Release of adsorbed fibronectin from temperature-responsive culture surfaces requires cellular activity

We have previously developed a temperature-responsive cell culture surface by grafting poly(N-isopropylacrylamide) that changes its surface hydrophobicity in response to temperature. While this surface shows similar hydrophobicity to that of commercial polystyrene cell culture surfaces and facilitates cell adhesion and proliferation at 37 degrees C, grafted polymer becomes hydrophilic below 32 degrees C and releases spread cultured cells without trypsin. Temperature-regulated cell detachment requires cell metabolic activity requiring ATP consumption, signal transduction, and cytoskeleton reorganziation. Precoating these surfaces with fibronectin (FN) improves spreading of less adhesive cultured hepatocytes and reducing culture temperature releases cultured cells from FN-adsorbed grafted surfaces. Immunostaining with anti-FN antibody revealed that only FN located beneath cultured cells is removed from culture surfaces after reducing temperature. FN adsorbed to surface areas lacking direct cell attachment remained surface-bound after reducing temperature. A novel concept of active cell detachment is also discussed.     

Correlation between Hydroxyapatite Crystallite Orientation and Ultrasonic Wave Velocities in Bovine Cortical Bone

The mineral component of bone is mainly composed of calcium phosphate, constituting 70% of total bone mass almost entirely in the form of hydroxyapatite (HAp) crystals. HAp crystals have a hexagonal system and uniaxial elastic anisotropy. The objective of this study was to investigate the effect of HAp crystallite preference on macroscopic elasticity. Ultrasonic longitudinal wave velocity and the orientation of HAp crystallites in bovine cortical bone are discussed, considering microstructure, density, and bone mineral density (BMD). Eighty cube samples of cortical bone were made from two bovine femurs. The orientation of HAp crystallites was evaluated by integrated intensity ratio of (0002) peak using an X-ray diffractometer. Ultrasonic longitudinal wave velocity was investigated with a conventional pulse system. The intensity ratio of HAp crystallites and velocity were measured in three orthogonal directions; most HAp crystallites aligned in the axial direction of the femurs. Our results demonstrate a linear correlation between velocity and intensity ratio in the axial direction. Significant correlation between velocity and BMD values was observed; however, the correlation disappeared if we focused on the identical type of microstructure. In conclusion, differences in microstructure type have an impact on density and BMD, which clearly affects the velocity. In addition, at the nanoscopic level, HAp crystallites aligned in the axial direction also affected the velocity and anisotropy.     

Parathyroid hormone increases the expression level of matrix metalloproteinase-13 in vivo

Parathyroid hormone (PTH) increases serum calcium (Ca) by enhancing bone resorption and renal Ca reabsorption. However, detailed mechanisms of enhanced bone resorption by PTH remain to be elucidated. Although PTH has been shown to increase the expression level of osteoblastic matrix metalloproteinase (MMP)-13 in vitro, only limited results are available regarding the in vivo regulation of MMP expression. In the present study, we have examined expression levels of MMPs in PTH-infused rats. Infusion of 1.5 or 2.0 nmol/kg/day rat PTH(1–34) for 3 days resulted in a dose-dependent increase in serum Ca. PTH infusion also decreased serum phosphate levels and increased urinary excretion of Ca and phosphate. Infusion of PTH for 7 days resulted in less severe hypercalcemia and hypophosphatemia. Urinary Ca and phosphate excretion in rats infused for 7 days was less than that in rats infused for 3 days. Northern blot analysis showed that PTH infusion increased the expression level of MMP-13 in calvaria, although it did not affect MMP-2 expression. Furthermore, the time-course and severity of hypercalcemia and hypercalciuria correlated with the expression level of MMP-13. In situ hybridization also showed that PTH infusion increased the expression level of MMP-13 in femora. These results indicate that PTH enhances MMP-13 expression in vivo and suggest that PTH stimulates bone resorption at least partly by enhancing MMP-13 expression. Received: June 5, 2000 / Accepted: January 12, 2001     

A novel Doppler echocardiographic score reflecting cardiac functional status can predict adverse outcome in acute myocardial infarction

BACKGROUND: E/e' and s' are thought to reflect left ventricular diastolic and systolic function, respectively. However, there are no reports on the combined use of E/e' and s' in predicting the outcome in acute myocardial infarction (AMI). METHODS: For 20?months beginning in October 2006, we enrolled 65 AMI patients who had undergone Swan-Ganz (SG) catheterization and echocardiography just after reperfusion therapy. We measured the cardiac index (CI) and the pulmonary capillary wedge pressure (PCWP) via an SG catheter and determined routine echocardiographic indices, including transmitral flow velocity (E), mitral annulus velocities at systole (s') and early diastole (e'), and E/e'. In addition, we rounded off the values of s' (cm/s) and E/e' (ratio of cm/s to cm/s) to the nearest integer, and designated them the s'-score and E/e'-score, respectively. We also defined the cardiac status score as the s'-score subtracted from the E/e'-score. In Study 1, we investigated the relationships between hemodynamic parameters (CI and PCWP) and echocardiographic indices, including the cardiac status score. In Study 2, we excluded patients with Killip class ≥II, yielding a final study population of 55 patients in whom we investigated whether the cardiac status score could predict adverse cardiac events. RESULTS: Only the cardiac status score significantly correlated with both the PCWP and the CI. In the Cox proportional hazards model, significant predictors were the left ventricular ejection fraction (LVEF), estimated glomerular filtration rate (eGFR), and cardiac score ≥3.0. CONCLUSIONS: The novel score achieved in this study by subtracting the s'-score from the E/e'-score could be highly useful for predicting outcomes in AMI with Killip class I.     

Bronchoplastic procedures for lung cancer

Bronchoplastic procedures for patients with lung cancer are designed to achieve radical cure with preservation of functioning lung parenchyma. The operative results of 139 cases of lung cancer who underwent bronchoplasty between 1963 through 2007 were reviewed. The mean age of the patients was 62.5 years (range, 20 to 78 years). Sleeve lobectomy (SL) was performed in 119 cases, wedge lobectomy (WL) in 10 cases, sleeve segmentectomy (SS) in 5 cases, wedge segmentectomy (WS) in 2 cases, sleeve resection (SR) in 2 cases, and wedge resection (WR) in 1 case. Squamous cell carcinoma was the most frequently encountered histological type of disease (78%), followed by adenocarcinoma (12%) and other histological types (10%). The tumor was central in 125 patients (90%) and peripheral with nodal involvement in 14 patients (10%). Vascular resection and reconstruction was performed in 16 patients. Early major bronchial anastomotic complications occurred in 6 patients (4.3%). The 5-year survival rate in the patients with squamous cell carcinoma was 63.2%, and in patients with adenocarcinoma was 26.3%. SS for patients with early-stage squamous cell carcinoma of the segmental bronchus is a curative operation with preservation of the pulmonary function. Bronchoplasty without lung resection (SR, WR) is a reliable method for patients with low-grade malignant polypoid tumors arising from the bronchus. Patients with adenocarcinoma, N2 disease or major bronchial anastomotic complication show a worse prognosis.