10 documents found, page 1 of 1
BRACHIAL ARTERY ANEURYSM - A RARE CASE
Portela, Raquel; Marcos, David; Almeida, SaraIntroduction: Aneurysms in the upper limb, especially those in the brachial artery, are rare when compared with other peripheral arterial aneurysms. Most of these are pseudoaneurysms caused by trauma, including iatrogenic trauma, previous surgery and drug abuse. True aneurysms may be due to congenital connective tissue abnormalities, Kawasaki syndrome, Buerger’s disease and repetitive trauma, or to be idiopathi...
A SUSPICIOUS CASE OF HEART DYSFUNCTION
Torres Marcos, David; Ventura, Ludovic; Portela, Raquel; Esteves, Mário; Leitão, LaurindaIntroduction: Amyloid fibrils are polymers of proteins involved in various physiological processes. When there is an accumulation of defective amyloid fibrils, a condition called amyloidosis occurs. This can have several subtypes.Case Report: The authors report a case of a 78-year-old male, independent in his daily life, came to the medical center complaining of aggravating dyspnea in the last months. He has co...
Crosslinked bacterial cellulose hydrogels for biomedical applications
Almeida, Ana; Saraiva, João N.; Cavaco, Gonçalo; Portela, Raquel; Leal, Catarina R.; Sobral, Rita; Almeida, Pedro L.The skin, fundamental barrier that protects internal tissues, prevents pathogen invasion, and maintains the body fluid equilibrium, may be compromised upon traumas, such as incisions and burns. The healing process of such wounds is costly and usually hindered by the patient’s physiological conditions, associated diseases, inflammation and external factors, namely bacterial infections. Recently, increasing atten...
Antibiotic activity screened by the rheology of S. aureus cultures
Portela, Raquel; Valcovo, Filipe; Almeida, Pedro L.; Sobral, Rita; Leal, Catarina R.Multidrug resistant bacteria are one of the most serious public health threats nowadays. How bacteria, as a population, react to the presence of antibiotics is of major importance to the outcome of the chosen treatment. In this study we addressed the impact of oxacillin, a β-lactam, the most clinically relevant class of antibiotics, in the viscosity profile of the methicillin resistant Staphylococcus aureus (MR...
Bacterial cellulose: a versatile biopolymer for wound dressing applications
Portela, Raquel; R. Leal, Catarina; Almeida, Pedro L.; Sobral, RitaAlthough several therapeutic approaches are available for wound and burn treatment and much progress has been made in this area, room for improvement still exists, driven by the urgent need of better strategies to accelerate wound healing and recovery, mostly for cases of severe burned patients. Bacterial cellulose (BC) is a biopolymer produced by bacteria with several advantages over vegetal cellulose, such as...
Motility and cell shape roles in the rheology of growing bacteria cultures
Portela, Raquel; Almeida, Pedro L.; Sobral, Rita; R. Leal, CatarinaCell shape, size and self-motility appear as determinant intrinsic cell factors in the rheological behavior of living bacterial cultures during the growth process. In this work three different species were considered due to their differences on these intrinsic characteristics: two different strains of Staphylococcus aureus – strain COL and its isogenic cell wall autolysis mutant, RUSAL9 – both non-motile and Es...
S. aureus and E. coli Co-culture Growth Under Shear
Portela, Raquel; Almeida, Pedro L.; Sobral, Rita; R. Leal, CatarinaGrowing monocultures of two different species of human commensal/pathogenic bacteria, Staphylococcus aureus – a non-motile grampositive coccus and Escherichia coli – a motile gram-negative rod, were characterized using a real-time in situ rheology and rheo-imaging strategy. Subjecting bacterial populations to a shear flow is a closer approximation to bacterial thriving in the host, where they experience mechani...
Cell necklaces behave as a soft glassy material
Franco, Jose M.; Patricio, Pedro; Almeida, Pedro L.; Portela, Raquel; Sobral, Rita; R. Leal, CatarinaPreviously we have reported a complex and rich viscoelastic behavior observed during the Planktonic growth of S. aureus strain COL1. In particular, in stationary shear flow, the viscosity Keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the bactéria population stabilizes. In oscillatory flow, the elastic and viscous moduli exhibit power--‐l...
Staphylococcus aureus strains rheology during growth
Portela, Raquel; Almeida, Pedro L.; Patricio, Pedro; M.T., Cidade; Sobral, Rita; R. Leal, CatarinaThe study of the mechanical properties of living bacteria in a liquid rich medium, environment commonly used in laboratorial settings, opens a new perspective on the bacterial physiology and behaviour during population growth. In this work, the human pathogen Staphylococcus aureus was used as a study model due to its coccoid shape and regular morphology: MRSA strain COL [1] and its mutant strain RUSAL9 [2], whi...
Bacterial growth screened by rheology
Portela, Raquel; Pereira, M.; Sobral, Rita; Almeida, Pedro L.; R. Leal, CatarinaThe study of bacterial growth is a challenging field since it aims to describe the behaviour of microorganisms under different physical or chemical conditions. Bacterial growth as a biofilm is of particular interest as these gel-like structures are detrimental for all applications where “clean” surfaces are most important, and are related to failure of infection treatment, food spoilage and oil pipeline contami...