Biomedical subjects
Publications and source records attributed to A Tashiro.
A new cell line (XTY) was derived from a tumor of a female Xenopus laevis. This cell line has been proliferating in standard amphibian culture medium for more than 4 years (470 generations) and has a doubling time of 75.5 h at 25 degrees C. The cells aggregate into large groups, and their stellate morphology and the expression of desmin demonstrated by immunocytochemistry suggest that their origin is not epithelial.
A neuropathological analysis was performed in two autopsy cases of HTLV-I-associated myelopathy. The thoracic spinal cords were most severely affected and the histopathological findings consisted of mononuclear cell infiltration, marked destruction of myelin and axons and astrocytic gliosis. More than half the infiltrated cells were positive for pan-T cell marker; B cells were sparse in the parenchyma and subarachnoid spaces. CD4 and CD8 positive cells were found in the early stages of the lesions. CD8, however, predominated over CD4 in the other stages. It appeared that a chronic inflammatory process had started at the middle to lower thoracic cord and had extended gradually in both directions. The middle thoracic spinal cord is known to have the poorest blood supply, and the horizontal distribution of inflammatory cells at this region correlated with the most distal supply of the anterior spinal artery.
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To determine the origin of a mesothelioma of the atrioventricular node, immunohistochemical studies that used various antibodies, including the antibody against mesothelial cells, were performed on a mesothelioma of the atrioventricular node in a case. The lining cells of the tubules that composed the tumor were negative when tested with anti-mesothelial cell antibodies. Carcinoembryonic antigen was negative, but the secretory component was positive. Serotonin and calcitonin were positive in a few cells. We concluded that a mesothelial origin was unlikely, and it was suggested that the tumor was of an entodermal origin.
We performed an ultrastructural, morphometric comparison of mitochondria and myofibrils of cardiomyocytes using endomyocardial biopsy specimens in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Biopsies came from the right ventricular side of the interventricular septum in nine patients with HCM, nine with DCM, and nine controls with arrhythmia and/or ST depression. Morphometric analysis was carried out using electron microscopic photographs and an image analyser. Mitochondria were significantly greater in number and smaller in size in HCM than in the control group. In DCM, the size of mitochondria was also significantly smaller than in the control group, although their number was similar to that of the control group. No statistically significant difference was found regarding the size of mitochondria between HCM and DCM. The percentages of both mitochondrial and myofibrillar areas in cytoplasm were smaller in the DCM than the HCM and control groups, though no difference was seen between the latter two. The ratio of mitochondrial area to myofibrillar area was almost the same in each group. These results suggest increased mitochondrial function to match hypertrophic cardiomyocytes in HCM, and decreased mitochondrial function and cardiomyocytic contractility in DCM.
This paper reports the nature of abnormally expressed Forssman (F) antigen in the lymph node cells of MRL/MpJ-lpr/lpr, autoimmune mice, and also reports its autoantibody in sera. By acetylation study of the F antigen with [14C]acetic anhydride, we concluded that the F antigen was not a glycolipid but a glycoprotein. Several bands of F-active glycoproteins were identified on a nitrocellulose sheet after purification by an anti-F antibody affinity column. Hemolysis of SRBC by some sera from MRL/MpJ/lpr/lpr was inhibited by purified F glycoprotein and also by F glycolipid. The antibody in the serum, however, seemed to be more specific for F glycoproteins than F glycolipid, but the opposite was the case for rabbit anti-F glycolipid antibody. No significant difference of the SRBC hemolysis levels was observed between the sera from MRL/MpJ-lpr/lpr and its congenic MRL/MpJ-+/+ mice.
Cardiac dysfunction and ECG abnormalities were demonstrated in a 51-year-old woman suffering from secondary hemochromatosis in sideroblastic anemia. Hemosiderin deposition in vacuolized and disarrayed myocytes was disclosed by microscopic examination of the first biopsy specimen of endomyocardial tissue. Three months after administration of deferoxamine mesylate, an iron-chelating agent, the clinical findings were improved. The second endomyocardial biopsy revealed marked depletion of hemosiderin deposition in the myocytes, and improvement of myocyte vacuolization and disarray. Ultrastructurally, the highly electron-dense granules in the myocytes were also decreased in number and density. X-ray microanalysis revealed a prominent peak of Fe in the granules. In a liver specimen obtained by needle biopsy 5 months after the second endomyocardial biopsy, marked hemosiderin deposition still remained.
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The relation between myocardial histological changes and ventricular tachycardia (VT) in cardiomyopathy was investigated. Right ventricular endomyocardial biopsy and 24-hour ECG-monitoring were performed in 19 patients with dilated cardiomyopathy (DCM) and 22 with hypertropic cardiomyopathy (HCM). Cardiomyopathy was histologically divided into the following four groups: group A, hypertrophy without disarray of myocytes (3 DCM and 7 HCM); group B, hypertrophy with disarray of myocytes (14 HCM); group C, fibrosis (9 DCM and 1 HCM); and group D, diffuse myocytic degeneration (7 DCM). VT was observed in 20% (2 of 10 patients) of group A, 14% (2 of 14) of group B, 80% (8 of 10) of group C, and 71% (5 of 7) of group D. The degenerating myocytes and/or the irregular distribution of fibrosis may play an important role in the etiology of VT in cardiomyopathy.
We reported two cases of glomerulocystic kidney (GCK). Case 1 was a 35-day-old male who was born at 38 weeks of gestation and weighed 1750 g at birth. He showed chromosomal aberration and surface anomaly, and was diagnosed as having pentalogy of Fallot. There were no signs of renal disturbance. At autopsy, subcapsular cysts composed of dilated Bowman's capsules were found. Case 2 was a 63-year-old man. He suffered from mild cerebral infarction at the age of 45. At the age of 51, he was diagnosed as having chronic glomerulonephritis and began hemodialysis at the age of 55. He died of uremic lung at 63. Diffuse dilatation of Bowman's capsules were found in the renal cortices. In the liver, proliferation and cystic dilatation of interlobular bile ducts were noted. The patients with GCK without any severe disease in other organs show no or stable symptoms in the early period of life, but later developed severe renal insufficiency.
The gag proteins of human retroviruses such as human immunodeficiency virus (HIV-1) are specifically myristoylated in their amino termini (1, 2, 3). N-myristoyl glycinal diethylacetal (N-Myr-GOA) and other N-Myr-compounds (N-Myr-Gly-GOA, N-Myr-Gly-Gly-GOA and N-Myr-Gly-Gly-Gly-GOA) were newly synthesized and investigated for activity of antimyristoylation of these gag proteins and for influence on viral replication. Of the N-Myr-compounds tested, N-Myr-GOA most severely inhibited the protein myristoylation; N-Myr-Gly-GOA also inhibited it, but moderately. Furthermore, it was observed that N-Myr-GOA at 20 microM caused noticeable inhibition (about 80%) of the production of mature HIV in the HIV-1-infected MT-4 cells. In this system, N-Myr-GOA substantially inhibited more than 90% of the N-myristoylation of p17 gag protein produced in the HIV-1-infected MT-4 cells. These results suggest that the N-myristoylation of p17 gag protein of HIV-1 may be essential in its structural assembly or maturation.
Novel antibodies were raised against a synthetic NH2-terminal myristoyl glycine moiety which is characteristic of N-myristoyl-proteins. Antisera raised against N-myristoyl-Gly-hemocyanin reacted with N-myristoyl-Gly-[125I]albumin. The immunoreaction was competed for by albumin conjugated with N-myristoyl-glycine, while underivatized albumin had no effect. Of the [3H]myristate-labeled proteins detected, pp60v-src, which is a transforming protein of Rous sarcoma virus, and p19gag and p17gag, which are core proteins in the human T-cell leukemia virus and the human immunodeficiency virus, were identified as N-myristoylated proteins by the radioimmunoprecipitation analyses with the antibody.
We have produced a new edentulous model, which is maintained at the human body temperature, for higher grade model practice and pre-clinical education. A soft material, its thickness based on the value of the oral mucosa, covers the surface of this model. It takes 4 minutes to reach the body temperature after turning on the switch, and it consumed about 9 watts per hour. This new model is useful for teaching clinical characteristics of impression materials in which the setting time is influenced by the temperature. Improvements are under consideration to fit some thermal and pressure sensors to the buccal and labial parts to make a more sophisticated patient simulator.
A 27-year-old-male with hepatic reticuloendothelial failure was reported. He was proved by laparoscopy as having alcoholic liver cirrhosis. In spite of the absence of hepatic colloid uptake, hepatobiliary scan with Tc-99m HIDA and Ga-67 citrate produced satisfactory liver images.
In a Japanese institution for the handicapped with confirmed continuous outbreaks of hepatitis B virus (HBV) infection by horizontal nosocomial transmission, 29 susceptible subjects (8 institutionalized children and 21 medical staff) were injected intramuscularly with anti-human HBs immunoglobulin (HB Ig) and subcutaneously with HB vaccine. All cases acquired HBs antibody after injection of HB Ig and seropositivity for HB after the third inoculation of HB vaccine was 78.6%. No new case of HB occurred among the study population throughout the period investigated. This suggested the effectiveness of HB Ig and HB vaccine in the prevention of horizontal nosocomial transmission of HBV.
N-Myristoyl (N-Myr-) glycinal (aminoacetoaldehyde, GO) diethylacetal (A), which is abbreviated as N-Myr-GOA, and other N-Myr-compounds (N-Myr-Gly-GOA, N-Myr-Gly-Gly-GOA, and N-Myr-Gly-Gly-Gly-GOA) were newly synthesized and then employed for NH2-terminal antimyristoylation of structure proteins in the human T-cell leukemia virus (HTLV-I) and the human immunodeficiency virus (HIV). The protein myristoylation of structure proteins p19gag, of HTLV-I, and p17gag, of HIV, was determined separately, using radiolabeled myristic acid, in vitro. The radiolabeled proteins, after immunoprecipitation with an antiserum to adult T-cell leukemia (ATL) or the anti-p17gag monoclonal antibody of HIV, were identified as p19gag of HTLV-I and p17gag of HIV by fluorography after SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The protein myristoylation was resistant to NH2OH-treatment. Of the N-Myr-compounds tested, N-Myr-GOA remarkably prevented the myristoylation of p19gag and p17gag, but N-Myr-Gly-Gly-GOA and N-Myr-Gly-Gly-Gly-GOA did not.
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