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Biomedical subjects

M Ohmi

Publications and source records attributed to M Ohmi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Quantitative analysis of cardiac 3-L-nitrotyrosine during acute allograft rejection in an experimental heart transplantation.

BACKGROUND: Recent studies have shown that nitric oxide interacts with superoxide to form peroxynitrite, a potent oxidant that modifies cellular proteins producing 3-L-nitrotyrosine (N-Tyr). This study was designed to evaluate N-Tyr quantitatively with high-performance liquid chromatography (HPLC) during cardiac allograft rejection. METHODS: Rat transplanted hearts (allogeneic or syngeneic grafts) were examined with HPLC analysis, immunohistochemistry for N-Tyr, and histological studies on 0, 1, 3, and 7 days after transplantation. RESULTS: No histological rejection was found in syngeneic grafts, or day 0 or 1 allografts. HPLC demonstrated that N-Tyr in allografts increased on day 1 and continued to increase through day 7, while N-Tyr was not detected in any syngeneic grafts. Immunostaining of the allografts did not show N-Tyr on day 1. CONCLUSION: These results demonstrate that N-Tyr shows a time-dependent accumulation in cardiac allografts during acute rejection. N-Tyr detection using HPLC may be an useful maker for early diagnosis of acute rejection before pathological rejection occurs.

Acute Disease↗
PubMed1999

Fontan with pedicled pericardium.

Pedicled pericardium is a useful viable material for cardiac surgery. In an adolescent case, the extracardiac lateral tunnel of a Fontan connection was successfully constructed with pedicled pericardium. This procedure is expected to allow the growth of the tunnel and to need no anti-coagulant therapy, while careful long-term follow-up is necessary.

Child↗
PubMed1999

Cardioprotective effect of orally administered angiotensin-converting enzyme inhibitor against ischemia. Reperfusion injury in the isolated rat heart.

Angiotensin-converting enzyme inhibitors are reported to be cardioprotective against ischemia/reperfusion injury. Few studies have been made, however, on the cardioprotectiveness of orally administered angiotensin-conrerting enzyne inhibitors. Wistar rats were pretreated with oral delapril--30 mg/kg/day in the low-dose group and 90 mg/kg/day in the high-dose group--for one week. Cardiac function recovery was assessed after ischemia/reperfusion in the isolated working heart model. Rat hearts in the high-dose group were also reperfused with a solution containing nitro-L-arginine methyl ester, a nitric-oxide synthase inhibitor. Oral pretreatment of delapril did not affect baseline cardiac function. The percentage of cardiac output recovery for controls was 22 +/- 4.5%, for the low-dose group 44 +/- 6.5% (P < 0.05 versus controls), and for the high-dose group 76 +/- 5.3% (P < 0.001 versus controls and low-dose). Although coronary vascular resistance at the end of reperfusion showed no difference, mean coronary vascular resistance early after reperfusion was significantly lower (P < 0.0001) in both delapril groups than in control. In the high-dose group, reperfusion with L-NAME significantly increased coronary vascular resistance after ischemia/reperfusion and attenuated the cardioprotectiveness of delapril (P < 0.05 versus without nitro-L-arginine methyl ester). We thus found that oral administration of delapril was cardioprotective dose-dependently against ischemia/reperfusion injury. Nitric oxide appeared to be involved in the mechanism behind this cardioprotective effect.

Administration, Oral↗
PubMed1999

Remnant omental transfer for the mediastinitis after coronary bypass surgery with right gastroepiploic artery.

A one-stage procedure for the treatment of mediastinitis after coronary bypass surgery utilizing the right gastroepiploic artery is described. This procedure consists of thorough debridement of mediastinal pus and necrotic tissue, excision of infected sternal bone, mediastinal irrigation, and immediate transfer of the "remnant" omental pedicle based on the "left" gastroepiploic artery without postoperative drainage or irrigation. Recently, this procedure was applied to our patients followed by excellent results.

Aged↗
PubMed1999

[Acquired pulmonary stenosis caused by mediastinal mature teratoma: a case report].

A 13-year-old girl was admitted with a sudden onset of chest oppression. Mediastinal teratoma was suspected on chest X-ray and CT scan. A grade 2/6 systolic murmur was heard at the upper left sternal area and cardiac catheterization showed mild pulmonary stenosis. After resection of the tumor, the murmur disappeared and histopathological diagnosis was mature teratoma. This is a rare case report of pulmonary stenosis caused by mediastinal mature teratoma.

Adolescent↗
PubMed1999

Gaze orientation during full-field and peripheral field passive optokinesis.

During full-field optokinetic nystagmus the mean position of gaze shifts the eyes in the direction of the fast phase. The driving force for this, pre-supposes that the preferred locus for the position control system, is shifting gaze into the direction where the motion is coming from. In this study, six subjects were examined to determine whether the absence of the central visual field would influence the mean position of gaze during passive optokinesis. Our findings indicate that a full field and a central field restricted to 20 deg, evoked gaze shifts of up to 7 deg into the direction of the fast phase. However, when the central field was masked by either 12.5 deg or 25 deg the mean gaze position was found to be significantly reduced (p < 0.05). This effect was not influenced by the velocity of the stimulus (p > 0.05). These results lead us to conclude that gaze orientation during optokinesis is strongly influenced by the area of retina stimulated. The role of the slow eye movement control system and possible cognitive strategies adopted during selective spatial attention are discussed in the light of this finding.

Adult↗
PubMed1998

Successful management of left main bronchial stenosis as a rare complication of pericardiectomy.

We present a rare complication of pericardiectomy and the effective management thereof. A 67-year-old female with dyspnea and upper abdominal pain was received at our department upon referral. Chest roentgenogram and cardiac catheterization preceded a diagnosis of constrictive pericarditis. Pericardiectomy was performed subordinate to median sternotomy and left anterolateral thoracotomy. Extubation was carried out on day 2 but reintubation was necessitated on the same day as a result of progressive dyspnea. Chest roentgenogram revealed an atelectasis of the left lung. Fiberoptic bronchoscopy showed left main bronchial stenosis resulting from a pulsating external structure. A postoperative computed tomogram substantiated the stenotic left main bronchus between the dilated left pulmonary artery and the thoracic descending aorta. An expandable metallic stent for the treatment of this complication was selected over other invasive procedures. Two years of follow-up reveal no complications. Accordingly, an expandable metallic stent has demonstrated its effectiveness not only on bronchial stenosis due to malignancy or tuberculosis but on benign cases such as this as well.

Aged↗
PubMed1998

[Open distal anastomosis or aortic balloon occlusion technique during complete aortic arch replacement].

The technique of open distal anastomosis or application of aortic balloon occlusion catheter designed to occlude the descending thoracic aorta have been used in 33 and 19 patients, respectively, to control bleeding during the procedure of distal anastomosis for complete aortic arch replacement with a prosthetic graft. These two techniques allowed us a simple approach to the lesion and the avoidance of clamp injury to the fragile aortic tissue. Open distal anastomosis was applied for 91% patients of operated aortic dissection and all emergent cases, it's duration ranged from 10 to 110 minutes with an average of 58 minutes under 18.2 degrees C of lowest esophageal temperature. On the other hand, aortic occlusion balloon was inserted for mainly true aortic aneurysm patients without an emergency, and helped to maintain the perfusion pressure on a lower part of body around 50 mmHg by the 1550 ml/min in an average of perfusion flow femoral artery under 21.2 degrees C of temperature. The difference of postoperative renal and liver function evaluated by serum enzyme levels of total bilirubin, GOT, GPT, LDH, creatinine and BUN did not reach to statistical significance between the patients using open distal anastomosis and balloon occlusion, however, the incidence of postoperative complication including either renal, liver dysfunction, abdominal problem or paraplegia was significantly higher in the patient group with open distal technique. Either open distal anastomosis or aortic balloon occlusion technique would be appropriately selected according to the patient's characteristics or the condition of aortic disease to be operated.

Aged↗
PubMed1998

Tricuspid valve closure for neonatal Ebstein's anomaly.

A respirator-dependent 11-day-old boy with Ebstein's anomaly is presented. His cardiac anomaly with progressive cardiomegaly was first noticed at 24 weeks' gestation on fetal echocardiography. After birth, he required mechanical ventilation because of massive tricuspid regurgitation and restricted pulmonary blood flow. The operation of tricuspid valve patch closure, resection of right atrial wall, and central shunt successfully weaned him from the respirator on postoperative day 13. Cavopulmonary anastomosis was performed without problem when the patient was 8 months of age.

Ebstein Anomaly↗
PubMed1998

Brain damage after aortic arch repair using selective cerebral perfusion.

BACKGROUND: Selective cerebral perfusion is one of the most popular methods for cerebral protection during aortic arch repair. However, causes of postoperative brain damage are not fully understood. We analyzed brain damage after aortic arch repair using selective cerebral perfusion for true aortic arch aneurysm in regard to preoperative cerebral infarction and intracranial and extracranial occlusive arterial disease. METHODS: Over a 9-year period, 60 patients with true aortic arch aneurysm underwent aortic arch repair using selective cerebral perfusion. Postoperative brain damage was evaluated in regard to preoperative cerebral infarction detected by computed tomography, magnetic resonance imaging, or both in 50 patients and intracranial and extracranial occlusive arterial disease detected by digital subtraction angiography, magnetic resonance angiography, or both in 35 patients. RESULTS: Seven (12%) of the 60 patients died within 30 days of operation. Postoperative brain damage occurred in 6 (10.5%) (3, coma, and 3, hemiplegia) of 57 patients; 3 patients who died without awakening were excluded. Preoperatively, old cerebral infarction was detected in 9 patients (18%), and silent cerebral infarction (lacunar infarction and leukoaraiosis) was diagnosed in 26 patients (52%). Postoperative brain damage occurred in 3 (33%) of the 9 patients with preoperative cerebral infarction and in 3 (23%) of 13 patients with negative preoperative brain findings; this excludes 2 patients who died without awakening. No patient with silent cerebral infarction had postoperative brain damage. Occlusive arterial disease was detected in 7 patients (20%). The incidence of brain damage in these patients was 71% (5/7), which was significantly greater than that of 4% (1/28) in patients without occlusive arterial disease (p < 0.001). CONCLUSIONS: Silent cerebral infarction may not be a risk factor for postoperative brain damage. Preoperative evaluation of intracranial and extracranial occlusive arterial disease provides important information as to whether a patient might sustain brain damage after aortic arch repair using selective cerebral perfusion.

Aged↗
PubMed1998

Replacement of the ascending aorta and aortic valve with a composite graft: operative and long-term results.

The purpose of this study is to analyze our treatment experience on patients with ascending aortic aneurysms, with aortic regurgitation. From January 1974 to December 1995, 49 patients underwent replacement of the aortic valve and ascending aorta with a composite graft, in which primary operation cases were 44 and reoperation ones were 5. The Bentall technique was used in 20 patients, the button technique in 11, the interposition graft technique in 11, and a combination of the interposition graft and button technique in 7. All but one reoperation cases underwent the interposition graft technique. Hospital mortality was 30% for the Bentall technique, and 9.1% for the button technique and 9.1% for the interposition graft technique; there was no hospital mortality in the combination of the interposition graft and button technique. Hospital mortality of interposition graft technique in primary operation cases was 9.1%, and that in reoperation cases was 0%. Hospital mortality in patients underwent from 1974 to 1985 was 30.8%, 27.8% from 1986 to 1991, and 0% from 1992 to 1995. Five late deaths occurred in the Bentall group (35.7%) and one late death in the button technique (9.1%). Not late deaths in the other groups have occurred. In summary, operative mortality in Bentall technique group was higher than that of the other groups. Operative results were improved by the change of operative methods. The interposition graft technique is preferable for patients undergoing reoperation or when tension on the ostial anastomoses may occur. The button technique is best for patients with aortic dissection or inflammation involving the coronary ostia.

Adult↗
PubMed1998

[Brain damage following aortic arch repair with regard to techniques of selective cerebral perfusion and preoperative cerebral lesions].

One hundred and twenty-nine aortic aneurysm patients (true 68 and dissection 61) underwent aortic arch repair from January 1987 to December 1995. Postoperative brain damage was evaluated regarding both preoperative brain lesions and techniques of selective cerebral perfusion (SCP) in that one pump for SCP until April 1992, then two pumps were employed, one for right and the other for left hemisphere of the brain. Overall hospital mortalities were 21% in true and 13% in dissecting aneurysms. Ten patients were complicated with postoperative brain damages (coma 8 and hemiplegia 2), registering 7.8% of total patients. Both history of stroke and silent cerebral infarction (SCI) detected by CT and/or MRI were considered to be positive in the mean of having preoperative brain lesions. Although there was no significant difference between incidences of postoperative brain damage in true and dissecting aneurysms, registering 11% and 4% respectively, preoperative brain lesions in true aneurysm (68%) was significantly greater than dissecting aneurysm (32%). Furthermore, the incidence of postoperative brain damage was 22% in one-pump SCP which was significantly greater than 3% in two-pumps SCP in the patients with a true aneurysm. But there was no postoperative brain complication in patients with SCI even using either one two pumps for SCP. The present data suggest two-pumps SCP is better technique for cerebral protection compared to one-pump SCP for aortic arch repair.

Adult↗
PubMed1998

Sutureless ringed graft replacement of descending thoracic aorta with extensive calcification.

A 79-year-old hypertensive woman, with fusiform shaped atherosclerotic aneurysm in the descending thoracic aorta whose medial layer was maintained by an extensive solid calcium plate (porcelain aorta), was successfully treated using a sutureless intraluminal ringed graft. Spools of the ring were fixed by circumferential ligatures at both proximal and distal sites of anastomosis and a dilated segment of the aorta was replaced with the tube graft.

Aged↗
PubMed1998

[Long-term surgical results of acute aortic dissection].

Between 1988 and 1997, 69 patients underwent surgery for acute aortic dissection: 65 patients had an acute type A (AcA) and 8 an acute type B (AcB) aortic dissection. The hospital mortalities were 16.9% for AcA and 25% for AcB. Actuarial survival rates including hospital deaths after 5 and 8 years were 70% and 58% for AcA patients and no late death or cardiovascular event occurred in AcB patients during follow-up periods. Freedom from cardiovascular events was 88% and 70% at 5 and 8 years, and freedom from reoperation was 94% at 5 and 8 years for operative survivors of AcA. There were no differences on actuarial survival rates between ascending aortic repair and arch repair, ringed-graft and suture anastomosis, and postoperatively patent false lumen and closed false lumen. There were no differences on freedom from cardiovascular events between ascending aortic repair and arch repair, and ringed-graft and suture anastomosis, however, patients with postoperatively patent false lumen showed significantly lower freedom from cardiovascular events registering 85% and 59% at 5 and 8 years compared with 94% at 5 and 8 years in patients with closed false lumen.

Acute Disease↗
PubMed1997

[Redo operation after surgery for aortic aneurysm and dissection].

Thirteen patients who underwent redo operation after surgical treatment of aortic aneurysm and dissection were presented. In 8 patients, redo operations were performed for aortic dissection following aortic valve replacement. A-C bypass, the Koster-Collins operation and replacement of thoracic aorta. In the other 5 patients, the reasons for redo operation were aortic root enlargement after replacement of ascending aorta and aortic valve replacement, pseudoaneurysm and aneurysmal dilatation around coronary button for the Bentall operation and recurrent aneurysm after patch aortoplasty and thoracoabdominal replacement using the Crawford's maneuver. To prevent these redo operation, adequate selection of surgical procedures and meticulous operative techniques should be required in primary operation.

Aortic Dissection↗
PubMed1997

[Early and late results of replacement of the ascending aorta and/or aortic arch using selective cerebral perfusion].

From 1987 to 1994, 116 patients received replacement of the ascending and/or aortic arch using selective cerebral perfusion. They were 82 male and 34 female, with average age of 64 years. There were 63 dissecting and 53 true aneurysms. Extent of replacement was: ascending aorta in 13, aortic root in 2, aortic arch in 93, and aortic root and complete arch in 8. Aortic arch replacements were composed of: 29 partial proximal aortic arch replacements, 44 complete aortic arch replacements, and 20 partial distal aortic arch replacements. Nineteen (16.4%) hospital deaths occurred. Univariate testing of pre-, intra-, and post-operative variables followed by stepwise logistic regression analyses identified elderly, ischemic heart disease, postoperative neurologic complication, cardiac dysfunction, renal failure, and massive bleeding as factors having independent association with hospital mortality. Neurologic complication was found in 10 patients (8.6%), and risk factor for this complication was preoperative peripheral vascular disease. Follow-up of hospital survivors documented an overall cumulative 5-year survive rate of 69%. There was no significant difference between dissection and true aneurysms in 5-year survive ratios, which were 63% and 82%, respectively. During follow-up periods, 18 patients died. Half of these cases were vascular deaths, caused by rupture, sudden death and secondary operation. Univariate analyses followed by stepwise Cox testing indicated that chronic obstructive pulmonary disease and a history of postoperative massive bleeding were associated with decreased later survival. Our experience suggests that selective cerebral perfusion is a safe technique for the repair of ascending aorta and/or aortic arch problems. High-risk subgroups of patients with these aortic problems can be identified by risk factors. Aggressive and careful management is necessary for such subgroups to improve early and late survival rates.

Adult↗