Biomedical subjects

M Okazaki

Publications and source records attributed to M Okazaki.

At least 361 records · Page 20Linked to original sources

PubMed1992

[Use of beta-agonist inhalation concomitantly with regular beclomethasone dipropionate in patients with bronchial asthma--as required or on a regular basis].

We investigated whether regular use of beta-agonist inhalation concomitantly with regular beclomethasone dipropionate (BDP) inhalation is necessary in chronic bronchial asthma. Twenty chronic asthmatic patients who were stable on regular BDP and beta-agonist inhalation were studied. After a 2 week observation period, the patients were randomly assigned to two groups. One group received BDP 400 micrograms/day (2 puffs 4 times) and beta-agonist inhalation as required for 4 weeks. This period was followed by 4 weeks of treatment with BDP 400 micrograms/day and regular beta-agonist inhalation. The other group received these treatments in the reverse order. No significant differences among the two groups were observed in attack score, ADL score, sleep score, and %PEFR. In addition, no differences were detected in these parameters between the periods of regular use of beta-agonist and the periods of use as required. The frequency of inhalation of beta-agonist during the use as required period correlated with the sleep score and difference in %PEFR between morning and night, and was significantly lower than the frequency of inhalation during the period of regular. From these results, we conclude that inhalation of beta-agonist on a regular basis is not necessary to achieve the same degree of relief of symptoms as treatment with beta 2-agonist and BDP inhalation on regular basis in patients with chronic asthma.

Administration, Inhalation↗

PubMed1992

Emergent embolization for control of massive hemorrhage from a splanchnic artery with a new coaxial catheter system.

Emergent superselective embolization with a 3.0 F (1 mm) coaxial catheter and a steerable guidewire was performed in 27 patients with massive hemorrhage from a small-caliber splanchnic artery. Eight patients had intraperitoneal hemorrhage, 3 had hemobilia, 9 had gastric hemorrhage, and 7 had intestinal hemorrhage. Out of 27 patients, 7 had hemorrhage from a splanchnic artery pseudoaneurysm. Complete cessation of bleeding was obtained in all patients initially, but in 3 patients gastric hemorrhage recurred later. Otherwise, there was no rebleeding nor any major complication such as marked infarction of tissue or misplacement of embolic materials. This coaxial catheter system was highly reliable for achieving superselective catheterization in small-caliber arteries, minimizing the volume of infarcted tissue and allowing maximal preservation of splanchnic organic function. We conclude that this system represents a major advance in interventional radiology.

Adolescent↗

PubMed1991

Influence of hepatitis B virus infection and age on mode of growth of hepatocellular carcinoma.

According to the extent of hepatic involvement of the tumor and that of portal vein invasion at the time of initial diagnosis, patients with hepatocellular carcinoma (HCC) were grouped into three or four groups. Correlations among the extent of hepatic involvement, extent of portal vein invasion, and prevalence of hepatitis B surface antigen (HBsAg) and age distribution were examined. The extent of hepatic involvement of the tumor and that of portal vein invasion were significantly greater in patients with positive HBsAg compared with findings in the negative patients (P less than 0.001). For cases of both positive and negative HBsAg, patients with a more extensive HCC were significantly younger. Results of the multivariate logistic regression analysis showed that hepatitis B antigenemia and younger age were statistically significant and independent positive predictors of extensive HCC. These results strongly suggest that hepatitis B surface antigenemia and age play an important role in the growth mode and the kinetics of HCC in Japanese patients.

Adult↗

PubMed1991

Subtypes of protein kinase C in rat cerebral microvessels.

Protein kinase C in rat cerebral microvessels was characterized. By hydroxyapatite column chromatography, protein kinase C in the soluble fraction was resolved into two major peaks corresponding to type II and III enzymes, in the proportion of 57% and 38%, respectively. Since each subtype is considered to have a distinct role, the high proportion of type II enzyme found in this study suggests that this type may be involved in specific functions of the cerebral microvessels.

Animals↗

PubMed1991

Stimulatory effects of brain natriuretic peptide on cyclic GMP accumulation and tyrosine hydroxylase activity in cultured bovine adrenal medullary cells.

We studied the effect of brain natriuretic peptide (BNP) on the accumulation of cyclic GMP and the phosphorylation and activity of tyrosine hydroxylase, compared with that of atrial natriuretic peptide (ANP), in cultured bovine adrenal medullary cells. 1. BNP as well as ANP increased cellular cyclic GMP accumulation in a concentration-dependent manner (10-1000 nmol/l). BNP (1 mumol/l) and ANP (1 mumol/l) produced a 60-fold and 30-fold increase in cyclic GMP accumulation, respectively. 2. The stimulatory effects of BNP and ANP on cyclic GMP accumulation were observed even when Ca2+ or Na+ was removed from the incubation medium. 3. 12-O-Tetradecanoylphorbol 13-acetate (TPA), an activator of protein kinase C, inhibited the stimulatory effect of BNP on cyclic GMP accumulation in a concentration-dependent manner (1-100 nmol/l). Furthermore, the BNP-induced accumulation of cyclic GMP was attenuated by forskolin (1 mumol/l), an activator of adenylate cyclase. 4. BNP (1 mumol/l) and ANP (1 mumol/l) caused a significant increase in phosphorylation and activity of tyrosine hydroxylase in the cells. 5. In digitonin-permeabilized cells, cyclic GMP (1-100 mumol/l) activated tyrosine hydroxylase in the presence of ATP and Mg2+. These results suggest that BNP stimulates the accumulation of cyclic GMP in a manner similar to that of ANP. The increased accumulation of cyclic GMP by these peptides may be negatively modulated by protein kinase C and cyclic AMP and may cause the phosphorylation and activation of tyrosine hydroxylase in cultured bovine adrenal medullary cells.

Adrenal Medulla↗

PubMed1991

An examination of learned helplessness among attention-deficit hyperactivity disordered boys.

We employed a learned helplessness paradigm to compare the performance of 23 boys with attention-deficit hyperactivity disorder (ADHD) and a comparable group of 22 nonreferred boys. The boys attempted to solve two different sets of 10 find-a-word puzzles, one set following exposure to solvable puzzles, and one set following exposure to insolvable puzzles. Results revealed that the ADHD boys solved significantly fewer puzzles than did the control boys. In addition, the ADHD boys gave up on significantly more puzzles, and this was especially true following the insolvable condition when it occurred during the second set of puzzles. The ADHD boys also reported being more frustrated by the task than were the control boys. Finally, among the control boys, support was obtained for Diener and Dweck's (1978) distinction between mastery-oriented and helpless children. However, this distinction did not appear to operate in the same fashion for the ADHD boys.

Achievement↗

PubMed1991

Preclinical detection of MEN 2A gene carrier using linked DNA markers.

We have performed preclinical risk estimation of multiple endocrine neoplasia type 2A (MEN 2A) by using the polymorphic DNA markers tightly linked to the MEN2A locus. The gene for MEN 2A has been assigned to the pericentromeric region of chromosome 10 by linkage analysis. The preclinical detection of gene carriers in MEN 2A families using tightly linked DNA markers is useful for surgical treatment at an early stage. The DNA markers, RBP3 (retinol-binding protein 3, interstitial) and FNRB (fibronectin receptor, beta polypeptide), are both tightly linked to the MEN2A locus, and are localized to opposite sides of the MEN2A locus. We have used RBP3 and FNRB as markers for preclinical diagnosis. Of 18 Japanese families with MEN 2A, 6 families are informative for both loci, and other 10 families are informative for either RBP3 or FNRB. In one informative family, a 20-year-old female is predicted to be the gene carrier (probability; about 99%). She should be carefully followed up till full penetrance age. We conclude that DNA-based prediction of MEN 2A is an effective procedure for clinical use.

Asian People↗

PubMed1991

Angiographic management of massive hemobilia due to iatrogenic trauma.

Ten patients with massive hemobilia in shock or preshock status were treated with angiography. The hemobilia had been induced by iatrogenic trauma: biliary drainage in seven patients, and surgery, liver biopsy, and angiography in one patient each. Angiography was performed on all patients. Embolization was performed in nine, and in the one remaining patient, spasm of the right anterior hepatic artery and catheter manipulation injured the intima and obliterated the artery. In seven patients with hepatic artery pseudoaneurysm, gelfoam particles were injected in five, however, extravasation could not be prevented in four of these patients. Permanent embolic materials were added and complete hemostatis was obtained. Hemobilia never recurred in any patient. Emergency embolization should be considered as the initial treatment of choice for hemobilia and when pseudoaneurysms are discovered, they should be obliterated by permanent embolic materials. Moreover, tumor thrombus in the portal vein is not a contraindication for this procedure.

Aged↗

PubMed1991

Crystallographic behaviour of fluoridated hydroxyapatites containing Mg2+ and CO3(2-) ions.

Fluoridated hydroxyapatites containing small amounts of magnesium and carbonate ions were synthesized at 80 and 60 degrees C to examine their inhibiting properties regarding apatite crystal growth, in contrast to the promoting action of fluoride. The shortening of a-axis and c-axis dimensions of the apatite crystals, as revealed by X-ray diffraction analysis, suggested that both magnesium and carbonate ions were substituted into the apatite crystals. The a-axis dimensions also decreased with the degree of fluoridation. The infrared spectra due to CO3(2-) ions at 875 cm-1 were shifted with increasing fluoride content. The overall crystallinity was inhibited in comparison with that of Mg and CO3-free fluoridated hydroxyapatites, but recovered considerably with increased fluoride content. The apparent solubility of the apatites at pH 4.0 and 37 degrees C was higher than that of Mg and CO3-free fluoridated hydroxyapatites at lower fluoride contents, but gradually approached the latter at higher fluoride content. After 1 month's incubation, dicalcium phosphate dihydrate was formed from fluoride-free Mg-CO3 apatite synthesized at 60 degrees C.

Carbonates↗

PubMed1991

Fluoridated hydroxyapatites synthesized with organic phosphate ester.

Fluoridated hydroxyapatites with various fluoride contents were synthesized with organic phosphate ester monomer as a source of P at pH 9.5 and 80 degrees C. The a-axis dimensions of the fluoridated hydroxyapatites decreased with the increase of the fluoride content in the same way as the fluoridated hydroxyapatites synthesized with inorganic phosphate under the same conditions. However, for the same calculated degree of fluoridation in the feed solution, fluoridated hydroxyapatites synthesized with organic P had higher fluoride contents than those synthesized with inorganic P. The crystallinity of the former decreased initially, then increased with increasing fluoride content; but on the whole it was lower than that of the latter. The apparent solubility at pH 4.0 and 37 degrees C decreased dramatically and monotonically with increasing fluoride content and approached an almost constant value at a fluoride content above that of fluorapatite, at which value calcium fluoride was detected.

Calcium↗

PubMed1991

Prediction of portal vein invasion by hepatocellular carcinoma: a correlations between portal vein tumor thrombus and biochemical tests.

Hepatocellular carcinoma patients were categorized into three grades according to the extent of portal vein invasion by the tumor. Correlations between the extent of portal vein invasion and values of alpha-fetoprotein (AFP), and various biochemical tests were examined. The extent of portal vein invasion by the tumor significantly correlated with the values of glutamic oxaloacetic transaminase (GOT), glutamic oxaloacetic transaminase: glutamic pyrubic transaminase (GOT:GPT), lactic dehydrogenase (LDH), alkaline phosphatase, leucinaminopeptidase (LAP), gamma-glutamic transpeptidase (gamma-GTP) and log10AFP. Results of the multivariate logistic regression analysis showed the values of LAP, LDH, log10AFP and GOT:GPT to be statistically significant independent indicators of portal vein invasion by hepatocellular carcinoma. The calculated probability for portal vein tumor thrombus, which was derived from the results of a step wise multivariate logistic regression procedure, revealed high accuracy and specificity for predictability. To design effective therapy and to predict the prognosis, it would be beneficial to obtain additional information from this calculated probability in patients with hepatocellular carcinoma.

Adult↗

PubMed1991

A case of pheochromocytoma associated with meningioma.

We have recently observed a rare case of pheochromocytoma associated with meningioma. To determine the mechanism of such a coexistence in this particular case, we compared the constitutional and pheochromocytoma genotypes of the patient using polymorphic four DNA markers, and we found a loss of heterozygosity at the D1S7 locus. A loss of heterozygosity at this locus has previously been reported by Mathew et al. in pheochromocytoma patients, and our results were in agreement with that study. Therefore the allelic deletion at the D1S7 locus may be an important step in the tumorigenesis of pheochromocytoma in this case.

Adrenal Gland Neoplasms↗

PubMed1991

Effect of cigarette smoking on theophylline pharmacokinetics in rats.

The effect of acute cigarette smoke inhalation on the plasma levels of theophylline administered orally and parenterally to rats has been studied. The animals were exposed to smoke containing low- or high-nicotine/tar concentration for 10 min immediately after oral, intraperitoneal (i.p.) or intravenous (i.v.) administration of theophylline. The plasma levels of theophylline when administered orally (20 mg kg-1) were lower in the two cigarette smoke-inhaling groups than in the non-smoking restrained control group, with the lowest values in the high-nicotine/tar group. The plasma levels (8 and 12 h after administration) in the high-nicotine/tar group when theophylline was administered i.p. (10 mg kg-1), were also slightly lower than in the non-smoking restrained control group but this was not significant. When theophylline was administered i.v. (5 mg kg-1), there was no difference between the high-nicotine/tar group and the non-smoking restrained control group. These data indicate that cigarette smoke inhalation causes suppression or delay of theophylline absorption from the gastrointestinal tract.

Administration, Oral↗

PubMed1991

Intraperitoneal hemorrhage from hepatocellular carcinoma: emergency chemoembolization or embolization.

From 1982 to 1990, 38 patients with intraperitoneal hemorrhage from hepatocellular carcinoma (HCC) underwent treatment with emergency embolization with or without anticancer drug and iodized oil. Before emergency embolization, 24 patients had a serum total bilirubin value of 3.0 mg/dL or less (group A) and 14 patients had hyperbilirubinemia, with a serum bilirubin level greater than 3.0 mg/dL (group B). Successful hemostasis was achieved in all patients. The mean length of survival was 165 days in group A and 13 days in group B. A significant correlation (P less than .00003) between serum bilirubin level and prognosis was obtained. While tumor thrombus in the portal vein made the prognosis poor, there was no significant difference in prognosis between groups with and without tumor thrombus (P = .145). Emergency embolization is an effective treatment in patients with intraperitoneal hemorrhage from HCC. The prognosis for patients with HCC depends on the serum bilirubin level before embolization.

Adult↗

PubMed1991

Succinylcholine-induced acceleration and suppression of electrically evoked acetylcholine release from mouse phrenic nerve-hemidiaphragm muscle preparation.

The effects of a depolarizing neuromuscular blocker on electrically evoked acetylcholine (ACh) release were studied using a mouse phrenic nerve-diaphragm muscle preparation preloaded with [3H]-choline, and the changes in muscle tension were recorded simultaneously. Succinylcholine at a low concentration (1 microM) enhanced evoked [3H]-ACh release, which tended to follow the increase in peak amplitude of tetanic tension; whereas at high concentrations (10 and 30 microM), it simultaneously reduced both release and tension. Decamethonium even at 10 and 30 microM had little effect on [3H]-ACh release despite producing a significantly greater reduction in tension compared with succinylcholine. (+)-Tubocurarine (5 microM) prevented the enhancing effect of [3H]-ACh release induced by 1 microM, but not the decreasing effect induced by 10 microM succinylcholine. These results suggest that succinylcholine induced acceleration at low concentrations due to a positive feedback mechanism through presynaptic nicotinic ACh receptors and the inhibition of ACh release at high concentration contributes in part to the neuromuscular blockade.

Acetylcholine↗

PubMed1991

Specific IgE, IgG and IgG4 antibodies against house dust mite in patients with bronchial asthma.

Serum levels of total IgE, specific IgE, IgG and IgG4 against house dust mite were measured in mite-sensitive asthma patients receiving immunotherapy with house dust. Serum levels of total IgE, mite specific IgE and IgG did not significantly change during the course of hyposensitization. Increased levels of mite specific IgG4 were observed in patients during immunotherapy. The increase in specific IgG4 was dependent on the total dose of house dust administered in both children (r = 0.636, p less than 0.001) and adults (r = 0.629, p less than 0.01). However, the increase of specific IgG4 in adults was not as apparent as in children. These results might suggest that mite specific IgG4 is a useful immunological marker in the immunotherapy for allergic asthma, and that IgG4 antibody acts as a blocking antibody in atopic bronchial asthma.

Adolescent↗

PubMed1991

Fiberoptic ductoscopy of the breast: a new diagnostic procedure for nipple discharge.

A fiberoptic ductoscopy system was successfully developed by means of which we were able to observe the duct cavity of the breast. Two kinds of silicafiberscopes with outer diameters 0.80 and 0.45 mm were used in the present study. Fiberoptic ductoscopy was applied to 52 ducts in 46 patients with nipple discharge for whom no tumor was palpable; the intraductal appearance could be observed in 47 ducts from 41 patients (90.3%). Fourteen ducts from 13 patients were operated upon and were histologically diagnosed as carcinoma (four cases), intraductal papilloma (nine ducts from eight patients) and mastitis (one case). The internal surface of a normal duct was lustrous and smooth. Cancer growing on the surface of a duct wall appeared white and was slightly elevated, forming a bridging structure. The intraductal papillomas formed intraductal solid nodules, being yellow in most cases and red at the site of hemorrhage. Fiberoptic ductoscopy can be used to recognize the growth of minute intraductal lesions in cases of nipple discharge. Clinical endoscopic diagnosis for minute intraductal lesions will make an important contribution to the early detection of cancer and the evaluation of nipple involvement in intraductal carcinoma.

Breast Neoplasms↗

PubMed1991

Iatrogenic hemobilia: how to approach it.

Hemobilia after surgical or non-surgical interventions on the liver, biliary tree and pancreas is a serious postoperative complication. Two different therapeutic approaches i.e. superselective hepatic artery embolization and surgical management were retrospectively evaluated in a group of 19 patients. Superselective embolization showed a lower mortality and morbidity than did surgery. Superselective embolization resulted in a higher success rate in terms of control of bleeding and identification of the origin of the bleed.

Adult↗