Biomedical subjects

Joji Mochida

Publications and source records attributed to Joji Mochida.

At least 19 recordsLinked to original sources

PubMed2007

Molecular effects of sodium hyaluronate on the healing of avian supracoracoid tendon tear: according to in situ hybridization and real-time polymerase chain reaction.

Hyluronic acid (HA) on tissue healing has been controversial. We examined the molecular pharmacology of HA injection at the suture site in an acute model of supracoracoid tendon laceration using chickens, an injury of a nonweight-bearing joint considered similar to the human shoulder. Expression of mRNAs encoding alpha I (I) and alphaI (III) procollagens was localized using in situ hybridization (ISH). Intensities of mRNA expression for alpha I (I) and alpha I (III) procollagens, transforming growth factor-beta1 (TGF- beta1), basic fibroblast growth factor (bFGF), and insulin-like growth factor (IGF) were determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Histologically, chickens with HA injection (HA group) showed early restoration of continuity at the laceration site than saline-injection controls (saline-injection group). By ISH, the expression rate of cells at the lesion site that contained alpha I (I) and alpha I (III) procollagen mRNAs were somewhat higher in the HA group than in the saline-injection group. By RT-PCR, the HA- and saline-injection groups showed no significant difference in expression of alpha I (I) and alpha I (III) procollagen mRNA between weeks 1 and 6. The saline -injection group exhibited significant decrease in TGF-beta1 expression between weeks 1 and 3, and in bFGF expression between weeks 1 and 2; however, the HA group showed no such decrease. As for IGF, no difference was appreciable in both groups between weeks 1 and 6. A single injection of HA could cause earlier restoration of continuity at the lacerated site of the supracoracoid tendon.

Adjuvants, Immunologic↗

PubMed2006

Bioengineered chondrocyte sheets may be potentially useful for the treatment of partial thickness defects of articular cartilage.

Some treatments for full thickness defects of articular cartilage, such as cultured chondrocyte transplantation, have already been done. However, to overcome osteoarthritis, we must further study the partial thickness defect of articular cartilage. It is much more difficult to repair a partial thickness defect because few repairing cells can address such injured sites. We herein show that bioengineered layered chondrocyte sheets using temperature-responsive culture dishes may be a potentially useful treatment for partial thickness defects. We evaluated the property of these sheets using real-time PCR and histological findings, and allografted these sheets to evaluate the effect of treatment using a rabbit partial model. In conclusion, layered chondrocyte sheets were able to maintain the cartilageous phenotype, and could be attached to the sites of cartilage damage which acted as a barrier to prevent a loss of proteoglycan from these sites and to protect them from catabolic factors in the joint.

Animals↗

PubMed2006

Feasibility of using a human nucleus pulposus cell line as a cell source in cell transplantation therapy for intervertebral disc degeneration.

STUDY DESIGN: Assessment of the potential use of an immortalized human nucleus pulposus cell line as an alternative cell source in cell transplantation therapy for intervertebral disc degeneration. OBJECTIVES: To evaluate the effect of transplanting the human nucleus pulposus cell line into a disc degeneration model in rabbits and to define whether it is capable of becoming an alternative cell source for cell transplantation therapy for disc degeneration. SUMMARY OF BACKGROUND DATA: Interest in cell transplantation therapy for disc degeneration has been growing for several years, and a range of different cell types have been examined as possible donor cells. In addition, the establishment of a novel cell line that possesses some of the major characteristics of a normal human nucleus pulposus cells has been reported. METHODS: Human nucleus pulposus cell line was established, and cells were transplanted into a rabbit disc degeneration model. At 4, 8, and 24 weeks after transplantation, inhibition of intervertebral disc degeneration was assessed by examining the disc height, macroscopic appearance, histologic findings, and immunohistochemistry. In addition, aggrecan, versican, and Type II collagen gene expression in the nucleus pulposus were measured semiquantitatively at the mRNA level. Furthermore, the survival of transplanted cells was examined using immunohistochemistry for Simian Virus 40 T antigen, and the presence of graft-versus-host reaction was assessed by immunohistochemistry for CD4 and CD58. RESULTS: The disc height was significantly greater in the transplanted group than in the degenerative group's disc from 4 weeks' posttransplantation. Macroscopically, the nucleus pulposus was absent and there was loss of disc height in the degenerative group at 24 weeks after transplantation, whereas the nucleus pulposus was preserved in the transplanted group. Histologic examination showed that the structure of the inner anulus fibrosus was significantly preserved in the transplanted group, and the boundary between the nucleus and anulus could be clearly visualized. Expression of mRNAs of the nucleus pulposus matrix, aggrecan, and Type II collagen was significantly greater in the transplanted group than in the degenerative group. This indicates that transplantation of human nucleus pulposus cell line helped to preserve the matrix of the nucleus pulposus. Thus, transplantation of a human nucleus pulposus cell line was shown to delay disc degeneration in this rabbit model. CONCLUSION: The human nucleus pulposus cell line may become an alternative cell source for cell transplantation therapy of intervertebral disc degeneration.

Adult↗

PubMed2006

Development of a diagnostic system for osteoarthritis using a photoacoustic measurement method.

BACKGROUND AND OBJECTIVES: We demonstrated that photoacoustic measurement enables viscoelastic characterization of biological tissue. The purpose of this study was to develop a practical photoacoustic measurement system for diagnosis of osteoarthritis (OA) by viscoelastic characterization of articular cartilage. STUDY DESIGN/MATERIALS AND METHODS: The portable system consists of a commercially available 3rd harmonic Q-switched Nd:YAG laser as a light source and a transducer, which is arranged coaxially with an optical fiber. Cell proliferation tests were performed to study the effect of laser irradiation on chondrocytes. Photoacoustic measurements were performed using enzymatically treated cartilage as a model of OA. RESULTS: There was no significant damage of chondrocytes caused by laser irradiation (100 microJ/mm2, 5 Hz, 30 shots). The change in relaxation times measured by the photoacoustic measurement had a positive correlation with time of enzymatic treatment, that is, the degree of cartilage degeneration. CONCLUSIONS: We have developed a noninvasive photoacoustic measurement system designed for arthroscopic use and have demonstrated the applicability of this system to the diagnosis of OA-like cartilage degeneration.

Acoustics↗

PubMed2006

Intramedullary spinal cord metastasis: a clinical and imaging study of seven patients.

OBJECTIVES: Intramedullary spinal cord metastasis (ISCM) is a rare complication of cancer. This complication has been studied by magnetic resonance imaging (MRI) more frequently in the clinical context to improve the survival time of cancer patients. However, the number of the reports of its clinical management or radiographic findings is small. To investigate the clinical and imaging characteristics of ISCM, seven cases of ISCM of a nonneurogenic origin were examined retrospectively. METHOD: Data regarding the site of the primary neoplasm, location of other metastases, initial symptoms, interval from the original diagnosis of cancer to the onset of neurologic symptoms, time course from initial symptoms to urinary retention, MRI data, and outcome after radiologic or surgical intervention were investigated. RESULTS: Five patients had lung cancer metastases, and one each had breast or uterine cancer metastases. The progression of neurologic deficit was rapid, and the average period between the occurrence of initial symptoms and urinary retention was 25 days. The averaged survival period from the diagnosis of ISCM was 5 months in three patients. (One patient is alive, and the data could not be obtained in another three patients.) MRI characteristics were useful for diagnosis, including large high signal intensity areas on T2-weighted images and strong ring or inhomogeneous enhancement on gadopentetate dimeglumine-enhanced T1-weighted images. Surgery was performed on two patients, but total removal could not be achieved. Radiotherapy was effective in treating neurologic deficit in five patients. CONCLUSION: Surgical treatment is seldom indicated for ISCM, and radiotherapy is recommended as soon as possible after a diagnosis is made from MRI.

Aged↗

PubMed2005

Differentiation of mesenchymal stem cells transplanted to a rabbit degenerative disc model: potential and limitations for stem cell therapy in disc regeneration.

STUDY DESIGN: An in vivo study to assess the differentiation status of mesenchymal stem cells (MSCs) transplanted to the nucleus pulposus of degenerative discs in a rabbit model. OBJECTIVES: To evaluate the fate of MSCs transplanted to the nucleus pulposus of degenerative discs in a rabbit and to determine whether they are a suitable alternative for cell transplantation therapy for disc degeneration. SUMMARY OF BACKGROUND DATA: Although MSCs have been proposed as candidate donor cells for transplantation to treat intervertebral disc degeneration, their differentiation after transplantation has not been adequately investigated. METHODS: Autologous MSCs, labeled with green fluorescent protein, were transplanted into mature rabbits. Consecutive counts of transplanted MSCs in the nucleus area were performed for 48 weeks after transplantation. Differentiation of transplanted cells was determined by immunohistochemical analysis. The proteoglycan content of discs was measured quantitatively using a dimethylmethylene blue assay, and mRNA expression of Type I and II collagen, aggrecan and versican was measured semi-quantitatively using reverse transcription polymerase chain reaction. RESULTS: Many cells that were positive for green fluorescent protein were observed in the nucleus pulposus of cell-transplanted rabbit discs 2 weeks after transplantation. Their number increased significantly by 48 weeks. Some GFP-positive cells were positive for cell-associated matrix molecules, such as Type II collagen, keratan sulfate, chondroitin sulfate, aggrecan, and the nucleus pulposus phenotypic markers, hypoxia inducible factor 1 alpha, glutamine transporter 1, and matrix metalloproteinase 2. MSCs did not show significant expression of these molecules before transplantation. Biochemical and gene expression analyses showed significant restoration of total proteoglycan content and matrix-related genes compared with nontransplanted discs. CONCLUSIONS: MSCs transplanted to degenerative discs in rabbits proliferated and differentiated into cells expressing some of the major phenotypic characteristics of nucleus pulposus cells, suggesting that these MSCs may have undergone site-dependent differentiation. Further studies are needed to evaluate their functional role.

Animals↗

PubMed2005

Surgical treatment for injuries of the middle and lower cervical spine.

We reviewed the surgical treatment of 31 patients with burst fractures or teardrop dislocation fractures in the middle and lower cervical spine. Patients were treated with anterior instrumentation, posterior instrumentation, or a combination of both. Patients were evaluated radiographically and with the Frankel neurological outcomes grading scale. Anterior decompression and fusion restored the spinal canal diameter by approximately 60% whereas the posterior or combined approaches restored the canal diameter by only 6%. In addition, nine of 24 patients treated anteriorly gained improved neurological function whereas none of the patients treated posteriorly had neurological improvement. Based on the anatomical and neurological findings, the study demonstrates that anterior fusion is preferable to posterior fusion for the treatment of burst fractures and tear-drop dislocation fractures of the middle and lower cervical spine.

Adolescent↗

PubMed2005

Regenerative effects of transplanting mesenchymal stem cells embedded in atelocollagen to the degenerated intervertebral disc.

Intervertebral disc (IVD) degeneration, a common cause of low back pain in humans, is a relentlessly progressive phenomenon with no currently available effective treatment. In an attempt to solve this dilemma, we transplanted autologous mesenchymal stem cells (MSCs) from bone marrow into a rabbit model of disc degeneration to determine if stem cells could repair degenerated IVDs. LacZ expressing MSCs were transplanted to rabbit L2-L3, L3-L4 and L4-L5 IVDs 2 weeks after induction of degeneration. Changes in disc height by plain radiograph, T2-weighted signal intensity in magnetic resonance imaging (MRI), histology, immunohistochemistry and matrix associated gene expressions were evaluated between normal controls (NC) without operations, sham operated with only disc degeneration being induced, and MSC-transplanted animals for a 24-week period. Results showed that after 24 weeks post-MSC transplantation, degenerated discs of MSC-transplanted group animals regained a disc height value of about 91%, MRI signal intensity of about 81%, compared to NC group discs. On the other hand, sham-operated group discs demonstrated the disc height value of about 67% and MRI signal intensity of about 60%. Macroscopic and histological evaluations confirmed relatively preserved nucleus with circular annulus structure in MSC-transplanted discs compared to indistinct structure seen in sham. Restoration of proteoglycan accumulation in MSC-transplanted discs was suggested from immunohistochemistry and gene expression analysis. These data indicate that transplantation of MSCs effectively led to regeneration of IVDs in a rabbit model of disc degeneration as suggested in our previous pilot study. MSCs may serve as a valuable resource in cell transplantation therapy for degenerative disc disease.

Aggrecans↗

PubMed2005

Atelocollagen for culture of human nucleus pulposus cells forming nucleus pulposus-like tissue in vitro: influence on the proliferation and proteoglycan production of HNPSV-1 cells.

Nucleus pulposus (NP) is responsible for maintaining function and structure of the disc. Scaffolds to culture disc cells three-dimensionally are emphasized in recent reports on development of a new method for treating disc degeneration using cell transplantation and tissue engineering. Among artificial scaffolds and cell carrying materials, Atelocollagen is a collagen gel that has an advantage in safety issues over others. However, to date there has been no study that investigated culture of human nucleus pulposus cells in Atelocollagen. To investigate whether Atelocollagen could be used as a culture scaffold and if it has any effect on cell proliferation and proteoglycan (PG) production, as well as to find the optimal commercially available Atelocollagen for NP cell transplantation and tissue engineering, we cultured human NP cell line HNPSV-1, in three different Atelocollagen and compared with alginate. Furthermore, NP-like tissues were generated using these cells and different Atellocollagen solutions. Results showed that both DNA synthesis and content is significantly greater when cultured in Atelocollagen than in alginate. On the other hand, proteoglycan synthesis and accumulation was significantly greater in alginate compared with the 0.3% Atelocollagen scaffolds; with 3% Atelocollagen, however, results were similar. NP-like tissue generated by Atelocollagen showed good water and proteoglycan preservation. The current study demonstrates that the use of Atelocollagen as an in vitro culture scaffold for three-dimensional culture of human NP cell lines is indeed feasible and moreover, Atelocollagen possesses the potential to become a candidate scaffold for cell transplantation or tissue engineering for the treatment of intervertebral disc degeneration.

Adult↗

PubMed2005

Low-intensity pulsed ultrasound stimulates cell proliferation and proteoglycan production in rabbit intervertebral disc cells cultured in alginate.

Intervertebral disc degeneration, one of the major causes of low-back pain, is known to result from alteration in biosynthesis of proteoglycan in the disc. Therefore, upregulating the synthesis of proteoglycan in intervertebral disc cells may be one approach in treating disc degeneration. Based on the finding that low-intensity pulsed ultrasound stimulates proteoglycan synthesis in rat chondrocytes, we investigated whether low-intensity pulsed ultrasound stimulates biological properties of rabbit intervertebral disc cells in vitro. Nucleus pulposus cells and annulus fibrosus cells isolated from rabbits were cultured in alginate beads. Cells were stimulated for 20 min each day for 5-12 days, starting on the third day after seeding. An ultrasound signal consisting of a 200 micros burst sine wave of 0.5 MHz repeating at 1 kHz, with an intensity of 0, 7.5, 15, 30, 60, 120 mW/cm2 spatial and temporal average, was applied. DNA and proteoglycan synthesis were evaluated by measuring [3H]-thymidine and [35S]-sulfate incorporation. DNA and proteoglycan content in beads were measured by Hoechst 33258 dye method and dimethylmethylene blue assay. Results demonstrated positive effects on DNA synthesis and content, following low-intensity pulsed ultrasound stimulation with intensities of 7.5 and 15 mW/cm2. Furthermore, ultrasound stimulation significantly upregulated [35S]-sulfate incorporation and proteoglycan content compared to the control group, following 5 days of stimulation in both nucleus pulposus and annulus fibrosus cells. These findings suggest the possible application of low-intensity pulsed ultrasound in biological repair of intervertebral disc degeneration.

Alginates↗

PubMed2005

Whole genome association study of rheumatoid arthritis using 27 039 microsatellites.

A major goal of current human genome-wide studies is to identify the genetic basis of complex disorders. However, the availability of an unbiased, reliable, cost efficient and comprehensive methodology to analyze the entire genome for complex disease association is still largely lacking or problematic. Therefore, we have developed a practical and efficient strategy for whole genome association studies of complex diseases by charting the human genome at 100 kb intervals using a collection of 27,039 microsatellites and the DNA pooling method in three successive genomic screens of independent case-control populations. The final step in our methodology consists of fine mapping of the candidate susceptible DNA regions by single nucleotide polymorphisms (SNPs) analysis. This approach was validated upon application to rheumatoid arthritis, a destructive joint disease affecting up to 1% of the population. A total of 47 candidate regions were identified. The top seven loci, withstanding the most stringent statistical tests, were dissected down to individual genes and/or SNPs on four chromosomes, including the previously known 6p21.3-encoded Major Histocompatibility Complex gene, HLA-DRB1. Hence, microsatellite-based genome-wide association analysis complemented by end stage SNP typing provides a new tool for genetic dissection of multifactorial pathologies including common diseases.

Arthritis, Rheumatoid↗

PubMed2005

New strategies for disc repair: novel preclinical trials.

Degeneration of lumbar intervertebral discs is a major cause of low back complaints, an irreversible occurrence with no currently available treatment. Furthermore, various surgical procedures can accelerate disc degeneration. On the other hand, recent experimental studies on disc cells have demonstrated an important role for the nucleus pulposus in preserving overall disc structure. The author's group has already found that nucleus pulposus cells activated annulus fibrous cells, and reinsertion of nucleus pulposus cells slowed further disc degeneration. We have designed three subsequent studies that were designed to examine further possibilities for clinical transplantation: (1) activation of nucleus pulposus cells by mesenchymal stem cells; (2) focus on the multilineage differentiation potential of mesenchymal stem cells as an alternative cell source for cell transplantation therapy of disc degeneration; (3) the possibility of a human nucleus pulposus cell line as a cell source for cell transplantation therapy. Activation of nucleus pulposus could be achieved by co-culture with autogenous mesenchymal stem cells allowed to have direct cellular interaction. This would be a useful clinical cell source. Induction of nucleus pulposus cells by autogenous mesenchymal stem cells also would be an important subject for a clinical trial. Clinical application of the cells derived from a human nucleus pulposus cell line is an important project to be undertaken in the near future.

Animals↗

PubMed2005

Potential and origin of the hematopoietic population in human skeletal muscle.

While mononuclear cells isolated from murine skeletal muscle were shown to be capable of hematopoietic activity, similar hematopoietic cells (HC) recently were reported to exist in primate muscle. We investigated muscle-derived HC from young and adult human subjects. Although hematopoietic stem cells were rare in muscle, their frequency nonetheless was approximately four times greater than in peripheral blood. These cells in muscle appeared to originate from CD45(+) bone marrow cells. Our results suggested an additional function of human skeletal muscle as a reservoir of HC.

Adolescent↗

PubMed2005

Residual neck pain after traumatic spondylolisthesis of the axis.

OBJECTIVE: Most patients with traumatic spondylolisthesis of the axis are treated nonsurgically. Some patients do not develop symptoms, but others experience strong and persistent neck pain. To clarify the factor that plays a major role in residual neck pain after this fracture, we reviewed nine patients who underwent conservative treatment. METHODS: Patients were assessed via telephone interviews an average of 62 months after injury and were divided into two groups: those with and those without neck pain. Angulation and anterior translation between the second and third cervical vertebrae were measured on lateral radiograms at the time of injury, removal of brace, and final follow-up. Fracture lines were also investigated by computed tomography. RESULTS: At the time of final follow-up, the average angulation was 6.3 degrees and the average translation was 5.3 mm in the neck-pain group and 0.6 degrees and 0.2 mm, respectively, in the no-symptom group. In patients with fracture lines present on the articular surface of the inferior face joints, angulation persisted or increased, even though the fractures were hemilateral. This was compatible with severe neck pain. In contrast, angulation and translation were improved in patients with an intact inferior articular surface of the axis, and pain was not reported. CONCLUSIONS: Injury on the inferior articular surface of the axis may disturb spontaneous healing of C2-C3 subluxation and cause residual neck pain. It is necessary to assess the presence of injury to the inferior facet bilaterally with plain or computed tomograms.

Activities of Daily Living↗

PubMed2005

The behavior of thoracic trabecular bone during flexion.

Thoracic compression fractures are often described as anterior wedge fractures. Although the radiographic signs of these fractures are easily identified, the mechanism of the trabecular failure is not well understood. The current study addressed this mechanism in the lower thoracic spine by measuring the trabecular strain. Trabecular strain was measured in six human thoracic cadaver spines during 1) compressive and 2) flexural loading. The strains were measured at incremental loads using a texture correlation. They were analyzed by global contour plots and regional analysis of the T11 vertebrae. Specimens loaded under only compression exhibited uniform strains in the vertebral body. During flexion, however, the strains were concentrated in the anterosuperior margin of the vertebral body and the compressive and shear strain magnitudes in this region were significantly increased. These results demonstrate that the flexural position places the lower thoracic spine at greater risk of anterior compression fracture as seen clinically.

Aged↗

PubMed2004

Upregulation of the viability of nucleus pulposus cells by bone marrow-derived stromal cells: significance of direct cell-to-cell contact in coculture system.

STUDY DESIGN: Upregulation of the viability of nucleus pulposus cells by coculture with bone marrow-derived stromal cells using a novel culture system. OBJECTIVES: The objective was to apply a novel coculture system having direct cell-to-cell contact between nucleus pulposus cells and bone marrow-derived stromal cells for stimulation of nucleus pulposus cells. SUMMARY OF BACKGROUND DATA: Reinsertion of nucleus pulposus cells was effective for treatment of intervertebral disc degeneration. However, obtaining highly viable nucleus pulposus cells was necessary to achieve successful results. Thus, an alternative method to upregulate the biologic and metabolic viabilities of nucleus pulposus cells was desired. METHODS: Nucleus pulposus cells and bone marrow-derived stromal cells were isolated from New Zealand white rabbits. A 6-well culture plate and insert with track-etched membrane having 0.4 microm pores at the bottom were used for coculture. Nucleus pulposus cells were monocultured, cocultured conventionally (having no direct cell-to-cell contact) with bone marrow-derived stromal cells, or cocultured having direct cell-to-cell contact with bone marrow-derived stromal cells. On day 4 of coculture, nucleus pulposus cells were evaluated for proliferation using WST-8 assay, deoxyribonucleic acid synthesis by measuring [H]-thymidine uptake, and proteoglycan synthesis by measuring [S]-sulfate uptake. We also quantified cytokines in supernatants from the culture system. RESULTS: Cell proliferation, deoxyribonucleic acid synthesis, and proteoglycan synthesis of nucleus pulposus cells were significantly upregulated in samples cocultured having direct cell-to-cell contact. Moreover, evaluations of supernatants revealed that growth factors associated with proliferation and cellular metabolism of nucleus pulposus cells were increased. CONCLUSIONS: Direct cell-to-cell contact in coculture system between nucleus pulposus cells and bone marrow-derived stromal cells accomplished significant upregulation in viability of nucleus pulposus cells.

Animals↗

PubMed2004

Immortalization of human nucleus pulposus cells by a recombinant SV40 adenovirus vector: establishment of a novel cell line for the study of human nucleus pulposus cells.

STUDY DESIGN: Establishment and characterization of a de novo cell line derived from human nucleus pulposus cells using a recombinant simian virus 40 (SV40) adenovirus vector. OBJECTIVES: To assess the feasibility of human nucleus pulposus cell line procurement and to evaluate the character of the resultant outcome to better understand the nature of human nucleus pulposus cells. SUMMARY OF BACKGROUND DATA: Despite recent advances in disc cell biologic research, the fundamental nature of nucleus pulposus cells, especially in the context of human cell lines, is still not well understood. Therefore, a broad-based analysis of these cells is of significant necessity. Because of the limited amount of existing human cells, establishment of an immortal cell line would greatly facilitate resource supply. METHODS: After release of informed consent, tissue samples of nucleus pulposus were obtained from the lumbar intervertebral disc of a 19-year-old man undergoing anterior fusion for burst fracture. Samples with no apparent damage were selected and digested enzymatically for primary culture and then were infected with recombinant SV40 adenovirus vector (Ad/SV40). The infected cells were maintained in culture for more than 40 population doublings, after which they were considered immortalized. Next, confirmation of expression of T antigen was performed and resultant immortalized cell lines were designated and classified as human nucleus pulposus cell line derived from Ad/SV40 infection-1 (HNPSV-1). HNPSV-1 cells were characterized and compared with their mother cells under two designated culture conditions: monolayer and three-dimensional. Morphologic and immunocytochemical analyses were performed at various intervals. Cell proliferation, DNA synthesis, proteoglycan synthesis, gene expression profiling, and karyotypic analyses were also performed. Moreover, HNPSV-1 cells were injected into rabbit discs to assess the presence of tumorigenesis. RESULTS: Recombinant SV40 adenovirus vector infected nucleus pulposus cells with relatively high efficiency (90%> at multiplicity of infection 100). HNPSV-1 demonstrated marked prolongation of cell life with continuous cell doublings for over 5 months (60-100 cell population doublings). Despite significant increase in cell proliferation and DNA synthesis when compared with its mother cells, resultant cell lines expressed strikingly similar cell morphology and functional characteristics. Atypical karyotypes were noted; however, no apparent tumorigenesis was seen in rabbit discs 24 weeks after injection of HNPSV-1. CONCLUSIONS: HNPSV-1 was successfully established using recombinant SV40 adenovirus vector. Results showed that human nucleus pulposus cells are capable of immortalization with maintenance of original cell characteristics. It is anticipated that these cells will be useful for in vitro studies of the biologic nature of human nucleus pulposus cells.

Adenoviruses, Human↗

PubMed2004

[Characterization of intervertebral disc--disc cells and pericellular microenvironment].

The intervertebral disc is classified as fibrocartilage, and has distinct functional and mechanical properties. The disc, composed of the nucleus pulposus and annulus fibrosus, varies in density, anatomic features, and in the morphology of their constituent cells. This heterogeneity has hampered detailed investigations of disc cellular metabolism. Focusing on the heterogeneity, we cultured disc cells under various conditions to examine the cellular metabolism, specifically glycosaminoglycan accumulation and pericellular microenvironment, and succeeded in mechanically isolating disc chondrons from annulus fibrosus. We believe that disc chondron also plays an important role in maintaining cartilageous phenotype in terms of cell-matrix interaction of the intervertebral disc.

Cell Culture Techniques↗