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Biomedical subjects

Y Tsukada

Publications and source records attributed to Y Tsukada.

At least 307 records · Page 17Linked to original sources
PubMed1981

Neurochemical and morphological studies on the myelin of peripheral nervous system from Shiverer mutant mice: absence of basic proteins common to central nervous system.

Shiverer mouse is characterized by poor lamella formation and absence of major dense line in the CNS myelin. PNS of the Shiverer was normal with regard to myelin lamellar formation, immunohistochemical staining of the Schwann cells by S-100 protein, and the activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase. Analysis of the purified myelin by SDS-polyacrylamide gel electrophoresis revealed that P1 and Pr, which are common to BP in CNS, and PM protein were missing, while P0 and P2 proteins were of the same level as the control.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1981

Serum alpha-fetoprotein in rats after ligation of the common bile duct: relation to ductular cell (oval cell) proliferation.

Serum AFP levels were measured by radio-immunoassay in rats at various periods after ligation and section of the common bile duct and after sham-ligation. Transient elevations of serum AFP reaching statistically significant levels occurred at 3 to 10 days, 17 days and 28 days after ligation of the common bile duct but not in sham-operated rats. The peak elevations of serum AFP followed waves of mitosis in both the ductular cells and the hepatocytes as measured by autoradiography. Proliferation of hepatocytes, however, remained minor when compared to ductular cell multiplication. Ultra-structural and histochemical studies of the liver clearly distinguished ductular (oval) cells from hepatocytes and provided no evidence of transition from ductular cells to hepatocytes. Our findings suggest that ductular cell proliferation in the rat induced by ligation of the common bile duct may produce elevations in the serum AFP.

Animals↗
PubMed1981

Regional, cellular, and subcellular distribution of Thy-1 antigen in rat nervous tissues.

The regional, cellular, and subcellular distribution of Thy-1 antigen in rat nervous tissues was investigated with rabbit and anti-rat thymus antiserum. Thy-1 antigen was found most abundantly in the cerebrum, including the cerebral cortical layer, caudate nucleus, thalamus, and hypothalamus, and in the midbrain. It was found in lower amounts in the pons, medulla oblongata, cerebellum, and spinal cord. The content of Thy-1 antigen, however, was low in the retina, cervical sympathetic ganglion, and sciatic nerve, and there was little in the pineal body and adrenal medulla. Thy-1 antigen was present in the neuronal cell-enriched fraction, whereas the glial cell-enriched fraction lacked Thy-1 antigen. In a subcellular fractionation study, Thy-1 antigen was found to occur mainly in the synaptosomal membrane and microsomes and was low in the highly purified myelin fraction. The amount of Thy-1 antigen in the cerebral synaptosomal fraction was much higher than those in the cerebellar synaptosomal fraction. The distribution of Thy-1 antigen among the respective areas within the cerebrum was not significantly different, and it is suggested that Thy-1 antigen may be present evenly in the neuronal membranes of the cerebrum. Based on these results, Thy-1 antigen is considered to represent a useful marker of cerebral neuronal membranes, especially in the synaptic region, regardless of the kind of neurotransmitters.

Adrenal Medulla↗
PubMed1981

2-Deoxyglucose incorporation in the cerebellum of weaver and nervous mutant mice.

The 2-deoxyglucose autoradiographic method has been used to study activity in cerebellum of the weaver and nervous mutant mice. Patterns of 2-deoxyglucose incorporation into the cerebral hemispheres from weaver and nervous strains did not differ significantly from those of the controls. In the normal cerebellum, 2-deoxyglucose incorporation was maximal in the granular layer, where mossy fibers form synapses with the dendrites of granule cells. In the cerebellum of nervous mice, which lacks Purkinje cells, the incorporation of the 2-deoxyglucose was maximal in the granular layer, but the incorporation into the molecular layer appeared less than in the control. The incorporation into the cerebellum from weaver, which lacks granule cells, was much higher than that of the control, the maximal incorporation being found in the Purkinje cell layer and in cell masses located in the white matter. These data suggest that the heterologous synapses that mossy fibers or climbing fibers form with the cells in the Purkinje cell layer and the cells in the white matter in the weaver cerebellum are functional.

Animals↗
PubMed1981

Viral hepatic diseases and microsomal arylamidase activity in liver tissue.

The relationship between microsomal arylamidase activity, determined by a micromethod, and changes of hepatocytes was studied in biopsy samples taken from 107 patients with normal liver histology and viral hepatic diseases. The activities in healthy carriers and chronic persistent hepatitis patients were significantly greater than those of controls, acute hepatitis and chronic active hepatitis patients, and showed a significant greater than those of controls, acute hepatitis and chronic active hepatitis patients, and showed a significant correlation to morphologic criteria. Ultrastructurally, regularly increased smooth endoplasmic reticulum (SER) was found especially in healthy carriers. The arylamidase activity reflects virus-induced changes of the SER in healthy carriers and viral hepatic diseases.

Aminopeptidases↗
PubMed1981

Physiochemical and immunochemical characterization of gamma-glutamyl transpeptidase from yolk sak tumor and ascitic hepatoma (AH-66) cells.

gamma-Glutamyl transpeptidases, purified from rat yolk sac tumor and AH-66 hepatoma cell lines resemble this enzyme system from rat kidney in their amino acid composition and antigenicity, but differ by having a higher carbohydrate content. The different carbohydrate contents resulted in the tumor cell and rat kidney enzymes having different molecular weights. Isoelectric focusing of the neuraminidase-treated enzymes showed that a substantial portion of the enzymes from yolk sac tumor and AH-66 cells shifted to a form with an isoelectric point at pH 7.4. However, a heterogeneous pattern was still found in the kidney enzyme even after extensive neuraminidase treatment.

Amino Acids↗
PubMed1981

Hydralazine-induced hepatitis.

Three patients developed hepatic injury two months, ten months and two years, respectively, after hydralazine therapy for hypertension. Clinical and biochemical recovery followed discontinuation of drug therapy. Liver biopsies of the three patients revealed varying degrees of centrilobular necrosis. Complement 3 and Complement 4 levels were measured and found to be low in the patient with poor liver synthetic function, as was evident from the low serum albumin level and prolonged prothrombin time. Hydralazine-induced liver injury may be due to abnormality of drug metabolism in the liver.

Chemical and Drug Induced Liver Injury↗
PubMed1980

Squamous cell carcinomas and adenosquamous carcinomas originating from the thyroid gland.

Three cases of squamous cell carcinoma and 3 cases of mixed squamous and glandular carcinoma were reported. Pathologic differential diagnosis of these rare primary tumors of the thyroid gland were discussed. All except 1 case occurred in elderly patients; their clinical behavior was more aggressive than that of differentiated carcinoma. It is suggested that the tumor be treated more vigorously at its initial stage.

Adenocarcinoma↗
PubMed1980

2'-3'-cyclic nucleotide 3'-phosphohydrolase activity in the central nervous system of a myelin deficient mutant (Shiverer).

Shiverer is a recessive autosomal mutant characterized by the deficiency of the myelin in the central nervous system. 2',3'-Cyclic nucleotide 3'-phosphohydrolase (CNPase) activity of the various parts of the central nervous system from the Shiverer did not differ significantly from those of the control. The analysis of the protein profiles of the purified myelin from the Shiverer showed a greatly decreased proportion of proteolipid protein, and almost complete absence of small and large basic proteins, and intermediate protein. Woldgram protein accounted for a much larger percentage of the total myelin protein than is the case in myelin from the control. Proteolipid protein, small and large basic proteins, and intermediate protein were found to be undetectable or decreased in various parts of the central nervous system from the Shiverer. Morphological observation by optic and electron microscope showed that the myelination of the optic nerve was equally affected as the spinal cord.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1980

Effect of horse antibody to rat alpha-fetoprotein upon the growth of AH-66 in Donryu rats.

Studies were undertaken to evaluate whether the intraperitoneal administration of horse antibody to rat alpha-fetoprotein (HabRatAFP) would inhibit or prevent the growth of AH-66 tumor cells inoculated into Donryu male rats. In animals inoculated with tumor subcutaneously there was 100% tumor growth in uninjected control animals and the administration of HabRatAFP prevented tumor growth in 7/24 (29%) of the animals. When animals were inoculated with tumor intraperitoneally, the inhibition of tumor growth by HabRatAFP only occurred at tumor-cell doses of 50,000, 10,000, and 5,000. In these three groups, 15/35 (43%) of those animals treated with HabRatAFP did not develop tumor whereas 1/36 (3%) of the normal horse-serum treated animals did not develop tumor. The majority of those animals which were cured of their tumors by HabRatAFP treatment resisted tumor rechallenge. Studies were done to elucidate the mechanisms responsible for the anti-tumor effect of HabRatAFP, AH-66 tumor cells which were placed into millipore chambers, implanted intraperitoneally, were killed by the intraperitoneal administration of HabRatAFP. Studies were conducted to see if treatment with HabRatAFP to rat AFP might increase the immunogenicity of an inoculum of X-irradiated tumor cells. In one experiment, no animals which received only X-irradiated tumor cells resisted tumor rechallenge with 5 X 10(6) tumor cells whereas 6/11 (54.5%) of those animals which received X-irradiated tumor cells and treatment with HabRatAFP resisted tumor rechallenge.

Animals↗
PubMed1980

Cystadenocarcinoma of the ovary in a 4-year-old: benign transformation during therapy.

Ovarian tumors comprise only 1% of all tumors in females below the age of 17 years. Of these, the epithelial tumors are the least common, being particularly rare before puberty and then increasing in frequency with advancing age after puberty. The youngest girl previously reported in the literature with an epithelial ovarian tumor was a 9-year-old child with an ovarian papillary cystadenocarcinoma. This is the only case thus far reported of a malignant ovarian epithelial tumor occurring before puberty. Only histologically benign appearing glands were detected in the resected tumor masses, on a second-look laparotomy following the use of multiagent chemotherapy.

Antineoplastic Agents↗
PubMed1980

Biosynthesis of interstitial types of collagen by albumin-producing rat liver parenchymal cell (hepatocyte) clones in culture.

We have analyzed collagenous components produced by an albumin-producing rat liver parenchymal cell clone (BB) in culture. The cells secreted over 90% of the [3H]proline-labeled collagenous components into the medium after 18 h of incubation in vitro. Analysis of the components by sodium dodecyl sulfate-polyacrylamide gell electrophoresis and by carboxymethylcellulose chromatography of cyanogen bromide peptides after separation of individual collagen chains showed that the cells produced type I, type I trimer, and type II collagens in the ration 59:29:4. These components account for over 90% of the collagen isolated. Type I and type I trimer collagens were present in both the medium and cell layer fractions, but type III collagen was found solely in the medium. The cells also produced other minor collagenous components, one of which was quite similar to type V collagen. Analysis of collagen components produced by another liver parenchymal cell clone (BC) and by three subclones derived from BB cells showed that these cloned cells synthesized similar types of collagen. These results support the idea that parenchymal cells play an essential role in the heaptic connective tissue metabolism under normal and pathological conditions.

Animals↗
PubMed1980

Immunoradioautographic study of alpha-fetoprotein in hepatoma cells.

Trypsin treatment, which is frequently used in the field of immunocytochemistry to faciliate conjugated antibody penetration through the cell membrane, was applied for the immunoradiographic demonstration of alpha-fetoprotein in ascites hepatoma cells using 125I-labeled anti rat alpha-fetoprotein antibody. No significant number of silver grains were detectable in the group without trypsin treatment, while numerous silver grains were recognizable in the ascites hepatoma cells after trypsin treatment. This indicates that trypsin treatment is effective for the immunoradiographic demonstration of alpha-fetoprotein and contributes to the quantitative immunoradioautographic investigation.

Animals↗
PubMed1980

Effect of food restriction on serotonin metabolism in rat brain.

The brain concentration of 5-hydroxytryptamine (5-ht) and 5-hydroxyindoleacetic acid (5-HIAA) increased in rats maintained on restricted volume of low-protein or normal-protein diet, whereas these two agents decreased in rats fed low-protein diet ad libitum. In these two food-restricted groups brain 5-HT and 5-HIAA concentrations were not correlated with brain tryptophan hydroxylase activity, but the concentrations correlated closely with cerebral tryptophan concentrations. The cerebral tryptophan concentration in the two food-restricted groups was not consistent with the total or free tryptophan concentration in plasma. In these restricted rats cerebral tryptophan concentration was elevated, and, unlike the plasma tryptophan, it showed no diurnal variation. These results suggested that tryptophan uptake into the brain from plasma was enhanced by limiting food volume intake. Tryptophan uptake was increased by glucagon injection without changing the plasma tryptophan level, but injection of hydrocortisone or insulin had little or no effect on tryptophan concentration in either the plasma or brain. D-Glucose injection elevated plasma tryptophan concentration but decreased brain tryptophan concentration.

Animals↗
PubMed1980

Perinatal changes in amino acid metabolism of rat brain, especially alanine and glutamic acid.

The changes in both the levels of some free amino acids and their metabolism in the rat brain during the first 24 hr of postnatal life were studied. The content of glutamic acid decreased for the first 2 hr; it remained at the lowest level for the next 4 hr, when it began to increase. The content of alanine decreased for the first 6 hr and approached the adult level. Oxygen consumption, glucose oxidation, and pyruvate formation in the cerebral slices of the 24-hr-old rats were as much as 150% of that of the 19-day-old fetus. The distribution profile of radioactivity incorporated into the cerebral amino acids from the subarachnoid-injected [U-14C]glucose was also changed. In the 2- and 6-hr-old rats, 50% of the total radioactivity recovered in the free amino acids was in alanine. Its rate decreased to 30% in the 24-hr-old and was 2% in the adult, while the radioactivity incorporated into glutamic acid increased. Alanine aminotransferase activity started to increase at birth and had the highest level at 24 hr after birth. It then decreased and finally reached the same level as shown at birth. However, aspartate aminotransferase increased during the first 6 hr after birth and did not change until the end of the first day of life.

Aging↗