Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography.

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol-processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.

Dependence of optical attenuation coefficient and mechanical tension of irradiated human cartilage measured by optical coherence tomography.

As banked human tissues are not widely available, the development of new non-destructive and contactless techniques to evaluate the quality of allografts before distribution for transplantation is very important. Also, tissues will be processed accordingly to standard procedures and to minimize disease transmission most tissue banks will include a decontamination or sterilization step such as ionizing radiation. In this work, we present a new method to evaluate the internal structure of frozen or glycerol processed human cartilages, submitted to various dosis of irradiation, using the total optical attenuation coefficient retrieved from optical coherence tomography (OCT) images. Our results show a close relationship between tensile properties and the total optical attenuation coefficient of cartilages. Therefore, OCT associated with the total optical attenuation coefficient open a new window to evaluate quantitatively biological changes in processed tissues.

Effects of ionizing radiation and preservation on biomechanical properties of human costal cartilage.

Tissue banks around the world store human cartilage obtained from cadaveric donors for use in diverse reconstructive surgical procedures. To ensure this tissue is sterile at the time of distribution, tissues may be sterilized by ionizing radiation. In this work, we evaluate the physical changes in deep frozen costal cartilage (-70 °C) or costal cartilage preserved in high concentrations of glycerol (>98 %) followed by a terminal sterilization process using ionizing radiation, at 3 different doses (15, 25 and 50 kGy). Tension and compression tests were carried out to determine the mechanical changes related both to the different preservation methods and irradiation doses. For both methods of preservation, tension strength was increased by about 24 %, when cartilage tissue was irradiated with 15 kGy. Deep frozen samples, when irradiated with 25 or 50 kGy, had a decrease in their mechanical performance, albeit to a lesser extent than when tissues were preserved in high concentration of glycerol and equally irradiated. In conclusion, processing in high concentration of glycerol did not increase tissue protection against radiation damage; while cartilage preserved in high concentrations of glycerol withstands radiation up to 25 kGy, deep frozen human costal cartilage may be sterilized with a doses up to 50 kGy without significant mechanical impact.

In vitro construction of a potential skin substitute through direct human keratinocyte plating onto decellularized glycerol-preserved allodermis.

This work demonstrates that glycerol-preserved acellular allodermis can be used as support for the proliferation of human keratinocytes and that the characteristics of this bioengineered tissue suggest its possible use as a permanent skin substitute for therapeutic challenges such as extensive burns as well as its possible use as an in vitro model for pharmacological studies. The removal of all basal membrane components during preparation of the dermal support also provides an original in vitro situation that allows observation of the reorganization of the dermal-epidermal junction. The tissue composite obtained is constituted of dermis covered by a well attached, multistratified epithelium with morphological characteristics that resemble human epidermis as evidenced by light and transmission electron microscopy, including the neoformation, albeit incomplete, of the dermal-epidermal junction. Assessment of involucrin and cytokeratin 14 expression by immunohistochemical assays established differentiation patterns. Both immerse and air-liquid interface culture systems were tested.

[Immediate breast reconstruction with the use of a microsurgical flap of the rectus abdominis muscle]. / Reconstrução mamária imediata com o uso do retalho microcirúrgico do músculo reto abdominal.

Breast cancer in advanced stages is a condition still frequently diagnosed in the female patients of this hospital. The surgical treatment proposed tends to be radical and mutilating. The importance of the breast for the female self-image is recognized, as well as the sameness of the prognosis of the disease after breast reconstruction, for which different techniques may be proposed to the patients. Among them is the use of the m. rectus abdominis as musculo-cutaneous free flap. This paper reports our experience in regard to the indication, tactics, results and complications of this technique.