Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach t...Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride （NaF） on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin （IL）-1β, matrix metalloproteinase 9 （MMP9）, and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL （receptor activator of nuclear factor KB ligand） and macrophage colony-stimulating factor （M-CSF）. The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells （NFAT） cl was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATcl, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.展开更多
BACKGROUND Pyogenic granuloma(PG)is a localized,reddish and vascularized hyperplastic lesion of the connective tissue which occurs in the oral cavity.In most cases,the presence of this lesion does not show alveolar bo...BACKGROUND Pyogenic granuloma(PG)is a localized,reddish and vascularized hyperplastic lesion of the connective tissue which occurs in the oral cavity.In most cases,the presence of this lesion does not show alveolar bone resorption.The pathology is diagnosed clinically with some caution.However,the diagnosis and treatment are usually corroborated with histopathological evidence.CASE SUMMARY Three clinical cases of PG associated with bone loss were described in this study.The three patients presented tumor-like growth which bled on touch,and were associated with local irritant factors.Radiographs showed bone loss.All cases were treated with conservative surgical excision.The scarring was satisfactory,and there was no case of recurrence.The diagnoses were based on clinical findings,and were confirmed histopathologically.CONCLUSION The occurrence of oral PG with bone loss is unusual.Therefore,clinical and radiographic evaluations are important for the diagnosis.展开更多
Doxycycline （DOX） exhibits anti-inflammatory and MMP inhibitory properties. The objectives of this study were to evaluate the effects of DOX on alveolar bone repair. Controls （CTL） and DOX-treated （10 and 25 mg. ...Doxycycline （DOX） exhibits anti-inflammatory and MMP inhibitory properties. The objectives of this study were to evaluate the effects of DOX on alveolar bone repair. Controls （CTL） and DOX-treated （10 and 25 mg. kg- 1） molars were extracted, and rats were killed 7 or 14 days later. The maxillae were processed and subjected to histological and immunohistochemical assays. Hematoxylin-eosin staining （7th day） revealed inflammation in the CTL group that was partly reversed after DOX treatment. On the 14th day, the CTL group exhibited bone neoformation, conjunctive tissue, re-epithelization and the absence of inflammatory infiltrate. DOX-treated groups exhibited complete re-epithelization, tissue remodelling and almost no inflammation. Picrosirius red staining in the DOXlO group （7th and 14th days） revealed an increased percentage of type I and III collagen fibres compared with the CTL and DOX25 groups. The DOXlO and DOX25 groups exhibited increases in osteoblasts on the 7th and 14th days. However, there were fewer osteoclasts in the DOXlO and DOX25 groups on the 7th and 14th days. Wnt-lOb- immunopositive cells increased by 130% and 150% on the 7th and 14th days, respectively, in DOX-treated groups compared with the CTL group. On the 7th day, Dickkopf （Dkk）-I immunostaining was decreased by 63% and 46% in the DOXlO and DOX25 groups, respectively. On the 14th day, 69% and 42% decreases in immunopositive cells were observed in the DOXlO and DOX25 groups, respectively, compared with the CTL group. By increasing osteoblasts, decreasing osteoclasts, activating Wnt lOb and neutralising Dkk, DOX is a potential candidate for bone repair in periodontal diseases.展开更多
Keratocystic odontogenic tumors(KCOTs,previously known as odontogenic keratocysts) are aggressive,noninflammatory jaw lesions with a putative high growth potential and a propensity for recurrence.This article puts tog...Keratocystic odontogenic tumors(KCOTs,previously known as odontogenic keratocysts) are aggressive,noninflammatory jaw lesions with a putative high growth potential and a propensity for recurrence.This article puts together a summary of the serial studies related to KCOTs undertaken by the author’s research group in recent years.Intraosseous jaw cysts with a solely orthokeratinized lining epithe-lium have been suggested to differ from the typical KCOTs.We report 20 cases of such cyst type under the term of ’orthokeratinized odontogenic cyst(OOC)’.Apart from the presence of a keratinizing epithelial lining,the OOC lacks the other histological features of KCOT,exhibits little if any tendency to recur,has no apparent association with NBCCS,may be cured by simple enucleation,and may thus constitute its own clinical entity.Mutations in PTCH1 gene are responsible for NBCCS and are related in tumors associated with this syndrome.We have so far detected 26 PTCH1 mutations(2 mutations occurred twice) in 10 out of 34(29.4%) sporadic and 14 out of 16(87.5%) NBCCS-associated KCOTs.The 26 mutations consisted of 10 frameshift,2 nonsense,3 aberrant splicing,4 in-frame insertion/deletion/ duplication and 7 missense mutations.Two missense mutations in PTCH2 were also detected in 2 out of 15 NBCCS related KCOT patients.By contrast,no pathogenic mutation was detected in SMO.Thus,our data,together with reports from ther groups,indicate that defects of PTCH1 are involved in the pathogenesis of syndromic as well as sporadic KCOTs.The pathogenic role of PTCH2 requires further investigation.A series of in vitro studies on bone resorption of KCOTs and ameloblastomas were undertaken by this group.The results indicate that odontogenic lesions could promote bone resorption in vitro and it is likely to be related to some of the cytokines secreted by the lesions.展开更多
文摘Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride （NaF） on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin （IL）-1β, matrix metalloproteinase 9 （MMP9）, and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL （receptor activator of nuclear factor KB ligand） and macrophage colony-stimulating factor （M-CSF）. The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells （NFAT） cl was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATcl, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.
文摘BACKGROUND Pyogenic granuloma(PG)is a localized,reddish and vascularized hyperplastic lesion of the connective tissue which occurs in the oral cavity.In most cases,the presence of this lesion does not show alveolar bone resorption.The pathology is diagnosed clinically with some caution.However,the diagnosis and treatment are usually corroborated with histopathological evidence.CASE SUMMARY Three clinical cases of PG associated with bone loss were described in this study.The three patients presented tumor-like growth which bled on touch,and were associated with local irritant factors.Radiographs showed bone loss.All cases were treated with conservative surgical excision.The scarring was satisfactory,and there was no case of recurrence.The diagnoses were based on clinical findings,and were confirmed histopathologically.CONCLUSION The occurrence of oral PG with bone loss is unusual.Therefore,clinical and radiographic evaluations are important for the diagnosis.
基金the financial support of the Brazilian National Research Council(CNPq)
文摘Doxycycline （DOX） exhibits anti-inflammatory and MMP inhibitory properties. The objectives of this study were to evaluate the effects of DOX on alveolar bone repair. Controls （CTL） and DOX-treated （10 and 25 mg. kg- 1） molars were extracted, and rats were killed 7 or 14 days later. The maxillae were processed and subjected to histological and immunohistochemical assays. Hematoxylin-eosin staining （7th day） revealed inflammation in the CTL group that was partly reversed after DOX treatment. On the 14th day, the CTL group exhibited bone neoformation, conjunctive tissue, re-epithelization and the absence of inflammatory infiltrate. DOX-treated groups exhibited complete re-epithelization, tissue remodelling and almost no inflammation. Picrosirius red staining in the DOXlO group （7th and 14th days） revealed an increased percentage of type I and III collagen fibres compared with the CTL and DOX25 groups. The DOXlO and DOX25 groups exhibited increases in osteoblasts on the 7th and 14th days. However, there were fewer osteoclasts in the DOXlO and DOX25 groups on the 7th and 14th days. Wnt-lOb- immunopositive cells increased by 130% and 150% on the 7th and 14th days, respectively, in DOX-treated groups compared with the CTL group. On the 7th day, Dickkopf （Dkk）-I immunostaining was decreased by 63% and 46% in the DOXlO and DOX25 groups, respectively. On the 14th day, 69% and 42% decreases in immunopositive cells were observed in the DOXlO and DOX25 groups, respectively, compared with the CTL group. By increasing osteoblasts, decreasing osteoclasts, activating Wnt lOb and neutralising Dkk, DOX is a potential candidate for bone repair in periodontal diseases.
文摘Keratocystic odontogenic tumors(KCOTs,previously known as odontogenic keratocysts) are aggressive,noninflammatory jaw lesions with a putative high growth potential and a propensity for recurrence.This article puts together a summary of the serial studies related to KCOTs undertaken by the author’s research group in recent years.Intraosseous jaw cysts with a solely orthokeratinized lining epithe-lium have been suggested to differ from the typical KCOTs.We report 20 cases of such cyst type under the term of ’orthokeratinized odontogenic cyst(OOC)’.Apart from the presence of a keratinizing epithelial lining,the OOC lacks the other histological features of KCOT,exhibits little if any tendency to recur,has no apparent association with NBCCS,may be cured by simple enucleation,and may thus constitute its own clinical entity.Mutations in PTCH1 gene are responsible for NBCCS and are related in tumors associated with this syndrome.We have so far detected 26 PTCH1 mutations(2 mutations occurred twice) in 10 out of 34(29.4%) sporadic and 14 out of 16(87.5%) NBCCS-associated KCOTs.The 26 mutations consisted of 10 frameshift,2 nonsense,3 aberrant splicing,4 in-frame insertion/deletion/ duplication and 7 missense mutations.Two missense mutations in PTCH2 were also detected in 2 out of 15 NBCCS related KCOT patients.By contrast,no pathogenic mutation was detected in SMO.Thus,our data,together with reports from ther groups,indicate that defects of PTCH1 are involved in the pathogenesis of syndromic as well as sporadic KCOTs.The pathogenic role of PTCH2 requires further investigation.A series of in vitro studies on bone resorption of KCOTs and ameloblastomas were undertaken by this group.The results indicate that odontogenic lesions could promote bone resorption in vitro and it is likely to be related to some of the cytokines secreted by the lesions.
