P1959Impact of hemodialysis in patients undergoing bypass surgery for peripheral arterial disease - 10-year follow-up study

Background

Although lower extremities bypass surgery has been commonly performed as the standard option to treat peripheral artery disease (PAD) even in patients on hemodialysis (HD) as well as general population, poorer prognosis still remains major problems in this specific population. In this 10-year follow-up study, we investigated the impact of HD after surgical revascularization in patients with PAD.

Methods

A total of 660 patients undergoing successfully bypass surgery were enrolled. Patients with acute limb ischemia were excluded. We compared 392 HD patients with 428 limbs and 268 non-HD (NHD) patients with 296 limbs during 10 years follow-up period. Primary endpoint was defined as major adverse cardiovascular events (MACE) including all-cause death, non-fatal myocardial infarction and stroke. Second endpoint was major adverse limb events (MALE) including any revascularization and major amputation. To minimize the differences of clinical characteristics between the two groups, propensity score adjusting with all baseline variables was performed.

Results

Prevalence of diabetes (53.3% vs. 35.2%), critical limb ischemia (77.5% vs. 52.1%) and infra-popliteal artery (48.2% vs. 19.6%) were higher in HD group compared to NHD group (p<0.0001 in all), inversely, age was younger in HD group than in NHD group (67±9 years vs. 71±9 years, p<0.0001). The 30-day mortality rate was comparable (3.1% in HD group vs. 1.5% in NHD group, p=0.19). The 10-year event-free survival rate for MACE was significantly lower in HD group compared to NHD group (45.3% vs. 67.4%, p<0.0001) and for MALE (60.0% vs. 80.0%, p=0.0007), respectively. After propensity score adjustment, the freedom rate from MACE was still lower in HD group compared to NHD group [45.6% vs. 67.6%, hazard ratio (HR) 1.89, 95% confidence interval (CI) 1.33–2.72, p=0.0003], however, the rate from MALE was statistically comparable between the two group (65.7% vs. 76.9%, 1.27, 95% CI 0.87–1.90, p=0.21). Furthermore, although the 10-year limb salvage rate was crudely lower in HD group compared to NHD group (80.6% vs. 91.6%, HR 1.57, 95% CI 1.05–2.40, p=0.0027), it was comparable after propensity score adjustment (89.4% vs. 90.1%, HR 1.09, 95% CI 0.59–1.88, p=0.79). Also, the mortality rate was consistently lower in HD patients (adjusted HR 2.37, 95% CI 1.62–3.50, p<0.0001).

Conclusion

The long-term freedom rate from MACE and mortality was markedly lower in HD patients compared to non-HD patients. However, the rate from MALE, especially limb salvage rate was similar between HD and NHD after adjustment for clinical characteristics. These results suggest that detection at the early stage of PAD may potentially improve the poor outcomes in this high risk population.

P1582Prognostic value of C-reactive protein/albumin ratio for cardiovascular morbidity and mortality in end-stage renal disease patients with incident haemodialysis therapy

Background

Hypoalbuminemia, a manifestation of protein-energy wasting or malnutrition, is commonly observed in patients with end-stage renal disease (ESRD), and is associated with chronic inflammation and increasing cardiovascular (CV) risk. Recently, C-reactive protein (CRP)/albumin ratio at discharge is reportedly a well-predictor of mortality in severe sepsis or cancer patients.

We investigated prognostic value of the CRP/albumin ratio at just starting haemodialysis (HD) therapy for CV morbidity and mortality in patients with ESRD.

Methods

A total of 1,548 ESRD patients were enrolled and were divided into quartiles according to CRP/albumin levels at initiation of HD; quartile 1 (Q1): <0.22, Q2: 0.23–0.54, Q3: 0.55–1.83 and Q4: >1.84. They were followed up for 10-year after starting HD therapy. Primary endpoint was CV events defined as hospitalization due to CV events such as cardiac disease, stroke and peripheral artery disease and CV death. We also evaluated the incremental value with C-index when CRP alone, albumin alone and the CRP/albumin ratio were added into a model with established risk factors.

Results

During follow-up period (median: 59 months), 512 cases experienced CV events (33.1%) including 165 cases of CV deaths (10.7%). Kaplan-Meier analysis shows that CV event-free survival rates for 10 years were 63.5%, 53.8%, 47.5% and 31.9% in Q1, Q2, Q3 and Q4, and that CV survival rates were 90.4%, 83.9%, 77.2% and 64.6% in Q1, Q2, Q3 and Q4, respectively (p<0.0001 in both). After adjustment for all baseline variables, elevated CRP/albumin ratio was identified as an independent predictor for CV events [hazard ratio (HR) 1.51, 95% confidence interval (CI) 1.11–2.07, p=0.0093 for Q2 vs. Q1, HR 1.79, 95% CI 1.33–2.42, p<0.0001 for Q3 vs. Q1and HR 2.27, 95% CI 1.70–3.07, p<0.0001 for Q4 vs. Q1, respectively]. As to CV mortality, similar results were obtained (HR 1.80, 95% CI 0.98–3.44, p=0.056 for Q2 vs. Q1, HR 2.56, 95% CI 1.45–4.71, p=0.0009 for Q3 vs. Q1 and HR 2.66, 95% CI 1.53–4.86, p=0.0004 for Q4 vs. Q1, respectively). Furthermore, adding the CRP/albumin ratio to a baseline model with established risk factors improved the C-index greater than that of CRP alone or albumin alone, respectively (0.715 from 0.692, p=0.0095 and from 0.683, p=0.0019)

Conclusion

The CRP/albumin ratio, which easily available from daily practice, could strongly stratify the risk of future CV morbidity and mortality in ESRD patients who need HD therapy.

Therapeutic effect of carbon monoxide-releasing molecule-3 on acute lung injury after hemorrhagic shock and resuscitation

Hemorrhagic shock and resuscitation (HSR) induces a pulmonary inflammatory response and frequently causes acute lung injury. Carbon monoxide-releasing molecule-3 (CORM-3) has been reported to liberate and deliver CO under physiological conditions, which exerts organ-protective effects during systemic insults. The present study aimed to determine whether the administration of CORM-3 following HSR exerts a therapeutic effect against HSR-induced lung injury without any detrimental effects on oxygenation and hemodynamics. To induce hemorrhagic shock, rats were bled to a mean arterial blood pressure of 30 mmHg for 45 min and then resuscitated with the shed blood. CORM-3 or a vehicle was intravenously administered immediately following the completion of resuscitation. The rats were divided into four groups, including sham, HSR, HSR/CORM-3 and HSR/inactive CORM-3 groups. Arterial blood gas parameters and vital signs were recorded during HSR. The histopathological changes to the lungs were evaluated using a lung injury score, while pulmonary edema was evaluated on the basis of the protein concentration in bronchoalveolar lavage fluid and the lung wet/dry ratio. We also investigated the pulmonary expression levels of inflammatory mediators and apoptotic markers such as cleaved caspase-3 and transferase-mediated dUTP-fluorescein isothiocyanate nick-end labeling (TUNEL) staining. Although HSR caused significant lung histopathological damage and pulmonary edema, CORM-3 significantly ameliorated this damage. CORM-3 also attenuated the HSR-induced upregulation of tumor necrosis factor-α, inducible nitric oxide synthase and interleukin-1β genes, and the expression of interleukin-1β and macrophage inflammatory protein-2. In addition, the expression of interleukin-10, an anti-inflammatory cytokine, was inversely enhanced by CORM-3, which also reduced the number of TUNEL-positive cells and the expression of cleaved caspase-3 following HSR. Although CORM-3 was administered during the acute phase of HSR, it did not exert any influence on arterial blood gas analysis data and vital signs during HSR. Therefore, treatment with CORM-3 ameliorated HSR-induced lung injury, at least partially, through anti-inflammatory and anti-apoptotic effects, without any detrimental effects on oxygenation and hemodynamics.

Perioperative risk factors for acute kidney injury after off-pump coronary artery bypass grafting: a retrospective study

Background

Acute kidney injury (AKI) after cardiac surgery is associated with increased morbidity and mortality. Although morbidity of AKI after off-pump coronary artery bypass grafting (OPCAB) has been investigated, little is known about risk factors for AKI after OPCAB. To identify risk factors for AKI, we examined the association between perioperative variables and AKI after OPCAB.

Findings

We reviewed the medical records of consecutive adult patients who underwent isolated OPCAB between January 2010 and February 2013 in a single institute, retrospectively. The primary outcome was the incidence of AKI evaluated using Acute Kidney Injury Network classifications during the first 48 h postoperatively. We investigated preoperative and intraoperative variables, including hemodynamic parameters, as potential risk factors for AKI. The relationship between candidates of AKI and incidence of AKI was examined by multivariate logistic regression analysis.A total of 298 patients were enrolled in this study. Acute kidney injury occurred in 47 patients (15.7%). Multivariate logistic regression analysis showed that intraoperative furosemide administration (odds ratio [OR], 5.163; 95% confidence interval, 2.171 to 12.185; P < 0.001] and diabetes mellitus (OR, 1.954; 95% confidence interval, 1.004 to 3.880; P = 0.049) were significantly associated with AKI.

Conclusions

Intraoperative furosemide administration and diabetes mellitus were significantly associated with AKI in patients who had received OPCAB.

Impact of diabetes and glycaemic control on peripheral artery disease in Japanese patients with end-stage renal disease: long-term follow-up study from the beginning of haemodialysis

AIMS/HYPOTHESIS

End-stage renal disease (ESRD) patients with diabetes have been regarded as being at the highest risk of cardiovascular disease. We therefore investigated the relationship between diabetes and the incidence of peripheral artery disease (PAD) in new haemodialysis patients.

METHODS

We enrolled 1,513 ESRD patients who had just begun haemodialysis therapy. They were divided into two groups: those with (n = 739) and those without diabetes (n = 774). The endpoint was the development of PAD, defined as ankle brachial pressure index ≤ 0.9 or toe brachial pressure index <0.7 in patients with an ankle brachial pressure index >0.9.

RESULTS

According to the Kaplan-Meier method, the 10 year event-free rate for development of PAD and lower limb amputation was significantly lower in the diabetes group than in the non-diabetes group (60.3% vs 82.8%, HR 2.99, 95% CI 2.27, 3.92, p<0.0001 and 93.9% vs 98.9%, HR 5.59, 95% CI 2.14, 14.7, p = .0005 for PAD and lower limb amputation, respectively). In patients with diabetes, quartile analysis of HbA1c levels showed that the highest quartile group (≥ 6.8% [51 mmol/mol]) had significant development of PAD and lower limb amputation compared with lower quartile groups (PAD HR 1.63, 95% CI 1.17, 2.28, p = .0038; lower limb amputation HR 2.99, 95% CI 1.17, 7.70, p = .023).

CONCLUSIONS/INTERPRETATION

Diabetes was a strong predictor of PAD after initiation of haemodialysis therapy in patients with ESRD. In addition, higher HbA1c levels were associated with increased risk of developing PAD and requiring limb amputation in such diabetic populations.

Effect of artificial carbon dioxide foot bathing on critical limb ischemia (Fontaine IV) in peripheral arterial disease patients

BACKGROUND

It has been reported that artificial carbon dioxide (CO(2)) foot bathing improves subcutaneous microcirculation in peripheral arterial disease (PAD) patients. However, the effect for critical limb ischemia (CLI) with ulceration or gangrene (Fontaine stage IV) is not identified. The physiological effects of CO(2) bathing and the outcome of limb salvage in such patients were studied.

METHODS

In 18 healthy volunteers (Study I), the dorsal pedis peripheral blood flow was measured by a laser Doppler flow-meter during CO(2) foot bathing (1000 ppm, 37 degrees C) for 10 min. A Holter electrocardiogram was also recording in the same period. Blood flow and cell volume significantly increased during bathing. Eighty-three CLI limbs (Fontaine IV) in 68 PAD patients (Study II) underwent artificial CO(2) foot bathing (for 10 minutes twice daily >2 months) were followed up >6 months.

RESULTS

In Study I, analysis of heart rate variability showed that high frequency amplitude (HFA) considerably increased and the ratio of low frequency amplitude to HFA (LF/HF) noticeably decreased during bathing. In Study II, 69 limbs (83.1%) could be salvaged. Twenty-seven of 28 limbs (96.4%) which have ulcer and gangrene in only one toe, 13/16 limbs (81.2%) in multiple toes and 29/39 limbs (74.4%) in all toes and/or heel respectively were saved.

CONCLUSIONS

The effect of CO(2) enriched water on the subcutaneous microcirculation might be brought about by peripheral vasodilation reflected by increased parasympathetic and decreased sympathetic activity, and the artificial CO(2) foot bathing is clinically effective on salvage of CLI (Fontaine stage IV) limbs.

[An elderly case of ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade]

We reported a case of successful aortic arch replacement using selective cerebral perfusion for ruptured distal aortic arch aneurysm (DAAA) with cardiac tamponade. A 80-year-old man who had preoperative episode of severe chest pain. Computed tomography showed saccular DAAA and pericardial effusion. He was diagnosed as ruptured DAAA with hemorrhagic cardiac tamponade. We performed urgent graft replacement of the aortic arch using selective cerebral perfusion. Postoperatively he had no complication. Thirty days after the operation he was discharged from the hospital and he is now leading a normal life.

Predictability of dielectric properties for ischemic injury of the skeletal muscle before reperfusion

OBJECTIVE

The purpose of this study is to assess whether or not dielectric properties could predict the severity of ischemic injury of the skeletal muscle before reperfusion to prevent the myonephropathic metabolic syndrome (MNMS).

METHODS

Japanese White rabbits were anesthetized and their hind limbs were subjected to 0, 2, 4, and 6 h of ischemia and then 10 h of reperfusion (n = 4, 5, 6, and 6). Dielectric properties of the gastrocnemius muscle were measured and tan delta(m) and D were calculated from them. To assess ischemic injury, we also measured (a) creatine phosphate kinase (CPK) and aldolase, (b) spectrophotometric assay of triphenyltetrazolium chloride assay, and (c) histological evaluation by H & E staining, 10 h after reperfusion.

RESULTS

The tan delta(m) increased and D decreased significantly compared with those in preischemia (P < 0.01). The tan delta(m) value just before reperfusion significantly correlated positively with the maximum value of CPK (CPK(max)) or the maximum value of aldolase (ALD(max)) (r = 0.73, 0.69) and negatively with %TTC (r = 0.66). The D value just prior to reperfusion significantly correlated negatively with CPK(max) and ALD(max) (r = 0.81, 0.86) and positively with %TTC (r = 0.79) after reperfusion, respectively. Histologically, skeletal muscle necrosis was detected in 11 out of 12 skeletal muscles with tan delta(m) values which were 3.70 or more and 11 out of 14 muscles with D values which were 1.47 or less.

CONCLUSION

The severity of skeletal muscle ischemic injury can be evaluated before reperfusion by measuring the dielectric properties during ischemia.

[Reoperation for diffuse supravalvular aortic stenosis with Williams syndrome--extended patch aortoplasty and extra-anatomic bypass from the ascending aorta to the descending aorta in a median sternotomy]

A case of diffuse supravalvular aortic stenosis (SVAS) with Williams syndrome is reported. In this case of severe diffuse SVAS, we performed the diamond-patch aortoplasty in a child. However he has been suffering from residual SVAS. At 9-years old, the myocardial injury was noted by myocardial scintigraphy. Preoperative cardiac catheterization and angiography revealed the hypoplastic ascending aorta and arch with a pressure gradient of 89 mmHg at the distal site from the left subclavian artery. Through only a median stenotomy, an extended patch aortoplasty between the valsalva sinus and distal arch was performed and an extraanatomic bypass from the ascending aorta to the descending aorta was employed using a 10 mm tube graft. We realize this technique is available because this method can relieve the left ventriculus of the pressure load and operate via only median sternotomy.

[Decreasing sarcoplasmic reticular calcium gives rise to myocardial protection--the effect of thapsigargin for myocardial protection under conditions of normothermia]

Deceasing sarcoplasmic reticular (SR) calcium may contribute to the myocardiac protection against ischemia and reperfusion-induced injury. Therefore, using the isolated working rat heart model, we investigated the effect of Thapsigargin (TH)-induced SR calcium diminution on the myocardial protection when added either before onset of ischemia or at time of reperfusion under conditions of normothermic ischemia. Hearts (n = 6/group) from male Wistar rats were aerobically (37 degrees C) perfused (20 min) with bicarbonate buffer. In the experimental protocol A, this was followed by a 3 min infusion of St. Thomas' Hospital cardioplegic solution No. 2 (STS) containing various concentrations of TH. Hearts were then subjected to 34 min of normothermic (37 degrees C) global ischemia and 35 min of reperfusion (15 min Langendorff, 20 min working). Reperfusion cardiac functions at 20 min of working perfusion was measured and compared with the preischemia values. STS added to 0.1 and 0.25 mumol/L TH improved recovery of aortic flow after 20 min reperfusion from 47 +/- 3% in the TH free controls to 62 +/- 3, 63 +/- 2% (n = 6) (p < 0.05). There was no difference in creatine kinase (CK) leakage during Langendorff reperfusion between the TH treated groups and the control group. In the experimental protocol B, 3 min of cardioplegia without TH and 34 min of ischemia (37 degrees C) were followed by a 10 min Langendorff reperfusion with various concentrations of TH, then 10 min Langendroff reperfusion for washing out, and 20 min working reperfusion. When TH was added to reperfusate the recovery of aortic flow did not change, 0.5 mumol/L TH group had the detelious effect. Thus, TH, when added to the cardioplegia, enhanced myocardial protection. We conclude that lessened uptake of Ca2+ into sarcoplasmic reticulum by inhibitors of the Ca(2+)-ATPase pump can decrease ischemia and reperfusion-induced injury.

Primary cardiac leiomyosarcoma growing rapidly and causing right ventricular outflow obstruction

Leiomyosarcomas are extremely rare primary cardiac tumors. We report a rapidly growing primary leiomyosarcoma of the right ventricle, which obstructed the right ventricular outflow tract within one month after symptom onset in a 68-year-old man. Two-dimensional echocardiography was useful in diagnosing the extent and progression of the tumor. The tumor was surgically resected on an emergency basis, and the right ventricle and pulmonary artery were successfully reconstructed. Recurrence of the tumor on the right ventricle was observed, and the patient was overcome by sudden dyspnea and died three months after surgery.

[The temperature dependency of the protective properties of the St. Thomas' Hospital cardioplegic solution, the University of Wisconsin solution, and Bretschneider buffered solution]

We studied three preservation solutions such as St. Thomas' hospital cardioplegic solution No. 2 (ST), the University of Wisconsin solution (UW) and Bretschneider's solution (BR) for protective properties, especially in terms of temperature dependence during the preservation. Rat hearts were studied and divided into three groups; ST. UW and BR. In each group, six hearts were carried out perfusion, cardioplegic infusion, ischemia and reperfusion for four different conditions. Using an isolated working rat heart model, the hearts were subjected to 5 minutes Langendorff perfusion followed by 20 minutes working perfusion. During this working period, cardiac functions such as aortic and coronary flow, aortic pressure, and heart rates were measured every 5 minutes. After working perfusion, 3 minutes of cardioplegic infusion was carried out either with UW, ST, and BR at 37, 20, 4, 1 degree C. The hearts were subjected to either 35 min at 37 degrees C, 120 min at 20 degrees C, 300 min at 4 degrees C, or 450 min at 1 degree C. The hearts were immersed in the same solution during ischemia. The hearts were reperfused at 37 degrees C, initially in the Langendorff mode for 15 min. Coronary effluent was collected for the measurement of CK leakage during reperfusion. The heart were then converted to the working mode for 20 minutes. During working reperfusion period, the variables of cardiac function were again measured and expressed as a percentage of their individual preischemic control values. Under conditions of 37 degrees C ischemia, % recovery of cardiac output (%CO) in ST group is 62.8 +/- 2.8%, although the hearts preserved with UW and BR were not recovered. Under conditions of 20 degrees C ischemia, %CO in UW, ST and BR were 46.8 +/- 2.7, 82.0 +/- 3.1 and 41.4 +/- 2.6%, respectively. Under conditions of 4 degrees C ischemia, %CO in UW, ST and BR were 66.2 +/- 8.0, 68.6 +/- 2.3 and 47.2 +/- 2.9%, respectively. Under conditions of 1 degrees C ischemia, %CO in UW, ST and BR were 70.6 +/- 3.3, 56.5 +/- 1.6 and 43.0 +/- 2.5%, respectively. In conclusions, ST revealed the best protective properties for the heart preservation between 37 degrees C and 20 degrees C ischemia. The properties of ST was similar to that of UW under conditions of 4 degrees C, although UW showed most excellent protective properties under conditions of 1 degrees C ischemia. These results suggested that, protective ability of preservation solution might be changed by the temperature during preservation period.

[The effect of continuous perfusion with St. Thomas' Hospital cardioplegic solution containing glucose, insulin and L-aspartate on functional recovery after myocardial preservation in the rat]

The aim of this study was to determine the effect of the continuous perfusion with St. Thomas' Hospital cardioplegic solution (ST solution) containing glucose, insulin and L-aspartate upon post-preservation recovery of cardiac function in the isolated rat heart.

METHODS

Hearts from Wistar male rats were perfused with Krebs-Henseleit bicarbonate buffer (KHBB) solution and cardiac function was measured using an isolated working heart preparation. Hearts were then preserved by continuous perfusion, (1) with ST solution or ST solution containing L-aspartate (20 mmol/L9 at 20 degrees C and 4 degrees C for 12 hours, (2) with ST solution containing L-aspartate at 4 degrees C for 24 hours, (3) with ST solution containing glucose (9 mmol/L) and insulin (10 U/L solution) or ST solution containing glucose, insulin and L-aspartate at 20 degrees C for 24 hours. This was followed by 15 minutes of Langendorff perfusion and 20 minutes of working perfusion with KHBB solution. During the working perfusion in the post-preservation period, cardiac function was remeasured.

RESULTS

(1) At 20 degrees C, percent recovery of cardiac output (%CO) was 57.7 +/- 3.8% and 79.9 +/- 1.4*% in the L-aspartate-free group and the L-aspartate-containing group, respectively (*p < 0.05). At 4 degrees C, %CO was 74.4 +/- 2.2% and 80.5 +/- 1.7% in the L-aspartate-free group and the L-aspartate-containing group, respectively (NS). (2) %CO in L-aspartate-containing group at 4 degrees C decreased to 46.8 +/- 2.4% when preservation time was extended to 24-hours from 12 hours. (3) On the other hands, the addition of L-aspartate to the ST solution containing glucose and insulin resulted in an additive protection and %CO was 76.0 +/- 1.1% even after 24 hour preservation at 20 degrees C.

CONCLUSIONS

Our results indicate that L-aspartate as an additive to perfusion medium might be beneficial for myocardial preservation, and that at 20 degrees C, the addition of L-aspartate to the ST solution containing glucose and insulin could improve the post-preservation recovery after the 24-hour preservation.

[A surgically treated case of ruptured true aortic arch aneurysm in association with Stanford type A chronic dissection]

A 72-year-old woman was admitted to our hospital because of hemosputum. Enhanced CT showed ruptured true aortic arch aneurysm. True aortic arch aneurysm ruptured at distal portion of aneurysm. The aorta was chronically dissected from an entry proximal to ruptured portion, to ascending aorta. Ascending aorta to aortic arch was replaced with 20 mm gelatin sealed graft under selective cerebral perfusion with hypothermia. Post-operatively tracheostomy was done because of respiratory failure, and there was some leak from distal anastomosis portion which was 42 mm in diameter at the operation. So replacement of descending thoracic aorta was performed using elephant trunk of the previously replaced graft. Post-reoperative course has been uneventful. She weaned from respiratory support. True aortic arch aneurysm combined with Stanford type A dissection is very rare. We presented ruptured true aortic arch aneurysm in association with Stanford type A chronic dissection which had an entry in true aneurysm.

[Treatment of patients with chronic dissecting aortic aneurysm (DeBakey type IIIb) presenting with compromised renal perfusion]

We reviewed our experience for 6 patients of chronic dissecting aortic aneurysm (DeBakey type IIIb) with the false lumen extending into the abdominal aorta and the renal arteries being perfused from the false lumen. In three cases, whose abdominal aorta presenting with large aneurysmal lesions, we performed graft replacement of the thoracic descending aorta and abdominal aorta simultaneously. In other three cases, whose abdominal aorta presenting without aneurysmal lesions, and moreover age advanced or perioperative conditions poor, we performed graft replacement of thoracic descending aorta, using double barreled distal anastomosis technique to ensure of enough blood flow into both true and false lumens. All patients survived and there were no early postoperative complications. In 3 cases of thoracic aortic replacement alone, the mean follow-up term was 38 months, postoperative computed tomography showed neither apparent expansion of the false lumen nor compression of the true lumen of the abdominal aorta, and postoperative renal function were maintained. In conclusion, in treatment of chronic dissecting aortic aneurysm (DeBakey type IIIb) presenting with compromised renal perfusion, we considered that replacement of the thoracic descending aorta and abdominal aorta brings patient the most radical improvements. But in the patients, who are elder or in poor perioperative conditions, the replacement of thoracic descending aorta using double barreled distal anastomosis technique is one easier applicable and safer procedure to preserve the renal perfusion.

[Coronary artery bypass grafting in cases with the atherosclerotic ascending aorta]

Among 172 cases of coronary artery bypass grafting, 9 cases (5%) revealed severely atherosclerotic ascending aorta. In 3 of the 9 cases, total aortic cross-clamping in the distal anastomoses of saphenous vein graft (SVG) and partial aortic clamp in the proximal anastomoses of SVG were performed. In 1 case with this technique, cerebral infarction was occurred. In 4 cases, total aortic cross-clamping in the distal and proximal anastomoses of SVG was performed. In 2 of these cases with this technique, cerebral infarctions were occurred. Hypothermic circulatory arrest was performed in 2 of the rest. In one case that was predicted to have atherosclerosis of ascending aorta prior to operation, the left internal thoracic artery was anastomosed to the left anterior descending, and SVG to the right coronary artery with hypothermia and ventricular fibrillation. And during the proximal anastomoses of SVG, hypothermic circulatory arrest without aortic clamping was initiated. In another case, atherosclerosis of ascending aorta was noted after aortic cross-clamping. Then the aorta was declamped, hypothermic circulatory arrest was established, the aorta was opened, the diseased segment was resected, and proximal anastomoses of SVG was performed to Dacron patch which was implanted for aortic wall. There were no cerebral infarction in last two patients.

[A trial of antegrade perfusion to the lower half of the body with selective cerebral perfusion for repair of aortic arch aneurysm combined with atherosclerosis obliterance]

A 73-year-old man with aortic arch aneurysm combined with atherosclerosis obliterance underwent aortic arch replacement. As he had bilateral femoral artery obstruction, we instituted ECC with arterial perfusion through the ascending aorta. Then, the left ventricle started dilating due to mild degree of aortic regurgitation. So with selective cerebral perfusion, we perfused the lower half of the body through a Foley balloon catheter which was inserted from the aortic arch antegradely. We could perfuse with the catheter for 20 minutes for core cooling and then during repair until the catheter disturbed the operation. The Foley catheter had given us some difficulties for handling during the procedure. Based on this experience, we have made a catheter which had both a balloon for aortic occlusion and a tube for perfusion and which we could keep away from operative fields, similar to the way we used antegradely insertable aortic occlusion balloon catheter.

[Changes in analgesic levels, plasma concentrations and epidurogram during long-term continuous epidural block]

The change of analgesic levels, plasma concentrations and the radiographical changes of epidural space due to continuous epidural block were studied in 54 patients receiving pain relief. All the patients received 2 ml per hour of 2% lidocaine or 0.5% bupivacaine via the catheter over two weeks. The effect of epidural block was determined on 1, 2, 4, 7, 10 and 14 days, the epidurogram was performed on 1, 7, 14 days, and plasma concentration of lidocaine or bupivacaine was measured on 1, 3, 7, 14 days. We removed catheters in 8 patients because of infection around the catheter, pain in the back during injection, the leakage of anesthetics, and spontaneous removal. The effects and plasma concentrations of epidural block decreased significantly after a week, and the mean segmental number of radiographic spread decreased significantly after two weeks. The decreasing effect or duration of epidural block was due to decrease in spread of anesthetics because of adhesion around the catheter in the epidural space. We conclude that the safety period of continuous epidural block is within 2 weeks.

[The effects of glucose and insulin upon functional recovery in the rat heart preserved by continuous perfusion with St. Thomas' Hospital cardioplegic solution]

The aim of this study was to determine the effect of the continuous perfusion with Krebs-Henseleit bicarbonate buffer (KHBB) solution or St. Thomas' Hospital cardioplegic solution (ST solution) containing glucose and insulin upon the post-preservation recovery in the isolated rat heart.

METHODS

Hearts from male Wistar rats (n = 6/group) were subjected to working perfusion with KHBB solution for measurement of cardiac function. They were continuously perfused (1) with KHBB solution or ST solution for 12 hours at 20 degrees C, (2) with ST solution for 12 hours at 37 degrees C, 20 degrees C or 4 degrees C, (3) with ST solution or ST solution containing glucose (9 mmol/L) for 12 hours at 20 degrees C or 4 degrees C, and (4) with ST solution containing glucose (9 mmol/L) or ST solution containing glucose (9 mmol/L) and insulin (10 U/L solution) for 20 hours at 20 degrees C. This was followed by 15 min of Langendorff perfusion and 20 min of working perfusion with KHBB solution. During the second working perfusion after preservation, cardiac function was measured again.

RESULTS

(1) Percent recoveries of cardiac output (%CO) preserved with KHBB and ST solution were 44.9 +/- 4.0 and 57.7 +/- 3.8%, respectively (p < 0.05). (2) %CO after preservation with ST solution at 37, 20, 4 degrees C were 0*, 57.7 +/- 3.8 and 74.4 +/- 2.2*%, respectively (*p < 0.05 vs the 20 degrees C group). (3) At 20 degrees C, glucose addition to ST solution increased %CO to 76.5 +/- 2.4% from 57.7 +/- 3.8% in glucose-free ST solution group (p < 0.05). However, at 4 degrees C, glucose addition to ST solution was rather harmful and decreased %CO to 61.4 +/- 2.8% from 74.4 +/- 2.2 in glucose-free ST solution group (p < 0.05). (4) The addition of insulin to the glucose-containing ST solution resulted in a significant increase in %CO from 24.6 +/- 4.0% in the insulin-free solution to 69.2 +/- 2.0%.

CONCLUSIONS

Our results indicate that 1) ST solution might be better than KHBB solution for a continuous perfusion medium of myocardial preservation, and 2) at 20 degrees C, the addition of glucose and insulin to the ST solution could be beneficial for the continuous infusion as a method of preservation, however, at 4 degrees C, these addition might be harmful, suggesting the temperature dependence in the utility of energy substrate.

[The effects of Ebselen upon post-ischemic functional recovery in rat heart]

The effects of Ebselen (DR-3305) upon cardiac function and CK leakage with or without ischemia reperfusion insults were investigated in this isolated working rat heart study. In order to evaluate the effects of Ebselen upon cardiac function, it was administrated to the isolated rat heart with Langendorff perfusion for 15 min at 100 cmH2O. Cardiac functions such as aortic and coronary flow, heart rate and aortic pressure, before and after Ebselen treatment, were measured and expressed as percent of the control value. The coronary resistance was significantly reduced in 100 nM, 500 nM and 1000 nM of Ebselen pretreatment with dose dependent manner. However pretreatment with 1000 nM of Ebselen significantly decreased cardiac output with significant increase of CK leakage. The myocardial protective effects of Ebselen in the cardioplegia or reperfusate were investigated under conditions of normothermic ischemia. After measuring preischemic cardiac functions, the St. Thomas' Hospital cardioplegic solution was infused for 3 min followed by 35 min of global ischemia at 37 degrees C. Hearts were then aerobically reperfused for 15 min in the Langendorff mode. Subsequently, cardiac function was measured and expressed as percent of the preischemic control value. Ebselen addition to the St. Thomas' cardioplegic solution did not possess any myocardial protective effects, although addition to reperfusate possess the protective abilities at a concentration of 10 nM. From these data, Ebselen, which was one of the free radical scavenger, had the myocardial protective effects if it was added to reperfusate at a concentration of 10 nM.

[Use of ketamine combined with local anesthetics in epidural anesthesia]

Postoperative pain relief and sedation with epidural ketamine were studied. Twenty-four patients for elective upper abdominal surgery were divided into 4 groups. Epidural catheter was inserted into thoracic epidural space before induction of general anesthesia. In each group, either 0.25% bupivacaine 5 ml only, ketamine 0.1 mg.kg-1 + bupivacaine 5 ml, or ketamine 0.3 mg.kg-1 + bupivacaine 5 ml, or ketamine 0.5 mg.kg-1 + bupivacaine 5 ml was injected into epidural catheter for complaint of pain in recovery room. In ketamine injected groups, blood pressure and heart were unchanged, but respiration rate increased significantly. Patients in ketamine 0.3 or 0.5 mg.kg-1 injected groups, pain relief and sedation score were significantly intensified, but patients in ketamine 0.5 mg.kg-1 injected group, incidence of pain in the back during injection and headache was high. We conclude that epidural ketamine is useful for postoperative pain relief, and the superior dose of epidural ketamine is 0.3 mg.kg-1.

[Myocardial preservation by continuous perfusion of Krebs-Henseleit solution--the temperature dependency of the optimal perfusion pressure]

The aim of this study was to determine the temperature dependency of the optimal pressure in myocardial preservation by continuous perfusion with Krebs-Henseleit bicarbonate buffer (KHBB) solution. Hearts from Wistar male rats were perfused with KHBB solution and cardiac function (aortic flow) was measured using an isolated working rat heart preparation. In the preliminary experiment, hearts were then preserved using Langendorff perfusion with KHBB solution of 37, 20 or 4 degrees C for 2 hours at a perfusion pressure of 100 cmH2O. This was followed by 15 min of Langendorff perfusion (37 degrees C, 100 cmH2O) and 20 min working perfusion. The 37 degrees C group and 20 degrees C group exhibited better functional recoveries of aortic flow (%AF) in the post-preservation period compared to the 4 degrees C group. In the test experiment, hearts were preserved using Langendorff perfusion for 4 hours at 37 degrees C or for 8 hours at 20 degrees C at various perfusion pressures. At 37 degrees C, %AF after 4 hours of the preservation were 64.7 +/- 2.6, 69.0 +/- 3.2, 81.9 +/- 3.1, 94.7 +/- 3.3 and 63.5 +/- 4.0% (p < 0.05 vs the 100 cmH2O group) at the perfusion pressure of 100, 60, 20, 15 and 10 cmH2O, respectively. %AF after 8 hours of the preservation at 15 cmH2O was 56.3 +/- 2.5%. At 20 degrees C, %AF after 8 hours of the preservatin was 78.9 +/- 3.3, 81.9 +/- 2.3, 67.4 +/- 1.9 and 65.9 +/- 2.2% (p < 0.05 vs the 60 cmH2O group) at the perfusion pressure of 60, 30, 10 and 15 cmH2O, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen radical-induced inhibition of alkaline phosphatase activity in reconstituted membranes

The effects of lipid peroxidation on membrane-bound enzyme activity were examined using reconstituted membranes consisting of intestinal alkaline phosphatase (ALP) and phosphatidylcholine (PC) or dipalmitoylphosphatidylcholine (DPPC). When the PC-reconstituted membranes were incubated with ascorbic acid/Fe2+, the ALP activity decreased with increases in the thiobarbituric acid-reactive substances and conjugated diene values in a time-dependent manner. The kinetic studies on the ALP activity with varying the p-nitrophenyl phosphate or beta-glycerophosphate concentrations showed that the inhibition of the enzyme activity by treatment with these oxidizing agents is mainly due to a decrease in the Vmax value rather than a change in the Km value. The results with several antioxidants suggested that ascorbic acid/Fe(2+)-induced inhibition of the ALP activity is related to generation of .OH radicals. Modification of the reconstituted membranes with malondialdehyde, trans-2-nonenal, or n-heptaldehyde did not affect the ALP activity, suggesting that the secondary degraded products of lipid hydroperoxides had no influence on the enzyme activity. Increasing bityrosine production in the membrane constituents was observed by ascorbic acid/Fe2+ treatment, depending on the incubation time. This finding suggests the possibility that amino acid modifications in the protein molecule are induced by the treatment. Furthermore, the contribution of the lipid organization in ascorbic acid/Fe(2+)-induced inhibition of the ALP activity in the reconstituted membranes was examined by measurements of the fluorescence anisotropy of diphenylhexatriene-labeled membranes. In addition, it was found that the ALP activity in DPPC-reconstituted membranes was also inhibited by treatment with ascorbic acid/Fe2+, similar to the case in PC-reconstituted ones. On the basis of these results, a possible mechanism of ascorbic acid/Fe(2+)-induced inhibition of membrane-bound ALP activity is discussed.

Evolution of the glutamine synthetase gene, one of the oldest existing and functioning genes

We performed molecular phylogenetic analyses of glutamine synthetase (GS) genes in order to investigate their evolutionary history. The analyses were done on 30 DNA sequences of the GS gene which included both prokaryotes and eukaryotes. Two types of GS genes are known at present: the GSI gene found so far only in prokaryotes and the GSII gene found in both prokaryotes and eukaryotes. Our study has shown that the two types of GS gene were produced by a gene duplication which preceded, perhaps by > 1000 million years, the divergence of eukaryotes and prokaryotes. The results are consistent with the facts that (i) GS is a key enzyme of nitrogen metabolism found in all extant life forms and (ii) the oldest biological fossils date back 3800 million years. Thus, we suggest that GS genes are one of the oldest existing and functioning genes in the history of gene evolution and that GSI genes should also exist in eukaryotes. Furthermore, our study may stimulate investigation on the evolution of "preprokaryotes," by which we mean the organisms that existed during the era between the origin of life and the divergence of prokaryotes and eukaryotes.

[The effects of potassium concentration in reperfusion solution upon myocardial protection]

The effects of potassium in reperfusion solution (RS) and the influence of sodium on this effect were studied. Experimental time course was as followed: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 or 35 min at 37.5 degrees C, 15 min early Langendorff reperfusion with several different potassium concentration modified with Krebs Henseleit Bicarbonate Buffer (KHBB) containing 145 mM and 110 mM sodium and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Potassium in RS possessed bell shaped dose response nature with optimal concentration of 10 mM in the condition of 145 mM sodium but 6 m in the condition of 110 mM in terms of percent recovery of aortic flow. Although higher potassium reperfusion produced less Creatine Kinase leakage.

[A case of late-onset SLE complicated with EDTA-dependent pseudothrombocytopenia]

A 57-year-old man was admitted to our clinic with complaints of proximal myalgia in extremities. He was diagnosed as late-onset SLE based on the findings of pleuritis, pericarditis, arthritis and antibodies to DNA and cardiolipin. Aggregation of the platelets and the decreased counts of platelets were observed when EDTA was used as anticoagulant for the blood tests. However, the platelet aggregation was not noted with normal counts of platelets when Heparin-Theophylline was used as anticoagulant. From this observation, EDTA-dependent pseudothrombocytopenia was diagnosed and IgM class of EDTA-dependent anti-platelet antibody was detected by means of flow cytometry. Administration of prednisolone at 40mg/day reduced the symptoms and EDTA-dependent pseudothrombocytopenia, and EDTA-dependent anti-platelet antibody disappeared. His clinical course suggested that EDTA-dependent pseudothrombocytopenia was closely associated with the disease activity of SLE.

[The effects of osmolarity in reperfusion solution upon myocardial protection]

The effects of several different osmolarity in reperfusion solution were studied. Experimental time course was as follows: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution (STS) followed by global ischemia for 33 min at 37.5 degrees C, 15 min early Langendorff reperfusion with different osmolarity by adding sucrose and 5 min late reperfusion with Krebs Henseleit bicarbonate buffer, followed by 20 min working perfusion. Percent recoveries of aortic flow showed that 290 mOsm/L in reperfusion solution possessed optimal protective properties with bell shaped dose response characteristics.

Conversion of bialaphos to other oligopeptides containing phosphinothricin by Streptomyces hygroscopicus

Two oligopeptides containing phosphinothricin were accumulated in the culture of bialaphos (BA) producer Streptomyces hygroscopicus SF1293 when large amount of BA was added to the culture at idio phase. One of the oligopeptides was a new substance, BA dimer (phosphinothricyl-alanyl-alanyl-phosphinothricyl-alanyl-alan ine), and the other was a known substance called If (phosphinothricyl-alanyl-alanyl-phosphinothricin). Though BA none producing mutants which were blocked at the steps 1, 10 and 13, respectively in BA biosynthesis also converted BA to BA dimer and If, the mutants blocked at the step 11 (alanylation) could not curry out the conversion. Antibiotic activities of BA dimer and If were lower than 1/100 of BA.

The bialaphos biosynthetic genes of Streptomyces viridochromogenes: cloning, heterospecific expression, and comparison with the genes of Streptomyces hygroscopicus

The bialaphos resistance gene, bar, was used as a selectable marker to isolate the bialaphos production genes (bap) from the Streptomyces viridochromogenes genome. The S. viridochromogenes bar gene was cloned on overlapping restriction fragments using pIJ680 and pIJ702 in the bialaphos-sensitive host, S. lividans. Although the restriction endonuclease cleavage map of these fragments was not similar to the bap cluster of S. hygroscopicus, the presence and location of bar and four other bap genes as well as a gene required for the transcriptional activation of the cluster (brpA) was demonstrated by heterologous cloning experiments using a series of previously characterized bialaphos-nonproducing S. hygroscopicus mutants. Since recombination-deficient mutants of streptomycetes have not been isolated, restored function provided by cloned homologous DNA results from both recombination (marker rescue) and complementation in trans. In contrast to our previously reported homologous cloning experiments where we were able to define the position of mutant alleles by recombination, in these heterologous cloning experiments we observed little if any recombination between plasmid-cloned genes and the chromosome. As a result, this approach allowed us to define the location and orientation of functional genes using a genetic complementation test. The organization of the clustered S. viridochromogenes bap genes was indistinguishable from the corresponding S. hygroscopicus mutant alleles. The fact that the S. viridochromogenes transcriptional regulatory gene, brpA, functioned in S. hygroscopicus implied that some transcriptional regulatory signals may also be interchangeable. In these two Streptomyces species, which have considerable nucleotide sequence divergence, the complex biochemical and genetic organization of the bialaphos biosynthetic pathway is conserved.

Intestinal parasitic infections among schoolchildren in Chiang Mai, northern Thailand: an analysis of the present situation

Stool examination from primary schoolchildren in Chiang Mai Province, north Thailand, was performed to determine the present state of parasitic infections in this area. Out of a total of 491 children, 239 proved positive (48.7%). The most common type of parasite was found to be soil-transmitted helminths such as hookworm (26.3%) or Strongyloides stercoralis (11.2%), while Ascaris lumbricoides was not so prevalent (1.2% being positive in one school out of three). These results are in contrast to earlier reports showing higher prevalence rates, leading the authors to hypothesize that improvements in sanitary conditions and eradication projects have been effective. Opisthorchiasis is another parasitic disease with a relatively high prevalence rate of 7.5%. This disease rate increases with age and it was found in two out of three schools (8.3-15.8%) and was the most common type of helminth infection. Ascariasis was not seen in these two schools, but strongyloidiasis was found to be the second most prevalent helminthiasis, having a higher infection rate than hookworm. Therefore, eradication efforts now need to be directed toward eliminating opisthorchiasis and strongyloidiasis in addition to continuing to eradicate ascariasis and hookworm infections. The most common protozoal infection with a high pathogenicity in this region was found to be giardiasis (7.7%).

The bialaphos resistance gene (bar) plays a role in both self-defense and bialaphos biosynthesis in Streptomyces hygroscopicus

We inactivated the bialaphos (BA) resistance gene (bar) of a BA producer, Streptomyces hygroscopicus, by the gene replacement technique. The resulting BA-sensitive mutant (Bar-) was able to produce little BA but considerable amount of an intermediate demethylphosphinothricin (DMPT). The Bar- mutant was still able to convert the N-acetyl derivative (AcDMPT) of DMPT to BA. Introduction of normal bar containing plasmid restored both BA resistance and BA biosynthesis to levels as high as the parental BA producer. By contrast, introducing a multi copy glutamine synthetase gene (glnA) into the Bar- mutant restored BA resistance but not BA production. Thus, the bar gene plays a crucial role in both self-defense and a step of BA biosynthesis in the BA-producing S. hygroscopicus.

The bialaphos biosynthetic genes of Streptomyces hygroscopicus: cloning and analysis of the genes involved in the alanylation step

We have isolated and studied the genes involved in the alanylation step in the biosynthesis of a herbicide, bialaphos which is produced by Streptomyces hygroscopicus. Three bialaphos-nonproducing mutants, NP60, NP61 and NP62, isolated from S. hygroscopicus by treatment with N-methyl-N'-nitro-N-nitrosoguanidine were defective for the alanylation step and were not restored to productivity by any locus of the gene cluster previously cloned. Three plasmids were isolated using NP60, NP61 and NP62 as recipients. The genes which restored productivity to NP61 and NP62 hybridized to the contiguous region of the bialaphos biosynthetic gene cluster. The gene cluster involved in the bialaphos production was about 35 kb long. The gene which restored productivity to NP60 did not hybridize to the bialaphos biosynthetic gene cluster. VM3 and VM4, putative alanylation blocked mutants, were derived from a bialaphos producer by gene replacement of an unidentified region of the biosynthetic gene cluster with an in vitro altered DNA sequence. The genes which restored productivity to VM3 and VM4 were located between the genes which code for phosphinomethylmalic acid synthase and demethylphosphinothricin acetyltransferase in the cluster. These results suggest that multiple genes are involved in the alanylation step.

Replacement of Streptomyces hygroscopicus genomic segments with in vitro altered DNA sequences

We have developed a method for gene replacement in Streptomyces hygroscopicus which permits introduction of an in vitro derived mutation carried on a plasmid into the chromosome. We constructed the plasmid pMSB212 which can replicate in S. hygroscopicus and contains the step5 gene of the bialaphos biosynthetic pathway which was inactivated by a frame-shift mutation caused by filling in the cohesive ends of the EcoR I site in the structural gene. pMSB212 was introduced into a bialaphos producer strain and by protoplast regeneration of the primary thiostrepton-resistant transformants, non-producing mutants, were obtained. Biochemical and genetical analyses indicated that these mutants were specifically blocked by introduction of the frame-shift mutation in the step5 gene on the chromosome. This method will enable us to obtain isogenic mutants of known genes and to identify new genes encoded on a cloned fragment.

Cloning of a streptomycin-production gene directing synthesis of N-methyl-L-glucosamine

A Streptomyces bikiniensis DNA fragment complementing a deficiency in streptomycin (Sm) production was cloned on the plasmid vector pIJ385. Host strain S. bikiniensis SD 1 used as the recipient in cloning displayed deficiency in biosynthesis of N-methyl-L-glucosamine, one of the moieties of Sm. The cloned fragment on the multicopy plasmid pIJ385 conferred sevenfold increase in Sm production in comparison with the wild-type parental strain. By subcloning, the region complementing the Sm deficiency of SD 1 was narrowed to a 3.0-kb fragment.