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Biomedical subjects

T Isobe

Publications and source records attributed to T Isobe.

At least 199 records · Page 11Linked to original sources
PubMed1988

S-100 beta positive T cell leukemia.

We reported a peculiar case with T cell leukemia. The patient was a 34-year-old woman showing extensive splenomegaly and marked leukemic cell proliferation and running a rapid fatal clinical course. The leukemic cells were morphologically ordinary lymphocytes showing suppressor/cytotoxic(s/c) T cell phenotypes and containing S-100b protein. Southern blot analysis revealed rearrangement of the beta chain genes of the T cell receptor (TcR) of the leukemic cells. Because these phenotypic and morphologic features were identical with those of S-100 beta+T lymphocytes (S-100 beta +TL) in normal human peripheral blood, we regarded this case as S-100 beta +T cell leukemia. We discussed clinicopathological features of S-100 beta +T cell leukemia/lymphoma by assessing similar cases reported so far. S-100 beta +T cell leukemia/lymphoma is a new type of s/c T lymphocytic leukemia/lymphoma with aggressive features.

Adult↗
PubMed1988

Difference between amino acid residues in the metal-ligand environments of iron- and manganese-superoxide dismutases.

Alignment of the amino acid sequences of the Pseudomonas ovalis and Photobacterium leiognathi iron-superoxide dismutases (Fe-SODs) with the known sequences of the manganese-superoxide dismutases (Mn-SODs) shows that both types of SOD are highly homologous (33-53% identity) and share residues for the metal coordination. The amino acid residues that form the environment of the metal ions appear to be also conserved between the Fe- and Mn-SODs, except that the Phe-84 and Gln-154 in the Mn-SODs are replaced by Tyr and Ala, respectively, in the Fe-enzymes. Since this latter residue contributes to formation of the hydrophobic metal-ligand environment through hydrogen bonding with Trp-133 and Tyr-34 in the Mn-SODs, its substitution by Ala should cause different micro environments between the metal centers of the Fe- and Mn-SODs. This difference may account for the metal specificity of both types of SODs demonstrated by previous reconstitution experiments.

Amino Acid Sequence↗
PubMed1987

Amino acid sequence of iron-superoxide dismutase from Pseudomonas ovalis.

The amino acid sequence of iron-superoxide dismutase from Pseudomonas ovalis was deduced by the analyses of peptides derived from limited hydrolysis of the aminoethylated or pyridylethylated apoprotein with trypsin, Staphylococcus aureus V8 protease, and dilute acid hydrolysis. The polypeptide chain contains 195 amino acid residues and has a calculated Mr of 21,421. The sequence is highly homologous (65% identity) to the recently published sequence of the iron-superoxide dismutase from Photobacterium leiognathi. It is also homologous to the known sequences of the manganese-superoxide dismutase by sharing 33-53% identical residues. Alignment of the superoxide dismutase sequences and the available structural information from X-ray crystallography suggest that the ligands to the iron in the P. ovalis superoxide dismutase are His-26, His-74, Asp-156 and His-160, which align with the ligands to the manganese in the Thermus thermophilus manganese-superoxide dismutase. The sequence information of the P. ovalis dismutase will facilitate refinement of the X-ray crystallographic data that are now available at 2.9 A resolution.

Amino Acid Sequence↗
PubMed1987

Brain 14-3-3 protein is an activator protein that activates tryptophan 5-monooxygenase and tyrosine 3-monooxygenase in the presence of Ca2+,calmodulin-dependent protein kinase II.

We have found that the 14-3-3 protein, an acidic neuronal protein, is substantially identical to the 'activator' protein [(1981) J. Biol. Chem. 256, 5404-5409] that activates tryptophan 5-monooxygenase and tyrosine 3-monooxygenase in the presence of Ca2+, calmodulin dependent protein kinase II. This finding is based on the remarkable similarity of both these proteins in physicochemical, biochemical and immunochemical properties, as well as on detection for the 14-3-3 protein of an activator activity towards tryptophan 5-monooxygenase. The result suggests that the 14-3-3 protein plays a role in the regulation of serotonin and noradrenaline biosynthesis in brain.

14-3-3 Proteins↗
PubMed1987

Purification of S-100a0 protein from rat kidney.

In order to corroborate our previous finding that kidney may contain a considerable amount of S-100-like antigen, concentrations of S-100a0, S-100a and S-100b antigens in rat kidney were determined by an enzyme immunoassay system, which can quantify these 3 forms of S-100 protein separately. It was revealed that rat kidney was rich in S-100a0 antigen, while it was the least occurring form in brain. To confirm the above results, S-100-like antigen in rat kidney was purified, and its physicochemical properties were compared with those of S-100 proteins of bovine brain. Electrophoretic mobility, calcium binding ability, apparent molecular weight, amino acid composition as well as elution profiles from butyl-Sepharose and anion exchange columns were similar to those of S-100a0 protein of bovine brain. These results indicate that S-100a0 protein is not a protein unique to brain, as had long been believed.

Amino Acids↗
PubMed1987

Interaction of polymorphonuclear leukocytes with calcium pyrophosphate dihydrate crystals deposited in chondrocalcinosis cartilage.

Electron microscopy was used to investigate the characteristics of calcium pyrophosphate dihydrate (CPPD) crystals in chondrocalcinosis (pseudogout syndrome). Crystals in midzone cartilage were frequently seen adjacent to chondrocytes. Great variation in crystal size and shape was observed. Most of the pyrophosphate crystals that had been phagocytosed by polymorphonuclear leukocytes of synovial fluid from patients with acute pseudogout were small (less than or equal to 1 micron), indicating that small crystals can cause intense inflammation. Large numbers of polymorphonuclear leukocytes became attached to the eroded articular surface and phagocytosed microcrystals. Interaction of polymorphonuclear leukocytes with CPPD crystals in the superficial region of articular cartilage may stimulate the release of inflammatory mediators.

Aged↗
PubMed1987

Amino acid substitutions in inherited albumin variants from Amerindian and Japanese populations.

We report an effort to determine the basis for the altered migration of seven inherited albumin variants detected by one-dimensional electrophoresis in population surveys involving tribal Amerindians and Japanese children. An amino acid substitution has thus far been determined for four of the variants. The randomness in the albumin polypeptide of these and the other sixteen independently ascertained amino acid substitutions of albumin and proalbumin thus far established was analyzed; the clustering of eight of these at two positions in the six-amino acid propeptide sequence seems noteworthy. By comparison with other proteins studied by electrophoresis, albumin exhibits "average" variability. It is a paradox that individuals who, for genetic reasons, lack albumin exhibit no obvious ill effects; yet, electrophoretic variants of albumin are no more numerous than are variants of proteins, the absence of which results in severe disease.

Albumins↗
PubMed1987

Clinical studies of renal disease in Sjögren's syndrome.

When 17 patients with Sjögren's syndrome, without apparent clinical manifestations of renal disease, were examined renal function studies frequently indicated abnormalities in their renal phosphate handling. The percentage tubular reabsorption of phosphate (%TRP) was decreased in six (35.3%), and maximal tubular reabsorption rate for phosphate (TmPO4/GFR) was low in eight (47.1%). In contrast, indices of renal calcium handling and serum parathyroid hormone levels were normal, suggesting that the abnormalities of phosphate metabolism were due not to extrinsic, but rather to intrinsic disease processes occurring in the kidney in Sjögren's syndrome. When the patients were divided into two groups according to the presence or absence of a renal tubular acidification defect (RTAD), patients with RTAD were younger (p less than 0.005), had longer disease duration (p less than 0.01), lower creatinine clearance (p less than 0.05), and higher incidence of low %TRP (p less than 0.05). Thus the patients with lower creatinine clearance generally had disease of longer duration at diagnosis and tended also to have defects in concentrating and acidifying the urine.

Adult↗
PubMed1987

Cases with familiar amyloid neuropathy starting of the upper limbs and having hepatic disorder.

Here we are reporting two cases consisting of a male patient and his elder sister from Kagashima in Gifu City and both suffering from polyneuropathy of dissociation type and skin amyloidosis. In the former, the presence of amyloid was demonstrated not only in the skin, but also in the stomach, liver and gums. He was also diagnosed suffering from chronic hepatitis of inactive type. He responded to DMSO and Cepharanthin. In the patients, no urinary Bence Jones protein nor blood M component was detected and the amyloid exhibited resistance to potassium permanganate treatment. The neuropathy of the patients were slightly different from that of the Portuguese type which starts on lower extremities as well as those conventionally have been reported in Japan.

Adult↗
PubMed1986

Pure red cell aplasia in association with malignant histiocytosis.

The authors report a case of malignant histiocytosis complicated with pure red cell aplasia. Erythrophagocytic histiocytes were found only rarely and no histiocyte ingested erythroblasts. Neither serum immunoglobulin G nor peripheral blood T-cells have any inhibitory activity to erythroid colony growth from allogeneic bone marrow. Pure red cell aplasia is an unusual complication in malignant histiocytosis.

Anemia, Aplastic↗
PubMed1986

Identification of the C-terminal portion of a protein by comparative peptide mapping.

A method is presented for the simple identification of C-terminal fragment of proteins. The method consists of (i) C-terminal processing of a protein by carboxypeptidase and (ii) comparative peptide mapping of the intact and carboxypeptidase-excised protein after fragmentation by endoproteinase or by chemical cleavage. The peptide mapping was performed by means of high-performance reversed-phase chromatography, where the C-terminal fragment was identified as a peptide peak that was lost or decreased in the carboxypeptidase-excised protein. The C-terminal sequence of the protein could be then determined by sequential Edman degradation of the C-terminal fragment collected from the peptide mapping chromatography. The sensitivity of the method depends solely on the peptide detection and subsequent Edman degradation, currently available techniques of which require a nanomole to subnanomole quantity of protein. The present method can be coupled with conventional carboxypeptidase technology because it utilizes a protein portion remaining after carboxypeptidase digestion while released amino acids are needed in the conventional technique. The method would be particularly valuable in finding a gene probe site for a RNA message coding for the C-terminal portion of a molecule.

14-3-3 Proteins↗
PubMed1986

The complete amino acid sequence of vitelline coat lysin.

The vitelline coat lysin of a top shell, Tegula pfeifferi, is a single polypeptide consisting of 118 amino acid residues and having a relative molecular mass of 13800. The complete amino acid sequence of the vitelline coat lysin was determined by the analyses of five peptides obtained by cyanogen bromide degradation and three fragments obtained by Staphylococcus aureus protease digestion of the protein. The sequence showed the presence of microheterogeneities in the vicinity of the C-terminal half of the molecule and the existence of two homologous domain structures.

Amino Acid Sequence↗