BACKGROUND: It is very important to explore an optimal loading force that can both allow effective intrusion and cause no damage to the teeth.OBJECTIVE: To investigate the optimal loading conditions, including loading force values and directions, in the intruding mechanics of maxillary anterior teeth.METHODS: A three-dimensional finite element model (3D FEM) of the maxillary anterior teeth was constructed to include the periodontal ligament (PDL), alveolar bone, and appliance (brackets and wire). The initial stress distribution and force of the maxillary anterior teeth were analyzed when the 3D FEM was loaded with different intruding force values and directions. RESULTS AND CONCLUSION: The optimal value of the intruding force for 6 anterior teeth fell within the range from 0.5 N to 1.0 N. The maximum stress was detected at the distal cervical level of the lateral incisor, and a relatively even distribution of initial stress was observed at 20° palatal deviation to the Y axis. The results suggest that using mini-screw implants at the labial region between the canine and lateral incisor and a combined 0.5-1.0 N intruding force with a distal force could be an optimal intrusion force system by which patients with normal occlusion could obtain a pure intrusion of anterior teeth.

Objective To investigate the biological activities of a conditioned medium for human dermal papilla. Methods Culture medium of the lower passage human dermal papilla cells was collected as the conditioned medium. The growth pattern and the growth curve of the higher passage human dermal papilla cells cultured with conditioned medium were observed in vitro. And the morphology of the co-culture of the higher passage human dermal papilla cells and the lower passage human dermal papilla cells was observed. Results The higher passage human dermal papilla cells, which was cultured with conditioned medium from the lower passage human dermal papilla cells, showed aggregative growth pattern. And the growth curve of the higher passage human dermal papilla cells was much better than that in the control groups (P

Objective To investigate the effects of staphylococcal enterotoxin A SEA gene on target cells mediated by replicative-deficient recombinant adenovirus vector. Methods Lymphocytes of C57BL/6 mice were infected with various titers of recombinant adenoviruses. Supernatants were collected after 12 h, 24 h, 48 h, 72 h, 96 h, 120 h and 144 h of incubation and analyzed for proliferation of lymphocytes by MTT assay. IL-2 level in the culture supernatants was measured with ELISA. The killing effect of lymphocytes was also observed by MTT assay. Results Proliferation response and elevated levels of IL-2 were observed in experimental group. The killing effect on B16 cells was stronger in experimental group, which seemed to be dose-dependent with the increase of ratio of lymphocytes/target cells. Conclusions SEA gene can be expressed in lymphocytes of C57BL/6 mice mediated by replicative-deficient recombinant adenovirus vector. The expressing products can activate lymphocytes of C57BL/6 mice, which kill B16 cells in vitro.

Objective To evaluate the effect of resurfacing facial atrophic acne scars with 2790 nm YSGG fractional laser.Methods 38 patients with facial atrophic acne scars were treated with the 2790 nm YSGG fractional laser.All patients were randomly divided into two groups:group A using the combination with ablative and non-ablative mode of treatment; group B only using the non-ablative mode throughout the entire face,four treatment sessions for each patient,6 weeks interval.Comparative photographs were taken by using VISIA.Specific complexion analysis was used to identify and quantify depressed scars and texture,and patient satisfaction was graded with a 4-point scale.Results All of facial atrophic acne scars obtained different degree of improvement were treated by 4 times.In groups A and B,cure rate achieved 56.0 ％ and 30.8 ％,respectively.All the 38 patients had a chieved efficacy (81.6 ％),and they were satisfied with the results (84.2 ％).No severe side effect was observed.Conclusions 2790 nm YSGG laser is easy to manipulate and is more exactly than other lasers.It is especially effective in enhancing the clinical outcomes of scar revision with less complications and pigmentation,and thereby 2790 nm YSGG fractional laser can provide the patients with superficial scar in face as an additional therapeutic option.

Objective To investigate the location and proliferation of human hair follicle stem cells. Methods The expression of keratin 19(K19) in the human hair follicles on the occiput was detected by immunohistochemical staining, and the positive area was located. The follicle epithelium containing the K19-positive area above the hair bulb were cultured with or without mesenchymes (dermal papilla cells, DPCs) at the air-liquid interface of the collagen gel. When the proliferating colonies formed, the distance from the colony to the bottom of hair follicles was measured and the relationship between the K19-positive position and the proliferation colonies was analyzed. The ultrastructure of the proliferation colony was observed by transmission electron microscopy. Results Two portions were found positive for K19 in the outer root sheath of the human hair follicles, the upper one being at the bulge region and the lower one at the outer root sheath above the hair bulb. The proliferating colony formed only when the epithelium of the hair follicle was co-cultured with mesenchymes cells. The statistical analysis suggested the lower portion positive for K19 and the proliferation colonies in the culture were traced to locate at the same site of the human hair follicles. Under electron microscopy, juvenile cells, mature keratinocytes and apoptotic cells were found in the proliferating colonies. Conclusions The human hair follicles may contain two distinct reservoirs for stem cells, which locate in the bulge area and in the region of the outer root sheath above the hair bulb, respectively. Mesenchymes are needed for the proliferation of stem cells. New stem cells, mature keratinocytes and apoptotic cells may be three endings of the stem cells′ proliferation.

Objective To investigate Th1/Th2 pattern of response in psoriasis and to study the effects of CTLA4Ig on Th1/Th2 shift in psoriasis. Methods The levels of IL-2, IFN-?and IL-4 were assessed by ELISA in the supernatant of cultured peripheral blood mononuclear cells (PBMCs) from 33 patients with psoriasis vulgaris and 20 healthy blood donors. Cytokine synthesis was induced by activation with phytohemagglutinin (PHA) and staphylococcal enterotoxin B (SEB) with or without CTLA4Ig. Results Levels of IL-2, IFN-?and IL-4 were markedly increased by PBMCs from psoriatic patients incubated with SEB (P

Objective　To investigate the actions of extra cellular medium in growth and differentiation of hair follicle and to look for growth adjusting factors for dermal papilla cells (DPC). Methods　Dermal papilla cells were isolated and cultivated with two steps method and the cells were identified by immunohistochemical staining for actin. Influence was examined on the adhesion and growth of dermal papilla cells by chondroitin sulfate A, chondroitin sulfate C and heparin sulfate. Results　Two steps method of enzyme digestion for isolating and cultivating dermal papilla cells was an efficient method and large amount of dermal papilla of high purity were harvested with this method. The method is very simple and easy to manege with. Increased adhesion and growth of dermal papilla cells were observed in specimen treated with chondroitin A and heparin sulfate. No significant effects was observed in the cells treated with chondroit in sulfate C. Conclusion　Some extra cellular medium can regulate the adhesion and growth of dermal papilla cells and therefore influence the growth and development of hair follicle.

Objective To screen and analyze genes differentially expressed within dermal papillae cells(DPC)with aggregative behavior.Methods Total RNA was extracted from DPC with and without ag-gregative behavior,and double-stranded cDNA were synthesized by using SMART cDNA synthesis.The cD-NA fragments of differentially expressed genes in dermal papillae cells with aggregative behavior were isolat-ed by suppression subtractive hybridization,sequencing,and then subtracted library was set up.Positive clones were screened by PCR method and verified by cDNA dot blot and then analyzed through homologous retrieving.Results A subtractive cDNA library of DPC with aggregative behavior was successfully construct-ed.The results of screening and cloning of the library showed that DPC with aggregative behavior could ex-press genes related to homologous aggregation,regnlation of growth,differentiation and development,and sig-nal transduction proliferation and cycle control,which included known genes(capping protein,paladin,vas-cular endothelial growth factor),hematopoietic stem/progenitor cells(HSPC)related genes(HSPC011and HSPC016)and a new gene.Conclusions The construction of subtractive library of DPC lays solid founda-tion for screening and cloning new and specific genes related to aggregative behavior of DPC.Several genes may cooperatively involve in homologous aggregation,and regnlation of growth of DPC.Among these genes,capping protein and palladin may be closely related to aggregative behavior of DPC,and VEGF and HSPC re-lated clones may be responsible for the status of higher proliferation of DPC.

OBJECTIVETo explore the short-term impact of ambient PM(10) on daily non-accidental death, cardiovascular and respiratory death of residents in Beijing.

METHODSMortality data of residents in Beijing during 2006 to 2009 were obtained from public health surveillance and information service center of Chinese Center for Disease Control and Prevention, contemporaneous data of average daily air concentration of PM(10), SO(2), NO(2) were obtained from Beijing Environment Protection Bureau (year 2005 - 2006) and public website of Beijing environmental protection (year 2007 - 2009), respectively, contemporaneous meteorological data were obtained from china meteorological data sharing service system. Generalized addictive model (GAM) of time serial analysis was applied. In additional to the control of confounding factors such as long-term trend, day of the week effect, meteorological factors, lag effect and the effects of other atmospheric pollutants were also analyzed.

RESULTSDuring year 2006 to 2009, the number of average daily non-accidental death, respiratory disease caused death, cardiovascular and cerebrovascular diseases caused death among Beijing residents were 140.1, 15.0, 65.8, respectively;contemporaneous medians of average daily air concentration of PM(10), SO(2), NO(2) were 123.0, 26.0, 58.0 µg/m(3), respectively;contemporaneous average atmosphere pressure, temperature and relative humidity were 10.1 kPa, 13.5°C and 51.9%, respectively. An exposure-response relationship between exposure to ambient PM(10) and increased daily death number was found as every 10 µg/m(3) increase in daily average concentration of PM(10), there was a 0.1267% (95%CI: 0.0824% - 0.1710%) increase in daily non-accidental death of residents, 0.1365% (95%CI: 0.0010% - 0.2720%) increase in respiratory death and 0.1239% (95%CI: 0.0589% - 0.1889%) increase in cardiovascular death. Ambient PM(10) had greatest influence on daily non-accidental and cardiovascular death of the same day, while its greatest influence on respiratory death occurred 5 days later.

CONCLUSIONThe ambient PM(10) pollution increased daily non-accidental, respiratory disease caused, cardiovascular and cerebrovascular diseases caused deaths among residents in Beijing, and lag effect existed as for the effect of ambient PM(10) pollution on respiratory disease caused death.

Air Pollutants ; analysis ; Air Pollution ; analysis ; Cardiovascular Diseases ; mortality ; China ; epidemiology ; Environmental Exposure ; analysis ; Humans ; Mortality ; Particle Size ; Particulate Matter ; analysis ; Respiratory Tract Diseases ; mortality ; Time Factors

Objective To investigate the effect of Aidi injection combined with chemotherapy on CD+4CDhi25CDlow127regulatory T (Treg) cells in peripheral blood of advanced non-small-cell lung cancer (NSCLC).Methods Sixty patients with advanced NSCLC were randomly divided into the study group (treated with Aidi injection combined with chemotherapy) and the control group (treated with chemotherapy).The levels of CD+4CDhi25CDlow127Treg cells were detected by flow cytometry (FCM), and TGF-β1 and IL-10 levels were determined by enzyme linked immunosorbent assay (ELISA) before and after chemotherapy. A group consisted of 20 healthy persons was set up meanwhile.Results There was a significantly higher percentage of CD+4CDhi25CDlow127Treg cells in patients with NSCLC (5.77±1.50) % than that(3.84±0.96) % of healthy volunteers (P=0.000).The IL-10 and TGF-β1 levels[(24.09±6.74), (197.76±43.76) ng/ml]in the serum of patients with NSCLC were also significantly higher than that[(19.39±5.73), (141.13±32.17) ng/ml]of healthy volunteers (P =0.006,P =0.002). In control group, levels of CD+4CDhi25CDlow127 Treg cells were obviously lower than that before chemotherapy (P =0.048).Levels of TGF-β1 and IL-10[(22.25±6.79), (184.85±49.11) ng/ml]were slightly decreased, which showed no significant difference contrast to pretherapy[(24.37±8.10), (197.16±44.57) ng/ml](P =0.276, P =0.314).In study group, levels of CD+4CDhi25CDlow127Treg cells and TGF-β1, IL-10[(4.36±1.19) %,(20.16±4.73), (165.42±39.57) ng/ml]were obviously lower than that before chemotherapy[(5.78±1.50) %,(23.81±5.15), (198.35±43.68) ng/ml](P=0.000, P=0.003, P =0.006).Conclusion The CD+4CDhi25CDlow127 Treg cells in the peripheral blood of advanced NSCLC patients is significantly increased. Aidi injection combined with chemotherapy can obviously reduce the level of CD+4CDhi25CDlow127 Treg cells in patients with advanced NSCLC, and the combined therapy could improve the immune function of patients.