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S Asano

Publications and source records attributed to S Asano.

At least 91 records · Page 5Linked to original sources
PubMed2000

The effect of granulocyte colony-stimulating factor administration in healthy donors before bone marrow harvesting.

To investigate whether granulocyte colony-stimulating factor (G-CSF) administration to donors before harvest may lighten the burden imposed on them and accelerate the bone marrow (BM) recovery, we administered 2 microgram/kg/d of G-CSF for five consecutive days before the marrow harvest. All of the donors tolerated the G-CSF administration well without severe adverse events. After 5 d of G-CSF treatment, CD34+ cells and granulocyte-macrophage colony-forming units (GM-CFU) in the donors' BM exceeded baseline values by 4.2-fold (range 0.71-316) and 1.6-fold (0.28-118) respectively. The concentration of total nucleated cells (x 107/ml) in the graft increased from 1.61 (0.95-3.23) to 2.44 (1.27-4.01). Although we collected 1020 ml of BM and obtained 1.50 x 1010 nucleated cells from unprimed donors, 940 ml of BM were sufficient to obtain 2.14 x 1010 nucleated cells from primed donors. However, G-CSF-primed BM did not shorten the time to tri-lineage engraftment and the duration of hospitalization compared with unprimed BM, although primed BM contained more CD34+ cells than baseline values. We consider that the advantages of BM priming are not the acceleration of BM recovery but rather the reduction of blood loss during BM harvesting.

Adolescent↗
PubMed2000

Cytokine requirement for the development of T-lymphoid lineage potential in clonal lymphohaematopoietic progenitors in vitro.

The early process of T-cell development prior to thymic colonization has been poorly investigated because of the lack of a sensitive assay. We have developed a two-step in vitro culture system by combining a clonal culture with a fetal thymus organ culture (FTOC) and analysed the early development of T cells from lymphohaematopoietic progenitors. Cells of immature colonies derived from bone marrow cells of 5-fluorouracil (5FU)-treated mice using various combinations of early acting cytokines were transferred into a FTOC. All the combinations of stem cell factor (SCF), interleukin (IL)-3 and IL-6 capable of inducing colony formation supported T-cell generation. IL-11 and the Flt3 ligand possessed T-lineage promotional effects similar to IL-6 and SCF respectively. However, there were some quantitative differences in the final T-cell yield among cytokine combinations. Thus, the commitment towards T lineage in lymphohaematopoietic progenitors may be an event determined intrinsically rather than induced by specific stimuli, but there may be a hierarchy between the activity of cytokines in further development. Furthermore, we examined the T-lineage potential of individual colonies derived from Lin(-)c-Kit(+)Sca-1(+) cells clone-sorted from post-5FU marrow cells. No colonies that contained only myelocytic progenitors showed T-lineage potential, but 23.3% of colonies with a haematopoietic multipotentiality did. Therefore, the divergence of the T lineage from other lineages such as myeloid potential may occur at an early stage of the hierarchy of haematopoiesis. The proposed method should prove valuable for exploring the molecular and cellular changes that occur during early T-cell development before thymic colonization.

Animals↗
PubMed2000

Review article: acute inorganic mercury vapor inhalation poisoning.

Mercury contamination is a serious environmental problem worldwide. Two primary sources of contamination are dumping of large quantities of inorganic mercury and exposure in the mining industry. Although the actual fatal level of mercury vapor is not known, exposure to more than 1-2 mg/m3 of elemental mercury vapor (Hg0) for a few hours causes acute chemical bronchiolitis and pneumonitis. Two hours after exposure, lung injury appears as hyaline membrane formation, and finally, extensive pulmonary fibrosis occurs. Clinical findings correlate with the duration of exposure, the concentration of mercury, and the survival time after exposure. There is no correlation between pathological findings and the concentration of mercury in the tissues. Necrosis of proximal convoluted tubules may be attributed to the disruption of the enzyme systems of Hg2+-sulfhydryl compounds. Metallothionein protein (MT), induced by the accumulation of Hg2+ in the kidneys, may play an important role in detoxication after it forms a non-toxic Hg2+-MT compound. Despite the deposition of mercury in the brain, compared with organic mercury, inorganic mercury did not seem to damage the neurons. Drugs such as chelating agents and corticosteroids appear to effectively decrease the inflammation and delay pulmonary fibrosis.

Environmental Exposure↗
PubMed2000

Reactive follicular hyperplasia in the lymph node lesions from systemic lupus erythematosus patients: a clinicopathological and immunohistological study of 21 cases.

To clarify the clinicopathological and immunohistological findings of reactive follicular hyperplasia in systemic lupus erythematosus (SLE) lymphadenopathy, we examined 21 such cases, including four males and 17 females. Three main patterns could be delineated: pattern A, histological features of Castleman's disease (n = 6); pattern B, follicular hyperplasia with pronounced arborizing vasculature in the paracortex resembling T-zone dysplasia with hyperplastic follicles (n = 6); and pattern C, follicular hyperplasia without any other specific findings (n = 9). The patients who showed patterns A and B on histology were all female with a median age of 36 years, and presented with the lymphadenopathy within 4 months, some before a definitive diagnosis could be made. The group with pattern C included four males and five females with an age ranging from 20 to 58 years (mean, 37 years). In seven of them, the lymphadenopathy was noted 6 months or more after the therapy had been initiated. In a virological study, a small to moderate number of the lymphoid cells were positive for the Epstein-Barr virus-encoded small RNA in five of 10 cases examined. Human herpesvius 8 was not detected in the four cases examined by polymerase chain reaction and immunohistochemistry. The present study demonstrated that SLE lymphadenopathy showed histological variety and occasionally represented histopathological findings of multicentric Castleman's disease or findings similar to T-zone dysplasia with hyperplastic follicles in the biopsied specimens. We emphasize that careful attention to these morphological features, together with clinical and laboratory examinations, should allow a firm diagnosis of SLE to be made, providing information that is pertinent to the treatment of the disease. Moreover, disarray of the follicular dendritic cell (FDC) network, which could be easily detected by immunohistochemistry, was found in approximately 60% of our series. SLE lymphadenopathy should be listed as one of the diseases occasionally associated with disarray of the FDC network, although its clinicopathological significance remains unclear.

Adult↗
PubMed2000

In vitro generation of dendritic cells derived from cryopreserved CD34+ cells mobilized into peripheral blood in lymphoma patients.

BACKGROUND: Dendritic cells (DC) are APC that initiate primary T-cell dependent immune responses. They have been shown to be generated from CD34+ cells in BM, placental/umbilical cord blood (CB), and G-CSF mobilized peripheral blood CD34+ cells (PBSC). In recent clinical studies, DC were used as a vaccine for cancer patients and showed induction of their antitumor effects. Cryopreservation of CD34+ cells is important to extend the availability of cellular therapy with DC. However, little is known about the effect of cryopreservation on the functional maturation of DC. METHODS: PBSC harvested from lymphoma patients mobilized with G-CSF and undergoing leukapheresis were cryopreserved at -135 degrees C for 3 days. Freshly isolated or cryopreserved PBSC were cultured with GM-CSF/SCF/tumor necrosis factor-alpha (TNF-alpha). After 14 days of culture, DC were harvested, washed, and used for phenotypical and functional analysis. RESULTS: Cryopreserved PBSC, as well as freshly-isolated PBSC cultured for 14 days, gave rise to CD1a+ /CD4+ /CD11c+ /CD14low+ /CD25( -)/CD40+ / CD45RO+/CD80+/CD83+/CD86+/HLA-DR+ cells with dendritic morphology. DC derived from cryopreserved PBSC mobilized with G-CSF showed a similar endocytic capacity and chemotactic migratory capacities when compared with DC derived from freshly-isolated G-CSF mobilized PBSC. These DC also exhibited similar capacities in the primary allogeneic T-cell response. DISCUSSION: These results indicate that cryopreserved G-CSF mobilized PBSC cultured with GM-CSF/SCF/TNF-alpha gave rise to DC that were morphologically, phenotypically and functionally similar to DC derived from fresh G-CSF mobilized PBSC. The observation indicates the clinical usefulness of cryopreserved CD34+ cells from lymphoma patients.

Antigens, CD34↗
PubMed2000

Ex vivo gene therapy using granulocyte-macrophage colony-stimulating factor-transduced tumor vaccines.

There is no standard effective therapy for metastatic renal-cell carcinoma (RCC) or prostate cancer. Both of these cancers may be immunogenic, so therapy targeted to a tumor-associated antigen may be effective. Transduction of the gene encoding granulocyte-macrophage colony-stimulating factor has shown promise in preclinical studies, and clinical trials are in their early stages. Both autologous cancer cells and partially HLA-matched allogenic cells are being studied. No dose-limiting side effects have been observed, and a few patients have had transient objective tumor regressions. Further trials with more frequent and, probably, longer immunization schedules are needed to define efficacy.

Animals↗
PubMed2000

Mutational analysis of the putative K(+)-binding site on the fourth transmembrane segment of the gastric H(+),K(+)-ATPase.

By means of a functional expression system and site-directed mutagenesis, we analyzed the role of the putative K(+)-binding site, Glu-345, located in the fourth transmembrane segment of the gastric H(+),K(+)-ATPase alpha-subunit. In the present study, we used several mutants, with alanine, isoleucine, leucine, glutamine, valine, lysine, and aspartic acid instead of Glu-345, and analyzed the H(+),K(+)-ATPase partial reactions of the mutants to determine the precise role of this residue. All the mutants except E345Q exhibited no H(+),K(+)-ATPase activity. The E345Q mutant showed 3-times higher affinity for ATP. This mutation shifted the optimum pH toward a more alkaline one. The E345A, E345I, E345L, E345V as well as E345Q mutants were phosphorylated with ATP as in the case of the wild-type H(+),K(+)-ATPase, whereas the E345K mutant was not phosphorylated. The E345Q mutant was dephosphorylated in the presence of K(+), but its affinity for K(+) was significantly lower than that of the wild type. The E345A, E345I, E345L, and E345V mutants did not exhibit sensitivity to K(+) in the dephosphorylation step below 3 mM K(+). Therefore, Glu-345 is important for the conformational change induced by K(+), especially in the dephosphorylation step in which K(+) reacts with the enzyme from the luminal side with high affinity and accelerates the release of inorganic phosphate. The glutamic acid in the fourth transmembrane segment is conserved, and was found to be involved in the cation-induced conformational change in H(+),K(+)-ATPase as well as Na(+),K(+)-ATPase and Ca(2+)-ATPase, however, the precise roles of the side chain in the function were different.

Adenosine Triphosphate↗
PubMed2000

Establishment and characterization of a colonic epithelial cell line MCE301 from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.

We produced an immortalized colonic epithelial cell line, MCE301, using fetal mice transgenic for the temperature-sensitive simian virus 40 large T-antigen gene. MCE301 cells showed epithelial-like morphology and maintained tight connections with neighboring cells. The cells grew at a permissive temperature (33 degrees C), but the growth of the cells was significantly prevented at the nonpermissive temperature (39 degrees C). The cells expressed large T-antigen at 33 degrees C but not at 39 degrees C. MCE301 cells were not transformed, as judged by the absence of anchorage-independent growth in soft agar gel and lack of tumor formation in nude mice. Electron microscopic studies showed that the cells formed microvilli-like structures on the cell surface and junctional complexes such as tight junctions and desmosomes between the cells. The cells expressed cytosketal (acidic cytokeratins and actin), basement membrane (laminin and collagen type IV) and junctional complex proteins (ZO-1 and desmoplakin I + II), as judged by specific antibodies. Fetal bovine serum, epidermal growth factor, insulin-like growth factor and insulin significantly increased the cell growth at 33 degrees C. Moreover, MCE301 cells expressed colonic mucin Muc2 mRNA as demonstrated by reverse transcriptase-polymerase chain reaction, indicating that the cells originate from mucus-secreting cells. Alkaline phosphatase, a brush border-associated enzyme, was detected in the cells. Sodium butyrate (2 mM), an inducer of cellular differentiation, markedly elevated alkaline phosphatase activity. Thus, the present mouse colonic epithelial cell line MCE301 possessing these unique characteristics should provide a useful in vitro model of colonic epithelium.

Alkaline Phosphatase↗
PubMed2000

Sudden deterioration of aortic regurgitation due to rupture of a raphal cord on the conjoined cusp.

A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.

Aortic Valve Insufficiency↗
PubMed2000

Hematopoietic repopulating ability of cord blood CD34(+) cells in NOD/Shi-scid mice.

Although umbilical cord blood (CB) is increasingly being used as an alternative to bone marrow (BM) as a source of transplantable hematopoietic stem cells (HSC), information on the hematopoietic repopulating ability of CB HSC is still limited. We recently established a xenotransplantation system in NOD/Shi-scid mice to evaluate human stem cell activity. In the present study, we transplanted 5 to 10 x 10(4) CB CD34(+) cells into six NOD/Shi-scid mice treated with anti-asialo GM1 antiserum to investigate the hematopoietic repopulating ability of CB. The BM of all recipients contained human CD45(+) cells 10 to 12 weeks after the transplantation (43.8 +/- 17.7%). Clonal culture of the recipient BM cells revealed the formation of various types of human hematopoietic colonies, including myelocytic, erythroid, megakaryocytic, and multilineage colonies, indicating that CB HSC can differentiate into hematopoietic progenitors of various lineages. However, the extent of the differentiation and maturation differed with each lineage. CD13(+)/CD14(+)/CD33(+) myelocytic cells were mainly repopulated in BM and peripheral blood (PB). While CD41(+) megakaryocytic cells and platelets were present, few glycophorin A(+)CD71(+) or hemoglobin alpha-containing erythroid cells were detected. CD19(+) B cells were the most abundantly repopulated in NOD/Shi-scid mice, but their maturational stage differed among the hematopoietic organs. Most of the BM CD19(+) cells were immature B cells expressing CD10 but not surface immunoglobulin (Ig) M, whereas more mature CD19(+)CD10(-) surface IgM(+) B cells were predominantly present in spleen and PB. CD3(+) T cells were not detected even in the recipient thymus. The transplantation to the NOD/Shi-scid mouse may provide a useful tool for evaluating the repopulating ability of transplantable human HSC.

Animals↗
PubMed2000

Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 1). Effects of 2-weeks daily administration of estradiol benzoate.

As part of a collaborative project to assess whether a 2-weeks administration period is sufficient to detect testicular toxicity of various compounds, male rats were subcutaneously administered 0, 5, 20, 50 or 100 micrograms/kg of estradiol benzoate (E2B), a known testicular toxicant, daily for 2 or 4 weeks. After 4-weeks, suppression of body weight gain, increase in the weight of the adrenal gland, and gross changes such as decrease in size of the prostate and seminal vesicles, and increase in size of the adrenal gland were observed in the 5, 20, 50 and 100 micrograms/kg groups. On histopathological examination, degeneration/necrosis of Pachytene spermatocytes, atrophy of Leydig cells, mature spermatid retention (Lee, et al., 1993) at stages IX, X and XI, and atrophy of ducts of the epididymides were also observed in the 5, 20, 50 and 100 micrograms/kg groups. After 2-weeks, the same changes were also observed with 20, 50 and 100 micrograms/kg, but not 5 micrograms/kg. These results indicate that the toxic effects of E2B are detectable by administration for 2 weeks at an appropriate dose level.

Adrenal Glands↗
PubMed2000

Significance of lysine/glycine cluster structure in gastric H+,K+-ATPase.

Gastric H+,K+-ATPase consists of alpha- and beta-subunits. The catalytic alpha-subunit contains a very unique structure consisting of lysine and glycine clusters, KKK(or KKKK)AG(G/R)GGGK-(K/R)K, in the amino-terminal cytoplasmic region. This structure is well conserved in all gastric H+,K+-ATPases from different animal species, and was postulated to be the site controlling the access of cations (or proton) to its binding site. In this report, we studied the role of this unique structure by expressing several H+,K+-ATPase mutants of the alpha-subunit together with the wild-type beta-subunit in HEK-293 cells. Even after replacing all the positively-charged amino acid residues (six lysines and one arginine) in the cluster with alanine or removing all the glycine residues in the cluster, the mutants preserved the H+,K+-ATPase activity, and showed similar affinity for ATP and K+ as well as similar pH profiles as those of wild-type H+,K+-ATPase, indicating that the cluster is not indispensable for H+,K+-ATPase activity and not directly involved in determination of the affinity for cation (proton).

Adenosine Triphosphate↗
PubMed2000

Neuroendoscopic aqueductal stent placement procedure for isolated fourth ventricle after ventricular shunt placement. Case report.

Isolated fourth ventricle (IFV) is a rare complication in patients who undergo shunt placement, and it is not easily corrected by surgical procedures. The authors report a case of IFV that was successfully treated with an aqueductal stent placed under direct visualization by using a neuroendoscope. This 36-year-old suffered meningitis after partial resection of a brainstem pilocytic astrocytoma, and subsequently developed hydrocephalus for which a ventriculoperitoneal shunt was placed. Nine months later, the patient presented with progressive cerebellar ataxia, and magnetic resonance imaging revealed slitlike supratentorial ventricles and a markedly enlarged fourth ventricle, which were compatible with the diagnosis of IFV. The surgical procedure described was performed under visualization through a styletlike slim optic fiberscope inserted into a ventricular catheter. The catheter, with the endoscope inside it, was passed through the foramen of Monro and then through the aqueduct to reach the enlarged fourth ventricle, where membranous occlusion of the foramen of Magendie was clearly visualized. The tip of the catheter was placed in the fastigium of the fourth ventricle. After the procedure, the size of the fourth ventricle was reduced and the patient's symptoms improved. Thus, it is concluded that endoscopic aqueductal stent placement is a simple and safe surgical procedure for treatment of IFV.

Adult↗
PubMed2000

[Chronic subdural hematoma associated with malignancy: report of three cases].

Three cases of chronic subdural hematoma (CSH) associated with malignancy are reported. Case 1; A one-year-old girl was referred for vomiting and convulsions. Left CSH was removed, and her symptoms disappeared. Cytological examination of chronic subdural hematoma revealed abnormal white blood cells. A clinical diagnosis of acute monocytic leukemia was made after the laboratory examination. Remission was achieved by chemotherapy, but she died one year after the operation. Case 2; A 72-year-old woman was referred for right hemiparesis and urinary incontinence. Left CSH was irrigated, and her clinical symptoms immediately disappeared. Cytological examination of chronic subdural hematoma revealed abnormal white blood cells. A clinical diagnosis of chronic lymphocytic leukemia was made after the laboratory examination. No treatment was given since there were no clinical symptoms of chronic lymphocytic leukemia. Case 3; A 70-year-old woman who had been affected with early gastric cancer and mammary cancer for the previous two years was admitted to our clinic because of headache, right hemiparesis and consciousness disturbance. Left CSH was irrigated, and her clinical symptoms improved. However, there was a tendency to bleed because disseminated intravascular coagulation had occurred, and CT showed bilateral subdural hematoma. A second irrigation was performed, but her symptoms did not improve. Left acute subdural hematoma, which was removed by craniotomy, occurred three days after the second operation. Pathological examination of the outer membrane of the subdural hematoma revealed invasion of adenocarcinoma. She died three days after the third operation. It is recommended that both the cytological and the histological examinations be performed when possible, since they are simple to perform and very useful in some cases.

Adenocarcinoma↗
PubMed2000

Constitutively active STAT5A and STAT5B in vitro and in vivo: mutation of STAT5 is not a frequent cause of leukemogenesis.

We recently identified several constitutively active forms of signal transducers and activators of transcription 5 (STAT5) using polymerase chain reaction-driven random mutagenesis followed by retrovirus-mediated expression screening. All constitutively active STAT5 showed constitutive phosphorylation on their tyrosine residues and induced factor-independent growth in a mouse interleukin-3-dependent cell line, Ba/F3. Sequence analysis of these active STAT5 revealed two important mutations: S710F and N642H. The N642H mutation localized in the SH2 domain was able to induce autonomous growth of Ba/F3 cells by itself, whereas S710F in the effector domain was able to induce autonomous growth of Ba/F3 cells in concert with a second mutation including H298R and E150G. Recently, constitutive activation of STAT5 has been reported in patients' leukemic cells and is implicated in leukemogenesis. We attempted to clarify whether leukemic cells harbored activating mutations primarily in STAT5 proteins, and analyzed the sequence of STAT5 derived from 49 leukemic patients. No mutations were found, however, in the regions surrounding S710 and N642 of STAT5A and corresponding residues of STAT5B. We also cloned full-length cDNAs for STAT5s from three patients whose leukemic cells exhibited constitutive tyrosine phosphorylation of the STAT5 protein and expressed the derived STAT5 proteins in Ba/F3 cells. However, none of these clones exhibited constitutive tyrosine phosphorylation or gave rise to FI proliferation of Ba/F3 cells. These results indicate that constitutive activation of STAT5 is a secondary event in most leukemias.

Animals↗