Three-dimensional Biomimetic Technology: Novel Biorubber Creates Defined Micro- and Macro-scale Architectures in Collagen Hydrogels.

Tissue scaffolds play a crucial role in the tissue regeneration process. The ideal scaffold must fulfill several requirements such as having proper composition, targeted modulus, and well-defined architectural features. Biomaterials that recapitulate the intrinsic architecture of in vivo tissue are vital for studying diseases as well as to facilitate the regeneration of lost and malformed soft tissue. A novel biofabrication technique was developed which combines state of the art imaging, three-dimensional (3D) printing, and selective enzymatic activity to create a new generation of biomaterials for research and clinical application. The developed material, Bovine Serum Albumin rubber, is reaction injected into a mold that upholds specific geometrical features. This sacrificial material allows the adequate transfer of architectural features to a natural scaffold material. The prototype consists of a 3D collagen scaffold with 4 and 3 mm channels that represent a branched architecture. This paper emphasizes the use of this biofabrication technique for the generation of natural constructs. This protocol utilizes a computer-aided software (CAD) to manufacture a solid mold which will be reaction injected with BSA rubber followed by the enzymatic digestion of the rubber, leaving its architectural features within the scaffold material.

A model system for primary abdominal closures.

The foreign body response to medical devices and materials implanted in the human body, including scarring, fibrous encapsulation, and potential rejection, is a longstanding and serious clinical issue. There are no widely acceptable or safe therapies for ameliorating the foreign body response. Clinical complications resulting from the response include disfigurement of silicone prostheses and loss of function of devices such as implanted pacemakers, stents, and shunts. Cellularized implants and stem cells placed in the body are also subject to the foreign body response with the added issue that the regenerative repair intended to be prompted by the graft may be inhibited. Beneficial modification of the body's reaction to implanted materials, medical devices, engineered constructs, or stem cells would be a fundamentally important therapeutic advance.As part of investigating the cellular response, we have developed a model which uses cells isolated from skeletal muscle biopsy, cultured, and proliferated in vitro. These satellite cells, which are mononucleated progenitor cells, reside between the plasma membrane of the muscle fiber and the basal membrane that encompasses the fiber. While usually quiescent, these cells become activated following muscle damage. Once activated, the satellite cells proliferate, migrate to injured muscle, and participate in repair by fusing with existing muscle fibers or by differentiating into new skeletal muscle fibers. Satellite cells have been shown to be heterogeneous populations of stem cells and progenitor cells. We have developed an explant method for isolating, sorting, enriching, and culturing these cells for use in skeletal muscle regenerative medicine to determine if the foreign body response can be inhibited by manipulating the cell-cell communication.

[Sensorineural hearing loss evolution in Vogt-Koyanagi-Harada syndrome]. / Evolución de la hipoacusia neurosensorial bilateral en el síndrome de Vogt Koyanagi Harada.

Vogt-Koyanagi-Harada syndrome is an autoimmune multisystem disease, characterized by the association of ocular inflammatory manifestations (uveitis and retinal detachment) and extraocular lesions such as meningismus and tegumentary or auditory findings. We report the case of a Hispanic woman with this syndrome.

[Clinical characteristics of tinnitus in Ménière's disease]. / Comportamiento del acúfeno en la enfermedad de Ménière.

INTRODUCTION: Ménière's disease is characterised by vertigo, hearing loss and tinnitus. Various studies assess the problem of vertigo and audition deficit in Ménière's disease, but only a few of these relate to the clinical characteristics of tinnitus, the aim of this study. MATERIAL AND METHODS: A transversal descriptive study of the behaviour of tinnitus in 88 patients in different stages of Ménière's disease treated in a tertiary hospital was carried out. The different characteristics of disease were analysed: intensity was evaluated with an analogue-visual scale, subjective tonality through tonal shade references, the impact on the patient's quality of life was tested by a self-appraisal questionnaire, and competence level was evaluated with the Tinnitus Handicap Inventory. Epidemiologic factors, personal records, hearing thresholds and evolution in the number of vertiginous crises in the previous six months were also taken into account. RESULTS: The average time of evolution of the disease was 15.4 years. The results evidence the development of tinnitus of moderate intensity (5/10) and low frequency (46%), with a slight impact on quality of life. Worsening in the quality of life related to hearing affectation and/or advanced stages of the disease was also observed. We identified high frequency tonality, a medical record of depression and youth as unfavourable prognostic factors. There was no relationship found with the years of evolution of the disease or with the number of vertigo crises. CONCLUSION: In large samples of long evolution Ménière's disease, patients do not perceive tinnitus as a problem that produces serious impairment in their quality of life.

[Early start eosinophilic granuloma of the temporal bone]. / Granuloma eosinofílico de inicio precoz y localización temporal.

Langerhans cell histiocytosis is a disease of unknown aetiology which may be isolated or affect multiple organs and which frequently affects the head and neck, with cranial compromise being one of the most common manifestations in children over five years. We present the case of a three year old girl with no otologic history who came to our hospital with a clinic of subperiostic abscess, subsequently diagnosed as eosinophilic granuloma. We describe the treatment and clinical evolution of the case.

The F-box protein Dia2 regulates DNA replication.

Ubiquitin-mediated proteolysis plays a key role in many pathways inside the cell and is particularly important in regulating cell cycle transitions. SCF (Skp1/Cul1/F-box protein) complexes are modular ubiquitin ligases whose specificity is determined by a substrate-binding F-box protein. Dia2 is a Saccharomyces cerevisiae F-box protein previously described to play a role in invasive growth and pheromone response pathways. We find that deletion of DIA2 renders cells cold-sensitive and subject to defects in cell cycle progression, including premature S-phase entry. Consistent with a role in regulating DNA replication, the Dia2 protein binds replication origins. Furthermore, the dia2 mutant accumulates DNA damage in both S and G2/M phases of the cell cycle. These defects are likely a result of the absence of SCF(Dia2) activity, as a Dia2 DeltaF-box mutant shows similar phenotypes. Interestingly, prolonging G1-phase in dia2 cells prevents the accumulation of DNA damage in S-phase. We propose that Dia2 is an origin-binding protein that plays a role in regulating DNA replication.