Heel Reconstruction With Bipedicled Flap: A Salvage Procedure

Reconstruction of the heel region poses great challenge to plastic surgeons not only due to calcaneal bone lying just deep to the subdermal fat pad but also due to easily exposed Achilles tendon. In order to achieve permanent closure of the heel defect, exposed bone or tendon—or both—should be covered with durable, preferably sensate, well-vascularized, thin skin flaps. Even though fasciocutaneous free flaps remain the gold standard in the reconstruction of heel defects with exposed bone or tendon, a significant number of these patients are older individuals with multiple comorbidities such as diabetes mellitus, hypertension, atherosclerosis, and peripheral vascular disease. In this study, with a clinic series consisting of 6 patients (1 female, 5 males), we present a new technique of reconstruction with a bipedicled flap as a safe, reliable, and efficient reconstructive modality in the treatment of heel defects in cases where free flaps and other more sophisticated reconstructive options are either not feasible or have failed. Achieving complete reconstruction of defects in all 6 patients, this technique proves to be successful as a salvage procedure in reconstruction of heel defects.

Hybrid Complexes of High and Low Molecular Weight Hyaluronans Highly Enhance HASCs Differentiation: Implication for Facial Bioremodelling

Background/Aims: Adipose-derived Stem Cells (ASCs) are used in Regenerative Medicine, including fat grafting, recovery from local tissue ischemia and scar remodeling. The aim of this study was to evaluate hyaluronan based gel effects on ASCs differentiation and proliferation. Methods: Comparative analyses using high (H) and low (L) molecular weight hyaluronans (HA), hyaluronan hybrid cooperative complexes (HCCs), and high and medium cross-linked hyaluronan based dermal fillers were performed. Human ASCs were characterized by flow cytometry using CD90, CD34, CD105, CD29, CD31, CD45 and CD14 markers. Then, cells were treated for 7, 14 and 21 days with hyaluronans. Adipogenic differentiation was evaluated using Oil red-O staining and expression of leptin, PPAR-γ, LPL and adiponectin using qRT-PCR. Adiponectin was analyzed by immunofluorescence, PPAR-γ and adiponectin were analyzed using western blotting. ELISA assays for adiponectin and leptin were performed. Results: HCCs highly affected ASCs differentiation by up-regulating adipogenic genes and related proteins, that were also secreted in the culture medium. H-HA and L-HA induced a lower level of ASCs differentiation. Conclusion: HCCs-based formulations clearly enhance adipogenic differentiation and proliferation, when compared with linear HA and cross-linked hyaluronans. Injection of HCCs in subdermal fat compartment may recruit and differentiate stem cells in adipocytes, and considerably improving fat tissue renewal.

Pulmonary heart valve replacement using stabilized acellular xenogeneic scaffolds; effects of seeding with autologous stem cells

Background: We hypothesized that an ideal heart valve replacement would be acellular valve root scaffolds seeded with autologous stem cells. To test this hypothesis, we prepared porcine acellular pulmonary valves, seeded them with autologous adipose derived stem cells (ADSCs) and implanted them in sheep and compared them to acellular valves. Methods: Fresh porcine pulmonary valve roots were decellularized with detergents and enzymes. ADSCs were isolated from subdermal fat and injected within the acellular cusps. Valves were then implanted in an extra-anatomic pulmonary position as RV to PA shunts: Group A (n=6) consisted of acellular valves and Group B (n=6) of autologous stem cell-seeded acellular xenografts. Sheep were followed up for 6 months by echocardiography and histologic analysis was performed on explanted valves. Results: Early evolution was favorable for both groups. All Group A animals had physiologic growth without any signs of heart failure and leaflets were found with preserved structure and mobility, lacking signs of thrombi, inflammation or calcification. Group B sheep however expressed signs of right ventricle failure starting at one month, accompanied by progressive regurgitation and right ventricle dilatation, and the leaflets were found covered with host tissue. No cells were found in any Group A or B explants. Conclusions: Acellular stabilized xenogeneic pulmonary valves are reliable, stable, non-immunogenic, non-thrombogenic and non-calcifying scaffolds with excellent hemodynamics. Seeding these scaffolds with autologous ADSCs was not conducive to tissue regeneration. Studies aimed at understanding these novel observations and further harnessing the potential of stem cells are ongoing.

Effects of migration distance on whole-body and tissue-specific energy use in American shad (Alosa sapidissima)

We examined total and tissue-specific energy content of upstream-migrating American shad (Alosa sapidissima) in the Connecticut River. Total energy depletion over the course of the 228-km migration ranged from 35 to 60%. The approximate contributions of different tissues to energy use during migration were white muscle 57%, subdermal fat 27%, red muscle 8%, viscera 6%, and liver 2%. American shad preferentially use energy stores in the skin and its subdermal fat layer (depleted by 63%) while sparing red muscle protein. Both lipid and protein were used as energy sources throughout migration, although lipids were depleted to a greater extent (e.g., white muscle lipid decreased 48% and protein 30%). Large fish expended 2-21% more energy during migration than small fish. Migrating to upriver sites (198-228 km) is 50-100% more energetically expensive than to lower river sections for females. This suggests that upriver range expansion may be limited by females in that they may have reached a threshold level of energy expenditure in this upriver area. American shad may possess physiological mechanisms for tissue-specific energy use allowing maintenance of critical tissues necessary for postspawning survival.

Ultrasonic Body Condition Measurements for Computerized Dairy Management Systems

The body condition (BC) score is recognized in the dairy industry as an essential tool for managing the energy reserves of the dairy cow, which is essential for sustaining optimal and efficient production over several lactations. The current use of BC scoring depends on the accuracy of subjective visual estimates, and this limits its kusefulness as a management aid in the dairy industry. A measuring tool that would frequently provide objective data on the cow's body reserves would be a major contribution to efficient dairy herd management. Ultrasonic sensors have the potential to be developed into an efficient BC measuring device, and the experimental use of such sensors for subcutaneous fat thickness (SDFT) estimates, as an indication for BC in beef cattle, supports this assumption. The purposes of this project were: 1. To compare visual BC scoring and ultrasonic fat thickness with on-line automated body weight (BW) measurements as monitors of nutritional adequacy of dairy cows at various stages of lactation. 2. To determine the effects of variation in digestive fill in early and late lactation on the accuracy of body weight measurements in lactating cows. 3. To modify an existing ultrasonic system and develop a specialized, low-cost sensor for repeatable determination of body condition scores by users with minimal training and skill. 4. To develop a standard for the assignment of body condition scores based on ultrasonic measurements of subdermal fat thickness. The procedure to execute these objectives involved: 1. Frequent measurement of BW, milk yield (MY), BC (visually scored) and subdermal fat thickness ultrasonically measured of dairy cows, and data analysis on average and individual basis. 2. Testing and selection of an appropriate special-purpose sensor, finding an optimum body location for working an ultrasonic measurement, prcessing the signals obtained, and correlating the resulting measurements with performance responses in lactating cows. Linking the ultrasonic signals to BC scores, and developing a BC scoring data acquisition system are the first steps towards fulfilling the necessary requirements for incorporating this device into an existing dairy herd management system, in order to provide the industry with a powerful managment tool. From the results obtained we could conclude that: 1. BC does not correlate with BW changes during all stages of lactation, although in general terms it does. These results were confirmed by individual cow BW and BC data obtained during the course of lactation, that were supported by individual objective ultrasonic measurement of SDFT. 2. BW changes reflect energy metabolism reliably ony after peak milk yield; early in lactation, a decrease in BW expresses mobilization of body reserves only qualitatively, and not quantitatively. 3. Gastrointestinal content increases throughout the whole period during which dry matter intake (DMI) increases. The drastic increase very early in lactation prevents the use of BW changes as a basis for quantitative estimatio of energy meatabolism; at this stage of lactation, konly a BC score or any other direct measurements willl provide a quantitative estimate of energy metabolism. 4. Ultrasonic measurements of subdermal fat thickness can be used to quantify changes that correlate with the actual condition of the cow, as assessed by performance and the traditional way of scoring. 5. To find the best site on the cow's body at which to obtain responses to BC and its changes in the course of lactation, additional sites have to be examined. From the present study, it seems that the sites between ribs 12 and 13 have the potential for this purpose. 6. The use of templates made it easier to repeat measurements at a desired site and spot. However, the convenient easy-to-handle way to standardize the measurement, described in this study, koffers scope for improvement. 7. The RF peak values of the A-mode are better indicators of the location of fat layer borders than image analysis, from the point of view of future commercial development. 8. The distances between the RF peaks of the A-mode can be automatically measured by suitable software, for future commercial development. 9. Proper analysis of daily body weight and milk yield data can provide the necessary information on body condition changes during lactation, until a direct BC measurement device is developed. 10. In any case, at least one visual BC assessment has to be done, preferably immediately after calving, for calibration purposes.