G Takeo’s research while affiliated with Nagasaki University and other places

This study was undertaken to clarify the role of complement in acetylcholine receptor loss and degeneration of the postsynaptic membrane in myasthenia gravis (MG). We examined the end-plate morphology in rats with passively transferred immunoglobulin G (IgG) from myasthenic patients and the effect of complement by treatment of the rats with cobra venom factor. We injected peroxidase-labeled alpha-BuTx (P-BuTx) into the extensor digitorum longus (EDL) muscle to label the motor end-plates. Three hours later, 100 mg of IgG from MG patients or healthy controls was injected into the tail vein. The EDL was removed 48 hours after the injection of IgG. The presence of macrophages and degeneration of the postsynaptic membrane were seen in 4 of 6 IgG samples from MG patients and a decrease in AChRs in the other 2 samples. These changes were reversed completely by treatment with cobra venom factor in all but one case in which the end-plates were severely degenerated. Injection of MG IgG only never induced end-plate morphology changes. The results suggest that complement has a critical role in degeneration of the postsynaptic membrane and AChR loss at the motor end-plates in the passively transferred model and probably in human MG.

A 68-year-old woman was admitted to Nagasaki University Hospital complaining of gait disturbance. She had suffered from hemifacial spasm since the age of 56 and had undergone neurovascular decompression for the spasm in another hospital five years before admission. At surgery, the vertebral and posterior inferior cerebellar arteries had been separated from the facial nerve with cotton string and attached to the clivus with alpha-cyanoacrylate monomer. Although the hemifacial spasm had improved postoperatively, the patient had suffered from gait disturbance and headache for two months after surgery, and hearing disturbance and hemifacial palsy on the same side as the hemifacial spasm for seven months after surgery. At the time of the present admission, contrast-enhanced CT scan revealed a mass at the left cerebello-pontine angle. In the T1-weighted inversion recovery sequence of MRI, the mass showed a slightly lower intensity than that of surrounding tissues. In the T2-weighted spin echo sequence of MRI, it showed a heterogenously low intensity with some high intensity spots. We diagnosed this mass as a foreign-body granuloma and treated it with dexamethasone injected intramuscularly. Edema decreased around the granuloma, and her gait disturbance improved markedly. But the hearing disturbance and hemifacial palsy did not improve at all, indicating that these two symptoms might not be caused only by brain edema but also by direct damage due to granuloma or inflammation. We thought that the steroid hormone elicited good results in the treatment of inoperable foreign-body granuloma.

The involvement of peripheral nerves and nerve roots often leads to neurological manifestations which have frequently been described in association with diabetes mellitus. Whether there is any specific involvement of the central nervous system in this process has yet to be determined. Recently, many reports have suggested that significant neurophysiologic abnormalities in the central nervous system can sometimes be found in diabetic patients. In order to accurately examine the existence of central nervous system involvement in patients with diabetes mellitus, comparisons of 123I-IMP (IMP) washout rates were made between normal adults (n = 19, average age 43.3 years) and diabetic patients (n = 23, average age 43.3 years), and these results were graphically demonstrated by color images. Early images were obtained 30 minutes after intravenous injection, while delayed images were made 4 hours after injection. The IMP washout rate was obtained by subtracting the values of the delayed image with the early image. The standard deviation (SD) of the IMP washout rate for each patient was compared to the averaged SD obtained from healthy adults. After calculating the deviation from SD levels of healthy adults, we made an image of the patient's IMP washout rates. These images were divided into seven degrees (I, II: normal, III, IV: borderline, V-VII: abnormal) and the ratio of each degree was expressed by a histogram in each cerebral hemisphere as the washout rate index. In 23 diabetic subjects, seven patients were found to be borderline while sixteen patients were abnormal. These impairments were not related either to the presence of diabetic neuropathies or the duration of disease.(ABSTRACT TRUNCATED AT 250 WORDS)

The combined administration of enoxacin, a new quinolone, and fenbufen, a non-steroidal anti-inflammatory drug induced convulsions in mice, but convulsion did not occur when a single administration of each drug was given. Inhibition by enoxacin of [3H]muscimol binding to mouse and human brain membranes was remarkably facilitated by fenbufen. These inhibitions were much more prominent in the hippocampus and frontal cortex than in the cerebellum of human and mouse brain. Enoxacin and fenbufen each at a high concentration produced a moderate and slight inhibition of the [3H]muscimol binding, respectively, in the hippocampus and frontal cortex but not in the cerebellum. It would thus appear that the drug interaction between enoxacin and fenbufen on the gamma-aminobutyric acidA receptor in hippocampus and frontal cortex plays a role in inducing convulsions.