AIM: To study the possible role of nitric oxide (NO) in the development of periodontitis and the relationship between the NO concentration and the attachment loss. METHODS: Seventy- two Sprngue- Dawley rats were randomly assigned to two groups, the control group and periodontitis group. Experimental periodontitis in rats was produced by a ligature of braided silk. The nitric oxide concentration was indirectly ascertained by the concentration of nitrite (NO2-) and nitrate (NO3-)in the gingival tissue, which was assayed by spectrophotometry. The attachment loss (AL) was measured by the technology of the cellular graphics engineering research. The histopathologic change in periodontium was observed under a light microscope by using the histotomy. RESULTS: Compared to control group, the NO2-/NO3 - concentration in gingival tissue was significantly higher in periodontitis group at four weeks and eight weeks following ligation (P＜0.01). In periodontitis group, the NO2-/NO3 - concentration in gingival tissue was higher at eight weeks than that at four weeks following ligation (P＜0.01). At four weeks and eight weeks, the AL in experimental periodontitis in rats was significantly increased than that at one week after ligation ( P＜0.01); and the AL was also much higher at eight weeks than that at four weeks (P＜0.01). CONCLUSIONS: The NO2-/NO3- concentration in the gingival tissue in periodontitis group was significantly higher than that in control group. These results demonstrate that the NO2-/NO3- concentration is related to the severity of AL, and NO synthesis is very important to the process of inflammation and lesion in periodontium. Reducing NO production may be of great therapeutic value in the treatment of periodontitis.

Objective To study the clinical features of pulmonary Langerhans cell histiocytosis.Methods Restrospectively review of 7 cases of pulmonary Langerhans cell histiocytosis proved by pathology with the clinical,physical,radiological,pathological and pulmonary function presentation.Results Seven cases were all male,aged from 17 to 37.Four of them are cigarette smokers.The major symptoms were cough and laboring dyspnea,and pneumothorax presented in five cases.As to pulmonary function presentation,obstructive pattern presented in three cases,restrictive pattern and mixed pattern presented in two cases respectively,and the carbon monoxide diffusing capacity was decreased in four cases.The abnormalities present predominantly in the upper and middle lung fields on chest high-resolution CT scan.Lung cysts and reticular changes presented in six cases and nodules presented only in one case.The diagnosis was established by surgical lung biopsy.The positive cases of staining for the S-100,CD1a antigens,and CD68 were 7/7,4/5 and 5/6 respectively.Conclusion PLCH patients are typically young adults,often present with cough,laboring dyspnea and pneumothorax.Pulmonary function presentation is nonspecific and the carbon monoxide diffusing capacity may be decreased.The characteristic features of HRCT are bilateral reticulonodular areas and cysts change that predominantly involved the upper and middle lung zones with relative sparing of the lung bases.The pathologic feathers are interstitial infiltration of bronchiole walls and epithelium by LCH cells and cyst formation.The staining for CD1a antigens and the S-100 proteins is positive by immunohistochemical analysis.

AIM: To study the effect of local application of indomethacin on acute pulpitis. METHODS: Traumatic pulpitis model in rats was established by means of pulp exposure, radioimmunoassay (RIA) was used to measure the kinetic changes of the levels of PGE_2、6-keto-PGF_~1? and TXB_2 of pulpal tissues. RESULTS: Local application of indomethacin could more effectively inhibit the cyclo-oxygenase pathway than zinc oxide engenol in the early stage of pulpitis and reduce the production of prostaglandins. CONCLUSION: Local application of indomethacin may have a therapeutic effect on acute pulpitis. [

AIM: The purpose of this study was to investigate the role of interleukin-4 (IL-4) in the development of periodontitis in mice by low dosage of Trichinella spiralis (T. spiralis) infection.METHODS: Twenty-seven male Kunming mice in specific pathogen free grade were randomly divided into three groups: (1) the normal control group;(2) the experimental periodontitis group, which was produced by ligature of braided silk around the first maxillary molar, and was inoculated with putative periodontopathic bacteria;(3) the periodontitis with T. spiralis infection group. The mice were sacrificed at the end of 1, 3 and 5 weeks. The probing depth (PD) was measured before the mice were euthanized. The histological change of periodontal tissues was observed under the microscope after the samples were stained with hematoxylin and eosin. Furthermore, the serum level of IL-4 was determined by ELISA. RESULTS: (1) The serum level of IL-4 in T. spiralis-infected group was significantly higher than that in experimental periodontitis group (P<0.01). (2) The PD in T. spiralis-infected group was significantly lower than that in experimental periodontitis group (P<0.01). (3) Only a mild inflammatory response was observed in T. spiralis-infected animals. CONCLUSION: T. spiralis infection upregulates IL-4 expression and attenuates periodontitis in mice.

AIM: To evaluate the effect of mechanical periodontal treatment combined with tetracycline on per iodontal attachment level (AL) and the avidity of serum antibody against porphyromonas gingivalis( P. gingivalis) in patients with aggressive periodontitis(AgP). METHODS: Twenty- five patients with AgP and twenty periodontally healthy controls were studied (HS). Clinical examination and recordings of AL were performed before and 3,6 and 12 months after the periodontal treatment. The avidity of IgG antibody against P. gingivalis lipopolysaccharide(LPS) was measured by diethylamine dissociation ELISA. RESULTS: A significant improvement in AL was observed following treatment ( P ＜ 0. 01 ). The avidity of serum IgG antibody against P. gingivalis increased compared with controls, and was decreased significantly after mechanical periodontal treatment combined with tetracycline (P ＜ 0. 01 ). CONCLUSION: Ourresults demonstrate that mechanical periodontal treatment combined with tetracycline provides clinically favorable results in patients with AgP.

[ ABSTRACT] AIM:To investigate the distribution of mast cells ( MCs) and the expression of transforming growth factor-β(TGF-β) on tryptase positive MCs in different types of human periapical diseases.METHODS:Total 78 cases of specimens were involved in this study, including healthy control, periapical cyst and periapical granuloma.The tissue sam-ples were fixed in 10% formalin for at least 48 h, stained with hematoxylin and eosin for histopathological examination, stained with toluidine blue staining for identifying MCs and MCs degranulation, and stained with double immunofluores-cence for identification of tryptase-TGF-βdouble positive MCs.RESULTS:The density of tryptase-TGF-βdouble positive MCs in the periapical lesions was significantly higher than that in the healthy controls ( P<0.01) .The number of TGF-βpositive MCs in the periapical cyst was significantly higher than that in the periapical granuloma ( P<0.01 ) .Compared with toluidine blue staining, the number of MCs with double immunofluorescence staining significantly increased ( P <0.01).CONCLUSION:The TGF-βpositive MCs may play an important role in the pathogenesis of human chronic peria-pical diseases, particularly in the formation of fibrous tissue in periapical cyst.Double immunofluorescence staining is more sensitive than the traditional toluidine blue staining for identifying MCs.

AIM: To assess the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with type I collagen on pulp capping in cats. METHODS: Freshly exposed pulps of thirty cats were capped with four different pulp capping agents: rhBMP-2/collagen I, calcium hydroxide, type I collagen and bovine serum albumin as control. The reparative dentinogenesis and osteocalcin content were assessed after 1 week, 2 weeks and 4 weeks by means of histology and radioimmunoassay. RESULTS: the pulpal tissues of the teeth capped with rhBMP-2/collagen showed mild inflammation and odontoblast differentiation with tublar dentin bridge on the exposed site. The level of bone ?-carboxyglutamic containing protein(BGP) in the group of rhBMP-2 with collagen I was significantly higher than that of the other three groups (P

AIM: This study was aimed to assess the effect of mineral trioxide aggregate (MTA) combined with fibronectin on reparative dentinogenesis and odontoblast differentiation, investigate the possible mechanism underlying traumatized pulp repair, which would facilitate the choosing of ideal pulp capping agents. METHODS: 192 teeth from 16 adult cats were used. Class V cavties were prepared on the facial surface. The pulps of cats were exposed mechanically and then capped directly with MTA, MTA combined with fibronectin, calcium hydroxide, fibronectin and starch as control. The pulpal tissue reactions were assessed by light microscopy at healing interval of 1 and 4 weeks.RESULTS: 1 week after pulp capping, no reparative dentin formation was observed in each group. 4 weeks after pulp capping, the dental pulps capped with MTA/fibronectin showed no or slight cellular inflammatory responses and odontoblast differentiation with tublar dentin bridge on the exposed sites. In MTA group, the dental pulps showed slight to moderate cellular inflammatory responses with osteodentin formation. In calcium hydroxide group, the pulps showed moderate to severe inflammatory responses with calcified matrix. In fibronectin and starch group, no dentin bridge formation was observed, the pulps showed severe cellular inflammatory responses.CONCLUSION: (1) MTA combined with fibronectin induced to form complete and tublar dentin bridge. In MTA group, most of the formed dentin bridge was irregular and osteodentin. (2) MTA combined with fibronectin is a bioactive pulp-capping agent and has a great worth in vital pulp therapy.

Objective: To investigate the effect of polarizing the immune response toward the Th2 type, using intestinal nematode (Trichinella spiralis) infection, on subsequent experimental periodontitis. Methods:Thirty six SPF KM mice were randomly divided into three groups. Periodontitis group: experimental periodontitis was induced by wrapping a 5/0 silk ligature inoculated with putative periodontopathic bacteria around the first maxillary molar. Th2-polaried group: After the mice were infected with low dosage Trichinella spiralis, the experimental periodontitis model was established at that time as above. Mice were sacrificed at the end of 1, 4, 8, 12 weeks. The histological analysis of periodontal tissues was observed by microscope after the samples were stained with hematoxylin and eosin (H&E). The concentrations of IFN--y and IL-4 in mouse serum were determined by ELISA. Results; The results showed that compared with control group Th2-polaried mice had high levels of IL-4 prior nematode infection reduced the severity of periodontitis, and subsequent infection of the periodontium with oral pathogens developed minimal lesions. Few or no osteoclasts were detected in lesions of Th2-polaried group. Conclusion;These results indicate a protective role of nematode infection in Thl cell-driven periodontal damage and prompt consideration of a novel therapeutic strategy in periodontitis based on im-munological distraction.

AIM:To evaluate therapeutic effect of Zhiqi oral solution on adult periodontitis. METHODS: Supragingival scaling and root planning were carried out in 100 patients with adult periodontitis. Then the patients with periodontitis were divided into two groups randomly. 32 patients in the control group took orally Metronidazole and 68 patients in the experimental group took orally Zhiqi oral solution. The pain reaction, bleeding index, probing depth, plaque index, changes of microorganisms in periodontal pocket and side effect before and after the treatment were observed at a 30 days observation period. RESULTS:Zhiqi oral solution had a therapeutic effect on periodontitis, compared with the control group ( P