Development of an experimental model of septic knee arthritis in rats through intra-articular inoculation of Staphylococcus aureus.

Haematogenous models of septic arthritis have some inherent disadvantages, such as the manifestation of arthritis relies on chance, the size of the inoculum is unknown and the number of animals to be studied cannot be reduced because the animals cannot serve as their own controls. This study aimed to develop a rat model of knee septic arthritis by injecting a known inoculum of Staphylococcus aureus into the joint. The left knees of 27 Sprague Dawley rats were injected with four different inoculum concentrations of a sensitive strain of S. aureus (30,000 colony-forming units (CFUs), n = 3; 18,550 CFUs, n = 6; 15,500 CFUs, n = 9; and 7700 CFUs, n = 9); the right knees served as controls. Clinical, microbiological and histological variables were assessed two and seven days later. The main criterion for diagnosing septic arthritis was a positive culture of synovial fluid. The rate of microbiologically confirmed septic arthritis was high for all inoculum concentrations (3/3, 6/6, 8/9 and 7/9, respectively), and the rate of bacteraemia was also high. Animal welfare was better for the two lowest inoculum concentrations. No animal reached the pre-established humane end points. Overall, the third inoculum was considered the most suitable. Thus, acute septic arthritis can be caused in rats by inoculating 15,000 CFUs of an ATCC strain of S. aureus directly into the knee joint. Overall, the model seems to be useful for studying the effectiveness of drugs for the treatment of acute septic arthritis.

Development and Characterization of Polyester and Acrylate-Based Composites with Hydroxyapatite and Halloysite Nanotubes for Medical Applications.

We aimed to study the distribution of hydroxyapatite (HA) and halloysite nanotubes (HNTs) as fillers and their influence on the hydrophobic character of conventional polymers used in the biomedical field. The hydrophobic polyester poly (ε-caprolactone) (PCL) was blended with its more hydrophilic counterpart poly (lactic acid) (PLA) and the hydrophilic acrylate poly (2-hydroxyethyl methacrylate) (PHEMA) was analogously compared to poly (ethyl methacrylate) (PEMA) and its copolymer. The addition of HA and HNTs clearly improve surface wettability in neat samples (PCL and PHEMA), but not that of the corresponding binary blends. Energy-dispersive X-ray spectroscopy mapping analyses show a homogenous distribution of HA with appropriate Ca/P ratios between 1.3 and 2, even on samples that were incubated for seven days in simulated body fluid, with the exception of PHEMA, which is excessively hydrophilic to promote the deposition of salts on its surface. HNTs promote large aggregates on more hydrophilic polymers. The degradation process of the biodegradable polyester PCL blended with PLA, and the addition of HA and HNTs, provide hydrophilic units and decrease the overall crystallinity of PCL. Consequently, after 12 weeks of incubation in phosphate buffered saline the mass loss increases up to 48% and mechanical properties decrease above 60% compared with the PCL/PLA blend.

Pseudomonas aeruginosa rugose small-colony variants have adaptations that likely promote persistence in the cystic fibrosis lung.

Pseudomonas aeruginosa is recognized for its ability to colonize diverse habitats, ranging from soil to immunocompromised people. The formation of surface-associated communities called biofilms is one factor thought to enhance colonization and persistence in these diverse environments. Another factor is the ability of P. aeruginosa to diversify genetically, generating phenotypically distinct subpopulations. One manifestation of diversification is the appearance of colony morphology variants on solid medium. Both laboratory biofilm growth and chronic cystic fibrosis (CF) airway infections produce rugose small-colony variants (RSCVs) characterized by wrinkled, small colonies and an elevated capacity to form biofilms. Previous reports vary on the characteristics attributable to RSCVs. Here we report a detailed comparison of clonally related wild-type and RSCV strains isolated from both CF sputum and laboratory biofilm cultures. The clinical RSCV had many characteristics in common with biofilm RSCVs. Transcriptional profiling and Biolog phenotypic analysis revealed that RSCVs display increased expression of the pel and psl polysaccharide gene clusters, decreased expression of motility functions, and a defect in growth on some amino acid and tricarboxylic acid cycle intermediates as sole carbon sources. RSCVs also elicited a reduced chemokine response from polarized airway epithelium cells compared to wild-type strains. A common feature of all RSCVs analyzed in this study is increased levels of the intracellular signaling molecule cyclic di-GMP (c-di-GMP). To assess the global transcriptional effects of elevated c-di-GMP levels, we engineered an RSCV strain that had elevated c-di-GMP levels but did not autoaggregate. Our results showed that about 50 genes are differentially expressed in response to elevated intracellular c-di-GMP levels. Among these genes are the pel and psl genes, which are upregulated, and flagellum and pilus genes, which are downregulated. RSCV traits such as increased exopolysaccharide production leading to antibiotic tolerance, altered metabolism, and reduced immunogenicity may contribute to increased persistence in biofilms and in the airways of CF lungs.

Uncooperative Patient With an Infected Elbow Osteosynthesis: Alternative Management With Topical Sevoflurane.

INTRODUCTION: Treatment of an infected osteosynthesis is usually a complicated process, with its complexity increasing when unforeseen situations appear. Typically, the therapeutic management of such situations is challenging because they are not anticipated in the medical literature and physicians have to look for and adapt novel solutions to a specific patient condition. CASE REPORT: A 41-year-old, uncooperative, homeless man, presented to the emergency room with a left olecranon fracture. After planned surgery, the surgical wound became infected with a methicillin-sensitive Staphylococcus aureus because the treatment took place in an unhygienic outpatient hospital setting. The patient refused to remain in the hospital and also failed to complete antibiotic courses prescribed (culture-guided rifampicin 600 mg daily plus levofloxacin 500 mg daily). Instead of removing the osteosynthesis material, the infection was successfully treated by repeated applications of 5 mL of sevoflurane into the surgical wound. Subsequently, wound healing was achieved with a combination of a brief course of negative pressure wound therapy (NPWT), use of silver-impregnated dressings, and irrigation of the wound with sevoflurane. Sevoflurane also provided topical analgesic to ameliorate the pain caused by removing the NPWT sponge. Interestingly, despite extremely poor compliance by the patient to all standard treatment regimens, and the clinical decision to retain the implant, the infection was resolved, and the fracture was consolidated. CONCLUSIONS: Local application of sevoflurane in the wound bed appears to exhibit analgesic, antimicrobial, and positive healing effects. It could be a promising alternative treatment to be included as a therapeutic option for wound care.

Radiographic and Functional Results following Subtalar Arthroereisis in Pediatric Flexible Flatfoot.

INTRODUCTION: Flexible flatfoot (FFF) is one of the most common skeletal disorders in children. In symptomatic patients who do not respond to conservative measures, surgery may be an option. Subtalar arthroereisis consists of limiting excessive eversion of the subtalar joint through different types of implants. MATERIALS AND METHODS: We carried out a retrospective study of 16 patients (32 feet) intervened for FFF with a subtalar device (arthroereisis), across the period of 2008-2015 with a minimum follow-up period of one year. Pre- and postoperative measures of the Moreau-Costa-Bartani angle, dorsoplantar (DP) and lateral (L) talocalcaneal angle, talonavicular coverage angle, and naviculocuboid overlap were used to evaluate correction of the deformity. Two expert surgeons from the Pediatric Orthopedics Unit took separate measurements of these angles for subsequent analysis purposes and to obtain the interobserver correlation coefficient for quantitative variables. Pre- and postoperative differences in the measurement of angles were ascertained using Student's t-test for paired samples; and a functional evaluation of the patients intervened was carried out pre- and postoperatively by administering the parent version of the Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) during a clinical interview. All statistical analyses were performed using the SPSS v. 19.0 program (SPSS, Chicago, IL), with values being deemed statistically significant at p<0.05. RESULTS: A breakdown of the study population showed 81.25% (13 patients) males and 18.75% (3 patients) females, with mean age of 9 years (7-11). The interobserver coefficient for quantitative variables displayed a very high degree of concordance (0.7-0.9), indicating that the validity of the measures was adequate. Pre- and postoperative analysis of differences in the measurement of angles was statistically significant (p<0.005). In terms of functional evaluation, the postoperative results were positive, with statistical significance for the "school and play", "emotional", and "footwear" domains of the OxAFQ-C scale and no differences in the "physical" domain. CONCLUSION: Subtalar arthroereisis is a valid option for the treatment of symptomatic pediatric flatfoot, with good postoperative functional and radiographic results.

Wideband phantoms of different body tissues for heterogeneous models in body area networks.

One of the key issues about wireless technologies is their interaction with the human body. The so-called internet of things will comprise many devices that will transmit either around or through the human body. These devices must be tested either in their working medium, when possible, or in the most realistic one. For this purpose, tissue-like phantoms are the best alternative to carry out realistic analyses of the performance of body area networks. In addition, they are the conventional way to certify the compliance of commercial standards by these devices. However, the number of phantoms that work in large bandwidths is limited in literature. This work aims at presenting chemical solutions that will be useful to prepare a variety of wideband tissue phantoms. Besides, the colon was mimicked in two ways, the healthy tissue and the malignant one, taking into account studies that relate changes on the relative permittivity with cancer. They were designed on the basis of acetonitrile in aqueous solutions as described in a previous work. Thus, many scenarios could be developed such as multilayers which imitate parts of the heterogeneous body.

Red eyes presenting with a fistulous lesion in the left lower extremity: a case report.

INTRODUCTION: Very few cases of scar sarcoidosis affecting the eyes and bone together have been reported in the last few years. CASE PRESENTATION: We report a case of a 49-year-old Spanish man with recurrent bilateral granulomatous uveitis and a fistulous nodular lesion in the left pre-tibial region (scar granuloma) on the site of an 8-year-old scar. He presented with bilateral hilar adenopathies and elevation of inflammatory markers and angiotensin-converting enzyme. A histologically confirmed sarcoid of the tibia with a radiologic appearance unusual for long tubular bone involvement was observed. He also had bilateral ophthalmologic involvement. CONCLUSIONS: Sarcoidosis is a disease of unknown cause histologically characterized by non-caseating granulomas that can involve any organ or tissue. Osseous sarcoidosis is a relatively rare presentation. However, on the basis of cases reported in the literature, sarcoid lesions on bones are generally asymptomatic. Biologic agents are considered an alternative therapy for sarcoidosis resistant to conventional treatment.

Sevoflurano tópico como tratamiento analgésico y antimicrobiano de tenosinovitis piógena de los flexores de la mano. Caso clínico / Topical sevoflurane as analgesic and antimicrobial treatment of pyogenic flexor tenosynovitis of the hand. Case report

Presentamos el caso de un paciente con una tenosinovitis piógena del 5° dedo de la mano, tratado inicialmente con desbridamiento quirúrgico y antibioterapia empírica. La evolución fue desfavorable, pues el dedo presentaba un defecto de cobertura con signos infecciosos en la herida y las curas resultaban muy dolorosas. Al paciente se le ofertaron varias opciones quirúrgicas y, mientras se decidía por alguna, aceptó por escrito iniciar curas con sevoflurano líquido tópico (según protocolo vigente para uso de fármacos fuera de indicación). El efecto analgésico del sevoflurano apareció rápidamente, y la evolución posterior de la herida fue muy favorable, pues los signos infecciosos desaparecieron y el defecto de cobertura se había cerrado tras tres semanas de empleo de sevoflurano tópico, sin necesidad de nuevas cirugías. Este caso ejemplifica que el uso fuera de indicación de sevoflurano tópico para tratar heridas complejas puede evitar actuaciones quirúrgicas, mucho más agresivas para los pacientes.

The clinical case is presented on a patient suffering from pyogenic tenosynovitis affecting the 5th finger of the hand, which was initially treated with surgical debridement and empirical antibiotic treatment. The clinical outcome was unfavourable, since the finger presented with a coverage defect, and the wound seemed to be infected. Wound cleaning and dressings were very painful. The patient was asked to choose between several surgical therapeutic alternatives, but he gave written informed consent to be treated with topical sevoflurane, following an approved protocol for the off-label use of this drug. Pain was accurately controlled after sevoflurane application, and the wound exhibited a very good outcome with disappearance of the clinical signs of infection and complete closure of the defect coverage after three weeks of sevoflurane, with no new surgical procedures. The present clinical case illustrates how the off-label use of topical sevoflurane for the treatment of complicated wounds could be useful to avoid surgical procedures that are more aggressive for patients.

Silvoflurano tópico en infección superficial por SARM tras artroplastia de rodilla: caso clínico / Topical sevoflurane for superficial MRSA infection after knee arthroplasty: case report

Intentar el tratamiento retentivo de material protésico ante heridas quirúrgicas infectadas por gérmenes resistentes es objeto de debate, especialmente cuando el agente causal es un Staphylococcus aureus resistente a meticilina (SARM). Una paciente diabética y con obesidad tipo I sufrió infección de la herida quirúrgica tras artroplastia de rodilla que no evolucionó bien con antibioterapia empírica y terapia hiperosmolar. Se planificó una reintervención que fue demorada por motivos extramédicos (falta de terapia de presión negativa para cubrir la herida postoperatoria, pues se preveía no poder realizar cierre primario). Mientras se conseguía este material, y tras obtener el consentimiento de la paciente, se iniciaron irrigaciones de la herida con sevoflurano tópico off-label, pues ese fármaco ha mostrado capacidad antimicrobiana. La evolución clínica fue excelente desde el inicio a pesar de que en el cultivo se aisló un SARM resistente a la antibioterapia empírica, por lo que se desestimó la reintervención y se continuó con sevoflurano tópico junto a la antibioterapia dirigida por antibiograma, lográndose la curación completa de la herida tras 6 semanas. Durante ese tiempo, la paciente no experimentó ningún efecto adverso atribuible al sevoflurano. El sevoflurano tópico aparece como una valiosa nueva opción terapéutica ante heridas postoperatorias infectadas, especialmente cuando los gérmenes causantes son resistentes a los antibióticos convencionales.

It is challenging to try a retentive treatment of prosthetic material superinfected by resistant microorganisms, especially when the causative agent is a methicillin-resistant Staphylococcus aureus (MRSA). A diabetic, obese female patient suffered from a postoperative wound infection after a knee arthroplasty. Initial treatment with antibiotics and hyperosmolar therapy failed and clinical evolution was no good. Surgery was scheduled, but it was delayed due to nonmedical reasons (lack of negative-pressure therapy to cover the wound since primary wound closure was anticipated to be very improbable to perform). While waiting for this therapy, off-label irrigations with topical sevoflurane were started after obtaining written consent, since this drug has exhibited antimicrobial properties. Clinical evolution turned out to be excellent since the very beginning, even though a MRSA resistant to the antibiotics empirically administered was isolated. Thus, surgery was discarded, and culture-guided antibiotic therapy was added to topical sevoflurane, which was followed by a complete healing of the wound after 6 weeks. Sevoflurane treatment was well tolerated as the patient reported no adverse effects. Therefore, treating postsurgical wounds with topical sevoflurane appears as a valuable new alternative, especially when infections are caused by microorganisms resistant to conventional antibiotics.

Aplicación de lipotransferencia en la reconstrucción mamaria por cáncer / Application of lipotransference in breast reconstruction due to cancer

RESUMEN Introducción: El resultado estético de la reconstrucción mamaria depende de varios factores difíciles de evaluar, la aplicación de la lipotransferencia ofrece alternativas para lograr mejores resultados estéticos y mayor satisfacción de las pacientes. Objetivo: Introducir la técnica de lipotransferencia en el instituto nacional de oncología de Cuba Métodos: Se realizó un estudio descriptivo, prospectivo, de corte longitudinal, en 10 pacientes a las que se les practicó técnica de lipotransferencia para reconstrucción mamaria por cáncer, que fueron operadas en el Instituto Nacional de Oncología y Radiobiología (INOR), en el período comprendido entre noviembre de 2016 y noviembre de 2018. Resultados: La técnica fue aplicada con mejores resultados estéticos en pacientes reconstruidas con expansión tisular. Se logró mejorar la disponibilidad de tejidos y amortiguar los daños de la radioterapia. La cantidad de grasa infiltrada fue hasta 400 ml, lo que propició mejorar la calidad de los tejidos y el contorno de la mama reconstruida. Obteniéndose con ello mejor simetría. Conclusiones: La aplicación de esta técnica complementaria, permite obtener mejores resultados estéticos y de esta mejor simetría en pacientes reconstruidas por cáncer de mama(AU)

ABSTRACT Introduction: The aesthetic result of breast reconstruction depends on several factors that are difficult to evaluate. The application of lipotransference offers alternatives to achieve better aesthetic results and greater patient satisfaction. Objective: To introduce the lipotransference technique in the Cuban National Institute of Oncology Methods: A descriptive, prospective, longitudinal-section study was carried out in 10 patients who underwent lipotransfer technique for breast reconstruction due to cancer, who underwent surgery at the National Institute of Oncology and Radiobiology (INOR), in the period between November 2016 and November 2018. Results: The technique was applied with better aesthetic results in reconstructed patients with tissue expansion. Tissue availability was improved and the damage from radiation therapy was cushioned. The amount of fat infiltrated was up to 400 ml, which favored improving the quality of the tissues and the contour of the reconstructed breast. Thus obtaining better symmetry. Conclusions: The application of this complementary technique allows obtaining better aesthetic results and this better symmetry in patients reconstructed for breast cancer(AU)

2-Methylcitrate-dependent activation of the propionate catabolic operon (prpBCDE) of Salmonella enterica by the PrpR protein.

The function of the PrpR protein of Salmonella enterica serovar Typhimurium LT2 was studied in vitro and in vivo. The PrpR protein is a sensor of 2-methylcitrate (2-MC), an intermediate of the 2-methylcitric acid cycle used by this bacterium to convert propionate to pyruvate. PrpR was unresponsive to citrate (a close structural analogue of 2-MC) and to propionate, suggesting that 2-MC, not propionate, is the metabolite that signals the presence of propionate in the environment to S. enterica. prpR alleles encoding mutant proteins with various levels of 2-MC-independent activity were isolated. All lesions causing constitutive PrpR activity were mapped to the N-terminal domain of the protein. Removal of the entire sensing domain resulted in a protein (PrpR(c)) with the highest 2-MC-independent activity. Residue A162 is critical to 2-MC sensing, since the mutant PrpR protein PrpR(A162T) was as active as the PrpR(c) protein in the absence of 2-MC. DNA footprinting studies identified the site in the region between prpR and the prpBCDE operon to which the PrpR protein binds. Analysis of the binding-site sequence revealed two sites with dyad symmetry. Results from DNase I footprinting assays suggested that the PrpR protein may have higher affinity for the site proximal to the P(prpBCDE) promoter.

Propionyl coenzyme A is a common intermediate in the 1,2-propanediol and propionate catabolic pathways needed for expression of the prpBCDE operon during growth of Salmonella enterica on 1,2-propanediol.

The studies reported here identify propionyl coenzyme A (propionyl-CoA) as the common intermediate in the 1,2-propanediol and propionate catabolic pathways of Salmonella enterica serovar Typhimurium LT2. Growth on 1,2-propanediol as a carbon and energy source led to the formation and excretion of propionate, whose activation to propionyl-CoA relied on the activities of the propionate kinase (PduW)/phosphotransacetylase (Pta) enzyme system and the CobB sirtuin-controlled acetyl-CoA and propionyl-CoA (Acs, PrpE) synthetases. The different affinities of these systems for propionate ensure sufficient synthesis of propionyl-CoA to support wild-type growth of S. enterica under low or high concentrations of propionate in the environment. These redundant systems of propionyl-CoA synthesis are needed because the prpE gene encoding the propionyl-CoA synthetase enzyme is part of the prpBCDE operon under the control of the PrpR regulatory protein, which needs 2-methylcitrate as a coactivator. Because the synthesis of 2-methylcitrate by PrpC (i.e., the 2-methylcitrate synthase enzyme) requires propionyl-CoA as a substrate, the level of propionyl-CoA needs to be raised by the Acs or PduW-Pta system before 2-methylcitrate can be synthesized and prpBCDE transcription can be activated.

Method for generating solitons sustained by competing nonlinearities by use of optical rectification.

We put forward a method for generating engineerable competing quadratic and cubic nonlinearities in suitable settings in which frequency generation is accompanied by optical rectification. The novel scheme is based on the full exploitation of the geometrical conditions that determine the magnitude of the rectified fields and translates the different orientations of an elliptical pump beam into tunable nonlinearities, which can be used to act on the spectral composition and overall features of optical solitons.