Purification and characterization of a trypsin-like protease from the culture supernatant of Actinobacillus actinomycetemcomitans Y4

We purified and characterized a protease from Actinobacillus actinomycetemcomitans. The protease was isolated from the culture supernatant by sonication in phosphate-buffered 3-[(3 cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). The protease was purified by acetone precipitation, followed by column chromatography with Arginine Sepharose 4B, DEAE Sepharose CL-6B, Sephacryl S-200HR and HiTrap Q. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified protease showed a clear band at approximately 50 kDa. The protease showed trypsin-like activity with hydrolytic activity for the synthetic substrates N alpha-benzoyl-DL-arginine p-nitroanilide (BApNA) and N alpha benzoyl-DL-lysine p-nitroanilide (BLpNA). The activity of the protease was stable at pH 7.0 to approximately 8.0. The activity of the protease was inhibited by leupeptin, phenylmethylsulfonyl fluoride (PMSF), and EDTA, but was not affected by dithiothreitol (DTT), cysteine, 2-mercaptoethanol, pepstatin or soybean trypsin inhibitor. These data suggest that this protease is a serine protease or metallo protease. This enzyme extensively degraded collagen type I and fibronectin.     

Use of biodegradable polylactic acid barrier materials in the treatment of grade II periodontal furcation defects in humans--Part I: A multicenter investigative clinical study.

This study evaluated two bioresorbable polylactic acid barriers (Epi-Guide and Guidor) to determine if design differences were of therapeutic significance in the treatment of Grade II furcation defects in humans. Forty patients with bilaterally matched, Grade II furcation defects in maxillary or mandibular first or second molars were treated in a multicenter study. Comprehensive initial periodontal therapy, followed by defect debridement and root preparation, preceded randomized membrane placement. Data collected from all three investigative centers were pooled and analyzed using an analysis of variance appropriate for a counterbalancing design. Both barrier types produced measurable improvements of clinical probing values. Barrier exposure scores taken through the eighth week postoperative revealed that Epi-Guide was less likely to become exposed than Guidor. The findings of this study, which was conducted over a 12-month period, demonstrated that Epi-Guide and Guidor were comparable as measured by clinical probing determinations.     

The distribution of nitric oxide synthetase in Vcx and its relation with the expression of FOS induced by teeth movement in rats]

It was studied the central role of nitric oxide(NO) during experimental teeth movement and the relation between nitric oxide synthetase (NOS) positive neurons and FOS like immunoreactivity (FLN) with the NADPH-diaphorase histochemistry and immunocytochemical reaction method. Results indicated that NOS positive neurons and FLN showed typical distribution in Vcx and there was some overlap between them. It suggests that NO is involved in the central modulation of the stimulating message of teeth movement, and which further explains the central modulation mechanism of experimental teeth movement in rats.     

IL—1,IL—6,TNF对人TMJ滑膜细胞蛋白合成的影响

目的：研究人ＴＭＪ滑膜细胞（ＳＭＣ）蛋白质合成能力，与其它组织细胞的差异，及细胞因子对这方面的影响。方法：采用体外培养的ＳＭＣ、ＴＧＣ、ＮＭＣ３种细胞及无血清培养液，应用紫外分光光度仪在２８０ｎｍ波长处，对培养上清中的蛋白含量进行测定，并与加用ＩＬ－１、ＩＬ－６、ＴＮＦ后蛋白质合成的量进行对比观察。结果：正常状态下，ＴＧＣ蛋白合成量最高，ＯＤ值达０．１４，而ＳＭＣ最低，为０．０７９。在加用细胞因子作用４８ｈ后，ＳＭＣ蛋白含量达到０．１１７，提高３０％，而ＴＧＣ、ＮＭＣ却下降１０％～３０％。结论：正常状态下ＳＭＣ合成蛋白质成份较其它细胞少，而细胞因子可刺激ＳＭＣ蛋白质合成增加，这些蛋白成份中可能具有影响关节炎症的物质。     

唾液对体外培养NIH—3T3及MEC—1细胞粘附的影响

目的：探讨人唾液对正常及肿瘤细胞在体外粘附有无不同影响。方法：接种ＮＩＨ—３Ｔ３及ＭＥＣ－１细胞在预先涂有或未涂唾液的２４孔培养板上，用细胞计数法分别在接种后２、４、６和８ｈ计数贴壁细胞。结果：ＮＩＨ－３Ｔ３细胞及ＭＥＣ－１细胞在涂有唾液的塑料底物上在２、４、６、和８ｈ其贴壁抑制率分别为３５％、４１％、２６％、３４％和１０％、９％、８％、４％。结论：人全唾液能抑制体外培养的ＮＩＨ－３Ｔ３细胞的粘附，但对ＭＥＣ－１细胞的影响不大。     

A point mutation of the ED1 gene in a Japanese family with X-linked hypohidrotic ectodermal dysplasia

X-linked hypohidrotic ectodermal dysplasia (EDA) is characterized by the hypoplasia or absence of hair, teeth and sweat glands. In this study, the authors investigated the ED1 gene in a Japanese family with X-linked hypohidrotic ectodermal dysplasia. The only affected male fulfils the diagnostic criteria for this disorder. His parents were not consanguineous and both of them were healthy. After informed consent, genomic DNA was isolated from the peripheral blood lymphocytes or oral buccal epithelial cells of all members of the family. A polymerase chain reaction fragment containing exon 9 of the ED1 gene was amplified using primers. The patient's amplified fragment, as well as those from his father, mother and sister, were directly sequenced. The sequence from the patient revealed a point mutation (G1149A) in exon 8 of the ED1 gene, which changes codon 291 from glycine to arginine. Heterozygosity was demonstrated in his mother and sister. This mutation has not been reported previously. The amino acid substitution is predicted to disrupt the transmembrane domain, which strongly implies that this is the disease-causing mutation in the family.     

Effect of a peripheral NMDA receptor antagonist on glutamate-evoked masseter muscle pain and mechanical sensitization in women

AIMS: To test the hypothesis that local injection of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine would significantly attenuate glutamate-evoked masseter mechanical sensitization and muscle pain in healthy young women either taking oral contraceptives (W+OC) or not taking oral contraceptives (W-OC). METHODS: Experimental pain was evoked in 47 healthy female subjects (W+OC, n=25; W-OC, n=22) by 2 injections of glutamate (0.2 mL, 1 mol/L) into the masseter muscle. A first injection of glutamate alone was followed by a second injection, 35 minutes later, of glutamate combined with ketamine (0, 1, or 10 mmol/L). Evoked pain intensity was scored on a 10-cm electronic visual analog scale (VAS). Distribution of perceived pain was drawn on a lateral view of the face (pain drawing). Masseter muscle pressure pain thresholds (PPT) and pressure-pain tolerances (PPTOL) were determined bilaterally before and at regular time intervals after injections. Analyses of variance (ANOVA) were used to test the data. RESULTS: There were no main effects of ketamine on any of the VAS pain parameters or on the pain drawing (ANOVAs: P > .055). Furthermore, there were no differences in PPT, PPTOL, VAS peak pain, duration, overall VAS pain, or pain drawing when W-OC were compared with W+OC (ANOVAs: P > .087). Repeated injection of glutamate alone significantly decreased PPT and PPTOL (ANOVAs: P < .001); however, this effect was not significantly attenuated by ketamine. CONCLUSIONS: Peripherally administered ketamine had no effect on glutamate-evoked masseter muscle pain and sensitization in healthy young women, which contrasts with recent observations in healthy young men. Further studies will be needed to reveal the mechanisms that underlie this apparent sex-related difference in ketamine-mediated analgesia.     

Common implant esthetic complications

Today, osseointegration of implants is readily attainable with high long-term survival rates. Consequently, clinicians are now focusing on improving implant esthetics and are starting to incorporate this parameter into their definition of implant success. However, studies measuring factors that affect implant esthetics and implant esthetic outcomes are lacking in the literature. A satisfactory esthetic outcome requires the clinician to be aware of the different factors affecting esthetics during the preplanning, surgical, and prosthetic phases of implant placement. This article addresses the etiologies of esthetic complications during each of these 3 phases and provides preventive and corrective treatment suggestions for these situations.     

Influence of sex hormones on the periodontium

OBJECTIVES: Sex hormones have long been considered to play an influential role on periodontal tissues, bone turnover rate, wound healing and periodontal disease progression. The objectives of this review article are to (1) address the link between sex hormones and the periodontium, (2) analyse how these hormones influence the periodontium at different life times and (3) discuss the effects of hormone supplements/replacement on the periodontium. MATERIALS AND METHODS: Two autonomous searches were performed in English language utilizing Medline, Premedline and Pubmed as the online databases. Publications up to 2002 were selected and further reviewed. In addition, a manual search was also performed including specific related journals and books. RESULTS: It is certain that sexual hormones play a key role in periodontal disease progression and wound healing. More specifically, these effects seem to differentiate by gender as well as lifetime period. In addition, the influence of sex hormones can be minimized with good plaque control and with hormone replacement. CONCLUSION: Despite profound research linking periodontal condition with sex hormones kinetics, more definitive molecular mechanisms and therapy still remain to be determined.