2-甲酰(乙酰)取代喹啉缩氨基硫脲的合成

缩氨基硫脲类化合物有抗肿瘤、抗病毒和抗菌等多种药理活性。Barret等首次报道了乙二醛二缩氨基硫脲(Ⅰ)的抗疟活性。Klayman等研究了缩     

Resin-retained bridges in the treatment of traumatized dentition*

Abstract Resin-retained bridges can be used as the definitive treatment, as well as for interim treatment. Compared with conventional fixed prostheses, there are some advantages which make this treatment especially useful in traumatized dentition. The ultra conservative approach makes the adhesive bridge a standard treatment option in cases of uncertain prognostic factors. However, in such specific situations as traumatized dentition some complicating factors may be present. These complicating factors must be recognized and eliminated to create situations in which this kind of restoration can be succesful. Therapeutic and patient-related factors are discussed using data from longitudinal clinical studies. Available clinical information indicates the anterior adhesive bridge to be a permanent restoration'. However, a benefit-cost analysis is necessary to weigh the value of this restorations.     

Five year survival of posterior adhesive bridges. Influence of bonding systems and tooth preparation

The present study reports the final analysis of a randomized controlled clinical trial in which different designs of posterior resin-bonded bridges were evaluated for a period of at least 5 years. The operational hypothesis was that the bonding system and the preparation design used in posterior resin-bonded bridges have an influence on the survival and clinical functioning of these restorations. Survival in this study was defined at two levels: (1) 'primary' survival (survival without any debonding), and (2) 'functional' survival (survival including loss of retention on one occasion and successful rebonding of the original resin-bonded bridge without further debonding). Preparation of grooves in abutment teeth for posterior resin-bonded bridges appeared to be beneficial to their chance of survival. Resin-bonded bridges placed in the maxilla have a better prognosis than those made in the mandible. The bonding systems used in this study (etching/Clearfil F2, sand blasting/Panavia EX and silica-coating/Microfill Pontic C) appear to have no influence on the chance of failure with regards to the 'primary' survival. In rebonded posterior resin-bonded bridges, the bonding system silica coating/Microfill Pontic C was more retentive than the other systems tested.     

Partial models in fixed prosthodontics

In general there is consensus regarding the required criteria for crown- and bridge restorations. However, the variety in methods used for their fabrication is large. Textbooks and courses tend to advocate the use of full arch impressions without supplying objective data indicating better clinical behaviour of these restorations compared with the use of quadrant impressions. This article presents advantages, disadvantages, indication and essential steps when using quadrant models.     

An analysis of clinical studies on resin-bonded bridges.

Many clinical data on resin-bonded bridges (RBBs) have been published in the last ten years. The survival rates vary widely, and the conclusions are sometimes conflicting. A method of combining the results of different studies in order to draw conclusions about the effectiveness of therapeutic concepts is meta-analysis. The aims of the meta-analysis in this study were: (1) to assess an "overall" survival ratio for RBBs and (2) to explore relationships between potential success factors and reported survival times. About 60 publications with clinical data on RBBs were reviewed. Following a number of inclusion criteria (information adequate to calculate or assess survival rates, as well as adequate information about the patients, the designs, and types of RBBs), 16 different samples were used for this meta-analysis. A weighted multiple-regression analysis revealed no significant effects of "type of retention" and "location" on the survival percentages. Kaplan-Meier estimates were used to assess overall survival in a secondary analysis with the data from all 16 samples (n = 1598). The overall survivals were: one year, 89 +/- 1%; two years, 84 +/- 1%; three years, 80 +/- 1%; and four years, 74 +/- 2%.     

Activated protein C decreases plasminogen activator-inhibitor activity in endothelial cell-conditioned medium

Confluent cultures of endothelial cells from human umbilical cord were used to study the effect of activated human protein C (APC) on the production of plasminogen activators, plasminogen activator-inhibitor, and factor VIII-related antigen. Addition of APC to the cells in a serum-free medium did not affect the production of tissue-type plasminogen activator (t-PA) or factor VIII-related antigen; under all measured conditions, no urokinase activity was found. However, less plasminogen activator-inhibitor activity accumulated in the conditioned medium in the presence of APC. This decrease was dose dependent and could be prevented by specific anti-protein C antibodies. No decrease was observed with the zymogen protein C or with diisopropylfluorophosphate-inactivated APC. APC also decreased the t-PA inhibitor activity in endothelial cell-conditioned medium in the absence of cells, which suggests that the effect of APC is at least partly due to a direct effect of APC on the plasminogen activator- inhibitor. High concentrations of thrombin-but not of factor Xa or IXa-- had a similar effect on the t-PA inhibitor activity. The effect of APC on the plasminogen activator-inhibitor provides a new mechanism by which APC may enhance fibrinolysis. The data suggest that activation of the coagulation system may lead to a secondary increase of the fibrinolytic activity by changing the balance between plasminogen activator(s) and its (their) fast-acting inhibitor.     

Food avoidance is associated with reduced dentitions and edentulousness

Objectives

To investigate associations between food avoidance and dental status, age, gender, and socio-economic status (SES).

Materials and methods

The Chinese sample comprised 1463 dentulous (≥ 1 tooth in each jaw) and 124 edentulous (in one or both jaws) participants aged ≥ 40 yrs. The Vietnamese sample comprised 2820 dentulous and 253 edentulous participants aged ≥ 20 yrs. Food avoidance due to chewing difficulties was scored for regionally common 4 soft and 4 hard foods. Dental status was classified according to the multi-level hierarchical dental functional classification system (HDFC) based on the number and location of teeth and posterior occlusal pairs. Associations were analyzed using multivariate logistic regression analyses.

Results

For dentulous participants, the chance of avoiding foods was significantly larger with < 10 teeth in each jaw (OR = 2.26 (Chinese sample), respectively 1.74 (Vietnamese sample)), incomplete anterior region (OR = 1.78, respectively 1.84), “impaired” premolar region (OR = 2.22, respectively 1.71), or “impaired” molar region (OR = 2.46, respectively 1.84). Edentulous participants had twice the chance of avoiding foods (OR = 2.01 respectively 2.20). Avoiding foods was significantly associated with higher age. Participants of low SES (Chinese sample, OR = 1.93) and females (Vietnamese sample, OR = 1.27) had a larger chance of avoiding foods.

Conclusions

Avoiding foods was significantly associated with reduced dentitions, edentulousness, and higher age; low SES only in the Chinese and being female only in the Vietnamese sample.

Clinical relevance

Incomplete anterior regions, “impaired” premolar or molar regions, and especially edentulousness can be considered significant risk indicators for food avoidance.

     

Dental functional status with and without tooth replacement in a Chinese adult population

The objective of this study is to investigate the prevalence of missing teeth and prosthodontic replacements in a Chinese adult population using a hierarchical dental functional classification system. A total of 1,462 dentate subjects over 40 years from Shandong Province, China were included and categorized in the functional classification system with and without tooth replacements. Depending on replacements, subjects could be reclassified (promoted) to categories reflecting higher functionality. "Promotions" were considered indicators for prosthodontic effectiveness. Homogeneities after dichotomization into functional categories appeared to be moderate to good. In the "≥10 teeth in each jaw" branch, mean number of teeth and posterior occluding pairs were 27.93 ± 2.74 and 7.10 ± 1.94, respectively. In the branch "<10 teeth in each jaw," these figures were 16.17 ± 5.54 and 1.49 ± 1.45. Fixed dental prostheses (FDPs) added on average 3.5 artificial teeth; 46% of subjects with FDP promoted to a higher functional level. For removable dental prostheses (RDPs), these numbers were 8.5% and 79%, respectively. Promotion value per tooth added was significantly higher for FDPs. The classification system was able to quantify the effectiveness of teeth replacements. It was shown that RDPs were more effective when higher numbers of teeth were replaced, while FDPs were more effective per artificial tooth added.