TS) of combined bleaching, using a modified protocol with at-home bleaching. METHODS: Eighty participants were randomized into two groups. In the combined group, a desensitizing gel was applied (10 minutes) prior to in-office bleaching (35% hydrogen peroxide (H2O2), 2×15 minute applications) and at-home bleaching (4% H2O2, 2×30 minutes for 21 days) started the next day. In the at-home group, only the at-home bleaching was performed. Color was recorded at the beginning and postbleaching with two scales (VITA Classical and Bleachedguide) and Easyshade spectrophotometer. The TS was recorded daily with a 0-10 visual analogue scale (VAS) and five-point numeric rating scale (NRS). RESULTS: A 40% lower risk (RR=1.4; 95% CI 1.1-1.9) was observed in the at-home group. Higher color change and intensity of TS [mean difference 2.3 (95% CI 1.3-3.3) in the VAS] was observed in the first week for the combined group. After the end of the protocol, a bleaching degree was detected for both groups, with no significant difference between both groups (p>0.05). CONCLUSION: The combined group produced a slightly higher degree of color change than at-home bleaching but with a higher risk and intensity of TS.

Nanostructured systems increase the in vitro cytotoxic effect of bullfrog oil in human melanoma cells (A2058).

The aim of this work was to investigate the in vitro cytotoxic effect of previously developed nanocapsules, nanoemulsion, and microemulsion based on bullfrog oil (BFO) against human melanoma cells (A2058). The nanosystems were produced as described in previous studies and characterized according to droplet/particle distribution and zeta potential. The biocompatibility was evaluated by the determination of the hemolytic potential against human erythrocytes. The cytotoxicity assessment was based on MTT and cell death assays, determination of Reactive Oxygen Species (ROS) levels, and cell uptake. The nanosystems were successfully reproduced and showed hemolytic potential smaller than 10% at all oil concentrations (50 and 100 µg.mL-1) (p < 0.05). The MTT assay revealed that the nanosystems decreased the mitochondrial activity up to 92 ± 2% (p < 0.05). The study showed that the free BFO induced cell apoptosis, while all the nanostructured systems caused cell death by necrosis associated with a ROS overproduction. This can be related to the increased ability of the nanostructured systems to deliver the BFO across all cellular compartments (membrane, cytoplasm, and nucleus). Finally, these results elucidate the in vitro BFO nanosystems cytotoxic effect against human melanoma cells (A2058), revealing the emulsified ones as the most cytotoxic systems. Overall, the findings suggest that the safety and antineoplastic activity of these systems can be further investigated by in vivo studies.

Quantum Biochemical Investigation of Lys49-PLA2 from Bothrops moojeni.

Envenomation via snakebites occurs largely in areas where it is harder to access the hospital. Its mortality rate and sequelae acquired by the survivors symbolize a big challenge for antivenom therapy. In particular, the homologous phospholipase A2 (Lys49-PLA2) proteins can induce myonecrosis and are not effectively neutralized by current treatments. Thus, by taking advantage of crystallographic structures of Bothrops moojeni Lys49-PLA2 complexed with VRD (varespladib) and AIN (aspirin), a quantum biochemistry study based on the molecular fractionation with conjugate cap scheme within the density functional theory formalism is performed to unveil these complexes' detailed interaction energies. The calculations revealed that important interactions between ligands and the Lys49-PLA2 pocket could occur up to a pocket radius of r = 6.5 (5.0 Å) for VRD (AIN), with the total interaction energy of the VRD ligand being higher than that of the AIN ligand, which is well-correlated with the experimental binding affinity. Furthermore, we have identified the role played by the amino acids LYS0069, LYS0049, LEU0005, ILE0009, CYS0029, GLY0030, HIS0048, PRO0018, ALA0019, CYS0045, TYR0052, TYR0022, PRO0125*, and PHE0126* (LYS0069, LYS0049, GLY0032, LEU0002, and LEU0005) in the VRD↔Lys49-PLA2 (AIN↔Lys49-PLA2) complex. Our simulations are a valuable tool to support the big challenge for neutralizing the damages in victims of snakebites.

Exploring human porphobilinogen synthase metalloprotein by quantum biochemistry and evolutionary methods.

Previous studies have shown the porphobilinogen synthase (PBGS) zinc-binding mechanism and its conservation among the living cells. However, the precise molecular interaction of zinc with the active center of the enzyme is unknown. In particular, quantum chemistry techniques within the density functional theory (DFT) framework have been the key methodology to describe metalloproteins, when one is looking for a compromise between accuracy and computational feasibility. Considering this, we used DFT-based models within the molecular fractionation with conjugate caps scheme to evaluate the binding energy features of zinc interacting with the human PBGS. Besides, phylogenetic and clustering analyses were successfully employed in extracting useful information from protein sequences to identify groups of conserved residues that build the ions-binding site. Our results also report a conservative assessment of the relevant amino acids, as well as the benchmark analysis of the calculation models used. The most relevant intermolecular interactions in Zn2+-PBGS are due to the amino acids CYS0122, CYS0124, CYS0132, ASP0169, SER0168, ARG0221, HIS0131, ASP0120, GLY0133, VAL0121, ARG0209, and ARG0174. Among these residues, we highlighted ASP0120, GLY0133, HIS0131, SER0168, and ARG0209 by co-occurring in all clusters generated by unsupervised clustering analysis. On the other hand, the triple cysteines at 2.5 Å from zinc (CYS0122, CYS0124, and CYS0132) have the highest energy attraction and are absent in the taxa Viridiplantae, Sar, Rhodophyta, and some Bacteria. Additionally, the performance of the DFT-based models shows that the processing time-dependence is more associated with the choice of the basis set than the exchange-correlation functional.

Proposal of an iELISA for Mycoplasma bovis diagnosis in dairy cattle and associated risk factors / [Proposta de um iELISA para diagnóstico de Mycoplasma bovis em bovinos leiteiros e fatores de risco associados]

Mycoplasma bovis is a highly contagious agent associated with several pathologies in cattle. The detection of reactive antibodies to M. bovis by Indirect Enzyme-Linked Immunosorbent Assay (iELISA) identifies if there was an exposure to the microorganism. The current study aimed to optimize an iELISA from M. bovis total cell antigen, applying it to bovine serum samples, and to evaluate risk factors. Serum samples were obtained from 400 cows from 17 herds from Southeast Brazil. In the optimization of iELISA, the following was established: 2 µg/mL of antigen, sera dilution 1:300, and conjugate dilution 1:15000. The frequency was 62.3% (249/400) of reactive animals and 100% (17/17) of reactive herds. Risk factors were: herds with more than 100 animals (OR= 3.1; CI= 95%); Holstein breed (OR= 72.5; CI= 95%); cows (OR= 29.7; CI= 95%); intensive breeding system (OR= 3.3; CI= 95%); associated small ruminant production (OR= 4.4; CI= 95%); milk production above 500L (OR= 2.9; CI= 95%); no quarantine (OR= 1.5; CI= 95%); mechanical milking (OR= 5.5; CI= 95%) and cases of mastitis (OR= 5.5; CI= 95%). The proposed iELISA was able to detect antibodies reactive to M. bovis in bovine serum. Knowledge of these risk factors can assist in the implementation of prophylactic measures.(AU)

Mycoplasma bovis é um agente altamente contagioso relacionado a várias patologias em bovinos. A detecção de anticorpos reativos a M. bovis por Ensaio de Imunoadsorção Enzimática Indireto (iELISA) identifica se houve exposição ao microrganismo. O presente estudo teve como objetivo otimizar um iELISA de antígeno celular total de M. bovis, aplicando-o a amostras de soro bovino, bem como avaliar fatores de risco. Amostras de soro foram obtidas de 400 vacas de 17 rebanhos da Região Sudeste do Brasil. Na otimização do iELISA foram obtidos: 2µg/mL de antígeno, diluição dos soros 1:300 e do conjugado 1:15000. A frequência de animais reativos foi de 62,3% (249/400) e de 100% (17/17) para os rebanhos. Os fatores de risco foram: rebanhos com mais de 100 animais (OR= 3,1; IC= 95%); raça Holandesa (OR= 72,5;IC= 95%); vacas (OR= 29,7;IC= 95%); sistema intensivo (OR= 3,3; C= 95%); produção de pequenos ruminantes (OR= 4,4;IC=95%); produção de leite acima de 500L (OR= 2,9;IC= 95%); sem quarentena (OR= 1,5;IC= 95%); ordenha mecânica (OR= 5,5;IC= 95%) e casos de mastite (OR= 5,5;IC= 95%). O iELISA proposto foi capaz de detectar anticorpos reativos a M. bovis no soro bovino. O conhecimento desses fatores de risco pode auxiliar na implementação de medidas profiláticas.(AU)

Non-lactose-fermenting uropathogenic Escherichia coli from dogs: virulence profile characterization.

Non-lactose-fermenting Escherichia coli (NLFEC) has a few descriptive studies restricted to human infections. In the present study, isolates of NLFEC obtained from urine samples of dogs with hyperadrenocorticism were characterized regarding their virulence ability, biofilm formation capacity and antimicrobial susceptibility profile. Escherichia coli lactose-fermenting strains from urinary infection in dogs with the same conditions were analysed to provide comparisons. The non-lactose-fermenting E. coli strains were classified as belonging to clade I E. coli, whereas the lactose-fermenting strains were classified in phylogroup B2. All strains presented virulence markers to adhesion, iron acquisition, toxins, colicin and cytotoxin production, and biofilm regulation. Components of the extracellular matrix in addition to the in vitro biofilm formation ability were observed in the strains. Multidrug resistance (MDR) profiles were observed by in vitro susceptibility tests to all NLFEC strains. In summary, non-lactose-fermenting uropathogenic E. coli from dogs behaves similar to lactose-fermenting E. coli, exhibiting MDR profile, and pathogenic potential of promote animal infections.