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Biomedical subjects

Y Endo

Publications and source records attributed to Y Endo.

At least 631 records · Page 35Linked to original sources
PubMed1986

Mechanism of in vitro antitumor effects of interleukin 1 (IL 1).

In vitro studies suggest that purified IL 1 beta derived from normal human peripheral blood monocytes and human myelomonocytic cell line THP-1 cell supernatants was capable of modest augmentation of NK activity of purified LGL and of promoting monocyte cytotoxicity for the human melanoma A375 target cells. In addition, purified IL 1 beta also has direct cytostatic and cytocidal effects for A375 cells. A375 melanoma cells were cloned to obtain a homogeneous population of IL 1 receptor-bearing target cells. Recombinant human IL 1 alpha inhibited the proliferation of these cells within 48-72 h in a dose-dependent manner. Similar doses of recombinant IL 1 alpha exhibited inhibitory effects on the ornithine decarboxylase (ODC) activity of A375 cells by 6-24 h. Putrescine, a nontoxic product of the ODC pathway, could prevent the cytostatic effect of recombinant IL 1 alpha on these tumor target cells. This observation indicates that inhibition of the ODC pathway is causally related to the antiproliferative effect of IL 1 on these tumor cells.

Cell Cycle↗
PubMed1986

Glomerular IgA deposition in pulmonary diseases.

Glomerular changes of 70 cases of pulmonary diseases and 25 control cases among 1100 consecutive autopsy cases were studied by light, immunofluorescence, and electron microscopy. These pulmonary diseases consisted of 11 cases of chronic obstructive bronchiolitis (COB), 15 cases of bronchopneumonia, 4 cases of acute interstitial pneumonia, 22 cases of idiopathic interstitial pneumonia (IIP), and 18 cases of lung cancer free from IIP. Bacteriological examination of the lung was performed in these cases including control cases on autopsy. Mesangial IgA deposition was predominant in 25 out of the 70 study cases (36%) frequently accompanied by C3, whereas slight mesangial IgA deposition was observed in one of the control cases. Incidence of IgA deposition was 64% in IIP, 54.5% in COB, 13.3% in bronchopneumonia, 16.7% in lung cancer and 25% in acute interstitial pneumonia. The results of the present study suggest that recurrence or persistence of inflammatory processes of the lung leads to IgA-mediated immune abnormalities and to mild mesangial changes with predominant IgA deposition, which are similar to the immunopathologic features of IgA nephropathy.

Aged↗
PubMed1986

Measurement of iodide in urine using the iodide-selective ion electrode.

A simple and rapid way to measure the concentration of iodide in urine with an iodide-selective ion electrode was described. Potentiometric equilibrium was attained in less than 5 min, and a linear calibration curve was obtained over the potassium iodide (KI) concentration range of 10(-2) to 10(-6) M. The coefficients of variation ranged from 6.2 to 10.0% within assay, and 5.4 to 14.4% between assays. The serial dilution of 3 urine samples with different concentration of iodide showed good linear correlations passing through zero. In practice, the chloride ions in urine did not cause serious errors in the measurement of iodide at molar ratios of chloride ion to iodide up to 2 X 10(4). A good linear correlation was obtained between iodide concentrations in urine determined by the electrode method and by the conventional chemical method (r = 0.92). A linear correlation was also observed between the iodide concentrations of 24 h collected urine and those of single morning urine (r = 0.91). The normal iodide content in single morning urine specimens from 127 Japanese people was 5.3 to 62.0 X 10(-6) moles/g creatinine.

Adult↗
PubMed1986

Des-O-methylolivoretin C is a new member of the teleocidin class of tumor promoters.

Des-O-methylolivoretin C, a demethylated form of olivoretin C, is a naturally occurring compound in Streptomyces mediocidicus and Streptoverticillium olivoreticuli. Des-O-methylolivoretin C is a regioisomer of teleocidin B, which has the same activity as teleocidin. The tumor-promoting activity of des-O-methylolivoretin C was studied in a two-stage carcinogenesis experiment on mouse skin in comparison with that of teleocidin. Treatments with 7,12-dimethylbenz[a]anthracene (DMBA) plus des-O-methylolivoretin C and DMBA plus teleocidin induced tumors in 63.3% and 84.6% of the mice, respectively, in week 30. The difference in the tumor-promoting activities of des-O-methylolivoretin C and teleocidin is presumably related to the regioisomeric difference in the cyclohexene ring.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1986

[The active structure of tumor promoters].

Diterpene esters containing 12-0-tetradecanoylphorbol-13-acetate (TPA) and the alkaloid teleocidins are structurally unrelated natural products that exhibit similar potent skin tumor-promoting activity. These promoters are classified as TPA-type promoters because they bind equally to the phorbol ester receptor. TPA can be considered as an amphiphilic compound, with a hydrophilic domain spanning the C-3 to C-20 region of the molecule and a lipophilic domain consisting of the acyl substituents on C-12 and C-13. Teleocidins can also be considered as amphiphilic compounds, with the hydrophilic domain spanning the C-11 to C-14 region of the molecule and the lipophilic domain consisting of the alkyl substituents on C-6, C-7 and C-12. Teleocidins exist in two conformational states, the TWIST form and the SOFA form, in solution. From the ratio of the two conformations in solution, the free-energy difference between them was calculated to be 0-1.5 kcal/mol. Therefore a possible role of one of the two conformations should be considered in the modeling of receptor mapping. Computer modeling of the SOFA form of teleocidins and TPA showed a marked similarity with regards to the hydrogen bonding sites of the hydrophilic substituents. In this case, good superposition of the lipophilic regions of both types of compounds was obtained.

Carcinogens↗
PubMed1986

Effects of diltiazem hydrochloride in diabetics.

The effects of diltiazem hydrochloride on insulin secretion and glucose tolerance were studied in diabetic subjects treated with dietary management alone for their glycemic control. Sixteen diabetic subjects with heart complaints and/or abnormal electrocardiographic findings which were compatible with diagnosis of ischemic heart disease were given diltiazem hydrochloride 90 mg daily for a mean of 9.3 +/- 1.0 (SE) months and oral 100 g glucose tolerance tests (o-GTT) were performed before and after the administration of diltiazem hydrochloride. As a control group, 14 diabetic patients with roughly the same level of fasting blood glucose and the same degree of glucose intolerance were selected, and in these patients oral 100 g glucose tolerance tests were also performed before and after a mean follow up period of 12.6 +/- 1.5 months. Although improvement in glucose tolerance was observed at the end of the trial in the group of patients with diltiazem hydrochloride, control group also showed improved glucose tolerance and there was no significant difference in the change of glucose tolerance between both groups. No significant change of IRI response in oral 100 g glucose tolerance test was observed in both groups. We could, therefore, conclude from these observations that diltiazem hydrochloride with usual clinical dosage dose not exert unfavourable effects on glucose tolerance and insulin secretion in the mild diabetic patients.

Aged↗
PubMed1986

Mechanism of action of ricin and related toxic lectins on eukaryotic ribosomes.

We have studied on the mechanism of ricin action on rat liver ribosomes and present evidence which shows that the toxin inactivates ribosomes by modifying two bases at positions G-4323 and A-4324 of 28S rRNA adjacent to alpha-sarcin cleavage site. Further results showing that those phosphodiester bonds are very labile against alkaline digestion and aniline-treatment strongly suggest that these purine bases are removed by N-glycosidase activity of the toxin. In parallel, we also present evidence showing that abrin and modeccin have the same activity on eukaryotic ribosomes as ricin does.

Animals↗