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Biomedical subjects

Y Itoh

Publications and source records attributed to Y Itoh.

At least 19 recordsLinked to original sources
PubMed1992

The alpha 3 beta 3 and alpha 1 beta 1 complexes of ATP synthase.

Two catalytic structures of H(+)-motive ATP synthase (Fig. 1), the alpha 3 beta 3 oligomer (M(r) = 319,581) and alpha 1 beta 1 promoter (M(r) = 106,527) (Fig. 2), were isolated using high pressure liquid chromatography (Fig. 3) and polyacrylamide gel electrophoresis (Figs. 4 and 5). These were reconstituted from the alpha and beta subunits of thermophilic F1 (TF1), and the alpha 3 beta 3 oligomer was also crystallized. Common to both F1 and the alpha 3 beta 3 oligomer were the nucleotide specificity, the two Km values, the presence of protomer-oligomer activities, and the one-hit--one-kill phenomenon. A synchrotron experiment on the ATP hydrolysis cycle revealed the dynamic shrinkage and expansion of F1(44) that correspond, respectively, to the ATP-induced association and ADP-induced dissociation of the alpha 3 beta 3 oligomer. The oligomer, like mitochondrial F1 and TF1, exhibited two kinds of ATPase activity: one was cooperative and was inhibited by only one inhibitor per hexamer, and the other was inhibited by three inhibitors per hexamer.

Adenosine Triphosphate↗
PubMed1992

Pancreatic islet abnormalities in sudden infant death syndrome. Qualitative and quantitative analyses of 15 cases.

The pancreata of 15 autopsy cases of sudden infant death syndrome (SIDS) and those of 14 age-matched controls were examined qualitatively and quantitatively to re-evaluate the relationship between pancreatic islet abnormalities and sudden death in infancy. Histopathologically, a diffuse or focal form of nesidioblastosis and septal islets were frequently observed in the pancreata of both groups. Endocrine cell dysplasia was found only in 2 infants who had died of SIDS. Quantitatively, there was little difference of islet cell composition between the SIDS cases and the controls. A relatively high proportion of islet cell area to total pancreatic tissue area was demonstrated in the SIDS group (8.46 +/- 4.90% in the pancreatic head; 8.66 +/- 4.23% in the pancreatic body to tail) in comparison with the controls (5.32 +/- 1.77%; 5.63 +/- 1.60%). Although nesidioblastosis and septal islets were considered to be within the limits of normal variation during pancreatic development, endocrine cell dysplasia and quantitatively unusual proliferation of the pancreatic endocrine tissue suggest the possibility that abnormalities in the endocrine pancreas may be causally related to sudden death in infancy.

Humans↗
PubMed1992

Two sisters producing anti-U1RNP exhibit serological concordance and clinical discordance.

Two sisters had autoimmune responses to the U1RNP particle that were quantitatively similar and/or identical in molecular characteristics. No other autoantibodies were demonstrable. Both sisters immunoprecipitated only U1RNA, had a reaction of identity in gel diffusion, bound the 68-kDa band in HeLa cell extract in Western blot, and reacted almost equally to a rabbit anti-idiotypic reagent made against either sister's isolated anti-U1RNP Fab fragments. They both carried a DR4 allele, which has been associated with anti-U1RNP production in several studies. While the sisters both had Raynaud's phenomenon, their clinical pictures were otherwise dissimilar. One had a seizure disorder (Ju); the other had polymyositis and features of scleroderma (Je). In sister Ju, Raynaud's phenomenon was manifest for the first time in association with the appearance of precipitating anti-U1RNP.

Adult↗
PubMed1992

Autoantibodies to the Ro/SSA autoantigen are conformation dependent. II: Antibodies to the denatured form of 52 kD Ro/SSA are a cross reacting subset of antibodies to the native 60 kD Ro/SSA molecule.

The immune response to the Ro/SSA particles is conformation dependent. In sera with only anti-Ro/SSA precipitins, the autoantibodies to the 60 kD Ro/SSA are largely to the native 60 kD Ro/SSA while autoantibodies to the 52 kD Ro/SSA particle when present are exclusively to the denatured 52 kD Ro/SSA particle. Antibodies eluted from a recombinant 52 kD Ro/SSA fusion protein reacted in a sandwich ELISA which only measures antibody to native 60 kD Ro/SSA antigens and this reaction is largely inhibited by native homogeneous 60 kD Ro/SSA. In addition, antibody binding to the 52 kD Ro/SSA antigen in Western blot is also strongly inhibited by native 60 kD Ro/SSA. These experiment strongly suggest that reactivity of denatured 52 kD Ro/SSA antigen represents a cross reaction with autoantibodies directed to the native 60 kD Ro/SSA antigen. As a corollary of these experiments, data are presented that suggest the hY-RNAs are not associated with the 52 kD Ro/SSA protein but only with the 60 kD Ro/SSA protein. These data are consistent with the hypothesis that the autoanti-Ro/SSA response is driven by native 60 kD Ro/SSA and the immune response to denatured 52 kD Ro/SSA is largely a cross-reactive subset of the immune response to native 60 kD Ro/SSA.

Antibody Specificity↗
PubMed1992

Autoantibodies to the Ro/SSA antigen are conformation dependent. I: Anti-60 kD antibodies are mainly directed to the native protein; anti-52 kD antibodies are mainly directed to the denatured protein.

Recent studies have shown that Ro/SSA autoantigen is heterogeneous and the autoanti-Ro/SSA response is correspondingly heterogeneous. There are two isoform families; the 60 kD forms and the 52 kD forms. We studied the antigenic difference between the native and denatured Ro/SSA isoforms and found that the autoanti-Ro/SSA response to the native 60 kD antigen is quite homogeneous. All anti-Ro/SSA sera recognize the native kD antigen regardless of the reactivities to the 60 kD band on the Western blot. Surprisingly, no anti-Ro/SSA sera without anti-La/SSB reacts with the native 52 kD Ro/SSA, although sera with both precipitating anti-Ro/SSA and anti-La/SSB can immunoprecipitate the native 52 kD antigen. Anti-Ro/SSA sera exist which react exclusively with the native 60 kD Ro/SSA protein (10/43, 23%) while no anti-Ro/SSA sera have been found which react exclusively with the denatured 52 kD Ro/SSA antigen. In sera with anti-Ro/SSA precipitins alone, only antibody to the denatured 52 kD Ro/SSA molecule is found! In sera with anti-Ro/SSA and anti-U1 RNP precipitins, no antibody to either native or denatured 52 kD Ro/SSA is found, while in sera with both anti-Ro/SSA and anti-La/SSB precipitins, antibodies to both the native and denatured forms of 52 kD Ro/SSA are present. These data suggest that the anti-Ro/SSA response to the 60 kD molecule is driven by the native 60 kD Ro/SSA molecule while the molecular identification of the antigen drive in the anti-52 kD Ro/SSA response is unknown.

Antibodies, Antinuclear↗
PubMed1979

Primary rhabdomyosarcoma of the cerebrum. An ultrastructural study.

A case of primary cerebral rhabdomyosarcoma in a 51-year-old female is reported. The histogenesis of this tumor is discussed. The clinicopathological features of 10 previously reported similar tumors of the CNS are briefly reviewed. Histologically the tumor was polymorphic, but composed of poorly differentiated cells interpreted as rhabdomyoblasts without definite cross-striation. Electron microscopy established that the poorly differentiated cells were of rhabdomyosarcomatous nature, compatible with presumptive myoblasts and analogous to developing fetal muscle.

Brain Neoplasms↗
PubMed1979

Crystalloid inclusions reminiscent of Hirano bodies in autolyzed peripheral nerve of normal wistar rats.

In a study of experimental autolysis of peripheral nerves of normal Wistar rats, crystalloid inclusions similar to Hirano bodies were observed. They occurred in the nuclei and cytoplasms of Schwann cells and in myelinated axons. They first developed after a 12-h autolysis and increased in number and size with time. Their fine structure, localization, and morphogenesis are discussed in relation to the autolysis of the cellular organelles.

Animals↗
PubMed1979

Ultrastructure of neurofibrillary tangles in progressive supranuclear palsy.

The fine structure of neurofibrillary tangles in the hippocampal gyrus, substantia nigra, pontine nuclei and locus coeruleus of the brain was postmortem studied in a case of progressive supranuclear palsy. Straight tubules and twisted tubules were observed in both the cortical and subcortical neurofibrillary tangles. Most tubules appeared separately in each neuron but a few straight tubules were mixed with the twisted tubules in the cortical tangles. The implication and possible significance of this findings are discussed.

Aged↗
PubMed1979

The fine structure of blood cells in ceroid-lipofuscinosis (Spielmeyer-Vogt's disease).

Peripheral blood and bone marrow in a case of juvenile type of Spielmeyer-Vogt's disease were examined with the light and electron microscope for the occurrence of curvilinear profile (CLP), rectilinear profile (RLP), finger-print profile (FPP) and other inclusions. A large quantity of parallel tubular arrays (PTAs) and a few CLPs, RLPs and FPPs were present in the cytoplasm of the lymphocytes. In addition, many plasma cells in the bone marrow contained FPPs, RLPs and CLPs in the vacuoles of their cytoplasm. The other relevant inclusions were observed in the cytoplasm of the bone marrow cells. Moreover, amorphous or membranous inclusions with rectilinear or curvilinear profiles were seen in some vacuoles in the cytoplasm of many erythrocytes. The incidence of these characteristic inclusions in the plasma cells or the erythrocytes were not described nor the present. The correlation and the diagnostic significance of these characteristic inclusions were discussed.

Adolescent↗
PubMed1979

Demonstration of hepatitis B e antigen in hepatitis B core particles obtained from the nucleus of hepatocytes infected with hepatitis B virus.

Liver tissue infected with hepatitis B virus was homogenized and nuclei were separated by centrifugation. Hepatitis B core particles were obtained from the nucleus by the digestion with pronase followed by ultracentrifugation in a sucrose density gradient. Hepatitis B core particles were then treated with sodium dodecyl sulphate and 2 mercaptoethanol and tested for hepatitis B e antigen (HBeAg) by the haemagglutination method. The antigenicity of HBeAg was clearly demonstrated in hepatitis B core particles so treated, although untreated core particles did not reveal any detectable HBeAg activity. The localization of HBeAg in hepatitis B core particles was further supported by the results of a fluorescent antibody technique. When a frozen section of the liver infected with hepatitis B virus was stained with the specific rabbit antibody against HBeAg labelled with fluorescent isothiocyanate, only nuclei of hepatocytes were stained, in a similar distribution to hepatitis B core antigen visualized by fluorescent antibody against hepatitis B core antigen in a nearby section.

Cell Nucleus↗
PubMed1979

Tissue distribution of human alpha1-microglobulin.

Human alpha(1)-microglobulin was isolated from the urine of patients with tubular proteinuria, and its molecular weight was established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis at 33,000 daltons. The carbohydrate content was 21.7%. Anti-alpha(1)-microglobulin serum was prepared and observed to react monospecifically in gel diffusion to purified alpha(1)-microglobulin, as well as to normal human serum and urine. Sera from the domestic chicken, mouse, rat, rabbit, dog, calf, cow, goat, sheep, and horse, however, did not react to anti-alpha(1)-microglobulin serum in immunodiffusion. The lymphocyte culture supernate was found to contain alpha(1)-microglobulin. Both thymus-derived(T)- and bone marrow-derived(B)-lymphocyte culture media clearly displayed a specific precipitin line against anti-alpha(1)-microglobulin serum when tested with the Ouchterlony immunodiffusion method. The tissue distribution of alpha(1)-microglobulin was studied under immunofluorescence, and a positive staining was recognized on the lymphocyte surface. Identical staining patterns were noted on both T and B lymphocytes, though B lymphocytes took a more intense stain. It would thus seem quite possible that lymphocytes are the primary source of alpha(1)-microglobulin and that this is filtered through the glomerular basement membrane and partly reabsorbed by the renal tubules. This, then, would suggest the possibility that alpha(1)-microglobulin shares some immunological role in vivo with lymphocytes and(or) is one of the membrane proteins of lymphocytes.

Alpha-Globulins↗