Dual wavelength 5-aminolevulinic acid photodynamic therapy using a novel flexible light-emitting diode unit

Background

Photosensitizers used for photodynamic therapy (PDT) to treat dermatologic disease are metabolized into mainly protoporphyrin IX (PpIX), which has five absorption wavelength peaks: 410?nm, 510?nm, 545?nm, 580?nm, and 630?nm. Although only red light around 635?nm and blue light around 400?nm are used as light sources for PDT, the efficiency of PDT might be improved by using multiple wavelengths, including those that correspond to the other absorption peaks of PpIX. Furthermore, because the target disease often occurs on the face, a flexible-type light-source unit that can be fitted to the lesion without unnecessarily exposing the mucous membranes, e.g., the eyes, nostrils, and mouth, is preferred.

Clinical background of cases showing a positive culture of pleural effusion at Shin-Kokura Hospital over a period of 5 years

We investigated the clinical background of patients at Shin-Kokura Hospital who showed a positive culture of pleural effusion during the period from January 1998 through December 2002. Microorganism cultures of the pleural effusions of 127 patients were performed in this 5-year period. Seventeen patients showed a positive microorganism culture from a pleural effusion, and 12 of these patients (70.6%) were 60 years old or more. Ten patients were diagnosed with thoracic empyema. Thirteen patients had an underlying disease such as malignancy (5 cases), diabetes mellitus (4 cases), etc. A purulent effusion and a high concentration of lactic dehydrogenase (LDH) in the pleural fluid were more frequently recognized in the positive-culture group. A total of 21 strains of microorganism were isolated from the 17 patients, including 10 strains of Gram-positive cocci, 6 strains of Gram-negative bacilli, 3 strains of anaerobes, 1 strain of mycobacterium (Mycobacterium tuberculosis), and 1 strain of fungus. Susceptibility to antimicrobial agents was generally good for most of the microorganisms isolated. Of the 17 patients, chest-tube drainage was performed in 13, and 6 needed a surgical operation. Twelve patients improved, but 5 died. In this study, thoracic empyema accounted for 58.8% of the 17 cases with a positive culture of pleural effusion. Of the 10 thoracic empyema patients, 5 patients needed surgical treatment in spite of adequate antimicrobial treatment and chest-tube drainage. Our data indicate that thoracic empyema is still difficult to treat, and thus adequate and rapid treatment is needed for any pleural infection.     

Observations in simultaneous microencapsulation of 5-fluorouracil and leucovorin for combined pH-dependent release.

5-Fluorouracil (5-FU) in combination with leucovorin (LV) is nowadays the standard treatment in colon cancer and would be a candidate to be delivered orally to the colon. Eudragit P-4135F or Eudragit RS100 were used separately to prepare microspheres by an oil/oil emulsification process trapping 5-FU and LV simultaneously. Scanning electron microscopy permitted a structural analysis, process parameters were analyzed and drug loading and release profiles were recorded. Particle size varied between 123 (RS100) and 146 microm (P-4135F). Generally, higher encapsulation rates were found with RS100 (5-FU, 60.3+/-9.7%; LV, 81.4+/-8.6%) compared to P-4135F (5-FU, 48.3+/-2.0%; LV, 55.4+/-2.7%). Microparticles made from Eudragit RS100 released the incorporated drug combination within 8 h not exhibiting general differences between the kinetics of both drugs. P-4135F was found to maintain the undesired 5-FU release at pH 6.8 lower than 25% within 4 h while at pH 7.4, a nearly immediate release (within 15 min) was observed. Although the release was similar at pH 7.4, at pH 6.8 LV showed a distinct initial drug loss of about 60% and a complete release within 2 h. SEM analyses revealed a substantial presence of LV crystals on the particle surface provoking a distinct burst effect of LV. These observations were concluded to be related to the high lipophilicity of P-4135F provoking a separation between P-4135F and LV during the preparation process.     

Effect of the free radical scavenger MCI-186 on spinal cord reperfusion after transient ischemia in the rabbit

Objective: Paraplegia remains a serious complication of aortic operations. The production of free radicals during reperfusion after transient ischemia is believed to induce secondary spinal neuronal injury, resulting in paraplegia. The aim of the present study was to clarify the protective effect and method of administration of antioxidants on the neurological and histological outcome in the animal model for reperfusion injury after transient spinal cord ischemia. Methods: New Zealand white rabbits underwent surgical exposure of the abdominal aorta that was clamped for 15 minutes to achieve spinal cord ischemia. Group A animals received two 10 mg/kg doses of 3-methyl-l-phenyl-2-pyrazolin-5-one (MCI-186) at the time of release of the aortic clamp and 30 minutes later. In group B, MCI-186, 5 mg/kg, was given three times, at the time of aorta clamp release, 30 minutes and 12 hours later. In group C (control group), one dose of vehicle was administered. Neurological status was assessed using modified Tarlov’s score until 168 hours after operation. Spinal cord sections were examined microscopically to determine the extent of ischemic neuronal damage. Results: Groups A and B animals had better neurological function than group C (p(0.001). In contrast, group C animals exhibited paraplegia or paraparesis with marked neuronal necrosis. The number of surviving neurons within examined sections of the spinal cord was significantly greater in group B than in group C (p(0.001). Conclusion: In a 15-minute ischemia-reperfusion model using rabbits, systemic repetitious administration of MCI-186, a free radical scavenger, was found to have a protective effect on the spinal cord neurons both neurologically and histologically. We postulate that the drug minimizes the delayed neuronal cell death for reperfusion injury after transient ischemia by reducing the free radical molecules. Moreover, it was thought that we could protect delayed neuronal cell death more effectively by administering MCI-18612 hours later.