[Thoracic aortic aneurysm associated with pseudocoarctation; report of a case]

A 20-year-old woman without any significant history of disease was referred for further investigation of an aortic arch aneurysm. The arterial blood pressure in the right arm was higher than in the left arm and in both legs. An multi-detector row computed tomography (MDCT) and an aortogram revealed narrowing of the middle aortic arch, kinking at the ligamentum arteriosum, subsequent multiple aneurysmal formation, and stenosis and narrowing of the descending aorta. The left subclavian artery branched from the 1st aneurysm. We resected the aneurysms and reconstructed the distal aortic arch and left subclavian artery using a woven polyester graft. This case was diagnosed as thoracic aortic aneurysm associated with pseudocoarctation, which is a quite rare congenital anomaly.

Size effects of nanomaterials on lung inflammation and coagulatory disturbance

Effects of nano-sized materials (nanomaterials) on subjects with predisposing inflammatory disorders have not been well elucidated. This study examined the effects of pulmonary exposure to TiO2 nanomaterials on lung inflammation induced by lipopolysaccharide (LPS) and consequent systemic inflammation with coagulatory disturbance in mice, in particular regarding their size-dependency. Also, gene expression pattern in the lung was compared among the experimental groups using cDNA microarray analysis. ICR male mice were divided into 8 experimental groups that intratracheally received vehicle, three sizes (15, 50, 100 nm) of TiO2 nanomaterials (8 mg/kg), LPS (2.5 mg/kg), or LPS plus nanomaterials. Twenty four h after the treatment, these nanomaterials exacerbated the lung inflammation and vascular permeability elicited by LPS, with an overall trend of amplified lung expressions of cytokines such as interleukin (IL)-1beta, macrophage chemoattractant protein (MCP)-1, and keratinocyte chemoattractant (KC). LPS plus nanomaterials, especially of a size less than 50 nm, elevated circulatory levels of fibrinogen, IL-1beta, MCP-1, and KC, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. cDNA microarray analyses revealed that there was no difference in gene expression pattern between the LPS group and the LPS + nanomaterial. These results suggest that nanomaterials exacerbate lung inflammation related to LPS with systemic inflammation and coagulatory disturbance, and that the exacerbation is more prominent with smaller nanomaterials than with larger ones.

65 NUCLEAR REPROGRAMMING OF PORCINE CELLS AND THEIR USE AS DONOR CELL FOR NUCLEAR TRANSFER AFTER TREATMENT IN XENOPUS EGG EXTRACTS

Revealing an adequate cell state for nuclear reprogramming is essential to achieve efficient production of cloned embryos and animals. Previous reports suggest that nuclei from undifferentiated cells such as blastomeres or embryonic stem cells can support efficient development of cloned embryos to term. In recent years, differentiated somatic cells are frequently used for donor cells because of ease of preparation and application for genetic modification. The efficiency of the somatic cell nuclear transfer (SCNT) is still extremely low. We hypothesized that somatic cells that had been reprogrammed to dedifferentiated states before SCNT might support higher developmental ability of SCNT embryos. To test this hypothesis, porcine fibroblast cells were treated with Xenopus egg extracts, and the extract-treated cells (ETCs) were used as donor cell for SCNT to examine their ability to support early embryonic development. Xenopus egg extracts were prepared from activated S-phase eggs. Porcine fibroblast cells (106/mL) were permeabilized by 500 ng mL-1 of Streptolysin O and were incubated in the egg extracts with the energy-regenerating system for 2 hours at 23�C. After the extract treatment, permeabilized membranes were resealed in DMEM containing 2 mM CaCl2. The ETCs were fused with porcine enucleated oocytes and simultaneously activated. The reconstructed embryos were cultured in PZM-3 medium for 7 days. All statistical differences were analyzed by ANOVA. Reprogramming of ETCs was evaluated on changes of chromatin states and gene expression. Chromatin-binding proteins of ETCs were separated and analyzed on SDS-PAGE. Some proteins were incorporated onto and/or released from chromatins after the extract treatment. Especially, Xenopus egg-specific linker histone B4 was assembled on chromatins. Non-permeabilized control cells did not show these protein exchanges. Deacetylation of histone H3 lysine9 was detected in half number of ETCs in an ATP-dependent manner. In contrast, a high population of histone H3-acetylated cells was observed in buffer-treated cells as well as cells before the extract treatment. The pluripotent marker gene expression, such as OCT4 and SOX2, was also observed in ETCs after culture. The gene expression of these genes was not detected in non-treated cells. These results indicate that the extract treatment induces or triggers a part of dedifferentiation of somatic cells. These ETCs were used as donor cell for SCNT, and reconstructed cloned embryos were cultured. SCNT embryos showed no significant difference in cleavage rates and developmental rates to the blastocyst stage (25%) compared with non-treated control cells (26%). However, the total cell number of embryos at the blastocyst stage was significantly higher in SCNT embryos from ETCs compared with those of control cells (62 � 7 vs. 43 � 2, respectively; P < 0.05). These results indicate that the extract treatment before nuclear transfer may stimulate cell proliferation of SCNT embryos but not improve early development. More studies, however, are needed to investigate their developmental ability to term.

[A case of extracardiac unruptured aneurysm of sinus of Valsalva with obstruction of the right coronary artery and aortic regurgitation]

A 67-year-old female was admitted to our hospital with heart failure. Echocardiography, chest CT and MRA revealed an unruptured aneurysm of sinus of Valsalva. Cardiac catheterization and angiography detected obstruction of the ostium of the right coronary artery and moderate aortic regurgitation. Operative findings showed an extracardiac unruptured aneurysm arising from the right sinus of Valsalva. The orifice of the aneurysm was closed with Gore-Tex patch, then aortic valve replacement combined with single CABG to RCA was simultaneously performed. The pathological findings strongly suggested its acquired origin.

A case of intravascular large B-cell lymphoma mimicking erythema nodosum: the importance of multiple skin biopsies

BACKGROUND

Intravascular lymphoma is a rare disease characterized by the proliferation of neoplastic monuclear cells within the lumens of small blood vessels. The neoplastic cells are usually of B-cell origin, and rarely of T-cell or histiocytic origin. Although this clinicopathological entity of lymphoma has not been listed in general pathological classifications such as REAL classification or the Working Formulation, it is recently in the WHO classification scheme, which is essentially an updated REAL scheme, and the EORTC classification scheme.

METHODS

In this report, a 62-year-old woman with intravascular large B-cell lymphoma was observed by clinical, histopathological, immunohistochemical and molecular methods.

RESULTS

A 62-year-old woman presented with large erythematous macules on the bilateral thighs and lower legs. The lesions were accompanied with hard, tender, intradermal or subcutaneous nodules mimicking erythema nodosum. Histopathological examination in the first biopsy revealed non-specific panniculitis compatible with erythema nodosum. The second biopsy revealed emboli of atypical lymphocytes within many of the dilated and proliferated vessels in the deep dermis and subcutaneous tissue. These cells were positive for L-26 and kappa light chain, and negative for lambda light chain, factor VIII-related antigen, CD30, CD34, CD68 and UCHL-1. These findings confirmed the diagnosis of intravascular large B-cell lymphoma. A laboratory examination showed a high level of LDH and abnormal cells in the bone marrow. An MRI of the brain and computed tomographic (CT) scans of the chest and abdomen revealed no evidence of malignancy. Before the treatment, the size of the nodules decreased spontaneously by about 50% in one month and significantly in two months. Although combination chemotherapy, which consisted of CHOP, brought her partial remission, she experienced neurological symptoms 6 months after the initial treatment and died of brain metastasis 9 months after the treatment.

CONCLUSIONS

This is a unique case for two following reasons: 1) the first biopsy revealed non-specific findings compatible with erythema nodosum; and 2) before the treatment, the nodules regressed spontaneously. Dermatologists should take multiple skin biopsies for EN lesions with the non-specific histopathological findings not to refute the existence of this disease.

[Effectiveness of retrograde tepid blood cardioplegia in valve surgery combined with coronary artery bypass grafting]

The purpose of this study was to evaluate the usefulness of continuous retrograde continuous tepid blood cardioplegia (CTBC) in 8 patients underwent multivalve surgery combined with coronary artery bypass grafting (CABG) (Group 1), in comparison with antegrade CTBC in 10 patients with single valve replacement (Group 2). Aortic crossclamp time in Group 1 (187.9 +/- 55.2 minutes) was significantly longer than that (94.1 +/- 27.4) in Group 2 (p < 0.005). There was no hospital death in both groups. Spontaneous recovery rate of the heart beat following aortic declamping was 75% in Group 1, 90% in Group 2 (ns). Postoperative max CK-MB was 87.9 +/- 43.1 IU/l in Group 1, 74.8 +/- 27.0 IU/l in Group 2 (ns). During the early postoperative period, LVSWI significantly increased in both groups, whereas RVSWI showed no significant increase in both groups. Accordingly, in Group 1 in spite of longer aortic crossclamp time comparing Group 2, myocardial protection was considered to be satisfactory. In conclusion, retrograde CTBC is useful as an intraoperative myocardial protection in multivalve surgery combined with CABG which must need much longer aortic cross clamp time.

[Emergency coronary artery bypass grafting for left main coronary artery disease]

Emergency coronary artery bypass grafting (CABG) for acute coronary syndrome due to left main coronary artery (LMCA) disease still remains to be a therapeutic challenge. Seventy consecutive patients underwent CABG for LMCA disease were divided into two groups, that is 21 patients with emergency CABG (Group E) and 49 with scheduled CABG (Group S). There were four in-hospital deaths (mortality rate: 19.1%) in Group E and two (4.1%) in Group S. Three of 4 deaths in Group E had cardiogenic shock associated with acute myocardial infarction (AMI) preoperatively, and low output syndrome followed by multiple organ failure postoperatively. All of four deaths cases received intermittent cold GIK cardioplegia as an intraoperative myocardial protection. On the other hand, seven cases, received retrograde continuous warm blood cardioplegia (CWBC), including AMI with shock due to LMCA occlusion and concomitant CABG and valve replacement complicated with aortic regurgitation, all survived operations. In conclusion, retrograde CWBC may be useful as an intraoperative myocardial protection in emergency CABG for AMI with shock due to LMCA occlusion.

Effectiveness of continuous warm blood cardioplegia in cardiac valve re-replacement

BACKGROUND AND AIM OF THE STUDY

In order to achieve better operative results, myocardial protection for cardiac valve re-replacement must be further improved. The aim of this study was to compare the efficacy of continuous warm blood cardioplegia (CWBC) with that of intermittent cold potassium cardioplegia (ICPC) in cardiac valve re-replacement.

METHODS

A total of 49 consecutive patients underwent elective cardiac valve re-replacement via sternal re-entry; 27 patients received CWBC and 22 ICPC. During surgery, a narrower dissection of the heart was used in the CWBC group. The myocardial protective effects and operative outcome were analyzed in the two groups.

RESULTS

Two ICPC patients died in hospital, one from cerebral bleeding and one from low output syndrome. The rate of spontaneous recovery of the heart-beat after aortic declamping was significantly higher in CWBC patients than in the ICPC group (92.3% versus 13.6%, p < 0.001). Postoperatively, maximum serum creatine kinase-MB levels were significantly lower in CWBC patients than in ICPC patients (25.5 +/- 6.0 versus 81.1 +/- 26.0 IU/l, p < 0.02). Left ventricular stroke work index in the CWBC group showed significantly better recovery in the early postoperative period compared with that in the ICPC group. Extraction of myocardial oxygen (range: 0.33 to 0.35) and lactate (range: -0.02 to 0.14) in CWBC patients was maintained within the normal range immediately after aortic declamping and in the early postoperative period. In contrast, in ICPC patients extraction of myocardial oxygen (range: 0.18 to 0.23) and lactate (range: -0.27 to -0.17) was impaired during the same period. Postoperative (24-h) blood loss was significantly less in CWBC patients than in ICPC patients (p < 0.02).

CONCLUSION

In cardiac valve re-replacement surgery through sternal re-entry, and without wide exposure of the heart, continuous warm blood cardioplegia provides much greater myocardial protection than does intermittent cold potassium cardioplegia.

[Polymyalgia rheumatica and myelitis associated with anti-cardiolipin antibody]

A 78-year-old woman was admitted to our hospital on September 14, 1992, because of systemic myalgia and stiffness, joint pain, and gait disturbance. She had begun to feel headache and pain in the neck and shoulder in the middle of August, 1992. The pain became systemic, and was accompanied by a low-grade fever, which was unresponsive to NSAIDs. On admission, she had no joint swelling or deformities in the extremities. Neurological examination revealed weakness in the right leg, hypoalgesia below the left C4 level, hyperreflexia in the right extremities, and right Babinski's sign. The erythrocyte sedimentation rate was very high (100 mm/h). Levels of other acute phase reactants were also high. Tests for antinuclear antibody and anti-cardiolipin antibody were positive, but a test for rheumatoid factor was negative. Creatine kinase activity was within normal limits. A T1-weighted magnetic resonance image of the cervical spine at 0.5 T showed an intramedullary low signal. A T2-weighted image showed a borderless spindle-like high signal. Four nodules enhanced by Gd DTPA were seen at C1-C4. The age at onset, myalgia, stiffness, and erythrocyte sedimentation rate were considered to be consistent with a diagnosis of polymyalgia rheumatica. Glucocorticoid treatment was therefore started, and a dramatic clinical improvement was evident within a few days. The patient was discharged from hospital on November 30, 1992. To our knowledge, myelopathy complicated by polymyalgia rheumatica has never been reported previously. Recently, some patients with polymyalgia rheumatica have been reported to have anti-cardiolipin antibody in serum. In the present case anti-cardiolipin antibody may have played a role in the formation of microemboli or in angitis of the cervical spine.

[Emergency coronary artery bypass grafting in elderly patients]

Emergency coronary artery bypass grafting (CABG) in elderly patients still remains to be a therapeutic challenge for cardiac surgeons. The purpose of this study was to review the operative results of our emergency CABG in elderly patients and evaluate it's problems comparing with younger patients. Consecutive forty-three patients underwent emergency CABG for the past ten years were divided into two groups, that is 13 patients aged 75 years or older (group 1) and 30 younger than 75 years old (group 2). There were three in-hospital deaths (mortality rate: 23.1%) in group 1 and three (10.0%) in group 2. The lowest postoperative Ccr (19.1 +/- 8.9 ml/ min) in group 1 was significantly lower (p < 0.02) than that (35.6 +/- 14.4 ml/min) in group 2. Respiratory Index on the first postoperative day, which indicates lung dysfunction when it comes up to 2.0 or more, showed 2.65 in mean value in group 1 compared with 1.31 in group 2 (p < 0.05). Severe infections like sepsis were developed in 4 patients (30.8%) in group 1 and 2 (6.7%) in group 2 (p < 0.05). In conclusion, it was clearly suggested that kidney protection by earlier myocardial revascularization, prevention of severe infection and earlier introduction of respiratory physiotherapy in the postoperative period were advisable to improve the operative results of emergency CABG in elderly patients.

[A case report of subacute panencephalitis associated with specific T cells sensitized to proteolipid protein (PLP) synthetic peptides identified with rubella virus]

A 37-year-old woman was admitted to the hospital on October 4, 1991 because of fever, headache, and abnormal behavior. Although she was treated with aciclovir, she developed encephalitis, which slowly manifested itself over the next month as meningeal irritation, loss of consciousness, partial seizure, and quadriparesis. Her cerebrospinal fluid showed mild lymphocytic pleocytosis without protein elevation. Serum IgG antibody titer to rubella virus was elevated, but the rubella virus could not be detected in the cerebrospinal fluid by PCR amplification. Her consciousness level improved slowly, and by the end of November she suffered only dystonic posture of her right arm and hand. By the middle of December, there were no abnormal neurological findings except some extrapyramidal tract signs and symptoms, such as tremor and rigidity. The serum rubella virus IgG titer had fallen back into the normal range. Her illness was diagnosed as subacute panencephalitis, and she recovered completely about 5 months after the onset of the disease. The lack of rubella virus in the cerebrospinal fluid suggests that panencephalitis may not be dependent on virus replication within the central nervous system. Specific T cells sensitized to proteolipid protein synthetic peptides (PLP158-166) identified with rubella virus were detected in this case during the active stage. These observations imply that subacute panencephalitis may be dependent on an immune-mediated mechanism and that PLP-specific T cells may play an important role in pathogenesis of the disease.

[A case of amoebiasis as a latent infection]

A 69-year-old male was admitted because of constipation and abdominal distension. A colon fiberscopic examination revealed the formation of ulceration. The trophozite of Entamoeba histolytica was detected from from the specimens of colon mucosal biopsy of the ulcer. The stool was positive for the cysts of E. histolytica too. He had been in China and Southeast Asia during World War II. He returned home and experienced amoebic dysentry, and was treated with Emethin hydrochlolide. He suffered from amoebic disentry in 1970 and was treated with Emethine hydrochrolide again. After the War he had not gone abroad, and was not a homosexual. So this case was considered a latent infection of E. histolytica from the War. This time he was treated with metronidazol and minocycline. After the therapy, cysts were negative in the stool and the ulcer was cured on the colon fiberscopic examination.

[Experiences of reoperative coronary artery bypass grafting by left thoracotomy without aortic clamping]

We reported two cases which had reoperative coronary artery bypass grafting (CABG) through the left thoracotomy approach without aortic clamping with good results. Case 1. A 50-year-old man, who underwent a double CABG to left anterior descending coronary artery (LAD) and right coronary artery (RCA) in 1983, had a recurrent unstable angina due to new significant stenosis of the diagonal branch (DG) and obtuse marginal branch (OM) in 1989. He was reoperated upon, having a new double CABG to DG and OM through the left thoracotomy using hypothermic ventricular fibrillation without aortic clamping for the myocardial protection without any blood transfusion. Case 2. A 61-year-old man, who underwent a double CABG to LAD and RCA in 1982, had a recurrent unstable angina and a left ventricular aneurysm in 1991. He had a reoperation of a single CABG to OM combined with left ventricular aneurysmectomy by the same approach. Both cases showed satisfactory recoveries of the left ventricular function in the early postoperative period and patent grafts on postoperative angiograms. The left thoracotomy approach is a preferable alternative to median resternotomy for the reoperative CABG to OM, DG and left ventricular aneurysmectomy.

[Myocardial protection during aortic valve replacement: effectiveness of continuous warm blood cardioplegia]

Effectiveness of continuous warm blood cardioplegia (CWBC) during aortic valve replacement (AVR) was studied by comparing with intermittent cold GIK cardioplegia (ICGC) in 32 patients who underwent AVR using CWBC in 16 and ICGC in the other 16 patients. There was no operative nor hospital death in this series. In CWBC group, spontaneous recovery of the heart beat following aortic declamping was seen in 14 of 16 patients (87.5%), in contrast only in 4 of 16 (25%) in ICGC group. During the early postoperative period, left ventricular stroke work index (g.m/beat/m2) significantly increased from 41.0 +/- 14.4 to 55.9 +/- 8.0 (p < 0.001) in CWBC group, whereas no significant increase was found in ICGC group. Right ventricular stroke work index significantly increased only in CWBC group as well. In CWBC group, myocardial oxygen and lactate extraction rates were maintained within normal range during aortic cross-clamping, suggesting satisfactory myocardial preservation with an aerobic metabolism. In conclusion, CWBC is superior to ICGC as a myocardial protection during AVR.

[Repeat open heart surgery using continuous warm blood cardioplegia]

Myocardial protection during repeat open heart surgery still remains to be further improved. The purpose of this study was to evaluate the usefulness of continuous warm blood cardioplegia (CWBC) comparing with intermittent cold GIK cardioplegia (ICGC) in repeat open heart surgery. Twenty-four patients underwent repeat open heart surgery through re-sternotomy (11 mitral, 6 aortic 5 double, 2 congenital) were divided into two groups, that is 10 received CWBC (warm group) and 14 ICGC (Cold group). Spontaneous recovery of heart beat was obtained in 9 of 10 patients (90.0%) in warm group, in contrast only 2 of 14 (14.3%) in cold group (p < 0.001) following aortic declamping. Postoperative peak level of serum CK-MB in warm group (25.9 +/- 7.4 IU/l) was significantly lower than that (83.1 +/- 24.6) in cold group. In warm group left and right ventricular stroke work index significantly increased at 24 hours postoperatively, whereas no significant increase was found in cold group. Postoperative bleeding in the first 24 hours was less (553.8 +/- 38.9 ml) in warm group than that (974.3 +/- 54.1 ml) in cold group. In warm group 3 patients were operated on without homologous blood transfusion, in contrast none in cold group. Our results clearly demonstrated that CWBC was preferable to ICGC for myocardial protection in repeat open heart surgery.

Mechanism of changes of the collagen matrix of reperfused myocardium in donor heart preservation

Isolated canine hearts were preserved for 6 hours at 5 degrees C followed by normothermic reperfusion for 2 hours. Dogs were divided into two groups: group I (group Ia [n = 7] and group Ib [n = 3] with the left ventricle unloaded during reperfusion) received a preservation solution containing potassium (20 mmol/L), and group II (n = 9) received University of Wisconsin solution. Left ventricular diastolic function was better preserved in group II. Degradation and loss of the collagen network during reperfusion, as assessed by scanning electron microscopy, were more extensive and significantly more frequent in group Ia than in group II (6/7 versus 2/9; p < 0.05). Furthermore, extensive disruption of the collagen network was significantly more prevalent in hearts with a left ventricular end-diastolic pressure of more than 20 mm Hg than in hearts with a left ventricular end-diastolic pressure of less than 20 mm Hg (8/10 versus 0/6; p < 0.05), and no disruption of the collagen network occurred in group Ib, regardless of the type of preservation solution. These results suggest that the greatest disruption is caused by barotrauma resulting from an elevated left ventricular end-diastolic pressure after ventricular dysfunction caused by ischemic reperfusion injury.

[From Bentall's operation to its modification by Suzuki: improved technique for replacement of both aortic valve and ascending aorta]

To improve the result of surgery for replacement of both aortic valve and ascending aorta, we developed a new technique which is characterized as follows. 1) The composite graft is made during surgery according to the operative findings with tilting disc valve and very low porosity woven Dacron graft. 2) Proximal anastomosis is reinforced by double fixation method. 3) Coronary arteries are reimplanted directly into the graft as a Carrel patch. Thirty-four patients underwent this surgery with no operative death. One died in the hospital and 4 died in the late stage unrelated to the surgical technique. We recommend this method as a new standard technique for replacement of both aortic valve and ascending aorta.

[Clinical study on the prognosis of complete denture wearers covering 10 years. 4. Masticatory efficiency]

The purpose of this study was to estimate masticatory efficiency of complete denture wearers. The subjects were 72 patients, treated before 5-10 years at students' clinic of Tsurumi University, School of Dental Medicine. The masticatory efficiencies with peanuts and Kamaboko were calculated. Results 1. The mean masticatory efficiency with peanuts for 63 patients was 35.8%, and with Kamaboko (steamed fishpast) for 64 patients was 94.5%, in comparison with natural dentition. 2. The mean masticatory efficiency with peanuts was 124.3%, and with Kamaboko was 99.6%, for complete denture wearers. 3. Comparing the measured value of masticatory efficiency with 5 to 10 years wearing period, there was significant difference in the masticatory efficiency between peanuts and Kamaboko. 4. There was significant difference in the masticatory efficiency with peanuts between the group needed new denture and the group not needed but there was not significant difference with Kamaboko.

[Adrenomedullary epinephrine excretion and myocardial norepinephrine release during cardiopulmonary bypass]

It has long been known that shock or surgical stress promotes an epinephrine (E) excretion from the adrenomedullary glands. In fourteen adult cardiac patients, plasma E values in both superior vena cava (SVC) cannula and inferior vena cava (IVC) cannula during total cardiopulmonary bypass (CPB) are studied at three stages, before aortic cross clamp (pre AXC), after release of aortic cross clamp (post AXC) and at 34 degrees C rectal temperature in rewarming (34 degrees C RT). Although E values in both SVC and IVC are slightly higher values than normal in pre AXC, they increase sharply to peaked values at post AXC and decline uniformly close to normal at 34 degrees C RT. IVC-E is constantly significantly higher (statistically) than SVC-E at each of all three stages. It is strongly suggested that E response to CPB is mainly originated from the adrenomedullary glands, and cardiac reflex which has sympathetic efferent limbs triggered by myocardial ischemia can indicate the increase in E during AXC. Myocardial norepinephrine (NE) release in heart ischemia such as acute myocardial infarction has been generally accepted. To examine whether myocardial NE release occurs during AXC, if there is the association of NE release with any clinical parameters, the second investigation is done in twenty-six adult cardiac patients. Plasma NE values in both the radial artery (A) and the coronary sinus (CS) are measured at six stages, pre AXC (stage 1), post AXC (stage 2), post CPB (stage 3), three hours after off CPB (stage 4), six hours off CPB (stage 5) and twelve hours off CPB (stage 6).(ABSTRACT TRUNCATED AT 250 WORDS)