Delaying effect of pyrroloquinoline quinone on age-related skin aging in mice and its mechanisms / 中华皮肤科杂志

Objective:To investigate the effect of pyrroloquinoline quinone (PQQ) on age-related skin aging in mice and its mechanisms.Methods:Thirty Kunming mice were fed in specific pathogen-free condition, and equally divided into 3 groups: young group was fed with a normal diet for 8 months, old group was fed with a normal diet for 20 months to establish a mouse model of natural aging, and PQQ group was fed with PQQ-containing forages (4 milligrams of PQQ per kilogram of normal forages) for 20 months. After feeding, the mouse dorsal skin tissues were obtained, hematoxylin and eosin (HE) staining was performed to measure the epidermal and dermal thickness, Masson staining to detect changes in total skin collagen, immunohistochemical study to detect changes in expression of the proliferation marker Ki67, transmission electron microscopy to detect changes in autophagosomes in the mouse skin, and Western blot analysis to determine the expression of autophagy-related proteins Beclin1, LC3Ⅱ/LC3Ⅰ, and p62. Statistical analysis was carried out by using one-way analysis of variance for intergroup comparisons followed by least significant difference (LSD) - t test for multiple comparisons. Results:HE and Masson staining showed that the epidermal and dermal thickness and the percentage of area of dermis stained positive for collagen among the total area of dermis in the tested region were significantly lower in the old group (15.67 ± 0.36 μm, 87.95 ± 11.86 μm, 22.12% ± 1.72%, respectively) than in the young group (29.37 ± 0.25 μm, 264.93 ± 10.34 μm, 45.03% ± 1.54%, respectively, all P<0.05) , and significantly higher in the PQQ group (25.53 ±0.47 μm, 145.01 ± 9.71 μm, 31.17% ± 1.20%, respectively) than in the old group (all P<0.05) . Immunohistochemical study revealed that the expression of Ki67 was significantly lower in the old group (13.74% ± 3.06%) than in the young group (29.07% ± 2.79%, P<0.05) and PQQ group (21.20% ± 1.47%, P<0.05) . Transmission electron microscopy showed that the number of autophagosomes in the skin was significantly higher in the old group than in the young group ( P<0.05) , but significantly lower in the PQQ group than in the old group ( P<0.05) . As Western blot analysis revealed, the old group showed significantly decreased Beclin1 expression and LC3 Ⅱ/LC3 Ⅰ ratio, but significantly increased p62 expression compared with the young group (all P<0.05) ; compared with the old group, the PQQ group showed significantly increased Beclin1 expression and LC3Ⅱ/LC3Ⅰratio, but significantly decreased p62 expression (all P<0.05) . Conclusion:PQQ can delay the age-related skin aging in mice, likely by increasing the proliferative capacity of mouse skin cells and promoting skin autophagy.

Comparison of the clinical effects of mini phalangeal external fixation and mini plate in the treatment of the metacarpal bone head intraarticular fractures / 中国综合临床

Objective To compare the clinical effects of mini phalangeal external fixation and mini plate in the treatment of intraarticular fractures of the metacarpal bone head,and to provide a theoretical basis for clinical selection of surgical plan. Methods Seventy?four cases of metacarpal bone head intraarticular fractures treated in Huizhou People′s Central Hospital from March 2014 to March 2016 were selected as the research object. All cases were closed fractures and were randomly divided into the external fixation group and the mini plate group,37 cases in each group and treated respectively with the mini phalangeal external fixator and mini AO plate. The patients were followed up for 6 months to 1 year,the function of the metacarpophalangeal joint,the union of the fracture and the incidence of side effects were compared between the two groups. Results The excellent rates of the external fixation group at 6 months and I year after operation were 91. 9% ( 34/37) and 97. 3%( 36/37) respectively,which were significantly higher than those of the mini plate group ( 73. 0%( 27/37) ,81. 2%( 30/37 ) ) , the difference was statistically significant (χ2 = 7. 120, 7. 062, P<0. 05 ) . The complication rate of the external fixation group was 2. 7%( 1/37) ,which was significantly lower than that of the mini plate group ( 24. 3% ( 9/37 ) ) , the difference was statistically significant ( P=0. 014 ) . The average fracture healing time in the external fixator group was (2. 6±0. 4) months,which was significantly lower than that in the mini plate group (3. 1±0. 7) months,the difference was statistically significant (t=2. 40,P<0. 001) . Conclusion In the treatment of metacarpal bone head fracture,the external fixation has small trauma,can do cross joint fixation,and maintain a good fixation strength,and promote the healing of fracture and the recovery of metacarpophalangeal joint function. It is worthy of clinical application.

The treatment effects and mechanisms of pyrroloquinoline quinone on defective teeth and mandible in Bmi-1 knockout mice / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the treatment effects and mechanisms of pyrroloquinoline quinine(PQQ) on defective teeth and mandible in Bmi-1 knockout mice.</p><p><b>METHODS</b>Male and female Bmi1(+/-) mice were paired with each other from the same nest. At the age of 7 weeks, the mice were divided into three groups, the wild type mice received normal diet(10 mice, WT group), Bmi1(-/-) mice received normal diet (10 mice, BKO group), and the Bmi1(-/-) mice received normal diet and PQQ diet(10 mice, BKO+PQQ group). X-ray and micro- CT were used to detect mandible and dental size and bone mineral density. HE staining, histochemical and immunohistochemical methods were respectively used to detect alveolar bone thickness of cortical bone, predentin thickness of mandibular first molar, mandibular osteoblast number and osteoclast number. Flow cytometry was used to detect reactive oxygen species(ROS) levels of various organs(femur, thymus and liver). The data were statistically analyzed with one-way ANOVA and t test.</p><p><b>RESULTS</b>Compared with BKO mice, BKO+PQQ mice partially rescued total body phenotype, increased body weight and prolonged survival time. X- ray and micro- CT showed the size of the mandible and teeth and bone mineral density of PQQ+BKO mice increased compared with BKO mice. In PQQ+BKO mice, mandibular alveolar bone cortical thickness [(68.65 ± 0.25) µm] was significantly different from that in BKO mice [(42.45 ± 0.35) µm] (P<0.01). There was significant difference in predentin thickness of mandibular first molar between PQQ+BKO mice [(4.25 ± 0.15) µm] and BKO mice [(31.55 ± 0.35) µm] (P<0.001). The number of osteoblasts in the mandible of BKO+PQQ mice [(38.45 ± 0.25) cell/mm³] was significantly higher than that in the BKO mice [(18.15 ± 0.55) cell/mm³] (P<0.01). However, the number of osteoclasts in the BKO+PQQ mice [(9.45 ± 0.25) cell/mm³] was significantly lower than that in the BKO group [(14.25 ± 0.35) cell/mm³] (P<0.01). Compared with the BKO group, ROS levels of the femur, thymus and liver in the BKO+PQQ mice were significantly decreased (P<0.01).</p><p><b>CONCLUSIONS</b>The results indicate that PQQ may have treatment effects on defective teeth and mandible through promoting osteoblast bone formation and reducing osteoclast bone resorption, scavenging ROS and reducing DNA damage.</p>

Detection of microlymphatic vessels density in oral squamous cell carcinoma / 实用口腔医学杂志

Objective:To approach the role of lymphangiogenesis in oral squamous cell carcinoma(OSCC). Methods: Immunohistochemical double staining technique was utilized to distinguish lymphatic vessels from blood vessels. MLVD was determined by manual counting to analyze the relationship with lymph node metastasis. Results: MLVD was significantly higher in 40 OSCC than 14 normal mucosa(P<0.01). MLVD in OSCC showed a statistically significant relationship with regional lymph node metastasis, depth of invasion(P<0.01). Conclusion: Lymphangiogenesis might occur in growth, infiltration and metastasis of OSCC. Detection of MLVD in OSCC might be important to evaluate tumor metastasis and judge prognosis.