Search PubMed⌕ Search

Biomedical subjects

K Ohtani

Publications and source records attributed to K Ohtani.

At least 235 records · Page 13Linked to original sources
PubMed1984

Intracranial hemorrhage in the full-term neonate and young infant: correlation of the location and outcome.

The cranial computed tomography (CT) and outcome for 13 full-term neonates and 12 young infants with intracranial hemorrhage (ICH) were studied. The full-term neonates had perinatal asphyxia or neurological signs such as seizures. All infants were breast-fed and showed bleeding diathesis. In the full-term neonates there was a high incidence of intraventricular hemorrhage (IVH) and hemorrhage around the falx. The location of the hemorrhage on CT and brain pathology suggested that the original site of IVH might be the choroid plexus vessels in the lateral ventricle or in the subependymal layer. On the other hand, the sites of ICH in infants were multifocal compared with those in full-term neonates. Subdural hemorrhage (SDH) was seen more frequently and IVH less frequently in infants than in full-term neonates. The cases with SDH frequently showed accompanying cerebral infarction followed by porencephaly. Thus, SDH with cerebral low density on CT may predict a poor prognosis.

Brain↗
PubMed1984

Analysis of the vagal reflex tracheal constriction in the dog.

We devised a preparation for measuring the vagal reflex tracheal constriction following the bronchoconstriction induced by histamine inhaled in the bronchial side in dogs. Properties of the vagal reflex tracheal constriction were investigated using this preparation. Histamine inhaled in the bronchial side caused the tracheal constriction following the bronchoconstriction. The tracheal constriction was inhibited by section of the bilateral superior laryngeal nerves or vagal cooling, respectively, but was not completely blocked. The combination of section of the bilateral superior laryngeal nerves and vagal cooling abolished the tracheal constriction. An i.v. administration of pentobarbital reduced both bronchoconstriction and tracheal constriction. These findings indicate that the tracheal constriction observed in the present study is mediated by the vagal reflex arc and that the extravagal pathway consisting of the recurrent and superior laryngeal nerves plays a role in a part of the afferent pathway of the vagal reflex airway responses. When the bronchoconstriction was completely abolished by isoproterenol inhaled in the bronchial side, the reflex tracheal constriction still existed. Transient inflation and deflation of the lungs caused reflex tracheal dilatation and constriction, respectively. We conclude that the vagal reflex airway constriction is due to complex effects which may be mediated by plural sensory receptors in the airways.

Animals↗
PubMed1983

Sleep apnea and nocturnal myoclonus in elderly persons in Vilcabamba, Ecuador.

Four men (M age 90.5 years) and four women (M age 91.2 years) in Vilcabamba, Ecuador (a community noted for people with extreme longevity) volunteered for sleep recordings using four-channel Medilog portable cassette recorder. Of the eight physically healthy persons recorded, only one man displayed sleep apnea syndrome. No nocturnal myoclonus was observed. Low incidence of sleep apnea of elderly persons in Vilcabamba may be due to a low barometric pressure and/or lack of drug abuse.

Aged↗
PubMed1983

Effect of BR-227, a new bromhexine derivative, on secretory activities of tracheal secretory cells.

The effects of BR-227 on secretory activities of canine tracheal secretory cells including behavior of mucus glycoproteins were investigated histologically and histochemically. Following BR-227 treatment at a concentration of alcian blue at pH 2.5 and periodic acid-Schiff (AB (pH 2.5)/PAS) decreased in a concentration-dependent manner. Furthermore, a decrease in the thickness of the acini of submucosal glands and in marked increase in the ratio of acinar inner diameter of the gland to tracheal wall were induced after application of BR-227 at a concentration range of 10(-7) to 10(-4) M. The numbers of goblet and submucosal glandular cells which stained blue and purple with AB (pH 2.5)/PAS were decreased by BR-227 treatment in a concentrations-dependent way, whereas the cells which stained red were markedly increased. In the experiment using a combination of AB at pH 1.0 and PAS, a decrease in sulfated glycoproteins in those secretory cells was observed. Total saccharide and protein concentrations in the incubation fluid increased with BR-227 treatment, while N-acetylhexomsamine concentration tended to decrease. These findings suggest that BR-227 stimulates secretory activities of both goblet cells and submucosal glands, and lowers mucus viscosity in the secretory cells.

Animals↗
PubMed1983

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↗
PubMed1983

[Effect of quinine on methamphetamine-induced anorexia].

Two experiments were done to examine the effect of quinine (Q) on methamphetamine (MA)-induced anorexia in rats. They were fasted throughout (water allowed ad libitum) except for a period of 6 hr (10:00-16:00) every day when powder food was offered. In the first experiment, the drug-admixed food (DAF) method was used for testing the effect of MA in combination with Q and MA alone on food consumption and the growth curve. However, the possibility exists that MA plus Q-admixed food increases the aversive reaction. Considering this possibility, we used the injection method in the second experiment. Rats received Q orally by a stomach tube and MA by subcutaneous injection. The injection was made 30 min before the presentation of food. In the DAF method, food consumption and weight of the MA and MA plus Q groups were inhibited. The inhibitions of the MA plus Q group were more potent than that of the MA group. In the injection method, the inhibitions of food consumption and growth curve in the MA plus Q group were significantly different from that of the MA group and were dose-dependent on MA. Tolerance to MA, as index of MA- induced anorexia, developed rapidly in the injection method, while tolerance to MA in the DAF method did not develop during the experiment. These results indicate that Q can markedly potentiate MA- induced anorexia.

Administration, Oral↗
PubMed1982

Intestinal absorption of several beta-lactam antibiotics. III. Competitive inhibition behavior among zwitterionic beta-lactam antibiotics in the rat intestinal absorption.

Competitive inhibitory behavior among zwitterionic beta-lactam antibiotics in the rat intestinal absorption process was examined. Intestinal absorption of cephradine and cephalexin was significantly inhibited by cyclacillin. The mutual inhibition between these amino-cephalosporins was also observed. On the other hand, in the pretreatment experiments with cyclacillin, it was found that absorption of cephradine was significantly inhibited, but the inhibitory effect of cyclacillin was not observed for cephalexin. These results showed that cephradine had a common carrier-mediated transport mechanism with cyclacillin which is not present in the absorption process of cephalexin. It was postulated that the mutual inhibition between cephradine and cephalexin is based on the competitive inhibition in the accumulation or uptake by the intestinal mucosa.

Animals↗
PubMed1980

Purification and characterization of Tora-bean (Phaseolus vulgaris) lectin.

A lectin purified from the Tora-bean (Phaseolus vulgaris) by affinity chromatography with Con-A Sepharose was shown to be a glycoprotein containing 7.8% neutral sugars (D-mannose, N-acetyl-D-glucosamine, L-fucose, and D-xylose, in a molar ratio of 9.6 : 2.0 : 0.6 : 0.7). Its molecular weight was 130,000, as estimated by exclusion gel chromatography, and SDS gel electrophoresis showed that it consists of four subunits of molecular weight 32,000. The lectin reacts with various glycoproteins, i.e., blood group substances, human parotid salivary glycoprotein, fetuin, and bovine submaxillary mucin. Divalent cations, such as Ca2+, Mn2+, and Mg2+, appear to stimulate its reactivity. Inhibition tests using the glycopeptide fragment from fetuin and some oligosaccharides, as well as the binding test with 14C-N-acetyl-lactosamine suggest that the sequence of D-galactose, N-acetyl-D-glucosamine, and D-mannose residues in the carbohydrate chain of fetuin is essential for binding.

Acetylglucosamine↗