MR measurement of visceral fat: assessment of metabolic syndrome.

One diagnostic criterion for metabolic syndrome is obesity from the accumulation of visceral fat; others include abdominal circumference and area of visceral fat as measured by computed tomography (CT) at the umbilical level. We evaluated visceral fat using frequency-selective excitation magnetic resonance (MR) imaging SPAIR (spectral attenuation with inversion recovery) water suppression THRIVE (3D T1-high resolution isotropic volume examination). Fifty of 70 slices with 2-mm interval were used to render and measure volume of visceral fat ranging within 10 cm of the umbilicus; the area of visceral fat at the umbilical level was also measured. Imaging was completed using breath hold within 14 s. Image processing was easier than using CT.     

Significance of lateral biopsy specimens during transrectal ultrasound-guided prostate biopsies in Japanese men

OBJECTIVES: Lateral biopsies are thought to have a better cancer detection rate compared with standard sextant biopsies. This study aimed to determine whether lateral peripheral zone biopsies in Japanese men who underwent transrectal ultrasound-guided prostate biopsies provided a significantly higher cancer detection rate than sextant biopsies. METHODS: Between 1999 and 2004, data were collected from 461 men who underwent prostate biopsy and had enough data regarding the performance of lateral biopsies for statistical analysis. There were two categories in this study: (i) patients who underwent sextant prostate biopsies; and (ii) patients who underwent sextant biopsies plus lateral biopsies. RESULTS: Prostate cancer was detected in 141 (30.6%) of 461 patients. It was detected in 24 (22.2%) of 108 patients who underwent sextant biopsies and 117 (33.1%) of 353 patients who underwent sextant plus lateral biopsies. Lateral biopsies were not associated with a statistically higher rate of positive biopsy findings; however, we found a significantly higher ratio of patients with positive findings in those with prostate specific antigen (PSA) levels 10 ng/mL (one of 71, 1.4%) among those who had positive cores only in lateral biopsy samples (P < 0.0001). CONCLUSIONS: Lateral biopsies did not show a significantly higher detection ratio of prostate cancer compared to sextant biopsies. However, lateral biopsies were more effective than sextant biopsies in patients with lower PSA levels. Our findings might be useful for the establishment of biopsy strategies to detect prostate cancer, especially in patients with lower PSA levels.     

Does H2-receptor antagonist alter the renal function of cyclosporine-treated kidney grafts?

Histamine-type 2 antagonists (H₂-blockers) as represented by cimentidine have been shown to adversely affect renal allograft function, particularly when coadministered with cyclosporine, currently a major immunosuppressant. To determine whether or not a newer and more powerful H₂-blocker, famotidine, would produce similar adverse effects, we assessed seven cyclosporine-treated renal allograft recipients with regard to changes in their renal function on or off the H₂-blocker over a one-week period. Neither the administration nor withdrawal of famotidine (20–40 mg/day) resulted in any significant changes in serum creatine, BUN, urine output or cyclosporine trough levels, suggesting that famotidine can be safely administered as an H₂-blocker to cyclosporine-treated renal allograft recipients.     

N-acetylaspartate is an axon-specific marker of mature white matter in vivo: a biochemical and immunohistochemical study on the rat optic nerve.

Axonal pathology is a major cause of neurological disability in multiple sclerosis. Axonal transection begins at disease onset but remains clinically silent because of compensatory brain mechanisms. Noninvasive surrogate markers for axonal injury are therefore essential to monitor cumulative disease burden in vivo. The neuronal compound N-acetylaspartate, as measured by magnetic resonance spectroscopy, is currently the best and most specific noninvasive marker of axonal pathology in multiple sclerosis. The possibility has been raised, however, that N-acetylaspartate is expressed also by oligodendroglial lineage cells. In order to investigate N-acetylaspartate specificity for white matter axons, transected rat optic nerves were analyzed by high-performance liquid chromatography and immunohistochemistry. In transected adult nerves, N-acetylaspartate and N-acetyl aspartylglutamate decreased in concordance with axonal degeneration and were undetectable 24 days posttransection. Nonproliferating oligodendrocyte progenitor cells, oligodendrocytes, and myelin were abundant in these axon-free nerves. At 24 days posttransection, N-acetylaspartate was increased (42%; p = 0.02) in nontransected contralateral nerves. After transection at postnatal day 4, total N-acetylaspartate decreased by 80% (P14; p = 0.002) and 94% (P20; p = 0.003). In these developing axon-free nerves, 25 to 33% of oligodendrocyte progenitor cells were proliferating. These data validate magnetic resonance spectroscopy measurements of N-acetylaspartate as an axon-specific monitor of central nervous system white matter in vivo. In addition, the results indicate that neuronal adaptation can increase N-acetylaspartate levels, and that 5 to 20% of the N-acetylaspartate in developing white matter is synthesized by proliferating oligodendrocyte progenitor cells.