Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 469 records · Page 26Linked to original sources

PubMed1998

Successful surgical treatment of an Edwards type IIIB right aortic arch aneurysm: report of a case.

A true aneurysm of the right aortic arch which accompanies various branching characteristics is very rare. We report herein the successful surgical treatment of an elderly patient found to have an Edwards type IIIB right aortic arch aneurysm encircling and compressing the trachea. The complete right aortic arch and right subclavian artery were reconstructed through the inside of the aneurysm using selective cerebral perfusion. The patient recovered well, with no residual neurologic deficit and with resolution of the dyspnoic attacks he had suffered preoperatively.

Aortic Aneurysm, Thoracic↗

PubMed1998

Repeat tricuspid valve replacement for acquired valvular heart disease: report of a case.

A patient was admitted to our hospital for investigation of exertional dyspnea and liver dysfunction, 10 years after undergoing mitral valve replacement (MVR) and tricuspid valve replacement (TVR) using a Bjork-Shiley mechanical valve and a Carpentier-Edwards bioprosthesis, respectively. Echocardiographic examinations, magnetic resonance imaging (MRI), and cardiac catheterization subsequently revealed severe degenerative changes of the artificial tricuspid valve. Thus, a repeat TVR with plication of his enlarged right atrium that was compressing the right lung was performed. The extracorporeal circulation was adjusted so that the oxygen saturation of the hepatic vein was maintained above 50% to prevent liver damage. The patient had a good postoperative course and has encountered no further problems since his discharge from hospital.

Female↗

PubMed1998

[Surgical treatment with infarction exclusion technique and postoperative percutaneous cardiopulmonary support for a patient with ventricular septal perforation--a case report].

A 76-year-old woman was referred to our hospital because of postinfarction ventricular septal perforation (VSP). VSP occurred twelve days after acute myocardial infarction and resulted in interventricular shunt with Qp/Qs of 4.8. Because she suffered from pulmonary edema and oligouria, she underwent emergent surgical treatment after application of the intraaortic balloon pump. The infarction involved whole of right ventricle and the infero-posterior wall of left ventricle, and the location of the perforation was infero-septum with the size of 10 x 6 mm. A bovine pericardial patch was tailored in a triangular shape of approximately 7 x 7 x 5 cm. The base of the patch was sutured to the fibrous annulus of the mitral valve and medial margin of the patch was sewn to healthy septal endocardium. And the lateral side of the patch was sutured to the posterior wall of the left ventricle. Because of difficulty in weaning of the cardiopulmonary bypass, a percutaneous cardiopulmonary support system (PCPS) was inserted via femoral artery and vein with a flow support of 2.0 L/min. After 4 days support of PCPS, improvement of right ventricular function was detected by echocardiogram and PCPS was removed. While PCPS support, low dose heparin to maintain ACT level around 150 seconds was continuously administered. Any complication including bleeding and thrombosis was not remarkable. The patient was discharged on the 53th postoperative day, and is now doing well.

Aged↗

PubMed1998

[Ischemic preconditioning in the aged heart--myocardial protective effect as compared with the mature heart].

It is now well established that pre-treatment with sublethal ischemia, followed by reperfusion, will delay myocardial necrosis during a later sustained ischemic episode, termed ischemic preconditioning (IPC); this has been confirmed experimentally and clinically. However, the effects for the senescent heart differ from those of the mature heart at both functional and cellular levels which have not yet been determined. Comparisons were made between aged (> 135 weeks, n = 18) and mature (15 approximately 20 weeks, n = 8) rabbit hearts which underwent 30 min. normothermic global ischemia with 120 min reperfusion in a buffer-perfused isolated, paced heart model, and the effects of IPC on post-ischemic functional recovery and infarct size were investigated. Ischemic preconditioned hearts (n = 6) were subjected to one cycle of 5 min. global ischemia and 5 min. reperfusion prior to global ischemia. Global ischemic hearts (n = 6) were subjected to 30 min. global ischemia without intervention. Control hearts (n = 6) were subjected to perfusion without ischemia. Post-ischemic functional recovery was better in the ischemic preconditioned hearts than in the global ischemic hearts in both aged and mature hearts. However, in the aged hearts, post-ischemic functional recovery was slightly reduced compared to that of the mature hearts, and only the coronary flow was well-preserved. In the mature hearts, myocardial infarction in the ischemic preconditioned hearts (14.9 +/- 1.3%) and in the control hearts (1.0 +/- 0.3%) was significantly decreased (p < 0.01) compared to that of the global ischemic hearts (32.9 +/- 5.1%). In the aged hearts, myocardial infarction in the ischemic preconditioned hearts (18.9 +/- 2.7%) and in the control hearts (1.1 +/- 0.6%) was significantly decreased (p < 0.001) compared to that of the global ischemic hearts (37.6 +/- 3.7%). The relationship between infarct size and post-ischemic functional recovery of left ventricularpeak developed pressure (LVDP) was linear and the correlation negative, with r = -0.934 (p < 0.001) and -0.875 (p < 0.001) for mature and aged hearts respectively. The data suggest that, in the senescent myocardium, the cellular pathways involved ischemic preconditioning responses that were post-ischemic, and that functional recovery was worse as compared to that of the mature myocardium. Furthermore, the effects of post-ischemic functional recovery became consistently weaker during the control period of 120 min. reperfusion after a prolonged ischemic insult in a buffer perfused isolated rabbit model. However, the effects of infarct size limitation were well-preserved in both senescent and mature myocardia.

Aging↗

PubMed1998

[Does adenosine administration during the early reperfusion period affect ischemic preconditioning?].

We hypothesized that the adenosine administration during the early reperfusion period might affect ischemic preconditioning (IPC) and might reduce infarct size and enhance post-ischemic functional recovery. Twenty-four anesthetized rabbits underwent 30 min. normothermic global ischemia with 120 min. reperfusion in a buffer-perfused isolated, paced heart model and divided into four groups. Global ischemic hearts (GI, n = 6) were subjected to 30 min. global ischemia without intervention. Control hearts (n = 6) were subjected to perfusion without ischemia. Ischemic preconditioned hearts (IPC, n = 6) were subjected to one cycle of 5 min. global ischemia and 5 min. reperfusion prior to global ischemia. IPC + Ado hearts (n = 6) received IPC and adenosine administration (100 m mol/L) during 3 min. early reperfusion period. Post-ischemic functional recovery was better in IPC + Ado hearts as compared to GI and IPC hearts, but the effect of post-ischemic functional recovery in IPC + Ado hearts became weaker during 120 min. reperfusion after prolong ischemic insult. Infarct size were 1.0 +/- 0.3% in Control hearts, 32.9 +/- 5.1% in GI hearts, 13.8 +/- 1.3% in IPC hearts and 8.1 +/- 0.9% in IPC + Ado hearts Infarct size in IPC hearts was significantly decreased (p < 0.01) as compared to GI hearts. The reduction rate against myocardial necrosis in IPC + Ado hearts versus GI hearts was higher as compared to IPC hearts versus GI hearts (p < 0.001, IPC + Ado hearts vs GI hearts; p < 0.01, IPC hearts vs GI hearts; p = ns, IPC + Ado hearts vs Control hearts). These data suggest that adenosine administration during the early reperfusion period reinforce IPC effect and reduce myocardial reperfusion injury. Cardiomyoprotective effects of IPC and exogenous adenosine are exerted during early reperfusion after coronary occlusion in the isolated perfused rabbit hearts.

Adenosine↗

PubMed1998

Morphological findings in non-episode biopsies of kidney transplant allografts treated with FK506 or cyclosporine.

We conducted an analysis of biopsy specimens of non-episode renal allografts from patients treated with tacrolimus (FK506) or cyclosporine (CsA) to evaluate chronic drug-induced nephropathy in stable allografts. A total of 38 biopsy specimens from stable functioning renal allografts were examined. The patients had been treated with FK506 (n = 16) or CsA (n = 18) as main immunosuppressant for 0.3 to 7.4 years. Of the 38 biopsy specimens, 15 showed mild drug-induced arteriolopathy (hyalinosis or insudative change of arterioles and small arteries) with striped-form interstitial fibrosis, 10 showed minimum interstitial cellular infiltration (borderline rejection), 2 showed IgA nephropathy, 4 showed evidence of chronic rejection (transplant nephropathy) and 12 showed no abnormal findings. Of 34 renal allograft biopsy specimens with stable function, 22 (65%) showed pathological evidence of drug-induced nephropathy. There were no significant qualitative or quantitative differences between FK506- and CsA-associated nephropathy.

Biopsy↗

PubMed1998

Pancreatic pseudocyst associated with eating disorder.

We describe a patient with an eating disorder and hyperamylasemia originating from the salivary glands, who developed pancreatitis with a huge pancreatic pseudocyst. A 40-year-old woman was referred for the treatment of an eating disorder that had persisted for 9 years. She was admitted with abdominal pain, diarrhea, and nausea. She had bilateral parotid enlargement with marked elevation of total serum amylase level (3288 IU/l; normal range, 60-220) and an isolated increase of salivary isoamylase activity. After her symptoms resolved, oral intake of food was commenced. She subsequently complained of abdominal pain; this was associated with a slight elevation of serum pancreatic isoamylase and lipase levels, and a huge pancreatic pseudocyst was detected. Percutaneous drainage of the pseudocyst was successful. Endoscopic retrograde cholangiopancreatography demonstrated irregularity of the pancreatic duct. Based on these findings, the final diagnosis was parotid enlargement and acute exacerbation of chronic pancreatitis associated with a pancreatic pseudocyst in a patient with an eating disorder.

Adult↗

PubMed1998

A new quadruple therapy for the eradication of Helicobacter pylori. Effect of pretreatment with omeprazole on the cure rate.

To elucidate whether pretreatment with omeprazole decreases the cure rate of Helicobacter pylori infection with a new quadruple therapy, and thus, whether this pretreatment should not be used in clinical practice, we conducted a randomized trial. Ninety patients with chronic peptic ulcer disease and nonulcer dyspepsia, with biopsy-proven H. pylori infection were randomly assigned to the two following regimens: Group 1 (n = 45) received omeprazole 20 mg once daily for 2 weeks (days 1-14), and 500 mg amoxicillin granules and 250 mg metronidazole thrice daily, and roxithromycin 150 mg twice daily for 1 week (days 8-14), Group 2 (n = 45) received the same antibiotic treatment as group 1 for 1 week (days 1-7), in addition to omeprazole treatment for 2 weeks (days 1-14). Four weeks after the treatment ended, endoscopy was repeated, with two biopsy specimens each taken from the antrum and the corpus (total of four specimens) for a urease test, histological analysis, and culture to establish cure of infection. A patient was regarded as cured only if all three methods gave negative results for H. pylori. In the intention-to-treat analysis, 42 of 45 patients (93.3%; 95% confidence intervals [CI], 81.7%-98.6%) in group 1 were cured compared with 43 of 45 patients (95.6%; 95% CI, 84.9%-99.5%) in group 2. In the per-protocol analysis, the corresponding figures were 42/44 (95.5%; 95% CI 84.5%-99.4%) and 43/44 (97.7%; 95% CI, 88.0%-99.9%). There were no significant differences in the cure rate between the two groups on either analysis. All patients, except for one who had an allergic reaction, completed the treatment regimens. Fifty to sixty percent of the patients had no side effects while the rest had mild to moderate side effects. The new quadruple therapy consisting of omeprazole, amoxicillin, metronidazole, and roxithromycin appears suitable for use in clinical practice, as the cure rate was 95% and no severe side effects were observed. Pretreatment with omeprazole did not reduce the cure rate for this new quadruple therapy.

Adult↗

PubMed1998

A combination of preductal aortic coarctation and type B dissection: report of a case.

We present herein the case of a 39-year-old man found to have significant coarctation of the preductal aorta combined with a type B dissection, associated with Marfan's syndrome. This extremely rare pathological combination could be defined preoperatively only by a three-dimensional computed tomography scan. By means of selective cerebral perfusion, the coarctation was resected, and the total aortic arch was replaced with a Dacron graft.

Adult↗

PubMed1998

Pulmonary circulatory parameters as indices for the early detection of acute rejection after single lung transplantation.

We investigated the relationship between the changes in the pulmonary blood flow and histology during acute rejection following single lung transplantation. In single lung transplantation using adult mongrel dogs, immunosuppression with cyclosporine and azathioprine was discontinued after postoperative day 14 to induce rejection. Doppler flow probes were placed adjacent to the ascending aorta and the left pulmonary artery to measure the blood flow on a daily basis. In addition, chest roentgenograms were also examined daily. The pulmonary pressure was measured using a Swan-Ganz catheter prior to and following the induction of rejection. Open lung biopsies were performed when the left pulmonary artery flow decreased to half of the prerejection value. The pulmonary artery flow decreased to 14.3% of the aortic flow 5 days after the discontinuation of immunosuppression. The graft pulmonary vascular resistance increased significantly compared to the prerejection values (P < 0.001). This was not accompanied by any abnormalities on chest roentgenography. The histology was consistent, with marked perivascular lymphocytic infiltration with little alveolar or interstitial changes. During rejection, the increased pulmonary vascular resistance in the graft was probably the result of perivascular inflammatory cell infiltration, which was seen prior to changes on chest roentgenography. Changes in the left pulmonary artery flow and histology thus appear to be closely correlated in the early stages of acute rejection.

Animals↗

PubMed1998

Laparoscopic orchiopexy of intraabdominal undescended testis associated with congenital diaphragmatic hernia.

Laparoscopy is an advantageous method for the repair of intraabdominal undescended testis since both an abdominal exploration and vascular elongation can be effectively performed by laparoscopic assistance. A 3-year-old boy and a 1-year-old boy complaining of unilateral nonpalpable left testes were observed following previous congenital diaphragmatic hernia repairs on the day of birth. In these operations, a laparoscopic working sheath was inserted through a small supraumbilical incision. On each boy, a laparoscopically intraabdominal testis was found close to the left internal inguinal ring. In addition, a 10-mm trocar port was placed in the right lower abdominal quadrant and a 5-mm port was placed in the left lower quadrant. For the purpose of orchiopexy, the left testicular vessels were isolated over their full length. The left side of the testis was pulled through the inguinal ring to an inguinal canal divided by the abdominal wall, and then was retracted into the scrotum. The internal ring was thereafter closed externally by the fascia transversalis. Both patients are doing well, with no testicular atrophy or inguinal hernia for 1 and 2 years, respectively, after the above operations.

Child, Preschool↗

PubMed1998

Novel polymorphisms in the beta ig-h3 gene.

We found three novel polymorphisms in the beta ig-h3 gene in patients with gelatinous drop-like corneal dystrophy: (1) a substitution from CTC to CTT at codon 472 that did not alter an amino acid; (2) a substitution from GCG (Ala) to GTG (Val) at codon 480; and (3) a substitution from C to T in intron 10, three nucleotides upstream from the acceptor site of exon 11. The allelic frequencies of the C:T polymorphism at codon 472 and in intron 10 in the Japanese population were estimated to be 0.778:0.222 and 0.954:0.046, respectively. Although the codon 480 substitution was not observed in 54 unrelated healthy Japanese people, the substation did not co-segregate with the disease phenotype, suggesting that this was a rare, non-deleterious alteration.

Corneal Dystrophies, Hereditary↗

PubMed1998

Granular corneal dystrophy with homozygous mutations in the kerato-epithelin gene.

PURPOSE: To report a family with several members affected with granular corneal dystrophy Groenouw type 1. Three members of the family were affected with a severe placoid type of corneal dystrophy. To determine the relationship between gene mutations and phenotypic variations of the disease, we analyzed the kerato-epithelin gene. METHODS: The pedigree included a consanguineous marriage of two affected individuals. The three family members affected with a severe form of corneal dystrophy were offspring of these parents. However, the phenotype of other affected family members was typical granular corneal dystrophy. We isolated genomic DNA from leukocytes of the family members. Exons of the keratoepithelin gene were amplified by the polymerase chain reaction and were analyzed using the single-strand conformation polymorphism technique. Mutations were identified by direct sequencing method and restriction digestion analysis. RESULTS: The three severely affected family members exhibited homozygous mutations at codon 555 (arginine to tryptophan) in the keratoepithelin gene, whereas those with typical granular corneal dystrophy had the heterozygous mutation at the same codon. Unaffected family members did not have the mutation. CONCLUSIONS: We determined that the severe phenotype of granular corneal dystrophy is caused by homozygous mutations in the kerato-epithelin gene. Clinical manifestation of the severe phenotype is a placoid type of corneal dystrophy and early recurrence after surgery. Granular corneal dystrophy appears to be the first ophthalmic disease in which homozygosity for a dominant allele has been genetically identified.

Adolescent↗

PubMed1998

Two distinct kerato-epithelin mutations in Reis-Bücklers corneal dystrophy.

PURPOSE: Two patients were diagnosed with Reis-Bücklers corneal dystrophy (RBCD), although the pattern and severity of corneal opacification differed. To see whether there was a genetic basis for these phenotypic variations, we analyzed beta ig-h3, the gene that codes for kerato-epithelin and that contains a mutation (Arg555Gln) that causes RBCD. METHODS: A 30-year-old man with honeycomb-shaped subepithelial opacities in his central cornea and a 25-year-old man with progressive subepithelial geographic opacities were both considered to have RBCD. We isolated genomic DNA from leukocytes of the two patients and their family members and screened for an Arg555Gln kerato-epithelin mutation. Then we analyzed all exons of the gene using the single-strand conformation polymorphism (SSCP) technique to search for any other kerato-epithelin mutations. RESULTS: The patient with honeycomb-shaped opacities had an Arg555Gln kerato-epithelin mutation that caused his RBCD, whereas the patient with geographic opacities did not; instead, he had a new kerato-epithelin mutation (Arg124Leu), which cosegregated with his family members. CONCLUSIONS: The variant of RBCD characterized by honeycomb-shaped opacities is caused by an Arg555Gln kerato-epithelin mutation. On the other hand, a new kerato-epithelin mutation, Arg124Leu, was found to cause the RBCD variant characterized by recurrent epithelial erosions and progressive geographic subepithelial opacification. Codon 124 is a hot spot for kerato-epithelin mutations, where the mutations responsible for three autosomal dominant corneal dystrophies--lattice type I (Arg124Cys), Avellino (Arg124His), and the variant of RBCD with geographic rather than honeycomb opacities (Arg124Leu)--are located.

Adult↗

PubMed1998

Left ventricular volume predicts postoperative course in patients with ischemic cardiomyopathy.

BACKGROUND: The left ventricular end-systolic volume index (LVESVI) helps to predict postoperative left ventricular function in patients with ischemic cardiomyopathy. METHODS: We retrospectively assessed the ability of preoperative variables to predict death and the development of postoperative congestive heart failure in 41 patients with a preoperative ejection fraction of less than 0.30. RESULTS: A preoperative LVESVI of greater than 100 mL/m2 was identified as an independent predictor of death by Cox's proportional hazards model. Diabetes and a preoperative LVESVI of greater than 100 mL/m2 were independent predictive risk factors for the development of postoperative congestive heart failure. Postoperative congestive heart failure developed in 2 of the 23 patients (8.7%) who had a preoperative LVESVI of less than 100 mL/m2 and in 10 of the 16 patients (62.5%) who had a preoperative LVESVI of greater than 100 mL/m2. The actuarial survival rate during follow-up in patients who had a preoperative LVESVI of less than 100 mL/m2 was significantly greater than that in patients who had a preoperative LVESVI of greater than 100 mL/m2. The actuarial rate of freedom from congestive heart failure during the follow-up period also was greater in patients who had a preoperative LVESVI of less than 100 mL/m2. CONCLUSIONS: Our results suggest that the preoperative LVESVI predicts the development of postoperative congestive heart failure and the actuarial survival rate in patients with ischemic cardiomyopathy.

Aged↗

PubMed1998

Impact of retrograde cerebral perfusion with posterolateral thoracotomy on distal arch aneurysm repair.

BACKGROUND: Repair of distal aortic arch aneurysms is difficult to accomplish through a median sternotomy or left thoracotomy, and stroke and respiratory disorders often become lethal complications with the use of circulatory arrest. We investigated the use of retrograde cerebral perfusion with a posterolateral thoracotomy in the repair of distal arch aneurysms. METHODS: Thirty-eight patients underwent repair of a distal arch aneurysm. They were divided into three groups according to the method of surgical repair used. Sixteen patients (group I) underwent proximal anastomosis of the graft with the use of an aortic cross-clamp. Eight patients (group II) underwent open proximal anastomosis with the use of retrograde cerebral perfusion (oxygenated blood perfusion through a superior vena cava cannula) and a median sternotomy and anterolateral thoracotomy. Fourteen patients (group III) also underwent open anastomosis with the use of retrograde cerebral perfusion (cerebral perfusion through blood returned to the right atrium with the patient in the Trendelenburg position) and a posterolateral thoracotomy. RESULTS: The operative mortality rate in group I was 25.0%; 4 of 16 patients died of stroke, myocardial infarction, and intestinal necrosis. In group II, 3 of 8 patients (37.5%) died of respiratory failure and aortic dissection. In group III, only 1 of 14 patients (7.1%) died, as a result of heart failure. CONCLUSIONS: The use of retrograde cerebral perfusion with a posterolateral thoracotomy is an alternative method that minimizes the risk of stroke and respiratory failure during distal aortic arch operations.

Adult↗

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

Influence of functional tricuspid regurgitation on right ventricular function.

BACKGROUND: Although right ventricular (RV) function has been extensively studied during the past decade, few reports have described the influence of functional tricuspid regurgitation (TR) on RV function. METHODS: One hundred forty-two patients with left-side valvular heart disease associated with TR were enrolled in the study and divided into three groups according to tricuspid annular diameter: group 1 (n = 66), tricuspid annular diameter less than 40 mm; group 2 (n = 58), tricuspid annular diameter of 40 to 50 mm; and group 3 (n = 18), tricuspid annular diameter greater than or equal to 50 mm. In groups 2 and 3, the right heart parameters had deteriorated to the point that TR repair was necessary. The mean follow-up period was 102 months after the operation. RESULTS: In each of the three groups, as pulmonary arteriolar resistance index increased, RV forward stroke work index increased in a linear fashion. The slope of the linear regression line was progressively less in group 1, 2, and 3 preoperatively. Postoperatively, this line moved in a parallel manner in group 1 and became steeper in group 2, consequently becoming similar in both groups. However, in group 3, although the slope became steeper in spite of a remarkable decrease of TR, it remained less when compared with groups 1 and 2. In addition, the right heart parameters also improved, but still remained worse in group 3 than group 2; 7 patients undergoing a flexible annuloplasty have shown gradual aggravations in TR and late postoperative clinical manifestations. CONCLUSIONS: Functional TR with severely dilated annulus may produce an irreversible deterioration of RV function. The preoperative relationship between pulmonary arteriolar resistance index and RV forward stroke work index, that is, RV systolic function to pressure afterload, might predict a postoperative fate of the right heart function.

Cardiac Catheterization↗