Biomedical subjects
Publications and source records attributed to T Isobe.
Internal herniation through the broad ligament is extremely rare. We report a case in which radiologic examinations including computed tomography (CT) were performed. A strangulated loop in the Douglas fossa was well-demonstrated by CT. CT can provide some clues to the diagnosis of this condition.
A calmodulin-dependent protein kinase from canine myocardial cytosol was purified 1150-fold to apparent homogeneity with a 1.5% yield. The purified enzyme had a Mr of 550,000 with a sedimentation coefficient of 16.6 S, and showed a single protein band with a Mr of 55,000 (55K protein), determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme had a specific activity of 1.6 mumol/mg protein/min, and Ka values of 67 nM and 1.1 microM for calmodulin and Ca2+, respectively, using chicken gizzard myosin light chain as substrate. Calmodulin bound to the 55K protein. The purified enzyme had a broad substrate specificity. Endogenous proteins including glycogen synthase, phospholamban, and troponin I from the canine heart were phosphorylated by the enzyme. These results suggest that the purified enzyme works as a multifunctional protein kinase in the Ca2+, calmodulin-dependent cellular functions of the canine myocardium, and that the enzyme resembles enzymes detected in the brain, liver, and skeletal muscle.
The limited proteolysis of bovine brain calmodulin with trypsin in the presence or absence of various metal ions was reinvestigated in detail by HPLC. With metal ion-free calmodulin, limited proteolysis occurred at Arg 37 and Arg 106 with a cleavage ratio of 1 to 5, resulting in fragments consisting of residues 1-37, 38-148, 1-106 and 107-148. Fragments 1-37 and 107-148 accumulated under metal ion-free conditions. In the presence of calcium ions, the susceptibility of these sites to trypsin decreased and limited proteolysis occurred at Lys 77 as already reported by other workers. Fragment 78-148 accumulated, whereas fragment 1-77 was unstable under calcium-bound conditions, giving smaller peptides. Upon binding of manganese ions, calmodulin underwent a change of susceptibility to trypsin, resulting in cleavage at Lys 77, as observed for calcium-bound calmodulin. In the presence of zinc or magnesium ions, calmodulin was cleaved at the same sites as metal ion-free calmodulin under conditions where calmodulin would be expected to bind the respective ions.
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Rat brain S-100 (S-100b) and ox brain S-100a0, S-100a and S-100b have been tested for their ability to control the assembly and disassembly of brain microtubule proteins in the presence of either Ca2+ or Zn2+, in vitro. In the presence of Ca2+, single S-100 isoforms have similar, if not identical, effects, i.e. they inhibit assembly and promote disassembly. In the presence of Zn2+ from 0.1 to 1 mM (free concentration), rat S-100 and ox S-100a and S-100b inhibit assembly, while S-100a0 is without effect. These data are briefly discussed in relation to the cellular localization of single S-100 isoforms in the brain.
The complete amino acid sequence of an amyloidogenic Bence Jones protein (NIG-84) from an individual with myeloma-associated systemic amyloidosis has been determined. The protein, with a blocked N-terminus, represents a complete light chain consisting of 217 residues and it has a structural feature characteristic of the V lambda II subgroup. In addition to a two-residue insertion at positions 28 and 29, it has an additional rare insertion of alanine at position 100. NIG-84 is an example of the first complete sequence presented for the amyloidogenic Bence Jones protein of the V lambda II subgroup.
The amino acid sequence of bovine brain micro glutamic acid-rich protein was determined by analysis of tryptic and Trimeresurus flavoviridis protease peptides of the molecule. The protein comprised 82 amino acid residues and has an Mr of 8992. The established sequence was highly homologous (90% identity) to the sequence of C-terminal 82 residues of the neurofilament 68-kDa protein from porcine spinal cord; there are differences of 8 residues which could be species-specific amino acid substitutions. This indicates that the micro glutamic acid-rich protein may arise by a restricted proteolysis of the neurofilament 68-kDa protein, with the break occuring toward the C-terminus.
The complete amino acid sequence of the variable region of a Bence Jones protein NIG-77 from an individual with myeloma-associated systemic amyloidosis has been determined. This protein represents a complete light chain consisting of 216 residues and it has a sequence characteristic of V lambda I subgroup, which is closely homologous to that of another amyloidogenic V lambda I Bence Jones protein NIG-51, differing by 20 of 111 residues (82% homology). In contrast, it differs by 29 residues (74% homology) to that of non-amyloidogenic V lambda I light chain NIG-64. This finding shows that, in accordance with our previous report(1), the V lambda I-related light chains can further be divided into two distinct subsubgroups, V lambda I-1 and V lambda I-2, and the latter property seems to be more prone in association with the amyloid process.
The complete amino acid sequence has been determined of a unique protein from a 55-years-old female with multiple myeloma associated with Fanconi syndrome. It existed in a monomer form with an apparent molecular weight of 10K daltons, and was consisted of 106 amino acid residues. The sequence was characteristic of the V-region of lambda light chains and was highly homologous with that of the first 106 residues of V lambda III subgroup. The presence of an intact light chain as well as a 13K daltons fragment, corresponding to the entire C-region, strongly suggests that the unique component is a catabolic product from the intact light chain rather than an aberrant product of synthesis.
Human Bence Jones proteins of lambda type, Wh and Nei, both of which belong to subgroup II, contain an asparagine-linked sugar chain. Their carbohydrate moieties were liberated as oligosaccharides by hydrazinolysis and labeled by reduction with NaB3H4 after N-acetylation. Structural studies of each oligosaccharide by sequential exoglycosidase digestion in combination with methylation analysis revealed that Wh lambda contains the mono- and disialylated oligosaccharides (Formula: see text). These oligosaccharides are different from the oligosaccharides found in another lambda-type Bence Jones protein, Sm lambda, by Chandrasekaran et al. [Chandrasekaran, E. V., Mendicino, A., Garver, F. A., & Mendicino, J. (1981) J. Biol. Chem. 256, 1549-1555] and Garver et al. [Garver, F. A., Chang, L. S., Kiefer, C. R., Mendicino, J., Chandrasekaran, E. V., Isobe, T., & Osserman, E. F. (1981) Eur. J. Biochem. 115, 643-652].
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We report the successful treatment of gastrointestinal amyloidosis with dimethyl sulfoxide. A 37 year-old man with adult-onset Still's disease suffered from diarrhea. Upper and lower gastrointestinal endoscopy revealed edematous mucosa, white patches, erosions and bleeding and amyloid deposits were demonstrated in biopsy specimens. After a period of 3 months dimethyl sulfoxide and prednisolone therapy, improvement in the endoscopic appearance of the gastrointestinal tract was observed. Amyloid deposits in biopsy specimens were reduced in the stomach and negative in the large intestine.
S-100 protein was detected in a small number of human peripheral T-lymphocytes by a direct immunoperoxidase method with the use of monospecific antibody to S-100 protein. Complemented-mediated lysis using monoclonal antibodies revealed that the S-100+ T-lymphocytes bore OKT3, OKT8, and OKT11 antigens but not OKT4, OKM1, HLA-DR, HNK1 (Leu-7) antigens on their surface. Immunoelectron micrography showed that S-100 T-lymphocytes were small lymphocytes with poorly developed cellular organelles. These findings clearly indicated that S-100+ T-lymphocytes belonged to the OKT8+ T-cell subset, the so-called suppressor/cytotoxic T-cell subset. Although the function of the S-100+ T-lymphocytes is unclear, S-100 protein may be a useful cytoplasmic marker for the subdivision of the heterogeneous OKT8+ lymphocyte population.
A unique amyloid fibril protein (Nis) was extracted from a patient with medullary carcinoma of the thyroid (MCT). This amyloid protein has a molecular weight of approximately 17,000 daltons, and has different amino acid composition from AA, AL or AF type amyloid fibril proteins. Immunochemical analysis using antiserum raised against Nis-DAM and Nis-GAM proteins disclosed that positive reactions were obtained only with degraded amyloids of MCT and with sera from patients with MCT. In contrast, there were negative reactions for other type of amyloid proteins, sera from other type of amyloid, normal sera or urinary proteins. Therefore Nis-amyloid fibril protein has some antigenic determinants characteristic of MCT-related amyloid fibril protein.
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An amino acid substitution of Met for Val at position 30 of plasma prealbumin is known to be closely related to heredo-familial amyloidotic polyneuropathy(FAP). As a first step in development of a direct method for diagnosis of the disease, cDNA for normal human prealbumin was cloned and its nucleotide sequence was determined. Our results showed that the nucleotide substitution responsible for the Val----Met change results in formation of new restriction sites for BalI and NsiI. By Southern blot hybridization analysis, the expected restriction sites were actually detected in the prealbumin locus of patients. Thus, a method was developed for diagnosis of the disease presymptomatically and prenatally.