Interaction of preservation methods and radiation sterilization in human skin processing, with particular insight on the impact of the final water content and collagen disruption. Part I: process validation, water activity and collagen changes in tissues cryopreserved or processed using 50, 85 or 98% glycerol solutions.

Current regulatory requirements demand an in-depth understanding and validation of protocols used in tissue banking. The aim of this work was to characterize the quality of split thickness skin allografts cryopreserved or manufactured using highly concentrated solutions of glycerol (50, 85 or 98%), where tissue water activity (aw), histology and birefringence changes were chosen as parameters. Consistent aw outcomes validated the proposed processing protocols. While no significant changes in tissue quality were observed under bright-field microscopy or in collagen birefringence, in-process findings can be harnessed to fine-tune and optimize manufacturing outcomes in particular when further radiation sterilization is considered. Furthermore, exposing the tissues to 85% glycerol seems to derive the most efficient outcomes as far as aw and control of microbiological growth.

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.

Harnessing stakeholder perspectives to improve the care of osteoporosis after a fracture.

UNLABELLED: This study used in-depth interviews and focus groups to evaluate osteoporosis care after a fracture. Patients (eligible women aged 67 who sustained a clinical fracture(s)), clinicians, and staff stated that an outreach program facilitated osteoporosis care management, but more-tailored education and support and increased participation of orthopedic specialists appear necessary. INTRODUCTION: Osteoporosis treatment reduces fracture risk, but screening and treatment are underutilized, even after a fracture has occurred. This study evaluated key stakeholder perspectives about the care of osteoporosis after a fracture. METHODS: Participants were from a nonprofit health maintenance organization in the United States: eligible women members aged 67 or older who sustained a clinical fracture(s) (n = 10), quality and other health care managers (n = 20), primary care providers (n = 9), and orthopedic clinicians and staff (n = 28); total n = 67. In-depth interviews and focus groups elicited participant perspectives on an outreach program to patients and clinicians and other facilitators and barriers to care. Interviews and focus group sessions were transcribed and content-analyzed. RESULTS: Patients, clinicians, and staff stated that outreach facilitated osteoporosis care management, but important patient barriers remained. Patient knowledge gaps and fatalism were common. Providers stated that management needed to begin earlier, and longer-term patient support was necessary to address adherence. Orthopedic clinicians and staff expressed lack of confidence in their osteoporosis management but willingness to encourage treatment. CONCLUSIONS: Although an outreach program assisted with the management of osteoporosis after a fracture, more-tailored education and support and increased participation of orthopedic specialists appear necessary to maximize osteoporosis management.

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.

Lactic acidosis rates in type 2 diabetes.

OBJECTIVE: To provide a context for the interpretation of lactic acidosis risk among patients using metformin, we measured rates of lactic acidosis in patients with type 2 diabetes before metformin was approved for use in the U.S. RESEARCH DESIGN AND METHODS: Using electronic databases of hospital discharge diagnoses and laboratory results maintained by a large, nonprofit health maintenance organization (HMO). we identified possible lactic acidosis events in three geographically and racially diverse populations with type 2 diabetes. We then reviewed hard-copy clinical records to confirm and describe each event and determine its likely cause(s). RESULTS: From >41.000 person-years of experience, we found four confirmed, three possible, and three borderline cases of lactic acidosis. In each case, we identified at least one severe medical condition that could have caused the acidosis. The annual confirmed event rate is similar to published rates of metformin-associated lactic acidosis. CONCLUSIONS: Lactic acidosis occurs regularly, although infrequently, among persons with type 2 diabetes, at rates similar to its occurrence among metformin users. The medical conditions with which both metformin-associated and naturally occurring lactic acidosis co-occur are also its potential causes. The observed association between metformin and lactic acidosis may be coincidental rather than causal. This possibility merits further study

[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.

The percentage of inspired oxygen at different flow rates during nebulisation.

The aim of this study was to determine the mean value for the fraction of inspired oxygen (FiO2) in normal subjects at oxygen flow rates of 2L/min, 4L/min and 6L/min during mouthpiece nebulisation. The FiO2 was defined as the fractional extraction of oxygen at the mouth. The variation in the FiO2 during normal and deep breathing was also studied in order to assess whether a significant difference in the FiO2 occurred. Breathing at a normal tidal volume, the values of the FiO2 were 27.5 per cent, 30.8 per cent and 34.9 per cent respectively. The values during deep breathing were 24.4 per cent, 27.9 per cent and 31.3 per cent respectively. It was clearly evident that the FiO2 during deep breathing was approximately 3 per cent less than that during normal tidal breathing.

Tensor fascia lata musculocutaneous flap for abdominal wall reconstruction.

We report a case of abdominal wall reconstruction following excision of irradiated skin and a ventral hernia. A very large tensor fascia lata musculocutaneous flap was used with good results. The anatomical features of this flap make it an excellent method of abdominal wall reconstruction.