Silk fibroin-based dressings with antibacterial and anti-inflammatory properties.

Silk fibroin is a fibrillar protein obtained from arthropods such as mulberry and non-mulberry silkworms. Silk fibroin has been used as a dressing in wound treatment for its physical, chemical, mechanical, and biological properties. This systematic review analyzed studies from PubMed, Web of Science, and Scopus databases to identify the molecules preferred for functionalizing silk fibroin-based dressings and to describe their mechanisms of exhibiting anti-inflammatory and antibacterial properties. The analysis of the selected articles allowed us to classify the dressings into different conformations, such as membranes, films, hydrogels, sponges, and bioadhesives. The incorporation of various molecules, including antibiotics, natural products, peptides, nanocomposites, nanoparticles, secondary metabolites, growth factors, and cytokines, has allowed the development of dressings that promote wound healing with antibacterial and immunomodulatory properties. In addition, silk fibroin-based dressings have been established to have the potential to regenerate wounds such as venous ulcers, arterial ulcers, diabetic foot, third-degree burns, and neoplastic ulcers. Evaluation of the efficacy of silk fibroin-based dressings in tissue engineering is an area of great activity that has shown significant advances in recent years.

First serological and molecular detection of Toxoplasma gondii in guinea pigs (Cavia porcellus) used for human consumption in Nariño, Colombia, South America.

Consumption of undercooked meat is one of the main transmission routes for Toxoplasma gondii worldwide. In the South American Andes, the guinea pig (Cavia porcellus) is a domestic rodent representing one of the main sources of animal proteins for indigenous communities. Although T. gondii infects a wide range of rodents worldwide, the natural impact of the infection on guinea pig populations is still unknown. Our study conducted in guinea pigs that were bred in traditional systems located in the village of José María Hernández (Nariño, Colombia) revealed the presence of T. gondii antibodies in 33.3% (23 out of 69) guinea pigs evaluated, with a cut-off point of 25 for the modified direct agglutination test. Conventional PCR detection of the T. gondii-specific RE fragment (529 bp) in 207 collected tissues demonstrated the presence of T. gondii DNA in several organs, including the brain (16/69), muscle (12/69), and heart (4/69), with an overall molecular detection frequency of 27.5% (19 out of 69 guinea pigs). This is the first report of natural infection of guinea pigs with T. gondii, demonstrating their potential epidemiological role in transmitting the infection to autochthonous populations.

Recent molecular techniques for the diagnosis of Zika and Chikungunya infections: A systematic review.

Zika virus (ZIKV) and Chikungunya virus (CHIKV) are arboviruses that cause important viral diseases affecting the world population. Both viruses can produce remarkably similar clinical manifestations, co-circulate in a geographic region, and coinfections have been documented, thus making clinical diagnosis challenging. Therefore, it is urgent to have better molecular techniques that allow a differential, sensitive and rapid diagnosis from body fluid samples. This systematic review explores evidence in the literature regarding the advances in the molecular diagnosis of Zika and Chikungunya in humans, published from 2010 to March 2021. Four databases were consulted (Scopus, PubMed, Web of Science, and Embase) and a total of 31 studies were included according to the selection criteria. Our analysis highlights the need for standardization in the report and interpretation of new promising diagnostic methods. It also examines the benefits of new alternatives for the molecular diagnosis of these arboviruses, in contrast to established methods.

Susceptibility to endemic Aedes-borne viruses among pregnant women in Risaralda, Colombia.

OBJECTIVES: Aedes-borne viruses (ABV) affect humans on every inhabited continent and frequently cause epidemics. Recent epidemics of chikungunya and Zika viruses (ZIKV) highlight that preparedness for future epidemics requires assessment of susceptibility, particularly among high-risk groups. We sought to determine immunity against the three major circulating ABV among pregnant women in an ABV-endemic area of Colombia. METHODS: A cross-sectional seroprevalence study was performed, enrolling women presenting to Labor and Delivery. Cord blood and maternal peripheral blood samples were obtained. IgG seroprevalence to flaviviruses and chikungunya was determined by ELISA. An abbreviated neutralization test was used to estimate the frequency and magnitude of immunity to Zika and four dengue serotypes. Cluster analyses explored epidemiologic factors associated with seroprevalence. RESULTS: Most women exhibited high levels of neutralizing antibodies to one or more ABV; however, nearly 20% were seronegative for flaviviruses. Our research took place after the epidemic peak of the ZIKV outbreak in Colombia in 2016. However, only 20% of pregnant women had high levels of Zika-neutralizing antibodies consistent with likely protective immunity to ZIKV. CONCLUSION: Hence, a high proportion of pregnant women in Risaralda remain susceptible to one or more ABV including the teratogenic ZIKV, indicating a risk for future epidemics in this region.

Comparison of the Scorpionism Caused by Centruroidesmargaritatus, Tityuspachyurus and Tityus n. sp. aff. metuendus Scorpion Venoms in Colombia.

Among other scorpion species, Colombia has two genera of the Buthidae family Centruroides and Tityus, considered to be dangerous to humans. This research shares scientific knowledge aiming to a better understanding about the pathophysiological effects of such venoms. The venom of the three species: Centruroides margaritarus, Tityus pachyurus, and T. n. sp. aff. metuendus with biomedical interest were studied. An initial pre-glycemic sample was taken from ICR mice. They were later intraperitoneally inoculated with doses of 35% and 70% of LD50 of total venom. Poisoning signs were observed during a 6-h period to determine the level of scorpionism. After observation, a second glycemic sample was taken, and a histopathological evaluation of different organs was performed. This work revealed that all three venoms showed considerably notorious histopathological alterations in main organs such as heart and lungs; and inducing multiple organ failure, in relation to the glycemia values, only C. margaritatus and T. n. sp. aff. metuendus showed significant changes through manifestation of hyperglycemia. According to the Colombian scorpionism level; signs were mild to severe affecting the autonomous nervous system.

Silk fibroin nanocomposites as tissue engineering scaffolds - A systematic review.

Silk fibroin is a protein with intrinsic characteristics that make it a good candidate as a scaffold for tissue engineering. Recent works have enhanced its benefits by adding inorganic phases that interact with silk fibroin in different ways. A systematic review was performed in four databases to study the physicochemical and biological performance of silk fibroin nanocomposites. In the last decade, only 51 articles contained either in vitro cell culture models or in vivo tests. The analysis of such works resulted in their classification into the following scaffold types: particles, mats and textiles, films, hydrogels, sponge-like structures, and mixed conformations. From the physicochemical perspective, the inorganic phase imbued in silk fibroin nanocomposites resulted in better stability and mechanical performance. This review revealed that the inorganic phase may be associated with specific biological responses, such as neovascularisation, cell differentiation, cell proliferation, and antimicrobial and immunomodulatory activity. The study of nanocomposites as tissue engineering scaffolds is a highly active area mostly focused on bone and cartilage regeneration with promising results. Nonetheless, there are still many challenges related to their application in other tissues, a better understanding of the interaction between the inorganic and organic phases, and the associated biological response.

Antiproliferative activity of thiazole and oxazole derivatives: A systematic review of in vitro and in vivo studies.

Thiazole and oxazole are compounds with a heterocyclic nucleus that have attracted the attention of medicinal chemistry due to the great variety of biological activities that they enable. In recent years, their study has increased, finding a wide range of biological activities, including antifungal, antiparasitic, anti-inflammatory, and anticancer activities. This systematic review provides evidence from the literature on the antiproliferative and antitumor activities of thiazole and oxazole and their derivatives from 2014 to April 2020. Three bibliographical databases were consulted (PubMed, Web of Science, and Scopus), and a total of 32 studies were included in this paper based on our eligibility criteria. The analysis of the activity-structure relationship allows us to conclude that most of the promising compounds identified contained thiazole nuclei or derivatives.

A systematic review of FTA cards® as a tool for viral RNA preservation in fieldwork: Are they safe and effective?

BackgroundDetection and characterization of viral RNA pathogens from fieldwork are challenging due to the instability of the RNA molecule. FTA cards® have proved useful for sample storage and latter identification of pathogens with importance for agricultural, animal and human health: however, for optimal handling, processing, and biosafety measures are not well-established. ObjectiveThis systematic review aims to summarize the reported effectiveness of FTA cards® for storage and transport of viral RNA, as well as the conditions for their handling and use in downstream processes. Finally, the biosafety measures required to protect researchers and clinical lab workers are considered. MethodsWe performed a systematic review following the PRISMA statement. We searched MEDLINE (PubMed), Scopus and Web of Science using the keywords "FTA cards" AND "RNA". Articles were screened by title and abstract, and after examination of inclusion and exclusion criteria, relevant information was extracted. The quality of the studies was assessed, and the evidence was qualitatively summarized. ResultsA total of 175 records were retrieved, and 11 additional documents were found by checking references of the eligible articles. A total of 47 articles were included. Samples from animals accounted for 38.3% of the publications, which identified viruses that cause disease in poultry, wild birds, suids, or bovids. Three different methods for RNA extraction were reported. Other factors that vary across reports include the size of RNA amplicon, storage temperature, and duration of storage. Only fourteen articles tested the inactivation of the virus on the FTA card®, and in one case, the virus remained infective. ConclusionFTA cards® could be a suitable option for RNA virus storage and transport for fieldwork in areas where proper conditions for RNA preservation are difficult to achieve. Three different protocols have been used for RNA detection from this matrix. Biospecimens in the form of dried blood spots should be considered potentially infectious unless specifically treated to inactivate viral pathogens.

Silk fibroin hydrogels from the Colombian silkworm Bombyx mori L: Evaluation of physicochemical properties.

Hydrogel scaffolds are important materials in tissue engineering, and their characterization is essential to determine potential biomedical applications according to their mechanical and structural behavior. In this work, silk fibroin hydrogels were synthesized by two different methods (vortex and sonication), and agarose hydrogels were also obtained for comparison purposes. Samples were characterized by scanning electron microscopy, infrared analysis, thermo-gravimetrical analysis, confined compression test, and rheological test. The results indicate that nanofibers can be obtained via both silk fibroin and agarose hydrogels. The mechanical tests showed that the Young's modulus is similar to those found in the literature, with the highest value for agarose hydrogels. All the hydrogels showed a shear-thinning behavior. Additionally, the MTT test revealed that silk fibroin hydrogels had low cytotoxicity in THP-1 and HEK-293 cells, whereas the agarose hydrogels showed high toxicity for the THP-1 cell line. The results indicate that silk fibroin hydrogels obtained from a Colombian silkworm hybrid are suitable for the development of scaffolds, with potential applications in tissue engineering.

Anti-inflammatory activity of triazine derivatives: A systematic review.

Triazines are heterocyclic compounds with a variety of biological activities that have been increasingly studied in recent years due to their versatile structure (three isoforms) and the different derivatives that can be synthesized from them to ensure functional motifs. This systematic review provides the evidence in the literature of the in vitro and in vivo anti-inflammatory activity of triazine derivatives from 2008 to June 2018. Four bibliographical databases were consulted (PubMed, Web of Science, EMBASE and Scopus), and a total of 48 studies were included in this paper based on our eligibility criteria. Although 35.17% of evaluated triazines were demonstrated to be promising anti-inflammatory agents, further studies need to be conducted to explore their pharmacological profiles in the medical research of drug discovery to control the risk factors and pathophysiology of several chronic inflammation-based diseases.

Inflammatory Markers in the Staging of Bipolar Disorder: A Systematic Review of the Literature / Marcadores inflamatorios en la estadificación del trastorno bipolar: una revisión sistemática de la literatura

ABSTRACT Background: Previous studies suggest that inflammatory molecules play an important role in the pathophysiology of Bipolar Disorder (BD). The evidence suggests that BD may present a progressive course. Therefore there are theories that postulate the relationship between progression and stages of the disease with distinct peripheral biomarkers. Objective: The aim of this study was to carry out a systematic review of the literature of studies about the association between peripheral inflammatory markers and clinical variables related with staging in BD patients. Methods: We conducted a systematic review using electronic databases: PubMed, SciELO, LiLACS and PsycINFO. Keywords were divided into inflammatory markers and, BD and staging. Studies involving euthymic BD patients, studies evaluating peripheral biomarkers and studies correlating these with clinical variables related to neuroprogression or stage of BD were included. Results: We present and discuss the methods and findings of ten articles. The inflammatory markers were measured with different techniques and show some contradictories results. The TNF superfamily and inflammatory cytokines may have a relationship with the neuroprogression of the disease. Conclusions: This study suggests that TNF and ILs could play a role in neuroprogression. However, longitudinal studies are needed to clarify the relationship between factors associated with neuroprogression.

RESUMEN Introducción: Estudios previos indican que las moléculas inflamatorias tienen un papel importante en la fisiopatología del trastorno bipolar (TB). La evidencia apunta a que el TB puede presentar un curso progresivo. Por lo tanto, existen teorías que han postulado una relación entre la progresión y los estadios de la enfermedad con diferentes biomarcadores Revisión sistemática periféricos. Objetivo: El objetivo de este estudio es realizar una revisión sistemática de la literatura de los estudios sobre la asociación entre los marcadores inflamatorios periféricos y las variables clínicas relacionadas con la estadificación en los pacientes con TB. Métodos: Se llevó a cabo una revisión sistemática usando las bases de datos electrónicas PubMed, SciELO, LiLACS y PsycINFO. Las palabras clave se dividieron en marcadores inflamatorios y TB y estadificación. Se incluyeron estudios que evaluaron a pacientes con TB en fase de eutimia, estudios que evaluaron biomarcadores periféricos y estudios que correlacionaron dichos marcadores con las variables clínicas relacionadas con la neuroprogresión o estadificación del TB. Resultados: Se presentan y se discuten los métodos y los hallazgos de 10 artículos. Los marcadores inflamatorios se determinaron con diferentes técnicas y mostraron resultados contradictorios. La super familia del factor de necrosis tumoral y las citocinas inflamatorias podrían tener una relación con la neuroprogresión de la enfermedad. Conclusiones: El presente estudio indica que el factor de necrosis tumoral y las intereucinas pueden tener un papel en la neuroprogresión del TB. Sin embargo, se requieren estudios longitudinales con el fin de clarificar la relación entre los factores asociados con la neuro-progresión.

Inflammatory Markers in the Staging of Bipolar Disorder: A Systematic Review of the Literature.

BACKGROUND: Previous studies suggest that inflammatory molecules play an important role in the pathophysiology of Bipolar Disorder (BD). The evidence suggests that BD may present a progressive course. Therefore there are theories that postulate the relationship between progression and stages of the disease with distinct peripheral biomarkers. OBJECTIVE: The aim of this study was to carry out a systematic review of the literature of studies about the association between peripheral inflammatory markers and clinical variables related with staging in BD patients. METHODS: We conducted a systematic review using electronic databases: PubMed, SciELO, LiLACS and PsycINFO. Keywords were divided into inflammatory markers and, BD and staging. Studies involving euthymic BD patients, studies evaluating peripheral biomarkers and studies correlating these with clinical variables related to neuroprogression or stage of BD were included. RESULTS: We present and discuss the methods and findings of ten articles. The inflammatory markers were measured with different techniques and show some contradictories results. The TNF superfamily and inflammatory cytokines may have a relationship with the neuroprogression of the disease. CONCLUSIONS: This study suggests that TNF and ILs could play a role in neuroprogression. However, longitudinal studies are needed to clarify the relationship between factors associated with neuroprogression.

Plant expression systems, a budding way to confront chikungunya and Zika in developing countries?

Plant expression systems could be used as biofactories of heterologous proteins that have the potential to be used with biopharmaceutical aims and vaccine design. This technology is scalable, safe and cost-effective and it has been previously proposed as an option for vaccine and protein pharmaceutical development in developing countries. Here we present a proposal of how plant expression systems could be used to address Zika and chikungunya outbreaks through development of vaccines and rapid diagnostic kits.

Importancia del diagnóstico de laboratorio de Zika durante el embarazo y su posible asociación con el síndrome de Guillain-Barré / Relevance of laboratory diagnosis of Zika during pregnancy and its possible association with Guillain-Barré syndrome

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Comparison of five protocols to extract DNA from paraffin-embedded tissues for the detection of human papillomavirus.

Formalin-fixed paraffin-embedded (FFPE) tissues are a valuable source of DNA with which to perform large retrospective studies on the epidemiology of HPV infection. Five different DNA extraction protocols were carried out to evaluate the DNA obtained from FFPE samples with polymerase chain reaction (PCR) using two primer sets to amplify a constitutive human gene, ß-globin, and two primer sets to detect the L1 and E6 HPV genes. From the five DNA extraction protocols evaluated, the best results were obtained with protocol A, corresponding to a crude extract from the sample. With the procedures described herein, we were able to amplify DNA extracted from archival paraffin blocks stored for six years. However, the amplification products were more efficiently obtained with primers that amplified shorter fragments. This result indicates that a major factor limiting the extraction process in these samples is DNA fragmentation, a factor that will naturally vary between the different specimens evaluated. Also, depending upon the extraction method, PCR amplification of a human gene does not necessarily guarantee the successful extraction of viral DNA. In conclusion, different DNA and HPV detection methods can significantly influence the results. Therefore, the DNA extraction methods and primers used for DNA amplification in fixed tissues need to be chosen carefully, depending on the specific requirements of the study being carried out.

Toxoplasmosis as a travel risk.

Toxoplasma gondii is a protozoan parasite with worldwide distribution that infects more than one third of the global population. Primary infection in immunocompetent individuals is usually asymptomatic; however, different organs can be affected in immunocompromised individuals leading to the development of encephalitis, myocarditis or pneumonitis. The prevalence of infection with Toxoplasma as well as its genetic structure varies geographically and for that reason travel may be considered as a risk factor to acquire the infection. As toxoplasmosis is a foodborne disease, health care providers should give health education on prevention measures to all prospective travelers in order to decrease the risk of infection in endemic areas. This review presents an overview of the infection with T. gondii with some considerations for travelers to and from endemic zones.

Anti-Toxoplasma activity of natural products: a review.

Toxoplasma gondii is an intracellular parasite widely distributed in nature. Infection is asymptomatic in immunocompetent individuals; however, various clinical manifestations may occur in immunocompromised individuals. Although there are medications for the treatment of toxoplasmosis, such as pyrimethamine and sulfonamide, they cannot always be used due to adverse reactions or to therapeutic failures related to intolerance or malabsorption of drugs and to parasite drug resistance. In recent years, the search for new antimicrobial agents derived from plants has intensified because a quarter of synthetic drugs that are currently prescribed have been isolated from a plant source, demonstrating that natural products are important in the development of new drugs. A systematic literature search was conducted to evaluate the use of natural products as an alternative for the treatment of T. gondii infection. The search was conducted for the 2000-2014 period in Science Direct, Scopus, PubMed, EMBASE, and SciELO databases, using the following MeSH terms: anti-Toxoplasma activity, toxoplasma AND natural products, toxoplasma AND plant extracts. Ethnobotanical and experimental evidence (in vitro/in vivo) was found supporting the use of natural products as a source for the discovery of new therapies against T. gondii.

ß(2) -adrenoreceptor polymorphisms in asthmatic and non-asthmatic schoolchildren from Colombia and their relationship to treatment response.

Asthma is a chronic and recurrent disease. Its high prevalence around the world is the result of a complex interaction between genetic and environmental factors. The genetic aspects of susceptibility, severity, and response to treatment in asthma are of great scientific interest. The purpose of the study was to establish the relationship between the Gln27Glu and Arg16Gly alleles of the ß(2) -adrenergic receptor (ADRB2) gene with respect to the susceptibility to and severity of asthma, as well as the response to treatment in mestizo schoolchildren. 109 schoolchildren with asthma diagnosis and 137 asymptomatic controls were genotyped for the Arg16Gly and Gln27Glu alleles of the ADRB2 gene by minisequencing. Allele, genotype, and haplotype frequencies of the ADRB2 gene between asthmatic and non-asthmatic as well as demographic, clinical, and spirometric variables among asthmatic patients according to their genotype were compared. ADRB2 gene expression was determined by real-time quantitative PCR. No statistical differences were found in allele, genotype, and haplotype frequencies of the ADRB2 gene between cases and controls. We did not find differences between asthmatic patients classified according to their ADRB2 genotypes and haplotypes when evaluating demographic, clinical, and spirometric variables. The ADRB2 genotype and haplotype are not associated with spirometric responses or ADRB2 gene expression after administration of a ß-(2) agonist plus a glucocorticoid. These results suggest that in the group of mestizo schoolchildren studied, the Arg16Gly and Gln27Glu polymorphisms are not markers of susceptibility or severity of asthma and do not affect ADRB2 gene expression during the rescue therapy.

Use of dimethyldioxirane in the epoxidation of the main constituents of the essential oils obtained from Tagetes lucida, Cymbopogon citratus, Lippia alba and Eucalyptus citriodora.

Dimethyldioxirane (DMDO), a widely used oxidant in organic synthesis is considered an environmentally friendly oxygen transfer reagent because acetone is the only byproduct formed in its oxidation reactions. This work describes the isolation of the main constituents (terpenes) in the essential oils obtained from Tagetes lucida, Cymbopogon citratus, Lippia alba and Eucalyptus citriodora, their epoxidation with DMDO in acetone solution and the characterization of the resulting epoxides by GC-MS (EI) and NMR. This is one of the first reports involving the application of dioxirane chemistry to essential oils in order to generate modified compounds with potential uses in several areas of medicine and industry.