Search PubMed⌕ Search

Biomedical subjects

M Kawada

Publications and source records attributed to M Kawada.

At least 73 records · Page 4Linked to original sources
PubMed1996

[A case of a univentricular heart developed subaortic stenosis after fontan operation].

The patient was a seven-old-boy with univentricular heart of left ventricular morphology with transposition of the great arteries and coarctation of the Aorta. Pulmonary artery banding and coarctactomy (subclavian flap method) were performed as prior surgery during infancy and significant subaortic stenosis (SAS) was not identified before or immediately after Fontan operation. SAS was suspected in an ejection murmur that developed without symptoms two years and five months after Fontan operation. It became clear that the SAS was caused by both restrictive ventricular septal defect and narrowing of outlet chamber (right ventricle). Surgery was performed with myectomy in the outlet chamber, enlargement of ventricular septal defect and a patch enlargement of the right ventricle outflow tract for relief of the SAS. Postoperative pressure gradient across the subaortic component was decreased, however, valve regurgitation remained grade I to II. The mechanisms of SAS after Fontan operation are related to hypertrophy of the subaortic component that incorporates the infundibulum and trabeculae. Careful morphological investigation is essential in patients with risk factors for SAS Mild deterioration of the ventricular compliance due to progressive SAS may result in reduction of the cardiac function and patient's quality of life. Adequate surgical treatment to relieve the SAS is considered essential before and after Fontan operation.

Aortic Coarctation↗
PubMed1996

[A case report of surgical treatment for left ventricular papillary fibroelastoma].

A case of surgical treatment for left ventricular papillary fibroelastoma was reported. The patient was 75-year-old male who was admitted with complete A V block. Transesophageal echocardiogram revealed a mobile rounded mass (15 mm x 15 mm) in the LV attached to the IVS. On the basis of this echo finding, operation was performed. Under cardiopulmonary bypass, an incision was made in the ascending aorta and the tumor was successfully removed through the aortic valve. The postoperative course was uneventful. To our knowledge, our case is the 10th surgical case in the Japanese literatures.

Aged↗
PubMed1996

Free thyroxine concentrations in serum measured by equilibrium dialysis in chronic renal failure.

The serum concentration of free thyroxine (FT4) is often low in patients with chronic renal failure (CRF) with low serum concentrations of triiodothyronine (T3). We evaluated the serum FT4 concentration by using both an equilibrium dialysis RIA kit (D-FT4) and a labeled-antibody kit (M-FT4) in two different groups of CRF patients, undergoing chronic hemodialysis (HD, n = 145) or not (non-HD, n = 30), and in a group of normal healthy subjects (n = 58). Thyroid peroxidase antibodies and thyroglobulin antibodies were not detected in any patient. Serum FT4 concentrations (mean +/- SD, pmol/L) by the D- and M-FT4 assays were, respectively, 21.5 +/- 4.6 and 16.6 +/- 2.0 in the healthy subjects, 17.8 +/- 4.3 and 13.9 +/- 3.6 in the non-HD patients, and 16.9 +/- 4.9 and 10.7 +/- 1.9 in the HD patients. By the D-FT4 assay, results for both CRF groups were significantly different from those for the healthy group (P <0.01), as were the results for each pair of groups by the M-FT4 assay (P <0.01). FT4 values were reported as being within the healthy reference range by D-FT4 in 73 of 113 HD subjects who had low T3 and low M-FT4 values. Serum FT4 concentrations measured by both assay kits showed a significant inverse correlation with the serum concentration of creatinine (P <0.01), but the serum concentrations of sex-hormone-binding globulin did not differ significantly among the three groups. Our results indicate that the low FT4 concentration measured by D-FT4 in patients with CRF, particularly those on HD, probably reflects the actual, mild nonthyroidal illness of renal failure.

Adult↗
PubMed1995

Suppression of in vitro invasion of human fibrosarcoma cells by a leupeptin analogue inhibiting the urokinase-plasmin system.

A leupeptin analogue, pyroglutamyl-Leu-Arg-CHO (Pyr-Leu-Arg-CHO), is an inhibitor of urokinase and plasmin, while leupeptin inhibits only plasmin. Pyr-Leu-Arg-CHO was shown to inhibit in vitro invasion of human fibrosarcoma HT1080 cells reducing cellular collagenase activity. Pyr-Leu-Arg-CHO suppressed the invasion of the cells in a Boyden chamber assay with an IC50 of 12 micrograms/ml. Addition of plasminogen to HT1080 cells increased the type IV collagenase activity, and Pyr-Leu-Arg-CHO inhibited this activation of the collagenase with an IC50 of 3 micrograms/ml. Leupeptin inhibited both the invasion and collagenase activation at higher concentrations than that of Pyr-Leu-Arg-CHO. The gelatin zymography of the conditioned medium revealed that a new gelatinolytic band, possibly an activated form of MMP-2, appeared by the addition of plasminogen. The activation of MMP-2 was also inhibited strongly by Pyr-Leu-Arg-CHO. These results indicate that Pyr-Leu-Arg-CHO suppresses the in vitro invasion by preventing the activation of type IV collagenase through inhibition of the urokinase-plasmin system.

Amino Acid Sequence↗
PubMed1995

Induction of erythroid differentiation in leukaemic K562 cells by an S-adenosylhomocysteine hydrolase inhibitor, aristeromycin.

We have isolated an unusual nucleoside, aristeromycin, from the culture filtrate of Actinomycetes as a compound that induces normal morphology in v-ablts-NIH3T3 cells. Aristeromycin also induced erythroid differentiation in abl-expressing human chronic myelogenous leukaemia K562 cells. It did not affect the amount of Abl or the Abl-associated tyrosine kinase activity in either v-ablts-NIH3T3 or K562 cells. As a potent inhibitor of S-adenosylhomocysteine hydrolase, aristeromycin inhibited methylation of phosphatidylethanolamine to form phosphatidylcholine in K562 cells. Among aristeromycin analogues, the activity to inhibit S-adenosylhomocysteine hydrolase was paralleled with the induction of erythroid differentiation. Thus, aristeromycin inhibits abl functions indirectly, possibly by inhibiting biological methylations.

3T3 Cells↗
PubMed1995

Truncus arteriosus with interrupted aortic arch: successful correction using autologous flap.

A newborn baby with type II truncus arteriosus and type B interrupted aortic arch was successfully treated by creating a pulmonary tract using autologous flap made from truncal wall without excision of the pulmonary artery and by reconstructing the aortic arch with direct anastomosis. This method provided excellent hemodynamics with wide reconstruction of the pulmonary tract without conduit.

Anastomosis, Surgical↗
PubMed1995

Eosinophilic neuronal inclusions in the thalamus of ageing B6C3F1 mice.

The age-related incidence of thalamic neuronal inclusions in the brains of aged B6C3F1 mice and their histopathological and ultrastructural features were studied. Round to oval or rod-shaped eosinophilic inclusions, which were frequently observed in the neurons of the thalamic area, were stained positively with phosphotungstic acid haematoxylin. The inclusions were detected first at 32 weeks of age and the incidence and severity were higher in older animals, all of the mice being affected after 58 weeks of age. Ultrastructurally, the inclusions appeared as sheaves of parallel osmiophilic filaments in the perikaryon of the neurons in the thalamus. Thus thalamic neuronal inclusions in mice seem to be age-related, but their significance remains unclear.

Aging↗
PubMed1995

Inostamycin, an inhibitor of P-glycoprotein function, interacts specifically with phosphatidylethanolamine.

The mechanism of inostamycin action was further studied. When multidrug-resistant KB-C4 cells were preincubated with inostamycin for 30 min, the accumulation of [3H]vinblastine was increased for as long as 48 h thereafter. Inostamycin inhibited azidopine binding to P-glycoprotein, even after KB plasma membranes had been preincubated with inostamycin and washed. Carbon 14-labeled inostamycin bound to KB plasma membranes irreversibly, but the binding capacity did not parallel the amount of P-glycoprotein in three KB cell lines. Inostamycin was found to interact specifically with purified phosphatidylethanolamine. These results suggest that inostamycin can inhibit P-glycoprotein irreversibly by binding to plasma membranes irreversibly through phosphatidylethanolamine.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Polymorphism of the angiotensin converting enzyme gene and clinical aspects of IgA nephropathy.

To investigate the relationship between the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene and the onset and progression of IgA nephropathy, we studied this polymorphism in 48 patients (21 males and 27 females) with IgA nephropathy and 104 normal controls (51 males and 53 females) using the polymerase chain reaction method. There was no difference in either the genotype or allele frequency of the I/D polymorphism between the patients and normal controls (D allele frequency; 0.303 and 0.325, respectively). But, the mean slope of the reciprocal of the serum creatinine concentration was significantly steeper (p < 0.05) in the patients with the D allele (-0.0104 +/- 0.007 dl.mg-1.month-1) than those without the D allele (-0.0055 +/- 0.008 dl.mg-1.month-1). The mean percentage of the glomeruli with sclerosis or segmental lesions obtained from each renal biopsy specimen was significantly larger (p < 0.02) in the patients with the D allele (49.5 +/- 17.8%) than in those without (33.3 +/- 22.9%). These results suggest that 1. the ACE gene polymorphism is not related to the onset of IgA nephropathy, but 2. the progression of IgA nephropathy may be influenced by the polymorphism which may be involved in glomerular hypertension.

Adult↗
PubMed1994

Adamantane as a brain-directed drug carrier for poorly absorbed drug. 2. AZT derivatives conjugated with the 1-adamantane moiety.

Five AZT (azidothymidine) prodrugs conjugated with the 1-adamantane moiety via an ester bond were synthesized to improve the transport of AZT into the central nervous system (CNS). In in vitro degradation studies with rat and human plasma, it was demonstrated that the prodrugs were degraded enzymatically and converted quantitatively to their parent drug. AZT. As assessed by octanol-buffer partitioning, the prodrugs were much more lipophilic than AZT and were expected to penetrate the blood-brain barrier (BBB) readily. In in vivo studies, in which the prodrugs were administered intravenously to rat, the prodrugs in brain tissue were detected at 7-18 times higher concentrations than AZT in spite of the negligible amount of the prodrug in the cerebrospinal fluid. These results indicate that the introduction to AZT of the 1-adamantane moiety results in the enhancement of the BBB penetration. This pharmaceutical approach would be beneficial for the efficient treatment of the CNS infection by human immunodeficiency virus.

Adamantane↗
PubMed1994

Spontaneous vascular mineralization in the brains of cows.

The frequency of occurrence and the characteristics of vascular mineralization in the brains of cows were studied. Mineralized lesions were found in the pallidal arteries in eight of 13 cows. They appeared as basophilic deposits in the arterial walls, were sheath-like or tubular in shape, and were accompanied by intimal oedema or fibrous thickening. The deposits were positive for periodic acid-Schiff, von Kossa's, alizarin red and Berlin blue stains. Elemental analysis revealed the presence of large amounts of phosphorus, calcium and zinc, as well as small amounts of iron, copper and sodium.

Animals↗
PubMed1994

Spontaneous aortic arteriosclerosis in layer chickens.

Aortas of 21 grower chickens (both sexes) aged 30-130 days and of 51 layer hens aged 500 days were examined histopathologically. Aortic sclerotic lesions were classified histopathologically into six stages. As early as 30 days, the abdominal aortas of growers had cellular-fibrous plaques that became more severe with advancing age. The majority of the abdominal aortas of all the 500-day-old layers had a conspicuous increase of collagen fibres, with atheromatous lesions in 23 (45.1%). These sclerotic changes were most severe in the distal aortas.

Animals↗
PubMed1994

Noninvasive quantitative evaluation of the morphology of the major pulmonary artery branches in cyanotic congenital heart disease. Angiocardiographic and echocardiographic correlative study.

BACKGROUND: Precise noninvasive evaluation of pulmonary artery (PA) morphology is extremely important for medical and surgical management of patients with cyanotic heart disease. In this study, the accuracy of two-dimensional echocardiography combined with color Doppler flow mapping to assess the size, stenosis, and atresia of the major PA branches was examined using a new parasternal approach. METHODS AND RESULTS: With the use of right and left high parasternal windows, we visualized each of the major portions along the right (R-PA) and left (L-PA) pulmonary arteries in 45 of the 47 examinations (96%) in 38 patients with cyanotic heart disease. The patients were between 13 days and 20 years old (mean age, 2.9 years). The internal diameters of the major PA branches were measured at three points along the R-PA (the proximal, mid, and distal portions) and at the proximal and distal portions on the L-PA in systole by both two-dimensional echocardiography and angiography. In addition, the diameter of the stenosis in the PA branch was measured. These PA values as determined by two-dimensional echocardiography correlated well with those obtained by angiography (r = .95 to .97). By two-dimensional echocardiography with color Doppler flow mapping, 17 of 19 lesions with stenoses or atresia of the major PA branches were predicted as defined by angiography (sensitivity, 89.5%; specificity, 100%). Differences between the distal parts of the L-PA and R-PA of > 30% in diameter were determined by angiography in 15 examinations and by two-dimensional echocardiography in 12 examinations (sensitivity, 80%; specificity, 97.4%). CONCLUSIONS: Our technique permits noninvasive evaluation of the size, stenoses, and atresia of the major portions of the PA branches in patients with cyanotic heart disease both before and after surgery.

Angiocardiography↗
PubMed1994

Ameloblastic fibro-odontoma in the mandibular incisor of a cow.

Odontogenic neoplasm was found in the mandibular incisor area of a 3-year-old Japanese black ox. Macroscopically, the cut surface was white and firm with streaks of hard tissue. Histologically, the tumor was composed of enamel organ structures with odontogenic hard tissue in fibromatous areas. It was diagnosed as ameloblastic fibro-odontoma. The absence of the 4th permanent incisor confirmed by radiography and microscopic examination strongly suggests that this tumor has been originated from the tooth germ tissues of the permanent left 4th incisor.

Animals↗
PubMed1994

[A new liver support system composed of functional human cells and a radial-flow bioreactor].

An artificial liver will be useful for the treatment of acute hepatic failure and a bridge of liver transplantation. The current reports suggest that the hybrid type of artificial liver composed of functional human liver cells and a bioreactor is practical for clinical use. In the present study, we succeeded high density culture on a large-scale of human functional hepatoma (JHH-7) using a newly developed radial flow packed-bed bioreactor. Since the shear stress of this bioreactor is lower than the other type, high density culture without cell damage is possible. JHH-7 cells produced large amounts of human albumin and other liver specific proteins, and then have the function of ammonia metabolism in the system. This study suggests that a radial flow bioreactor will be developed as a new type of artificial liver.

Albumins↗
PubMed1994

[A case of IgA nephropathy associated with psoriasis vulgaris].

Nephrotic syndrome due to IgA nephropathy was found in a 45-year-old man with psoriasis vulgaris. He was first diagnosed as psoriasis vulgaris at 20 years age and had exhibited proteinuria since 37 years of age. Recently, he developed nephrotic syndrome with unfavorable progression of psoriasis. The conditions of psoriasis and nephrotic syndrome were consistently parallel, and both diseases responded to corticosteroid therapy. The specimens from renal biopsy showed mesangial proliferative glomerulonephritis and sclerosis with mesangial deposition of IgA. Therefore, we diagnosed this case as IgA nephropathy. Twelve cases with chronic glomerulonephritis associated with psoriasis vulgaris have been published. All biopsied specimens from these cases showed mesangial deposition of IgA. Immune abnormalities have been reported in both diseases. The pathogenesis of psoriasis vulgaris and IgA nephropathy may be related through an immune mechanism.

Adult↗