Antibacterial and antibiofilm effects of flufenamic acid against methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) infections are one of the most serious surgery complications, and their prevention is of utmost importance. Flufenamic acid is a non-steroid anti-inflammatory drug approved for clinical use to relieve inflammation and pain in rheumatoid arthritis patients. In this study, we explored the antibacterial efficacy of flufenamic acid and the mechanisms underlying this effect. By using minimal inhibitory concentration (MIC), time-kill, resistance induction assays, and the antibiotic synergy test, we demonstrated that flufenamic acid inhibited the growth of methicillin-resistant staphylococci and did not induce resistance when it was used at the MIC. Furthermore, flufenamic acid acted synergistically with the beta-lactam antibiotic oxacillin and did not show significant toxicity toward mammalian cells. The biofilm inhibition assay revealed that flufenamic acid could prevent biofilm formation on medical implants and destroy the ultrastructure of the bacterial cell wall. RNA sequencing and quantitative RT-PCR indicated that flufenamic acid inhibited the expression of genes associated with peptidoglycan biosynthesis, beta-lactam resistance, quorum sensing, and biofilm formation. Furthermore, flufenamic acid efficiently ameliorated a local infection caused by MRSA in mice. In conclusion, flufenamic acid may be a potent therapeutic compound against MRSA infections and a promising candidate for antimicrobial coating of implants and surgical devices.

Chest Wall Seroma Following Surgery for Malignant Pleural Effusion / Seroma en la pared torácica tras cirugía por derrame pleural maligno

No disponible

Neurilemmoma showing a unique growth pattern in the lateral chest wall: both inside and outside the thoracic cavity.

We report the first case of the intercostal neurilemmoma showing a unique growth pattern in the lateral chest wall (both inside and outside the thoracic cavity). Usually, intrathoracic neurilemmoma is found in the posterior mediastinum and bulge from the inner surface of the bony thorax toward the thoracic cavity. This unique growing pattern of neurilemmoma arising from intercostal nerve was clearly demonstrated by computed tomography and ultrasonography.

Characterization of Longissimus thoracis, Semitendinosus and Masseter muscles and relationships with technological quality in pigs. 1. Microscopic analysis of muscles.

Three porcine muscles (Longissimus thoracis, Semitendinosus, Masseter), known to have large differences in biochemical and histological traits, were fully characterized and the link between muscle structure and quality evaluated. The oxidative Masseter had more pigment, higher content of metmyoglobin, haem iron, protein and collagen, and was redder with higher fibre numbers, fibre circularity, pH and water holding capacity than the glycolytic Longissimus. Fibre type distribution showed predominance of type IIB in Longissimus and Semitendinosus white, type I in Semitendinosus red and IIA in Masseter. Type I fibres were larger than type IIB and IIA in Semitendinosus and Masseter, respectively, but not in the Longissimus, indicating that fibre size is muscle dependent. Muscle redness was positively correlated with type I fibre traits, haem iron and metmyoglobin, and negatively associated with type II fibre characteristics, non-haem iron and oxymyoglobin. Expressible juice had positive correlation with fibre size and negative with fibre number and connective tissue.

Unique histological features of the left atrial posterior wall.

The left atrial posterior wall (LAPW) plays a critical role in atrial fibrillation, but the underlying mechanism remains unclear. In the present study, we sought to characterize the histological features of the LAPW. Different atrial regions were dissected from hearts of normal Sprague-Dawley rats and humans. Haematoxylin/eosin and van Gieson staining were used to analyse atrial cardiomyocyte arrangement and collagen distribution, respectively. Intercellular junctions were evaluated by transmission electron microscopy. In contrast with other atrial regions, the LAPW exhibited more disorganized cardiomyocytes, larger intercellular spaces and variable myocardial fibre arrangement. The proportion of collagen was significantly higher in the LAPW than in other atrial regions. Interestingly, desmosomes were sparse along with intercellular gaps in the LAPW. In summary, distinct disarrangement of cardiomyocytes and an abundance of collagen exist in the LAPW. The sparsity of desmosomes in the LAPW may be related to the heterogeneous distribution and separation of atrial myocytes.

Chest wall reconstruction with two types of biodegradable polymer prostheses in dogs.

OBJECTIVE: Currently, the choice of chest wall prosthesis remains a challenging problem for thoracic and reconstructive surgeons. The purpose of this study is to investigate the feasibility of newly developed biodegradable prostheses. METHODS: Two types of chest wall prostheses made from degradable polymer, collagen coated polydioxanone (CCP) mesh and chitin fiber reinforced polycaprolactone (CFRP) strut, were developed and studied. Adult mongrel dogs were subjected to extensive resection and reconstruction of anterior-lateral chest wall, CCP mesh was used in six dogs, the combination of CCP mesh and CFRP strut was used in four dogs, and polypropylene (PP) mesh in two dogs, as contrast. RESULTS: With good integration with tissue, CCP meshes maintained strength in the chest wall for more than 8 weeks and were completely resorbed within 24 weeks, and satisfactory short-term and long-term chest wall stabilization was achieved. The combined use of CCP mesh with CFRP strut provided a firmer chest wall in the early postoperative course. A mild wound infection developed in one animal with CCP mesh but resolved without sequelae, and no added complications were observed with the additional use of CFRP strut. CONCLUSIONS: Our experimental study shows that the CCP mesh and CFRP prosthesis were favorable for chest wall repair. The advantages of biodegradable copolymer give them promise as an excellent addition to the available reconstructive techniques currently in use.