Membrane Surface Nanostructures and Adhesion Property of T Lymphocytes Exploited by AFM

The activation of T lymphocytes plays a very important role in T-cell-mediated immune response. Though there are many related literatures, the changes of membrane surface nanostructures and adhesion property of T lymphocytes at different activation stages have not been reported yet. However, these investigations will help us further understand the biophysical and immunologic function of T lymphocytes in the context of activation. In the present study, the membrane architectures of peripheral blood T lymphocytes were obtained by AFM, and adhesion force of the cell membrane were measured by acquiring force–distance curves. The results indicated that the cell volume increased with the increases of activation time, whereas membrane surface adhesion force decreased, even though the local stiffness for resting and activated cells is similar. The results provided complementary and important data to further understand the variation of biophysical properties of T lymphocytes in the context of in vitro activation

Enhanced Growth and Osteogenic Differentiation of Human Osteoblast-Like Cells on Boron-Doped Nanocrystalline Diamond Thin Films

Intrinsic nanocrystalline diamond (NCD) films have been proven to be promising substrates for the adhesion, growth and osteogenic differentiation of bone-derived cells. To understand the role of various degrees of doping (semiconducting to metallic-like), the NCD films were deposited on silicon substrates by a microwave plasma-enhanced CVD process and their boron doping was achieved by adding trimethylboron to the CH4:H2 gas mixture, the B∶C ratio was 133, 1000 and 6700 ppm. The room temperature electrical resistivity of the films decreased from >10 MΩ (undoped films) to 55 kΩ, 0.6 kΩ, and 0.3 kΩ (doped films with 133, 1000 and 6700 ppm of B, respectively). The increase in the number of human osteoblast-like MG 63 cells in 7-day-old cultures on NCD films was most apparent on the NCD films doped with 133 and 1000 ppm of B (153,000±14,000 and 152,000±10,000 cells/cm2, respectively, compared to 113,000±10,000 cells/cm2 on undoped NCD films). As measured by ELISA per mg of total protein, the cells on NCD with 133 and 1000 ppm of B also contained the highest concentrations of collagen I and alkaline phosphatase, respectively. On the NCD films with 6700 ppm of B, the cells contained the highest concentration of focal adhesion protein vinculin, and the highest amount of collagen I was adsorbed. The concentration of osteocalcin also increased with increasing level of B doping. The cell viability on all tested NCD films was almost 100%. Measurements of the concentration of ICAM-1, i.e. an immunoglobuline adhesion molecule binding inflammatory cells, suggested that the cells on the NCD films did not undergo significant immune activation. Thus, the potential of NCD films for bone tissue regeneration can be further enhanced and tailored by B doping and that B doping up to metallic-like levels is not detrimental for cells

Determine the prevalence of coronary artery disease (CAD) risk factors in depressed retired population

Background: Coronary artery disease (CAD) accounts for nearly 50 percent of all deaths per year in Iran. Method: This study was performed to determine the prevalence of CAD risk factors in 300 Iranian depressed retired populations between ages of 50-70 years who were recruited with cluster random sampling. Demographic data and risk factors were determined by taking history, laboratory tests and physical examination. Results: Average age was 60.73. There was 162 females (54) and 138 males(46). 19(6.3) of participants were diabetic, 36(12) were smoker, and 63(21) had positive familial heart disease history. 183(61) had Total cholesterol level>200 mg/dl, 96 (32) triglyceride>200 mg/dl, 142(47.3) LDL-C>130 mg/dl, 16(5.3) HDL-C140 mmHg, 27(9) diastolic blood pressure>90 mmHg. Conclusion: The incidence of coronary artery disease is rapidly increasing, and risk factors such as Hypertension had the strongest association with CAD in our retired population. Medical treatment was recommended to the retired people

Osteochondral regeneration of a critical size defect in a minipig model using adipose-derived stem cells in association with an hydrogel of oligo(polyethylene glycol) fumarate

Summary. Autologous and heterologous adipose derived stem cells associated to an oligo(polyethylene glycol) fumarate hydrogel scaffold are able to promote a complete regeneration of the subchondral bone and a cartilage-like tissue in a critical osteochondral defect in a minipig model Introduction. Osteochondral tissue loss caused by high-energy trauma, disease, and tumor resection have always been a very troublesome problem for orthopedic surgeons. During normal bone defect healing, undifferentiated mesenchymal stem cells, in the presence of suitable stimuli, proliferate and differentiate into osteoblasts and chondrocytes forming bone tissue and cartilage, and repairing the injury. However, in some cases, defects fail to healing and surgical intervention is often required. Tissue engineering is an innovative approach that overcome the standard surgical procedures, to achieve the regeneration of bone and cartilage tissues. Adipose-derived Stem Cells (ASCs), isolated from the stromal vascular fraction derived from subcutaneous fat tissue, show a multi-differentiative ability which may be exploited, alone or in association with suitable scaffolds, as novel and efficient tools for bone and cartilage regeneration. Methods. ASCs, isolated from seven adult male minipigs, expanded in culture, were used to repair a critical femoral osteochondral defect in association with an hydrogel scaffold of oligo(polyethylene glycol) fumarate (OPF). In the peripheral part of the trochlea of each animals four defects (diameter 9mm, depth 8mm) were created, and then treated with constructs made of OPF scaffold pre-seeded with either autologous or heterologous ASCs. Untreated defects and defects filled by just scaffold were included as controls. Results. ASCs were rapidly isolated with an average of 6.45x104\ub14.34x104 per ml of processed adipose tissue. All the swine ASC populations were analyzed in vitro: their doubling times were of 59.2\ub116.6 hours and their clonogenic ability was stable and greater than human ASCs (15.7\ub18.2%). Their osteogenic differentiation ability was shown by collagen production and extracellular calcified matrix deposition (+136% and +70% of osteo- vs undifferentiated ASCs, respectively). 4 weeks after subcutaneous fat withdrawal, constructs made with 3x106 of either autologous or heterologous undifferentiated ASCs were implanted in the bone defects. No side-effects have been observed during the follow up and 6 months later, animals were sacrificed and knees explanted. Gross appearance analyses showed quite satisfactory filling of the lesions in all the samples, with the exception of one animal, whose joint appeared infected and not healed. Good osteointegration was observed by MRI evaluation. Histological and immunohistochemical analyses revealed an increased expression of collagen type II in the ASCs+OPF treated groups compared to the groups treated with the OPF hydrogel alone. In addition, biomechanical analyses confirmed the histological results showing an improved elastic module of the new formed cartilage tissue. Conclusion. ASCs were able to promote a quite complete regeneration of the subchondral bone and a cartilage-like tissue and might be considered a treatment option for the regeneration of osteochondral defects. Moreover, since no differences were observed between autologous and heterologous constructs, the possibility of an allogeneic use of these cells is also supported and encouraging for a future clinical practice