Relationship between magnetic resonance imaging and histopathologic findings in thrombosis in the oral and maxillofacial region: a case report.

Histopathologic changes are observed during the clinical course of thrombosis, and the evaluation of such changes by magnetic resonance imaging (MRI) might enhance the accuracy of qualitative diagnosis of the disease. The relationship between histopathologic and MRI findings in the chronic phase of deep venous thrombosis (DVT) that developed in the masseter muscle of a 50-year-old Japanese female patient is described. Two regions with different MRI signal intensities were identified, and a 3-layer structure was observed by microscopy. The distinct MRI regions correlated with the microscopic structure, suggesting that MRI can be used for qualitative imaging of a maxillofacial thrombus.

Enhancement of the effect of 5-aminolevulinic acid-based photodynamic therapy by simultaneous hyperthermia.

In the present study, we have investigated a combination of photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) and simultaneous hyperthermia (HT) on osteosarcoma (HOSM-1) cells, squamous cell carcinoma (KB) cells and fibroblasts (HF), including an assessment of the differences in the sensitivity of these cells to such treatment in vitro. The intracellular accumulation of protoporphyrin IX (PPIX) formed by metabolism of ALA in mitochondria and the influence of the treatment on the mitochondrial membrane potential were evaluated using flow cytometry. The antitumor effects of HT, PDT using ALA (ALA-PDT) and ALA-PDT combined with HT (PDT+HT) were determined by an MTT assay. Western blot analysis of the expression of heat shock protein 60 (Hsp60) and Hsp70 was performed to evaluate the mitochondrial stress caused by each treatment. The intracellular PPIX accumulation in HOSM-1 cells was about 2-fold higher than that in KB cells. An antitumor effect of ALA-PDT and PDT+HT was obtained in each cell line, and indicated a synergistic interaction of the combination therapy in tumor cells. A marked degree of depolarization of the mitochondrial membrane was observed in both tumor cell lines, and there was no marked difference in the degree of depolarization between the cell lines. Marked expression of Hsp60 was observed in HOSM-1 cells treated with PDT+ HT and ALA-PDT, but not in KB cells. Slightly increased expression of Hsp70 was observed for all treatments in both tumor cell lines. These results suggest that the antitumor effect of ALA-PDT therapy against malignant tumor cells is enhanced by simultaneous HT. Furthermore, the differences in sensitivity to these therapies between the two cell types may have occurred because PPIX was not effectively utilized in HOSM-1 cells, compared to its utilization in KB cells.

Efficacy of combined photodynamic and hyperthermic therapy with a new light source in an in vivo osteosarcoma tumor model.

OBJECTIVE: In this study, we investigated the efficacy of Super Lizer (SL) as a new light source in photodynamic therapy (PDT) with hyperthermia in an in vivo osteosarcoma tumor model. MATERIALS AND METHODS: Nude mice in three study groups (PDT only, PDT with hyperthermia in low energy, and PDT with hyperthermia in high energy) and three control groups (no treatment, photosensitizer only, and hyperthermia only) were implanted subcutaneously with human osteosarcoma cells and injected with a photosensitizing hematoporphyrin derivative (HPD) at a total dose of 10 mg/kg, in all study groups and in control group 2. At 72 h after light treatment, mice were sacrificed. RESULTS: The tumor volume growth rates in the heat-only (1.50) and PDT-only (1.40) groups were significantly lower than the growth rate in the no-treatment group (1.82). Further, the tumor volume growth rate in the PDT with hyperthermia in high-energy group (1.19) was significantly lower than in the heat- or PDT-only groups. CONCLUSION: Although non-laser PDT, including SL-PDT, may be beneficial only in the treatment of superficial tumors because of limited light penetration, PDT combined with hyperthermia may extend the utility of PDT in antitumor treatment. The use of SL as a new light source in PDT may significantly advance antitumor therapy due to its simplicity, ease, and cost benefit.

Magnetic resonance imaging of synovial proliferation in temporomandibular disorders with pain.

OBJECTIVE: The objective of this study was to assess the clinical significance of synovial proliferation in patients with painful temporomandibular disorders based on magnetic resonance imaging findings. METHODS: The current study was conducted in 100 joints of 100 patients with unilateral painful temporomandibular disorders. One hundred joints on the contralateral side of patients with unilateral disease were used as nonpain group. Areas in the articular space that showed a low signal intensity on T1-weighted imaging, a high signal intensity on T2-weighted imaging, and high signal intensity on gadolinium-enhanced fat-suppressed T1-weighted imaging were judged to be regions of synovial proliferation. RESULTS: Synovial proliferation alone was observed in 8.0% of the pain group, but in none of the nonpain group. Synovial proliferation + effusion was observed in 33.0% of the pain group and in 7.0% of the nonpain group. Effusion alone was observed in 7.0% of the pain group and in 3.0% of the nonpain group. The mean visual analog scale value of pain was in the order of synovial proliferation alone > synovial proliferation + effusion > effusion alone. The incidence rates of anterior displacement of the disk were 100% for synovial proliferation alone, 93.9% for synovial proliferation + effusion, 57.1% for effusion alone, and 57.7% for "without synovial proliferation/effusion." CONCLUSIONS: Strong correlations were observed between synovial proliferation, pain, and disk displacement. It is considered that evaluating effusion alone provides only limited information on the disease state in painful temporomandibular disorders. Thus, it is essential to include enhanced T1-weighted imaging as a means to judge the disease state as well as to assess disease progression.