Hyperparathyroid crisis in a pediatric patient.

Primary hyperparathyroidism is rarely found in the pediatric population. Delays in diagnosis due to vague symptoms can lead to severe disease manifestations such as osteitis fibrosa cystica. We report a rare case of primary hyperparathyroidism in a 13-year-old girl who presented with a pathological femur fracture and numerous brown tumors.

Volume analysis of preadipocyte injection for vocal cord medialization.

OBJECTIVE: To compare the volume retention of injected preadipocytes with that of standard fat injection in a paralyzed rabbit true vocal cord. STUDY DESIGN: Prospective analysis with blinded data collection. METHODS: Thirteen New Zealand white rabbits were divided into two groups. Group 1 consisted of seven animals undergoing left-side vocal cord paralysis by resection of a 1-cm segment of the left-side recurrent laryngeal nerve and abdominal fat harvest for isolation of preadipocytes. Preadipocytes were cultured under sterile conditions in cell culture media. Animals in group 2 also underwent left-side vocal cord paralysis without fat harvest. After 10 to 14 days, in a second procedure, group 1 underwent injection of 0.1 mL cultured autologous preadipocytes, and group 2 underwent routine injection of 0.1 mL abdominal fat harvested during the same procedure. At 6 and 12 months, volumetric analysis was performed. RESULTS: Volume analysis at 6 months showed a mean volume of 0.029 mL retained fat in group 2 representing a retention of approximately 29% (SD = 0.023) of the original injected volume. Retention in group 1 animals approximated 0.002 mL (SD = 0.0024) or 2% of the injected volume. Analysis at 12 months showed a mean volume of 0.008 mL (SD = 0.0078) in group 2 and of 0.002 mL (SD = 0.0015) in group 1. Group 2 showed significantly higher volumes of the injected fat at 6 and 12 months (P <.033). CONCLUSION: Volumes obtained with standard fat injection were superior to those obtained with preadipocyte injection at both 6 and 12 months.

Age-related differences of neutrophil activation in a skeletal muscle ischemia-reperfusion model.

Free tissue transfers and replantation of amputated limbs are better tolerated by young adolescents than mature adults. The authors hypothesized that this observation may be, in part, because of an attenuated ischemia-reperfusion (IR) injury in younger patients. Because neutrophils have been identified as a critical cell line responsible for IR injury, the authors investigated the effects of animal age on the degree of neutrophil activation in a rat model. Activation was evaluated by monitoring expression of integrin surface markers (mean fluorescence intensity [MFI] of CD11b) and oxidative burst potential (MFI of dihydrorhodamine [DHR] oxidation) by flow cytometry in neutrophils analyzed after 4 hours of ischemia and 1, 4, and 16 hours of reperfusion in a gracilis muscle flap model in mature adult and young adolescent rats. Neutrophil activation was also evaluated in control sham-operated animals, which underwent elevation of gracilis muscle flaps without exposure to an ischemic insult. Muscle edema, determined by wet-to-dry muscle weight ratio, and muscle viability, determined by nitro blue tetrazolium (NBT) staining, were completed for gracilis muscles exposed to ischemia after 24 hours of reperfusion for each of the groups. Integrin expression, assessed by MFI of CD11b, was increased significantly in ischemic muscles of mature adult rats at 4 hours of reperfusion (71.10+/-3.53 MFI vs. 54.88+/-12.73 MFI, p=0.025). Neutrophil oxidative potential, assessed by MFI of DHR oxidation, was increased significantly in ischemic muscles of mature adult rats compared with young adolescent rats at 1 hour of reperfusion (78.10+/-9.53 MFI vs. 51.78+/-16.91 MFI, p=0.035) and 4 hours of reperfusion (83.69+/-15.29 MFI vs. 46.55+/-8.09 MFI, p=0.005). Increased edema formation was observed in the ischemic muscles of mature adult rats when compared with young adolescent rats (1.25+/-0.04 vs. 1.12+/-0.05, p=0.031) after 24 hours of reperfusion. A trend toward decreased muscle viability was observed in the mature adult rats when compared with young adolescent rats (23.7+/-3.1% NBT staining vs. 32.3+/-13.7% NBT staining, p=0.189) after 24 hours of reperfusion. The authors present evidence of an attenuated IR injury in young adolescent animals when compared with mature adult rats. These findings emphasize the importance that studies involving IR injury should be performed with consideration of animal age.

A tissue-engineering technique for vascularized laryngotracheal reconstruction.

OBJECTIVE: To perform laryngotracheal reconstruction (LTR) using a vascularized neotracheal segment. DESIGN: A neotracheal segment was created within the sternocleidomastoid muscle. An anterior cricoid split procedure was performed using a pedicled, vascularized neotracheal segment. Results were compared with a control group that underwent anterior cricoid split using standard (avascular) autografted cartilage. Cross-sectional area, cartilage viability, extrusion, mucosalization, and wound healing were compared between groups. SUBJECTS: Sixteen female New Zealand white rabbits. INTERVENTIONS: Eight animals underwent placement of a cartilage-wrapped silicone implant into the sternocleidomastoid muscle. After 2 weeks, the silicone implant was removed, leaving a fibrovascular "foreign body" capsule and the interwoven autografted cartilage. The neotracheal segment was trimmed to create an anterior graft for LTR. The remaining animals underwent standard anterior graft LTR using autografted auricular cartilage. The reconstructed segments were harvested for comparison at 2 and 4 weeks. RESULTS: All reconstructed animals survived the postoperative period. No significant differences in stenosis rates or mucosalization were noted between groups. Two animals in the standard LTR group had microabscess formation, and no graft extrusions were encountered. CONCLUSION: A pedicled neotracheal graft can be used for anterior cricoid split procedures in rabbits.

Hsp70 in the inferior colliculus of Fischer-344 rats: effects of age and acoustic stress.

Heat shock proteins 72 and 73 (hsp72 and hsp73) were studied in the inferior colliculus (IC) of Fischer-344 rats to determine if their levels are altered during normal aging and following exposure to intense acoustic noise. Three age groups of rats (3, 18, and 25 months) were exposed to ambient sound (control) or broad-band noise at 108 dB sound pressure level (0.0004 dyn/cm2) for 30 min. Western blotting procedures were used to measure hsp72 and hsp73 in ICs and cerebella (positive control). Immunohistochemistry was performed using 3-month olds to study the localization patterns of hsp72 and hsp73 in both structures. The IC and cerebellum exhibited immunolabeling over neuronal somata and proximal dendrites. Ambient levels of hsp72 in supernatants from aged rats were reduced 56.5%+/-7.8% in the IC relative to 3-month olds. This decrease may render the IC more susceptible to stress-related damage. An increase in constitutive hsp73 (350.7%+/-70.4%) was observed in IC pellet fractions from animals exposed to the 108-dB noise when compared to the ambient-noise controls, suggestive of a lipoprotective role for hsp73. This elevation was consistent across age groups. No noise-induced changes in hsp72 were detectable in the IC, indicating that loud sounds may not be an appropriate stimulus for hsp72 induction in this structure.