Biomechanical evaluation of human and porcine auricular cartilage.

OBJECTIVES/HYPOTHESIS: The mechanical properties of normal auricular cartilage provide a benchmark against which to characterize changes in auricular structure/function due to genetic defects creating phenotypic abnormalities in collagen subtypes. Such properties also provide inputs/targets for auricular reconstruction scaffold design. Several studies report the biomechanical properties for septal, costal, and articular cartilage. However, analogous data for auricular cartilage are lacking. Therefore, our aim in this study was to characterize both whole-ear and auricular cartilage mechanics by mechanically testing specimens and fitting the results to nonlinear constitutive models. STUDY DESIGN: Mechanical testing of whole ears and auricular cartilage punch biopsies. METHODS: Whole human cadaveric ear and auricular cartilage punch biopsies from both porcine and human cartilage were subjected to whole-ear helix-down compression and quasistatic unconfined compression tests. Common hyperelastic constitutive laws (widely used to characterize soft tissue mechanics) were evaluated for their ability to represent the stress-strain behavior of auricular cartilage. RESULTS: Load displacement curves for whole ear testing exhibited compliant linear behavior until after significant displacement where nonlinear stiffening occurred. All five commonly used two-term hyperelastic soft tissue constitutive models successfully fit both human and porcine nonlinear elastic behavior (mean R(2) fit >0.95). CONCLUSIONS: Auricular cartilage exhibits nonlinear strain-stiffening elastic behavior that is similar to other soft tissues in the body. The whole ear exhibits compliant behavior with strain stiffening at high displacement. The constants from the hyperelastic model fits provide quantitative baselines for both human and porcine (a commonly used animal model for auricular tissue engineering) auricular mechanics. LEVEL OF EVIDENCE: NA

CHD7 mutations and CHARGE syndrome in semicircular canal dysplasia.

OBJECTIVE: To determine whether patients with semicircular canal dysplasia have mutations in CHD7. BACKGROUND: CHARGE syndrome is a nonrandom clustering of congenital anomalies, including ocular coloboma, heart defects, choanal atresia or stenosis, retarded growth and development, genital hypoplasia, and inner and outer ear anomalies including deafness. Semicircular canal dysplasia has been included as a major diagnostic criterion for CHARGE syndrome. Mutations in the gene CHD7 on chromosome 8q12.1 are a major cause of CHARGE syndrome, but the extent to which patients with semicircular canal dysplasia have CHD7 mutations is not fully understood. STUDY DESIGN: Cross-sectional analysis of CHD7 in 12 patients with semicircular canal dysplasia and variable clinical features of CHARGE syndrome. RESULTS: We identified 6 CHD7 mutations, 5 of which occurred in patients who fulfilled Verloes' diagnostic criteria for typical CHARGE syndrome, and three of which were previously unreported. Of the 3 remaining CHD7 mutation-positive patients, one had atypical CHARGE by diagnostic criteria. Four MRI records were available, which revealed 2 patients with cochlear nerve aplasia and 1 patient with Chiari 1 malformation. CONCLUSION: These data provide additional evidence that CHD7 mutations are a significant cause of semicircular canal atresia in children with full or partial CHARGE syndrome.

Attitudes of Cairo University medical students toward smoking: the need for tobacco control programs in medical education.

BACKGROUND: Tobacco smoking rates are increasing in developing countries and so are tobacco-related chronic diseases. Reported figures from the WHO show rates of smoking in Egypt as high as 20% but limited information is available about smoking specifically among physicians and medical students. MATERIALS AND METHODS: Final-year medical students of Cairo University were surveyed regarding their tobacco behavior and attitudes using a modified Global Health Professions Student Survey. We approached 220 students by randomly selecting clinical units into which they were assigned and requested completion of the survey. RESULTS: Ever users of some form of tobacco comprised 46.7% of students sampled, current users of cigarettes comprised 17.4%, and current users of water pipe 'sheesha' comprised 17.6%. The vast majority (87.7%) of students believed that smoking is a public health problem in Cairo and supported restriction of tobacco. Yet, only 58.5% stated that they were taught it is important for physicians to provide tobacco education materials to patients. Among ever users of cigarettes, 54.4% believed health professionals do not serve as health role models for patients, and only a small percentage of all students (34.2%) stated that they had received some form of training on smoking cessation in their medical curriculum to be able to instruct patients. CONCLUSION AND RECOMMENDATIONS: A high rate of smoking was revealed among medical students in Cairo. Overall, approximately 23.4% of students were currently smoking cigarettes and/or sheesha, and 46.7% were ever users of some form of tobacco. A formal antitobacco program for medical students should be incorporated into their medical curriculum to change the attitudes of medical students and overcome the anticipated increase in chronic diseases in Egypt.

Postoperative outcomes following closed head injury and craniotomy for evacuation of hematoma in patients older than 80 years.

OBJECT: Advances in the management of trauma-induced intracranial hematomas and hemorrhage (epidural, subdural, and intraparenchymal hemorrhage) have improved survival in these conditions over the last several decades. However, there is a paucity of research investigating the relation between patient age and outcomes of surgical treatment for these conditions. In this study, the authors examined the relation between patient age over 80 years and postoperative outcomes following closed head injury and craniotomy for intracranial hemorrhage. METHODS: A consecutive population of patients undergoing emergent craniotomy for evacuation of intracranial hematoma following closed head trauma between 2006 and 2009 was identified. Using multivariable logistic regression models, the authors assessed the relation between age (> 80 vs ≤ 80 years) and postoperative complications, intensive care unit stay, hospital stay, morbidity, and mortality. RESULTS: Of 103 patients, 27 were older than 80 years and 76 patients were 80 years of age or younger. Older age was associated with longer length of hospital stay (p = 0.014), a higher rate of complications (OR 5.74, 95% CI 1.29-25.34), and a higher likelihood of requiring rehabilitation (OR 3.28, 95% CI 1.13-9.74). However, there were no statistically significant differences between the age groups in 30-day mortality or ability to recover to functional baseline status. CONCLUSIONS: The findings suggest that in comparison with younger patients, patients over 80 years of age may be similarly able to return to preinjury functional baselines but may require increased postoperative medical attention in the forms of rehabilitation and longer hospital stays. Prospective studies concerned with the relation between older age, perioperative parameters, and postoperative outcomes following craniotomy for intracranial hemorrhage are needed. Nonetheless, the findings of this study may allow for more informed decisions with respect to the care of elderly patients with intracranial hemorrhage.