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Biomedical subjects

Y Horii

Publications and source records attributed to Y Horii.

At least 163 records · Page 9Linked to original sources
PubMed1989

The role of macrophages on the expression of sex difference in the susceptibility to Brugia pahangi infection in C57BL/6 mice.

The role of macrophages or eosinophils on the expression of sex difference in the susceptibility to a primary Brugia pahangi infection in C57BL/6 mice was investigated by using a macrophage blockade technique (carbon treatment) or a histamine type 1 (H1) receptor antagonist (promethazine). Carbon treatment remarkably inhibited macrophage exudation, reduced the resistance of female mice, and completely abolished sex difference in the susceptibility to B. pahangi infection. Although promethazine treatment inhibited eosinophil exudation, it caused only a little increase (not significant) in the recovery rate of worms. These results suggest that macrophages have more important role(s) than do eosinophils on the expression of sex difference in the susceptibility to a primary B. pahangi infection in C57BL/6 mice.

Animals↗
PubMed1989

Frequency modulation characteristics of sustained /a/ sung in vocal vibrato.

Frequency modulation characteristics of sustained vowel phonations in vocal vibrato were investigated. Eight male singers produced sustained /a/ in vibrato at low-, middle-, and high-pitch levels with comfortable loudness. The recorded voice samples were digitized and analyzed by a program yielding a plot of fundamental frequencies (Fo) of individual fundamental cycles. Modulation frequency, extent, rates of Fo increase and decrease, and modulation jitter and modulation shimmer were measured for individual modulation cycles. Central tendency and variability of these measures, intercorrelations among these measures, and temporal patterns of frequency modulations were investigated. Results indicated (1) significant effects of pitch levels on modulation frequency, (2) more regularity in modulation frequency than extent, (3) predominantly linear temporal patterns of frequency modulation, and (4) faster Fo increase than decrease. Implications of these findings for the nature of underlying mechanisms of frequency control in vocal vibrato are discussed.

Adult↗
PubMed1989

Effect of human interferons on morphological differentiation and suppression of N-myc gene expression in human neuroblastoma cells.

The activity of human interferons (HuIFNs) to induce morphological changes and the suppression of N-myc gene expression on human neuroblastoma cells (GOTO and KP-N-RT) was evaluated. Morphological differentiation, characterized as the extension and bifurcation of neurites, the formation of multinucleated giant cells and the formation of neurite networks, was induced by treatment with recombinant HuIFN-gamma (rHuIFN-gamma) and also with natural HuIFN-gamma on human neuroblastoma cells (GOTO and KP-N-RT). But recombinant HuIFN-alpha A and recombinant HuIFN-beta did not induce any changes. The rHuIFN-beta and rHuIFN-gamma inhibited the growth of GOTO and KP-N-RT cells more strongly than the rHuIFN-alpha A did. The expression of N-myc gene was suppressed in GOTO cells treated with rHuIFN-gamma. The suppressive effect of rHuIFN-gamma was dependent on the duration of the treatment. However, rHuIFN-alpha A and rHuIFN-beta did not suppress N-myc gene expression. Moreover, both morphological differentiation and the suppressive effect on N-myc gene expression by rHuIFN-gamma were inhibited in the presence of cycloheximide. These results suggest that the morphological changes and N-myc gene expression in neuroblastoma cells are closely related. Furthermore, this decreased N-myc gene expression during the morphological differentiation may be related to the proteins induced by HuIFN-gamma.

Cell Differentiation↗
PubMed1989

A multifunctional cytokine (IL-6/BSF-2) and its receptor.

Interleukin 6 (IL-6)/B cell stimulatory factor 2 is a multifunctional cytokine produced by both lymphoid and nonlymphoid cells. IL-6 regulates immune response, acute phase reaction, and hematopoiesis. It was found that IL-6 production by T cells is dependent on macrophages, and IL-6 is one of essential factors for pokeweed mitogen induced immunoglobulin production. Both high- and low-affinity IL-6 receptors were identified. The molecular cloning of IL-6 receptors demonstrated that this receptor is a member of the immunoglobulin superfamily. The deregulated production of IL-6 is suggested to be involved in the pathogenesis of autoimmune diseases and in the development of multiple myeloma.

Animals↗
PubMed1989

Eosinophil hyporesponse of jirds induced by microfilariae of Brugia pahangi.

Male jirds (Meriones unguiculatus) were inoculated sc with 100 infective larvae of Brugia pahangi. After 16 weeks, the animals were reinoculated with a comparable number of organisms. Blood eosinophil responses during the 5 weeks subsequent to this attempt to reinfect were much lower than those of comparable naive animals, while the response to a heterologous infection (Toxocara canis) was comparable to that of controls. Mebendazole was given to infected animals for 2 weeks beginning 5 weeks (prepatent) or 16 weeks (patent) after infection. At comparable intervals after drug administration, the animals were reinoculated with infective larvae and the blood eosinophil response was measured over a 5 week period. The response in the animals treated during the prepatent period was higher than the untreated infected controls. Treatment during the patent period had no demonstrable effect. Jirds made artificially microfilaremic by intravenous inoculation of viable filaria before and after the standard infecting dose had a low eosinophil response to infective larvae. A primary experience of jirds with the microfilariae of B. pahangi evokes an eosinophil response. Subsequent inoculation of larvae did not produce a comparable response.

Animals↗
PubMed1989

Effect of testosterone on the susceptibility of C57BL/6 mice to infection with Brugia pahangi with reference to inflammatory cell response.

Effects of testosterone on the susceptibility and inflammatory cell responses of C57BL/6 mice infected intraperitoneally with Brugia pahangi larvae were examined. On day 15 postinfection, female mice showed significantly greater resistance than did males, and peritoneal cell responses (lymphocytes, macrophages, and eosinophils) were great in females. Castration of highly susceptible male mice increased their resistance and peritoneal cell responses to the level of female mice; whereas, castration of female mice did not affect the susceptibility and cell responses. Furthermore, testosterone treatment at a physiological dose in the castrated male mice or a pharmacological dose in female mice suppressed resistance and inflammatory cell responses. These results suggest that male sex hormone, testosterone, but not female sex hormone has a regulatory role in the susceptibility and cellular response of C57BL/6 mice to infection with B. pahangi, and it causes differences between sexes in susceptibility.

Animals↗
PubMed1989

Effect of macrophage blockade on the resistance to a primary Brugia pahangi infection of female BALB/c mice.

Role of macrophages in the higher resistance of female BALB/c mice than males to a primary Brugia pahangi infection was investigated. Macrophage blockade by carbon injection on the day of infection or by carrageenan injection one day before infection was effective to reduce the higher resistance of females to the level of males. The timing of macrophage blockade seems to be critical because carbon treatment on day 0 or 5 post-infection (PI) was much more effective than the same treatment on day 10 PI. These results suggest that macrophages play an important role in the expression of the higher resistance of female BALB/c mice than males to a primary B. pahangi infection.

Animals↗
PubMed1988

Regulation of BSF-2/IL-6 production by human mononuclear cells. Macrophage-dependent synthesis of BSF-2/IL-6 by T cells.

Regulation of BSF-2/IL-6 production in peripheral mononuclear cells (MNC) was studied. BSF-2 mRNA expression in mitogen-stimulated MNC showed a biphasic response, the first peak around 4 h and the second peak around 48 h. This was caused by different kinetics of BSF-2 mRNA expression in distinct subpopulations of MNC; M phi expressed BSF-2 mRNA at 5 h in the absence of any stimulation, and mitogen-stimulated T cells and B cells expressed BSF-2 mRNA 48 h after stimulation. Immunohistochemical staining of the cells with anti-BSF-2 antibody demonstrated that macrophages, T cells and B cells could produce BSF-2. T cells in peripheral MNC produced BSF-2 in the presence of M phi. The requirement of macrophage for BSF-2 production in T cells could be replaced by TPA but not by IL-1 or BSF-2.

B-Lymphocytes↗
PubMed1988

Schwannian cell differentiation of human neuroblastoma cell lines in vitro induced by bromodeoxyuridine.

In normal development the neural crest gives rise to sympathetic neuroblasts, sensory and autonomic ganglia, as well as Schwann cells. One tumor arising from this tissue is the neuroblastoma (NB), a malignancy of the adrenergic component of the sympathetic nervous system. Recent histological studies have shown that neuroblastomas can present with a schwannian cell component, rich in S100 protein. We have investigated the differentiation of NB cell lines, GOTO and RT-LN-1, into a schwannian cell phenotype using bromodeoxyuridine (BrdU). This agent induced morphological changes in these cell lines. Flat-epithelial cells were identified in the GOTO cell line and both flat-epithelial and neuronal phenotypes were found in the RT-LN-1 cell line. S100 protein (beta-Subunit) was induced in both cell lines after 18-25 days of BrdU treatment as determined by enzyme-linked immunoassay. In addition increase in the beta-subunit of S100 protein was identified in BrdU-treated flat-epithelial cells by indirect immunofluorescence using a monoclonal antibody specific for the beta-subunit of the protein. Cyclic nucleotide phosphodiesterase activity significantly increased in both BrdU-treated NB cell lines, as compared with nontreated cells. However no significant increase of glial fibrillary acidic protein in BrdU-treated cells was found either by enzyme-linked immunoassay or indirect immunofluorescence using a monoclonal antibody to glial fibrillary acidic protein. Thus, cells with Schwann cell characteristics can clearly be identified in the neuroblastoma cell lines after BrdU treatment. Fluorescence-activated cell sorting analysis revealed no quantitative changes in cell membrane antigens recognized by monoclonal antibodies UJ-13A (neuroectodermal associated antigen) and anti-Thy-1 (Thy-1) on BrdU treatment. In contrast, UJ-127-11 (neuroectodermal associated) decreased, and W6/32 and BB7.7 (HLA-ABC) and BBM.1 (beta 2-microglobulin) markedly increased in both BrdU-treated cell lines. No induction of L243 (HLA-DR), B7/21 (HLA-DP), and Genox 3.55 (HLA-DQ) was noted. The increased HLA-ABC (HLA class I) antigen may enable BrdU-treated NB cells to be recognized by cytotoxic T-cells. This may be related to the pathological evidence that NB patients whose tumors are rich in S100 protein have a better prognosis. Further studies on the potential of differentiation agents to induce a phenotypic change, that is associated with an improved prognosis for NB patients, are required.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1988

Autocrine generation and requirement of BSF-2/IL-6 for human multiple myelomas.

Human B cell stimulatory factor 2 (BSF-2) was originally characterized and isolated as a T cell-derived factor that caused the terminal maturation of activated B cells to immunoglobulin-producing cells. Molecular cloning of the complementary DNA predicts that BSF-2 is a protein of relative molecular mass (Mr) 26,000 similar or identical to interferon beta 2, hybridoma plasmacytoma growth factor and hepatocyte stimulating factor. IL-6 has been proposed as a name for this molecule. It is now known that BSF-2 has a wide variety of biological functions and that its target cells are not restricted to normal B cells. Responses are also seen in T cells, plasmacytomas, hepatocytes, haematopoietic stem cells, fibroblasts and rat phoeochromocytoma, PC12 (Satoh, T. et al., manuscript in preparation). Of particular interest to this report is that human BSF-2 is a potent growth factor for murine plasmacytomas and hybridomas. This observation suggested to us that constitutive expression of BSF-2 or its receptor could be responsible for the generation of human myelomas. In this study we report that myeloma cells freshly isolated from patients produce BSF-2 and express its receptors. Moreover, anti-BSF-2 antibody inhibits the in vitro growth of myeloma cells. This is direct evidence that an autocrine loop is operating in oncogenesis of human myelomas.

Antibodies↗
PubMed1988

The essential role of B cell stimulatory factor 2 (BSF-2/IL-6) for the terminal differentiation of B cells.

The role of recombinant B cell stimulatory factor 2 (BSF-2/IL-6) in the regulation of growth and differentiation of B cells was investigated. rBSF-2 at 200 pg/ml could induce 50% of the maximum Ig production in B lymphoblastoid cell lines, the specific activity being estimated as 5 X 10(6) U/mg. rBSF-2 augmented PWM-induced IgM, IgG, and IgA production in mononuclear cells (MNC); the effect was exerted by directly acting on PWM-induced B blast cells to induce Ig production. However, rBSF-2 did not induce any growth of activated B cells. In contrast, rBSF-2 showed a potent growth activity on a murine hybridoma clone, MH60.BSF2. The concentration required for half-maximal [3H]TdR uptake was approximately 5 pg/ml, which was 40 times less than that required for Ig induction in a B cell line. Anti-BSF-2 antibody inhibited PWM-induced Ig production in MNC, but not PWM-induced proliferation. The antibody was effective even when added on day 4 of an 8-d culture, indicating that BSF-2 is one of the essential late-acting factors in PWM-induced Ig production.

Antibodies↗
PubMed1988

Diagnosis of neuroblastoma metastasis in bone marrow with a panel of monoclonal antibodies.

Neuroblastoma, along with rhabdomyosarcoma, Ewing's sarcoma, and acute lymphoblastic leukemia/lymphoma, is one of the small, round-cell tumors of childhood. All of these malignancies show a propensity to metastasize to bone marrow. Occasionally when the clinical picture is unclear and the tumor is particularly anaplastic, it can be difficult to arrive at a diagnosis by conventional histological and biochemical procedures. In the present study, a panel of nine monoclonal antibodies was used to undertake a detailed analysis of seven bone marrows contaminated with tumor cells: six cases of stage IV neuroblastoma, and one case of stage IV-S neuroblastoma. The antibody profiles obtained were compared with those deduced from the studies of over 20 marrows from patients with acute lymphoblastic leukemia. A comparison of these data with those obtained from the studies of rhabdomyosarcoma and Ewing's sarcoma cell lines and tissues suggests that when high levels of tumor cells are present in the marrow, it is possible to obtain a confident diagnosis of either neuroblastoma or acute lymphoblastic leukemia. In addition, the immunocytological identification of neuroblasts in bone marrow enables accurate staging without histological examination.

Antibodies, Monoclonal↗
PubMed1988

Spectral energy distribution in four types of infant vocalizations.

The distribution of spectral energy among four types of infant vocalizations was compared via computerized spectral analyses of "pain-induced," "fussy," and "hungry" cries and "cooing" of 30 2-6-month-old infants. Visual inspection indicated that "pain-induced" cries could be differentiated from "fussy" and "hungry" cries and that "cooing" could be differentiated from all cries on the bases of (1) the relative amplitude levels of the high-frequency components; (2) the average fundamental frequency; and (3) the overall spectral energy levels. Analysis of variance showed that (1) the mean spectral energy (MSE) levels of "pain-induced" cries were significantly higher than those of the other two types of cries and that the MSE of all three types of cries was significantly higher than that of cooing; and (2) that the mean spectral energy in any vocalization by 6-month-old infants of either sex was significantly lower than that in any vocalization of younger infants.

Crying↗
PubMed1988

Vocal shadowing in singers and nonsingers.

Five nonsingers and five singers vocally matched the pitches of frequency modulated tones. Subject responses to the shadowing task were analyzed in terms of accuracy, and in terms of duration and speed characteristics of pitch changes. In addition, each frequency change was categorized according to hit, overshoot, undershoot, or oscillate patterns. Singers were found to effect pitch changes in significantly less time than the nonsingers. This finding was attributed to more direct patterns (hits) and faster maximum speeds obtained by the singers. Both groups demonstrated a direct relationship between the size of the pitch change and each of the duration and speed parameters examined. Similarly, for both groups, pitch lowering was faster than pitch raising. Faster speeds and more direct paths in effecting pitch changes were viewed as evidence of greater vocal proficiency in singers as compared to nonsingers. Implications of the data for mechanical and physiological aspects of voice frequency control are discussed.

Adult↗