An 8-month-old boy with congenital fibromuscular dysplasia presenting with shock caused by sudden renal hemorrhage.

Fibromuscular dysplasia (FMD) is a non-atheromatous, non-inflammatory, multifocal segmental angiopathy. FMD is the most common cause of pediatric renovascular hypertension. Aneurysmal formation of the main renal artery and distal branches is a rare complication of FMD in infancy. We report an 8-month-old boy with FMD presenting with shock caused by sudden renal hemorrhage that necessitated removal of one kidney. A diagnosis of renovascular hypertension resulting from intimal type FMD with aneurysmal formation was made on the basis of the presence of hypertension, elevation of PRA and aldosterone activity, pathological findings and the results of renal angiography. Our findings suggest that it is therefore necessary to consider FMD with aneurysmal formation as a possible cause of hypertension and renal hemorrhage in infants.

Peripheral neuroglial death induced by cisplatin administration in newborn rats.

To determine the target of cytotoxicity of cisplatin (CDDP), we injected newborn rats with 2 mg/kg CDDP and examined the trigeminal ganglion for possible cell death. A nick translation method for DNA fragmentation revealed CDDP-induced glial cell death. DNA fragmentation was detected in both Schwann cells and satellite cells. Satellite cell death was observed as early as 0.5 day after injection, most frequent at 1-3 days and subsided thereafter. The incidence of neuronal death was very low and comparable to that observed in vehicle control rats. CDDP has selective toxicity to peripheral glial cells, though the damage did not culminate in cell death in adults. The glial toxicity may contribute to clinical symptoms of CDDP neuropathy.

Apoptotic cascade of neurons in the subcortical sensory relay nuclei following the neonatal infraorbital nerve transection.

A terminal transferase-mediated dUTP nick end labeling (TUNEL) method was utilized for detection of neuronal death in the subcortical relay nuclei of the trigeminosensory system following the infraorbital nerve transection in newborn rats. At 18-24 h after injury, numerous TUNEL-positive profiles were found within the ventroposteromedial thalamic nucleus (VPM) contralateral to the injury, whereas the VPM on the ipsilateral side and of the age-matched normal control contained only a few profiles per section. Electron microscopy revealed that the TUNEL-positive profiles were apoptotic neurons. The ventral part of the ipsilateral brainstem sensory trigeminal nuclear complex (the nucleus principalis, and the subnuclei oralis and interpolaris) exhibited statistically significant 65-70% increase in number of apoptotic neurons compared to the contralateral side. Taken together with our previous study [T. Sugimoto, C. Xiao, H. Ichikawa, Neonatal primary neuronal death induced by capsaicin and axotomy involves an apoptotic mechanism, Brain Res. 807 (1998) 147-154], the present results demonstrated a cascade of apoptosis in the primary, secondary and tertiary order sensory neurons along the neuroaxis.

Electron microscopic demonstration of nick end-labeled DNA fragments during capsaicin-induced apoptosis of trigeminal primary neurons in neonatal rats.

DNA fragmentation was induced in the trigeminal ganglion of newborn rats by subcutaneous capsaicin injection (50 mg/kg). Twenty-four hours later, numerous roundish profiles were intensely labeled by both a DNA polymerase I-mediated nick translation method and a terminal transferase-mediated tailing method. Direct electron microscopic examination of labeled profiles indicated that the labeled profiles were neurons at earlier stages of apoptosis. DNA fragmentation signal was first detected in the nucleoplasm and later spread to the cytoplasm. The cell finally disintegrated forming many small apoptotic bodies. DNA fragmentation signal in the apoptotic bodies was readily labeled by the tailing but not the translation method.