Utility of MRI in prostate cancer / 日本農村医学会雑誌

For diagnosis of prostate cancer, MRI was performed in 91 patients prior to prostate biopsy, and prostate cancer was detected in 37 patients. The ability of MRI diagnosis compared with biopsy was accuracy 0.84, sensitivity 0.95, and specificity 0.76.In 26 patients (14 patients with prostate cancer) from whom MR images were obtained by diffusion weighted imaging, ADC value and PSA value showed a reverse correlation significantly.The ADC value was 0.97±0.23-3mm2/sec in the cancer area, 1.51±0.20-3mm2/sec in the normal peripheral zone, and 1.47±0.12-3mm2/sec in the normal central zone. The ADC value in the cancer area was smaller than that in the normal peripheral area or in the normal central zone significantly (p<0.001).The relation between ADC value and Gleason score did not show any correlation. However, when the Gleason score was under 6, ADC value was 1.11±0.20-3mm2/sec, and when it was over 7, ADC value was 0.81±0.19-3mm2/sec which showed a lower value than the ADC value with Gleason score under 6 significantly (p<0.05).MRI was effective for visualization of prostate cancer. We concluded that pre-biopsy MRI in prostate cancer would allow not only systemic-biopsy but also accurate targeting-biopsy, and it would improve the diagnosric ability of biopsy.

Functional Significance of Stress-relieving Act of Chewing and it Effect on Brain Activation by Strees / 日本農村医学会雑誌

The chewing-related neuronal mechanism underlying stress relief, was evaluated by use of fMRI. For this purpose we examined the effect of chewing a moderately hard gum without any taste (X type, Lotte Co. LTd., Tokyo) on brain activation caused by a noisy sound stress, on plasma levels of catecholamines and ACTH. The stress significantly increased the blood oxygenation level-dependent (BOLD) signals in the amygdala and the medial prefrontal cortex, and elevated plasma levels of noradrenaline, dopamine and ACTH. However, this chewing suppressed not only the stress-induced increase in BOLD signals in these two regions, but also the stress-induced elevation in plasma levels of these catecholamines and ACTH. The results suggested that chewing might be a useful therapy for reducing stress.