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Biomedical subjects

M Kurosawa

Publications and source records attributed to M Kurosawa.

At least 91 records · Page 5Linked to original sources
PubMed1997

65-kilodalton protein phosphorylation in human peripheral blood eosinophils.

To evaluate the presence of protein phosphorylation in peripheral blood eosinophils, venous blood was drawn from normal healthy volunteers. Eosinophils were isolated on a Percoll gradient and were incubated with [gamma32P]ATP in the presence of Mg2+. After stopping the reaction, SDS-PAGE was performed and autoradiographs were prepared to determine the incorporation of 32P into proteins. Eosinophils developed at least 24 protein bands below 116.25 kD by SDS-PAGE. In the autoradiographs, one distinct radioactive band was observed with a molecular weight of 65 kD. 32P incorporation into the 65-kD band was dependent on Mg2+ concentration and maximal response was observed at concentrations of 2-6 mM MgCl2. 32P incorporation into the band was dependent on the reaction time and temperature of the reaction system. Acid hydrolysis showed that [32P]phosphate radioactivity in the cells was present primarily as phosphoserine, indicating the presence of 65-kD protein phosphorylation in human peripheral blood eosinophils.

Adult↗
PubMed1997

Inhibition of substance P-induced histamine release from rat peritoneal mast cells by ultraviolet light B irradiation: decreased intracellular calcium as a partial mechanism.

BACKGROUND: Ultraviolet light irradiation has been shown to suppress immunological reactions of irradiated individuals, however, less attention has been paid to the effects on neurogenic inflammation. OBJECTIVE: We have investigated the effect of ultraviolet light B (UVB) irradiation on substance P (SP)-induced histamine release from rat mast cells. METHODS: Rat peritoneal mast cells were treated with UVB irradiation and challenged by SP. Histamine release from the cells and intracellular calcium concentrations ([Ca2+]i) in the cells were measured. RESULTS: UVB irradiation at doses used in the present study did not induce histamine release from mast cells. UVB irradiation at doses from 25 to 200 mJ/cm2 inhibited 10(-5) mol/L SP-induced histamine release in a dose-dependent manner. On the other hand, SP-induced increase of [Ca2+]i was inhibited by UVB irradiation only at doses of 100 and 200 mJ/cm2. CONCLUSION: These data suggest that UVB irradiation inhibits histamine release from SP-activated rat peritoneal mast cells partially through the suppression of an increase in [Ca2+]i.

Animals↗
PubMed1996

Nucleotide sequences of the hepatitis C virus core region in patients without anti-core antibody.

Second-generation assays for detection of hepatitis C virus (HCV) infection that include reactivity of antibodies to core, NS3, NS4 are used because of their high sensitivity. Among these antibodies, anti-core antibody seems to be the most sensitive. However, there are some patients without anti-core antibodies, although HCV RNA is detectable by reverse transcription-polymerase chain reaction and branched DNA assay. The mechanism for the absence of anti-core antibody on its own is unclear. We therefore determined the nucleotide and deduced amino acid sequences of the core region obtained from two anti-core antibody-negative patients with HCV RNA (genotype 1b) and compared them with those of four anti-core antibody-positive patients and a previously reported sequence. Amino acids spanning 1-47, which seemed to exist in major B cell epitopes, were found to be completely conserved among these patients. Furthermore, the predictive binding motif to HLA DR4 (a.a 81-90) was completely conserved in both of the anti-core antibody-negative patients. There were various mutations in the residual amino acids spanning 49-108, but specific mutations could not be found in anti-core antibody-negative patients. These data indicate that the absence of anti-core antibody in two patients is not due to the presence of some formerly unknown viral variants, but due to a possible defect in the host's immune system.

Amino Acid Sequence↗
PubMed1996

Reversal effect of itraconazole on adriamycin and etoposide resistance in human leukemia cells.

Itraconazole is a triazole antifungal agent that inhibits cell membrane serol biosynthesis. Currently, itraconazole is a potent candidate for in vivo use to revert multidrug resistance in acute leukemias, with the added benefit of its antifungal effect. As previously reported, itraconazole, as well as verapamil, reversed adriamycin-resistant K562 cells (K562/ADR) and HL60 cells (HL60/ADR) in dosages compatible to the plasma levels achieved by the therapeutic dosages used for the treatment of fungal infections. By RT-PCR analysis of mdr1, mdr3, and mrp mRNA, these adriamycin-resistant cells showed a higher expression of the transcript of these genes than those of the parent cells. By FACS analysis, both the adriamycin-resistant cells showed a higher expression of P-glycoprotein on their cell surfaces. These results suggested the involvement of itraconazole in the mdr gene and/or mrp gene product-associated resistance. Furthermore, itraconazole partially reversed etoposide resistance in both the K562 and K562/ADR cells. The present study suggests that itraconazole may reverse multidrug resistance, at least in part, via a classical MDR-associated mechanism.

Antibiotics, Antineoplastic↗
PubMed1996

CV6209 inhibits airway wall thickening and airway hyperresponsiveness to histamine induced by intravenous administration of platelet-activating factor in guinea pigs.

We studied the effect of intravenous administration of platelet-activating factor (PAF) on airway responsiveness to histamine and airway wall thickening in guinea pigs. Guinea pigs were killed and the lungs were fixed in formalin. Slides from paraffin-embedded sections of the lungs were stained and the airways that were cut in transverse section were measured by tracing enlarged images using a digitizer. Moreover, airway resistance (Raw) was determined by a pulmonary mechanics analyzer and we calculated two indices, an index of airway wall thickening and one of airway hyperresponsiveness to histamine, from changes of baseline-Raw and peak-Raw following intravenous administration of histamine before and after PAF administration. The infusion of 600 ng/kg PAF for 1 h induced an increase in the thickness of the airway wall in main bronchi demonstrable by histological examination. In analysis of airway function, the infusion of 600 ng/kg PAF for 1 h induced airway hyperresponsiveness to histamine with airway wall thickening. The PAF antagonist CV6209, which was given intravenously 30 min prior to PAF administration, inhibited these effects of PAF in a dose-dependent manner, suggesting PAF may induce airway wall thickening and airway hyperresponsiveness through PAF receptors in the airways.

Airway Resistance↗
PubMed1996

Stroking of the abdomen causes decreased locomotor activity in conscious male rats.

The specific aim of the present study was to determine if stroking in conscious rats can influence spontaneous locomotor behavior in an open-field arena. For this purpose, conscious rats were held across the scapula and the ventral side of the abdomen was stroked at a pressure of 100-150 mm H2O and at a speed of approximately 20 cm/s. The stimulation frequency was approximately 40 strokes/min and the duration 2, 5, and 10 min. Animals held for 10 min served as controls. There was a significant decrease in rearing and locomotion and a significant increase in peripheral activity in the open-field arena after the treatment. Maximal effects were obtained after 5 min of stroking. These effects were consistent with a stroking-induced sedative effect similar to that seen in this open-field arena model following neuroleptics or large doses of oxytocin.

Animals↗
PubMed1996

Antipyretic effect of Lumbricus spencer in acetylsalicylic acid-induced asthma.

Lumbricus spencer, which has been used as an antipyretic in Chinese and Japanese folk medicine and whose antipyretic components are identified to be eicosatetraenoic acid and eicosapentaenoic acid, was given orally in a single dose of 500 mg to febrile patients with acetylsalicylic acid-induced asthma (AIA) in placebo-controlled design. The antipyretic effect of Lumbricus spencer was observed with no exacerbation of asthmatic symptoms. Single oral administration of 500 mg of Lumbricus spencer did not affect the respiratory functions in the patients. Moreover, there were no significant changes in symptom scores and airway lability as measured by daily variations in peak expiratory flow after one week administration of 1500 mg/d of Lumbricus spencer. This pilot study suggests that Lumbricus spencer can be administered safely to febrile patients with AIA without bronchospasm.

Adult↗
PubMed1996

Membranocystic changes in the panniculitis of dermatomyositis.

Clinically apparent panniculitis is rare in dermatomyositis. The common histopathological findings are infiltration of lymphocytes, epithelioid cells and plasma cells in the fat lobules, along with varying degrees of fat degeneration and fibrosis. We report a 65-year-old woman with dermatomyositis who developed panniculitis with a characteristic histological change known as a membranocystic lesion. Although this change has been observed in various diseases affecting the subcutaneous fat tissue, it has rarely been reported in dermatomyositis. Dermatomyositis should be included in the diseases showing a membranocystic lesion.

Aged↗
PubMed1996

Characteristics of histamine release from cultured human mast cells.

BACKGROUND: The mast cell is one of the important cells in the pathogenesis of allergic disorders. However, isolating human mast cells is a laborious procedure. Recently, cultured human mast cells raised from umbilical cord blood cells have become available. It is necessary to examine whether these cells are useful in investigating the role of mast cells in human diseases. OBJECTIVE: The phenotype of mast cells depends on their anatomical sites. To examine which phenotype of mast cells these cultured mast cells most closely resemble, their ability to release was investigated. METHODS: The mast cells were raised from human umbilical cord blood cells in the presence of stem cell factor and interleukin-6. To determine the mast cell subtypes, the mast cells were immunocytochemically stained for tryptase and chymase. The cultured mast cells were then stimulated with various secretagogues, and histamine release was measured by a fluorometric technique using high-performance liquid chromatography. RESULTS: The immunocytochemical staining for mast cell proteases revealed that virtually all cells contained tryptase, the definitive marker of mast cells, and that about a quarter of the cells contained chymase. Anti-IgE effectively stimulated these mast cells to release histamine in a dose-dependent, time-dependent manner. The release was completed in about 30 min. One of the non-specific stimuli, calcium ionophore A23187, also induced histamine release in a dose-dependent, time-dependent manner. In contrast, compound 48/80 and substance P failed to induce histamine release from these cells. CONCLUSION: Cultured human mast cells resemble lung mast cells in their ability to release histamine. They will help in studying the functional properties of human mast cells and may contribute to clarifying the pathophysiology of human allergic diseases.

Antibodies, Anti-Idiotypic↗
PubMed1996

[Transverse lesion of the spinal cord due to mucormycosis in an AML patient].

A 54 year old man complained exertional dyspnea and palpitation since November 1989. As he was diagnosed with marked anemia, leukocytosis and thrombocytopenia by his work place doctor, he was admitted to our hospital. Acute myelogenous leukemia was diagnosed based on laboratory findings. BHAC-DMP, BHAC-MEP and A triple V therapies were only partially effective. Fine nodular shadows in all lung fields and a semicircular mass in the right lower lobe next to the thoracic vertebra were evident on the chest X-P since the end of March 1990. He was treated with antibiotics and amphotericin B but the abnormal lung shadows did not disappear. He had sudden onset of paraplegia and loss of all sensation below Th6 on May 1. Aparavertebral mass in the right lower lobe was detected by CT and MRI, for which radiotherapy was performed but without improvement. He died of respiratory failure on May 12. Autopsy showed that the semicircular paravertebral mass continued to the main pulmonary vein and epidural area of the thoracic cord (Th6-8). Microscopically, mucormycosis was found. Necrosis due to mucor embolism was found in the thoracic cord. It is usually difficult to diagnose mucormycosis in immunocompromised patients while they are alive. It is important to suspect mucormycosis if any infarction symptoms or infections resistant to antibiotics develop in immunocompromised patients.

Fatal Outcome↗
PubMed1995

Massage-like stroking of the abdomen lowers blood pressure in anesthetized rats: influence of oxytocin.

The aim of this study was to determine how massage-like stroking of the abdomen in rats influences arterial blood pressure. The participation of oxytocinergic mechanisms in this effect was also investigated. The ventral and/or lateral sides of the abdomen were stroked at a speed of 20 cm/s with a frequency of 0.017-0.67 Hz in pentobarbital anesthetized, artificially ventilated rats. Arterial blood pressure was recorded with a pressure transducer via a catheter in the carotid artery. Stroking of the ventral, or both ventral and lateral sides of the abdomen for 1 min with a frequency of 0.67 Hz caused a marked decrease in arterial blood pressure (approx. 50 mmHg). After cessation of the stimulation blood pressure returned to the control level within 1 min. The maximum decrease in blood pressure was achieved at frequencies of 0.083 Hz or more. Stroking only the lateral sides of the abdomen elicited a significantly smaller decrease in blood pressure (approx. 30 mmHg decrease) than stroking the ventral side. The decrease in blood pressure caused by stroking was not altered by s.c. administration of an oxytocin antagonist (1-deamino-2-D-Tyr-(Oet)-4-Thr-8-Orn-oxytocin, 1 mg/kg) directed against the uterine receptor. In contrast, the administration of 0.1 mg/kg of oxytocin diminished the effect, which was antagonized by a simultaneous injection of the oxytocin antagonist. These results indicate that the massage-like stroking of the abdomen decreases blood pressure in anesthetized rats. This effect does not involve intrinsic oxytocinergic transmission. However, since exogenously applied oxytocin was found to diminish the effect of stroking, oxytocin may exert an inhibitory modulatory effect on this reflex arc.

Abdomen↗
PubMed1995

Analysis of the p53 gene mutations in acute myelogenous leukemia: the p53 gene mutations associated with a deletion of chromosome 17.

In order to determine the relevance of the p53 tumor suppressor gene mutations in acute myelogenous leukemia (AML), we analyzed the p53 gene in genomic DNA of 18 unselected cases of AML by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing. We detected three cases (16.7%) with the p53 gene mutations showing only the mutant alleles; the high incidence in cases with loss of a whole chromosome 17 (two of three) contrasted with the low incidence in cases without abnormalities of chromosome 17 (one of 15). These cases containing the mutations of the p53 gene showed a poor prognosis. Although we analyzed a rather small series of patients, these findings suggest that the p53 gene mutations might be involved in the progression and prognosis of at least some cases of AML.

Base Sequence↗
PubMed1995

Megakaryocytic differentiation of a leukemic cell line, MC3, by phorbol ester: induction of glycoprotein IIb/IIIa and effects on expression of IL-6, IL-6 receptor, mpl and GATA genes.

We investigated megakaryocytic differentiation in a newly-established Ph1-positive leukemic cell line, MC3, which showed tri-lineage immunophenotypes (myeloid antigens2+, CD19(1+) and CD41a1+) and was positive for CD34 and CD38. TPA induced MC3 cells to differentiate to an early stage of megakaryocyte lineage exhibiting an increase in the expression of platelet glycoproteins (GP) IIb/IIIa (CD41a), and an increase in cell size and nuclear ploidy. TPA treatment also enhanced the expression of GPIIb mRNA, and induced the expression of interleukin-6 (IL-6) and its receptor mRNAs, while it did not induce transcripts of the genes IL-11 and mpl ligand, and further decreased the transcript of the mpl gene. Consistent with these findings, MC3 cells treated with TPA showed an increased expression of GATA-1, but not GATA-3 transcripts, whereas those without TPA treatment expressed only the GATA-2 transcript. These results provide an insight into the study for the regulatory mechanism of megakaryocytopoiesis and leukemic cell differentiation.

Antigens, CD↗
PubMed1995

Increase of meningeal blood flow after electrical stimulation of rat dura mater encephali: mediation by calcitonin gene-related peptide.

1. The dura mater encephali of the rat was exposed and the blood flow around branches of the medial meningeal artery was monitored with a laser Doppler flowmeter. Changes in the meningeal blood flow (MBF) following electrical stimulation of the dura mater at a parasagittal site were registered. The effects of human calcitonin gene-related peptide (h-alpha CGRP) and the CGRP antagonist (h-alpha CGRP8-37) on the MBF were tested. 2. Electrical stimulation with rectangular pulses of 0.5 ms, 10-20 V, 5-10 Hz and a duration of 30 s caused an increase of the MBF in 14 out of 16 rats tested. The increases were dependent on stimulus strength and frequency. 3. The increase in MBF was inhibited in a dose-dependent manner by topical application of 0.1 ml of h-alpha CGRP8-37 at concentrations of 10(-7) - 10(-5) M. The highest dose abolished the increase in MBF. 4. Topical administration of 0.1 ml of h-alpha CGRP at a concentration of 10(-4) M increased the basal MBF by 15% on average. 5. It is suggested that the increase in MBF following electrical stimulation of the dura mater is mediated by the release of CGRP. The contribution of the dural afferent and sympathetic and parasympathetic efferent nerve fibres to this response are discussed.

Animals↗
PubMed1995

Calcitonin gene related peptide released from dural nerve fibers mediates increase of meningeal blood flow in the rat.

The parietal dura mater encephali of the rat was shown by immunohistochemistry to be densely innervated by calcitonin gene related peptide (CGRP) immunoreactive nerve fibers spreading around the medial meningeal artery and its branches. Electrical stimulation of the dural surface (10-20 V, 5-10 Hz, 10-30 min) caused a depletion of CGRP-immunopositive fibers, suggesting a release of CGRP. The dural blood flow around branches of the medial meningeal artery was also monitored with a laser Doppler flowmeter. Short periods (30 s) of electrical stimulation with parameters that presumably released CGRP form nerve fibers caused a repeatable and constant increase of the blood flow for 1-2 min. This evoked increase could dose dependently be inhibited by topical application of the CGRP antagonist hCGRP8-37. Accordingly, administration of hCGRP increased the basal blood flow. We conclude that stimulation of trigeminal afferents innervating the dura mater releases CGRP from peptidergic afferent terminals, thereby causing vasodilatation and increasing the meningeal blood flow, an important element of neurogenic inflammation.

Animals↗
PubMed1995

Effects of rhG-CSF on infection complications and impaired function of neutrophils secondary to chemotherapy for non-Hodgkin's lymphoma. Hokkaido Study Group of Malignant Lymphoma, and rhG-CSF, Japan.

It has been previously demonstrated that the administration of recombinant human granulocyte-colony stimulating factor (rhG-CSF) ameliorates the decrease of the polymorphonuclear neutrophils (PMNs) count after the cytotoxic chemotherapies, thereby reducing the infection complications associated with neutropenia. In this multi-center study, we studied the prophylaxtic effect of rhG-CSF administration on infection complications in patients with non-Hodgkin malignant lymphoma, who received cytotoxic chemotherapies (CHOP or ProMACE/CytaBOM). rhG-CSF administration reduced the frequency of infection complications, and there was no obvious difference in it's frequency between the CHOP-treated and the ProMACE/CytaBOM-treated groups when administered with rhG-CSF, thereby indicating that third generation therapy for NHL may be safely completed in Japanese in combination with rhG-CSF administration. Furthermore, we investigated both the in vitro and the in vivo effects of rhG-CSF on the function of PMNs in patients with NHL and healthy donors, and revealed that the administration of rhG-CSF for NHL patients receiving cytotoxic chemotherapy brought on an improvement of the production of active oxygen but did not affect serum levels of IFNs, IL-1-beta, and IL-6, inspite of a slight elevation of TNF-alpha. Consistent with these results, in vitro treatment of PMNs with rhG-CSF induced no significant production of these inflammatory cytokines and their mRNA expressions. Furthermore, rhG-CSF administration showed no significant effects in vivo on the expression of CD11a, CD11b and LECAM-1 on PMNs and integrins on platelets.

Adult↗
PubMed1995

Establishment and characterization of a new Ph1-positive chronic myeloid leukemia cell line MC3 with trilineage phenotype and an altered p53 gene.

A new Ph1-positive leukemic cell line (MC3) expressing the P210bcr/abl oncoprotein was established from a patient with CML in blast crisis. The MC3 cells showed the trilineage phenotype of myeloid, lymphoid (CD19) and megakaryocytoid lineages, and had a proliferative response to rhIL-1 and rhIL-3 in the serum-free culture. These results and the expression of CD34 indicated that the MC3 cells have characteristics of hematopoietic progenitor cells. Recently, it has been documented that alterations of the p53 gene in leukemic cells are frequently detected during the blast crisis of CML. The MC3 cells contained the altered p53 gene. In addition, the original leukemic cells showed the point-mutational activation of the N-ras gene and an additional chromosomal abnormality inv(3q), but the MC3 cells contained no such abnormalities, indicating that not all of the original leukemic cells had these abnormalities. Thus, the MC3 cell line may provide several insights into investigations of the blast crisis in CML as well as hematopoietic progenitor cells.

3T3 Cells↗