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Biomedical subjects

T Shinohara

Publications and source records attributed to T Shinohara.

At least 253 records · Page 14Linked to original sources
PubMed1990

Analysis of the human, bovine and rat 33-kDa proteins and cDNA in retina and pineal gland.

A monoclonal antibody (mAb) was produced against a bovine retinal 33-kDa protein. Several clones of 33-kDa protein were isolated from each library of cDNA from human, bovine and rat retinas and rat pineal gland by mAb screening and by hybridization with cDNA probes. Each of the four cDNA sequences was determined and amino acid (aa) sequences were deduced from the nucleotide sequences. The latter were nearly identical in rat retina and rat pineal gland (99.6%) and were similar in human, bovine and rat retina (more than 87%). Each of these cDNAs had one long ORF and encoded 245 or 246 aa. The deduced aa sequences in rat retina and rat pineal gland were virtually identical and the sequences in human, bovine and rat retina were highly homologous (more than 88%). The predicted Mr for each of these proteins was 28,246 in the human, 28,176 in bovine, 28,143 in rat retina, and 28,129 in rat pineal gland. Each of the sequences has a putative site for phosphorylation by A kinase; we have confirmed that the putative site is Ser73. These results show that the 33-kDa proteins in the retina and pineal gland have the same sequences and the same phosphorylation site and suggest that the functional role of this protein is the same in the retina and pineal gland.

Amino Acid Sequence↗
PubMed1990

Molecular mimicry between a uveitopathogenic site of S-antigen and viral peptides. Induction of experimental autoimmune uveitis in Lewis rats.

S-Antigen (S-Ag) is a well characterized 45,000 m.w. photoreceptor cell protein. When injected into susceptible animal species, including primates, it induces an experimental autoimmune uveitis, a predominantly T cell-mediated autoimmune disease of the retina and uveal tract of the eye, and of the pineal gland. In this study we found an amino acid sequence homology between a uveitopathogenic site of S-Ag, several viral proteins and one additional nonviral protein. An experimental autoimmune uveitis and pinealitis was induced in Lewis rats with these different synthetic peptides, corresponding to the amino sequence of hepatitis B virus DNA polymerase, gag-pol polyprotein of Baboon endogenous virus and gag-pol polyprotein of AKV murine leukemia virus and potato proteinase inhibitor IIa, which contain three or more consecutive amino acids identical to peptide M in S-Ag. Lymph node cells from rats immunized with either peptide M or the different synthetic peptides showed a significant degree of cross-reaction. Mononuclear cells from monkeys (Macaca fascicularis) immunized with peptide M also showed significant proliferation when incubated with either peptide M or synthetic peptides as measured by in vitro lymphocyte mitogenesis assay using [3H]TdR. Based on our findings we conclude that a viral infection may sensitize the mononuclear cells that can cross-react with self proteins by a mechanism termed molecular mimicry. Tissue injury from the resultant autoantigenic event can take place in the absence of the infectious virus that initiated the immune response.

Amino Acid Sequence↗
PubMed1990

The mechanical filtration coefficient (Lp) of the cell membrane of cultured glioma cells (C6).

The mechanical filtration coefficient (Lp) of the membrane of cultured glioma cells was determined from the rate of swelling of the cells. The swelling was induced by exposing the cells to distilled water. Assuming that cells swell in a symmetrical manner, Lp was 2.2 x 10(-8) cm/s.mmHg, or 1.7 x 10(-4) microns/s.cmH2O when calculated from changes of the cell diameter.

Cell Membrane↗
PubMed1990

S-antigen: from gene to autoimmune uveitis.

Retinal S-antigen (S-Ag) is capable of inducing experimental autoimmune uveitis (EAU) in laboratory animals. EAU may serve as an animal model for studying human uveitis. As a first step we have determined the nucleotide sequence of an S-Ag gene and its cDNAs. The amino acid sequences were deduced from the cDNAs of various animals and human. Four uveitopathogenic sites in bovine S-Ag were characterized. One of the sites (peptide M) has sequence homology with non-self proteins from baker's yeast, potato, E. coli, hepatitis B virus, moloney murine leukemia virus, Moloney murine sarcoma virus, AKR murine leukemia virus and baboon endogenous virus. Mononuclear cells from animals immunized with peptide M showed significant proliferation when incubated with synthetic peptides corresponding to the amino acid sequences of the above-mentioned foreign proteins. In addition, all the peptides induced EAU in Lewis rats with a dose of 10-2000 micrograms. Moreover, native histone H3 from baker's yeast histone H3 induced EAU in Lewis rats. Thus, we found several examples of antigenic mimicry between self and non-self proteins. These findings establish a base to study further the mechanism of autoimmune inflammation.

Amino Acid Sequence↗
PubMed1990

Problems of mass screening for neuroblastoma: analysis of false-negative cases.

The Japanese mass screening (MS) system for neuroblastoma at 6 months of age has resulted in the earlier diagnosis of the tumor with excellent therapeutic results. However, some problems are involved in the present MS system. We present six false-negative cases, ages ranging from 1 year 11 months to 3 years 11 months. Neuroblastoma cell taken from four of these patients were studied biologically. These patients had advanced disease (one was stage III; five were stage IV). Three of the patients have died and one is terminally ill despite undergoing surgery combined with intensive chemotherapy. Cytogenetic analysis performed in three cases showed that all the cases had diploid chromosome mode associated with 1P-, double minutes (DMs), or marker chromosomes. N-myc oncogene analysis, performed in four cases, showed amplification in two; one patient had diploid chromosomes, but the other was not examined cytogenetically. These findings were strikingly different biologically from those of cases found by MS. The majority of neuroblastomas detected by MS were found to be triploid tumors without N-myc amplification. These findings suggest that the main reason for the false-negative results in the patients we examined is that they were tumor-free or the tumors were so small in size that they were unable to produce urinary vanillylmandelic acid and or homovanillic acid levels high enough to be detected at the time of MS. Therefore, we conclude that MS at 6 months of age is too early to detect neuroblastoma with a diploid chromosome mode and/or amplified N-myc oncogene. We propose that MS at the age of 1 year 6 months would be more effective to pick up these cases, because treatment strategies depend on the different biological characteristics of tumor cells.

Adrenal Gland Neoplasms↗
PubMed1990

In situ hybridisation with digoxigenin-labelled DNA probes for detection of viral genomes.

The applicability of a recently developed non-radioactive DNA labelling and detection method, which uses the digoxigenin (DIG) enzyme linked immunosorbent assay (ELISA) system, for the detection of viral infections in pathology specimens by in situ hybridisation, was examined. Its efficacy was compared with that of biotin and radioisotope labelling methods. Three cases of progressive multifocal leucoencephalopathy, two of verruca vulgaris, and seven cases of laryngeal papilloma were studied. The sensitivity of the DIG labelled probe was almost the same as that of a 35S-labelled probe in the dot-blot hybridisation test. Using in situ hybridisation with 35S-labelled and DIG labelled probes, the levels of the hybridised signals detected were similar. The biotin labelled probe was less sensitive, particularly in the cases of laryngeal papilloma. The DIG labelling and detection method was highly sensitive and applicable to the detection of viral infection by ISH, and is preferable to a radiolabelled probe, especially when in situ hybridisation is done in the pathology laboratory.

Biotin↗
PubMed1990

Lymphocyte responses to peptide M and to retinal S-antigen in uveitis patients.

A synthetic amino acid, peptide M18 (18 amino acids in length which correspond to the amino acid positions 303-322 of bovine S-antigen: DTNLASSTIIKEGIDKTV), is capable of inducing experimental autoimmune uveitis in monkeys and Hartley guinea pigs as well as Lewis rats. Recently, the amino acid sequence of human S-antigen corresponding to peptide M was found to be virtually identical to that of bovine S-antigen. To investigate the role of the epitope corresponding to peptide M in human uveitis, 21 patients with uveitis were tested for proliferation of peripheral mononuclear cells against peptide M18 and bovine S-antigen. Six of the 21 patients responded to S-antigen and 4 of these 6 patients responded to peptide M18. These findings show that peptide M18 is immunogenic in man and provide additional support to the hypothesis that the amino acid sequence which corresponds to peptide M might be involved in uveitic conditions in man.

Adolescent↗
PubMed1990

Analysis of genes coding for S-antigen, interstitial retinol binding protein, and the alpha-subunit of cone transducin in patients with retinitis pigmentosa.

We screened 526 unrelated patients with autosomal dominant, autosomal recessive, or simplex retinitis pigmentosa for evidence of mutations of the genes encoding S-antigen (S-Ag), interstitial retinol binding protein (IRBP), and the alpha-subunit of cone-specific transducin. Restriction fragment length polymorphisms (RFLPs) were identified at each of these loci. Within each set of patients with a particular genetic type of retinitis pigmentosa, RFLP alleles at each of these loci showed no departure from Hardy-Weinberg equilibrium. No gene deletions or rearrangements could be detected in any patient. Furthermore, in each of six pedigrees (one autosomal dominant, one autosomal recessive, three Usher's syndrome type I, and one Laurence-Moon-Bardet-Biedl syndrome) there was no co-segregation of the disease with alleles determined by RFLPs at the locus for S-antigen. At the IRBP locus, lack of co-segregation was seen in one autosomal dominant, two autosomal recessive, and three Usher's syndrome type I pedigrees. Finally, one pedigree with autosomal recessive retinitis pigmentosa showed no co-segregation of the disease with alleles at the locus for the alpha-subunit of the cone-specific transducin. These data support the idea that the genes coding for S-Ag, IRBP, and the alpha-subunit of the cone-specific transducin do not play an etiologic role in the families with retinitis pigmentosa so far studied.

Alleles↗
PubMed1990

[Chromosome abnormalities in myelodysplastic syndrome].

We performed chromosomal analysis in 18 patients with myelodysplastic syndrome (MDS). According to the French-American-British (FAB) cooperative study group and Research Group of Japanese Ministry of Welfare Classification, our cases with MDS were classified into four subtypes as follows; refractory anemia [RA], 6 cases; refractory anemia with excess of blasts [RAEB], 4; chronic myelomonocytic leukemia [CMML], 3; refractory anemia with excess of blasts in transformation [RAEB-T], 4; and refractory cytopenia [RC], 1. Thirteen patients (72%) had chromosomal abnormalities and frequently observed chromosomal abnormalities were trisomy 8, -7/7q-, 20q-, trisomy 1q and 5q-. The mean survival were as follows; RA: 22.5 months, RAEB: 13.2 months, CMML: 15 months, RAEB-T: 5.5 months. Progression to overt leukemia occurred in 5 patients (27.7%): 1 of four patients with RAEB, 1 of three patients with CMML and 3 of four patients with RAEB-T. In conclusion, chromosomal abnormalities were most frequently observed in the patient with RAEB-T who had shortest survival time among the patients with MDS. On the other hand, chromosomal abnormalities were less frequently observed in the patients with RA and they showed relatively better prognosis than the other types of MDS.

Adult↗
PubMed1990

[Alzheimer's neurofibrillary tangles in a 52-year-old patient with severe brain damage].

A woman, who had been developmentally delayed since her birth, further deteriorated after she got an episode of high fever of unknown origin at 2 years of age. At the age of 52 years, she died of liver cancer after a long-standing HB virus carrier state. Neuropathological examination revealed brain atrophy, narrowed white matter, myelin pallor, fibrillary gliosis and status marmoratus of the thalamus. These findings suggested the primary cause of the brain pathology in this case to be a developmental destructive process which should have taken place in the early stage of brain development. In addition, neurofibrillary tangles (NFT) were noticed in the hippocampus, locus ceruleus and nucleus basalis of Meynert, but no senile plaques were found anywhere. These NFT changes seemed to be closely resembling to those of the Fukuyama type congenital muscular dystrophy. But the reason why NFT occur in this case is still obscure and probably different from that in the Down syndrome or in physiological senility.

Brain↗
PubMed1990

An arginine carboxypeptidase generated during coagulation is diminished or absent in patients with rheumatoid arthritis.

A novel arginine carboxypeptidase that is generated during blood coagulation is diminished in sera obtained from patients with rheumatoid arthritis. The enzyme, which is unrelated to carboxypeptidase N, is more effective than lysine in removing terminal arginine from small synthetic substrates and may function in vivo in the removal of terminal arginine from inflammatory peptides such as C3a and C5a. Either diminished levels of this enzyme or an inability to generate it may be an important consideration in the mechanisms involved in the local inflammation that is observed in patients with rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1990

Effect of glycerol on the hemodynamics of acutely induced ischemic area in the cerebral cortex of cats.

The effect of glycerol on the hemodynamics of ischemic areas of the brain was examined. Employing a photoelectric apparatus, the CBV (vol%), mean transit time of blood(s), and CBF (ml/100 g/min) in the cortex of the left ectosylvian gyrus were determined in 16 anesthetized cats before, at 1 hr, and at 2 hr after left MCA occlusion. In 10 cats, 10% glycerol in 5% fructose saline was intravenously administered at a speed of 5 ml/kg/hr at 1 hr after MCA occlusion. The other animals served as the control. In the group given glycerol, the relation between the values of CBF at 1 hr after MCA occlusion (X) and those at 2 hr after MCA occlusion (Y) was curvilinear and could be expressed by the regression curve, Y = 0.04X2 - 0.26X + 7.68 (R2 = 0.86). In the control group without glycerol, however, a linear relation expressed by the equation, Y = 0.76X + 5.96 (R2 = 0.94), was obtained. Comparison between the two relations indicated that glycerol improved the hemodynamics in the mild ischemic area with a relatively higher CBF. Severely ischemic areas showed no improvement.

Animals↗
PubMed1990

[A clinical study of death in profound mental retardation with motor disturbance].

Among 848 cases of profound mental retardation with motor disturbance admitted to Metropolitan Medical Center of Severely Handicapped in the last 20 years, 98 died. The 94 cases whose cause of death was determined were clinically investigated. There was no difference in sex, and 72% of the patients died before the age of 15 years. Half of the patients died of pneumonia; sudden death occurred in 9, and ileus in 8. These three were thought to be the most important and characteristic causes of death in severely handicapped patients. In recent years, deaths due to pneumonia have decreased and those due to ileus have disappeared, but deaths due to malignant neoplasm have begun to be recognized. There were also some deaths from intracranial hemorrhage in young children, and some deaths from tracheal bleeding in those who had tracheal tubes. These two were also important causes of death in the patients. Sudden death had certain characteristics: most cases were adolescent or young patients with mixed quadriplegia who were sensitive to environmental changes and often showed marked hypertonia by athetosis, and in addition, all of their acute changes occurred between 5 and 8 a.m. or between 6 and 9 p.m.

Adolescent↗
PubMed1989

Rat pineal S-antigen: sequence analysis reveals presence of alpha-transducin homologous sequence.

S-antigen (S-Ag) is a soluble, highly antigenic protein, the administration of which induces autoimmune uveitis. This protein is found in the retina and pineal. Retinal S-Ag from three species has been sequenced. In this study rat pineal S-Ag was sequenced. Clones were isolated from a rat pineal lambda gt11 cDNA library by probing with a 300 bp fragment of mouse retinal S-Ag cDNA containing the 5'-coding region. The largest clone isolated (RPS-118; 1364 bp) contained the entire coding sequence. Comparison of the rat pineal and mouse retinal S-Ag nucleotide sequences indicated a high homology (95%). The deduced amino acid sequence was found to contain 403 residues (congruent to 44 992 Da). Comparison of the rat pineal and mouse retinal S-Ag amino acid sequences also revealed high homology (97%). The similarity of both the nucleotide and amino acid sequences of rat pineal and mouse retinal S-Ag indicates that expression of the S-Ag gene in both tissues is similar. Further analysis of the rat pineal S-Ag sequence indicated that it contained essentially the same major uveitopathogenic region of S-Ag present in bovine retina; minor uveitopathogenic sites were somewhat different. As is true of retinal S-Ag, rat pineal S-Ag contains the same consensus phosphoryl-binding site present in many GTP/GDP-binding proteins and a homologous sequence found in the C-terminus of alpha-transducin. These sequences may play a role in the action of pineal S-Ag in transmembrane signal transduction.

Amino Acid Sequence↗