Associations between venous thromboembolism onset,D-dimer,and soluble fibrin monomer complex after total knee arthroplasty

Growth factors such as nerve growth factor (NGF) and insulin-like growth factor-1 (IGF-1) have been shown to play a role in the healing process of nerve injury. Recent researches have also shown that oxytocin administration activates these growth factors of importance for the healing of nerve tissue. The objective of the present study was to evaluate the effects of oxytocin on peripheral nerve regeneration in rats. Twenty-four male Sprague-Dawley rats were underwent transection damage model on the right sciatic nerve and defective damage model on the left sciatic nerve. The animals were assigned to one of two groups: control group or treatment group (received 80 mg/kg oxytocin intraperitoneally for 12 weeks). The sciatic nerve was examined, both functionally (on the basis of climbing platform test) and histologically (on the basis of axon count), 3, 6, 9, and 12 weeks after the injury. Also, stereomicroscopic and electrophysiological evaluations were carried out. Significantly greater improvements in electrophysiological recordings and improved functional outcome measures were presented in the treatment group at 12-week follow-up. Stereomicroscopic examinations disclosed prominent increases in vascularization on proximal cut edges in the oxytocin group in comparison with the control group. Higher axon counts were also found in this group. Intraperitoneal oxytocin administration resulted in accelerated functional, histological, and electrophysiological recovery after different sciatic injury models in rats.     

Transplantation of mesenchymal stem cells in a canine disc degeneration model

Transplantation of mesenchymal stem cells (MSCs) is effective in decelerating disc degeneration in small animals; much remains unknown about this new therapy in larger animals or humans. Fas‐ligand (FasL), which is only found in tissues with isolated immune privilege, is expressed in IVDs, particularly in the nucleus pulposus (NP). Maintaining the FasL level is important for IVD function. This study evaluated whether MSC transplantation has an effect on the suppression of disc degeneration and preservation of immune privilege in a canine model of disc degeneration. Mature beagles were separated into a normal control group (NC), a MSC group, and the disc degeneration (nucleotomy‐only) group. In the MSC group, 4 weeks after nucleotomy, MSCs were transplanted into the degeneration‐induced discs. The animals were followed for 12 weeks after the initial operation. Subsequently, radiological, histological, biochemical, immunohistochemical, and RT‐PCR analyses were performed. MSC transplantation effectively led to the regeneration of degenerated discs. FACS and RT‐PCR analyses of MSCs before transplantation demonstrated that the MSCs expressed FasL at the genetic level, not at the protein level. GFP‐positive MSCs detected in the NP region 8 weeks after transplantation expressed FasL protein. The results of this study suggest that MSC transplantation may contribute to the maintenance of IVD immune privilege by the differentiation of transplanted MSCs into cells expressing FasL. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:589–600, 2008     

Effect of cell number on mesenchymal stem cell transplantation in a canine disc degeneration model

Transplantation of mesenchymal stem cells (MSCs) inhibits the progression of disc degeneration in animal models. We know of no study to determine the optimal number of cells to transplant into the degenerated intervertebral disc (IVD). To determine the optimal donor cell number for maximum benefit, we conducted an in vivo study using a canine disc degeneration model. Autologous MSCs were transplanted into degenerative discs at 10⁵, 10⁶, or 10⁷ cells per disc. The MSC‐transplanted discs were evaluated for 12 weeks using plain radiography, magnetic resonance imaging, and gross and microscopic evaluation. Preservation of the disc height, annular structure was seen in MSC‐transplantation groups compared to the operated control group with no MSC transplantation. Result of the number of remaining transplanted MSCs, the survival rate of NP cells, and apoptosis of NP cells in transplanted discs showed both structural microenvironment and abundant extracellular matrix maintained in 10⁶ MSCs transplanted disc, while less viable cells were detected in 10⁵ MSCs transplanted and more apoptotic cells in 10⁷ MSCs transplanted discs. The results of this study demonstrate that the number of cells transplanted affects the regenerative capability of MSC transplants in experimentally induced degenerating canine discs. It is suggested that maintenance of extracellular matrix by its production from transplanted cells and/or resident cells is important for checking the progression of structural disruption that leads to disc degeneration. Published by Wiley Periodicals, Inc. J Orthop Res 28:1267–1275, 2010     

Low‐intensity pulsed ultrasound stimulation enhances TIMP‐1 in nucleus pulposus cells and MCP‐1 in macrophages in the rat

Recent studies have reported that low‐intensity pulsed ultrasound (LIPUS) stimulates cell proliferation and proteoglycan production in rabbit intervertebral disc cells, and moreover promotes the secretion of MCP‐1 (monocyte chemotaxis protein‐1) from macrophages in a disc organ culture model. These findings suggest the possible application of LIPUS for biological repair of disc degeneration and herniation. Although the mechanisms involved are not well understood, several cytokine pathways may play a role. Therefore, in order to evaluate the effect of LIPUS stimulation on cytokine production by nucleus pulposus cells and macrophages, in vitro culture studies were designed. Nucleus pulposus cells and macrophages were collected from Sprague‐Dawley rats, cultured separately in a monolayer, and stimulated with LIPUS for 7 days. After culture, the culture medium and the cells were analyzed by cytokine array, RT‐PCR, and ELISA. Cytokine array showed that LIPUS stimulation significantly upregulated TIMP‐1 (tissue inhibitor of metalloproteinase‐1) in the nucleus pulposus and MCP‐1 in macrophages in comparison with the control. This was confirmed at the gene level by RT‐PCR in nucleus pulposus cells and macrophages after stimulation with LIPUS. Quantitative evaluation of these proteins by ELISA showed higher levels in nucleus pulposus cells and macrophages stimulated by LIPUS than in controls. These results showed that LIPUS stimulation significantly activated TIMP‐1 and MCP‐1 in nucleus pulposus cells and macrophages at both the protein and gene levels, suggesting that LIPUS may be a promising supplemental treatment for intervertebral disc herniation. © 2008 Orthopaedic Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:865–871, 2008     

Metatarsal Periosteal Plantar Ganglion Cyst Associated With Stress Fracture: A Case Report

We encountered a rare case of a periosteal ganglion cyst at the plantar aspect of the metatarsal that induced a stress fracture in a 77-year-old female. The clinical manifestation of the plantar ganglion cyst of the foot was not evident because of its location deep beneath the plantar fascia. A pressure cortical indentation was detected at the metatarsal neck on the initial radiographs. Magnetic resonance imaging showed a stress fracture of the metatarsal with a ganglion cyst. The stress fracture was thought to have resulted from several factors, including structural weakness due to bony absorption from the ganglion cyst, osteoporosis that induced a fragility fracture, and a load-induced fatigue fracture. The fracture completely healed following complete resection of the ganglion cyst with the surrounding periosteum along with medication for osteoporosis. When confirmation of a stress fracture is necessary or when presentation of a stress fracture is atypical, magnetic resonance imaging should be considered to confirm or rule out any other associated pathologic features. Resection of the periosteal ganglion cyst with the surrounding periosteum is important to prevent recurrence.     

A New Powder Design Method to Improve Inhalation Efficiency of Pranlukast Hydrate Dry Powder Aerosols by Surface Modification with Hydroxypropylmethylcellulose Phthalate Nanospheres

Purpose. A new particle design method to improve the aerosolization properties of a dry powder inhalation system was developed using surface modification of hydrophobic drug powders (pranlukast hydrate) with ultrafine hydrophilic particles, hydroxypropylmethylcellulose phthalate (HPMCP) nanospheres. The mechanism of the improved inhalation properties of the surface-modified particles and their deposits on carrier particles (lactose) was clarified in vitro. Methods. Drug particles were introduced to aqueous colloidal HPMCP dispersions prepared by emulsion-solvent diffusion techniques followed by freeze- or spray-drying of the resultant aqueous dispersions. The surface-modified powders obtained with HPMCP nanospheres and their mixture with lactose powders were aerosolized by Spinhaler and their mode of deposition in lung was evaluated in vitro using a twin impinger. To elucidate the inhalation mechanism of these surface modified particles, we measured their modified micromeritic properties, such as surface topography, specific surface area, dissolution rate, and dispersibility in air. Results. Dramatically improved inhalation properties of the surface modified powder, i.e. a two-fold increase in emission and a three-fold increase in delivery to deep lung, were found in vitro compared with the original unmodified powder. Improved inhalation was also found with the surf ace-modified drug deposited on lactose particles. Those improvements were attributed to the increased surface roughness and hydrophilicity of the surface-modified particles, and the resultant increased dispersibility in air. Conclusions. Surface modification of hydrophobic drug particles with HPMCP nanospheres to improve hydrophilicity was extremely useful in increasing the inhalation efficiency of the drug itself and the drug deposited on carrier; this was attributed to increased dispersibility in air and emission from the device, for spray- and freeze-dried particles, respectively.     

Human nucleus pulposus cells significantly enhanced biological properties in a coculture system with direct cell‐to‐cell contact with autologous mesenchymal stem cells

Activated nucleus pulposus (NP) cells can be reinserted into the disc to inhibit intervertebral disc degeneration. Experimental studies in animals showed that using a coculture system with direct cell‐to‐cell contact with mesenchymal stem cells (MSCs) significantly upregulated the biological activity of NP cells. The purpose of this study is to determine whether this activation of NP cells by autologous MSCs is applicable to human cells in vitro. Human NP tissue was obtained from surgical specimens and MSCs from bone marrow of 10 subjects. Six‐well culture plates and inserts were used for culture; 1.0 × 10⁴ NP cells were seeded onto each insert and incubated alone, in standard coculture with 1.0 × 10⁴ MSCs, or cocultured with direct cell‐to‐cell contact. NP cell proliferation, DNA synthesis, and proteoglycan (PG) synthesis were evaluated. Chromosome abnormalities in the activated NP cells and tumorigenesis of the cells were evaluated in an additional 10 patients by microscopic examination for segmented cells and histological assessment of activated cells transplanted into nude mice. Cell proliferation, DNA synthesis, and PG synthesis were significantly upregulated. The positive effects of the coculture system with direct cell‐to‐cell contact seen in animal studies were also confirmed in human cells. Chromosome abnormalities and tumorigenesis were not observed in the activated NP cells. In conclusion, a coculture system with direct cell‐to‐cell contact demonstrated a significant positive effect, enhancing the biological properties of human NP cells, as it did in animal models. These results should prove useful for conducting trials leading to the clinical use of activated NP cell transplantation. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:623–630, 2010     

Synergistic effect of low‐intensity pulsed ultrasound on growth factor stimulation of nucleus pulposus cells

Low‐intensity pulsed ultrasound (LIPUS) has been reported to stimulate the activity of various cells. We have reported that the capacity of human intervertebral nucleus pulposus cell line to synthesize proteoglycan (PG) was increased by exposure to LIPUS, and postulated that one of the mechanisms underlying this response was an increase in expression of the transforming growth factor‐β type I receptor gene (TGFβR1). Therefore, the present study was conducted to assess the synergistic effect of LIPUS and TGF‐β on nucleus pulposus cells harvested from canines. The cells were cultured under four different sets of conditions: control group (Group A), LIPUS group (Group B), TGF‐β1 group (Group C), and LIPUS + TGF‐β1 group (Group D). They were evaluated by measuring cell proliferation, PG synthesis, PG content, gene expression of TGFβR1, and TGF‐β1 concentration. There were no significant differences in proliferation during culture. However, PG synthesis and endogenous TGF‐β1 production increased and demonstrated a synergistic effect between LIPUS and TGF‐β. Because LIPUS is safe and noninvasive, the results of the present study suggest that it would be a promising new therapy for prevention of intervertebral disc degeneration, which is said to be one of the primary causes of low back pain. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1574–1581, 2007     

Surface-modified Antiasthmatic Dry Powder Aerosols Inhaled Intratracheally Reduce the Pharmacologically Effective Dose

Purpose. The aim of this study was to construct a reliable dry powder inhalation (DPI) testing system for use in guinea pigs. Using this system, we were able to demonstrate the superiority of pulmonary administration of hydrophilically surface-modified pranlukast hydrate powder (SM-DP) over IV and PO administration as reflected in improved pharmacological action. Our ultimate aim is the development of an ideal treatment system for bronchial asthma involving topical administration to the lung. Methods. The reliability of the present DPI system was validated by continuously monitoring the concentration and particle size distribution of aerosols generated with an ambient particulate monitor and an Andersen air sampler, respectively. The pharmacological effect of SM-DP intratracheally administered to guinea pig was investigated by measuring the degree of bronchoconstriction and microvascular leakage induced by leukotriene D₄. Results. The mass concentration of aerosols generated by the DPI system was stable and the mass median aerodynamic diameter of aerosols insufflated from the respirator of the DPI system ranged from 1.4 to 1.7 m, within respirable limits. Inhibition of bronchoconstriction and airway microvascular leakage induced by leukotriene D₄ was achieved successfully with a dramatically lower dose of DP, or a further lower dose of SM-DP, comparable with that of the drug solution injected intravenously. The plasma pranlukast hydrate level with SM-DP at 50% inhibition of bronchoconstriction and airway microvascular leakage was reduced to 1/10 or less that following IV and PO administration. Conclusions. The hydrophilically surface-modified pranlukast hydrate powders were ideally aerosolized by the present DPI system, and were uniformly deposited in the lung lobes after inhalation. The pulmonary administration system with SM-DP is strongly recommended as an ideal system for the treatment of bronchial asthma in order to avoid systemic side-effects due to a dramatically reduced ED₅₀, comparable with or lower than IV, and the low plasma concentration of drug, 1/12 or less than that following IV and PO administration.