Detection of lipid peroxidation and hydroxyl radicals in brain contusion of rats

To examine the relationship between the free radicals and brain tissue damage, we investigated the intensity of brain hydroxyl (OH) radical generation and lipid peroxidation in the rat contusion injury model. A unilateral contusion was induced by a weight-drop method. All rats were decapitated six hours after the injury, and brain samples were taken from three portions (core, peripheral, and distal) to examine the specific gravity as an indicator of brain edema, generation of OH using an electron paramagnetic resonance spectrometer (EPR), and malondialdehyde (MDA) and 4-hydroxyalkenals production. Analysis of the specific gravity revealed cerebral edema on the ipsilateral side in the injured group. The signal intensity of EPR in the core and peripheral portions in the contusion group was significantly higher than that in the distal portion of the contusion group and that of all portions in the control animals. No significant difference was observed between the core and peripheral portions of the contusion group. The MDA and 4-hydroxyalkenals production was significantly higher in the core and peripheral portions than in the distal portion of the contusion group and that of all portions of the control group. The degree of posttraumatic brain edema was closely correlated with the increase of DMPO-OH adduct, MDA, and 4-hydroxyalkenals. These results support the current concept that free radical production following traumatic brain injury may induce lipid peroxidation and may be the direct cause of edema formation.

Repair of ruptured anastomotic aneurysm: elephant trunk technique after endovascular covered stents

Endovascular covered stents were successfully applied to temporarily halt hemoptysis and postpone surgical intervention in a 69-year-old man with a ruptured anastomotic false aneurysm of the distal aortic arch. Surgical graft implantation was performed successfully by the elephant trunk technique 14 days after the endovascular stent-grafting, at which time aspiration pneumonia had subsided.

Mitral valve repair through combined left atrial and ventricular approach for congenital mitral stenosis

A 3-year-old boy underwent mitral valve repair for congenital mitral stenosis through combined superior-septal atriotomy and apical left ventriculotomy. The operation was performed safely with excellent exposure of the subvalvular apparatus by the ventricular approach, while sufficient visualization of the valvular lesion was obtained by the atrial approach. Postoperative echocardiography demonstrated normal left-ventricular motion and no residual mitral stenosis.

Mitral valve repair with extensive resection of the anterior leaflet for regurgitation due to Barlow's disease. Report of a case

We recently performed mitral valve repair for a case of mitral regurgitation due to Barlow's disease, which is relatively rare in Japan. Both the anterior and posterior leaflets were affected by advanced myxomatous change, and appeared markedly thickened and redundant. Although extensive resection of the anterior leaflet is not a generally accepted method, nearly one fourth of the anterior leaflet was resected in this case. Now, at 36 months after the operation, there is only trivial regurgitation and the patient is doing well and without symptoms. We believe that extensive resection of the anterior leaflet can be a useful treatment for repair of a redundant anterior leaflet with excess tissue.

[Successful surgical treatment for type B aortic dissection with Marfan's syndrome after aortic root and mitral valve replacement: report of a case]

A 30-year-old female with Marfan's syndrome underwent aortic root replacement for annuloaortic ectasia and mitral valve replacement for mitral regurgitation. She remained well until 16 months postoperatively when she had sudden onset of pain. Preoperative angiogram showed Stanford B aortic dissection. Thoracoabdominal aortic replacement was performed successfully under deep hypothermic bypass.

Effects of lecithinized superoxide dismutase on traumatic brain injury in rats

Only small amounts of superoxide dismutase (SOD) are present in the extracellular space to scavenge excess amounts of superoxide anions (02-) released after traumatic brain injury (TBI). Experiments were performed in rats with cerebral contusion produced by weight-drop technique. We investigated the effects of exogenous lecithinized SOD (PC-SOD) on accumulation of 02- produced in our model, by measuring the level of SOD activity (using the NBT-reducing method) and the expression of copper, zinc-SOD (Cu, Zn-SOD) mRNA (by Northern blot analysis). As determined by tissue-specific gravity, administration of PC-SOD reduced brain edema in the periphery of the lesion 6 h after contusion. SOD activity increased in the peripheral region at 30 min after contusion, but returned to normal levels at 6 h after TBI. Administration of PC-SOD increased SOD activity up to 6 h after TBI. The expression of Cu, Zn-SOD mRNA increased in the core region, peripheral portion, and contralateral hemisphere up to 6 h after TBI, then was suppressed in all three regions by PC-SOD. Our results confirm the important role of 02- in the development of brain edema after TBI and indicate that PC-SOD diminishes brain edema through a protective effect against 02-.

Surgical repair for atrial septal defect in patients over 70 years of age

Atrial septal defect (ASD) is the most common congenital heart anomaly encountered in adults. For patients over 60 years old, acceptable operative mortality and symptomatic improvement following surgery have been reported. We reviewed patients with ASD aged over 70 years and studied their preoperative hemodynamics, the surgical procedures used and the results. Between January 1994 and December 1996, 18 patients over the age of 40 years underwent surgical repair of ASD. Four patients were over 70 years of age (Group A). The other 14 patients were studied as a control group (Group B). We compared the preoperative clinical status, hemodynamic data, and surgical results between the two groups. The postoperative clinical status of Group A was studied during the follow-up period. The NYHA functional class of the elderly patients was greater than that of the middle-aged patients. None of the elderly patients had pulmonary hypertension. Moderate or severe tricuspid valve regurgitation (TR) due to annular dilatation was found, and tricuspid annuloplasty was performed in all four elderly patients. There were no operative or hospital deaths in either group. The NYHA functional class and TR improved in all the aged patients after surgery. In order to prevent progressive tricuspid annular dilatation due to an intraatrial left to right shunt, surgical closure of ASD should be performed for physically active adult patients.

[Preservation of olfaction in frontal transbasal approach]

Lesions in the frontal base and clival area have conventionally been approached using the transbasal approach described by Derome and Guiot. However, this approach necessitates removal of the crista galli and sectioning of the olfactory rootlets with the associated risk of anosmia and cerebrospinal fluid leak and, in addition, complex reconstruction of the frontal base is required. We describe a new approach to deeply situated tumors in the frontal base, parasellar and clival area which is a modification of Spetzler's craniofacial approach with preservation of olfaction. In this approach, circumferential osteotomy cuts are made around the cribriform plate to permit en block removal with its attachment to both the dura and underlying mucosa. Opening of the dura is avoided and the cribriform bone is used to reconstruct the frontal base. Three patients underwent surgery using this approach for treatment of recurrent pituitary adenoma in two cases and for clivus chordoma in one. In one patient, olfactory function was not preserved because resection of nasal mucosa was small. In the other two patients, however, olfaction was preserved by creating a cribriform plate complex with a sufficient area of resection of nasal mucosa and tumors were completely removed. Olfaction can be preserved, CSF leakage can be prevented, and facial skin incision and complex frontal base reconstruction can be avoided when this technique for maintaining normal olfactory-cribriform anatomy is used in frontal transbasal approaches.

Hemoptysis from an emphysematous bulla developing after open-heart surgery: report of a case

We present herein the case of a 62-year-old woman with an emphysematous bulla who developed intractable hemoptysis 16 days after undergoing mitral and aortic valve replacement with tricuspid annuloplasty. A bronchoscopic examination with balloon occlusion of the bronchial lumen revealed that the blood source was the right middle lobe bronchus. A computed tomographic (CT) scan of the chest subsequently demonstrated a blood-filled emphysematous bulla in the right middle lobe. A right middle lobectomy was performed and the bulla was observed to be swollen with clotted blood. The respiratory tract bleeding stopped immediately after the lobectomy. Pathohistological examinations suggested that disruption of the pulmonary vessels in the wall of the bulla had caused the respiratory tract bleeding.

[A patient with mitral stenosis due to infective endocarditis]

A 51-year-old woman presented with mild stenosis of the mitral valve which had become thickened and rigid due to infective endocarditis, manifesting as persistent fever of up to 40 degrees C and general fatigue of a few days' duration. A harsh systolic murmur was heard. Multiple blood cultures revealed alpha-streptococcus. Echocardiography disclosed asymmetric septal hypertrophy (interventricular septal thickness/posterior wall thickness, 19/14 mm) and systolic anterior wall motion of the mitral valve. Continuous wave Doppler ultrasonography showed a peak left ventricular outflow tract pressure gradient of 170 mmHg. Transesophageal echocardiography revealed vegetations on the anterior mitral leaflet, aortic valve and interventricular septum along the left ventricular outflow tract. In particular, the anterior mitral leaflet was thickened and moved poorly. The calculated mitral valve areas was 1.5 cm2 and peak diastolic left atrium-left ventricle pressure gradient was 7 mmHg. A specimen of the mitral valve did not reveal commissural adhesion, but the anterior mitral leaflet showed marked fibrous thickening caused by scarred vegetation. Based on these findings, the diagnosis was hypertrophic obstructive cardiomyopathy complicated by infective endocarditis and "mitral stenosis". Valvular regurgitation is a common complication of active and healed infective endocarditis. In contrast, infective endocarditis rarely causes valvular stenosis except for stenosis caused by large fungus vegetation.

[Preventive concomitant aortic root replacement for annuloaortic ectasia in a patient with Marfan syndrome undergoing mitral valve replacement for mitral regurgitation]

A 28-year-old woman presented with Marfan syndrome combined with severe mitral regurgitation and annuloaortic ectasia. The ascending aorta was dilated to 48 mm in diameter without aortic regurgitation. Considering the increased operative risk due to complication with aortic dissection, simultaneous replacement of the mitral valve and aortic root were performed. Her postoperative course was uneventful. Several options of the surgical treatment for Marfan syndrome are discussed.

Expression of cell division cycle 2 kinase transcription in chronically rejected cardiac allografts of nonhuman primates

Accurate diagnosis and prevention of graft arteriosclerosis, known as chronic rejection, is critical to the success of cardiac transplantation, but often is difficult to attain. Expression of cell division cycle (cdc) 2 kinase, which plays a critical role in cell transition through the G2/M phase, is critical to the proliferation of vascular smooth muscle cells. To evaluate the usefulness of cdc2 kinase expression for pathophysiological analysis of chronic rejection, heterotopic cardiac transplantation was performed in Japanese monkeys (n = 7). Standard reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ RT-PCR were performed to evaluate the expression. In the coronary arteries of chronically rejected allografts, enhanced cdc2 kinase expression was observed in thickened intima and media, while none was expressed in native hearts. The cdc2 kinase was also expressed before the intimal thickening occurred. These results indicate that enhanced expression of cdc2 kinase is a sensitive indicator for chronic cardiac rejection; targeting cdc2 kinase may be a viable gene therapy for prevention of this vasculopathy.

Nonmuscle and smooth muscle myosin heavy chain expression in rejected cardiac allografts. A study in rat and monkey models

BACKGROUND

Diagnosis of acute rejection and graft arteriosclerosis (chronic rejection) is critical to the success of cardiac transplantation, but accurate diagnosis is often difficult. We have reported that there are three types of vascular myosin heavy chain (MHC) isoforms: SM1, SM2, and SMemb. SM2 is specifically expressed in differentiated smooth muscle cells (SMCs). SMemb is a nonmuscle-type MHC abundantly expressed in SMCs of fetal aorta.

METHODS AND RESULTS

To evaluate the usefulness of MHC expression for diagnosis and analysis of acute and chronic rejection, heterotopic cardiac transplantation was performed in rats and monkeys. Immunohistochemistry, electron microscopy, and Northern blot assay were performed to evaluate MHC expression. SMemb was expressed in spindle-shaped cells located in acutely rejected myocardium in the rats and monkeys. These cells were also observed in areas lacking cellular infiltration. These SMemb-positive cells were activated fibroblasts or myofibroblasts. SMemb mRNA was enhanced parallel to the progression of acute rejection. In the coronary arteries of chronically rejected allografts, enhanced SMemb and reduced SM2 expression was observed in both thickened intima and media. The reduced medial SM2 expression was observed before the intimal thickening occurred. These cells were phenotypically modulated SMCs.

CONCLUSIONS

Altered expression of MHC isoforms is a sensitive indicator in the diagnosis of acute and chronic cardiac rejection. The pathophysiology of this alteration in MHC isoform expression should be studied further to elucidate the pathogenesis of cardiac rejection.

Successful conduit repair using aortic homograft in a Jehovah's Witness child

A 10-year-old female child of the Jehovah's Witness faith presented with congenitally corrected transposition of the great arteries (S,L,L), pulmonary atresia, and a ventricular septal defect. A successful surgical correction was performed using an aortic homograft as a valved extracardiac conduit without the use of homologous blood or blood products. We used permanent splinting of the sternum with a methyl methacrylate resin plate to prevent compression of the conduit.

Mitral valve replacement after percutaneous transvenous mitral commissurotomy

Percutaneous transvenous mitral commissurotomy is widely performed as the first choice of the non-pharmacological treatments for mitral stenosis. Five patients have been identified who required mitral valve replacement after percutaneous transvenous mitral commissurotomy. The causes leading to mitral valve replacement were mitral regurgitation in three cases and insufficient commissurotomy in two. Massive mitral regurgitation is one of the most serious complications of percutaneous transvenous mitral commissurotomy. This report aims to elucidate the mechanism of massive mitral regurgitation occurring during percutaneous transvenous mitral commissurotomy. In every such case, there was a large tear in the posterior leaflet without any split in the commissures. The Japanese literature reports that 16 patients have undergone mitral valve replacement for massive regurgitation after percutaneous transvenous mitral commissurotomy: 14 of these cases had a tear in one of the leaflets and no evidence of splitting of the posterior commissure. These facts indicate that relative fragility of the leaflets as compared with rigidity of commissural fusion, especially in the posterior commissure, is an important factor of massive mitral regurgitation during percutaneous transvenous mitral commissurotomy.

[Echocardiographic evaluation of hemodynamic function of CarboMedics heart valve in the aortic position in patients with small aortic annuli]

Hemodynamic parameter of CarboMedics heart valve in the aortic position was evaluated using Doppler echocardiography in 46 patients with small aortic annuli. The size of prosthetic valve were 19 mm in 6 cases, 21 mm in 15 and 23 mm in 25. In patients with 19 mm valve, trans-valvular peak pressure gradient was 42.2 +/- 11.8 mmHg, mean pressure gradient was 17.3 +/- 9.3 mmHg, and left ventricular systolic pressure was 174 +/- 12 mmHg. These values were significantly larger than those of the other two groups. Effective orifice area index, discharge coefficient, doppler velocity index and stroke volume showed no significant difference among each group. After aortic valve replacement for aortic stenosis, left ventricular mass decreased to around 70% of preoperative value in all groups, but significant left ventricular hypertrophy remained at two years postoperatively. We conclude that hemodynamic performance of CarboMedics heart valve in the aortic position was satisfactory, although 19 mm valve seemed to be fairly small for adult patients and deliberate patient selection is necessary.

Mid-term result of one and one half ventricular repair in a patient with pulmonary atresia and intact ventricular septum

A 10-year-old girl was referred to us with a diagnosis of pulmonary atresia and intact ventricular septum with a severely hypoplastic right ventricle and atrial septal defect. Her tricuspid valve diameter (TVD) was 48.5% of normal, with a TVD Z-score of -6.7, while right ventricular end-diastolic volume was 53.4% of normal. As a definitive procedure, one and one half ventricular repair using a bidirectional cavopulmonary shunt (BCPS) was performed instead of a Fontan procedure. The postoperative course was uneventful without episodes of low cardiac output or elevated right atrial pressure. She has been doing well during a follow-up period of 3 years.

[Successful redo-AVR with cryopreserved allograft for prosthetic valve endocarditis : report of a case]

A 20-year-old male undergoing mechanical aortic valve replacement suffered from prosthetic valve endocarditis by Coagulase negative Staphylococci 3 months postoperatively. Echocardiography revealed left ventricular distention, severe paravalvular leakage, valve detachment and large periannular abscess adjacent to the left main coronary artery. Redo-AVR was successfully performed with a cryopreserved aortic allograft by cylinder technique. The orifice of abscess was covered with the aortic wall of the graft. Postoperative echocardiography showed trivial central regurgitation and the abscess cavity went on vanishing. He discharged from hospital 2 months later without any symptom.