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SUMMARY A radioimmunoassay system for determining content of glutamate dehydrogenase (GDH) in human leukocytes was established and studied in 14 patients with spinocerebellar ataxia or atypical Parkinsonism. The protein content of leukocyte GDH was decreased in four patients and the reduction in the protein content was proportional to that in the enzyme activity. The ratio of GDH activity to protein content was invariable in healthy controls, diseased controls and patients with reduced GDH activity. These results suggested that at least a portion of the partial GDH deficiency was due to the decreased level of the enzyme protein.Spinocerebellar degeneration is a heterogeneous disease complex, and the majority of the diseases have not been characterised biochemically. Recently, several authors have reported the partial deficiency in glutamate dehydrogenase (GDH; EC 1.4.1.3) activity in leukocytes, fibroblasts, platelets and muscles from patients with nondominant or dominant form of olivopontocerebellar atrophy (OPCA).' -These findings suggested that systemic abnormality of glutamate metabolism might be related to a subgroup of OPCA. However, it remains unclear whether or not GDH deficiency is aetiologically significant, and little is known about the mechanism by which GDH activity is reduced.In this study, we established a radioimmunoassay for determination of GDH protein content in human leukocytes and studied patients with spinocerebellar ataxia. Materials and methodsFourteen patients with spinocerebellar degeneration or atypical Parkinsonism and eight age-matched, healthy controls were studied. Four patients who showed significantly lower level of GDH activity than controls are presented below. No members with similar diseases were known in the families of each case. Decreased glutamate dehydrogenase protein in spinocerebellar degenerationEnzyme assay of leukocyte GDH Leukocytes were separated with 6% dextran from heparinised venous blood, and were disrupted by freeze and thaw cycles. These cells were subjected to enzyme assay and radioimmunoassay. GDH activities were measured fluorometrically by a modification of the method described by Plaitakis et al.2 Aliquots of the homogenate were incubated at 47 5'C for 60 minutes. The activity determined after incubation was considered to represent "heat-stable" GDH. This value was subtracted from the total activity to obtain the activity of "heat-labile" GDH.Radioimmunoassay of leukocyte GDH protein GDH proteins purified from bovine liver, rat liver and bacteria (Proteus species) were purchased from Sigma USA. Rabbits were subcutaneously injected with 1 mg of bovine liver GDH emulsified in Freund's complete adjuvant at 2-week intervals and were bled 7 days after the third injection. The specificity and cross-reactivity of the antiserum was tested by immunoblot analysis with protein extracts from rat cerebellum and liver, and by ELISA using GDH purified from bovine liver, rat liver and bacteria as antigens. Crossreactivity of the antiserum with human GDH was evidenced ...

1. Contractions to 5-hydroxytryptamine (5-HT) and histamine of longitudinal muscle from the isolated ileum of the tree shrew (Tupaia), guinea-pig and rat were investigated by constructing doseresponse curves and studying the effects of various antagonists. 2 In the Tupaia and rat ileum the contraction to 5-HT was reduced by methysergide but not affected by tetrodotoxin (TTX), morphine, hexamethonium (C6) or atropine. The response of guineapig ileum to 5-HT was not significantly inhibited by methysergide or C6, but was blocked by TTX, morphine and atropine.3 Histamine-induced contraction of Tupaia and guinea-pig ileum was antagonized by diphenhydramine but not by TTX, morphine, C6 or atropine. Histamine was almost without effect on the rat ileum.

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The angiographic demonstration of an occluded vertebral artery in a patient with a brain-stem syndrome was first reported by Riechert in 1952, and similar cases have been described by various authors subsequently. The common site of the vertebral occlusion was in the area between the arch of the atlas and the junction of the vertebral arteries. Since routine brachial angiography has been initiated in this clinic, occlusion of the vertebral artery at this site has been noticed more frequently than expected. Despite good visualization of the vertebral artery, the injected contrast material sometimes stopped before the junction of the vertebral arteries, and the basilar artery was not demonstrated in a number of patients who did not have clinical evidence of vertebral or basilar artery occlusion. This observation has been mentioned by Sutton and Hoare (1951), and by Krayenbuhl and Ya,argil (1957a) and was considered by them to be due to technical failure or vascular spasm. This explanation did not seem satisfactory for many instances in which we encountered an apparent vertebral artery occlusion. Therefore a series of 150 consecutive brachial angiograms has been reviewed in order to determine the frequency with which occlusion of the vertebral artery with or without symptoms occurs, and if possible to elucidate further its clinical and physiological significance. METHODThe initial 100 brachial angiograms were carried out by a percutaneous catheterization technique (Shenkin, Tatsumi, and Bantley, 1962) and the subsequent 50 using a direct percutaneous method as suggested by Siqueira, Karras, Cannon, and Bucy (1962). The latter method was not only less time consuming but seldom if ever interfered with the quality of the brachial pulse after the study was completed. A thin-wall 18 gauge needle was introduced into the brachial artery percutaneously at the antecubital fossa and connected to an automatic injector. Fifty-five millilitres of 60% methylglucamine diatrizoate (Renografin) were injected into the brachial artery with a pressure of 425 lb. The first film was exposed when 30 ml. of the dye had been injected and a series of six films was taken at one-second intervals in the antero-posterior and lateral projections simultaneously. The right brachial injection One hundred and fifty consecutive patients were studied with the above methods and the series is composed of 27 patients suspected of harbouring a brain tumour, 30 patients with a space-occupying lesion, 32 cases of subarachnoid haemorrhage, and 61 patients with cerebrovascular disease. Of these 150 cases, 15 patients were subjected to bilateral brachial angiography for the following reasons:1 Six patients suffering from subarachnoid haemorrhage failed to demonstrate the basilar artery by right brachial angiography.2 Seven patients representing a suspected vascular lesion within the brain-stem failed to demonstrate the basilar artery by a unilateral brachial injection.3 Studies in two patients had already demonstrated multiple occlusive disease of major cerebr...