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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 685 records · Page 38Linked to original sources
PubMed1989

[Magnetic resonance imaging of lumbosacral lipomas in infants].

Magnetic resonance imaging (MRI) was conducted on infants with lumbosacral lipomas. Based on Chapman's classification (1982), these MRIs were classified into three representative types: caudal, dorsal and transitional. As confirmed by intraoperative observations, the relation between the lipomas and the spinal cord was clearly disclosed in the preoperative MRI. However, in the dorsal type, the intraoperative view of the margin between the lipomas and spinal cord was different from the MRI findings. Postoperative MRI disclosed the existence of residual lipomas and the change in the low conus medullaris. Moreover, preoperative and postoperative changes in the hydromyelia could be observed.

Child↗
PubMed1989

[Sacral meningomyelocele in an adult: a case report].

A 59-year-old male had a fluctuating large mass on the sacral region existed after birth. Sagittal MRI (T1-weighted image) disclosed a large fluid space in the mass and also revealed that sacral nerves extended caudally in the cyst. Enlargement of the sac may result in stretching of the spinal cord.

Humans↗
PubMed1989

[Cerebello-pontine angle epidermoid with cerebellar atrophy; report of a case].

The inside of an epidermoid is formed by masses of epithelial debris, desquamative keratin and cells derived from the epithelial capsule which accumulate very slowly within the capsule. As a result, the growth of the tumor is very slow, and the clinical signs are very diverse and bizarre because of the situation and extension of the epidermoids throughout the basal cisterns. A 52-year-old housewife was admitted to our clinic with complaints of dizziness and gait disturbance. The abnormal neurological findings were truncal ataxia, lt-trigeminal disturbance, lt-facial palsy, lt-hearing disturbance, lt-cerebellar signs (dysmetria, dysdiadochokinesia) and nystagmus. CT scan revealed low density area in the prepontine cistern and lt-cerebello-pontine angle, which was not enhanced following intravenous injection of the contrast medium. Metrizamide CT cisternography showed staining of the tumor heterogeneously revealing a honeycomb appearance. MRI showed the tumor clearly as well as the severe atrophy of the lt-cerebellar hemisphere and the pontine basal area. In this case atrophy of the cerebellar hemisphere and pons may have resulted from being compressed by the tumor. Because of this, we think it necessary to stress that early diagnosis and operation of the epidermoid are very important.

Carcinoma, Squamous Cell↗
PubMed1988

Proteasomes (multi-protease complexes) as 20 S ring-shaped particles in a variety of eukaryotic cells.

Latent multicatalytic protease complexes, named proteasomes, were purified to apparent homogeneity from various eukaryotic sources, such as human, rat, and chicken liver, Xenopus laevis ovary, and yeast (Saccharomyces cerevisiae), and their functional and structural properties were compared. They showed latency in breakdown of [methyl-3H]casein, but were greatly activated in various ways, such as by addition of polylysine. They all degraded three types of fluorogenic oligopeptides at the carboxyl side of basic, neutral, and acidic amino acids, and the three cleavage reactions showed different spectra for inhibition, suggesting that they had three distinct active sites. The proteasomes all seemed to be seryl endopeptidases with similar pH optima in the weakly alkaline region. Their physiochemical properties, such as their sedimentation coefficients (19 S to 22 S), diffusion coefficients (2.0-2.6 X 10(-7) cm2 s-1), molecular masses (700-900 kDa), and circular dichroic spectra, were similar. Their amino acid compositions were also very similar. Electron microscopy showed that they had similar well-defined symmetrical morphology, appearing to be ring-shaped particles with a small hole in the center. All the proteasomes seemed to be multisubunit complexes consisting of 15-20 polypeptides with molecular masses of 22-33 kDa and isoelectric points of pH 3-10, but they showed species-specific differences in subunit multiplicity. Moreover, they differed immunologically, as shown by Ouchterlony tests and immunoblotting analyses, although cross-immunoreactivities of some subunits or domains were observed. These results indicate that the sizes and shapes of these proteasomes have been highly conserved during evolution, but that they show species-specific differences in immunoreactivities and subunit structures. Thus proteasomes with similar structure and function seem to be ubiquitously distributed in eukaryotic organisms ranging from man to yeast. This distribution implies the general importance of these proteasomes for proteolysis.

Amino Acids↗
PubMed1988

N-terminal amino acid sequence of the deep-sea tube worm haemoglobin remarkably resembles that of annelid haemoglobin.

The deep-sea giant tube worm Lamellibrachia, belonging to the phylum Vestimentifera, contains two extracellular haemoglobins, an Mr 3,000,000 haemoglobin and an Mr 440,000 haemoglobin. The former has a hexagonal bilayer structure and consists of six polypeptide chains (AI-VI); a study of its haem content shows that not all of the chains contain haem. The Mr 440,000 haemoglobin consists of four haem-containing chains (BI-IV). We isolated most of the chains by reverse-phase chromatography and determined the amino acid sequences of the 21-45 N-terminal residues. Eight chains (AI-IV and BI-IV) showed significant homology with haem-containing chains of annelid giant haemoglobin. The highest homology was found between Lamellibrachia chain AI and Tylorrhynchus chain I; surprisingly, 18 out of the 20 N-terminal residues are identical. On the other hand, chain AV, with an unusual Mr of 32,000, showed a rather different sequence and is likely to be a non-haem chain which might act as a linker protein in the assembly of the haem-containing chains. From these results, we conclude that the tube worm Mr 3,000,000 haemoglobin is highly homologous with annelid haemoglobin.

Amino Acid Sequence↗
PubMed1988

Amino acid sequence of a calcium-binding protein (TCBP-10) from Tetrahymena.

The amino acid sequence of a calcium-binding protein obtained from the cilium and cell body of Tetrahymena, designated as TCBP-10 (Tetrahymena calcium-binding protein; molecular mass = 10 kDa [Ohnishi, K. and Watanabe, Y. (1983) J. Biol. Chem. 258, 13978-13985] was determined. It is composed of 102 amino acid residues. The exact molecular mass is calculated to be 11563 Da. From the amino acid sequence analysis, it has two EF-hand-type calcium-binding sites.

Amino Acid Sequence↗
PubMed1988

Comparison of serum protein removal in haemodialysis therapy by partly protein-permeable haemodialysers.

Partly protein-permeable haemodialysers were evaluated during haemodialysis therapy for removal of serum low-molecular-mass proteins (10,000-76,000) in patients with chronic renal failure. The six haemodialyser membranes used were cuproammonium rayon (CL-S12W), cellulose acetate (Duo-Flux HP and FF-22), ethylene-vinyl alcohol copolymer (KF-101-15), polyacrylonitrile (H12-2400S) and polymethyl methacrylate (BK2.0H). The analysis was carried out by gel permeation chromatography, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoresis (2-DE). The removal of ten serum proteins per haemodialysis therapy was also carried out by the immunodiffusion method. The protein removal in each haemodialyser is qualitatively comparable to that obtained by SDS-PAGE and 2-DE. beta 2-Microglobulin in the haemodialysate obtained with BK2.0H was removed to a lesser extent than that from the other haemodialysers, which seems to be the reason for its adsorption in the BK2.0H haemodialyser, which contains a polymethyl methacrylate membrane. The amount of serum protein excretion during haemodiafiltration treatment using the partly protein-permeable haemodialysers decreased in the order KF-101-15C greater than BK2.0H greater than CL-S12W greater than Duo-Flux HP greater than FF-22 greater than H12-2400S.

Blood Proteins↗
PubMed1988

Amino acid sequence of starfish oocyte depactin.

The amino acid sequence of starfish oocyte depactin was determined by aligning lysyl endopeptidase, Staphylococcus aureus V8 protease, and cyanongen bromide peptides. Starfish oocyte depactin is composed of 150 amino acid residues and the N terminus is free proline. The molecular weight is calculated to be 17,590, in good agreement with the value estimated by sodium dodecyl-polyacrylamide gel electrophoresis. Prediction of the secondary structure shows that depactin contains 64% alpha-helix. Comparison of depactin sequence with those of other proteins shows no significant similarity.

Actin Depolymerizing Factors↗
PubMed1988

Amino acid sequence of the calcium-binding light chain of myosin from the lower eukaryote, Physarum polycephalum.

We have established a new method for preparing Physarum myosin whose actin-activated ATPase activity is inhibited by micromolar levels of Ca2+. This Ca2+-inhibition is mediated by the Ca2+ binding to the myosin rather than by the Ca2+-dependent modification of the phosphorylated state of the myosin (Kohama, K., and Kendrick-Jones, J. (1986) J. Biochem. (Tokyo) 99, 1433-1446). Ca2+-binding light chain (CaLC) has been suggested to be primary importance in this Ca2+ inhibition (Kohama, K., Takano-Ohmuro, H., Tanaka, T., Yamaguchi, T., and Kohama, T. (1986) J. Biol. Chem. 261, 8022-8027). The amino acid sequence of CaLC was determined; it was composed of 147 amino acid residues and the N terminus was acetylated. The molecular weight was calculated to be 16,131. The homology of CaLC in the amino acid sequence with 5,5'-dithiobis-(2-nitrobenzoic acid) light chain and alkali light chain of skeletal muscle myosin were rather low, i.e., 25% and 30%, respectively. Interestingly, however, the CaLC sequence was 40% homologous with brain calmodulin. This amino acid sequence was confirmed by sequencing the cloned phage DNA accommodating cDNA coding CaLC. Northern and Southern blot analysis indicated that 0.8-kilobase pair mRNA was transcribed from a single CaLC gene. This is the first report on the amino acid sequence of myosin light chain of lower eukaryotes and nucleotide sequence of its mRNA.

Amino Acid Sequence↗
PubMed1988

A marker epitope of attenuated Plasmodium berghei.

Plasmodium berghei XAT is an irradiation-induced, permanent attenuated derivative from high-virulence P. berghei NK65. Monoclonal antibodies against XAT were developed. By immunofluorescence screening, one monoclonal antibody was identified that was reactive with XAT at the schizont stage but not with NK65 nor with any other stage of intra-erythrocytic development of either parasite. The monoclonal antibody precipitated a 240-kD molecule from metabolically labeled XAT antigens. This molecule was thought to be a marker epitope of the attenuated parasite.

Animals↗
PubMed1988

Differential refractometric determination of binding of sodium dodecyl sulfate to protein using high-performance gel chromatography.

When sodium dodecyl sulfate (SDS) is added to a high-performance gel chromatographic column equilibrated with a buffer solution containing SDS at a level above the critical micelle concentration, the surplus SDS migrates as micelles giving a sharp peak. The presence of an unfolded protein in the sample solution gives a polypeptide peak in advance of the SDS micelle peak. As the result of SDS binding to the polypeptide, the SDS micelle peak is attenuated in comparison to that in the absence of protein. Thus the amount of SDS bound to the polypeptide can be determined accurately and simply from the decrease in the area of the SDS micelle peak. This approach is particularly useful for precise determination of bound SDS, which is pertinent to understanding the state of the protein polypeptide-SDS complex under the conditions of SDS-polyacrylamide gel electrophoresis.

Chromatography, High Pressure Liquid↗
PubMed1988

Dermoid cyst of the anterior fontanel: advantage of MRI for the diagnosis.

We report two Japanese infants with congenital dermoid cysts of the anterior fontanel. The histological, computed tomographic and magnetic resonance imaging (MRI) findings as to the cyst are described. MRI is the most useful preoperative investigative aid for ruling out intractanial extension.

Dermoid Cyst↗
PubMed1988

Branched-chain amino acid aminotransferase of Escherichia coli: overproduction and properties.

ilvE gene of Escherichia coli was inserted into the region downstream of the tac promotor. As a result, the branched-chain amino acid aminotransferase was overproduced by about a hundred-fold in E. coli W3110. The overproduced aminotransferase was purified from cell extracts about 40-fold to homogeneity. Chemical and physicochemical analyses confirmed that it was a product of the ilvE gene. The enzyme existed in a hexamer with a subunit molecular weight of 34,000; the double trimer model of the enzyme presumed by the previous chemical cross-linking experiments (Lee-Peng, F.-C. et al. (1979) J. bacteriol. 139, 339-345) was supported by electron micrographs. The circular dichroic (CD) spectrum of branch-chain amino acid aminotransferase had double negative maxima at 210 and 220 nm. The alpha-helical content was estimated to be about 40% from the CD spectrum in the region of 200 to 250 nm. The absorption spectrum of the enzyme showed two peaks at 330 and 410 nm. There was no pH-dependent spectral shift. The CD spectrum of the coenzyme, pyridoxal 5'-phosphate, had negative peaks at 330 and 410 nm. These spectral properties of branched-chain amino acid aminotransferase were quite different from those of E. coli aspartate aminotransferase. Each subunit bound approximately 1 mol of pyridoxal 5'-phosphate. A lysyl residue, which forms a Schiff base with the aldehyde group of the pyridoxal 5'-phosphate, was identified in the primary structure of the enzyme.

Amino Acid Sequence↗
PubMed1988

Alcohol-induced enhancement of intestinal gamma-glutamyl transpeptidase activity in rats and humans: a possible role in increased serum gamma-glutamyl transpeptidase activity in alcoholics.

It is a well-known phenomenon that serum gamma-glutamyltranspeptidase (gamma-GTP, EC 2.3.2.2.) activity is increased after chronic consumption of ethanol, and gamma-GTP has been, therefore, widely used as a sensitive marker for detection of alcoholism and its related liver disease. However, the precise mechanisms whereby the chronic ethanol consumption leads to an increase in serum gamma-GTP activity are not fully understood. In the present study, we investigated the relationship between the intestinal and serum gamma-GTP activities after chronic ethanol consumption both in rats and humans. Chronic ethanol feeding to rats resulted in a significant increase in serum gamma-GTP activity associated with a significant increment of the intestinal gamma-GTP activity. The histochemical staining of gamma-GTP in the mucosa of the small intestine of these animals demonstrated enhanced gamma-GTP activity at the microvilli of the brush border membrane, lamina propria of the mucosa, and endoplasmic reticulum of the intestinal epithelial cell. The augmented activity in the lamina propria was mainly localized at the submucosal lymphatics. Histology of the small intestine of human alcoholics was, more or less, similar to those observed in alcoholic rats. We further investigated the gamma-GTP activity in the mesenteric lymph using the animal model of lymphorrhea, and found that the gamma-GTP activity was increased by 83% when expressed per unit of lymph in the ethanol-fed rat, accompanied by a marked decrease of serum gamma-GTP activity, suggesting a close relationship between the serum and the intestinal gamma-GTP via the lymphatic channel.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1988

Purification and properties of the gamma-butyrobetaine-binding protein from an Agrobacterium sp.

A binding protein for gamma-butyrobetaine was purified from osmotic shock fluid of an Agrobacterium sp. It was a monomeric protein with an apparent molecular weight of 52,000 or 53,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively. The isoelectric point was 4.3, as determined by isoelectric focusing. Amino acid analysis of the protein showed that Asx and Glx were predominant components and that the protein contained no cysteine. The dissociation constant of this protein for gamma-butyrobetaine was found to be 0.7 microM by equilibrium dialysis. Attempts to sequence the amino-terminal end with the Edman method failed, suggesting that this region of the protein is blocked.

Amino Acid Sequence↗
PubMed1988

Postprandial celiac and superior mesenteric blood flows in conscious dogs.

Celiac and superior mesenteric arterial blood flows were measured simultaneously in conscious beagle dogs. The responses to food were completely different between the two arteries. Celiac flow increased quickly to 180-200% of the control 2 min after food but started to decline rapidly to preprandial levels, though greater than 90% of food was still in the stomach. It remained at preprandial levels over the next 1-6 h. Superior mesenteric flow increased gradually in 20-50 min (peak: 230%) and remained above the control levels for 3-6 h. The celiac response was inhibited by vagal block, hexamethonium, and gastric mucosal anesthesia by oxethazaine but not by atropine, phenoxybenzamine, or propranolol. Postprandial superior mesenteric hyperemia was blocked by mucosal anesthesia and was reduced by atropine by 80%. Ganglionic or adrenergic blockades were without effect. It is concluded that the celiac peak response to food is mediated by a nonadrenergic, noncholinergic vagal reflex in conscious dogs. Extrinsic nerves probably play little part in the postprandial increase of superior mesenteric flow.

Animals↗