Remarkable Phenotypic Virulence Factors of Microsporum canis and Their Associated Genes: A Systematic Review

Microsporum canis is a widely distributed dermatophyte, which is among the main etiological agents of dermatophytosis in humans and domestic animals. This fungus invades, colonizes and nourishes itself on the keratinized tissues of the host through various virulence factors. This review will bring together the known information about the mechanisms, enzymes and their associated genes relevant to the pathogenesis processes of the fungus and will provide an overview of those virulence factors that should be better studied to establish effective methods of prevention and control of the disease. Public databases using the MeSH terms "Microsporum canis", "virulence factors" and each individual virulence factor were reviewed to enlist a series of articles, from where only original works in English and Spanish that included relevant information on the subject were selected. Out of the 147 articles obtained in the review, 46 were selected that reported virulence factors for M. canis in a period between 1988 and 2023. The rest of the articles were discarded because they did not contain information on the topic (67), some were written in different languages (3), and others were repeated in two or more databases (24) or were not original articles (7). The main virulence factors in M. canis are keratinases, fungilisins and subtilisins. However, less commonly reported are biofilms or dipeptidylpeptidases, among others, which have been little researched because they vary in expression or activity between strains and are not considered essential for the infection and survival of the fungus. Although it is known that they are truly involved in resistance, infection and metabolism, we recognize that their study could strengthen the knowledge of the pathogenesis of M. canis with the aim of achieving effective treatments, as well as the prevention and control of infection.

Effectiveness of Omega-3 Fatty Acid Supplementation in Improving the Metabolic and Inflammatory Profiles of Mexican Adults Hospitalized with COVID-19

BACKGROUND AND OBJECTIVES

The development of severe COVID-19 is related to the preexistence of comorbidities and an inadequate nutritional status. The latter is a critical factor for the development of infection and the progression of the disease. Notably, optimal nutrition impacts immune system function, as malnutrition is related to high cytokine levels in the late phase of the disease, correlating with a poor prognosis. In this sense, omega-3 fatty acids (O3FAs) have anti-inflammatory properties that may reduce morbidity and mortality from COVID-19 infection. O3FAs are linked to a better prognosis in COVID-19 patients.

MATERIALS AND METHODS

In this randomized, double-blind clinical trial, we evaluate the administration of O3FAs to unvaccinated Mexican patients for two weeks starting after the first two hours of hospitalization.

RESULTS

The findings support the notion that O3FAs (in a dose high enough to satisfy human physiological requirements in a short time, one capsule of 1.4 g O3FAs daily) exert a comprehensive multi-systemic modulatory influence, affecting inflammatory and metabolic pathways. Significant perturbations in biomarkers, including absolute neutrophil count, hematocrit, and platelet indices, underscore the compound's anti-inflammatory effect. Concurrently, the intervention modulates pivotal metabolic and hepatic parameters, attenuating cardiovascular risk profiles and expediting patient convalescence. These multifarious effects are likely orchestrated through intricate biochemical mechanisms and are subject to individual variations predicated on metabolic factors.

CONCLUSIONS

The results of this trial support the notion that O3FA supplementation has beneficial effects on COVID-19 patients with moderate presentation by regulating metabolism and limiting inflammation.

In Silico and In Vivo Evaluation of the Maqui Berry (Aristotelia chilensis (Mol.) Stuntz) on Biochemical Parameters and Oxidative Stress Markers in a Metabolic Syndrome Model

Metabolic syndrome (MetS) is a complex disease that includes metabolic and physiological alterations in various organs such as the heart, pancreas, liver, and brain. Reports indicate that blackberry consumption, such as maqui berry, has a beneficial effect on chronic diseases such as cardiovascular disease, obesity, and diabetes. In the present study, in vivo and in silico studies have been performed to evaluate the molecular mechanisms implied to improve the metabolic parameters of MetS. Fourteen-day administration of maqui berry reduces weight gain, blood fasting glucose, total blood cholesterol, triacylglycerides, insulin resistance, and blood pressure impairment in the diet-induced MetS model in male and female rats. In addition, in the serum of male and female rats, the administration of maqui berry (MB) improved the concentration of MDA, the activity of SOD, and the formation of carbonyls in the group subjected to the diet-induced MetS model. In silico studies revealed that delphinidin and its glycosylated derivatives could be ligands of some metabolic targets such as α-glucosidase, PPAR-α, and PPAR-γ, which are related to MetS parameters. The experimental results obtained in the study suggest that even at low systemic concentrations, anthocyanin glycosides and aglycones could simultaneously act on different targets related to MetS. Therefore, these molecules could be used as coadjuvants in pharmacological interventions or as templates for designing new multitarget molecules to manage patients with MetS.

Nutritional Status and Poverty Condition Are Associated with Depression in Preschoolers

Consensus has been reached that symptoms of depression can begin as early as preschool. Nevertheless, only few studies have associated environmental (malnutrition) and social factors (poverty condition, access to health systems, etc.) to the onset of depression in preschoolers. The aim of this study was to explore possible associations between malnutrition (underweight, overweight/obesity), poverty status (home quality, overcrowding), access to healthcare systems and the presence of depressive symptoms in the preschoolers of a semi-rural community. In total, 695 children between 3 and 6 years from the municipality of Chiconcuac, Mexico were evaluated for symptoms of depression with the Preschool Depression Scale for Teachers (ESDM 3-6). Additionally, they were assessed for nutritional status and divided into three groups (low weight, normal weight, overweight/obesity), and their parents were asked to fill out a social demographic questionnaire. Malnutrition status OR = 2.702, 95% CI [1.771-4.145]; UW OR = 4.768, 95% CI [2.570-8.795] and OW/OB OR = 1.959, 95% CI [1.175-3.324]; poverty condition per se OR = 1.779, 95% CI [0.9911-2.630]; housing quality OR = 2.020, 95% CI [0.9606-2.659] and overcrowding = 1.619, 95% CI [0.8989-4.433] were associated to a greater risk for children to show depressive symptoms (DS). Access to healthcare was negatively related with the risk of presenting DS (OR = 0.660, 95% CI [0.3130 to 1.360]). Social and environmental factors such as malnutrition, home quality and overcrowding may increase the risk of presenting DS as soon as in preschool.

Relationship of Sporotrichosis and Infected Patients with HIV-AIDS: An Actual Systematic Review

Background: Sporotrichosis is a fungal infection that can affect both humans and animals, caused by a species of thermo-dimorphic fungi of the genus Sporothrix. This pathology can be acquired by subcutaneous traumatic inoculation through contact with contaminated plants, soil or decomposing organic matter, and/or by inhalation of conidia. The infection can progress to chronic skin infection, or it can even spread to blood vessels, lymph, muscles, bones, and other organs, such as the lungs and nervous system. Those disseminated types are usually associated with cellular immunodeficiency and infection by inhalation, which explains why people living with human immunodeficiency virus (PLHIV) get infected in such a manner. This virus changes the natural history of sporotrichosis, producing a greater fungal load. Methods: The search was carried out in three databases: Pubmed, Scopus, and Scielo. Eligible articles were considered as those that described sporotrichosis in patients infected with HIV-AIDS, as well as case series. Results: A total of 24 articles were selected, with a sum of 37 patients with sporotrichosis and HIV infection. Of these patients, 31 came from Brazil, two from the United States, one from South Africa, one from Bangladesh, and two from an unspecified region. Regarding epidemiology, a predominance of the male sex was found in 28 of the 37 cases (75.6%), while nine were female (24.3%). Conclusions: Sporotrichosis infection continues to present in a more severe and disseminated way among HIV-positive subjects with lower CD4+ counts.

Mortality and Survival Factors in Patients with Moderate and Severe Pneumonia Due to COVID-19

During the pandemic, some mortality-related factors were age, sex, comorbidities (obesity, diabetes mellitus, and hypertension), recovery time, hospitalizations, and biochemical markers. The present work aimed to identify the mortality and survival factors in adults with moderate and severe pneumonia due to COVID-19 during the first and second waves of the pandemic in Mexico at a third-level hospital (High-Specialty Regional Hospital of Ixtapaluca (HRAEI), Ixtapaluca, Estado de Mexico, Mexico). A database was generated using information from the electronic clinical records of patients hospitalized from December 2021 to August 2022. Survival analysis was performed associating age, sex, longer recovery times, and some drugs. The risk factors found were age in the patients between 40 and 60 years (OR = 1.70), male sex (OR = 1.53), the presence of comorbidities (OR = 1.66) and hypertension (OR = 2.19), work occupation (construction workers OR = 5.22, factory workers OR = 3.13, unemployed OR = 2.93), the prehospital use of metamizole sodium (OR = 2.17), cough (OR = 1.73), and in-hospital oxygen therapy (reservoir mask OR = 6.6). The survival factors found in this study were working in the healthcare field (OR = 0.26), the prehospital use of certain medications (paracetamol OR = 0.65, dexamethasone OR = 0.55, and azithromycin OR = 0.47), presenting ageusia (OR = 0.5) and hyporexia (OR = 0.34), and the time using in-hospital oxygen therapy (device 1 OR = 0.72). Prehospital treatment needs to be reevaluated as dexamethasone and azithromycin proved to be protective factors. Likewise, providing aggressive oxygen therapy during hospital admission decreased mortality risk.

Tibolone Improves Memory and Decreases the Content of Amyloid-β Peptides and Tau Protein in the Hippocampus of a Murine Model of Alzheimer's Disease

BACKGROUND

Alzheimer's disease (AD) affects women more than men and consequently has been associated with menopause. Tibolone (TIB) has been used as a hormone replacement therapy to alleviate climacteric symptoms. Neuroprotective effects of TIB have also been reported in some animal models.

OBJECTIVE

This study aimed to assess the effect of TIB on memory and Aβ peptides and tau protein content in the hippocampus and cerebellum of transgenic 3xTgAD ovariectomized mice.

METHODS

Three-month-old female mice were ovariectomized. Ten days after surgery, animals were divided into four groups: wild-type (WT)+vehicle; WT+TIB (1 mg/kg); 3xTgAD+vehicle; and 3xTgAD+TIB (1 mg/kg). TIB was administered for three months, and memory was evaluated using the object-in-context recognition task. Subsequently, animals were decapitated, and the hippocampus and cerebellum were dissected. Using commercial ELISA kits, these brain structures were homogenized in a PBS buffer for quantifying Aβ40 and Aβ42 and phosphorylated and total tau.ResultsA long-term memory deficit was observed in the 3xTgAD+vehicle group. In contrast, TIB treatment improved long-term memory in the 3xTgAD+TIB group than those treated with vehicle (p < 0.05). Furthermore, TIB treatment decreased Aβ and tau content in the hippocampus of 3xTgAD mice compared to vehicle-treated groups (p < 0.05). No significant changes were observed in the cerebellum.

CONCLUSION

Chronic treatment with TIB showed neuroprotective effects and delayed AD neuropathology in the 3xTgAD mice. Our results support hormone replacement therapy with TIB in menopausal women for neuroprotection.

Frequency of Candida spp. in the Oral Cavity of Asymptomatic Preschool Mexican Children and Its Association with Nutritional Status

Malnutrition is a public health problem in developing countries, affecting the child population, which favors the appearance of infections such as oral candidiasis. In Mexico, information on the presence of oral colonization by Candida spp. in asymptomatic children is scarce. The present study aimed to determine the presence of Candida spp. in the oral cavity of asymptomatic preschool Mexican children and its association with their nutritional status. A sample of oral mucosa was obtained using a sterile swab and then inoculated in Sabouraud dextrose agar with antibiotics, and the yeast growth was phenotypically identified. The anthropometric profile of children was performed based on the guidelines of the International Society for the Advancement of Kinanthropometry. In addition, eating habits were investigated. The possible associations between the variables were determined through the chi-square test (IC95%, p < 0.05) (GraphPad Prism 8.0). Among the 743 assessed children (403 boys and 340 girls), the average age was 4.6 years, and the average nutritional status was normal (53.7%), followed by undernutrition (28.4%), overweight (12.4%) and obesity (5.5%). In 52 children, Candida was isolated, and the identified species were C. albicans (87.8%), C. glabrata (11.5%), C. krusei (5.8%) and C. parapsilosis (1.9%). The frequency of colonization was greater in males of six years (69.23%). There was no significant association between the colonization by Candida spp. and the nutritional status; however, a relation was observed with a high intake of simple carbohydrates.

Polyphenols as potential enhancers of stem cell therapy against neurodegeneration

The potential of polyphenols for treating chronic-degenerative diseases (particularly neurodegenerative diseases) is attractive. However, the selection of the best polyphenol for each treatment, the mechanisms by which they act, and their efficacy are frequently discussed. In this review, the basics and the advances in the field, as well as suggestions for using natural and synthetic polyphenols alone or in a combinatorial strategy with stem cell assays, are compiled and discussed. Thus, stem cells exhibit several responses when polyphenols are added to their environment, which could provide us with knowledge for advancing the elucidation of the origin of neurodegeneration. But also, polyphenols are being included in the innovative strategies of novel therapies for treating neurodegenerative diseases as well as metabolic diseases related to neurodegeneration. In this regard, flavonoid compounds are suggested as the best natural polyphenols due to their several mechanisms for acting in ameliorative effects; but increasing reports are involving other polyphenols. Even if some facts limiting bioactivity prevent them from conventional use, some natural polyphenols and derivatives hold the promise for being improved compounds, judged by their induced effects. The current results suggest polyphenols as enhancers of stem cell therapy against the targeted diseases.

Does the Fetus Limit Antibiotic Treatment in Pregnant Patients with COVID-19?

During pregnancy, there is a state of immune tolerance that predisposes them to viral infection, causing maternal-fetal vulnerability to the adverse effects of COVID-19. Bacterial coinfections significantly increase the mortality rate for COVID-19. However, it is known that all drugs, including antibiotics, will enter the fetal circulation in a variable degree despite the role of the placenta as a protective barrier and can cause teratogenesis or other malformations depending on the timing of exposure to the drug. Also, it is important to consider the impact of the indiscriminate use of antibiotics during pregnancy can alter both the maternal and fetal-neonatal microbiota, generating future repercussions in both. In the present study, the literature for treating bacterial coinfections in pregnant women with COVID-19 is reviewed. In turn, we present the findings in 50 pregnant women hospitalized diagnosed with SARS-CoV-2 without previous treatment with antibiotics; moreover, a bacteriological culture of sample types was performed. Seven pregnant women had coinfection with Staphylococcus haemolyticus, Staphylococcus epidermidis, Streptococcus agalactiae, Escherichia coli ESBL +, biotype 1 and 2, Acinetobacter jahnsonii, Enterococcus faecium, and Clostridium difficile. When performing the antibiogram, resistance to multiple drugs was found, such as macrolides, aminoglycosides, sulfa, dihydrofolate reductase inhibitors, beta-lactams, etc. The purpose of this study was to generate more scientific evidence on the better use of antibiotics in these patients. Because of this, it is important to perform an antibiogram to prevent abuse of empirical antibiotic treatment with antibiotics in pregnant women diagnosed with SARS-CoV-2.

Candida glabrata Antifungal Resistance and Virulence Factors, a Perfect Pathogenic Combination

In recent years, a progressive increase in the incidence of invasive fungal infections (IFIs) caused by Candida glabrata has been observed. The objective of this literature review was to study the epidemiology, drug resistance, and virulence factors associated with the C. glabrata complex. For this purpose, a systematic review (January 2001-February 2021) was conducted on the PubMed, Scielo, and Cochrane search engines with the following terms: "C. glabrata complex (C. glabrata sensu stricto, C. nivariensis, C. bracarensis)" associated with "pathogenicity" or "epidemiology" or "antibiotics resistance" or "virulence factors" with language restrictions of English and Spanish. One hundred and ninety-nine articles were found during the search. Various mechanisms of drug resistance to azoles, polyenes, and echinocandins were found for the C. glabrata complex, depending on the geographical region. Among the mechanisms found are the overexpression of drug transporters, gene mutations that alter thermotolerance, the generation of hypervirulence due to increased adhesion factors, and modifications in vital enzymes that produce cell wall proteins that prevent the activity of drugs designed for its inhibition. In addition, it was observed that the C. glabrata complex has virulence factors such as the production of proteases, phospholipases, and hemolysins, and the formation of biofilms that allows the complex to evade the host immune response and generate fungal resistance. Because of this, the C. glabrata complex possesses a perfect pathogenetic combination for the invasion of the immunocompromised host.

In Silico-Based Design and In Vivo Evaluation of an Anthranilic Acid Derivative as a Multitarget Drug in a Diet-Induced Metabolic Syndrome Model

Metabolic syndrome (MetS) is a complex disease that affects almost a quarter of the world's adult population. In MetS, diabetes, obesity, hyperglycemia, high cholesterol, and high blood pressure are the most common disorders. Polypharmacy is the most used strategy for managing conditions related to MetS, but it has drawbacks such as low medication adherence. Multitarget ligands have been proposed as an interesting approach to developing drugs to treat complex diseases. However, suitable preclinical models that allow their evaluation in a context closer to a clinical situation of a complex disease are needed. From molecular docking studies, compound 1b, a 5-aminoanthranilic acid derivative substituted with 4'-trifluoromethylbenzylamino and 3',4'-dimethoxybenzamide moieties, was identified as a potential multitarget drug, as it showed high in silico affinity against targets related to MetS, including PPAR-α, PPAR-γ, and HMG-CoA reductase. It was evaluated in a diet-induced MetS rat model and simultaneously lowered blood pressure, glucose, total cholesterol, and triglyceride levels after a 14-day treatment. No toxicity events were observed during an acute lethal dose evaluation test at 1500 mg/kg. Hence, the diet-induced MetS model is suitable for evaluating treatments for MetS, and compound 1b is an attractive starting point for developing multitarget drugs.

Inflammation Parameters Associated with Metabolic Disorders: Relationship Between Diet and Microbiota

The metabolic syndrome (MetS) includes numerous interrelated clinical, anthropometric, biochemical, and metabolic components and has become a public health problem due to its impact on morbimortality. Inflammation is a central mechanism underlying the etiology and clinical manifestations of MetS, contributing to its related pathological outcomes. Dietary patterns have been associated with the promotion of the diversity of microbiota in the digestive tract. Recently, research has focused on the importance of microbiota changes associated with MetS and inflammation. Other studies have been performed to understand the impact of prebiotics, probiotics, and synbiotics as allies on diet, inflammation, and MetS parameters. This review analyses the correlation between metabolic disorders, inflammation parameters, gut microbiota, and how diet has been involved as treatment of MetS and the modulation of inflammation and microbiota.

Nutritional Status Influences Oxidative Stress and Insulin Resistance in Preschool Children

Background: Child malnutrition represents a major public health problem with physiological, psychological, and social short- and long-term implications. Objective: To compare the influence of nutritional status on oxidative stress (OS) markers in children aged 3-6 years. Methods: Children were categorized into four groups: underweight, normal weight, overweight, and obesity. Glucose (Glu), cholesterol (Chol), high-density lipoproteins, insulin, triacylglycerols (TG), triacylglycerols/glucose (TyG) index, and the homeostasis model assessment of insulin resistance (HOMA-IR) were analyzed. In addition, OS [malondialdehyde (MDA) and 3-nitrotyrosine (3-NT)] and antioxidant defense markers [superoxide dismutase (SOD), catalase (CAT), and the ratio of reduced/oxidized glutathione (GSH/GSSG)] were quantified. Results: Children with obesity showed significantly higher levels of MDA and 3-NT, and increased SOD activity compared with normal weight children. Glu, Chol, TG levels, TyG indexes, HOMA-IR, MDA, 3-NT, and SOD positively correlated with body mass index (BMI) and Centers for Disease Control and Prevention percentiles (CDC PC). However, CAT concentration and the GSH/GSSG ratio correlated negatively with BMI and CDC PC. In children with underweight, we found a positive correlation of TG levels and TyG indexes with BMI, whereas both markers positively correlated with BMI and CDC PC in children with overweight. MDA negatively correlated with BMI in children with underweight, while a positive association was observed in children with overweight. Finally, SOD, CAT, and GSH/GSSG negatively correlated with both BMI and CDC PC in children with overweight. Conclusions: Malnutrition, especially obesity, is associated with metabolic and OS disturbances in preschool children. It is urgent to design strategies to prevent malnutrition in this age group since this stage of development is crucial to potentially avoid future co-morbidities.

Epidemiology of Systemic Mycoses in the COVID-19 Pandemic

The physiopathologic characteristics of COVID-19 (high levels of inflammatory cytokines and T-cell reduction) promote fungal colonization and infection, which can go unnoticed because the symptoms in both diseases are very similar. The objective of this work was to study the current epidemiology of systemic mycosis in COVID-19 times. A literature search on the subject (January 2020–February 2021) was performed in PubMed, Embase, Cochrane Library, and LILACS without language restrictions. Demographic data, etiological agent, risk factors, diagnostic methods, antifungal treatment, and fatality rate were considered. Eighty nine publications were found on co-infection by COVID-19 and pneumocystosis, candidiasis, aspergillosis, mucormycosis, coccidioidomycosis, or histoplasmosis. In general, the co-infections occurred in males over the age of 40 with immunosuppression caused by various conditions. Several species were identified in candidiasis and aspergillosis co-infections. For diagnosis, diverse methods were used, from microbiological to molecular. Most patients received antifungals; however, the fatality rates were 11–100%. The latter may result because the clinical picture is usually attributed exclusively to SARS-CoV-2, preventing a clinical suspicion for mycosis. Diagnostic tests also have limitations beginning with sampling. Therefore, in the remainder of the pandemic, these diagnostic limitations must be overcome to achieve a better patient prognosis.

Plasma Levels of Amyloid-β Peptides and Tau Protein in Mexican Patients with Alzheimer's Disease

BACKGROUND

Alzheimer's disease (AD) causes memory deficit and alterations in other cognitive functions, mainly in adults over 60 years of age. As the diagnosis confirmation is performed by a postmortem neuropathological examination of the brain, this disease can be confused with other types of dementia at early stages. About 860,000 Mexicans are affected by dementia, most of them with insufficient access to adequate comprehensive health care services. Plasma biomarkers could be a rapid option for early diagnosis of the disease.

OBJECTIVE

This study aimed to analyze some plasma biomarkers (amyloid-β, tau, and lipids) in Mexican AD patients and control subjects with no associated neurodegenerative diseases.

METHODS

Plasma amyloid-β peptides (Aβ40 and Aβ42), total and phosphorylated tau protein (T-tau and P-tau), and cholesterol and triglyceride levels were quantified by enzyme-linked immunosorbent assay in AD patients and control subjects.

RESULTS

In Mexican AD patients, we found significantly lower levels of Aβ42 (p < 0.05) compared to the control group. In contrast, significantly higher levels of P-tau (p < 0.05) and triglycerides (p < 0.05) were observed in AD patients compared to controls. Furthermore, a significant correlation was found between the severity of dementia and plasma P-tau levels, Aβ42/Aβ40 and P-tau/T-tau ratios, and triglycerides concentrations. This correlation increased gradually with cognitive decline.

CONCLUSION

The detection of these plasma biomarkers is an initial step in searching for a timely, less invasive, and cost-efficient diagnosis in Mexicans.

Maqui berry (Aristotelia chilensis) extract improves memory and decreases oxidative stress in male rat brain exposed to ozone

Introduction: Prolonged ozone exposure can produce a state of oxidative stress, which in turn causes alterations in the dynamics of the brain and affects memory and learning. Moreover, different investigations have shown that high flavonoid content berries show a great antioxidant activity. The relationship between the protective effect of the maqui berry extract and its antioxidant properties in the brain has not been studied in depth. Objectives: The present study evaluated whether the protection exerted by the aqueous extract of maqui berry in brain regions associated with cognitive performance is due to its antioxidant capacity. Methods: Sprague Dawley rats were exposed to 0.25 ppm ozone and administered with maqui berry extracts. At the end of the treatments, spatial learning and short- and long-term memory were evaluated, as well as oxidative stress markers. Results: The administration of 50 and 100 mg/kg of the aqueous extract of maqui berry was effective in preventing the cognitive deficit caused by chronic exposure to ozone. The antioxidant effect of the administration of maqui berry was analyzed in the prefrontal cortex, hippocampus, and amygdala. Oxidative stress markers levels decreased and the enzymatic activity of superoxide dismutase diminished in animals exposed to ozone treated with the 50 mg/kg dose of maqui berry. Discussion: These results show a relationship between protection at the cognitive level and a decrease in oxidative stress markers, which suggests that the prevention of cognitive damage is due to the antioxidant activity of the maqui berry.

In Silico Study of Polyunsaturated Fatty Acids as Potential SARS-CoV-2 Spike Protein Closed Conformation Stabilizers: Epidemiological and Computational Approaches

SARS-CoV-2 infects host cells by interacting its spike protein with surface angiotensin-converting enzyme 2 (ACE2) receptors, expressed in lung and other cell types. Although several risk factors could explain why some countries have lower incidence and fatality rates than others, environmental factors such as diet should be considered. It has been described that countries with high polyunsaturated fatty acid (PUFA) intake have a lower number of COVID-19 victims and a higher rate of recovery from the disease. Moreover, it was found that linoleic acid, an omega-6 PUFA, could stabilize the spike protein in a closed conformation, blocking its interaction with ACE2. These facts prompted us to perform in silico simulations to determine if other PUFA could also stabilize the closed conformation of spike protein and potentially lead to a reduction in SARS-CoV-2 infection. We found that: (a) countries whose source of omega-3 is from marine origin have lower fatality rates; and (b) like linoleic acid, omega-3 PUFA could also bind to the closed conformation of spike protein and therefore, could help reduce COVID-19 complications by reducing viral entrance to cells, in addition to their known anti-inflammatory effects.

Comparative assessment of flatfoot in preschool children

Background

The increase or reduction of the medial longitudinal arch (MLA) can affect essential functions in the foot biomechanics with long-term health consequences. The aim of the present study was to determine the height of the MLA in children from 3 to 6 years of age through five methods of footprint analysis for the diagnosis of flat foot.

Methods

A cross-sectional observational study was conducted with 367 children aged 3 to 6 years in a municipality of the State of Mexico. We conducted a complete postural evaluation, plantoscopy by Viladot classification, and footprint analysis calculating the height of the ALM using the Clarke angle (CA), the Staheli index (SI), the Chippaux-Smirak index (CSM), and the gamma angle (gA).

Results

The prevalence of flat feet using the podoscope was 57.7%. Through the angles and indexes, the prevalence was 86.9% for SI, 83.3% for CSI, 95.9% for CA, and 22.3% for gA. The gA was less sensitive for flat foot detection compared to CSI, SI and CA.

Conclusions

Based on the present results, we propose that footprint analysis should be used for flat foot diagnosis besides the classic evaluation by podoscope. We recommend that flat foot diagnosis and surveillance should be included on in the consultation of the healthy child, as a trend for podalic architecture can be detected from early ages.

Monoamines and their Derivatives on GPCRs: Potential Therapy for Alzheimer's Disease

Albeit cholinergic depletion remains the key event in Alzheimer's Disease (AD), recent information describes stronger links between monoamines (trace amines, catecholamines, histamine, serotonin, and melatonin) and AD than those known in the past century. Therefore, new drug design strategies focus efforts to translate the scope on these topics and to offer new drugs which can be applied as therapeutic tools in AD. In the present work, we reviewed the state-of-art regarding genetic, neuropathology and neurochemistry of AD involving monoamine systems. Then, we compiled the effects of monoamines found in the brain of mammals as well as the reported effects of their derivatives and some structure-activity relationships. Recent derivatives have triggered exciting effects and pharmacokinetic properties in both murine models and humans. In some cases, the mechanism of action is clear, essentially through the interaction on G-protein-coupled receptors as revised in this manuscript. Additional mechanisms are inhibition of enzymes for their biotransformation, regulation of free-radicals in the central nervous system and others for the effects on Tau phosphorylation or amyloid-beta accumulation. All these data make the monoamines and their derivatives attractive potential elements for AD therapy.

Effect of tibolone pretreatment on kinases and phosphatases that regulate the expression and phosphorylation of Tau in the hippocampus of rats exposed to ozone

Oxidative stress (OS) is a key process in the development of many neurodegenerative diseases, memory disorders, and other pathological processes related to aging. Tibolone (TIB), a synthetic hormone used as a treatment for menopausal symptoms, decreases lipoperoxidation levels, prevents memory impairment and learning disability caused by ozone (O3) exposure. However, it is not clear if TIB could prevent the increase in phosphorylation induced by oxidative stress of the microtubule-associated protein Tau. In this study, the effects of TIB at different times of administration on the phosphorylation of Tau, the activation of glycogen synthase kinase-3β (GSK3β), and the inactivation of Akt and phosphatases PP2A and PTEN induced by O3 exposure were assessed in adult male Wistar rats. Rats were divided into 10 groups: control group (ozone-free air plus vehicle [C]), control + TIB group (ozone-free air plus TIB 1 mg/kg [C + TIB]); 7, 15, 30, and 60 days of ozone exposure groups [O3] and 7, 15, 30, and 60 days of TIB 1 mg/kg before ozone exposure groups [O3 + TIB]. The effects of O3 exposure and TIB administration were assessed by western blot analysis of total and phosphorylated Tau, GSK3β, Akt, PP2A, and PTEN proteins and oxidative stress marker nitrotyrosine, and superoxide dismutase activity and lipid peroxidation of malondialdehyde by two different spectrophotometric methods (Marklund and TBARS, respectively). We observed that O3 exposure increases Tau phosphorylation, which is correlated with decreased PP2A and PTEN protein levels, diminished Akt protein levels, and increased GSK3β protein levels in the hippocampus of adult male rats. The effects of O3 exposure were prevented by the long-term treatment (over 15 days) with TIB. Malondialdehyde and nitrotyrosine levels increased from 15 to 60 days of exposure to O3 in comparison to C group, and superoxide dismutase activity decreased. Furthermore, TIB administration limited the changes induced by O3 exposure. Our results suggest a beneficial use of hormone replacement therapy with TIB to prevent neurodegeneration caused by O3 exposure in rats.

Effects of estrogen receptor modulators on cytoskeletal proteins in the central nervous system

Estrogen receptor modulators are compounds of interest because of their estrogenic agonistic/antagonistic effects and tissue specificity. These compounds have many clinical applications, particularly for breast cancer treatment and osteoporosis in postmenopausal women, as well as for the treatment of climacteric symptoms. Similar to estrogens, neuroprotective effects of estrogen receptor modulators have been described in different models. However, the mechanisms of action of these compounds in the central nervous system have not been fully described. We conducted a systematic search to investigate the effects of estrogen receptor modulators in the central nervous system, focusing on the modulation of cytoskeletal proteins. We found that raloxifene, tamoxifen, and tibolone modulate some cytoskeletal proteins such as tau, microtuble-associated protein 1 (MAP1), MAP2, neurofilament 38 (NF38) by different mechanisms of action and at different levels: neuronal microfilaments, intermediate filaments, and microtubule-associated proteins. Finally, we emphasize the importance of the study of these compounds in the treatment of neurodegenerative diseases since they present the benefits of estrogens without their side effects.

Neuroprotective effects of tibolone against oxidative stress induced by ozone exposure

INTRODUCTION

Oxidative stress increases brain lipid peroxidation, memory and motor deficits and progressive neurodegeneration. Tibolone, a treatment for menopausal symptoms, decreases lipid peroxidation levels and improves memory and learning.

AIM

To study the effect of chronic administration of tibolone on lipid peroxidation, memory and motor deficits in ozone induced oxidative stress.

MATERIALS AND METHODS

100 male Wistar adult rats were randomly divided into 10 experimental groups: control (C) was exposed to an airstream for 60 days; C + tibolone, airstream exposure plus 1 mg/kg of tibolone for 60 days; groups 3-6 were exposed to ozone for 7, 15, 30, and 60 days, and groups 7-10 received 1 mg/kg of tibolone treatment by oral gavage for 7, 15, 30 and 60 days and were then exposed to ozone. We determined the effect of tibolone on memory and motor activity. Hippocampus was processed to determine the content of 4-hydroxynonenal and nitrotyrosine by Western blot. Four animals were perfused and processed for analysis of neuronal death.

RESULTS

In the hippocampus, administration of 1 mg/kg of tibolone for 30 days prevented increased levels of lipid peroxidation and protein oxidation, whereas after 60 days prevented neuronal death in the CA3 region caused by exposure to ozone. Therefore, tibolone prevents cognitive deficits in short- and long-term memory on the passive avoidance task and prevents a decrease in exploratory behavior and an increase in freezing behavior.

CONCLUSION

Our results indicate a possible neuroprotective role of tibolone as a useful treatment to prevent oxidative stress neurodegeneration.