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Biomedical subjects

K Ohno

Publications and source records attributed to K Ohno.

At least 739 records · Page 41Linked to original sources
PubMed1981

Enzymic formation of difructose anhydride IV from bacterial levan.

A novel enzyme for producing difructose anhydride IV (di-D-fructofuranose 2,6' : 6,2' dianhydride) from levan of Bacillus mesentericus was prepared from a culture of Arthrobacter ureafaciens, and the conditions and method to determine the enzymatic activity were determined. Levan of Bacillus subtilis also yielded the difructose dianhydride, but inulin, inulobiose, sucrose, levanbiose, and levantriose did not produce it on enzymic reaction under similar test conditions.

Arthrobacter↗
PubMed1981

Developmental alteration in RNA metabolism of E1 mouse brain.

The contents of brain RNA rose rapidly until 14 days after birth and then dropped. They were lower in the E1 than in the non-convulsive mice between 56 and 100 days of life. The contents of acid-soluble UMP and their specific radioactivities, three hours after an intracranial injection of [3 H]-orotic acid, were not different in the same age of E1 and non-convulsive mouse brains. From four to 20 days after birth, the specific and relative specific radioactivities, representing the ratio of brain RNA synthesis, of the E1 mice were lower than those of the non-convulsive strains, while the E1 mice, applying convulsions once a week, exhibited higher values during the periods from 56 to 100 days of age as compared with the non-stimulated E1 or non-convulsive strains.

Aging↗
PubMed1981

Phospholipids of the lung in normal, toxic, and diseased states.

The highly pulmonary concentration of 1,2-dipalmitoyl-sn-glycerol-3-phosphorylcholine (dipalmitoyllecithin) and its implication as an important component of lung surfactant have promoted investigation of phospholipid metabolism in the lung. This review will set the contents including recent informations for better understanding of phospholipid metabolism of the lung in normal state (physiological significances of lung phospholipids, characteristics of phospholipids in lung tissue and alveolar washing, biosynthetic pathways of dipalmitoyllecithin, etc.) as well as in toxic states (pulmonary oxygen toxicity, etc.) and in diseased states (idiopathic respiratory distress syndrome, pulmonary alveolar proteinosis, etc.) Since our main concern has been to clarify the most important route for supplying dipalmitoyllecithin, this review will be focused upon the various biosynthetic pathways leading to the formation of different molecular species of lecithin and their potential significance in the normal, toxic, and diseased lungs.

Fetus↗
PubMed1981

Mandibular growth following ankylosis operation in childhood.

To clarify the effects of operation for temporomandibular joint (TMJ) ankylosis in early childhood on mandibular growth, cephalometric x-ray films of two congenital cases in children who were operated at 2 years old were obtained longitudinally for 9 years. Comparison with those operated at 12 years old, and normal children at the same age, gave the following results: (1) Mandibular retrognathia is slighter than in cases operated later; (2) The mandibles showed a rate of growth nearly the same as that of normal mandibles postoperatively; (3) Forward-downward craniofacial growth was recognized in the cases of early operation; and (4) In the unilateral case, the deviation of the median line of the mandible to the affected side became slighter postoperatively. At present, functional restoration is satisfactory in early-operated cases. In conclusion, it is suggested that restoration of function of the TM joint by early operation is more effective for mandibular growth.

Age Factors↗
PubMed1981

Effects of benzothiazepine derivative (CRD-401) on blood pressure, excretion of electrolytes, and plasma renin activity.

A benzothiazepine derivative, CRD-401, was administered orally in a dosage of 60 to 120 mg/day to 14 patients with various renal diseases. The systolic pressure was lowered slightly in some cases after administration of CRD-401. Urine volume and urinary excretion of electrolytes were increased by the drug in most patients except those with severe renal dysfunction. The plasma renin activity was increased to about twice the premedication value in most patients. Although the mechanism of increasing action of CRD-401 on plasma renin activity was assumed to be related to the reabsorption capacity of renal tubules for electrolytes, some questions still remain unanswered. The mechanism of this drug action, therefore, could not be elucidated completely in this study.

Adolescent↗
PubMed1981

[Coexistent congenital arteriovenous malformation an aneurysms of the scalp (author's transl)].

A rare case with coexistent extracranial congenital arteriovenous malformation and aneurysms of the occipital artery is presented. A 32-year-old man visited Tachikawa National Hospital with the complaints of occasional dizziness and a gradually growing pulsatile mass in the left occipital region. The patient had had no head trauma. Neurological examination revealed no abnormality. Physical examination showed a round and pulsating tumor measuring 4 cm x 7 cm in the retroauricular region on the left side, which lost its pulsation and consistency upon compressing the left common carotid artery. Left selective external carotid angiography demonstrated a tortuous and locally enlarged occipital artery with venous drainage around the artery and an arteriovenous malformation (AVM) in the retroauricular region and neck. The patient was successfully treated by surgical embolization of the feeding arteries with ligation of the left external carotid artery and partial excision of aneurysms under general endotracheal anesthesia. The postoperative course was uneventful. Fourteen months after the operation there is no evidence of recurrence of the pulsatile mass and the preoperative symptoms. Microscopic examination of the excised artery and aneurysms showed partial disappearance of the internal elastic lamina and muscle layer of the artery. Capillary nevi noted over the ear, retroauricular region, neck, and shoulder on the left side without history of head trauma and angiographic findings suggest that the AVM was congenital. In addition, we think that the aneurysms of the left occipital artery on the side ipsilateral to the AVM may have originated from the site of the arterial wall lacking the internal elastic lamina and developed due to hemodynamic mechanism associated with the AVM. Although the treatment of choice for extracranial, congenital and traumatic, AVMs is ideally total excision, careful embolization of the nidus with ligation of the feeders seems to be the most opportune procedure of choice as the second-best treatment in cases in which the nidus of the AVM occupies extensive areas of the head or face and which have little chance of developing serious signs and symptoms such as massive hemorrhage.

Adult↗
PubMed1980

Extraction and partial purification of acyl-CoA:1-acyl-sn-glycero-3-phosphocholine acyltransferase from rat liver microsomes.

Acyl-CoA:1-acyl-sn-glycero-3-phosphocholine acyltransferase (EC 2.3.1.23) was extracted from rat liver microsomes with an aqueous dispersion of 1-acyl-sn-glycero-3-phosphocholine, a substrate of the enzyme, and purified up to 30-fold. The procedure includes removal of unrelevant proteins and lipids by washings of microsomes with a buffer of high ionic strength and with buffers containing detergents, extraction of the enzyme with an aqueous dispersion of 1-acyl-sn-glycero-3-phosphocholine, and chromatography by gel filtration. The acyltransferase was eluted from a Ultrogel AcA 34 column at a position with a Kav of 0.122; an elution position of a protein with a molecular weight of 225 000. The partially purified enzyme was active over a wide range of pH with an optimum at around pH 8. Depending on the acyl donors, different rates of the reaction were obtained by the preparation. The order was: arachidonoyl-CoA greater than linoleoyl-CoA = oleoyl-CoA greater than palmitoyl-CoA. The enzyme preparation acylated 1-acyl-sn-glycero-3-phosphocholine, 1-acyl-sn-glycero-3-phospho-ethanolamine and 1-acyl-sn-glycero-3-phosphoinositol but not acylated 2-acyl-sn-glycero-3-phosphocholine, 1-acyl-sn-glycerol 3-phosphate or diacylglycerol. Some sulfhydryl-binding reagents inactivated the enzyme.

1-Acylglycerophosphocholine O-Acyltransferase↗
PubMed1980

Entry of opioid peptides into the central nervous system.

Cerebrovascular permeability of four modified opioid peptides--[D-Ala2]methionine enkephalin amide, beta-[D-Ala62,14C-Homoarg69]lipotropin 61 -69, alpha-[D-Ala2,14C-Homoarg9]endorphin, and beta-[D-Ala2,14C-Homoarg]endorphin--ranged from 1.4 to 3.9 X 10(-6) centimeters per second in brain regions of the conscous rat. These significant permeabilities should allow the peptides to fill the extracellular brain space with a half time of 3 to 11 minutes, as a result of a step increase in plasma concentration of unbound peptide.

Animals↗
PubMed1980

Altered activity of bacteriorhodopsin in high concentrations of guanidine hydrochloride.

Bacteriorhodopsin from Halobacterium halobium was stable and active in high concentrations of guanidine hydrochloride. However the decay of the intermediate with absorption maximum at 407 nm and the uptake of protons from the medium were remarkably delayed. At alkaline pH values, all the molecules of bacteriohodopsin existed as the 407 nm intermediate in the light, and one proton per bacteriorhodopsin molecule was released.

Bacteriorhodopsins↗
PubMed1980

Quantitative aspects of reversible osmotic opening of the blood-brain barrier.

Retrograde infusion of a hypertonic arabinose solution into the right external carotid artery of rats reversibly increases cerebrovascular permeability to [14C]sucrose in the right cerebral hemisphere. PA ([14C]sucrose permeability x capillary surface area) rises from a control mean of 11 x 10(-6) S-1 to above 200 x 10(-6) S-1. The rise correlates with an increased staining of the brain by intravascular Evans blue, and is followed by a transient, 1-1.5% increase in brain water content. At least 20 s of infusion is required for 1.6 M arabinose solution to effectively open the blood-brain barrier. The increase in cerebrovascular permeability is temporary, however, because PA remains slightly elevated 1-2 h after infusion and is normal 6 h after infusion. It is suggested that osmotic barrier opening is mediated by cerebrovascular dilatation as well as by shrinkage of the vascular endothelium. By quantitatively defining thresholds of infusate concentration and infusion time for osmotic barrier opening, and by characterizing the time course of increased PA, the experiments establish criteria for applying the osmotic method to experimental pharmacology of the central nervous system.

Animals↗