Synthesis and Characterization of a Bioartificial Polymeric System with Potential Antibacterial Activity: Chitosan-Polyvinyl Alcohol-Ampicillin.

Bio-artificial polymeric systems are a new class of polymeric constituents based on blends of synthetic and natural polymers, designed with the purpose of producing new materials that exhibit enhanced properties with respect to the individual components. In this frame, a combination of polyvinyl alcohol (PVA) and chitosan, blended with a widely used antibiotic, sodium ampicillin, has been developed showing a moderate behavior in terms of antibacterial properties. Thus, aqueous solutions of PVA at 1 wt.% were mixed with acid solutions of chitosan at 1 wt.%, followed by adding ampicillin ranging from 0.3 to 1.0 wt.% related to the total amount of the polymers. The prepared bio-artificial polymeric system was characterized by FTIR, SEM, DSC, contact angle measurements, antibacterial activity against Staphylococcus aureus and Escherichia coli and antibiotic release studies. The statistical significance of the antibacterial activity was determined using a multifactorial analysis of variance with ρ < 0.05 (ANOVA). The characterization techniques did not show alterations in the ampicillin structure and the interactions with polymers were limited to intermolecular forces. Therefore, the antibiotic was efficiently released from the matrix and its antibacterial activity was preserved. The system disclosed moderate antibacterial activity against bacterial strains without adding a high antibiotic concentration. The findings of this study suggest that the system may be effective against healthcare-associated infections, a promising view in the design of novel antimicrobial biomaterials potentially suitable for tissue engineering applications.

Polyphenolic extracts of edible flowers incorporated onto atelocollagen matrices and their effect on cell viability.

The phenolic extract of chives flowers (Allium schoenoprasum, Liliaceae), introduced Sage (Salvia pratensis, Lamiaceae), European elderberry (Sambucus nigra, Caprifoliaceae) and common dandelion (Taraxacum officinale, Asteraceae) were characterised by High Performance Liquid Chromatography and incorporated in different concentrations onto atelocollagen thin films. In order to assess the biological impact of these phenolic compounds on cell viability, human immortalised non-tumorigenic keratinocyte cell line was seeded on the thin films and cell proliferation was determined by using an MTT assay. In addition, their antimicrobial activity was estimated by using an agar diffusion test. Data indicated the concomitance between cell viability and concentration of polyphenols. These findings suggest that these phenolic-endowed atelocollagen films might be suitable for tissue engineering applications, on account of the combined activity of polyphenols and collagen.

Bovine Decellularized Amniotic Membrane: Extracellular Matrix as Scaffold for Mammalian Skin.

Decellularized membranes (DM) were obtained from bovine amniotic membranes (BAM) using four different decellularization protocols, based on physical, chemical, and mechanical treatment. The new material was used as a biological scaffold for in vitro skin cell culture. The DM were characterized using hematoxylin-eosin assay, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR-ATR), and differential scanning calorimetry (DSC). The in vitro cytotoxicity of DM was evaluated using MTT. The efficacy of decellularization process was assessed through DNA quantification and electrophoresis. All the used protocols showed a high effectiveness in terms of elimination of native cells, confirmed by DNA extraction and quantification, electrophoresis, and SEM, although protocol IV removes the cellular contents and preserve the native extracellular matrix (ECM) architecture which it can be considered as the most effective in terms of decellularization. FTIR-ATR and DSC on the other hand, revealed the effects of decellularization on the biochemical composition of the matrices. There was no cytotoxicity and the biological matrices obtained were a source of collagen for recellularization. The matrices of protocols I, II, and III were degraded at day 21 of cell culture, forming a gel. The biocompatibility in vitro was demonstrated; hence these matrices may be deemed as potential scaffold for epithelial tissue regeneration.

[Renal angioleiomyoma with a myogenic and melanocytic immunophenotype, as a variant of angiomyolipoma]. / Angioleiomioma renal con patrón inmunohistoquímico miogénico y melanocítico como variante del angiomiolipoma.

We present a case of a 67 year old male with a cortical nodular tumour of the left kidney. During a year's follow-up with ultrasound and MRI, the tumour was seen to increase in size by 16-20 mm. The nodule was surgically removed. Microscopically it was well defined and unencapsulated, with a proliferation of typical fusiform cells of smooth muscle cell appearance, clumped around well vascularized areas. Immunohistochemically, the neoplasm was positive for muscle markers (smooth muscle actin, desmin and caldesmon) and melanocyte markers (HMB-45 and Melan A). Our case would appear to be a renal neoplasm with an angioleiomyomatous pattern, but with immunohistochemical characteristics of angiomyolipoma (PEComa), however, without either a lipomatous or lipid cell component. We found no previous reports of this type of tumour in the literature.

Genetic counseling in a case of congenital hemivertebrae.

A case of in utero spondylothoracic dysostoses is diagnosed during a routine third trimester ultrasound scan in a low-risk patient. Ultrasound showed spine deformation, hemivertebrae and crab-like ribs. The newborn had no other associated anomalies except inguinal hernia, and karyotype was normal. Bidimensional and 3-4D ultrasound imaging as well as radiograph of the fetus and photos of the newborn are presented and discussed. Sporadic cases are difficult to diagnose and classify, as they are probably due to genetic heterogenicity. Sporadic cases of hemivertebrae are rare and not always lethal. Fetal ultrasound scan findings can help predict prognosis, enabling the parents' informed decision making.

(PVA/Chitosan/Fucoidan)-Ampicillin: A Bioartificial Polymeric Material with Combined Properties in Cell Regeneration and Potential Antibacterial Features.

Chitosan, fucoidan, and polyvinyl alcohol are categorized as polymers with biomedical applications. Ampicillin, on the other hand, is considered as an important antibiotic that has shown effectivity in both gram-positive and gram-negative micro-organisms. The aforementioned polymers possess unique properties that are considered desirable for cell regeneration although they exhibit drawbacks that can affect their final application. Therefore, films of these biomaterials were prepared and they were characterized using FTIR, SEM, XRD, degree of swelling and solubility, and MTT assay. The statistical significance of the experiments was determined using a two-way analysis of variance (ANOVA) with p < 0.05. The characterization techniques demonstrated that the obtained material exhibits properties suitable for cell regeneration, and that a higher concentration of natural polymers promotes cells proliferation to a greater extent. The presence of PVA, on the other hand, is responsible for matrix stability and dictates the degree of swelling and solubility. The SEM images demonstrated that neither aggregations nor clusters were formed, which is favorable for the biological properties without detrimental to the morphological and physical features. Cell viability was comparatively similar in samples with and without antibiotic, and the physical and biological properties were not negatively affected. Indeed, the inherent bactericidal effect of chitosan was reinforced by the presence of ampicillin. The new material is an outstanding candidate for cell regeneration as a consequence of the synergic effect that each component provides to the blend.

ZNF366 is an estrogen receptor corepressor that acts through CtBP and histone deacetylases.

The regulation of gene expression by estrogen receptor-alpha (ERalpha) requires the coordinated and temporal recruitment of diverse sets of transcriptional co-regulator complexes, which mediate nucleosome remodelling and histone modification. Using ERalpha as bait in a yeast two-hybrid screen, we have identified a novel ERalpha-interacting protein, ZNF366, which is a potent corepressor of ERalpha activity. The interaction between ZNF366 and ERalpha has been confirmed in vitro and in vivo, and is mediated by the zinc finger domains of the two proteins. Further, we show that ZNF366 acts as a corepressor by interacting with other known ERalpha corepressors, namely RIP140 and CtBP, to inhibit expression of estrogen-responsive genes in vivo. Together, our results indicate that ZNF366 may play an important role in regulating the expression of genes in response to estrogen.

Physical and Morphological Changes of Poly(tetrafluoroethylene) after Using Non-Thermal Plasma-Treatments.

A commercial formulation of poly(tetrafluoroethylene) (PTFE) sheets were surface modified by using non-thermal air at 40 kHz frequency (DC) and 13.56 MHz radiofrequency (RF) at different durations and powers. In order to assess possible changes of PTFE surface properties, zeta potential (ζ), isoelectric points (IEPs) determinations, contact angle measurements as well as Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) imaging were carried out throughout the experimentation. The overall outcome indicated that ζ-potential and surface energy progressively changed after each treatment, the IEP shifting to lower pH values and the implicit differences, which are produced after each distinct treatment, giving new surface topographies and chemistry. The present approach might serve as a feasible and promising method to alter the surface properties of poly(tetrafluoroethylene).

T:G mismatch-specific thymine-DNA glycosylase (TDG) as a coregulator of transcription interacts with SRC1 family members through a novel tyrosine repeat motif.

Gene activation involves protein complexes with diverse enzymatic activities, some of which are involved in chromatin modification. We have shown previously that the base excision repair enzyme thymine DNA glycosylase (TDG) acts as a potent coactivator for estrogen receptor-alpha. To further understand how TDG acts in this context, we studied its interaction with known coactivators of nuclear receptors. We find that TDG interacts in vitro and in vivo with the p160 coactivator SRC1, with the interaction being mediated by a previously undescribed motif encoding four equally spaced tyrosine residues in TDG, each tyrosine being separated by three amino acids. This is found to interact with two motifs in SRC1 also containing tyrosine residues separated by three amino acids. Site-directed mutagenesis shows that the tyrosines encoded in these motifs are critical for the interaction. The related p160 protein TIF2 does not interact with TDG and has the altered sequence, F-X-X-X-Y, at the equivalent positions relative to SRC1. Substitution of the phenylalanines to tyrosines is sufficient to bring about interaction of TIF2 with TDG. These findings highlight a new protein-protein interaction motif based on Y-X-X-X-Y and provide new insight into the interaction of diverse proteins in coactivator complexes.

Intervención educativa sobre salud bucal en niños prescolares / Educational intervention on oral health in preschool children

RESUMEN Fundamento: por su alta prevalencia, las enfermedades bucales son una de las principales causas de molestias en la población infantil y pueden ser evitadas a través de la promoción de salud desde edades tempranas. En Cuba, los aspectos relacionados con la promoción y educación para la salud tienen prioridad y constituyen objetivos esenciales de la organización de acciones dirigidas al menor de 19 años. Objetivo: determinar la efectividad de un programa educativo sobre salud bucal en niños de prescolar. Métodos: se realizó un estudio de tipo prexperimental en la escuela primaria "Celia Sánchez Manduley" de Santa Clara, entre noviembre de 2018 hasta enero de 2020. La investigación se desarrolló en cuatro etapas; se emplearon diferentes métodos teóricos y empíricos: análisis documental, entrevista, guía de evaluación para la entrevista y triangulación de los resultados. Resultados: al inicio de la intervención predominaron los niños con higiene bucal deficiente y el nivel de información sobre salud bucal se consideró no adecuado. Después de implementado el programa educativo "Aprendo a cuidar mis dientes", mejoró el nivel de información sobre salud e higiene bucal de los prescolares y se comprobó una correcta interpretación del dibujo realizado por los infantes. Conclusiones: el programa educativo aplicado demostró su efectividad al resolver las deficiencias identificadas en el diagnóstico.

ABSTRACT Background: due to its high prevalence, oral diseases are one of the main causes of discomfort in the child population and can be avoided through health promotion from an early age. In Cuba, aspects related to health promotion and education have priority and constitute essential objectives of the organization of actions aimed at children under 19 years of age. Objective: to determine the effectiveness of an educational program on oral health in preschool children. Methods: a pre-experimental study was carried out at the "Celia Sánchez Manduley" elementary school in Santa Clara, from November 2018 to January 2020. The research was carried out in four stages; Different theoretical and empirical methods were used: documentary analysis, interview, evaluation guide for the interview and comparative analysis of the results. Results: at the beginning of the intervention, children with poor oral hygiene predominated and the level of information on oral health was considered inadequate. After the implementation of the educational program "They learn to take care of their teeth", the level of information on health and oral hygiene of the preschool children improved and a correct interpretation of the drawing made by the infants was verified. Conclusions: the applied educational program demonstrated its effectiveness in resolving the deficiencies identified in the diagnosis.

HaCaT Keratinocytes Response on Antimicrobial Atelocollagen Substrates: Extent of Cytotoxicity, Cell Viability and Proliferation.

The effective and widely tested biocides: Benzalkonium chloride, bronopol, chitosan, chlorhexidine and irgasan were added in different concentrations to atelocollagen matrices. In order to assess how these antibacterial agents influence keratinocytes cell growth, cell viability and proliferation were determined by using MTT assay. Acquired data indicated a low toxicity by employing any of these chemical substances. Furthermore, cell viability and proliferation were comparatively similar to the samples where there were no biocides. It means that regardless of the agent, collagen-cell-attachment properties are not drastically affected by the incorporation of those biocides into the substrate. Therefore, these findings suggest that these atelocollagen substrates enhanced by the addition of one or more of these agents may render effectiveness against bacterial stains and biofilm formation, being the samples referred to herein as "antimicrobial substrates" a promising view in the design of novel antimicrobial biomaterials potentially suitable for tissue engineering applications.

T:G mismatch-specific thymine-DNA glycosylase potentiates transcription of estrogen-regulated genes through direct interaction with estrogen receptor alpha.

Nuclear receptors (NR) classically regulate gene expression by stimulating transcription upon binding to their cognate ligands. It is now well established that NR-mediated transcriptional activation requires the recruitment of coregulator complexes, which facilitate recruitment of the basal transcription machinery through direct interactions with the basal transcription machinery and/or through chromatin remodeling. However, a number of recently described NR coactivators have been implicated in cross-talk with other nuclear processes including RNA splicing and DNA repair. T:G mismatch-specific thymine DNA glycosylase (TDG) is required for base excision repair of deaminated methylcytosine. Here we show that TDG is a coactivator for estrogen receptor alpha (ERalpha). We demonstrate that TDG interacts with ERalpha in vitro and in vivo and suggest a separate role for TDG to its established role in DNA repair. We show that this involves helix 12 of ERalpha. The region of interaction in TDG is mapped to a putative alpha-helical motif containing a motif distinct from but similar to the LXXLL motif that mediates interaction with NR. Together with recent reports linking TFIIH in regulating NR function, our findings provide new data to further support an important link between DNA repair proteins and nuclear receptor function.

[Systematic review about the usefulness and prognostic value of the p53 oncoprotein and proliferation marker Ki-67 for upper urinary tract transitional cell carcinoma]. / Revisión sistemática sobre la utilidad y el valor pronóstico de la oncoproteína p53 y el marcador de proliferación Ki-67 en el car- cinoma de células transicionales del tracto urinario superior.

OBJECTIVES: To perform a systematic review on the expression and prognostic value of the p 53 oncoprotein and Ki 67 proliferation marker in transitional cell carcinoma of the upper urinary tract. METHODS: A systematic review of cohort, prospective and retrospective studies from 1/1/1990 to 11/24/2003 has been undertaken, performing a bibliographic search both manual and electronic in the main databases. 632 works were found using the keywords "ureter, renal and pelvis tumor", and 14 with "ureter, renal and pelvis tumor, and immunohistochemical". RESULTS: 509 patients were studied; they were selected from 7 retrospective studies about the usefulness of p53 and Ki 67 in transitional cell carcinoma of the upper urinary tract published between 1995 and 2002 (three Spanish studies, three Japanese and one North American). Each one analyzes between 37 and 121 cases, with a mean age of 66.8 years (range 63.0-74.7) and a predominance of male sex in 100% of the studies. The pyelocalyceal site was the most frequent in these series. Treatment is another issue taken into consideration in this papers, being nephroureterectomy the most frequently found. The p53 and Ki 67 percentage expression in various studies has been related to clinical and histological factors. Only 5 studies performed a multivariate analysis using Cox regression models. Three of them deal with Ki 67 and two with p53, although one of the p53 studies associates cyclin E determinations. Only two out of three studies about Ki 67 were considered evaluable, because multivariate analysis was not performed in the other one. CONCLUSIONS: 1) There are a few studies and they are very heterogeneous in terms of design, selection criteria, follow-up, and use of prognostic variables. 2) The analyzed studies establish that oncoprotein p53 and proliferation marker Ki 67 are prognostic factors for transitional cell carcinoma of the upper urinary tract, and 3) To perform a meta-analysis was deemed not indicated because of the heterogeneicity of the studies found in our search.