Aloe vera mucilage loaded gelatin electrospun fibers contained in polylactic acid coaxial system and polylactic acid and poly(e-caprolactone) tri-layer membranes for tissue engineering.

BACKGROUND: Polymeric electrospun mats have been used as scaffolds in tissue engineering for the development of novel materials due to its characteristics. The usage of synthetic materials has gone in decline due to environmental problems associated with their synthesis and waste disposal. Biomaterials such as biopolymers have been used recently due to good compatibility on biological applications and sustainability. OBJECTIVE: The purpose of this work is to obtain novel materials based on synthetic and natural polymers for applications on tissue engineering. METHODS: Aloe vera mucilage was obtained, chemically characterized, and used as an active compound contained in electrospun mats. Polymeric scaffolds were obtained in single, coaxial and tri-layer structures, characterized and evaluated in cell culture. RESULTS: Mucilage loaded electrospun fibers showed good compatibility due to formation of hydrogen bonds between polymers and biomolecules from its structure, evidenced by FTIR spectra and thermal properties. Cell viability test showed that most of the obtained mats result on viability higher than 75%, resulting in nontoxic materials, ready to be used on scaffolding applications. CONCLUSION: Mucilage containing fibers resulted on materials with potential use on scaffolding applications due to their mechanical performance and cell viability results.

SNPs in genes related to the repair of damage to DNA in clinical isolates of M. tuberculosis: A transversal and longitudinal approach.

The presence of SNPs in genes related to DNA damage repair in M. tuberculosis can trigger hypermutagenic phenotypes with a higher probability of generating drug resistance. The aim of this research was to compare the presence of SNPs in genes related to DNA damage repair between sensitive and DR isolates, as well as to describe the dynamics in the presence of SNPs in M. tuberculosis isolated from recently diagnosed TB patients of the state of Veracruz, Mexico. The presence of SNPs in the coding regions of 65 genes related to DNA damage repair was analyzed. Eighty-six isolates from 67 patients from central Veracruz state, Mexico, were sequenced. The results showed several SNPs in 14 genes that were only present in drug-resistant genomes. In addition, by following of 15 patients, it was possible to describe three different dynamics of appearance and evolution of non-synonymous SNPs in genes related to DNA damage repair: 1) constant fixed SNPs, 2) population substitution, and 3) gain of fixed SNPs. Further research is required to discern the biological significance of each of these pathways and their utility as markers of DR or for treatment prognosis.

Mutational Dynamics Related to Antibiotic Resistance in M. tuberculosis Isolates from Serial Samples of Patients with Tuberculosis and Type 2 Diabetes Mellitus.

Genetic variation in tuberculosis is influenced by the host environment, patients with comorbidity, and tuberculosis-type 2 diabetes mellitus (TB-T2DM) and implies a higher risk of treatment failure and development of drug resistance. Considering the above, this study aimed to evaluate the influence of T2DM on the dynamic of polymorphisms related to antibiotic resistance in TB. Fifty individuals with TB-T2DM and TB were initially characterized, and serial isolates of 29 of these individuals were recovered on day 0 (diagnosis), 30, and 60. Genomes were sequenced, variants related to phylogeny and drug resistance analyzed, and mutation rates calculated and compared between groups. Lineage X was predominant. At day 0 (collection), almost all isolates from the TB group were sensitive, apart from four isolates from the TB-T2DM group showing the mutation katG S315T, from which one isolate had the mutations rpoB S450L, gyrA A90G, and gyrA D94G. This pattern was observed in a second isolate at day 30. The results provide a first overview of the dynamics of mutations in resistance genes from individuals with TB-T2DM, describing an early development of resistance to isoniazid and a rapid evolution of resistance to other drugs. Although preliminary, these results help to explain the increased risk of drug resistance in individuals with TB and T2DM.

Study of Electrospun Membranes Composed of PCL and Tilapia-Skin Collagen with Tetracycline or Chloramphenicol in Contact with Human Skin Fibroblasts for Wound Dressing Treatment.

Diabetic foot ulcers are a common complication of diabetes mellitus and can lead to severe infections and delayed wound healing. The development of effective wound dressings is crucial to promoting faster healing and preventing infections. This investigation aims to fabricate and characterize electrospun meshes composed of poly(ε-caprolactone) and collagen, extracted from tilapia skin. Additionally, tetracycline and chloramphenicol were incorporated into the dressings to explore their potential to combat wound infections. A comprehensive characterization was carried out, covering the physical structure, chemical composition, and potential application-related properties of the materials by the combination of scanning electron microscopy, Fourier transform infrared (FTIR), mechanical analysis, cell viability, live/dead staining, and microbiological analysis. Changes in mechanical properties were observed, related to the morphology of the membranes; the presence of the active molecules is evidenced by FTIR analysis; cell viability above control was observed for all the prepared membranes, and they were active in antimicrobial tests, suggesting that the developed materials have the potential to be further explored as wound dressings or scaffolds for diabetic foot ulcers.

High-fidelity 3D live-cell nanoscopy through data-driven enhanced super-resolution radial fluctuation.

Live-cell super-resolution microscopy enables the imaging of biological structure dynamics below the diffraction limit. Here we present enhanced super-resolution radial fluctuations (eSRRF), substantially improving image fidelity and resolution compared to the original SRRF method. eSRRF incorporates automated parameter optimization based on the data itself, giving insight into the trade-off between resolution and fidelity. We demonstrate eSRRF across a range of imaging modalities and biological systems. Notably, we extend eSRRF to three dimensions by combining it with multifocus microscopy. This realizes live-cell volumetric super-resolution imaging with an acquisition speed of ~1 volume per second. eSRRF provides an accessible super-resolution approach, maximizing information extraction across varied experimental conditions while minimizing artifacts. Its optimal parameter prediction strategy is generalizable, moving toward unbiased and optimized analyses in super-resolution microscopy.

l-Isoleucine-Schiff Base Copper(II) Coordination Polymers: Crystal Structure, Spectroscopic, Hirshfeld Surface, and DFT Analyses.

A new copper(II) coordination polymer was synthesized from the l-isoleucine-Schiff base and characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, single-crystal X-ray diffraction (XRD) analysis, electronic paramagnetic resonance, and thermogravimetric analysis. XRD analysis confirmed the square planar coordination geometry of metallic centers and a zipper-like polymer structure. Vibrational, electronic, and paramagnetic spectroscopies and thermal analysis were consistent with the crystal structure. A Hirshfeld surface (HS) and density functional theory (DFT) analyses were employed to gain additional insight into interactions responsible for complex packing. The quantitative examination of two-dimensional (2D) fingerprint plots revealed, among other van der Waals forces, the dominating participation of H···H and H···Cl interactions in the molecular packing. The use of computational methods provided great help in detailing the supramolecular interactions occurring in the crystal, which were mainly van der Waals attractions. The electronic transition analysis helped corroborate the electronic transitions observed experimentally in the absorption spectrum. The frequency and vibrational mode analysis gave a deeper insight into the characterization of the CuLCL complex.

A Versatile Urea Type Linker for Functionalizing Natural Glycans and Its Validation in Glycan Arrays.

The isolation from organisms and readily available glycoproteins has become an increasingly convenient source of N-glycans for multiple applications including glycan microarrays, as reference standards in glycan analysis or as reagents that improve bioavailability of protein and peptide therapeutics through conjugation. A problematic step in the isolation process on a preparative scale can be the attachment of a linker for the improved purification, separation, immobilization and quantification of the glycan structures. Addressing this issue, we firstly aimed for the development of an UV active linker for a fast and reliable attachment to anomeric glycosylamines via urea bond formation. Secondly, we validated the new linker on glycan arrays in a comparative study with a collection of N-glycans which were screened against various lectins. In total, we coupled four structurally varied N-glycans to four different linkers, immobilized all constructs on a microarray and compared their binding affinities to four plant and fungal lectins of widely described specificity. Our study shows that the urea type linker showed an overall superior performance for lectin binding and once more, highlights the often neglected influence of the choice of linker on lectin recognition.

Extending resolution within a single imaging frame.

The resolution of fluorescence microscopy images is limited by the physical properties of light. In the last decade, numerous super-resolution microscopy (SRM) approaches have been proposed to deal with such hindrance. Here we present Mean-Shift Super Resolution (MSSR), a new SRM algorithm based on the Mean Shift theory, which extends spatial resolution of single fluorescence images beyond the diffraction limit of light. MSSR works on low and high fluorophore densities, is not limited by the architecture of the optical setup and is applicable to single images as well as temporal series. The theoretical limit of spatial resolution, based on optimized real-world imaging conditions and analysis of temporal image stacks, has been measured to be 40 nm. Furthermore, MSSR has denoising capabilities that outperform other SRM approaches. Along with its wide accessibility, MSSR is a powerful, flexible, and generic tool for multidimensional and live cell imaging applications.

Electrospun Cellulose Acetate Membranes Coated with Polypyrrole and Their Potential Application in the Recovery of Metals.

The purpose of this paper is to study the effect of polypyrrole (PPy) on cellulose acetate (CA) membranes prepared by the electrospinning technique (controlled variables) in the recovery of gold complexes of aqueous solutions that are environmentally ecofriendly. CA-PPy membranes were characterized by SEM, EDS, FTIR spectroscopy, contact angle measurements, electrical conductivity, and mechanical tests. They were submerged in two aqueous solutions using two gold complexes, AuI2 - and AuBr4 -, at room temperature. The recovery percentage was evaluated for several hours using the atomic adsorption technique for both complexes. The main findings indicate that the percentage of recovery in the first hours of the test was very high (>80%). The adsorption efficiency maxima were similar for both complexes (91%). The Langmuir model suggests the formation of a monolayer on the surface. The electrical conductivity did not change over time, and the mechanical properties indicate reuse in several experiments. Furthermore, the theoretical analysis showed that the system is helpful at acidic pH, funding its minimum energy. It is shown in this study that the used CA-PPy membranes show adsorption, absorption, and reusable properties with the effective recovery of the complexes in the first hours. These membranes could substitute for materials that are not environmentally ecofriendly.

Fluorescence fluctuation-based super-resolution microscopy: Basic concepts for an easy start.

Due to the wave nature of light, optical microscopy has a lower-bound lateral resolution limit of approximately half of the wavelength of visible light, that is, within the range of 200 to 350 nm. Fluorescence fluctuation-based super-resolution microscopy (FF-SRM) is a term used to encompass a collection of image analysis techniques that rely on the statistical processing of temporal variations of the fluorescence signal. FF-SRM aims to reduce the uncertainty of the location of fluorophores within an image, often improving spatial resolution by several tens of nanometers. FF-SRM is suitable for live-cell imaging due to its compatibility with most fluorescent probes and relatively simple instrumental and experimental requirements, which are mostly camera-based epifluorescence instruments. Each FF-SRM approach has strengths and weaknesses, which depend directly on the underlying statistical principles through which enhanced spatial resolution is achieved. In this review, the basic concepts and principles behind a range of FF-SRM methods published to date are described. Their operational parameters are explained and guidance for their selection is provided.

Due to light's wave nature, an optical microscope's resolution range is 200 to 350 nanometers. Several techniques enhance resolution; this work encompasses several fluorescence fluctuation super-resolution (FF-SMR) methods capable of achieving nanoscopic scales. FF-SRM is known to be suitable for fixed or live-cell imaging and compatible with most conventional microscope setups found in a laboratory. However, each FF-SRM approach has its strengths and weaknesses, which depend directly on the underlying principles through which enhanced spatial resolution is achieved. Therefore, the basic concepts and principles behind diverse FF-SRM methods are revisited in this review. In addition, their operational parameters are explained, and guidance for their selection is provided for microscopists interested in FF-SRM.

Whole genome sequencing analysis to evaluate the influence of T2DM on polymorphisms associated with drug resistance in M. tuberculosis.

BACKGROUND: Type 2 diabetes mellitus (T2DM) has been associated with treatment failure, and the development of drug resistance in tuberculosis (TB). Also, whole-genome sequencing has provided a better understanding and allowed the growth of knowledge about polymorphisms in genes associated with drug resistance. Considering the above, this study analyzes genome sequences to evaluate the influence of type 2 diabetes mellitus in the development of mutations related to tuberculosis drug resistance. M. tuberculosis isolates from individuals with (n = 74), and without (n = 74) type 2 diabetes mellitus was recovered from online repositories, and further analyzed. RESULTS: The results showed the presence of 431 SNPs with similar proportions between diabetics, and non-diabetics individuals (48% vs. 52%), but with no significant relationship. A greater number of mutations associated with rifampicin resistance was observed in the T2DM-TB individuals (23.2% vs. 16%), and the exclusive presence of rpoBQ432L, rpoBQ432P, rpoBS441L, and rpoBH445L variants. While these variants are not private to T2DM-TB cases they are globally rare highlighting a potential role of T2DM. The phylogenetic analysis showed 12 sublineages, being 4.1.1.3, and 4.1.2.1 the most prevalent in T2DM-TB individuals but not differing from those most prevalent in their geographic location. Four clonal complexes were found, however, no significant relationship with T2DM was observed. Samples size and potential sampling biases prevented us to look for significant associations. CONCLUSIONS: The occurrence of globally rare rifampicin variants identified only in isolates from individuals with T2DM could be due to the hyperglycemic environment within the host. Therefore, further studies about the dynamics of SNPs' generation associated with antibiotic resistance in patients with diabetes mellitus are necessary.

SNPs in Genes Related to DNA Damage Repair in Mycobacterium Tuberculosis: Their Association with Type 2 Diabetes Mellitus and Drug Resistance.

Genes related to DNA damage repair in Mycobacterium tuberculosis are critical for survival and genomic diversification. The aim of this study is to compare the presence of SNPs in genes related to DNA damage repair in sensitive and drug-resistant M. tuberculosis genomes isolated from patients with and without type 2 diabetes mellitus (T2DM). We collected 399 M. tuberculosis L4 genomes from several public repositories; 224 genomes belonging to hosts without T2DM, of which 123 (54.9%) had drug sensitive tuberculosis (TB) and 101 (45.1%) had drug resistance (DR)-TB; and 175 genomes from individuals with T2DM, of which 100 (57.1%) had drug sensitive TB and 75 (42.9%) had DR-TB. The presence of SNPs in the coding regions of 65 genes related to DNA damage repair was analyzed and compared with the resistance profile and the presence/absence of T2DM in the host. The results show the phylogenetic relationships of some SNPS and L4 sub-lineages, as well as differences in the distribution of SNPs present in DNA damage repair-related genes related to the resistance profile of the infecting strain and the presence of T2DM in the host. Given these differences, it was possible to generate two discriminant functions to distinguish between drug sensitive and drug resistant genomes, as well as patients with or without T2DM.

Conocimientos del pie diabético en el personal médico en formación de la Universidad de Antioquia / Knowledge of the diabetic foot in physician in training in the city of Medellín

RESUMEN Introducción: el pie diabético es el causante de casi el 85 % de las amputaciones no traumáticas, ocasionando discapacidades importantes. Por ello, el personal de la salud debe estar capacitado para el reconocimiento temprano de esta condición, así como para su adecuado tratamiento. Por lo anterior, nos proponemos recopilar el conocimiento que tienen los médicos en formación del último año de la carrera Medicina de la Universidad de Antioquia, para la evaluación del pie diabético y la estratificación del riesgo de amputación. Métodos: los participantes fueron estudiantes de medicina del último año de la Universidad de Antioquia. A estos se les realizó un cuestionario que debían autodiligenciar, que constaba de 22 preguntas acerca del conocimiento sobre la evaluación y estratificación del riesgo de amputación en los pacientes con pie diabético. Resultados: fueron 148 participantes. En general, los conocimientos sobre la evaluación y estratificación del riesgo son bajos. El 16,9 % de los participantes saben realizar la prueba de monofilamento y el 22,3 % sabe interpretarla. También existe un desconocimiento acerca de los factores de riesgo para la amputación; solo el 20,9 % de los encuestados demuestran conocimientos del tema. Conclusión: el nivel de conocimiento sobre pie diabético, su diagnóstico y estratificación del riesgo es baja en los participantes del estudio. Lo anterior indica que los estudiantes de último año de medicina de la universidad de Antioquia poseen una información superficial sobre el tema, lo cual puede llevar a un retraso en el diagnóstico y la implementación de un tratamiento oportuno.

SUMMARY Justification: The diabetic foot is the cause of up to 85% of non-traumatic amputations, leading to major disabilities. Therefore, health personnel must be trained for the early recognition of this condition, as well as for the adequate treatment. We set out to identify the knowledge that doctors in training of the last year of the medical degree of the University of Antioquia have for the evaluation of the diabetic foot, as well as for the stratification of the risk of amputation. Methods: Participants were medical students of the last year in the University of Antioquia, whom were asked a self-monitoring questionnaire that consisted of 22 questions about knowledge on evaluation and stratification of the risk of amputation in patients with diabetic foot. Results: There were 148 participants. In general, knowledge about risk assessment and stratification is low. Seventeen percent of the participants know how to perform the monofilament test and 22.3% know how to interpret it. There is also a lack of knowledge about the risk factors for amputation; only 20.9% of the respondents demonstrate knowledge of the subject. Conclusion: The level of knowledge about diabetic foot, its diagnosis and risk stratification is low in the study participants. The foregoing indicates that last year medical students at the University of Antioquia have superficial information on the subject, which can lead to a delay in the diagnosis and implementation of timely treatment.

Nitrous oxide and methane in a changing Arctic Ocean.

Human activities are changing the Arctic environment at an unprecedented rate resulting in rapid warming, freshening, sea ice retreat and ocean acidification of the Arctic Ocean. Trace gases such as nitrous oxide (N2O) and methane (CH4) play important roles in both the atmospheric reactivity and radiative budget of the Arctic and thus have a high potential to influence the region's climate. However, little is known about how these rapid physical and chemical changes will impact the emissions of major climate-relevant trace gases from the Arctic Ocean. The combined consequences of these stressors present a complex combination of environmental changes which might impact on trace gas production and their subsequent release to the Arctic atmosphere. Here we present our current understanding of nitrous oxide and methane cycling in the Arctic Ocean and its relevance for regional and global atmosphere and climate and offer our thoughts on how this might change over coming decades.

The role of a changing Arctic Ocean and climate for the biogeochemical cycling of dimethyl sulphide and carbon monoxide.

Dimethyl sulphide (DMS) and carbon monoxide (CO) are climate-relevant trace gases that play key roles in the radiative budget of the Arctic atmosphere. Under global warming, Arctic sea ice retreats at an unprecedented rate, altering light penetration and biological communities, and potentially affect DMS and CO cycling in the Arctic Ocean. This could have socio-economic implications in and beyond the Arctic region. However, little is known about CO production pathways and emissions in this region and the future development of DMS and CO cycling. Here we summarize the current understanding and assess potential future changes of DMS and CO cycling in relation to changes in sea ice coverage, light penetration, bacterial and microalgal communities, pH and physical properties. We suggest that production of DMS and CO might increase with ice melting, increasing light availability and shifting phytoplankton community. Among others, policy measures should facilitate large-scale process studies, coordinated long term observations and modelling efforts to improve our current understanding of the cycling and emissions of DMS and CO in the Arctic Ocean and of global consequences.

Genetic diversity and drug susceptibility of Mycobacterium tuberculosis in a city with a high prevalence of drug resistant tuberculosis from Southeast of Mexico.

BACKGROUND: Mexico is on the top five countries with the highest number of TB cases in America continent, nevertheless, information about genotypes circulating is practically unknown. Considering the above this study aims to characterize the genetic diversity of TB in the city of Veracruz, México. METHODS: A cross-sectional study was conducted among positive smear samples from patients living in Veracruz City, samples were cultured, and first-line drug profiles determined. Genotyping was made by spoligotyping and MIRU-VNTR 24 loci. Associations of lineages, clusters, and variables were also analyzed. RESULTS: Among the 202 isolates analyzed resistance to at least one drug was observed in 60 (30%) isolates and 41(20%) were multidrug-resistant. Three major lineages were identified: L4/Euro-American (88%), L1/Indo-Oceanic (9%), and L2/East Asian (3%). The Euro-American lineage included more than six sublineages, the most abundant were: H (32%), T (23%), LAM (18%), and X (12%). 140 isolates (70%) were placed in 42 SITs patterns. CONCLUSIONS: These results provide the first baseline data on the genetic structure of TB in the city of Veracruz. Sublineages H, X and LAM were predominant; however, it was founded an important diversity of genotypes that could contribute to the dispersion of TB and explain the high prevalence. This information might be useful for the development of further interventions to reduce impact of TB.

Interventions to Improve Clinical Coordination between Levels: Participatory Experience in a Public Healthcare Network in Xalapa, Mexico.

INTRODUCTION: Coordination of care can be improved through an intervention or a combination of several ones. In addition, it is recommended to encourage the active involvement of professionals in the design, implementation and assessment of coordination mechanisms. OBJECTIVE: To analyse the factors that influence the implementation of participatively designed interventions and their effects on clinical coordination between levels of care in a public healthcare network of health services in Xalapa, Veracruz, Mexico. METHODS: A qualitative, descriptive-interpretative study, for which individual interviews and discussion groups with a criterion sample of participants: Local Steering Committee and the Professional Platform. A content analysis, with mixed category generation and segmentation by intervention and topics, was carried out. According to the problem analysis, participants designed two sequential interventions: offline virtual consultation, and joint training meetings on maternal health and chronic diseases. RESULTS: Respondents perceived a differentiated impact on clinical coordination according to intervention: greater in the case of joint maternal health trainings and limited for the chronic diseases meetings, as they were the offline virtual consultation was rarely used. CONCLUSION: The involvement of professionals in designing the interventions, as well as institutional support and reflexive methods for training, all decisively improved clinical coordination between levels.

Diversidad genética de Mycobacterium tuberculosis circulando en la jurisdicción V de Jalapa, Veracruz, México / Genetic diversity of Mycobacterium tuberculosis circulating in the jurisdiction V from Jalapa, Veracruz, Mexico

ANTECEDENTES: El estado de Veracruz se ubica en el sureste de México y presenta una alta prevalencia de tuberculosis (TBC) y drogo resistencia. Sin embargo, la composición de los genotipos circulantes es poco conocida. OBJETIVO: Caracterizar la diversidad genética de la TBC en la jurisdicción sanitaria V del estado de Veracruz. MÉTODOS: Estudio transversal realizado en aislados clínicos de pacientes con TBC residentes de la jurisdicción V. Se determinó la sensibilidad a medicamentos de primera línea. La genotipificación se realizó mediante espoligotipificación y MIRU-VNTR 15 loci. RESULTADOS: Entre los 74 aislados analizados se observó resistencia a un fármaco en 44 (59%) aislados. Linaje L4 (EuroAmericano) se presentó en 73 aislados. Se identificaron cinco sublinajes; H (40%), T (22%), LAM (16%), X (13%) y U (7%). El 32% de los aislados se agrupó mediante su espoligotipo y 40% en 10 complejos clonales. CONCLUSIONES: Es la primera descripción sobre la estructura genética de TBC en la región central de Veracruz. La diversidad de genotipos podría contribuir a su dispersión en la región. Esta información será útil para el desarrollo de intervenciones y reducir el impacto de TBC en la población.

BACKGROUND: The state of Veracruz is placed in southeastern Mexico and has a high prevalence of tuberculosis (TB) and drug resistance. Nevertheless, the composition of circulating genotypes in the central region of the state is partially known. AIM: To characterize the genetic diversity of TB in the sanitary jurisdiction V of the state of Veracruz. METHODS: A cross-sectional study was conducted among clinical isolates from patients with TB living in the jurisdiction V, in Jalapa Ver., Mexico. Sensitivity to first-line drugs was determined, and genotyping was performed by spoligotyping and MIRU-VNTR 15 loci. RESULTS: Among the 74 isolates analyzed, resistance to one drug was observed in 44 isolates. L4 (EuroAmerican) was the major lineage identified. Five sublineages were the most abundant; H (40%), T (22%), LAM (16%), X (13%) and U (7%). Only 32% of the isolates were clustered by spoligotype and 40% were placed in ten clonal complexes. CONCLUSIONS: This is the first description of the genetic structure of TB in the central region of Veracruz. The diversity of genotypes could contribute to its dispersion. This information will be useful for the development of interventions to reduce the impact of TB in the population.