Biomedical subjects

N Yanai

Publications and source records attributed to N Yanai.

At least 55 records · Page 3Linked to original sources

PubMed1997

Arrest in primitive erythroid cell development caused by promoter-specific disruption of the GATA-1 gene.

To elucidate the in vivo function of GATA-1 during hematopoiesis, we specifically disrupted the erythroid promoter of the GATA-1 gene in embryonic stem cells and generated germ line chimeras. Male offspring of chimeras bearing the targeted mutation were found to die by 12.5 days post coitus due to severe anemia while heterozygous females displayed characteristics ranging from severe anemia to normal erythropoiesis. When female heterozygotes were crossed with transgenic males carrying a reporter gene, which specifically marks primitive erythroid progenitors, massive accumulation of undifferentiated erythroid cells were observed in the yolk sacs of the GATA-1-mutant embryos, demonstrating that GATA-1 is required for the terminal differentiation of primitive erythroid cells in vivo.

Animals↗

PubMed1997

Novel smooth muscle cell lines from transgenic mice harboring temperature-sensitive SV40 large T-antigen gene. Temperature-dependent expression of smooth muscle myosin heavy chain-1 and calponin genes.

We have established novel vascular smooth muscle cell lines (SVS30 and SVS24 cells) which retain the expression of specific markers for smooth muscle cells, such as alpha-actin, smooth muscle myosin heavy chain-1, and calponin, from transgenic mice harboring the temperature-sensitive SV40 large T-antigen gene. SVS cell lines showed temperature-dependent growth and the expression of SV40 large T-antigen. Interestingly, protein and mRNA levels of smooth muscle myosin heavy chain-1 and calponin seen in culture at the non-permissive temperature (39 degrees C) were higher than those at the permissive temperature (33 degrees C). These results suggest that SV40 large T-antigen affects the expression of smooth muscle-specific markers in SVS cell lines, and that some of the characters in SVS cell lines can be controlled by culture temperature. SVS cell lines should be quite valuable tools with which to study the regulation of phenotypic modulation of smooth muscle cells, and to identify smooth muscle specific transcription factors which involve the expression of smooth muscle myosin heavy chain-1 and calponin genes.

Animals↗

PubMed1997

Methotrexate as a possible cause of ovarian cysts formation: experience with women treated for ectopic pregnancies.

OBJECTIVE: To evaluate ovarian morphology after either salpingostomy or local injection of methotrexate (MTX) to cause regression of tubal pregnancies and to define potential correlation to other clinical parameters. DESIGN: Prospective longitudinal follow-up. SETTING: Department of Obstetrics and Gynecology, Haemek Medical Center, Afula, Israel. PATIENT(S): One hundred one women who were treated for tubal pregnancy: 58 by salpingostomy and 43 by local MTX injection. INTERVENTION(S): Serial blood sampling for beta-hCG and serial transvaginal sonographic evaluation. MAIN OUTCOME MEASURE(S): Appearance of cysts in the ovaries and their location with regard to the side in which the tubal pregnancy occurred. RESULT(S): In 6 of 42 (14.3%) patients who were treated with MTX, multiple (range, three to six) ovarian cysts occurred, as compared with 1 of 55 (1.8%) in those who underwent salpingostomy. The largest cyst was 9.4 cm in diameter. No relation of cyst occurrence to the side of the ectopic pregnancy was recorded. The women who developed cysts did not differ in either initial serum beta-hCG levels or in the rate of its subsequent regression. CONCLUSION(S): Multiple ovarian cysts may occur in 15% of patients who are treated with intra-amniotic MTX to cause regression of tubal ectopic pregnancy.

Adult↗

PubMed1997

Selective stimulation of granulopoiesis in vitro by established bone marrow stromal cells.

Bone marrow is a major granulopoietic organ whose hematopoietic microenvironment is comprised of stromal cells. In the present work, we examined the regulation of in vitro granulopoiesis with an established line of bone marrow stromal cells. In coculture of the progenitor cells on the particular stromal cell lines from bone marrow, large granulocyte (G) colonies consisting of over 200 cells were formed without G-CSF for 5 days. Stromal cells supported development of Gr-1 (granulocyte specific surface marker)-negative progenitors into Gr-1 and myeloperoxidase positive granulocytes. Seventy percent of the large G-colonies were formed on the stromal layers even in the presence of anti-G-CSF antibody, which indicates the G-CSF independent pathway of granulopoiesis. Inhibition of the large G-colony formation by the addition of anti-adhesion molecules, such as very late activation antigen-4 (VLA-4) and CD31 (PECAM-1), suggested the role of cell-to-cell adhesion in stroma-supported granulopoiesis.

Animals↗

PubMed1997

[A case of acquired immunodeficiency syndrome with disseminated Mycobacterium avium complex infection in which M. avium was isolated from bone marrow].

A 46-year old man was admitted to a hospital because of cough and dyspnea. He was diagnosed as interstitial pneumonia and was treated with prednisolone (PSL) and antibiotics. The symptoms improved temporarily but he soon developed acute respiratory failure and was transferred to our hospital. Chest X-ray and CT revealed ground-glass opacities in both lung fields. He was treated with methyl PSL, antibiotics, and antimycobacterial drugs but he died on the fourth hospital day. Retrospectively, hematologic laboratory examinations revealed that CD4+ cell count was 0/microliter and serological tests for HIV were positive by both EIA and Western blot methods. The culture of the bone marrow specimens was positive for mycobacteria other than M. tuberculosis, and the bacilli were identified as Mycobacterium avium. Thus, his disease was eventually diagnosed as disseminated Mycobacterium avium complex (MAC) infection. In the past reports, the diagnosis of disseminated MAC infection was most often made by blood cultures, however, the isolation of MAC from bone marrow is another sensitive and specific method for the diagnosis of this infection. In some cases, bone marrow examination would be useful to diagnose disseminated MAC infection.

AIDS-Related Opportunistic Infections↗

PubMed1997

A new type-II membrane protein in erythropoietic organs enhances erythropoiesis.

Erythropoiesis is regulated by erythropoietin and microenvironment of erythropoietic organs such as fetal liver and spleen in mice. We developed in vitro erythropoietic microenvironment by established stromal cell lines from erythropoietic organs, in which proliferation and differentiation of erythroid progenitor cells are supported by direct cell-to-cell contact between erythroid progenitor cells and the stroma cells. To identify the functional molecules of the stromal cells, we established monoclonal antibodies which detected specific molecules of the erythropoietic organs. Among those monoclonal antibodies, 11 D exhibited specific immunohistochemical staining of the red pulp of spleen where erythropoiesis dominates. Using this monoclonal antibody, we cloned a new gene (SMAP-1) which codes a type-II membrane protein. Over expression of its antisense cDNA in a stroma cell line caused a decrease in the erythropoietic supporting activity. Thus, SMAP-1 may play an important role in the erythropoietic stimulatory activity of the stromal cells.

Animals↗

PubMed1997

[Clinical evaluation on causes of death in patients with pulmonary tuberculosis who died within one year after diagnosing as TB].

We evaluated the cause of death in patients with pulmonary tuberculosis who died within one year after diagnosing as tuberculosis. Of 325 bacillary patients during the past seven years, 43 (13.2%) died within one year. Twenty-three patients (53.5%) died directly of tuberculosis. In this group, 13 patients died in emaciation state. Most of them were aged and under a poor nutritional condition. Some patients died in spite of improvement of tuberculosis. The fact indicates the need to detect tuberculosis as early as possible in elderly persons, and treatment should be initiated immediately. Eight patients died of respiratory failure and their chest X-ray film showed wade-spread tuberculosis. Seven of the patients died in spite of initiating treatment within one month after the onset of symptoms. This fact suggests the importance of regular check up by chest X-ray to detect tuberculosis early. Two patients died of massive hemoptysis. They had an episode of bloody sputum and the laboratory examination showed anemia. On the other hand, 20 patients died due to coexisting diseases unrelated to tuberculosis. Ten patients died of malignant diseases and most of them were lung cancer. Two patients died of hepatic failure possibly caused by the adverse reaction of TB chemotherapy. The interval between the onset of the treatment and death was less than a month, and the fact suggests the need to observe carefully for adverse reactions especially in the early stage of treatment.

Aged↗

PubMed1996

Establishment of a novel chondrocyte-like cell line derived from transgenic mice harboring the temperature-sensitive simian virus 40 large T-antigen gene.

We established a clonal chondrocyte-like cell line (TC6, TC stands for large T immortalized chondrocyte-like cell line) derived from articular cartilage of transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. TC6 cells exhibited spindle-like or polygonal morphology and grew well at 33 degrees C in alpha-minimal essential medium supplemented with 0.5% fetal bovine serum. After confluence, these cells formed nodules that were positive for staining with alcian blue. Northern blot analysis demonstrated that these cells expressed messenger RNAs (mRNA) of the genes encoding cartilage-specific proteins such as type II procollagen, link protein, and aggrecan. Furthermore, the expression of type II procollagen and link protein genes in TC6 cells was regulated by parathyroid hormone and basic fibroblast growth factor, suggesting the presence of the receptors for the hormone and cytokine. The expression of link protein mRNA in TC6 cells was regulated in a time-dependent manner and was enhanced in culture within a week and increased continuously up to 10-fold by the end of 4 weeks. Expression of mRNAs encoding type II procollagen and versican/PG-M also increased moderately during the culture period. TC6 cells expressed type I procollagen mRNA, however, its level declined along with time in culture in contrast to the enhancement of the genes encoding cartilage-specific molecules in these cells. Interestingly, alkaline phosphatase mRNA expression was barely detectable in the TC6 cells in their growing phase while it was enhanced dramatically more than 7-fold by day 14 in culture. These results indicate that the TC6 cells could serve as an excellent model for the studies on chondrocyte physiology.

Animals↗

PubMed1996

Phenotypic change and proliferation of murine Kupffer cells by colony-stimulating factors.

Kupffer cells were isolated from C57BL/6 mice by collagenase perfusion and assessed for response to colony-stimulating factors (CSFs) in terms of their phenotypic change and proliferation. Kupffer cells expressed F4/80, but not Mac-1, CD71, or asialo-GM1 initially. This phenotype pattern was different from that of alveolar and peritoneal macrophages. After stimulation with recombinant human macrophage CSF (M-CSF) or mouse granulocyte-macrophage CSF (GM-CSF), Kupffer cells expressed Mac-1 and a low level of CD71 in addition to F4/80 and increased in phagocytotic activity in association with the expression of CR3. Both M-CSF and GM-CSF, but not human IL-3, induced the proliferation of Kupffer cells in a dose-dependent manner, and after 7 days, the number of the cells increased to about four to six times the initial number. The relatively high dose of GM-CSF downmodulated the M-CSF receptor on Kupffer cells and inhibited the cell proliferation induced by the optimal dose of M-CSF. These data indicated that murine Kupffer cells have a different phenotype from other macrophages and that they respond to M-CSF and GM-CSF, leading to functional maturation and proliferation.

Animals↗

PubMed1996

Sequencing of a 65 kb region of the Bacillus subtilis genome containing the lic and cel loci, and creation of a 177 kb contig covering the gnt-sacXY region.

Within the framework of an international project for the sequencing of the entire Bacillus subtilis genome, this paper communicates the sequencing of a chromosome region containing the lic and cel loci (65 kb), which creates a 177 kb contig covering the region from gnt to sacXY. This 65 kb region contains 64 ORFs (62 complete and two partial genes). The 14th, 15th and 17th genes correspond to licT, licS and katE, encoding the antiterminator for licS transcription, beta-glucanase (lichenase) and catalase 2, respectively. The 11th, 30th, 36th, 39th, 41st, 45th-48th, 51st and 58th genes are designated deaD, pepT, galE, aldY, msmX, cydABCD, sigY and katX because their products probably encode ATP-dependent RNA helicase, tripeptidase, UDP-glucose 4-epimerase, aldehyde dehydrogenase, multiple sugar-binding transport ATP-binding protein, the respective components of cytochrome d ubiquinol oxidase and ATP-binding cassette transporter, sigma-factor of RNA polymerase and catalase, respectively. The 60th-64th genes are celRABCD, which are probably involved in cellobiose utilization. Gene organization and gene features in the gnt-sacXY region are discussed.

Bacillus subtilis↗

PubMed1996

A retinal pigment epithelium-derived cell line from transgenic mouse harboring temperature-sensitive simian virus 40 large T-antigen gene.

We established a retinal pigment epithelium-derived cell line from transgenic mouse harboring temperature-sensitive simian virus 40 T-antigen gene (tsSV40T) and examined its characteristics. We enucleated both eyes from a 2-month-old transgenic mouse and removed the retinal pigment epithelial (RPE) cells and neuroretinal cells. After cloning the RPE cells, we obtained a cell line (RPET). RPET cells grew well at 33 degrees C but not at 37 degrees C, expressing on the temperature-sensitive character of tsSV40T, and maintained characters of RPE cells such as T1-tyrosinase production, phagocytosis of rod outer segments, and presence of cytokeratin, microvilli on the cell surface and lysosome-like granules around the Golgi apparatus in the cytoplasm. Conditioned medium (CM) from a culture of neuroretinal cells harboring tsSV40T was essentially required for growth. The factor(s) in CM was heat-and acid labile, but was resistant to trypsin digestion. In the presence of 3% CM, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) and strong effects on RPET cells, whereas insulin, insulin-like growth factor I (IGF-I), and IGF-II had moderate growth effects. Interestingly, none of these growth factors stimulated the RPET cells in the absence of CM. EHS-Matrix had growth effect, whereas laminin, collagen types I and IV, and fibronectin had no marked growth effects on RPET cells. RPET cells were morphologically changed on a laminin-coated dish. They could not spread on the coated dish, and the majority of the cells floated. But when the floating cells were transferred to non-coated dishes, they immediately attached themselves. These results suggest that RPET cells are a good model for for finding novel growth factor(s) and for investigating the mechanism of cell-laminin attachment.

Animals↗

PubMed1996

Macrophage colony-stimulating factor induces interleukin-8 production in human monocytes.

We have investigated the stimulatory effect of recombinant human macrophage colony-stimulating factor (rhM-CSF) on interleukin-8 (IL-8) production by human peripheral blood monocytes. When monocytes were prepared from peripheral blood and cultured for 24 hours, the average amount of IL-8 in the culture medium was about 8.9 +/- 3.2 ng/2 x 10(5) cells. In contrast, the production of IL-8 by monocytes increased to a level of 19.2 +/- 4.7 ng/2 x 10(5) cells in response to rhM-CSF. This induction by rhM-CSF was dose-dependent. Northern blot analysis showed that expression of IL-8 at the pretranslational level was enhanced after M-CSF treatment. Kinetic studies showed that secretion of IL-8 from monocytes was enhanced within 2 hours after exposure to rhM-CSF, and a saturation level, which was reached around 48 hours, was two-fold higher than that of cells without M-CSF treatment. In addition, conditioned medium of M-CSF-stimulated monocytes activated the chemotaxis of human neutrophils, and this activity was significantly inhibited by anti-IL-8 antibody. These results, taken together, suggest that M-CSF can affect many cellular functions through regulation of IL-8 expression in monocytes.

Animals↗

PubMed1996

v-src interferes with the in vitro erythropoietic stimulatory ability of spleen stromal cells through repression of vascular cell adhesion molecule-1 and stem cell factor.

A mouse spleen stromal cell line, MSS62, can create an in vitro erythropoietic microenvironment in which development of erythropoietin-responsive progentor cells is stimulated by cell-cell contact via stem cell factor (SCF)/c-Kit and vascular cell adhesion molecule-1 (VCAM-1)/very late activation antigen-4 (VLA-4) interactions between stromal and erythroid cells. To find out the effect of src on the erythropoietic microenvironment, MSS62 cells were transfected with v-src oncogene, and its effect on erythropoietic stimulatory activity was measured. Transfectants with high v-Src activity showed reduction in erythropoietic stimulatory activity. A decrease in cell-surface VCAM-1 and SCF mRNA was accompanied by high v-Src activity. These results suggest that v-Src interferes with the erythropoietic stimulatory activity of the stromal cells through repression of VCAM-1 and SCF.

Animals↗

PubMed1996

[Four cases of tuberculous meningitis--clinical significance of pleocytosis with polymorphonuclears as the predominating cell type in CSF].

It has been well known that tuberculous meningitis cases have moderate pleocytosis with mononuclears as predominating cell type in cerebrospinal fluid (CSF). But there are some reports of tuberculous meningitis in which polymorphonuclears was predominant in CSF. In this study, we investigated differential cell counts of CSF in 4 tuberculous meningitis cases. In 3 of the 4 cases, the CSF had a polymorphonuclears preponderance on admission. The elevated ratio of polymorphonuclears seemed to relate with the severity of the disease, and the ratio declined promptly after the initiation of chemotherapy. The 2 cases, which showed extremely high ratio of polymorphonuclears, showed poor prognosis, one died and the other had the severe sequelae such as notable disturbances of consciousness with hydrocephalus. This study suggests that differential cell counts of CSF is a useful measures to predict the prognosis and to follow up patients with tuberculous meningitis. The finding of a polymorphonuclears preponderance in CSF would suggest the severity and activities of the disease and should be considered as an alarm sign in tuberculous meningitis.

Adult↗

PubMed1995

Cloning and sequencing of a 23-kb region of the Bacillus subtilis genome between the iol and hut operons.

Within the framework of an international project for the sequencing of the entire Bacillus subtilis genome, a 23-kb chromosomal segment, which covers the region between the iol and hut operons, has been cloned and sequenced, creating a 99-kb contig from the gnt operon to the wapA locus. This region (23351 bp) contains 25 complete open reading frames (ORFs; genes) including deoR, dra, nupC and pdp and two partial ones. The region (5140 bp) containing these four genes, being also sequenced by H. H. Saxild et al., was sequenced by subjecting a long polymerase chain reaction product to random sequencing using phage M13mp19. However, we could detect no conflict, between two independently determined sequences, which could be attributed to our sequencing method. A homology search for the 24 newly identified gene products revealed significant homology to known proteins in 14 of them. It was notable that three proteins, encoded by the successive genes (yxeMNO), exhibited meaningful homology to the E. coli GlnHPQ products constituting a periplasmic ATP-dependent transport system for glutamine.

Bacillus subtilis↗

PubMed1995

Bone marrow stromal cells induce myeloid and lymphoid development of the sorted hematopoietic stem cells in vitro.

Regulation of development of hematopoietic stem cells was examined by culturing Lin- c-Kit+ Sca1+ stem cells sorted from bone marrow (BM) cells by fluorescence-activated cell sorting on a layer of TBR59, a BM stromal cell line established from simian virus 40 T-antigen gene transgenic mice. The sorted stem cells did not show self-renewal, but two waves (at 7 and 13 days) of a cobblestone formation were induced by the stromal cell layer. The cobblestones were formed by finite cell division (eight divisions on average) of sorted Lin- c-Kit+ Sca1+ stem cells, and divided cells were still immature. The c-Kithigh stem cell population was induced to form the first wave of cobblestone formation committed to myeloid lineage, whereas c-Kitlow population was induced to form the second wave of this formation committed to lymphoid lineage. Both cobblestone formations require c-Kit function, but very late activation antigen-4-vascular cell adhesion molecule-1 interaction plays different parts in the two lineages.

Animals↗

PubMed1995

Thrombin and TGF-beta promote human leptomeningeal cell proliferation in vitro.

Some disorders of the central nervous system, such as trauma, meningitis, or subarachnoid hemorrhage (SAH), result in inflammation and fibrosis of the arachnoid membranes followed by hydrocephalus. To clarify the role of growth factors in the pathophysiology of arachnoid fibrosis, we investigated the response of leptomeningeal (LM) cells to growth factors elevated in the cerebrospinal fluid (CSF) of patients with subarachnoidal inflammation. We examined the proliferative responses of LM cells to thrombin, transforming growth factor-beta (TGF-beta), epidermal growth factor (EGF), acidic fibroblast growth factor (aFGF), platelet derived growth factor (PDGF), tumor necrosis factor-beta (TNF-beta) and interleukin 1-beta (IL1-beta). Thrombin, TGF-beta, EGF, aFGF and PDGF promoted LM cell proliferation. TGF-beta enhanced the proliferative effect of thrombin and EGF on LM cells. These findings suggest that thrombin and TGF-beta, which may be elevated in CSF following SAH, may cause subarachnoid fibrosis and subsequent hydrocephalus.

Animals↗

PubMed1995

Bone marrow stromal cells selectively stimulate the rapid expansion of lineage-restricted myeloid progenitors.

Bone marrow stromal cells serve hematopoietic microenvironments where different blood cells are controlled in their growth and differentiation. To characterize functions of stromal cells, 33 bone marrow stromal cells including preadipocytes, endothelial cells, and fibroblasts were established from transgenic mice harboring temperature-sensitive SV40 T-antigen gene and their selective stimulatory abilities to support large colony formation of lineage-specific hematopoietic progenitor cells (erythroid, monocyte/macrophage, granulocyte, and monocyte-granulocyte) were examined. Among established stromal cells, 27 clones showed erythropoietic stimulatory activity in the presence of erythropoietin. On myeloid progenitors, the stromal cells showed lineage-restricted stimulatory activity and a reciprocal relationship was observed between granulocyte formation and macrophage formation, but these activities were not dependent on the amount of produced colony-stimulating factors (CSFs). Our present study with many stromal cells established from bone marrow indicated that each stromal cell in the bone marrow may provide the preferable microenvironment for a rapid expansion of the lineage-restricted progenitor cells in combination with CSFs.

Animals↗