Antibacterial effect of water-soluble chitosan on representative dental pathogens Streptococcus mutans and Lactobacilli brevis

Dental caries is still a major oral health problem in most industrialized countries. The development of dental caries primarily involves Lactobacilli spp. and Streptococcus mutans. Although antibacterial ingredients are used against oral bacteria to reduce dental caries, some reports that show partial antibacterial ingredients could result in side effects. OBJECTIVES: The main objective is to test the antibacterial effect of water-soluble chitosan while the evaluation of the mouthwash appears as a secondary aim. MATERIAL AND METHODS: The chitosan was obtained from the Application Chemistry Company (Taiwan). The authors investigated the antibacterial effects of water-soluble chitosan against oral bacteria at different temperatures (25-37ºC) and pH values (pH 5-8), and evaluated the antibacterial activities of a self-made water-soluble chitosan-containing mouthwash by in vitro and in vivo experiments, and analyzed the acute toxicity of the mouthwashes. The acute toxicity was analyzed with the pollen tube growth (PTG) test. The growth inhibition values against the logarithmic scale of the test concentrations produced a concentrationresponse curve. The IC50 value was calculated by interpolation from the data. RESULTS: The effect of the pH variation (5-8) on the antibacterial activity of water-soluble chitosan against tested oral bacteria was not significant. The maximal antibacterial activity of water-soluble chitosan occurred at 37ºC. The minimum bactericidal concentration (MBC) of water-soluble chitosan on Streptococcus mutans and Lactobacilli brevis were 400 µg/mL and 500 µg/mL, respectively. Only 5 s of contact between water-soluble chitosan and oral bacteria attained at least 99.60% antibacterial activity at a concentration of 500 µg/mL. The water-soluble chitosan-containing mouthwash significantly demonstrated antibacterial activity that was similar to that of commercial mouthwashes (>;99.91%) in both in vitro and in vivo experiments. In addition, the alcohol-free mouthwash exhibited no cytotoxicity and no oral stinging. To the best of our knowledge, this was the first study to combine in vitro and in vivo investigations to analyze the antibacterial properties of water-soluble chitosan-containing mouthwash. CONCLUSIONS: This study illustrated that water-soluble chitosan may be a viable alternative to commercial mouthwashes in the future

Experiential learning of HIV self-test among student nurses: A qualitative study

Background: There is increasing demand for HIV self-tests, and nurses play an important role in counselling and assisting in the testing process. Traditional lecture-based nursing education has not typically focused on self-testing procedures, and there is little understanding of clients' experiences of self-testing. Objectives: To understand the experiential learning (EL)of student nurses during the process of self-testing for HIV. Design: This study used a qualitative design. Settings: A college in northern Taiwan. Participants: We recruited a purposive sample of 30 nursing students. Methods: The OraQuick self-test was used as the self-testing tool in this study. After participants used the OraQuick self-test, they underwent a semi-structured interview during the post-test counselling period. All interview data were subjected to line-by-line content analysis. Results: We extracted nine themes of nursing students' experiences during experiential learning of HIV self-test. In the pre-test stage, they recalled possible risk behaviors for HIV infection, decided to complete the self-test alone or asked for significant others to accompany them, and endured emotional fluctuations immediately prior to the test. When waiting for the test results, they felt isolated from the outside world. Some participants also began questioning the accuracy and safety of the test, and either viewed the results immediately or later on. In the post-test stage, some participants reported being uncertain about the results. Participants reported a greater understanding of the personal impact of testing and revealed their needs for support. Some identified a sense of loss and linked this to the rapid and direct delivery of test results. Conclusions: Our results can be used to guide HIV-related education courses and prevention programs. Experiential learning has the potential to improve HIV pre and post-test counselling, as nurses develop both clinical knowledge and personal insight of the testing process

Continuous epidermal growth factor receptor-tyrosine kinase inhibitor administration in primary lung adenocarcinoma patients harboring favorable mutations with controlled target lung tumors dose not hinder survival benefit despite small new lesions

AbstractBackgroundIn this study, we investigated the efficacy of continuous epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) administration in lung adenocarcinoma patients harboring favorable mutations regarding the progressive disease (PD) status with appearance of indolent new lesions.MethodsFrom June 2010 to October 2012, 102 patients with lung adenocarcinoma, harboring favorable EGFR mutations and treated with EGFR-TKI were analyzed. Definite new lesions were detected during EGFR-TKI therapy, even though the primary target tumors were controlled.ResultsOf the 102 patients, 57 continued and 45 discontinued EGFR-TKI therapy. The median overall survival was 529 days for the discontinuation group and 791 days for the continuation group (p = 0.0197). Median survival time after the discontinuation of EGFR-TKI was 181 days and 115 days in the discontinuation and continuation groups, respectively (p = 0.1776), whereas median survival time after the appearance of indolent new lesions was 204 days and 262 days, respectively (p = 0.0237).ConclusionContinuous EGFR-TKI administration in favorable EGFR-mutative lung adenocarcinoma patients with controlled primary tumors did not hinder the survival benefit, despite the appearance of new lesions