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Biomedical subjects

Y Kinoshita

Publications and source records attributed to Y Kinoshita.

At least 19 recordsLinked to original sources
PubMed1992

Activation of Src-like protein-tyrosine kinase Lyn and its association with phosphatidylinositol 3-kinase upon B-cell antigen receptor-mediated signaling.

Crosslinking of membrane-bound immunoglobulins, which are B-cell antigen receptors, causes proliferation and differentiation of B cells or the inhibition of their growth. The receptor-mediated signaling involves tyrosine phosphorylation of cellular proteins. The Src-like protein-tyrosine kinase Lyn is expressed preferentially in B cells and is an intracytoplasmic constituent of the B-cell antigen receptor complex. Crosslinking of membrane-bound immunoglobulin M with antibody induced rapid increases in the kinase activities of Lyn and Lyn-associated phosphatidylinositol 3-kinase. Crosslinking of B-cell antigen receptor also induced association of Lyn with an 85-kDa noncatalytic subunit of phosphatidylinositol 3-kinase. Thus, Lyn is functionally associated with membrane-bound immunoglobulin M and seems likely to participate in B-cell antigen receptor-mediated signaling.

B-Lymphocytes↗
PubMed1992

Morphological and functional alterations of the hypothalamic-pituitary system in brain death with long-term bodily living.

Hypothalamic hormones as well as anterior pituitary hormones were detected in the peripheral plasma after the diagnosis of brain death. It is possible that residual hypothalamic tissue was functioning after satisfying the usual criteria of total brain death. To examine this possibility, endocrinological and morphological alterations of the hypothalamic-pituitary system was evaluated in 28 brain dead patients. Intrinsic ADH was depleted in the plasma shortly after the diagnosis of brain death. Anterior pituitary hormones were initially detected in all patients, but gradually disappeared. The direct TRH (thyrotropin releasing hormone) stimulation to the anterior lobe was responded to well. Morphological studies showed a partial necrosis of the anterior lobe and the preservation of the posterior lobe for as long as a week. These data prove that the pituitary is partially preserved after brain death. LH-RH (luteinizing hormone releasing hormone) was detected in the peripheral plasma of all patients and GRF (growth hormone releasing factor) was detected in half of the patients for as long as 15 days, but autopsy revealed the fact that the brain tissue including the hypothalamus became extensively necrotic after the sixth day of brain death. In order to solve this controversy it is proposed that these hormones originate from extracranial tissues such as pancreas. The detection of hypothalamic hormones after the diagnosis of brain death therefore is not contradictory to the concept of total brain death.

Adolescent↗
PubMed1992

Acinar cell carcinoma of the pancreas with elevated serum alpha-fetoprotein levels: a case report and a review of 28 cases reported in Japan.

A 60-year-old male with elevated serum AFP levels is reported. Other tumor markers apart from AFP were normal. Serum AFP did not bind to Con A or Lentil-lectin by affinity chromatography. Abdominal ultrasonography, computed tomography and endoscopic retrograded cholangiopancreatography demonstrated a tumor extending from the body to the tail of the pancreas. The tumor was strongly suggested to be an acinar cell carcinoma of the pancreas, based on the histological findings of the resected specimen. The peroxidase-antiperoxidase method showed cancer cells to be positive for AFP. In Japan, only 27 cases of pancreatic cancer with elevated serum AFP level have been reported. This is the first Japanese case of pancreatic cancer in which the binding of serum AFP to lectins was investigated.

Carcinoma↗
PubMed1992

Establishment of an enzyme immunoassay using monoclonal antibody (HG1-219) and its application for the diagnosis of hepatocellular carcinoma.

A monoclonal antibody (MoAb HG1-219) against a human gastric cancer cell line (HuG-1) and its shedding antigen (HG1-219 Ag) was generated and a solid-phase sandwich enzyme immunoassay (EIA-219) was developed. The mean serum HG1-219 Ag concentration in normal individuals was 30.5 +/- 14.5 U/ml measured by EIA-219. When the mean +3 SD of the antigen concentration in normal individuals was used as a cut-off level, 4.3% (2/47) of patients with chronic hepatitis, 9.1% (4/44) of cirrhotic patients and 37.5% (18/48) of patients with hepatocellular carcinoma (HCC) had HG1-219 Ag above the cut-off value. The positive rates of a-fetoprotein (AFP) (> 400 ng/ml) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) for HCC were 26.7% (12/45) and 33.3% (12/36), respectively. There was no significant correlation between HG1-219 Ag and AFP or PIVKA-II in patients with HCC. The combination assay of EIA-219, AFP and PIVKA-II for HCC gave the positive rate of 75% (27/36). The effect of periodic acid on the HG1-219 Ag and the inhibition of EIA-219 by CA 19-9 suggest that the epitope of HG1-219 Ag is a suger chain similar to CA 19-9.

Animals↗
PubMed1992

Characterization of multiple forms of carbonyl reductase from chicken liver.

Three enzyme forms (CR1, CR2 and CR3) of carbonyl reductase were purified from chicken liver with using 4-benzoylpyridine as a substrate. CR1 was a dimeric enzyme composed of two identical 25-kD subunits. CR2 and CR3 were monomeric enzymes whose molecular weights were both 32 kD. CR1 exhibited 17 beta-hydroxysteroid dehydrogenase activity as well as carbonyl reductase activity in the presence of both NADP(H) and NAD(H). CR2 and CR3 had similar properties with regard to substrate specificity and inhibitor sensitivity. They could exhibit the activity only with NADPH and had no hydroxysteroid dehydrogenase activity. CR2 and CR3 cross-reacted with anti-chicken kidney carbonyl reductase antibody, though CR1 did not. The results suggest that CR1 is a hydroxysteroid dehydrogenase, and CR2 and CR3 are similar to each other and to the kidney enzymes.

17-Hydroxysteroid Dehydrogenases↗
PubMed1992

Absence of response to hypothalamic stimulation test in brain death.

Immunoreactive corticotropin-releasing hormone (CRH) and growth hormone-releasing hormone (GHRH) are present in the plasma of the brain dead patients. These hypothalamic hormones may reflect some residual brain function after brain death. To examine the hypothalamic function, insulin-induced hypoglycemia and arginine infusion were performed in brain dead patients. Plasma CRH and GHRH were present initially, but levels did not increase significantly for 120 minutes after insulin injection. GH, adrenocorticotropic hormone, and cortisol levels did not increase either. Arginine load did not induce GH. These results suggest that hypothalamic hormones in the plasma after whole brain death do not reflect hypothalamic functions. The hormones may originate from extrahypothalamic sources such as the pancreas or adrenal gland.

Adolescent↗
PubMed1992

[Pedunculated hepatocellular carcinoma suspected of right adrenal tumor: a case report].

We report a rare case of extrahepatic growing hepatocellular carcinoma which was clinically diagnosed as right adrenal tumor. A 61-year-old woman was admitted for further examination of right flank pain and hypertension. Abdominal computed tomographic scan and echogram revealed a suprarenal mass. Hypercatecholaminemia was suspected from urinary analysis. Preoperative diagnosis was right adrenal tumor; suspected pheochromocytoma. On operation, we found the tumor was pedunculated from right lobe of liver and compressing normal right adrenal gland. Its clinical diagnosis was hepatocellular carcinoma. Ten months after operation she is still alive. We discuss the difficulty of differential diagnosis between extrahepatic growing hepatocellular carcinoma and adrenal tumor.

Adrenal Gland Neoplasms↗
PubMed1992

Enhancement of DNA synthesis in rat thymocytes by stimulating their muscarinic acetylcholine receptors.

The binding of 3H-acetylcholine (ACh) to acetylcholine receptors (AChRs) on rat thymocytes was examined and found to be inhibited by the treatment with several antagonists against nicotinic and muscarinic AChRs. This result suggested that thymocytes have AChRs with different affinity, and bear both nicotinic and muscarinic AChRs on their surfaces. To make clear the functional significance of the AChRs, DNA synthesis of the thymocytes stimulated with ACh was examined. 3H-thymidine uptake of thymocytes was significantly increased when the cells were stimulated with ACh or another cholinergic agonist. The increment of DNA synthesis caused by ACh in thymocytes was not reduced by treatment with nicotinic antagonists, but was decreased by treatment with any of the muscarinic antagonists. Concentration of the intracellular second messengers, inositol 1,4,5-triphosphate (IP3) and guanosine 3',5'-cyclic monophosphate (cGMP) was also made higher by ACh stimulation. It is discussed that the enhancement of intracellular IP3 and cGMP concentrations after stimulation of muscarinic AChRs appears to be related with the increment of thymocyte DNA synthesis.

Acetylcholine↗
PubMed1979

Studies on hematopoietic stem cells: XI. Lack of erythroid burst-forming units (BFU-E) in patients with aplastic anemia.

The marrow concentration of erythropoietic precursors was examined in normal donors and patients with idiopathic aplastic anemia using a plasma clot culture system. On time course observations the heterogeneity of human erythroid precursors assayable in culture was demonstrated. To evaluate human erythropoiesis in vitro, the benzidine-positive colonies were divided into three groups: small colony, containing 8-50 cells; medium-sized colony, containing 50-500 cells; and large colony, containing more than 500 cells. The majority of the large colonies assumed the morphology of erythropietic bursts (BFU-E) consisted of several subcolonies. The small colonies were counted as CFU-E1, the medium-sized as CFU-E2, and the large as BFU-E to evaluate the erythroid precursor cell compartment in aplastic anemia. The marrow concentration of CFU-E1 and CFU-E2 was shown to be quantitatively diminished in aplastic anemia. In addition, there was no ability of the marrow cells from aplastic patieints to grow BFU-E in vitro even in the presence of a large dose of erythropoietin. This lack of BFU-E colony growth may play an important role in the mechanism of the erythropoietic deficiency in aplastic anemia.

Anemia, Aplastic↗
PubMed1979

Incorporation of serum albumin into the developing dentine and enamel matrix in the rabbit incisor.

Rabbit serum albumin labeled with 125I was injected into rabbits (650-870 g). The incorporation pattern of the labeled albumin into the developing dentine and enamel matrix was studied 1 h, 6 h, and 3 days after the injection using autoradiography. Silver grains were observed over the predentine 1 h after the injection. They were found over the dentine matrix adjacent to the predentine-dentine junction at 6 h. The silver grain band was concentrated over the internal dentine matrix at 3 days. However, no appreciable amount of the silver grains could be seen over the enamel matrix at any time after the injection. It is possible that there might be some physiological barrier between the extravascular fluid and the enamel matrix. The role of the albumin in dentine is discussed.

Amelogenesis↗