ABSTRACT:Because of the paucity of primate experimental models, the precise molecular mechanism of ischemic neuronal death remains unknown in humans. This study focused on nonhuman primates to determine which cascade necrosis or apoptosis is predominantly involved in the development of delayed (day 5) neuronal death in the hippocampal CA1 sector undergoing 20 min ischemia. We investigated expression, activation, and/or translocation of -calpain, lysosome-associated membrane protein-1 (LAMP-1), caspase-3, and caspase-activated DNase (CAD), as well as morphology of the postischemic CA1 neurons and DNA electrophoresis pattern. Immunoblotting showed sustained (immediately after ischemia until day 5) and maximal (day 3) activation of -calpain. The immunoreactivity of activated -calpain became remarkable as coarse granules at lysosomes on day 2, while it translocated throughout the perikarya on day 3. The immunoreactivity of LAMP-1 also showed a dynamic and concomitant translocation that was maximal on days 2-3, indicating calpain-mediated disruption of the lysosomal membrane after ischemia. In contrast, immunoblotting demonstrated essentially no increase in the activated caspase-3 at any time points after ischemia, despite upregulation of pro-caspase-3. Although expression of CAD was slightly upregulated on day 1 or 2, or both, it was much less compared with lymph node or intestine tissues. Furthermore, light and electron microscopy showed eosinophilic coagulation necrosis and membrane disruption without apoptotic body formation, while DNA electrophoresis did not show a ladder pattern, but rather a smear pattern. Sustained calpain activation and the resultant lysosomal rupture, rather than CAD-mediated apoptosis, may cause ischemic neuronal necrosis in primates.

The exact molecular mechanism of ischemic neuronal death still remains unclear from rodents to primates. A number of studies using lower species animals have suggested implication of apoptosis cascade, while using monkeys the authors recently claimed necrosis cascade by calpain-induced leakage of lysosomal cathepsins (calpain-cathepsin hypothesis). This paper is to study implications of apoptotic versus necrotic cascades for the development of hippocampal CA1 neuronal death in the primate brain undergoing complete global ischemia. Here, we focused on two terminal cell death effectors; caspase-activated DNase (CAD) and lysosomal enzyme DNase II, in the monkey CA1 sector undergoing 18 min ischemia. The expressions of their mRNA and proteins, and the subcellular localizations as well as ultrastructure and speci®c DNA gel electrophoresis were examined. Expression of CAD was much less in the normal brain, compared with the lymph node or heart tissues. On day 1 after ischemia, however, CAD mRNA and protein were signi®cantly increased in the CA1 sector, and then CAD protein immunohistochemically showed a translocation from the perikarya into the nucleus. Activated DNase II protein was signi®cantly increased on days 2 and 3 after ischemia, and also showed a similar translocation indicating lysosomal leakage. Although the post-ischemic CA1 neurons showed positive terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) staining on days 3±5, they showed eosinophilic coagulation necrosis on light microscopy, and frank membrane disruption and mild chromatin condensation on electron microscopy. Furthermore, DNA smear pattern typical for necrosis was observed instead of DNA laddering. These data altogether suggest that the post-ischemic CA1 neuronal death of the monkey occurs not by apoptosis but by necrosis with participations of lysosomal enzymes DNase II and cathepsins as well as CAD. The interactions between apoptotic (caspase-3 and CAD) and necrotic (calpain, cathepsin and DNase II) cascades should be studied further.

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We report a Japanese man who presented with multiple cranial nerve palsies with hepatitis B virus-related multiple hepatocellular carcinoma (HCC). He presented with right III, IV, VI, IX, X, and XII cranial nerve palsies. Metastases involving the clivus and the right occipital bone from HCC were diagnosed by the findings of magnetic resonance imaging of the head, cerebral angiography, and 2-deoxy-2-[18 F]fluoro-D-glucose positron emission tomography/computed tomography. In this case, over one-year survival and improvement of neurological signs were achieved by radiotherapy in spite of multiple skull metastases, which are extremely rare.

This paper describes a new technique and preliminary clinical results of remote after-loading transurethral irradiation for cancer of the prostate. As of January 1986, twelve patients with adenocarcinoma of the prostate have been treated by our radiotherapy technique. Clinically, 3 patients were in stage B2, 3 in stage C, 3 in stage D1 and 3 in stage D2. These patients have been followed up for 13 to 33 months with a median follow-up period of 20.6 months. The dose of transurethral irradiation was 9-10 Gy. to the prostatic capsule and about 2 Gy. to the rectum in one procedure. We repeated this radiotherapy 3 to 4 times within an about 1-month period. Three patients in stage D1 and one patient in stage C received an additional external beam radiation (40 Gy.) to the entire pelvis. A needle biopsy was also performed every 4-6 months after irradiation. Local tumor response proved rapid and satisfactory as verified by a rectal examination and ultrasonography. The biopsies revealed a 70% negative rate within one year. The most common side effect was transient frequency observed in 7 patients. Severe complications such as incontinence, urethral stricture, or proctitis were not evident. This study suggests that intracavitary irradiation of cancer of the prostate is effective and safe. This method may have wider application.