• Korean Journal of Clinical Laboratory Science
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• v.37 no.1
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• pp.35-40
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• 2005

This paper reports the morphological nature of the remodelled interface process between implants and surrounding bone after 1, 4, 6, 8 and 12 weeks of implantation of smooth machined implants into rat tibias. After 4 weeks of implantation, histochemical analysis showed that the new bone was growing in direct contact with the implant. In the forming process, the activatived osteoblast cells migrated toward the interface and colonized the surface at the contact areas. This immature woven bone, rich in osteocyte lacunae, was deposited directly onto the implant surface. Osteoblast activity was found to continue ill 12 weeks of implantation The osteoblasts in lacunar areas developed numerous processes and synthesized bone matrix, after all, surrounded by secreting matrix. At the 12th week, the amount of newly formed bone matrix between bone and implant increased in mineralization. The mineralized mature bone contained well organized collagen fibers with characteristic banding pattern bone tissue formation around the implant.

• International Journal of Oral Biology
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• v.45 no.3
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• pp.92-98
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• 2020

Periodontitis is a bacteria-induced inflammatory disease associated with alveolar bone loss. Osteoclast is a macrophage-lineage cell that exhibits phagocytic activity; however, osteoclast phagocytic activity has not been demonstrated under pathological conditions. Diabetes is a pathological condition that exacerbates alveolar bone loss via periodontitis; therefore, we examined phagocytic osteoclasts in diabetic rats that had periodontitis. The rats were divided into the control (C), periodontitis (P), and diabetes with periodontitis (DP) groups. Diabetes and periodontitis were induced by streptozotocin injection and ligature of the mandibular first molars, respectively. On days 3 and 20 after the ligature, the rats were sacrificed, and osteoclasts containing inclusions were quantified by tartrate-resistant acid phosphatase staining. On day 3, there were more osteoclasts containing inclusions in the DP group than in the C group. Among inclusions, osteocyte-like cells and dense bodies were more frequently observed in the DP group than in the C group. Cytoplasm-like structures were elevated more in the DP group than in the C and P groups. However, no differences were observed on day 20. Interestingly, some osteoclasts were in contact with the osteocytes within the exposed lacunae and contained several inclusions within a large vacuole. Thus, the elevation of phagocytic osteoclasts in rats with diabetes and periodontitis provides insight into the role of osteoclast phagocytic activity under pathological conditions.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.114-117
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• 2017

A 42-year-old man was admitted to our hospital with complaints of low back pain and intermittent right thigh pain. Twelve weeks before admission, the patient received intradiscal electrothermal therapy (IDET) at a local hospital. The patient still reported low back pain after the procedure that was managed with narcotic analgesics. Follow-up magnetic resonance imaging (MRI) was performed, and his referring physician thought the likely diagnosis was spondylodiscitis at the L4-5 spinal segment with a small epidural abscess. At admission to our department, the patient reported aggravated low back pain. Blood test results, including the erythrocyte sedimentation rate and C-reactive protein levels, were slightly elevated. Biopsy samples of the L4, L5 vertebral bodies and disk were obtained. The material underwent aerobic, anaerobic, fungal, mycobacterial cultures and histologic examination. Results of all cultures were negative. Histologically, necrosis of the bone was evident from the number of empty osteocyte lacunae. In addition, there was no evidence of infection based on biopsy results. No antibiotic treatment was administered on discharge. Repeat computed tomography and MRI performed 12 months after IDET showed a bony defect in the L4 and L5 vertebral bodies, and a decrease in the size of the L4-5 intervertebral disc lesion. We report a case of lumbar vertebral osteonecrosis induced by IDET and discuss etiology and radiologic features.