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Biomedical subjects

M Oka

Publications and source records attributed to M Oka.

At least 775 records · Page 43Linked to original sources
PubMed1979

Protective immune response in mice immunized with antigens from Trypanosoma gambiense-infected mouse blood.

Immunogenicity and property of antigens obtained from Trypanosoma gambiense-infected mouse blood (IMP) were examined. A strong vaccine effect against intravenous challenges with 3 x10(3) parasites given on study day 3, 5, or 14 (day 0 = immunization) was observed in mice immunized with a combination of IMP (2 mg protein/mouse) and Freund's complete adjuvant (FCA). But when the challenge was given on day 21 or 30, per cent survival in mice dropped to the 20- and 40-per cent level, respectively. Among fractioned components of IMP, IMP-1, IMP-2, and imp-3, by gel filtration with Sephadex G-200, all of the mice immunized with IMP-1 antigen alone or together with FCA and challenged on day 5 were able to conquer intraperitoneal challenges with 1 x10(2) parasites. Mice immunized with IMP-2 or IMP-3 died within 6 days after challenge. Moreover, protection efficacy shown by IMP-1p (144,000 xg sediment of IMP-1) antigen in mice was similar to that by IMP and IMP-1 antigens. IMP-3 yielded a single precipitin line against mouse anti-IMP serum by Ouchterlony double diffusion method but this response was eliminated when the antiserum was absorbed by IMP-1p. No precipitin line was identified between mouse anti-IMP serum and IMP-1 or IMP-2. From electron microscopic observations, elements of IMP-1 and IMP-1p are possibly corresponded to the fragments of filopodia of the parasites.

Agglutination Tests↗
PubMed1979

Pathological and microbiological studies on calf pneumonia occurring in mass rearing facilities.

Pathological and microbiological studies were conducted on lesions in the lungs of 194 calves from mass rearing facilities. Macroscopically, the lesions were classified into six forms: nonlesion, atelectasis, mild pneumonia, moderate pneumonia, advanced pneumonia, and advanced pneumonia accompanied with abscess. Histopathological examination revealed bronchopneumonia in most of the calves. Lesions more advanced than moderate pneumonia were complicated with desquamation, severe exudation, and necrosis. Bacteriologically, Pasteurella sp. was isolated often in combination with Staphylococcus sp. from about a half of the atelectatic cases. With the development of pneumonic lesions, Pasteurella sp. was isolated at a high frequency in combination with Haemophilus sp., Streptococcus sp., and Corynebacterium sp. Prominent necrosis was more often seen in cases with Pasteurella haemolytica isolated than in cases with only Pasteurella multocida isolated. Mycoplasma sp. and Ureaplasma sp. were isolated from distinctly pneumonic lesions. Advanced pneumonic lesions were observed in many calves over 30 days of age. The importance of environmental and managerial improvement was also emphasized, since calf pneumonia tended to break out in facilities under unsatisfactory conditions in the present work.

Animals↗
PubMed1978

Ultra-violet radiation and 8-methoxypsoralen have actions similar to those of known inhibitors of thromboxane A2 synthesis in rat mesenteric blood vessels.

In the rat mesenteric vascular bed three structurally different agents (imidazole, benzydamine and N-0164) which have been reported to be inhibitors of thromboxane (TX) A2 synthesis at certain concentrations, all have a characteristic spectrum of action. They inhibit pressor responses to noradrenaline and angiotensin with equal potency and the inhibition can be reversed by exogenous PGE2: they do not inhibit responses to potassium. Ultra-violet (UV) radiation has a similar spectrum of action. The main difference between the action of imidazole and that of UV radiation is that the former is rapidly reversible while the latter is not. However, irradiation administered to preparations inhibited by imidazole has no irreversible effect provided that the radiation is switched off before the imidazole is removed. The imidazole protects against radiation damage suggesting that the drug may stabilize the site affected by UV light. 8-methoxypsoralen, a light sensitizing agent used in treatment of psoriasis also inhibited noradrenaline and angiotensin but not potassium responses and seemed to make the preparation more sensitive to radiation damage. It is possible that UV radiation and 8-methoxypsoralen may inhibit TXA2 synthesis but this requires confirmation by direct methods.

Angiotensin II↗
PubMed1978

Influence of agents which modulate thromboxane A2 synthesis or action on R3230AC mammary carcinoma.

The effects of agents which modulate thromboxane A2 synthesis or action, were tested in the R3230AC transplanted mammary tumour. Three different inhibitors of thromboxane A2 synthesis or action (copper, dipyridamole and diazepam) all caused an increase in tumour growth. Colchicine and melatonin, both stimulators of thromboxane A2 synthesis, inhibited the growth of the tumour significantly.

Animals↗
PubMed1978

Minoxidil in severe hypertension.

Minoxidil has been administered to 16 patients with severe hypertension and renal failure. In every patient the indication for minoxidil treatment was resistance to conventional drugs. The final dose of minoxidil was 2.5--30 mg (average 20) and it was combined with a beta-blocking agent and a diuretic (or dialysis). The therapy was given for 1--27 months (average 12). The average supine BP fell from 200/130 to 164/96 mmHg and the upright BP from 200/120 to 152/90 mmHg. No hypotensive reactions occurred. In most patients the progression of hypertensive organ changes was arrested. No major vascular complications have occurred during the 16 years of treatment. Prickling of the skin and hirsutism were common side-effects. The other side-effects observed were oedema in five patients and development of latent diabetes in three. In four patients minoxidil treatment was discontinued for following reasons: successful reconstruction of the renal artery after stenosis, renal transplantation, severe oedema and hirsutism. The risk of hirsutism is a contraindication to prolonged minoxidil administration in most femal patients. Minoxidil is especially indicated in uncontrolled renal hypertension.

Adolescent↗
PubMed1978

Effects of antiepileptics on both behavioral and electrographic seizure patterns induced by maximal electroshock in rats.

Effects of antiepileptics on both behavioral (TE) and electrographic seizure patterns induced by maximal electroshock were studied simultaneously in the same animal. The results obtained are as follows. All the antiepileptics used in this study depressed the TE seizure. Imipramine, biperiden, and lidocaine also depressed TE seizure, although they are not classified as antiepileptics. Phenobarbital, primidone, trimethadione, carbamazepine, ethosuximide, diazepam, clozapine, and imipramine had a depressant effect on electrographic seizures. However, phenytoin, ethotoin, phenacemide, and acetazolamide did not influence the electrographic seizure, in spite of having a strong effect on TE seizure. The present procedure, i.e., that of simultaneous observation of both behavioral and electrographic seizure patterns induced by maximal electroshock in the same animal, provides information which cannot be obtained from either behavior or EEG observation alone.

Animals↗
PubMed1978

Hypertension induced by adrenocortical dysfunction--hypertension in 17 alpha-hydroxylase deficiency and metopirone-induced hypertension.

Hypertension in 17 alpha-hydroxylase deficiency was studied by comparing it with hypertension in Cushing syndrome or that in primary aldosteronism. Furthermore, the role of endogenous increases of ACTH, deoxycorticosterone, and 18 alpha-hydroxy-deoxycorticosterone upon blood pressure was studied in rats by administerating metopirone. Hypertension in 17 alpha-hydroxylase deficiency was considered to be more similar to that in primary aldosteronism from the studies on renin components, pressor responses to angiotensin II and norepinephrine, and renin responses to stimulations. Plasma catecholamines were slightly decreased in 17 alpha-hydroxylase deficiency. The hypertension was alleviated by the administeration of dexamethasone in 2 of 3 patients with 17 alpha-hydroxylase deficiency. However, in the remaining one who had an accelerated hypertension and normal renin, the hypertension was not alleviated by dexamethasone. In the animal studies, hypertension induced by metopirone was accelerated by salt loading of uni-lateral nephrectomy plus salt loading. In those rats, plasma ACTH, and deoxycorticosterone were markedly increased.

Adrenal Hyperplasia, Congenital↗
PubMed1978

Cardiac involvement in polymyositis.

Sixteen cases of polymyositis (PM) were treated at the Central Hospital, Jyväskylä. Features of cardiac involvement were observed in 11 cases (69%). The heart diseases which developed or worsened after the onset of PM were grouped as follows: (1) Sole disturbance of conduction--one case, (2) congestive heart failure--four cases, (3) coronary heart disease with or without congestive heart failure--six cases. Three patients suffered an acute myocardial infarction. Electrocardiography revealed arrhythmias in eight cases and disturbances of conduction in three. In one patient complete atrioventricular block and congestive heart failure necesssitated installation of an intracardiac pacemaker. In four patients congestive heart failure progressed to death. In two autopsied cases changes suggestive of PM were found in the heart muscle. Involvement of the heart in PM was prognostically a bad sign.

Adolescent↗
PubMed1978

Inhibition by trichlormethiazide of catecholamine release from perfused bovine adrenals.

Effect of thiazides on catecholamine release was examined using perfused bovine adrenal glands in vitro. Thiazides, such as trichlormethiazide and methyclothiazide inhibited catecholamine release evoked by carbamylcholine although they did not inhibit catecholamine release evoked by excess potassium. Thus it seems that these drugs inhibit catecholamine release release by an anticholinergic mechanism. Such inhibitory effect of thiazide on catecholamine release may be involved in the antihypertensive effect of these drugs.

Adrenal Glands↗
PubMed1978

Acetylation phenotype in rheumatoid arthritis.

The acetylation rate of INH was studied in 39 patients with RA; 20 patients with cardiac arrhythmia served as controls. Statistically, no significant difference was observed between the groups. The percentages of rapid acetylators in the RA and control groups were higher (59 and 55%, respectively) than the reported incidence in the Finnish population, 44% (11). The polymorphic acetylation phenotype was not correlated with either clinical parameters of RA or with sensitivity to gold salts.

Acetylation↗