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Biomedical subjects

I Adachi

Publications and source records attributed to I Adachi.

At least 199 records · Page 11Linked to original sources
PubMed1991

[First-pass metabolism of acetaminophen in thyroxine treated rats].

The study on the first-pass metabolism of acetaminophen was carried out in normal and thyroxine-treated rats, administered 30 mg/kg by three routes of intravenous, intraperitoneal, and oral one. Unconjugated acetaminophen and two major metabolites, glucuronide and sulfate in the plasma and urine were then measured 5 and 24 h after the administration, respectively. It was found that there was no difference in total percentage of excreted amount, independent of the routes for administration, between normal and thyroxine-treated rats. This fact shows that acetaminophen is absorbed completely from the gastrointestinal tract. However, it was also found that the extraction ratio of gastrointestinal tract in thyroxine-treated rats became smaller, and that the volume of distribution and total body clearance became larger than those in normal rats. The first-pass metabolism of acetaminophen was found to be influenced by the continuous administration of thyroxine.

Acetaminophen↗
PubMed1991

[Promotion of intestinal drug absorption by milk fat globule membrane].

A soybean oil emulsion was prepared by using milk fat globule membrane (MFGM) materials as an emulsifier. Its stability and effect on the intestinal absorption of vitamin D3, amphotericin B and kanamycin were studied. The MFGM emulsion was as highly stable as a Tween 80 emulsion. When the MFGM emulsion was sonicated with ultrasonic disrupter, the emulsion became more stable. Quantification of vitamin D3 in the intestinal lymph indicated that the MFGM emulsion enhanced lymphatic absorption of vitamin D3. The recovered percentage of vitamin D3 emulsified with MFGM in the lymph was 1.4 times that by Tween 80, and 2.5 times that of oil-in-water suspension. Statistically significant difference was found among them (p less than 0.05). The volumes of an oil phase in the emulsion affected the absorption of vitamin D3. The recovered percentage of vitamin D3 from the lymph increased with reducing the volume of the oil phase. Sonication of the emulsion did not affect the intestinal drug absorption. Furthermore, the MFGM emulsion had no effect on the intestinal absorption of amphotericin B and kanamycin.

Amphotericin B↗
PubMed1991

GRP (gastrin-releasing peptide)-containing nerves in the rat stomach and stress-induced depletion of their synaptic vesicles. An electron microscope study.

Gastrin-releasing peptide (GRP)-containing nerves are extremely numerous in the mucosa of the gastric body. Our previous study demonstrated that depletion of GRP from the nerves occurred in close relation to ulceration in the stomach. The present study deals with the ultrastructure of the GRP-immunoreactive nerves under normal conditions and its changes induced by conditions of stress. The immunoreactivity for GRP was recognized selectively in large cored vesicles in the swollen axoplasm of the nerves. The same axoplasm further revealed immunonegative small clear vesicles which were believed to contain acetylcholine. In materials where the GRP-immunoreactive nerves markedly decreased in number, both large and small synaptic vesicles were depleted from the nerves. These findings suggest that GRP and acetylcholine coexist in single nerves in the oxyntic mucosa, and that by nerve stimulation, they are coreleased into the lamina propria.

Acetylcholine↗
PubMed1991

Small cell carcinoma of the uterine cervix showing Cushing's syndrome caused by ectopic adrenocorticotropin hormone production.

A uterine cervical cancer is reported in a woman who developed Cushing's syndrome. The tumor measured 1.3 x 0.7 cm, and was a pure small cell carcinoma, identical to that in the lung. The primary tumor cells showed argyrophilia with Grimelius staining and reacted positively to the anti-chromogranin antibody. Clinically, the neoplasm behaved in an aggressive manner in spite of adjuvant chemotherapy and radiotherapy, and the patient died of widespread metastasis. Cushing's syndrome was noted after the occurrence of liver metastasis with an elevation of the serum adrenocorticotropin hormone (ACTH) level. At autopsy, metastatic tumor cells from the liver reacted immunohistochemically positively not only to anti-ACTH but also to antichromogranin, anti-gastrin and anti-calcitonin antibodies. This is the first report of an immunohistochemical analysis of, and comparison of primary and metastatic sites in cervical carcinoma showing Cushing's syndrome.

ACTH Syndrome, Ectopic↗
PubMed1991

Cytotoxic activity of FK973 against human oral and breast cancer cells.

FK973 (11-acetyl-8-carbamoyloxymethyl-4-formyl-14-oxa-1, 11-diazatetracyclo [7.4.1.0.0] tetradeca-2, 4, 6-trien-6, 9-diyl diacetate), an analogue of mitomycin C (MMC), was tested against human oral squamous cancer cell lines Ca 9-22, HSC-2, HSC-3, breast adenocarcinoma cell lines MCF-7, BT-20 and breast ductal carcinoma cell line T-47D using MTT assay. FK973 showed cytotoxic effects against six tested cell lines and much wider effective dose range than MMC, adriamycin (ADM), and cisplatin (CDDP). FK973 was the most potent of the four drugs tested against the growth of the three squamous cancer cell lines derived from oral cavity. However, in breast cancer cell lines, FK973 was less potent than MMC and ADM. FK973 was time and dose dependent. The combination effects of FK973 with 5-Fluorouracil (5FU) or CDDP were synthetical. It may be a promising candidate for the treatment of oral and breast cancer.

Adenocarcinoma↗
PubMed1991

Inhibitory effect of triptolide on colony formation of breast and stomach cancer cell lines.

Triptolide (Tri) is a diterpenoid triepoxide isolated from Tripterygium wilfordii Hook F. The effects of Tri on the colony formation of breast cancer cell lines MCF-7 and BT-20, stomach cancer cell lines MKN-45, MKN-7, and KATO-III, and promyelocytic leukemia cell line HL-60 were reported. Using Hamburger-Salmon's double layer agar technique with certain modifications, cancer cells were cultured in 0.3% agar in a highly humidified atmosphere of 5% CO2 at 37 degrees C for 14-21 d. Colonies were counted on d 14 (occasionally d 21) with the colony analyzer system CA-7A. Of the 5 solid tumor cell lines tested, 4 showed diminished colony formation in soft agar by greater than 70% of control value in Tri 10(-8) mol.L-1 (continuous exposure). The magnitudes of the inhibitory effect of Tri on most breast and stomach cancer cell lines were similar to that on the leukemia cell line HL-60. IC50 were 0.504-1.22 micrograms.L-1. The clinically achievable peak plasma concentration (PPC) of Tri was estimated as 0.15 mg.L-1, being 72-126 times higher than the IC70 of the cancer cell lines except KATO-III. The results suggest that Tri might have a potential therapeutic effect on some types of solid tumors, e.g., breast and stomach cancers.

Antineoplastic Agents↗
PubMed1991

[Evaluation of myocardial uptake of thallium-201 in whole body scintigraphy].

Whole body scintigraphy (WBS) was performed to assess the myocardial uptake in the dipyridamole (DP), exercise loading (EX) and thallium-201 (Tl-201) myocardial scintigraphy. DP-WBS was studied in 15 patients (pts), EX-WBS was studied in 17 pts and resting (RE)-WBS was studied in 20 pts. All pts had some kinds of heart disease clinically, but their myocardial scintigraphy showed no abnormal findings. DP-WBS and EX-WBS were performed both immediately (early image DP-E, EX-E) and 3 hours later (delayed image EX-D, DP-D) after injection of Tl-201. RE-WBS were performed immediately (early image REST) after injection of Tl-201 only. The percent myocardial uptake, background ratio of the myocardium and washout ratio of some organs were calculated from the ROIs (region of interest) over the whole body, heart, lung, mediastinum, abdomen and thighs. The myocardial uptake of DP-E was 9.1 +/- 1.4%, myocardial uptake of EX-E was 6.3 +/- 0.8% and myocardial uptake of REST was 7.1 +/- 1.2%. The thighs uptake of DP-E was 10.4 +/- 1.1%, thighs uptake of EX-E was 25.3 +/- 2.6% and thighs uptake of EX-E was 25.3 +/- 2.6% and thighs uptake of REST was 10.1 +/- 1.5%. The percent myocardial uptake of DP-E was not only higher than that of EX-E (p less than 0.001) but also higher than that of REST (p less than 0.01). Thus, we conclude that DP scintigraphy showed clearer myocardial image than EX scintigraphy.(ABSTRACT TRUNCATED AT 250 WORDS)

Dipyridamole↗
PubMed1991

Effects of continuous vindesine administration of advanced breast cancer resistant to chemotherapy including adriamycin.

Vindesine (VDS) at a dose of 1.2 mg/m2/day was administered by intravenous drip infusion for five days to advanced breast cancer patients with multiple organ metastases who had developed a clinical resistance to various chemotherapeutic agents. The blood concentration of VDS was determined serially by radioimmunoassay, and the anticancer effect and side effects were evaluated. Of the 31 patients selected for this study, 29 were eligible, and the treatment was effective (complete or partial remission) in 11 (38%). There was, however, no correlation between clinical effects and VDS blood concentration. Continuous VDS administration induced various side effects, but all were controllable. Blood concentration was correlated with side effects. Continuous intravenous administration of VDS is considered to have a therapeutic effect on advanced breast cancer which has developed resistance to multiple-drug therapy including adriamycin.

Adult↗
PubMed1990

Parathyroid hormone-related protein is a possible autocrine growth inhibitor for lymphocytes.

Adult T-cell leukemia (ATL)-related cells have the ability to produce a newly-isolated calcium-regulating protein, parathyroid hormone-related protein (PTHrP). The present study revealed that lectin-stimulated normal lymphocytes produce immunoreactive (IR)-PTHrP. When the T-cell-enriched fraction was purified from normal lymphocytes and then treated with lectin, a similar amount of IR-PTHrP was detected, suggesting that IR-PTHrP is an actual product of T-lymphocytes. A biologically active fragment of PTHrP, PTHrP(1-34), suppressed DNA synthesis in lectin-stimulated lymphocytes at concentrations greater than 50 pg/mL; the same concentration range of IR-PTHrP detected in the cultured media of lectin-stimulated lymphocytes. Therefore, it is reasonable to postulate that PTHrP is a cytokine inhibiting the cellular growth of normal lymphocytes.

Cell Division↗
PubMed1990

Comparison of biological activities of endothelin-1, -2 and -3 in murine and human fibroblast cell lines.

The effects of three forms of endothelin (ET), ET-1, -2 and -3, on intracellular free Ca2+ concentration ([Ca2+]i) and their receptor binding activities have been compared in murine fibroblast cell line Swiss 3T3 as well as diploid human fibroblast cell line FS-4. In both cell lines, ET-1 and -2 induced a profound increase in [Ca2+]i with a similar dose-response relationship; ET-3 was far less potent. ET-1 and -2 showed specific binding to both cell lines with similar dissociation constants and numbers of binding sites. Negligible specific binding of ET-3 was detected. These findings indicate that these two fibroblast populations possess high affinity receptors for ET-1 and -2 and practically no ET-3 receptors for ET-3, and binding of ET-1 and -2 increases [Ca2+]i in these cell lines.

Animals↗
PubMed1990

Proteolysis and orientation on reconstitution of the coated vesicle proton pump.

We recently proposed a structural model for the ATP-dependent proton pump from clathrin-coated vesicles (Arai, H., Terres, G., Pink, S., and Forgac, M. (1988) J. Biol. Chem. 263, 8796-8802). To test this model further, we have carried out additional structural analysis of the (H+)-ATPase in both the detergent-solubilized and reconstituted states in this and the following paper (Adachi, I., Puopolo, K., Marquez-Sterling, N., Arai, H., and Forgac, M. (1990) J. Biol. Chem. 265, 967-973). The orientation of the reconstituted proton pump was determined by analyzing the effect of detergent on ATP hydrolysis and by quantitating the extent of labeling of luminally oriented subunits using a membrane-impermeant reagent. Greater than 90% of the reconstituted (H+)-ATPase is oriented with the cytoplasmic surface facing outward. Treatment of the reconstituted (H+)-ATPase with trypsin results in rapid cleavage of the 100-, 73-, 58-, 38-, and 34-kDa subunits and slower cleavage of the 40- and 33-kDa subunits, consistent with our previous results indicating that all of these polypeptides have some portion of their mass exposed to the cytoplasmic surface. The 19- and 17-kDa subunits, by contrast, appear resistant to cleavage by trypsin in both the detergent-solubilized and reconstituted states, consistent with their being buried extensively in the hydrophobic phase of the bilayer. Treatment of the enzyme with trypsin under conditions in which the 100-, 73-, 58-, 38-, and 34-kDa subunits have been cleaved results in a species which is virtually inactive with respect to proton transport but retains 50% of the original ATPase activity, suggesting that proteolysis has resulted in uncoupling of these two activities. Cleavage of both the 73- and 58-kDa subunits by trypsin at a site 1-2 kDa from the amino terminus is inhibited in the presence of 2',3'-O-(2,4,6-trinitrophenyl)-ATP, consistent with the suggestion that both the 73- and 58-kDa subunits may be nucleotide binding proteins.

Adenosine Triphosphate↗
PubMed1990

Dissociation, cross-linking, and glycosylation of the coated vesicle proton pump.

In order to refine further our structural model of the coated vesicle (H+)-ATPase (Arai, H., Terres, G., Pink, S., and Forgac, M. (1988) J. Biol. Chem. 263, 8796-8802), we have extended our structural analysis to identify peripheral and glycosylated subunits of the pump as well as to identify subunits which are in close proximity in the native (H+)-ATPase complex. Treatment of the purified, reconstituted (H+)-ATPase with 0.30 M KI in the presence or absence of ATP or MgATP results in the release of the 73-, 58-, 40-, 34-, and 33-kDa subunits, leaving behind the 100-, 38-, 19-, and 17-kDa subunits in the membrane. Because the former group of polypeptides is released from the membrane in the absence of detergent, they correspond to peripheral membrane proteins. To determine which subunits are in close proximity, cross-linking of the purified (H+)-ATPase was carried out using the cleavable, bifunctional amino reagent 3,3'-dithiobis(sulfosuccinimidylpropionate) followed by two-dimensional gel electrophoresis. These studies indicate that contact regions exist between the 73- and 58-kDa subunits as well as between the 17-kDa subunit and the 40-, 34-, and 33-kDa subunits. To test for glycosylation of the (H+)-ATPase, the detergent-solubilized complex was treated with neuraminidase followed by electrophoresis and blotting using a peanut lectin/horseradish peroxidase conjugate. Galactose-inhibitable staining of the 100-kDa subunit, together with affinity chromatography of the intact (H+)-ATPase on peanut lectin agarose, indicates that the 100-kDa subunit is glycosylated, most likely at a site exposed on the luminal side of the membrane. These results, together with those presented in the preceding paper (Adachi, I., Arai, H., Pimental, R., and Forgac, M. (1990) J. Biol. Chem. 265, 960-966), were used in the construction of a refined model of the coated vesicle (H+)-ATPase.

Biological Transport, Active↗
PubMed1990

The induction of a hypercoagulable state by medroxyprogesterone acetate in breast cancer patients.

The effects of medroxyprogesterone acetate (MPA) on the mechanism of coagulation in postmenopausal patients were studied and compared with those of tamoxifen by a retrospective analysis. The coagulation test parameters tested included platelet count, bleeding time, clotting time, prothrombin time, activated partial thromboplastin time, and the levels of fibrinogen, fibrin degradation products, factor II, factor V, plasminogen, alpha 2-plasmin inhibitor (alpha 2-PI) and alpha 2-plasmin inhibitor-plasmin complex (alpha 2-PI-P). A shortened APTT was noted and the levels of factors II, V, alpha 2-PI and alpha 2-PI-P were also out of the normal range during treatment in the MPA-treated group. However, these abnormal parameters recovered to within the normal range from 6 months or more after the commencement of treatment without any termination of drug administration. The patients were all asymptomatic. In contrast, a slight prolongation of bleeding time which persisted for more than 6 months was observed in the patients treated with tamoxifen. These data suggest that MPA causes a hypercoagulable state and that any change must be carefully monitored during treatment with either MPA or tamoxifen.

Antineoplastic Agents↗
PubMed1990

In vitro sensitivity test of breast cancer cells to hormonal agents in a radionucleotide-incorporation assay.

Breast cancer cell lines (MCF-7, T47D, BT-20 and STT-11) and fresh cells from malignant effusions of eight breast cancer patients were examined for their in vitro sensitivity to 17 beta-estradiol (E2), tamoxifen and toremifene in a miniaturized, improved nucleic acid precursor incorporation assay (MINI assay). Seven of the eight patients received either tamoxifen or toremifene following a MINI assay and the correlation was examined between in vitro sensitivity and clinical responses to the hormonal agents. In cell lines, E2 stimulated thymidine incorporation by estrogen receptor (ER)-rich cells, MCF-7 and T47D, but not by ER-poor cells, BT-20 and STT-11. Tamoxifen induced both ER-mediated and -unmediated effects in ER-rich cells. The latter effect was also observed in ER-poor cells. Toremifene had less ER-unmediated effect in all of the cells tested than tamoxifen did. The ER-mediated effect of toremifene was weaker than that of tamoxifen in cell lines but was equipotent to tamoxifen in fresh cells. E2 affected thymidine incorporation by cells withdrawn from patients who showed a partial response to the anti-estrogens. No clear correlation was demonstrated between in vitro sensitivity to anti-estrogens of fresh cells and clinical response to these agents. The present results suggest that 1) the MINI assay is a useful system to investigate hormonal effects on breast cancer cell lines; 2) clinical responses to anti-estrogens are not predicted by in vitro response to the agents but might be predicted by the in vitro response to E2; and 3) toremifene has a smaller non-specific effect on breast cancer cells than tamoxifen and is equipotent to tamoxifen in the ER-mediated effect in vitro.

Adult↗
PubMed1990

[Effects of cepharanthine on liposomal permeability and size].

Effects of cepharanthine, one of membrane-stabilizing agents, on membrane permeability and on liposomal size were examined. When cepharanthine was added to the lipid before liposome formation, the size of liposome increased and the permeability did not change. On the other hand, when cepharanthine was added to the liposome suspension after liposome formation, no effect was found on liposomal size but the membrane permeability increased and lag time of initial leak of 5 (& 6)-carboxyfluorescein reduced dose-dependently.

Alkaloids↗
PubMed1990

[A study on pre-operative administration of 5'-DFUR in carcinomas of the gastric, breast, thyroid and colon].

Pre-operative chemotherapy for 7 days with 5'-DFUR (p.o.) were carried out in the patients with gastric, breast, thyroid and colon cancers. The concentration of 5-fluorouracil (5-FU) in tumor cells was higher than that in the normal tissue. In case of breast cancer, it was 10 times higher than normal tissue. The concentration of 5-FU at the metastatic lymph nodes in gastric cancer was considerably high. The pattern of DNA histogram changed when chemotherapy was applied, and we observed the G2 and M phase block.

Antineoplastic Agents↗
PubMed1989

Interferon-gamma down-regulates membrane adenylate cyclase activity of a murine macrophage-like cell line (P388D1).

Effects of recombinant murine interferon-gamma (rIFN-gamma) on the membrane adenylate cyclase of a murine macrophage cell line (P388D1) were investigated in order to explore the nature of a signal transmitted by IFN-gamma receptor. Following the incubation of P388D1 cells with 40 U/ml of rIFN-gamma, the intracellular level of cAMP gradually increased about twofold over the control level within 60 min, and then began to gradually decline to about half the control level by 24 h incubation. The initial rise in cAMP level appeared to be due to the modest activation of adenylate cyclase and not due to the inhibition of cAMP-phosphodiesterase. Later decrease of intracellular cAMP may be due to quantitative down-regulation of the adenylate cyclase system. The basal enzymatic activity of the membrane prepared from P388D1 cells exposed to IFN-gamma for 24 h was found to be reduced to about 20% of that of the control membrane. However, the quality of the adenylate cyclase system appeared unchanged, because the relative degree of the response of the down-regulated membrane adenylate cyclase to prostaglandin PGE2, NaF, guanylimidodiphosphate (GppNHp), choleara toxin (CT), or forskolin was found to remain unchanged. This quantitative down-regulation of adenylate cyclase must be due to the action of rIFN-gamma, since the prior treatment of rIFN-gamma with either acid (pH 2) or monoclonal anti-IFN-gamma antibody inhibited the ability of IFN-gamma to induce the down-regulation. The rIFN-gamma-induced down-regulation is a reversible process, since the adenylate cyclase activity of the membrane was found to be restored when the rIFN-gamma-exposed cells were cultured for 72 h in the absence of rIFN-gamma. In addition, the 48 h-incubation of P388D1 cells with rIFN-beta or IFN-alpha was found not to significantly affect the membrane adenylate cyclase system.

3',5'-Cyclic-AMP Phosphodiesterases↗