The relationship between the plasma concentration of bepridil and its efficacy in the treatment of atrial fibrillation in Japanese patients

Bepridil hydrochloride is used for treatment of atrial fibrillation (AF) in Japan. We investigated the relationship between plasma concentrations of bepridil just before dosing (Cbep) and its clinical efficacy in Japanese patients (n=36) with AF. Patients were treated orally with 100, 150 or 200 mg/d bepridil. Cbep were measured with UV-HPLC. In the first 14 d, when 150, 200, 250 or 300 ng/mL was set as a boundary value, the efficacy of bepridil was significantly higher in all patients with Cbep above than below the boundary value (p<0.05). In the maintenance stage (3 months longer after starting therapy), the efficacy of bepridil was significantly higher in patients with Cbep above than below 300 ng/mL (p=0.04). The clinical efficacy of bepridil was closely related to Cbep. The target value of Cbep to obtain a clinical benefit was approximately 300 ng/mL. Monitoring Cbep should be useful in the treatment of patients with AF.     

IL-17A stimulates the expression of inflammatory cytokines via celecoxib-blocked prostaglandin in MC3T3-E1 cells

Objective

The prostaglandins (PGs) released from osteoblasts can alter the process of bone remodelling. Recently, we showed that compressive force induced the expression of pro-inflammatory cytokine interleukin (IL)-17s and their receptors in osteoblastic MC3T3-E1 cells and that IL-17A was expressed most highly. Consequently, in the current study we examined the effect of IL-17A and/or celecoxib on PGE₂ production and the expression of cyclooxygenases (COXs) and inflammatory cytokines in MC3T3-E1 cells. We also examined the effects of PGE₂ and cyclohexamide on the expression of inflammatory cytokines.

Methods

Cells were cultured with or without IL-17A (0.1, 1.0, or 10 ng/ml) in the presence or absence of 10 μM celecoxib, a specific inhibitor of COX-2, for up to 72 h. Cells were pretreated with or without 10 μg/ml cycloheximide, protein synthesis inhibitor, for 30 min, and then cultured with 10 ng/ml IL-17A for 24 h. Cells were also cultured with or without 1.5 ng/ml PGE₂ for 24 h. PGE₂ production was determined by ELISA. The expression of COX-1, COX-2, IL-1α, IL-6, IL-8, IL-11, and TNF-α mRNAs and proteins was determined by real-time PCR and ELISA, respectively.

Results

The expression of COX-2, IL-1α, IL-6, IL-8, IL-11, and TNF-α, as well as PGE₂ production increased in the presence of IL-17A, whereas COX-1 expression did not change. Celecoxib blocked the stimulatory effect of IL-17A on the expression of COX-2, IL-1α, IL-6, IL-8, and IL-11 as well as PGE₂ production, whereas it did not block TNF-α expression. Cycloheximide pretreatment suppressed the expression of IL-17-induced inflammatory cytokines. The expression of IL-1α, IL-6, IL-8, and IL-11 increased by the addition of PGE₂, whereas TNF-α expression was not affected.

Conclusion

These results suggest that IL-17A stimulates the expression of bone resorption-related inflammatory cytokines through an autocrine mechanism involving celecoxib-blocked PGs, mainly PGE₂, in osteoblasts.     

Use of quantitative PCR to evaluate methods of bacteria sampling in periodontal patients

Periodontal disease is associated with specific periodontal pathogens and may persist as gingivitis or progress to more severe disease. The bacteria involved in disease initiation and progression have not been identified. We used quantitative polymerase chain reaction (PCR) to compare the levels of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, and total bacteria detected by different sampling methods. On the basis of the results of clinical examinations, 57 patients were divided into 3 groups: healthy group (group A), gingivitis group (group B), and periodontitis group (group C). Bacterial samples were collected from saliva, mouthwash, and by paper-point sampling of gingival crevicular fluid (GCF), and the samples were analyzed with quantitative PCR targeting 16S rRNA. The numbers of total bacteria in samples of GCF, saliva, and mouthwash were 10? to 10?, 10?, and 10?, respectively, per milliliter. The number of P. gingivalis in GCF samples was lower than 10 in group A; however, in groups B and C, the values were 103 and 10?, respectively, indicating that the number of P. gingivalis increased with worsening clinical status. Findings were similar in the samples of saliva and mouthwash. The numbers of T. forsythia showed a pattern similar to that of P. gingivalis in all 3 samples. These results suggest that saliva and mouthwash samples are clinically useful for bacterial testing of periodontal diseases by quantitative PCR. In addition, mouthwash sampling is more feasible and straightforward than saliva sampling.