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Yutaka Okita

Publications and source records attributed to Yutaka Okita.

At least 19 recordsLinked to original sources
PubMed2006

Controlled release of basic fibroblast growth factor from gelatin hydrogel sheet improves structural and physiological properties of vein graft in rat.

OBJECTIVES: Autologous vein grafts are still widely used, but their long-term patency is suboptimal. The objective of the current study was to determine whether wrapping a vein graft in gelatin hydrogel sheet incorporating basic fibroblast growth factor improves their mechanical and physiological properties. METHODS AND RESULTS: Autologous femoral vein was interposed into the abdominal aorta in rats. The rats were divided into 3 groups: nontreated grafts (group A), grafts wrapped in basic fibroblast growth factor-free gelatin hydrogel sheet (group B), and grafts wrapped in basic fibroblast growth factor-impregnated gelatin hydrogel sheet (group C). On day 1, endothelial desquamation was observed in group A, and the media in groups A and B were disrupted, staining positive in the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. In contrast, the media in group C remained intact and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-negative, associated with activation of MAPK. Graft dilation was significantly inhibited in groups B and C compared with group A, with those in group C showing the smallest degree of neointimal proliferation. At 8 weeks grafts in group C developed neointima with homogeneous elastic laminae, presence of rigid neoadventitia that displayed neovascularity, and the highest blood flow velocity. CONCLUSIONS: Wrapping vein grafts in basic fibroblast growth factor-impregnated gelatin hydrogel sheet improved their structural and physiological properties, and might therefore also improve long-term patency.

Anastomosis, Surgical↗
PubMed2006

A case of immature teratoma originating in intra-abdominal undescended testis in a 3-month-old infant.

Teratomas in an undescended testis are rare in infants. This report was the youngest case of immature teratoma originating in intra-abdominal undescended testis. A 3-month-old infant with cryptorchism was seen because of an asymptomatic palpable mass in the right abdomen. Ultrasonography and computed tomography revealed a multicystic large tumor with focal calcifications in the right side and serum tumor markers within normal limits. Complete resection of the tumor was performed and the histopathological diagnosis was made as immature teratoma of the right testis. Because retroperitoneal lymph nodes metastasis was observed in 3-month follow-up postoperatively, retroperitoneal lymphadenectomy and chemotherapy including bleomycin, etoposide, and cisplatin were performed. Presently, the infant has been free of recurrence for 3 years. We suggest that nonpalpable testis should undergo a careful evaluation and prompt resolution and that the subsequent finding of an intra-abdominal mass should make us think on the possibility of intra-abdominal testicular germ cell tumor. Postoperative adjuvant chemotherapy in combination with complete resection of the tumor is necessary for pediatric immature teratomas originating in intra-abdominal undescended testis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

His239Arg SNP of HRAD9 is associated with lung adenocarcinoma.

BACKGROUND: It was previously reported that a functional human (h) Rad9 protein accumulated in the nuclei of non-small cell lung carcinoma (NSCLC) cells. Those experiments, however, did not examine whether the hRad9 gene was mutated in those cells. The sequence of the HRAD9 gene in NSCLC cells was investigated. METHODS: The sequence of the HRAD9 was examined in tumor and peripheral normal lung tissues obtained from 50 lung adenocarcinoma patients during surgery. The expression of its mRNA using reverse transcription polymerase chain reaction (RT-PCR) was also examined. RESULTS: No sequence alterations were detected in the HRAD9 gene, which was found to be normally transcribed in surgically resected lung carcinoma cells. However, in eight (16.0%) cases a single nucleotide polymorphism (SNP) was observed at the second position of codon 239 (His/Arg heterozygous variant) of the gene. This frequency was significantly higher than that found in the normal population. CONCLUSIONS: Whereas the capacity to produce a functional hRad9 protein was intact in lung adenocarcinoma cells, a nonsynonymous SNP of HRAD9 was detected that might be associated with the development of lung adenocarcinoma.

Adenocarcinoma↗
PubMed2006

Determinants of rapid progression of aortic root dilatation and complications in Marfan syndrome.

BACKGROUND: Progressive aortic dilatation has prognostic significance in the Marfan syndrome. METHODS: To identify which patients were at high risk of rapid progression, we echocardiographically studied 43 patients (age 22 +/- 14 years) with the mean follow-up period of 5.2 +/- 3.2 years. Aortic diameters, left ventricular (LV) size, fractional shortening, and the severity of aortic and mitral regurgitation were assessed. Transmitral peak early and atrial flow velocities, their ratio and the deceleration time of peak early velocity were also obtained. RESULTS: Mean annual increases of aortic diameters were 0.4 +/- 0.3 mm at the annulus, 1.5 +/- 1.3 mm at the sinuses of Valsalva, 0.7 +/- 0.6 mm at the supraaortic ridge and 0.4 +/- 0.4 mm at the proximal ascending aorta. Patients were divided into 2 groups according to the aortic growth rate at the sinuses of Valsalva level: rapid (R, >3% per year, 15 patients) or slow (S, < or =3% per year, 28 patients) progression groups. Measured variables did not show significant differences between the 2 groups except older age, higher blood pressure and more severe aortic regurgitation in group R. Multiple regression analysis identified prolonged deceleration time as the most important variable predicting aortic complications. Aortic dissection occurred more frequently in group R (7 patients, 47%) than in group S (0%, P < 0.001). CONCLUSIONS: Marfan patients at older age, with higher blood pressure, and with significant aortic regurgitation were at high risk of progression of aortic dilatation, with the most remarkable increase at the sinuses of Valsalva. Prolonged deceleration time may relate to an increased risk for aortic complications.

Adolescent↗
PubMed2006

Pulmonary thromboendarterectomy for chronic pulmonary thromboembolism in protein C deficiency.

Pulmonary thromboendarterectomy was performed on a patient with chronic pulmonary thromboembolism showing thrombophilia. The patient was a 56-year-old female with the above condition complicated by congenital protein C deficiency. She was admitted to our hospital with severe dyspnea accompanied by right ventricular failure. A pulmonary arteriogram showed occlusion and stenosis from lobar to segmental arteries. Cardiac catheterization showed marked pulmonary hypertension. A lung perfusion scintigram revealed multiple defects in the right and left lungs. After the insertion of an inferior vena cava filter, she was operated on. Following a median sternotomy, thromboendarterectomy of the bilateral pulmonary arteries was performed using deep hypothermia and intermittent circulatory arrest. Circulatory arrest was employed in three periods totaling up to 36 minutes. After surgery, she had improvements in pulmonary hypertension and pulmonary vascular resistance. She maintained improved lung functions, and remained in the New York Heart Association functional class I for more than two years and eight months after surgery.

Endarterectomy↗
PubMed2006

Transplantation of the cryopreserved tracheal allograft in growing rabbits: effect of immunosuppressant.

Transplantation of a cryopreserved tracheal allograft is considered to be a useful strategy in treating congenital tracheal stenosis. Recent reports of tracheal transplant experiments have shown that the antigenicity of the trachea is decreased by cryopreservation, making transplantation of the trachea possible. However, we reported that cryopreserved tracheal allografts exhibited favorable patency, but no significant growth in an animal model. In this study, we hypothesize that an immune reaction may play a role in the failure of an allograft's growth. Each allograft was harvested from 90- to 120-day-old Japanese rabbits, immersed in preservation solution, stored in a programmable freezer until it reached -80 C, and then kept for 1 month. Orthotopic tracheal transplantation of four tracheal rings in an end-to-end fashion was performed in age-matched young rabbits. Ten recipients were classified into three groups: a group provided with tacrolimus (FK-506) as an immunosuppressant (n = 6), a group receiving a graft irradiated before transplantation (n = 2), and a control group (n = 2). All grafts were evaluated 4-8 weeks after transplantation (tacrolimus group: 3-13 weeks). Body weight gain of the tacrolimus group was less than that of the other two groups. All grafts were well incorporated with the recipients macroscopically, but the grafts showed no growth in diameter. Microscopic examination showed inflammation in the tacrolimus and control groups temporarily. The irradiated allografts had marked fibrosis in the subepithelium. Although calcification of the tracheal cartilage was present in all transplanted allografts, the difference between groups was not significant. Patency of the cryopreserved tracheal allografts was favorable but no growth occurred even with an immunosuppressant. Further studies are required to address the growth of the tracheal allograft.

Animals↗
PubMed2006

Percutaneous balloon fenestration and stent placement for lower limb ischemia complicated with type B aortic dissection.

We report a case of lower limb ischemia secondary to type B aortic dissection, which was successfully treated with endovascular aortic fenestration and stent placement. In this case, we were not able to restore adequate flow to the ischemic limb by means of aortic balloon fenestration alone, so additional stent placement was required to buttress the true lumen and fenestra. There was no recurrence of lower limb ischemia complications during the follow-up period. Aortic balloon fenestration with stent placement seems to be a safe and effective technique to salvage an ischemic lower limb complicated by acute aortic dissection.

Aortic Dissection↗
PubMed2006

Disruption of the vascular prosthesis caused by aortic calcification after replacement of the thoracoabdominal aortic aneurysm.

A 52-year-old man underwent a replacement of the thoracoabdominal aorta. The aorta was severely calcified, and was replaced by a 24-mm woven Dacron (Vascutek, Renfrewshire, Scotland) graft wrapped with the calcificated aneurysmal wall. His postoperative course was uneventful; however, he collapsed on the 18th postoperative day. He underwent an emergent thoracotomy and the wrapped aneurysmal wall was taken down. The prosthesis graft had a 1-mm disruption in the middle portion, which did not relate to the anastomoses. Experimental study ex vivo showed that disruption of the prosthesis could have occurred after a 3-week pulsatile force caused by a seashell simulating aortic calcification.

Animals↗
PubMed2006

Perforation of the Valsalva sinus after implantation of Medtronic Freestyle aortic bioprosthesis.

We report on structural valve deterioration in patients with the Medtronic Freestyle aortic bioprosthesis (Medtronic, Inc, Minneapolis, MN), including spontaneous perforation of the Valsalva sinus. These occurred in four prosthesis in 3 patients using the modified subcoronary method or full root technique. One patient died of ruptured pseudoaneurysm and the others survived reoperation well. Careful follow-up is required after Freestyle bioprosthesis implantation.

Aortic Rupture↗
PubMed2006

Surgical experience for the pulmonary artery sarcoma.

BACKGROUND: Pulmonary sarcoma arising from the pulmonary artery is a rare disease and its prognosis is disastrous. METHODS: Five patients who underwent surgery for pulmonary artery sarcoma were reviewed. RESULTS: All patients except one were initially diagnosed with pulmonary embolism. One patient with preoperative profound shock could not wean from cardiopulmonary bypass. Two patients are still surviving for 36 and 30 months, respectively. CONCLUSIONS: Early diagnosis and complete surgical resection is perhaps the best way to improve patients with pulmonary artery sarcoma.

Aged↗
PubMed2006

Surgical treatment for Kommerell's diverticulum.

OBJECTIVE: Kommerell's diverticulum, which is a rare condition, is a congenital abnormality of the aortic arch. The strategy of surgical treatment for Kommerell's diverticulum has not been established. METHODS: Between 1994 and 2004, 6 patients underwent surgery for Kommerell's diverticulum at our institute. Diagnoses included right aortic arch with aberrant left subclavian artery in 4 patients and left aortic arch with aberrant right subclavian artery in 2 patients. Indications for surgery were dilatation of Kommerell's aneurysm (n = 4) and dysphagia (n = 2). One patient underwent total arch replacement through the median sternotomy plus right thoracotomy. Five patients underwent replacement of the descending aorta and reconstruction in situ (n = 4) or ligation (n = 1) of the stenotic aberrant subclavian artery through the right (n = 3) or left (n = 2) thoracotomy. RESULTS: There were no patient deaths or patients who required rehospitalization. Mediastinitis occurred in 1 patient. This patient required mediastinal drainage and an omentopexy. Two patients who had dysphagia became asymptomatic. Postoperative angiographies in all patients were satisfactory. The patient whose aberrant subclavian artery was ligated had no ischemic symptom of the arm. At the midterm outcomes (mean follow-up length was 55.6 +/- 42.2 months, ranging 10-114 months), all patients resumed normal activities without any complications. CONCLUSIONS: Kommerell's diverticulum can be repaired safely with graft replacement concomitant with in situ reconstruction of the aberrant subclavian artery through thoracotomy.

Aged↗
PubMed2006

Recurrent severe mitral regurgitation due to left ventricular apical wall motion abnormality caused by coronary vasospastic angina: a case report.

A 76-year-old man developed congestive heart failure due to severe mitral regurgitation after episodes of vasospastic angina. Echocardiography demonstrated left ventricular apical akinesis with ballooning and deformity of the anterior mitral leaflet becoming concave toward the left atrium. The acetylcholine provocation test induced diffuse coronary vasospasm in the distal segments of both right and left coronary arteries and reproduced severe mitral regurgitation. Follow-up echocardiography demonstrated decreased mitral regurgitation with ameliorated apical wall motion. Coronary vasospasm remained refractory to antivasospastic medications and severe mitral regurgitation relapsed 1 month after discharge. Mitral valve annuloplasty with a Carpentier-Edwards physio ring was performed, and no recurrence of mitral regurgitation was observed despite some episodes of vasospastic angina. We speculate that vasospastic angina and the resultant apical wall motion abnormality caused tethering of the mitral subvalvular apparatus, leading to inappropriate mitral coaptation and severe regurgitation.

Aged↗