• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권4호
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• pp.266-274
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• 2020

Objectives: Melatonin induces human stem cells, converts pre-osteoblasts to mature osteoblasts, and reduces the duration of this transition. However, melatonin itself prevents activation of osteoclasts. Here, we evaluate the role of melatonin in prevention of bisphosphonate-related osteonecrosis of the jaw. Materials and Methods: In this experimental-interventional study, 30 rats were evaluated in 3 groups. The first and second groups received saline and zoledronic acid, respectively, for 4 weeks and the third group received 4 weeks of zoledronic acid and 3 weeks of melatonin simultaneously. First-right-maxillary-molar extraction was performed for all animals, which were sacrificed after 4 weeks of recovery. The extraction sockets were examined histologically for the presence of osteonecrosis, number of osteoclasts and fibroblasts, severity of inflammation, and vascularization. Data were analyzed by chi-square, one-way ANOVA, Tukey, Kruskal-Wallis and Fisher's exact statistical tests (α=0.05). Results: Osteonecrosis was observed in 20%, 90%, and 70% of the first, second and third groups, respectively (P=0.008). The lowest number of osteoclasts and fibroblasts was seen in the third group. Conclusion: Melatonin may effectively prevent some undesirable side effects of bisphosphonates. However, further studies are required to confirm the results of this study.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4084-4092
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• 2012

Theoretical calculations based on density functional theory (DFT) were performed to study the substituent effect on the geometric and electronic structures as well as the biological behavior of technetium-99m-labeled diphosphonate complexes. Optimized structures of these complexes are surrounded by six ligands in an octahedral environment with three unpaired 4d electrons ($d^3$ state) and the optimized geometry of $^{99m}Tc$-MDP agrees with experimental data. With the increase of electron-donating substituent or tether between phosphate groups, the energy gap between frontier orbitals increases and the probability of non-radiative deactivation via d-d electron transfer decreases. The charge distribution reflects a significant ligand-to-metal electron donation. Based on the calculated geometric and electronic structures and biologic properties of $^{99m}Tc$-diphosphonate complexes, several structure-activity relationships (SARs) were established. These results may be instructive for the design and synthesis of novel $^{99m}Tc$-diphosphonate bone imaging agent and other $^{99m}Tc$-based radiopharmaceuticals.

• Tuberculosis and Respiratory Diseases
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• 제55권3호
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• pp.280-286
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• 2003

목 적 : 폐암의 골전이 진단을 위해 흔히 이용하는 골주사는 예민도는 높으나 특이도가 낮아서, 악성 병변과 양성 병변을 구분하는 데에는 유용성이 낮다. 최근 전신 촬영이 가능한 $^{18}FDG$ PET이 암 진단에 널리 이용되고 있으므로 폐암의 골전이를 진단하는데 있어서 골주사와의 차이를 비교하기 위해 후향적 연구를 시행하였다. 방 법 : 폐암으로 진단된 환자 중 골수사와 전신 $^{18}FDG$ PET를 시행한 시간 차이가 1달 이내인 92명을 대상으로 하였다. 골전이의 판정은 골주사와 $^{18}FDG$ PET에서 이상 부위를 단순 X-선, 자기공명영상으로 평가하거나, 추적 영상검사로 확진하였다. 결 과 : 폐암의 골전이를 판정하는데 있어서 골주사의 민감도, 특이도, 정확도는 각각 59%, 71%, 68%이었으며, $^{18}FDG$ PET의 경우 각각 82%, 94%, 91%으로 $^{18}FDG$ PET이 골주사보다 특이도와 정확도에서 유의하게 우월하였다(p<0.0001). 결 론 : 폐암의 골전이를 평가하는데 있어서 $^{18}FDG$ PET은 전통적인 골주사보다 유용한 검사로 생각된다.