Objective:To investigate the effect of the antioxidant Tempol on the skin depigmentation of a vitiligo-like mouse model induced by the combination of the endogenous reactive oxygen species (ROS) producer AAPH and tyrosinase-related protein 2 (TRP2) -180 nonapeptide.Methods:A vitiligo-like skin depigmentation model was established by immunizing mice with injections of a TRP2-180 nonapeptide mixture into the foot pads twice and into the tails twice, with the injection interval being 1 week. After the first injection, 12 immune-induced mouse models of vitiligo were randomly divided into 4 groups (3 mice per group) : a model group, an AAPH group, a Tempol group, and a combined treatment group; additionally, 3 untreated mice injected with an ovalbumin (OVA) 257-264 peptide served as a sham control group. Mice in the AAPH group, the Tempol group, and the combined treatment group were subcutaneously injected with AAPH into the tails, intraperitoneally injected with Tempol, and received the above both treatments, respectively, while mice in the model group and the sham control group received phosphate-buffered saline injections into the tail and/or abdomen. Drug interventions were carried out 3 times per week for 3 consecutive weeks. Six weeks after the last immunization, mice were sacrificed. The area of depigmented macules on the tail was measured using a point-counting method, X-gal staining and double immunofluorescence staining were performed to assess the distribution and number of melanocytes, mast cells, and CD8 + T cells in depigmented macules on the tail. HaCaT cells were in vitro co-cultured with AAPH and/or Tempol, and a conventional culture group served as the control. Cellular ROS levels were measured by dichlorofluorescin diacetate labeling and flow cytometry; Western blot analysis was performed to determine the expression of matrix metalloproteinase 9 (MMP9) and stem cell factor (SCF) in cell lysates, and to detect soluble SCF levels in the culture supernatant. Comparisons among multiple groups were conducted using one-way analysis of variance, and multiple comparisons were performed using least significant difference- t test. Results:Depigmented macules were observed on the tails of mice in all groups except the sham control group. The area of depigmented macules was significantly larger in the AAPH group (7.27 ± 0.31 cm 2) than in the model group and combined treatment group (3.53 ± 0.21 cm 2, 4.07 ± 0.40 cm 2; t = 13.48, 11.56, respectively, both P < 0.001), while there was no significant difference between the Tempol group (3.30 ± 0.40 cm 2) and the model group ( P = 0.424). X-gal staining and double immunofluorescence staining showed that the number of melanocytes in the normal skin around the depigmented macules was significantly lower in the AAPH group and the combined treatment group than in the model group ( t = 6.31, 5.16, respectively, both P < 0.001), and no significant difference was observed between the AAPH group and the combined treatment group ( P = 0.516). The numbers of CD8 + T cells and mast cells were significantly higher in the AAPH group than in the model group and the combined treatment group (all P < 0.001). The numbers of the 3 types of cells mentioned above in the Tempol group did not differ from those in the model group (all P > 0.05). The ROS levels in HaCaT cells in the AAPH group were the highest, and significantly higher than those in the control group and the combined treatment group (both P < 0.001). Western blot analysis showed that the MMP9 level in the cell lysates and soluble SCF level in the culture supernatant were significantly higher in the AAPH group than in the control group and the combined treatment group (all P < 0.05) ; no significant difference was observed in the membrane-bound SCF level in cell lysates among the groups ( F = 0.06, P = 0.977) . Conclusion:The antioxidant Tempol could inhibit the formation of skin depigmented macules in vitiligo-like mouse models under AAPH-induced oxidative stress.

Objective:To investigate effects of rutin on ultraviolet irradiation (UVR) -induced human dermal fibroblast (FB) senescence and melanogenesis in mouse ear skin.Methods:The third- to fifth-passage FBs were divided into 4 groups: a blank control group, a UVR group, a rutin group, and a combined treatment group. In the UVR group, FBs were irradiated using an ultraviolet irradiator at a single dose of 0.6 J/cm 2 UVA combined with 0.03 J/cm 2 UVB once daily for 5 consecutive days; FBs in the rutin group were cultured in Dulbecco's modified Eagle medium containing 50 μmol/L rutin for 5 days; the combined treatment group received both UVR and the treatment with 50 μmol/L rutin for 5 days; the blank control group underwent no treatment. β-Galactosidase staining was performed to assess the senescence of FBs, real-time quantitative PCR (qPCR) to measure the telomere length in FBs, and Western blot analysis to detect the expression levels of stem cell factor (SCF) in FB cell lysates and culture supernatants. FB culture supernatants were collected from each group, and mixed with M254 medium at a ratio of 3∶1 to prepare conditioned medium, which was then used to treat PIG1 melanocytes for 24 hours. Western blot analysis was conducted to determine the tyrosinase (TYR) expression in PIG1 melanocytes in each group, while the 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay was applied to assess the proliferative activity of PIG1 cells in each group. Ten Dct-LacZ transgenic mice were divided into a control group and a UVR group. For each mouse, 5% rutin-containing cream was topically applied to the right ear after UVR, while the left ear treated with the cream base alone served as a control. Skin biopsies were performed after 4 weeks, followed by X-gal staining and Avidin/fluorescein isothiocyanate (FITC) staining to count the numbers of melanocytes and mast cells in mouse ear skin. Results:In the UVR group, the number of senescent FBs (25.67 ± 2.89), relative protein expression levels of SCF (1.95 ± 0.22), and relative levels of SCF in the cell culture supernatant (1.52 ± 0.34) were all significantly higher than those in the blank control group (5.67 ± 1.56, 0.95 ± 0.11, 1.01 ± 0.31, respectively), while these indicators were significantly lower in the combined treatment group (12.00 ± 1.63, 1.32 ± 0.19, 1.15 ± 0.32, respectively) than in the UVR group (all P < 0.05). The relative telomere length in FBs was significantly shorter in the UVR group (0.49 ± 0.12) than in the blank control group (0.94 ± 0.11; LSD- t = 3.15, P = 0.021), but significantly longer in the combined treatment group (0.81 ± 0.13) than in the UVR group (LSD- t = 4.30, P = 0.034). After the treatment with FB conditioned medium, the relative expression level of TYR in PIG1 melanocytes and the number of EdU-positive cells were significantly higher in the UVR group (2.54 ± 0.21, 33.54 ± 3.21, respectively) than in the blank control group (0.97 ± 0.19, 21.45 ± 2.51, respectively; both P < 0.001), but significantly lower in the combined treatment group (1.63 ± 0.12, 18.54 ± 3.87, respectively) than in the UVR group (both P < 0.001). X-gal staining and Avidin/FITC staining showed that the numbers of melanocytes and mast cells in the mouse left ear skin in the UVR group (5.00 ± 1.22, 98.60 ± 8.47, respectively) were significantly higher than those in the mouse left ear skin in the control group (1.80 ± 0.45, 53.80 ± 5.76, respectively) and those in the mouse right ear skin treated with the rutin-containing cream in the UVR group (2.80 ± 0.45, 69.60 ± 8.89, respectively) (all P < 0.05) . Conclusion:Rutin may inhibit UVR-induced skin melanogenesis by suppressing the senescence of dermal FBs and paracrine secretion of SCF.

Objective:To investigate the effect of the antioxidant Tempol on the skin depigmentation of a vitiligo-like mouse model induced by the combination of the endogenous reactive oxygen species (ROS) producer AAPH and tyrosinase-related protein 2 (TRP2) -180 nonapeptide.Methods:A vitiligo-like skin depigmentation model was established by immunizing mice with injections of a TRP2-180 nonapeptide mixture into the foot pads twice and into the tails twice, with the injection interval being 1 week. After the first injection, 12 immune-induced mouse models of vitiligo were randomly divided into 4 groups (3 mice per group) : a model group, an AAPH group, a Tempol group, and a combined treatment group; additionally, 3 untreated mice injected with an ovalbumin (OVA) 257-264 peptide served as a sham control group. Mice in the AAPH group, the Tempol group, and the combined treatment group were subcutaneously injected with AAPH into the tails, intraperitoneally injected with Tempol, and received the above both treatments, respectively, while mice in the model group and the sham control group received phosphate-buffered saline injections into the tail and/or abdomen. Drug interventions were carried out 3 times per week for 3 consecutive weeks. Six weeks after the last immunization, mice were sacrificed. The area of depigmented macules on the tail was measured using a point-counting method, X-gal staining and double immunofluorescence staining were performed to assess the distribution and number of melanocytes, mast cells, and CD8 + T cells in depigmented macules on the tail. HaCaT cells were in vitro co-cultured with AAPH and/or Tempol, and a conventional culture group served as the control. Cellular ROS levels were measured by dichlorofluorescin diacetate labeling and flow cytometry; Western blot analysis was performed to determine the expression of matrix metalloproteinase 9 (MMP9) and stem cell factor (SCF) in cell lysates, and to detect soluble SCF levels in the culture supernatant. Comparisons among multiple groups were conducted using one-way analysis of variance, and multiple comparisons were performed using least significant difference- t test. Results:Depigmented macules were observed on the tails of mice in all groups except the sham control group. The area of depigmented macules was significantly larger in the AAPH group (7.27 ± 0.31 cm 2) than in the model group and combined treatment group (3.53 ± 0.21 cm 2, 4.07 ± 0.40 cm 2; t = 13.48, 11.56, respectively, both P < 0.001), while there was no significant difference between the Tempol group (3.30 ± 0.40 cm 2) and the model group ( P = 0.424). X-gal staining and double immunofluorescence staining showed that the number of melanocytes in the normal skin around the depigmented macules was significantly lower in the AAPH group and the combined treatment group than in the model group ( t = 6.31, 5.16, respectively, both P < 0.001), and no significant difference was observed between the AAPH group and the combined treatment group ( P = 0.516). The numbers of CD8 + T cells and mast cells were significantly higher in the AAPH group than in the model group and the combined treatment group (all P < 0.001). The numbers of the 3 types of cells mentioned above in the Tempol group did not differ from those in the model group (all P > 0.05). The ROS levels in HaCaT cells in the AAPH group were the highest, and significantly higher than those in the control group and the combined treatment group (both P < 0.001). Western blot analysis showed that the MMP9 level in the cell lysates and soluble SCF level in the culture supernatant were significantly higher in the AAPH group than in the control group and the combined treatment group (all P < 0.05) ; no significant difference was observed in the membrane-bound SCF level in cell lysates among the groups ( F = 0.06, P = 0.977) . Conclusion:The antioxidant Tempol could inhibit the formation of skin depigmented macules in vitiligo-like mouse models under AAPH-induced oxidative stress.

Objective:To investigate effects of rutin on ultraviolet irradiation (UVR) -induced human dermal fibroblast (FB) senescence and melanogenesis in mouse ear skin.Methods:The third- to fifth-passage FBs were divided into 4 groups: a blank control group, a UVR group, a rutin group, and a combined treatment group. In the UVR group, FBs were irradiated using an ultraviolet irradiator at a single dose of 0.6 J/cm 2 UVA combined with 0.03 J/cm 2 UVB once daily for 5 consecutive days; FBs in the rutin group were cultured in Dulbecco's modified Eagle medium containing 50 μmol/L rutin for 5 days; the combined treatment group received both UVR and the treatment with 50 μmol/L rutin for 5 days; the blank control group underwent no treatment. β-Galactosidase staining was performed to assess the senescence of FBs, real-time quantitative PCR (qPCR) to measure the telomere length in FBs, and Western blot analysis to detect the expression levels of stem cell factor (SCF) in FB cell lysates and culture supernatants. FB culture supernatants were collected from each group, and mixed with M254 medium at a ratio of 3∶1 to prepare conditioned medium, which was then used to treat PIG1 melanocytes for 24 hours. Western blot analysis was conducted to determine the tyrosinase (TYR) expression in PIG1 melanocytes in each group, while the 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay was applied to assess the proliferative activity of PIG1 cells in each group. Ten Dct-LacZ transgenic mice were divided into a control group and a UVR group. For each mouse, 5% rutin-containing cream was topically applied to the right ear after UVR, while the left ear treated with the cream base alone served as a control. Skin biopsies were performed after 4 weeks, followed by X-gal staining and Avidin/fluorescein isothiocyanate (FITC) staining to count the numbers of melanocytes and mast cells in mouse ear skin. Results:In the UVR group, the number of senescent FBs (25.67 ± 2.89), relative protein expression levels of SCF (1.95 ± 0.22), and relative levels of SCF in the cell culture supernatant (1.52 ± 0.34) were all significantly higher than those in the blank control group (5.67 ± 1.56, 0.95 ± 0.11, 1.01 ± 0.31, respectively), while these indicators were significantly lower in the combined treatment group (12.00 ± 1.63, 1.32 ± 0.19, 1.15 ± 0.32, respectively) than in the UVR group (all P < 0.05). The relative telomere length in FBs was significantly shorter in the UVR group (0.49 ± 0.12) than in the blank control group (0.94 ± 0.11; LSD- t = 3.15, P = 0.021), but significantly longer in the combined treatment group (0.81 ± 0.13) than in the UVR group (LSD- t = 4.30, P = 0.034). After the treatment with FB conditioned medium, the relative expression level of TYR in PIG1 melanocytes and the number of EdU-positive cells were significantly higher in the UVR group (2.54 ± 0.21, 33.54 ± 3.21, respectively) than in the blank control group (0.97 ± 0.19, 21.45 ± 2.51, respectively; both P < 0.001), but significantly lower in the combined treatment group (1.63 ± 0.12, 18.54 ± 3.87, respectively) than in the UVR group (both P < 0.001). X-gal staining and Avidin/FITC staining showed that the numbers of melanocytes and mast cells in the mouse left ear skin in the UVR group (5.00 ± 1.22, 98.60 ± 8.47, respectively) were significantly higher than those in the mouse left ear skin in the control group (1.80 ± 0.45, 53.80 ± 5.76, respectively) and those in the mouse right ear skin treated with the rutin-containing cream in the UVR group (2.80 ± 0.45, 69.60 ± 8.89, respectively) (all P < 0.05) . Conclusion:Rutin may inhibit UVR-induced skin melanogenesis by suppressing the senescence of dermal FBs and paracrine secretion of SCF.

Objective This paper expounds the present situation of the construction and probes into the development path of the medical characteristic disciplines,so as to provide guidance for the development of the characteristic disciplines of local medical colleges and universities.Methods According to the general characteristics of the discipline construction of the local medical colleges and universities,through the analysis of the current situation of the objective development and the restriction of the bottleneck,to analyze the new methods and new ways for the development of the characteristic disciplines in local medical colleges and universities.Results Medical characteristic disciplineconstruction should pursue sustainable development,mining subject characteristics;concise direction of research,enhance the level of scientific research;focus on academic exchanges,build talent echelon;integrate all kinds of resources,construction of subject group;building performance evaluation,pioneering achievement innovation.Conclusions Local educational institutions and medical colleges and universities should fully understand the importance of characteristic disciplines to meet the needs of local development and create brand culture.The characteristic disciplines with prominent advantages,reasonable structure and sustainable development should be established.

OBJECTIVETo research the influence of K(2)O composition in the raw material on leucite microcrystallization and to study the effect of leucite content on compressive strength of the dental glass ceramics reinforced by leucite microcrystallization.

METHODSThe raw materials with different K(2)O content were treated by a decided thermal treatment system. The products were analyzed by polaring microscope and X-ray diffractometer, and their compressive strength was also tested.

RESULTSThe microstructure of products from high K(2)O component was remarkably good, at microcrystal size of 0.8 micro m and the compressive strength was 206.6 MPa. A positive correlation was found between leucite volume and the compressive strength when leucite volume was less than 50% (Vol%).

CONCLUSIONSThe component of K(2)O has a great effect on the microstructure and the properties of the leucite-microcrystal-reinforced dental glass ceramics and the content of leucite microcrystals has a notable influence on the compressive strength of the dental glass ceramics.

Compressive Strength ; Crystallization ; Dental Porcelain ; chemistry ; Glass ; chemistry ; Materials Testing