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Biomedical subjects

Y Kaneda

Publications and source records attributed to Y Kaneda.

At least 451 records · Page 25Linked to original sources
PubMed1983

Effect of dopamine on phosphate reabsorption in isolated perfused rabbit proximal tubules.

The effect of dopamine (10(-6) M) on PO4 reabsorption was studied in isolated and perfused proximal convoluted and straight tubules of the rabbit. In convoluted tubules, fluid reabsorption (JV), PO4 lumen-to-bath (JPO4lb), and net (net JPO4) fluxes did not change during dopamine exposure. In S3 segments bathed in rabbit serum, JV diminished significantly during dopamine exposure. JPO4 decreased by 20% (p less than 0.005) and net JPO4 decreased by 27% (p less than 0.02). The effect of dopamine was reversible upon removal of the drug.

Absorption↗
PubMed1982

Synthesis and immunoadjuvant activities of the repeating, disaccharide-dipeptide unit of the bacterial, cell-wall peptidoglycan and of some carbohydrate analogs.

The repeating disaccharide-dipeptide units of the bacterial, cell-wall peptidoglycan, one being O-(N-acetyl-beta-muramoyl-L-alanyl-D-isoglutamine)-(1 leads to 4)-2-acetamido-2-deoxy-D-glucose, and the other, O-(2-acetamido-2-deoxy-beta-D-glucosyl)-(1 leads to 4)-N-acetyl-muramoyl-L-alanyl-D-isoglutamine, have been synthesized. Some carbohydrate analogs, such as O-(N-acetyl-beta-muramoyl-L-alanyl-D-isoglutamine)-(1 leads to 4)-N-acetylmuramoyl-L-alanyl-D-isoglutamine, O-beta-D-glucosyl-(1 leads to 4)-N-acetylmuramoyl-L-alanyl-D-isoglutamine, and O-(6-acetamido-6-deoxy-beta-D-glucosyl)-(1 leads to 4)-N-acetylmuramoyl-L-alanyl-D-isoglutamine, were also synthesized. Their immunoadjuvant activities were examined in guinea-pigs.

Adjuvants, Immunologic↗
PubMed1982

Dopamine decreases fluid reabsorption in straight portions of rabbit proximal tubule.

The effects of DA and DA blockers on fluid transport, transepithelial potential difference (PD), and Na fluxes were studied in straight portions of the rabbit proximal tubule by the technique of microperfusion in vitro. DA (10(-6) M) added to the bath (rabbit serum) produced a significant decrease in fluid reabsorption (Jv, nl.min-2.mm-1) from 0.53 +/- 0.05 to 0.19 +/- 0.06 (n = 7, P less than 0.005). PD decreased from -2.7 +/- 0.5 to -1.2 +/- 0.4 mV (P less than 0.01). Drugs active on DA receptors were used to characterize the action of dopamine. Haloperidol (10(-8) M), lisuride (1.5 X 10(-9) M), and metoclopramide (10(-7) M) did not modify Jv by themselves but prevented the action of dopamine. Agonists of DA, Epinine and A 6,7 DTN, produced smaller or shorter decreases in Jv. A 6,7 DTN was active in the presence of alpha- and beta-adrenergic blockers. The serotonin antagonist methysergide decreases Jv by itself by 15%; in its presence DA was not effective. The effect of DA was accompanied by reductions of net Na flux and unidirectional lumen-to-bath and bath-to-lumen Na fluxes by approximately 25%. It is concluded that DA exerts a direct inhibitory effect on fluid transport by the pars recta. The evidence for the existence of DA receptor sites is not conclusive. The mechanism of action is uncertain, but an impairment of transcellular salt transport can be suggested.

Absorption↗
PubMed1982

Simple, direct measurement of lipoprotein X in serum.

This relatively simple method for quantitative estimation of lipoprotein X is based on assay of phospholipids in precipitates of lipoprotein X. We first remove other lipoproteins by precipitation with phosphotungstic acid solution. Lipoprotein X is then precipitated from the supernatant fluid with an alkaline solution of magnesium ion, and phospholipid is determined in this precipitate. Results are linearly related to concentration of lipoprotein X. The CV is less than 3%. Results correlated well with those for agar gel electrophoresis.

Cholestasis↗
PubMed1982

Peliosis hepatis. A specific lesion in the bovine liver.

So-called "Fumyaku-han" of the bovine liver was examined histologically. Localized hemorrhagic foci in the liver have turned out to be blood cavities lined with endothelium associated with hepatic cells. There was no sign of hepatic cell necrosis. The liver lesion was thus identified as phlebectatic type of peliosis hepatis based on histological characteristics and in the light of the literature.

Animals↗
PubMed1981

Synthesis of carbohydrate analogs (positional, configurational, and optical) of n-acetylmuramoyl-L-alanyl-D-isoglutamine, and their immunoadjuvant activities.

2-Acetamido-2-deoxy-4- and -6-O-(D-2-propanoyl-L-alanyl-D-isoglutamine)-D-glucopyranose, 2-acetamido-2-deoxy-3-O-(D-2-propanoyl-L-alanyl-D-isoglutamine)-D-allopyranose, -D-gulopyranose, -D-galactopyranose, -D-mannopyranose, and -L-idopyranose, and 3-O-(D-2-propanoyl-L-alanyl-D-isoglutamine)-D- and -L-glucopyranose were synthesized, in order to clarify the structural requirements for the immunoadjuvant activity of the carbohydrate moiety in N-acetylmuramoyl-L-alanyl-D-isoglutamine. Immunoadjuvant activity of the N-acetylmuramoyl-dipeptide analogs was examined in guinea-pigs.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1980

Mutagenicity screening of feed additives in the microbial system.

18 feed additives were tested for DNA-modifying effects by the repair test named "rec-assay" with Bacillus subtillis H17 (rec+) and M45 (rec-), and for mutagenicity with Escherichia coli WP2 hcr and 5 Salmonella typhimurium tester strains with the use of a top-agar overlay method. Carbadox, furazolidone, panazon and zoalene were positive in both assays. The former 3 were mutagenic for TA100, TA98 and WP2 hcr, while zoalene was mutagenic for all strains. These 4 compounds did not require a metabolic activation for their mutagenic activities. Nicarbazin was weakly mutagenic for TA1538 and TA98 with and without S9 mix. Amprolium and caprylohydroxamic acid also showed very weak mutagenicities only for TA100 with S9 mix and for WP2 hcr with and without S9 mix, resp. The mutagenic activities of carbadox, furazolidone and panazon for TA100 were reduced only by the addition of S9 mix, but not by S9 fraction or blood, whereas that of zoalene was decreased by any of the 3 factors.

Animal Feed↗
PubMed1978

Computer analysis of periventricular lucency on the CT scan.

Of 53 patients with periventricular lucency, 70% revealed obstructive hydrocephalus, mainly due to infratentorial tumors, and the remainder were cases of communicating hydrocephalus, usually secondary to subarachnoid hemorrhage. Of the patients with PVL, 95% had hypertensive hydrocephalus and 60% showed slightly dilated ventricles. Computer analysis was helpful in displaying PVL objectively and clarifying its nature. In experimentally induced obstructive hydrocephalus, PVL was observed at the acute hypertensive stage. We concluded that the pathogenesis of PVL might be the passive diffusion or acute extravasation of CSF into white matter through the disrupted ventricular wall, rather than transependymal absorption of CSF.

Animals↗
PubMed1975

[Myocardial sarcoidosis--pathological studies on 7 autopsy cases with particular reference to histological variations].

The present report consists of seven autopsy cases of myocardial sarcoidosis terminating in death 1 month to 5 years after the onset of symptoms. Histologically, they were classified into the following 4 types: a) diffuse nonspecific granulation, b) specific granuloma with giant cells, c) diffuse fibrosis with giant cells, and d) nonspecific fibrosis. Types a) and b) demonstrate active changes, while c) and d) are sequelae of active inflammation. Morphological changes of sarcoidosis were found not only in myocardium but also in both pericardium and endocardium. Although no final conclusions could be obtained as to whether the giant cells appearing in myocardium were of mesenchymal or myogenic origin, the authors favor the latter concept. Changes compatible to sarcoidosis found in other organs in acute cases were scarce and old. On the contrary, more active and variable changes were encountered in protracted cases. The authors consider giant cell myocarditis to be one type of sarcoidosis occurring in the heart.

Adult↗