Tuberculosis (TB) is an old disease caused by Mycobacterium tuberculosis. Although it has been known for humans for thousands of years, the treatment of this disease still requires a lengthy therapy with multiple antibiotics. Also, the emergence of multidrug-resistant strains made it more difficult to treat TB, calling for a novel treatment approach. In Photodynamic therapy (PDT), a photosensitizer, such as methylene blue (MB), is irradiated by a laser, generating reactive oxygen species and killing microorganisms. Here, using M. smegmatis as a model mycobacterium, we examined the utility of PDT in TB treatment. The photosensitizer MB alone showed weak antimicrobial activity; however, when irradiated by a laser, it efficiently killed M. smegmatis (> 97% killing with 30 mg/ml MB and 54 J/cm2 irradiation). Surprisingly, PDT showed more efficient killing activity toward drug-resistant strains of M. smegmatis than the drug-sensitive wild-type strain. In PDT, when the irradiation step alone (Intermittent PDT) or the entire PDT process was repeated (Repeated PDT), the bactericidal activity was significantly enhanced. Since PDT can be applied locally in a short period of time and kills mycobacterium irrespective of its antibiotic resistance status, we conclude that PDT can be a viable option for TB treatment.

OBJECTIVE: To examine the relation between the presence of penetration or aspiration and the occurrence of the clinical indicators of dysphagia. The presence of penetration or aspiration is closely related to the clinical indicators of dysphagia. It is essential to understand these relationships in order to implement proper diagnosis and treatment of dysphagia. METHODS: Fifty-eight poststroke survivors were divided into two groups: patients with or without penetration or aspiration. Medical records and videofluoroscopic swallowing examinations were reviewed. The occurrence of clinical indicators of dysphagia between two groups was analyzed with Cross Tabulation and the Pearson chi-square test (p<0.05). RESULTS: Poststroke survivors with penetration or aspiration had significantly high occurrences of delayed initiation of the swallow (p=0.04) and reduced hyolaryngeal elevation (p<0.01) than those without penetration or aspiration. CONCLUSION: The results of this study indicate that delayed initiation of the swallow is a strong physiological indicator of penetration or aspiration during the oral stage of swallowing in poststroke survivors. For the pharyngeal stage of swallowing, hyoid and laryngeal elevation is a key event related to occurrence of penetration or aspiration. Clinical indicators should be investigated further to allow appropriate implementation of treatment strategies for stroke survivors.
Deglutition ; Deglutition Disorders* ; Diagnosis ; Humans ; Medical Records ; Oral Stage ; Stroke ; Survivors*