Biomedical subjects

Y Toyoda

Publications and source records attributed to Y Toyoda.

At least 91 records · Page 5Linked to original sources

PubMed1999

Usefulness of cardiopulmonary bypass in reconstruction of inferior vena cava occupied by renal cell carcinoma tumor thrombus.

UNLABELLED: Aggressive surgical treatment in renal cell carcinoma is still controversial. The aim of this paper is to assess inferior vena caval (IVC) reconstruction for suprahepatic vena caval renal cell carcinoma (RCC) tumor thrombus. Twelve patients with suprahepatic vena caval thrombus from renal cell carcinoma who underwent surgical repair with cardiopulmonary bypass were evaluated. The vena caval defect was reconstructed by direct suture, patch repair, or graft replacement. Of 12 patients undergoing partial cardiopulmonary bypass, tumor thrombus extended to the junction of the hepatic vein in three patients and to the right atrium in one. Tumor thrombus was removed manually or with balloon catheter. Tumor thrombus in the right atrium was removed during electrical ventricular fibrillation. Repair of the IVC was performed by direct suture of the IVC wall in two patients, patch repair with expanded polytetrafluoroethylene (EPTFE) graft in seven, and graft replacement with an EPTFE graft in three. There were no operative deaths and the only postoperative complication was one patient death from pulmonary emboli. The four patients with nonlocalized disease died within 2 years, but four patients lived for more than 3 years postoperatively. Survival was 37.5% at 3 years and 18.8% at 5 years by the Kaplan-Meier's method. CONCLUSIONS: (1) Partial cardiopulmonary bypass is useful for the control of bleeding when tumor thrombus in the IVC extends to the junction of the hepatic vein. (2) Nephrectomy with tumor thrombectomy of the IVC is valuable, and long-term survival is possible in patients without distant metastases or regional lymph node metastases.

Adult↗

PubMed1999

Interleukin-12, interferon-gamma and interleukin-4 gene expression in cats infected with Toxoplasma gondii.

Interleukin-12, Interferon-gamma and Interleukin-4 mRNA levels in cells of the spleen and mesenteric lymph nodes of cats following primary and secondary infection with Toxoplasma gondii were examined by a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) method. Expression of Interleukin-12p40 mRNA and Interferon-gamma mRNA was observed after primary and secondary oral infection with Toxoplasma gondii. In contrast, no expression of IL-4 mRNA in the spleen and little expression in the mesenteric lymph nodes were observed after primary infection when the cats shed oocysts, however, the expression of IL-4 mRNA observed in the cats after secondary inoculation.

Animals↗

PubMed1999

[Concomitant mitral valvuloplasty and fenestrated total cavopulmonary connection: a case report].

A seven-year-old boy with tricuspid atresia successfully underwent a fenestrated total cavopulmonary connection and mitral valvuloplasty. Preoperative cardiac catheterization showed a mean pulmonary artery pressure of 16 mmHg. Pulmonary arteriography showed poor development of the branches (PA index: 180). Echocardiography revealed mild to moderate mitral valve incompetence due to prolapse of anterior leaflet. Mitral valve was exposed through the trans-septal approach. The excess chorda length was tucked into a longitudinal split in the top of the posterior papillary muscle. Then wedge resection of the redundant segment of the anterior leaflet and bilateral annuloplasty were performed. Finally, a total extracardiac cavopulmonary anastomosis with a 6 mm fenestration was completed. Postoperative clinical course was uneventful, and he is doing well with no recurrence of mitral incompetence 1 year after the operation.

Child↗

PubMed1999

Classic Blalock-Taussig shunt in neonates.

BACKGROUND: The choice of palliative procedure for neonates with congenital cyanotic heart defects remains controversial. Several reports have questioned whether the classic Blalock-Taussig shunt is adequate in neonates, because it shows a high rate of mortality and early shunt failure. The purpose of this study is to evaluate the early and late results of classic Blalock-Taussig shunt in neonates. METHODS: From December 1981 to December 1996, 31 neonates underwent a classic Blalock-Taussig shunt. Mean age at operation was 15.9 days (range, 2 to 28 days), and mean body weight was 3214 g (range, 2229 to 4468 g). The major diagnoses were pulmonary atresia with intact ventricular septum (6 patients) and with ventricular septal defect (4), univentricular heart (6), tricuspid atresia (5), tetralogy of Fallot (4), transposition of the great arteries (3), and double outlet right ventricle (3). RESULTS: There were no early deaths. There was one early shunt failure. The patient underwent a replacement of Blalock-Taussig shunt by vascular graft on the 1st postoperative day. Two patients with non-confluent central pulmonary artery underwent a contralateral modified Blalock-Taussig shunt on the 22nd and 42nd postoperative day, respectively. There were two late deaths before the definitive repair was performed. Twelve patients required an additional shunt operation. The mean interval between the initial and the second shunt procedure was 27.7 months (range, 6 to 67 months). Ten patients underwent definitive operation and the mean interval to that procedure was 55.5 months (range, 14 to 121 months). Shunt patency was 94.7+/-5.1% at 3 years. The freedom from cardiac event (cardiac deaths or repeat shunting procedure) was 80.5+/-7.1% at 1 year and 54.9+/-9.4% at 3 years. CONCLUSIONS: The classic Blalock-Taussig shunt has a low operative mortality and has provided excellent long-term palliation in the neonate. We conclude that a classic Blalock-Taussig shunt should be considered a reasonable choice in neonates requiring a palliative procedure for congenital cyanotic heart defects.

Heart Defects, Congenital↗

PubMed1999

[A surgical case of right coronary artery-right atrial fistula complicated with postoperative myocardial infarction].

We report a 10-year-old girl with a right coronary artery-right atrial fistula and aneurysm formation. The proximal orifice was closed from the inside of the aneurysm, and the distal orifice through the right atrium under cardiopulmonary bypass. On the 9th postoperative day, myocardial infarction developed due to thrombosis in the fistula stump and the dilated coronary artery. Thrombosis may have been induced by postoperative dehydration and inadequate anticoagulant therapy. It is important to minimize a fistula stump and to strictly administer postoperative anticoagulant therapy.

Arterio-Arterial Fistula↗

PubMed1999

Partial amino acid sequence and biological characterization of elegatoxin, hemorrhagic toxin from Trimeresurus elegans (Sakishimahabu) venom.

A hemorrhagic toxin, designated Elegatoxin, was isolated from the venom of Trimeresurus elegans using HW-55, DEAE-Sephacel, CM-Cellulose and Mono S column chromatographies. The purified toxin was shown to be homogeneous by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, isoelectric electrophoresis, and Ouchterlony immunodiffusion. Elegatoxin has a molecular weight of 26,000 with an isoelectric point of 8.6. The toxin demonstrated both hemorrhagic and proteolytic activities. Hemorrhagic activity was inhibited by ethylenediaminetetraacetic acid (EDTA), ethyleneglycol-bis-(2-amino-ethylether)N,N'-tetraacetic acid (EGTA), o-phenanthroline, and N-bromosuccinimide, but not by amidinophenylmethanesulfonyl fluoride hydrochloride (APMSF). The minimum hemorrhagic dose was found to be 0.8 microgram/mouse. Elegatoxin possesses proteolytic activity as evidenced by hydrolyzing type IV collagen, actin and the A alpha, B beta, and gamma chains of bovine fibrinogen. This purified toxin contains 1 mol of zinc and 2 mols of calcium per mol of protein and a partial amino acid sequence was determined. The pathological and biochemical properties of Elegatoxin were investigated, and these results are reported in this paper.

Amino Acid Sequence↗

PubMed1999

[Influence of PEEP on left ventricular diastolic function].

We investigated the influence of PEEP on left ventricular diastolic function using the pressure-volume loops by employing a micromanometer catheter and a conductance catheter placed in the left ventricle of the eight mongrel dogs. Time constant of diastolic interval was shortened under the condition of 15 cmH2O of PEEP compared with the control value (PEEP 0 cmH2O) and the diastolic stiffness constant was prolonged under 15 cmH2O of PEEP. It was considered that the shortened time constant of diastolic interval was due to the decrease of preload. The prolongation of diastolic stiffness constant was possibly due to compression of the heart by increased intrapleural pressure. We conclude that decreased compliance of left ventricle caused by PEEP might impair the left ventricular function.

Animals↗

PubMed1999

Surgical assessment of tricuspid valve replacement for severe tricuspid regurgitation without stenosis.

Eight patients undergoing tricuspid valve replacement (TVR) for severe tricuspid regurgitation (TR) without stenosis were subjected to the study. Four patients had primary TR due to trauma, infective endocarditis, or Ebstein's anomaly, and the other 4 had secondary TR associated with mitral valve lesions. The right heart pressure as well as clinical manifestations due to right heart failure showed deteriorated values in both the primary and secondary TR groups, though pulmonary arterial pressure was higher in the latter group. In 2 patients, initial annuloplasty procedures could not reduce TR sufficiently and were instantly abandoned for TVR. These 2 patients, one with congenital and one with secondary TR, died of intractable right heart failure early postoperatively, while the remaining 6 patients are alive to date, in the New York Heart Association (NYHA) functional class I, during the follow-up period of 6-192 (mean, 104) months. The 2 patients who died had shown a longer morbid duration and a lower preoperative right ventricular systolic function indicated by stroke work to pulmonary artery resistance. This paper might suggest that an earlier surgical intervention in severe TR is recommended before the right ventricular function deteriorates.

Adolescent↗

PubMed1998

Differences in the evolutionary pattern of feline panleukopenia virus and canine parvovirus.

Canine parvovirus (CPV) suddenly appeared in the late 1970s after which it showed continuous antigenic changes. Virological and molecular genetic analyses mainly focused on feline panleukopenia virus (FPLV) were conducted in this study because FPLV is the suspected ancestor of CPV; the way in which FPLV evolves may help to explain the emergence of CPV. Analysis of escape mutants against FPLV-specific monoclonal antibody showed that viruses possessing CPV-like properties were not easily detected in FPLV virus stocks. Phylogenetic analysis revealed that the nonstructural protein 1 (NS1) and capsid protein 2 (VP2) genes of FPLV changed with time. A similar tendency, however, was not observed in the FPLV VP2 proteins. In contrast, the topology of the phylogenetic tree of VP2 proteins of CPV basically concurred with that of the VP2 genes. Analysis of the ratio of nonsynonymous and synonymous substitutions revealed that synonymous substitutions exceeded nonsynonymous substitutions in both the NS1 and VP2 genes of FPLV, even when the analysis focused on specific regions in the VP2 gene that are known to be located on the capsid surface. Comparison of the CPV VP2 genes revealed that nonsynonymous substitution was found to dominate over synonymous substitution in one specific region in the VP2 gene. These results suggested that FPLV has changed mainly by random genetic drift. In contrast, after the appearance of CPV, changes in the CPV VP2 gene appear to be partly selected by certain positive selection forces. CPV and FPLV are known to be closely related viruses genetically and biologically, but the evolutionary mechanisms of the two viruses appeared to be different.

Amino Acid Substitution↗

PubMed1998

Mitral valve replacement in a patient with an extensively calcified mitral anulus: report of a case.

We report herein the case of a patient with chronic renal failure in whom mitral valve stenosis with extensive mitral anular calcification involving the entire anulus and leaflets was successfully treated surgically. Excision of both leaflets and partial resection of the anular calcification enabled the insertion of a 23-mm St. Jude Medical prosthetic valve. The technical difficulties involved with inserting the appropriate-sized prosthetic valve in a narrowed mitral anulus with heavy calcification are discussed following this case report.

Calcinosis↗

PubMed1998

Growth of the subclavian artery and the anastomosis in Blalock-Taussig shunt: absorbable versus nonabsorbable suture.

BACKGROUND: We evaluated the growth of Blalock-Taussig shunts placed with absorbable suture by cineangiographic findings and long-term results and compared them with those in an earlier group of patients in whom we used nonabsorbable suture. METHODS: Eighty-one patients had postoperative cineangiography 1 year or more after a Blalock-Taussig shunt procedure. From September 1985 to December 1994, 40 patients (group I) underwent a Blalock-Taussig shunt procedure with the use of absorbable polydioxanone suture, and from January 1980 to August 1989, 41 (group II) underwent the same operation with nonabsorbable polypropylene suture. Cineangiograms were reviewed to assess shunt patency and growth of the subclavian arteries and the subclavian artery-pulmonary artery anastomoses. RESULTS: At the Blalock-Taussig shunt operation, mean outer diameters of the subclavian artery and the anastomosis in group I were 3.8 +/- 0.1 mm and 4.1 +/- 0.1 mm, respectively and 3.9 +/- 0.1 mm and 4.0 +/- 0.1 mm in group II. The mean inner diameters of the subclavian artery and the anastomosis measured in postoperative cineangiograms were 7.9 +/- 0.5 mm and 4.6 +/- 0.2 mm, respectively in group I and 6.6 +/- 0.4 mm and 3.1 +/- 0.2 mm in group II. The diameters of both the subclavian artery (p < 0.05) and the anastomosis (p < 0.001) were significantly greater in group I than in group II. Five years after operation, 71.1% +/- 7.4% of patients in group I and 54.8% +/- 8.0% in group II had good palliation. CONCLUSIONS: The use of absorbable polydioxanone suture has an advantage in terms of growth of the diameters of the subclavian artery and the anastomosis in a Blalock-Taussig shunt and may improve the long-term results after this shunt operation in infancy.

Absorption↗

PubMed1998

Effects of cardiomyoplasty on right ventricular filling during volume loading.

BACKGROUND: Although cardiomyoplasty (CMP) is thought to improve ventricular systolic function, its effects on ventricular diastolic function are not clear. Especially the effects on right ventricular diastolic filling have not been fully investigated. Because pericardial influences are more pronounced in the right ventricle than in the left ventricle, CMP with its external constraint may substantially impair right ventricular diastolic filling. METHODS: Fourteen purebred adult beagles were used in this study. Seven underwent left posterior CMP, and 7 underwent a sham operation with a pericardiotomy and served as controls. Four weeks later, the hemodynamic effects of CMP were evaluated by heart catheterization before and after volume loading (central venous infusion of 10 mg/kg of 4.5% albumin solution for 5 minutes). RESULTS: In the CMP group, mean right atrial pressure and right ventricular end-diastolic pressure increased significantly from 3.1 +/- 1.2 mm Hg to 6.1 +/- 2.0 mm Hg (p < 0.001) and from 4.0 +/- 1.8 mm Hg to 9.6 +/- 2.5 mm Hg (p < 0.001), respectively. Volume loading in the control group did not significantly increase either variable. Right ventricular end-diastolic volume and stroke volume did not change significantly (from 53 +/- 9.3 mL to 60 +/- 9.0 mL and from 20 +/- 2.3 mL to 21 +/- 3.2 mL, respectively) in the CMP group. In the control group, however, right ventricular end-diastolic volume and stroke volume increased significantly from 45 +/- 7.7 mL to 63 +/- 14 mL (p < 0.05) and from 18 +/- 4.3 mL to 22 +/- 4.2 mL (p < 0.05), respectively. CONCLUSIONS: These results suggest that CMP may reduce right ventricular compliance and restrict right ventricular diastolic filling in response to rapid volume loading because of its external constraint.

Albumins↗

PubMed1998

A canine model of dilated cardiomyopathy induced by repetitive intracoronary doxorubicin administration.

OBJECTIVE: A simple and reproducible large animal model of dilated cardiomyopathy has yet to be developed. This study was performed to establish a canine model of dilated cardiomyopathy. METHODS: Six closed-chest pure-bred beagles weighing 8 to 12 kg (10 +/- 1.9 kg) underwent intracoronary infusion of doxorubicin (Adriamycin). Low-dose (0.7 mg/kg) doxorubicin was infused into the left main coronary artery through a 5F Judkins catheter. Infusions were repeated weekly for 5 weeks. We evaluated the effects on cardiac hemodynamics, chamber size, the neuroendocrine system, and cardiac ultrastructure before and 1 and 3 months after five intracoronary infusions of doxorubicin. RESULTS: Three months after treatment, fractional shortening (mean +/- standard error of the mean) had decreased from 36.5% +/- 0.8% to 21.7% +/- 1.4% (p = 0.0003), and left ventricular ejection fraction had decreased from 71.0% +/- 3.3% to 36.3% +/- 5.5% (p = 0.001). The left ventricular diastolic dimension had increased from 27.8 +/- 0.9 to 35.5 +/- 0.6 mm (p = 0.003), and the left ventricular end-diastolic volume had increased from 27.5 +/- 1.8 to 38.3 +/- 1.9 ml (p = 0.015). Left ventricular end-diastolic pressure had increased from 8.5 +/- 0.9 to 14.5 +/- 1.1 mm Hg (p = 0.01), and the stroke volume had decreased from 16.7 +/- 0.9 to 11.5 +/- 0.4 ml (p = 0.001). During the same period, the plasma norepinephrine concentration also increased from 114 +/- 27.4 to 423 +/- 88.9 pg/ml (p = 0.024), and plasma atrial natriuretic peptide levels increased from 33.8 +/- 7.0 to 76.5 +/- 14.8 pg/ml (p = 0.012). Histologic changes such as myofiber atrophy and cytoplasmic vacuolation, accompanied with interstitial fibrosis, were found predominantly in the left ventricle. CONCLUSION: Repeated intracoronary infusions of doxorubicin represent a simple and reliable technique to produce dilated cardiomyopathy in the dog. This model can be used to evaluate the effects of new therapies, especially surgical treatments such as dynamic cardiomyoplasty and reduction ventriculoplasty, on dilated cardiomyopathy.

Animals↗

PubMed1998

Surgical treatment for transvenous tumor extension into the heart: four cases.

From 1984 to 1996, four patients with transvenous intracardiac tumor extension underwent operations in the Kobe University Hospital. The primary tumors of two were intravenous leiomyomatoses originating from the uterus; a third patient had invasive thymoma, and the fourth patient had clear cell sarcoma of the kidney. In 1985, one patient had a curative, staged resection. One-stage operations were carried out in three patients, and all intracardiac tumors were successfully resected en bloc with the primary tumors under conditions of electrical ventricular fibrillation and mild hypothermia. Combined venous reconstructions were necessary for en bloc resection in three cases. Two patients with malignancy received postoperative chemoradiotherapy, and all four patients were discharged uneventfully from our hospital. We consider radical resection with curative intent only for patients with tumors extending into the heart. In these cases, a one-stage operation is preferable, and electrical ventricular fibrillation with mild hypothermia is a recommended method of circulatory assist because of its simplicity.

Adult↗

PubMed1998

Unrelated umbilical cord-blood stem cell transplantation: a report from Kanagawa Cord Blood Bank, Japan.

Umbilical cord-blood (CB) has been used as a source of hematopoietic stem cells in pediatric patients with sibling donors. As a result of the success with CB transplantation from sibling donors, pilot programs for the banking of unrelated donor CB were initiated in the organization of Kanagawa Cord Blood Bank, Japan in 1995. As of December 1997, unrelated donor CB was used to reconstitute hematopoiesis in seven patients aged 0.7-12.8 years, weighing 7-36 kg with high-risk leukemia (n = 5), myelodysplastic syndrome (n = 1), and immunodeficiency syndrome (n = 1). Engraftment of CB was achieved in six patients. The absolute neutrophil count reached 500/microliter in a median of 27 days; a platelet count of 20,000/microliter was reached by a median of 64 days in three patients who could be evaluated. Five patients are currently surviving. Grade I GVHD developed in three patients and grade III in one patient; no GVHD developed in three patients. Although only a small number of patients have been studied and the period of observation is too short to determine long-term survival, HLA-matched or HLA-mismatched CB from unrelated donors can provide an alternative source of hematopoietic reconstitution for clinical transplantation.

Blood Banks↗

PubMed1998

Fatal obstructive lung disease after haploidentical sibling cord blood transplantation.

We report the case of a patient with fatal obstructive lung disease after an HLA-haploidentical sibling cord blood transplant (CBT), with severe acute GVHD. A 2-year-old girl developed expiratory air trapping gradually with acute and chronic GVHD after CBT for the treatment of ALL. Anti-CMV and immunosuppressive therapy were ineffective, and the patient died of progressive respiratory acidosis. Necropsy of the lung revealed severe bronchiolitis obliterans with cytomegalic inclusion cells in the granulation tissues of the bronchiolitis. Thus, immunologic and GVHD problems can occur even in CBT.

Bronchiolitis Obliterans↗

PubMed1998

Genomic structure of the bovine PrP gene and complete nucleotide sequence of bovine PrP cDNA.

The present authors previously reported the nucleotide sequence of the 5' half of a cDNA encoding bovine prion protein (PrP) and the genomic structure of the bovine PrP gene encoding the 5' -untranslated region. Here they report the extent of intron 2 of the bovine PrP gene and the nucleotide sequence of the 3' half of bovine PrP cDNA that had not been determined before. This newly sequenced 3' half of the bovine PrP cDNA consisted of 2149 bp. The entire 3'-untranslated region (3'-UTR) was found to be encoded by a single exon, exon 3. One nucleotide polymorphism was found in the 3'-UTR. The length of intron 2 was estimated to be about 14 kbp. The structure of bovine PrP gene can be defined by combining the present results and previous reports on the bovine PrP gene.

Animals↗

PubMed1998

Cyclodextrin removes cholesterol from mouse sperm and induces capacitation in a protein-free medium.

Cyclodextrin, which stimulates cholesterol efflux from cells, was examined for its ability to induce capacitation of mouse spermatozoa. A chemically defined, protein-free medium was used for in vitro fertilization of cumulus-free mouse eggs. Fertilization did not occur in modified Krebs-Ringer bicarbonate medium (TYH) supplemented with 1 mg/ml polyvinylalcohol instead of BSA. However, fertilization was observed when spermatozoa were preincubated with methyl-beta-cyclodextrin (MBCD); fertilization rates increased dose-dependently from 0.25 to 0.75 mM MBCD. The fertilization rate decreased when 0.75 mM MBCD was added to both preincubation and fertilization media versus only the preincubation medium (21% vs. 53%); in sharp contrast, fertilization increased when 4 mg/ml BSA was present in both of the media versus the preincubation medium only (66% vs. 25%). At 0.75 mM, 2-hydroxy-beta-cyclodextrin had a lower ability to capacitate spermatozoa in vitro than MBCD (14% vs. 41%). Eggs fertilized by spermatozoa treated with MBCD (0.75 mM) developed to blastocysts (45%, 36 of 80) when cultured in KSOM. When 160 fertilized eggs were transferred to ICR recipients, 62 live offspring were born. After incubation of mouse spermatozoa for 90 min in 0.75 mM MBCD in TYH medium, the cholesterol content of the spermatozoa was significantly (p < 0.01) lower than that of the control (2.27 +/- 0.09 vs. 4.13 +/- 0.09 nmol unesterified cholesterol/10(7) sperm; mean +/- SEM, n = 5). The proportion of capacitated (B pattern) spermatozoa determined by chlortetracycline fluorescence was higher with MBCD treatment for 90 min than for the control (45% vs. 15%; p < 0.01). The proportion of acrosome-reacted (AR pattern) spermatozoa was not different between MBCD treatment and the control. Therefore, MBCD increased capacitation rather than the acrosome reaction of spermatozoa.

Animals↗