Objective: The purpose of this study was to investigate the effect of TNF-? on osteoclast differentiation in primary murine bone marrow cell culture with and without RANKL. Methods: M-CSF-dependent bone marrow cells were isolated from 5-6 weeks old mice, and cultured in the presence of M-CSF (25 ?g/L) with different concentrations of TNF-? (0, 1, 10, 100 ?g/L) for 5 days, the formation of TRAP(+) multinucleated cells was observed. These cells were also cultured in the presence of both RANKL (30 ?g/L) and M-CSF (25 ?g/L) with or without 10 ?g/L TNF-? for 4, 5, 6 and 9 days. The number of TRAP(+) multinucleated cells and resorption pits on dentine slices were counted under light microscope. Results: In the absence of RANKL, TNF-? was unable to induce osteoclast formation from murine bone marrow precursors. In the presence of RANKL, TNF-? augmented osteoclastogenesis and bone resorption, and this effect occurred only on the early stage. Conclusion: TNF-? enhances RANKL-induced osteoclast formation and function, but can’t substitute for RANKL. TNF-? stimulates osteoclast differentiation, but not survival.

Obesity is caused by the imbalance between caloric intake and energy expenditure. It is also influenced by genetic factors. Many genes,such as ob gene, ? 3 receptor gene, ucp 1 gene, may involved in the prevalence of obesity. Pharmacologic treatments include anorexigenic agents, lipase inhibitor, ? 3 receptor agonists and many newer antiobesity drugs, which provide prospective ways in treating obesity.

Objective:To compare the proliferation and osteoblastic differentiation of dental pulp stem cell (DPSC)isolated from normal and inflamed pulps of different degrees in Beagle immature premolars, and provide evidence for the use of inflammatory DPSC (IDPSC).Methods:This study evaluated 14 Beagle’s young premolars (21 roots).In the experiment group,irreversible pulpitis was induced by pulp exposure and the inflamed pulps were extracted 2 weeks and 6 weeks after the pulp chamber opening.For the control group,normal pulps were extracted immediately after the exposure.HE staining and real-time PCR were performed to confirm the inflammation.The cells were isolated from the inflamed and normal pulps (IDPSC and DPSC).Cell proliferation and osteoblastic differentiation potentials of the two cells were compared.Results:Inflammation cells infiltration was observed in the inflamed pulps by HE stai-ning.The expression of inflammatory factor was much higher in the 6 week inflamed pulp.IDPSC had higher potential of cell proliferation and osteoblastic differentiation potentials.Furthermore,the osteoblas-tic differentiation potentials of IDPSC from 2 week inflamed pulp were higher than those from 6 week in-flamed pulp.Conclusion:The potential of cell proliferation and osteoblastic differentiation of DPSC was enhanced at early stage of irreversible pulpitis,and reduced at late stage in Beagle immature premolars.

Objective: To establish the permanent tooth germ missing animal model for future research on the root resorption of deciduous tooth in the absence of permanent tooth germ. Methods: The permanent tooth germ missing animal model was established by surgical removal of the permanent tooth buds in a male 11-week-old Beagle dog. Root resorption of the deciduous teeth without permanent successors was observed by taking periapical films periodically,and compared with physiological root resorption. Once the sign of root resorption of the deciduous teeth without permanent successors was detected on radiographic films, the animal was sacrificed and the mandibular bone was collected for histological study. Results: Root resorption of the deciduous teeth with the presence of permanent tooth germ started at 20 weeks after birth, while root resorption of deciduous teeth without permanent tooth germ started 26-27 weeks which was significantly delayed. Histological studies showed that a large number of multinucleated giant cells were present on the pulpal surface of the root, while only few of them were seen on the outer surface. Conclusion: The permanent tooth germ missing animal model was successfully established in this study which simulated the case of congenital absence of permanent tooth germ in human. Root resorption of deciduous tooth without permanent tooth germ was significantly delayed than the deciduous tooth with permanent tooth germ.

Objective:To investigate the effect of TGF-? on osteoclast differentiation in primary murine bone marrow cell culture in the presence of receptor activator of NF-?B Ligand(RANKL) and macrophage colony stimulating facotr(M-CSF).Methods:M-CSF-dependent bone marrow cells were isolated from 5~6 weeks old mice,and cultured in the presence of RANKL at 30 ng/ml and M-CSF at 25 ng/ml with or without 1 ng/ml of TGF-? for 4 and 9 days respectively.TRAP positive multinucleated cells and resorption pits on dentine slices were counted under light microscope.Results:TRAP positive multinucleated cells were induced from murine bone marrow cell cultures with both RANKL and M-CSF,and these cells formed resorption pits on dentine slices.The number of TRAP positive multinucleated cells and resorption pits were significantly increased by 1 ng/ml of TGF-?(P

Objective To know the microbial pollution in the indoor air of classrooms and dormitories in a university and analyze the possible impact factors.Methods In April and May,2007,the indoor air sampling was conducted and the total count of air microbe in indoors was determined in eight classrooms and twenty dormitories by the impacting method.Results According to the related national hygienic standard of China, the total count of air microbe in all classrooms was qualified, the total count of air microbe in the dormitories was all qualified, but it was higher in male's dormitories compared with female's.Conclusion In general, there was not obviously indoor microbial pollution in the investigated university.

0.05) . Conclusion Air pollution can increase the risk of low birth weight and preterm birth in the exposed pregnant women.

Objective:To analyze the prognosis about periodontal ligament healing of replanted perma-nent teeth in children and to examine the associated factors.Methods: The sample consisted of 49 children with 61 avulsed permanent teeth, whose injuries had been managed in the period from 2000 to 2012.The clinical data of replanted teeth were collected, and the follow-up period was no less than 12 months .The factors were analyzed in relation to postoperative outcomes, classified as functional periodon-tal healing ( FH ) , infection-related ( inflammatory ) resorption ( IRR ) and replacement resorption ( RR) .Results:The functional healing rate was 23.0%, while replacement resorption rate was 72.1%. The replacement resorption ( ankylosis ) was usually observed earlier by clinical examination than by radiographic examination.86.0% (40/47) resorptive processes were diagnosed within the first year. Physiological storages, such as milk, saline and saliva were significantly better to periodontal ligament healing than nonphysiological storages, such as tap water and sterilizing solutions ( chloramine and alco-hol) .Functional healing was found significantly more frequent in canines and premolars.Conclusion:The factor significantly affecting periodontal ligament healing is storage medium.Replacement resorption is the most common type of root resorption.The replacement resorption diagnosis must combine the radio-graphic examination with the clinical examination.It is better to follow up more than 1 year after tooth re-plantation.

OBJECTIVE　To evaluate the availability and safety of a new carbapenem meropenem.METHODS　The randomized study was conducted in 60 patients with respiratory tract infections.They were divided into two groups:meropenem or imipenem/cilastatin.RESULTS　The cure rate,effective rate and bacterial clearance rate for meropenem were 80.0%,93.3%,92.3%,respectively and for those of imipenem/cilastatin were 76.7%,90.0% and 91.3%,respectively.The rate of adverse reactions for both meropenem/cilastatin was 3.3%.CONCLUSION　Meropenem appeared to be a highly effective and safe agent in treatment of respiratory tract infections.Its efficacy and safety are similar to that of imipenem/cilastatin.

Objective:To analyze the pulpal prognosis of replanted permanent teeth in children and to examine the associated factors .Methods:The samples consisted of 67 children with 81 avulsed perma-nent teeth treated in Peking University Hospital of Stomatology from 2000 to 2012 .Their clinical data of the replanted teeth were collected , and the follow-up period was no less than 12 months.The pulpal prognosis was classified as pulp necrosis and pulp non-necrosis .Results: The replantation within 30 minutes after avulsion led to the most significant increase in pulpal healing (P<0.05).The dental pulp of 80% ( 4/5 ) young permanent teeth replanted within 30 minutes remained vital , while all the teeth replanted after 30 minutes developed pulp necrosis within 60 days after replantation .Conclusion: The extra-alveolar period significantly affects the prognosis of pulp in immature permanent teeth after replanta-tion.When the extra-alveolar period is more than 30 minutes, the chance of pulp revascularization after replantation is very low , therefore pulp extirpation should be performed .