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Biomedical subjects

T Otsuka

Publications and source records attributed to T Otsuka.

At least 163 records · Page 9Linked to original sources
PubMed1996

Clinical significance of serum concentration of interleukin 8 in patients with bronchial asthma or chronic pulmonary emphysema.

Interleukin-8 (IL-8) belongs to the family of chemotactic cytokines and has been shown to activate neutrophils in vitro and in vivo. In this study, we measured IL-8 concentration in the serum of patients with pulmonary emphysema or bronchial asthma. IL-8 concentration in serum of emphysema patients was significantly higher than in asthmatics; in emphysema patients it was significantly correlated with the smoking index and the annual decrease of FEV1.0. In asthmatics IL-8 concentration was below the level of detection, but was markedly increased during exacerbation of asthma. Our findings suggest that IL-8 may be one of the causal factors in these diseases.

Adolescent↗
PubMed1996

Suppression of superoxide anion production by interleukin-10 is accompanied by a downregulation of the genes for subunit proteins of NADPH oxidase.

Interleukin-10 (IL-10) inhibited the production of superoxide anion (02-) by both unactivated and interferon-gamma (IFN-gamma)-activated human monocytes. Simultaneous addition of IL-10 with IFN-gamma at the start of incubation was necessary for an optimal inhibitory effect. The degree of inhibition was substantially comparable to that of IL-4, and the combination of suboptimal concentrations of IL-10 and IL-4 produced an additive effect. A similar effect was also obtained when viral IL-10 (vIL-10) was used instead of IL-10. The inhibitory effect of IL-10 was accompanied by the reduced accumulation of transcripts for heavy chain subunit of cytochrome b558 (gp9l-phox) and 47-kD cytosolic factor (p47-phox), components of the O2--generating NADPH oxidase system. Reduction of the mRNAs was distinct within 24 hours. On the other hand, the induced O2- production by human monocytic leukemia cell lines (THP-1 and HL60) was not inhibited by IL-10. The amount of gp9l-phox and p47-phox mRNAs remained unchanged even in the presence of excess amount of IL-1O. Taken together, these results suggest that IL-10 inhibits 02- production by downregulation of the gp9l-phox and p47-phox genes in human monocytes.

Depression, Chemical↗
PubMed1996

[Multiple bronchial varices].

A 54-year-old man was referred to our hospital because of hemoptysis. Fiberoptic bronchoscopy revealed irregular mucosa of the right B1, B2, B3, B8, B9, and B10, and the left B1+2 and B3. Bronchoscopic and histological findings indicated bronchial varices.

Bronchi↗
PubMed1996

[Pulmonary actinomycosis--diagnosis and therapy based on past reports of actinomycosis].

A 57-year-old man who complained of bloody sputum was admitted to the hospital because of a spherical mass on a chest X-ray film. Despite a detailed examination, no definitive diagnosis was obtained, and a left lower lobectomy was done. Histopathologic examination of tissue from the resected lobe revealed sulfur granules and branching filamentous bacteria, and therefore pulmonary actinomycosis was diagnosed. Examination of reports published in Japan in the last five years suggested a slight increase in the frequency of diagnosis before treatment of actinomycosis and a slight decrease in the frequency of surgical treatment. However, these changes are not surprising because the frequency of surgical treatment is 58%. These findings suggest that pulmonary actinomycosis should be included in the differential diagnosis of a mass on a chest X-ray film.

Actinomycosis↗
PubMed1995

Inhibition by interleukin-10 of inducible cyclooxygenase expression in lipopolysaccharide-stimulated monocytes: its underlying mechanism in comparison with interleukin-4.

Both interleukin-10 (IL-10) and IL-4 inhibited the prostanoid synthesis of lipopolysaccharide (LPS)-stimulated human monocytes, and their inhibition was shown to be based on a common mechanism to suppress the gene expression of inducible cyclooxygenase (COX). COX has been shown to exist in at least two distinct isoforms, designated COX-1 and COX-2, and their gene expressions exhibit different profiles. At both the protein and mRNA levels, the expression of COX-1 was constitutive and was not modulated by treatments with LPS, IL-10, or IL-4. In contrast, the expression of COX-2 was observed only after stimulation with LPS. IL-10 and IL-4 significantly inhibited LPS-induced COX-2 expression. Kinetic studies showed that they inhibited COX-2 mRNA expression within 1 hour after stimulation and that maximal inhibition was consistently observed at 5 hours. Moreover, the addition of cycloheximide (CHX) to LPS-stimulated monocytes resulted in a superinduction of COX-2 mRNA, whereas CHX almost abrogated the abilities of IL-10 and IL-4 to inhibit this gene expression. Experiments with actinomycin D showed that both cytokines accelerated the degradation of COX-2 mRNA. Furthermore, nuclear run-on experiments showed that both cytokines modestly inhibited LPS-induced COX-2 gene transcription. Thus, both cytokines seemed to regulate the COX-related pathway in a similar manner, although their receptor systems did not show any structural similarities. Considering recent findings showing that the drugs that exhibit a selective effect on COX-2 may be more preferable in inflammatory conditions, such biologic activities of IL-10 and IL-4 described above may offer useful tools in controlling inflammatory disorders in the future.

Cells, Cultured↗
PubMed1995

Localization of trkB and low-affinity nerve growth factor receptor mRNA in the developing rat retina.

The localization of trkB and low-affinity nerve growth factor receptor (LNGFR) mRNAs in the developing rat retina was examined by in situ hybridization. TrkB mRNA was expressed in the ganglion cell layer (GCL), in the inner border of the neuroblastic layer (NBL), and the inner border of the inner nuclear layer (INL). LNGFR mRNA was expressed in the GCL, in almost full thickness of the NBL, and in the intermediate part of the INL. Although both trkB mRNA and LNGFR mRNA were expressed in the GCL, the expression pattern was different between these mRNAs; trkB mRNA was expressed in almost all cells in the GCL uniformly and the expression of LNGFR mRNA varied greatly from cell to cell. In addition, the expression of both mRNAs, especially LNGFR mRNA seemed to be down-regulated at P7, when programmed cell death of the RGCs was prominent. These observations indicate that LNGFR may modulate the function of trkB and that trkB and LNGFR play important roles in the development and maintenance of the RGCs.

Animals↗
PubMed1995

Interleukin-10 selectively inhibits osteoclastogenesis by inhibiting differentiation of osteoclast progenitors into preosteoclast-like cells in rat bone marrow culture system.

Recombinant human interleukin-10 (hIL-10) inhibited the formation of osteoclast-like multinucleated cells in rat whole bone marrow cultures. The effect of hIL-10 on the process of osteoclast formation was further examined, since the process of osteoclast formation includes the proliferation and the differentiation of osteoclast progenitors into mononuclear preosteoclasts and the fusion of preosteoclasts into multinucleated osteoclasts. In the nonadherent bone marrow cell culture system, which was free of stromal cells and formed preosteoclast-like cells, hIL-10 significantly inhibited the formation of preosteoclast-like cells even at a very low concentration (0.5 U/ml). The strong inhibition appeared even after treatment with hIL-10 for only the first 24 h of the culture. However, hIL-10 did not affect the fusion process of preosteoclast-like cells to form osteoclast-like multinucleated cells in the rat coculture system of preosteoclast-like cells with primary osteoblasts. Furthermore, hIL-10 completely inhibited the colony formation induced by granulocyte macrophage colony-stimulating factor (GM-CSF). These findings suggest that the inhibition of osteoclastogenesis by hIL-10 started at the early stage of the differentiation of osteoclast progenitors to preosteoclasts.

Animals↗
PubMed1995

Water mobility in poly(ethylene glycol)-, poly(vinylpyrrolidone)-, and gelatin-water systems, as indicated by dielectric relaxation time, spin-lattice relaxation time, and water activity.

The mobility of water molecules present in poly(ethylene glycol) (PEG)-, poly(vinylpyrrolidone) (PVP)-, and gelatin-water systems was determined by dielectric relaxation and 17O NMR spectroscopy. Water activity was also measured. Dielectric relaxation spectra indicate that all the polymer systems studied contained water exhibiting a dispersion at a frequency > 10(9) Hz; in other words, water with high mobility close to that of bulk water. The dielectric relaxation time of the highly mobile water increased as polymer concentration increased. The PVP- and gelatin-water systems also contained water exhibiting a dispersion at a frequency < 10(9) Hz, which can be considered to be "bound water" with a restricted mobility because of its association with polymer molecules. Dielectric relaxation spectroscopy was used to determine water mobility separately for the populations of highly mobile water and bound water, whereas NMR relaxation spectroscopy was used to determine the average mobility of both populations. The spin-lattice relaxation time of water in these polymer-water systems showed a deviation from the isotropic two-state model. Dielectric relaxation data indicate that this deviation can be ascribed to variations in the relaxation time of highly mobile water caused by a change in polymer concentration. The dielectric relaxation time of highly mobile water in the gelatin system did not change with a change in polymer concentration to the extent that it did in the PEG and PVP systems. This result is consistent with a slight change in water activity of the gelatin system with increasing polymer concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Phenomena↗
PubMed1995

High incidence of a polymorphic variant of erythrocyte membrane protein, Band 3-Memphis, on a western Japanese island.

Band 3 is the major membrane protein of erythrocytes, which binds membrane skeletal proteins, glycolytic enzymes, and hemoglobin and transports various kinds of anions. Band 3-Memphis is a variant of Band 3, the amino terminal fragment of which depicts a slow electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gel. The frequency of Band 3-Memphis varies among populations, with a higher frequency among the Japanese. We investigated the frequency of Band 3-Memphis in a western Japanese island which is relatively isolated from the main islands, finding that the frequency of Band 3-Memphis of the inhabitants of this island is significantly higher than the frequency of the Japanese based on the survey in Kyushu Island. This indicates that there may be differences of population in the frequency of Band 3-Memphis in Japan and that Band 3-Memphis may be a good marker to genetically differentiate each population.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1995

Analysis of c-kit expression of human erythroleukemia cell line, HEL: clonal variation and relationship with erythroid and megakaryocytic phenotype.

The proto-oncogene c-kit encodes the receptor for a stem cell factor. We examined HEL, a human erythroleukemia cell line, in order to clarify the correlation between the c-kit receptor (KR) expression and lineage-specific phenotype. Although HEL cells are known to express KR, we found two relatively distinct HEL cell populations in terms of KR expression. We then subcloned HEL cell lines with clone sorting on the basis of KR expression and compared their various characteristics. The highly KR-expressing subline, HEL-P1, expressed a high level of glycophorin A (GPA), a known erythroid lineage marker. HEL-N1, in which most of the cells were KR-negative, showed a higher megakaryocytic lineage marker CD41b expression than HEL-P1. However, the expression of granulomonocytic lineage markers were not significantly different between the two subclones. Cell growth rate and cell cycle analysis also did not detect significant differences between the sublines. HEL-P1 cells gradually lost their KR expression in serum-containing culture, while the percentage of KR-positive HEL-N1 cells increased in serum-free culture. These observations indicate that KR expression was associated with the synchronous expression of GPA and inversely correlated with CD41b, and reversible transitions between KR-positive cells and KR-negative cells exist. We suggest that KR plays an important part in commitment of erythroid and megakaryocytic precursor cells.

Antigens, CD↗
PubMed1995

Effects of Bestatin on hematopoiesis in long-term human bone marrow cultures.

The effects of Bestatin (Ubenimex, UBX) on normal hematopoiesis were investigated using long-term bone marrow cultures (LTBMC) to determine whether it might enhance hematopoiesis over a long period, as well as induce the release of cytokines. LTBMC were inoculated with 0.1 or 1.0 microgram/ml of UBX at the onset of culture and was added at each weekly medium change. The cellularity and the content of the progenitors in nonadherent layer were examined each week for 5 weeks; those from the adherent layer were examined at week 5. The number of the nucleated mature cells and that of the myeloid progenitors from the nonadherent layer increased significantly (approximately two-fold) following treatment with UBX vs controls. The total number of colonies and the number of myeloid progenitors, but not that of erythroid progenitors, from the adherent layer increased significantly (about 1.5-fold) following treatment with 1.0 microgram/ml UBX. The level of interleukin-6 (IL-6) in the culture supernatants was significantly increased one day after the addition of 1.0 microgram/ml UBX. Findings indicate that UBX stimulated both the production of mature cells and myeloid progenitors on normal hematopoiesis in LTBMC. This was mediated by an indirect action via IL-6 production.

Aminopeptidases↗