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Biomedical subjects

M Okita

Publications and source records attributed to M Okita.

At least 19 recordsLinked to original sources
PubMed2004

Thirty cases of bronchial asthma associated with exposure to pet hamsters.

BACKGROUND: The identification, isolation, and elimination of allergen(s) causing bronchial asthma are the most efficient form of treatment. The pet industry has diversified recently, increasing the risk of exposure of pet owners to many unknown antigens. We clinically studied the characteristics of asthma associated with exposure to pet hamsters. METHODS: The study group comprised 30 adults in whom the onset, recurrence, or exacerbation of asthma was triggered by contact with pet hamsters. Clinical characteristics such as sex, age, period required for symptom onset, species of hamster, treatment and disease course, smoking status, and hamster-specific IgE antibodies in serum were studied. RESULTS: The male: female ratio of the study group was 1:1.3, and mean age was 37.7 years. Patients with no previous history of asthma initially presented with cough, progressing to episodes of asthma. Asthmatic symptoms were associated with hamster contact and ranged in severity from mild to severe. Three patients required hospital admission for treatment. The mean period from the start of hamster exposure to the onset of asthmatic episodes was 15.7 months. Dwarf hamsters were responsible for most cases. The CAP-RAST score for hamster-specific IgE antibodies was 1 to 4 in 22 patients and 0 in 8 patients. Eight patients with a score of 1 or higher for hamster-specific IgE antibodies had a CAP-RAST score of 0 for mite antigen. In these patients, terminating hamster contact resulted in a rapid improvement in symptoms, with no need for further treatment. Twenty-three of the 30 subjects (76.7%) were smokers. CONCLUSION: Exposure to pet hamsters is an important risk factor for the onset, recurrence, or exacerbation of asthma. Smoking may also increase the risk of asthmatic symptoms in patients exposed to hamsters.

Adult↗
PubMed2004

Clinical evaluation of response to long-term treatment with Pranlukast in patients with bronchial asthma.

BACKGROUND: Short-term treatment with pranlukast, a leukotriene receptor antagonist, has shown to be effective for the management of asthma. The effectiveness and safety of long-term treatment with pranlukast remains to be established. OBJECTIVES: The aim of this study was to determine the effects of pranlukast on morning peak expiratory flow rates (PEFRs), the diurnal variation of these values, and disease severity. METHODS: Fifteen men with bronchial asthma were studied for 5 years. During the first year, the subjects were treated with a bronchodilator; some also received inhaled and oral corticosteroids. During the next 4 years, the subjects received pranlukast in addition. RESULTS: Mean PEFR increased after the start of treatment with pranlukast. The increase in PEFR occurred later in subjects with more severe disease. Diurnal variation of PEFR was unchanged, but subsequently decreased. The condition of all subjects improved, but the greatest improvement was obtained in patients with mild to moderate asthma. CONCLUSIONS: Long-term treatment with pranlukast is effective for the management of bronchial asthma, particularly in patients with mild to moderate disease. Our results suggest that the effectiveness of antiasthmatic drugs should be evaluated over a period of years, rather than on a short-term basis.

Adrenal Cortex Hormones↗
PubMed2003

Inhibitory effects of D2 agonists by striatal injection on excessive release of dopamine and hyperactivity induced by Bay K 8644 in rats.

We investigated by means of behavioral and neurochemical studies the effects of either D(1) or D(2) agonist on excessive dopamine release and hyperactivity induced by the microinjection of Bay K 8644, and an L-type Ca(2+) channel stimulant, into the rat caudate putamen under a novel environmental condition. Hyperactivity (locomotor activity and rearing counts) and significant increases in extracellular dopamine levels induced by Bay K 8644 were concomitantly observed. D(1) agonist, SKF81297, administered into the caudate putamen did not block Bay K 8644-induced hyperactivity measured by monitoring both animal activity and increases in extracellular dopamine levels detected by microdialysis. Pretreatment with the D(2) agonists, bromocriptine, talipexole and pramipexole, into the caudate putamen significantly blocked Bay K 8644-induced hyperactivity for 45 min after Bay K 8644 administration, although the single administration of these agonists significantly potentiated locomotor activity and rearing behavior. Furthermore, these agonists significantly suppressed Bay K 8644-induced extracellular dopamine levels. Our results indicate that these D(2) agonists (1) act on postsynaptic neuronal D(2) receptors under conditions of normal or low dopamine release in the caudate putamen, and (2) act on presynaptic D(2) receptors (autoreceptors) when excessive levels of dopamine are released or hyperdopamine neuronal activity is induced. Consequently, the effect of D(2) agonists in the clinical treatment of Parkinson's disease may be due to stimulation of postsynaptic D(2) receptors rather than presynaptic autoreceptors.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed2003

[Torsion of the middle lobe after right upper lobectomy of the lung; report of a case and the review of the Japanese literatures].

We report a case of torsion of the residual right middle lobe of the lung, following right upper lobectomy for lung cancer. A 71-year-old man who had medical treatment for emphysema was admitted with a lung tumor on chest computed tomography. The tumor was diagnosed as pulmonary adenocarcinoma by transbronchial biopsy. Right upper lobectomy with mediastinal lymph node dissection, and partial resection of the right lower lobe were performed. On the following day, chest X-ray showed an opacification in the right upper lung field, which gradually increased. Bronchoscopic examination revealed a stenotic middle lobe bronchus. Torsion of the middle lobe was suspected, and rethoracotomy was performed on the second postoperative day. The middle lobe was torsed 90-degree counterclockwise around its bronchovascular pedicle. A middle lobectomy was performed secondary to severe congestion. The patient was discharged in good condition on the 11th postoperative day. In reviewing the literatures including this case, 13 of 16 torsions occurred after right upper lobectomy of the lung. Thirteen patients had rethoracotomy, 10 of them underwent resection of the rotated lung. Simple detorsion was carried out in 3 patients, and 1 of them developed cerebral infarction. Lung torsion was reported to be potentially life-threatening. Therefore, fixation of a remaining lobe should be performed. Exploratory thoracotomy should be performed without delay, if lung torsion is suspected.

Adenocarcinoma↗
PubMed2002

Influences of a dietary fatty acid composition on the emergence of glutathione S-transferase-P (GST-P) positive foci in the liver of carcinogen-treated rats.

The rats treated with a single i.p. injection of diethylnitrosoamine (DEN) and percial hepatectomy were fed for 11 weeks with a high fat diet mixed with 10% lard, eicosapentaenoic-acid-rich oil (EPA-oil) or arachidonic-acid-rich oil (AA-oil) and the emergence of glutathione S-transferase placental form (GST-P) in the liver was evaluated. There were no significant differences in the serum aminotransferase activities. The molar ratio of n-6 and n-3 fatty acid in the liver phospholipids was significantly low in the EPA-oil group compared with the other groups. In the EPA-oil group, the area percent and the unit area of GST-P positive foci were significantly smaller than the other groups. In the AA-oil group, no significant differences were recognized in the quantitative values for GST-P positive foci compared with the control and lard groups. In conclusion, a hepatic neoplasmic lesion induced by DEN was suppressed with EPA-rich fish oil, and arachidonic-acid-rich oil showed no effect of suppression or acceleration.

Administration, Oral↗
PubMed2001

Cloning of cDNA encoding a soybean allergen, Gly m Bd 28K.

A cDNA clone encoding a soybean allergen, Gly m Bd 28K, has been isolated. The clone has a 1567-bp cDNA insert with a 1419-bp open reading frame and a 148-bp 3'-untranslated region, followed by a polyadenylation tail. The open reading frame was shown to encode a polypeptide composed of 473 amino acids. The chemically determined amino acid sequences of the peptides obtained from the allergen, including its N-terminal peptide, were shown to be contained in the N-terminal region of the amino acid sequence deduced from the cDNA, showing that the first half of the cDNA encodes the allergen with a preceding segment of 21 amino acids. The peptide fragment including the allergen was expressed as a fusion protein with glutathione S-transferase in Escherichia coli and immunoblotted with the sera of soybean-sensitive patients and the monoclonal antibody against the allergen. Furthermore, homology analyses demonstrate that the polypeptide for the cDNA exhibits high homology with the MP27/MP32 proteins in pumpkin seeds and the carrot globulin-like protein. This finding suggests that the polypeptide may consist of a 21-amino acid segment as a part of the signal peptide and the proprotein, which may be converted to two mature proteins, Gly m Bd 28K and a 23-kDa protein, during the development of soybean cotyledons.

Allergens↗
PubMed2001

The effect of dietary polyunsaturated fatty acid on insulin sensitivity and lipid metabolism in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

The effects of insulin sensitivity and lipid metabolism of dietary lard, eicosapentaenoic acid-rich oil (EPA oil) or arachidonic acid oil (AA oil) in Otsuka Long-Evans Tokushima Fatty (OLETF) rats were examined. Blood glucose was not different in each group at 30, 60, 120 min on an oral glucose tolerance test. Fasting blood glucose levels were lower in lard and AA oil groups than in controls. Hepatic triglyceride concentration and liver histochemistry revealed that the fat content was higher in the lard group and the AA oil group than in controls. The EPA oil group showed TG levels as high as the control group. Serum total cholesterol in the EPA oil group was lower, while the level in the AA oil group was higher than in the lard and control groups. HDL cholesterol was 1.5-fold higher in the AA oil group than in controls. Dietary EPA oil or AA oil supplementation showed different effects on lipid metabolism in this model.

Animals↗
PubMed2001

Sandwich enzyme-linked immunosorbent assay system for micro-detection of the wheat allergen, Tri a Bd 17 K.

Seven monoclonal antibodies (mAbs) against the wheat allergen, Tri a Bd 17 K, were prepared to obtain mAbs suitable for a sandwich enzyme-linked immunosorbent assay (sandwich ELISA) for determination of the allergen. Two of the mAbs strongly immunoblotted the allergen purified from wheat flour. However, only one (1G11) of them was found to be suitable for sandwich ELISA. Epitope mapping against mAb-1G11 on the allergen showed that the mAb recognized the peptide containing Lys-38 and Gln-39 of the allergen. We developed a sandwich ELISA method consisting of Aleuria aurantia lectin for fixing the allergen and 1G11 as the first antibody that enabled 4-4,000 ng/well of the allergen to be determined.

Allergens↗
PubMed2001

Modest overexpression of neuropeptide Y in the brain leads to obesity after high-sucrose feeding.

Neuropeptide Y (NPY), one of the most abundant peptide transmitters in the mammalian brain, is assumed to play an important role in feeding and body weight regulation. However, there is little genetic evidence that overexpression or knockout of the NPY gene leads to altered body weight regulation. Previously, we developed NPY-overexpressing mice by using the Thy-1 promoter, which restricts NPY expression strictly within neurons in the central nervous system, but we failed to observe the obese phenotype in the heterozygote. Here we report that in the homozygous mice, overexpression of NPY leads to an obese phenotype, but only after appropriate dietary exposure. NPY-overexpressing mice exhibited significantly increased body weight gain with transiently increased food intake after 50% sucrose--loaded diet, and later they developed hyperglycemia and hyperinsulinemia without altered glucose excursion during 1 year of our observation period.

Aging↗
PubMed2001

[Desmoid tumor of the chest wall infiltrating into the brachial plexus: report of a resected case].

We report a case of a desmoid tumor which developed in the apex of the chest wall. A 18-year-old woman was admitted with left shoulder pain. Chest X-ray showed a mass shadow in the left upper lung field. Chest MRI demonstrated the mass infiltrated into the left brachial plexus. A desmoid tumor was suspected on percutaneous needle biopsy. Resection of the tumor was performed. The mass was 13 x 9 x 5 cm in size and diagnosed pathologically as desmoid tumor. Adjunctive postoperative radiation therapy of 60 Gy was done. Postoperative course was uneventful except motor disturbances of the left fingers. At 15 months postoperatively, there was no evidence of recurrence.

Adolescent↗
PubMed2001

[Influential factors in the elevation of serum creatine phosphokinase for the patients with Kanemi Yusho--freeze fracture study of rat muscle plasma membrane].

We studied the factors of the elevation of serum creatine phosphokinase (CK) using the data from the routine medical checkup of Kanemi Yusho patients during 1995 and 1999. We also studied rat muscle plasma membrane by the freeze fracture method, which were given the polychlorinated biphenyls (PCB) and controls. The patients with elevation of serum CK showed significant elevation of PCB in their blood but not in polychlorinated quanterphenyls (PCQ). The rat muscle plasma membrane showed a slight increase of orthognal array density but it was not statistically significant. The densities of caveolae and particles were not changed. Accordingly, PCB were thought to be a factor in the elevation of CK in the serum.

Animals↗
PubMed2000

Presynaptic L-type Ca(2)+ channels on excessive dopamine release from rat caudate putamen.

We investigated by means of behavioral and neurochemical studies the role of the nerve terminal L-type voltage sensitive Ca(2)+ channel on dopamine (DA) release. Microinjection of Bay K 8644 (BAYK), an L-type Ca(2)+ channel stimulant, into the rat caudate putamen increased locomotor activity and rearing behavior in a dose-dependent manner, whereas injections into the amygdala had no effect. DA receptor antagonists significantly blocked BAYK-induced hyperactivity. Significant increases of extracellular DA levels were detected by microdialysis 20 min after BAYK administration into caudate putamen and then declined. This increase was influenced by tetrodotoxin, an axonal Na(+) channel blocker. Pretreatment with nimodipine and nicardipine, but not nifedipine, which are 1, 4-dihydropyridine L-type Ca(2)+ channel antagonists, administered into the caudate putamen significantly blocked BAYK-induced hyperactivity and DA efflux. These results indicate that the extraordinary DA release in the caudate putamen was mediated by extreme stimulation of the nicardipine and nimodipine-sensitive L-type Ca(2)+ channel present in the nerve terminal of striatal DA neurons.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1999

Analysis of the fatty acid components in a perchloric acid-soluble protein.

We had previously found that a perchloric acid-soluble protein (PSP1) occurs in rat liver, and that this novel protein inhibits protein synthesis in a rabbit reticulocyte lysate system (T. Oka, H. Tsuji, C. Noda, K. Sakai, Y.-H. Hong, I. Suzuki, S. Muñoz, Y. Natori, J. Biol. Chem. 270 (1995) 30060-30067). In the present study, we analyzed lipid components bound to PSP1. Native PSP1 was purified from rat liver using Sephadex G-75, DE-52 cellulose and IgGPSP-affinity chromatography, and the lipid components were extracted. The components obtained from the purified PSP1 were shown to be free fatty acids by thin-layer chromatography. By GC-MS, six major fatty acids were identified as 14:0, 16:0, 18:0, 18:1, 18:2 and 20:4. 1 mol of PSP1 contained 1.26 mol of total fatty acid components. The fatty acid-binding assay of PSP1 showed that the Bmax was 1.25 mol fatty acid/mol PSP1 and the Kd value for palmitic acid was 6.03 microM. The concentration of PSP1 mRNA in rat liver increased 2.3-fold by the administration of peroxisome proliferator, bezafibrate. These findings show that PSP1 is a fatty acid-binding protein-like protein, which is involved in the intracellular metabolism of fatty acid and is quite different from the known fatty acid-binding proteins.

Animals↗
PubMed1999

Abnormal serum lysophospholipids in multiple myeloma patients.

Lysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA) mediate various kinds of biological activities and play an important role in cellular signal transduction. We analyzed serum phospholipids obtained from 16 multiple myeloma (MM) patients and observed that serum LPA level was significantly higher in MM patients (5.3 +/- 0.5 nmol/mL) than in normal controls (1.7 +/- 0.3 nmol/mL). LPC level was also higher than that in normal controls, and it correlated significantly with the concentration of LPA (r = 0.678, P < 0.01). In MM patients, palmitic acid/linoleic acid ratios in phosphatidylcholine and LPC were higher than those in normal controls. In the 12-mon follow-up study of two patients with the immune globulin G type, we recognized that the increase of LPC, LPA, and arachidonic acid/linoleic acid ratio in phosphatidylinositol corresponded with a decline in the serum albumin level and choline esterase activity.

Fatty Acids↗
PubMed1999

Decreased food intake and body weight in pancreatic polypeptide-overexpressing mice.

BACKGROUND & AIMS: Pancreatic polypeptide (PP) is a 36-amino acid hormone produced by F cells within the pancreatic islets and the exocrine pancreas. The definitive function of PP in mammalian physiology remains to be determined. This study examined the effects of chronic overexpression of PP through the development of PP transgenic mice. METHODS: PP transgenic mice were created by using mouse PP complementary DNA under the control of the cytomegalovirus immediate early enhancer-chicken beta-actin hybrid promoter (pCAGGS expression vector). RESULTS: A unique line of transgenic mice was created that overexpresses PP in the pancreatic islets with low levels of expression in other tissues including the brain. Plasma PP concentrations were more than 20 times higher than those of control littermates. However, PP overproduction led to postnatal lethality in half of the pups because of markedly decreased milk intake. The remaining PP transgenic mice gained less weight with specifically reduced food intake and fat mass compared with controls, a result that was more evident in male than in female mice. The transgenic mice exhibited a reduced rate of gastric emptying of a solid meal but had normal oxygen consumption and fasting leptin levels. Immunoneutralization with anti-PP antiserum reversed the phenotypic changes of transgenic animals. CONCLUSIONS: PP could be involved in feeding and body weight regulation partly through regulation of gastric emptying.

Animals↗
PubMed1999

Low plasma levels of docosahexaenoic acid in patients with liver cirrhosis and its correction with a polyunsaturated fatty acid-enriched soft oil capsule.

Plasma levels of docosahexaenoic acid (DHA, C22:6 omega 3) were found to be decreased in 11 patients with alcoholic and non-alcoholic liver cirrhosis depending on the severity of liver damage. In this reduction, we found impaired metabolism of omega-3 long-chain polyunsaturated fatty acids in the cirrhotic liver and poor dietary intake of DHA to involved in the reduction of DHA plasma levels. The deficiency of this fatty acid, which is concentrated in the nervous tissues, may be related to the impaired neural function observed in hepatic encephalopathy of these patients. Oral DHA supplementation was supplied in the form of a polyunsaturated fatty acid-enriched soft oil capsule (omega 3/omega 6 ratio = 0.91, and P/S ratio = 1.87). Twelve capsules per day (containing 408 mg DHA, which corresponds to one-fourth of the DHA content in a normal daily diet) improved the DHA contents in the plasma phospholipid fractions of 5 alcoholic patients with low DHA levels.

Aged↗