Background The role of antibiotics in the treatment of chronic obstructive pulmonary disease (COPD) exacerbations and their effectiveness in combination have not been clearly established. To determine whether using a combination of fluoroquinolones and beta-lactams improves the clinical and microbiological efficacy of antibiotics on day 20 of treatment, we conducted an open-label randomized trial based on clinical outcomes, microbiological clearance, spirometry tests, and signs of systemic inflammation in patients hospitalized with acute exacerbations of COPD. Methods We enrolled 139 subjects with COPD exacerbations, defined as acute worsening of respiratory symptoms leading to additional treatment. Patients were divided randomly into two groups: 79 patients using beta-lactam antibiotics alone and 60 using beta-lactam antibiotics plus fluoroquinolones. Clinical and microbiological responses, spirometry tests, symptom scores, and serum C-reactive protein (CRP) levels were evaluated. Results Clinical success, lung function, and symptoms were similar in patients with or without fluoroquinolone administration on days 10 and 20. Combination therapy was superior in terms of microbiological outcomes and reduction in serum CRP value. Although equivalent to monotherapy in terms of clinical success, the combination showed superiority in terms of microbiological success and a decrease in CRP. The combination therapy group had a higher microbiological success rate with gram-negative bacteria than the monotherapy group with Pseudomonas aeruginosa (100% vs. 33.3%, respectively) and Acinetobacter baumanii (100% vs. 20%, respectively) (P < 0.05). Conclusions Concomitant use of fluoroquinolone and beta-lactam antibiotics for bacterial infections during COPD exacerbations caused by gram-negative bacteria appear to be effective and should be applied in clinical practice.

The objective of this study is to propose solutions to attract investment capital for tourism development in Thanh Hoa province, Vietnam. Based on the theoretical framework following eclectic or "OLI model" developed by Dunning and Narula (1996) [Dunning, J., & Narula, R. (2003). Foreign direct investment and governments: catalysts for economic restructuring. Routledge.] and data of 660 questionnaires collected from a survey of tourism investors in Thanh Hoa provinces, we found some important influential factors affecting the attraction of investment for tourism development in Thanh Hoa province. In particular, the local government's policy of attracting capital appears to have the highest level of importance. The study has some policy implications to increase the attractiveness of investment capital in tourism development in the area.

Aims: Tenofovir and para-aminosalicylic acid (PAS) may be coprescribed to treat patients with concomitant infections of human immunodeficiency virus and Mycobacterium tuberculosis bacteria. Both drugs are known to have remarkable renal uptake transporter-mediated clearance. Owing to the lack of clinical studies on drug-drug interaction between the 2 drugs, we conducted a translational clinical study to investigate the effect of PAS on tenofovir pharmacokinetics (PK).Methods: Initially, we studied in vitro renal uptake transporter-mediated drug-drug interactions using stably transfected cells with human organic anion transporters (OAT1 and OAT3). Later, we estimated clinical drug interactions using static and physiologically based PK modelling. Finally, we investigated the effects of PAScalcium formulation (PAS-Ca) on tenofovir disoproxil fumarate PK in healthy male Korean subjects.Results: PAS inhibited OAT1-and OAT3-mediated tenofovir uptake in vitro. The physiologically based PK drug-drug interaction model suggested a 1.26-fold increase in tenofovir peak plasma concentration when coadministered with PAS. By contrast, an open-label, randomized, crossover clinical trial evaluating the effects of PAS-Ca on tenofovir PK showed significantly altered geometric mean ratio (90% confidence intervals) of maximum plasma concentration (C max ) and area under the curve (AUC 0-inf ) by 0.33 (0.28-0.38) and 0.29 (0.26-0.33), respectively. Conclusion:Our study findings suggest that the PAS-Ca formulation significantly reduced systemic exposure to tenofovir through an unexplained mechanism, which was contrary to the initial prediction. Caution should be exercised while predicting in vivo PK profiles from in vitro data, particularly when there are potential confounders such as pharmaceutical interactions.drug-drug interactions, organic anion transporter, para-aminosalicylic acid, pharmacokinetics, tenofovir Md Masud Parvez and Said Kalkisim contributed equally for the manuscript.

The studies on electron microstructure of the effect of the use of products that contain casein phosphopeptideamorphous calcium fluoride phosphate (CPP-ACPF) on enamel remineralization are still needed. It is important method to observe of the morphological changes of teeth in different conditions. Objective: To evaluate the remineralization potential of paste on enamel lesions using scanning electron microscopy (SEM). Methods: Sixty enamel specimens were prepared from extracted human premolars. The specimens were placed in a demineralizing solution for four days to produce artificial carious lesions. The specimens were then randomly assigned to two study groups: group A (control group) and group B. Group B was incubated in remineralizing paste (CPP-ACPF) for 30 minutes per day for 10 days. The control group received no intervention with remineralizing paste. All 60 specimens were stored in artificial saliva at 37 0 C. After remineralization, the samples were observed using SEM. Results: The statistical analysis showed a decrease in the lesion area between the demineralized and remineralized samples, but no significant difference was observed in the lesion depth for group B. There was a significant increase observed in both the lesion depth and lesion area for group A (p = 0.03). Conclusion: The results showed the capacity of CPP-ACPF in supplying calcium and phosphate to the enamel, decreasing the dissolution of the enamel surface and increasing the remineralization of the enamel surface.Keywords: CPP-ACPF, enamel, fluoride, remineralization, scanning electron microscopy How to cite this article: Ngoc VTN, Thuy PTH, Anh LQ, Son TM, Phuong NTT. The effect of casein phosphopeptideamorphous calcium fluoride phosphate on the remineralization of artificial caries lesions: an in vitro study. J Dent Indones. 2017;24(2): 45-49