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Biomedical subjects

M Kawada

Publications and source records attributed to M Kawada.

At least 109 records · Page 6Linked to original sources
PubMed1991

[A case report of Konno procedure for Ebstein's anomaly with subaortic stenosis after Hardy procedure and repair of coarctation and VSD].

A rare case of Ebstein's anomaly with coarctation and VSD is reported. Severe subaortic stenosis and LV dysfunction were progressed after PA banding and coarctation repair at four months old and Hardy procedure and VSD closure at five month old. Konno procedure was successfully performed with SJM 21A at one year and nine months old. Since coarctation type VSD may cause subaortic stenosis after its closure due to posteriorly deviated infundibular septum, anterosuperior margin of VSD would occasionally better to be eliminated at the time of VSD closure. This is the youngest one of Konno procedure to our knowledge.

Aortic Coarctation↗
PubMed1991

[Hemodynamic changes and ventricular function before and after Fontan procedure for univentricular heart].

Ventricular function and hemodynamic parameters before and after Fontan operation were studied in patients with univentricular heart (UVH) of left ventricular (LV) type (9 cases, ages: 6-66, mean 13 years) and right ventricular (RV) type (13 cases, ages: 6-17, mean 9 years) without atrioventricular valve regurgitation. The preoperative ejection fraction (EF) was poor and only 44% of LV type and 23% of RV type met the Choussat's criterion (EF greater than or equal to 60%). There were 2 hospital deaths each in LV type and in RV type, but their causes could not be attributed to preoperative parameters of ventricular function. In survivors, the EF reduced from 62.9 +/- 7.0% before Fontan procedure to 43.4 +/- 12.6% after the procedure in LV type (p less than .05) and from 54.5 +/- 7.0% to 47.0 +/- 9.0% in RV type (p less than .01), although the ventricular end-diastolic pressure (EDP) also reduced from 12.7 +/- 2.7 mmHg before to 6.6 +/- 1.9 mmHg after the operation in LV type (p less than .05) and 10.4 +/- 2.6 mmHg to 5.5 +/- 2.4 mmHg in RV type (p less than .05). the ventricular end-diastolic volume (EDV) also reduced from 185 +/- 35% to 126 +/- 58% of expected normal volume in LV type (p less than .05) and 173 +/- 28% to 99 +/- 18% of expected normal volume in RV type (p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Regulatory effects of epidermal growth factor and retinol on the glucocorticoid receptor level in cultured chick embryonic skin.

When undifferentiated skin from 13-day-old chick embryos was cultured in a chemically defined medium, glucocorticoid specifically decreased the dexamethasone-binding activity of the epidermal cytosol after 1 day of culture, 3 days before it induced formation of a cornified layer over the intermediate cells of the epidermis. The binding activity reappeared after removal of the steroid from the medium. This reappearance was inhibited by epidermal growth factor (EGF, 100 ng/ml). The Addition of 2 microM retinol resulted in a 3-fold increase in specific dexamethasone binding in the epidermal cytosol within 12 h with no change in the binding affinity. The inhibition of glucocorticoid-induced keratinization by retinol is due a to mechanism other than inactivation of the glucocorticoid receptor.

Animals↗
PubMed1990

[Pulmonary artery banding for double inlet left ventricle].

Thirteen patients with double-inlet left ventricle who had undergone pulmonary artery banding (PAB) were reviewed. At the time of PAB, the age ranged from 2 months to 3 years. Pulmonary-systemic arterial pressure ratio and pulmonary arterial mean pressure were reduced from 0.95 +/- 0.12 to 0.4 +/- 0.18, and from 57.3 +/- 11.6 mmHg to 29.9 +/- 12.7 mmHg after PAB. Pulmonary resistance showed no statistically significant change after PAB. (from 7.6 +/- 5.2 unit to 4.8 +/- 3.9 unit) Ventricular end-diastolic volume decreased from 379.9% +/- 140.0% to 275.7% +/- 118.0% after PAB. The smallest one was 170% who successfully underwent septation procedure. Ejection fraction significantly decreased from 64.5 +/- 6.1% to 56.3 +/- 7.9%. (p less than 0.005) Ventricular end-diastolic pressure showed no significant change after PAB. (from 9.2 +/- 2.8 mmHg to 9.9 +/- 2.0 mmHg) After PAB subaortic stenosis occurred in three cases and pressure gradient were 10, 20, and 85 mmHg, respectively. Seven cases, including three cases with subaortic stenosis, underwent septation procedure and all survived. Before septation, ventricular end-diastolic volume calculated as % of normal left ventricular volume ranged from 173% to 570% and pulmonary resistance ranged from 1.6 unit to 11 unit. These data suggested that the patients with double-inlet left ventricle had efficient ventricular volume and cardiac function for septation even after PAB.

Child, Preschool↗
PubMed1990

[Surgical treatment of hypoplastic left heart syndrome: a successful case report].

A successful case of Norwood operation for a 5-day-old infant with hypoplastic left heart syndrome is reported. Norwood procedure and central shunting with a 4 mm PTFE tube was performed. Cerebral and coronary artery were perfused independently during reconstruction of aorta in order to shorten the time of circulatory arrest. Post operative UCG documented un-obstructive systemic output from the right ventricle, well regulated pulmonary arterial blood flow and widely patent interatrial communication. This baby was discharged the hospital 66 days after surgery. He has been clinically well for six month after the operation.

Anastomosis, Surgical↗
PubMed1990

[Acute renal failure in a case of paroxysmal nocturnal hemoglobinuria--a review of literature in Japan].

A case of paroxysmal nocturnal hemoglobinuria (PNH) associated with acute renal failure (ARF) is described. A 57-year-old female, who had been diagnosed as having PNH in 1983 at Kochi Medical School, was admitted to our hospital in April 1989, because of ARF with dark urine after a common cold. Hemodialysis was performed 5 times for ARF, and after almost completely recovering from ARF, she was discharged. The renal biopsy showed the deposition of hemosiderin in the proximal tubular cells. We surveyed fourteen case reports of PNH associated with ARF in Japan including our case. Ten cases developed ARF after infection causing hemolytic attack. Twelve of 14 cases were treated by hemodialysis and 13 cases were reversible. The histopathology of their renal biopsies revealed the deposition of hemosiderin in the proximal tubular cells in six of seven cases and tubular necrosis in three cases. These data showed that hemolytic attack and dehydration related to infection facilitated the induction of ARF.

Acute Kidney Injury↗
PubMed1990

[Left ventricular function after Konno procedure for congenital aortic stenosis].

From February, 1984 to September, 1988, eighteen patients with congenital aortic stenosis underwent Konno procedure. There was no operative death, but one late death (5.6%). The annular diameter ranged from 9 mm to 23 mm (mean 15 mm). Preoperative left ventricular ejection fraction (LVEF) measured by cineangiography ranged from 0.59 to 0.92 (mean 0.77) and half of the patients had more than 0.80 of LVEF. Left ventricular function after the operation was evaluated at rest or during exercise by radionuclide ventriculography. Postoperative LVEF ranged from 0.59 to 0.89 (mean 0.75). Although there were no statistically significant changes between preoperative and postoperative LVEF, there was a trend that preoperative supernormal LVEF improved to normal after surgery. The response to exercise also improved in some cases after surgery. We concluded that Konno procedure can be safely undertaken with improvement of left ventricular function.

Adolescent↗
PubMed1990

Ten-year follow-up after valve replacement with the St. Jude Medical prosthesis in children.

Since 1979, 50 children, 4 months to 15 years of age, have successfully undergone cardiac valve replacement with the St. Jude Medical prosthesis (St. Jude Medical, Inc., St. Paul, Minn.). There were 24 boys and 26 girls. The valve replaced was mitral in 28 children, aortic in 15, mitral and aortic in 1, and mitral and tricuspid in 1. A left-sided tricuspid valve was replaced in 3 children. Anticoagulant therapy was maintained in all children; 40 children were treated with warfarin, whereas 10 children who underwent aortic or mitral valve replacement were on a regimen of aspirin combined with dipyridamole. The follow-up period, comprising 224 patient-years, ranged from 1 to 10 years. There were four valve-related complications: one from thromboembolism, two from valve thrombosis, and the other one from prosthetic valve endocarditis. Actuarial rate free from all valve-related complications at 10 years was 84.7%. There were four late deaths: one from valve thrombosis and the others from non-valve-related complications. Actuarial survival rate at 10 years was 90.8%. All surviving children are in functional class I, and no child so far has needed replacement of a prosthesis because of somatic growth. These results indicate that the St. Jude Medical prosthesis is a cardiac valve substitute of choice for valve replacement in children.

Actuarial Analysis↗
PubMed1990

[Surgical problems in d-TGA with VSD and PS associated with insertion of tricuspid valve chordae to the infundibular septum--the Rastelli operation by translocation of the infundibular septum].

Twelve (37.5%) out of 32 patients who underwent surgical repair of complete transposition of the great arteries (d-TGA) with ventricular septal defect (VSD) and pulmonary stenosis (PS) from 1978 to 1987 had insertion of tricuspid valve (TV) chordae to the infundibular septum, i.e. superior margin of the VSD, which precluded the ordinary Rastelli type operation. Of these 12 patients early 5 patients (ages: 2-11 mean 7 years) underwent atrial switch operations with VSD closure and pulmonary valvotomy with or without fibromyotomy, and recent 6 patients (age: 4-8, mean 6 years) underwent the Rastelli operation (3 cases) or REV (3) by translocating the infundibular septum with TV chordae to the right ventricular side of the internal conduit. None died in hospital in the former group and 1 in the latter. Pulmonary/systemic ventricular peak pressure ration (Ppv/sv) was 0.75 +/- 0.22 (mean +/- standard deviation) in the atrial switch group v. 0.49 +/- 0.08 in the Rastelli/REV group 1 month postoperatively. The higher Ppv/rv in the atrial switch group was attributed to the pressure gradient across the pulmonary outflow tract, which was 37.8 +/- 16.6 mmHg in the atrial switch v. 16.7 +/- 4.2 mmHg in the Rastelli/REV (p less than 0.05). No pressure gradient was demonstrated between left ventricle (LV) and aorta in the both groups. Pulmonary wedge pressure was higher in the atrial switch group (13.8 +/- 1.9 mmHg) than in the Rastelli/REV (10.0 +/- 2.7 mmHg) (p less than 0.05). Systemic atrioventricular (AV) valve regurgitation was noted in 2 of the atrial switch group but none in the Rastelli/REV.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1989

The X gene of hepatitis B virus induced growth stimulation and tumorigenic transformation of mouse NIH3T3 cells.

To examine the transforming potential of the X gene product of hepatitis B virus (HBV), the X-gene-containing region (referred to as the HBx region) was introduced into mouse NIH3T3 cells. Each transformed cell line expressed X-coding mRNA at a different level. A positive correlation was found between the level of X-coding mRNA and the saturation density of the cells. The HBx-transformed cell lines exhibited X protein production and tumor formation in nude mice. The function of HBV in oncogenesis may involve the continuous expression of the X-gene-coded product in the HBV DNA-integrated cells.

Animals↗
PubMed1989

Alpha-agonist modifies baroreflex vasoconstriction by a postjunctional mechanism in dogs.

1. We examined whether or not circulating alpha-agonist modified baroreflex vasoconstriction of the hindlimb, using anaesthetized dogs in which the limb was vascularly isolated and perfused with blood from a donor dog using a pulsatile pump. 2. The open-loop gain (G) of the baroreflex was estimated from changes in mean arterial pressure following mild quick haemorrhage from the aorta of the recipient dog. 3. The hindlimb perfusion pressure increased after haemorrhage due to neurogenic vasoconstriction. 4. An overall gain (Gh) of the baroreflex hindlimb vascular bed control system was estimated from the ratio of the increase in hindlimb perfusion pressure to the change in systemic arterial pressure of the recipient dog. 5. Administration of a relatively selective alpha 1-agonist with no prejunctional beta 2 stimulating action (phenylephrine) or a selective alpha 2-agonist (clonidine) to the donor dog increased its systemic arterial pressure and augmented Gh. 6. Since both drugs were administered to the donor dog and could not enter into the recipient dog, these drugs did not affect the recipient's sympathetic nervous system, including the central nervous system and afferent limb of the baroreflex system. Therefore, these drugs could modify baroreflex vasoconstriction of the hindlimb only at the junction of the efferent sympathetic nerve and the vascular smooth muscle. 7. It was concluded that postjunctional alpha-adrenoceptor stimulation augments neurogenic vasoconstriction.

Adrenergic alpha-Agonists↗
PubMed1989

Nitroglycerin relaxes canine coronary arterial smooth muscle without reducing intracellular Ca2+ concentrations measured with fura-2.

1. Changes in cytoplasmic Ca2+ concentration ([Ca2+]1) were measured simultaneously with force by a microfluorometric method using a calcium indicator, fura-2, in canine coronary arterial smooth muscle cells. 2. Depolarization by high (30-90 mM) KCl-physiological salt solution (PSS) produced concentration-dependent increases in force and [Ca2+]i. 3. The KCl-induced increase in [Ca2+]i abolished by Ca2+-free conditions and almost abolished by verapamil 10-5 M, suggesting that it was entirely due to the increased Ca2+ influx through voltage-dependent Ca2+ channels. 4. The [Ca2+]i force relationship in the presence of verapamil was not distinguishable from that of control. 5. Nitroglycerin produced a concentration-dependent, reversible contraction of the coronary artery that had been contracted by high KCl-PSS, without reduction of the increased [Ca2+]i. 6. The KCl-induced increase in [Ca2+]i was not affected by nitroglycerin and in a presence of nitroglycerin it was abolished by 10-5 M verapamil suggesting that it was caused by the influx of extracellular Ca2+. 7. The [Ca2+]-force curve was shifted to the right by nitroglycerin. 8. It is likely that nitroglycerin relaxes the coronary arterial smooth muscle b reducing the amount of myosin light chain phosphorylation even in the presence of raised [Ca2+]i produced by increased Ca2+ influx following depolarization.

Animals↗
PubMed1989

Oncogenic potential of hepatitis B virus.

The function of the X gene was clarified by examination of the transient production of hepatitis B virus (HBV) particles by transfected recombinant HBV DNA (pHBV-3 DNA) and its frameshift mutant (delta X) of the X open reading frame into hepatocellular carcinoma HuH-7 and HepG2 cells. No reduction of viral mRNAs was observed in the HuH-7 cells by the delta X mutant, whereas mRNAs underwent marked reduction in HepG2 cells. No reduction in core particle production was observed in HuH-7 cells, but in HepG2 cells reduction was considerable. To clarify the significance of the delta X mutation in the trans-acting function of the X gene in hepatoma cells, the chloramphenicol acetyl/transferase (CAT) assay was conducted. Transfection of plasmid pHBV-3 into HepG2 cells increased CAT activity of pSV2-CAT, while the delta X mutation clearly showed no stimulation of activity. On the other hand, in the HuH-7 cells, pHBV-3 exhibited no such stimulation. The trans-acting function of the X gene product in two different hepatoma cells was clearly shown to differ. Furthermore, transfection of X gene expression plasmid pKSV-HBx into mouse NIH3T3 cells increased the CAT activity of pSV2-CAT. Trans-activation was still detectable even following deletion of enhancer sequences in the pSV2CAT. The oncogenic potential of HBV is discussed with special attention to the X gene product, which may be able to activate a cellular transcription factor at the viral and cellular promotor sequences in the cells.

Animals↗
PubMed1989

[An experimental study of the use of fresh aortic valve homograft for the usage of the vena caval valve. Part 1. The evaluation of hemodynamics and cineangiographic study].

The purpose of this study is to develop a vena caval valve using the fresh aortic valve homograft. A preliminary study was performed in six dogs by interposing a cryopreserved aortic valve homograft with sinus Valsalva into SVC. After making the tricuspid regurgitation, the aortic valve homograft was closed by the regurgitant flow in the systolic phase and opened by the venous return in the diastolic phase. The preliminary study showed that the cryopreserved aortic valve homograft with sinus Valsalva was useful as a vena caval valve immediately after the implantation. Fresh aortic valve homografts were implanted in 11 dogs in the same manner. Eighteen pressure studies and cine-angiographies were performed in six dogs on 8 to 165 days after the implantation. Pressure studies showed minimal/small pressure gradients across the implanted homografts. However, cineangiography revealed appearance of regurgitation through the implanted homograft three months later. Thromboembolism was not happened in all dogs at all. Therefore, we concluded that the fresh aortic homograft with sinus Valsalva might be clinically feasible for use as a vena caval valve.

Animals↗
PubMed1989

[New selection criterion for Fontan procedure: pulmonary artery clamping test and pulmonary vascular resistance in increased pulmonary blood flow].

A new selection criterion for Fontan procedure, pulmonary artery clamping test (PACT) was developed and employed in 13 candidates for Fontan procedure. PACT was aimed to evaluate the response of pulmonary vascular bed to increased pulmonary blood flow and calculate the pulmonary vascular resistance in the increased pulmonary blood flow as a selection criterion for Fontan procedure, preoperatively. After a median sternotomy incision, an electromagnetic flow meter was employed for measuring the pulmonary blood flow (Qp) on the pulmonary trunk. By clamping the left pulmonary artery and the right pulmonary artery, right pulmonary vascular resistance and the left pulmonary resistance in the pulmonary blood flow of Qp were calculated respectively. By means of electrical analogue, right and left lungs were simulated as resistors in parallel. And the equivalent pulmonary vascular resistance Rpc was calculated as the predicted pulmonary vascular resistance in the increased pulmonary blood flow of two times Qp. Fontan procedure was performed in 9 cases with a Rpc of less than 3 unit.m2 with a successful result and no death. Postoperative cardiac index ranged from 2.6 to 3.7 L/min.m2 with a mean of 2.8 L/min.m2. Postoperative pulmonary vascular resistance ranged from 1.6 to 3.2 unit.m2. Postoperative cardiac index was correlated with postoperative pulmonary vascular resistance. And postoperative pulmonary vascular resistance was well correlated with equivalent pulmonary vascular resistance but was not correlated with preoperative pulmonary vascular resistance measured by Fick's method at the preoperative catheterization. In Fontan procedure, the pulmonary blood flow frequently increases to a certain degree postoperatively. And pulmonary vascular resistance is not a static resistance, but a dynamic resistance. Hence, in discussing a pulmonary vascular resistance as a selection criterion for Fontan procedure, the pulmonary blood flow in which the pulmonary vascular resistance stand should be taken into account. Equivalent pulmonary vascular resistance Qpc is a theoretical selection criterion for Fontan procedure and well reflects the postoperative pulmonary vascular resistance. Fontan procedure can be successfully performed with a Rpc of less than 3 unit.m2.

Adolescent↗
PubMed1989

[Pulmonary valve replacement using the right ventricle-pulmonary artery bypass without cardiopulmonary bypass].

We underwent pulmonary valve replacement using the right ventricule pulmonary artery bypass without cardiopulmonary bypass. This right heart bypass was consisted of the vascular graft and the polystyrene tube. The vascular graft was anastomosed to the main pulmonary artery and the polystyrene tube was inserted into the free wall of the right ventricle. These were connected with a cannulating magnetic flow probe. After the bypass was established, the pulmonary artery was clamped and divided. The pulmonary valves were excised and the pulmonary valve replacement was undergone with a pulmonary valve homograft. Hemodynamics during the pulmonary valve replacement was stable and the postoperative course was uneventful. One month later, the cardiac catheterization and cineangiography showed that the implanted homograft was effective sufficiently. We concluded that this right heart bypass was useful for the pulmonary valve replacement.

Anastomosis, Surgical↗