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A surf zone with large breaking waves produces more spray than do offshore regions. Latent heat of spray evaporation causes change in the surrounding temperature and wind velocity, resulting in further alterations in temperature, wind velocity and heat flux. Spray in a surf zone with large breaking waves may have unignorable effect on determination of a local meteorological field because of this interconnected relationship as well as its higher population than in the open ocean. In this study, the effects of the spray latent heat on a meteorological field were investigated. The authors propose a method for estimating latent heat of spray vaporization over the ocean. The method was applied to a meso-scale meteorological model to perform numerical experiments with consideration of heat flux by spray. Although the contribution of heat flux on the ocean was as small as 2.5%, fluctuations of air temperature and wind velocity increased over time due to the effects of spray. The fluctuations are thought to cause uncertainty in weather prediction. Numerical experiments with spray provided predictions of air temperature and wind velocity near a coast line that were consistent with observational data, especially when the population of spray droplets increased by two orders of magnitude as is often observed in a coastal area.

The purpose of this paper is to prove the reliability of artificial hip joints’ surface generated by the electrolytically treated grinding process; the evaluation was carried out in a hip simulator and animal tests. The evaluation indicated that the fabricated hyper-hemispherical shaped artificial hip joints presented a high quality smoother surface than 10 nm in Ra. The fabricated surface also showed its ability to prevent crystalline phase transition during the hip simulation test, suggesting that the stably modified layer was generated via grinding process. The results of animal test showed that the fabricated surface could have a highly-improved biocompatibility.

Toolpath generation for a multi-axis medical machine tool is a challenging task. In surgical procedures, it is difficult to apply industrial CAM technology owing to the requirement for quick toolpath generation and the likelihood of tool interference with complex structures of the target area. The objectives of this study are to optimize the initial position and posture of the cutting tool for performing the ideal skin incision and to minimize contact between the cutting tool and the surrounding area. We propose a novel toolpath strategy based on geometric models. It can be potentially applied to general machine-assisted surgeries.

Basic fibroblast growth factor (bFGF) and growth and differentiation factor (GDF)-5 stimulate the healing of medial collateral ligament (MCL) injury. However, the effect of isolated and combined use of bFGF/GDF-5 remains still unclear. We investigated cellular proliferation and migration responding to bFGF/GDF-5 using rabbit MCL fibroblasts. Rabbit MCL injury was treated by bFGF and/or GDF-5 with peptide hydrogels. Gene expression and deposition of collagens in healing tissues were evaluated. bFGF/GDF-5 treatment additively enhanced cell proliferation and migration. bFGF/GDF-5 hydrogels stimulated Col1a1 expression without increasing Col3a1 expression. Combined use of bFGF/GDF-5 stimulated type I collagen deposition and the reorganization of fiber alignment, and induced better morphology of fibroblasts in healing MCLs. Our study indicates that combined use of bFGF/GDF-5 might enhance MCL healing by increasing proliferation and migration of MCL fibroblasts, and by regulating collagen synthesis and connective fiber alignment.

Biomechanical stimuli have fundamental roles in the maintenance and remodeling of ligaments including collagen gene expressions. Mechanical stretching signals are mainly transduced by cell adhesion molecules such as integrins. However, the relationships between stress-induced collagen expressions and integrin-mediated cellular behaviors are still unclear in anterior cruciate ligament cells. Here, we focused on the stretch-related responses of different cells derived from the ligament-to-bone interface and midsubstance regions of human anterior cruciate ligaments. Chondroblastic interface cells easily lost their potential to produce collagen genes in non-stretched conditions, rather than fibroblastic midsubstance cells. Uni-axial mechanical stretches increased the type I collagen gene expression of interface and midsubstance cells up to 14- and 6-fold levels of each non-stretched control, respectively. Mechanical stretches also activated the stress fiber formation by shifting the distribution of integrin alphaVbeta3 to the peripheral edges in both interface and midsubstance cells. In addition, integrin alphaVbeta3 colocalized with phosphorylated focal adhesion kinase in stretched cells. Functional blocking analyses using anti-integrin antibodies revealed that the stretch-activated collagen gene expressions on fibronectin were dependent on integrin alphaVbeta3-mediated cellular adhesions in the interface and midsubstance cells. These findings suggest that the integrin alphaVbeta3-mediated stretch signal transduction might have a key role to stimulate collagen gene expression in human anterior cruciate ligament, especially in the ligament-to-bone interface.

Optimal control of the machining process in orthopedic surgery can not only increase productivity but also ensure safety during tool usage. The authors have developed a technology for a force control system. The system has two modes of operation: the “air-cutting mode” and the “force control mode.” In the air-cutting mode, tool feed is scheduled by predicting the air and bone-cutting zones from the CAD/CAM system. In the force control mode, the software monitors the cutting force and the cutting temperature, and it controls the feed override according to the difference between the real and the desired cutting force. The software is installed on a robot controller, and its effectiveness is evaluated with a urethane bone.

We prospectively evaluated the disease-specific features of the early postoperative plasma D: -dimer value and the relationship with deep venous thrombosis and/or pulmonary thromboembolism (DVT/PE) in 95 patients following total knee arthroplasty. Patients in whom DVT/PE was highly suspected were diagnosed by high-resolution multi-detector row computed tomography scanning (MDCT). Forty-nine knees in 46 patients with rheumatoid arthritis (RA, 24 knees) or osteoarthritis (OA, 25 knees) were finally recruited. DVT/PE was detected in 28 (57.1%) of the 49 cases examined by diagnostic MDCT: 12 (50.0%) of the 24 cases of RA, and 16 (64.0%) of the 25 cases of OA. Of these, PE was found in 11 cases (39.2%), but none of them showed clinical symptomatic signs of dyspnea or chest pain. In both RA and OA cases, there were statistically significant differences in the D: -dimer value on postoperative day 3 (P = 0.027) and after day 28 (P = 0.037) between the groups with and without DVT/PE. In OA cases, there were significant differences between the two groups on postoperative days 1 (P = 0.034), 3 (P = 0.020), 5 (P = 0.005), and 7 (P = 0.045), respectively. At the baseline, perioperative D: -dimer levels in the RA group without DVT/PE were higher than in the OA group. However, multivariate logistic regression analysis showed that RA was not a significant risk factor of DVT/PE in comparison with OA. In conclusion, individual evaluation of the D: -dimer level between RA and OA should provide a more precise predictive indicator of early postoperative DVT/PE.

To differentiate benign from malignant bone tumors by analyzing the vascular distribution within bone tumors with dynamic contrast-enhanced MRI.We studied dynamic contrast-enhanced MRI for 49 bone tumors (22 malignant and 27 benign tumors). Seven small regions of interest (ROI) were set inside the largest portion of each tumor. Four ROI were placed evenly on the periphery and three ROI were placed evenly on the line of the longest breadth within the tumor. The slope of the curve (%Slope) was calculated on the time-intensity curves of the whole tumor and of each ROI. The variance values for the %Slope of the ROI were calculated to assess the dispersion of the intensity change at each ROI within the tumor.Mean value of the %Slopes of whole tumor regions for malignant bone tumors (70.4 +/- 60.3%) was significantly higher than that for benign bone tumors (37.6 +/- 52.9%) (P = 0.015), although giant cell tumor (GCT), a locally aggressive tumor, had a relatively higher %Slope. Mean value of the variance of %Slopes for malignant bone tumors (3485.9 +/- 5942.5) was significantly higher than that for all benign tumors (470.4 +/- 583.9) (P = 0.012), indicating that the %Slope values of seven ROI within malignant bone tumors varied more widely compared with the ROI inside benign bone tumors. GCT also demonstrated a lower value.Our method of analyzing the signal intensity change at seven separate regions that evaluates the vascular distribution within a tumor could be a useful tool for differentiating between benign and malignant bone tumors.

In successful knee arthroplasty, the femur and the tibia must be shaped to fit an artificial joint. The recent trend towards MIS (Minimally Invasive Surgery) to decrease the length of the required incision in the skin has increased surgical difficulty, since the open access area is small. The developed system consists of (1) a preplanning system providing a CAD function, (2) a multi-axis CAM system which avoids cutting the skin and the ligament, and keeps the cutting time within acceptable limits, and (3) a 7-axis machine tool that assures the safety of the patient and the surgeon, and enables MIS.

Regional gene therapy, which involves the delivery of growth factors to a specific anatomic site, has the potential to enhance bone formation in clinical application. Helper-dependent adenoviral vectors, which have deleted all of the viral coding regions, have been shown to be safe and highly efficient with long-lasting transgene expression. In this study, we constructed a helper-dependent adenoviral vector producing bone morphogenetic protein-2 (AdHDBMP-2). The AdHDBMP-2 increased the alkaline phosphatase activity of W-20-17 cells in vitro. In addition, when AdHDBMP-2 infected rat bone marrow cells were implanted into the hindlimbs of SCID mice, orthotopic bone formation was shown at 2 weeks. To our knowledge, this is the first study to demonstrate bone formation with the helper-dependent adenoviral vector with the BMP-2 expression cassette. This type of gene therapy vector could prove to be highly useful for bone augmentation in patients with bone loss associated with trauma, revision total joint arthroplasty, or cancer.

Clinical and radiographic studies were performed on 228 hips of 145 patients with avascular necrosis of the femoral head (ANFH). The patients were divided into three groups: group A consisted of 33 patients with systemic lupus erythematosus (SLE) who had been treated with systemic corticosteroids (59 hips); group B consisted of 41 patients with a history of corticosteroid treatment, excluding patients with SLE (69 hips); and group C consisted of 71 patients with no history of corticosteroid use (100 hips). Of the 228 hips, 80 hips at an early stage of the necrosis, but not showing collapse, were selected and classified by the criteria of the Japanese Investigation Committee (JIC) to define the natural history of the disease. In the SLE patients (group A), there was a predisposition to bilateral involvement and multiple sites of bone necrosis. Eighty percent of the femoral heads followed at an early stage had collapsed at the end of the follow-up, the incidence of collapse in group A being higher than that in the other groups. The collapses in group A were predominantly types 1C, 2, and 3B according to the JIC criteria. The incidence of collapse was significantly lower in type 1A and type 3A than in the other types. The classification proposed by the JIC, in terms of types with regard to size and location of the necrotic area on antero-posterior radiographs, was very useful for evaluation of the risk of collapse as well as for selecting appropriate treatment modalities, either conservative or surgical, during the early stages of ANFH.

We examined the differential expressions of collagen types IV, III and I in the developing feto-maternal placental tissue of pregnant rats by a combination of in situ hybridization and immunohistochemistry. At day 9.5 of gestation, polygonal invasive cytotrophoblasts from the ectoplacental cone, which was modifying the maternal central artery, revealed intensely expressed alpha 1 (IV) and alpha 1 (III) collagen mRNAs. The localization patterns of these translated products, collagen type IV and procollagen type III, were slightly different in the invasive cytotrophoblasts. Collagen type IV densely deposited intracellularly and intercellularly in the maternal central artery and in the thickened basement membranes of the cytotrophoblasts. However, expression of alpha 1 (I) collagen mRnA and procollagen type I was hardly detectable in the cytotrophoblasts. At day 13 of gestation, a high level of alpha 1 (IV) collagen mRNA was expressed in the cytotrophoblastic cell layer (trophospongium) and in the invasive large cytotrophoblasts. A moderate level of alpha 1 (III) collagen mRNA was also expressed mainly in the cytotrophoblasts, while alpha 1 (I) collagen mRNA was expressed at very low levels. Interestingly, procollagen type III failed to show linear immunoreactivity in the subepithelial extracellular matrix beneath the maternal artery with the invasive cytotrophoblasts. Additional quantitative analyses of these type IV, III, and I collagen mRNA levels in in situ hybridization experiments between several cell types also revealed significant differences individually. Electron-microscopic study detected no cross-striated collagen fibers in the thickened basement membrane-like structures adjacent to the invasive cytotrophoblasts. Fibrillar and basement membrane collagen gene expressions, their protein syntheses, and the processing of these procollagens seems to be developmentally regulated in the invasive cytotrophoblasts during the organization of feto-maternal placental tissue. The remodeling of the maternal central artery by the invasive cytotrophoblasts is important for ensuring the adequate blood supply to the developing placenta and fetus.