The whole thigh muscles are covered with the fascia lata, which could have morphological and mechanical features that match the underlying muscles' functions. In this study, we investigated the morphological and elastic properties of the human fascia lata taken from four (anterior, medial, lateral, and posterior) sites on the thigh of 17 legs of 12 cadavers (6 males and 6 females, 75-92 years). The thickness of the fascia lata was determined with a caliper. The interwoven collagen fiber's directions were measured and classified into longitudinal, transverse, and diagonal in two opposing directions, relative to the thigh. Tensile strength test along the longitudinal and transverse directions was performed, and the stiffness, Young's modulus, and hysteresis were determined. Fascia lata at the lateral site (0.8 ± 0.2 mm) was significantly thicker compared to other sites (0.2-0.3 mm). Fiber's directions showed substantial variability among sites, and longitudinally directed fibers were higher in proportion (28-32%) than those in other directions (20-27%) at all sites except for the posterior site. The stiffness and Young's modulus in the longitudinal direction (20-283 N/mm; 71.6-275.9 MPa, highest at the lateral site) were significantly higher than in the transverse direction (3-16 N/mm; 3.2-41.9 MPa, lowest at the lateral site). At the medial site, the proportion of the transversely directed fibers was higher in females than males, with higher stiffness and Young's modulus thereof. The present study shows that the fascia lata possesses site- and gender-dependence of the morphological characteristics and elastic properties.

Background: A chronic subdural hematoma (CSDH) is considered to be an inflammatory and angiogenic disease. The CSDH outer membrane, which contains inflammatory cells, plays an important role in CSDH development. Osteopontin (OPN) is an extracellular matrix protein that is cleaved by thrombin, generating the N-terminal half of OPN, which is prominently involved in integrin signal transduction. We explored the expression of the N-terminal half of OPN in CSDH fluid and the expression of integrins α9 and β1 and the downstream components of the angiogenic signaling pathways in the outer membrane of CSDHs. Methods: Twenty samples of CSDH fluid and eight samples of CSDH outer membrane were collected from patients suffering from CSDHs. The concentrations of the N-terminal half of OPN in CSDH fluid samples were measured using ELISA kits. The expression levels of integrins α9 and β1, vinculin, talin-1, focal adhesion kinase (FAK), paxillin, α-actin, Src and β-actin were examined by Western blot analysis. The expression levels of integrins α9 and β1, FAK and paxillin were also examined by immunohistochemistry. We investigated whether CSDH fluid could activate FAK in cultured endothelial cells in vitro. Results: The concentration of the N-terminal half of OPN in CSDH fluid was significantly higher than that in the serum. Western blot analysis confirmed the presence of these molecules. In addition, integrins α9 and β1, FAK and paxillin were localized in the endothelial cells of vessels within the CSDH outer membrane. FAK was significantly phosphorylated immediately after treatment with CSDH fluid. Conclusion: Our data suggest that the N-terminal half of OPN in CSDH fluid promotes neovascularization in endothelial cells through integrins α9 and β1. The N-terminal half of OPN, which is part of the extracellular matrix, plays a critical role in the promotion of CSDHs.

In this study, after confirming the suppression of autonomic nervous function by isoflurane anesthesia using autonomic antagonists, we pharmacologically investigated the involvement of vasomotor and cardiac sympathetic functions in systolic blood pressure variability (SBPV) frequency components in conscious rats at rest and during exposure to low-ambient temperature (LT-exposure, 9°C for 90 min). Under unanesthesia, phentolamine administration (α-adrenoceptor antagonist, 10 mg/kg) decreased the mid-frequency component (MF 0.33–0.73 Hz) and inversely increased the high-frequency component (HF 1.3–2.5 Hz). The increased HF was suppressed by subsequent treatment with atenolol (β-adrenoceptor antagonist, 10 mg/kg), but not with atropine (muscarinic receptor antagonist, 10 mg/kg). Moreover, phentolamine administration after atenolol decreased MF, but did not increase HF. LT-exposure increased MF and HF; however, phentolamine pretreatment suppressed the increased MF during LT-exposure, and atenolol pretreatment dose-dependently decreased the increased HF. These results suggest that MF and HF of SBPV may reflect α-adrenoceptor-mediated vasomotor function and β-adrenoceptor-mediated cardiac sympathetic function, respectively, in the conscious state.

Chronic subdural hematoma (CSDH) is an angiogenic disease that is involved with many inflammatory mediators. Tie2 is predominantly expressed in the embryonic endothelium and plays an important role in the maturation and stabilization of the vasculature. Angiopoietin (Ang)1 and Ang2 are well-known ligands of the Tie2 receptor. We examined the expression of Ang1 and Ang2 in CSDH fluid and the expression of Tie-2 receptor and components of the angiogenic signaling pathways in the outer membrane of CSDH. Twenty-five samples of CSDH fluid and eight samples of outer membrane of CSDH were included. The concentrations of Ang1 and Ang2 in the CSDH fluid were measured using enzyme-linked immunosorbent assay (ELISA) kits. The expression of Tie2, phosphoinositide 3-kinase (PI3K), protein kinase B (Akt) mechanistic target of rapamycin (mTOR), GβL, 70 kDa ribosomal protein S6 kinase (p70S6K), eukaryotic initiation factor 4E (eIF-4E), and β-actin was examined by a Western blot analysis. The expression of Tie2, Akt, and mTOR was also examined by immunohistochemistry. The concentration of Ang2 in CSDH fluid was significantly higher than that in the serum or cerebrospinal fluid (CSF), and also higher than that of Ang1 in CSDH fluid. Tie2, PI3K, Akt, mTOR, GβL, p70S6K, and eIF-4E were detected in all cases. In addition, Tie2, Akt, and mTOR were localized in the endothelial cells of vessels in the CSDH outer membrane. Our data suggest that Ang2, although not Ang1, in CSDH fluid promotes angiogenesis in endothelial cells through the Tie2 receptor. The Ang2/Tie2 signaling pathway might therefore be a useful therapeutic target for treating the growth of intractable CSDH.