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Biomedical subjects

A Kato

Publications and source records attributed to A Kato.

At least 559 records · Page 31Linked to original sources
PubMed1989

[Acute febrile neutrophilic dermatosis (Sweet's syndrome) in a patient with agnogenic myeloid metaplasia].

A 60-year-old man with a one-year history of agnogenic myeloid metaplasia was admitted to the hospital because of fever and a skin eruption. He had fever, anemia, hepatosplenomegaly, and a raised painful erythematous plaque in the face. The same kind of skin lesion developed thereafter at a venipuncture site in the left forearm. Bacterial cultures were negative. There was no response to antibiotic treatment. A biopsy specimen of the skin lesion revealed a dense dermal infiltration with mature neutrophils. A diagnosis of Sweet's syndrome was made. Fever and skin eruptions responded rapidly to prednisolone (PSL). Although the disease frequently recurred on rapid tapering of PSL, skin lesions cleared without scarring on a prolonged course of PSL. Four months after withdrawal of PSL, Sweet's syndrome recurred. A high dose PSL was given without benefit. He died of disseminated candidiasis.

Acute Disease↗
PubMed1989

[Mathematical analysis of equilibrium on 2-site immunoradiometric assay using anti-human TSH monoclonal antibody].

A mathematical analysis of equilibrium was adapted on a practical 2-site immunoradiometric assay (IRMA) using 10 murine monoclonal antibodies (Mabs) to human TSH. The affinity constant of 10 Mabs was from 2.5 x 10(8) to 3.3 x 10(10) M-1. The dose-response curves using appropriate combinations of Mab-coated bead and 125I-labeled Mab were compared with the theoretical curves calculated from mathematical analysis of equilibrium. Theoretical curves were directly affected by the affinity constants in which antibodies with higher affinity constants showed higher binding activity of tracer. However, the curves which antibodies have more than 1 x 10(9) M-1 and 1 x 10(10) M-1 for capture antibody and tracer antibody did not show remarkable change, but were similar with the curve obtained from unlimited affinity constant. From these curve, the maximum and minimum detectable dose were approx. 2 x 10(-10) M and 4 x 10(-14) M, respectively. Seven out of 10 experimental curves for TSH showed good consistency with the corresponding theoretical curves which indicated that a mathematical analysis of equilibrium was useful to presume experimental results using monoclonal antibody.

Antibodies, Monoclonal↗
PubMed1988

Characterization of specific receptors for atrial natriuretic factor on cultured bovine brain capillary endothelial cells.

A specific receptor for rat atrial natriuretic factor (rANF) was identified on primary cultures of bovine brain capillary endothelial cells (BBCEC's). Cultured BBCEC's have been developed in our laboratory as an in vitro model of the blood-brain barrier. The binding of [125I]-rANF was rapid, reversible, saturable and unaffected by the presence of hormonal peptides such as insulin, vasopressin and angiotensin II. Scatchard analysis of competitive binding studies indicated the presence of a single class of binding sites for rANF with a dissociation constant of 400 pM and maximal binding capacity of 52 fmol/mg total cell protein. Binding of [125I]-rANF was inhibited to varying degrees by atriopeptins I-III with atriopeptin III being the most potent and atriopeptin I being the least potent. BBCEC's also rapidly internalized [125I]-rANF (100% after 60 min at 37 degrees C) by a temperature-dependent process.

Animals↗
PubMed1988

Difference between two major size classes of carrot rDNA repeating units is due to reiteration of sequences of about 460 bp in the large spacer.

Based on the previous observation that the different regions between two major size classes of carrot rRNA genes are located in their large spacer, detailed physical maps of the spacer region were constructed by cloning, followed by restriction analysis. As a result, the different regions were restricted to BamHI segments of 1.3 kb and 1.8 kb. Sequence analysis of these segments revealed that the shorter one carried one truncated and two complete copies of about 460 bp of repetitious sequences, while the longer one contained one truncated and three full copies of the repetitious sequences. S1 nuclease mapping data suggest that either transcription initiation sites or processing sites of precursor rRNA are located in the repetitious sequence closest to the 18 S rRNA coding region.

Base Sequence↗
PubMed1988

Plasmodium falciparum: gene structure and hydropathy profile of the major merozoite surface antigen (gp195) of the Uganda-Palo Alto isolate.

The gene encoding the 195,000-Da major merozoite surface antigen (gp195) of the FUP (Uganda-Palo Alto) isolate of Plasmodium falciparum, a strain widely used for monkey vaccination experiments, has been cloned and sequenced. The translated amino acid sequence of the FUP gp195 protein is closely related to the sequences of corresponding proteins of the CAMP (Malaysia) and MAD-20 (Papua New Guinea) isolates and more distantly related to those of the Wellcome (West Africa) and K1 (Thailand) isolates, supporting the proposed allelic dimorphism of gp195 within the parasite population. The prevalence of dimorphic sequences within the gp195 protein suggests that many gp195 epitopes would be group-specific. Despite the extensive differences in amino acid sequence between gp195 proteins of these two groups, the hydropathy profiles of proteins representative of both groups are very similar. The conservation of overall secondary structure shown by the hydropathy profile comparison indicates that gp195 proteins of the various P. falciparum isolates are functionally equivalent. This information on the primary structure of the FUP gp195 protein will enable us to evaluate the possible roles of conserved, group-specific and variable epitopes in immunity to the blood stage of the malaria parasite.

Amino Acid Sequence↗
PubMed1988

Reduced somatostatin-28-(1-12)-like immunoreactivity in cerebral cortex of dogs with an Eck fistula and somatostatin molecular forms in brain.

Somatostatin-28-(1-12)-like immunoreactivity (S28(1-12)LI) in brains of Eck fistula dogs, prepared as an experimental model of hepatic encephalopathy, was measured. Significant reductions of S28(1-12)LI were observed in all cortical regions of Eck fistula dogs. The reductions of S28(1-12)LI were significantly correlated with decreases in somatostatin-14-like immunoreactivity (S14LI) in the cortical region. The ratios of S28(1-12)LI to S14LI in all cortical regions were not different between Eck fistula and normal dogs. Additionally, no difference in gel chromatographic profiles of S28(1-12)LI and S14LI was observed between Eck fistula and normal dogs. These results imply that reduced somatostatin immunoreactivity in hepatic encephalopathy may be caused not by altered degradation but by reduced production of prosomatostatin. Our S28(1-12)LI assay system could detect prosomatostatin(1-76) and S28(1-12) and the S14LI system prosomatostatin, S28 and S14. S28(1-12)LI/S14LI ratios in cortex were 0.64-0.83 and these were significantly different from those (1.02-1.36) in thalamus, midbrain and medulla. Relative proportions of prosomatostatin (20%) and S28 (23-24%) in cortex were larger than those (6-7% and 5-7%, respectively) in thalamus, midbrain and medulla. The differential distribution of these molecular forms suggests that processing of prosomatostatin in cortex may be different from that in thalamus, midbrain and medulla.

Acute Kidney Injury↗
PubMed1988

Correlation of surface properties with conformational stabilities of wild-type and six mutant tryptophan synthase alpha-subunits substituted at the same position.

The surface properties of wild-type and six mutant alpha-subunits of tryptophan synthase substituted at the same position, 49, which is buried in the interior, were measured by surface tension, foaming and emulsifying properties to correlate the surface properties with the stabilities. The conformational stabilities of the seven alpha-subunits differed dramatically depending on the characteristics of the substituting residues [Yutani et al. (1987) Proc. Natl. Acad. Sci., 84, 4441-4444]. The mutant proteins substituted by isoleucine and phenylalanine in place of glutamic acid at position 49 were more stable than the other proteins and showed higher surface tension and lower foaming and emulsifying properties than the wild-type and other mutant proteins. Good correlations were observed between these surface properties and values of the Gibbs free energy of unfolding in water, of the proteins. This indicates that the surface properties of the alpha-subunits of tryptophan synthase depend closely on the conformational stabilities.

Amino Acids↗
PubMed1988

Bleeding tendency caused by IgG inhibitor to factor XIII, treated successfully by cyclophosphamide.

A case exhibiting bleeding tendency caused by an acquired inhibitor to factor XIII is reported. The patient, a hitherto healthy 87-year-old Japanese man, presented with a massive subcutaneous bleeding, leading to severe anaemia. The routine coagulation study was normal except for a decreased plasma factor XIII level, which was 3% of the control level by the dansylcadaverine incorporation assay. An inhibitor of factor XIII was demonstrated to be present in the IgG fraction of the patient's plasma; by immunoblotting this inhibitor was shown to bind specifically the a and a' subunits of factor XIII. The IgG fraction suppressed the transglutaminase activity of activated factor XIII, but did not inhibit the molecular transformation of subunit a to a' in the activation process. Massive infusion of plasma and factor XIII concentrate was effective for controlling the bleeding temporarily. In the long-term prednisolone was ineffective for suppressing the plasma inhibitor level and bleeding episodes recurred. A small daily dose (50 mg) of cyclophosphamide, however, effectively decreased the inhibitor level and controlled bleeding.

Aged↗
PubMed1988

In vitro study on corneal permeability to bunazosin.

Corneal permeability of bunazosin, one of the alpha-adrenergic receptor antagonists, was investigated in vitro using excised rabbit cornea mounted on a corneal permeability apparatus, and the enhancing effects of various acids on the permeability of bunazosin were evaluated. Caprylic and capric acid elevated octanol/water partition coefficient of bunazosin, and corneal permeability was increased, probably as a result of ion-pair formation between them. Neither bunazosin, these acids, or the ion-pair caused corneal swelling. These acids, in contrast, had little effect on the partition of pilocarpine, or on corneal permeability.

Adrenergic alpha-Antagonists↗
PubMed1988

Corneal permeability to bunazosin in rabbits.

Topical and systemic absorption of bunazosin after topical instillation was investigated in rabbits. Corneal permeability of bunazosin in vivo was increased by the addition of caprylic acid in amounts equimolar to bunazosin. Aqueous humor levels of bunazosin were significantly elevated. These results correlated well with those obtained in vitro experiments. Contrarily, the levels of plasma were not significantly affected and only slightly lowered by caprylic acid.

Adrenergic alpha-Antagonists↗
PubMed1988

Studies on improved corneal permeability to bunazosin.

Various factors influencing corneal permeability to bunazosin were investigated. The permeability of the cornea to bunazosin increased with increasing pH, either in the presence or absence of caprylic acid; the permeability to bunazosin and the partition of bunazosin were both enhanced by caprylic acid and both enhancements became maximal when the molar ratio of bunazosin: caprylic acid became unity; the permeability to methylparaben, a non-ionic permeant, was not increased by caprylic acid or capric acid and the permeability was not increased by the pretreatment of the cornea with caprylic acid. Furthermore, protein-bunazosin interaction was not affected by caprylic acid. The present results suggest that the enhancement of permeability caused by caprylic acid is attributable only to the increased partition of bunazosin to the corneal membrane.

Adrenergic alpha-Antagonists↗