PubMed Health⌕ Search

Biomedical subjects

H Oyaizu

Publications and source records attributed to H Oyaizu.

At least 19 recordsLinked to original sources
PubMed2006

Synergistic effects of injection of bone marrow cells into both portal vein and bone marrow on tolerance induction in transplantation of allogeneic pancreatic islets.

We have established a new method for allogeneic pancreatic islet (PI) transplantation: relatively low doses of irradiation followed by simultaneous transplantation of PIs and bone marrow cells (BMCs) via the portal vein (PV). In the present study, we have compared this method with intra-bone marrow (IBM)-bone marrow transplantation (BMT), and with a combination of both methods. Streptozotocin (STZ)-induced diabetic-recipient rats, Fischer 344 (F344, RT1A(l), RT1B(l)), were irradiated 1 day before transplantation. PIs of Brown Norway rats (BN, RT1A(n), RT1B(n)) were transplanted into the liver of the diabetic F344 rats via the PV. BMCs from BN rats were injected into the recipients' bone marrow (IBM), PV or intravenously (IV) or by a simultaneous combination of PV plus IBM (PV+IBM). We compared graft survival among the groups of '9 Gy+IBM'(10/10 accepted), '9 Gy+PV'(7/10 accepted), '9 Gy+IV'(0/7 accepted), '9 Gy+PV+IBM'(8/8 accepted), '8.5 Gy+IBM'(4/9 accepted), '8.5 Gy+PV'(0/7 accepted), '8.5 Gy+IV'(0/7 accepted), '8.5 Gy+PV+IBM'(9/12 accepted), '8 Gy+IBM'(2/10 accepted) and '8 Gy+PV+IBM'(2/8 accepted). As we reported previously, PV-BMT is more effective in inducing the acceptance of allogeneic PIs than IV-BMT. However, IBM-BMT requires less pretreatment than PV-BMT. (PV+IBM)-BMT was found to be the most effective in inducing the acceptance of allogeneic PIs. These results suggest that allogeneic PI-transplantation in conjunction with (PV+IBM)-BMT could become a viable strategy.

Animals↗
PubMed2005

Microbial indices of soil fertility.

AIMS: To find the new microbial parameters explaining the soil fertility from the microbial community viewpoint. METHODS AND RESULTS: Fatty acid methyl ester (FAME) analysis and terminal-restriction fragment length polymorphism (T-RFLP) analysis were carried out using 16 differently treated plots from the same field that had been kept under different fertilizer management systems since 1984. It was found that organic fertilizer application had small impact, whereas chemical fertilizer application, especially ammonium-nitrogen fertilizer, had strong impact on microbial community structures. Principal component analysis was conducted based on soil chemical and physical parameters, crop yields, FAMEs and terminal-restriction fragments (T-RFs) to provide 10 FAMEs and 10 T-RFs showing strong relation with soil fertility. CONCLUSION: We defined these 10 FAMEs and 10 T-RFs as 'keystone' biological parameters explaining soil fertility in the soil. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the FAMEs and T-RFs related to soil fertility. Both analyses are rapid, inexpensive and reproducible means. As field assessment needs precise and rapid analysis, FAME and T-RFLP analyses and these new parameters are very useful to analyse soil fertility at biological viewpoint.

Agriculture↗
PubMed2004

Degradation of polycyclic aromatic hydrocarbons by a newly isolated dibenzofuran-utilizing Janibacter sp. strain YY-1.

The dibenzofuran (DF)-utilizing bacterium strain YY-1 was newly isolated from soil. The isolate was identified as Janibacter sp. with respect to its 16S rDNA sequence and fatty acid profiles, as well as various physiological characteristics. In addition to DF, strain YY-1 could grow on fluorene and dibenzothiophene as sole sources of carbon and energy. It was also able to cometabolize a variety of polycyclic aromatic hydrocarbons including dibenzo- p-dioxin, phenanthrene, and anthracene. The major metabolites formed from DF, biphenyl, dibenzothiophene, and naphthalene were identified by using gas chromatography-mass spectrometry as 2,3,2'-trihydroxybiphenyl, biphenyl-dihydrodiol, dibenzothiophene 5-oxide, and coumarin, respectively. These results indicate that strain YY-1 can catalyze angular dioxygenation, lateral dioxygenation, and sulfoxidation.

Actinomycetales↗
PubMed2004

Involvement of dendritic cells in sarcoidosis.

BACKGROUND: Sarcoidosis is a systemic granulomatous disease of unknown aetiology. It has been suggested that T helper type 1 (Th1) polarisation is associated with the pathophysiology of sarcoidosis, but the mechanism of skewing towards Th1 has not been elucidated. Dendritic cells (DCs) are known to regulate immune responses. This study was performed to determine whether DCs are involved in the aetiology of sarcoidosis. METHODS: The numbers of peripheral blood DCs in 24 patients with sarcoidosis were analysed and biopsy specimens from four patients were stained immunohistochemically using monoclonal antibodies. RESULTS: The numbers of both myeloid and lymphoid DC subsets were significantly decreased in the blood and mature DCs were found in the granulomas of patients with sarcoidosis. A number of interferon-gamma (IFN-gamma) producing T cells were also detected in the sarcoid granuloma, as well as many interleukin (IL)-4 producing T cells. Double staining of the biopsy specimen using anti-fascin and anti-CD3 antibodies showed an anatomical interaction between DCs and T cells. CONCLUSIONS: These findings suggest that the blood DC subsets may migrate into the affected tissues, contributing to the formation of the granulomas in sarcoidosis. It is hypothesised that the migrating DCs may regulate the T cell response in sarcoidosis, at least in the granulomatous lesions.

Adult↗
PubMed2002

Oligonucleotide probe for detecting Enterobacteriaceae by in situ hybridization.

AIMS: To develop oligonucleotide probes for visualizing bacteria belonging to Enterobacteriaceae. METHODS AND RESULTS: 24-mer oligonucleotide probe (probe D) was designed by comparison of 16S rDNA sequences of 35 species of Enterobacteriaceae, eight species of Vibrionaceae and six species of Pasteurellaceae. The sequence of the probe corresponding to the complementary sequence of a position 1251-1274 of Escherichia coli 16S rRNA was found to be a highly conserved region of 16S rDNA sequence in Enterobacteriaceae different from that of Vibrionaceae and Pasteurellaceae. The fluorescent dye-labelled probe was tested for the specificity by in situ hybridization and epifluorescence microscopy. Seventy-six out of 78 strains belonging to Enterobacteriaceae were visualized in an optimal hybridization condition. No bacterial strains belonging to Vibrionaceae (31 strains) and Gram-positive bacteria (three strains) were visualized. CONCLUSIONS: In situ hybridization using probe D allows the detection of bacterial cells belonging to Enterobacteriaceae without false positive reaction. SIGNIFICANCE AND IMPACT OF THE STUDY: In situ hybridization techniques using the probe D are potential tools for detecting Enterobacteriaceae in food and water samples.

DNA, Bacterial↗
PubMed2001

Copper and zinc fractions affecting microorganisms in long-term sludge-amended soils.

The influences of Zn and Cu on soil enzyme activities (acid phosphatase, alkaline phosphatase, arylsulfatase, cellulase, dehydrogenase, protease (z-FLase), urease, beta-D-glucosidase and beta-D-fructofuranosidase (invertase)) and microbial biomass carbon were investigated in agricultural soils amended with municipal sewage sludge or compost since 1978. The trace metals in the soils were fractionated using a sequential extraction method. Long-term application of the sewage sludge and composts caused accumulations of Cu and Zn in the soils, ranging from 140 to 144 and from 216 to 292 mg kg(-1), respectively. The percentage of Cu was highest in the NaOH- and HNO3-extractable fractions (44-51% and 38-46%, respectively), while the percentage of Zn was highest in the HNO3- and EDTA-extractable fractions (65-83% and 11-32%, respectively). Although the percentage of the bioavailable fractions (sum of KNO3 + H2O-, NaOH-, and EDTA-extractable amounts) of Cu (53-64%) was higher than that of Zn (15-37%), the percentage of the most labile fractions (KNO3 + H2O) of Zn (2.1-5.9%) was larger than that of Cu (1.1-2.4%). The size of the microbial biomass carbon increased with the application of sewage sludge or compost. For some enzymes, however, the ratio of the enzyme activity to microbial biomass was lower in the soils amended with sewage sludge or compost than that in the control soil. The soil enzyme activities were more adversely affected by Zn than by Cu. From a multiple regression analysis, it was found that dehydrogenase, urease, and beta-D-glucosidase activities were reduced by the KNO3 + H2O-extractable fraction of Zn in the soils. These microbial activities seem to be sensitive to Zn stress, indicating the possibility that they might be useful bioindicators for evaluation of the toxic effects of Zn on microorganisms in the soils.

Agriculture↗
PubMed2001

Protection of T cells from radiation-induced apoptosis by Cepharanthin.

Cepharanthin (CE) is a medicine that contains several biscoclaurine alkaloids. We examined the effects of CE on radiation-induced T cell apoptosis. Radiation induced apoptosis on T cells in a dose-dependent manner, while CE inhibited radiation-induced apoptosis. CE also attenuated the cytotoxic effects of radiation on the proliferative response of T cells. CE inhibited not only the loss of mitochondrial transmembrane potential but also the activation of caspase 3 in irradiated T cells. Radiation plus CE induced the up-regulation of Bax and the down-regulation of Bcl-2 in T cells in comparison with radiation alone. These results suggest that CE inhibits the signal transduction pathway of apoptosis induced by radiation, regardless of the expression of Bcl-2 or Bax.

Adult↗
PubMed2001

An autopsy case of giant cell myocarditis probably due to a non-steroidal anti-inflammatory drug.

An autopsy case of giant cell myocarditis (GCM) in a 74-year-old woman is presented. She suffered from hepatic dysfunction, skin eruption and disseminated intravascular coagulation due to the side-effects of a non-steroidal anti-inflammatory drug. After admission, heart failure progressed rapidly, and the patient died suddenly. At autopsy, her heart was slightly enlarged and the heart muscle was thickened with many small whitish nodules. She was diagnosed with GCM because of the infiltration of multinuclear giant cells, histiocytes, eosinophils and lymphocytes into the heart. We did not find any similar lesions in any other organs. Giant cell myocarditis, the etiology of which is not defined, is a rare disease with unfavorable prognosis. This case suggests the possibility of drug-induced GCM.

Aged↗
PubMed2001

The response of the phosphate uptake system and the organic acid exudation system to phosphate starvation in Sesbania rostrata.

It is well known that the P(i) uptake system via the high-affinity P(i) transporter and the organic acid exudation system via PEPC are enhanced in the roots of P(i)-starved plants. In this paper, we compared the expression of these two systems in Sesbania rostrata, a leguminous plant, on whose roots and stems it forms nodules. When S. rostrata plants were transferred to a 0 microM P(i) nutrient solution, the expression of both the high-affinity P(i) transporter and PEPC was enhanced within 2 d. The enhancement of the expression of the high-affinity P(i) transporter genes and the PEPC gene coordinated with the increases in the P(i) uptake rate and the PEPC activity, respectively. This suggests that the expression of the high-affinity P(i) transporters and PEPC is regulated in part at the transcript level. Furthermore, we examined which of the environmental or the endogenous P(i) level regulates the expression of these two systems. The P(i) content in the 6-day-old plants decreased to a lower level than that in the 15-day-old plants when grown in a 30 microM P(i) solution. At that time, the expression of the high-affinity P(i) transporters and PEPC was enhanced only in the 6-day-old plants. Moreover, the P(i) content in plants forming many nodules on their stems decreased. The expression of the high-affinity P(i) transporters and PEPC was then enhanced in the nodulated plants. These facts suggest that the expression of these two systems may be regulated by the P(i) content in the plants, not by the P(i) concentration in the soil.

Fabaceae↗
PubMed2001

A proposal for the unification of five species of the cyanobacterial genus Microcystis Kützing ex Lemmermann 1907 under the rules of the Bacteriological Code.

Genomic DNA homologies were examined from six Microcystis (cyanobacteria) strains, including five different species, Microcystis aeruginosa, Microcystis ichthyoblabe, Microcystis novacekii, Microcystis viridis and Microcystis wesenbergii. All DNA-DNA reassociation values between two strains of M. aeruginosa and the other four species exceeded 70%, which is considered high enough for them to be classified within the same bacterial species. It is proposed to unify these five species into M. aeruginosa under the Rules of the Bacteriological Code and NIES843T (= IAM M-247T) is proposed as the type strain. Two other species, Microcystis flos-aquae and Microcystis pseudofilamentosa, should be regarded as morphological variations of this unified M. aeruginosa. The current taxonomy of cyanobacteria depends too much upon morphological characteristics and must be reviewed by means of bacteriological methods as well as traditional botanical methods.

DNA, Bacterial↗
PubMed2001

Methanoculleus chikugoensis sp. nov., a novel methanogenic archaeon isolated from paddy field soil in Japan, and DNA-DNA hybridization among Methanoculleus species.

A strictly anaerobic, irregularly coccoid, methanogenic archaeon, strain MG62T (= JCM 10825T = DSM 13459T), was isolated from paddy field soil in Chikugo, Fukuoka, Japan. The cells stained gram-negative, were 1.0-2.0 microm in diameter, were lysed by SDS and hypotonic solutions and were flagellated. Motility was not observed. The strain was able to use H2/CO2, 2-propanol/CO2, formate, 2-butanol/CO2 and cyclopentanol/CO2 as substrates for methanogenesis, but did not utilize acetate, ethanol, methanol or methylamines. The optimum temperature and pH were 25-30 degrees C and 6.7-7.2. Analysis of lipid component parts (core lipids, phospholipid polar head groups and glycolipid sugar moieties) showed the characteristic pattern of members of the family Methanomicrobiaceae except for the absence of glucose as a glycolipid sugar moiety. The G+C content of the DNA was 62.2 mol %. Sequence analysis of the 16S rDNA revealed that the strain belonged to the genus Methanoculleus. The strain had DNA-DNA hybridization values of less than 50% with type strains of Methanoculleus species. On the basis of phenotypic, genotypic and phylogenetic characteristics, the name Methanoculleus chikugoensis sp. nov. is proposed for strain MG62T (= JCM 10825T = DSM 13459T). The DNA hybridization study also revealed the close relationships of three species, Methanoculleus olentangyi, Methanoculleus bourgensis and Methanoculleus oldenburgensis, among Methanoculleus species.

Base Composition↗
PubMed2000

Phylogenetic affiliation of the pseudomonads based on 16S rRNA sequence.

The broad and vague phenotypic definition allowed the genus Pseudomonas to become a dumping ground for incompletely characterized polarly flagellated, gram-negative, rod-shaped, aerobic bacteria, and a large number of species have been accommodated in the genus Pseudomonas. The 16S rRNA sequences of 128 valid and invalid Pseudomonas species, which included almost valid species of the genus Pseudomonas listed in the Approved Lists of Bacterial Names, were obtained: sequences of 59 species were determined and those of 69 species were obtained from the GenBank/EMBL/DDBJ databases. These sequences were compared with the sequences of other species of the Proteobacteria. Fifty-seven valid or invalid species including Pseudomonas aeruginosa (type species of the genus Pseudomonas Migula 1894) belonged to the genus Pseudomonas (sensu stricto). Seven subclusters were formed in the cluster of the genus Pseudomonas (sensu stricto), and the resulting clusters conformed well to the rRNA-DNA hybridization study by Palleroni (1984). The other species did not belong to the genus Pseudomonas (sensu stricto) and were related to other genera, which were placed in four subclasses of the Proteobacteria (alpha, beta, gamma and gamma-beta subclasses). Twenty-six examined species, which were not included in the cluster of the Pseudomonas (sensu stricto) and have not been transferred to other genera as yet, are listed alphabetically: 'Pseudomonas abikonensis', Pseudomonas antimicrobica, Pseudomonas beijerinckii, Pseudomonas beteli, Pseudomonas boreopolis, 'Pseudomonas butanovora', Pseudomonas carboxydohydrogena, Pseudomonas cissicola, Pseudomonas doudoroffii, Pseudomonas echinoides, Pseudomonas elongata, Pseudomonas flectens, Pseudomonas geniculata, Pseudomonas halophila, Pseudomonas hibiscicola, Pseudomonas huttiensis, Pseudomonas iners, Pseudomonas lanceolata, Pseudomonas lemoignei, Pseudomonas mephitica, Pseudomonas pictorum, Pseudomonas saccharophila, Pseudomonas spinosa, Pseudomonas stanier, Pseudomonas syzygii and Pseudomonas woodsii. The phylogenetic affiliations of these 26 pseudomonads species are shown.

Cloning, Molecular↗
PubMed2000

A new method for bone marrow cell harvesting.

To minimize contamination of bone marrow cells (BMCs) with T cells from the peripheral blood, a new "perfusion method" for collecting BMCs is proposed using cynomolgus monkeys. Two BM puncture needles are inserted into a long bone such as the humerus, femur, or tibia. One needle is connected to an extension tube and the end of the tube is inserted into a culture flask to collect the BM fluid. The other needle is connected to a syringe containing 30 ml of phosphate-buffered saline. The solution is pushed gently from the syringe into the medullary cavity, and the medium containing the BM fluid is collected into the culture flask. There is significantly less contamination with peripheral blood, determined from the frequencies of CD4(+) and CD8(+) T cells, when using this method (<6%) than when using the conventional method (>20%) consisting of multiple BM aspirations from the iliac crest. Furthermore, the number and progenitor activities of the cells harvested using this "perfusion method" are greater than those harvested using the conventional aspiration method. This perfusion method was carried out 42 times using 15 cynomolgus monkeys, and no complications such as pulmonary infarction or paralysis were observed. These findings suggest that the "perfusion method" is safe and simple and would be of great advantage in obtaining pure BMCs, resulting in a less frequent occurrence of acute graft-versus-host-disease in allogeneic BM transplantation.

Animals↗
PubMed2000

[An autopsy case of thymic carcinoma producing various tumor markers and the examination of 222 autopsy cases of thymic malignant tumor in Japan].

The autopsy of a 76-year-old Japanese female patient, which revealed thymic carcinoma with various tumor markers such as NSE, CYFRA, and CA-125, is presented. The patient died from hepatic failure because the liver was overtaken by the tumors. At autopsy, the thymic carcinoma was found to have metastased only in the liver. From microscopical analyses and electron microscopical findings, we diagnosed poorly differenciated squamous cell carcinoma of thymic origin. In the histochemical analyses, the tumor cells were positively stained in CA 125, CA 19-9, EMA, NSE, AE 1, AE 3, CEA, S-100, glimerius and Bcl-2. These date suggest that the tumor cells produced various tumor markers. In 222 autopsy cases of thymic malignant tumor observed in Japan over a period of 4 years, the dominant pathohistological image was squamous cell carcinoma. It is interesting that the greatest number of combined malignant tumors with thymic malignancies were thyroid papillary carcinomas.

Aged↗
PubMed2000

[Rapid development of multiple meniscal signs complicating invasive pulmonary aspergillosis in a patient receiving chemotherapy for acute leukemia].

This report describes the rapid development of multiple meniscal signs complicating invasive pulmonary aspergillosis in a 53-year-old man receiving chemotherapy for acute leukemia. While undergoing first induction therapy for AML, he developed chest pain, and multiple bilateral infiltrations were seen in chest roentgenograms. Administration of antibiotics, antifungal agents, steroid pulse therapy and G-CSF was begun. Pulmonary cavities with meniscal signs developed. The next day, pneumothorax and hemothorax were noted. Although drainage and mechanical ventilation were performed, the patient died after massive hemoptysis. Invasive pulmonary aspergillosis was diagnosed at autopsy.

Aspergillosis↗
PubMed1999

Phylogenetic relationships between toxic and non-toxic strains of the genus Microcystis based on 16S to 23S internal transcribed spacer sequence.

16S to 23S ribosomal DNA internal transcribed spacer sequences of 47 strains of the genus Microcystis were determined. Derived maximum likelihood and DNA distance trees indicated that Microcystis can be divided into three clusters. The first cluster included toxic and non-toxic strains, the second only toxic ones, and the third only non-toxic ones. The tree topologies were not necessarily correlated with morphospecies distinction or phycobilin pigment composition, and one genotype may have more than one morphotype. Phylogenetic analysis based on intergenic spacer sequences was thought to be effective for understanding relationships among closely related species and strains.

Base Sequence↗
PubMed1999

Age-dependent abnormalities of hematopoietic stem cells in (NZW x BXSB)F1 mice.

The (NZW x BXSB)F1 (W/BF1) mouse is known as an autoimmune-prone strain which develops lupus nephritis, thrombocytopenia due to platelet-specific autoantibodies, leukocytosis, and myocardial infarction. In this experiment, we investigated the age-dependent abnormalities of the hematopoietic stem cells (HSCs) and hematopoiesis in this mouse. White blood cell counts (especially Mac-1- or Gr-1-positive cells) in the peripheral blood of 12-week-old W/BF1 mice increased in comparison with those of four-week-old W/BF1 or normal mice. To investigate whether the abnormal hematopoiesis can be attributed to the HSCs of W/BF1 mice, colony-forming unit in spleen (CFU-S) and colony-forming unit in culture (CFU-C) assays were performed. Day 12 CFU-S counts of 12-week-old W/BF1 mice significantly increased in comparison with those of four-week-old W/BF1 mice or normal mice. In the CFU-C assay, CFU-GEMM and CFU-GM counts in 12-week-old W/BF1 mice increased in comparison with those of four-week-old W/BF1 or control mice. The bone marrow cells (BMCs) from 12-week-old W/BF1 mice showed a high level of G-CSF and a low level of GM-CSF in mRNA expression. To examine the effect of HSCs from 12-week-old W/BF1 mice on the onset of autoimmune diseases and the abnormal hematopoiesis, T- and B-cell-depleted BMCs of four-week-old or 12-week-old W/BF1 mice were transplanted to C3H mice. Recipient C3H mice that had received the BMCs from 12-week-old W/BF1 mice showed an earlier onset of autoimmune diseases and a shorter survival rate than those that had received the BMCs from four-week-old W/BF1 mice. These data suggest that the HSCs from 12-week-old W/BF1 mice showing the symptoms of autoimmune diseases have the capacity to induce autoimmune diseases earlier than the HSCs from four-week-old W/BF1 mice.

Age of Onset↗