BACKGROUND:Age and dental age are shown to have some limitations in predicting skeletal maturity.
OBJECTIVE:To compare the mandibular length in boys and girls with Class I and Class II skeletal patterns by using the cervical vertebrae maturation, and to provide valid reference index for orthodontical treatment.
METHODS:The lateral cephalograms of the 160 cases of Class I (40 males and 40 females) and Class II (40 males and 40 females) skeletal patterns, aged 8-15 years, were taken before orthodontic treatment. The sample was grouped according to stages of the cervical vertebrae maturation (Hasse and Farman method), and the mandibular length was measured separately. The results were statistical y analyzed by the independent-sample t test.
RESULTS AND CONCLUSION:No matter you are a male or female, the mandibular length of Class I was greater than that of Class II at the early stages of growth and development. In the Class I pattern, the mandibular lengths of boys were greater than those of girls at accelerated, transition, and deceleration stages (P<0.05), whereas in the Class II pattern, the mandibular lengths of boys were greater than those of girls at accelerated, transition, and deceleration stages (P<0.05). The present results indicate a sexual dimorphism in the mandibular length at almost al stages of bone maturation, but the possibility of a later“catch up”growth period occurs on Class II girls. And this information has important orthodontic clinical implications.

The palliative care has become an important part of social civilization. Its treatment of advanced patients with no response to the treatment of patients with positive and comprehensive care, paying attention to the people-oriented conforms to the Chinese nationHeperfectly. In palliative care practice,Heconcept penetrates in the happening of the disease and development, treatment and special and complex and changeful in interpersonal relationship. The ultimate goal of He is also a palliative care. The concept of reconciliation will promote the development of palliative care.

Carrying out researches in urban community health service centers can effectively promote the improvement of management system, the cultivation of talents and the formation of characteristic service, leading to the institutional development.This paper summarizes the role and significance of researches in promoting the overall development of urban community health service center in order to provide reference for the relevant medical institutions based on the experiences in Shanghai Fenglin Community Health Service Center.

Objective To estimate the influences of N-acetyl cysteine (NAC) on a chemical hypoxiamimetic agent CoCl2 induced-injury to, and expressions of inflammatory factors by, an immortal human skin keratinocyte line HaCaT. Methods HaCaT cells were treated with CoCl2 of 2000 μmol/L for 4 hours to set up a chemical hypoxia-induced cell model of skin injury. NAC of various concentrations ( 1000, 2000, 3000 μmol/L)was used to pretreat HaCaT cells for 2 hours prior to the establishment of cell model. After these treatments,cell viability was detected by cell counting kit 8 (CCK-8), the levels of interleukin 6 and 8 (IL-6 and -8) and tumor necrosis factor α (TNF-α) in culture supernatant by ELISA kits, mitochondrial membrane potential (MMP) by rhodamine 123 (Rh123) staining and photofluorography, intracellular reduced glutathione (GSH)content by glutathione detection kit. Results An obvious decline was observed in HaCaT cell viability after pretreatment with various concentrations of NAC for 2 hours. The treatment with CoCl2 of 2000 μmol/L for 4 hours induced an elevation in the supernatant levels of IL-6, IL-8 and TNF-α and a decrease in GSH content and MMP, while the pretreatment with NAC for 2 hours retarded the CoCl2-induced increase in IL-6 and IL-8 levels as well as decrease in GSH content and MMP. Conclusion The reactive oxygen species (ROS) scavenger NAC can protect against CoCl2-induced injury to and inflammatory reaction in HaCaT cells, which may be associated with a decrement in oxidative stress.

Aim To explore the effect of survivin in PC12 cells against injuries induced by cobalt chloride(CoCl_2).Methods PC12 cells were exposed to CoCl_2 at different doses in different time to set up the chemical hypoxia induced PC12 cells injuries model.Cell viability was tested by using cell counter kit-8.Dose-effect(200～1 000 μmol·L~(-1))and time-effect(0～48 h)relationship between hypoxia induced by CoCl_2 and the expression of survivin was evaluated by western blot.Results PC12 cells viability was inhibited significantly by CoCl_2 in a dose and time dependent manners;At the concentrations from 200 to 600 μmol·L~(-1) CoCl_2 for 24 h,survivin expression was upregulated in a dose dependent manner,peaking at 600 μmol·L~(-1) CoCl_2 treatment,exceeding this concentration of CoCl_2,with dose increasing,survivin expression decreased.At the dose of CoCl_2 up to 1 000 μmol·L~(-1),survivin did not express basically;Treatment with 600 μmol·L~(-1) CoCl_2 in different time,within the range of 0～36 h,the expression of survivin enhanced in time dependent manner.But with the extension of time,survivin expression was declining; 17-allylamino-17-demethoxygeldanamycin (2 μmol·L~(-1)),an inhibitor of Hsp90,not only decreased survivin overexpression but also obviously enhanced the injuries of PC12 cells induced by CoCl_2,which didn't damage PC12 cells alone.Conclusion Upregulation of survivin expression may be one of the endogenous defense mechanisms for PC12 cells against chemical hypoxia.

[Objective] To explore the cytoprotecfion of hydrogen sulfide (H_2S) against cobalt chloride (CoCl_2)-induced apeptosis in PC12 cells and the underlying mechanisms. [Methods] CoCl_2 (a chemical hypoxia-mimetic agent) was used to establish the chemical hypoxia-induced PC12 cell injuries model. Sodium hydrosulfide (NaHS) was used as a H_2S donor. The viability of PC12 cells was measured by CCK-8 assay. The percentage of apeptotic cells was assessed by propidium iodide stain flow cytometry (FCM). The morphological change of apeptotic cells was tested by using the chromatin dye Hoechst 33258. The mitochondrial membrane potential (MMP) was analyzed by rhodamine 123 staining and photofluorography. The level of reactive oxygen species (ROS) in PC12 cells was measured by DCFH-DA staining and photofluorography. [Results] CoCl_2 induced a decrease in cell viability and an increase in percentage of apeptosis in PC12 cells along with dissipation of MMP as well as overproduction of ROS. When PC12 cells were treated with Naris 30 min before CoCl_2 treatment a decrease in viability of PC12 cells induced by 600 μmol/L CoCl_2 was concentration-dependently blocked by NaHs (100, 200, and 400 μmol/L). Pretreatment with NaHS at 200 and 400 μmol/L obviously reduced the apepetotic percentage of PC12 cells induced by 600 μmol/L CoCl_2 and inhibited the dissipation of MMP and overproduction of ROS. [Conclusion] H_2S protected PC12 cells against CoCl_2-induced apeptosis, which may be associated with the inhibition of H_2S on the dissipation of MMP and overproduction of ROS induced by CoCl_2.

This paper briefly introduces the working procedure of in vitro diagnostic products (IVD) industrial standards, and elaborates the importance of professional standards for production and supervision. Based on the analysis of working progress during the past 10 years, some problems and countermeasures on project setting, participation, standard material, personnel training, work cycle are put forward, which are helpful for the future development of the IVD.
Diagnostic Techniques and Procedures ; standards ; Humans ; Reference Standards

AIM:To observe the characterization in neural cells derived from the hippocampus of embryonic rats and to examine the effect of myelin-associated glycoprotein(MAG) on the proliferation,differentiation and neurite growth of neural stem cells(NSCs).METHODS:The hippocampus cells of embryonic rats were isolated and cultured in vitro.The expressions of nestin and doublecortin,the marks of NSCs,were observed by immunocytochemical method.The rate of proliferating cells was examined by BrdU immunocytochemistry.The average neuronal neurite length and the percentage of differentiated neurons were detected by immunocytochemistry staining.RESULTS:The hippocampus cells of 16 days old embryonic rats had the characteristics of NSCs.The percentage of differentiated neurons(?-tubulin Ⅲ-positive cells) was 18.17%?2.79% and the average neuronal neurite length was(136.27?33.66)?m,seven days after the differentiation initiated in vitro in control group.After NSCs were treated with MAG-Fc(200 ?g/L),the percentage of differentiated neurons and the average neurite length were decreased,respectively,to 10.05%?3.42%(P0.05).CONCLUSION:MAG-Fc inhibits the differentiation and neurite growth of the NSCs,but has no effect on the proliferation.

AIM:To investigate the ability of a metal complex ammonium tetrathiomolybdate (ATTM) to re-lease H2 S and its cytoprotective effect on an oxidative injury model .METHODS:Released H2 S was absorbed in a reaction flask from ATTM dissolved in the cell medium .Staining with dichlorodihydrofluorescein diacetate or rhodamine 123 fol-lowed by photofluorography was conducted for the observation of reactive oxygen species ( ROS) and mitochondrial mem-brane potential (ΔΨm) levels, respectively.Cell viability and release of lactate dehydrogenase (LDH) from the cells were measured with commercial kits.RESULTS:Similar to another H2S donor GYY4137, ATTM had an ability to release H2S in the cell medium in a dose-dependent manner .Treatment of human skin HaCaT cells with ATTM at concentrations of 25~400 μmol/L didn’ t significantly alter cell viability .Exposure of the cells to ultraviolet rays or a ROS donor H 2 O2 in-creased the intracellular ROS levels .Treatment with 400 μmol/L H2 O2 significantly reduced the viability of HaCaT cells (P<0.01).However, before the treatment with H2O2, pretreatment with ATTM at 100 and 200 μmol/L markedly pre-vented the H2O2-induced cell injury (P<0.01).In addition, the treatment with H2O2 triggeredΔΨm loss (P<0.01) and LDH release from the cells (P<0.01).Prior to suffering from H2O2 injury, the preconditioning with 200 μmol/L ATTM significantly improved ΔΨm levels ( P<0.05 ) and attenuated LDH release from the cells ( P<0.01 ) .CONCLUSION:ATTM is capable of releasing H 2 S and protecting human skin cells against oxidative injury .

AIM:To investigate the role of caveolin-1 on epithelial-mesenchymal transition (EMT) in human bronchial epithelial (HBE) cells induced by transforming growth factor beta 1 (TGF-β1).METHODS:Immunofluorescence, real-time PCR and Western blot were applied to detect the mRNA and the protein expression of caveolin-1 in the 16HBE cells during EMT.The influence of siRNA-mediated silencing of caveolin-1 on EMT in the 16HBE cells was detected by Western blot.RESULTS:Caveolin-1 was widely present on the cell membrane of the 16HBE cells.The expression of caveolin-1 at mRNA and protein levels was significantly decreased in a time-dependent manner in the 16HBE cells compared with control group (P<0.05) after stimulation with TGF-β1.The morphologic changes of the 16HBE cells induced by TGF-β1 were promoted by caveolin-1 silencing compared with TGF-β1 group.The protein expression of E-cadherin and α-SMA induced by TGF-β1 was promoted by caveolin-1 silencing compared with TGF-β1 group (P<0.05).The phosphorylation levels of AKT and Smad3 were the highest at 30 min and increased significantly compared with control group (P<0.05) after stimulated with TGF-β1.Treatment of the 16HBE cells with TGF-β1 for 30 min after silencing caveolin-1 gene for 24 h significantly increased the phosphorylation levels of AKT and Smad3 compared with TGF-β1 group (P<0.05).CONCLUSION:TGF-β1 down-regulates the expression of caveolin-1 in the 16HBE cells.Caveolin-1 may participate in TGF-β1/Smad pathway and PI3K-AKT pathway, which are the signal transduction pathways for TGF-β1 inducing EMT.