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Biomedical subjects

H Asai

Publications and source records attributed to H Asai.

At least 73 records · Page 4Linked to original sources
PubMed1990

Breathing patterns in asthmatic children during attack.

Breathing patterns in asthmatic children during attack were studied using multielectrode impedance pneumography. A great number of respiration patterns were analyzed by a personal computer. During severe attacks, a pattern of prolonged expiratory time was noted. Inspiratory time, however, did not change, regardless of the severity of the asthmatic attack. No remarkable changes in breathing patterns were recognized during mild attacks. It was, therefore, considered that breathing patterns remained essentially unchanged except in cases of severe asthmatic attacks.

Adolescent↗
PubMed1990

Intraperitoneally injected cultured mast cells suppress recruitment and differentiation of bone marrow-derived mast cell precursors in the peritoneal cavity of W/Wv mice.

Bone marrow-derived mast cell precursors form large mast cell colonies in methylcellulose and are designated as L-CFU-Mast. The effect of differentiated mast cells on recruitment and differentiation of L-CFU-Mast was investigated by using genetically mast cell-deficient WBB6F1-W/Wv mice. Giant granules of C57BL/6-bgJ/bgJ (Chediak-Higashi syndrome) mice were used as a marker to identify the origin of L-CFU-Mast and differentiated mast cells. Practically no L-CFU-Mast are present in the peritoneal cavity of WBB6F1-W/Wv mice. When bone marrow cells of WBB6F1(-)+/+ mice were i.v. injected, the concentration of +/+(-)type L-CFU-Mast increased in the peritoneal cavity of WBB6F1-W/Wv mice and became several times greater than that of nontreated WBB6F1(-)+/+ mice. This increase of L-CFU-Mast was suppressed by a prior i.p. injection of bgJ/bgJ-type cultured mast cells. The differentiation of the +/+(-)type L-CFU-Mast to morphologically identifiable mast cells was also suppressed by the i.p. injection of bgJ/bgJ-type cultured mast cells. The present results suggest that the suppression of recruitment and differentiation of L-CFU-Mast is a physiological function of differentiated mast cells.

Animals↗
PubMed1990

[Effects of urinastatin against nephrotoxicity of cisplatinum].

Nephrotoxicity is the major side effect of cisplatinum (CDDP) and it is often the dose limiting factor. We have studied the effect of urinastatin (US) to decrease the nephrotoxicity of CDDP administration. 28 patients with gynecological cancer treated by chemotherapy including CDDP (13 mg/m2 daily for 5 days) were assigned to two groups, the group with US (n = 14) and the group without US (n = 14). The former was added each 150,000 units of US before and after administration of CDDP. The BUN, serum creatinine (Cre), creatinine clearance (Ccr) and the excretion of beta 2-microglobulin (beta 2-MG) index and N-acetyl-beta-glucosaminidase(NAG)index were measured. The BUN, Cre and Ccr were within normal range during four cycles. However NAG index rose remarkably when CDDP was treated by CDDP. And the increase in NAG index, which reflect the magnitude of renal tubal damage, was less in the group with US than in the group without US. It was suggested that US had effects to reduce nephrotoxicity of CDDP in chemotherapy, and that we could treat patients by high dose CDDP.

Adult↗
PubMed1989

Purification and characterization of Ca2+/calmodulin-dependent actin-binding proteins from squid retina.

Ca2+/calmodulin (CaM)-dependent actin-binding proteins (CABPs) of 92, 105, 120 and 135 kDa were purified from squid retina. These proteins were eluted from the CaM affinity column in a Ca2+-dependent manner, and binding of the CABPs to F-actin was regulated by Ca2+/CaM. Electron microscopic observations employing the low-angle rotary shadowing technique showed the CABP molecules to have granular shapes similar to the granular proteins associated with actin filaments in squid rhabdomeral microvilli. We have previously reported that these actin filaments are fragmented upon exposure to light [(1988) J. Cell Biol. 106, 1151-1160]. Since the intracellular Ca2+ concentrations of the invertebrate retina are elevated during the light illumination, these results indicate that the CABPs are directly associated with the actin filament in the microvilli of the squid photoreceptors. We therefore suggest that the CABPs may regulate the light-induced structural changes of the microvillar cytoskeleton.

Actins↗
PubMed1989

Change in the summating potential and action potential during the fluctuation of hearing in Ménière's disease.

Summating potential (SP) and action potential (AP) were monitored by extratympanic electrocochleography (ECoG) during the fluctuation of hearing in 8 patients with Ménière's disease. The relationship of SP and AP parameters to pure-tone hearing threshold level was examined. The correlational analysis revealed the following: AP amplitude decreases with increase in the hearing threshold level at higher frequencies (2-8 kHz), whereas it alters independently of the change in the hearing threshold level at lower frequencies (0.25-1 kHz). -SP amplitude is unchanged irrespective of changes in the hearing threshold level at any frequency. The ratio of -SP to AP amplitude increases with increase in the hearing threshold level at higher frequencies (2-8 kHz), whereas it alters independently of the change in the hearing threshold level at lower frequencies (0.25-1 kHz).

Action Potentials↗
PubMed1989

Effect of 5-fluorouracil on "primitive" hematopoietic stem cells that reconstitute whole erythropoiesis of genetically anemic W/Wv mice.

The potential to reconstitute the whole erythropoiesis of a genetically anemic (WB X C57BL/6)F1-W/Wv (WBB6F1-W/Wv) mouse for at least 8 weeks was compared between 5-fluorouracil (5FU)-treated and nontreated bone marrow cells. C57BL/6-Pgk-1b/Pgk-1a female mice, in which each stem cell had either A-type or B-type phosphoglycerate kinase (PGK) owing to the random inactivation of one of two X chromosomes, were used as donors. As a marker of the reconstitution, electrophoretic pattern of hemoglobin was used. The concentration of the stem cells that reconstitute the whole erythropoiesis of WBB6F1-W/Wv mouse was higher in the marrow of donors that had received an injection of 5FU two days previously (two-day 5FU-treated) than in the marrow of nontreated donors. In the marrow of four-day 5FU-treated mice, however, the concentration was comparable to that of nontreated mice. The PGK electrophoretic pattern of WBB6F1-W/Wv mice reconstituted by nontreated marrow cells was comparable to the PGK pattern of WBB6F1-W/Wv mice reconstituted by four-day 5FU-treated marrow cells. Thus, a single stem cell with extensive proliferative potential rather than multiple spleen colony-forming units appeared to be responsible for the erythropoietic reconstitution in the transplantation of nontreated healthy marrow cells as well as 5FU-treated marrow cells.

Anemia↗
PubMed1989

Lymphoid differentiation of the hematopoietic stem cell that reconstitutes total erythropoiesis of a genetically anemic W/Wv mouse.

We investigated whether the stem cell that reconstitutes total erythropoiesis of a WBB6F1-W/Wv mouse differentiates into lymphoid lineage. The electrophoretic pattern of hemoglobin was used as a marker of the reconstitution; 3-phosphoglycerate kinase (PGK), an X chromosome-linked enzyme was used as a tool for estimating clonality. We injected 10(5) bone marrow cells of 5-FU treated C57BL/6-Pgk-1b/Pgk-1a female mice, in which each stem cell had either A-type PGK or B-type PGK due to random inactivation of one of two X chromosomes, into genetically anemic (WB x C57BL/6)F1-W/Wv (hereafter WBB6F1-W/Wv) mice that contained only B-type PGK. The recipient WBB6F1-W/Wv mice, in which erythropoiesis was reconstituted with donor cells for a long term, were killed and the PGK patterns of bone marrows, thymus, lymph nodes, and Peyer's patches were examined. A considerable amount of A-type PGK was detected in the lymphoid organs of the WBB6F1-W/Wv mice in which erythrocytes showed only A-type PGK when killed. In contrast, A-type PGK was scarcely detectable in the lymphoid organs of the WBB6F1-W/Wv mice in which erythrocytes showed only B-type PGK when killed. The present results suggest that the hematopoietic stem cells estimated by the erythropoiesis reconstituting assay differentiate into lymphoid lineage and that the long-term erythropoiesis reconstitution assay is useful for detecting the true primitive hematopoietic stem cells.

Anemia↗
PubMed1989

[Electro-ophthalmological analysis of Behçet's disease].

Six patients with complete type Behçet's disease were studied electro-retinographically and electro-oculographically. The electrical responses tested include the hyperosmolarity response in the EOG, the oscillatory potentials and the rapid off-response in the ERG. The oscillatory potentials diminished in five eyes of four cases. In all except one of these eyes the rapid off-response and the hyperosmolarity response were within normal ranges. The hyperosmolarity response was suppressed in one eye which suffered from severe diffuse uveitis and iridocyclitis accompanied with hypopyon. The a-wave, the b-wave, the oscillatory potentials and the rapid off-response were also abnormal in this eye. The hyperosmolarity response was abnormal in an eye with severe ocular lesions of Behçet's disease, while the oscillatory potentials were frequently abnormal even in the earlier stages of the disease. The hyperosmolarity response originates in the retinal pigment epithelial layer. The oscillatory potentials originate in the inner retinal layer. Our findings are compatible with the hypothesis that the initial retinal lesions take place in the inner retinal layer in Behçet's disease.

Adolescent↗
PubMed1989

Histamine synthesis by mouse T lymphocytes through induced histidine decarboxylase.

When spleen cells of C57BL/6 mice or mast cell-deficient W/Wv mice were cultured, their histidine decarboxylase (HDC) activity increased with increases in the histamine concentration in the cells and the medium. Addition of concanavalin A (Con A) or Escherichia coli lipopolysaccharide (LPS) enhanced the increase. The removal of adherent cells reduced both the control HDC activity and the response to the mitogens. Purified T lymphocytes responded to Con A but not to LPS. Neither Con A nor LPS had any effect on B lymphocytes. Treatment of T cells with anti-Thy-1.2 and complement completely abrogated the induction of HDC. Histamine synthesis dependent on Con A by T cells was stimulated by the addition of conditioned medium from peritoneal adherent cells activated with LPS. The addition of recombinant interleukin-1 (rIL-1) or peritoneal adherent cells fixed with paraformaldehyde significantly enhanced HDC induction dependent on Con A in T cells. These results suggest that histamine is synthesized by T lymphocytes through HDC and that the reaction was enhanced by a soluble factor(s) released from macrophages.

Animals↗
PubMed1989

Different repopulation profile between erythroid and nonerythroid progenitor cells in genetically anemic W/Wv mice after bone marrow transplantation.

Repopulation kinetics of erythrocytes and neutrophils and replacement of hematopoietic progenitors were studied in genetically anemic (WB x C57BL/6)F1-W/Wv (WBB6F1-W/Wv) hosts after bone marrow transplantation from C57BL/6-bgJ/bgJ or C57BL/6-bgJ/bgJ;Pgk-1a/Y mice. Electrophoretic pattern of hemoglobin was used as a marker of donor-type erythrocytes, giant granules of bgJ/bgJ mice as a marker of donor-type neutrophils, and A-type phosphoglycerate kinase-1 (PGK-1) as a marker of hematopoietic colonies produced by donor-derived progenitor cells. Repopulation of donor-type erythrocytes was significantly faster than that of donor-type neutrophils. Moreover, the extent of replacement was greater for erythroid progenitor cells than for nonerythroid progenitor cells. When nonirradiated WBB6F1-W/Wv mice with B-type PGK-1 received 10(5) bone marrow cells from C57BL/6-bgJ/bgJ;Pgk-1a donors, only approximately 20% replacement of erythroid progenitor cells gave rise to total reconstitution of erythrocytes. The present result suggests that normal multipotential stem cells may preferentially differentiate into erythroid lineage cells in anemic WBB6F1-W/Wv hosts and that normal erythroid progenitor cells may suppress the differentiation of erythroid progenitors of WBB6F1-W/Wv hosts.

Anemia↗
PubMed1988

Efficacy of defibrinogenation and steroid therapies on sudden deafness.

Effects of defibrinogenation therapy and steroid therapy for sudden deafness were compared by paired double-blind testing. The average hearing recovery for five frequencies (250 to 4000 Hz) was more than 30 dB; overall improvement rate was 57.3% (47/82) for the patients assigned to defibrinogenation therapy and 38.7% (31/80) for the patients assigned to steroid therapy. Thus, the former treatment resulted in significantly better hearing recovery.

Administration, Oral↗
PubMed1988

Fibroblast-dependent growth of mouse mast cells in vitro: duplication of mast cell depletion in mutant mice of W/Wv genotype.

In spite of the apparent depletion of mast cells in tissues of mutant mice of W/Wv genotype, cells with many features of mast cells do develop when bone marrow cells of W/Wv mice are cultured in the presence of pokeweed mitogen-stimulated spleen cell-conditioned medium (PWM-SCM). In order to resolve this discrepancy and facilitate the analysis of the W mutation, we attempted to establish an in vitro system in which the in vivo defect of W/Wv mice can be reproduced. Cultured mast cells (CMC) were developed from bone marrow cells of either W/Wv or congenic +/+ mice, and then co-cultured with NIH/3T3 mouse fibroblasts in media supplemented only with fetal calf serum (i.e., in the absence of PWM-SCM). Under this condition, CMC from +/+ mice continued to divide and were maintained for more than 4 weeks. The supportive effect of NIH/3T3 cells required close-range interactions with CMC and was not due to synthesis of the known mast cell growth factors, interleukins 3 and 4. By contrast, CMC from W/Wv mice were not maintained, and the number of mast cells remaining after 4 weeks of co-culture was only 1% of the normal +/+ counterparts. Thus, the humoral factor-independent and cell contact-dependent system presented here revealed the intrinsic defects in growth and differentiation of CMC derived from W/Wv mice and might be useful for biochemical and molecular analysis of the gene product(s) encoded at the W locus.

Animals↗
PubMed1988

An analysis of the hyper-sharp phenomenon of myosin diffusion in an F-actin/ATP solution by computer simulation.

The diffusion of myosin molecules was demonstrated using schlieren optics and Rayleigh fringe optics. A hyper-sharp schlieren pattern appeared near the boundary between the upper and lower parts of the diffusion cell at a time when ATP in the lower part had almost been consumed. The mechanism underlying the appearance of the hyper-sharp peak was investigated by means of computer simulations based on random-walk theory. The schlieren pattern with the hyper-sharp peak could be reproduced on the computer with the assumptions that a myosin molecule can be detached from an actin filament only on binding of ATP and that it can then move along actin filaments or diffuse in the aqueous solution. The results of the computer simulations are in good agreement with the experimental data.

Actins↗
PubMed1988

The selectivity of newly synthesized ergot derivatives to alpha 1- and alpha 2-adrenoceptors, D1- and D2-dopaminergic receptors, muscarinic acetylcholinoceptors and beta-adrenoceptors.

1. We tested affinities of newly synthesized ergot derivatives to alpha 1- and alpha 2-adrenoceptors, D1- and D2-dopamine receptors, muscarinic acetylcholinoceptors and beta-adrenoceptors using radioligand binding techniques. 2. BAM-1110 was alpha 2-selective, though its affinity to alpha 2-adrenoceptors was one tenth less than that of yohimbine. 3. BAM-1303, which was non-selective, had high affinity to alpha-adrenoceptors. The pKi-values for BAM-1303 was 10.11 against both [3H]prazosin (alpha 1-ligand) and [3H]rauwolscine (alpha 2-ligand). 4. New ergot derivatives were selective to D2-dopamine receptors. BAM-1125 and BAM-1303 had high selectivity to D2-receptors. 5. They had less affinity to muscarinic receptors and beta-adrenoceptors.

Animals↗
PubMed1988

In vitro increase of histidine decarboxylase activity and release of histamine by peritoneal resident cells of mast cell-deficient W/Wv mice; possible involvement of macrophages.

When peritoneal resident cells (PRCs) of genetically mast cell-deficient WBB6F1-W/Wv mice were cultured in vitro for 5 h at 37 degrees C, their histidine decarboxylase [HDC, L-histidine carboxylase, E.C. 4.1.1.22] activity increased 10-fold. Since inhibitors for energy production and mRNA and protein syntheses inhibited this increase of HDC activity, it appeared to represent de novo synthesis of the enzyme, i.e., induction. This increase was followed by an increase in the amount of histamine in the culture medium of the cells, indicating that histamine synthesized by the induced HDC was not stored in the cells but was quickly released. Mast cells were not involved in the HDC induction, because the extents of HDC induction in PRCs of W/Wv and wild type +/+ mice were similar. The removal of T cells with anti-Thy-1,2 antibody and complement from the PRCs did not affect the HDC induction, but the removal of phagocytes decreased the induction to one-tenth in spite of a 2-fold increase in the proportion of B cells in the PRCs. After separation of the PRCs into adherent and non-adherent fractions, the increase in HDC activity was found to be associated with the adherent fraction that was mostly positive to esterase staining. These results suggest that HDC was induced in peritoneal macrophages.

Animals↗