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Biomedical subjects

Y Hirota

Publications and source records attributed to Y Hirota.

At least 271 records · Page 15Linked to original sources
PubMed1990

Identification and isolation of calcium-dependent and -independent bovine immunoglobulins reactive with sepharose 4B.

Calcium-dependent and -independent Sepharose 4B-binding bovine serum proteins were isolated by affinity chromatography on unsubstituted Sepharose 4B using 2 mM ethylenediamine tetraacetic acid followed by 0.1 M galactose. They appeared in two different protein peaks by gel filtration on Sephacryl S-200. The earlier eluted protein was demonstrated to be immunologically IgM, whereas the retarded one IgG. From these findings, Sepharose 4B-binding bovine serum proteins are suggested to be calcium-dependent and -independent immunoglobulins IgM and IgG.

Animals↗
PubMed1990

Isolation and hemagglutinating activities of bovine immunoglobulins reactive with melibiose.

Calcium-dependent and -independent bovine immunoglobulins (IgM and IgG) reactive with melibiose were isolated by affinity chromatography on melibiose-coupled Sepharose 4B. Hemagglutination and hemagglutination inhibition were carried out to study their carbohydrate specificities. Human and animal erythrocytes were agglutinated by these bovine IgM, whereas those were not by bovine IgG at the highest concentrations used. Neuraminidase- and pronase-treated erythrocytes were more strongly agglutinated by these IgM than untreated ones. On the other hand, melibiose-reactive human immunoglobulins isolated from AB serum showed strong hemagglutinating activities to rabbit erythrocytes. Hemagglutination of neuraminidase-treated human type B erythrocytes by calcium-independent bovine IgM reactive with melibiose was effectively inhibited by galactose, methyl alpha-D-galactopyranoside and melibiose, whereas that was not by methyl beta-D-galactopyranoside, lactose, and other substances at the highest concentrations used. Similar results were also obtained in hemagglutination inhibition with untreated rabbit erythrocytes and calcium-independent human immunoglobulins (IgM and IgG) reactive with melibiose. However, hemagglutination of pronase-treated human type A erythrocytes by calcium-dependent bovine IgM reactive with melibiose was not at all inhibited by these substances at the highest concentrations used. From these results, bovine serum is found to also contain antibodies with a specificity for alpha-linked galactosyl residues as found for human AB serum reported previously.

Animals↗
PubMed1990

Successful chemotherapy on a pregnant non-Hodgkin's lymphoma patient.

We report a case of a non-Hodgkin's lymphoma (NHL) patient treated successfully with combination chemotherapy during pregnancy who delivered a full-term baby. A 29 year-old patient with cervical and inguinal lymphadenopathy in the 27th week of gestation was referred to our hospital. The diagnosis of lymph node biopsy was NHL (diffuse, large cell type with B-cell phenotype). Three courses of CHOP regimen (adriamycin, cyclophosphamide, vincristine and prednisolone) were given before delivery. The patient has been in complete remission for three years and her baby has been in normal development. Our case supports previous reports that chemotherapy in the third trimester may be given safely on NHL patients.

Adult↗
PubMed1990

[Effects of 5-hydroxyeicosatetraenoic acid (5-HETE) on progesterone and prostaglandin production by human corpora lutea].

The present study was undertaken to assess the effects of 5-hydroxyeicosatetraenoic acid (5-HETE) on steroidogenesis and prostaglandin (PG) production in cultured luteal cells derived from human corpora lutea in the mid-luteal phase. The luteal cells were cultured with 5-HETE at 10, 100, 500, or 1,000 ng/ml in the absence or presence of hCG at 100 ng/ml for 10 days. The addition of 5-HETE to the culture media did not affect growth curves of cultured luteal cells. 5-HETE significantly inhibited progesterone (P) production by cultured luteal cells in a dose-related fashion on day 2. P production stimulated by exposure to hCG was also reduced significantly in response to 5-HETE. The addition of 5-HETE did not affect estradiol production by cultured luteal cells. The production of 6-keto-PGF1 alpha by cultured luteal cells in the presence of 5-HETE was slightly but not significantly less than that observed in the absence of 5-HETE. However, 5-HETE affects neither PGF2 alpha nor PGE2 production by cultured luteal cells throughout the culture period. The present study demonstrates that 5-HETE inhibits P production in cultured luteal cells by a mechanism(s) other than through PG production. These data suggest the involvement of a lipoxygenase pathway in the synthesis of P and 6-keto-PGF1 alpha of luteal cells.

Adult↗
PubMed1990

[Phase I study of YNK01 (1-beta-D-arabinofuranosylcytosine-5'-stearylphosphate)].

Phase I study of YNK01 (1-beta-D-arabinofuranosylcytosine-5'-stearylphosphate), a derivative of cytosine arabinoside (Ara-C), was conducted by cooperative study groups between January 1986 and June 1987. The dosage for the single and 5-day oral administration ranged 50 to 1,200 and 100 to 900 mg/body/day, respectively. The main adverse effects were myelo-suppression and gastrointestinal toxicities such as nausea, vomiting, anorexia and diarrhea. In the single administration, the maximum tolerated dose (MTD) could not be determined, however, in the 5-day schedule MTD was considered to be 700 to 900 mg/body/day, and the dose limiting factor to be thrombocytopenia. After the single administration (800 mg/body/day) of YNK01, the plasma concentration of Ara-C, an active metabolite of YNK01, was 3.43 ng/ml (Cmax) at 24 hrs. and 0.82 ng/ml at 72 hrs. During the 5-day administration for 300 mg/body/day and 500 mg/body/day, the Ara-C concentration changed from 2.3 to 4.1 ng/ml, and from 1.5 to 11.9 ng/ml respectively, and sustained almost the same concentration as to during the administration period until the 2nd day after the completion of the administration.

Administration, Oral↗
PubMed1990

[Long-term remission of a case of Burkitt's lymphoma accompanied by cardiac tamponade treated by surgical resection and intensive chemotherapy].

A 26-year-old woman was admitted to our hospital because of abdominal mass. She became ileus and an emergency operation was consequently performed. A histological examination of the abdominal tumor indicated proliferation of undifferentiated lymphoblasts with intermingled histiocytes so called "starry sky appearance". The diagnosis was Burkitt's lymphoma. On the 4th post-operative day, a cardiac tamponade became evident. The pericardial effusion contained many lymphoblasts and the diagnosis was pericarditis due to the invasion of lymphoma cells. The pericarditis was successfully treated by infusion of doxycycline into the pericardial space following drainage. The patient responded to systemic chemotherapy with complete remission. 7 courses of systemic chemotherapy along with intrathecal infusions for CNS prophylaxis were subsequently carried out. A state of complete remission has continued for more than 13 months. Cardiac tamponade accompanied by Burkitt's lymphoma is quite rare and has not ever been reported in Japan in our knowledge. The efficacy of surgical treatment before systemic chemotherapy and the series of intrathecal infusions for CNS prophylaxis was demonstrated in this case.

Adult↗
PubMed1990

[123I-IMP single photon emission computed tomography (SPECT) study in childhood epilepsy].

N-isopropyl-p[123I]-iodoamphetamine (IMP) single photon emission computed tomography (SPECT), X-ray computed tomography (X-CT) and magnetic resonance imaging (MRI) were performed in 18 children with idiopathic seizures. In children with idiopathic seizures SPECT identified abnormal lesions in the highest rate (50%) compared with X-CT (11%) and MRI (13%), but the findings of SPECT poorly correlated with the foci on electroencephalography (EEG). Idiopathic epilepsy with abnormal uptake on SPECT was refractory to medical treatments and frequently associated with mental and/or developmental retardation. Perfusion defects identified on SPECT probably influenced the development of the brains in children. IMP SPECT is useful in the diagnosis and medical treatment in children with seizures.

Adolescent↗
PubMed1990

[Effectiveness of synthetic calcitonin derivative (elcatonin) on the bone pain and serum calcium concentration in multiple myeloma].

Fifteen patients (8 male and 7 female) with multiple myeloma, who were admitted to our hospital between July 1986 and August 1988 and suffering from pain and hypercalcemia, were treated with synthetic calcitonin derivative (elcatonin: ECT). ECT was administered intravenously at a dose of 10-640 units twice daily. Seven patients were treated with ECT (ECT group), and eight patients received combination treatment with ECT and other form of chemotherapy (combination group). With regard to the pain score (PS), significant analgesic effects in both groups were observed during 1-4 week treatments (p less than 0.05). There were no significant differences in PS between two groups. Serum calcium levels in the combination group at 1 and 4 weeks were significantly lower than the initial value (p less than 0.05). Hypocalcemia was not seen in any of the patients. Urinary excretion of calcium at 1 week in ECT group was higher than the initial value (p less than 0.05). The observed toxicities of ECT were slight nausea and vomiting in only 2 patients. These findings suggest that ECT is an useful agent for the treatment of pain and hypercalcemia accompanied with multiple myeloma.

Aged↗
PubMed1989

Imbalance of deoxyribonucleoside triphosphates, DNA double-strand breaks, and cell death caused by 2-chlorodeoxyadenosine in mouse FM3A cells.

The mechanism of the cytotoxic action of 2-chlorodeoxyadenosine in mouse FM3A cells was investigated. Imbalance of the dNTP pools occurred within 3 h of treatment with 20 microM 2-chlorodeoxyadenosine; the dATP and dGTP pools were depleted and the dTTP pool increased. 2-Chlorodeoxyadenosine added to the culture medium broke mature DNA strands, giving fragments of 100-200 kilobase pairs as found by orthogonal-field-alternation gel electrophoresis. DNA strand breaks, measured by this technique, were observed in the treated cells about 12 h after the addition. The cells also lost viability at about 12 h. Breaks in the single and double strands of DNA, as measured by alkaline and neutral filter elution, became evident 18 h after treatment with 20 microM 2-chlorodeoxyadenosine; there were as many single-strand breaks as would be caused by 130 rads of gamma-ray irradiation. Double-strand breaks were equivalent to those caused by 2180 rads of gamma-ray irradiation. Comparison of the ratio of single- and double-strand breaks caused by 2-chlorodeoxyadenosine to that following radiation suggested that 2-chlorodeoxyadenosine broke only double strands. Cycloheximide inhibited the breakage of DNA double strands and the cell death caused by this compound. Flow cytometric studies of cytostasis brought about by 2-chlorodeoxyadenosine in FM3A cells showed that cells accumulated in the earlier part of the S phase. 2-Chlorodeoxyadenosine decreased DNA synthesis more than RNA or protein synthesis. The breaks in double strands of DNA were probably important in the cell death caused by 2-chlorodeoxyadenosine. The intracellular dNTP imbalance may trigger these events.

Animals↗
PubMed1989

High-resolution transmission electron microscopy of inorganic materials in cellular and topological random systems.

The structure of amorphous Se films, in the topological random system, has been studied by the computer-simulation, electron diffraction (ED), and high-resolution transmission electron microscopy (HRTEM). As an example of HRTEM of the cellular random system, our recent investigation on Ba-ferrites is reviewed beforehand. In HRTEM images of spin-glass BaTi2-xSnxFe4O11 (x less than 0.6), magnetic clusters or clusters of FeO6-octahedra surrounded by TiO6-octahedra have been found. The structure of BaSn2Fe4O11 (x = 2) has been determined. The ordering of Sn (Ti) and Fe ions increases with increasing x, which interprets the change from the spin-glass state to nonspin-glass state at x = 0.6. It is shown that a cluster of polarized lattice ions is detectable in images of polar-glass BaxK2-xFexTi6-xO13 (x greater than or equal to 1.2). The structure models of amorphous Se films forming on a substrate have been constructed on a computer, and their radial distribution function (RDF) and HRTEM images have been calculated. Experimental RDF and HRTEM images have been obtained from vacuum-deposited amorphous Se films and are compared with the calculated ones. It is concluded that in the as-deposited films most of Se molecules may be composed of Se atoms as small as three and that by the electron-beam irradiation the molecules link to form spiral chains in amorphous state and then arrange to have the hexagonal crystal structure.

Chemical Phenomena↗
PubMed1989

A cell division regulatory mechanism controls the flagellar regulon in Escherichia coli.

The formation of flagella in various thermosensitive (Ts) cell division mutants of Escherichia coli was examined at the nonpermissive temperature. The number of flagella per unit cell length decreased sharply after shifting the culture temperature from 30 degrees to 40 degrees C in the following Ts mutants: ftsC108, ftsD1033, ftsE1181, ftsF1141, ftsG29, ftsZ84, parA110, dnaB42, nrdB, and dnaG. It was found that transcription of genes responsible for the formation and/or function of flagella (hag, fla, mot, che) decreased significantly at 40 degrees C. However, in the ftsI730 mutant at the nonpermissive temperature, or in penicillin G treated wild-type cells, cell division was blocked but formation of flagella continued. Moreover, when the cfcA1 mutation, of a gene involved in coordinating DNA replication and cell division, was introduced into the dnaB42 mutant strain, inhibition of cell division and also of formation of flagella at 40 degrees C was relaxed. These results indicate that the flagellar regulon is under the control of a cell division regulatory mechanism.

Cell Division↗
PubMed1989

Measurement of human granulocyte-macrophage colony-stimulating factor (GM-CSF) by enzyme-linked immunosorbent assay.

An IgG monoclonal antibody against recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), designated HGM1, was produced by fusion of immune mouse splenocytes with HAT-sensitive murine myeloma cells. A sandwich enzyme-linked immunosorbent assay (ELISA) for measurement of human GM-CSF was developed using this HGM1 and a polyclonal antibody against GM-CSF raised in a rabbit. GM-CSF in culture supernatants of phytohemagglutinin (PHA)- or concanavalin A (Con A)-stimulated peripheral blood mononuclear cells (PBMC) were measured by this ELISA system and the conventional CFU-GM colony formation method. The data indicated that the ELISA was highly efficient and sensitive for the detection of as little as 50 pg/ml recombinant GM-CSF. The CFU-GM colony assay may be influenced by other cytokines which can enhance or suppress colony formation, and ELISA for GM-CSF is more useful for kinetic studies of precise levels of production from PBMC.

Animals↗
PubMed1989

Myocardial revascularization with combined arterial grafts utilizing the internal mammary and the gastroepiploic arteries.

Coronary artery bypass grafting with a combined arterial graft using both the internal mammary artery and the right gastroepiploic artery was performed in 22 patients during a 21-month period. There were 17 men and 5 women ranging in age from 34 to 73 years (mean age, 53.4 years). Three patients were having a reoperation, and 2 patients had no segment of long saphenous vein available. Twelve patients were less than 55 years old. The mean number of distal anastomoses including vein grafts was 3.2 and the mean number of arterial grafts was 2.5 per patient. The mean aortic cross-clamp time was 63.8 minutes and the mean cardiopulmonary bypass time was 116.7 minutes. There was 1 early and 1 late death. The other 20 patients are alive without angina. Studied within 3 postoperative months, graft patency was 95% (19/20) in internal mammary artery and 93% (14/15) in gastroepiploic artery grafts. It is concluded that the combined arterial graft can be used safely and effectively, and its application facilitates complete revascularization with more arterial and fewer vein grafts.

Adult↗
PubMed1989

Relationship between changes in power spectra of electroencephalograms and arterial halothane concentration in infants.

A power spectral analysis of electroencephalograms (EEGs) was performed in 30 infants who underwent plastic surgery for cleft lip or cleft palate. The study was conducted to investigate whether there was a significant correlation between EEG changes and arterial halothane concentration in infants. The power spectral analysis of EEGs was performed by the fast Fourier transform (FFT). Arterial halothane concentration was measured with gas chromatography. The relationship between the changes in the power spectra of EEGs and the arterial halothane concentration was examined by means of a multivariate analysis. Prior to administration of halothane, two kinds of EEG patterns were discernible. In one pattern the peak of the EEG power spectra was seen in the slow wave band (slow wave group); in the other the peak of the power spectra was present in the fast wave band (fast wave group). In the occipital lead the multiple correlation coefficient and the index of determination of the slow wave group were 0.71 and 0.50, respectively, and those of the fast wave group were 0.78 and 0.61, respectively. A significant correlation was proved to be present between the normalized values of the EEG power spectra and arterial halothane concentration in the occipital lead. Therefore, the results of the present study suggest that the relationship between changes in the power spectra of EEGs in the occipital lead and arterial halothane concentration in infants can be expressed by means of multiple regression formulas.

Anesthesia, Inhalation↗
PubMed1989

Protective effect of recombinant murine granulocyte-macrophage colony-stimulating factor against Pseudomonas aeruginosa infection in leukocytopenic mice.

The effects of recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) against Pseudomonas aeruginosa infection in ICR mice were investigated. Mice were treated with cyclophosphamide (CPA) and were then injected intraperitoneally with rmGM-CSF three times daily, beginning on the day after CPA treatment, for 7 days. The number of peripheral blood leukocytes in both CPA- and rmGM-CSF-treated mice and control CPA-treated mice reached a nadir on day 4, when P. aeruginosa was injected intraperitoneally. The administration of rmGM-CSF significantly increased the proportion of survivors among mice infected with a lethal dose of P. aeruginosa. This effect was further analyzed by monitoring sequential changes in leukocyte count and bacterial growth in various organs. The number of bacteria in the peritoneal cavities, peripheral blood samples, and livers of GM-CSF-treated mice decreased to an undetectable level after a transient increase, and the number was significantly lower than that in control mice. In GM-CSF-treated mice, the neutrophil levels in peripheral blood started to increase 5 days after CPA administration and were consistently higher than those in controls. Furthermore, the neutrophils in GM-CSF-treated mice were more mature morphologically. Thus, the prophylactic effect of rmGM-CSF against P. aeruginosa infection may result from a rapid recovery of myelopoiesis and a partial enhancement of mature neutrophil function.

Animals↗
PubMed1989

Isolation and characterization of an Escherichia coli mutant having temperature-sensitive farnesyl diphosphate synthase.

The screening of a collection of highly mutagenized strains of Escherichia coli for defects in isoprenoid synthesis led to the isolation of a mutant that had temperature-sensitive farnesyl diphosphate synthase. The defective gene, named ispA, was mapped at about min 10 on the E. coli chromosome, and the gene order was shown to be tsx-ispA-lon. The mutant ispA gene was transferred to the E. coli strain with a defined genetic background by P1 transduction for investigation of its function. The in vitro activity of farnesyl diphosphate synthase of the mutant was 21% of that of the wild-type strain at 30 degrees C and 5% of that at 40 degrees C. At 42 degrees C the ubiquinone level was lower (66% of normal) in the mutant than in the wild-type strain, whereas at 30 degrees C the level in the mutant was almost equal to that in the wild-type strain. The polyprenyl phosphate level was slightly higher in the mutant than in the wild-type strain at 30 degrees C and almost the same in both strains at 42 degrees C. The mutant had no obvious phenotype regarding its growth properties.

Alkyl and Aryl Transferases↗