Search PubMed⌕ Search

Biomedical subjects

T Nagata

Publications and source records attributed to T Nagata.

At least 613 records · Page 34Linked to original sources
PubMed1978

Ultrastructural localization of glycogen in the granulocytes of normal rabbit bone marrow.

The glycogen of rabbit granulocytes has been studied in glutaraldehyde and osmium tetroxide fixed bone marrow by the periodic acid-thiocarbohydrazide-silver proteinate procedure (PA-TCH-SP). The PA-TCH-SP procedure involved the staining of intracytoplasmic glycogen more densely than the routine lead citrate staining. The PA-TCH-SP procedure demonstrated the intracytoplasmic glycogen in all three kinds of granulocytes. Though a sequence of intensity was observed in each stage of cell maturation, intracytoplasmic glycogen increased generally in accordance with cell maturation in the granulocytes. Functional significance of the glycogen in the granulocytes was discussed in relation to its staining. A very weak reaction in the granules of the granulocytes was described in relation to their contents.

Animals↗
PubMed1978

A modified wire-loop method for quantitative electron microscopic radioautography.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography without any special instrument in introduced. Seven grids carrying ultrathin sections are attached to a glass block with double-coated Scotch tape. They are coated with a wire-loop, 2.5 cm in diameter. Ten glass blocks are then stuck on a slide, exposed, developed, fixed and stained simultaneously. Employing this method, the emulsion coating and the following procedures are easily accomplished under an identical condition.

Autoradiography↗
PubMed1978

Histochemical studies of mucosubstances in metaplastic epithelium of the stomach, with special reference to the development of intestinal metaplasia.

Processes in the development of intestinal metaplasia of the stomach were investigated from the morphological and histochemical approaches using light and electron microscopic techniques. The specimens taken from 38 gastric carcinomas and 15 gastric and/or duodenal ulcers were subjected to this study. Morphological appearances of the intestinal metaplasia observed in routine examination with hematoxylin and eosin staining was able to divided into complete and incomplete metaplasia by the light and electron microscope histochemical stainings of the mucosubstances. The columnar cells at the area of the incomplete metaplasia had both the properties of the intestinal epithelia and the gastric foveolar epithelia. The incomplete as well as the complete metaplasia arose from the generative cells at the isthmus of the gland. The generative cells, however, sometimes gradually transformed to produce the complete metaplastic cells. The two processes of the development of the intestinal metaplasia were proposed and discussed.

Duodenal Ulcer↗
PubMed1978

Behavioral effects of protirelin in schizophrenia.

The effects of protirelin were compared with those of placebo in a multi-institutional, double-blind, controlled study of 143 chronic schizophrenic patients. Treatment with neuroleptics was continued during the study and 4 mg protirelin per day was orally administered for 14 days. Protirelin appeared to be significantly superior to placebo on the physicians' global ratings of efficacy. Increased motivation for work was isolated as a target effect but such symptoms as facial expression, emotional rapport, and psychomotor activity also appeared to be improved by addition of protirelin to the neuroleptics. Onset of the therapeutic effect of protirelin occurred within a week of medication in most of the patients who showed improvement. No adverse reactions were encountered.

Adult↗
PubMed1978

Bacteriophage lambda carrying the Escherichia coli chromosomal region of the replication origin.

A transducing phage lambdaasn was isolated. The late gene region of its genome was found to have been substituted by an Escherichia coli chromosomal segment containing the genes bgIR, bgIC, glmS, uncA, and asn. Restriction endonuclease cleavage mapping and electron microscopic analysis of the lambdaasn DNA revealed that the size of the bacterial segment is approximately 1.75 X 10(7) daltons, corresponding to about 26.4 kilobases. The circular DNA of lambdaasn was digested with restriction endonuclease EcoRI, diluted, and sealed with DNA ligase. When the reaction mixture was used to transform a recipient E. coli strain, a small plasmid of about 1 X 10(7) daltons (named pMCR115) was obtained. Restriction endonuclease cleavage mapping of pMCR115 and other evidence suggested that it contained the replication origin (oriC) of the E. coli chromosome.

Chromosomes, Bacterial↗
PubMed1978

Urinary excretion of acid glycosaminoglycans and hydroxyproline in a patient with oculo-cerebro-renal syndrome.

The metabolism of ground substance in connective tissue of an 18-year-old boy with oculo-cerebro-renal syndrome was studied. He had characteristic clinical and laboratory findings described by Lowe et al. such as growth retardation, mental deficiency, glaucoma, cataracta, decreased muscle tone, metabolic acidosis, aminoaciduria and osteomalacia. The urinary excretion of acid glycosaminoglycans and of total hydroxyproline were 27 mg/day (as glucuronic acid) and 280 mg/day respectively on admission. Both values decreased to the upper limits of normal level transiently during treatment with alkali and vitamin D2. At that time, an improvement in bone abnormalities, a decrease of serum alkaline phosphatase, and an elevation of serum inorganic phosphate were observed. The therapy prevented him from progressive osteomalacia and cured him of it, but mucopolysacchariduria and hydroxyprolinuria did not disappear. Analytical electrophoresis on cellulose acetate sheets showed that urinary acid glycosaminoglycans were composed of undersulfated chondroitin 4-/6-sulfate and heparan sulfate with a ratio of 6:4, on admission. After oral administration of alkali, the excretion of heparan sulfate decreased and undersulfated chondroitin 4-/6-sulfate was determined as a main component of urinary acid glycosaminoglycans. The clinical and laboratory data in this case suggested that the increased excretion of acid glycosaminoglycans and total hydroxyproline was caused by abnormal metabolism in connective tissues, especially by the bone abnormalities, in this syndrome.

Adolescent↗
PubMed1978

Urinary acid glycosaminoglycans in a patient with oculo-cerebro-renal syndrome.

An 18-year-old boy with oculo-cerebro-renal syndrome excreted a large amount of acid glycosaminoglycans in urine. The identification and characterization of the acid glycosaminoglycans were carried out by the methods of preparative column electrophoresis, ion exchange chromatography, gelfiltration, paper chromatography of the chondroitinase digests and chemical analysis. On admission to hospital, the main components of the urinary acid glycosaminoglycans were undersulfated chondroitin 4-sulfate of large molecular weight and heparan sulfate. Three months after oral administration of the supplement of alkali, the excretion of heparan sulfate and the molecular size of chondroitin 4-sulfate decreased significantly, although the amount of urinary acid glycosaminoglycans remained at a high level (about 25 mg/day). The decrease of heparan sulfate and the shift to a smaller molecule of chondroitin 4-sulfate were coincident with the improvement in clinical and laboratory findings. These results suggest that the abnormal metabolism of acid glycosaminoglycans is a characteristic manifestation in this case and the studies on ground substance metabolism might be an important approach to the pathogenesis of this syndrome.

Adolescent↗
PubMed1977

Fine structural and ultracytochemical studies on the lymphocytes in three types of genetic mucopolysaccharidoses.

Lymphocytes from 6 patients with 3 types of genetic mucopolysaccharidoses (Hurler's syndrome, Hunter's syndrome and Morquio's syndrome) contained numberous vacuoles in their cytoplasm. The size of the vacuoles ranged from approximately 300 nm to 750 nm. The percentage of the lymphocytes with vacuoles varied from 10% to 38%. The vacuoles showed acid phosphatase activity, which indicated their lysosommal nature. Staining with dialyzed iron solution usually localized acid mucosubstance in the peripheral region of these vacuoles after glutaraldehyde fixation. Ferritin and horseradish peroxidase were observed in the vacuoles after incubation of the patient's lymphocytes with these tracers. This finding indicates the participation of endocytosis in the formation of these vacuoles.

Acid Phosphatase↗
PubMed1977

Electron microscopic dry-mounting radioautography for diffusible compounds by means of ultracryotomy.

Cultured HeLa cells or mouse liver and pancreas tissues were labeled with 3H-thymidine, -uridine or -glycine for varying periods in vitro, frozen in liquid nitrogen and cut on an LKB ultrotome equipped with LKB Cryokit. Dry ultrathin sections were mounted on grid meshes and were either air-dried, freeze-substituted or freeze-dried, and were covered with dry films of radioautographic emulsions, exposed, developed, stained and were observed in electron microscopes. After a number of trials, it was possible to obtain fairly good preservation of both cell structure and radioisotopes by means of freeze-dried and dry-mounted ultrathin frozen sections. However, the results are not completely satisfactory at the present time.

Animals↗
PubMed1977

Demonstration of intracytoplasmic glycogen of megakaryocytes and blood platelets by means of the periodic acid-thiocarbohydrazide-silver proteinate method.

The glycogen of megakaryocytes and blood platelets has been investigated in glutaraldehyde and osmium tetroxide fixed tissues by the periodic acid-thiocarbohydrozide-silver proteinate method (PA-TCH-SP). The PA-TCH-SP method involves the staining of intracytoplasmic glycogens more densely than the routine lead citrate method. Glycogen having a mean particle diameter of 21.1 nm has been shown localizing in the matrix of mature megakaryocytes, while that of glycogen in the platelets was 26.2 nm. The staining pattern of the glycogen in blood platelets was classified into three groups according to staining intensity. It is found that the PA-TCH-SP method is a very suitable one for the demonstration of intracytoplasmic glycogen from the viewpoints of reaction specificity, reproducibility, fineness of reaction products, sufficiency of electron density, and experimental cost. This method is also a very useful one for differentiating intracytoplasmic glycogens and ribosomes.

Animals↗
PubMed1977

Effects of eye movements upon excitability of cat superior colliculus as tested by electrical stimulation of the cortico-collicular pathway.

Influences of saccadic eye movements upon excitability of superior colliculus (SC) were examined in chronic cats carrying implanted electrodes and in encéphale isolé cats. Excitability of SC was assessed by recording responses of SC to electrical stimulation of cortico-collicular (CC) pathway. The SC response to stimulation of CC fibers consisted of two componenets, i.e. presynaptic T and postsynaptic R. Eye movements enhanced R but did little change T. Enhancement of the postsynaptic component R was ascribable to a central factor on the basis of the following results: 1) Enhancement of R occurred independently of whether the ambient illumination was present or not. 2) Saccade-like movements of a slit of light in front of immobilized eyes never induced enhancement of R. 3) PRF stimulation, effective to cause saccade-like eye movements, always elicited enhancement of R, independent of the ambient condition of eyes and even after eyes had been immobilized.

Animals↗
PubMed1977

Electrical activity of superior colliculus associated with eye movements in alert cats.

Eye movement potentials (EMPs) were recorded from the superior colliculus (SC) of awake cats. When cats moved the eyes in front of a patterned or diffuse field, the EMP appeared as a sequence of the three components; EMP1, EMP2 and EMP3. The EMP1-EMP2-complex occurred while the eyes were moving and it had a wave form similar to that of the flash-evoked response. The EMP3 was seen 30-50 msec after the end of eye movement. In dark only the EMP3 was observed; its delay after the end of eye movement was as large as 70 msec. By placing electrodes at various depths of SC, the EMP was found to originate in the superficial layers. In immobilized, encéphale isolé cats, placed in dark or made blind by enucleation, the followings were observed; 1) Passive movements of the eye did not give rise to any significant electrical activity of SC. 2) Spontaneous mass activity of the oculomotor nucleus, that would result in eye movements if the cats were not paralysed, was followed by sharp wave activity of SC and this was the same after the visual cortex had been ablated bilaterally. From these findings it is concluded for the EMPs of awake cats that the EMP1-EMP2-complex is a response to retinal impulses caused by movements of images, whereas the EMP3 is due to an extraretinal factor such as the corollary mechanism. Besides the EMPs as described above, some activity was found to occur about 150 msec before the onset of eye movement. This EMP, called early EMP, seemed to appear when it was followed by eye movements with relatively high speeds.

Action Potentials↗