A segmental root development as an unusual healing response to the revitalization of mandibular second premolar

A 15-year-old patient reported persistent pain in the left mandibular second premolar (#35) following a traumatic bite 3 months ago. Clinical examination revealed a fractured central cusp suggestive of dens evaginatus. Intraoral periapical radiograph revealed an immature permanent tooth with a periapical radiolucency. A diagnosis of pulp necrosis with symptomatic apical periodontitis was made. The tooth was treated according to the revised guidelines of regenerative endodontic procedure by the American Association of Endodontics. The follow-up evaluation revealed a complete resolution of periapical pathology. A detached radiopaque tissue was appreciated at the 12-month follow-up. It resembled a broken root tip at the 24-month follow-up. Both the main root body and disjointed root tip developed independently. A cone-beam computed tomography evaluation at the 36-month follow-up confirmed the segmented development of the apical root tip.

Expressions of cytokeratin 14 and proliferating cell nuclear antigen in the Hertwig's epithelial root sheath of a Vps4b knockout mouse / 华西口腔医学杂志

OBJECTIVES@#The effect of Vps4b gene mutation on the expressions of cytokeratin 14 (CK14) and proliferating cell nuclear antigen (PCNA) in the Hertwig's epithelial root sheath (HERS) is investigated.@*METHODS@#The bilateral mandibular tissues of mouse on postnatal days 5, 9, 11, 15, and 19 were removed. The mandibular first molar tissue sections were obtained after paraffin embedding. The CK14 and PCNA expressions in the epithelial root sheath of the normal mouse and Vps4b knockout mouse were compared through immunohistochemistry.@*RESULTS@#On postnatal day 5, the normal mouse began to form HERS and had a strong positive PCNA expression in the HERS cells; on postnatal day 9, the HERS structure was continuous, and PCNA was positive in the HERS cells; on postnatal day 11, a small portion of HERS began to break, and PCNA was weakly positive in the HERS cells; on postnatal day 15, HERS continued to fracture; PCNA was weakly and positively expressed in the HERS cells on the root surface; on postnatal day 19, the tooth root reached normal physiological length, and PCNA was positively expressed in the HERS cells of the terminal part. Similar to the normal mouse, the gene knockout mouse also formed a HERS structure on postnatal day 5. However, HERS began to break on postnatal day 9. On postnatal day 19, only a few fragments of HERS were found on the root surface, and the root development was immature. Moreover, the expression intensity of PCNA in the gene knockout mouse was decreased.@*CONCLUSIONS@#The Vps4b gene mutation may change the CK14 and PCNA expressions, leading to abnormal root development.

The role of bone morphogenetic protein signaling pathway in tooth root development / 华西口腔医学杂志

The bone morphogenetic protein (BMP) family is an important factor in the regulation of cell ular life activities and in the development of almost all tissues. BMP-mediated signaling plays an important role in tooth root development, which is a part of tooth development. Epithelial and mesenchymal interactions are involved in tooth root development, but the BMP signaling pathway has a different effect on tooth root development in epithelial and mesenchymal. This review summarizes the advances of BMP signaling in tooth root development.

Effect of epidermal growth factor on proliferation and migration ability of amelanotic melanocytes in human hair follicle outer root sheath / 重庆医学

Objective To investigate the effect of epidermal growth factor (EGF) on proliferation and migration ability of amelanotic melanocytes (AMMC) in human hair follicle outer root sheath.Methods AMMC were purified to the third generation by the variant enzyme method.Then AMMC was identified by the immunohistochemical method;the changes of cellular proliferation and migration ability after intervention by different concentrations of EGF were detected by using CCK8 and Tianswell in vitro chamber migration test.Results The third generation AMMC immaro histochemical staining showed NKI/beteb staining positive and HMB-45 staining negative.The OD values of CCK8 test and the Transwell in vitro chamber migration assay results showed that its promoting proliferation and migration effects were increased with the EGF concentration increase,but when further increasing concentration,the effects had no obvious enhancement.Conclusion A certain concentration range of EGF in vitro can promote AM-MC proliferation and migration.

308 nm excimer laser combined with piperine activated the production of melanin in amelanotic melanocytes in outer root sheath of hair / 重庆医学

Objective To study the mechanism of 308 nm excimer laser combined with piperine activated the production of melanin in amelanotic melanocytes in outer root sheath of hair(AMMC) ,and promote the expression of TRP‐1、TRP‐2 protein . Methods AMMC were in incubated for 24、72、120 h in different groups(combination therapy group ,the 308 nm excimer laser group ,the piperine group ,the positive control group and the control group) .Then the melanin content was measured .The expres‐sion change of TRP‐1 and TRP‐2 in cells were observed by laser scanning confocal microscopy .Results Four groups increased the AMMC cellular melanin content .Four different groups could promote melanin content at different degrees .The combination therapy group played the strongest role in promoting function .And the function was the most obviously in 24 h ,it also was concentration dependent .0 .5 mmol/L piperine in combination group and piperine group could produce promoting effect of within 72 h on the ex‐pression of TRP‐1 ,but its role was not evident in the expression of TRP‐2 .308 nm excimer laser had effects both on TRP 1 and TRP 2 .Conclusion 308 nm excimer laser combination with piperine can increase the activation of amelanotic melanocytes in outer root sheath of hair .

Use of hair root sheath for barr body determination.

Determination of sex is useful in Forensic Medicine. Barr bodies can be seen hair root sheath cells. The presence of barr bodies indicates that sex of the person is female. They are inactive X chromosome. The Barr bodies are also known as sex chromatin. Hair can present in the crime scene. Hair is trace evidence. The stain used was aceto-orcein. The percentage of barr bodies was found to be 28-49 %. The study was carried out for eight months and it was found that barr bodies persisted for eight months. It can be present anywhere at the crime scene. Hair of the accused can be present in hands of victim due to cadaveric spasm. Hair of victim can be found on the clothes of the accused. There is average fall in percentage of barr bodies with the passage of time due to the start of decomposition changes in the root sheath cells.

Sox9 Increases the Proliferation and Colony-forming Activity of Outer Root Sheath Cells Cultured In Vitro

BACKGROUND: beta-catenin plays a pivotal role in hair follicle development and hair growth cycle. OBJECTIVE: The aim of this study was to identify beta-catenin-regulated genes in cultured human hair outer root sheath (ORS) cells. METHODS: Primary cultured ORS cells were transduced with recombinant adenovirus expressing N-terminal truncated beta-catenin (constitutive active form), and beta-catenin-regulated genes were identified. RESULTS: Overexpression of the constitutively active form of beta-catenin led to induction of Sox9 expression at both mRNA and protein levels. To investigate the potential role of Sox9, we made the recombinant adenovirus expressing green fluorescent protein-tagged Sox9, and then transduced into cultured ORS cells. Interestingly, Sox9 induced the expression of keratin 15, increased the proliferation of ORS cells in vitro, and enhanced colony-forming activity. CONCLUSION: Our results suggest that Sox9 is a beta-catenin-regulated gene in ORS cells, and has potential importance in the regulation of hair follicle homeostasis.

Expressions of Cytokeratin and Ki-67 in the Development of the Pilomatricoma / 대한피부과학회지

BACKGROUND: Pilomatricoma (PM) is benign follicular tumor composed of the basophilic cells, transitional cells, shadow cells, squamoid cells and keratin filaments/amorphous debris. At present, PM is assumed to differentiate toward hair-forming cells of hair follicles but definite direction is not clear. OBJECTIVES: This study was made in order to investigate the pathways of cell differentiation associated with sudden keratinization in PM. METHODS: In the present study, 19 cases of human PM was histopathologically examined and classified into 4 groups according to the chronological stages. RESULTS: In the chronological stages according to Kaddu's classification, there were 2 cases of early lesion, 6 cases of fully developed lesion, 7 cases of early regressive lesion and 4 cases of late regressive lesion. The basophilic cells changed into the shadow cells or amorphous debris through the transitional cells moving toward the exterior of the PM, as well as toward the interior. As keratinization occurs, some inner basophilic cells which had been located in marginal areas of keratinization lost their tight cell-cell bonding. These cells showed edematous/vesicular and squamoid changes. High molecular weight cytokeratin was expressed in a linear pattern in some early and fully developed lesions. There were fewer layers of basophilic cells between the stroma and squamoid cells/amorphous debris than between the stroma and shadow cells. Ki-67 was expressed strongly both basal and overlying basophilic cells. Apoptotic bodies were detected in most transitional cell layers and some amorphous debris zones. CONCLUSIONS: The present study suggests dual pathways of cell differentiation in PMs. In the sudden keratinization pathway, the basophilic cells, transtional cells, shadow cells, and squamoid cells are suddenly keratinized, and the basophilic cells become early the transitional cells or squamoid cells. Cytoplasmic expressions of Ki-67 and cytokeratin in the basophilic cells show that the basophilic cells differentiate toward the innermost layer of the outer root sheath cells.

Culture of outer root sheath cells of murine vibrissa follicles in vitro and expression of uPA/uPAR / 第三军医大学学报

Objective To establish a method for the cultivation of hain follicle outer root sheath (ORS) cells of murine vibrissa and to study their expression of uPA/uPAR. Methods The ORS cells of murine vibrissa were cultured by combination of enzyme digestion and tissue culture with the feeder layer of dermal sheath cells of the hair follicle. The cells and their uPA/uPAR expression were identified by immunocytochemistry (ICC). Results The feeder layer of DS was suitable for the culture of ORS cells. ORS cells expressed uPA/uPAR protein. Conclusion The DS of hair follicle is a better feeder layer for the growth of ORS cells. ORS cells have the ability to migrate and proliferate.

Reconstruction and histologic characteristics of bilayer skin substitute inoculated of human hair follicle cells / 第三军医大学学报

Objective To study histologic characteristics of bilayer skin substitute reconstructed by cells from human hair follicle and whether the skin appendage can be induced based on the bilayer skin substitute.Methods After composite chitosan bilayer skin substitute was reconstructed with dermal papilla cells and outer root sheath cells or dermal sheath cells and outer root sheath cells,its histologic characteristics was investigated in vitro and after transplanted onto SD albino rats.Results Composite chitosan bilayer skin substitute reconstructed by cells from hair follicle had closely arranged epithelium cells and outstanding cornification;Epithelial cords linked with epidermis could be seen in dermis.However,there was no certain hair follicle-like structure formation either in vitro or in vivo.Conclusion Hair follicle cells are good source for skin substitute reconstruction,but it can not induce skin appendage formation through skin substitute by now.

Growth Effect of Minoxidil and Minoxidil Sulfate on Cultured Human Keratinocytes and Outer Root Sheath Cells

No abstract available.