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Biomedical subjects

T Matsuda

Publications and source records attributed to T Matsuda.

At least 1,405 records · Page 78Linked to original sources

Improved method for the isolation and preliminary characterization of human DAF (decay-accelerating factor).

DAF (decay-accelerating factor) is one of the integral membrane proteins of erythrocytes, and is considered to play an important role in the regulation of complement activation. The purification of DAF has been impeded by the difficulty in removing glycophorin. We devised an effective method for removing glycophorin. Through the limited trypsinization of stromata prior to the extraction of DAF, glycophorin was readily digested so that the DAF could be purified free of glycophorin by DEAE-Sephacel and Bio-Gel A 0.5 m chromatographies. On SDS-PAGE, DAF from trypsinized stromata showed the same mobility as that from native stromata: its molecular weight was estimated to be about 70 kDa. Amino acid analysis of DAF showed high contents of serine and glutamic acid. The amino-terminal sequence of DAF prepared by the present method, determined for the 29 residues, did not show significant homology with that of glycophorin.

Amino Acid Sequence↗

Specificity to ovomucoid domains of human serum antibody from allergic patients: comparison with anti-ovomucoid antibody from laboratory animals.

The reactivity of IgG and IgE antibodies from egg allergy patients to ovomucoid and its domain fragments was examined quantitatively, and compared with that of rabbit and mouse IgG anti-ovomucoid antibodies. The human antibodies reacted with the carbohydrate-containing domain fragments more strongly than the animal antibodies. In contrast, the human antibodies did not react with the carbohydrate-free third domain, whereas the animal antibodies definitely reacted. These results suggested that the sites and structures recognized by allergic individuals as ovomucoid antigenic determinants are not necessarily the same as those recognized by laboratory animals.

Animals↗

Classification and surgical correction of postburn axillary contractures.

Postburn axillary contractures should be surgically corrected as soon as the diagnosis has been established in order to avoid deeper tissue involvement. We have classified axillary contractures based upon local anatomic conditions and present procedures for correction of each type that we find most suitable. Type I contractures are characterized by a linear web at either axillary fold with minimal adjacent scarring. A double Z-plasty with Y-V advancement is the procedure of choice. Type II contractures involve either axillary fold, with adjacent skin scarring. A double incisional release on both sides of the hair-bearing area is the procedure of choice. Type III contractures are characterized by linear webs at both axillary folds without involvement of the adjacent skin. The procedure of choice in these cases is a double incisional release. Type IV axillary contractures involve the hair-bearing area and the periaxillary region. This diffuse scar contracture is best treated by a single incisional release.

Axilla↗

Enhancement of in vitro erythropoiesis by peripheral blood mononuclear cells from allogeneic marrow recipients in the early post-transplant period.

The effect of peripheral blood mononuclear cells (PBMCs) from bone marrow recipients on in vitro growth of erythroid burst-forming units (BFU-E) was studied. PBMCs were obtained from 5 allogeneic, 1 syngeneic and 1 autologous bone marrow recipient(s) at different intervals after transplantation. The number of BFU-E was significantly increased when donor bone marrow cells were co-cultured with PBMCs obtained from allogeneic marrow recipients in the early post-transplant period. No effect was observed using PBMCs obtained in the later post-transplant period, PBMCs from a syngeneic marrow recipient, or PBMCs from an autologous marrow recipient. The BFU-E enhancing activity was present among T cells and was abolished by treating them with OKT3 or OKT4 antibody and complement. These observations suggest that chimeric T lymphocytes, probably of the helper/inducer subset, from allogeneic marrow recipients in the early post-transplant period have a potent enhancing effect on in vitro erythropoiesis.

Adolescent↗

Enzyme-linked immunosorbent assay measurement of fluctuations in antibody titer and antigenemia in cancer patients with and without candidiasis.

Antibody titers against purified sulfate-soluble fraction (PSSF) obtained from cytoplasmic extracts of Candida albicans were determined retrospectively over a 2-year period for 123 cancer patients by enzyme-linked immunosorbent assay. Antibody against cell wall mannan (CWM) was also measured by the hemagglutination test and the production of precipitins by a serum interacting with a yeast cell homogenate by immunodiffusion. Invasive candidiasis determined by histological evidence at autopsy was present in 10 patients. Fourfold or greater rises in anti-CWM and anti-PSSF antibodies were detected for eight of the patients with invasive candidiasis at 14 to 22 days after the onset of fever. The immunodiffusion test was positive for four patients with invasive candidiasis. For patients with no evidence of candidiasis, significant rises in anti-CWM and anti-PSSF antibodies were observed at a frequency of 20 and 10%, respectively. The concentrations of serum mannan were sequentially measured by the enzyme-linked immunosorbent assay. Antigenemia (greater than or equal to 3 ng/ml) was found in 9 of the 10 patients with invasive candidiasis and in 2 of the 4 patients with thrush, whereas the serum of 1 of the 36 patients with no evidence of candidiasis was positive for antigen. The first antigenemia antedated significant rises in antibody levels against Candida species by 6 to 23 days.

Animals↗

Effects of a thromboxane synthetase inhibitor (OKY-046) and a lipoxygenase inhibitor (AA-861) on bronchial responsiveness to acetylcholine in asthmatic subjects.

The effect of a selective thromboxane synthetase inhibitor, OKY-046, and a selective 5-lipoxygenase inhibitor, AA-861, on bronchial responsiveness to acetylcholine was studied in 23 asthmatic subjects. The provocative concentration of acetylcholine producing a 20% fall in forced expiratory volume in one second (PC20 FEV1) was measured before and after oral administration of OKY-046 (3000 mg over four days) and AA-861 (1100 mg over four days) and inhalation of OKY-046 (30 mg) in 10, 10, and nine asthmatic subjects respectively. Baseline values of FEV1 and forced vital capacity (FVC) were not altered by oral OKY-046, oral AA-861, or inhaled OKY-046. The geometric mean value of PC20 FEV1 increased significantly from 0.55 to 2.24 mg/ml after oral OKY-046, but was unchanged after inhalation of OKY-046 and after oral administration of AA-861. These results suggest that thromboxane A2 may play a part in bronchial hyperresponsiveness to acetylcholine.

Acetylcholine↗

Visualization of moving fluid: quantitative analysis of blood flow velocity using MR imaging.

A new method for the measurement of blood flow using magnetic resonance imaging has been developed. The flow velocities are calculated from the distances that the fluid has moved. The distances are directly visualized by a new pulse sequence. In a phantom study, the measured flow rates showed very good correlation with actual flow rates of up to 20 l/min (3 m/sec). In a volunteer study, pulsatile flow velocities of a large artery were measured with electrocardiographic gating. The flow pattern of a cardiac cycle at the abdominal aorta is similar to that revealed by other methods of measurement, such as Doppler ultrasound. This method allows reasonably accurate quantitative analysis of blood flow in the large arteries.

Blood Flow Velocity↗

Hemolysis due to high-dose intravenous gammaglobulin treatment for patients with idiopathic thrombocytopenic purpura.

Two adult patients with chronic idiopathic thrombocytopenic purpura (ITP) were treated with high-dose intact immunoglobulin (high-dose IgG). Haptoglobin levels in both cases declined significantly during high-dose IgG, following the increase in platelet counts to normal level. In one of them apparent hemolytic anemia was observed. The findings strongly support the hypothesis that the effect of high-dose intact IgG treatment on ITP patients is due to sequestration of IgG-coated autologous red blood cells by the reticuloendothelial system and the saturation of the macrophages by red blood cells.

Adult↗

Development of autologous specific reactivity to human neuroblastoma.

Antigenic analysis of neuroblastoma cells was performed by autologous typing and indirect immunofluorescent test combined with absorption tests. Serum of a patient with neuroblastoma before treatment showed weak reactivity with cultured autologous neuroblastoma cells, while serum obtained from the same patient 3 months after chemotherapy exhibited strong reactivity with the same indicator cells. This reactivity was absorbed with neither cultured autologous fibroblasts nor allogeneic tumor cells from seven neuroblastoma and two melanoma patients. In addition, cultured hematopoietic cells from two subjects, normal fetal and adult tissues also failed to remove the reactivity. This reactivity, however, was completely removed by the absorption with the cultured autologous neuroblastoma cells and the homogenate, suggesting that these neuroblastoma cells may express tumor specific antigen(s), located on neither normal cells in any stage of the development nor other malignant cells, although the cells and tissues we tested may not be adequate to confirm this.

Abdominal Neoplasms↗

Antidiuretic effects of dibutyryl-cyclic AMP microinjected into the hypothalamic paraventricular nucleus in a water-loaded and ethanol-anesthetized rat.

Effects of dibutyryl-cyclic AMP (db-cAMP) and cyclic AMP (cAMP) when microinjected into the hypothalamic paraventricular nucleus (PVN) in a water-loaded and ethanol-anesthetized rat on the rate of urine outflow, urine osmotic pressure and other visceral functions were investigated. The microinjection of db-cAMP decreased the rate of urine outflow with concomitant increase in the urine osmotic pressure, but did not change mean blood pressure, heart rate, respiration rate and rectal temperature. The antidiuretic effect of db-cAMP was more potent than the effect of cAMP, the median effective doses (ED50) being approx. 40 nmol for db-cAMP and more than 300 nmol for cAMP, respectively. The time-courses for the antidiuretic effects and for the increase in the urine osmotic pressure showed a similar pattern, with the maximal effect at approx. 30 to 40 min and the duration of approx. one hour or longer. The effect of db-cAMP was potentiated by pretreatment with methylxanthines and inhibited by pretreatment with atropine. A second microinjection of db-cAMP induced a less potent antidiuretic effect than the first microinjection (tachyphylaxis). The results indicated the antidiuretic effects of microinjection of db-cAMP and cAMP into the PVN, and a possible mechanism for this was discussed.

1-Methyl-3-isobutylxanthine↗

Antidiuretic effects of alpha- and beta-adrenoceptor agonists microinjected into the hypothalamic paraventricular nucleus in a water-loaded and ethanol-anesthetized rat.

Effects of catecholamines microinjected into the paraventricular nucleus in the hypothalamus on urine outflow in a rat which was loaded with water and anesthetized with ethanol were studied. L-Norepinephrine, L-epinephrine and L-isoproterenol induced potent antidiuresis with similar time courses to each other. The ED50 values for L-norepinephrine, L-epinephrine and L-isoproterenol were approximately 5, 10 and 5 nmol, respectively. The D-isomer of isoproterenol demonstrated no significant antidiuretic activity. The effect of L-norepinephrine was inhibited strongly by premicroinjection of alpha- and beta-adrenoceptor antagonists. The effect of DL-isoproterenol was inhibited strongly by beta-adrenoceptor antagonists, but not affected by alpha-adrenoceptor antagonist. Premicroinjection of a muscarinic antagonist, atropine, partially inhibited anti-diuretic effects induced by L-norepinephrine and DL-isoproterenol. Visceral functions other than urine outflow such as mean blood pressure, respiration rate, heart rate and rectal temperature were not significantly altered when the urine outflow decreased down to 20-30% of the control by microinjection of L-norepinephrine and DL-isoproterenol. The results demonstrated that stimulation of alpha- and beta-adrenoceptor in the paraventricular nucleus induced potent antidiuretic effects, partial inhibition of which by atropine suggested a possible presynaptic facilitation of the release of ACh by the stimulation of the adrenoceptors.

Adrenergic alpha-Agonists↗

Antidiuretic effects of dibutyryl-cyclic AMP microinjected into the hypothalamic supraoptic nucleus in water-loaded and ethanol-anesthetized rats.

Effects of dibutyryl-cyclic AMP (db-cAMP) and cyclic AMP (cAMP) microinjected into the hypothalamic supraoptic nucleus (SON) which contains the neurons synthesizing and releasing antidiuretic hormone upon the outflow and the osmotic pressure of urine and the other visceral functions were investigated in water-loaded rats anesthetized with ethanol. When microinjected into the SON the dibutyryl analog of cAMP induced dose-dependent antidiuretic effects without significant effects on any other visceral functions. Dibutyryl-cAMP was much more effective than cAMP; The ED50 value for db-cAMP was approx. 200 nmol versus more than 500 nmol for cAMP. The time course of the antidiuretic effects was relatively slow with minimal urine outflow appearing only after more than 1/2 hour post-injection. The effects induced by db-cAMP demonstrated tachyphylaxis and were partially inhibited by pretreatment with atropine or theophylline, which suggests that the antidiuretic effects were mediated through muscarinic and adenosine receptors present in the nucleus.

Anesthesia↗

Antidiuretic effects of methionine-enkephalin and 2-D-alanine-5-methionine-enkephalinamide microinjected into the hypothalamic supraoptic and paraventricular nuclei in a water-loaded and ethanol-anesthetized rat.

Effects of methionine-enkephalin (ME) and 2-D-alanine-5-methionine-enkephalinamide (DAMEA) microinjected into the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei, which contain neurons synthesizing and releasing antidiuretic hormone, upon the outflow and the osmotic pressure of urine and the other visceral functions were studied in a rat which was loaded with water and anesthetized with ethanol. These opioid peptides when microinjected into the SON or PVN induced potent antidiuretic effects in dose-dependent and time-dependent manners with no significant effects on the other visceral functions. The approx. ED50 values for DAMEA were 1.3 (in the SON) and 0.7 (in the PVN) nmol, and the values for ME were 110 (in the SON) and 60 (in the PVN) nmol. The antidiuretic effects showed slow onset and long duration, with a minimal urine outflow at approx. 0.5 hr after microinjection and an approx. 2 hr-duration. The effects induced by the opioid peptides were inhibited by pretreatment with naloxone or atropine, without effects of pretreatment with alpha- or beta-adrenoceptor antagonists, suggesting that the antidiuretic effects were mediated through an opioid receptor having low sensitivity to naloxone and also possibly mediated through a muscarinic receptor which was stimulated probably by the ACh released by the opioid peptides.

Anesthesia↗

Additive effects of isoproterenol-phenylephrine aerosol following ipratropium bromide on airway obstruction in older patients with intrinsic asthma and chronic bronchitis.

The additive bronchodilating effect of isoproterenol-phenylephrine aerosol following ipratropium bromide was examined in seven intrinsic asthmatic patients and seven chronic bronchitic patients. FVC, FEV1 and Zrs were measured before and 30 min. after inhalation of ipratropium, 40 micrograms. Then inhalation of isoproterenol, 600 micrograms and phenylephrine, 570 micrograms was added and the pulmonary functions were measured 30 min. later. The age, baseline values of FVC and FEV1, and the increases in FEV1 and 1/Zrs with ipratropium did not differ between the two. Isoproterenol-phenylephrine aerosol following ipratropium produced further increases in FEV1 and 1/Zrs in asthmatic patients but no additive increases in bronchitic patients. These findings indicate that the role of autonomic nervous system, especially adrenergic system, on airway obstruction may be different between asthmatic and bronchitic patients and the method applied in this study may be helpful in differentiating these airway disorders.

Aerosols↗

Contractile effects of Bay k 8644, a dihydropyridine calcium agonist, on isolated femoral arteries from spontaneously hypertensive rats.

Agonist actions of methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)- pyridine-5-carboxylate (Bay k 8644) were investigated in femoral and mesenteric arteries from 6-week-old spontaneously hypertensive rats (SHRs), and data compared with findings in normotensive Wistar-Kyoto rats (WKYs). The addition of Bay k 8644 produced a dose-dependent contraction in SHR femoral artery with a pD2 value of 8.55. Maximum contraction induced by this agonist (1 X 10(-7) M) was comparable to the maximum developed by K+-depolarization. Bay k 8644 was much less effective in eliciting the contractile responses on WKY femoral artery. Contractile responses of mesenteric and tail arteries to Bay k 8644 were weak and were not significantly different between SHR and WKY. Thoracic aorta was sensitive to the contractile response to Bay k 8644, but the sensitivity was not significantly different between SHR and WKY. Increased responsiveness to exogenously applied K+ was also observed in SHR femoral artery as compared to WKY. Contractile responses of SHR femoral artery to Bay k 8644 were antagonized competitively by nifedipine (pA2 = 8.36), a dihydropyridine Ca++ antagonist, but noncompetitively by diltiazem, a non-dihydropyridine Ca++ antagonist. When the effect of nifedipine on the dose-response curve for Bay k 8644 was determined in WKY femoral artery, there was a similar extent of rightward displacement of the dose-response curve to that seen in SHR. Nifedipine was less efficacious in relaxing the contractile response to Bay k 8644 compared to the contractile response to K+ in SHRs femoral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

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