Search PubMed⌕ Search

Biomedical subjects

H Mitsui

Publications and source records attributed to H Mitsui.

At least 91 records · Page 5Linked to original sources
PubMed1994

Increased retention of small chromosomes in a novel yeast mutant.

MSC201 and MSC202 are novel yeast mutant strains in which a 10-kb linear yeast artificial chromosome (YAC) was stably maintained in unselective medium during mitotic cell division. After culturing for 35 cycles of cell division, about 50% of MSC cells retain YAC3 DNA, compared to 0.001% of the wild-type AB1380 strain. Southern blot hybridization analysis with pBR322 DNA as the probe showed that in the MSC transformants, YAC DNA remained in a linear form free of cellular chromosomal DNA. The msc201 mutation was shown to be recessive by the rapid loss of the YAC in a diploid strain made by mating with AB1375, which has a genetic background similar to that of the MSC strain. Linear YAC DNA with a centromere was stabilized in MSC201 better than a linear construct lacking a centromere sequence.

Chromosomes, Artificial, Yeast↗
PubMed1994

Stimulation of partial development of human mast cells by supernatant fluid from mouse fibroblast cultures.

Fibroblasts have been implicated as culture-competent cells for the mast cell lineage in several species. In man, fibroblast monolayers sustain the ultrastructural phenotype and function of isolated human lung mast cells and permit the differentiation and full maturation of human mast cells from their agranular precursors in cord blood cells. We examined whether development and maturation of the mast cell lineage in man can be achieved by a supply of the soluble products present in fibroblast culture supernatants. Suspension cultures of cord blood cells were supplemented with culture supernatants derived from two different murine fibroblast lines; controls were not supplemented. The cultures were sampled for light and electron microscopy at 6, 7 and 8 weeks. Human mast cells developed in quantity when cultures were supplemented with the supernatants from BALB/c 3T3 fibroblasts, in reduced numbers when supplemented with Swiss Albino 3T3 fibroblast supernatants, and not at all in culture media alone. By ultrastructural criteria, the newly developed mast cells did not achieve full maturity; they did continue to synthesize new granules and to undergo intragranular maturational events. Small numbers of mature basophils persisted in suspension cultures, and many were undergoing piecemeal degranulation. Other cell lineages noted included eosinophils, neutrophils, macrophages and endothelial cells. We conclude that a factor(s) of fibroblast origin permits the differentiation and partial maturation of human mast cells from their agranular precursors in cord blood, but that fibroblasts must be physically present for complete maturation of these lineages to occur.

Animals↗
PubMed1994

Charcot-Leyden crystal protein distribution in basophils and its absence in mast cells that differentiate from human umbilical cord blood precursor cells cultured in murine fibroblast culture supernatants or in recombinant human c-kit ligand.

Suspension cultures of human umbilical cord blood mononuclear cells supplemented with c-kit ligand-containing additives give rise to a mixture of cells belonging to several lineages. Among those that differentiate in quantity are mature basophils, immature mast cells, and neutrophilic myelocytes. We used an ultrastructural immunogold method to detect the Charcot-Leyden crystal (CLC) protein, an eosinophil- and basophil-specific protein, to study cells that were obtained at sequential times from 3 to 14 weeks in culture. Basophils (and eosinophils, which were present in smaller numbers) labeled for the CLC protein; mast cells did not. The labeled basophil subcellular sites included formed intragranular, cytoplasmic and nuclear CLCs, cytoplasmic particle-filled and homogeneously dense granules, cytoplasm, nucleus, plasma membrane, and cytoplasmic and Golgi area vesicles. Individual basophil ultrastructural phenotypes similar to those associated with stimulated release and recovery reactions showed the expected variations in the gold-labeled subcellular compartments. Macrophages also were labeled for CLC protein within endocytotic-lysosomal structures; neutrophilic myelocytes did not contain CLC protein. On the basis of findings reported here, the combined ultrastructural morphology and immunogold phenotyping of cells differentiating in c-kit ligand-supplemented cultures allows accurate lineage assignment of the developing cells.

3T3 Cells↗
PubMed1994

Correlation between the layer of an intimal tear and the progression of aortic dissection.

Thoracic aortas isolated from dogs were evaluated to determine the correlation between the depth of an intimal tear and the progression of aortic dissection. Thoracic aortas obtained from 99 adult mongrel dogs were used. An intimal tear (aortic pocket) was created on the aortic wall and the aorta was connected in series to a closed circuit (150 mmHg/100 mmHg and 60 beats/min). The progression of the dissection was most notable in the aortic pocket prepared in the first one-third of the external media (87.5%). There was no correlation however between the width of the pocket and the progression of dissection. Examinations of samples from surgical patients have shown that dissection usually progresses at the same site. This has been attributed to the diseased media. Our results demonstrated that dissection occurred almost always at the same site without any medial changes suggesting that whether dissection develops or not likely depends upon whether the intimal tear reaches the first one-third of the external media or not.

Aortic Dissection↗
PubMed1994

Experimental model for MDS-like myelodysplasia in transgenic mice harboring the SV40 large-T antigen under an immunoglobulin enhancer.

The SV40 large T gene under the control of immunoglobulin enhancer induced hyperproliferation of multi-lineage hematopoiesis in transgenic mice. Hence the disease has been considered to be an appropriate experimental model for MDS-like myelodysplasia, sequential pathological changes in the development of the disease are introduced in the report. Huge splenomegaly was the major gross abnormality, which developed with 100% frequency; neither hepato-renal, nor other thymico-lymphatic involvement was common. During the progressive increase in splenic weight, extensive proliferation of multi-lineage hemopoiesis was prominent, although no differences were apparent in the cellular proportions of each hematopoietic element compared with normal spleens, either in flow-cytometric analysis using markers for each subset of hematopoietic elements, or in the histological findings. In the later phases of the disease, the proliferating cell type tended to shift to a variety of single to oligo-lineage hemopoiesis, but the majority of mice still showed the presence of multi-lineage hemopoiesis; histologically, such hemopoiesis was somewhat dysplastic, but had no apparent nature of leukemic infiltration. Several transplantation-assays essentially supported the low neoplastic potential of proliferating cells even in later phase. A long-term observation was made aiming to induce more frequent transition of this abnormal hemopoiesis into a single-lineage neoplasm by transplantation of pre-onset spleen cells, as well as bone-marrow cells from transgenic mice at an early phase of the disease, into lethally irradiated C57BL/6 mice. This trial resulted in a variety of neoplastic growths in the recipients; not only was myelodysplastic hypercellularity seen, but also, single-lineage hemopoietic malignancies, such as B-cell lymphomas/leukemias, histiocytic malignancies, and even myeloid leukemias. The transition from multi-lineage myelodysplasia into single lineage hemopoiesis at some frequency is reminiscent of myelodysplastic syndromes (MDS) in humans. Higher frequency of transition into lymphoid malignancies may be due partly to the immunoglobulin enhancer used as a promoter unit. The results that the SV40 large T antigen was expressed in every proliferating cells, there was no apparent increase in multi-CSFs activity; together with the results of the transplantation assays suggest that the hyperproliferation of the cells is directly induced by the expression of SV40 large T antigen in the hemopoietic cells themselves.

Animals↗
PubMed1994

Humoral inhibitor of rat hepatocyte DNA synthesis from patients with fulminant liver failure.

Sera and ultrafiltrates (relative molecular mass < 10,000 Da) from patients with fulminant liver failure inhibit hepatocyte DNA synthesis in vivo. In this study the effects of ultrafiltrates from pooled sera from fulminant liver failure patients in the United Kingdom and plasma ultrafiltrates from fulminant liver failure patients in Japan have been investigated in primary cultured rat hepatocytes, with incubation for up to 72 hr. Both types of ultrafiltrate inhibited the incorporation of [3H]thymidine into acid-precipitable material and reduced the cell labeling index as determined on autoradiography in hepatocytes stimulated by epidermal growth factor and insulin compared with normal sera/plasma ultrafiltrates. The inhibitory effects observed were dose dependent, reversible when the fulminant liver failure ultrafiltrate was removed and were not associated with increased release of lactate dehydrogenase or suppression of protein synthesis as assessed on the basis of the incorporation of [3H]leucine. The effects appeared to be specific for hepatocytes; in preliminary experiments DNA synthesis was not inhibited in cultured fibroblasts (NIH 3T3 cells). These experiments are further evidence of the presence of an inhibitory factor of relative molecular mass less than 10,000 Da in the blood of patients with fulminant liver failure.

Adolescent↗
PubMed1993

Functional expression of interleukin 2 receptor in a human factor-dependent megakaryoblastic leukemia cell line: evidence that granulocyte-macrophage colony-stimulating factor inhibits interleukin 2 binding to its receptor.

Human interleukin 2 (IL-2) is a member of the class of crucial regulators of lymphocyte proliferation. The action of IL-2 is known to be mediated through binding to a specific IL-2 receptor (IL-2R) which comprises at least two distinct proteins: IL-2R alpha (p55) and IL-2R beta (p70-75). However, the expression and function of IL-2R are largely unknown in acute myeloblastic leukemia cells. In a human granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, or stem cell factor-dependent myeloid leukemia cell line (M07E), IL-2 was found to stimulate proliferation in a dose-dependent manner and to augment GM-CSF- and stem cell factor-induced proliferation of M07E cells. The expression of IL-2R beta on M07E cells was detectable with 125I-IL-2 binding and affinity cross-linking analyses and with a monoclonal antibody against IL-2R beta, Mik-beta 1. Although the expression of IL-2R beta was not down-regulated but somewhat up-regulated by treatment with GM-CSF in both mRNA and protein levels, GM-CSF was found to compete (75%) with radiolabeled IL-2 for binding to IL-2R on M07E cells, whereas no competition of GM-CSF binding was observed with IL-2 even at a 400-fold molar excess. These results suggest that IL-2R may be functionally expressed in some cases of acute myeloblastic leukemia cells and raise the possibility that IL-2 may have some effects on human myelopoiesis.

Binding, Competitive↗
PubMed1993

Development of human mast cells from umbilical cord blood cells by recombinant human and murine c-kit ligand.

Both human and mouse c-kit ligand induced differentiation of human mast cells in a long-term culture of the mononuclear cells of umbilical cord blood. Growth factor activity for human mast cells present in conditioned medium of BALB/3T3 fibroblasts was due to mouse c-kit ligand. Recombinant c-kit ligand induced differentiation and proliferation of mast cell progenitors in early stages of culture. However, apparent selective growth of mast cells by c-kit ligand in cord blood cell cultures is mainly due to the effect of the cytokine to selectively maintain survival of immature mast cells. Electron microscopic analysis indicated that human mast cells developed by c-kit ligand were similar to human mast cells in the lung and gut mucosa, while those developed in coculture of cord blood cells with Swiss albino/3T3 fibroblasts were similar to skin mast cells. This conclusion was supported by the fact that the majority of mast cells developed by c-kit ligand contained only tryptase in their granules, whereas those developed in the cocultures contained both tryptase and chymase. It was also found that mast cells developed by c-kit ligand were immature even after culture for 14 weeks. Nevertheless, these cells express Fc epsilon RI, and could be sensitized with human IgE for anti-IgE-induced release of histamine, prostaglandin D2, and leukotriene C4.

Animals↗
PubMed1993

Ultrastructural morphology of immature mast cells in sequential suspension cultures of human cord blood cells supplemented with c-kit ligand; distinction from mature basophilic leukocytes undergoing secretion in the same cultures.

The ability to culture human mast cells and, thus, to determine their ontogeny and possible relationships to other lineages has been facilitated by new studies using cocultures of cord blood cells with mouse fibroblasts and recombinant human or murine c-kit ligand-supplemented suspension cultures of cord blood cells. In this study, we examined c-kit ligand-supplemented cord blood cell suspension cultures designed so that the effects of growth factor source, individual cord sample, and culture time (3-17 weeks) on the developing mast cell lineage could be individually evaluated. We found that human mast cells, basophils, neutrophils, eosinophils, macrophages, megakaryocytes, and endothelial cells were present in these cultures. The numbers of mast cells and their granules increased with culture time; mature basophils, present in quantity in 3-week cultures, decreased in number and released granule contents with increased culture times. The mast cell lineage developed similarly, regardless of which factor preparation was added to cultures, but considerable variability existed among individual donors from whom cord bloods were obtained. Unlike the mature, crystal-containing mast cells that regularly developed in fibroblast cord blood cocultures (Furitsu et al. [1989] Proc. Natl. Acad. Sci. USA 86, 10039-10043), human mast cells failed to attain full maturity in the suspension cultures examined here, regardless of individual cord sample, added growth factor, or culture time. Furthermore, unlike cells of the basophil lineage in which granule content release was regularly observed, morphologic evidence of secretion from human mast cells was absent. Instead, these cells were actively undergoing granule building as determined by the increasing numbers of granules and filling of these containers over culture time. Crystal granules never developed, even at the maximum culture time of 17 weeks. We conclude that fibroblasts are necessary and sufficient for the differentiation and maturation of human mast cells in vitro from their agranular precursors in cord blood but that soluble c-kit ligand is not.

Animals↗
PubMed1993

Identification of a gene family (kat) encoding kinesin-like proteins in Arabidopsis thaliana and the characterization of secondary structure of KatA.

A gene family, designated kat, has been characterized in Arabidopsis thaliana by genomic Southern hybridization and nucleotide sequencing analysis. The kat gene family includes at least five members, named katA, katB, katC, katD and katE, whose products share appreciable sequence similarities in their presumptive ATP-binding and microtubule-binding motifs with known kinesin-like proteins. The carboxyl-terminal region of the KatA protein deduced from the nucleotide sequence of the cDNA clone has considerable homology with the mechanochemical motor domain of the kinesin heavy chain. The predicted secondary structure of the KatA protein indicates two globular domains separated by a long alpha helical coiled coil with heptad repeat structures, such as are commonly found in kinesin-like proteins.

Amino Acid Sequence↗
PubMed1993

Development of human mast cells from their progenitors.

Two types of human mast cells, which are morphologically similar to skin mast cells and lung mast cells, respectively, can be developed from pluripotent stem cells under different culture conditions. The major growth factor for mast-cell development is c-kit ligand, which induces mastocytosis in vivo. However, this cytokine is not sufficient for full maturation of the cells.

Cell Differentiation↗
PubMed1993

Effect of okadaic acid on histamine release from rat peritoneal mast cells activated by anti-IgE.

The effect of okadaic acid, a potent inhibitor of protein phosphatase 1 and 2A, on histamine release from mast cells has been investigated. Okadaic acid strongly and dose-dependently inhibited histamine release from mast cells induced by anti-IgE. The IC50 value of okadaic acid on histamine release induced by anti-IgE was 3.2 nM. However, okadaic acid failed to inhibit histamine release induced by A23187 and compound 48/80. Moreover, okadaic acid showed no effect on the initial rise in intracellular Ca2+, Ca(2+)-mobilization from intracellular Ca(2+)-stores and the generation of inositol trisphosphate. These results suggest a possible involvement of protein phosphatase 2A in the histamine release from mast cells induced by anti-IgE.

Animals↗
PubMed1993

Human and murine recombinant c-kit ligands support the development of human mast cells from umbilical cord blood cells: ultrastructural identification.

The recently identified ligand for c-kit, a protooncogene encoded by the W locus in mice, is a member of the tyrosine kinase receptor family with growth factor activity for mouse mast cells. Mature human mast cells regularly develop from agranular precursors in cord blood in long-term cocultures of cord blood and murine fibroblasts. Since the c-kit ligand is a product of murine fibroblasts, we examined the growth effect of recombinant human c-kit ligand (stem cell factor), of recombinant murine c-kit ligand (mast cell growth factor), and of a partially purified fraction derived from mouse fibroblast culture supernatant on the mast cell lineage of humans by electron microscopy in 8-week cultures of cord blood cells. We found that immature mast cells which developed in cultures containing the recombinant ligand for c-kit of human or murine origin as well as the naturally occurring c-kit ligand in 3T3 fibroblast supernatants were identical. Thus, each of these sources of the c-kit ligand exerted identical effects on the ontogeny of human mast cells as they develop from their agranular precursors in cord blood. Full maturity of factor-supported mast cells did not occur.

3T3 Cells↗
PubMed1993

C-kit ligand induction of immature neutrophils in cultures of human umbilical cord blood.

Human cord blood cells cultured in suspension with soluble c-kit ligand produce immature mast cells from their agranular precursors; cocultures of cord blood and mouse 3T3 fibroblasts produce fully mature human mast cells. We noted cells of the neutrophil lineage in the c-kit ligand-supplemented suspension cultures. Similar cultures were prepared from individual cord bloods with several sources of the c-kit ligand, including mouse fibroblast conditioned media, a partially purified mouse 3T3 fibroblast factor(s), recombinant human stem cell factor, recombinant murine mast cell growth factor, and were sampled sequentially for routine and cytochemical ultrastructural studies. These studies show that peroxidase-positive azurophilic granule-containing neutrophilic myelocytes develop in quantity from their agranular precursors in cord blood when the c-kit ligand is present, but little to no maturation to mature neutrophils with specific granules occurs. Specific granules were also absent in the neutrophil precursors. The effect of c-kit ligand in vitro on two cell lineages in man is similar--i.e., it permits the development of immature cells to differentiate from their agranular precursors in cord blood, but complete maturation to fully mature mast cells or neutrophils does not occur.

Animals↗
PubMed1993

Hybrid total knee arthroplasties in rheumatoid arthritis.

One hundred and sixty-eight total knee arthroplasties (TKA) with cementless femoral components, cemented tibial and patellar components were performed in 98 patients with rheumatoid arthritis (RA) between 1989 and 1992. At 1-4 years followup the hybrid TKA in RA provided satisfactory results when compared to the cemented TKA. There were no signs of loosening about the cementless femoral component. The results indicate that the hybrid TKA is comparable to a fully cemented knee even in the patients with severe RA at one to four years followup.

Adult↗
PubMed1992

Elongation factor-1 alpha gene determines susceptibility to transformation.

Elongation factor-1 alpha (EF-1 alpha), an essential component of the eukaryotic translational apparatus, is a GTP-binding protein that catalyses the binding of aminoacyl-transfer RNAs to the ribosome. Expression of the EF-1 alpha gene decreases towards the end of the lifespans of mouse and human fibroblasts, but forced expression of EF-1 alpha prolongs the lifespan of Drosophila melanogaster. Eukaryotic initiation factor-4E, another component of the translational machinery, is mitogenic or oncogenic when constitutively expressed in some mammalian cells. Thus, components of the protein synthesis apparatus seem to be involved in the control of cell proliferation. Using expression cloning, we have isolated a complementary DNA clone from a BALB/c 3T3 mouse fibroblast variant, A31-I-13 (ref. 10), which specifies a factor determining the susceptibility of BALB/c3T3 to chemically and physically induced transformation. Here we report that the factor is EF-1 alpha and that its constitutive expression causes BALB/c 3T3 A31-I-1 (ref. 10), C3H10T1/2 (ref. 11) and Syrian hamster SHOK fibroblasts to become highly susceptible to transformation induced by 3-methylcholanthrene and ultraviolet light. EF-1 alpha messenger RNA is also constitutively expressed in a quiescent culture of the highly susceptible variant A31-I-13. We conclude that the removal of regulation of the expression of these components of the translational machinery may predispose cells to become more susceptible to malignant transformation.

3T3 Cells↗