Biomedical subjects

Y Kuniyoshi

Publications and source records attributed to Y Kuniyoshi.

At least 19 recordsLinked to original sources

PubMed2003

Role of tetrahydrobiopterin on ischemia-reperfusion injury in isolated perfused rat hearts.

AIM: It has recently been shown that nitric oxide synthase in the presence of suboptimal levels of tetrahydrobiopterin (BH(4)), an essential cofactor of nitric oxide synthase, may favor increased production of oxygen free radicals. This study was designed to define the role of BH(4) in myocardial ischemia-reperfusion injury. METHODS: Isolated perfused rat hearts were subjected to 37 degrees C ischemia and reperfusion. Hearts were received with BH(4) or vehicle for 5 min just before ischemia and during the first 5 min of the reperfusion period. The effects of BH(4) on left ventricular function, myocardial contents of lipid peroxidation and high energy phosphates, and levels of lactate dehydrogenase and nitrite plus nitrate in perfusate before ischemia and after reperfusion were estimated. Moreover, the effect of BH(4) given with 2,4-diamino-6-hydroxypyrimidine (DAHP), a selective inhibitor of BH(4) production, intraperitoneally 24 h before the experiments were estimated. RESULTS: BH(4) improved contractile and metabolic abnormalities in reperfused hearts. Furthermore, BH(4) significantly alleviated ischemic contracture during ischemia, and restored diminished perfusate levels of nitrite plus nitrate after reperfusion. On the other hand, DAHP-treatment aggravated ischemia-reperfusion induced functional and metabolic abnormalities. Administration of BH(4) improved DAHP-induced functional and metabolic abnormalities. CONCLUSION: Results demonstrated that BH(4) lessens ischemia-reperfusion injury in isolated perfused rat hearts. Conversely, deficiency of BH(4) seems to accelerate endothelial dysfunction and myocardial ischemia-reperfusion injury. Present data may be compatible with the hypothesis that nitric oxide synthase in the presence of insufficiency of BH(4) serve as the cause of oxidative injury.

Animals↗

PubMed2002

[Impact of multi-segmental aortic clamping and distal aortic perfusion on the prevention of postoperative paraplegia during thoracoabdominal aortic graft replacement].

OBJECTIVE: We present the impact of multisegmental aortic clamping under distal aortic perfusion and segmental artery reimplantation on the prevention of postoperative paraplegia during thoracoabdominal aortic graft replacement. PATIENTS: During the last 14 years in 47 patients (age range: 22 to 82 years; average: 57,9 +/- 13,2 years; 16 females and 31 males) with thoracoabdominal aortic aneurysm a graft replacement was performed with adjuncts of normothermic partial bypass and multisegmental aortic clamping. As many patent segmental arteries as possible were reimplanted. RESULTS: Five patients died during hospitalization, for an in-hospital mortality rate of 10,6 %. In the elective patients (n = 40), the hospital mortality rate was 7,5 %. The average number of segmental aortic clampings per patient was 2,83 +/- 1,19 times. In 39 patients (82,9 %), 117 segmental arteries were reimplanted or preserved by beveled anastomosis. Eighty-three out of 117 segmental arteries (70,9 %) were located between TH9 and L2. Postoperative paraplegia/paraparesis did not occur in any patient. CONCLUSION: In view of our results reimplantation of as many segmental arteries as possible under multisegmental aortic clamping with adequate distal aortic perfusion can be recommended for effective prevention of spinal cord ischemia in TAAA surgery.

Adult↗

PubMed2001

Optical determination of low-level water concentrations in organic solvents using fluorescent acridinyl dyes and dye-immobilized polymer membranes.

The fluorescent acridinyl indicators 4-(9-acridinyl)-N-(5-hexenyl)-N-methylaniline (KD-F0011), 6-(9-acridinyl)-1,2,2,3-tetramethyl-2,3-dihydro- 1H-perimidine (KD-F0021), and 6-(9-acridinyl)-2-(3-butenyl)-1,2,3-trimethyl-2,3-dihydro-1H-perimidine (KD-F0022) were designed, synthesized, and applied for highly sensitive optical determination of low-level water in organic solvents. All these dyes were found useful as fluorescence indicators for the detection of water below 1% (v/v) in different solvent media with a low detection limit of 0.002% (v/v) or 20 mg/L (22 ppm by weight) for KD-F0021 in THF solution. Sensing membranes made from poly(ethylene glycol) dimethacrylate by photocopolymerization with the indicator KD-F0011 were also prepared. Using the membrane sensor, the lowest detection limit of 0.001% (v/v) or 14 mg/L (20 ppm) water was achieved in diethyl ether samples. This system enables the continuous monitoring of the water content in a flow-through arrangement, where single-wavelength excitation (404 nm) and single-wavelength detection (532 mm) can be used for the fluorescence determination, allowing a simple measurement setup. In a continuous-flow experiment using THF samples, fully reversible and fast signal changes with t95% = 1-2 min for water concentrations up to 0.50% (v/v) were observed. A detection limit of 0.004% (v/v) or 40 mg/L (45 ppm) water in THF was achieved. These characteristics make this type of sensor a useful tool for the online continuous monitoring of water present as an impurity in organic media, which is difficult to achieve using a Karl Fischer instrument.

Journal Article↗

PubMed2001

Acute aortic dissection associated with Sheehan's syndrome.

A 69-year-old woman with Sheehan's syndrome who suffered acute Stanford type A aortic dissection had received corticosteroids and thyroid hormones for over 20 years. The entire ascending aorta was replaced in emergency graft replacement. We administered twice the usual dose of methylprednisolone during cardiopulmonary bypass and twice the patient's usual dose of prednisolone from postoperative day 1 to 6. The usual 100 micrograms of levothyroxine sodium was given orally from postoperative day 1. The patient's postoperative course was uneventful. This case emphasizes the importance of early active supplementary treatment with steroids and thyroid hormones for major surgery in patients with Sheehan's syndrome.

Acute Disease↗

PubMed2001

One-stage operation for descending thoracic aortic aneurysm and left lung cancer: a case report.

We performed concomitant graft replacement for descending thoracic aortic aneurysm and pulmonary resection for squamous cell carcinoma of the left upper lobe in a 79-year-old man. The tumor reached the parietal pleura. No distance metastasis was found, and the tumor was diagnosed preoperatively as a stage IIB (N0, M0, T3) tumor. The descending thoracic aortic aneurysm was saccular, with greatest diameter being 55 mm, and extending from TH5 to TH8. A left upper lobectomy was performed, and after irrigation with a large volume of saline diluted with povidone iodine, graft replacement for the aortic aneurysm was performed under femoro-femoral partial bypass. To prevent postoperative graft infection, the greater omentum was dissected and placed over the resected pulmonary hilum and the graft. The patient's postoperative course was uneventful. There was no sign of infection, and the patient was discharged 1 month after surgery. Artificial graft wrapping with the greater omentum was useful for the prevention of the postoperative graft infection in this case of surgical treatment of lung cancer and descending thoracic aortic aneurysm.

Aged↗

PubMed2001

Cardiac reoperation in a patient with osteogenesis imperfecta: a case report.

A case of a 40-year-old man with dehiscence of the prosthetic aortic valve and recurrence of mycotic aneurysm of the left ventricular outflow tract with osteogenesis imperfecta is presented. He had an operation of aortic valve replacement and direct closure of the mycotic aneurysm for infective endocarditis twenty-one months ago. We performed reoperation of prosthetic aortic valve, patch closure of the mycotic aneurysm and graft replacement of the ascending aorta. He was complicated with multiple fractures of bilateral scapla and dislocation of left shoulder one postoperative day. Fortunately, cardiac reoperation was performed successfully in this patient despite anticipated difficulties with tissue friability with osteogenesis imperfecta.

Adult↗

PubMed2001

Left ventricular pseudoaneurysm after sutureless repair of subacute left ventricular free wall rupture: a case report.

A 65-year-old woman presenting with a left ventricular pseudoaneurysm 27 months after sutureless repair of a subacute left ventricular free wall rupture complicating acute myocardial infarction is described. An autologous pericardial patch and gelatin resorcin formaldehyde (GRF) glue were used in the repair. A small pseudoaneurysm bulged out over the true aneurysm of the left ventricle. We performed a Dor operation and concomitant bypass grafting to the right coronary artery. Although sutureless repair is an effective procedure for subacute left ventricular free wall rupture, left ventricular pseudoaneurysm in the late postoperative period may be a rare problem after this repair.

Aged↗

PubMed2001

Management of the heart rate during coronary artery bypass grafting on the beating heart: newly devised methods of decreasing heart rate--a preliminary report-.

BACKGROUND: To develop new methods for achieving bradycardia, we studied the feasibility of producing transient, reversible bradycardia with atrial stimulation and cooling of the sinoatrial node. METHODS: In an animal study, the atrium was stimulated electrically during the refractory period of the atrioventricular node. Alternatively, an area of the sinoatrial node was cooled regionally. The two methods were also performed in combination. In a clinical study, atrial stimulation was applied in seven consecutive patients who underwent coronary artery bypass grafting (CABG). RESULTS: In the animal study, atrial stimulation was effective only when 2 mg/kg of diltiazem was administered. Such atrial stimulation decreased heart rate (beats/minute) from 95.8+/-16.9 to 64.2+/-20.0 (the average reduction from the control value 66.1+/-10.3%). Cooling the sinoatrial node decreased heart rate, and was effective with or without administration of diltiazem. Heart rate was decreased from 156.6 31.7 to 110.7+/-21.7 (average reduction from control value 71.3+/-9.2%) before using diltiazem and from 102.0+/-11.9 to 63.5+/-13.9 (average reduction from control value 62.0+/-10.4%) after administration of diltiazem. By combining the two methods, heart rate was decreased from 102.0+/-12.3 to 44.6+/-9.1 (average reduction from control value 43.5+/-6.3%). In our clinical study, the atrial stimulation method was effective. CONCLUSION: Atrial stimulation or regional cooling of the sinoatrial node slowed the heart rate. By combining the two methods, the heart rate was slowed to 40. Clinically, atrial stimulation was effective in CABG patients.

Aged↗

PubMed2000

Surgical treatment of multiple inflammatory aortic aneurysms of the aortic arch and thoracoabdominal aorta.

A 67-year-old woman hospitalized with pleuritis was treated with antibiotics. Although the inflammation was resolved, saccular aneurysms in the aortic arch and thoracoabdominal aorta enlarged rapidly. We conducted graft replacement of the aortic arch, but despite careful blood pressure control, the thoracoabdominal aneurysm rapidly enlarged even further. We conducted graft replacement of the thoracoabdominal aorta on day 25 after the first operation. The postoperative course was uneventful and no exacerbation was found 18 months after the second operation. These multiple aortic aneurysms were diagnosed as inflammatory because bacterial tests of blood and aneurysmal walls were all negative and cells infiltrating aneurysmal walls were pathologically plasma cells.

Aged↗

PubMed1999

Surgical treatment of traumatic aneurysm of the ascending aorta.

Traumatic aneurysm of the ascending aorta is a rare event. This case describes a patient with such an aneurysm, resulting from injuries received in a motorcycle accident. The patient was admitted to the emergency room of a local hospital complaining of chest pain, and was subsequently referred to our institution. On admission, a chest x-ray showed mediastinal widening. Computed tomography and aortography revealed an ascending aortic aneurysm and contusion of the upper lobe of the right lung. Due to concerns about bleeding from the lung contusion, surgery was delayed for one week. During surgery, intimal tears were detected at two sites in the ascending aorta. The wall of the ascending aorta was subsequently resected and a prosthetic graft inserted. The postoperative period was uneventful and a postoperative aortogram showed that the graft had molded well.

Accidents, Traffic↗

PubMed1999

Successful surgical treatment of impending rupture of thoracoabdominal aortic aneurysm in an elderly patient with severe pulmonary emphysema.

In a case of successful surgery for impending thoracoabdominal aortic aneurysmic rupture, an 83-year-old man with severe pulmonary emphysema was transferred to our hospital diagnosed with impending aneurysmic rupture. The aneurysm had been pointed out 2.5 years ago but surgical repair was not undertaken due to the patient's severe pulmonary emphysema. After admission, computed tomography showed an enlarging saccular thoracoabdominal aortic aneurysm. Emergency surgery was conducted because of severe pain below the left costal margin. We resected the wall of the saccular aortic aneurysm and reconstructed the aorta with an on-lay patch under femoro-femoral bypass and selective visceral organ perfusion. Tracheostomy provided respiratory care on the day following surgery. The patient was weaned from respiratory support 6 days after surgery. Postoperative aortography showed that the reconstructed thoracoabdominal aorta functioned satisfactorily. The patient remains in good health 18 months after surgery.

Aged↗

PubMed1999

A new devised skirted elephant trunk technique.

A simple and effective new elephant trunk technique was devised and applied to two patients with a successful result. In advance before the operation, an arch graft with a skirted elephant trunk was made. This was done by inserting a smaller, 22 mm diameter sized graft into the arch graft at the distal end and suturing it so as to leave a skirt extending over the smaller graft. This configuration facilitates the distal anastomosis and effectively shortens anastomotic time.

Adult↗

PubMed1999

Two-stage operation for multiple aneurysms of the thoracic aorta, abdominal aorta, and left common iliac artery in an octogenarian.

Multiple aortic aneurysms are well described in the surgical literature. However, there are many problems related to surgical treatment of elderly patients with such aneurysms. This report presents the case, an octogenarian with multiple aortic aneurysms that were successfully treated by graft replacement. An 82-year-old man with a descending aortic aneurysm was referred to our institution for surgery. In addition to the previously diagnosed aneurysm, computed tomography and aortography showed an abdominal aortic aneurysm and a left common iliac aneurysm. Since the patient was an elderly man with chronic obstructive pulmonary disease, a two-stage operation was performed. The abdominal aortic aneurysm and left common iliac aneurysm were resected first due to the risk of thromboembolism from the abdominal aortic aneurysm during surgery involving replacement of the descending aorta under femoro-femoral (F-F) bypass. Fifty-two days after the first operation, a second operation was performed to repair the descending aortic aneurysm. The postoperative course was uneventful. Angiography after the operation showed satisfactory replacement of the multiple aortic aneurysms. The patient was discharged 25 days after the second operation.

Aged↗

PubMed1999

Sutureless technique for subacute left ventricular free wall rupture: A case report of an 85-year-old.

This case was an 85-year-old female who developed left ventricular free wall rupture (LVFWR) of the anterior wall 13 days after an acute myocardial infarction. She was further complicated with an ascending aortic aneurysm and severe aortic regurgitation. The wall was repaired using a sutureless technique with an autologous pericardial patch and GRF glue without cardiopulmonary bypass. Although the complication of a left ventricular aneurysm was seen, the postoperative course was uneventful. Nevertheless, she is doing well 9 months after surgery.

Aged↗

PubMed1998

[Thoracoscopic surgery for diagnosis of interstitial pneumonia special reference to medicoeconomical effect].

We compared thoracoscopic surgery (TS) and open thoracotomy for the diagnosis of interstitial pneumonia. Intraoperative blood loss and duration of postoperative chest drainage were significantly less with TS than with thoracotomy. The length of postoperative hospital stay and social insurance costs with TS was significantly less than with thoracotomy. These results show that TS for the diagnosis of interstitial pneumonia is superior to open thoracotomy in terms of surgical stress and cost.

Adult↗

PubMed1998

[A case of traumatic aneurysm of the brachiocephalic artery].

Traumatic aneurysm of the brachiocephalic artery is rate. We presented a case of traumatic aneurysm of the brachiocephalic artery caused by traffic accident. A 28-year-old woman suffered a blunt chest trauma. A chest X-ray revealed a widening of the superior mediastinum and multiple rib fractures. CT scanning demonstrated left hemothorax with lung contusion and upper mediastinal hematoma. An aortography was performed which showed aneurysmal dilatation at the origin of the brachiocephalic artery. The patient underwent an operation 24 hours after chest injury. An aorto-right common carotid artery and right subclavian artery bypass with bifurcated Dacron graft was performed while monitoring temporary artery pressure. After resection of aneurysm, We found that about 3 cm longitudinal laceration of intima on the posterior wall of brachiocephalic artery. Her post operative condition was good and no neurological defect was noted.

Accidents, Traffic↗

PubMed1998

Successful treatment of bilateral deep femoral aneurysms and multiple iliac aneurysms associated with severe aortic valve disease: report of a case.

We report herein the case of a patient in whom aneurysms of the bilateral deep femoral arteries (DFA) and multiple iliac aneurysms associated with severe aortic valve disease were successfully treated by a two-staged operation. The patient was a 74-year-old man who had dense calcification of the ascending aorta and aortic arch. Prior to aortic valve replacement (AVR), the aneurysms of the DFA and internal iliac arteries were resected. The terminal end of the abdominal aorta and bilateral common iliac arteries were then reconstructed with a Y graft to be used as a possible alternative arterial input route in place of the ascending aorta for extracorporeal circulation during the AVR. The inferior mesenteric artery (IMA) was well developed, and the external iliac arteries and their branches were preserved at aneurysmectomy. Postoperatively, there was no ischemia of the pelvic organs or the hip muscles. The AVR was subsequently performed 5 weeks after the first operation, and the patient was discharged after an uneventful postoperative course.

Aged↗

PubMed1998

Improvement in esophageal varices and liver histology postoperatively in Budd-Chiari syndrome.

BACKGROUND: In the past 17 years, 32 patients with Budd-Chiari syndrome were treated by reconstruction of the occluded inferior vena cava and reopening of the hepatic veins under femoro-femoral normothermic extracorporeal partial bypass. The mean follow-up was 8 years (range, 1.5 to 17 years). METHODS: To evaluate the benefits of our operative procedure, we compared the preoperative, early postoperative, and late postoperative endoscopic appearance of the esophageal varices and the histologic findings of the liver tissue obtained intraoperatively and at a later date. RESULTS: The esophageal varices found preoperatively in 29 patients (90.6%) had disappeared in 7 patients by the time of discharge, and in 2 patients they disappeared 4 to 7 years after surgery. In the remaining 20 patients, the grade of the esophageal varices was reduced markedly. Histologic examination of the liver showed cirrhosis in 22 patients, fibrosis in 9 patients, and severe congestion in 1 patient. Inspection of the liver in the late postoperative period (in 10 patients) showed improvement in centrilobular congestion and no increase in interlobular fibrosis. CONCLUSIONS: Gradual and steady improvement of esophageal varices and hepatic fibrosis can be achieved after our operative procedure.

Adult↗