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Biomedical subjects

K Yagi

Publications and source records attributed to K Yagi.

At least 505 records · Page 28Linked to original sources
PubMed1988

[Transition of occurrence of anisakiasis and its paratenic host fishes in Japan, with pathogenesis of anisakiasis].

The number of anisakiasis according to a nation-wide statistical survey totaled 4682 cases until June 1987 in Japan. Of these 4296 cases are gastric anisakiasis (including 215 cases of gastric terranovasis), 375 intestinal anisakiasis and 11 extra-gastrointestinal anisakiasis. Pseudoterranova larva does not invade the intestine, and worms are vomited in most cases. Clinical diagnosis of intestinal anisakiasis is more difficult than that of gastric anisakiasis, and it also is hard to find the worm itself in histopathological examination. Therefore the number of actual intestinal anisakiasis is probably 3 times more than that of the reported cases. The cases of gastrointestinal-wall perforation by worms are increasing, which means immune response by granuloma formation is important. The catches of paratenic hosts and the rate of infection vary with year. In addition, the kind of paratenic host fishes are different between the southern and northern areas of Japan. The paratenic hosts reported by patient are closely related to the catches of kinds of those fishes in the respective areas. Recently, cases by eating sardine are increasing in the southern area. Urticaria as a complication is related to the diagnostic rate, and intraperitoneal bacterial infection by the gastrointestinal perforation by worms is closely related to the prognosis.

Animals↗
PubMed1987

Communication between two globular domains of calmodulin in the presence of mastoparan or caldesmon fragment. Ca2+ binding and 1H NMR.

Ca2+ binding to calmodulin was measured in the presence of mastoparan or caldesmon fragment. Mastoparan and caldesmon fragment were used as model compounds of enzymes and cytoskeleton proteins, respectively, working as the target of calmodulin. Although the Ca2+ bindings of the two globular domains of calmodulin occur independently in the absence of the target peptide (or proteins), mastoparan and caldesmon fragment increased the affinity of Ca2+ and, at the same time, produced the positive cooperative Ca2+ bindings between the two domains. The result of Ca2+ binding was compared with 1H NMR spectra of calmodulin in the presence of equimolar concentration of mastoparan. It is known that a conformation change of the C-terminal half-region (C-domain) occurs by the Ca2+ binding to C-domain. A further change in conformation of C-domain was demonstrated by the Ca2+ binding to the N-terminal half-region (N-domain) in the presence of mastoparan. It indicates that the two domains of calmodulin get into communication with each other in the associated state with the target, and we concluded that the Ca2+ binding to the N-domain is responsive to the development of calmodulin function.

Animals↗
PubMed1987

Interaction of dimers of inactive enkephalin fragments with mu opiate receptors.

Dimeric analogues of the inactive enkephalin fragment Tyr-D-Ala-Gly were synthesized by cross-linking with alkanediamine at the C-terminus. Biological evaluation of these dimers (H-Tyr-D-Ala-Gly-NH)2.(-CH2-)n (DTREn), where n = 0-6, revealed that the fragment inactive for mu receptors was activated by its dimerization, with the maximum activation found with DTRE2, and that the dimer was highly mu-selective. So-called "handicapped" dimers, which lack one of the essential groupings required for enkephalin activity, were found to be far less active, indicating that the dimer interacts bivalently with mu receptors. It seems, therefore, that mu opiate receptors contain at least two equivalent binding sites which are extremely close to each other.

Animals↗
PubMed1987

Purification and partial characterization of adenosine diphosphatase activity in bovine aorta microsomes.

Anti-aggregatory activities in bovine aorta microsomal fractions were solubilized with Triton X-100 and separated into two fractions by DEAE-Sepharose CL-6B. One fraction strongly inhibited arachidonic acid-induced platelet aggregation, and the other inhibited ADP-induced aggregation. The latter fraction contained ADPase activity. The ADPase activity was further purified by affinity chromatography. The purified enzyme had specific activities of 43.8 and 48.2 mumol of Pi/min/mg protein for ADP and ATP, respectively. The enzyme required calcium or magnesium ions and it was insensitive to ATPase inhibitors, namely oligomycin and ouabain, and to adenylate kinase inhibitor, Ap5A. Polyacrylamide gel electrophoretic experiments indicated that only one enzyme was involved. This was confirmed by the parallel behavior of ADPase and ATPase activities throughout all the purification steps. These results suggest that the main anti-aggregatory activity of bovine aorta microsomes for ADP-induced aggregation is due to an ATP diphosphohydrolase (EC 3.6.1.5).

Adenosine Diphosphate↗
PubMed1987

Synergistic interactions between footshocks and non-osmotic hypovolemia on vasopressin secretion in rats.

The effects of i.p. injected hypertonic NaCl and polyethylene glycol on the magnitude of increase in plasma vasopressin after footshocks were studied in male rats, to determine whether hypovolemia and body fluid osmolality interact with noxious stimuli on vasopressin secretion. Present data have demonstrated that non-osmotic hypovolemia but not body fluid hyperosmolarity interact significantly and synergistically with footshocks to potentiate vasopressin secretion.

Animals↗
PubMed1987

Inhibitory effect of immobilized microsomal proteins on platelet aggregation.

Bovine aorta microsome was solubilized by 0.5% Triton X-100, and then immobilized on agarose gel (Sepharose 4B). Immobilized microsomal proteins (I-MP) inhibited platelet aggregations induced by ADP, arachidonic acid, collagen, and thrombin. The decrease of free platelet count in sheared whole blood was suppressed by I-MP. The anti-aggregatory activity of I-MP on arachidonic acid-induced aggregation was inhibited by 15-HPETE. This result suggests that I-MP contains PGI2 synthetase activity. It is considered that immobilization of enzymatic systems in aorta microsome which limited platelet aggregation is effective to provide an antithrombogenicity to the artificial polymers for artificial organs, especially used under the conditions which frequently induced platelet aggregation.

Animals↗
PubMed1987

Isolation and characterization of a calmodulin binding fragment of chicken gizzard caldesmon.

A calmodulin binding portion was separated from chicken gizzard caldesmon by chymotryptic digestion and it was purified through two column chromatography steps on calmodulin-Sepharose and Ultrogel AcA 44. The isolated fragment has an estimated molecular weight of 35,000 (35K) and it was possibly derived from the C-terminal portion of caldesmon. The affinity of the 35K fragment for calmodulin was determined by using the characteristic calmodulin-dependent mobility shift in polyacrylamide gel electrophoresis. The 35K fragment retained the actin binding site of caldesmon. The interaction of the 35K fragment with actin was released in the presence of Ca2+ and calmodulin.

Actins↗
PubMed1987

Yeast calmodulin: structural and functional differences compared with vertebrate calmodulin.

Calmodulin of the baker's yeast (Saccharomyces cerevisiae) showed a similar affinity for Ca2+ to that of vertebrate calmodulin. The maximum binding number of Ca2+ to yeast calmodulin was, however, 3 mol/mol, which is lower than that of vertebrate calmodulin (4 mol/mol). The same maximum activity of porcine brain phosphodiesterase was attained when 100 times higher concentration of yeast calmodulin than that of vertebrate calmodulin was added. On the other hand, the maximum activation of chicken gizzard myosin light chain kinase was attained with 1,000 times higher concentration of yeast calmodulin than that of vertebrate calmodulin, and the maximum activity with yeast calmodulin was less than 1/5 of that with vertebrate calmodulin. Several amino acid substitutions observed in the yeast calmodulin, particularly at the alpha-helical rod connecting the two globular domains, may affect the interaction mode of various target enzymes with this calmodulin.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1987

Intractable epilepsy and disturbed visuomotor performance.

The factors relevant to intractability, types of epilepsy and impairment of dexterity in patients with intractable epilepsy were studied independently in different groups of patients. The factors relevant to intractable epilepsy that were disclosed in 202 patients, who required hospitalization more than twice, were as follows: strong seizure propensity, neuropsychiatric disorders including mental deterioration of various degrees, ataxia, personality changes and psychotic episodes, intolerance to antiepileptic drugs due to acute or chronic side effects, idiosyncrasy and internal disorders, self-induced seizure, misdiagnosis and mistreatment, and breakdown of family care of patients. The types of epilepsy in 224 patients with intractable epilepsy whose seizures were not adequately controlled and recurred on a monthly basis in spite of hospitalization were classified as follows: 101 patients with localization-related epilepsies or syndromes, 106 with generalized epilepsies or syndromes, 16 with undetermined epilepsies or syndromes and one with specific syndrome. In regard to partial epilepsies, frontal lobe epilepsy and partial epilepsy with multiple foci were at least partially intractable as temporal lobe epilepsy. With respect to intractable generalized epilepsies, miscellaneous symptomatic generalized epilepsies like intractable grand mal epilepsy with progressive mental retardation in childhood were as important as Lennox-Gastaut or West syndrome though it defies classification into any established syndromes. The proposed International Classification of Epileptic Syndromes and Epilepsies was found adequate for analysis of intractable epilepsy. The disturbance of fine motor performance found in 84 patients who participated in occupational therapy was investigated by test programs comprising nine subbatteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

In vitro maintenance of terminal-differentiated state in hepatocytes entrapped within calcium alginate.

In cultured hepatocytes entrapped within Ca-alginate, liver-specific functions such as induction of tyrosine aminotransferase and serine dehydratase were stimulated by increasing the cell density. In contrast, a growth-related function such as induction of glucose-6-phosphate dehydrogenase was strongly stimulated by decreasing the cell density. This reciprocal regulation was mimicked by the addition of plasma membranes purified from adult rat liver to entrapment cultures at low cell density. Also, gluconeogenesis from lactate was stimulated by the addition of epinephrine (alpha,beta-agonist) with propranolol (beta-blocker). These results suggest that entrapped hepatocytes maintain not only terminal-differentiated state but also alpha-adrenergic response as shown in vivo.

Alginates↗
PubMed1987

Molecular cloning of cDNA for rat liver general acyl CoA dehydrogenase and homology between the rat liver and pig kidney enzymes.

cDNA clone for general acyl CoA dehydrogenase (GAD) was isolated from a rat liver cDNA expression library in lambda gt11 using anti-pig kidney GAD antibody. Size of the isolated cDNA was estimated to be 1.5-1.6 kb. By immunological analysis of fusion protein and epitope selection, the cDNA clone was identified as that containing the GAD gene. Partial amino acid sequence deduced from nucleotide sequence of the cDNA coincided with that of the pig kidney enzyme. The antibody cross-reacted with rat liver enzyme and molecular weights of these enzyme proteins were shown to be almost the same. All these results indicate that rat liver GAD shares a common structure with pig kidney enzyme.

Acyl-CoA Dehydrogenases↗