Optimizing the transport and storage conditions of current Good Manufacturing Practice -grade human umbilical cord mesenchymal stromal cells for transplantation (HUC-HEART Trial).

BACKGROUND: The HUC-HEART Trial is a clinical study of intramyocardial delivery of current Good Manufacturing Practice (cGMP)-grade human umbilical cord multipotent stromal cells (HUC-MSCs) in ischemic cardiomyopathy where 2 × 107 cells are administered to peri-infarcted myocardium. Prior to the onset of the trial, we aimed to optimize the transport/storage conditions for obtaining the highest cell viability and proliferation rate of cells to be transplanted. METHODS: Cells were tested after being transported in phosphate-buffered saline (PBS) or Ringer's lactate-based (RL) transport media supplemented with human serum albumin (HSA) and/or hydroxyethyl starch (HES) at two temperatures (2-10°C or 22-24°C). RESULTS: The effects of transport conditions on cell viability following 6 h were found highest (93.4 ± 1.5) in RL-based media at 2-10°C. Karyotypes were found normal upon transportation in any of the formulations and temperatures. However, the highest proliferation rate was noted (3.1-fold increase) in RL (1% HSA) media at 2-10°C over 6 days in culture. From that point, RL (1% HSA) media at 2-10°C was used for further experiments. The maximum cell storage time was detected around 24 h at 2-10°C. Extended storage periods resulted in a decrease in cell viability but not in MSC marker expression. An increase in actin quantity was detected in hypoxia (5% O2) groups in early culture days; no difference was noted between hypoxic versus normoxic (21% O2) conditions in later days. DISCUSSION: The overall results suggest that non-commercial, simple media formulations with extended storage intervals at 2-10°C temperatures are capable of retaining the characteristics of clinical-grade HUC-MSCs. The above findings led us to use RL (1% HSA) media at 2-10°C for transport and storage in the HUC-HEART Trial; 23 patients received HUC-MSCs by August 2018; no adverse effects were noted related to cell processing and transplantation.

The effect of CYP1A1 and GSTP1 isozymes on the occurrence of aortic aneurysms.

BACKGROUND: Aortic aneurysms are vascular diseases that are associated with high mortality and morbidity. Cytochrome P450 CYP1A1 and glutathione S-transferase (GSTP1) isozymes were searched and compared with the patients who had experienced aortic surgery due to aortic aneurysm and atherosclerotic patients without aneurysm to find the relation of the oxidative stress with the aneurysms. MATERIALS AND METHODS: Study group consisted of the patients with the diagnosis of aortic aneurysm (group I, n: 12) and control group who were operated for coronary bypass surgery: preoperatively drug users (group II, n: 21) and nonusers (group III, n: 15). Paraffin sections (4 µm thick) of aortic biopsy materials were stained with hematoxylin and eosine, CYP1A1 and GSTP1 immunohistochemical markers. The specimens were evaluated using light microscopy at 40- to 400-fold magnification. RESULTS: The expressions of CYP1A1 and GSTP1 isozymes were found statistically significantly higher in the patients who have an aortic aneurysm than both the control groups (p < 0.05). There was no significant association between protein expressions, drugs and duration of usage, patient's demographic variables, and smoking (p > 0.05). CONCLUSIONS: In this pioneering study, CYP1A1 and GSTP1 isozymes are related with the aneurysms. The strategy that prevents the oxidative stress for the patients who had aortic aneurysms could be a valuable choice of searching to effect the aneurysmal progression.

Which type of conditioning method protects the spinal cord from the ischemia-reperfusion injury in 24 hours?

OBJECTIVE: This study was designed to test the effects of different types of preconditioning and postconditioning methods on spinal cord protection following aortic clamping. METHODS: The animals (rabbits) were divided into sham-operated, ischemic preconditioning, remote ischemic preconditioning, simultaneous aortic and ischemic remote preconditioning, and ischemic postconditioning groups. After neurological evaluations, ultrastructural analysis and immunohistochemical staining for caspase-3 were evaluated after 24 h following ischemia. RESULTS: The neurological outcomes of the remote ischemic preconditioning (4.2 ± 0.4) and ischemic postconditioning (4.6 ± 0.8) groups were significantly improved when compared with the ischemia group (2.2 ± 04). The immunohistochemical analysis revealed that the lowest percentage of apoptosis was in-group ischemic preconditioning at 12.5 ± 30.6%. In the comparison of intracellular edema in an ultrastructural analysis, the ischemic preconditioning and ischemic postconditioning groups had significantly lower values than the ischemia group. CONCLUSION: The conditioning methods attenuate ischemia-reperfusion injury for spinal cord injury. Ischemic and remote preconditioning and also postconditioning methods are simple to perform and inexpensive.

Effect of conditioning on visceral organs during indirect ischemia/reperfusion injury.

BACKGROUND: The mortality and morbidity rates of even extensive thoracoabdominal replacement have improved markedly in recent years. We investigated the effects of a temporary occlusion of the aorta as a direct precondition and temporary occlusion of the axillary artery for remote preconditioning to determine any effects that preconditioning may have on indirect (nonischemic) injuries to visceral organs (indirect effects of remote ischemia/reperfusion injury). METHODS: Thirty-seven New Zealand white rabbits were divided into five groups: controls (sham-operated; group 1); direct ischemia to the infrarenal aorta without preconditioning (group 2); direct ischemic preconditioning to the infrarenal aorta (group 3); remote ischemic preconditioning before clamping the infrarenal aorta (group 4); and simultaneous direct aortic and remote ischemic preconditioning before the clamping and during clamping of the infrarenal aorta (group 5). We used a 30-minute ischemia period for aortic occlusion for spinal cord ischemia/reperfusion. The axillary artery was used for remote preconditioning. After 24 hours, tissue specimens of the internal organs were obtained. RESULTS: Myocardial congestion was the main pathology detected in all groups. Histopathologic evaluation of tissue samples taken from the hearts showed no significant differences in terms of the degree of polymorphonuclear leukocyte (PMNL) infiltration and edema between the groups. Lung congestion and pneumonic cell infiltration were detected in all the groups. Pneumonic cell infiltration was significantly high in groups 2 and 3. Cell infiltration was lowest in group 4 at 71.4% of normal values, which differed from the normal values of 25-33.3% in the other groups (P < 0.05). Although there is a difference between the groups in case of renal congestion, there is not any difference as tubular damage and PMN. There was a significant difference with regard to renal congestion between groups 2 and 3. Renal congestion was normal in 80% of the kidneys in group 3. This differed from the normal values observed in the other groups (14.3-57.1%, P < 0.05). Liver congestion was detected in all groups. CONCLUSIONS: Different preconditioning methods may play an important role in distinct organ injuries during aortic cross-clamping. The visceral organs that exhibited positive and constructive results with direct and remote preconditioning included the lungs and kidneys during indirect ischemia/reperfusion injury. Remote ischemic conditioning was determined to be especially advantageous as a protection method, due to the fact that it is easy to use and effective for indirect ischemia/reperfusion injury.

Right ventricular and septal function in patients with pulmonary hypertension.

OBJECTIVE: Pulmonary hypertension (PHT) exacerbates the functions of both ventricles. This prospective, randomised study was planned to investigate the effects of PHT on kinetics of both ventricles and the septum. METHODS: Twenty-five patients were randomly selected among the patients who had been planned to undergo mitral valve replacement (MVR) because of isolated mitral stenosis and divided into two groups according to their preoperative pulmonary artery pressure (PAP) values. Blood pool gated single photon emission tomography (BPGS) and transthoracic echocardiography were performed. Ventricles' regional, global and functional parameters were also assessed by using pulsed wave Doppler tissue imaging (DTI). RESULTS: Preoperative and postoperative PAP of the group 1 (PAP < 50 mmHg) were 40.0 ± 2.8 and 30.0 ± 2.6 mmHg (p = 0.03), group 2 (PAP ≥ 50 mmHg) were 71.9 ± 4.7 and 50.6 ± 3.5 mmHg (p < 0.05). The global right and left ventricle scores were decreased after the operation. The decrement was only significant in group 2. Considering the septal kinetics, right ventricle septal score was decreased from 7.6 to 3.3 (p < 0.05) in group 1, from 3.8 to 1.6 (p < 0.05) in group 2 postoperatively. CONCLUSION: Following MVR, a decrement in PAP values, and an improvement in ventricular function, especially in the right ventricular and septal kinetics were achieved. Furthermore, it was found that both DTI and BPGS techniques are beneficial to investigate the functional changes postoperatively and in the follow-up period of the patients who undergo mitral valve surgery.

Influence of blood collection systems on coagulation tests.

OBJECTIVE: Coagulation tests are influenced by pre-analytic conditions such as blood collection systems. Change of glass collection tubes with plastic ones will cause alteration of the test results. The aim of this study was to compare three plastic blood collection tubes with a standard glass blood collection tube and each plastic collection tube with the other two for possible additional tube-to- tube differences. MATERIAL AND METHODS: A total of 284 blood samples were obtained from 42 patients receiving warfarin during their routine controls, besides 29 healthy volunteers. Subgroup analyses were done according to health status. RESULTS: Our study demonstrated that different blood collection tubes have a statistically significant influence on coagulation tests. The magnitude of the effect depends on the tube used. However most of the tests performed on samples obtained from any tube correlated significantly with results obtained from other tube samples. CONCLUSION: Although blood collection tubes with different brands or properties will have distinct effects on coagulation tests, the influence of these blood collection tubes may be relatively small to interfere with decision-making on dose prescription, therefore lack clinical importance. Correlations between the results showed that, one of these plastic blood collection tubes tested in our study, can be used interchangably for a wide variety of coagulation assays. CONFLICT OF INTEREST: None declared.

Relation between the frequency of CD34⁺ bone marrow derived circulating progenitor cells and the number of diseased coronary arteries in patients with myocardial ischemia and diabetes.

BACKGROUND: Bone marrow-derived circulating progenitor cells (BM-CPCs) in patients with coronary heart disease are impaired with respect to number and mobilization. However, it is unknown whether the mobilization of BM-CPCs depends on the number of diseased coronary arteries. Therefore, in our study, we analysed the correlation between the diseased coronary arteries and the frequency of CD34/45+ BM-CPCs in peripheral blood (PB) in patients with ischemic heart disease (IHD). METHODS: The frequency of CD34/45+ BM-CPCs was measured by flow cytometry in 120 patients with coronary 1 vessel (IHD1, n = 40), coronary 2 vessel (IHD2, n = 40), coronary 3 vessel disease (IHD3, n = 40) and in a control group of healthy subjects (n = 40). There was no significant difference of the total number of cardiovascular risk factors between IHD groups, beside diabetes mellitus (DM), which was significantly higher in IHD3 group compared to IHD2 and IHD1 groups. RESULTS: The frequency of CD34/45+ BM-CPCs was significantly reduced in patients with IHD compared to the control group (CD34/45+; p < 0.001). The frequency of BM-CPCs was impaired in patients with IHD3 compared to IHD1 (CD34/45+; p < 0.001) and to IHD2 (CD34/45+; p = 0.001). But there was no significant difference in frequency of BM-CPCs between the patients with IHD2 and IHD1 (CD34/45+; p = 0.28). In a subgroup we observed a significant negative correlation between levels of hemoglobin AIc (HbAIc) and the frequency of BM-CPCs (CD34/45+; p < 0.001, r = -0.8). CONCLUSIONS: The frequency of CD34/45+ BM-CPCs in PB is impaired in patients with IHD. This impairment may augment with an increased number of diseased coronary arteries. Moreover, the frequency of CD34/45+ BM-CPCs in ischemic tissue is further impaired by diabetes in patients with IHD.

Resveratrol shows vasoprotective effect reducing oxidative stress without affecting metabolic disturbances in insulin-dependent diabetes of rabbits.

PURPOSE: Resveratrol has been shown to have vasoprotective effects by upregulating oxidative defense mechanisms in a variety of pathophysiological conditions. However, the effect of resveratrol on diabetic oxidative stress and vascular and metabolic abnormalities is not completely understood. Therefore, this study was designed to evaluate whether long-term resveratrol supplementation has a protective effect on vascular function and integrity in association with metabolic parameters and oxidative stress in insulin-dependent diabetes. METHODS: Diabetes was induced in rabbits with alloxan and maintained for 8 weeks. We used a resveratrol dose of 5 mg/L (10 weeks, starting 14 days before alloxan injection) and 50 mg/L (8 or 10 weeks, starting concomitantly or 14 days before alloxan injection) in the drinking water of rabbits. RESULTS: Relaxation to acetylcholine was impaired (control 75.6 ± 3.59%, versus diabetic 42.23 ± 2.53%) and contractions to phenylephrine increased (control 136.89 ± 2.27%, versus diabetic 159.37 ± 6.27%) in aortas from diabetic animals. These changes were associated with increased basal or NAD(P)H-induced superoxide production, as well as lipid peroxide and superoxide dismutase (SOD) levels in the aortic samples. The maximal relaxation to acetylcholine improved by 75.74 ± 9.04% in diabetic rabbits treated with resveratrol. The increased contractions to phenylephrine were not restored to control values after resveratrol treatments, but sensitivity to the contractions tended to decrease. Resveratrol increased nitrite/nitrate levels and suppressed basal or NAD(P)H-induced superoxide production and lipid peroxide levels in the aortas. Importantly, resveratrol increased serum insulin levels without affecting blood glucose and the lipid profile in diabetic rabbits. Using electron microscopic examinations, resveratrol was found to markedly protect the endothelial integrity from diabetes. CONCLUSION: Overall, there was no noticeable difference between resveratrol treatment groups on the recovery from diabetes. Our results indicate that resveratrol alleviates type 1 diabetes-induced vasculopathy by decreasing vascular oxidative stress and thereby increasing the bioavailability of nitric oxide without changing metabolic abnormalities.

Umbilical cord mesenchymal stromal cells engraft and transdifferentiate into cardiomyocyte-like cells following acute myocardial ischemia⋆.

OBJECTIVE: Human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs) gained importance in acute/chronic ischemic cardiomyopathy because of their outstanding regenerative potential in various pathologic conditions. The present study was designed to determine to what extent hUC-MSCs contribute to myocardial regeneration in acute experimental myocardial infarction (MI) in rats. METHODS: Animals were assigned into two groups; the control group received intramyocardial PBS injections, while the hUC-MSC group received calcein-AM-labeled 8.8 × 106/kg hUC-MSCs. Three weeks following the acute MI induction, rats were sacrificed after assessing the left ventricular (LV) function using echocardiography. For the assessment of infarct size, the triphenyl tetrazolium chloride (TTC) test was used in isolated hearts. Collagen-rich scar tissue was demonstrated using Masson's trichrome staining, followed by the detection of cardiac troponin I (cTnI), α-sarcomeric actin (α-SA), von Willebrand factor (vWF), CD68 and CD206 expressions in control and cell-injected sections. RESULTS: Echocardiography revealed a significant difference (P = 0.037) in the LV ejection fraction between groups. TTC assays demonstrated a significant difference (P = 0.006) between the groups regarding the ratio of the infarcted LV area. Calcein-AM-loaded cells were identified mostly in ischemic myocardium. Transplanted cells also expressed human-specific cTnI, providing concrete proof of transdifferentiation into cardiomyocytes, and α-SA. vWF+ cells verified the neovascularization in the ischemic myocardium. Finally, a slight shift from pro-inflammatory to anti-inflammatory macrophages (CD68+/CD206+) was noted in both groups. CONCLUSIONS: We found that the intramyocardial transplanted hUC-MSCs engrafted and partially transdifferentiated into cardiomyocytes, reduced scar formation, and induced angiogenesis through the association of pro/anti-inflammatory macrophages.

Intramyocardial Transplantation of Umbilical Cord Mesenchymal Stromal Cells in Chronic Ischemic Cardiomyopathy: A Controlled, Randomized Clinical Trial (HUC-HEART Trial).

BACKGROUND AND OBJECTIVES: The HUC-HEART Trial (ClinicalTrials.gov Identifier: NCT02323477) was a controlled, prospective, phase I/II, multicenter, single-blind, three-arm randomized study of intramyocardial delivery of human umbilical cord-derived mesenchymal stromal cells (HUC-MSCs) combined with coronary artery bypass-grafting (CABG) in patients with chronic ischemic cardiomyopathy (CIC). The trial aimed to assess (i) the safety and the efficacy of cell transplantation during one-year follow-up, (ii) to compare the efficacy of HUC-MSCs with autologous bone-marrow- derived mononuclear cells (BM-MNCs) in the same clinical settings. METHODS AND RESULTS: Fifty-four patients who were randomized to receive HUC-MSCs (23×106) (n=26) or BM-MNCs (70×107) (n=12) in combination with CABG surgery. The control patients (n=16) received no cells/vehicles but CABG intervention. All patients were screened at baseline and 1, 3, 6, 12 months after transplantation. Forty-six (85%) patients completed 12 months follow-up. No short/mid-term adverse events were encountered. Decline in NT-proBNP (baseline∼ 6 months) in both cell-treated groups; an increase in left ventricular ejection fraction (LVEF) (5.4%) and stroke volume (19.7%) were noted (baseline∼6 or 12 months) only in the HUC-MSC group. Decreases were also detected in necrotic myocardium as 2.3% in the control, 4.5% in BM-MNC, and 7.7% in the HUC-MSC groups. The 6-min walking test revealed an increase in the control (14.4%) and HUC-MSC (23.1%) groups. CONCLUSIONS: Significant findings directly related to the intramyocardial delivery of HUC-MSCs justified their efficacy in CIC. Stricter patient selection criteria with precisely aligned cell dose and delivery intervals, rigorous follow-up by detailed diagnostic approaches would further help to clarify the responsiveness to the therapy.

Alterations in cerebrospinal fluid PO(2), PCO(2), and pH measurements during and after experimental thoracic aortic cross-clamping.

In a model of aortic cross-clamping, we studied the use of a multiparameter sensor for measurement of cerebrospinal fluid (CSF) PO(2), PCO(2), and pH during and after aortic cross-clamping. The present study addressed the above-mentioned alterations and their relation according to time intervals. In 31 pigs, a sensor was introduced into the intrathecal space and epidural laser Doppler was used to measure spinal cord blood flow (SCF). By placing the aortic clamp at different levels, three different spinal cord ischemia groups were obtained (mild, moderate, and severe). CSF variables with SCF were studied for 25%, 50%, and 100% changes according to baseline level. In the clamping period, SCF decreased 71.5%, 40.0%, and 33.3% in groups 1, 2, and 3, respectively. CSF O(2) tension reached 0 in group 1, decreased 74.8% in group 2, and was 12.7% in group 3. CSF CO(2) tension increased 247.2% and 202.0% in groups 1 and 2, respectively, but slightly increased in group 3. The maximum reaction time of CSF O(2) tension was about 16.7-26.9min, although this range was 34.5-49.8min in CSF CO(2) tension. We recognized that O(2) tension reacts faster than PCO(2) and pH. It is possible for O(2) tension to be used faster than produced CO(2) in the ischemic medium, although it is known that the diffusion rate of CO(2) is much higher. Spinal cord O(2) tension monitoring is an important method to detect ischemic changes.

Coronary atherosclerosis distribution and the effect of blood glucose level on operative mortality/morbidity in diabetic patients undergoing coronary artery bypass grafting surgery: a single center experience.

OBJECTIVE: The study aim was to investigate the effect of blood glucose level on atherosclerotic lesion distribution and the contribution to the operative mortality/morbidity in diabetic patients who underwent coronary artery bypass grafting (CABG). METHODS: Between 1986-2003, a total of 2095 patients with diabetes mellitus underwent CABG. The analysis was carried out retrospectively from the clinical records. The patients were divided into four groups according to the blood glucose levels that were obtained when they first applied to hospital; Group 1 (492 patients with blood glucose < 120 mg/dl), group 2 (1112 patients with blood glucose - 120-200 mg/dl, group 3 (261 patients with blood glucose 201-250 mg/dl) and group 4 (230 patients with blood glucose > 250 mg/dl). One way ANOVA test was used for the statistical analysis of continuous variables and Chi-square test was used for analyzing the categorical variables. RESULTS: Emergent operation rate due to acute ischemia gradually increased from Group 1 to Group 4 and reached 6.6% in Group 4 (p=0.005). Operation time and the duration of cardiopulmonary bypass and cross clamp were significantly longer in patients with high blood glucose levels (p<0.05). Necessity for inotropic drug administration postoperatively (p<0.05) and mechanical support (p<0.05) were significantly higher also. The hospital mortality in group 3 was 9.6% and in group 4 was 11.3% (p=0.09). No statistically significant difference was found in terms of morbidity between the groups (p>0.05). The multi-vessel coronary artery disease was more common in groups with high blood glucose level (p<0.05). As the blood glucose level raised, patients were more frequently (p<0.05) confronted with distal left anterior descending artery, middle circumflex artery and right coronary artery lesions. CONCLUSION: Uncontrolled blood glucose level not only increased the perioperative complications but also the incidence of middle and distal coronary artery lesions. It is necessary to diagnose and aggressively treat the high blood glucose level especially before the CABG.

Penetrating cardiac injuries.

BACKGROUND: This study was planned to evaluate patients with penetrating cardiac injury. METHODS: Twenty-two patients had cardiac injury among twenty-five patients who had been referred to our hospital with a suspicion of this diagnosis. Data of the patients were retrospectively evaluated. RESULTS: Echocardiography could be performed in 11 patients with stable haemodynamics and pericardial effusion was established in all of them with one false positive result. The patient with false positive result had left internal thoracic artery and venous injury. Cardiac tamponade was seen in 17 (77%) patients. Injury sites were right ventricle 10 (45.5%), left ventricle 7 (31.8%), left ventricle consisting left anterior descending artery 2 (9.1%), right atrium 1 (4.5%) and pericardial injuries and hematoma 2 (9.1%). The mean physiologic index (PI) of the patients was 10.68+/-5.63, penetrating cardiac trauma index was (PCTI) 14.09+/-6.3, penetrating thoracic trauma index (PTTI) was 17+/-8.84 and organ injury scale according to the American Association for the Surgery of Trauma (AAST/OIS) was 3.86+/-1.25. Mortality rate was 27.3% with 6 out of 22 patients. PI, PCTI, PTTI and AAST/OIS scores of the non-survivors were significantly higher than those of the survivors (p<0.05). While there was no difference between survivors and non-survivors regarding the presence of tamponade and the frequency of the associated abdominal injury, left ventricular and left anterior descending artery injuries and associated lung injuries were more common in non-survivors (p<0.05). CONCLUSION: Non-survivors with penetrating cardiac injury have higher PI, PCTI, PTTI and AAST/OIS scores and they are more severely injured patients comparing to the survivors.

Effect of carbon dioxide insufflation on free internal thoracic artery flows: is it a vasodilator?

BACKGROUND: This study was conceived to evaluate the effect of carbon dioxide insufflation on free internal thoracic artery flows. METHODS: We studied 56 consecutive patients who underwent coronary artery bypass grafting in which the left internal thoracic artery was anastomosed to the left anterior descending artery. The first 26 consecutive internal thoracic arteries were harvested as a pedicled graft (group 1), and the next 30 consecutive internal thoracic arteries were dissected by using the carbon dioxide insufflation technique (group 2). The internal thoracic artery harvesting was performed by 2 experienced surgeons by using the same instrumentation and technique. First, free flows of the internal thoracic arteries were registered after distal cutting of the vessel in both groups. After the first measurements, diluted papaverine was sprayed on the internal thoracic artery pedicle only in group 1, and then second measurements were registered after 15 minutes in both groups. Hemodynamic parameters were recorded with each measurement. RESULTS: The first free flow measurement was significantly higher in the carbon dioxide-insufflated internal thoracic arteries (group 2, 60 +/- 32 mL/min; group 1, 28 +/- 19 mL/min; P <.05). Although the second free flow measurement of the carbon dioxide-insufflated group was higher than in group 1, the difference was not statistically significant (68 +/- 46 mL/min vs 53 +/- 32 mL/min; P =.53). CONCLUSIONS: Carbon dioxide insufflation of the internal thoracic artery is an efficient technique to increase the flow and seems to be safe, simple, and reliable. When the internal thoracic artery is harvested in a carbon dioxide-insufflated fashion, arterial spasm and reduced early flow may be avoided, even without vasodilator agents such as papaverine.

Magnesium-enriched coronary sinus retroperfusion during acute coronary artery occlusion.

BACKGROUND: The protective effect of coronary sinus retroperfusion in cases of ischaemic myocardium is clearly known. It restores the blood flow to the ischaemic tissue, reduces the infarct size, and improves the left ventricular pump function. METHODS: In this study, we investigated the effects of coronary sinus retroperfusion with the addition of magnesium sulphate on myocardial haemodynamics. A total of sixteen animals were entered into the study and divided equally into four groups: group I, control group, left anterior descending (LAD) coronary artery occlusion only; group II, LAD artery occlusion and Mg SO infusion; group III, LAD occlusion and retrograde coronary sinus perfusion; and group IV, LAD occlusion, retrograde coronary sinus perfusion and Mg SO infusion.(4) (4) RESULTS: Haemodynamic measurements were obtained throughout the study, at baseline, during the first and third hour of occlusion, and in the second, fourth and sixth hour of reperfusion. Although, the cardiac index was decreased in all groups, in the second hour of reperfusion it was significantly higher in groups III and IV compared to the control group. In the second hour of reperfusion cardiac index values were 56 +/- 5 and 63 +/- 6 ml/kg per min in groups III and IV respectively (P < 0.05) and as time passed this incremental change in groups III and IV became more apparent. In the fourth hour of reperfusion, group II showed significantly higher values than the control group. Group IV had higher values compared to group III at the fourth and sixth hours post-reperfusion. In general there were significant differences between groups II, III and IV at four and six hours post-reperfusion. The first derivative of pressure measured over time-the dP/dt value-was higher in groups III and IV compared to the control group in the first hour of occlusion (being 1650 +/- 55 and 1700 +/- 35 in groups III and IV respectively, and 1420 +/- 45 in the control group) and these differences continued throughout the occlusion and the reperfusion periods (P < 0.05). Group IV had the highest left ventricular stroke work index (LVSWI) values compared to the other groups in various pulmonary capillary wedge pressure (PCWP) measurements (P < 0.05). It was 0.78 g.m/kg at the 20 mmHg PCWP. CONCLUSIONS: Magnesium, if administered in an antegrade direction had only a limited effect, whereas magnesium-enriched retrograde coronary sinus perfusions appeared to significantly protect the ischaemic myocardium against the hazardous effects of ischaemic reperfusion injury.

The renin-angiotensin system genetic polymorphisms and rheumatic mitral valve disease.

BACKGROUND AND AIM OF THE STUDY: Angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism, angiotensinogen (AGT) gene polymorphism and angiotensin II type 1 receptor (AT1R) polymorphism in relation to rheumatic mitral valve disease were examined in a case-control study to investigate possible relationships between these gene polymorphisms and rheumatic mitral valve disease in patients undergoing mitral valve replacement (MVR). METHODS: A total of 50 patients with rheumatic mitral valve disease and undergoing MVR was compared with 50 normal, and age- and sex-matched control subjects. ACE I/D, AGT gene M235T and AT1R-adenine/cytosine 1166 (A1166C) genotype polymorphisms were identified by polymerase chain reaction (PCR) -based restriction analysis. RESULTS: ACE I/D polymorphism differed significantly between the groups. The control group mostly represented the heterozygote ID allele (74%), while the MVR group showed frequencies of 60% for the homozygote DD and II alleles. MM homozygote frequency was significantly greater in controls, but TT homozygote frequency was significantly greater in the MVR group. AT1R-A1166C genotype polymorphism also differed significantly between groups; the MVR group had 73.7% of the AC heterozygote allele, while controls had 64.4% of the AA and 66.7% of the CC homozygote alleles. CONCLUSION: These results provided evidence of an association between ACE I/D polymorphism, M235T polymorphism and AT1R-A1166C genotype polymorphism and rheumatic mitral valve disease.

The place of closed mitral valvotomy in the modern cardiac surgery era.

BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the long-term efficacy of closed mitral valvotomy (CMV). METHODS: Data obtained over a 36-year period from 1,134 patients who underwent CMV were analyzed. The analysis was carried out retrospectively from hospital records, with follow up examinations being conducted mainly at the outpatient clinic. RESULTS: In-hospital mortality (< or = 30 days after surgery) was 0.4% (n = 5, all closed procedures). Cardiac failure was the main cause of early death, and postoperative peripheral embolism occurred in five cases (0.5%). Freedom from thromboembolism was 99.0 +/- 0.5% at 36 years. Operative results were satisfactory in most patients, and severe mitral incompetence was seen only in three cases. Post-valvotomy mitral regurgitation occurred in 88 patients (7.7%) during the first year after CMV. Reoperation was performed in 500 patients (44.1%). The mean interval between CMV and reoperation was 141.1 +/- 80.8 months (range: 1-436 months). Fourteen patients were reoperated on for mitral regurgitation, 485 for mitral restenosis, and five for mixed mitral valve disease (stenosis and regurgitation). Freedom from reoperation after CMV was 81.4 +/- 1.3% at 10 years, 16.4 +/- 2.1% at 20 years, 3.1 +/- 1.2% at 20 years, and 0% at 36 years. Cox regression analysis indicated that impaired functional capacity, reduced mitral valve area, gradual increase in left atrial diameter and postoperative mitral insufficiency increased the reoperation rate after CMV. CONCLUSION: When compared with percutaneous balloon or surgical open valvotomy, CMV represents a satisfactory technique in terms of simplicity, high efficacy and lower cost.

Cardiac valve replacement with mechanical prostheses in patients aged 65 years and over.

BACKGROUND AND AIM OF THE STUDY: Recent data regarding the performance of mechanical prostheses in patients aged > or =65 years are scant. Hence, the outcome of mechanical prosthesis implantation in this age group has been retrospectively evaluated. METHODS: Between January 1990 and October 2002, 253 patients (163 males, 90 females) aged > or =65 years (mean age 68.2 years) underwent aortic valve replacement (AVR) and/or mitral valve replacement (MVR) at the authors' institution. RESULTS: Among the patients, 94 (37.2%) had MVR, 137 (54.1%) had AVR, and 22 (8.7%) had MVR+AVR. In total, 99 patients (39.1%) had concomitant coronary artery bypass grafting (CABG). The early mortality rate was 11.1%; that for patients aged > or =70 years was greater than that for patients aged 65-69 years (14.5% versus 9.6%, p <0.001). The overall actuarial survival was 91.3 +/- 2.4% at 5 years, 81.1 +/- 4.1% at 8 years, and 73.8 +/- 6.3% at 10 years. Actuarial survival for patients with isolated AVR and MVR at 10 years was 84.7 +/- 6.0% and 61.4 +/- 18.8%, respectively. Actuarial survival at 10 years for patients with isolated valve replacement was 76.1 +/- 8.1%, and 68.7 +/- 10.2% for patients with concomitant CABG (p = 0.680). Actuarial survival at 10 years was 81.3 +/- 6.9% for patients aged 65-69 years, and 50.3 +/- 11.0% for patients aged > or =70 years (p = 0.001). Freedom from a major thromboembolic event was 99.4 +/- 0.7% at five years and 86.3 +/- 6.0% at 10 years, while freedom from hemorrhage was 90.4 +/- 2.6% and 70.3 +/- 6.8%, respectively. CONCLUSION: Mechanical prostheses can be used in patients aged > or =65 years, with favorable results. However, on the basis of the present findings, patients aged > or =70 years have a reduced early and late survival.

The impact of different spectral Doppler criteria on the proportion of high-grade internal carotid artery stenosis in patients undergoing duplex scanning.

AIM: To investigate the impact of different spectral Doppler criteria on the proportion of high-grade ICA stenosis in patients undergoing carotid artery duplex scanning. MATERIAL AND METHODS: Duplex scans of 4,548 internal carotid arteries (ICA) in 2,349 patients were retrospectively analyzed. The following different criteria were applied for each scan for definition of ICA stenosis > or = 70%: Criteria I=ICA peak systolic velocity (PSV) > 130 cm/sec and ICA end-diastolic (EDV) > 100 cm/sec, Criteria II=PSV ICA/common carotid artery (CCA) ratio > 4, Criteria III=ICA PSV > or = 230 cm/sec, Criteria IV=ICA PSV > 230 cm/sec and/or ICA EDV > or = 100 cm/sec and/or PSV ICA/CCA ratio > or = 3.2. RESULTS: The frequency of detecting a > or = 70% ICA stenosis with criteria I, II, III, and IV were 5.5%, 6.8%, 8.4%, and 9.6%, respectively (p < 0.05). CONCLUSION: The use of various duplex criteria significantly affected the number of scans receiving a diagnosis of ICA stenosis of > or = 70%.

Contractile response of different segments of the latissimus dorsi muscle to chronic stimulation.

OBJECTIVE: This study was planned to investigate if there is any difference in terms of the muscle force between the distal and proximal segments of the latissimus dorsi muscle. SUBJECTS AND METHODS: An inplantable mock circulation system was placed around the latissimus dorsi muscle. The wrapping procedure around the implantable mock circulation was performed by using two different latissimus dorsi muscle segments. In group 1, the very proximal and in group 2, very distal part of the latissimus dorsi were wrapped. The main difference is the blood supply to the distal part of the latissimus dorsi that was interrupted during dissection. During the stimulation period which lasted 120 minutes, the pressure developed in this system and adenosine triphosphate (ATP) levels were measured. RESULTS: The stimulation at 20 Hz did not result in any change in pressure and metabolic data. When it was switched to 43 and 85 Hz, ATP levels decreased with a resultant drop in pressure in group 2. However ATP levels were 15.9 +/- 2.2 micromol/gr and 14.8 +/- 2.5 micromol/gr in group 1, 12.0 +/- 1.4 micromol/gr and 6.1 +/- 1.2 micromol/gr in group 2 at 43 and 85 Hz respectively (p < 0.05) at the end of the 90 minutes. The pressures at the same time interval were 89 +/- 11 and 102 +/- 7 mmHg in group 1, 61 +/- 7 and 65 +/- 8 mmHg in group 2 (p < 0.05). CONCLUSION: In this study, we demonstrated that changes in the distal segment of the latissimus dorsi muscle affects its performance in terms of metabolic and pressure changes during high frequency electrical stimulation at 43 and 85 Hz.