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Biomedical subjects

T Inaba

Publications and source records attributed to T Inaba.

At least 271 records · Page 15Linked to original sources

Inhibition of human hepatic glutathione S-transferase isozymes by ethacrynic acid and its metabolites.

The comparative inhibition of ethacrynic acid (EA) and its known metabolites against glutathione S-transferase (GST) was investigated using human livers procured from kidney donors. EA and all three metabolites of EA had an inhibitory effect against conjugation between 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH). The GSH adduct of EA (EA-GSH) was the most potent inhibitor of GSTs; EA-GSH was approximately one order of magnitude more potent than the parent EA, while L-cysteine conjugate of EA (EA-cysteine) and N-acetyl-L-cysteine conjugate of EA (EA-mercapturate) were approximately two orders of magnitude less potent than the parent EA. Further metabolism of EA-GSH conjugate is suggested to be a detoxification process in terms of GST activities.

Cytosol↗

Genomic organization, chromosomal localization, and independent expression of human cyclin D genes.

Murine cDNA clones for three cyclin D genes that are normally expressed during the G1 phase of the cell cycle were used to clone the cognate human genes. Bacteriophage and cosmid clones encompassing five independent genomic loci were partially sequenced and chromosomally assigned by an analysis of somatic cell hybrids containing different human chromosomes and by fluorescence in situ hybridization to metaphase spreads from normal peripheral blood lymphocytes. The human cyclin D1 gene (approved gene symbol, CCND1) was assigned to chromosome band 11q13, cyclin D2 (CCND2) to chromosome band 12p13, and cyclin D3 (CCND3) to chromosome band 6p21. Pseudogenes containing sequences related to cyclin D2 and cyclin D3 mapped to chromosome bands 11q13 and 6p21, respectively. Partial nucleotide sequence analysis of exons within each gene revealed that the authentic human cyclin D genes are more related to their mouse counterparts than to each other. These genes are ubiquitously transcribed in human tumor cell lines derived from different cell lineages, but are independently and, in many cases, redundantly expressed. The complex patterns of expression of individual cyclin D genes and their evolutionary conservation across species suggest that each family member may play a distinct role in cell cycle progression.

Amino Acid Sequence↗

Quantitative measurements of prostatic blood flow and blood volume by positron emission tomography.

Prostatic blood flow was measured with 15oxygen-water by positron emission tomography using a 1-compartment model. A dynamic study method was applied to 9 normal subjects, 6 with benign prostatic hypertrophy (BPH) and 11 with advanced stages C to D2 prostatic adenocarcinoma. Prostatic blood flow was 15.7 +/- 7.5 ml. per minute per 100 gm. in normal controls, 17.7 +/- 5.2 ml. per minute per 100 gm. in BPH patients and 29.4 +/- 7.8 ml. per minute per 100 gm. in prostatic cancer patients. Prostatic blood flow negatively correlated well with age in the normal subjects. Prostatic blood volume was also estimated by the steady state method using 15oxygen-carbon monoxide. Prostatic blood volume was 8.1 +/- 2.6% in normal controls, 8.9 +/- 1.1% in BPH patients and 6.1 +/- 2.1% in prostatic cancer patients. Blood flow in the prostatic cancer tissue was higher than that in the normal (p < 0.001) or BPH (p < 0.01) tissue. A significant difference in prostatic blood volume was also observed between BPH and cancer tissues (p < 0.02).

Adenocarcinoma↗

Novel type of clonally involved cytoplasmic immunoglobulin-negative cells in multiple myeloma: flow cytometric study.

In order to identify myeloma cells and their precursor cells, we studied bone marrow samples from 39 patients with multiple myeloma, including 2 with plasma cell leukemia, using dual parameter cytometry of both DNA and cytoplasmic immunoglobulin (Cyt-Ig). Myeloma cells from 25 patients (64.1%) were aneuploid and those from the remaining 14 patients were diploid. In 25 patients with aneuploid myeloma, we found a small component of cells which had aneuploid DNA content without Cyt-Ig in addition to myeloma cells showing aneuploidy with Cyt-Ig. These aneuploid Cyt-Ig-negative cells were considered to be clonally involved because they were aneuploid, and detected predominantly in patients with stage III myeloma. This suggests that these cells may contribute to disease progression. The characteristics of these cells are described and the relationship between these cells and myeloma precursor cells is discussed.

Aneuploidy↗

Effects of interleukin-3 and interleukin-6 on peripheral blood cells from multiple myeloma patients and their clinical significance.

The effects of interleukin-3 (IL-3) and interleukin-6 (IL-6) on nonadherent mononuclear cells (NMC) from the peripheral blood of 28 patients with multiple myeloma (MM), 3 patients with monoclonal gammopathy of undetermined significance (MGUS), and 3 normal controls were investigated. In 15 of 27 evaluable patients with MM, monoclonal-cytoplasmic-immunoglobulin (cIg)-positive plasma cells appeared from the T-cell-depleted NMC after 10 days of culture in the presence of IL-3 and IL-6. These changes were not observed in the T cell fraction of myeloma blood or in the T-cell-depleted NMC obtained from cases of MGUS or from normal controls. The percentage of cIg-positive plasmacytoid cells after 10 days of culture was significantly higher in the presence of both IL-3 and IL-6 than with each interleukin alone or the control medium. Furthermore, these changes were often observed in untreated patients. These findings suggest that myeloma precursor cells exist in the peripheral blood of MM patients, especially at diagnosis, and differentiate into cIg-positive cells in the presence of IL-3 and IL-6. This assay may be useful in discriminating the early stage of myeloma from MGUS.

Antigens, CD↗

Pharmacological studies on 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one (T-614), a novel antiinflammatory agent. 4th communication: inhibitory effect on the production of interleukin-1 and interleukin-6.

In vitro effects of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614), a novel antiinflammatory compound, on the production of interleukin-1 (IL-1) and/or interleukin-6 (IL-6) by human monocytes and the THP-1 cells of a human monocytic cell line, were examined. T-614 inhibited the release of immunoreactive IL-1 beta from these cells stimulated with lipopolysaccharides (LPS) in a dose-dependent manner (0.3-30 micrograms/ml). The release of IL-6 from THP-1 cells, as determined by the assays for its hepatocyte-stimulating activities and immunoreactivities, was inhibited by T-614 with the IC50 values of 2.0 and 6.6 micrograms/ml, respectively. Northern blotting analysis using LPS-stimulated THP-1 cells indicated that the inhibitory effect of T-614 on IL-1 beta production is caused by the suppression of IL-1 beta mRNA expression. The inhibition of cytokine production by T-614 may provide an important insight into the additional mechanisms contributing to its antiinflammatory activities.

Anti-Inflammatory Agents, Non-Steroidal↗

Prevention of estrus in the queen with chlormadinone acetate administered orally.

The possibility of estrus prevention in the queen by the oral administration of chlormadinone acetate was examined. The animals used were 29 mature and 15 immature queens. For 16 mature females, 4-12.5 mg was given daily by mouth for 7 days every 3 months. Ten of the 16 queens given this treatment came into estrus within 4 months of the first treatment. For 28 females including the immature, 2-12.5 mg was given once a week throughout the experiment. This treatment prevented estrous activity for at least 1 year. In the queens in this study, the side effects were not observed excepting an increase in body weight during treatment. Our results showed that oral administration of this drug weekly is safe and reliable for long-range prevention of estrus in queens.

Administration, Oral↗

[A reproductive study of Weiser-Maples guinea pigs].

The Weiser-Maples (WE) guinea pig strain was introduced by Backshire Co., Ltd. (USA) in 1977. We have been breeding WE strain guinea pigs for skin melanization research. The WE guinea pig colony produced 1271 pups in 417 litters from May 1978 through December 1983. Breeding date are shown below. The mean litter size was 3.05, the stillborn rate was 15.2%, the weaning rate for live-born pups was 93.5% and the sex ratio was 1.01. The average age at first vaginal membrane rupture was 31.4 days at which time body weight was 290.5g. The mean length of the first 7 estrous cycles was about 17 days, with no cyclical variation in length. The mean duration of gestation was 67.9 days. Duration of pregnancy varied with litter size. There was an inverse relationship between litter size and duration of pregnancy. Most of the pups were delivered alive in mid-pregnancy with a parturition range of 56 to 76 days. The probability of pup death depends on gestational length: the lowest incidence of mortality was seen in litters born at 70 days. The mortalities were related to litter size but not to parity. There was an inverse relationship between birth weight and litter size. In WE guinea pigs, the mean weight for a litter of 1 was 120 g; for a litter of 5, the mean body weight was 58g. Male body weights were slightly heavier than female at birth and at weaning age. The mean body weights are shown below, date of birth: female 88.3g, male 93.3g, weaning age (2 weeks): female 181.1g, male 198.8g and 30 weeks: female 758.7g, male 1018.0g. These date for WE guinea pigs are comparable to those of other strains.

Animals↗

[Congenital malformation of the skeleton in Weiser-Maples guinea pigs].

Some abnormalities were observed in the occipital bone, cervical vertebrae and thoracic vertebrae of Weiser-Maples guinea pigs. In the occipital bone, the medial basilar impression was suggested to occur in 40 (32.8%) out of 122 animals. The basilar impression was classified into right, left and both side types and observed in 24, 11 and 5 animals, respectively. The basilar impression was known to be accompanied in human with some anomalies such as platybasia, Klippel-Feil syndrome, deformation of foramen magnum and so-on. These anomalies were also observed in guinea pigs. The fusion of the axis with the 3rd cervical vertebra was observed in 12 (10.5%) out of 114 animals. The deformation was sometimes observed in the temporal, interparietal, atlas and axis as well as the occipital bone. The fusion of the 7th cervical vertebra with the 1st thoracic vertebra was found in 46 (51.7%) out of 89 animals. This fusion was thought to have no relation with the basilar impression. Weiser-Maples guinea pigs are now in 19 generations of sibmating. Because these abnormalities as mentioned above are all thought to be inherited, the selective breeding will make Weiser-Maples guinea pigs suitable for the study of the basilar impression.

Animals↗

Diazepam metabolism by rat and human liver in vitro: inhibition by mephenytoin.

1. Diazepam metabolism and its association with mephenytoin hydroxylase were studied in vitro using human and rat livers. 2. Enzyme kinetic parameters were obtained for the formation of p-hydroxydiazepam (p-hydroxy-DZP), N-desmethyldiazepam (NDZ), and temazepam (TMZ) from diazepam (DZP) in rat liver fractions. The Km values for formation in rat of p-hydroxy-DZP, NDZ and TMZ were 14 +/- 3 (SEM) microM, 44 +/- 4 and 63 +/- 8, respectively; clearance values calculated from Vmax/Km were 5.7, 3.2 and 4.9 ml/g per min, respectively. 3. Mephenytoin (MP) competitively inhibited, in rat liver, the formation of NDZ, but not the formation of p-hydroxy-DZP or TMZ; in human liver neither NDZ nor TMZ formation was inhibited by MP. 4. In seven different human livers the formation of p-hydroxy-DZP represented a minor pathway compared to the formation of NDZ and TMZ.

Animals↗

Role of monocyte colony-stimulating factor in foam cell generation.

Recently, we reported that human monocyte colony-stimulating factor (M-CSF) stimulates the clearance of lipoproteins containing apoB100 via both low density lipoprotein receptor-dependent and -independent pathways in target cells of M-CSF, and reduces plasma cholesterol level (Journal of Biological Chemistry, 265:12869-12875, 1990). This suggests a linkage of cytokines to the metabolic regulation of plasma cholesterol. Furthermore, we found a significant role of M-CSF in cholesterol metabolism of human monocyte-derived macrophages. M-CSF enhanced not only the uptake of acetylated low density lipoprotein and oxidized low density lipoprotein in macrophages, but also the efflux of cholesterol from cholesterol-loaded macrophages. To elucidate in vivo effects of M-CSF on cholesterol efflux from tissues, we administered an intravenous injection of 3H-cholesterol (150 microCi) into WHHL rabbits 1 month before starting M-CSF treatment. We observed an increased cholesterol efflux from tissues to plasma high density lipoprotein after M-CSF treatment when cholesterol efflux was estimated as the change in specific radioactivity of plasma high density lipoprotein-cholesterol. This result suggests that M-CSF can enhance the excretion of cholesterol from target cells of M-CSF, such as cholesterol-loaded macrophages in the arterial wall, and reduce the rate of atherogenesis.

Cells, Cultured↗

[Auer rods-positive neutrophils observed at diagnosis increased after remission induction in patient with acute promyelocytic leukemia].

50-year-old male was admitted to our hospital because of gingival bleeding and fever in August 1987. The leukocyte count was 13,300/microliters with 80.5% leukemic promyelocytes and bone marrow was hypercellular with 86.4% leukemic promyelocytes. A small number of mature neutrophils containing Auer rods were seen in bone marrow. On a diagnosis of acute promyelocytic leukemia and treated with induction chemotherapy consisting of behenoyl-arabinofuranosyl cytosine (BHAC), daunorubicin, 6-mercaptopurine (6-MP) and prednisolone (PSL) was reformed. After cytoreduction, leukemic cells reappeared in the peripheral blood, concomitant with mature neutrophils having Auer rods. Vitamin D3 was not effective as a differentiation inducing agent. Complete remission was obtained in November 1987 by the reinduction chemotherapy consisting of BHAC, aclarubicin, 6-MP and PSL. In this case, neutrophils with Auer rods might have been derived from the leukemic clone and differentiation of leukemic promyelocytes by intensive chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

Pharmacological studies of the new antiinflammatory agent 3-formylamino-7-methylsulfonylamino-6-phenoxy-4'-1-benzopyran-4-o ne. 2nd communication: effect on the arachidonic acid cascades.

The in vitro and in vivo effects of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0), a new antiinflammatory agent, on arachidonic acid metabolism were investigated in comparison with those of reference drugs. Although the inhibitory effect of T-614 on the synthesis of prostaglandins by rabbit renal microsomes was very weak (IC50 of 58 micrograms/ml), T-614 effectively inhibited the prostaglandin E2 (PGE2) generation by mouse fibroblasts stimulated with bradykinin with an IC50 value of 0.47 micrograms/ml. The suppressive effect of T-614 on the PGE2 generation in fibroblasts was also found when cells were stimulated with Ca ionophore A23187, but not when induced with arachidonic acid. T-614 suppressed the A23187-induced PGE2 generation by rat macrophages, but not the leukotriene B4 production. In addition, 5-lipoxygenase activities in guinea-pig peritoneal exudated cells were not inhibited. In in vivo experiments, at doses of more than 1 mg/kg, T-614 reduced the PGE2 contents in inflammatory exudate of rat carrageenin-sponge type inflammation, but it was almost inactive in inhibiting gastric prostaglandins production up to 100 mg/kg. T-614 also did not affect the urinary PGE2 excretion in rats, and slightly inhibited the thromboxane synthesis in rat blood. Furthermore, the convulsion-induced increase of PGE2 in mouse brain was inhibited by T-614. These data suggest that T-614 inhibits the production of cyclooxgenase-mediated products with apparently different mode from classical non-steroidal antiinflammatory drugs, and may partly explain the discrepancy in pharmacological properties between this compound and other drugs.

Animals↗

Collection of peripheral blood stem cells mobilized by high-dose Ara-C plus VP-16 or aclarubicin followed by recombinant human granulocyte-colony stimulating factor.

We developed an effective method for harvesting large numbers of peripheral blood stem cells (PBSC) for use in autotransplantation. Twenty patients with hematological malignancies were treated with high doses of Ara-C (12 g/m2) and VP-16/aclarubicin followed by administration of rhG-CSF (50 micrograms/m2). The optimal time for starting PBSC collection was determined by monitoring the CD34-positive stem cells in blood using immunomagnetic beads. PBSC were collected with a CS-3000 blood cell separator. A total blood volume between 7000 and 9000 ml was processed in each apheresis. Under these conditions, a total of 64 apheresis procedures was performed in the 20 patients. The mean numbers of mononuclear cells and of CFU-GM harvested per apheresis were 4.1 x 10(8)/kg and 110 x 10(4)/kg, respectively. A number of CFU-GM sufficient for engraftment (> 30 x 10(4)/kg) could be harvested by a single apheresis in 15 of the 20 patients. So far, 11 patients have been transplanted with PBSC and obtained rapid hematopoietic recovery. The median time to recover neutrophils more than 0.5 x 10(9)/l was 10 days, and that for platelets 50 x 10(9)/l was 11 days. This method for harvesting large numbers of PBSC allows safer autotransplantation in patients with chemoradiosensitive tumors, and is applicable to older patients.

Aclarubicin↗

Pharmacological studies of the new antiinflammatory agent 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-o ne. 1st communication: antiinflammatory, analgesic and other related properties.

The antiinflammatory, analgesic and antipyretic activities of 3-formylamino-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-on e (T-614, CAS 123663-49-0) were investigated in various animal models and compared with those of nimesulide, indomethacin and ibuprofen. The antiinflammatory potency of T-614 on carrageenin-induced paw edema, paper disk granuloma and established adjuvant arthritis was greater than that of ibuprofen, but slightly lower than those of nimesulide and indomethacin. In acute inflammatory models, unlike indomethacin, T-614 suppressed the edemas provoked by dextran and bromelain in rats, but its inhibitory action on ultraviolet erythema in guinea-pigs was weak. Although the analgesic activity of T-614 was hardly demonstrated in writhing tests in mice, its potency against the inflammatory pain such as Randall-Selitto test, adjuvant-induced hyperalgesia and antigen-induced arthritic pain in rats was superior to that of ibuprofen. Moreover, it had a potent analgesic effect on urate-induced synovitis in dogs. T-614 exerted a prompt and strong antipyretic effect in both yeast-induced febrile rats and lipopolysaccharide-induced febrile rabbits. T-614 had virtually no gastrointestinal ulcerogenic action and did not affect water and sodium excretion in rats. T-614 is a novel antiinflammatory compound with different pharmacological properties from that of the reference drugs.

Animals↗