Caries arresting effect of silver diamine fluoride on dentine carious lesion with S. mutans and L. acidophilus dual-species cariogenic biofilm

Objectives: This in vitro study investigated the effects of silver diamine fluoride (SDF) on dentine carious lesion with cariogenic biofilm. Study Design: Thirty human dentine blocks were inoculated with Streptococcus mutans and Lactobacillus acidophilus dual-species biofilm to create carious lesion. They were equally divided into test and control group to receive topical application of SDF and water. After incubation anaerobically using micro-well plate at 37oC for 7 days, the biofilms were evaluated for kinetics, morphology and viability by colony forming units (CFU), scanning electron microscopy (SEM), and confocal microscopy (CLSM), respectively. The carious lesion underwent crystal characteristics analysis, evaluation of the changes in chemical structure and density of collagen fibrils using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and immune-labeling. Results: The log CFU of S. mutans and L. acidophilus in the test group was significantly lower than control group. SEM and CLSM showed confluent biofilm in control group, but not in test group. XRD showed the loss of crystallinity of dentine due to the dissolution of hydroxyapatite crystal structure in test group was less than control group. FTIR showed that log [Amide I: HPO42-] for test vs. control group was 0.31±0.10 vs. 0.57±0.13 (p<0.05). The gold-labeling density in test vs. control group was 8.54±2.44/µm2 vs. 12.91±4.24/µm2 (p=0.04). Conclusions: SDF had antimicrobial activity against the cariogenic biofilms and reduced demineralization of dentine. Key words:Caries, caries arrest, dentine, silver, silver diamine fluoride, fluoride, biofilm,cariogenic.     

Sexual difficulties within a group of patients with vulvodynia

Dyspareunia, caused by vulvodynia, has, like other sexual problems, evolved from being conceptualized as a psychological problem through a period when it became viewed by the medical world as a physical problem. It is now seen as being a combination of psychological and physical factors. However, no research to our knowledge has explored in depth the level of sexual and relationship difficulties of this population. This investigation involved 172 women (85 suffering with vulvodynia and 87 women in a control group with general dermatology conditions) to establish the prevalence of relationship and sexual difficulties, using validated questionnaires, a newly devised symptom checklist and a structured interview. The results demonstrated increased levels of sexual and relationship difficulties within the vulvodynia group that need further exploration.     

Foreign Surgeons at Work

Delayed hypersensitivity reactions are associated with the interaction of antigen with cells rather than with serum antibody. Various concepts of delayed hypersensitivity have been developed, largely from animal experiments. This paper explores some of these concepts and suggests some of the implications of further work in this field.     

A pharmacotherapy review of the novel,oral antithrombotics

Coagulation disorders account for a high incidence of death in the U.S. due to stroke, myocardial infarction, and venous thromboembolism. In the past few years, numerous agents have been brought to market for the treatment of thromboembolism or prevention of thromboembolism. Similar to warfarin, these agents can cause bleeding disorders, which may exacerbate dental care treatment plans. This literature review examines the newer agents for the treatment of thromboembolism disorders, common side effects and drug interactions, the specific medical conditions each agent treats, and the dental perspective on how to medically management patients prescribed these medications.     

白藜芦醇对动物离体心房收缩力和心率作用的种属差异性比较

目的:观察白藜芦醇对豚鼠、小鼠和家兔离体心肌收缩力和心率的影响。方法:实验于2005-08/2006-12在河北医科大学西校区实验中心完成。①实验分组:离体豚鼠、小鼠和家兔心肌各分为9组:空白对照组、溶剂对照组、递增累积浓度白藜芦醇组(浓度为10-6,3×10-6,10-5,3×10-5,10-4,3×10-4mol/L),白藜芦醇对照组(5×10-5mol/L),ATP敏感性钾通道阻断剂格列苯脲(5×10-5mol/L)预孵育 白藜芦醇组,钙激活钾通道阻断剂四乙胺(10-3mol/L)预孵育 白藜芦醇组,电压依赖性钾通道阻断剂4-氨基吡啶(10-3mol/L)预孵育 白藜芦醇组,内向整流钾通道阻断剂氯化钡(10-4mol/L)预孵育 白藜芦醇组,乙酰胆碱调节钾通道阻断剂阿托品(10-5mol/L)预孵育 白藜芦醇组。②实验方法:不同类型的钾通道阻断剂均预孵育15min后,分别加入白藜芦醇(终浓度为5×10-5mol/L),连续记录30min,与相应动物白藜芦醇对照组相比较。③评估指标:分析不同阻断剂与白藜芦醇联用对心房收缩力下降率及心率抑制率的影响。结果:①白藜芦醇可降低豚鼠和小鼠离体心肌收缩力和心率(P<0.05),并被ATP敏感性钾通道阻断剂格列苯脲和钙激活钾通道阻断剂四乙胺部分阻断。②白藜芦醇可降低家兔离体心肌心率,格列苯脲可阻断白藜芦醇的负性变时作用。③电压依赖性钾通道阻断剂4-氨基吡啶、内向整流钾通道阻断剂氯化钡、乙酰胆碱调节钾通道阻断剂阿托品均不能阻断白藜芦醇对3种不同动物离体心房收缩力和心率的作用(P>0.05)。结论:白藜芦醇可呈剂量依赖性减慢豚鼠、小鼠和家兔的心率,白藜芦醇可减弱豚鼠心肌收缩力,其作用是与开放ATP敏感性钾通道有关,而与电压依赖性钾通道、内向整流钾通道和乙酰胆碱调节钾通道无关。同时,钙激活钾通道也参与了白藜芦醇对豚鼠和小鼠离体心房收缩力和/或心率的抑制作用。白藜芦醇对离体心肌收缩力和心率的作用有种属差异性。     

D1 receptor stimulation inhibits dopamine cell activity after reserpine treatment but not after chronic SCH 23390: an effect blocked by N-methyl-D-aspartate antagonists.

Single unit recordings were conducted to examine the effects of systemic D1 agonist SKF 38393 on the firing rate of substantia nigra pars compacta dopamine (DA) neurons in rats pretreated subchronically with reserpine or chronically with a D1 antagonist. The effect of N-methyl-D-aspartate receptor antagonists on these processes was also investigated. An i.v. injection of SKF 38393 (10 mg/kg) significantly inhibited DA cell activity by approximately 70% in rats pretreated with reserpine (1 mg/kg, s.c.) for 6 days and studied under conditions of local anesthesia. SKF 38393 exerted no effect in reserpinized rats anesthetized with chloral hydrate. The SKF 38393-induced inhibition was reversed by the D1 antagonist SCH 23390, but not by the preferential D2 antagonist haloperidol. This effect of SKF 38393 was observed in 60% of the rats as early as 3 to 8 hr after the first reserpine injection, and the inhibition remained significant 5 to 15 days (averaging 64 and 58%) after termination of the 6-day reserpine treatment. The N-methyl-D-aspartate antagonists ketamine, at anesthetic doses (100 mg/kg, i.p.), and MK 801, at a nonanesthetic dose (0.15 mg/kg, i.v.), completely blocked the inhibitory effect of SKF 38393. In contrast, DA cells recorded in rats pretreated with SCH 23390 for 7 to 21 days, followed by a 4-day washout period, failed to respond to SKF 38393. Because nigrostriatal DA neurons do not appear to express D1 receptors, these results suggest that D1 receptors can exert an indirect inhibitory effect on the activity of nigral DA neurons, presumably through striatonigral neuronal pathways.(ABSTRACT TRUNCATED AT 250 WORDS)     

A study of HLA (Bg) on red cells and platelets by immunoblotting with monoclonal antibodies

HLA class I antigens (Bg) on red cells (RBCs) are expressed by some normal donors and by many patients with systemic lupus erythematosus (SLE). To identify the membrane components previously detected by hemagglutination with HLA class I-specific monoclonal antibodies (MoAbs), RBC membrane preparations were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotted with the HLA class I MoAbs. Two components were obtained that reacted with the MoAbs: a heavy chain of 45 kDa and a light chain termed beta2-microglobulin (beta2-M) of 11 kDa. The effect of chloroquine and acid elution in stripping HLA antigens is shown to be due to the removal of beta2-M, as only that component was detected in eluates from reactive RBCs. Neither antibody elution method affected the heavy chain expression assessed by immunoblotting. It is concluded that HLA class I antigens on RBCs are integral membrane components of the type normally found and wisely distributed on many nucleated cells. Platelets, which have stronger HLA class I antigen expression, were also studied, and their membrane preparations yielded heavy chain and beta2-M molecules; the effect of chloroquine treatment was harder to assess than that of acid elution, owing to the sensitivity with which both components are detected in immunoblotting. In eluates obtained from acid treatment only beta2-M is detected.     

Incorporation of adenovirus in calcium phosphate precipitates enhances gene transfer to airway epithelia in vitro and in vivo.

Adenovirus (Ad)-mediated gene transfer to airway epithelia is inefficient because the apical membrane lacks the receptor activity to bind adenovirus fiber protein. Calcium phosphate (CaPi) precipitates have been used to deliver plasmid DNA to cultured cell lines. However, such precipitates are not effective in many primary cultures or in vivo. Here we show that incorporating recombinant adenovirus into a CaPi coprecipitate markedly enhances transgene expression in cells that are resistant to adenovirus infection. Enhancement requires that the virus be contained in the precipitate and viral proteins are required to increase expression. Ad: CaPi coprecipitates increase gene transfer by increasing fiber-independent binding of virus to cells. With differentiated cystic fibrosis (CF) airway epithelia in vitro, a 20-min application of Ad:CaPi coprecipitates that encode CF transmembrane conductance regulator produced as much CF transmembrane conductance regulator Cl- current as a 24-h application of adenovirus alone. We found that Ad:CaPi coprecipitates also increased transgene expression in mouse lung in vivo; importantly, expression was particularly prominent in airway epithelia. These results suggest a new mechanism for gene transfer that may be applicable to a number of different gene transfer applications and could be of value in gene transfer to CF airway epithelia in vivo.