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  • Author or Editor: Seiichi Ishikawa x
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Kimihiko Sawakami, Kei Watanabe, Kazuhiro Hasegawa, Noriaki Yamamoto, Taketoshi Shimakura, Masayuki Ohashi, Hirokazu Shoji, Tatsuki Mizouchi, Yuki Tanaka, Hiroyuki Segawa, Seiichi Ishikawa, Toru Hirano, Hiroyuki Kawashima, Naoto Endo, and Hideaki E. Takahashi

OBJECTIVE

Teriparatide (TPTD) is a potent promoter of early-stage osteogenesis and may be a useful adjuvant therapy to reduce complications related to bone fragility in spinal surgery patients with osteoporosis. However, effective neoadjuvant TPTD therapy regimens remain poorly understood. This study aimed to examine the effect of preoperative TPTD administration on cancellous bone with bone histomorphometry and to clarify the timing of preoperative TPTD administration for patients with spinal fusion and osteoporosis.

METHODS

In this longitudinal multicenter study, 57 patients with spinal fusion and osteoporosis, who consented to undergo iliac biopsy, were allocated to the following treatment groups: neoadjuvant TPTD therapy group (n = 42) and no neoadjuvant therapy (NTC) group (n = 15). Patients in the TPTD group were categorized into subgroups on the basis of duration of preoperative TPTD administration, as follows: 1 month (n = 9), 2 months (n = 8), 3 months (n = 9), 4 months (n = 7), and 6 months (n = 9). All patient samples were preoperatively double labeled with tetracycline, and iliac biopsies were performed during spinal fusion surgery. Histomorphometric analyses were performed on nondecalcified, thin-sliced specimens. Specimens were classified on the basis of TPTD administration duration and subsequently compared with those of the NTC group. Postoperative complications and Oswestry Disability Index scores were evaluated at 1 and 2 years after surgery.

RESULTS

There were no demographic differences between groups. Mineralizing surface/bone surface, a key parameter of dynamic bone formation, started to increase after 1 month of TPTD administration; this increase became significant after 3 months of administration and peaked at 4 months, with a 6-fold increase relative to that of the NTC group. The patients who received preoperative TPTD for 3 months or more had superior clinical results in terms of the osteoporotic complication rate and Oswestry Disability Index scores, except for bisphosphonate-pretreated patients.

CONCLUSIONS

When considering neoadjuvant TPTD therapy, the authors recommend at least 3 months of preoperative administration to provide a more substantial anabolic effect from the early postoperative stage.

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Yasumu Kijima, Masakazu Ishikawa, Toru Sunagawa, Kazuyoshi Nakanishi, Naosuke Kamei, Kiyotaka Yamada, Nobuhiro Tanaka, Seiichi Kawamata, Takayuki Asahara, and Mitsuo Ochi

Object

Despite intensive efforts in the field of peripheral nerve injury and regeneration, it remains difficult to achieve full functional recovery in humans following extended peripheral nerve lesions. In this study, the authors examined the use of blood-derived CD133+ cells in promoting the repair of peripheral nerve defects.

Methods

The authors transplanted phosphate-buffered saline (control), mononuclear cells, or CD133+ cells embedded in atelocollagen gel into a silicone tube that was used to bridge a 15-mm defect in the sciatic nerve of athymic rats (12 animals in each group). At 8 weeks postsurgery, molecular, histological, and functional evaluations were performed in regenerated tissues.

Results

The authors found that sciatic nerves in which a defect had been made were structurally and functionally regenerated within 8 weeks after CD133+ cell transplantation. From macroscopic evaluation, massive nervelike tissues were confirmed only in rats with CD133+ cell transplantation compared with the other groups. Morphological regeneration in the samples after CD133+ cell transplantation, as assessed using toluidine blue staining, was enhanced significantly in terms of the number of myelinated fibers, axon diameter, myelin thickness, and percentage of neural tissue. Compound muscle action potentials were observed only in CD133+ cell–treated rats. Furthermore, it was demonstrated that the transplanted CD133+ cells differentiated into Schwann cells by 8 weeks after transplantation.

Conclusions

The results show that CD133+ cells have potential for enhancement of histological and functional recovery from peripheral nerve injury. This attractive cell source could be purified easily from peripheral blood and could be a feasible autologous candidate for peripheral nerve injuries in the clinical setting.