Renal dysfunction has been associated with poor outcomes of wound healing in the diabetic population. The purpose of this study was to create an excisional wound healing model in diabetic mice with renal dysfunction to investigate the combined effects of diabetes and nephropathy on cutaneous ulcers. Renal impairment was introduced in diabetic db/db mice through unilateral nephrectomy and electrocoagulation of the contralateral kidney. Renal function was subsequently monitored with assays of blood urea nitrogen and spot urinary protein/creatinine ratio. After 8 weeks, splinted, full‐thickness excisional wounds were created on the dorsal skin and harvested on postoperative days 7 and 14 for further evaluation of wound healing. Renal injury promoted the increase of blood urea nitrogen 3 weeks after initial operation, which was maintained at double the control level throughout the study, concomitantly leading to a significant increase of spot urinary protein excretion. Diabetic mice with renal injury displayed notably impaired wound healing processes, concurrent with reductions in cellular proliferation and angiogenesis, as well as increases in M1 polarized macrophages, infiltrated neutrophils, oxidative stress, and cellular apoptosis. Furthermore, quantitative polymerase chain reaction (qPCR) results displayed corresponding changes of related genes (TNF‐α, IL‐1β, SOD2) in the wounds of renal injured db/db mice. Renal manipulation in this study accelerated the progress of renal impairment, which was demonstrated to aggravate impaired cutaneous wound healing in diabetic mice.
Background:
Traumatic muscle loss often results in poor functional restoration. Skeletal muscle injuries cannot be repaired without substantial fibrosis and loss of muscle function. Given its regenerative properties, the authors evaluated outcomes of fetal tissue-derived decellularized matrix for skeletal muscle regeneration. The authors hypothesized that fetal matrix would lead to enhanced myogenesis and suppress inflammation and fibrosis.
Methods:
Composite tissue composed of dermis, subcutaneous tissue, and panniculus carnosus was harvested from the trunk of New Zealand White rabbit fetuses on gestational day 24 and from Sprague-Dawley rats on gestational day 18 and neonatal day 3, and decellularized using a sodium dodecyl sulfate–based negative-pressure protocol. Six, 10-mm-diameter, full-thickness rat latissimus dorsi wounds were created for each treatment, matrix was implanted (excluding the defect groups), and the wounds were allowed to heal for 60 days. Analyses were performed to characterize myogenesis, neovascularization, inflammation, and fibrosis at harvest.
Results:
Significant myocyte ingrowth was visualized in both allogeneic and xenogeneic fetal matrix groups compared to neonatal and defect groups based on myosin heavy chain immunofluorescence staining. Microvascular networks were appreciated within all implanted matrices. At day 60, expression of Ccn2, Col1a1, and Ptgs2 were decreased in fetal matrix groups compared to defect. Neonatal matrix-implanted wounds failed to show decreased expression of Col1a1 or Ptgs2, and demonstrated increased expression of Tnf, but also demonstrated a significant reduction in Ccn2 expression.
Conclusions:
Initial studies of fetal matrices demonstrate promise for muscle regeneration in a rat latissimus dorsi model. Further research is necessary to evaluate fetal matrix for future translational use and better understand its effects.
Background
While negative impacts of radiation on breast reconstruction have been well accepted, timing of autologous breast reconstruction in the setting of postmastectomy radiation therapy (PMRT) is still evolving. This study aims to address the dilemma of breast reconstruction timing in patients receiving PMRT.
Methods
A retrospective chart review was performed evaluating patients who underwent PMRT and autologous breast reconstruction. Postoperative complication and revision rates were compared.
Results
Thirty‐six immediate (immediate breast reconstruction [IBR]) and 89 delayed reconstructions (delayed breast reconstruction [DBR]) were included with comparable patient characteristics between groups. Overall complication rates were not significantly different, or when separately assessing for surgical site infections, wound dehiscence, fat necrosis, or substantial volume loss. No free flaps were lost in either group. Revision rates were significantly lower in the IBR group (p = 0.02). DBR resulted in appreciably larger volumes of fat grafting to the therapeutically reconstructed breast (p = 0.01) and more contralateral mastopexies (p = 0.02). No significant difference was observed in fat necrosis excision, breast reduction, or need for secondary flap reconstruction or prosthetic use for volume loss.
Conclusions
IBR in the setting of PMRT does not result in higher rates of complications and requires fewer overall revisions, making it a compelling option for patients undergoing PMRT.
Medical students are increasingly seeking global health service-learning opportunities; however, the impact of these interventions is often not assessed. In this article, the authors describe a model for global health service-learning programs as well as a pilot tool for assessing program impacts on populations traditionally difficult to evaluate. Specifically, a group of medical students from the United States, in collaboration with local health officials and a global NGO, successfully implemented a training program for parteras, or traditional birth attendants, in Mexico. The training included educational objectives from the Ministry of Health. A pilot assessment tool was developed which included oral pretest and posttest self-reported knowledge and task-specific ability in 12 program-specific categories. The assessment was administered in an effort to determine educational impact: parteras, who were receptive to students as teachers, reported increased knowledge and skill in all topics except nutrition and postpartum care. The results of the assessment suggest that undergraduate medical students, when collaborating with a facilitating organization, community-based healthcare workers, and local ministries of health, can improve lay birth attendants' confidence in basic obstetric knowledge and skills through global service-learning. Moreover, creative assessments are required to understand impacts on difficult to access populations.
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