Progress for targeting adenosine A2A receptors in cancer immunotherapy / 药学学报

Immunotherapy has completely changed the paradigm of clinical tumor treatment, but immune checkpoint inhibitors still have low objective response rates and are prone to drug resistance for most solid tumors. The immune suppression tumor microenvironment and complicated tumor immune escape mechanisms are key factors that affect the clinical outcome and response rates. Therefore, it is critical to reverse the obstacle of the tumor microenvironment to improve immunotherapy efficacy. The immune suppression caused by the increased level of adenosine in the tumor microenvironment raises the attention of people. Targeting adenosine receptors, especially A2AR, will be an effective strategy to improve immunotherapy efficacy. Targeting the adenosine-A2A pathway can increase immune infiltration, enhance immune cell function, and partially reverse immunotherapy-insensitive "cold tumors" to "hot tumors" to enhance treatment response rates and improve the efficacy of current immunotherapy. At present, many adenosine receptor inhibitors have shown good results in clinical trials, especially in combination with immune checkpoint inhibitors, chemotherapy, and adoptive cell transfer therapeutic drugs, which are expected to be used for tumor immunotherapy to bring new breakthroughs. This article reviews the accumulation mode of adenosine in the tumor microenvironment, the role of A2AR and their regulatory mechanism in immune response, the progress of A2AR inhibitors in clinical trials, potential risks to target A2AR, and the prospects for therapeutic targeting A2AR.

Observation on therapeutic efficacy of thunder-fire moxibustion for hypomenorrhea after induced abortion / 针灸推拿医学（英文版）

Objective: To observe the clinical efficacy of thunder-fire moxibustion for hypomenorrhea after induced abortion. Methods: A total of 74 patients with hypomenorrhea after induced abortion were randomized into two groups, with 37 cases in each group. The control group was treated with conventional hormone sequential therapy, and the observation group was treated with thunder-fire moxibustion. The course of treatment was 3 menstrual cycles. The traditional Chinese medicine (TCM) symptom scores, menstrual volume, endometrial thickness and the sex hormone levels were observed before and after treatment. The clinical efficacy was compared after treatment. Results: The total effective rate in the observation group and the control group was 91.4％ and 73.5％, respectively, and the difference between the two groups was statistically significant (P<0.05). After treatment, the TCM symptom scores in both groups decreased significantly (all P<0.05), and the scores in the observation group were lower than those in the control group (P<0.05). The menstrual volume, endometrial thickness and each sex hormone level of the patients in both groups were significantly improved after treatment (all P<0.05), and the improvements in the observation group were more significant than those in the control group (all P<0.05). Conclusion: Thunder-fire moxibustion can significantly improve the clinical symptoms of patients with hypomenorrhea after induced abortion; it can increase menstrual volume and endometrial thickness, and regulate the sex hormone levels, producing a better curative effect than the conventional hormone sequential therapy.

Effects of intradermal needle therapy plus pinaverium bromide on gastrointestinal hormone levels in irritable bowel syndrome-diarrhea patients / 针灸推拿医学（英文版）

Objective: To observe the clinical efficacy difference in treating irritable bowel syndrome-diarrhea (IBS-D) of liver-qi stagnation and spleen-deficiency pattern with different treatment protocols, and the effects on serum levels of 5-hydroxytryptamine (5-HT), substance P (SP) and vasoactive intestinal peptide (VIP), for unveiling the mechanism of intradermal needle therapy plus pinaverium bromide in treating IBS-D. Methods: A total of 123 IBS-D patients were divided into an observation group, a Western medication group and an integrated Western and Chinese medication group using the random number table method, with 41 cases in each group. The Western medication group was given oral pinaverium bromide, 50 mg each time and 3 times a day. The integrated Western and Chinese medication group was given additional Chinese herbal medicine Tong Xie Yao Fang, one dose each day. The observation group was given additional intradermal needle therapy on the basis of the Western medication group. The whole intervention lasted for 6 weeks. Before and after treatment, the scores of gastrointestinal symptoms, traditional Chinese medicine (TCM) symptoms, irritable bowel syndrome (IBS) symptom severity scale (IBS-SSS) and IBS quality of life (IBS-QOL) questionnaire, as well as the serum levels of 5-HT, SP and VIP were observed. The clinical efficacy was estimated. Results: The total effective rate was 92.7％ in the observation group, 68.3％ in the Western medication group and 78.1％ in the integrated Western and Chinese medication group. The total effective rate was higher in the observation group than in the other two groups, and higher in the integrated Western and Chinese medication group than in the Western medication group, showing statistical significance (all P<0.05). After treatment, the scores of gastrointestinal symptoms, TCM symptoms and IBS-SSS showed significant decreases in the three groups, presenting statistical significance compared with the baseline (all P<0.05); the scores of gastrointestinal symptoms, TCM symptoms and IBS-SSS were notably lower in the observation group than in the other two groups (all P<0.05), and lower in the integrated Western and Chinese medication group than in the Western medication group (all P<0.05). After treatment, the eight component scores of IBS-QOL showed significant increases in the three groups compared with the baseline (all P<0.05); the eight component scores in IBS-QOL were significantly higher in the observation group than in the other two groups (all P<0.05), and higher in the integrated Western and Chinese medication group than in the Western medication group (all P<0.05). After treatment, the serum levels of 5-HT, SP and VIP decreased markedly in the three groups compared with the baseline (all P<0.05); the serum levels of 5-HT, SP and VIP were significantly lower in the observation group than in the other two groups (all P<0.05), and lower in the integrated Western and Chinese medication group than in the Western medication group (P<0.05). Conclusion: Treatment with intradermal needle therapy plus pinaverium bromide results in significant improvements in the gastrointestinal symptoms and quality of life in patients with IBS-D of liver-qi stagnation and spleen deficiency pattern, and effectively regulates the gastrointestinal hormone production.

Current Status of Etiology, Epidemiology, Clinical Manifestations and Imagings for COVID-19

Coronavirus disease 2019 (COVID-19) is a transmissible respiratory disease that was initially reported in Wuhan, China in December 2019. With the alarming levels of COVID-19 spread worldwide, the World Health Organization characterized COVID-19 as a pandemic. Over the past several months, chest CT has played a vital role in early identification, disease severity assessment, and dynamic disease course monitoring of COVID-19. The published data has enriched our knowledge on the etiology, epidemiology, clinical manifestations, and pathologic findings of COVID-19. Additionally, as the imaging spectrum of the disease continues to be defined, extrapulmonary infections or other complications will require further attention. This review aims to provide an updated framework and essential knowledge with which radiologists can better understand COVID-19.

Optimized cutoff maternal age for adverse obstetrical outcomes: a multicenter retrospective cohort study in Urban China during 2011 to 2012 / 中华医学杂志(英文版)

BACKGROUND@#China's two-child policy has led to a trend of aging in pregnancy which was associated with adverse outcomes. This study aimed to identify the clinically cutoff maternal age for adverse obstetric outcomes in China.@*METHODS@#This secondary analysis of a multicenter retrospective cohort study included data of childbearing women from 39 hospitals collected in urban China during 2011 to 2012. Logistic regression was used to assess the adjusted odds ratios (aOR) of adverse outcomes in different age groups in comparison to women aged 20 to 24 years. The adjustments included the location of the hospital, educational level, and residence status. Clinically cutoff age was defined as the age above which the aOR continuously become both statistically (P  2) significant.@*RESULTS@#Overall, 108,059 women were recruited. In primiparae, clinically cutoff maternal ages for gestational diabetes (aOR: 2.136, 95% confidence interval [CI]: 1.856-2.458, P < 0.001), placenta previa (aOR: 2.400, 95% CI: 1.863-3.090, P < 0.001), cesarean section (aOR: 2.511, 95% CI: 2.341-2.694, P < 0.001), hypertensive disorder (aOR: 2.122, 95% CI: 1.753-2.569, P < 0.001), post-partum hemorrhage (aOR: 2.129, 95% CI: 1.334-3.397, P < 0.001), and low birth weight (aOR: 2.174, 95% CI: 1.615-2.927, P < 0.001) were 27, 31, 33, 37, 41, and 41 years, respectively. In multiparae, clinically cutoff ages for gestational diabetes (aOR: 2.977, 95%CI: 1.808-4.904, P < 0.001), hypertensive disorder (aOR: 2.555, 95% CI: 1.836-3.554, P < 0.001), cesarean section (aOR: 2.224, 95% CI: 1.952-2.534, P < 0.001), post-partum hemorrhage (aOR: 2.140, 95% CI: 1.472-3.110, P < 0.001), placenta previa (aOR: 2.272, 95% CI: 1.375-3.756, P < 0.001), macrosomia (aOR: 2.215, 95% CI: 1.552-3.161, P < 0.001), and neonatal asphyxia (aOR: 2.132, 95% CI: 1.461-3.110, P < 0.001) were 29, 31, 33, 35, 35, 41, and 41 years, respectively.@*CONCLUSIONS@#Early cutoff ages for gestational diabetes and cesarean section highlight a reasonable childbearing age in urban China. The various optimized cutoff ages for different adverse pregnancy outcomes should be carefully considered in childbearing women.

Study of Gq mutations and their inhibitors in uveal melanoma / 药学学报

Uveal melanoma (UM) is one of most common ocular cancers and is extremely malignant; so far there is no effective treatment. Moreover, the survival period is only 2-7 months after metastasis. It has been proven that more than 83% of uveal melanomas harbor mutations in G protein subunit α q (GNAQ) or G protein subunit α 11 (GNA11), among which 95% are a Q209P/L single-site mutation. Q209P/L mutations lead to dysfunction of guanine triphosphatase (GTPase) in the G protein and result in constitutive activation of downstream pathways including mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT), Ras homologue (Rho)/ Rho-associated kinase (Rock)/Yes-associated protein (YAP) and others. Therefore, targeting GNAQ/GNA11 mutations are potential strategies for UM treatment. This review will focus on roles of G protein mutations in UM progression, and the potential therapeutic effects of GNAQ/GNA11 inhibitors, and will provide insights into basic and clinical research on UM treatment.

Interpretation of American Academy of Sleep Medicine(AASM) clinical practice guideline for treatment of adult obstructive sleep apnea with positive airway pressure / 中国实用内科杂志

Recently, the publication of the new guideline for positive airway pressure(PAP) treatment of obstructive sleep apnea(OSA) in adults by the American Academy of Sleep Medicine(AASM) has caused a great response. Based on the quality of evidence, the balance of clinically significant benefits and harms, patient evaluation and preferences and use of resources, the new guidelines are divided into three types, which were good practice statements, strong recommendations and conditional recommendations. This guideline establishes clinical practice recommendations on OSA diagnosis, patients selection, initiation of PAP treatment, PAP ventilation mode,health education, behavior intervention, as well as follow-up. Unlike drug therapy, the medical insurance policy and management of PAP ventilator in China are different from those of European countries and America, therefore, the implementation of the guidelines should be in line with Chinese national conditions. This paper introduced and interpreted the changes in the new guidelines.

Protective effect and regulating effect on FXR/SHP gene of electroacupuncture preconditioning on myocardial ischemia-reperfusion injury in rats / 中国针灸

OBJECTIVE@#To explore the protective mechanism of electroacupuncture preconditioning on myocardial ischemia-reperfusion injury in rats.@*METHODS@#A total of 88 SPF-grade Wistar male rats were randomized into a normal group, a sham-operation group, a model group and an electroacupuncture (EA) group, 22 rats in each one. The rats in the normal group received normal diet and no intervention was given for 7 d. The rats in the sham-operation and the model group were bound for 20 min, once a day for 7 d. In the EA group, EA, continuous wave, 2 Hz and 1 mA, was applied at "Neiguan" (PC 6), "Zusanli" (ST 36) and "Guanyuan" (CV 4) for 20 min, once a day for 7 d. In the 8th day, the blood was collected by abdominal aortic method 60 min after intraperitoneal injection of 10% urethane anesthesia by 10 mL/kg in the normal group, and then the tissue of heart was collected. In the model group and the EA group, ligating the left anterior descending coronary artery (LAD) was adopted for 20 min and reperfusion was applied for 40 min, then the samples were collected. The rats in the sham-operation group recevied open-chest operation and no other intervention, the samples were collected in 60 min. Nitro Blue Tetrazolium Chloride monohydrate (NBT) stain was used to detected myocardial infarct size and weight, ELISA was used to measured myocardial injury markers and inflammatory factors (LDH、CK、cTnI), and the fluorescent quantitative PCR method was used to determine the expressions of FXR and SHP gene.@*RESULTS@#①There was no significant difference between the normal group and the sham-operation group in myocardial infarct size and weight (>0.05) .Compared with the normal group, myocardial infarct size and weight were higher in the model group (0.05). Compared with the normal group, the serum contents of LDH、CK、cTnI were higher in the model group (<0.05). Compared with the model group, the serum contents of LDH、CK、cTnI were lower in the EA group (<0.05). ③The expressions of FXR and SHP gene in the model group were higher than those in the normal group (<0.05). The expressions of FXR and SHP gene in the EA group were lower than those in the model group (<0.05).@*CONCLUSION@#Electroacupuncture preconditioning could significantly improve cardiac function of rats with myocardial ischemia-reperfusion, reduce infarct size and inflammatory factors, and down-regulate the expressions of FXR and SHP gene. The protective effect may generate based on regulation of FXR/SHP apoptosis signal pathway.

Training and Demand Analysis of Health Information Management Undergraduate Talents against the Background of "Internet + Medical" / 医学信息学杂志

The paper discusses the training situation of Chinese undergraduate talents majoring in health information management from the aspects including setup of the health information management specialty in higher learning institutions in China,enrolment programs and arrangement of major courses,analyzes demands of hospital informatization on health information talents,and providing reference for the training of more qualified talents of the specialty.

Progress on the role of autophagy in spinal cord injury / 中国骨伤

In recent years, the study of autophagy in spinal cord injury (SCI) gradually becomes the hot spot. However, the function of autophagy in the injured spinal cord is still controversial. In order to further understand the role of autophagy after SCI, we summarized the activation of autophagy, autophagic cell death, the relationship between autophagy and apoptosis, the function of autophagy in promoting the molecular metabolism and the role of autophagy after spinal cord injury. We concluded that the role of autophagy after SCI is a double-edged sword. Upregulating the level of autophagy appropriately can promote damaged proteins metabolism and inhibit apoptosis. However, excessive activation of antophagy may induce autophagic cell dealth. So we consider that the proper regulation of autophagy will be a new target in the treatment of SCI.

Efficacy of short-term educational intervention for parents of preschool children with anxiety / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the efficacy of short-term educational intervention for parents of preschool children with anxiety.</p><p><b>METHODS</b>Forty-nine children with Spence Preschool Anxiety Scale (SPAS) scores of ≥ 48 were randomly divided into intervention and control groups. The children's parents in the intervention group received a collective curriculum on children's anxiety management six times, while the control group was only followed up. All children were evaluated for anxiety by the SPAS 3 and 6 months later, and then the results were compared between the two groups.</p><p><b>RESULTS</b>The test was completed in 21 cases of the intervention group and 22 cases of the control group. At month 3, the intervention group had a significantly lower percentage of children with SPAS scores of ≥ 48 than the control group (62% vs 91%; P<0.05), and this percentage was also significantly lower in the intervention group than in the control group at month 6 (52% vs 82%; P<0.05). At month 3, the intervention group had a significantly reduced mean SPAS score, which was significantly lower than that of the control group (69 ± 12 vs 81 ± 12; P<0.01). At month 6, both groups showed significant decreases in SPAS score, but still the SPAS score was significantly lower in the intervention group than in the control group (65 ± 13 vs 78 ± 13; P<0.01).</p><p><b>CONCLUSIONS</b>Early short-term education for parents can relieve their preschool children's anxiety effectively, but the long-term effect needs to be evaluated by follow-up.</p>

Knockout of the iha gene in uropathogenic Escherichia coli and its influence on biofilm formation / 第二军医大学学报

Objective To construct the adhesin gene iha mutant of uropathogenic Escherichia coli (UPEC) strain W140, and analyze the effects of iha deletion on UPEC biofilm formation. Methods Knockout of the iha genewas done with plasmid pKD46, pKD3, and pCP20 of Red recombinant system. pKD46 was transformed into W140 strain to express the three recombination proteins of λ phage. The chloramphenicol resistance gene flanked by flipase recognition target (FRT) of pKD3 was amplified by PCR and transformed into W140 strain to replace the iha gene. Finally pCP20 was transformed into W140 strain and expressed flipase recombinase, which deleted the chloramphenicol resistance gene between FRT sites. The differences of biofilm formation ability between the wild strain and the mutant were measured by crystal violet staining. Results PCR verification and DNA sequencing indicated that the iha gene was successfully knocked out and UPEC W140Δiha was constructed. The biofilm growth level of the mutant was significantly lower than that of wild strain (P<0. 01). Conclusion The iha gene and its encoding product are involved in the process of UPEC biofilm formation. Suppressing iha gene may provide a new target for controlling urinary tract infection.

Clinical effects of surgical vs manual reduction of ankle fractures / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the clinical effects of surgical vs manual reduction of ankle fractures.</p><p><b>METHODS</b>From March 2006 to April 2010,301 patients with ankle fractures were analyzed retrospectively, of whom 134 patients were treated by manual reduction and plaster fixation, and the other 167 patients underwent surgical treatment. In manual reduction group, there were 86 males and 48 females with a mean age of (38.2 +/- 15.7) years, involving Weber-Denis A in 55 cases,Weber-Denis B in 60 cases, and Weber-Denis C in 19 cases. In surgical reduction group, there were 115 males and 52 females with a mean age of (39.6 +/- 11.9) years, involving Weber-Denis A in 59 cases, Weber-Denis B in 52 cases and Weber-Denis C in 56 cases. The score of the ankle's symptoms and function was calculated according to Mazur,and the difference was analyzed by Chi-squire test.</p><p><b>RESULTS</b>Of the 114 patients with Weber-Denis A, 55 patients were in manual reduction group, with excellent, good, acceptable and poor results in 18, 20, 11 and 6 patients respectively vs 26, 25, 6 and 2 in surgical reduction group of 59 patients. In patients with Weber-Denis B, there were 60 patients in manual reduction group, with excellent, good, acceptable and poor results in 20 , 26, 8 and 6 patients vs 25, 21, 5, and 1 in surgical reduction group of 52 patients. There was no significant difference in clinical effects between the two group of Weber-Denis A and B. The remaining 75 patients belonged to Weber-Denis C, of whom 19 patients were in manual reduction group,with excellent, good, acceptable and poor results in 2, 3, 7 and 7 patients vs 21, 18, 11 and 6 in surgical reduction group of 56 patients. There was no significant difference in clinical effects between the two groups of Weber-Denis C (P=0.007).</p><p><b>CONCLUSION</b>The clinical effect of surgical reduction group was obviously better than that of manual reduction group for Weber-Denis C, and therefore surgical intervention is recommended for this type of fracture.</p>

Application of surgical robotic system in patients with gastric cancer: a report of 120 cases / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the safety, feasibility, and efficacy of robotic gastrectomy for gastric cancer using da Vinci surgical system.</p><p><b>METHODS</b>A total of 120 patients who underwent robotic gastrectomy using da Vinci surgical system for gastric cancer from May 2010 to April 2012. Data regarding surgical and early oncological outcomes were systematically collected in a specific database for statistical analysis.</p><p><b>RESULTS</b>There were 74 males and 46 females, with a mean age of 58.5 (22-80) years old. The type of robotic operation included 62 distal subtotal gastrectomies, 35 total gastrectomies, and 23 proximal gastrectomies. Reconstruction of the alimentary tract was achieved using extracorporeal method through a minilaparotomy in 55 cases, and intracorporeal robot-sewn anastomosis in 65 cases. There was 1 conversion (0.9%). The operative time was (245±50) min and the docking time (17±5) min. The blood loss was (70±45) ml. The number of harvested lymph nodes was 22.5±10.7. The resection margins were negative in all surgical specimens. The postoperative pathological stage consisted of stage I B in 24 cases, stage II in 28, stage III A in 47, and stage III B in 21. Six patients (5%) developed postoperative complication including 1 case of duodenal stump leakage, 2 cases of esophagus-gastric leakage, 1 case of small bowel obstruction, 1 case of delayed gastric emptying, and 1 case of abdominal bleeding. All the complications were cured by reoperation or conservative therapy, and there were no postoperative 30-day deaths. The postoperative hospital stay was (6.3±2.6) days.</p><p><b>CONCLUSION</b>Robotic gastrectomy for the treatment of gastric cancer is a feasible and safe procedure, and is advantageous in terms of lymphadenectomy and alimentary tract reconstruction.</p>

Comparative study on clinical efficacy of robot-assisted and laparoscopic gastrectomy for gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the clinical efficacy of robot-assisted procedure with laparoscopic surgery for gastric cancer.</p><p><b>METHODS</b>The clinical data of patients who underwent gastrectomy in the Department of General Surgery in the Affiliated Jinling Hospital, Nanjing University Medical College from January 2009 to December 2011 were retrospectively analyzed. There were 97 patients undergoing robotic gastrectomy(ROB group) and 70 patients undergoing laparoscopic gastrectomy (LAP group). The following parameters were compared between these two groups: intraoperative factors, oncologic outcomes, and short-term surgical outcomes.</p><p><b>RESULTS</b>All the operations were performed successfully without conversion. Compared with the LAP group, the ROB group had less intraoperative blood loss [(80.8±53.1) vs. (153.7±26.4) ml, P=0.001], more number of lymph node dissection [(23.1±5.4) vs. (20.0±4.3), P=0.001], longer operative time [(272.3±46.1) vs. (240.3±89.1) min, P=0.001], earlier semifluid diet time [(3.2±0.8) vs. (3.6±1.2) d, P=0.002], shorter postoperative hospital stay [(6.1±2.6) vs. (6.9±2.3) d, P=0.037]. There were no significant differences in the length of distal and proximal margin, postoperative ambulation time, ventilation time and postoperative complications(all P>0.05).</p><p><b>CONCLUSIONS</b>The robotic gastrectomy is safe and feasible for gastric cancer. It has many advantages such as less blood loss, more number of lymph node dissection and quicker recovery. Similar radical resection can be achieved compared to laparoscopic gastrectomy.</p>

Oxidative stress and peripheral skeletal muscle dysfunction in rats with emphysema / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Peripheral skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD) may be due to the disease per se or as a result of concomitant confounding factors. Although the mechanistic basis for this functional impairment is uncertain, oxidative stress may play a role. The purpose of this study was to investigate whether local oxidative stress is associated with the reduced peripheral skeletal muscle performance in rats with emphysema.</p><p><b>METHODS</b>In situ mechanical properties of gastrocnemius were measured in Sprague-Dawley rats 5 months after intratracheal instillation of either elastase (EMP, n = 10) or normal saline (CON, n = 10). Lipofuscin inclusions, myocyte apoptosis and antioxidant enzyme activities were examined in the gastrocnemius muscle.</p><p><b>RESULTS</b>Lipofuscin inclusions were significantly higher in the gastrocnemius muscle of EMP compared with CON (3.2 + or - 0.4 vs. 1.7 + or - 0.4, P < 0.01). The activities of antioxidant enzymes were significantly increased in muscle homogenates of EMP as compared to CON. No significant differences were found in myocyte apoptosis between EMP and CON (1.2 + or - 0.9 vs. 1.0 + or - 0.8, P > 0.05). EMP decreased the fatigue endurance of gastrocnemius muscle (half-time to fatigue recovery: (150.0 + or - 55.4) seconds vs. (55.2 + or - 29.3) seconds, P < 0.01) and had no effect on maximal tetanic force ((467.4 + or - 36.6) g vs. (493.2 + or - 30.5) g, P > 0.05). A significantly positive correlation was found between the level of lipofuscin inclusions and the half-time to fatigue recovery of gastrocnemius muscle in EMP (r = 0.664, P < 0.05).</p><p><b>CONCLUSION</b>Local oxidative stress may have important functional consequences for peripheral skeletal muscle in rats with EMP.</p>

Immunolocalization of receptor activator of NF-kappaB ligand and osteoprotegerin during mouse mandibular first molar eruption / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the immunolocalization of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG), and to explore the correlation between their expressions and activity of osteoclast during first mandibular molar eruption.</p><p><b>METHODS</b>Mouse mandibles dissected from postnatal day 1.5 to 14.5 were stained respectively for multinucleated osteoclasts using tartrate-resistant acid phosphatase (TRAP) staining, and RANKL and OPG protein expression was examined by immunohistochemical staining.</p><p><b>RESULTS</b>The two peak values of osteoclast/acreage in the occlusal and basal region were both observed on the P1.5 and P9.5; while the two peak values in the lateral region were on P3.5 and P9.5. During the mouse molar eruption, burst of osteoclastogenesis was associated with high expression of RANKL and low expression of OPG.</p><p><b>CONCLUSIONS</b>RANKL and OPG could have a close relationship with the osteoclast activity and two developmental apexes were observed during the molar eruption. The occlusal movement was relatively stable, meanwhile the temporarily accelerative movement to the basal and lateral regions could occur.</p>

Effect of composite restoration on the reinforcement of teeth / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the effect of composite restoration on reinforcement of weakened tooth structure and the possible mechanism.</p><p><b>METHODS</b>Sixty freshly extracted non-carious maxillary premolars were collected and divided into 6 groups with 10 specimen in each group. MOD cavities (buccolingual width: 2.8 to 3.2 mm; palatal cusp width: 2.0 mm; cusp height: 5.0 mm) were prepared individually. Group 1 was prepared and not restored (control). The other 5 groups were restored with silver amalgam alloy (group 2), Z250 without bonding (group 3), F2000 (group 4), Z250 (group 5) and Z350 nanocomposite (group 6) (3M ESPE) respectively. The fracture resistance of the tested teeth was determined by applying a vertical splitting load through a specially shaped steel rod at a crosshead speed of 1 mm/min. The data were analyzed by ANOVA.</p><p><b>RESULTS</b>The average fracture resistance of the 6 groups was: (245.29 +/- 39.49) N (group 1), (255.09 +/- 42.14) N (group 2), (267.34 +/- 31.56) N (group 3), (293.90 +/- 33.42) N (group 4), (337.81 +/- 32.63) N (group 5) and (349.08 +/- 32.93) N (group 6). There was no significant difference between the group 1, group 2 and group 3. The fracture resistance of group 4, group 5 and group 6 was higher than that of group 1 and group 2 (P < 0.05). Significant difference was noted between group 5 and group 3 (P < 0.01). The fracture resistance of group 4 was much lower than that of group 5 and group 6 (P < 0.01). No significant difference was found between group 5 and group 6.</p><p><b>CONCLUSIONS</b>The use of composite increased the fracture resistance of the tooth with an MOD restoration. This effect was related to the adhesive force, polymerization shrinkage stress and the elastic modulus of the composite.</p>