Preventing brain aging by the artificial enforcement of the unfolded protein response:future directions

As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly dependent on aging as a major risk factor and has a profound impact on various aspects of the lives of individuals and their families.

Distinct patterns of mucosal apoptosis in H pylori-associated gastric ulcer are associated with altered FasL and perforin cytotoxic pathways

AIM: To analyze the level of apoptosis in different mucosal compartments and the differential expression of Fas/Fas-ligand and perforin in H pylori-associated gastric ulcer. METHODS: Antral specimens from patients with H pylori-related active gastric ulcer (GU), H pylori-related gastritis, and non-infected controls were analysed for densities and distribution of apoptotic cells determined by the TdT-mediated dUDP-biotin nick-end-labelling method. GU patients were submitted to eradication therapy with follow-up biopsy after 60 d. Fas, FasL, and perforin-expressing cells were assessed by immunoper- oxidase, and with anti-CD3, anti-CD20 and anti-CD68 by double immunofluorescence and confocal microscopy. Quantitative analysis was performed using a computer- assisted image analyser. RESULTS: H pylori-infected antrum showed greater surface epithelial apoptosis which decreased after eradi- cation therapy. In the lamina propria, higher rates of mononuclear cell apoptosis were observed in H pylori- gastritis. Co-expression of Fas with T-cell and macro- phage markers was reduced in GU. FasL- and perforin-expressing cells were increased in H pylori-infection and correlated with epithelial apoptosis. Perforin-expressing cells were also increased in GU compared with H pylori- gastritis. CONCLUSION: Epithelial apoptosis is increased in H pylori-infection and correlates to FasL- and perforin- expression by T cells. Expression of perforin is correlated with the tissue damage, and may represent the enhance- ment of a distinct cytotoxic pathway in GU. Increased expression of FasL not paralleled by Fas on T-cells and macrophages may indicate a reduced susceptibility to the Fas/FasL-mediated apoptosis of lymphoid cells in H pylori-infection.

Inosine: a novel treatment for sciatic nerve injury

Trauma to the peripheral nervous system often results in loss of motor and sensory functions of the affected area of the body,leading to a series of functional impairments(Allodi et al.,2012).Injuries to peripheral nerves initiate a series of complex events,known as Wallerian degeneration,which allows the injured axons to regenerate and reinnervate their targets(Allodi et al.,2012).Damage to a nerve induces multiple alterations,which include:axonal degeneration,breakdown of myelin sheath,Schwann cells(SC)proliferation and conversion to a repair phenotype which express cytokines and chemokines that allow the infiltration and activation of macrophages(Mietto et al.,2015;Jessen and Mirsky,2016).

Influence of Saliva and Mucin on the Adhesion of <i>Candida</i>Oral Clinical Isolates

Objectives: This research work intends to clarify the role of artificial saliva, in particularly the role of mucin, a salivary protein, on the surface properties and adhesion ability of Candida spp. oral clinical isolates to abiotic surfaces. Methods: Four oral clinical isolates of Candida spp. were used: two Candida albicans strains (AC;AM) and two Candida parapsilosis strains (AD;AM2). The strains were isolated from patients using oral prosthesis. The microorganisms were cultured in the absence or presence of mucin and artificial saliva, and their adhesion to an abiotic surface (coated with mucin and artificial saliva) was evaluated. Results: The presence of mucin per se onto the abiotic surface decreased the adhesion of all strains, although the combination of mucin with artificial saliva had reduced this effect. No direct correlation between adhesion and the surface free energies of adhesion of the microorganisms was found. Significance: Candida spp. were human commensal microorganisms that became pathogenic when the host immune defenses were compromised. Medical devices were colonized by Candida spp. particularly, oral prostheses, which might lead to the degradation of the prostheses and systemic infections. The salivary secretions that constantly cover the oral cavity influenced Candida spp. adhesion process. Therefore, it was important to understand the interactions between Candida spp., salivary proteins and the characteristic of oral prosthesis when developing materials for oral prostheses.

Virulence Factors in Methicillin-Resistant Staphylococcus aureus Isolated from ICU Units in Brazil

Species of Staphylococcus are common in hospital infection (HI). Methicillin resistant S. aureus (MRSA) has also become a serious problem in Brazilian HI. The aim of this study was to characterize the pathogenicity of methicillin-resistant S. aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) isolated in public hospitals. The clinical isolates were obtained from intensive care unit. The MRSA and MSSA strains were genotyped by PCR for detection genes related to virulence factors. Moreover, the strains were tested for biofilm formation and cytokine induction in macrophages. Three strains of MRSA (9.68%) expressed the Sea gene, one (3.23%) Seb, 17 (54.84%) Spa and seven (22.58%) had PVL. Two MSSA strains (2.98%) expressed the Sea gene, three (4.48%) Seb, 18 (26.87%) Spa and 11 (16.42%) showed positive results for the PVL gene. There was no expression of Sec and CflA between MRSA and MSSA strains. Among MRSA and MSSA isolates, none statistical differences were observed in biofilm production. The analysis of cytokine induction in the inflammatory response of J774 macrophages by MRSA and MSSA isolates did not show statistical difference. Understanding the mechanisms of pathogenesis of S. aureus could provide important clues for both preventing and treating infection caused by these organisms.

Molecular approaches for spinal cord injury treatment

Injuries to the spinal cord result in permanent disabilities that limit daily life activities.The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic injuries.Despite decades of research,there is still no efficient treatment for spinal cord injury.Many strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord injury.Among these,molecular compounds are currently being used for neurological recovery,with promising results.These molecules target the axon collapsed growth cone,the inhibitory microenvironment,the survival of neurons and glial cells,and the re-establishment of lost connections.In this review we focused on molecules that are being used,either in preclinical or clinical studies,to treat spinal cord injuries,such as drugs,growth and neurotrophic factors,enzymes,and purines.The mechanisms of action of these molecules are discussed,considering traumatic spinal cord injury in rodents and humans.

Gangliosides in nervous system development,regeneration,and pathologies

Gangliosides,sialic acid-containing sphingolipids,are major constituents of neuronal membranes.According to the number of sialic acids and the structure of the oligosaccharide chain,gangliosides can be classified as simple or complex and grouped in different ganglio-series.Hundreds of gangliosides have been identified in vertebrate cells,with different expression patterns during development and related to several physiological processes,especially in the nervous system.While GD3 and its O-acetylated form,9acGD3,are highly expressed in early developmental stages,GM1,GD1a,GD1b,and GT1b are the most abundant ganglioside species in the mature nervous system.Mutations in enzymes involved in ganglioside metabolism can lead to the accumulation of specific species,a condition termed gangliosidosis and usually marked by severe neurological impairment.Changes in ganglioside levels have also been described in several neurodegenerative diseases,such as Alzheimer’s and Parkinson’s.In this review,we summarized recent information about the roles of GD3,9acGD3,GM1,GD1a,GD1b,GT1b,and other ganglioside species in nervous system development and regeneration,as well as clinical trials evaluating possible therapeutic applications of these molecules.

Synaptic pathology in multiple sclerosis:a role for Nogo-A signaling in astrocytes?

Multiple sclerosis(MS)is characterized as an inflammatory demyelinating disease that affects the central nervous system(CNS),leading to sensory,motor and cognitive impairments.Ultimately,axonal denudation culminates in axonal lesions and neurodegeneration.Inflammatory demyelinating lesions in MS are associated with infiltration of immune cells combined with activation of the resident CNS inflammatory cells,astro-and microglia.

Relation of COVID-19 with liver diseases and their impact on healthcare systems:The Portuguese case

BACKGROUND The impact caused by the coronavirus disease 2019(COVID-19)on the Portuguese population has been addressed in areas such as clinical manifestations,frequent comorbidities,and alterations in consumption habits.However,comorbidities like liver conditions and changes concerning the Portuguese population's access to healthcare-related services have received less attention.AIM To(1)Review the impact of COVID-19 on the healthcare system;(2)examine the relationship between liver diseases and COVID-19 in infected individuals;and(3)investigate the situation in the Portuguese population concerning these topics.METHODS For our purposes,we conducted a literature review using specific keywords.RESULTS COVID-19 is frequently associated with liver damage.However,liver injury in COVID-19 individuals is a multifactor-mediated effect.Therefore,it remains unclear whether changes in liver laboratory tests are associated with a worse prognosis in Portuguese individuals with COVID-19.CONCLUSION COVID-19 has impacted healthcare systems in Portugal and other countries;the combination of COVID-19 with liver injury is common.Previous liver damage may represent a risk factor that worsens the prognosis in individuals with COVID-19.

Robotic in situ bioprinting for cartilage tissue engineering

Articular cartilage damage caused by trauma or degenerative pathologies such as osteoarthritis can result in significant pain,mobility issues,and disability.Current surgical treatments have a limited capacity for efficacious cartilage repair,and long-term patient outcomes are not satisfying.Three-dimensional bioprinting has been used to fabricate biochemical and biophysical environments that aim to recapitulate the native microenvironment and promote tissue regeneration.However,conventional in vitro bioprinting has limitations due to the challenges associated with the fabrication and implantation of bioprinted constructs and their integration with the native cartilage tissue.In situ bioprinting is a novel strategy to directly deliver bioinks to the desired anatomical site and has the potential to overcome major shortcomings associated with conventional bioprinting.In this review,we focus on the new frontier of robotic-assisted in situ bioprinting surgical systems for cartilage regeneration.We outline existing clinical approaches and the utilization of robotic-assisted surgical systems.Handheld and robotic-assisted in situ bioprinting techniques including minimally invasive and non-invasive approaches are defined and presented.Finally,we discuss the challenges and potential future perspectives of in situ bioprinting for cartilage applications.

Oxidative stress in N88S seipinopathy:novel insights into the mechanisms of neurodegeneration and therapeutic avenues

Lipid droplets (LDs) are ubiquitous cellular orga nelles that perform functions mostly dedicated to energy homeostasis and lipid metabolism.As neutral lipid depots (triacylglycerol,sterol esters),they can be rapidly mobilized through lipase-mediated hydrolysis (lipolysis) or via lipophagy,a specific form of autophagy devoted to consumption of LDs inside the lysosome.

Retrospective Epidemiological Analysis of Colles’ Fracture in Patients Admitted in Fernandes Távora Hospital

Background: Colles’ fracture is a type of fracture of the distal third of the radius and its most common cause is falling from patient’s own height and, epidemiologically, it is more common in the elderly. Objectives: The main objective of this study is to analyze the epidemiology of Colles’ fracture retrospectively, in patients admitted to Fernandes Távora Hospital. Materials and Methods: This retrospective study conducted at the Fernandes Távora Hospital used 1030 radiographic images of patients with wrist fractures. Results: (After a careful analysis) It was found that this type of fracture occurred with a greater frequency in age groups of 50 to 69, 60 to 69, and 40 to 49 years old, which corresponds to 59.5% of patients and the most affected sex were females (51.1%). Conclusion: The study concluded that this type of bone injury is more common in people aged 40 to 69 years old, especially in women, because of their geometry and bone composition. It is evident that Colles’ fracture impacts the life of the affected person, therefore, an adequate diagnosis and treatment having utmost importance.

Epidermal growth factor receptor and K-Ras in non-small cell lung cancer-molecular pathways involved and targeted therapies

Lung cancer is currently the leading cause of cancer death in Western nations.Non-small cell lung cancer(NSCLC)represents 80%of all lung cancers,and adenocarcinoma is the predominant histological type.Despite the intensive research carried out on this field and therapeutic advances,the overall prognosis of these patients remains unsatisfactory,with a 5-year overall survival rate of less than 15%.Nowadays,pharmacogenetics and pharmacogenomics represent the key to successful treatment.Recent studies suggest the existence of two distinct molecular pathways in the carcinogenesis of lung adenocarcinoma:one associated with smoking and activation of the K-Ras oncogene and the other not associated with smoking and activation of the epidermal growth factor receptor(EGFR).The K-ras mutation is mainly responsible for primary resistance to new molecules which inhibit tyrosine kinase EGFR(erlotinib and gefitinib)and most of the EGFR mutations are responsible for increased tumor sensitivity to these drugs.This article aims to conduct a systematic review of the literature regarding the molecular pathways involving the EGFR,K-Ras and EGFR targeted therapies in NSCLC tumor behavior.

3D Photo-Fabrication for Tissue Engineering and Drug Delivery

The most promising strategies in tissue engineering involve the integration of a triad of biomaterials, living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing milieu present in human tissues, and that stimulate tissue repair and regeneration. To be clinically effective, these environments must replicate, as closely as possible, the main characteristics of the native extracellular matrix(ECM) on a cellular and subcellular scale. Photo-fabrication techniques have already been used to generate 3D environments with precise architectures and heterogeneous composition, through a multi-layer procedure involving the selective photocrosslinking reaction of a light-sensitive prepolymer. Cells and therapeutic molecules can be included in the initial hydrogel precursor solution, and processed into 3D constructs. Recently, photofabrication has also been explored to dynamically modulate hydrogel features in real time, providing enhanced control of cell fate and delivery of bioactive compounds. This paper focuses on the use of 3D photo-fabrication techniques to produce advanced constructs for tissue regeneration and drug delivery applications. State-of-the-art photo-fabrication techniques are described, with emphasis on the operating principles and biofabrication strategies to create spatially controlled patterns of cells and bioactive factors. Considering its fast processing, spatiotemporal control, high resolution, and accuracy, photo-fabrication is assuming a critical role in the design of sophisticated 3D constructs. This technology is capable of providing appropriate environments for tissue regeneration, and regulating the spatiotemporal delivery of therapeutics.

胶质细胞/神经元比例在不同种属不同脑区内的非均匀变化及其对脑功能和脑进化的意义

大部分学者认为,胶质细胞与神经细胞的比例随着脑组织大小的增加而增加,在人脑中,大约90%的细胞为胶质细胞。但此观点存在2个方面的错误:一是胶质细胞与神经元的比例不会随着脑组织大小而均匀的增加,二是胶质细胞并非人脑中的主要的细胞种类。本文将对胶质细胞/神经元比例的研究的起源、支持胶质细胞/神经元比例随脑组织大小增加而增加观点的原始证据、在不同的脑区(如脑白质和全脑)中,胶质细胞/神经元比例是否随脑组织大小增加而增加、以及有关胶质细胞/神经元的比例并非均匀的随脑体积的增加而增加,而是因为神经细胞的平均体积增加而导致神经细胞密度降低的最新的支持证据做一综述。研究认为,胶质细胞/神经元比例的变化与较大体积神经元的代谢消耗较大无关(假设此消耗与神经元的密度变化无关),而仅仅与脑内神经细胞的体积变化有关,而胶质细胞的体积变化较小,这些特点都与脑的生理功能相关。新研究表明,在90 000 000年的进化史中,胶质细胞/神经元的比例在哺乳动物脑内的不同区域非均匀的变化,提示胶质细胞和神经元之间相互作用是脑功能的基础。

Virulence Factor Profile of Staphylococcus aureus Isolated from Bovine Milk from Brazil

This study investigates the biofilm formation, presence and distribution of virulence genes and the capacity to induce an inflammatory response in strains of Staphylococcus aureus isolated from milk samples in Bahia, Brazil. A total of 132 samples of raw milk were collected from four dairy farms (designated A to D) located in southwestern Bahia, in the municipality of Vitória da Conquista, from October/2009 to September/2010. After processing of the samples, 94 (71.2%) S. aureus isolates were obtained. These strains were subjected to the antibiogram method MIC (Minimum Inhibitory Concentration). As for the pathogenicity, tests were performedin vitrobiofilm formation induced by glucose. Moreover, we performed PCR for their virulence genes: sea (enterotoxin A), seb (B), sec (C), pvl (Panton-Valentine Leukocidin), clfA (Clumping Factor A) and spa (protein A) and analysis of cytokine induction in the inflammatory response of J774 macrophages by exocellular lipoteichoic acid. No isolates were resistant to oxacillin and vancomycin. In biofilm production, 5.31% (5/94) isolates did not produce biofilm, 5.31% (5/94) of the samples were poor producers, 15.96% (15/94) strains were moderate producers, 18.09% (17/94) were producers and 55.32% (55/94) of isolates were strong biofilm producers. One (1.06%) isolate expressed the seb gene, one (1.06%) sec, 18 (19.2%) cflA and 44 (46.8%) had spa. There was no expression of sea and pvl between isolates analyzed. The analysis of cytokine induction in the inflammatory response did not show statistical difference in the levels of IL-6, TNF-α and IL-10 induction. However, there was statistical difference in IL-1 induction between isolates from different farms. Thus, it appears that the results obtained in this study show significant effects for the region studied, since it is an important dairy region, hence the need for further studies, with the intent of attracting funding that contributes to improving prevention and control in both dairy farms and dairy industries, since milk contamination poses a serious potential health risk to consumers.

Mechanobiology of the cell surface:Probing its remodeling dynamics using membrane tether pulling assays with optical tweezers

Mammalian cell surfaces consist of the plasma membrane supported by an underneath cortical cytoskeleton.Together,these structures can control not only the shape of cells but also a series of cellular functions ranging from migration and division to exocytosis,endocytosis and differentiation.Furthermore,the cell surface is capable of exerting and reacting to mechanical forces.Its viscoelastic properties,especially membrane tension and bending modulus,are fundamental parameters involved in these responses.This viewpoint summarizes our current knowledge on how to measure the viscoelastic properties of cell surfaces employing optical tweezers-based tether assays,paving the way for a better understanding of how cells react to external mechanical forces,with a glance on their remodeling dynamics and possible consequences on downstream cellular processes.

From Micro to Macro: Regulation Up- and Down-Adult Neurogenesis Process

Neurogenesis in the adult brain has been a field of growing interest. There are two neurogenic niches in the mammalian adult brain: subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ), producing new neurons that use the rostral migratory stream (RMS) to reach olfactory bulb (OB). Cells in these two discrete regions retain the capacity to generate multiple lineages in vitro and in vivo. Thus far, the mechanisms involved in the regulation of these cells have not been well elucidated, once the underlying cellular signaling mechanism is not fully understood. The aim of this work is to collect the most recent papers published in this field to elucidate the signaling pathways involved in the adult “up” and “down” neurogenesis. The most cited pathways included directly or indirectly associations with neurotrophins and transcription factors. This work provides a schema showing the outline from “macro” to “micro” signaling for neurogenesis in the SGZ of the hippocampus. It also includes a session linking neurogenesis to the pathophysiology of mood disorders and stress-related cognitive dysfunctions. Further characterization of these molecular components could provide greater insight into the mechanisms involved in the regulation of neurogenesis in the adult brain.

Spectrophotometric Assay for the Quantification of Plasma Ethanol Levels in Mice through Chromium-Ethanol Oxidation-Reduction Reaction

The quantification of blood/plasma ethanol concentration (BEC/PEC) is of great importance in experiments involving basic research, clinical studies, and bioethanol production. Traditional methods commonly used to measure BEC can be expensive and require high-cost equipment and qualified labor. The aim of this study was to develop a low-cost method that can be performed with simple infrastructure commonly available in research laboratories. For this, we developed a protocol to quantify PEC in mice, using the method of reduction of potassium dichromate by ethanol. However, this oxidation-reduction (redox) reaction is not specific to ethanol. Thus, the PEC was measured following a sequence of chemical reactions to eliminate the reductive interfering substances presented in the samples. Firstly, we evaluated the sensitivity of the dichromate reactive to ethanol and to different reducing substances found in the plasma, in order to determine which the main interfering substances are. Next, once the main interfering substances were determined in the dichromate reduction, plasma was assayed for PEC. First, mice received intraperitoneally (i.p.) saline (basal reading, 0% ethanol) or ethanol injections (0.5, 1, 2, 3, and 4 g/kg) and had their plasma collected. After plasma deproteinization and plasma glucose oxidation, it was mixed with the dichromate/acetic acid reactive, and then the products of the redox reaction were determined by the spectrophotometric method. Then, we determined the PEC with the same plasma samples using a commercial ethanol assay kit as a positive control. We found an excellent correlation between the administered ethanol doses and PECs in both the methods analyzed. The values of PEC found in the dichromate reaction method were similar to those obtained in the literature with the same ethanol doses, and to the commercial enzyme activity assay. Therefore, despite the need for a background reading, this method can be successfully applied to determine PEC using low-cost chemical reagents.

Green Nanotechnology from Plant Extracts: Synthesis and Characterization of Gold Nanoparticles

The advantage of using plants in nanoparticles synthesis is that they are easily available, safe to handle and possess a broad variability of metabolites such as antioxidants, nucleotides and vitamins. The aim of this study was to investigate the effects of Green and Zimbro tea and also Green coconut water as a reducing and stabilizer agent in gold nanoparticle synthesis. The gold nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Dynamic light scattering (DLS) and Transmission electron microscopy (TEM) analysis. Their physical stability was determined using a UV-Vis spectrophotometer over several days during storage at room temperature. We observed that green chemical process to obtain gold nanoparticles did not require any external chemicals reagent for stabilization of nanoparticulate. Absorption measurements indicated that the plasmon resonance wavelength appears around 530 nm. X-ray diffracto-grams of gold nanoparticles evidenced the presence of Au-rich (fcc) phases. TEM analysis showed a homogeneous dispersion of nanoparticles and some agglomerates. Differences in size and shape of the nanoparticles were observed. Zeta potential of AuNPs synthetized in presence of Green tea was -33 mV indicating stability of the synthesized nanoparticles.