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Biomedical subjects

A Kato

Publications and source records attributed to A Kato.

At least 451 records · Page 25Linked to original sources

[The effect of beta-adrenergic blockade on the plasma potassium elevation induced by acute respiratory acidosis during halothane or fentanyl anesthesia].

The effect of beta-adrenergic blockade on the plasma potassium elevation induced by acute respiratory acidosis (CO2 inhalation) was studied in adult mongrel dogs during halothane or fentanyl anesthesia. Twenty-two dogs were divided into 4 groups: halothane-control (HC, n = 15), halothane-beta-blockade (H beta, n = 8), fentanyl-control (FC, n = 15) and fentanyl-beta-blockade (F beta, n = 10). Beta-blockade was achieved by continuous infusion of propranolol. The maximum levels of plasma potassium after 14% CO2 inhalation were 5.0 +/- 0.7 mM (mean +/- SD) in HC, 6.1 +/- 0.8 mM in H beta, 4.3 +/- 0.4 mM in FC and 4.8 +/- 0.5 mM in F beta. With halothane anesthesia more prominent elevation was observed in the beta-blockade group (P < 0.05), but with fentanyl anesthesia this elevation was not significantly different between the two groups. In acute respiratory acidosis, pH-induced plasma potassium elevation is suppressed by simultaneously increased catecholamines, especially epinephrine. Beta-adrenergic blockade, therefore, may cause severe hyperkalemia due to inhibition of adrenergic potassium disposal. During fentanyl anesthesia plasma potassium elevation was less marked than during halothane. This indicates that fentanyl has less suppressing action on the secretion of stress hormones, including epinephrine, under similarly stressful conditions as halothane anesthesia.

Acidosis, Respiratory↗

The primary structure of two proteins from the large ribosomal subunit of rice.

We isolated two rice cDNAs which encode an open reading frame of 389 amino acids. Their deduced amino acid sequence corresponded to the ribosomal protein (r-protein). A comparison of amino acid sequence shows that the deduced amino acid sequence of one cDNA is homologous to Arabidopsis, yeast and the rat r-protein L3. Another encoded products with a high degree of homology to the rat r-protein L7A and yeast r-protein L4.

Amino Acid Sequence↗

The primary structure of two proteins from the small ribosomal subunit of rice.

We isolated two rice cDNAs which encode an open reading frame of 117 amino acids or 82 amino acids. Their deduced amino acid sequence correspond to the ribosomal proteins (r-protein). A comparison of the amino acid sequence shows that the deduced amino acid sequence of one cDNA is homologous to the rat r-protein S20 and Xenopus r-protein S22. Another encoded products with a high degree of homology to the rat r-protein S21 and the yeast r-protein YS25.

Amino Acid Sequence↗

Molecular structure of ras-related small GTP-binding protein genes of rice plants and GTPase activities of gene products in Escherichia coli.

We isolated two rice cDNA clones (ric1 and ric2) encoding proteins homologous to the ras-related small GTP-binding protein. The amino acid sequences of ric1 and ric2 are conserved in four regions involved in GTP binding and hydrolysis which are characteristic in the ras and ras-related small GTP-binding protein genes. In addition, two consecutive cysteine residues near the carboxyl-terminal end required for membrane anchoring are also present in ric1 and ric2. The ric1 and ric2 proteins synthesized in Escherichia coli possessed GTPase activity (i.e. hydrolysis of GTP to GDP).

Amino Acid Sequence↗

Novel surface functional properties of polymannosyl lysozyme constructed by genetic modification.

The surface functional properties of glycosylated lysozyme were investigated by using polymannosyl and oligomannosyl enzymes at the position 49 by genetic modification [Nakamura, S. et al. (1993) J. Biol. Chem. 268, in press]. The polymannosyl lysozyme exhibited excellent emulsifying properties superior to those of commercial emulsifiers in addition to heat stability, while the oligomannosyl lysozyme did not. The surface tension of the polymannosyl lysozyme was greatly decreased correspondingly to the enhanced emulsifying properties, although that of oligomannosyl protein was not. The emulsifying activity and the emulsion stability of the polymannosyl lysozyme were stable in acidic pH or high salt conditions; in addition, they were greatly enhanced also by preheating the polymannosyl lysozyme. Thus novel surface functional properties of polymannosyl lysozyme in addition to heat stability suggest the direction of the design of new functional proteins by genetic modification.

Animals↗

Hyperglycosylation of hen egg white lysozyme in yeast.

The large molecular size of N-glycosylated lysozyme with a polymannose chain was predominantly expressed in the yeast carrying the lysozyme expression plasmid in 9-fold greater secretion compared with the wild type. Complementary DNA encoding hen egg white lysozyme was subjected to site-directed mutagenesis to obtain the Asn-X-Ser/Thr sequence that is the signal for asparagine-linked (N-linked) glycosylation. At positions 49, 67, 70, and 103, the signal for N-linked glycosylation was created. Only the mutant lysozyme whose glycine 49 was substituted with asparagine was expressed in the two types of glycosylated forms, a small oligomannose chain (Man18GlcNAc2)-linked form and a large polymannose chain (Man310GlcNAc2)-linked form, whereas other mutants were not glycosylated. The secreted amount of polymannosyl lysozyme was much higher than that of the oligomannosyl lysozyme. Both types of glycosylated lysozymes were susceptible to endo-beta-N-acetylglucosaminidase cleavage of their carbohydrate chains. The average molecular masses of oligomannosyl and polymannosyl lysozymes were 18 and 71 kDa, respectively. The length of the polymannose chain was found to be 200-350 residues/molecule of lysozyme according to the estimation of the molecular mass distribution by low angle laser light scattering measurements. The protein conformation estimated by CD analysis was completely conserved in these glycosylated lysozymes. The enzymatic activities of oligomannosyl and polymannosyl lysozymes were 100 and 91%, respectively, of wild-type protein when glycol chitin was used as a substrate. In addition, the polymannosyl lysozyme revealed remarkable heat stability in that no coagulation was observed under conditions in which the wild-type lysozyme coagulated. Thus, this novel glycoprotein can be used as a reporter in studies of the processing and sorting of glycoproteins and as a model of the expression of foreign genes in yeast for the construction of stable enzymes.

Animals↗

[Embolization of the internal maxillary artery for severe epistaxis--including an experience of the approach from the superficial temporal artery].

Six cases of severe epistaxis were treated with the super-selective intraarterial embolization of the internal maxillary artery. Tens of fragments of Gelfoam were delivered into the distal internal maxillary artery and, additionally, embolized by several pieces of the coils. In a case with cerebral infraction, catheter was inserted via the superficial temporal artery. There were no complications due to these procedures in all cases of this study. It is considered that therapeutic intraarterial embolization of the internal maxillary artery is an effective therapy for severe epistaxis and the superficial temporal artery approach is useful for selected cases.

Aged↗

Molecular assembly of influenza virus: association of the NS2 protein with virion matrix.

The NS2 protein, one of the two nonstructural proteins of influenza A virus, was found to exist in virus particles. By immunochemical method, the average number of NS2 in a virus particle was estimated to be 130-200 molecules. After solubilization of viral envelope, NS2 was still associated with ribonucleoprotein cores, but was later dissociated upon removal of the M1 protein. A filter-binding assay in vitro indicated direct protein-protein contact between M1 and NS2. Following chemical cleavage of the M1 protein, NS2 bound only a C-terminal fragment of M1. By immunoprecipitation, NS2-M1 complexes were also detected in virus-infected cell lysates. These observations altogether indicate specific molecular association between M1 and NS2. Biological significance of M1-NS2 interaction is discussed.

Animals↗

Isolation and characterization of a rice cDNA which encodes a ubiquitin protein and a 52 amino acid extension protein.

We isolated a rice cDNA clone encoding the ubiquitin protein fused to a ribosomal protein. This clone encodes a single ubiquitin polypeptide and extension protein of 53 amino acids. This extension protein shows a high degree of homology with those of the yeast ubil or ubi2 gene, both of which encode the same protein. Northern blot analysis suggested that the expression pattern of this gene is more similar to other ribosomal protein genes not linked to ubiquitin protein than to the polyubiquitin gene.

Amino Acid Sequence↗

Isolation and characterization of a rice cDNA clone encoding ATP/ADP translocator.

We isolated a rice cDNA clone which encodes an open reading frame of 382 amino acids. Its deduced amino acid sequence corresponds to an ATP/ADP translocator protein. Its homology with a maize ATP/ADP translocator was 83.9% in nucleotide sequence, and 90.2% of the amino acid level. Expression of this gene is regulated by such external stresses as salinity and low temperature.

Amino Acid Sequence↗

Isolation and characterization of a rice cDNA similar to the bovine brain-specific 14-3-3 protein gene.

We isolated a rice cDNA clone which is similar to the bovine brain-specific 14-3-3 protein (an activator protein of tyrosine and tryptophan hydroxylase involved in the synthetic pathway of monoamine) gene. The deduced amino acid sequence of the cDNA indicated a surprising similarity to a potent inhibitor of Ca(2+)-phospholipid-dependent protein kinase C. DNA blot analysis indicated that this gene is located at more than a single locus in rice genome DNA. Expression of this gene is regulated by external stresses.

14-3-3 Proteins↗

Retroperitoneal fibrosis associated with scirrhous gastric cancer.

A case of retroperitoneal fibrosis associated with scirrhous gastric cancer is reported. A sixty two-year-old Japanese female was admitted because of acute renal failure. The patient's serum creatinine level showed 3.2 mg/dl while the blood urea nitrogen level was 23 mg/dl. An ultrasound study of the upper abdomen revealed bilateral hydronephrosis. Drip infusion pyelography revealed a dilated right renal pelvis without ureteral obstruction. The left kidney was not opacified, suggesting a functional disorder. Gastrography and gastrofiberscopy revealed scirrhous gastric cancer. Signet ring cell carcinoma was later demonstrated histologically by biopsy specimens. CT demonstrated a prominent thickening of the gastric wall and hydronephrosis, although no prevertebral soft tissue masses were observed. A total gastrectomy was performed with failure to surgically decompress the ureters because fibrous plaque had firmly enveloped the retroperitoneal structures. Biopsy specimens of the retroperitoneum revealed an invasion of the tumor cells and prominent fibrosis. As an etiology of renal failure, ureteral stenosis resulting from secondary retroperitoneal fibrosis was also considered.

Acute Kidney Injury↗

A rapid quantitative method for detecting infectious bursal disease virus using polystyrene latex microspheres.

A monoclonal antibody (mAb) to infectious bursal disease virus (IBDV) was bound to polystyrene latex microspheres. The microspheres agglutinated with extracts of bursae and sera from chickens infected with all strains or isolates of IBDV tested. Agglutination appeared within a 10-min reaction time. The assay could detect a 10(3.7) to 10(4.5) mean embryo infective dose (EID50) of the virus in 0.01 ml and the titer of the assay was 10- to 40-times higher than that of the agar gel precipitin test.

Animals↗