Ophthalmic administration of a 10-fold-lower dose of conventional nanoliposome formulations caused levels of intraocular pressure similar to those induced by marketed eye drops.

The purpose of this study was to compare the in vivo efficacy of several timolol (TM)-loaded liposomal formulations with current TM antiglaucoma treatment (aqueous 0.5% w/v eye drops). In this study, conventional liposomes (CL) and deformable liposomes, without (DL1) and with ethanol (DL2) were prepared and characterized. In addition, in vitro release and permeation studies, as well as in vivo lowering intraocular pressure (IOP) and biocompatibility studies were performed. It was found that the quali and quantitative lipid bilayer composition played a significant role in modifying the physical properties of vesicles. The deformability study and electronic microscopy images revealed that membrane elasticity of DL1 and DL2 was much higher than CL. However, in vitro permeation results showed that the flux and permeability coefficient were significantly higher in CL compared to DL. The IOP study revealed that TM-loaded CL showed the best pharmacological activity, in comparison to deformable vesicles. Compared to the eye drops, CL formulation could equally reduce the IOP but using a concentration 10-fold lower, whereas the effective time was significantly longer. In addition, the formulations showed no irritant effects after instillation on the ocular surface.

Infecciones por micobacterias en otorrinolaringología: revisión de la literatura / Mycobacterial infections in otolaryngology: review

Las micobacterias constituyen un grupo de bacilos aeróbicos no capsulados y no móviles, algunos de los cuales son patógenos causantes de graves enfermedades en los mamíferos incluyendo tuberculosis y lepra. Chile, a pesar de pertenecer al grupo de países de baja prevalencia de tuberculosis en América, presentó un enlentecimiento en la curva de descenso de incidencia. Así mismo, se ha visto un aumento de micobacterias atípicas tanto en muestras pulmonares como extrapulmonares respecto a décadas anteriores. Por otra parte, las infecciones por micobacterias adquieren importancia en otorrinolaringología dado que la tuberculosis de cabeza y cuello representa alrededor del 10% a 35% de los casos de tuberculosis, siendo su localización más frecuente los ganglios linfáticos. La siguiente revisión abarcará los cuadros de infecciones por micobacterias en otorrinolaringología, sus manifestaciones clínicas, diagnóstico y tratamiento.

Mycobacteriums are a group of aerobic non-capsuled and non-mobile bacillus some of which can cause diseases in mammals such as tuberculosis and leprosy. Chile, despite belonging to the group of countries with low prevalence of tuberculosis in America, presented a slowing in the decline in incidence curve. At the same time there has been an increase in atypical mycobacterium in pulmonary and extrapulmonary samples, comparedto past decades. On the other hand infections by mycobacterium become important because the head and neck tuberculosis accounts for about 10%-35% of cases of tuberculosis, the most common site being the lymph nodes. The following review will cover mycobacterial infections in otolaryngology clinical manifestations, diagnosis and treatment.

Development of a mechanism and an accurate and simple mathematical model for the description of drug release: Application to a relevant example of acetazolamide-controlled release from a bio-inspired elastin-based hydrogel.

Transversality between mathematical modeling, pharmacology, and materials science is essential in order to achieve controlled-release systems with advanced properties. In this regard, the area of biomaterials provides a platform for the development of depots that are able to achieve controlled release of a drug, whereas pharmacology strives to find new therapeutic molecules and mathematical models have a connecting function, providing a rational understanding by modeling the parameters that influence the release observed. Herein we present a mechanism which, based on reasonable assumptions, explains the experimental data obtained very well. In addition, we have developed a simple and accurate "lumped" kinetics model to correctly fit the experimentally observed drug-release behavior. This lumped model allows us to have simple analytic solutions for the mass and rate of drug release as a function of time without limitations of time or mass of drug released, which represents an important step-forward in the area of in vitro drug delivery when compared to the current state of the art in mathematical modeling. As an example, we applied the mechanism and model to the release data for acetazolamide from a recombinant polymer. Both materials were selected because of a need to develop a suitable ophthalmic formulation for the treatment of glaucoma. The in vitro release model proposed herein provides a valuable predictive tool for ensuring product performance and batch-to-batch reproducibility, thus paving the way for the development of further pharmaceutical devices.

Challenges and opportunities in polymer technology applied to veterinary medicine.

An important frontier in the administration of therapeutic drugs to veterinary species is the use of different polymers as drug delivery platforms. The usefulness of polymers as platforms for the administration of pharmaceutical and agricultural agents has been clearly recognized in the recent decades. The chemical versatility of polymers and the wide range of developed controlled-release strategies enhance the possibilities for the formulation of active molecules. In particular, the veterinary area offers opportunities for the development of novel controlled-release drug delivery technologies adapted to livestock or companion animal health needs. In some cases, it also allows to improve profitability in meat production or to meet the safety criteria related to drug residues. A number of factors affect the selection of polymers and subsequent properties of the controlled-release drug delivery system. However, their selection also dictates the release kinetics of the drug from the delivery system. Such choices are therefore crucial as they affect the success and potential of the delivery system for achieving the therapeutic goals of the veterinarian. It is the intention of this review to give an overview of the most relevant polymers, which are used or have been tested as drug delivery release rate modifiers in the veterinary field. The article highlights some recent developments focusing on their advantages and applications and analyzes the future direction of the scientific and technological advancements in this area.

Surgical treatment of distal tarsal joint luxations in three horses.

The clinical signs, radiographic findings, surgical treatment, and outcome of three horses with luxation of the distal tarsal joints are reported. Two patients showed luxations of the tarsometatarsal joint whereas luxation of the proximal intertarsal joint was found in one case. Open reduction, followed by internal fixation was performed in two horses and closed reduction with a transfixation pin cast was performed in the third. The treatment in all three cases resulted in a satisfactory clinical outcome.

In vitro biomechanical evaluation and comparison of a new prototype locking plate and a limited-contact self compression plate for equine fracture repair.

OBJECTIVE: To determine if the mechanical properties (strength and stiffness) of a new prototype 4.5 mm broad locking plate (NP-LP) are comparable with those of a traditional 4.5 mm broad limited-contact self compression plate (LC-SCP), and to compare the bending and torsional properties of the NP-LP and LC-SCP when used in osteotomized equine third metacarpal bones (MC3). METHODS: The plates alone were tested in four-point bending single cycle to failure. The MC3-plate constructs were created with mid-diaphyseal osteotomies with a 1 cm gap. Constructs were tested in four-point bending single cycle to failure, four-point bending cyclic fatigue, and torsion single cycle to failure. RESULTS: There were not any significant differences in bending strength and stiffness found between the two implants. The MC3-NP-LP construct was significantly stiffer than the MC3-LC-SCP in bending. No other biomechanical differences were found in bending, yield load in torsion, or mean composite rigidity. Mean cycles to failure for bending fatigue testing were similar for both constructs. CLINICAL SIGNIFICANCE: The NP-LP was comparable to the LC-SCP in intrinsic, as well as structural properties. The NP-LP construct was more rigid than the LC-SCP construct under four-point bending, and both constructs behaved similarly under four-point bending cyclic fatigue testing and torsion single cycle to failure. The new NP-LP implant fixation is biomechanically comparable to the LC-SCP in a simulated MC3 fracture.

Complete caecal bypass without ileal transection for caecal impaction in horses: seven clinical cases (1997-2007).

OBJECTIVES: To report the clinical outcome in seven horses following use of a newly described surgical technique for treating caecal impaction. METHODS: The medical records of seven horses with caecal impaction treated surgically using a stapling technique to create a complete caecal bypass without ileal transection were reviewed. Data were obtained from the records and through telephone interviews with case-associated personnel. RESULTS: The mean age was 10 years (range 2-22 years) and duration of colic ranged from 24 h to 2 weeks. Five horses had type II motility dysfunction and the remaining two had type I. Mean surgical time was 185 min (range 146-245 min) and the horses were hospitalised for a mean of 12.4 days (range 9-22 days); 71% (5/7) were discharged from hospital and all five were alive 60 days from the surgery date. One horse was lost to follow-up. The four (66.7%) available remaining horses were alive ≥ 1 year (long-term survivors). CONCLUSIONS: Complete caecal bypass without ileal transection for clinical cases of caecal impaction had comparable outcomes to complete bypass with ileal transection. The technique is easy to perform, has the potential to reduce surgical time, compared with traditional bypass techniques, and may reduce the risk of intraoperative abdominal contamination. It is recommended for use in clinical cases in which caecal bypass is desirable.

Tórax móvil traumático / Traumatic flail chest

El tórax móvil es una entidad poco frecuente en niños debido a la mayor elasticidad de la pared costal comparado con adultos. Se presenta una niña de 20 meses que ingresa a la Unidad de Cuidados Intensivos Pediátricos, quien embestida por un automóvil, sufrió un politraumatismo severo con tórax móvil. Se realiza una revisión de esta entidad en la literatura

Tórax móvil traumático / Traumatic flail chest

El tórax móvil es una entidad poco frecuente en niños debido a la mayor elasticidad de la pared costal comparado con adultos. Se presenta una niña de 20 meses que ingresa a la Unidad de Cuidados Intensivos Pediátricos, quien embestida por un automóvil, sufrió un politraumatismo severo con tórax móvil. Se realiza una revisión de esta entidad en la literatura