Search

Objective: To preliminarily explore the mechanism of tensile stress regulating endochondral osteogenesis of condyle by analyzing the expression profiles of significantly different microRNAs (miRNAs) in exosomes of rat mandibular condylar chondrocytes (MCC) under quiescent and cyclic tensile strain (CTS) conditions. Methods: Rat condylar chondrocytes were cultured under static and CTS conditions respectively (10 SD rats, male, 2 weeks old), and exosomes were extracted. The two groups of exosomes were named as control group and CTS group respectively. The differential expression miRNAs were screened by high-throughput sequencing. Bioinformatics analysis and prediction of target genes related to osteogenesis were performed by TargetScan and miRanda website. Results: The exosomes of rat condylar chondrocytes cultured under tensile stress showed a "double concave disc" monolayer membrane structure, the expression of CD9 and CD81 were positive, and the particle size distribution accorded with the characteristics of exosomes, which was consistent with that of static cultured rat condylar chondrocytes. A total of 85 miRNAs with significantly different expression were detected by high-throughput sequencing ( P <0.05). The main biological processes and molecular functions of differential miRNAs were biological processes and protein binding, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathway enrichment analysis showed that there was significant enrichment in mammalian target of rapamycin (mTOR) signal pathway. The candidate target genes of miR-199a-5p include bone morphogenetic protein 3 (BMP3), endothelin converting enzyme 1, and miR-186-5p may target Smad8 and BMP3 to exert osteogenesis-related functions. Conclusions: Compared with static state, tensile stress stimulation can change the expression of miRNAs such as miR-199a-5p, miR-186-5p in the exocrine body of rat condylar chondrocytes, which can be considered as a mean to regulate the application potential of the exosomes.

Malocclusion is one of the three most common oral diseases reported by World Health Organization(WHO). In China, its incidence rate is rising. Malocclusion seriously affects the dental and maxillofacial function, facial appearance and growth development of nearly 260 million children in China, and what is more, it affects their physical and mental health development. Malocclusion occurrence is related to genetic and environmental factors. Early treatment of malocclusion can create a good dental and maxillofacial development environment, correct abnormal growth and control the adverse effects of abnormal genetic factors. It can effectively reduce the prevalence of children's malocclusion and enhance their physical and mental health. This is an urgent need from the economic perspective of our society, so it has great practical and social significance. Experts from the project group "standard diagnose and treatment protocols for early orthodontic intervention of malocclusions of children" which initiated by China National Health Institute of Hospital Administration wrote the "China Experts' Consensus on Preventive and Interceptive Orthodontic Treatments of Malocclusions of Children", which aims to guide and popularize the clinical practice, improve the clinical theory and practice level, and accelerate the disciplinary development of early treatment of children's malocclusion in China. The consensus elaborates the harmfulness of malocclusion and the necessity of early treatment, and brings up the principles and fundamental contents. Based on the law of dental and maxillofacial development, this paper puts forward the guiding suggestions of preventive and interceptive treatments in different stages of dental development ranging from fetus to early permanent dentition. It is a systematic project to promote and standardize the early treatment of malocclusion. Through scientific and comprehensive stratified clinical practice and professional training, the clinical system of early treatment of malocclusion in China will eventually be perfected, so as to comprehensively care for children's dental and maxillofacial health, and improve their oral and physical health in China.

MicroRNA (miRNA) are a class of small non-coding single-stranded RNA that exert their biological effects by binding to target messenger RNA (mRNA). There is new evidence that miRNA may play an important role in regulating the growth and development of mandibular condylar cartilage. In this paper, the production and mechanism of miRNA are reviewed, and the progress of studies on the growth and development of mandibular condylar cartilage, which is helpful to further study the growth and development of mandibular condylar cartilage.

Rapid palatal expansion (RPE) is commonly used to correct transverse maxillary deficiencies and recognized as a reliable orthopedic procedure in children and adolescents. For adults, however, conventional RPE has been considered rarely successful and can produce undesirable dental effects. Along with the development of digital techniques and mini-implant anchorage, a novel method called miniscrew-assisted RPE (MARPE) has become available for the treatment of maxillary transverse deficiency in older patients recently. In this article, the biomechanical principles and indications of MARPE, the advances in device design, the clinical effects, the matters needing attention and limitations of this method, and the stability after expansion are discussed.

Objective: To improve the understanding of clinical characteristics of streptococcal toxic shock syndrome (STSS) caused by Streptococcus pyogenes ( S. pyogenes ) in children. Methods: A retrospective study was conducted to analyze the clinical data of STSS caused by S. pyogenes (culture-confirmed) in 7 tertiary hospitals during 2010-2017 in China. Clinical and laboratory data were collected by reviewing the medical records. Results: Fifteen cases of STSS, including 9 males, were confirmed and the ages of the patients ranged from 6 months to 15 years, with median age of 3 years. All cases had the positive blood culture for S. pyogenes and only 3 cases had short course of β-lactam treatment before blood culture. Medical evaluation was initiated within (5.1±4.6) days after symptom onset. All patients had fever, and 13 patients had multiple organ dysfunction and 10 patients had disseminated intravascular coagulationl (DIC). Twelve cases had severe pneumonia with or without skin and (or) soft tissue infections. Underlying conditions included giant hemangioma of the skin in 2 patients and varicella in 1 patient. All isolated strains in 14 cases were sensitive to penicillin G, ceftriaxone/cefotaxime, vancomycin, but 12 and 13 isolates were resistant to clindamycin and erythromycin, respectively. Eight patients died, and 5 of them died within 24 hours after admission. One patient was lost to follow-up after intended discharge against medical advice. Conclusion: STSS caused by S. pyogenes in children is a severe syndrome with rapid clinical progression and high mortality rate, and thus the pediatricians should be aware of STSS and immediately initiate aggressive treatment for the suspected cases.

Objective: To investigate the effects of oridonin combined with capecitabine on the proliferaction of MDA-MB-231 human breast cancer cells. Methods: Effect of different concentrations(10, 20 and 40 μmol/L)of oridonin, capecitabine and their combination on the proliferation of MDA-MB-231 cells after incubation for 24 or 48 h was studied. Then, the effect of 5 μmol/L of oridonin, capecitabine and their combination on cell colony formation was detected. Finally, influence of 20 μmol/L of oridonin, capecitabine and their combination on morphological alteration of nucleus, cell cycle and apoptosis was explored. Results: The inhibition rate on MDA-MB-231 cells after incubation with 20 μmol/L oridonin or capecitabine for 48 h was 49.5% and 58.6%, respectively, while the inhibition rate against proliferation of MDA-MB-231 cells reached 94.6% with combination of 20 μmol/L oridonin and capecitabine. Cells incubated with combination of oridonin and capecitabine formed fewer and smaller colonies ( P <0.01). Meanwhile, cells in the combination group arrested at S and G2/M phases at the same time, and combination of two drugs caused more apoptotic cells ( P <0.01). Conclusion: Oridonin combined with capecitabine can synergistically inhibit the proliferation of MDA-MB-231 human breast cancer cells.

During the past decade, the anchorage implants have been widely used in the orthodontic treatment. Many scholars have studied the influence of different factors on anchorage implant's primary stability, including anchorage implant's material properties, structural design, surgical procedure, bone condition, loading force's magnitude and direction. This article is to review the influence of anchorage implant's shape, dimension, neck design and thread design on its primary stability.

Objective: To analyze the clinical characteristics of blood stream infection caused by Streptococcus agalactiae in children and the drug-resistance of the isolates., Method: All cases with Streptococcus agalactiae growth in blood or cerebrospinal fluid cultures from January 1, 2011 to December 31, 2015 were enrolled by checking the laboratory information system (LIS) from 7 Class 3 Grade A hospitals (4 in Zhejiang, 2 in Shanghai and 1 in Chongqing). Clinical data were collected for analysis. χ(2) test, t test and non parametric test were used in the study., Result: One hundred and eighty-one pediatric cases of blood stream infection caused by Streptococcus agalactiae were included in current study. Eighty-six cases (47.5%) were male, and with age range from one day to 9 years (media 13 days). Thirty cases (16.6%) were premature infants and 127 cases (70.2%) were born via vaginal delivery. Seventy-one cases (39.2%) had early onset (<7 d) infections, and 106 cases (58.6%) had late onset (7-89 d) infections. Seventy-eight cases (43.1%) were complicated with purulent meningitis. Incidences of vaginal delivery(81.7%(58/71) vs. 62.3%(66/106)), shortness of breath moaning (43.7%(31/71) vs. 15.1%(16/106)) and preterm premature rupture of membranes (25.4%(18/71) vs. 3.8%(4/106)) were higher in the early onset infection group compared with the late onset group(P all<0.05). However, the number of cases who had fever(25.4%(18/71)vs.85.8%(91/106)) and complicated with purulent meningitis (29.6%(21/71) vs. 53.8%(57/106)) in early onset infections group was less than that in the late onset group(P both<0.05). The blood cultures of most patients (87.8%) were performed before the use of antibiotics. Drug-resistant tests showed that the sensitive rates to penicillin G, ceftriaxone and cefotaxime were 98.9%, 99.0% and 99.0% respectively. All strains were sensitive to vancomucine. The rates of resistance to clindamycin and erythromycin were 68.0% and 34.0%, respectively. Only 39 cases (22.0%) were treated with single antibiotics of either penicillins or cephalosporins, 80 cases (45.2%) were treated with antibiotics containing β lactamase inhibitor, 61 cases (34.5%) were treated with either meropenem or cefoperazone-sulbactam. One hundred and fifty-four cases were cured, while 19 died (including 13 complicated with purulent meningitis) and 8 lost to follow up after giving up of treatment., Conclusion: The incidence and mortality of blood stream infection caused by Streptococcus agalactiae complicated with purulent meningitis are high in children. Penicillin is the first choice in treatment. Antibiotics should be selected accorrding to the drug-resistance test.

Purpose: To evaluate the condylar morphological changes in adult Angle Class I malocclusionpatients before and after orthodontic treatment using a cone-beam CT (CBCT)., Methods: Images of 25 adult Angle Class I patients (5 males, 20 females) who had no temporomandibular joint disorder symptom were involved in this study, and Mimics 10.01 software was used to reconstruct the three-dimensional condyle and measure the height of condyle, the area and bone density of the largest cross sectional plane and sagittal plane, and the volume and bone density of the whole and upper three-dimensional condyle before and after orthodontic treatment. Paired t test was used for comparison between pre- and post-treatment condylar metric analysis with SPSS 19.0 software package., Results: After treatment, the area and bone density of the largest cross sectional plane and sagittal plane were reduced significantly(P<0.05). The volume and bone density of the whole three-dimensional condyle and bone density of the upper three-dimensional condyle were reduced significantly(P<0.05)., Conclusions: Adaptive bone remodeling of the condyle may occur due to alternation of occlusion by orthodontic treatment in adult Angle Class I malocclusion patients.

Taking two kinds of vegetables (Brassica rapa and Amaranthus mangostanus) and one insect species (Prodenia litura) as test materials, a greenhouse pot experiment was conducted to study the transfer characteristics of cadmium (Cd) in soil-vegetable-insect food chain and the distribution patters of different Cd chemical forms in the organs of the two vegetables. With the increasing concentration of applied Cd in soil, the biomass of the two vegetables decreased significantly, while the Cd concentration in the vegetables had a significant increase. The Cd concentration in the vegetable organs decreased in the order of stem > root > leaf for A. mangostanus, and of stem > leaf > root for B. rapa. The Cd concentration in P. litura larvae also increased with the increasing concentration of Cd in soil, and the maximum Cd concentration in the P. litura larvae on B. rapa and A. mangostanus was 36.7 and 46.3 mg x kg(-1), respectively. In the feces of the larvae on B. rapa and A. mangostanus, the Cd concentration was up to 190 and 229.8 mg x kg(-1), respectively, suggesting that the most part of Cd absorbed by P. litura larvae was excreted out of their bodies via feces. In the organs of the two vegetables, NaCl-extractable Cd was the dominant Cd form (> 70%), followed by d-H2O- and ethanol-extractable Cd, while the HAc-extractable Cd (insoluble cadmium phosphate), HCl-extractable Cd (insoluble cadmium oxalate), and residual Cd only had a very low concentration. Such a present pattern of different Cd forms in vegetable organs could be conducive to the Cd transfer in the food chain. P. litura could ease Cd poison by excreting large amount of absorbed Cd via feces, and effectively restrict the transfer of Cd to next trophic level. Since B. rapa and A. mangostanus could accumulate large amount of Cd in their biomass, the two vegetables were suggested not to be planted in highly Cd-contaminated soil.

Objective: To compare activation and concentration of insulin, and blood glucose control in patients between insulin added into "all in one" bags and syringes at parenteral nutrition (PN)., Methods: From April 2006 to August 2006, 20 consecutive patients after gastrointestinal operations were recruited and randomized to instillation group and pump group. In instillation group, the insulin was directly added into PN and transfused. In pump group, the insulin was added into syringes and transfused by infusion pump. Activation and concentration of insulin, and blood glucose in patients were measured at beginning infusion, infused 1000 ml, infused 2000 ml, and remained 100 ml daily for the first 3 days after operation., Results: There was a tendency of decrease for the activation and concentration of insulin in both groups with the time. There was no significant difference of activation of insulin between the two groups (P = 0.347). There were no significant differences of blood glucoses between the two groups, and between the four time points in each groups (P > 0.05). There were no complications association with blood glucoses in the two groups., Conclusions: Both of activation and concentration of insulin at PN decreased gradually and slightly with the time no matter the ways of insulin infusion. Activation of insulin and blood glucoses in patients are no significant differences between the two groups. Insulin can be safely added into "all in one" bags at PN.

Objective: To investigate the effects of triple-helix forming oligonucleotide (TFO) and antisense oligonucleotide (ASO) on androgen receptor (AR) expression and tumor growth of human prostate cancer xenografts in nude mice., Methods: Thirty-two nude mice were inoculated with human prostate cancer cells of the line LNCaP-C4-2 were randomized into 4 equal groups: TFO treatment group, undergoing intra-tumor injection of TFO at the dose of 25 mgxkg(-1)x(2d)(-1) for 14 times, ASO treatment group, undergoing intra-tumor injection of ASO at the same dose for 14 times, SCO group, undergoing intra-rumor injection of sequence control oligonucleotide (SCO) at the same dose for 14 times, and control group. The body weight and xenograft tumor volume of the nude mice were monitored during the therapy. 28 days later venous blood samples were collected to measure the level of prostate specific antigen (PSA) by radioimmunoassay and then the mice were killed with their tumors taken out to measure the weight, and RT-PCR, immunohistochemistry, and radioligand binding assay were used to detect the AR gene mRNA and protein expression in the tumor tissues., Results: By the end of experiment the volumes and weights of tumor of the ASO and ASO groups were all significantly lower than those of the control group (all P < 0.01) with the inhibition rates of 67.55% and 41.06% respectively, and the volumes and weights of tumor of the TFO group were all significantly lower than those of the ASO group (all P < 0.05). The tumor weight and AR expression levels of TFO group were significantly lower than those of ASO group (P < 0.05). The serum PSA level of TFO group was (6.6 +/- 1.0) ng/ml, significantly lower than that of the ASO group [(19.8 +/- 3.7) ng/ml, P < 0.05]. The mRNA and protein expression levels of AR of the TFO group were significantly lower than those of the other groups (all P < 0.05). There were no significant differences in all the above mentioned markers between the SCO and control groups (all P > 0.05)., Conclusion: TFO shows significantly higher inhibitory effect on AR expression and tumor growth of human prostate cancer xenograft than ASO, and is a promising agent for prostate cancer gene therapy.

Objective: To study the effects of melatonin (MT) on nerve cell apoptosis and the expression of bcl-2 and cytochrome C genes in rat cerebrum with deltamethrin induction., Methods: 35 male Wistar rats were randomly divided into five groups (eight rats per group): olive oil control, deltamethrin-treated (12.5 mg/kg), deltamethrin plus melatonin (25.0 mg/kg, 50 mg/kg and 100 mg/kg respectively) group. Animal models were established by intraperitoneal injection deltamethrin in rats. Nerve cell apoptosis and the protein expression of bcl-2 and cytochrome C genes were detected by flow cytometry with PI staining and immunohistochemistry respectively., Results: Compared with DM group (20.73 +/- 3.34), the positive expression gradation of the bcl-2 protein in nerve cell was increased significantly in MT groups (DM + MT(25) was 45.26 +/- 3.84, DM + MT(50) 39.4 +/- 4.04 and DM + MT(100) 34.4 +/- 4.52) (P < 0.05) but significantly lower than the control group (59.33 +/- 4.03). Compared with DM group (34.86 +/- 4.15), the cytochrome C protein in nerve cell was decreased significantly in MT groups (20.53 +/- 3.17, 28.73 +/- 2.61 and 28.66 +/- 4.82 respectively) (P < 0.05). Compared with DM group (23.06 +/- 3.63), the apoptotic rate in nerve cell was decreased significantly in MT groups [(15.0 +/- 1.77)%, (14.88 +/- 1.84)% and (11.75 +/- 1.93)% respectively] (P < 0.05)., Conclusion: MT can protect nerve cell against deltamethrin induced brain injury by inhibiting nerve cell apoptosis, downregulate the protein expression of cytochrome C gene and upregulate the protein expression of bcl-2 gene.

Aim: To investigate CTGF's role in bleomycin-induced pulmonary fibrosis., Methods: Kunming mice were intratracheally administered with bleomycin to establish pulmonary fibrosis model. The expression of CTGF was studied by immunohistochemical method and RT-PCR. The degree of fibrosis was evaluated by pulmonary hydroxyproline assay., Results: CTGF protein and mRNA were not expressed in normal mice. However, they were detected in pulmonary fibrotic mice from day 7 after bleomycin treatment, and increased as fibrosis developed (P <0.01). CTGF protein's expression was correlated with hydroxyproline content in lung tissue (r=0.92, P <0.01)., Conclusion: CTGF plays a role in pulmonary fibrosis. Detection of CTGF may be an early and sensitive marker for evaluating the occurrence and development of pulmonary fibrosis.

Background & Objective: It was indicated that there was relationship between estrogen and colorectal cancer. Estrogen receptor (ER) and progesterone receptor (PR) were expressed in colorectal cancer tissue. They were measured using immunohistochemistry with various results,but there was little quantitative study. This study was designed to quantitatively measure the expression of ER and PR in tumor tissues and normal mucosas and analyze its relationship with clinicopathological parameters in colorectal cancer., Methods: ER and PR expression in cytoplasm and nucleus of tumor tissues and normal mucosas from 45 colorectal cancer patients were quantitatively measured using radioligand binding assay (RBA)., Results: ER and PR were expressed in all tumor tissues and normal mucosas. In cytoplasm, the ER expression level of tumor tissues was higher than that of normal mucosas; they were 7.96+/-3.69 fmol/mg protein and 4.34+/-2.84 fmol/mg protein (P< 0.01) respectively. And that was the same for PR expression; they were 3.89+/-2.64 fmol/mg protein and 2.50+/-1.73 fmol/mg protein(P< 0.01)respectively. In nucleus, the ER expression level of tumor tissues was higher than that of normal mucosas; they were 18.42+/-8.30 fmol/mg protein and 11.24+/-5.44 fmol/mg protein (P< 0.01)respectively. And that was the same for PR expression, they were 9.36+/-5.90 fmol/mg protein and 7.84+/-7.41 fmol/mg protein (P< 0.05) respectively. There was positive correlation between ER and PR expression in cytoplasm and nucleus of tumor tissues (P< 0.01) respectively,so was in cytoplasm in normal mucosas (P< 0.01) respectively, but not in nucleus (P >0.05). There was correlation between ER expression in tumor tissues and patients' age,and the expression in these people over 45 years old was higher than those less 45 years old (P< 0.05), but no correlation between tumor tissues PR expression and age (P >0.05). There was no correlation between tumor tissues ER, PR expression and sex, staging, tumor location, size, gross and histological type, invasive depth, lymph nodes metastasis, or tumor tissue CEA expression (P >0.05)., Conclusions: ER and PR expression in colorectal tumor tissues were higher than those in normal mucosas, and there was positive correlation between ER and PR expression in tumor tissues. All these indicate that ER in colorectal cancer tissues has some activity. The level of the ER, PR expression in tumor tissue could not predict the malignant biological behaviors of colorectal cancer.

Background & Objective: Recombinant human growth hormone (rhGH) has been proved effective in clinic, such as promoting protein synthesis and decreasing the mortality. But there are still many arguments on whether it can be used in hepatocellular carcinoma (HCC) patients. rhGH cannot work except that it combines to its own receptor growth hormone receptor (GHR). The current study was designed to explore the expression of GHR in HCC tissues and to investigate the viability of rhGH for HCC treatment., Methods: Radioreceptor assays were used to determine growth hormone receptor (GHR) in 40 HCC tissues; 6 normal liver tissues were used as control. Receptor binding capacity(RT) and affinity constant(Kd) of GHR were calculated by Scatchard's method; the relationship between RT of GHR in cancer and clinicopathologic factors were also analyzed., Results: The growth hormone- specific singular binding site, namely GHR, was detected respectively in 35 HCC cases and control tissues. The RT and Kd of GHR were 18.5416+/-4.1686 fmol/mg protein and 0.6319+/-0.1978 nmol/L in tumor tissues, 39.5467+/-3.4770 fmol/mg protein and 0.6167+/-0.1007 nmol/L in control tissues, respectively. Compared with the normal liver tissue, RT of GHR in tumor was lower (P< 0.05) but Kd did not show any difference(P >0.05). The RT of the GHR was negatively relevant to the tumor size and disease stage, but was not associated with differentiation of tumor, ages of the patients or whether the patient suffered from cirrhosis at the same time. GHR was undetectable in 5 cases., Conclusion: This study showed that most of the HCC tissues express low levels of GHR. Before their functions are well understood, rhGH should be very carefully used in HCC patients.

Background & Objective: Androgen receptor (AR) is closely associated with the genesis,development,treatment and assessment of prognosis of prostate carcinoma (PC) and hepatocellular carcinoma (HCC). How to determine the AR status accurately has important clinical significance. This study was designed to investigate the significance of androgen receptor(AR) in cell nucleus for assessment of the AR status of patients with PC and HCC., Methods: A total of 94 PC and 192 HCC tissues were analyzed for the affinity (KD),cytosol AR (AcR) and nuclear AR(AnR) using radioligand binding assay(RBA)., Results: In 94 PC tissues, the Bmax values of AcR and AnR were 58.82+/-34.73 and 543.70+/-249.44 fmol/mg protein which were significantly higher than those of the surrounding tissues (21.63+/-14.89 and 89.20+/-47.32 fmol/mg protein, P< 0.001). The KD values of AcR and AnR were 0.84+/-0.52 and 2.15+/-0.79 nmol/L which were not significantly different as compared with the surrounding tissues(0.78+/-0.49 and 2.24+/-0.84 nmol/L, P >0.50). In 192 HCC tissues, the Bmax values of AcR and AnR were 18.09+/-16.87 and 59.93+/-34.12 fmol/mg protein, which were significantly higher than those of the surrounding tissues (10.87+/-7.60 and 25.54+/-20.10 fmol/mg protein, P< 0.001 ). The KD values of AcR and AnR were 0.76+/-0.57 and 1.89+/-0.74 nmol/L)which were not significantly different as compared with the surrounding tissues(0.69+/-0.48 and 1.94+/-0.88 nmol/L, P >0.50). The ratio of AnR/AcR was also higher (P< 0.001). Of 94 PC tissues, 48.94% were both AcR and AnR positive, being lower than that of the tissues with positive AcR alone (77.66%). Of 192 HCC tissues, 34.09% were both AcR and AnR positive, being also lower than that of AcR positive alone (56.26%). However, 63.01% of PC and 62.03% of HCC AcR-positive tissues were accompanied by AnR-positive., Conclusion: Despite the fact that the Bmax of both AcR and AnR increased in PC and HCC tissues as compared to the surrounding tissues, the AnR showed more significant changes. In assessment of the AR status of PC and HCC tissues, it would be more accurate to analyze with both AcR and AnR than with AcR alone.

Objective: To investigate the effect of Sini Decoction (SND) on beta-adrenergic receptor (beta-AR) signal transduction in rats with myocardial ischemia., Methods: After beta-AR had been blocked by propranolol, the myocardial ischemia rats were established by pituitrin injection. The density of beta-AR in myocardial cell membrane was determined by radioligand binding assay, cAMP level in plasma and myocardial tissue was detected by radioimmunoassay (RIA), and the mRNA expression of beta 1-AR and beta 1-AR kinase (beta ARK-1) was measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) amplifying assay., Results: In myocardial ischemia group, the density of beta 1-AR was up-regulated and the mRNA expression of beta ARK-1 increased (P < 0.01), but the cAMP level in plasma and myocardium was lower than that in the normal group (P < 0.01 and P < 0.05). SND could promote beta 1-AR mRNA expression and inhibit beta ARK-1 mRNA expression so as to increase the density of beta-AR and cause significant raising of cAMP level in plasma and myocardium., Conclusion: SND could reduce the desensitization of beta 1-AR during myocardial ischemia and improve signal transduction of beta-AR.

The purpose of this study was to investigate the stress induced in the periodontal tissue of the upper central incisor by application of orthodontic forces. A three dimensional finite element model consist of tooth, periodontal ligament (PDL), cancellous and compact bone was established and the following results were obtained: (1) The highest stresses were observed on the root surface, the intermediate on the alveolar bone and the lowest in the PDL. (2) Stress condition on the surface of root and alveolar bone is very complex. The maximum, intermediate and minimum principle stresses on the same area are quite different, but the three principal stresses in the PDL are similar. (3) Regarding to tipping and torque movement, the stress value varied largely from the cervix to the apex, and there is stress concentration at the cervix and the apex. For bodily movement when M/F is -10.30, the stress induced is homogeneous and the difference of the stress values from the cervix to the apex is little, which seems to be more physiological.