Quantitative Rheed Analysis of Biaxially-Textured Polycrystalline MgO Films on Amorphous Substrates Grown by Ion Beam-Assisted Deposition

We have developed a computer simulation based on analytic calculation of reflection high energy electron diffraction (RHEED) patterns in the kinematic approximation for mosaic polycrystalline films for given values of electron beam incidence angle, polycrystalline texture, in-plane orientation distribution, and grain size. Although RHEED is most appropriately modeled using dynamical scattering theory, the computational efficiency of the kinematic approximation has enabled the development of a model suitable for real time measurement of crystallographic texture and in-plane orientation distributions for biaxially-textured films grown by ion beam-assisted deposition (IBAD). Using the simulation, we can quantitatively determine how RHEED spot shapes and relative intensities depend on the crystallographic texture and in-plane orientation distribution of polycrystalline films. RHEED patterns taken at 25 keV with incidence angle in the range 1–5 degrees from 10 nm thick, nominally [100]-textured MgO films grown on amorphous Si3N4 by IBAD were analyzed by comparing experimental RHEED phi rocking curves with those predicted by the simulation. For some films, an additional 200 nm thermally-grown MgO homoepitaxial layer was grown on top of the IBAD MgO layer. The model enables a quantitative correlation between biaxial texture and RHEED measurements. RHEED results are compared to X-ray rocking curve film analysis.

Effect of whole body resistance training on arterial compliance in young men

The effect of resistance training on arterial stiffening is controversial. We tested the hypothesis that resistance training would not alter central arterial compliance. Young healthy men (age, 23 +/- 3.9 (mean +/- s.e.m.) years; n = 28,) were whole-body resistance trained five times a week for 12 weeks, using a rotating 3-day split-body routine. Resting brachial blood pressure (BP), carotid pulse pressure, carotid cross-sectional compliance (CSC), carotid initima-media thickness (IMT) and left ventricular dimensions were evaluated before beginning exercise (PRE), after 6 weeks of exercise (MID) and at the end of 12 weeks of exercise (POST). CSC was measured using the pressure-sonography method. Results indicate reductions in brachial (61.1 +/- 1.4 versus 57.6 +/- 1.2 mmHg; P < 0.01) and carotid pulse pressure (52.2 +/- 1.9 versus 46.8 +/- 2.0 mmHg; P < 0.01) PRE to POST. In contrast, carotid CSC, beta-stiffness index, IMT and cardiac dimensions were unchanged. In young men, central arterial compliance is unaltered with 12 weeks of resistance training and the mechanisms responsible for cardiac hypertrophy and reduced arterial compliance are either not inherent to all resistance-training programmes or may require a prolonged stimulus.

Endothelial function of young healthy males following whole body resistance training

Given the increasing emphasis on performance of resistance exercise as an essential component of health, we evaluated, using a prospective longitudinal design, the potential for resistance training to affect arterial endothelial function. Twenty-eight men (23 +/- 3.9 yr old; mean +/- SE) engaged in 12 wk of whole body resistance training five times per week using a repeating split-body 3-day cycle. Brachial endothelial function was measured using occlusion cuff-induced flow-mediated dilation. After occlusion of the forearm for 4.5 min, brachial artery dilation and postocclusion blood flow was measured continuously for 15 and 70 s, respectively. Peak and 10-s postocclusion blood flow, shear rate, and brachial artery flow-mediated dilation (relative and normalized to shear rate) were measured pretraining (Pre), at 6 wk of training (Mid), and at 13 wk of training (Post). Results indicated an increase of mean brachial artery diameter by Mid and Post vs. Pre. Peak and 10-s postocclusion blood flow increased by Mid and remained elevated at Post; however, shear rates were not different at any time point. Relative and normalized flow-mediated dilation was also not different at any time point. This study is the first to show that peripheral arterial remodeling does occur with resistance training in healthy young men. In addition, the increase in postocclusion blood flow may indicate improved resistance vessel function. However, unlike studies involving endurance training, flow-mediated dilation did not increase with resistance training. Thus arterial adaptations with high-pressure loads, such as those experienced during resistance exercise, may be quite different compared with endurance training.

Transplantation of transduced chondrocytes protects articular cartilage from interleukin 1-induced extracellular matrix degradation

Gene therapy used in the context of delivering a therapeutic gene(s) to chondrocytes offers a new approach for treating chondrocyte-mediated cartilage degradation associated with various human arthropathies including osteoarthritis. In this study, gene delivery to human osteoarthritis chondrocytes in monolayer culture was demonstrated using two adenoviral vectors (Ad.CMVlacZ and Ad.RSVntlacZ) carrying the Escherichia coli beta-galactosidase marker gene, and a third vector (Ad.RSV hIL-1ra) containing the cDNA for human interleukin-1 receptor antagonist. At an moi of 10(3) plaque-forming units/chondrocyte, > 90% of the infected cells stained positive for E. coli beta-galactosidase activity, indicating a high efficiency of transduction. Genetically modified chondrocytes were then transplanted onto the articular surface of osteoarthritic cartilage organ cultures with and without the underlying subchondral bone. Both in situ staining of the cartilage organ cultures for E. coli beta-galactosidase activity and examination by scanning electron microscopy indicated that the transplanted chondrocytes adhered and integrated into the articular surface and continued to express transgenic protein. Chondrocytes transduced with Ad.RSV hIL-1ra and seeded onto the surface of osteoarthritic cartilage secreted high levels of biologically active IL-1 receptor antagonist. The Ad.RSV hIL-1ra-treated cartilage samples were resistant to IL1-induced proteoglycan degradation over 10 d of sustained organ culture. These data demonstrate that transplantation of transduced chondrocytes onto the articular surface protects cartilage from IL-1-induced extracellular matrix degradation.

A recombinant adenoviral vector expressing a soluble form of VCAM-1 inhibits VCAM-1/VLA-4 adhesion in transduced synoviocytes

Intra-articular injection of recombinant adenovirus has been shown to be a feasible approach to the introduction of genetic reagents into synovial tissues in vivo. Rheumatoid arthritis (RA) is an autoimmune disorder characterized by the infiltration of lymphocytes and monocytes into inflamed synovium. It has been hypothesized that the recruitment of T lymphocytes/monocytes into sites of chronic inflammation is mediated by enhanced binding of very late antigen-4 (VLA-4) to vascular cell adhesion molecule-1 (VCAM-1) expressed on microvascular endothelial cells. Additional evidence suggests that VLA-4 binding continues to be important within the inflamed synovial membrane, where it appears to play a role in T cell retention and activation. A feasible therapeutic strategy for RA could be to utilize a soluble congener of the VCAM-1 molecule to block VLA-4 binding. In order to test this concept, a recombinant serotype Ad5 human adenovirus encoding a secreted form of VCAM-1 (Ad.CBsVCAM) was constructed. Human synoviocytes were readily infected in vitro with Ad.CBsVCAM, and sVCAM-1 expression and processing were analyzed by immunoprecipitation studies. Secretion of transgenic sVCAM was identified by ELISA of tissue culture supernatants, and biological activity was demonstrated with cell adhesion assays. In vivo, transgenic sVCAM-1 expression was determined by immunohistochemical analysis and in situ hybridization of synovial tissue, and secretion of transgenic sVCAM-1 was demonstrated by ELISA of tidal knee lavage fluid. The results showed that recombinant adenovirus can mediate the expression of a biologically active sVCAM-1 by synoviocytes in vivo and suggest that this strategy may be useful for inhibiting T lymphocyte retention and activation within rheumatoid synovium.

Inhibition of interleukin-1-induced effects in synoviocytes transduced with the human IL-1 receptor antagonist cDNA using an adenoviral vector

In this report, we present data showing that a recombinant adenoviral vector (Ad.RSVIL-1ra) containing the cDNA for human interleukin-1 receptor antagonist protein (IL-1ra) can genetically modify synoviocytes both in vitro and in vivo. Human synoviocytes infected with Ad.RSVIL-1ra in vitro expressed and secreted high levels of human IL-1ra that were detected by ELISA of tissue culture supernatants. New Zealand White rabbits that received intra-articular injections of Ad.RSVIL-1ra expressed transgenic IL-1ra in synoviocytes, and secretion was detected for at least 4 weeks post-infection. Further, biological activity of the transgenic IL-1ra was demonstrated by its ability to inhibit IL-1-induced prostaglandin E2 (PGE2) synthesis in vitro and IL-1-induced glycosaminoglycan (GAG) degradation in vivo. These data demonstrate that recombinant adenoviral vectors can mediate the intra-articular expression of anti-inflammatory proteins and may be a reasonable method to deliver therapeutically relevant proteins for the regional treatment of synovial inflammation.

Expression of Escherichia coli beta-galactosidase and rat HPRT in the CNS of Macaca mulatta following adenoviral mediated gene transfer

Adenoviral-mediated gene transfer to the caudate nucleus of Macaca mulatta was accomplished using stereotactic injection of two distinct recombinant Ad5 vectors containing the gene for Escherichia coli beta-galactosidase and the cDNA for rat hypoxanthine-guanine phosphoribosylphosphotransferase (HPRT), respectively. Multiple analyses (including immunohistochemistry, histochemistry, transmission electron microscopy, RNA in situ hybridization, nucleotide pool analysis, and enzyme assay) confirmed efficient expression of beta-galactosidase and rat HPRT. Transgene expression was evident in both neurons and glia. Clinically, no evidence of meningitis or cerebritis was observed and no focal neurological deficits were detected in the animal. These preliminary studies indicate that recombinant adenovirus is capable of mediating high level transgene expression to the brains of higher order mammals.

Adenoviral-mediated gene transfer to rabbit synovium in vivo

Currently, treatment for rheumatoid arthritis and other inflammatory arthropathies is often ineffective in ameliorating the progression of the disease, particularly the invasive destruction of cartilage and bone by rheumatoid synovium. Multiple aspects of this inflammatory process are mediated by the synovial lining cells (synoviocytes). Genetic modification of these cells in vivo represents a potential method for the treatment of these conditions. In this report, we describe a novel technique for the genetic transduction of synovial lining cells in vivo using recombinant adenoviral vectors and intraarticular injection techniques. Purified high titer suspensions of a recombinant adenoviral vector containing the gene for Escherichia coli beta-galactosidase (AdCMVlacZ) were directly injected into the hind knees of New Zealand white rabbits. Synovial tissues were then examined for transgenic lacZ expression using a combination of in situ staining for beta-galactosidase activity, immunohistochemical staining, and transmission electron microscopy. High efficiency gene transfer and lacZ expression was observed in both type A and type B synoviocytes throughout the articular and periarticular synovium of the rabbit knee, with continued expression of transgenic lacZ detected for > or = 8 wk after infection.