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Biomedical subjects

M Hirano

Publications and source records attributed to M Hirano.

At least 703 records · Page 39Linked to original sources
PubMed1981

Functional abnormalities of hemoglobin Toyoake (142 (H20)beta, Ala leads to Pro).

Oxygen equilibrium of Hb Toyoake (142 (H20)beta, Ala leads to Pro) is characterized by an oxygen affinity 6-times higher than that of Hb A, a slightly decreased alkaline Bohr effect, diminished cooperativity, with Hill's coefficient decreased by 1.2, and reduced response to 2,3-diphosphoglycerate and inositol hexaphosphate. These properties are in qualitative agreement with those shown previously from oxygen equilibrium data for hemolysate containing Hb Toyoake. The heat of oxygenation was -13.5 kcal/mol for Hb Toyoake and -12.9 kcal/mol for Hb A at pH 7.4 in 0.1 M Cl- and they became equal when corrected for the heat of oxygen-linked proton and Cl- release. OxyHb Toyoake autooxidized faster than oxyHb A. The visible absorption spectrum and electron paramagnetic resonance spectrum of oxidized Hb Toyake indicated that oxidation of this hemoglobin, either by autooxidation or by K3Fe(CN)6, is followed by gradual conversion into hemichrome derivatives. The soret peak of deoxyHb Toyoake was lowered compared to that of deoxyHb A and the magnitude of narrow-banded oxy-minus-deoxy difference spectrum around 290 nm was smaller for Hb Toyoake than for Hb A, indicating that the former remains predominantly in the R state upon deoxygenation. The functional abnormalities, including tendency to lose heme groups previously reported, were interpreted in terms of structural disturbance by proline at 142beta of 141 leucine, 143 histidine, 145 tyrosine, and 146 histidine residues of the same beta chain.

Diphosphoglyceric Acids↗
PubMed1981

Localization of efferent neurons innervating the pharyngeal constrictor muscles and the cervical esophagus muscle in the cat by means of the horseradish peroxidase method.

Following horseradish peroxidase (HRP) injection into the cephalopharyngeal muscle (CeP), the hyopharyngeal muscle (HP), the thyropharyngeal muscle (TP), the cricopharyngeal muscle (CP) and the cervical esophagus muscle (CE) of the cat, labeled neurons were identified in the nucleus retrofacialis and the rostral part of the nucleus ambiguus ipsilaterally. The rostral end of the labeled cell column was located more rostrally for CeP and HP than for TP, CP and CE. No difference was noted within the former two or within the latter three. The level of the caudal end of the labeled cell column became more caudal in the order of CeP, HP, TP and CP. The caudal end was located more rostral for CE than for TP. The neurons for CE were located more ventro-laterally than those for the other muscles.

Animals↗
PubMed1981

Congenital methaemoglobinaemia due to NADH methaemoglobin reductase deficiency: successful treatment with oral riboflavin.

A Japanese family with congenital methaemoglobinaemia is described. The family pedigree was compatible with autosomal recessive type of inheritance. The increased methaemoglobin concentration was ascribed to the red cell NADH diaphorase deficiency associated with the almost complete lack of one of the two peaks of the diaphorase activity as separated by DEAE Sephadex column chromatography. The NADH diaphorase and NADH methaemoglobin reductase deficiency was limited to the red cells. The methaemoglobin content in the blood of the propositus was 17.8% and isoelectric focusing analysis on a polyacrylamide gel plate showed that the haemoglobin consisted of 65.2% oxyhaemoglobin (alpha 2+ beta 2+)2, 29.6% half-oxidized forms, 20.9% (alpha 3+ beta 2+)2 and 8.7% (alpha 2+ beta 3+)2, and 3% full-oxidized methaemoglobin (alpha 3+ beta 3+)2. Oral administration of riboflavin 120 mg/d resulted in a gradual but significant decrease in the level of the met-form haemoglobins in parallel with a gradual increase in the red cell flavin content. Riboflavin is considered to be effective by activating the NADPH diaphorase (NADPH flavin reductase) system and appears to be useful for the treatment of congenital methaemoglobinaemia.

Administration, Oral↗
PubMed1981

Emperipolesis observed in immature cells in blast crisis of chronic myelogenous leukaemia.

In a 62 year-old male with chronic myelogenous leukaemia, an acute phase developed with appearance of large immature cells in the bone marrow. A significant proportion of these cells was found to have engulfed autologous immature and polymorphonuclear neutrophils, erythroblasts, red cells and platelets. These abnormal cells were Philadelphia chromosome positive, and considered to be derived from the leukaemic cell line. Electron microscopic examinations revealed, in the cytoplasm of engulfed cells, no lysosomes or phagosomes which are typically seen in phagocytic cells, nor any evidence of degenerative changes in either engulfing or engulfed cells. These findings suggest that this phenomenon be considered as emperipolesis rather than phagocytosis. The pathophysiological mechanism of this phenomenon is uncertain.

Blood Platelets↗
PubMed1981

Pharmacological studies on BB-1502, a new bronchodilator.

The pharmacological activities of BB-1502 (9-cyclohexyl-2-n-propoxy-9H-adenine), a potent bronchodilator and inhibitor of cyclic AMP phosphodiesterase, were compared with those of aminophylline in a number of biological systems. IOn vitro, BB-1502 relaxed guinea pig tracheal tissue at a concentration ca. 600 times lower than that required for aminophylline. The ability of BB-1502 to inhibit cyclic AMP phosphodiesterase of guinea pig lung origin was 15 times greater than that of aminophylline. The direct bronchodilator activity of BB-1502 determined in guinea pigs by the intraduodenal route was 5 times greater and the duration of the action longer than that of aminophylline. In dogs, intraduodenal BB-1502 inhibited bronchoconstriction induced by pilocarpine, histamine, or acetylcholine and the activity of the new compound was 4 to 7 times more potent than that of aminophylline. In experimental asthma studies, orally administered BB-1502 protected guinea pigs from allergy-induced asthma provoked by an antigen challenge with aerosolized egg albumin and here the potency was 4 times greater that that of aminophylline. Ascaris antigen-induced asthma in dogs was completely inhibited by the oral administration of BB-1502 in a dose of 1 mg/kg with significant protection seen at 0.3 and 0.1 mg/kg. No complete protection was obtained with aminophylline in the dog asthma model. Cardiovascular effects observed with guinea pigs and dogs following the oral administration of BB-1502 were considerably less than those seen with aminophylline. CNS side effects were nil in rats when BB-1502 was given at 3 times the dose that produced significant stimulation by aminophylline. Acute lethal toxicity determined in mice by the oral route was similar for BB-1502 and aminophylline.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1981

Mutagenicity of smoke condensates induced by CO2-laser irradiation and electrocauterization.

Smoke condensates generated from mucous membrane of the canine tongue irradiated with a CO2 laser showed mutagenicity on Salmonella typhimurium TA98 under metabolic activation with S9 mix. Strain TA100 was not so sensitive to the condensates with or without S9 mix. Smoke condensates from electrocauterization on the mucosa of the canine tongue also showed mutagenic activity on TA98 and TA100 with S9 mix. The revertant number per mg of the smoke condensates from laser irradiation was one-half that of the smoke condensates from electrocauterization (1623 and 3371) in TA98. The mutagenic potency observed was comparable to that of cigarette smoke. The amount of these smoke condensates from 1 g of tissue was equivalent to those from 3--6 cigarettes as to total mutagenicity.

Animals↗
PubMed1981

[A case of psychomotor attack induced by the compression of carotid artery (author's transl)].

A patient with psychomotor attack beginning at the age of 60 showed no abnormal finding of EEG at rest, brain CT and other routine examination but cerebroangiography. Bilateral carotid angiography revealed the conspicuous course of anterior cerebral artery and the embryonic pattern of posterior cerebral artery. Vertebroangiography showed no image of the right posterior cerebral artery. Clinically the same as spontaneous attack was induced by the compression of right carotid artery, but the compression of left carotid artery did not provoke attack. From the finding of cerebroangiography above mentioned we guessed that the cerebral circulation impairment based on the abnormal form of Willis' circle and the process of aging caused the attack. This presumption might be supported by the fact the same as spontaneous attack was induced by the compression of right carotid artery. In this case furthermore, the evocability of attack, which the compression of carotid artery showed, was useful as one of indicators by which we judge the effect of antiepilepticus.

Brain↗
PubMed1981

Hb Toyoake: beta 142 (H20) Ala replaced by Pro. A new unstable hemoglobin with high oxygen affinity.

A new unstable hemoglobin with high oxygen affinity, Hb Toyoake: beta 142 (H20) Ala replaced by Pro, was found in Japanese male with a normal blood hemoglobin level, shortened red cell survival, and increased plasma erythropoietin. Hemoglobin studies showed heat and isopropanol instability, and an increased tendency to heme loss and to subunit dissociation. Electrophoresis of whole hemolysate showed inconstant abnormal bands with reduced mobilities due to progressive heme loss during the in vitro procedure. Isolated Hb Toyoake with normal heme content migrated slightly faster than HbA. Oxygen affinity of red cells was elevated with P50 of 17.0 mm Hg at pH 7.4 and 37 degrees C (normal 25.0 mm Hg). Studies on hemolysate implied that Hb Toyoake had an almost normal Bohr effect, a diminished cooperativity, and a reduced response to inositol hexaphosphate. These multiple abnormalities are associated with a substitution of Pro for beta 142 Ala, resulting in disruption of the H-helix and the adjacent C-terminal portion of beta chain, which contain residues crucial for normal oxygen binding.

Adult↗
PubMed1980

The two survival cases of alpha-pattern coma caused by large amounts of hypnotica and neuroleptica.

The EEGs of two men (42 and 63 years old) in coma who took large amounts of hypnotica and neuroleptica for intended suicides were occupied by an alpha pattern, and the patients were diagnosed as alpha-pattern coma. The prominent pattern in their EEGs changed from an alpha pattern to a theta pattern, and subsequently into an alpha pattern of low amplitude. The patients recovered without any residual neurological symptoms. It has been confirmed by our two cases, as well as by other reported cases, that the outcome of the alpha-pattern coma caused by drug poisoning is favorable. It is concluded that a longitudinal EEG recording should be performed as early as possible when the patient is in a comatose state.

Adult↗