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The use of autologous grafts in the reconstruction of nail-bed injuries is a topic that has received variable attention in the literature. With the exception of a few sentinel articles with large patient cohorts, most techniques have been reported with only anecdotal clinical support. Nail grafting remains, however, a subject that is extremely important in the total care of hand injuries. Grafting is one of the only reconstructive modalities for a majority of nail-bed injuries with avulsed tissue as well as for chronic, scarred nail deformities. We review the literature and summarize the techniques available for a variety of circumstances.

Using a hydrogen-electrode thermocell with a temperature difference of 8 K, the initial thermoelectric power ɛin has been determined for aqueous NaOH solutions from 0.003 to 0.2 molal at mean temperatures of 25 and 15°C. Graphs of a function of ɛin vs. a function of m1/2 yield infinitedilution limiting slopes as m1/2 → 0 which are shown to be in agreement with the five-term theory of this laboratory. Extrapolation of these curves to infinite dilution yields the value for the standard transported entropy of the hydroxide ion\(\bar \bar S^ \circ (OH^-- ) = 68.8 \pm 0.3J{\text{ - }}K^{ - 1} \).

The human ear is a defining feature of the face. Its subtle structures convey signs of age and sex that are unmistakable yet not easily defined. With analysis of normative cross-sectional data, this study explored anatomic and aesthetic differences in the ear between men and women, as well as changes in ear morphology with age. A total of 123 volunteers were randomly selected for this study. The cohort consisted of 89 women ages 19 to 65 years (median age, 42 years) and 34 men ages 18 to 61 years (median age, 35 years). The average total ear height across the entire cohort for both left and right ears was 6.30 cm, average lobular height was 1.88 cm, and average lobular width was 1.96 cm. As expected based on head size, significant sex-related differences were noted in the distance from the lateral palpebral commissure to both the helical root and insertion of the lobule. Measured distances in both vectors were approximately 4.6 percent longer in men than in women. Similarly, the height of the pinna was significantly larger in men than in women by approximately 6.5 percent. The average height and width of the lobule, however, were nearly identical in men and women. Analysis of age-related data showed a significant difference in the total ear height between the subpopulations; however, this difference was not significant after the lobular height was subtracted from total ear height, suggesting that the lobule was the only ear structure that changed significantly with age. In addition, lobular width decreased significantly with age. This study establishes normative data for ear morphology and clearly demonstrates the changes in earlobe morphology that occur with advancing age.

Platelet-derived growth factor BB (PDGF-BB) plays a central role in wound healing. Platelet-derived growth factor has been shown to accelerate healing in preclinical and clinical studies, but its wound-healing effects in older animals have not been examined. An ischemic incisional model in young female (5 months) and aged male (60 months) rabbits was used to determine the influence of platelet-derived growth factor on day 14 postwounding with reduced blood supply. Wounds in aged ischemic animals were severely impaired in breaking strength compared with their nonischemic control wounds and wounds in young animals (p < 0.001). Topical platelet-derived growth factor (10 microg per wound) partially reversed the reduction in breaking strength in aged ischemic animals but was ineffective in young animals. Histologic studies showed that new granulation tissue deposition and mononuclear cell infiltration was dramatically lower in ischemic wounds of aged animals compared with their control wounds as well as wounds from young animals under both nonischemic and ischemic conditions. Platelet-derived growth factor partially reversed this deficit in old ischemic wounds but not in young ischemic wounds. Epithelial growth was reduced in wounds from aged animals compared with wounds from young animals after 14 days of healing. Platelet-derived growth factor treatment increased ischemic wound epithelial growth in aged ischemic animals about threefold compared with paired controls. In conclusion, wound healing in aged rabbits was severely impaired by ischemia, and a single topical platelet-derived growth factor treatment partially reversed this deficit.

Impaired wound healing as a result of age is a well-documented phenomenon. However, the overall deficit in healing is substantially increased when the healing wound of an aged animal is ischemic. We hypothesized that both of these deficits are cytokine mediated. We have studied the messenger RNA expression of platelet-derived growth factor receptor-beta, using the rabbit dermal ulcer model of wound repair, in young (3 to 6 months) and aged (48 months and 60 months) rabbits under normal and ischemic conditions. Platelet-derived growth factor receptor-beta mRNA expression was measured with the use of quantitative reverse transcriptase-polymerase chain reaction with incorporation of a synthetic, nonhomologous DNA fragment complementary to platelet-derived growth factor receptor-beta primers as a competitive internal standard. Results in young rabbits showed a large upregulation of platelet-derived growth factor receptor-beta mRNA expression after wounding. In both aged animal groups, platelet-derived growth factor receptor-beta expression was found to be significantly decreased in nonischemic wounds relative to young nonischemic controls. Ischemia was found to have little effect on platelet-derived growth factor receptor-beta mRNA expression in young animals relative to matched controls. However, ischemia induced a large decrease in the platelet-derived growth factor receptor-beta mRNA levels of wounds of aged animals relative to paired aged nonischemic wounds. Results suggest an age-related delay in platelet-derived growth factor receptor-beta mRNA expression in healing wounds, as well as an age-related decline in responsiveness to confounding ischemia.