Competition/antagonism associations of biofilm formation among Staphylococcus epidermidis Agr groups I, II, and III

Sergio Martínez-García,César I. Ortiz-García,Marisa Cruz-Aguilar,Juan Carlos Zenteno,José Martin Murrieta-Coxca,Sonia Mayra Pérez-Tapia,Sandra Rodríguez-Martínez,Mario E. Cancino-Diaz,Juan C. Cancino- 한국미생물학회 2019 The journal of microbiology Vol.57 No.2

Staphylococci have quorum-sensing (QS) systems that enable cell-to-cell communication, as well as the regulation of numerous colonization and virulence factors. The accessory gene regulator (Agr) operon is one of the Staphylococcus genus QS systems. Three groups (I, II, and III) are present in Staphylococcus epidermidis Agr operon. To date, it is unknown whether Agr groups can interact symbiotically during biofilm development. This study analyzed a symbiotic association among Agr groups during biofilm formation in clinical and commensal isolates. Different combinations among Agr group isolates was used to study biofilm formation in vitro and in vivo (using a mouse catheter-infection model). The analysis of Agr groups were also performed from samples of human skin (head, armpits, and nostrils). Different predominant coexistence was found within biofilms, suggesting symbiosis type. In vitro, Agr I had a competition with Agr II and Agr III. Agr II had a competition with Agr III, and Agr II was an antagonist to Agr I and III when the three strains were combined. In vivo, Agr II had a competition to Agr I, but Agr I and II were antagonists to Agr III. The associations found in vitro and in vivo were also found in different sites of the skin. Besides, other associations were observed: Agr III antagonized Agr I and II, and Agr III competed with Agr I and Agr II. These results suggest that, in S. epidermidis, a symbiotic association of competition and antagonism occurs among different Agr groups during biofilm formation.

Numerical investigation of truck aerodynamics on several classes of infrastructures

Alejandro Alonso-Estébanez,Juan J. del Coz Díaz,Felipe P. Álvarez Rabanal,Pablo Pascual-Muñoz,Paulino J. García Nieto 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.26 No.1

This paper describes the effect of different testing parameters (configuration of infrastructure and truck position on road) on truck aerodynamic coefficients under cross wind conditions, by means of a numerical approach known as Large Eddy Simulation (LES). In order to estimate the air flow behaviour around both the infrastructure and the truck, the filtered continuity and momentum equations along with the Smagorinsky–Lilly model were solved. A solution for these non-linear equations was approached through the finite volume method (FVM) and using temporal and spatial discretization schemes. As for the results, the aerodynamic coefficients acting on the truck model exhibited nearly constant values regardless of the Reynolds number. The flat ground is the infrastructure where the rollover coefficient acting on the truck model showed lowest values under cross wind conditions (yaw angle of 90), while the worst infrastructure studied for vehicle stability was an embankment with downward-slope on the leeward side. The position of the truck on the road and the value of embankment slope angle that minimizes the rollover coefficient were determined by successfully applying the Response Surface Methodology.

Bio-structural monitoring of bone mineral alterations through electromechanical impedance measurements of a Piezo-device joined to a tooth

Tinoco Hector A.,Cardona Carlos I.,Marín-Berrio Maribel L. F.,García-Grisales Juliana,Gomez Juan P.,Roldan Samuel I.,Peña Fabio M.,Brinek Adam,Kalasová Dominika,Kaiser Jozef,Zikmund Tomas 대한의용생체공학회 2020 Biomedical Engineering Letters (BMEL) Vol.10 No.4

Bone presents different systemic functionalities as calcium phosphate reservoir, organ protection, among others. For that reason, the bone health conditions are essential to keep in equilibrium the metabolism of several body systems. Different technologies exist to diagnose bone conditions with invasive methods based on ionizing radiation. Therefore, there is a challenge to develop new ways to evaluate bone alterations in a noninvasive form. This study shows the assessment of a piezo-actuated device acting on a human tooth for the bio-monitoring of bone alterations. The bone diagnosis is performed by applying the electromechanical impedance technique (EMI), commonly used in structural health monitoring. For the experimental tests, five bone samples were prepared, and one was chosen as the monitoring. All samples were put in a decalcifying substance (TBD1 acid–base) at different times to emulate localized bone mineral alterations. Bone reductions were computed by using X-ray micro-computed tomography analyzing the morphometry. Electrical resistance measurements (piezo-device) were taken for the monitoring specimen meanwhile it was partially decalcified during 8520 seconds. In the frequency spectrum, several observation windows showed that the bone alterations gradually changed the electrical resistance signals which were quantified statistically. Results evidenced that the bone density changes are correlated with the electrical resistance measurements; these changes presented an exponential behavior as much as in the calculated index, and bone mineral reduction. The results demonstrated that bone alterations exhibit linear dependence with the computed statistical indexes. This result confirms that it is possible to observe the bone changes from the teeth as a future application.

Complications and local relapse after intraoperative low-voltage X-ray radiotherapy in breast cancer

Ana Alicia Tejera Hernández,Víctor Manuel Vega Benítez,Juan Carlos Rocca Cardenas,Neith Ortega Pérez,Nieves Rodriguez Ibarria,Juan Carlos Díaz Chico,Juan José García-Granados Alayón,Pedro Pérez Correa 대한외과학회 2020 Annals of Surgical Treatment and Research(ASRT) Vol.98 No.6

Purpose: To study those factors that influence the occurrence of surgical complications and local relapse in patients intervened for breast cancer and receiving intraoperative radiotherapy. Methods: Observational study on patients intervened for breast cancer with conservative surgery and intraoperative radiotherapy with low-voltage X-ray energy source (INTRABEAM), from 2015 to 2017 with 24 months minimum followup. Variables possibly associated to the occurrence of postoperative complications were analyzed with the Student t-test and the Fisher exact test; P < 0.05 considered significant. Subsequently, the construction of multiple multivariate analysis models began, thus building a logistic regression analysis using the IBM SPSS Statistics ver. 23 software. Local relapse was described. Results: The study included 102 patients, mean age of 61.2 years; mean global size of tumor, 12.2 mm. Complications occurred in 29.4%. Fibrosis was the most frequently observed complication, followed by postoperative seroma. Using a 45 mm or larger applicator were significantly associated with the occurrence of complications. Tumor size 2 cm or larger and reintervention showed borderline significant association. Only one case of local relapse was observed. Conclusion: Certain factors may increase the risk of complication after the use of intraoperative radiotherapy. Using external complementary radiotherapy does not seem to increase the rate of complications. Select patients and the involvement of a multidisciplinary team are essential for achieving good results

Sonographic evaluation of fetal scrotum, testes and epididymis

( Álvaro López Soto ),( Jose Luis Meseguer González ),( María Velasco Martínez ),( Rocío López Pérez ),( Inmaculada Martínez Rivero ),( Mónica Lorente Fernández ),( Olivia García Izquierdo ),( Juan Pe 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.5

External male genitalia have rarely been evaluated on fetal ultrasound. Apart from visualization of the penis for fetal sex determination, there are no specific instructions or recommendations from scientific societies. This study aimed to review the current knowledge about prenatal diagnosis of the scrotum and internal structures, with discussion regarding technical aspects and clinical management. We conducted an article search in Medline, EMBASE, Scopus, Google Scholar, and Web of Science databases for studies in English or Spanish language that discussed prenatal scrotal pathologies. We identified 72 studies that met the inclusion criteria. Relevant data were grouped into sections of embryology, ultrasound, pathology, and prenatal diagnosis. The scrotum and internal structures show a wide range of pathologies, with varying degrees of prevalence and morbidity. Most of the reported cases have described incidental findings diagnosed via striking ultrasound signs. Studies discussing normative data or management are scarce.

Three-Dimensional Bioprinting Scaffolding for Nasal Cartilage Defects: A Systematic Review

Chiesa-Estomba Carlos M.,Aiastui Ana,González-Fernández Iago,Hernáez-Moya Raquel,Rodiño Claudia,Delgado Alba,Garces Juan P.,Paredes-Puente Jacobo,Aldazabal Javier,Altuna Xabier,Izeta Ander 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.3

BACKGROUND: In recent years, three-dimensional (3D)-printing of tissue-engineered cartilaginous scaffolds is intended to close the surgical gap and provide bio-printed tissue designed to fit the specific geometric and functional requirements of each cartilage defect, avoiding donor site morbidity and offering a personalizing therapy. METHODS: To investigate the role of 3D—bioprinting scaffolding for nasal cartilage defects repair a systematic review of the electronic databases for 3D-Bioprinting articles pertaining to nasal cartilage bio-modelling was performed. The primary focus was to investigate cellular source, type of scaffold utilization, biochemical evaluation, histological analysis, in-vitro study, in-vivo study, animal model used, length of research, and placement of experimental construct and translational investigation. RESULTS: From 1011 publications, 16 studies were kept for analysis. About cellular sources described, most studies used primary chondrocyte cultures. The cartilage used for cell isolation was mostly nasal septum. The most common biomaterial used for scaffold creation was polycaprolactone alone or in combination. About mechanical evaluation, we found a high heterogeneity, making it difficult to extract any solid conclusion. Regarding biological and histological characteristics of each scaffold, we found that the expression of collagen type I, collagen Type II and other ECM components were the most common patterns evaluated through immunohistochemistry on in-vitro and in-vivo studies. Only two studies made an orthotopic placement of the scaffolds. However, in none of the studies analyzed, the scaffold was placed in a subperichondrial pocket to rigorously simulate the cartilage environment. In contrast, scaffolds were implanted in a subcutaneous plane in almost all of the studies included. CONCLUSION: The role of 3D—bioprinting scaffolding for nasal cartilage defects repair is growing field. Despite the amount of information collected in the last years and the first surgical applications described recently in humans. Further investigations are needed due to the heterogeneity on mechanical evaluation parameters, the high level of heterotopic scaffold implantation and the need for quantitative histological data. BACKGROUND: In recent years, three-dimensional (3D)-printing of tissue-engineered cartilaginous scaffolds is intended to close the surgical gap and provide bio-printed tissue designed to fit the specific geometric and functional requirements of each cartilage defect, avoiding donor site morbidity and offering a personalizing therapy. METHODS: To investigate the role of 3D—bioprinting scaffolding for nasal cartilage defects repair a systematic review of the electronic databases for 3D-Bioprinting articles pertaining to nasal cartilage bio-modelling was performed. The primary focus was to investigate cellular source, type of scaffold utilization, biochemical evaluation, histological analysis, in-vitro study, in-vivo study, animal model used, length of research, and placement of experimental construct and translational investigation. RESULTS: From 1011 publications, 16 studies were kept for analysis. About cellular sources described, most studies used primary chondrocyte cultures. The cartilage used for cell isolation was mostly nasal septum. The most common biomaterial used for scaffold creation was polycaprolactone alone or in combination. About mechanical evaluation, we found a high heterogeneity, making it difficult to extract any solid conclusion. Regarding biological and histological characteristics of each scaffold, we found that the expression of collagen type I, collagen Type II and other ECM components were the most common patterns evaluated through immunohistochemistry on in-vitro and in-vivo studies. Only two studies made an orthotopic placement of the scaffolds. However, in none of the studies analyzed, the scaffold was placed in a subperichondrial pocket to rigorously simulate the cartilage environment. In contrast, scaffolds were implanted in a subcutaneous plane in almost all of the studies included. CONCLUSION: The role of 3D—bioprinting scaffolding for nasal cartilage defects repair is growing field. Despite the amount of information collected in the last years and the first surgical applications described recently in humans. Further investigations are needed due to the heterogeneity on mechanical evaluation parameters, the high level of heterotopic scaffold implantation and the need for quantitative histological data.