127名汉族青年口腔唾液一氧化氮含量检测

目的 :研究健康汉族青年唾液中一氧化氮 (NO)含量正常参考值限 ,及其与口腔龋病、龈炎的关系。方法 :分别采集口腔正常 (42名 )、有龋病 (49名 )或龈炎 (36名 )的健康汉族青年学生口腔唾液 ,由专业人员用NO检测试剂盒 ,比色并计算出唾液中NO含量。结果 :男性唾液中NO含量值限为 0～ 2 40mol/L ,均值为(6 7.0 2 5± 39.0 6 5 ) μmol/L ;女性唾液中NO含量值限为 0～ 2 39μmol/L ,均值为 (76 .397± 34 .85 6 ) μmol/L。口腔正常组、龋病组、龈炎组唾液NO含量均值 ,分别为 (6 8.2 86± 37.432 ) μmol/L ,(6 8.6 82± 34 .6 2 7) μmol/L和 (79.70 0±40 .0 0 7) μmol/L ,经统计学检验 ,3组间唾液NO含量无显著差异 (P >0 .0 5 )。 结论 :汉族青年唾液NO含量正常参考值在 11～ 140 μmol/L ,唾液中NO含量在浅、中度龋和轻度龈炎者中 ,未见明显增高 (P >0 .0 5 )。     

Salivary osteocalcin levels are decreased in smoker chronic periodontitis patients

Oral Diseases (2011) 17 , 200–205 Objectives: This study was planned to investigate whether smoker chronic periodontitis patients exhibit different salivary concentrations of C‐telopeptide pyridinoline cross‐links of type I collagen (ICTP) and osteocalcin (OC) compared to the non‐smoker counterparts. Methods: Whole saliva samples, full‐mouth clinical periodontal recordings were obtained from 33 otherwise healthy chronic periodontitis patients and 36 systemically, periodontally healthy control subjects. Chronic periodontitis patients and healthy control subjects were divided into smoker and non‐smoker groups according to their self reports. Salivary ICTP, OC levels were determined by Enzyme‐linked Immunoassays. Results: Healthy control groups exhibited significantly lower values in all clinical periodontal measurements (P < 0.001). Smoker periodontitis patients revealed similar clinical periodontal index values with non‐smoker counterparts (P > 0.05). Chronic periodontitis patients exhibited significantly higher salivary OC levels than healthy controls (P < 0.05). Smoker periodontitis patients revealed lower salivary OC levels than non‐smoker counterparts (P < 0.001). Log ICTP levels in non‐smoker chronic periodontitis patients were higher than non‐smoker controls (P < 0.05). Smoker healthy control group revealed higher log ICTP levels than non‐smoker counterparts (P < 0.001). Conclusions: Within the limits of this study, it may be suggested that suppression of salivary osteocalcin level by smoking may at least partly explain the deleterious effects of smoking on periodontal status.     

牙周炎患者唾液一氧化氮的含量及其与牙周病指标相关性的研究

目的：研究牙周炎患者唾液一氧化氮（ＮＯ）的含量,及其与牙周病各临床指标的相关性。方法：选择成人牙周炎患者２３例为实验组,健康人２７例为对照组。记录牙周炎患者的牙龈出血指数（ＧＢＩ）、牙周袋深度（ＰＤ）和附着丧失量（ＡＬ）。ＮＯ的含量由检测唾液亚硝酸盐的含量来代表。测定实验组和对照组所有病例的唾液ＮＯ的含量。结果：对照组唾液ＮＯ的含量为２８．８０６±６．６０４μｍ／Ｌ,男女间无显著性差异。实验组唾液ＮＯ的含量为５５．３６１±１３．３１９μｍｏｌ／Ｌ,明显高于对照组。牙周炎患者唾液ＮＯ的含量与ＰＤ、ＡＬ间存在明显的正相关。结论：牙周炎患者唾液ＮＯ的含量显著高于健康人,并与牙周炎的严重程度有关。     

Association Between Periodontitis and Salivary Nitric Oxide Metabolites Among Community Elderly Koreans

Background: Nitric oxide (NO) is known to play an important role in many biologic systems, although the relationship between NO metabolites and periodontitis remains controversial. Moreover, little evidence of an association between salivary NO (S‐NO) and periodontitis in the general population has been reported. This study aims to investigate the relationship between S‐NO and periodontitis in an elderly Korean population. Methods: A cross‐sectional study was conducted using participants and salivary samples from Sunchang Elderly Cohort Study. The total number of final participants was 242 (91 males and 151 females; 48 to 93 years old). Periodontitis was determined by a clinical attachment loss of >6 mm at six probe points on 12 index teeth. NO was measured in unstimulated saliva via the Griess reaction. Sociodemographic status, general/oral health, and health‐related behaviors were investigated as confounders. Bivariate analysis and multivariable linear regression analyses including confounders were applied. Results: After controlling for age, sex, education, salivary flow rate, number of teeth, smoking status, physical activity, hypertension, and diabetes, three metabolites of S‐NO (total NO, nitrite, and nitrate) were independently associated with the percentage of probe points exhibiting periodontitis. Of these linear associations, total NO was found to have the strongest correlation with periodontitis (partial r = 0.181, P = 0.009). These associations were most pronounced in females (except for nitrate), non‐smokers, those without hypertension, and those without diabetes. Conclusions: Our data suggest that high concentrations of S‐NO are associated with severe periodontitis. Thus, S‐NO may serve as a potential biologic marker for detecting and monitoring periodontitis.     

Nitric oxide synthesis and severity of human periodontal disease

The expression of the inducible nitric oxide synthase enzyme (iNOS) is a response to an inflammatory stimulus and produces a large amount of nitric oxide (NO), which may act as a cytotoxic molecule against the invading microorganism and may be related to both harmful and beneficial effects to tissues. OBJECTIVE AND MATERIAL AND METHODS: In order to further characterize the presence of NO in human periodontal disease, we undertook a quantitative study of iNOS positive cells in samples of clinically healthy gingival tissues, plaque-induced gingivitis and localized chronic periodontitis using immunohistochemistry. RESULTS: A significant increase in the number of iNOS+ cells mm-2 was found in the samples of the gingivitis and periodontitis compared with those of the control. In all groups most of the polymorphonuclear cells showed intense immunoreactivity for iNOS independent of the disease stage, and the percentage of iNOS+ polymorphonuclear cells increased significantly in periodontal disease when compared with the control. CONCLUSION: Our results indicate that iNOS increases in the presence of periodontal disease. In addition, our findings suggest that polymorphonuclear cells present an additional activation pathway in periodontal disease, expressing significant iNOS and probably representing an important source of NO in human periodontal disease that has not been previously reported.     

Increase nitric oxide synthase activity in parotid glands from rats with experimental periodontitis

Oral Diseases (2010) 16 , 801–806 Objective: In this study we investigated the activity of the nitric oxide synthase (NOS) in parotid glands from rats with experimental periodontitis and controls. Methods: Periodontitis was produced by a ligature placed around the cervix of the two lower first molar. Experiments were carried out 22 days after the ligature. Results: Ligation caused an increase in parotid NOS activity. The selective blocker of the inducible isoform of the enzyme partially inhibited its activity in parotid glands from rat with ligature. In controls, the activity was partially inhibited by the antagonists of the selective neural and endothelial isoforms. NOS activity in rats with ligature was cyclic adenosine monophosphate (cAMP)‐dependent while in controls it was calcium‐dependent. Prostaglandin E₂ concentration was increased in parotid gland from rats with ligature. The inhibitor of prostaglandin production, FR 122047, diminished both, prostaglandin production and NOS activity. In rats with ligature unstimulated amylase released is increased. Both, prostaglandin and NOS were involved in the increment of amylase release. Conclusion: It can be concluded that in parotid glands from ligated rats, prostaglandin E₂ production is increased and, through cAMP accumulation, activates the inducible NOS isoform. The increment of nitric oxide production participates in the increase in basal amylase release.     

一氧化氮和一氧化氮合酶系统与骨组织创伤

一氧化氮是在一氧化氮合酶作用下氧化产生的一种小分子自由基气体,参与全身多种病理生理过程,如信息传递、血管张力调控、免疫防御、组织损伤和修复等。下面就一氧化氮和一氧化氮合酶系统在骨组织创伤修复中的作用作一综述。     

慢性牙周炎患者牙龈组织内诱导型一氧化氮合酶表达的研究

目的:研究牙周健康者和慢性牙周炎患者牙龈组织中诱导型一氧化氮合酶的表达强度,探讨一氧化氮在牙周病发病过程中的作用.方法:选择牙周健康组、慢性牙周炎活动期组,慢性牙周炎静止期组各20例,采取免疫组织化学的方法染色,光镜下观察牙龈组织内诱导型一氧化氮合酶的表达强度.结果:慢性牙周炎时牙龈组织中诱导型一氧化氮合酶主要在鳞状上皮和间质组织的细胞胞浆中阳性表达,正常组表达强度弱于慢性牙周炎静止期组和活动期组,慢性牙周炎静止期组表达强度弱于慢性牙周炎活动期组.结论:一氧化氮参与了慢性牙周炎的发生和发展过程,牙龈组织中诱导型一氧化氮合酶的表达强度与慢性牙周炎的炎症程度密切相关.     

Effectiveness of scaling and root planing versus modified Widman flap on nitric oxide synthase and arginase activity in patients with chronic periodontitis

BACKGROUND: Nitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase, which is an arginine-depleting enzyme, can compete with NOS for the common substrate L-arginine and thus inhibit NO production. OBJECTIVES: In the present study, we aimed to examine the correlation between the arginase and NOS activity in patients with chronic periodontitis and to compare the effects of scaling and root planing and modified Widman flap procedures on enzyme activity. MATERIAL AND METHODS: The study included 13 patients diagnosed with chronic periodontitis. Using a split-mouth design, the defects showing>or=7 mm of attachment loss were treated either with scaling and root planing or with modified Widman flap. Gingival biopsies from both sites were obtained at baseline and 2 months after periodontal treatment. Immunohistochemical staining was performed for evaluating NOS expression and specific arginase activity was determined spectrophotometrically. RESULTS: Although inflamed periodontal tissues demonstrated a strong inducible NOS (iNOS) expression at baseline, immunostaining decreased after periodontal treatment. iNOS expression intensity and the number of inflammatory cells showing iNOS expression were found to be higher in the scaling and root planing group compared to the modified Widman flap group. The specific activity of arginase was measured as 0.18+/-0.07 IU/mg protein in the modified Widman flap group and 0.25+/-0.11 IU/mg protein in the scaling and root planing group at baseline. After periodontal therapy, the enzyme level was increased to 0.68+/-0.14 IU/mg protein in the modified Widman flap and to 1.10+/-0.23 IU/mg protein in the scaling and root planing group. CONCLUSION: This study was the first report of evaluating the involvement of the arginine-NO pathway in chronic periodontitis and this might be considered to be of value in understanding the periodontal disease mechanisms.     

iNOS-derived nitric oxide stimulates osteoclast activity and alveolar bone loss in ligature-induced periodontitis in rats

Background: Inflammatory stimuli activate inducible nitric oxide synthase (iNOS) in a variety of cell types, including osteoclasts (OC) and osteoblasts, resulting in sustained NO production. In this study, we evaluate the alveolar bone loss in rats with periodontitis under long‐term iNOS inhibition, and the differentiation and activity of OC from iNOS‐knockout (KO) mice in vitro. Methods: Oral aminoguanidine (an iNOS inhibitor) or water treatment was started 2 weeks before induction of periodontitis. Rats were sacrificed 3, 7, or 14 days after ligature placement, and alveolar bone loss was evaluated. In vitro OC culture experiments were also performed to study the differentiation of freshly isolated bone marrow cells from both iNOS KO and wild‐type C57BL/6 mice. OC were counted 6 days later after tartrate‐resistant acid phosphatase staining (a marker of osteoclast identity), and bone resorption activity was assessed by counting the number of resorption pits on dentin disks. Results: Rats with ligature showed progressive and significant alveolar bone loss compared to sham animals, and aminoguanidine treatment significantly inhibited ligature‐induced bone loss at 7 and 14 days after the induction. In comparison to bone marrow cells from wild‐type mice, cells from iNOS KO mice showed decreased OC growth and the resulting OC covered a smaller culture dish area and generated fewer resorption pit counts. Conclusion: Our results demonstrate that iNOS inhibition prevents alveolar bone loss in a rat model of ligature‐induced periodontitis, thus confirming that iNOS‐derived NO plays a crucial role in the pathogenesis of periodontitis, probably by stimulating OC differentiation and activity.     

Immunoglobulin-degrading enzymes in localized juvenile periodontitis

Previous reports have indicated the association of periodontal diseases with elevated levels of serum immunoglobulin G (IgG) antibodies to periodontally relevant bacteria. Recent results from this laboratory suggest that enzymes proteolytic for immunoglobulins are important virulence factors of several periodontal bacteria. Specifically, enzymes from Porphyromonas (Bacteroides) gingivalis culture supernatant fluid (SF) cleaved human IgG (4 subclasses), IgA1 and IgA2, IgM, IgD and IgE. Proteolytic enzymes from Actinobacillus actinomycetemcomitans culture SF cleaved IgG, IgA and IgM. An enriched Ig proteolytic preparation from Capnocytophaga ochracea culture SF was shown to extensively cleave all 4 subclasses of human IgG. Extensive degradation of IgG and IgA in crevicular fluid samples on SDS-PAGE from periodontal disease sites of localized juvenile periodontitis (LJP) patients in comparison to little degradation in healthy sites indicated the potential role the proteolytic enzymes from periodontopathogenic bacteria may play in situ. Treatment of IgG with P. gingivalis, A. actinomycetemcomitans and C. ochracea SF resulted in similar patterns of degradation. LJP patients had significantly higher levels of IgG and IgA proteolytic activity in whole saliva than age-, sex-, and race-matched periodontal disease-free controls. However, not all of the proteolytic activity could be ascribed to bacterial proteases since neutrophils are also present in large numbers at diseased sites. Using similar techniques, lysates of neutrophils from healthy controls cleaved IgG, IgA and IgM. The observation of enhanced Ig cleavage activity in crevicular fluid and saliva in LJP patients suggest a role for Ig proteolytic enzymes in LJP.     

Protective effects of baicalin on ligature-induced periodontitis in rats

Background and Objective: Baicalin is a flavonoid compound purified from the medicinal plant, Scutellaria baicalensis Georgi, and has been reported to possess anti‐inflammatory and antioxidant activities. The purpose of this study was to test the ability of baicalin to influence the progression of experimental periodontitis in rats, as well as the expression of cyclooxygenase‐2 and inducible nitric oxide synthase. Material and Methods: Adult male Sprague–Dawley rats were subjected to placement of a nylon thread around the bilateral lower first molars and killed after 7 d. Baicalin (50, 100 or 200 mg/kg) was supplied to the animals by oral gavage, starting 1 d before the induction of periodontitis. The ligature group consisted of rats subjected to periodontitis and receiving vehicle (0.5% carboxymethylcellulose) alone. The alveolar bone loss and the area fraction occupied by collagen fibers were assessed. The expression of cyclooxygenase‐2 and inducible nitric oxide synthase protein in the gingiva were detected by immunohistochemistry and western blotting. Results: Baicalin‐treated groups presented with lower alveolar bone loss than that of the ligature group, reaching statistical significance at the dose of 200 mg/kg (p = 0.009). The area fraction of collagen fibers was significantly higher in the baicalin (200 mg/kg)‐treated group than in the ligature group (p = 0.047). Baicalin treatment significantly down‐regulated the protein expression for cyclooxygenase‐2 (p = 0.000) and inducible nitric oxide synthase (p = 0.003), compared with the ligature group. Conclusion: Baicalin protects against tissue damage in ligature‐induced periodontitis in rats, which might be mediated, in part, by its inhibitory effect on the expression of cyclooxygenase‐2 and inducible nitric oxide synthase. These activities could support the continued investigation of baicalin as a potential therapeutic agent in periodontal disease.     

Nitric oxide and tissue destruction

Nitric oxide (NO) is a free radical which has complex roles in both health and disease. It is now recognized that NO is essential for a vast spectrum of intracellular and extracellular events in a wide variety of tissues. NO has also been implicated in the pathogenesis of numerous inflammatory and autoimmune diseases. In this review we consider the roles of NO generally and in particular the implications for periodontal diseases.     

大鼠实验性牙周炎牙龈组织中一氧化氮含量改变的研究

目的:探讨NO在牙周炎病理进程中的作用。方法:健康Sprague-Dawley大鼠共72只,随机分为正常对照组和牙周炎组,每组36只。参照DiPaola法复制大鼠牙周炎动物模型。分别于术后1、4和8周时处死动物,每个时间点每组处死动物12只。采用分光光度仪测量大鼠牙龈组织中亚硝酸盐(NO2-)和硝酸盐(NO3-)的含量,以间接确定NO含量;采用组织切片法观察牙周组织的组织病理学改变;应用Tiger细胞图象仪测量附着丧失(AL)。结果:术后4周和8周时,牙周炎组牙龈组织NO2-/NO3-含量明显高于正常对照组(P<0.01);在牙周炎组,术后8周牙龈组织NO2-/NO3-含量明显高于术后4周(P<0.01)。在牙周炎组,术后4周和8周与术后1周比较,AL显著增加(P<0.01);术后8周与4周比较,AL显著增加(P<0.01)。结论:NO2-/NO3-含量与牙周组织的破坏程度、AL直接相关。NO的合成在牙周组织疾病的进程中发挥作用,提示在牙周炎的治疗中控制NO的合成具有临床应用价值。     

Inducible nitric oxide synthase expression in periodontitis

Recently, nitric oxide (NO) has been shown to be vital in inflammatory processes. Nitric oxide synthase (NOS) exists in three different isoforms, two constitutively produced with physiological roles, and an inducible form, iNOS, which is involved in inflammation. This study examined the localisation of iNOS in biopsies from patients with periodontitis using immunohistochemistry, and compared these with healthy tissue biopsies. Biopsies were obtained from 16 periodontitis patients undergoing periodontal surgery and from clinically healthy tissues of 5 patients having crown lengthening procedures. The periodontitis diseased tissue demonstrated a greater level of iNOS expression than the healthy tissue. The source of iNOS in the periodontal tissues was determined by our monoclonal antibody to be the macrophage, with the endothelial cells also contributing. A role for NO in the inflammatory response of periodontal tissues is suggested, but the precise role requires further elucidation.