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Biomedical subjects

H Mizuno

Publications and source records attributed to H Mizuno.

At least 271 records · Page 15Linked to original sources

Effects of spinasterol and sitosterol on plasma and liver cholesterol levels and biliary and fecal sterol and bile acid excretions in mice.

Effects of spinasterol and sitosterol on plasma and liver cholesterol levels and biliary and fecal sterol and bile acid excretions were examined with male mice. Both phytosterols were added to the diet at a 1% concentration and fed to mice for 15 days. Spinasterol increased the fecal cholesterol excretion and decreased the plasma and liver cholesterol levels, the bile acid pool size and the fecal bile acid excretion, especially those derived from chenodeoxycholic acid. Fecal coprostanol excretion remained unchanged. These changes were similar to those produced by sitosterol. These data led to the conclusions 1) that spinasterol, as well as sitosterol, inhibits cholesterol absorption, resulting in decreases of the plasma and liver cholesterol levels and 2) that when cholesterol absorption is inhibited, the synthesis of bile acids, especially that of chenodeoxycholic acid, decreases, suggesting that the dietary cholesterol is preferentially metabolized to chenodeoxycholic acid in mice.

Animals↗

Effects of 8-(2-fluoroethyl)-3 alpha-hydroxy-1 alpha H, 5 alpha H-tropaniumbromide benzilate (Ba598Br) on allergy- and drug-induced asthmas.

The effects of Ba598Br, a new atropine derivative possessing a quarternary ammonium salt structure, on the canine airway, including its antiasthmatic effects, were investigated. The in vivo airway resistance was determined using the modified Konzett-Rössler method. Inhalation of 0.01% of Ba598Br had an inhibitory effect against acetyl-choline (ACh, 10 micrograms/kg i.v.)-evoked bronchoconstriction. The effect of Ba598Br was more powerful and longer lasting than that of the same dose of atropine. Pretreatment with Ba598Br (0.3%) and atropine (0.3%) by inhalation produced a remarkable inhibitory effect on the asthmatic bronchoconstriction induced by inhalation of Ascaris suum antigen in naturally sensitized dogs. In this case, Ba598Br showed a potency of approx. twice that of atropine as estimated from the inhibitory percent. On the other hand, in the case of posttreatment (drugs being inhaled after the antigen inhalation), both drugs showed inhibitory effects of equal degree. As for the effects on increased airway secretion at the time of asthmatic attack, both drugs inhibited the excessive secretions without any remarkable change in the viscosity of the secretions. Inhalation of 0.3% Ba598Br showed a powerful antihistamine action with respect to histamine (Hist, 3 micrograms/kg i.v.)-induced bronchoconstriction after the bilateral cervical vagi and superior laryngeal nerves were amputated. However, almost no effect could be observed with the same dose of atropine. Both Ba598Br and atropine showed relaxing actions of the same degree against ACh contraction on the isolated canine trachea, bronchus and bronchiole preparations, with a particularly strong relaxation being observed in the bronchiole. On the other hand, Ba598Br showed relaxing actions against histamine-induced contractions, which were more powerful than those of atropine, in the bronchus and bronchiole. From the above findings, it is suggested that the Ba598Br inhalation brings about antiasthmatic effects by its persistent, powerful anticholinergic actions and its transient but powerful antihistamine actions.

Animals↗

[Treatment of multiple myeloma. High-dose intermittent administration of cyclophosphamide and prednisolone--follow up study of 10 years period].

Twenty patients with plasma cell myeloma were treated with high-dose (10 mg/kg) intermittent administration of cyclophosphamide for remission induction and maintenance therapy. High-dose intermittent administration of glucocorticosteroid hormone was also performed usually in parallel with large-dose of cyclophosphamide. A significant objective response was obtained in 12 of 20 patients (60.0%). The median survival was 32 months in all cases; 47 months in the responding cases. The response rate was not affected by the class of M-protein, the type of light-chain and/or the presence of bone lesions. All responders were on the 3rd stage. High-dose intermittent administration of cyclophosphamide was evaluated as very useful since it showed equivalent effects obtained by combination chemotherapy regimens, hardly producing bone marrow suppression.

Adult↗

Two-dimensional echo-cardiographic estimation of left atrial volume and volume load in patients with congenital heart disease.

To estimate the left atrial volume (LAV) and pulmonary blood flow in patients with congenital heart disease (CHD), we employed two-dimensional echocardiography (TDE). The LAV was measured in dimensions other than those obtained in conventional M-mode echocardiography (M-mode echo). Mathematical and geometrical models for LAV calculation using the standard long-axis, short-axis and apical four-chamber planes were devised and found to be reliable in a preliminary study using porcine heart preparations, although length (10%), area (20%) and volume (38%) were significantly and consistently underestimated with echocardiography. Those models were then applied and correlated with angiocardiograms (ACG) in 25 consecutive patients with suspected CHD. In terms of the estimation of the absolute LAV, accuracy seemed commensurate with the number of the dimensions measured. The correlation between data obtained by TDE and ACG varied with changing hemodynamics such as cardiac cycle, absolute LAV and presence or absence of volume load. The left atrium was found to become spherical and progressively underestimated with TDE at ventricular endsystole, in larger LAV and with increased volume load. Since this tendency became less pronounced in measuring additional dimensions, reliable estimation of the absolute LAV and volume load was possible when 2 or 3 dimensions were measured. Among those calculation models depending on 2 or 3 dimensional measurements, there was only a small difference in terms of accuracy and predictability, although algorithm used varied from one model to another. This suggests that accurate cross-sectional area measurement is critically important for volume estimation rather than any particular algorithm involved. Cross-sectional area measurement by TDE integrated into a three dimensional equivalent allowed a reliable estimate of the LAV or volume load in a variety of hemodynamic situations where M-mode echo was not reliable.

Adolescent↗

Control of growth hormone release in goats: effect of vagal cooling, feeding and artificial distension of the rumen.

It was confirmed that, as in overnight-fasted castrate male sheep, plasma growth hormone (GH) levels also fell in overnight-fasted castrate male goats shortly after they were given hay the following morning and that GH levels could also fall in anticipation of being fed. A further observation was that plasma GH levels usually remained low for 2--3 hours if the goats were allowed to continue eating but that if the hay was removed after only one hour of eating the plasma GH level rose 20--50 min later. Although initial attempts to determine the role of visceral stimuli in the regulation of GH release in castrate male goats by bilateral cooling of exteriorized vagi were inconclusive because of side-effects, they drew attention to the role of rumen distension and activation of stretch receptors in the modulation of GH release. This was investigated by artificial distension of the cranial sac of the rumen with a balloon in a castrate male, overnight-fasted goat prepared with a rumen fistula. Inflation of the balloon with warm water was followed by a fall, and deflation of the balloon by a rise, in plasma GH levels. It is concluded that rumen distension and hence activation of ruminal stretch receptors is a sufficient stimulus to explain the immediate inhibition of GH release by feeding in the goat. As a result of these, and other, observations during this work, it is also suggested that unrestrained release of GH, and hence large oscillations in plasma GH level, may occur in the goat unless it is suppressed by any of several factors, which include activation of rumen stretch receptors by feeding or inflation, anticipation of being fed, stress and metabolic satiety.

Animals↗

Effects of carbon dioxide on serum biochemical patterns and on histopathological changes of organs in rats.

The effects of carbon dioxide on serum biochemical patterns and on histopathological changes of organs were studied in male Sprague-Dawley rats which were anesthetized with a mixture of 40% carbon dioxide and 60% oxygen for 3 hr. This level of carbon dioxide is sufficient to maintain rats at an anesthetized level. There were gradual decreased in respiration, body temperature, heart rate, blood pressure and blood pH. At the same time there were significant increases in organ weight (lungs and kidneys), and in exudate to thorax, hematocrit, and serum biochemical patterns (glucose, phosphorus, uric acid, blood urea nitrogen, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase and alpha-hydroxybutyrate dehydrogenase). The weight of the liver, however, decreased slightly. There were minor abnormalities in both gross anatomy and histology (lungs, liver and kidneys). When the rats inhaled ordinary air, they awoke within a few minutes and recovered normal hematological level (pH 7.3, PaO2 120 mmHg and PaCO2 45 mmHg) within 24 hr.

Anesthesia↗