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T Kawano

Publications and source records attributed to T Kawano.

At least 253 records · Page 14Linked to original sources
PubMed1994

In-vitro enhancement of mouse embryonic development by co-culture with peritoneal macrophages.

The effects of peritoneal macrophages on mouse fertilization and embryonic development in vitro were examined by a co-culture method. In experiment 1, oocytes from F1 strain mice were inseminated and cultured with a monolayer of peritoneal macrophages to determine the effects of the macrophages on fertilization. In experiment 2, 1-cell embryos, fertilized in vivo from either a non-blocking or a blocking strain, were also incubated with peritoneal macrophages to determine whether these cells overcame the developmental arrest. Although the peritoneal macrophages had an adverse effect on fertilization in the F1 strain, embryonic development was significantly improved by the co-culture. This beneficial effect on embryonic development was also observed in the embryos fertilized in vivo from the strain that exhibited a 2-cell block. These results suggest that peritoneal macrophages provide an effective co-culture system for the in-vitro development of mouse embryos.

Animals↗
PubMed1994

Reaction mechanism underlying CMP-N-acetylneuraminic acid hydroxylation in mouse liver: formation of a ternary complex of cytochrome b5, CMP-N-acetylneuraminic acid, and a hydroxylation enzyme.

We have proposed that CMP-N-acetylneuraminic acid (CMP-NeuAc) hydroxylation is mediated by an electron transport system consisting of cytochrome b5 (b5), b5 reducing factor(s), and CMP-NeuAc hydroxylase, all of which have been detected in the cytosolic fraction of mouse liver [Kozutsumi, Y., Kawano, T., Yamakawa, T., & Suzuki, A. (1990) J. Biochem. 108, 704-706]. In order to elucidate the reaction mechanism underlying CMP-NeuAc hydroxylation, the interaction between b5 and the hydroxylase was studied using a b5-immobilized affinity column. The enzyme activity was retarded on the b5 column in the presence of the substrate, CMP-NeuAc, but not in the presence of the reaction product, CMP-N-glycolyneuraminic acid (CMP-NeuGc). These findings suggest that the binding of CMP-NeuAc to CMP-NeuAc hydroxylase changes the conformation of the enzyme so as to construct a recognition site for b5, followed by the formation of a ternary complex through this domain. Then the transport of electrons from NAD(P)H to the enzyme through b5 takes place, CMP-NeuAc is converted to CMP-NeuGc, and finally the ternary complex dissociates into its components to release CMP-NeuGc. It is known that a soluble form of b5 is abundant in erythrocytes and is synthesized from a mRNA different from that for the microsomal form of b5. In order to determine the origin of b5 detected in the cytosolic fraction of mouse liver, the molecular forms of b5 mRNA expressed in mouse liver were analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Alternative treatment may lower the need for use of extracorporeal membrane oxygenation.

Access to artificial surfactant and high frequency oscillatory ventilation (HFO) in Japan seems to affect the actual indications for extracorporeal membrane oxygenation (ECMO). The relation between the methods of treatment and survival and/or neurological sequelae of 27 neonates with severe respiratory failure who would have met the US ECMO entry criteria in the Neonatal Intensive Care Unit of National Children's Hospital, Tokyo between January 1988 and May 1992 were retrospectively analyzed. Out of 27 neonates, conventional treatment including artificial surfactant was successful in 6 cases (22%). High frequency oscillatory ventilation was used for the 21 cases who did not respond to conventional treatment and it was effective in 5 cases (19% of total). Extracorporeal membrane oxygenation was used on 11 (40% of total) of 16 cases who did not respond to HFO. Eight (29% of total or 73% of ECMO cases) of these cases survived and 3 cases (11% of total) died. The remaining 5 cases (19% of total) who met the exclusion criteria of ECMO died. No patient with respiratory distress syndrome (RDS) became ill enough to meet the US ECMO entry criteria. Six out of 8 congenital diaphragmatic hernia cases were saved on a delayed surgery protocol with HFO. Only about 1% of the neonates who were admitted to our NICU during the last 4 years needed ECMO treatment. Forty-one per cent of the patients who would have met the US ECMO entry criteria were treated successfully without ECMO. The necessity for ECMO is less in Japan than in the US because other methods can often be used successfully to treat severe respiratory disorders.

Extracorporeal Membrane Oxygenation↗
PubMed1994

Role of high-frequency ventilation in surfactant-depleted lung injury as measured by granulocytes.

Granulocytes were collected from the lung lavage fluid of surfactant-depleted rabbits to assess the relationship between granulocyte-related lung injury and ventilatory mode. The number of lavaged granulocytes was determined after 2 and 4 h of conventional mechanical ventilation (2CMV and 4CMV, respectively) or high-frequency oscillatory ventilation (2HFO and 4HFO, respectively). Stimulated respiratory bursts were assayed by luminol-dependent chemiluminescence (LDCL) with N-formyl-methionyl-leucyl-phenylalanine (FMLP) stimulation in four groups of rabbits. The number of lavaged granulocytes significantly increased with ventilatory duration in the CMV mode but not in the HFO mode. Meanwhile, peak LDCL response value with FMLP stimulation in 4CMV was substantially lower than values in the other three groups. The decrease in the granulocyte LDCL response in 4CMV suggests oxygen metabolite exhaustion in the cells. CMV increasingly induced the accumulation of granulocytes with activated respiratory bursts in the alveolar spaces with ventilatory duration. HFO did not cause granulocyte accumulation, nor did it impair granulocyte function. The results suggest that HFO is useful for the prevention of lung injury related to activated granulocytes.

Animals↗
PubMed1994

Intravascular ultrasound of coronary arteries in children. Assessment of the wall morphology and the lumen after Kawasaki disease.

BACKGROUND: The long-term clinical issue in Kawasaki disease (KD) concerns the coronary artery lesion. Two-dimensional echocardiography and coronary angiography are routine examinations to evaluate the coronary lesions; however, these are not adequate to assess the wall morphology of the coronary artery (CA). Intravascular ultrasound imaging (IVUS), a new technology for the evaluation of the coronary artery lumen and wall morphology in vivo, was performed for patients after KD in their long-term follow-up, and we examined the new insights it gave. METHODS AND RESULTS: IVUS was performed during cardiac catheterization in 20 subjects (10 patients after KD who still had coronary aneurysms or regressed coronary aneurysms, 2 after KD who had no coronary abnormal lesion, and 8 control patients with congenital heart disease and normal CA). We evaluated the wall structure at 10 to 15 sites of the CA in each patient. IVUS was performed with a commercially available ultrasound imaging catheter. Four sites of a CA aneurysm in KD demonstrated a markedly dilated lumen without thickened intima. One site of a CA aneurysm with calcification demonstrated an asymmetrical lumen by a dense echo with acoustic shadows. Twenty-two sites of a regressed CA aneurysm demonstrated a marked symmetrical or asymmetrical thickening of the intima with a dense echo, in which the size of the lumen was similar to that at a site near a regressed aneurysm. The sites of angiographically normal CA revealed normal structures and a thin intima in many instances. Nine of 28 sites in KD with a CA abnormal lesion, particularly near a coronary aneurysm or regressed aneurysm, demonstrated a mild thickening of the intima. All the 10 sites in KD without a CA abnormal lesion and all the 25 sites in patients with congenital heart disease with normal CA demonstrated a smooth intima. CONCLUSIONS: This study demonstrated that the site of a regressed coronary aneurysm has a markedly thickened but smooth intima. The sites of angiographically normal CA after KD with or without a coronary lesion demonstrated normal IVUS findings in most instances but in some cases revealed a mild intimal thickening. IVUS is useful to evaluate the CA wall morphology and may contribute to the assessment of long-term CA sequelae and the possible development of arteriosclerotic changes in KD.

Adolescent↗
PubMed1994

Inflammatory chemical mediators during conventional ventilation and during high frequency oscillatory ventilation.

Inflammatory chemical mediators, platelet-activating factor (PAF), thromboxane (TX) B2, and 6-keto-prostaglandin (PG)F1 alpha, were extracted from lung lavage fluid after conventional mechanical ventilation (CMV) and high frequency oscillatory ventilation (HFOV) to clarify the relation between mode of ventilation and lung injury in surfactant-depleted rabbit lungs. Anesthetized adult rabbits were tracheostomized, and surfactant depletion was induced by repeated saline lavage. Lung lavage for measurement of mediators was performed after 4 h of CMV at an FIO2 of 1.0 and a mean airway pressure of 15 cm H2O or HFOV (15 Hz) at an FIO2 of 1.0 or 0.21 and a mean airway pressure of 15 cm H2O. The number of total cells and polymorphonuclear leukocytes (PMN) and the levels of PAF, TXB2, and 6-keto-PGF1 alpha were measured by radioimmunoassay. Total respiratory compliance (Crs) was measured by the passive flow-volume curve method. The numbers of PMN, and the levels of PAF and TXB2 in lung lavage fluid were significantly greater during CMV than during HFOV. HFOV resulted in decreased production of PAF and TXB2 in a surfactant-depleted rabbit lung. Crs was significantly less during CMV than during HFOV. These results suggest that HFOV could prevent the release of such inflammatory chemical mediators and result in less lung injury than CMV.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Follow-up study of patients with "unilateral" moyamoya disease.

Sixty-four patients with "unilateral" occlusive disease of the circle of Willis were studied to evaluate progression to bilateral disease. Seventeen patients developed bilateral lesions during a period of 1-7 years after the diagnosis of unilateral lesion. Most of these patients had ischemic attack as the initial episode and had repeated attacks before admission. Young children, mostly less than 10 years of age, tended to develop bilateral lesions within 1-2 years, but adults tended to have only a unilateral lesion. Children or young adults with unilateral occlusive lesion of the terminal portion of the internal carotid artery are likely to develop bilateral disease within 1-5 years.

Adolescent↗
PubMed1994

Wall morphology of the pulmonary artery--intravascular ultrasound imaging and pathological evaluations.

The pathological assessment of the pulmonary vascular bed is essential for the diagnosis and management of congenital heart disease with pulmonary hypertension. To investigate the relationship between intravascular ultrasound (IVUS) findings and the Heath-Edwards (H.E.) grade of human pulmonary arteries, 40 pulmonary arterial segments from 17 autopsies and 5 patients with pulmonary hypertension were evaluated using a high-frequency IVUS imaging system. Histological observations were carried out at the same sites that were examined with IVUS and at the distal pulmonary arterioles of the same branches. The subjects were subdivided into 3 groups-group I: 7 patients with pulmonary hypertension (20 segments); group II: 10 patients without pulmonary hypertension (20 segments); and group III: 5 patients with pulmonary hypertension who were studied in vivo. All 20 segments from group I had a three-layered appearance, and 3 patients with H.E. grade < 3 had an increased thickness of the echolucent zone due to media hypertrophy without an intimal reaction. In contrast, IVUS findings from patients with severe pulmonary hypertension (H.E. grade > or = 3) showed an increased thickness with a bright inner layer due to intima hyperplasia. Evidence for a plaque-like lesion was defined in one patient with severe pulmonary hypertension. The percentage of wall thickness derived from IVUS was significantly correlated with that determined by histological examination in group I. The pulmonary artery walls in group II had a one-layer appearance. Similar IVUS findings were obtained from the in vivo study regardless of whether pulmonary hypertension was present. These findings indicate that the IVUS may be an unique technique for evaluating the morphology of the pulmonary artery or arteriole in pulmonary hypertension and may provide objective and quantitative evaluation without a lung biopsy.

Adolescent↗
PubMed1994

Expression of a functional endothelin (ETA) receptor in human meningiomas.

Endothelin (ET) receptor subtypes (ETA and ETB) in human meningiomas were characterized using quantitative receptor autoradiography. A single class of high-affinity 125I-ET-1 binding sites was localized in all meningioma tissue studied (dissociation constant: 2.4 +/- 0.3 nM, maximum binding capacity: 319 +/- 66 fmol/mg (mean +/- standard error of the mean for 13 tumors)). Unlabeled ET-1 showed a strong affinity for 125I-ET-1 binding to tissue sections of the tumors with a 50% inhibiting concentration (IC50) of 2.9 +/- 0.7 x 10(-9) M, whereas ET-3 showed a much lower affinity (IC50: 8.4 +/- 2.5 x 10(-6) M). Sarafotoxin S6c, a selective agonist for the ETB receptor, could not compete for 125I-ET-1 binding to meningiomas. Endothelin-1 significantly stimulated deoxyribonucleic acid (DNA) synthesis in a dose-dependent manner in cultured human meningioma cells. In contrast, no significant stimulation of DNA synthesis occurred with an S6c concentration up to 10(-7) M. Pretreatment of the meningioma cells with pertussis toxin, a bacterial toxin that adds adenosine 5'-diphosphate-ribose to the alpha subunit of guanine nucleotide binding (G) proteins such as Gi or G(o), induced a concentration-dependent reduction in ET-stimulated DNA synthesis in meningioma cells, but did not affect the epidermal growth factor-induced DNA synthesis. These observations suggest that the ETA receptor is predominantly expressed in human meningioma tissue and that ET may act as a growth factor on the meningioma cells by interacting with the ETA receptor and by pertussis toxin-sensitive mechanisms.

Adolescent↗
PubMed1994

[Hearing loss following discharge from the NICU].

We experienced 10 pediatric cases born between November of 1988 and November of 1992, whose ABR were normal at the time of discharge from the NICU, who subsequently developed hearing impairment. These children underwent thorough evaluations and the causes of their hearing loss are discussed herein. All 10 were born at full term, birth weights ranged from 2500g to 3826g, and all had severe cardiovascular and/or pulmonary disorders. Eight of the 10 had persistent pulmonary hypertension of the newborn (PPHN). During the four year period in which these 10 infants were born, a total of 25 PPHN cases were diagnosed in our NICU, i.e. the rate of hearing loss in PPHN infants was 32% (8/25). All 10 infants were intubated and maintained on mechanical ventilation for an average of 30 days. Five cases also required high frequency oscillation and six received extracorporeal membrane oxygenation (ECMO). During the same time period there were only eight surviving ECMO cases such that the rate of hearing loss was 75% (6/8). All 10 were treated with an aminoglycoside, furosemide and a muscle relaxant. As These infants are at very high risk for hearing impairment, follow-up at 6 and 12 months of age is essential.

Evoked Potentials, Auditory, Brain Stem↗
PubMed1994

[Interferon-induced retinal changes].

Fifty patients treated with interferon for chronic type C hepatitis, chronic type B hepatitis and renal cell carcinoma were examined for retinal complications. Retinal hemorrhages or cotton wool spots were observed in 23 (46%) of the patients. Retinal hemorrhages without cotton wool spots were found in 14 patients, cotton wool spots without retinal hemorrhages in 5 patients, and both hemorrhages and cotton wool spots in four patients. These findings were potentially reversible. There was one case of branch retinal artery occlusion and one case with microaneurysm. Red blood cell count decreased significantly in the patients with retinopathy compared with those without retinopathy (p < 0.05%). Patients with diabetes, hypertension, retinal arterial sclerosis, and anemia were at risk for retinopathy.

Carcinoma, Renal Cell↗
PubMed1994

[Hypopituitarism associated with empty sella after steroid pulse therapy in a patient with SLE].

A case of systemic lupus erythematosus (SLE) complicated with hypopituitarism after steroid pulse therapy is reported. A 46-years-old-female with a history of SLE starting in 1975 was admitted to our hospital in February 1991 for lupus nephritis. Steroid pulse therapy, 1000 mg methyl-prednisolone for 3 successive days as one therapy unit, was administered. Proteinuria improved remarkably, however, general fatigue and headache appeared 2 weeks after initiation of therapy. Endocrinological examination revealed hypopituitarism including the levels of TSH, FSH, GH and ACTH. The secretion of FSH and LH gradually improved after replacement therapy of dried thyroid. MRI examination of the brain revealed an empty sella. It is known that pituitary tumor, cerebrovascular accident and autoimmune lymphocytic hypophysitis cause hypopituitarism. In this case, it is unlikely that the pulse therapy may be responsible for the infarction of the anterior pituitary artery furthermore, there has been no articles describing such incidence after steroid pulse therapy. This case may be indicative of a very rare case in which the empty sella might have been exacerbated by the pulse therapy in the causation of hypopituitarism.

Drug Administration Schedule↗
PubMed1994

Vascular response to vasoactive agents in dialysed patients with chronic renal failure with and without diabetes mellitus.

Using a muscle bath technique the vascular response to KCl, noradrenaline, angiotensin II, acetylcholine, and sodium nitroprusside were evaluated in 13 patients with diabetes mellitus (DM group) and 15 nondiabetic (non-DM group) chronic renal failure patients treated with haemodialysis. There were no differences in age, duration of haemodialysis, blood pressure and the levels of plasma renin activity, noradrenaline, and parathyroid hormone between groups. After informed consent was obtained, a small piece of forearm vein was resected during the blood access surgery. The ring preparation of the blood vessel was sustained in the muscle bath filled with Krebs-Henseleit solution and the isometric tension development was recorded. All drugs produced concentration dependent responses in the ring preparations of both groups. Although there were no significant differences in Emax values for KCl- and angiotensin-II-induced contractions between groups, the value for noradrenaline in the DM group was significantly less than that in the non-DM group. Sodium nitroprusside completely relaxed the ring preparation precontracted by 10(-5) M noradrenaline. However, the response to acetylcholine in the DM group was significantly weaker than that in the non-DM group. These results suggest a reduced vascular response to noradrenaline and acetylcholine in dialysed diabetic renal failure patients, which may relate to the autonomic nervous system dysfunction.

Adult↗
PubMed1993

Altered glycosylation of beta 1 integrins associated with reduced adhesiveness to fibronectin and laminin.

The carbohydrate structures of the beta 1 integrins obtained from a mouse metastatic melanoma B16 F1 and its weakly metastatic wheat-germ agglutinin-resistant mutant Wa4-b1 were studied comparatively. The results indicated that the integrins from both cells contain high mannose-type and bi-, tri- and tetra-antennary complex-type sugar chains. No significant difference was found in the outer chain branching between both integrins, but sialylation of the sugar chains of the mutant's integrin was markedly decreased and almost all the outer chain moieties of tri- and tetra-antennary oligosaccharides of the mutant's integrin were fucosylated, resulting in the formation of X-antigenic determinants, Gal beta 1-->4 (Fuc alpha 1-->3) GlcNAc. In contrast, the integrin from parental cell contained no X-antigenic determinant. These structural differences found in the integrin are thought to account for the reduction in the metastatic potential of the mutant which also shows reduced adhesion to fibronectin and laminin as compared with the parental cell.

Animals↗
PubMed1993

Changes in monoaminergic neuronal function in the lower brain stem following subarachnoid hemorrhage induced in rats.

1. We investigated the function of monoaminergic neurons in the lower brain stem following subarachnoid hemorrhage (SAH) induced in rats, by measuring monoamine metabolites, using in vivo microdialysis techniques. 2. A dialysis probe was implanted in the nucleus tractus solitarius (NTS) and the perfusates were assayed by high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). 3. The main monoamine metabolites measured in the NTS extracellular space were 3,4-dihydroxyphenyl acetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA). 4. Monoamine metabolites in the rat NTS were nonspecifically increased, at least in the acute phase after cisternal injection of blood or saline. 5. The disappearance rates of the 5-HIAA decline and the early phase of DOPAC decline after pargyline administration (75 mg/kg, i.p.) were most rapid at 2 days after the induction of SAH, then recovered gradually. 6. These results suggest that functions of noradrenergic and serotonergic neurons in the NTS may be disturbed predominantly in the case of induced vasospasm in rats.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Regulation of biosynthesis of N-glycolylneuraminic acid-containing glycoconjugates: characterization of factors required for NADH-dependent cytidine 5'monophosphate-N-acetylneuraminic acid hydroxylation.

The hydroxylation of CMP-NeuAc has been demonstrated to be carried out by several factors including the soluble form of cytochrome b5. In the present study, mouse liver cytosol was subjected to ammonium sulfate fractionation and cellulose phosphate column chromatography for the separation of two other essential fractions participating in the hydroxylation. One of the fractions, which bound to a cellulose phosphate column, was able to reduce the soluble cytochrome b5, using NADH as an electron donor. The other fraction, which flowed through the column, was assumed to contain the terminal enzyme which accepts electrons from cytochrome b5, activates oxygen, and catalyses the hydroxylation of CMP-NeuAc. Assay conditions for the quantitative determination of the terminal enzyme were established, and the activity of the enzyme in several tissues of mouse and rat was measured. The level of the terminal enzyme activity is associated with the expression of N-glycolylneuraminic acid in these tissues, indicating that the expression of the terminal enzyme possibly regulates the overall velocity of CMP-NeuAc hydroxylation.

Animals↗
PubMed1993

Low serum apolipoprotein A-I level in patients with vasospastic angina.

The serum lipid and lipoprotein levels in 15 patients with vasospastic angina were compared with those in 33 patients with no angiographic coronary stenosis and no vasospastic angina after intracoronary acetylcholine infusion. The serum level of apolipoprotein A-I in patients with vasospastic angina (112 +/- 6 mg/dl) was significantly lower (p < 0.05) than that in patients without vasospasm (128 +/- 4 mg/dl). However, there were no differences between the two groups in the serum levels of cholesterol, triglycerides, high-density lipoprotein cholesterol, apolipoprotein A-II, and apolipoprotein B. Thus apolipoprotein A-I may play some role in the prevention of vasospastic angina.

Adult↗