HPLC法测定湖南产半夏药材中核苷成分含量的研究

目的:建立HPLC法同时测定湖南产半夏药材中尿苷、鸟苷和腺苷含量的方法。方法:采用Agilent ZORBX SBC18色谱柱,以水(A)-甲醇(B)为流动相,梯度洗脱,流速1.0m L/min,检测波长254nm,柱温30℃,进样量20μL。结果:尿苷、鸟苷和腺苷的线性范围分别为4.8~48μg/m L、5.2~52μg/m L、0.6~6μg/m L,加样回收率分别为99.86%、99.28%、100.09%,RSD分别为1.16%、0.54%、0.98%。3批生半夏尿苷、鸟苷和腺苷的平均含量分别为0.1162mg/g、0.1432mg/g、0.0183mg/g。结论:该方法准确性高、专属性强,能快速测定湖南产半夏中3种指标性成分的含量,为更好地控制湖南产半夏药材的质量并评价其药用价值提供依据。     

The up-regulation of heme oxygenase-1 expression in human gingival fibroblasts stimulated with nicotine

BACKGROUND: Cigarette smoking is a major risk factor in the development and further progression of periodontal diseases. Heme oxygenase-1 (HO-1) is known as a stress-inducible protein and functions as an antioxidant enzyme. There is limited information on the expression of HO-1 in smoking-associated periodontal disease. OBJECTIVES: The aim of the present study was to investigate the effects of nicotine on the expression of HO-1 protein in cultured human gingival fibroblasts in vitro and further to compare HO-1 expression in gingival tissues obtained from cigarette smokers and non-smokers in vivo. METHODS: Western blot assay was used to investigate the effects on human gingival fibroblasts exposed to nicotine. In addition, antioxidants catalase, superoxide dismutase (SOD), and N-acetyl-l-cysteine (NAC) were added to test how they modulated the effects on nicotine-induced HO-1 expression. Gingival biopsies taken from the flap surgery of 20 male patients with periodontal disease (10 cigarette smokers and 10 non-smokers) were examined by immunohistochemistry. RESULTS: The exposure of quiescent human gingival fibroblasts to 10 mm nicotine resulted in the induction of HO-1 protein expression in a time-dependent manner (p < 0.05). The addition of glutathione (GSH) precursor NAC inhibited the nicotine-induced HO-1 protein expression (p < 0.05). However, SOD and catalase did not decrease the nicotine-induced HO-1 protein expression (p > 0.05). The results from immunohistochemistry demonstrated that HO-1 expression was significantly higher in cigarette smokers (p < 0.05). HO-1 was noted in the basal layers of epithelium, inflammatory cells, and fibroblasts in specimens from cigarette smoking. CONCLUSIONS: Taken together, these results suggest that HO-1 expression is significantly up-regulated in gingival tissues from cigarette smokers, and nicotine may, among other constituents, be responsible for the enhanced HO-1 expression in vivo. The regulation of HO-1 expression induced by nicotine is critically dependent on the intracellular GSH concentration.     

Integrating oxalate desensitizers with total-etch two-step adhesive

Compromised bonding of total-etch adhesives to dentin treated with oxalate desensitizers results from the interference of a surface layer of acid-resistant crystals of calcium oxalate. We hypothesize that effective tubular occlusion and dentin bonding may be simultaneously achieved by depleting dentin surfaces of calcium with acids before desensitizer application. Dentin specimens treated with 4 oxalate desensitizers before or after being acid-etched were bonded with a two-step adhesive. Microtensile bond strengths ( micro TBS) were significantly lower, compared with the control, when oxalates were used before the specimens were acid-etched; in contrast, when oxalates were used after acid-etching. micro TBS were similar to nonoxalate-treated controls. Dentin surfaces and tubular orifices were covered with a surface layer of crystals when desensitizers were applied to fractured dentin and smear-layer-covered dentin before specimens were acid-etched. However, when the dentin was acid-etched prior to the application of oxalate desensitizers, the crystals were largely limited to the subsurface of dentinal tubules, where they did not interfere with subsequent resin bonding.     

Influence of polymerization conditions on monomer elution and microhardness of autopolymerized polymethyl methacrylate resin

Residual monomer contents and surface hardness are important factors in determining the serviceability of provisional restorations. The intent of this study was to systemically evaluate the effects of curing conditions on provisional polymethyl methacrylate (PMMA) resins which utilize a free-radical polymerization reaction. Combinations of the three curing factors of temperature, pressure, curing environment (water/air) were adjusted during the fabrication of autopolymerized specimen disks. The initial hardness of tested materials was measured with a microhardness tester 1 h after disc fabrication, and the amounts of residual methyl methacrylate (MMA) released into water were analyzed by reverse-phase HPLC after 7 d of water immersion. Results from multiple regressions showed that curing temperature was the dominant factor in improving resin surface hardness, whereas curing in water was the key factor for reducing the quantity of residual monomer. The pressure factor, which was thought to be critical for managing autopolymerized resins, showed no significant influences on the properties tested. ANOVA results showed that provisional PMMA resins cured in hot water, with or without pressure, significantly reduced the amount of residual MMA elution (up to 80%) and increased the microhardness values (up to 50%).     

Oral features in Kabuki make-up Syndrome

AIM: Kabuki make-up Syndrome is so named because of the characteristic facies of the affected patient. The face is similar to a Kabuki actor's mask. The main aim of this report was to describe the oral features in Kabuki Syndrome, focusing on the tooth anomalies. PATIENTS AND METHODS: Five subjects with Kabuki Syndrome, identified by the Child Neuropsychiatric Clinic of the University of Sassari, Italy, were enrolled. Their medical records were reviewed and oral and dental examinations were completed. The diagnosis was based upon the typical pattern of malformations and dysmorphic features reviewed by Matsumoto and Niikawa. RESULTS: All patients showed typical characteristics of the Syndrome such as a long palpebral fissure, lower palpebral eversion, arched eyebrows, short nasal septum, prominent and large ears, fingertip pads, mental retardation, and paramedian elevation of the lower lip. CONCLUSION: Kabuki make-up Syndrome is of unknown origin but a genetic aetiopathogenesis has been proposed. It is extremely rare; in Japan, where it is most frequent, it affects 1:32000 newborns. The typical facies of the syndrome, combined with general medical and dental examinations, are very important for diagnosis confirmation.     

New technologies in health care. Part 1: A moral and ethical predicament

With the rapid evolution of technology and the development and marketing of new procedures in dentistry, dentists have difficulty keeping pace with all of this new technology and information. How do these clinicians know whether a new product, technique or technological advance is good and should be recommended? At what point do they have an obligation to inform their patients about new procedures supported by research? This first report of a 2-part series investigates the ethical aspects of these issues and describes some of the professional ethical dilemmas and obligations involved when new therapies are offered to the public.     

A controlled study of the association of various dental anomalies with hypodontia of permanent teeth

Although hypodontia, or oligodontia, is one of the most common human dental anomalies observed, there have been few studies on the association of other anomalies occurring with it. The present investigation of 1032 patient records found that 65.7% of patients with hypodontia showed ankylosis of primary molars compared to only 1.5% of control children (P less than 0.001). In addition, taurodontism of the mandibular first permanent molar was observed in 34.3% of hypodontia cases compared to 7.1% in the controls (P less than 0.001). Other dental anomalies significantly associated with hypodontia include enamel hypoplasia (11.9%, P less than 0.01) and conical incisors (8.9%, P less than 0.01). In contrast, there were significantly more impacted teeth in control children compared to the hypodontia group. The results indicate that for patients with missing permanent teeth, clinicians should be alert to the possibility of these associated anomalies and their accompanying clinical implications.     

Postoperative mandibular stability after orthognathic surgery in patients with mandibular protrusion and mandibular deviation

Skeletal stability and temporomandibular joint (TMJ) signs and symptoms were analyzed in 23 patients in whom mandibular protrusion and mandibular deviation had been corrected using bilateral sagittal split ramus osteotomy (BSSRO group, n = 10) and unilateral SSRO and intraoral vertical ramus osteotomy (USSRO+IVRO group, n = 13). Miniplate fixation was used in SSRO but no fixation was used in IVRO. The ratio of condylar bony change was 30.4% (7/23) and all condylar bony changes were seen on the deviated side. All preoperative signs and symptoms of TMJ disorders (4/13 patients in the USSRO+IVRO group and 2/10 patients in the BSSRO group) disappeared after surgery. Comparing the USSRO+IVRO group and the BSSRO group, in patients without condylar bony change, the mandible in both groups was stable anteriorly and horizontally after surgery, even though there was a larger horizontal mandibular movement in the USSRO+IVRO group during surgery. Comparing patients with condylar bony change versus no condylar bony change in the USSRO+IVRO group, postoperative horizontal mandibular displacement was significantly larger in the condylar bony change group than in the no condylar bony change group. These results support the idea that USSRO+IVRO can be useful in correcting mandibular deviation as well as improving signs and symptoms of TMJ disorders. However, it also seems important to be aware of the possibility of horizontal mandibular relapse in patients with condylar bony change.     

Functional outcomes following surgical treatment of bilateral mandibular condylar fractures

Debate continues regarding unilateral or bilateral treatment for mandibular condylar fractures. This retrospective study evaluates the functional outcomes of bilateral condylar process fractures after surgical intervention. From May 1994 to December 2004, 51 adult patients with bilateral mandibular condylar process fractures were studied. There were 33 cases of bilateral condylar fractures (type I); 12 cases of condylar-subcondylar fractures (type II); and six cases of bilateral subcondylar fractures (type III). All patients underwent open reduction and internal fixation. Four patients had chin deviation, six had malocclusion, three had poor chewing function and eight had limited mouth opening. Type I patients had a significantly higher incidence of limited mouth opening (P = 0.039) and associated maxillary fractures (n = 12) and psychiatric disease (n = 6) which yielded significantly poor functional outcomes. Complications included transient facial paresis (n = 4), fracture and loosening of postoperative plates (n = 3) and surgical wound infections (n = 2). Open reduction with rigid fixation for bilateral condylar fractures provided satisfactory functional outcomes in this study. Concomitant maxillary fractures and underlying psychiatric problems are poor outcome factors. Aggressive rehabilitation in the first 9 months is important for early functional recovery.     

埋伏阻生牙导致牙根外吸收邻牙的预后的临床观察

目的 探讨埋伏阻生牙导致邻牙（恒牙）牙根外吸收（ERR）时,阻生牙拔除术后邻牙的预后。方法 以埋伏阻生牙导致邻牙（恒牙）ERR但可以正常行使功能的63例患者的75颗ERR邻牙作为研究对象,微创拔除埋伏阻生牙后,术后随访6月,观察ERR邻牙的预后情况,并分析预后与患者年龄、性别、牙根数量、牙根吸收类型、牙根吸收程度的关系。结果 在75颗ERR邻牙中,67颗（89.3%）为无症状活髓牙。ERR邻牙的预后与患者的年龄相关（r=0.330,P<0.05）,年龄低于30岁者ERR邻牙均保持了无症状活髓。ERR邻牙的预后与性别、牙根数量、牙根吸收类型、牙根吸收程度无相关性（P>0.05）。结论 对于因相邻埋伏阻生牙导致的牙根外吸收而无临床症状的恒牙,有较大概率在阻生牙拔除术后保存活髓,建议密切随访观察,不必行预防性根管治疗。