A long-term evaluation of periodontal phenotypes before and after the periodontal-orthodontic-orthognathic combined treatment of lower anterior teeth in patients with skeletal Angle class Ⅲ malocclusion / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the changes of periodontal phenotype (width of keratinized gingiva, thickness and height of alveolar bone) of lower anterior teeth in patients with skeletal class Ⅲ malocclusion before and after the periodontal-orthodontic-orthognathic combined treatment.@*METHODS@#In the study, 20 patients with skeletal class Ⅲ malocclusion (6 males and 14 females) completed the periodontal-orthodontic-orthognathic combined treatment were included from March 2017 to June 2022, with 39 central incisors, 40 lateral incisors and 40 canines. The mean age was (25.40±4.27) years (20-34 years). The mean follow-up time was (3.70±1.05) years from the beginning of periodontal corticotomy regenerative surgery (PCRS) to the end of the combined treatment. Cone-beam computed tomography (CBCT) was used to measure the thickness, area and height of alveolar bone by the same researcher, taken before the PCRS (T0), 6 months after the PCRS (T1), 12 months after the PCRS (T2), before the orthognathic surgery (T3), and after the periodontal-orthodontic-orthognathic combined treatment (T4). The periodontal clinical parameters were used to evaluate changes in the soft tissue by another researcher, measured before the PCRS (T0) and after the combined treatment (T4). Changes of soft and hard tissue were evaluated by the periodontal phenotype.@*RESULTS@#The width of keratinized gingiva increased significantly (all P < 0.001) in lower anterior teeth, the central incisors, lateral incisors and canines increased by (1.82±1.57) mm, (2.03±1.48) mm and (2.05±1.27) mm, respectively. The proportion of thick periodontal biotype in the central and lateral incisors increased significantly (all P < 0.001), while the changes of periodontal biotypes in the lower canines were not obvious. The thickness of labial alveolar bone of lower anterior teeth all increased significantly after periodontal corticotomy regenerative surgery and the combined treatment (all P < 0.001). The area of labial alveolar bone of lower anterior teeth also increased significantly after the combined treatment (all P < 0.001). The whole area of labial and lingual alveolar bone of central and lateral incisors increased (P < 0.001), while the whole area of canines remained the same. All The height of the alveolar bone increased (all P < 0.001) on the labial side after the treatment.@*CONCLUSION@#The periodontal phenotypes of lower anterior teeth were significantly improved after the periodontal-orthodontic-orthognathic combined treatment in patients with skeletal Angle class Ⅲ malocclusion. The improvement was long-termly stable, and the periodontal risk was reduced.

Establishment and Evaluation of Intestinal Injury Model of Mouse Acute Graft Versus Host Disease Based on An Organoid Technology / 中国实验血液学杂志

OBJECTIVE@#To establish an intestinal organoid model that mimic acute graft versus host disease (aGVHD) caused intestinal injuries by using aGVHD murine model serum and organoid culture system, and explore the changes of aGVHD intestine in vitro by advantage of organoid technology.@*METHODS@#20-22 g female C57BL/6 mice and 20-22 g female BALB/c mice were used as donors and recipients for bone marrow transplantation, respectively. Within 4-6 h after receiving a lethal dose (8.0 Gy) of γ ray total body irradiation, a total of 0.25 ml of murine derived bone marrow cells (1×107/mice, n=20) and spleen nucleated cells (5×106/mice, n=20) was infused to establish a mouse model of aGVHD (n=20). The aGVHD mice were anesthetized at the 7th day after transplantation, and the veinal blood was harvested by removing the eyeballs, and the serum was collected by centrifugation. The small intestinal crypts of healthy C57BL/6 mice were harvested and cultivated in 3D culture system that maintaining the growth and proliferation of intestinal stem cells in vitro. In our experiment, 5%, 10%, 20% proportions of aGVHD serum were respectively added into the organoid culture system for 3 days. The formation of small intestinal organoids were observed under an inverted microscope and the morphological characteristics of intestinal organoids in each groups were analyzed. For further evaluation, the aGVHD intestinal organoids were harvested and their pathological changes were observed. Combined with HE staining, intestinal organ morphology evaluation was performed. Combined with Alcian Blue staining, the secretion function of aGVHD intestinal organoids was observed. The distribution and changes of Lgr5+ and Clu+ intestinal stem cells in intestinal organoids were analyzed under the conditions of 5%, 10% and 20% serum concentrations by immunohistochemical stainings.@*RESULTS@#The results of HE staining showed that the integrity of intestinal organoids in the 5% concentration serum group was better than that in the 10% and 20% groups. The 5% concentration serum group showed the highest number of organoids, the highest germination rate and the lowest pathological score among experimental groups, while the 20% group exhibited severe morphological destruction and almost no germination was observed, and the pathological score was the highest among all groups(t=3.668, 4.334,5.309,P<0.05). The results of Alican blue staining showed that the secretion function of intestinal organoids in serum culture of aGVHD in the 20% group was weaker than that of the 5% group and 10% of the organoids, and there was almost no goblet cells, and mucus was stainned in the 20% aGVHD serum group. The immunohistochemical results showed that the number of Lgr5+ cells of intestinal organoids in the 5% group was more than that of the intestinal organoids in the 10% aGVHD serum group and 20% aGVHD serum group. Almost no Clu+ cells were observed in the 5% group. The Lgr5+ cells in the 20% group were seriously injuried and can not be observed. The proportion of Clu+ cells in the 20% group significantly increased.@*CONCLUSION@#The concentration of aGVHD serum in the culture system can affect the number and secretion function of intestinal organoids as well as the number of intestinal stem cells in organoids. The higher the serum concentration, the greater the risk of organoid injury, which reveal the characteristics of the formation and functional change of aGVHD intestinal organoids, and provide a novel tool for the study of intestinal injury in aGVHD.

Role of eNOS/PKG-1 pathway in L-Arginine against right ventricular remodeling induced by monocrotaline in rats / 中国药理学通报

Aim To investigate the role of eNOS/PKG- 1 pathway in L-arginine (L-arg) intervention in right ventricular remodeling induced by monocrotaline (MCT) in Sprague Dawley (SD) rats with the aid of the tool medicine L-NAME. Methods Twenty SD rats were randomly divided into control group, MCT group, L-Arg group and L-Arg + L-NAME group. The general condition of rats was observed; the right ventricular pressure of rats was measured by right heart catheterization; the rats and the right ventricle were weighed and the right ventricular mass index was calculated; the morphological changes of the right ventricular were observed by H&E staining; the protein expressions of cTnl, eNOS and PKG-1 were detected by Western blot in the right ventricular. Results Compared with control group, right ventricular max pressure and right ventricular mass index significantly increased ( P < 05) ; the weight of rats in MCT group was significantly reduced ( P < 0. 05); the right ventricular myocytes were hypertrophic, disordered and infiltrated with inflammatory cells; the protein expression of cTnl was obviously up-regulated ( P < 0. 05 ) ; the protein expressions of eNOS and PKG-1 were significantly down- regulated ( P < 0. 05 ) . L-arg could significantly improve the above changes ( P < 0. 05 ). However, the effects of L-arg were inhibited by eNOS inhibitor L- NAME. Conclusions L-arg can improve the right ventricular remodeling in rats induced by MCT, and the mechanism may be related to the up-regulation of the protein levels of eNOS and PKG-1.

Acupuncture for premature ovarian insufficiency: a systematic review and meta-analysis / 针灸推拿医学（英文版）

Objective: To analyze the effect of acupuncture versus hormone replacement therapy (HRT) for premature ovarian insufficiency (POI). Methods: China National Knowledge Infrastructure (CNKI), Wanfang Academic Journal Full-text Database (Wanfang), Chongqing VIP Database (CQVIP), China Biology Medicine Disc (CBM), Web of Science, Cochrane Library, PubMed, and Excerpta Medica Database (EMBASE) were searched up to January 31st, 2019 to identify randomized controlled trials (RCTs) evaluating the effect of acupuncture for POI. The primary outcome was the level of basal serum follicle- stimulating hormone (FSH). Secondary outcomes included serum levels of luteinizing hormone (LH), estradiol (E2) and anti-Müllerian hormone (AMH). Two authors extracted data independently and assessed the risk of bias and the methodological quality using the Cochrane's tool. Meta-analysis was conducted by RevMan version 5.3. Results: Eight eligible RCTs with a total of 496 POI patients were included in the meta-analysis. The pooled results showed that there was a significant reduction in the basal serum FSH level (MD=-5.82, 95％CI:-9.76 to -1.87, I2=82％, P=0.004) and a remarkable elevation in the basal E2 level (SMD=0.93, 95％CI: 0.34 to 1.52, I2=88％, P=0.002) in the acupuncture group when compared with the control. Subgroup analysis showed that compared with HRT, a significant decrease in the FSH level was observed in both acupuncture alone (MD=-4.53, 95％CI:-8.96 to -0.10, I2=73％, P=0.04) and acupuncture plus HRT (MD=-9.60, 95％CI:-17.60 to -1.61, I2=50％, P=0.02), while a remarkable elevation of E2 was only found in acupuncture plus HRT (SMD=1.43, 95％CI: 1.03 to 1.82, I2=0％, P<0.00001). There was no significant difference in the LH level between acupuncture and HRT (MD=-3.16, 95％CI:-9.41 to 3.10, I2=0％, P=0.32), only one trial reported AMH, and no significant difference was found between acupuncture and HRT. Conclusion: The present study indicated that acupuncture had an advantage over HRT in reducing serum FSH level and increasing serum E2 level in women with POI. However, evidence supporting the finding is limited due to the small sample size, potential methodological flaws and significant heterogeneity. Hence, this conclusion still needs to be verified by high-quality RCTs.

Application value of whole exome sequencing in critically ill neonates with inherited diseases / 中国当代儿科杂志

OBJECTIVE@#To study the application value of whole exome sequencing (WES) in critically ill neonates with inherited diseases.@*METHODS@#A total of 66 critically ill neonates with suspected inherited diseases or unclear clinical diagnosis who were admitted to the neonatal intensive care unit were enrolled as subjects. The clinical data of the neonates were collected, and venous blood samples were collected from the neonates and their parents for WES. The clinical manifestations of the neonates were observed to search for related pathogenic gene mutations.@*RESULTS@#Among the 66 critically ill neonates with suspected inherited diseases or unclear clinical diagnosis (34 boys and 32 girls), 14 (21%) were found to have gene mutations by WES. One neonate had no gene mutation detected by WES but was highly suspected of pigment incontinence based on clinical manifestations, and multiplex ligation-dependent probe amplification detected a heterozygous deletion mutation in exons 4-10 of the IKBKG gene. Among the 15 neonates with gene mutations, 10 (67%) had pathogenic gene mutation, 1 (7%) was suspected of pathogenic gene mutation, and 4 (27%) had gene mutations with unknown significance. Among the 15 neonates, 13 underwent chromosome examination, and only 1 neonate was found to have chromosome abnormality.@*CONCLUSIONS@#Chromosome examination cannot be used as a diagnostic method for inherited diseases, and WES detection technology is an important tool to find inherited diseases in critically ill neonates with suspected inherited diseases or unclear clinical diagnosis; however WES technology has some limitation and it is thus necessary to combine with other sequencing methods to achieve an early diagnosis.

Alveolar crest and relevant analysis of labial side of anterior teeth on skeletal Angle class III patients / 北京大学学报(医学版)

OBJECTIVE@#To measure the distance from cemento-enamel junction (CEJ) to alveolar crest (AC) of labial side of anterior teeth on skeletal Angle class III patients under direct vision during periodontal bone augmentation surgery and to make relevant analysis to find the relevant factors.@*METHODS@#In the study, 46 skeletal Angle class III patients (10 males and 36 females) received periodontal bone augmentation surgery of anterior teeth were included, with 67 jaws (27 maxillae and 40 mandibles) and 400 anterior teeth (161 maxillary anterior teeth and 239 mandibular anterior teeth). The mean age was 23.65 years. Maxillary anterior teeth consisted of 54 central incisors, 53 lateral incisors and 54 canines. Mandibular anterior teeth consisted of 79 central incisors, 80 lateral incisors and 80 canines. CEJ-AC was measured in three sites (mesial sites, central sites and distal sites) by Williams periodontal probes during periodontal bone augmentation surgery under direct vision by the same researcher.@*RESULTS@#The average CEJ-AC of 400 anterior teeth was (2.21±1.48) mm. The average CEJ-AC of maxillary anterior teeth was (1.72±1.13) mm, more than (2.54±1.60) mm of mandibular anterior teeth (P<0.05). The average CEJ-AC of canines was (2.42±1.78) mm, more than (2.06±1.27) mm of central incisors or (2.16±1.32) mm of lateral incisors (P<0.05). The average CEJ-AC of central sites was (3.04±2.01) mm, more than (1.79±0.86) mm of mesial sites or (1.81±0.89) mm of distal sites (P<0.05). CEJ-AC of 233 anterior teeth was more than 2 mm, accounting for 58.25%, and 117 anterior teeth with dehiscence were found, accounting for 29.25%. Multilevel and multivariate Logistic regression showed age, jaw, tooth and site were the relevant factors to the position of alveolar crest.@*CONCLUSION@#The position of alveolar crest of skeletal Angle class III patients who received periodontal bone augmentation surgery was lower than that of the general population, causing periodontal risks during decompensation orthodontics therapy before orthognathic surgery. The position of alveolar crest was lower in older patients than in younger patients, in mandibular teeth than in maxillary teeth, in canines than in central incisors or lateral incisors, and in central sites than in mesial sites or distal sites of labial side, which showed much higher risk.

Selecting and defining the clinical questions and outcomes of Guideline for the Emergency Treatment of Anaphylaxis / 北京大学学报(医学版)

OBJECTIVE@#To select and define the clinical questions and outcomes of Guideline for the Emergency Treatment of Anaphylaxis.@*METHODS@#A draft including clinical questions, which could be divided into foreground questions and background questions, and outcomes was drawn and revised by the secretary group for the guideline referring to the present guidelines with the guidance of a panel consisting of 7 experienced clinical medicine, pharmacy and nursing experts. Foreground questions and outcomes of the draft were voted into a final version after three rounds of counsels of 22 experienced medicine, pharmacy and nursing clinical experts using Delphi method including 3 rounds of inquiry. And the background questions were directly included in the guideline after the 22 experts' thorough revising. The research was carried out under the supervision of method ologists. Active coefficient, coefficient of variation and the frequencies of each score were calculated for quality control.@*RESULTS@#The draft of 34 foreground questions, 6 background questions and 6 outcomes was finally drawn up after thorough selecting and consulting. The 6 background questions revised by the clinical experts were all included. After three rounds of Delphi method, 28 pivotal clinical questions covering the diagnosis, preparation for the treatment, treatment and administration after the treatment, and 6 outcomes were defined and included for the guideline. The rest of the foreground questions, 4 of which were recognized as essential and 2 as important, were excluded from the guideline and left for further revising or updating. As for the outcomes, 4 of them were recognized as critical and the rest as important. The experts contributing to the research were active as the active coefficient reached 100%, and the degree of consensus was fine as the frequencies of the feedback scoring equal to or greater than 4 for all the 28 foreground questions included were greater than 75% and the result was settled in the first round. And 2 outcomes, fatality rate and severity, reached a higher degree of consensus with coefficient of variation less than 15%.@*CONCLUSION@#After thorough and rigorous selecting, the clinical questions and outcomes to be included in the Guideline for the Emergency Treatment of Anaphylaxis were finally selected and defined via Delphi method, guiding the future development of the guidelines.

Survival analysis of 118 chronic lymphocytic leukemia patients with abnormal TP53 gene in the era of traditional immunochemotherapy / 中华血液学杂志

Objective: To analyze the survival and first-line immune-chemotherapy (CIT) of chronic lymphocytic leukemia (CLL) with abnormal TP53 gene in the era of traditional CIT. Methods: The clinical data of 118 CLL patients diagnosed from January 2003 to August 2017 were collected. Survival was analyzed according to indicators including sex, age, Binet risk stratification, B symptoms, β(2)-microglobulin (β(2)-MG) , immunoglobulin heavy chain variable region gene (IGHV) mutation status, chromosome karyotype and TP53 gene deletion/mutation. The efficacy of first-line CIT of 101 CLL patients was further analyzed. Results: Among 118 patients, median progression-free survival (PFS) was 12 (95%CI 10.148-13.852) months and median overall survival (OS) was 53 (95%CI 41.822-64.178) months, only 30.5% patients survived over 5 years. Low β(2)-MG<3.5 mg/L indicated longer PFS (P=0.027) , female and Binet A patients had longer OS (P=0.011 and 0.013, respectively) . Of 118 patients, 17 (14.4%) didn't receive any therapy until follow-up time or the dead time. Among the 101 patients who received ≥1 CIT, median time to first treatment (TTFT) was 1 (0-62) months, patients in Binet A had longer TTFT (P<0.001) compared to the patients in Binet B/C. According to statistical needs, we divided those first-line CIT into four groups: there were 30 cases (29.7%) in mild chemotherapy group (mainly treated with nitrogen mustard phenylbutyrate or rituximab alone) , 32 cases (31.7%) in the fludarabine-containing group, 23 cases (22.8%) in high-dose methyprednisolone (HDMP) containing group and 16 cases (15.8%) in the other chemotherapy group. The first regimen contained HDMP can bring longer PFS (P<0.001) , however the OS between four groups had no statistical differences. Conclusion: CLL patients with abnormal TP53 gene had poor response to immunotherapy, rapid clinical progressing, first-line immunotherapy containing HDMP can prolong PFS and will create an opportunity for patients to participate in clinical trials of novel drugs.

Accuracy analysis of alveolar dehiscence and fenestration of maxillary anterior teeth of Angle class III by cone-beam CT / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the accuracy and reliability of detecting alveolar bone dehiscence and fenestration of maxillary anterior teeth of Angle class III by cone-beam computed tomography (CBCT).@*METHODS@#Eighteen Angle class III patients with 108 maxillary anterior teeth were included (3 males and 15 females) who accepted modified corticotomy in orthodontic therapy. The mean age was 23.6 years (18-30 years). The clinical detection of dehiscence and fenestration was done when modified corticotomy was performed by the same periodontist. The CBCT examination was conducted pre-operation and the detection of dehiscence and fenestration by CBCT was done by two periodontists. The data in modified corticotomy were used as the golden standard to calculate the parameters, such as sensitivity, specificity, positive and negative predictive values, Youden index (YI), positive and negative likelihood ratio. Kappa statistic was used to analyze the agreement between the clinical detection and the CBCT detection.@*RESULTS@#The incidence of dehiscence and fenestration was about 10.19% and 13.89% respectively, which mainly occurred on lateral incisors and canines. The median values of length and width of dehiscence were about 5 mm and 4 mm, and the median values of length and width of fenestration were 3 mm and 2 mm, respectively. Most fenestrations were detected on the middle third to the apical third of the root. For dehiscence, the agreement between clinical detection and CBCT detection was statistically significant (P<0.05). For fenestration, the agreement between clinical detection and CBCT detection was statistically significant (P<0.05). The values of sensitivity and specificity for detecting dehiscence were more than 0.7. The values of positive and negative predictive values for detecting dehiscence were 0.44 and 0.97. The values of sensitivity and specificity for detecting fenestration were 0.93 and 0.52. The values of positive and negative predictive values for detecting fenestration were 0.24 and 0.98.@*CONCLUSION@#For dehiscence, the agreement between clinical detection and CBCT detection was good. For fenestration, the agreement between clinical detection and CBCT detection was general. Detection of dehiscence and fenestration of maxillary anterior teeth of Angle class III by CBCT had limited diagnostic value in clinical practice with overestimation of dehiscence and fenestration incidence.

Anatomical study of the atypical azygos venous system and its clinical significance / 局解手术学杂志

Objective To investigate the morphology and classification of the atypical azygos venous system,and to provide reference for diagnosis and treatment of mediastinal and thoracic vascular diseases.Methods Thirty cadavers were perfused with 10%formalin solution, and immersed in the solution for one month before dissection.The vertebral levels of termination and diameters of the azygos,hemiazygos and accessory hemiazygos veins were examined.Results There were 24 cases of classical azygos venous system,which contained the azygos, hemiazygos and accessory hemiazygos veins.And there were 6 cases of atypical azygos venous system,which were further divided into 4 sub-groups.Namely,type a(2 cases)which showed an inverted"Y"shape;type b(2 cases)which was single column with hemiazygos and ac-cessory hemiazygos veins absent;type c(1 case)which showed an accessory hemiazygos vein draining into the left brachiocephalic vein;and type d(1 case)with azygos vein and double superior vena cava variation.Diameters of termination of the azygos,hemiazygos and accessory hemiazygos veins were(10.39 ±1.98)mm,(8.51 ±2.28)mm,and(6.29 ±1.56)mm,respectively.The vertebral levels of termination of the azygos,hemiazygos and accessory hemiazygos veins were T 4(83.3%),T7to T10,T4to T8respectively.Conclusion All morphometrical diameters and their termination levels can be used during preoperative CT evaluations before planning invasive mediastinal procedures.The re-sults of this study could be helpful in mediastinal surgery,mediastinoscopy and the surgery of the deformations of the vertebral column in the thoracic cavity.

The inhibitory effect of N-p-chlorobenzenesulfonyl-4-aminosalicylic acid on dextran sodium sulfate-induced ulcerative colitis / 药学学报

The study aims to explore the effects of N-p-chlorobenzenesulfonyl-4-amino salicylic acid on the dextran sodium sulfate (DSS)-induced ulcerative colitis in mouse. A total of 60 BALB/c mice were randomly divided into 6 groups (n=10):control group, DSS model group, 5-amino salicylic acid (5-ASA) group, and administration groups (N-p-chlorobenzenesulfonyl-4-aminosalicylic acid) 10, 20, 40 mg·kg-1. Model group were induced by drinking 4% (w/v) DSS solution for 7 days and normal water for the next 3 days. The positive group and drug group mouse were given 5-ASA (40 mg·kg-1) and N-p-chlorobenzene sulfonyl-4-amino salicylic acid (10, 20, 40 mg·kg-1) by gavage respectively. During the experiment, changes in body weight, bloody stool, fecal character and mental status were observed daily. Damage and repair of the colon mucosa and the pathological changes of important organs were observed by hematoxylin and eosin (HE) staining. Expression of inflammatory factors such as tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), macrophage inflammatory protein 2 (MIP-2), myeloperoxidase (MPO) in serum were detected by ELISA. The results showed that bloody stools and diarrhea emerged on the 4th day after model establishment in model mice. The number of bloody mice rose to ten, and blood and diarrhea began to appear in the administration group on the 7th day. Mental status was poor and body weight decreased significantly in model group since the 4th day, and the situation was improved in the administration group and 5-ASA group. Colons in the administration groups (10, 20, 40 mg·kg-1) were longer than those in the DSS model group. In the DSS model group, the colonic mucosa and submucosa of mice exhibited severe inflammatory cell infiltration, various degrees of necrosis, proliferation. In the middle dose group (20 mg·kg-1), the situation has improved slightly and the colonic mucosa showed mildly chronic inflammation and a small amount of inflammatory cells infiltration. The high dose group (40 mg·kg-1) showed normal colon mucosal, relatively complete epithelial structure and few inflammatory cell infiltration. The levels of IL-1β, IL-6, TNF-α, MIP-2 and MPO in the serum of mice were lower in the administration group (40 mg·kg-1) than in model group. Therefore, N-p-chlorobenzenesulfonyl-4-amino salicylic acid might be a feasible treatment for DSS-induced UC.

Current progress in functions of axon guidance molecule Robo and underlying molecular mechanism / 生理学报

The axon guidance molecule Robo is a transmembrane protein which is conserved during evolution. Robo and its ligand, Slit, have been implicated in regulating many developmental processes, such as axon guidance, neuronal migration, tumor metastasis, angiogenesis, lung morphogenesis, kidney morphogenesis, heart morphogenesis, ovary development and gonad development. Robo function mainly depends on the binding of its Ig1 domain to the LRR-2 domain of Slit ligand. Meanwhile, Robo function is also mediated by binding to some signaling molecules, including the heparan sulfate proteoglycans (HSPGs), GTPase-activating proteins (GAPs) and tyrosine kinase Abelson. Several transcription factors, including Hox, Midline and Nkx2.9, were shown to regulate robo expression. In addition, alternative splicing and transport regulation also affect Robo function. In this review, we summarized the studies on the molecular structure, functions and molecular mechanism of Robo, which would propose a novel strategy for the research of neural development, as well as prevention and treatment of nervous system diseases and cancers.

Effect of fluid flow-induced shear stress on osteoclast formation induced by osteocyte / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the role of osteocyte in bone remodeling due to mechanical loading in vitro.</p><p><b>METHODS</b>MLO-Y4 osteocyte-like cells were exposed to fluid flow-induced shear stress(12dyn/cm(2))for 0, 1, 2, 4, 6, 12, and 24 hours. Osteocyte exposed to shear stress at different time points were used in co-culture system for 9 days, and then the cells were stained with tartrate-resistant acid phosphatase on the 9(th) day and the amount of positively stained osteoclasts were counted and compared. The expressions of osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa (RANKL) were detected by semi-quantitative reverse transcription polymerase chain reaction (semi-quantitative RT-PCR).</p><p><b>RESULTS</b>Compared with bone cells without stimulation with fluid flow-induced shear stress, the amount of osteocytes significantly decreased at all time points after the application of fluid flow-induced shear stress (all P<0.05). The OPG expression at mRNA levels was significantly up-regulated in the first 12 hours (P<0.001), the RANKL mRNA expression was significantly down-regulated in the first 4 hours (P<0.05), and the RANKL/OPG ratio significantly decreased within 12 hours (P<0.01). However, all these indicators showed no significant difference at 24 hours when compared with the pre-stimulation level.</p><p><b>CONCLUSION</b>Osteocytes may act as mechanosensors that are able to inhibit bone resorption after mechanical loading; however, such effect shows certain adaptation ability to shear stress as time goes.</p>

Comparison between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in vitro / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To compare between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in co-culture system.</p><p><b>METHODS</b>MLO-Y4 cells and murine osteoblast cells were co-cultured with bone marrow cells with or without vitamin D₃ presence.Bone marrow cells were as control group. Tartrat resistant acid phosphatase (TRAP)+ giant cells with three or more nuclei were counted and compared under a microscope at day 9.</p><p><b>RESULTS</b>In the absence of vitamin D₃, (1963.3 ± 93.1)/plate osteoclasts were observed when MLO-Y4 cells co-cultured with bone marrow cells in 24-well plate.While only (12.7 ± 5.5)/plate osteoclasts were found in the osteoblast group, and (6.0 ± 1.0)/plate in control group. The statistical difference occurs for any two groups (P < 0.05). Vitamin D₃ could significantly increase osteoclast formation in the three groups.</p><p><b>CONCLUSIONS</b>Osteocytes could induce osteoclastogenesis without the presence of vitamin D₃ and vitamin D₃ could enhance the induction effects of MLO-Y4 and osteoblast cells.</p>

Expression of OPG and RANKL at protein level in human periodontal ligament cells and the effect of l_?,25(OH)_2 vitamin D_3 on the secretion of OPG protein in vitro / 北京大学学报(医学版)

Objective:To study the expression of osteoprotegerin(OPG)and receptor activator nuclearfactor kappa B ligand(RANKL)at protein level in human periodontal ligament cells(HPDLCs),and theeffect of 1?,25(OH)_2 vitamin D_3[1,25(OH)_2 vitD_3] on the secretion of OPG protein in vitro.Meth-ods:HPDLCs were harvested in vitro by sequential digestion with trypsin and collagenase.The expressionof RANKL in HPDLCs at protein level was tested by immunocyto-chemistry.Enzyme-linked immuno-adsordent assay(ELISA)was used to detect the OPG protein which was secreted into the culture mediumby HPDLCs cultured with and without 10~(-8) mol/L 1?,25(OH)_2 vitD_3 on the 0,2nd,4th,and 6th days,respectively.Results:RANKL protein was detected on the membrane and plasma of HPDLCs,and OPGprotein was secreted in the culture medium.The secretion of OPG protein was down-regulated by 10~(-8)mol/L 1?,25(OH)_2 vitD_3.Conclusion:HPDLCs have the bone metabolism system of OPG/RANKL,which works during the process of 1?,25(OH)_2 vitD_3 inducing HPDLCs.The conclusion has laid thegroundwork for the study on bone remodelling mechanisms of HPDLCs.