Effect of polycaprolactone nanocapsules loaded with essential oils on biofilm formation by Staphylococcus aureus strains isolated from bovine mastitis cases

Abstract Bovine infectious mastitis is largely resistant to antibacterial treatment, mainly due to mechanisms of bacterial resistance in the biofilms formed by Staphylococcus aureus. Melaleuca (MEO) and citronella essential oils (CEO) are promising agents for reducing or eliminating biofilms. Free melaleuca oil presented a medium Minimum Inhibitory Concentration (MIC) of 0.625% and a Minimum Bactericidal Concentration (MBC) of 1.250%, while free citronella oil showed medium MIC and MBC of 0.313%. Thus, free CEO and MEO demonstrate bacteriostatic and bactericidal potential. We generated polymeric nanocapsules containing MEO or CEO and evaluated their efficacy at reducing biofilms formed by S. aureus. Glass and polypropylene spheres were used as test surfaces. To compare the responses of free and encapsulated oils, strains were submitted to 10 different procedures, using free and nanoencapsulated essential oils (EOs) in vitro. We observed no biofilm reduction by MEO, free or nanoencapsulated. However, CEO nanocapsules reduced biofilm formation on glass (p=0.03) and showed a tendency to diminish biofilms on polypropylene (p=0.051). Despite nanoencapsulated CEO reducing biofilms in vitro, the formulation could be improved to modify the CEO component polarity and, including MEO, to obtain more interactions with surfaces and the biofilm matrix

Ballet dancers cardiorespiratory, oxidative and muscle damage responses to classes and rehearsals.

This study aimed to describe and compare ballet dancers' cardiorespiratory responses, muscle damage and oxidative stress levels during a ballet class (practice of isolated ballet exercises performed with barre/hand-rail support and across-the-floor movements to improve technical skills) and rehearsal (practice of ballet choreography involving technical-artistic skills to improve dancers' performance for shows). The 12 advanced female ballet dancers undertook three exercise sessions: maximum effort test, class and rehearsal. Heart rate (HR) and oxygen consumption (VO2) were continuously measured. Lactate was determined before 15 min and after class and rehearsal. Blood was sampled pre, post and 48 h after class and rehearsal for creatine kinase (CK), lipid peroxides (LPO) and glutathione analysis (GSSG/GSH). Class was of lower intensity than rehearsal as shown by VO2, HR and lactate values: VO2 (mL.kg(-1).min(-1)): 14.5±2.1 vs. 19.1±1.7 (p < 0.001); HR (bpm.min(-1)): 145.7±17.9 vs. 174.5±13.8 (p < 0.001); lactate (mmol.L(-1)): 4.2±1.1 vs. 5.5±2.7 (p = 0.049). CK (IU) increased following class and rehearsal, remaining high 48 h after: class (pre = 109.3±48.5; post = 144±60; 48 h = 117.2±64.6); rehearsal (pre = 78.6±52.1; post = 122±70.7; 48 h = 104.9±89.5). LPO (µM) increased from pre-class (1.27±0.19) to post-class (1.41±0.19) and went down after 48 h (1.20±0.22). No LPO time-course changes followed the rehearsal. GSSG/GSH decreased 48 h after class and rehearsal. Greater increases in LPO post-class suggest it promotes CK release by an oxidative membrane-damage mechanism. Physiological increases of LPO and CK in class indicate it prepares the dancers for exercise-induced oxidative stress and muscle damage during rehearsals. Ballet dancers' muscle damage and oxidative stress responses seem not to be dependent on exercise intensity based on VO2 responses.

Detección extramuros de enfermedades de la piel / Extramural detection of skin diseases

RESUMEN: Se informa la frecuencia de patologías de la piel obtenida de la atención durante varias jornadas y consultorios, realizada por el Servicio de Dermatología del Hospital Nacional, en localidades próximas a esta institución. Material y Métodos: Se evaluaron 948 sujetos, con predominio del sexo femenino (65%). Resultados: El grupo etario más frecuente fue el de 30 a 39 años. Se detectaron patologías graves: Cáncer de piel, lesiones precursoras de cáncer de piel, pénfigo, genodermatosis y lepra.

ABSTRACT: We report of the frequency of skin conditions made by a Dermatology Service for several days in adjacent communities of the National Hospital. Material and Methods: We evaluated 948 subjects, with predominance of female gender (65%). Results:The most common age group was between 30 to 39 years. Serious diseases were detected: skin cancer, precursor lesions for skin cancer, pemphigus, genodermatosis and leprosy.

Pioderma gangrenoso de rápida evolución / Pyoderma gangrenosum rapidly evolving

Se presenta caso de mujer adulta con múltiples lesiones ampollosas de 1 semana de evolución, acompañada de fiebre. Presentaba antecedentes de rectorragias ocasionales desde hace varios años. La colonoscopía detectó la presencia de Enfermedad inflamatoria intestinal, que se confirmó con la anatomía patológica. La biopsia de piel fue compatible con pioderma gangrenoso. La paciente mejoró con prednisona y aziatropina.

A case report of adult female with multiple bullous lesions of 1 week duration, accompanied by fever. She had a history of occasional rectal bleeding for several years. The colonoscopy detected the presence of inflammatory bowel disease, which was confirmed by pathology. Skin biopsy was consistent with pyoderma gangrenosum. The patient improved with prednisone and aziatropina.