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Biomedical subjects

H Urayama

Publications and source records attributed to H Urayama.

At least 19 recordsLinked to original sources
PubMed2003

Overexpression of transforming growth factor beta1 in smooth muscle cells of human abdominal aortic aneurysm.

OBJECTIVE: to examine the expression of transforming growth factor beta1 (TGF-beta1) and the cell kinetics of smooth muscle cells (SMCs) at the neck of abdominal aortic aneurysms (AAAs). MATERIALS AND METHODS: expression of alpha-smooth muscle actin and TGF-beta1 was evaluated by immunostaining, and cell kinetics were estimated by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay and Ki-67 immunostaining in 11 AAAs (at both the dilated region and the neck) and eight occlusive aortas. RESULTS: the TUNEL-positive SMC ratio in the neck and dilated region was significantly higher than in the occlusive aorta (p<0.01). The percentage of Ki-67-positive SMCs in the neck was significantly higher than in the dilated region (p<0.01) and the occlusive aorta (p=0.032). When compared with the occlusive aorta, the aneurysmal neck had increased TGF-beta1 expression (p=0.01) and reduced SMC density, and the aneurysmal dilated aorta had much more increased TGF-beta1 expression (p<0.01) and much more reduced SMC density (p<0.01). CONCLUSIONS: these results suggest that overexpression of TGF-beta1 might be associated with the reduction of SMC density through SMC apoptosis and reduced proliferative ability of SMCs, leading to dilatation in AAAs.

Aged↗
PubMed2003

Endobronchial occlusion method of bronchopleural fistula with metallic coils and glue.

We describe our technique for endobronchial occlusion of bronchopleural fistula (BPF) with metallic coils and glue through a fiber-optic bronchoscope under local anesthesia. After anchoring the vascular embolization coils at the fistula bronchus, cyanoacrylate glue was sprayed. The sprayed glue obliterates gaps between the coils and stabilizes them. This procedure successfully occluded fistula bronchus except in one post-pneumonectomy case of large fistula. This method may be one of therapeutic options for BPF, especially in patients at high risk for curative surgery under general anesthesia.

Bronchial Fistula↗
PubMed2001

Intrathoracic aneurysm of the innominate and right subclavian arteries: report of a case.

Aneurysms of the innominate and subclavian arteries are uncommon but associated with high mortality rates. We report herein the case of a 45-year-old man who presented with facial anhidrosis that developed several years after blunt thoracic trauma, in whom an aneurysm involving the innominate and subclavian arteries was revealed by preoperative examinations. Resection of the aneurysm and reconstruction from the ascending aorta to both the subclavian and common carotid arteries using a bifurcated graft was successfully performed without brain perfusion. Although the left posterior cerebral artery, which was not manipulated during surgery, became occluded, it was recanalized by thrombolysis. The patient was discharged in good health and has remained well since.

Anastomosis, Surgical↗
PubMed2000

Simultaneous determination of bromide, nitrite and nitrate ions in seawater by capillary zone electrophoresis using artificial seawater as the carrier solution.

We describe capillary zone electrophoresis (CZE) for the simultaneous determination of bromide, nitrite and nitrate ions in seawater. Artificial seawater was adopted as the carrier solution to eliminate the interference of high concentrations of salts in seawater. The artificial seawater was free from bromide ion to enable the determination of bromide ion in a sample solution. For the purpose of reversing the electroosmotic flow (EOF), 3 mM cetyltrimethylammonium chloride (CTAC) was added to the carrier solution. A 100 microm ID (inside diameter) capillary was used to extend the optical path length. The limits of detection (LODs) for bromide, nitrite, and nitrate ions were 0.46, 0.072, and 0.042 mg/L (as nitrogen), respectively. The LODs were obtained at a signal to noise ratio (S/N) of 3. The values of the relative standard deviation (RSD) of peak area for these ions were 1.1, 1.5, and 0.97%. The RSDs of migration time for these ions were 0.61, 0.69, and 0.66%. Artificial seawater samples containing various concentrations of bromide, nitrite, and nitrate ions were analyzed by the method. The error was less than +/-12% even if the concentration ratio of bromide ion to nitrite or nitrate ion was 20-240. The proposed method was applied to the determination of bromide, nitrite, and nitrate ions in seawater samples taken from the surface and the seabed. These ions in other environmental waters such as river water and rainwater samples were also determined by ion chromatography (IC) as well as this method.

Bromides↗
PubMed2000

Bilateral Jejuno-mesenteric flap for reconstruction of complicated pharyngoesophageal defect.

The surgical management of an infectious and fistulous wound with a pharyngoesophageal tumor is one of the greatest challenges for head and neck and plastic surgeons. The free jejunal transfer has been the standard technique for pharyngoesophageal reconstruction, and the free omental flap has been one of the most reliable methods for reconstructing contaminated wounds. A jejuno-mesenteric flap is suitable for such complicated wounds. Pharyngoesophageal defects are reconstructed by the jejunum, and contaminated and heavily irradiated neck wounds are covered with the mesenteric flaps connected with a revascularized jejunum. The technique described here possesses the advantages of both a free jejunal flap and an omentum flap. Therefore, it is a reliable method for reconstructing the pharyngoesophageal defects of complicated wounds.

Esophageal Neoplasms↗
PubMed2000

Plasminogen activators, matrix metalloproteinases and their inhibitors in implanted vascular prostheses.

OBJECTIVES: To examine the role of plasminogen activators (PAs) and matrix metalloproteinases (MMPs) in the healing of prosthetic grafts. METHODS: Thirty explanted grafts (16 Dacron and 14 PTFE) were studied immunohistochemically using antibodies to PAs, MMPs, and their inhibitors. The percentages of immunostain-positive multinucleated giant cells (MGC) were related to duration of implantation (early vs late), type of lesion (stenosis vs false aneurysm), graft material (Dacron vs PTFE), and graft status (occluded vs patent). RESULTS: All specimens were positive for PAs and MMPs. There were no significant differences in the percentages of MGCs positive for PAs, MMPs, or tissue inhibitor type 2 of MMP (TIMP-2) between the groups. The percentage of TIMP-1 in the aneurysm group (mean, 26%) was significantly lower than that of the stenosis group (mean, 46%) (p<0.05). CONCLUSION: After the implantation of a vascular prosthesis, PAs and MMPs are expressed in cell migration, proliferation and matrix construction. Under-expression of TIMP-1 may be related to the formation of an anastomotic aneurysm.

Anastomosis, Surgical↗
PubMed2000

Rupture of pseudointima in an implanted vascular prosthesis: immunohistological study of plasminogen activators and matrix metalloproteinases.

We investigated late-onset anastomotic stenosis in an implanted prosthetic graft. Rupture of the pseudointima and hemorrhaging from the vasa vasorum were observed at the border of the collagenous tissue and fibrin layer. An immunohistological study showed that the fibrin layer was positive for tPA, but weakly positive for PAI-1. Some neutrophils and monocyte/macrophages in the fibrin layer were immunostained for tPA, uPA, uPAR, and MMP-1, -2 and -3. Some spindle-shaped cells surrounding the graft were immunostained for uPA, uPAR, MMP-1, -2, -3, -7 and -9, and TIMP-1 and -2. The endothelial cells of some microvessels were positive for MMP-1 and -2, and tPA. Some multi-nucleated giant cells were immunostained for MMP-7 and-9, tPA, PAI-1, uPA, and uPAR. Overexpressed MMPs and PAs possibly caused instability of the pseudointima.

Aged↗
PubMed2000

[A case of a combined aortectomy with dissection of recurrent paraaortic lymph nodes of sigmoid colon cancer].

A combined aortectomy was performed on a patient with recurrence of sigmoid colon cancer in the paraaortic lymph nodes. The 48-year-old woman was found to have tumor recurrence in the lymph nodes in the area between the aortic bifurcation and the paraaortic area, accompanied by left hydronephrosis, four years after surgery for sigmoid colon cancer (H0, P0, ss, n3, stage IIIb). No metastasis to distant areas was detected at that time. The woman thus underwent a reoperation. Intraoperatively, the aortic bifurcation and the lymph nodes were seen as a mass. The mass involved the left common iliac vein and the left ureter, as well. Therefore, we resected the area from the aortic bifurcation to the bilateral common iliac arteries, the left common iliac vein, the left ureter and the left kidney en bloc, and replaced them with a Y-shaped graft. One year after the reoperation, a tumor metastasis to the liver was detected, and a partial hepatectomy was performed. At present, the patient is being managed at our outpatient clinic. The results suggest that extended resection, involving the aorta as well, is sometimes useful when dealing with tumor recurrence in the paraaortic lymph nodes, unaccompanied by blood-borne metastasis.

Aorta↗
PubMed1999

Insulin stimulates the growth and tube formation of human microvascular endothelial cells through autocrine vascular endothelial growth factor.

Insulin treatment is known epidemiologically as an independent risk factor for the progression of diabetic retinopathy. However, how insulin exacerbates the retinopathy is not yet fully understood. In this study, we investigate the effects of insulin on the growth and tube formation of microvascular endothelial cells (EC). When human skin microvascular EC were grown under various concentrations of insulin, DNA synthesis as well as tube formation of EC was found to be significantly stimulated. We obtained evidence that it is mainly vascular endothelial growth factor (VEGF) that mediates the angiogenic activity of insulin as follows. (1) Insulin upregulates the level of mRNA coding for secretory forms of VEGF, while the expression of the two VEGF receptor genes, kinase insert domain-containing receptor (kdr) and fms-like tyrosine kinase1 (flt1), was essentially unchanged by exposure to insulin. (2) A monoclonal antibody against human VEGF can completely neutralize both the proliferation and the tube formation of EC induced by insulin. The angiogenic effects of insulin were additive with those of hypoxia, a principal factor that causes angiogenesis. Further, insulin significantly stimulated plasminogen activator inhibitor-1 activity in EC. The results thus suggest that insulin not only elicits angiogenesis through the induction of autocrine VEGF but also is a predisposing factor for thrombogenesis, which may give rise to focal ischemia that could superdrive angiogenesis, thereby leading to the exacerbation of diabetic retinopathy.

Autocrine Communication↗
PubMed1999

Arterial anastomosis using the telescoping method and an elastomeric adhesive.

We experimentally studied a new technique for anastomosis of small arteries which involves the telescoping method and a surgical adhesive with the objective of examining its clinical potential. This technique was applied to the unilateral femoral arteries of 27 mongrel dogs. After division of the artery, the distal artery was incised longitudinally, and the proximal end was invaginated into the opened artery. One stay suture and the elastomeric adhesive PUP201 were placed in the anastomotic site. The bursting and tensile strength and the patency were examined, and a histopathological study was performed at various intervals up to 1 year after the operation. The bursting strength exceeded 500 mm Hg. The patency rate of the anastomosed arteries was 100%. The mean percentage of stenosis to diameter of the proximal normal lumen was 20% one year after operation. The luminal surface of the anastomosed line was healed smoothly, and thrombi between the telescoped arteries were replaced by elastofibrotic union. In conclusion, small arterial anastomosis using the telescoping method and an elastomeric adhesive is easy and safe and provides good patency.

Anastomosis, Surgical↗
PubMed1999

[Extended resection of the great vessels for primary lung cancer and mediastinal tumor].

From 1973 to 1998, we resected and reconstructed the great vessels in 44 patients with primary lung cancer or mediastinal tumor. Among them, 39 patients (28 with lung cancer and 11 with mediastinal tumor) and 5 patients (all with lung cancer) underwent reconstruction of the superior vena cava (SVC) and aorta, respectively. The SVC was repaired by expanded polytetrafluoroethylene (EPTFE) graft (n = 8), prosthetic patch (n = 5) or direct suture (n = 26). The aorta was repaired with temporary subclavian artery-descending aorta (n = 3), or left atrium-femoral artery bypass (n = 2). No complication or operative death occurred after surgery. The survival rate of the patients with lung cancer who underwent SVC reconstruction at 3 year and 5 year were 26.2% and 11.2%, respectively. Five of 11 (45.5%) patients with mediastinal tumor are alive at 5 years. We concluded that extended resection for primary lung cancer or mediastinal tumor invading the SVC is acceptable operation method for some patients.

Adult↗
PubMed1999

Exclusion of internal iliac arterial aneurysm concomitant with abdominal aortic aneurysm repair.

BACKGROUND: To study the long-term outcomes after exclusion of internal iliac arterial aneurysm performed concomitantly with abdominal aortic aneurysm repair in patients with ruptured aortic aneurysm or other high-risk conditions. METHODS: The 31 patients who participated in this study underwent emergency (N = 9) or elective surgery (N = 22). The abdominal aortic aneurysm and the common iliac artery were excluded together with the internal iliac aneurysm in 7 patients. Forty-three (12 bilateral and 19 unilateral) internal iliac aneurysms were excluded: 35 by proximal ligation only, 5 by proximal and distal ligation, and 3 by partial resection of the proximal part of the aneurysm. The platelet count and fibrinogen level were evaluated pre- and postoperatively. Pelvic organ ischemia, classed as ischemic colitis, buttock claudication and sexual dysfunction, was examined. RESULTS: The inferior mesenteric artery was reimplanted in 21 patients. The platelet count dropped significantly postoperatively, but the fibrinogen level increased and no bleeding tendency was noted. Ischemic colitis occurred in 7 patients, resulting in colonic infarction in 2 patients. The operative mortality was 16%, and the postoperative observation periods ranged from 4 days to 217 months (mean, 60 months). The incidence of buttock claudication and sexual dysfunction was 12% and 39%, respectively. The excluded aneurysms were all thrombosed at discharge, and no late rupture was noted. The 5- and 10-year survival rate after surgery was 56% and 51%, respectively. CONCLUSIONS: Exclusion of the internal iliac aneurysm concomitant with abdominal aortic aneurysm repair shows acceptable outcome when performed in patients with high-risk conditions.

Aged↗
PubMed1998

Larynx-preserving resection of the cervical esophagus for cervical esophageal carcinoma limited to the submucosal layer.

This report describes the surgical procedure consisting of larynx-preserving resection of the cervical esophagus and satisfactory lymphadenectomy. The sternum was split at the level of the 3rd intercostal space, which allowed an upper-mediastinal lymphadenectomy to be performed easily. The cervical esophagus was reconstructed using a free jejunal autograft. The stump of the thoracic esophagus and the caudad stump of the jejunal graft were anastomosed using a circular stapling instrument. The posterior part of the cephalad esophagojejunostomy was completed in two layers using the Lembert stitch. The wall of the cervical esophagus was opened to determine the oral cut line considering the safety margin from the carcinoma. After cervical esophagectomy was completed, suturing of the anterior wall was performed in one layer. The left cervical transverse artery and the internal jugular vein were employed for recipient vessels. This procedure is acceptable for high cervical esophageal carcinoma limited to the submucosal layer.

Carcinoma, Squamous Cell↗
PubMed1998

Long-term results of endarterectomy, anatomic bypass and extraanatomic bypass for aortoiliac occlusive disease.

Over the past 20 years, 214 patients in our hospital were operated on for aortoiliac occlusion, including an endarterectomy for 88 legs in 64 patients, an anatomic bypass for 178 legs in 105 patients, and an extraanatomic bypass for 51 legs in 45 patients. The extraanatomic group was older than the other two groups (70 years versus 64 years), and also showed a higher instance of critical ischemic symptoms than the other groups (49% versus 16%). The 10-year primary patency rate was 88% for an endarterectomy, 91% for an anatomic bypass, and 73% for an extraanatomic bypass. The 10-year survival rate was 71% for an endarterectomy, 49% for an anatomic bypass, and 24% for an extraanatomic bypass. The possible complications related to each surgical method included sexual dysfunction resulting from endarterectomy, and graft infection and anastomotic aneurysm in the prosthetic bypass. No ischemic symptoms in the donor limb were noted following an extraanatomic bypass. The selection of the appropriate surgical method for aortoiliac occlusion should thus be made after a careful review of the patient's general condition, the morphology of arterial occlusion, and the risk of possible complications for each type of surgery.

Adult↗
PubMed1998

Surgical drainage for idiopathic suppurative pylephlebitis.

Idiopathic suppurative pylephlebitis is quite rare and only a few cases have been reported. Conservative systemic administration of antibiotics and urokinase is reported to be effective. In this report, surgical drainage was performed on an 18-year-old man who complained of fever and abdominal pain. He had no past history of abdominal inflammatory disease or abdominal surgery. Ultrasonography and computed tomography showed wide spread thrombosis of the portal vein. Laparotomy was performed and the occluded superior mesenteric vein was incised. Massive pus was removed. Thereafter, a drain was placed at the opened mesenteric vein. Drainage resulted in a dramatic decrease in fever. Postoperative radiographic studies of the colon, the small intestine, and other organs did not show any abnormalities. Emergency surgical drainage was performed successfully, instead of systemic administration of antibiotics and urokinase. Surgical drainage may be useful for wide spread pylephlebitis and pylethrombosis.

Abdomen, Acute↗
PubMed1998

Prevention of spinal cord ischemia by selective intercostal arterial infusion of prostaglandin E1.

PURPOSE: A new protective method against the spinal cord ischemia that occurs during aortic clamping was investigated in dogs. Oxygenated blood containing prostaglandin E1 (PGE1) was administered at the clamped aortic segment, and the effect was evaluated by measurement of the sensory evoked spinal potential (SESP). METHODS: In 30 dogs, a thoracotomy was made with dissection of the thoracic aorta. After intravenous heparin (100 units/kg) was administered, the proximal and distal descending thoracic aortas were cross-clamped for 60 minutes. Group A (n=10) received oxygenated blood at the rate of 1.0 ml/kg/min. Groups B (n=10) and C (n=10) received oxygenated blood at the same rate, with PGE1 at the dosage of 25 and 50 ng/kg/min, respectively. The infusion was continuously administered throughout the entire period of ischemia. SESP was measured with epidural electrodes before clamping, 10 and 60 minutes after clamping, and 10 and 60 minutes after declamping. Neurologic outcome was assessed at 24 hours after the operation and graded according to the method of Tarlov. RESULTS: There was no significant hemodynamic change in any group. At 60 minutes after damping and at 10 and 60 minutes after declamping, the amplitude of SESP was lower than that at preclamping in groups A and B (p < 0.05). At 60 minutes after damping and at 10 and 60 minutes after declamping, the SESP was more markedly decreased in group A compared with groups B and C. Regarding postoperative neurologic outcome, the dogs with SESP amplitude of more than 50% of the preclamping control value at 60 minutes after clamping showed neither paralysis nor paraplegia. Seven of nine dogs with less than 50% SESP amplitude showed neurogenic deficit. In a comparison of groups A, B, and C, the Tarlov score for group A dogs was significantly lower than that for group C dogs (p < 0.05). CONCLUSION: In this model, PGE1 administration at the rate of 50 ng/kg/min showed sufficient spinal cord protection against ischemia without a decrease in the blood pressure. Further studies are needed to determine the dose that will provide the maximal protective effect and to determine the maximum duration of ischemia against which PGE1 shows protective effects.

Alprostadil↗
PubMed1998

Distortion of the radial artery by a mucinous cyst. Case reports.

Three cases of mucinous cyst situated close to the radial artery are reported. The patients complained of pain, a throbbing mass, or both at the wrist. Colour Doppler sonography showed distortion of the radial artery by the cyst in all three patients. In one patient the cyst was connected to a synovial sac by a pedicle, in another it was adherent to the radial artery but was identified histopathologically as a simple ganglion, and in the last patient a branch of the radial artery was involved in the cyst, which was identified histopathologically as an adventitial cyst. Mucinous cysts enlarge when subjected to mechanical stress. Excision is recommended for cysts that distort the radial artery.

Aged↗