Thrombolytic treatment of right atrial thrombus in a patient with B cell acute lymphoblastic leukemia: a case report.

Right atrial thrombus is a severe complication of central venous catheterization (CVC). Concomitant pulmonary embolism may aggravate the clinical picture by causing or increasing shortness of breath and decreasing effort capacity, palpitations, and tricuspid valve regurgitation. A 32-year-old female patient with B cell acute lymphoblastic leukemia receiving chemotherapy was treated with alteplase thrombolysis because of the development of catheter-related right atrial thrombus and accompanying pulmonary embolism. On echocardiography, it was observed that the thrombus in the right atrium had regressed completely, but thrombus was seen in the right main pulmonary artery. The same dose of alteplase was given 2 days later. There was no significant change in the echocardiography. Therefore, ultrasound-assisted catheter-directed thrombolysis was applied. Clinical and radiological improvement was observed.

The Functional Effects of Visfatin on Human Left Internal Mammary Artery.

ABSTRACT: Visfatin may play a role in vascular dysfunction in metabolic disorders. Apart from its insulin-mimetic actions, it has divergent actions in the cardiovascular system with discordant results in the literature. Thus, we aimed to study the effects of visfatin on vascular responses of the human left internal mammary artery. Sections of redundant human left internal mammary artery were cut into 3-mm wide rings and hung in 20-mL organ baths containing physiologic salt solution and attached to an isometric force transducer connected to a computer-based data acquisition system. Removing endothelium caused an increase in pD2 values for visfatin-induced relaxation responses (10 -12 -10 -7 M) (9.06 ± 0.21 and 11.08 ± 0.92, respectively). Nicotinamide phosphoribosyltransferase inhibitor FK866 (10 µM) reversed the visfatin-induced relaxations (10 -12 -10 -7 M) ( P = 0.024). Incubations with nitric oxide synthase inhibitor nitro- l -arginine methylester and guanylate cyclase inhibitor 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) caused significant reductions in relaxation responses of visfatin ( P = 0.011 and 0.008, respectively). Visfatin incubations decreased relaxation responses to acetylcholine but not to sodium nitroprusside. Incubations with visfatin did not change contractile responses to angiotensin II, endothelin-1, noradrenalin, and phenylephrine. In this study, visfatin caused endothelium-dependent relaxations mediated by nitric oxide-cyclic guanosine monophosphate pathway and nicotinamide phosphoribosyltransferase activity. Furthermore, visfatin-induced decreases in relaxation responses were also related to endothelium-derived nitric oxide.

Early postoperative rupture of Heartware outflow graft: A case report.

We know that new generation left ventricular assist devices (LVAD), significantly reduce the mortality of patients in the treatment of advanced heart failure disease, compared to optimal medical therapy. Day by day, we treat more heart failure patients with LVADs. Patients that can be cured are on the rise. But this also causes us to struggle with more complications. In this article, we present a case of cardiac tamponade due to rupture that occurred in the outflow graft of HeartWare left ventricular assist device (HVAD), a complication encountered for the first time as far as we know.

Extracorporeal Membrane Oxygenation Therapy-Assisted Cardiopulmonary Resuscitation and Successful Bridging to Cardiac Retransplant for Cardiac Allograft Vasculopathy.

Extracorporeal membrane oxygenation therapy is being used increasingly in different areas. It has become an indispensable assistant to clinicians for hypoxic pulmonary disorders, cardiogenic shock, resuscitation, and during cardiac surgery. In this case report, we describe a patient who is bridged to successful cardiac retransplant under extracorporeal membrane oxygenation therapy support after extracorporeal membrane oxygenation therapy-assisted cardiopulmonary resuscitation.

Bispectral Index Monitoring in Patients Undergoing Open Heart Surgery.

INTRODUCTION: To obtain the optimal anesthesia depth is not easy in cardiovascular surgery patients where the haemodynamic reserve is limited, due to reasons such as not being able to give the desired dose of anesthetic agent, or the change in the pharmacokinetics of the agent in the heart-lung machine. This study was planned to assess the contribution of bispectral index (BIS) monitoring in the depth of anesthesia. METHODS: The patients were divided into 2 groups, and BIS monitoring was used for each patient. Group 1 (G1 n=35): keeping the BIS monitor screen open, the anesthesia need was set. Group 2 (G2 n=35): BIS monitor was tied to the patient and the monitor screen was closed in such a way that the anaesthesist couldn't see the BIS value. When the recording time came, the data on the monitor was recorded. The need for the anesthetic agent was set according to the parameters such as haemodynamics or follow up of pupils, instead of BIS value, by titrating the anesthetic infusion doses. RESULTS: BIS values were similar in both groups before the induction, BIS values in both groups showed a decrease, showing no significant statistical difference (P>0.05). One patient in each group said that he dreamt, and one patient in G2 said that he had heard a noise and felt that he was taken from one place to another. CONCLUSION: The management should be done with clinical evaluation, haemodynamics and other monitorization methods and BIS monitoring findings together.

Bispectral index monitoring in patients undergoing open heart surgery

Abstract Introduction: To obtain the optimal anesthesia depth is not easy in cardiovascular surgery patients where the haemodynamic reserve is limited, due to reasons such as not being able to give the desired dose of anesthetic agent, or the change in the pharmacokinetics of the agent in the heart-lung machine. This study was planned to assess the contribution of bispectral index (BIS) monitoring in the depth of anesthesia. Methods: The patients were divided into 2 groups, and BIS monitoring was used for each patient. Group 1 (G1 n=35): keeping the BIS monitor screen open, the anesthesia need was set. Group 2 (G2 n=35): BIS monitor was tied to the patient and the monitor screen was closed in such a way that the anaesthesist couldn't see the BIS value. When the recording time came, the data on the monitor was recorded. The need for the anesthetic agent was set according to the parameters such as haemodynamics or follow up of pupils, instead of BIS value, by titrating the anesthetic infusion doses. Results: BIS values were similar in both groups before the induction, BIS values in both groups showed a decrease, showing no significant statistical difference (P>0.05). One patient in each group said that he dreamt, and one patient in G2 said that he had heard a noise and felt that he was taken from one place to another. Conclusion: The management should be done with clinical evaluation, haemodynamics and other monitorization methods and BIS monitoring findings together.

Effects of intraoperative diltiazem infusion on flow changes in arterial and venous grafts in coronary artery bypass graft surgery.

OBJECTIVE: This study aimed to show the effects of intra-operative diltiazem infusion on flow in arterial and venous grafts in coronary artery bypass graft surgery. METHODS: Hundred fourty patients with a total of 361 grafts [205 (57%) arterial and 156 (43%) venous] underwent isolated coronary surgery. All the grafts were measured by intraoperative transit time flow meter intra-operatively. Group A (n=70) consisted of patients who received diltiazem infusion (dose of 2.5 microgram/kg/min), and Group B (n=70) didn't receive diltiazem infusion. RESULTS: Mean graft flow values of left internal mammary artery were 53 ml/min in Group A and 40 ml/min in Group B (P<0.001). Pulsatility index (PI) values of left internal mammary artery for Group A and Group B were 2.6 and 3.0 respectively (P<0.001). No statistically significant difference was found between venous graft parameters. CONCLUSION: We recommend an effect of diltiazem infusion in increasing graft flows in coronary artery bypass graft operations.

Endovenous laser with miniphlebectomy for treatment of varicose veins and effect of different levels of laser energy on recanalization. A single center experience.

Varicose veins, associated with great saphenous vein (GSV) incompetence, are traditionally treated with conventional surgery. In recent years, minimally invasive alternatives to surgical treatment such as the endovenous laser ablation (EVLA) and radiofrequency (RF) ablation have been developed with promising results. Residual varicose veins following EVLA, regress untouched, or phlebectomy or foam sclerotherapy can be concomitantly performed. The aim of the present study was to investigate the safety and efficacy of EVLA with different levels of laser energy in patients with varicose veins secondary to saphenous vein reflux. From February 2006 to August 2011, 740 EVLA, usually with concomitant miniphlebectomies, were performed in 552 patients. A total of 665 GSV, 53 small saphenous veins (SSV), and 22 both GSV and SSV were treated with EVLA under duplex USG. At 84 patients, bilateral intervention is made. In addition, miniphlebectomy was performed in 540 patients. A duplex ultrasound (US) is performed to patients preoccupying chronic venous insufficiency (with visible varicose veins, ankle edema, skin changes, or ulcer). Saphenous vein incompetence was diagnosed with saphenofemoral, saphenopopliteal, or truncal vein reflux in response to manual compression and release with patient standing. The procedures were performed under local anesthesia with light sedation or spinal anesthesia. Endovenous 980-nm diode laser source was used at a continuous mode. The mean energy applied per length of GSV during the treatment was 77.5 ± 17.0 J (range 60-100 J/cm). An US evaluation was performed at first week of the procedure. Follow-up evaluation and duplex US scanning were performed at 1 and 6 months, and at 1 and 2 years to assess treatment efficacy and adverse reactions. Average follow-up period was 32 ± 4 months (3-55 months). There were one patient with infection and two patients with thrombus extension into the femoral vein after EVLA. Overall occlusion rate was 95%. No post-procedural deep venous thrombosis or pulmonary embolism occurred. Laser energy, less than 80 J/cm, was significantly associated with increased recanalization of saphenous vein, among the other energy levels. EVLA seems a good alternative to surgery by the application of energy of not less than 80 J/cm. It is both safe and effective. It is a well-tolerated procedure with rare and relatively minor complications.

Comparative Effects of Preoperative Angiotensin-converting Enzyme In-hibitor, Statin and Beta-blocker Treatment on Human Internal Mammary Artery Reactivity in Patients with Coronary Artery Disease: A Pilot Study.

PURPOSE: We investigated the effect of angiotensin-converting enzyme (ACE)- inhibitor, statin, and beta-blocker usage before coronary bypass surgery (CABG) on vascular reactivity of the internal mammary artery (IMA). METHODS: Patients, who underwent elective CABG were evaluated. Samples of IMA obtained from 22 patients were divided into 4 groups in respect of drugs used by patients before bypass surgery (control group, ACE inhibitor + statin group, ACE inhibitor + statin + beta-blocker group, and ACE inhibitor + beta-blocker group). The discarded, distal end section of IMA was carefully removed, and the vasoreactivity of IMA rings was evaluated in vitro using an organ chamber. Smooth muscle contractile function was tested on artery segments exposed to 10-80 mM KCl and norepinephrine. The endothelial function of IMA rings was assessed with acetylcholine (ACh) and bradykinin, while endothelium-independent vasorelaxation was evaluated by sodium nitroprusside (SNP). RESULTS: Both ACh and bradykinin caused concentration-dependent relaxation in endothelium-intact IMA rings. However, the maximal effect produced by endothelium-dependent agents in all treatment groups was more prominent when compared with the control group. There was no significant difference in the endothelium-dependent relaxation response of IMA between ACE inhibitor + statin, ACE inhibitor + beta-blocker and ACE inhibitor + statin + beta-blocker groups. The vasodilatory potency of SNP was similar in all groups. Similarly, contractile response to KCl or norepinephrine was not significantly different between groups. CONCLUSION: Use of ACE inhibitors and statins before bypass surgery may influence IMA vasoreactivity by improving endothelial control of vascular tone.

Primary intravascular synovial sarcoma: case report.

Synovial sarcoma (SS), a mesenchymal spindle cell tumor, displays variable epithelial differentiation, including glandular formation, and features a specific chromosomal translocation, t(X;18)(p11;q11). SS accounts for 5% to 10% of soft-tissue sarcomas. These tumors occur mostly in the joints, especially near the knee, but they also occur in other locations. Primary intravascular SS (IVSS) are extremely rare; only 6 well-documented cases have been reported in the English literature. We describe a new case of primary IVSS of the superior vena cava (SVC) in a 16-year-old boy. A transthoracic echocardiogram confirmed a large (4.8 × 4.6 cm) circumscribed mass filling the right atrium, as well as a moderate pericardial effusion. The mass extended from the SVC to the tricuspid valve but did not prevent valve coaptation. Surgery via a transatrial approach revealed a huge mass (8 to 12 cm) attached to the SVC via a 5-mm pedicle. The tumor was excised, and the patient experienced an uneventful postoperative course. Fluorescence in situ hybridization analysis revealed the presence of the SS-specific translocation.

The role of nitric oxide and potassium channels in the effect of adrenomedullin in human internal thoracic arteries.

We investigated the effects of adrenomedullin (ADM) and the role(s) of cyclooxygenase, nitric oxide (NO) synthase and potassium channels in the effects of ADM in human internal thoracic artery (ITA) rings. Samples of redundant ITA rings were suspended in organ baths and isometric tension was continuously recorded. ADM (10(-10)-10(-7)M) produced concentration-dependent relaxation responses in ITA rings precontracted by phenylephrine. The relaxant responses to ADM were significantly higher in endothelium-intact than denuded preparations. Incubation of ITA rings with indomethacin (10(-5)M) did not cause a significant decrease in relaxant responses to ADM, while 10(-4)M of N(omega)-nitro-L-arginine methyl ester caused a significant decrease. Both specific guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (5x10(-5)M) and ADM receptor antagonist ADM((22-52)) (10(-7)M) also caused significant decreases in relaxant responses to ADM. Neither 4-aminopyridine (5mM) nor glibenclamide (10(-5)M) caused significant alterations in vasodilatory effect of ADM. ADM-induced relaxation was significantly blunted by both charybdotoxin and apamin. The present study provided pharmacological evidence about the functional relaxant effect of ADM in human ITA preparations. The findings suggested that both Ca(2+)-activated potassium channels and endothelium, through release of NO play a major role in ADM-induced relaxations in isolated human ITA preparations.

Surgical treatment of left ventricular aneurysms: a comparison of long-term follow-up of left ventricular function for classic aneurysmectomy and endoaneurysmorrhaphy techniques.

OBJECTIVE: Myocardial infarction may be complicated by the formation of a left ventricular (LV) aneurysm that distorts the normal elliptical geometry of the ventricle to produce a dilated spherical ventricle with limited contractile and filling capacities. One of the consequences is congestive heart failure, which may be refractory to medical therapy and require surgical treatment. The aim of this study was to evaluate LV function in the late term following repair of LV aneurysm. METHODS: Ninety-seven patients underwent repair of postinfarctional LV aneurysms. Sixty-one patients (62.9%) underwent classic aneurysmectomy, and 36 patients (37.1%) had endoaneurysmorrhaphy. The mean age (+/-SD) of the 87 men (89.7%) and 10 women was 55.98 +/- 8.59 years. Coronary surgery was performed in 82 patients (84.5%), with a mean of 1.34 +/- 0.77 grafts/patient. The mean preoperative ejection fraction (EF) was 39.74% +/- 8.79% (classic, 39.92% +/- 8.90%; endoaneurysmorrhaphy, 39.43% +/- 8.61%; difference not statistically significant [NS]). Fifty-five patients (56.7%) had angina of Canadian Cardiovascular Society class III to IV (classic, 55.7%; endoaneurysmorrhaphy, 58.3%; NS), 31 patients (31.9%) were in New York Heart Association (NYHA) class III to IV (classic, 31.1%; endoaneurysmorrhaphy, 33.3%; NS), and the mean preoperative NYHA functional class was 2.88 +/- 0.74 (classic, 2.83 +/- 0.77; endoaneurysmorrhaphy, 2.97 +/- 0.71; NS). RESULTS: The mortality rate at <30 days was 9.8% (n = 6) in the classic aneurysmectomy group and 2.7% (n = 1) in the endoaneurysmorrhaphy group. Long-term follow-up was available for 80 of these patients. During a mean follow-up of 79.3 +/- 37.6 months (range, 6-156 months), 14 patients (17.5%) died of a cardiac-related cause (classic, 8 patients [16.6%]; endoaneurysmorrhaphy, 6 patients [18.7%]; NS). The cardiac-related survival rate was 82.5%. In the first year, at 5 years, and at 10 years, the survival rates of the patients who underwent classical aneurysmectomy were 98.8%, 93.5%, and 76.1%, respectively, and the rates for patients who underwent endoaneurysmorrhaphy were 100%, 93.0%, 71.2%, respectively (P = .2). In the follow-up patient population, the mean preoperative EF was 40.21% +/- 9.44% in the classic aneurysmectomy group and 39.34% +/- 8.61% in the endoaneurysmorrhaphy group. Postoperatively, mean EFs increased to 44.24% +/- 9.50% and 43.80% +/- 8.81%, respectively, at the last follow-up. NYHA functional class changed from 2.79 +/- 0.77 preoperatively to 1.60 +/- 0.73 postoperatively in the classic aneurysmectomy group and from 2.97 +/- 0.71 preoperatively to 1.34 +/- 0.54 postoperatively in the endoaneurysmorrhaphy group. There was no significant difference in hospital readmissions for cardiac causes (classic, 27.1%; endoaneurysmorrhaphy, 31.2%). CONCLUSION: LV aneurysm can be repaired with acceptable surgical risk. Surgical treatment of LV aneurysm is associated with an improvement in long-term survival and symptoms.

The effect of hydrogen peroxide in human internal thoracic arteries: role of potassium channels, nitric oxide and cyclooxygenase products.

INTRODUCTION: We investigated both the effect and the role(s) of potassium channels, nitric oxide (NO) and cyclooxygenase (COX) products in the effect of hydrogen peroxide (H(2)O(2)) in human internal thoracic artery (ITA) rings. MATERIALS AND METHODS: Samples of redundant ITA obtained from patients undergoing a coronary artery bypass graft surgery were cut into 3 mm wide rings and suspended in 20 ml organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. RESULTS: H(2)O(2) (10(-7)-10(-4) M) produced concentration-dependent relaxation responses in human ITA precontracted by phenylephrine. The relaxant responses to H(2)O(2) did not differ significantly between endothelium-intact and endothelium-denuded preparations. Incubation of human ITA rings with superoxide dismutase (50 U/ml) did not affect the relaxant responses to H(2)O(2), while 1,000 U/ml catalase caused a significant decrease. Incubation of endothelium-intact or endothelium-denuded human ITA rings with voltage-dependent potassium channel blocker 4-aminopyridine (5 mM) significantly inhibited the relaxant responses to H(2)O(2). COX inhibitor indomethacin (10(-5) M) also caused a significant inhibition. Incubation with ATP-dependent potassium channel blocker glibenclamide (10(-6) M) or Ca(2+)-activated potassium channel blocker iberiotoxin (10(-7) M) or NO synthase (NOS) blocker N(omega)-nitro-L: -arginine methyl ester (10(-4) M) did not alter relaxant responses of ITA rings to H(2)O(2). CONCLUSION: The findings of the present study suggested that H(2)O(2)-induced relaxation responses in human ITA were neither dependant on the endothelium nor blocked by NOS inhibition but they rather seem to depend on the activation of voltage-dependent potassium channels and COX.

The role of potassium channels in the vasodilatory effect of levosimendan in human internal thoracic arteries.

OBJECTIVE: We investigated the role of potassium channels in vasodilatory effect of levosimendan in human internal thoracic arteries. METHODS: Samples of redundant internal thoracic arteries obtained from patients undergoing a coronary artery bypass graft surgery were cut into 3 mm wide rings and suspended in 20 ml organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. RESULTS: Levosimendan (10(-8)-10(-5) M) or cromakalim (10(-8)-10(-5) M) produced concentration-dependent relaxation responses in human internal thoracic arteries precontracted by 10(-6) M phenylephrine. The relaxant responses to levosimendan did not differ significantly between endothelium-intact and endothelium-denuded preparations. Incubation of human internal thoracic artery rings with adenosine 3',5'-triphosphate (ATP)-dependent potassium channel blocker glibenclamide (10(-6) M) for 30 min significantly inhibited the relaxant responses to both levosimendan and cromakalim. The Ca2+-activated potassium channel blocker iberiotoxin (10(-7) M) also caused a significant but smaller inhibition on relaxant responses to levosimendan. Incubation of the rings with the voltage-dependent potassium channel blocker 4-aminopyridine (5 mM) for 10 min did not cause significant alterations in relaxant responses to levosimendan. CONCLUSIONS: The findings of this study suggested that levosimendan-induced relaxation responses in human internal thoracic arteries were depended on the activation of ATP-dependent and Ca2+-activated potassium channels.

Aortoiliac kissing stents: long-term results and analysis of risk factors affecting patency.

PURPOSE: To present the early and long-term results of aortoiliac kissing stents implantation and evaluate the risk factors affecting patency. METHODS: The data were retrospectively reviewed on 68 patients (64 men; mean age 55+/-11, range 32-77) who underwent kissing stents implantation during a 12-year period. The majority of patients (64, 94%) had claudication; 4 patients had rest pain. All were smokers. There were bilateral or unilateral stenoses in 42 (62%) patients, and unilateral occlusion and contralateral stenosis in 26 (38%). Lesions were treated with simultaneous implantation of self-expanding (n=52) or balloon-expandable (n=16) stents. After the procedure, patency was determined with Doppler ultrasonography or angiography at 1, 3, 6, and 12 months and annually thereafter. Primary, assisted primary, and secondary patency rates were calculated with Kaplan-Meier analysis on an intention-to-treat basis, and risk factors affecting the patency rates were determined with the Cox regression analysis. RESULTS: All procedures were technically and clinically successful. Complications occurred in 12%, but none required surgery. The follow-up period was 35+/-31 months. Primary, assisted primary, and secondary patency rates, respectively, were 76%, 90%, and 94% at 1 year; 63%, 86%, and 92% at 3 years; and 63%, 64%, and 81% at 5 years. In multivariate analysis, age <50 years and presence of iliac occlusion were identified as risk factors for reduced primary and assisted primary patency; a crossed configuration of kissing stents was identified as a risk factor for reduced primary patency. CONCLUSION: Implantation of kissing stents is a safe and effective alternative in the treatment of aortoiliac obstructions. However, overall primary and assisted primary patency rates are inferior to those reported for surgery. Long-term patency comparable to surgery may be obtained in patients >50 years and in those without an iliac occlusion, particularly if a favorable stent configuration is achieved.

The effect of pentoxifylline on haemolysis during cardiopulmonary bypass in open-heart surgery.

OBJECTIVE: Haemolysis has long been recognized as one of the responses to cardiopulmonary bypass (CPB). Pentoxifylline (PTX), a methylxanthine derivative, has been known for many years for its haemorrheological properties. In this prospective, randomized study, we investigated whether a PTX treatment would reduce the haemolysis during CPB. METHODS: The effect of PTX treatment on haemolysis during CPB was studied in 25 patients (PTX group). Oral PTX (1200 mg/day in 3 divided doses) treatment for 3 days was followed by 300 mg i.v. PTX administration after anaesthesia induction. The control group consisted of 25 patients with equivalent surgery but no PTX treatment. Blood samples were collected at seven time points: prior to CPB, at 5 and 10 min of CPB and 5, 10 and 15 min after removal of cross clamping and 10 min after weaning from bypass in order to measure the haemolysis parameters, which included free haemoglobin and haptoglobin. RESULTS: PTX-treatment caused statistically significant decrements in plasma free haemoglobin levels during CPB. On the other hand, plasma haptoglobin levels stayed higher in PTX-medicated patients during the CPB as compared to control subjects. CONCLUSIONS: These findings suggested that PTX may be an effective agent in reducing the haemolysis during CPB.

Comparison of the vasodilatory effect of nadroparin, enoxaparin, dalteparin, and unfractioned heparin in human internal mammary artery.

The aim of this study was to investigate whether the low-molecular-weight heparins (LMWHs) (eg, nadroparin, enoxaparin, and dalteparin) cause a vasodilatory effect in human internal mammary artery (IMA) and to further compare its effect with unfractioned heparin (UFH). Samples of redundant IMA obtained from 20 patients undergoing a coronary artery bypass graft surgery were cut into 3-mm-wide rings and suspended in 20-mL organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. LMWHs (0.5-6 U/mL) caused a concentration-dependent relaxation in the endothelium-intact human IMA rings, which were precontracted with Phe (10(-6) M) (P < 0.05). The vasodilator potency of LMWHs seems to be nearly similar while the maximal effect produced by LMWHs was less pronounced compared with that produced by UFH. Removal of endothelium totally abolished the responses of human IMA to LMWHs as well as UFH (P < 0.05). LMWHs-induced vasodilator effect was significantly attenuated by Nomega-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) but not indomethacin (10(-5) M). Our results have shown that LMWHs cause a dose-dependent relaxation in human IMA but are less effective than that produced by UFH. The vasorelaxant effects induced by each of LMWH are nearly similar and seem to be via endothelium-dependent mechanisms, including generation of nitric oxide.

Unfractioned heparin produces vasodilatory action on human internal mammary artery by endothelium-dependent mechanisms.

The aim of this study was to investigate whether unfractioned heparin produces a direct vasodilatory effect on the human internal mammary artery (IMA) and the possible underlying mechanisms. Samples of redundant IMA were obtained from 20 patients undergoing coronary artery bypass graft surgery, and concentration-response curves to unfractioned heparin were constructed. Unfractioned heparin (0.5-6 U/mL) caused a concentration-dependent relaxation in the endothelium-intact human IMA rings precontracted with phenylephrine (10(-6) M). Removal of endothelium significantly inhibited the responses of human IMA to unfractioned heparin (P < 0.05). Nomega-Nitro-L-arginine methyl ester (L-NAME, 10(-4) M), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10(-5) M) and L-NAME (10(-4) M) plus ODQ (10(-5) M) partially reduced unfractioned heparin-induced vasodilatory response in endothelium-intact rings, whereas indomethacin alone had no effect. The vasodilatory effect of unfractioned heparin was completely inhibited by 40 mM KCl in the presence of L-NAME, ODQ, and indomethacin. These results clearly demonstrated that unfractioned heparin causes a concentration-dependent vasodilatation in human internal mammary artery, and this action seems to be via endothelium-dependent mechanisms, including generation of nitric oxide and endothelium-derived hyperpolarizing factor.

A functional and histopathological comparison of proximal and distal saphenous vein contractility and morphology.

Variations in vascular reactivity and morphology of proximal and distal saphenous vein might affect its performance as a bypass conduit. Because peri- or postoperative graft spasm or intimal hyperplasia reduces patency, we compared the reactivity and morphology of human proximal and distal saphenous vein conduits. Isometric tension studies were performed in response to potassium chloride (80 mM), phenylephrine (10(-8) - 10(-5) M), norepinephrine (10(-8) - 10(-5) M), and angiotensin II (10(-11) - 10(-7) M). Relaxant responses were tested with acetylcholine (10(-9) - 10(-5) M), sodium nitroprusside (10(-10) - 10(-6) M), and diltiazem (10(-10) - 10(-4) M). Also, vein segments from proximal and distal leg saphenous vein grafts were collected for histopathologic investigation. In proximal and distal saphenous vein segments, we also examined the structure of intima, media, and adventitia, and we evaluated the smooth muscle cell/extracellular matrix ratio in the media. There was no significant difference (P > 0.05) between proximal and distal venous segments in response to vasoconstrictors or vasodilators. Similarly, investigation by light microscopy was unable to show any significant difference between proximal and distal conduits in vascular structure. The smooth muscle cell/extracellular matrix ratio was also similar in these graft materials. Our failure to find functional or morphologic differences between proximal and distal saphenous vein segments suggests that there is no advantage in using one of these preparations over the other as a conduit in coronary artery bypass operations.

Posttransplant lymphoma in renal and heart allograft recipients: a single center experience.

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of organ transplantation, with a reported incidence between 0.8% to 32%. Herein we retrospectively analyzed the patients who diagnosed as PTLD in Akdeniz University. Within the 782 (773 renal and 9 heart) transplant recipients six patients were diagnosed as PTLD (diffuse large B-cell lymphoma). Five of them had renal, one had cardiac transplantation. Three patients were diagnosed within the first year of transplantation. Five patients had abdominal disease one had central nervous system involvement. All patients had positive Epstein-Barr virus (EBV) and cytomegalovirus (CMV) IgG at the time of diagnose. EBV-DNA with polymerase chain reaction (PCR) was found to be negative in five patients. Only one patient was survived after the diagnosis of PTLD. In conclusion, even with treatment the mortality rate is high in patients with PTLD. In order to decrease the incidence of PTLD and related mortality, the risk factors should be evaluated with multicenter studies.