Background Ascending thoracic aortic aneurysm (ATAA) predisposes patients to aortic dissection and has been associated with diminished tensile strength and disruption of collagen. ATAA arising in patients with bicuspid aortic valve (BAV) develop earlier than those with tricuspid aortic valves (TAV) and have a different risk of dissection. The purpose of this study was to compare aortic wall tensile strength between BAV and TAV ATAAs and determine if the collagen content of the ATAA wall is associated with tensile strength and valve phenotype. Methods Longitudinally and circumferentially oriented strips of ATAA tissue obtained during elective surgery were stretched to failure and collagen content was estimated by hydroxyproline assay. Experimental stress-strain data were analyzed for failure strength and elastic mechanical parameters: α, β and maximum tangential stiffness. Results The circumferential and longitudinal tensile strengths were higher for BAV ATAA when compared with TAV ATAA. The α and β were lower for BAV ATAA when compared with TAV ATAA. The maximum tangential stiffness was higher for circumferential when compared with longitudinal orientation in both BAV and TAV ATAA. Amount of hydroxyproline was equivalent in BAV and TAV ATAA specimens. While there was a moderate correlation between the collagen content and tensile strength for TAV, this correlation is not present in BAV. Conclusion The increased tensile strength and decreased values of α and β in BAV ATAAs despite uniform collagen content between groups indicate that micro-structural changes in collagen contribute to BAV-associated aortopathy.

The goal of this work was to investigate the hypothesis that AAA wall exposed to hypoxia as a result of being adjacent to a thick intralumenal thrombus (ILT) exhibits impaired remodeling, leading to further degeneration. Pairs of AAA wall, selected based on disparate thicknesses of adjacent ILT, were snap frozen. QPCR was used to compare the gene expression. Protein levels were measured with Western blotting. MMP‐2 and ‐9 levels were measured with gelatin zymography. In separate paired samples, total wall thickness was measured on H&E‐stained sections. We found the activity, expression, and amounts of some genes and proteins to vary with ILT thickness within a given AAA, while others were at least spatially variable at the current sample number. For example, iNOS gene expression was up‐regulated in regions of AAA wall adjacent to thick ILT. Some protein levels were correlated to fold changes in ILT thickness. For example, calponin protein levels are negatively correlated to the fold increase in ILT thickness. AAA wall thickness was positively correlated to ILT thickness. The results support our hypothesis, suggesting that compared to AAA wall near thin ILT, the AAA wall adjacent to thick ILT has variable protein expression and impaired remodeling mechanisms. This work was supported by NIH R01‐HL79313.

Bicuspid aortic valve (BAV) is the most common congenital heart malformation occurring in 1–2% of the population with a high rate of morbidity [1]. There is a significantly higher rate of dilation of the aortic root in adults with a BAV when compared to the normal population and this condition is often associated with ascending thoracic aortic aneurysm (ATAA). ATAA is characterized as an enlargement of the aorta to twice its normal diameter. If left untreated, ATAA can lead to aortic dissection or rupture. Therefore, ATAA is recommended for prophylactic surgery when its diameter reaches about 5.5 cm. However, in certain high-risk cases, such as patients with BAV, ATAA may rupture when its diameter is less than 5.5 cm. Since ATAA dissection and rupture are biomechanical phenomena, better mechanical models are needed to more accurately predict these events over the predictive capability of diameter alone.

Purpose. Salivary testosterone concentrations have been used for monitoring testosterone levels in male adolescents and have been found to correlate closely with serum values. Data are lacking on such measurements in male adolescents with cystic fibrosis (CF), in which salivary gland abnormalities are commonly seen. Delayed sexual maturation occurs in many patients with CF, particularly those with severe disease. We examined the usefulness of salivary testosterone collection and measurement in male adolescents with CF. Methods. Forty boys with CF and 35 healthy control boys participated in the study. All boys were Tanner staged and had serum and salivary testosterone concentrations measured. Testosterone assays were performed using standard radioimmunoassay techniques. Results. The boys with CF were slightly older, lighter in body weight, and shorter. Serum and salivary testosterone concentrations were lower in the CF group than in the control group. A significant correlation was found between serum and salivary testosterone levels for boys with CF (r = .84) and for the control boys (r .86). Mean salivary testosterone increased as age progressed and as Tanner stage advanced. Conclusions. These results demonstrate that salivary testosterone measurements correlate well with serum values in male adolescents with CF and can be used in the monitoring of pubertal status.