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Biomedical subjects

M Ichihara

Publications and source records attributed to M Ichihara.

At least 55 records · Page 3Linked to original sources
PubMed1991

Augmented production of granulocyte-macrophage colony-stimulating factor and alpha/beta interferon in mice inoculated with heat-killed Corynebacterium liquefaciens.

We demonstrated that heat-killed Corynebacterium liquefaciens bacteria, as a known potent host immune activity modulator, stimulate spleen cells to produce granulocyte-macrophage (GM) colony-stimulating factor (CSF) and another CSF with similar activity, as well as alpha/beta interferon, when injected intravenously into mice. Alpha/beta interferon was shown to be produced by C. liquefaciens-activated plastic-G-10 column-adherent cells (A cells) in a thymus-independent manner. In contrast, augmented production of GM-CSF required the action of C. liquefaciens-activated T lymphocytes that collaborated with normal A cells. Non-T spleen cells from C. liquefaciens-stimulated athymic mice, however, produced an alternative CSF that partially replaced GM-CSF. Correspondingly, the numbers of GM-producing CFU developing in cultures of spleen cells from C. liquefaciens-treated euthymic or athymic mice were 10 to 30 times higher than those in cultures of spleen cells from untreated mice. These results suggest that gram-positive rods such as C. liquefaciens activate T and A cells for production of multiple cytokines and that potential cooperative actions of these cytokines underlie the known immunomodulatory action of coryneforms.

Animals↗
PubMed1991

Cytogenetic and clonal culture evaluation after response to low dose Ara-C in myelodysplastic syndromes.

Cytogenetic and bone marrow culture studies were performed sequentially in 13 patients with myelodysplastic syndromes (MDS) who responded to low dose cytosine arabinoside (Ara-C) treatment (complete in nine and partial in four patients). Of nine patients with initial clonal karyotypic abnormalities, six recovered a normal karyotype after attaining a response to treatment, but the other three patients retained partial or total karyotypic abnormalities. A new clonal karyotypic abnormality appeared after treatment in one patient. Eight patients showed normal colony growth of both granulocyte-macrophage colony-forming units and erythroid burst-forming units after treatment, but five were still defective. There was a clear difference in the duration of response to treatment between these two groups. Consolidation treatment was not effective in patients with persistent karyotypic abnormalities or defective colony formation. Although the number of patients studied is small, these results suggest that hemopoiesis in patients with MDS following a response to treatment with low dose Ara-C is heterogeneous. Consolidation chemotherapy is recommended to ensure and prolong the response in patients showing normalization of both cytogenetic and bone marrow culture results.

Adolescent↗
PubMed1990

[Therapeutic evaluation of combination therapy using C-425 and antibiotics in severe bacterial infections--a double blind group comparative study. The C-425 Research Group for Infectious Comparative Study].

Clinical usefulness of C-425, a native human immunoglobulin liquid preparation for intravenous injection, was studied in combination with antibiotics in severe bacterial infections in a double blind group comparison using an alkylated human immunoglobulin liquid preparation (Polyglobin, A.gamma G) as a reference drug. The following results were obtained: 1. C-425 or A.gamma G was administered to a total of 117 patients, of whom 89 patients, 45 in C-425 group and 44 in A.gamma G group, were included in the present analysis of efficacy and usefulness. Analysis of safety of the drugs included a total of 113 patients, 58 in C-425 group and 55 in A.gamma G group. 2. Efficacy and usefulness were graded according to a visual analog scale (VAS). 3. Mean efficacy values with standard deviations of VAS value were calculated at 52.0 +/- 34.9 for the C-425 group, and 47.2 +/- 34.8 for the A.gamma G group. The respective medians were 59.0 and 61.0. The Mann-Whitney U-test revealed no significant differences between the two groups. When those with VAS values of 50 or above were regarded as cases of effective treatment, the efficacy rates of the two groups were also practically comparable. 4. Side effects were not observed in either drug group. 5. Mean usefulness values with standard deviations were 52.3 +/- 34.9 for the C-425 group, and 47.9 +/- 35.0 for the A.gamma G group. The respective medians were 60.0 and 61.0. The Mann-Whitney U-test revealed no significant differences between the two groups. When the cases with VAS values of 50 or above were regarded as cases of useful treatment, there were no significant differences in the utility rates between the two groups. From these results, C-425 was considered to be useful for treating severe bacterial infections when used combined with antibiotics.

Adolescent↗
PubMed1990

Treatment of chronic granulocytic leukemia in the accelerated phase by transfusion of autologous buffy-coat cells--a case report.

We treated a patient with chronic granulocytic leukemia (CGL), in the accelerated phase by intensive chemotherapy followed by the infusion of cryopreserved peripheral blood buffy-coat cells. The cells had been stored for 32 months. The chemotherapy consisted of daunorubicin 40 mg X 2 days, vincristine 2 mg X 1 day, cytosine arabinoside (Ara-C) 200 mg X 6 days and prednisolone 30 mg X 7 days in the first week, then Ara-C 3 g/m2 X 3 days and cyclophosphamide 60 mg/kg X 2 days in the second week, but reversion to the chronic phase was not achieved. Therefore, total body irradiation (TBI) was added to repeated intensive chemotherapy followed by infusion of the remaining cells. Marrow recovery was good. The patient is currently alive and has been in the chronic phase for 22 months. This preliminary result indicates that this therapy may be tried soon after transformation in CGL and that TBI is an important part of therapy in BMT in the accelerated or blastic phase of CGL.

Adult↗
PubMed1988

Mechanism of increased kanamycin-resistance generated by protoplast regeneration of Streptomyces griseus. I. Cloning of a gene segment directing a high level of an aminoglycoside 3-N-acetyltransferase activity.

The genetic and biochemical basis of a 200-fold increase in kanamycin (KM)-resistance shown in Streptomyces griseus SS-1198PR generated by protoplast regeneration was investigated. A 15-kb Bcl I-DNA segment responsible for the KM-resistance was cloned into pIJ61 with Streptomyces lividans TK21 as host. The KM-resistance segment was then subcloned into pIJ702 as a 1.8-kb BamH I-Bgl II fragment with a BamH I site essential for the KM-resistance. Both S. lividans TK21 containing the cloned segments and S. griseus SS-1198PR showed multiple resistance to KM, dibekacin and gentamicin C complex. Cell free extracts from these strains inactivated the antibiotics in the presence of acetyl CoA in agreement with their resistance pattern. The structure of the inactivated KM-A was determined as 3-N-acetyl-KM-A indicating acetylation by an aminoglycoside acetyltransferase, AAC(3). The substrate range of the enzyme was unique and was designated AAC(3)-V. No genetic linkage was found between the cloned 15 kb Bcl I segment and the separately cloned streptomycin resistance gene (str) segment (3.8 kb Sph I fragment). The str genes cloned from both the parent (SS-1198) and the strain SS-1198PR were identical in their size, restriction site and function. In addition, these strains showed no significant difference in the total DNA digestion pattern. These results indicate that protoplast regeneration may cause a critical change in a specific region of DNA resulting in a high activity of an AAC(3) with a novel substrate range.

Acetylation↗
PubMed1984

Plasmids of Streptomyces kasugaensis MB273: their pock formation, their dispensable endonuclease cleavage sites for pock formation, and transformation of S. kasugaensis MB273 by them.

Plasmid-free strains of Streptomyces kasugaensis MB273 were isolated. In mating experiments S. kasugaensis MB273 was found to cause a lethal zygosis (pock) phenotype in a plasmid-free host. The pock-forming plasmids were identified as either pSK1* or pSK2* on the basis of their endonuclease cleavage-sites. The strain carrying pSK1* was found to induce pocks on the strain bearing pSK2*, and vice versa. The endonuclease cleavage-sites in pSK1* and pSK2* that were nonessential for pock formation were determined in deletion or insertion derivatives. The single sites for Bcl I and Sal I in pSK1* and for Bgl II in pSK2*, respectively, could be useful for DNA cloning without destroying pock-forming ability. Protoplasts of S. kasugaensis MB273-derivatives prepared in stationary phase of mycelial growth were competent for transformation, however, regeneration frequencies decreased during this phase.

Endonucleases↗
PubMed1980

Effect of niludipine on ischemic myocardial metabolism in the dog.

The effect of pretreatment with 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridine carbonic acid-bis(2-propoxyethyl) ester (niludipine, Bay a 7168) (10 microgram/kg i.v.) on myocardial metabolic response to coronary artery ligation was studied in dogs anesthetized with pentobarbital. The results are summarized as follows: 1. Bay a 7168 lowered systolic and diastolic blood pressures markedly, and decreased heart rate slightly. 2. Bay a 7168 increased the endo- and epicardial phosphorylase activity significantly. 3. Bay a 7168 increased the endo- and epicardial ATP levels significantly. 4. Coronary artery ligation increased the endo- and epicardial activity of phosphorylase and decreased the endo- and epicardial glycogen levels. 5. In the presence of Bay a 7168, acceleration of glycogenolysis being caused by coronary artery ligation, was not detected. 6. Changes in the levels of myocardial carbohydrate intermediates being caused by coronary artery ligation, were not modified by pretreatment with Bay a 7168.

Adenosine Triphosphate↗
PubMed1979

Effect of verapamil and nifedipine on ischemic myocardial metabolism in dogs.

The effect of pretreatment with verapamil (100 micrograms/kg i.v.) or nifedipine (10 micrograms/kg i.v.) on ischemic myocardial metabolism was studied in dogs anesthetized with pentobarbital. The results are summarized as follows: 1. Verapamil or nifedipine lowered both systolic and diastolic blood pressures markedly, and increased heart rate slightly. 2. Verapamil or nifedipine increased both endo- and epicardial phosphorylase activities significantly. 3. Coronary artery ligation increased the phosphorylase activity, and also increased the levels of glucose-6-phosphate, fructose-6-phosphate, and lactate, and decreased the levels of glycogen, fructose-1,6-diphosphate, and phosphocreatine in both endo- and epicardial layers, without affecting the level of the endo- and epicardial adenosine triphosphate. 4. In the presence of verapamil or nifedipine, coronary artery ligation did not increase but decreased the phosphorylase activity that had been increased by verapamil or nifedipine alone. 5. Changes in the levels of intermediates induced by coronary artery ligation were not markedly influenced by pretreatment of the dog with verapamil or nifedipine.

Animals↗
PubMed1968

[Tracheal ozena].

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Diabetes Complications↗