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S Tsuji

Publications and source records attributed to S Tsuji.

At least 1,009 records · Page 56Linked to original sources
PubMed1979

On the electromotor neurons of both electric organs of Pollimyrus isidori (Mormyridae, Teleostei).

The electromotor neurons (EMNs) of the adult electric organ of Pollimyrus isidori and the "giant neurons" (GNs) found in the more rostral part of the spinal cord were investigated both with light and electron microscopical methods. The two kinds of neuron are more or less similar in size, about 30 microns, and are found in the more dorsal part of the spinal cord. The EMNs show somatosomatic gap junctions, as do the GNs. In addition, chemical synapses could be found between nerve fibres and both types of neurons. Histochemical investigations show that the EMNs and the GNs are both AChE positive. On the basis of the arguments presented in the discussion, we believe that the "giant neurons" are the electromotor neurons of the larval electric organ of Pollimyrus isidori.

Acetylcholinesterase↗
PubMed1978

"Naked" spinal cord on a non-segmented baton-like bony structure in the tail of the electric fish Eigenmannia virescens (gymnotoidei).

The caudal spinal cord of Eigenmannia virescens is not enclosed in a neural canal of the vertebral column. In fact, a segmented vertebral column with neural and ventral arches is lacking and replaced by a non-segmented baton-like bony structure on which the free spinal cord is located. The baton cosists of calcified bone tissue with bone cells. Individual differences exist as far as the length of the rod is concerned. The "electromotor neurons" of this caudal part of the spinal cord are histochemically acetylcholinesterase-positive. The electrocytes which surround this part of the spinal cord show strong enzymatic activity on the posterior innervated face. However, there is also activity on the non-innervated lateral and anterior faces.

Acetylcholinesterase↗
PubMed1978

Ultracryotomy of nerve-electroplaque synapses for immunocytochemistry.

In order to carry out ultrastructural immunocytochemical localization of acetylcholinesterase at cholinergic synapses, ultrathin frozen sections of aldehyde-fixed electric organs of Electrophorus and Torpedo were obtained by a modified ultracryotome technique. Dry frozen sections, picked up with rabbit serum and negatively stained, revealed, in the postsynaptic regions of the neuro-electroplaque junction, the presence of numerous rod-like or pin-headed protrusions (30 X 40 A) attached perpendicularly at 60 A intervals to the hydrophobic lamina of the plasma membrane, forming a comb-like structure oriented toward the synaptic cleft. A possible correlation is suggested between this comb-like structure and the 'acetylcholine receptors' observed by other authors with high resolution electron microscopy either after classical preparative techniques or after freeze-etching, of the postsynaptic membrane of vertebrae cholinergic synapses.

Acetylcholinesterase↗
PubMed1978

The larval electric organ of the weakly electric fish Pollimyrus (Marcusenius) isidori (Mormyridae, Teleostei).

The larval electric organ of Pollimyrus isidori consists of four longitudinal tubes, a dorsal and a ventral pair, which begin behind the skull, end at the beginning of the caudal peduncle and show myotomic segmentation. The elementary units are, apparently, transformed muscle fibres called electrocytes. They are shorter and thicker than muscle fibres, with long stalks and are found in the medial part of the deep lateral muscle. Electron microscopy reveals a clear difference between the anterior and posterior face of the electrocyte. Anteriorly, deep linear invaginations of the surface membrane together with many small vesicles of about 100 nm diameter can be seen. Posteriorly, many plasma membrane invaginations and vacuoles are found together with numerous cytoplasmic organelles--pleiomorphic nuclei, Golgi apparatus, oblong mitochondria and multivesicular bodies. The stalk originates at the posterior face and the nerve terminals are situated at the distal end of the stalk. In the electrocyte, myofibrils, similar to those found in muscle fibres, can be detected with clearly visible Z lines but with only a suggestion of H zones. Two bundles of myofibrils can be seen arranged orthogonally in the electrocyte. Strong acetylcholinesterase activity was found on the anterior face and on the innervated stalk. Under the given recording conditions the overall discharge amplitude of the larval electric organ reaches a maximum of about 100 mV peak to peak. The pulse duration is 1 millisecond and the main phase is head-positive.

Animals↗
PubMed1978

Adrenoleukodystrophy. A correlative analysis of computed tomography and radionuclide studies.

A discrepancy in location of abnormality has been noted between computed tomography (CT) and radionuclide studies in patients with adrenoleukodystrophy (ALD). Radionuclide concentration occurs only in the periphery of the lesion or area of acute demyelinating process and no concentration is seen in the area af gliosis whereas gliosis appears as a low-density lesion in the CT scan. Forward migration of radionuclide uptake in the follow-up study is another characteristic feature of this disease.

Child↗
PubMed1977

Somatosensory evoked potentials. Diagnostic criteria and abnormalities in cerebral lesions.

In order to advance the practical application of measuring evoked cortical responses following electrical stimulation of the median nerve at the wrist (SEP) in clinical neurology, diagnostic criteria, consisting of the onset latency, peak latency and 2 indices of the first 3 negative components, and their left-and-right differences, were proposed and applied to 65 patients with cerebral lesions of various aetiologies. The criteria used were shown to be very useful in distinguishing between normal subjects and patients with cerebral lesions. The N1 and N2 components were related to the involvement of sensory pathways and were commonly associated with sensory impairment of all modalities or of deep proprioceptive and cortical modalities. The N3 component, on the other hand, was related to the presence of lesions and non-specific sites as well as non-specific symptomatology. SEP, judged by the present criteria, was shown to be useful as a complementary diagnostic aid in localizing the sites of lesions in sensory pathways and in evaluating sensory function, especially when used in combination with clinical symptomatology.

Adolescent↗
PubMed1976

Autosomal genetic control of the activity of a new variant ornithine transcarbamylase in chicken kidney.

The mode of inheritance of the gene for chick kidney ornithine transcarbamylase (OTC), found previously as a genetic variant, was investigated. White Leghorn B line males homozygous for the allele for the variant OTC gene were selected using the California Gray breed, having a near-absolute deficiency of the enzyme. Then further crosses of the two breeds were made. The mean value of the OTC level of F1 progeny was about 170 units. Chicks from the backcross generation were divided into two groups, of high activity and low activity, in a ratio of 1:1. F2 chicks were divided into three groups: one-fourth of the chicks were classified as a "super high" group, one-half were "high," and the remaining one-fourth were "low"; the mean values for OTC level were 356.7, 196.4, and 15.6 units, respectively. From these results, it was suggested that the variant OTC represents a simple autosomal incompletely dominant trait.

Animals↗
PubMed1976

A cooperative study of sarcoidosis in Asia and Africa: descriptive epidemiology.

An eight-nation cooperative epidemiological study revealed the Asian and African features of sarcoidosis. Almost every country reported from several to less than 30 cases, except for Japan which had already collected over 3,000 cases. Not a single case was found in the mass x-ray surveys conducted by several countries on a large scale (Tables 1 and 2). Although the number of the cases included in this study were small, this information is the first of this kind for Asia and Africa.

Africa↗