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Biomedical subjects

T Oka

Publications and source records attributed to T Oka.

At least 1,279 records · Page 71Linked to original sources
PubMed1983

[Clinical factors relating to the incidence of post-transfusion hepatitis following open heart surgery].

A retrospective study of post-transfusion hepatitis (PTH) has been made of 168 patients who had open-heart surgery between 1978 and 1981 at the Nagasaki University Hospital. The criteria of PTH was defined as an elevation of SGPT over 50 units with more than 2 weeks duration that occurred later than 3 weeks after the transfusion. PTH developed in 27 of the 168 patients (16%) and 26 of them were of the non-A, non-B type. The statistical analysis of these patients demonstrated that the following clinical factors significantly increased the incidence of PTH subsequent to open-heart surgery: (1) Use of plasma fractionating products made from pooled plasma, such as PPSB (p less than 0.001). (2) A large amount of blood and blood component transfusion (over 21 units, p less than 0.01). (3) Prolongation of the operation time (more than 330 minutes, p less than 0.05), cardiopulmonary bypass time (more than 90 minutes, p less than 0.05) and aortic cross-clamping time (more than 45 minutes, p less than 0.01), and (4) Surgery for cardiac lesions with left heart overloads (p less than 0.01).

Adult↗
PubMed1983

[The tumor--immunological significance of splenectomy for cancer therapy].

In animal experiment, 5 X 10(5) MH-134 tumor cells were transplanted s.c. on the back of the C3H/He mice. Three, seven, 14 and 21 days after tumor transplantation, splenectomy or sham operation were performed and the tumor growth and survival days were examined in each group. As the results, the tumor growth was inhibited and the survival days prolonged not only in the group splenectomized three days but also 21 days after tumor transplantation. Clinically, the effect of splenectomy in combination with immunotherapy on cell-mediated immunity and the survival rates were studied in the gastric cancer patients of upper and middle stomach with 90 cases of stage III and 48 cases at stage IV, totalling 138 cases who underwent total gastrectomy during 1965 and 1981. Immunotherapy was conducted with immunomodulator levamisole at a daily dose of 150 mg, three consecutive days every other week. As a result, splenectomy was not effective for advanced gastric cancer at stage III and in the patients spleen should be retained for immunotherapy. Splenectomy for gastric cancer at stage IV, particularly in combination with immunotherapy, produced augmentation of cell-mediated immunity and longer survival as well. Complications caused by splenectomy were small.

Animals↗
PubMed1983

Characterization of mutagenic fractions in beef extract and in cooked ground beef. Use of blue-cotton for efficient extraction.

Mutagenic components in commercial beef extract and in cooked ground beef were adsorbed from their aqueous solutions on cotton bearing covalently linked trisulfo-copper-phthalocyanine residues (blue-cotton). By repeating the adsorption and elution, efficient concentration of the mutagenic components with a satisfactory overall recovery was achieved. Carboxymethyl cellulose column chromatography was found to be an excellent means to separate 2-amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) from 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), two strong mutagens that have previously been found in heated beef samples. Chromatography of the mutagenic components of beef extract on this column gave two mutagenic fractions which corresponded to MeIQx and IQ in elution profile. In reversed-phase high performance liquid chromatography, the major active component of the MeIQx fraction and that of the IQ fraction behaved identically with standard samples of MeIQx and IQ, respectively. The contents of these mutagens in a sample of Difco beef extract were estimated at 200-300 ng of MeIQx and 20-40 ng of IQ per gram. By the same fractionation procedures, mutagenic substances in the cooked beef were fractionated into MeIQx-type and IQ-type components. The activity distribution among these two fractions was similar to that found for beef extract.

Adsorption↗
PubMed1983

[Clinical effect of latamoxef on newborn and premature infants].

Eleven infants ranging 2 days to 3 months of age were studied for clinical evaluation. Ten of them were diagnosed as sepsis or suspected to be septic. Another one contracted umbilical infection. In 7 of 10 cases, causative bacteria were detected by blood culture, that is S. epidermidis in 3 cases, E. cloacae in 2 cases, K. pneumoniae in 1 case and A. calcoaceticus in another. Those infants were treated by parenteral LMOX. Dosage was 30 to 75 mg/kg per day. Clinical results were excellent in 6 cases (3 cases of S. epidermidis, 2 of E. cloacae and 1 of K. pneumoniae) and good in another case (A. calcoaceticus). The other 3 infants clinically diagnosed as sepsis but not proven by blood culture were also treated successfully. The result of the umbilical infection in 1 case was good. Another group of 5 infants ranging 4 to 22 days of age were also treated by LMOX because of suspected bacterial infections. With these infants pharmacokinetic study was done. Peak serum levels after 1 hour drip infusion of 20 mg/kg ranged from 43 to 53 micrograms/ml. Average of half-lives was 2.7 hours. Estimation of distribution volume resulted in 350 to 523 ml/kg body weight.

Bacterial Infections↗
PubMed1983

The effects of droperidol and diazepam on the neural excitation of ketamine hydrochloride.

The effects of neuroleptics (droperidol and diazepam) were studied on the neural excitation by ketamine hydrochloride by means of the c-fiber reflex, in the spinal cat and the intact cat. Results can be summarized as follows: 1) Ketamine hydrochloride 125-500 micrograms/Kg i.v. facilitated the neural activity on the c-fiber reflex of the intact cat, but it depressed that of the spinal cat. 2) Droperidol 50-250 micrograms/Kg i.v. and diazepam 50-250 micrograms/Kg i.v. did not influence the neural activity on the c-fiber reflex of the intact cat, but it depressed that of the spinal cat. 3) Droperidol 125 micrograms/Kg i.v. followed by ketamine hydrochloride 125 micrograms/Kg i.v. facilitated the neural activity of the intact cat c-fiber reflex. 4) Diazepam 50 micrograms/Kg i.v. followed by ketamine hydrochloride 250 micrograms/Kg i.v. did not influence the neural activity of the intact cat c-fiber reflex. These data suggested that the neural excitation of ketamine hydrochloride was depressed by diazepam and that a small dose of droperidol did not depress the neural excitation of the intact cat.

Animals↗
PubMed1983

Pharmacodynamic and pharmacokinetic study of a slow-release formulation of furosemide in man.

A slow-release formulation of 40 mg furosemide as capsules (Eutensin) was investigated for its pharmacokinetic and pharmacodynamic properties in comparison with conventional tablets containing 40 mg furosemide (Lasix) in a single-blind clinical pharmacological trial in 6 healthy subjects. The following results were obtained: 1. The AUC0-24 after the administration of slow-release (SR) furosemide was about 42% of that after furosemide tablets. 2. Urine volume and urinary excretion of Na and Cl were significantly greater after furosemide tablets than after SR furosemide during the first 10 h after administration. No significant difference was observed between the two formulations in the urinary excretion of K, creatinine and uric acid. No significant difference was noted in every tested pharmacodynamic parameter during the cumulative 24 h after administration. It was concluded that SR furosemide may be used in the treatment of hypertension due to its characteristics of a slow-release diuretic feature, delayed peak blood concentration, delayed maximum diuretic effect and prolonged duration of action.

Adult↗
PubMed1982

The reversal of cortisol-induced inhibition of alpha-lactalbumin production by prostaglandins in the mouse mammary gland in culture.

Previous studies of cultured mammary gland from mid-pregnant mice showed that addition of cortisol at concentrations ranging from 3 X 10(-8) to 3 X 10(-6) M caused progressive increases in casein accumulation but marked decreases in alpha-lactalbumin accumulation in tissue cultured in the presence of insulin and prolactin (Ono, M., and Oka, T. (1980) Cell 19, 473-480). The present studies showed that the addition of prostaglandin (PG) E2 blocked the inhibitory effect of cortisol on the synthesis and accumulation of alpha-lactalbumin without affecting casein production. The effect of PGE2 was observed at a concentration as low as 6.6 X 10(-8) M and was maximal at 2.8 X 10(-6) M. Among various prostaglandins tested, PGE2 and PGE1 were most potent and other prostaglandins were also active with the potency decreasing in the following order: PGF1 alpha greater than or equal to PGF2 alpha greater than or equal to PGA2 greater than or equal to PGB2 greater than PGA1 greater than or equal to PGB1. Arachidonic acid was also effective, but only at very high concentrations, 6.6 X 10(-5)-1.6 X 10(-4) M. The ability of prostaglandins to allow a maximal formation of the two milk proteins suggests a possible modulatory role of prostaglandins in hormonal control of milk-protein synthesis.

Animals↗
PubMed1982

The choice of opiate receptor subtype by neo-endorphins.

The choice of opiate receptor subtype by alpha- and beta-neo-endorphin was studied in isolated preparations. Neo-endorphins had significant inhibitory actions on the electrically evoked contractions of guinea-pig ileum, mouse vas deferens and rabbit ileum as well as on the rabbit vas deferens which had been shown to contain kappa-receptors exclusively. Mr 2266, a relatively specific kappa-receptor antagonist, was more effective than naloxone, a relatively mu-receptor antagonist, to antagonize the agonist actions of neo-endorphins in either the guinea-pig and rabbit ileum or in the rabbit vas deferens. By contrast, in the mouse vas deferens, the effectiveness of Mr 2266 to antagonize the agonist actions of neo-endorphins was low and similar to that of naloxone. The potencies of neo-endorphins relative to that of ethylketocyclazocine, a representative kappa-receptor agonist, in the guinea-pig ileum were similar to those in the rabbit ileum but were significant different from those in the mouse vas deferens. The data indicate that neo-endorphins act as kappa-receptor agonists in either the guinea-pig and rabbit ileum or in the rabbit vas deferens while in the mouse vas deferens they act on opiate receptor subtypes other than kappa- and mu-receptors.

Animals↗
PubMed1982

Evidence that dynorphin-(1-13) acts as an agonist on opioid kappa-receptors.

The study concerned the opioid-receptor subtype on which dynorphin-(1-13) acts in in vitro isolated preparations. The potency of dynorphin-(1-13) relative to that of ethylketocyclazocine (Mr 2266), a representative kappa-receptor agonist, in inhibiting the electrically evoked contractions of the guinea-pig ileum was found to be similar to that found with either mouse was deferens or rabbit ileum. Moreover, Mr 2266 was found to be several-fold more effective than naloxone to antagonize the agonist actions of both kappa-receptor agonists such as ethylketocyclazocine, ketocyclazocine and bremazocine, and dynorphin-(1-13) either in the guinea-pig ileum, mouse vas deferens, or in rabbit ileum. Additionally, dynorphin-(1-13) was found to have a significant inhibitory action on the rabbit vas deferens which had been shown to contain kappa-receptors exclusively. The data indicate that dynorphin-(1-13) acts as an endogenous agonist on kappa-receptors.

Animals↗
PubMed1982

Clinical pharmacology of a new beta-adrenoceptor blocking drug, befunolol. Cross-over comparison with propranolol on repeated administration.

Repeated doses of a new beta-adrenoceptor blocking agent, befunolol, were administered orally to adult male volunteers for a cross-over comparison with propranolol. The beta-adrenoceptor blocking activity of befunolol was greater than that of propranolol when assessed by the percentage reduction in exercise-induced tachycardia. The elimination half-life of drug was significantly prolonged on repeated administration of propranolol, but not of befunolol. The percentage reduction in exercise-induced tachycardia was highly correlated with the log plasma level of each drug. Both drugs produced a significant reduction in pre-exercise systolic and diastolic blood pressure, and significant attenuation of exercise-induced rise in systolic blood pressure.

Adrenergic beta-Antagonists↗
PubMed1982

Ultrasonographic diagnosis of uriniferous perirenal pseudocyst.

A child with a traumatic uriniferous perirenal pseudocyst was presented. The diagnosis was not made by routine radiological studies, but ultrasound examination demonstrated a perirenal fluid accumulation clearly. The usefulness of the ultrasound examination in the diagnosis of this condition was emphasized. The characteristic finding in ultrasonogram consists of a hydronephrotic kidney and its invagination into the echolucent mass. When perirenal cystic lesions are demonstrated by ultrasound, the junctional zone between the cyst and kidney should be carefully checked for signs of invagination of the kidney into the cyst.

Child, Preschool↗
PubMed1982

Revascularization of autogenous skin grafts placed on irradiated tissue.

Vascular changes in rat skin after irradiation were examined microangiographically. Revascularization of the skin transplanted during the chronic stage after irradiation was also studied. The results obtained through these examinations revealed higher vascular densities at the acute and the subacute stages, and low values at the chronic stages compared with those of the control. Furthermore, when the skin grafts were transplanted to the irradiated beds in the chronic stage, primary revascularization was scant, and the inhibited capillary proliferation in the recipient sites prevented new vessel penetration. This explains to why grafts transplanted to previously irradiated beds fail to survive.

Angiography↗
PubMed1982

Localization of sudanophil material at the sites of calcification in dentine, and the compact bone and epiphyseal cartilage plate of tibia in the rat given beryllium carbonate.

The localization of sudanophil material at dentine, the compact bone and epiphyseal cartilage plate of tibia of rat given beryllium carbonate was examined. Sudanophil material was seen at the boundary parts between dentine and widened predentine, and between widened preosseous matrix and calcified bone, but it was not seen at the area corresponding to the zone of provisional calcification. These facts suggest that the localization of sudanophil material in hard tissue of rat with Be rickets was similar to that in vitamin D deficient-induced rickets. This sudanophil material was not disappeared by the enzymes such as papain, pepsin and hyaluronidase as described in vitamin D deficient-induced rickets (Irving, 1960, 1963). Accordingly, it was suggested that the substance was not proteins and mucopolysaccharide.

Animals↗
PubMed1982

A new antibiotic echinosporin (XK-213) - producing organism, isolation and characterization.

Streptomyces echinosporus MK-213 produces a noval antibiotic echinosporin (XK-213). Isolation of echinosporin was performed by absorption on activated carbon under acidic conditions and then eluted by aqueous acetone. The compound crystallized from methanol is a water soluble white solid composed of C10H9NO5. Echinosporin exhibits weak antibacterial activities against Gram-positive and -negative microorganisms and its shows antitumor activity.

Animals↗
PubMed1982

[Clinical results and pharmacokinetics of cefotaxime in newborn infants].

One full-term newborn infant and 2 premature ones were treated with cefotaxime for the treatment of suspected sepsis and umbilical suppurative inflammation. Pathogenic organisms could not be identified in all cases. A good result was obtained with the case of suspected sepsis. But the other 2 cases were not evaluable because underlying diseases such as massive pulmonary atelectasis or respiratory distress syndrome masked the effects of this agent. Serum levels of cefotaxime in 3 of the 4 cases were determined with bioassay. Time courses of the serum levels in 2 of them resulted in peculiar biphasic disappearance curves. This fact implies the possibility that desacetylation of cefroxime proceeds also in newborns as in adults and that desacetyl metabolite accumulates in the body owing to the premature function of the neonatal kidney.

Bacterial Infections↗