• Journal of Korean Neurosurgical Society
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• v.48 no.1
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• pp.1-7
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• 2010

Objective : Notochordal cells in the intervertebral disc interact with nucleus pulposus (NP) cells and support the maintenance of disc homeostasis by regulation of matrix production. However, the influence of notochordal cells has not been evaluated in the annulus fibrosus (AF), which is the primary pain generator in the disc. We hypothesized that the notochordal cell has the capacity to modulate inflammatory mediators secreted by AF cells secondary to stimulation. Methods : Notochordal and AF cells were isolated from adult New Zealand white rabbits. AF pellets were cultured with notochordal cell clusters or in notochordal cell-conditioned media (NCCM) for 24 or 48 hours with proinflammatory cytokines at varying concentrations. Gene expression in AF pellets were assayed for nitric oxide synthase (iNOS), cyclo-oxygenase (COX)-2, and interleukin (IL)-6 by real time reverse transcriptase polymerase chain reaction (RT-PCR). Results : AF pellet in NCCM significantly decreased the iNOS and COX-2 messenger ribonucleic acid (mRNA) levels compared to AF pellets alone and AF pellets with notochordal cells (p < 0.05). AF pellet resulted in dose-dependent iNOS and COX-2 expression in response to IL-$1{\beta}$, stimulation, demonstrating that 1 ng/ml for 24 hours yielded a maximal response. AF pellet in NCCM significantly decreased the expression of iNOS and COX-2 in response to 1ng/ml IL-$1{\beta}$, stimulation at 24 hours (p < 0.05). There was no difference in IL-6 expression compared to AF pellets alone or AF pellets with notochordal cell clusters. Conclusion : We conclude that soluble factors from notochordal cells mitigate the gene expression of inflammatory mediators in stimulated AF, as expected after annular injury, suggesting that notochordal cells could serve as a novel therapeutic approach in symptomatic disc development.

• Applied Microscopy
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• v.21 no.2
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• pp.39-56
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• 1991

The development of notochordal cells of nucleus pulposus was studied with electron microscope in human fetuses ranging from 30 mm to 260 mm crown-rump length. At 30 mm fetus, primitive notochordal cells were large with central nucleus, few organelles, and their cytoplasm usually contained dense glycogen and fine filaments. Notochordal cells at all ages contained bundles of fine filaments of indeterminate nature. One unusual feature of fetal notochordal cells was the consistent presense of rough endoplasmic reticulum surrounding poorly developed mitochondria. At 50 mm fetus, notochordal cells formed dense masses with interdigitating cell membranes connected by a variety of cell to cell junctions. With increasing age, the cell connections became slender threaded cytoplamic extending from cell and enclosed large extracellular space. Chondrocyte-like cells appeared to be separated by large volumes of extracellular matrix. Viable notochordal and condrocyte-like cells existed in specimen from all age. The extracellular spaces were filled with fibrillar and granular material by 90 mm fetus. Necrotic cells were distinguished by loss of their membrane integrity, vacuolization of their organelles, and the presence of dense osmiophilic masses. In adult tissue, notochordal cells became rounded or irregular in shape and developed a pericellular matrix consisting of collagen fibrile, and dense particle. The structure of notochordal cells and their persistance in the nucleus pulposus after fetal life suggested that they may have a significant role in the formation and maintenance of the nucleus pulposus. The presence of Golgi complex and well-developed endoplasmic reticulum in chondrocyte-like cells suggested that they are capable of producing and maintaining the extracellular matrix.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.59-69
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• 1997

The histological and histochemical study of the body of axis and 1st intervertebral disc in the Korean native cattle fetus was attempted to early developmental process. The experimental animals used in this study were collected from fetus of the Korean native cattle ranging from 50mm to 180mm in Crown-Rump length(CR-length). The results were summerized as follows: 1. The ossification centers appeared centrum 1 and centrum 2 of the axis in 110mm CR-length fetus of the Korean native cattle. The centrum 2 was formed little earlier than the centrum 1. 2. The histochemical reactions for collagenous fibers in the axis revealed negative in 50mm CR-length, mild positive in 90mm CR-length, and strong positive in 110mm CR-length, respectively. 3. Dense collagenous fibers were observed in the notochord through the centrum 2, and intervertebral disc developed into cuneiform dorsoventrally, It's contour looks like an annual ring. These fiber bundle arranged lamellar formation. 4. The intervertabral disc of 50mm CR-length fetus was composed mainly mesenchymal cells, and these cell showed aggregation in the central portion. The intervertebral disc of 110mm CR-length fetus was consisted of pricipally fibroblast, and notochordal sheath formed with two layers in the center.