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Biomedical subjects

A Watanabe

Publications and source records attributed to A Watanabe.

At least 919 records · Page 51Linked to original sources

Predictors of clinical hypomagnesemia. Hypokalemia, hypophosphatemia, hyponatremia, and hypocalcemia.

Four studies were conducted, each determining the frequency of hypomagnesemia in patients already found to have one abnormal electrolyte determination. Hypomagnesemia occurred in 42% of patients with hypokalemia, 29% of patients with hypophosphatemia, 27% of patients with hyponatremia, and 22% of patients with hypocalcemia. These observations suggest that detection of either hypokalemia, hypophosphatemia, hyponatremia, or hypocalcemia, all of which are routinely available determinations, should alert the clinician to order serum magnesium determinations because of the frequent association of hypomagnesemia with these electrolyte perturbations. Optimally, levels of serum Mg should be determined on a routine basis because of the frequency of the occurrence of hypomagnesemia in hospitalized patients.

Humans↗

[Case of cerebral aneurysm producing the aberrant regeneration of the oculomotor nerve].

We reported a 61-year-old woman who developed the associated movements in oculomotor muscles after the clipping of the IC-PC aneurysm which had produced the oculomotor palsy. It has generally been assumed that the phenomenon is the result of an aberrant regeneration of oculomotor nerve fibers. The sign of the aberrant regeneration may include any of the following: Pseudovon Graefe sign: retraction and elevation of the lid on downward gaze. Gaze lid dyskinesis: elevation of the involved lid on adduction of the eye. Inability to elevate or depress the globe: the globe neither elevates nor depress in up or down gaze. Retraction of the globe: the globe can be seen to retract on vertical movement. Adduction of the involved eye on attempted depression or elevation. Pseudo-Argyll Robertson pupil: the dilated pupil will not react to light but will contract when the medial rectus, inferior rectus, or elevators of the eye are stimulated. Monocular optokinetic response: in testing the vertical optokinetic response, the normal eye responds as usual but the affected eye either remains stationary or will show a slight horizontal nystagmus. All but category 4 were noted in our case.

Female↗

ApoVLDL of the Watanabe Heritable Hyperlipidemic rabbit and the cholesterol-fed rabbit.

The Watanabe Heritable Hyperlipidemic rabbit (WHHL rabbit) and the cholesterol-fed rabbit have been reported to show elevations of very low density (VLDL), intermediate density (IDL), and low density lipoproteins (LDL), and a broad-beta band on agarose-gel electrophoresis. We have studied the lipid and lipoprotein composition of WHHL rabbits and cholesterol-fed rabbits using ultracentrifugal analysis and isoelectric focusing. The total cholesterol (TC)/triglyceride (TG) ratios of VLDL, IDL, and LDL in WHHL rabbits were slightly elevated, but almost normal compared with those of cholesterol-fed rabbits, whose TC/TG ratios were markedly elevated compared with normolipidemic rabbits. ApoVLDL of WHHL rabbits showed no compositional changes in apoE and apoC isoforms, and no marked changes in the apoE/apoC ratios. But apoVLDL of cholesterol-fed rabbits showed a significant decrease of apoC-III, a significant increase of apoC-V, and marked elevation of the apoE/apoC ratio. We conclude that serum lipoprotein compositions in the WHHL rabbit were normal, while the lipoprotein lipid and apolipoprotein composition in the WHHL rabbit are different from those in cholesterol-fed rabbits.

Animals↗

Further studies on superoxide dismutase activities of macrocyclic polyamine complexes of copper(II).

The superoxide dismutase (EC 1.15.1.1) activities of new series of macrocyclic complexes with copper(II) have been measured. Chemical modifications in macrocyclic ring size, donor atom, donor atom number, substituents on the macrocyclic skeletons, and length of bridges linking two macrocycles are shown to have profound effects on the superoxide dismutase activities of the metal complexes. The quantitative measurement by the standard xanthine-xanthine oxidase assay, which depends on the conversion of nitroblue tetrazolium to formazan, has been corroborated by a direct assay method using an oxygen electrode.

Catalysis↗

Reduction of serum cholesterol in heterozygous patients with familial hypercholesterolemia. Additive effects of compactin and cholestyramine.

We studied the effects of the bile acid sequestrant cholestyramine, alone and in combination with the experimental agent compactin (ML-236B), a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, on serum levels of lipoproteins in 10 heterozygous patients with familial hypercholesterolemia. After cholestyramine treatment alone for 2 to 16 months, serum total and low-density lipoprotein cholesterol decreased by 20 and 28 per cent, respectively. With the addition of compactin for 12 weeks there was a 39 per cent total decrease in serum cholesterol from the control value--from 356 +/- 14 to 217 +/- 10 mg per deciliter (9.27 +/- 0.36 to 5.64 +/- 0.26 mmol per liter [mean +/- S.E.M.]; P less than 0.001)--and a 53 per cent decrease in low-density lipoprotein cholesterol--from 263 +/- 13 to 125 +/- 10 mg per deciliter (6.84 +/- 0.34 to 3.25 +/- 0.26 mmol per liter; P less than 0.001). High-density lipoprotein cholesterol, which had increased during cholestyramine treatment, remained at its higher level. No adverse effects were observed. If long-term safety can be demonstrated, the compactin-cholestyramine regimen may prove useful in heterozygous familial hypercholesterolemia. prove useful in heterozygous familial hypercholesterolemia.

Adult↗

Structure-biocompatibility relationship of condensation polymers.

Various condensation polymers including polyamides, polyesters, polyethers, polysulfonamides, polysulfonate, polyphosphonate, polyimide, polyamide-imides, polyimide, polyamide-imides, polyester-amides, etc. have been prepared and evaluated for their biocompatibility by a cell culture method. Cell attachment and cell growth are influenced by the chemical structures of the tested polymers. Aliphatic polyamides exhibited considerably different cell growth behavior than aromatic polyamides.

Biocompatible Materials↗

Alterations in neutral amino acid transport across the blood-brain barrier in hepatic failure.

The accelerated transport of the blood neutral amino acids into the brain in encephalopathic patients with fulminant hepatitis and advanced liver cirrhosis was demonstrated not only by determining the cerebrospinal fluid (CSF) aminogram but also by calculating the predicted velocity of the amino acid transport through the blood-brain barrier. Significant elevation in CSF aromatic amino acid (AAA) and methionine levels was observed in the encephalopathic patients. Arousal from hepatic encephalopathy by drip infusion of a branched chain amino acid (BCAA)-enriched solution was obtained coincidentally with the elevated BCAA levels and diminished concentrations of AAA and methionine in CSF. These clinical observations were confirmed experimentally in rats treated with carbon tetrachloride (CCl4) and D-galactosamine by obtaining the elevation of neutral amino acid contents in the brain and the slight increase in the brain uptake index (BUI) of a radiolabeled amino acid.

Amino Acids↗

Brain tyrosine hydroxylase activity and calculated amount of brain dopa synthesized in carbon tetrachloride-intoxicated rats.

Tyrosine hydroxylase activity in the corpus striatum was measured in a large dose of carbon tetrachloride (CC14)-intoxicated rats in order to confirm whether brain catecholamine contents decrease in acute hepatic failure or not. Theoretical amounts of dopa synthesized in the brain of the treated animals were calculated according to an equation of enzyme kinetics. Tyrosine hydroxylase activities in CCl4-injured rats were similar to those in control rats, and calculated amounts of brain dopa in liver-injured rats were rather higher as compared to those in untreated animals.

Amino Acids↗

Effects of imipramine on behavior and brain norepinephrine metabolism in tetrabenazine treated rats: comparative study of a single administration with repeated administrations of imipramine.

The effects of a single and repeated administrations of imipramine on the tetrabenazine-induced sedation in rats were studied. The 3-methoxy-4-hydroxyphenylethyleneglycol-sulfate (MHPG-SO4) level in the brain was measured. A single administration of imipramine of 20 mg/kg had no significant effect on the rats' locomotor activity and the brain MHPG-SO4. The administration of 30 mg/kg of tetrabenazine produced marked sedation and significantly increased the brain MHPG-SO4. The imipramine pretreatment reversed the tetrabenazine-induced sedation. The brain MHPG-SO4 in the rats treated with a single administration of imipramine along with tetrabenazine decreased significantly, compared with that in the rats treated with tetrabenazine only. The administration of alpha-methyl-para-tyrosine (alpha-MT) of 250 mg/kg suppressed the reversal of the tetrabenazine-induced sedation. The administration of Ro4-4602 of 50 mg/kg and L-3,4-dihydroxyphenylalanine (L-DOPA) of 100 mg/kg had no significant effect on the reversal. The repeated daily administrations of imipramine of 20 mg/kg reversed the tetrabenazine-induced sedation and produced the locomotor hyperactivity. When the rats were treated with the repeated administrations of imipramine for five days and had tetrabenazine administered on the last day, the brain MHPG-SO4 increased significantly as compared with that in the rats treated with a single administration of imipramine and tetrabenazine. There was no difference in the amount of locomotor activity between the rats administered imipramine of 20 mg/kg and tetrabenazine and those administered imipramine of 40 mg/kg and tetrabenazine. Several considerations were given to the above-mentioned results.

Animals↗

Effect of azathioprine and carbon tetrachloride on induction of hyperplastic liver nodule and hepatocellular carcinoma by diethylnitrosamine and N-2-fluorenylacetamide in rats.

The enhancing or inhibitory action of the hepatotoxic agents, carbon tetrachloride (CCl4) and azathioprine (AZP), on the evolution of hyperplastic liver nodule (HN) and hepatocellular carcinoma (HCC) in diethylnitrosamine (DEN)- and N-2-fluorenylacetamide (FAA)-treated rats (control group) was tested. The area of gamma-glutamyl transpeptidase(gamma-GTP)-positive HN and/or foci in the eighth week was remarkably small in rats fed on a diet containing FAA and AZP (the AZP group), but was quite large in rats fed a diet containing FAA in addition to repeated CCl4 injections (the CCl4 group). HCC was first detected in the 21st week and the incidence of HCC within the 36 weeks of the experiment was very high in the CCl4 group. However, no tumor, including HCC, was detected in the AZP group during this observation period. No essential differences in the biochemical characteristics of HCC between the control group and the CCl4 group were observed with respect to several enzyme activities. The increased activity of liver aniline hydroxylase observed 12 hr after the administration of FAA, AZP, or DEN decreased when AZP was administered simultaneously with FAA to rats treated with DEN in advance. The mechanisms of the enhancing of inhibitory effect observed are discussed with special reference to the drug-drug interactions.

2-Acetylaminofluorene↗

Further studies on the effects of flavine adenine dinucleotide on the platelet functions.

Flavine adenine dinucleotide (FAD) may inhibit not only the aggregation but also ATP release of platelets in vitro. FAD did not inhibit the synthesis of thromboxane from 1-14C-arachidonic acid by platelets. FAD was found to be hydrolyzed to FMN and AMP by a plasma enzyme, the activity of which in normal adults being estimated as 32.6 +/- 9.1 m microM/ml plasma/min and AMP, thus produced, and/or FAD might compete for the receptor sites on the platelet surface. This could be the mechanism of the inhibitory effect of FAD upon the platelet functions. The intravenous drip infusion of FAD in a dose of 0.2 mg/kg within 30 min was followed by no marked decrease of platelet aggregation, probably because the plasma concentration of FAD and/or AMP did not reach the levels high enough to suppress the platelet functions.

Adenosine Triphosphate↗