Impact of background factors on outcomes of pharmacological therapy for chronic low back pain: A nationwide multicenter prospective study.

BACKGROUND: Chronic low back pain (CLBP) is a major cause of chronic pain with nociceptive, neuropathic or both pain components, and a leading cause of disability. The objectives of this study were to determine the impact of background factors including previous use of drugs on outcomes of pharmacological therapy for CLBP in a nationwide multicenter prospective study. METHODS: The subjects were 474 patients (male: 41.9%, median age: 73.0) with CLBP. Background factors that could influence outcomes after pharmacological treatment for 6 months were examined: age, gender, body mass index (BMI), duration of CLBP, osteoporosis, history of spinal surgery, history of malignant tumor, smoking habit, employment status (yes or no), exercise habit (frequency), number of live-in family members, having something to do for pleasure, Center for Epidemiologic Studies depression scale (CES-D) score, and medication at baseline. Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) for LBP, JOA Back Pain Evaluation Questionnaire (JOABPEQ), Roland-Morris Disability Questionnaire (RDQ), Short-form 8-item health survey (SF-8), and EQ-5D were used for evaluation at baseline and after 6 months. Multivariate linear regression models were used in statistical analysis. RESULTS: Drugs for neuropathic pain at baseline (p < 0.001), Tramacet® at baseline (p < 0.05), weak opioids at baseline (p < 0.05), older age (p < 0.001), long disease duration (p < 0.005), history of spinal surgery (p < 0.001), and smoking habit (p < 0.001) had significant negative effects on outcomes. Employment (p < 0.05), exercise habit (p < 0.05), and CED-D at baseline (p < 0.001) had positive effects on outcomes. CONCLUSIONS: This is the first study to identify significant prognostic factors for outcomes of pharmacological treatment of CLBP. The neuropathic pain component of CLBP at baseline is a major significant negative factor for most outcomes involving improved pain, activities of daily life, and quality of life. Treatment strategies developed with consideration of these factors may be advantageous for recovery from CLBP.

Cost-effectiveness analysis of the pharmacological management of chronic low back pain with four leading drugs.

BACKGROUND: Chronic low back pain is a major health problem that has a substantial effect on people's quality of life and places a significant economic burden on healthcare systems. However, there has been little cost-effectiveness analysis of the treatments for it. Therefore, the purpose of this prospective observational study was to evaluate the cost-effectiveness of the pharmacological management of chronic low back pain. METHODS: A total of 474 patients received pharmacological management for chronic low back pain using four leading drugs for 6 months at 28 institutions in Japan. Outcome measures, including EQ-5D, the Japanese Orthopaedic Association (JOA) score, the JOA back pain evaluation questionnaire (BPEQ), the Roland-Morris Disability Questionnaire, the Medical Outcomes Study SF-8, and the visual analog scale, were investigated at baseline and every one month thereafter. The incremental cost-utility ratio (ICUR) was calculated as drug cost over the quality-adjusted life years. An economic estimation was performed from the perspective of a public healthcare payer in Japan. Stratified analysis based on patient characteristics was also performed to explore the characteristics that affect cost-effectiveness. RESULTS: The ICUR of pharmacological management for chronic low back pain was JPY 453,756. Stratified analysis based on patient characteristics suggested that the pharmacological treatments for patients with a history of spine surgery or cancer, low frequency of exercise, long disease period, low scores in lumbar spine dysfunction and gait disturbance of the JOA BPEQ, and low JOA score at baseline were not cost-effective. CONCLUSIONS: Pharmacological management for chronic low back pain is cost-effective from the reference willingness to pay. Further optimization based on patient characteristics is expected to contribute to the sustainable development of a universal insurance system in Japan.

A Japanese nationwide multicenter survey on perioperative complications of corrective fusion for elderly patients with adult spinal deformity.

BACKGROUND: Recently, corrective fusion surgery for patients with adult spinal deformity (ASD) has become common in Japan. This study aimed to clarify the status of surgeries for ASD in Japan, focusing on perioperative complications. A nationwide multicenter survey gathering information on surgically treated ASD patients was conducted by the committee for Adult Spinal Deformity of the Japanese Scoliosis Society. METHODS: This study was a review of retrospectively collected data from 18 spine scoliosis centers belonging to the Japanese Scoliosis Society. Patients who underwent corrective fusion surgery for ASD between 2011 and 2013 were included. Demographics, comorbidities, surgical data, and complications were investigated. RESULTS: A total of 1192 patients (mean age, 57.7 years) were included in this study. Of these, 611 patients were aged less than 65 years and 581 patients were aged 65 years or greater. The age distribution had two peaks, in the third and eighth decades. Deformities caused by degeneration represented 67% of the pathology in patients aged over 65 years; however, non-degenerative disease such as adult idiopathic scoliosis and syndromic or congenital deformity represented over 60% of pathology in patients aged less than 65 years. The iatrogenic deformity and reoperation rates were both less than 3%. The mean operation time and estimated blood loss were 370 min and 1642 ml, respectively. Major perioperative complications occurred in 160 patients (14.5%). The incidence of complications was significantly higher in patients aged over 65 years, including neurological deficits, hemorrhagic shock, hematoma, heart failure, and surgical site infection (p < 0.05). CONCLUSIONS: Older (aged over 65 years) ASD patients showed greater rates of deformity due to the occurrence of degeneration and vertebral fractures, as well as a higher incidence of peri-and postoperative complications. Efforts to reduce perioperative complications are therefore imperative, especially for elderly ASD patients in our aging society.

Sagittal alignment of the cervical spine in adolescent idiopathic scoliosis: a comparative study of 42 adolescents with idiopathic scoliosis and 24 normal adolescents.

PURPOSE: Kyphosis of the cervical spine has been reported in patients with adolescent idiopathic scoliosis (AIS). However, few reports have compared sagittal spine alignment of AIS patients with that of the normal population. The purposes of this study were (1) to analyze the characteristics of sagittal alignment, including the cervical spine, in AIS patients with a single thoracic curve (Lenke type 1) compared with the age-matched normal population and (2) to quantify the changes in sagittal alignment of the cervical spine and thoracic kyphosis following posterior spinal fusion. METHODS: In study 1, pre- and postoperative X-ray were measured for the following sagittal plane parameters: lumbar lordosis angle (L1-S1; LL), thoracic kyphosis angle (Th5-12; TK), sacral slope (SS), C7 plumb line (C7PL), cervical lordosis angle (C2-C7 angle; CL), and T1 slope. These measurements were then evaluated with CL and other parameters using spearman rank correlation coefficient between two groups. Comparison was made with the sagittal plane parameters from preoperative 42 AIS (AIS group) with main thoracic curve and 24 normal populations (Control group). In study 2, 38 operative AIS patients had at least 1-year follow-up. These patients (38 AIS patients after the correction surgery) were enrolled. We collected for each patient on pre- and postoperative sagittal plane parameters of X-ray. RESULTS: In study 1, LL and C7PL did not differ significantly between the groups. Although CL was observed in 10 of the 24 patients (41.7 %) in the Control group, the CL was smaller in the AIS group, with 6 of 42 patients (14.3 %). The CL correlated significantly with T1 slope (r = 0.634), C7PL (r = 0.684), and TK (r = 0.311) in the AIS group, and with T1 slope (r = 0.681) and C7PL (r = 0.451) in the Control group. No correlations were observed with respect to the TK. In study 2, the mean CL improved significantly from 7.2° kyphosis preoperatively to 0.1° kyphosis postoperatively. Interestingly, Spearman correlation analysis showed that the postoperative CL correlated significantly with postoperative TK (r = 0.607), postoperative T1 slope (r = 0.701), and postoperative C7PL (r = 0.373). CONCLUSIONS: There were no effects of scoliosis on sagittal spine parameters such as LL and C7PL in AIS patients with a main thoracic curve. Cervical spine alignment was affected by the thoracic deformity in the sagittal plane, as shown by the reduction in the CL after the operation. These findings suggest that TK may be a cause of cervical kyphosis in AIS patients.

Effect of depression and neuropathic pain using questionnaires on quality of life in patients with low back pain; cross-sectional retrospective study.

PURPOSE: The present study investigated the percentage of low back pain (LBP) patients who have depressive symptoms and neuropathic pain and analyzed the effects of these on the quality of life (QOL) in these patients. METHODS: Of the 650 new patients with LBP that visited the hospital between June 2012 and December 2013, 309 patients who completed questionnaires to assess LBP and QOL were included in the study. The questionnaire included demographic items, the self-rated depression scale (SDS)-Zung, the Japanese version of the PainDETECT questionnaire (PDQ-J), numerical pain rating scale (NRS), and QOL assessments. The patients were divided into two groups according to their SDS-Zung scores: a nondepressed group with SDS scores <40 and a depressed group with SDS-Zung scores ≥50. RESULTS: One hundred twenty-five patients (40.5 %) were classified as nondepressed and 63 (20.4 %) as depressed. The mean PDQ-J score was higher in depressed patients than in nondepressed patients. The frequency of neuropathic pain was greater in depressed patients, with neuropathic pain observed in 17 of the 63 (27 %) depressed LBP patients and 11 of the 125 (9 %) nondepressed LBP patients. The SDS-Zung and PDQ-J scores of LBP patients were correlated significantly (r = 0.261, p < 0.001). Depressed patients had higher pain NRS scores and lower QOL scores compared with nondepressed patients. CONCLUSIONS: Both the depressed patients and those with neuropathic LBP had a higher level of pain, greater pain-related disability, and poorer QOL compared with nondepressed patients. This is the first study to use the SDS-Zung and PDQ-J screening questionnaires to estimate the presence of neuropathic pain associated with depressive symptoms in LBP patients and to evaluate the impact of these on QOL.

Evaluation of quality of life and neuropathic pain in patients with low back pain using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire.

PURPOSE: To examine the impact that neuropathic or nociceptive pain has on the quality of life (QOL) in patients with low back pain (LBP) using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and the Japanese version of the PainDETECT Questionnaire (PDQ-J). METHODS: Between June 2012 and December 2013, 650 new patients were treated at our institution for LBP. All patients between the ages of 20 and 79 were asked to complete a set of questionnaires including the PDQ-J, a pain visual analog scale (VAS), the JOABPEQ, and the Short Form 36 (SF-36). Based on the PDQ-J scores, participants were classified into three groups: a neuropathic pain group, a nociceptive pain group, and an intermediate mixed pain group. Among them, patients with clear neuropathic and nociceptive LBP were selected. To investigate the differences between neuropathic and nociceptive LBP, diagnosis of spinal disorder, prevalence, age, gender, duration of symptoms, VAS scores, and self-reported general health (SF-36 and JOABPEQ) were compared between the neuropathic and nociceptive pain groups. RESULTS: Of 650 patients with LBP, 331 completed the questionnaires and were enrolled in the study. There were 193 men (58.3 %) and 138 women (41.7 %) with a mean age of 54.5 years (range 20-79 years). From the PDQ-J survey, 49 patients (15 %) were classified as having neuropathic pain, and 190 (58 %) were categorized as having nociceptive pain. Patients in the neuropathic pain group had significantly higher VAS scores and lower SF-36 and JOABPEQ scores compared to the nociceptive pain group. CONCLUSION: We examined the impact of nociceptive or neuropathic LBP on QOL. A comparison of JOABPEQ scores between LBP patients assessed by PDQ-J as having neuropathic pain or nociceptive pain suggests that neuropathic pain affects the social and psychological well-being of LBP patients.

Diffusion tensor imaging can detect the early stages of cartilage damage: a comparison study.

BACKGROUND: In the present study, we measured damaged areas of cartilage with diffusion tensor (DT) imaging and T2 mapping, and investigated the extent to which cartilage damage could be determined using these techniques. METHODS: Forty-one patients underwent arthroscopic knee surgery for osteoarthritis of the knee, a meniscus injury, or an anterior cruciate ligament injury. Preoperative magnetic resonance imaging of the knee was performed, including T2 mapping and diffusion tensor imaging. The presence of cartilage injury involving the medial and lateral femoral condyles and tibia plateau was assessed during surgery using the Outerbridge scale. The ADC, T2 values and fractional anisotropy of areas of cartilage injury were then retrospectively analysed. RESULTS: The ADC results identified significant differences between Outerbridge grades 0 and 2 (P = 0.041); 0 and 3 (P < 0.001); 1 and 2 (P = 0.045); 1 and 3 (P < 0.001); and 2 and 3 (P = 0.028). The FA results identified significant differences between grades 0 and 1 (P < 0.001); 0 and 2 (P < 0.001); and 0 and 3 (P < 0.001). T2 mapping identified significant differences between Outerbridge grades 0 and 2 (P = 0.032); 0 and 3 (P < 0.001); 1 and 3 (P < 0.001); and 2 and 3 (P < 0.001). Both the T2 mapping (R(2) = 0.7883) and the ADC (R(2) = 0.9184) correlated significantly with the Outerbridge grade. The FA (R(2) = 0.6616) correlated slightly with the Outerbridge grade. CONCLUSIONS: T2 mapping can be useful for detecting moderate or severe cartilage damage, and the ADC can be used to detect early stage cartilage damage. The FA can also distinguish normal from damaged cartilage.

Effect of amiloride on endoplasmic reticulum stress response in the injured spinal cord of rats.

After traumatic spinal cord injury (SCI), endoplasmic reticulum (ER) stress exacerbates secondary injury, leading to expansion of demyelination and reduced remyelination due to oligodendrocyte precursor cell (OPC) apoptosis. Although recent studies have revealed that amiloride controls ER stress and leads to improvement in several neurological disorders including SCI, its mechanism is not completely understood. Here, we used a rat SCI model to assess the effects of amiloride on functional recovery, secondary damage expansion, ER stress-induced cell death and OPC survival. Hindlimb function in rats with spinal cord contusion significantly improved after amiloride administration. Amiloride significantly decreased the expression of the pro-apoptotic transcription factor CHOP in the injured spinal cord and significantly increased the expression of the ER chaperone GRP78, which protects cells against ER stress. In addition, amiloride treatment led to a significant decrease in ER stress-induced apoptosis and a significant increase of NG2-positive OPCs in the injured spinal cord. Furthermore, in vitro experiments performed to investigate the direct effect of amiloride on OPCs revealed that amiloride reduced CHOP expression in OPCs cultured under ER stress. These results suggest that amiloride controls ER stress in SCI and inhibits cellular apoptosis, contributing to OPC survival. The present study suggests that amiloride may be an effective treatment to reduce ER stress-induced cell death in the acute phase of SCI.

Development of a novel vitrification method for chondrocyte sheets.

BACKGROUND: There is considerable interest in using cell sheets for the treatment of various lesions as part of regenerative medicine therapy. Cell sheets can be prepared in temperature-responsive culture dishes and applied to injured tissue. For example, cartilage-derived cell sheets are currently under preclinical testing for use in treatment of knee cartilage injuries. The additional use of cryopreservation technology could increase the range and practicality of cell sheet therapies. To date, however, cryopreservation of cell sheets has proved impractical. RESULTS: Here we have developed a novel and effective method for cryopreserving fragile chondrocyte sheets. We modified the vitrification method previously developed for cryopreservation of mammalian embryos to vitrify a cell sheet through use of a minimum volume of vitrification solution containing 20% dimethyl sulfoxide, 20% ethylene glycol, 0.5 M sucrose, and 10% carboxylated poly-L-lysine. The principal feature of our method is the coating of the cell sheet with a viscous vitrification solution containing permeable and non-permeable cryoprotectants prior to vitrification in liquid nitrogen vapor. This method prevented fracturing of the fragile cell sheet even after vitrification and rewarming. Both the macro- and microstructures of the vitrified cell sheets were maintained without damage or loss of major components. Cell survival in the vitrified sheets was comparable to that in non-vitrified samples. CONCLUSIONS: We have shown here that it is feasible to vitrify chondrocyte cell sheets and that these sheets retain their normal characteristics upon thawing. The availability of a practical cryopreservation method should make a significant contribution to the effectiveness and range of applications of cell sheet therapy.

A Cre knock-in mouse line on the Sickle tail locus induces recombination in the notochord and intervertebral disks.

Sickle tail (Skt) was originally identified by gene trap mutagenesis in mice, and the trapped gene is highly expressed in the notochord, intervertebral discs (IVD), and mesonephros. Here, we report the generation of Skt(cre) mice expressing Cre recombinase in the IVD due to target insertion of the cre gene into the Skt locus by recombinase-mediated cassette exchange. Crossing a conditional lacZ Reporter (R26R), Cre expression from the Skt(cre) allele specifically activates ß-galactosidase expression in the whole notochord from E9.5 onwards. In E15.5 Skt(cre);R26R embryos, reporter activity was detected in the nucleus pulposus and in a portion of the annulus fibrosus, resulting in expansion of Cre-expressing cells in the adult IVD. Reporter activity was also seen in the Skt(cre);R26R mesonephros at E15.5. These results suggest that Skt(cre) mice are useful for exploring the fate specification of notochordal cells and creating models for IVD-related skeletal diseases.

Hypoxia activates the notch signaling pathway in cells of the intervertebral disc: implications in degenerative disc disease.

OBJECTIVE: To investigate whether hypoxia regulates Notch signaling, and whether Notch plays a role in intervertebral disc cell proliferation. METHODS: Reverse transcription-polymerase chain reaction and Western blotting were used to measure expression of Notch signaling components in intervertebral disc tissue from mature rats and from human discs. Transfections were performed to determine the effects of hypoxia and Notch on target gene activity. RESULTS: Cells of the nucleus pulposus and annulus fibrosus of rat disc tissue expressed components of the Notch signaling pathway. Expression of Notch-2 was higher than that of the other Notch receptors in both the nucleus pulposus and annulus fibrosus. In both tissues, hypoxia increased Notch1 and Notch4 messenger RNA (mRNA) expression. In the annulus fibrosus, mRNA expression of the Notch ligand Jagged1 was induced by hypoxia, while Jagged2 mRNA expression was highly sensitive to hypoxia in both tissues. A Notch signaling inhibitor, L685458, blocked hypoxic induction of the activity of the Notch-responsive luciferase reporters 12xCSL and CBF1. Expression of the Notch target gene Hes1 was induced by hypoxia, while coexpression with the Notch-intracellular domain increased Hes1 promoter activity. Moreover, inhibition of Notch signaling blocked disc cell proliferation. Analysis of human disc tissue showed that there was increased expression of Notch signaling proteins in degenerated discs. CONCLUSION: In intervertebral disc cells, hypoxia promotes expression of Notch signaling proteins. Notch signaling is an important process in the maintenance of disc cell proliferation, and thus offers a therapeutic target for the restoration of cell numbers during degenerative disc disease.

Human telomerase reverse transcriptase and glucose-regulated protein 78 increase the life span of articular chondrocytes and their repair potential.

BACKGROUND: Like all mammalian cells, normal adult chondrocytes have a limited replicative life span, which decreases with age. To facilitate the therapeutic use of chondrocytes from older donors, a method is needed to prolong their life span. METHODS: We transfected chondrocytes with hTERT or GRP78 and cultured them in a 3-dimensional atelocollagen honeycomb-shaped scaffold with a membrane seal. Then, we measured the amount of nuclear DNA and glycosaminoglycans (GAGs) and the expression level of type II collagen as markers of cell proliferation and extracellular matrix formation, respectively, in these cultures. In addition, we allografted this tissue-engineered cartilage into osteochondral defects in old rabbits to assess their repair activity in vivo. RESULTS: Our results showed different degrees of differentiation in terms of GAG content between chondrocytes from old and young rabbits. Chondrocytes that were cotransfected with hTERT and GRP78 showed higher cellular proliferation and expression of type II collagen than those of nontransfected chondrocytes, regardless of the age of the cartilage donor. In addition, the in vitro growth rates of hTERT- or GRP78-transfected chondrocytes were higher than those of nontransfected chondrocytes, regardless of donor age. In vivo, the tissue-engineered cartilage implants exhibited strong repairing activity, maintained a chondrocyte-specific phenotype, and produced extracellular matrix components. CONCLUSIONS: Focal gene delivery to aged articular chondrocytes exhibited strong repairing activity and may be therapeutically useful for articular cartilage regeneration.

The relationship between the Wnt/ß-catenin and TGF-ß/BMP signals in the intervertebral disc cell.

Degeneration of the lumbar intervertebral disc (IVD) is a cause of low back pain. In osteoarthritis patients, an increase in ß-catenin accumulation has been reported. However, the molecular mechanisms involved in IVD remain unclear. In the present study, we examined the relationship of Wnt/ß-catenin and transforming growth factor-ß (TGF-ß)/bone morphogenetic protein (BMP) signals in the IVDs. We found that treatment of nucleus pulposus (NP) cells with the Wnt/ß-catenin activator lithium chloride (LiCl) results in the increased expression of ß-catenin mRNA and protein, and cell proliferation is decreased due to the activation of the Wnt/ß-catenin signals through the suppression of c-myc and cyclin-D1. In addition, T-cell-specific transcription factor (TCF) promoter activity was found to increase the following stimulation with LiCl alone, and was further increased when BMP2 was added, in comparison to the control group. We further observed the effects of treatment with PD98059, a specific inhibitor of the mitogen-activated protein kinase pathway, on TCF promoter activity in NP cells. These effects were largely attenuated by PD98059. Moreover, when transfected IVDs were co-transfected with R-Smad expression plasmids, there was a significant decrease in TCF reporter activity. We thereafter evaluated the effects of increased Wnt/ß-catenin activity on the transcriptional activity of the Smad binding element (SBE). As a result, LiCl suppressed the activity of SBE reporter activity. The present study demonstrates for the first time that there are opposing effects between the Wnt/ß-catenin and TGF-ß/BMP signals in IVDs, which is consistent with the Wnt/ß-catenin signals contributing to the pathogenesis of IVD degeneration.

Effects of a glycogen synthase kinase-3ß inhibitor (LiCl) on c-myc protein in intervertebral disc cells.

Wnt/ß-catenin (hereafter called Wnt) signaling is a key inducer and regulator of joint development, and is involved in the formation of bone and cartilage. We previously reported that Wnt signaling plays an essential role in the control of cell proliferation and cell senescence in intervertebral disc cells. In the present study, we provide evidence that the expression of c-myc, a key protein required for cell proliferation, is regulated by Wnt signaling. Our data also show that activation of Wnt signaling by LiCl, a Wnt signaling activator, leads to the suppression of c-myc promoter activity and expression. To ascertain whether Wnt signaling regulates the expression of c-myc, we measured both its transcript and protein expression. Following treatment with LiCl, c-myc expression was suppressed at both the mRNA and protein levels. In nucleus pulposus cells treated with c-myc, cell viability increased significantly, whereas treatment with a c-myc inhibitor decreased cell viability. Taken together, these results suggest that c-myc is an important factor that promotes the proliferation of nucleus pulposus cells. These findings provide new insight into the regulation and maintenance of cell proliferation in nucleus pulposus cells.

Measurement of diffusion in articular cartilage using fluorescence correlation spectroscopy.

BACKGROUND: Fluorescence correlation spectroscopy (FCS) provides information about translational diffusion of fluorescent molecules in tiny detection volumes at the single-molecule level. In normal states, cartilage tissue lacks vascularity, so chondrocyte metabolism depends on diffusion for molecular exchanges. The abundant extracellular matrix (ECM) of cartilage is maintained by a limited number of chondrocytes. ECM plays an important role in the regulation of chondrocyte functions. In this study, FCS was used to measure diffusion behaviors of albumin, the major protein of the intra-articular space, using normal and degenerated cartilage. Preliminary investigation of fluorescence dyes including Alexa 488, Rhodamine 6G and Rhodamine 123 was conducted to evaluate their properties in cartilage. RESULTS: The results indicate that the diffusion behaviors of fluorescently labeled albumin can be observed using FCS in both normal and chemically degenerated cartilage. CONCLUSIONS: This work demonstrates the capability of FCS for direct measurement of diffusion in cartilaginous ECM. When the diffusion characteristics of fluorescent probes in ECM are clarified using FCS evaluation, FCS will be applicable as a method for early diagnosis of osteoarthritis, which is accompanied by increased abnormalities of ECM and also as tool for evaluating bio-engineered artificial cartilage for autologous chondrocyte implantation.

Enhancement of intervertebral disc cell senescence by WNT/ß-catenin signaling-induced matrix metalloproteinase expression.

OBJECTIVE: To determine whether intervertebral disc (IVD) cells express ß-catenin and to assess the role of the WNT/ß-catenin signaling pathway in cellular senescence and aggrecan synthesis. METHODS: The expression of ß-catenin messenger RNA (mRNA) and protein in rat IVD cells was assessed by using several real-time reverse transcription-polymerase chain reaction, Western blot, immunohistochemical, and immunofluorescence analyses. The effect of WNT/ß-catenin on nucleus pulposus (NP) cells was examined by transfection experiments, an MTT assay, senescence-associated ß-galactosidase staining, a cell cycle analysis, and a transforming growth factor (TGFß)/bone morphogenetic protein (BMP) pathway-focused microarray analysis. RESULTS: We found that ß-catenin mRNA and protein were expressed in discs in vivo and that rat NP cells exhibited increased ß-catenin mRNA and protein upon stimulation with lithium chloride, a known activator of WNT signaling. LiCl treatment inhibited the proliferation of NP cells in a time- and dose-dependent manner. In addition, there was an increased level of cellular senescence in LiCl-treated cells. Long-term treatment with LiCl induced cell cycle arrest and promoted subsequent apoptosis in NP cells. Activation of WNT/ß-catenin signaling also regulated the expression of aggrecan. We also demonstrated that WNT/ß-catenin signaling induced the expression of matrix metalloproteinases (MMPs) and TGFß in NP cells. CONCLUSION: The activation of WNT/ß-catenin signaling promotes cellular senescence and may modulate MMP and TGFß signaling in NP cells. We hypothesize that the activation of WNT/ß-catenin signaling may lead to an increased breakdown of the matrix, thereby promoting IVD degeneration.

A diagnostic system for articular cartilage using non-destructive pulsed laser irradiation.

BACKGROUND AND OBJECTIVES: Osteoarthritis involves dysfunction caused by cartilage degeneration, but objective evaluation methodologies based on the original function of the articular cartilage remain unavailable. Evaluations for osteoarthritis are mostly based simply on patient symptoms or the degree of joint space narrowing on X-ray images. Accurate measurement and quantitative evaluation of the mechanical characteristics of the cartilage is important, and the tissue properties of the original articular cartilage must be clarified to understand the pathological condition in detail and to correctly judge the efficacy of treatment. We have developed new methods to measure some essential properties of cartilage: a photoacoustic measurement method; and time-resolved fluorescence spectroscopy. MATERIALS AND METHODS: A nanosecond-pulsed laser, which is completely non-destructive, is focused onto the target cartilage and induces a photoacoustic wave that will propagate with attenuation and is affected by the viscoelasticity of the surrounding cartilage. We also investigated whether pulsed laser irradiation and the measurement of excited autofluorescence allow real-time, non-invasive evaluation of tissue characteristics. RESULTS: The decay time, during which the amplitude of the photoacoustic wave is reduced by a factor of 1/e, represents the key numerical value used to characterize and evaluate the viscoelasticity and rheological behavior of the cartilage. Our findings show that time-resolved laser-induced autofluorescence spectroscopy (TR-LIFS) is useful for evaluating tissue-engineered cartilage. CONCLUSIONS: Photoacoustic measurement and TR-LIFS, predicated on the interactions between optics and living organs, is a suitable methodology for diagnosis during arthroscopy, allowing quantitative and multidirectional evaluation of the original function of the cartilage based on a variety of parameters.

The influence of Ho:YAG laser irradiation on intervertebral disc cells.

BACKGROUND AND OBJECTIVE: Various types of laser have been reported for percutaneous laser disc decompression (PLDD). The aim of this study was to understand the effects on intervertebral disc cells following Ho:YAG laser irradiation, using a three-dimensional culture model, and consider appropriate irradiation conditions. STUDY DESIGN/MATERIALS AND METHODS: Intervertebral discs from the lumbar spine were obtained from 36 female Japanese white rabbits and processed to obtain isolated cells in three-dimensional cultures. Photoacoustic and photothermal effects were investigated by irradiating three-dimensional cultures with Ho:YAG laser at 27 or 54 J. Residual cell counts after irradiation were estimated based on DNA content according to fluorometric assay. Lactate dehydrogenase levels were also investigated as a marker of damage to cell plasma membranes. Finally, proteoglycan synthesis was measured by rapid filtration assay of (35) S incorporation, as an index of matrix synthesis. RESULTS: Residual cell count tended to be higher in the 27-J group. Plasma membrane damage was higher and remained high longer after irradiation in the 54-J group. Proteoglycan synthesis was higher in the 27-J group than in the 54-J group, with some conditions (e.g., 90 mJ/pulse condition) showing marked activation of proteoglycan synthesis maintained for a long time after irradiation. CONCLUSIONS: Three-dimensional culture models of intervertebral disc cells are useful for clarifying relationships between cell reactions and photoacoustic and photothermal effects after laser irradiation. Total energy is closely related to optimization of irradiation conditions, which may allow optimization of cytoprotection and promotion of matrix synthesis in clinical practice.

[An innovative disc repair for the degeneration].

Experimental studies in various animals showed that using a coculture system with direct cell-to-cell contact with mesenchymal stem cells (MSCs) significantly upregulated the biological activity of nucleus pulposus (NP) cells. Activated NP cells can be reinserted into the disc to inhibit intervertebral disc degeneration. In human cells, the positive effects of the coculture system with direct cell-to-cell contact seen in animal studies were also evaluated and cell proliferation, DNA synthesis, and PG synthesis were significantly upregulated. Chromosome abnormalities and tumorigenesis were not observed in the activated NP cells. Then the authors have started the specially designed clinical trial under the control of Ministry of Health, Labour and Welfare and now post operative follow-up has been continued with expected good outcome.

Comparison of the Effectiveness of Pharmacological Treatments for Patients with Chronic Low Back Pain: A Nationwide, Multicenter Study in Japan.

INTRODUCTION: Chronic low back pain (CLBP) is a leading cause of disability, yet there is limited high-quality evidence to identify the most suitable pharmacological therapy. The purpose of this Japanese nationwide, multicenter, prospective study was to compare the effectiveness of four representative drug therapies-acetaminophen, celecoxib, loxoprofen, and a tramadol and acetaminophen (T+A) combination drug-to establish evidence for a drug of choice for CLBP. METHODS: Patients with CLBP (N=471) received one of the four treatments and were evaluated, prospectively and comprehensively, once every month for six months using a visual analog scale (VAS) for LBP, the Japanese Orthopedic Association (JOA) score, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), the Roland-Morris Disability Questionnaire (RDQ), the EuroQol five-dimensions three-levels (EQ-5D-3L), and the Short Form-8 item health survey (SF-8). We conducted multivariable linear regression analyses of the four drugs at 1 and 6 months after drug allocation. Differences with P<0.05 were considered statistically significant. RESULTS: Patients who received acetaminophen showed a significant improvement from baseline in the mental health subscale of the JOABPEQ at one month (P=0.02) and the JOA score at six months (P<0.01). None of the other outcome measures among the four drugs differed significantly. Across groups, all outcome measures, except the mental component summary (MCS) score of the SF-8, improved equivalently, although most measurements showed no obvious cumulative effect over six months. The MCS score of the SF-8 decreased gradually over six months in all groups. CONCLUSIONS: Most of the outcome measures among the treated groups were not significantly different, indicating similar treatment effects of the four drugs for CLBP. Our study indicated the limit of each outcome measure for evaluating the patient status, suggesting that a single outcome measure is insufficient to reflect treatment effectiveness.