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Renal osteodystrophy is one of the important complications in children with end stage renal disease. Non-invasive tools for evaluation of bone metabolism have been proposed in recent years. The aim of this study was to investigate the markers of metabolic bone disease and peritoneal clearance of these markers in children treated with continuous ambulatory peritoneal dialysis (CAPD). In this study, serum osteocalcin (OC) levels were found significantly higher in patients (107.98 +/- 99.99 ng/ml) than in the healthy control group (41.94 +/- 12.94 ng/ml; p0.05). Mean peritoneal clearance (Clp) of OC was 0.87 +/- 0.91 ml/min. There was no correlation between serum OC and Clp-osteocalcin. There was a positive correlation between serum phosphorus (P) and OC (r=0.394, p=0.031), alkaline phosphatase (ALP) and OC (r=0.520, p=0.003), and parathyroid hormone (PTH) and OC (r=0.441, p=0.017), whereas no correlation was found between OC and calcium (Ca) and OC and magnesium (Mg). There was also a significant correlation between serum ALP and PTH (r=0.714, p=0.0001). A positive correlation was found between serum PTH and Clp of PTH (r=0.471, p=0.009). In conclusion, Clp-osteocalcin is of no interest as a non-invasive marker of metabolic bone disease in children treated with CAPD. But significant correlation between serum OC and PTH, P, and ALP shows that serum OC could be used as a valuable non-invasive biochemical marker of metabolic bone disease.

Beckwith-Wiedemann syndrome is a somatic overgrowth syndrome characterized by a variable incidence of congenital anomalies, including hemihypertrophy, omphalocele, macroglossia and renal malformations. We report a child with Beckwith-Wiedemann syndrome and posterior urethral valves. Urethral valve resection was successfully performed under general anesthesia after voiding cystourethrography. This is the first report of Beckwith-Wiedemann syndrome associated with posterior urethral valves.

Anticoagulation is mandatory in all mechanical valve replacements and, when well-managed, permits both embolism and valve thrombosis to be kept at low levels. Here, we report the case of a male patient who has survived 30 years without anticoagulation following aortic valve replacement with the Björk-Shiley prosthesis.

Since 1986, the St. Jude Medical (SJM) mechanical heart valve prosthesis has been implanted in patients at the authors' institution. We present our experience of low-dose oral anticoagulation and antiplatelet therapy following SJM valve implantation.Among 2,585 patients (mean age 40.3 +/- 13.5 years) living in a rural environment, 865 underwent aortic valve replacement (AVR), 1,231 mitral valve replacement (MVR) and 489 double valve replacement (DVR). All patients received 2.5 mg/day warfarin and a combination of antiaggregation therapy (dypridamole 3 x 75 mg/day plus aspirin 100 mg/day), irrespective of their prothrombin time and cardiac rhythm.Postoperatively, 139 adverse events occurred (51 in AVR patients, 58 in MVR, 30 in DVR). Operative mortality rate was 5.9%, 4.7% and 6.1%, respectively, in the three groups (overall mortality rate 5.4%). The most frequent cause of operative mortality was low cardiac output. During follow up, there were 88 anticoagulant hemorrhages (1.2%/patient-year (pt-yr)), 11 paravalvular leaks (0.2%/pt-yr), 52 thromboembolisms (0.7%/pt-yr), 60 mechanical valve thromboses (0.8%/pt-yr) and 78 reoperations (1.1%/pt-yr). These complications occurred in 101 patients after AVR, in 125 after MVR, and in 63 after DVR (4.2%, 3.7% and 4.6% per pt-yr, respectively). Patient age (p = 0.0004), concomitant surgery (p = 0.0017) and late valve-related complications (p = 0.0159) were statistically significant mortality factors after AVR. Previous surgery was a significant risk factor for operative mortality after MVR (p0.05). Female gender (p = 0.0059) and age (p = 0.017) were significant risk factors for operative mortality after DVR (p0.01).Following implantation of the St. Jude Medical mechanical heart valve prosthesis, a fixed dose of 2.5 mg/day warfarin and combined dipyridamole/aspirin provided satisfactory results in terms of thrombosis, embolism and bleeding.

Protection of the brain is of vital importance during aortic arch aneurysms. In this study efficiency of retrograde cerebral perfusion was evaluated with the use of single photon emission computed tomography technique (SPECT) by using 99mTc hexamethylpropylene amine oxime (HMPAO).Four animals were used. The internal maxillary vein was the site of retrograde cerebral perfusion. The animals were studied after the heart rate and respiration were stopped with the use of the high dose drug administration and the brain was perfused with cold Ringer's lactated solution. After this procedure, 99mTc HMPAO-SPECT study was performed.In one animal we did not get any cerebral image because of the competent venous valve in the internal maxillary vein. In the remaining animals, normal brain perfusion was achieved.99mTc HMPAO-SPECT study documented that blood flow via the retrograde way meets the metabolic demand of the brain. Retrograde delivery of 99mTc HMPAO did not conclude any poorly perfused area in the brain when in given both sides and all parts of the brain can be effectively perfused by cerebral venous system in hypothermic conditions.

Minimally invasive techniques have gained recent interest in the realm of cardiac surgery. This report describes our initial experience with graft replacement of ascending aortic aneurysms using a superior mini-sternotomy approach.Between March 1997 and October 1997, four patients underwent operation for ascending aortic aneurysm via superior mini-sternotomy approach. There were two female and two male patients, ranging in age from 52 to 62 years (mean 53.7 +/- 7.6). All patients had the stigmata of Marfan's syndrome. Mean diameter of the ascending aortas was 6.1 +/- 0.9 cm. Composite graft replacement with coronary reimplantation was performed in all cases. In one patient hemiarch replacement was performed under total circulatory arrest. There was no hospital (30-day) mortality. Mean aortic cross clamp and cardiopulmonary bypass times were 63 +/- 14.1 minutes (range 44 to 78) and 116.7 +/- 43.3 minutes (range 81 to 177), respectively. One patient was re-explored for bleeding.Lengths of hospital stay ranged from 5 to 7 days (mean 5.5 +/- 1). Patients were followed-up for at least 18 months. One patient suffered a fatal stroke in her third postoperative month. All surviving patients were in NYHA Class I at the sixth postoperative month and thereafter.Minimally invasive graft replacement of ascending aortic aneurysms can be performed safely and effectively. Long term results are likely to be similar to those of conventional cases performed through a full median sternotomy.

Twelve animals entered in this study with the aim of documenting that superior mesenteric artery small occlusions lasting for one hour have adverse effects on the myocardium. Three hours after cross clamp removal CO decreased to 1.07 +/- 0.11 from 1.99-0.09 a preoperative value (p0.01) and PCWP increased to 17 +/- 3 from 8 +/- 3 a preoperative value. MOE reduced to 40-5% 3 hours after cross clamp removal. MLE was -0.21 +/- 0.11 three hours after clamp removal. Changes in MOE and MLE were commented as a defect in myocardial aerobic metabolism. As a result of this study it was concluded that toxic mediators are released from the intestine being reperfused after temporary occlusions of the SMA impair myocardial metabolism, resulting in decreased hemodynamic functions.

It is commonly held that preservation of the annulo-ventricular continuity during mitral valve replacement has a beneficial effect on postoperative ventricular function. This paper presents our eight-year experience with this technique.From 1986 to December 1992, 120 patients with rheumatic valve disease underwent mitral valve replacement (MVR) combined with preservation of the posterior leaflet of the mitral valve. The mean age was 33.87 years (range 16 to 63). The preoperative New York Heart Association (NYHA) class was III in 64% of the patients and IV in 3%. The early (30 day) mortality rate was 2.5% (3/120). Follow up was 100% complete. The total cumulative follow up was 477 patient-years (pty) with a mean 3.94 years (range: 2-8 years).The actuarial survival rate (including hospital mortality) was 87.6% at eight years. Advanced age (p = 0.0457), increased preoperative functional capacity (p = 0.0251), increased preoperative end-systolic diameter (p = 0.0352) and combined tricuspid reconstruction (p = 0.0001) were found to be independent parameters for a lower actuarial survival rate. Six patients (1.25%/pty) developed thromboembolic complications. Two of these were cerebrovascular accidents (0.41%/pty) and four were caused by mechanical valve thrombosis (1.83%/pty). Freedom from thromboembolic complications (including mechanical valve thrombosis) was 89.8% +/- 7.9%. Fifteen patients (3.14%/pty) developed valve failure, four (0.83%/pty) mechanical valve thrombosis and nine (1.88%/pty) bioprosthetic valve failure. Freedom from reoperation was 60.7% +/- 16.1%. One patient with a St. Jude Medical valve (0.2%/pty) suffered from prosthetic valve endocarditis. Three patients (0.62%/pty) died during the follow up period, and, freedom from all valve related complications was 51.4% +/- 16.1% at eight years.Preservation of the posterior leaflet during mitral valve replacement reduces the risk of early mortality and did not cause additional complications to the patients. Despite the beneficial effects of this technique in the long term this technique did not increase the long term survival in patients with associated impaired valvular and/or ventricular function.

Between September 1986 and January 1994, 129 St. Jude Medical prostheses were implanted in 113 patients who were 18-year-old or younger at the Cardiovascular Surgery Clinic of Turkiye Yuksek Ihtisas Hospital. Thirty-seven patients underwent aortic, 60 patients mitral and the remaining 16 patients double valve replacement. Overall hospital mortality was 7.9% (9/113). All patients received 2.5 mg/day warfarin from the first postoperative day, in addition 225 mg/day dipyridamole and 100 mg/day aspirin was given following the removal of mediastinal tubes. This regimen was continued indefinitely thereafter. Follow up period ranged between 2-94 months. Total follow up experience was 276.4 patient-years. There were five late deaths; the cause of death was prosthetic valve thrombosis in two patients, intracerebral hemorrhage in one, cardiomyopathy in one, and sudden death in one. Other late complications included one endocarditis, a further anticoagulant related bleeding and one paravalvular leak. There was no case of cerebral or peripheral embolism reported. Seven-year actuarial survival was 92.4 +/- 6.8% for the entire group, 84.6 +/- 13.8% after mitral and 100% after aortic or double valve replacement. In conclusion, low dose oral anticoagulation after heart valve replacement with St. Jude Medical prosthesis in this age group showed satisfactory clinical results.

Single-walled carbon nanotubes (SWNTs) are a fundamental family of distinct molecules, each bearing the possibility of different reactivities due to their intrinsically distinct chemical properties. SWNT syntheses generate a heterogeneous mixture of species with varying electronic character, lengths, diameters and helicities, (n,m), as well as other amorphous, graphitic and metal catalyst impurities. In recent years, selective syntheses and post-synthetic separation strategies have advanced, driven by the requirement for pure SWNTs displaying particular features. Covalent surface modifications are widely-used to adapt SWNTs for specific applications with modified solubility, compatibility and specific functionalities. In many cases, such reactions have been found to be selective, illuminating the fundamentally distinct chemistry of each (n,m) species. This differential reactivity has found immediate utility in facilitating the sorting of nanotubes according to specific diameter, electronic properties and, most importantly, helicity. In this tutorial review, we discuss a wide range of selective reactions, the mechanisms that are thought to govern selectivity, and the challenges of separating, characterising and regenerating the modified SWNTs.

This report describes an unusual case of subaortic stenosis in which hypertrophic obstructive cardiomyopathy was found in combination with both anomalous insertion of papillary muscle directly into the anterior mitral leaflet and "sawfish" systolic narrowing of the left anterior descending coronary artery. Definitive diagnosis was made on operation. We freed the left anterior descending coronary artery by incising the muscular bridge, resected both papillary muscles, and replaced the mitral valve.

Paraplegia after thoracic aortic aneurysm has an incidence of 2.2% to 24%. This study was planned to show the beneficial effects of prostacyclin on spinal cord ischemia.Twelve rabbits underwent 30 minutes of aortic occlusion. Six rabbits received prostacyclin, whereas the remaining rabbits did not. Prostacyclin administration was started with a rate of 5 ng/kg/min 5 minutes before aortic occlusion. This dosage was increased to 25 ng/kg/min during aortic occlusion. Prostacyclin administration after aortic occlusion was maintained for a period of 5 minutes. During this period, prostacyclin dosage was 5 ng/kg/min.One rabbit in the prostacyclin group and five rabbits in the control group were paraplegic. Arterial pressure proximal to the clamp was 65 +/- 7 mm Hg before aortic occlusion and 78 +/- 10 mm Hg during aortic occlusion in the control group and 68 +/- 12 mm Hg before aortic occlusion and 65 +/- 6 mm Hg during aortic occlusion in the prostacyclin group. Arterial pressure distal to the clamp was 11 +/- 4 mm Hg during aortic occlusion in the control group and 18 +/- 5 mm Hg during aortic occlusion in the prostacyclin group (p = 0.02).Intravenous prostacyclin reduced the neurologic injury caused by spinal cord ischemia and reperfusion after 30 minutes of aortic occlusion in the rabbit model.

In this study we attempted to investigate the importance of posterior leaflet preservation during mitral valve replacement (MVR). One hundred and forty randomly selected patients with isolated mitral insufficiency were studied, half of whom had MVR with preservation of the posterior leaflet (Group I), whereas in the other half conventional MVR was performed, without preservation of the posterior leaflet (Group II). Within these two groups there were no in hospital deaths, but 5 patients in Group II were admitted to the hospital with congestive heart failure and 3 of them died after approximately 6 months. Long term mortality rate was 4.2% in Group II. Ejection fraction (EF) decreased postoperatively from 56% to 50% in Group I (p less than 0.05), and from 59% to 49% in Group II (p less than 0.05). Fifteen patients in each group and aged below 30 with sinus rhythm and in the first functional capacity according to the New York Heart Association classification (NYHA) were subjected to exercise study, 18 months after the operation. After exercise EF increased from 47% to 64% in Group I and decreased from 51% to 47% in Group II. These findings suggested that MVR with the preservation of the chordae tendineae can be done with a low morbidity and mortality rate in the early and late postoperative period.

Mediastinitis developed following 58 of 8803 operative procedures involving median sternotomy at Türkiye Yüksek Ihtisas Hospital. There were 40 men and 18 women. Mediastinitis occurred within, on average, 10 days after the operation. No positive cultures were obtained in 37 patients; Staphylococcus aureus was the responsible pathogen in 18, Escherichia coli in 2, and Enterococcus in 1 patients. Thirty patients had a valve procedure, 24 aortocoronary bypass grafting, 1 a total correction for tetralogy of Fallot, 1 a primary closure of an atrial septal defect, and 2 had Bentall's procedure for an ascending aortic aneurysm. Fifty patients were treated by radical debridement and closed irrigation of the mediastinum with antibiotic solutions and 8 patients were treated with sternal debridement and transposition of the omentum. The mortality rate was 36% for the former, and 12.5% for the latter technique. Omentum transposition promoted rapid healing with a low mortality rate.

Because of the relative infrequency of Ebstein's anomaly the type of effective surgical treatment remains controversial. Various authors have reported different results depending upon the type of surgical treatment involved. In TYIH between 1974-1987, 30 cases with Ebstein's anomaly have been operated upon; 12 cases underwent surgical repair and in the remaining 18 cases a tricuspid valve replacement was performed. Four out of the 12 reconstruction cases remained on cardiopulmonary by-pass (CPB) because of the failure of the right ventricle and artificial valves were implanted in these cases. One of these patients died. In all, 3 patients died as a result of annuloplasty and the postoperative courses of these patients were eventful. Among the remaining 18 patients with artificial valve replacement only one patient died and the remainder of the tricuspid valve replacement group had an uneventful postoperative period.

The association of lower extremity peripheral vascular disease (PVD) in patients undergoing coronary artery bypass (CAB) has been studied in two groups of patients who have been operated upon between January and May 1987. Group 1 consists of 125 cases in which only resting ankle-arm pressure index (AAPI) were evaluated. Group 2 consists of 50 cases where both resting and after exercise AAPI were recorded. In total, 17 cases of one extremity and in 10 both lower extremity resting AAPI were below 0.9 (15.4%). In Group 2 comparison of resting and after exercise AAPI on both sides showed no statistically significant difference. However in Group 2, 13 cases (26%) had after exercise AAPI below 0.9 and in 26 (52%) cases after exercise AAPI were lower than the resting AAPI. This study showed that, although the coexistence of PVD in patients undergoing CAB is not as high as the coexistence of CAD in patients undergoing peripheral vascular procedures, this percentage can increase when the presence of PVD is evaluated with an exercise test whenever possible.

Between 1974 and April, 1988, 9 patients with congenital coronary artery fistulas underwent surgical repair. Of these, 4 were female and 5 male, ranging in age from 6 to 50 years (mean 28.2 +/- 18.9). Seven patients were symptomatic (congestive heart failure and/or angina), whereas in 2 patients the diagnosis was established through the investigation of an asymptomatic continuous murmur. The origin of the fistula was the left main coronary artery in 1, left anterior descending artery (LAD) in 2, circumflex artery (Cx) in 3, Cx + LAD in 2 and LAD + right coronary artery in 1 patient. The sites of termination of the fistulous tract were the pulmonary artery in 6, the right atrium in 1, the right ventricle in 1 and the left ventricle in 1 patient. In 2 cases the fistulous tracts were ligated without utilizing cardiopulmonary bypass (CPB). In 7 cases CPB was instituted and in 6 of these the fistulous communications were closed from within the termination chamber, in 1 patient the fistula was closed through a coronary arteriotomy during elective ventricular fibrillation. There was no operative mortality and long term follow-up was uneventful after a mean follow-up of 5.4 +/- 5.2 years, with 8 patients still completely asymptomatic. Surgical therapy is recommended for patients having coronary artery fistulas in order to prevent fistula-related complications. In those cases requiring CPB, closure of the fistula from the involved chamber only is suggested.

Four groups of patients were studied. Group I: Congenital cyanotic heart disease (CCHD), consisting of 24 subjects aged 5 to 28 (1.4); 18 males and 4 females. Group II: Acyanotic congenital heart disease (ACHD), consisting of 34 patients aged 5 to 42 (20.1); 17 males and 17 females. Group III: Rheumatic heart disease (RHD), consisting of 30 patients aged 11-54 (42.4); 9 males and 21 females. Group IV: Atherosclerotic heart disease (AHD), consisting of 35 patients aged 36 to 65 (49.2); 33 males and 2 females. The haematocrit value (Hct) was the highest in the CCHD group. Total amount of heparin (mg/kg) used during cardiopulmonary bypass was 5.4 in CCHD, 4.66 in ACHD, 4.8 in RHD and 4.6 in AHD group. Mean protamine values was 4.02; 4; 4.03; and 4 respectively. Although the difference of Hct value was statistically different between CCHD and RHD group (p less than 0.001), heparin need was not (p less than 0.1). One-way analysis of variance (F test) showed no difference for heparin need between the four groups (F3.119 = 0.64). Prothrombin time (PT) and activated partial thromboplastin time (aPTT) showed a positive correlation (r = 0.36 and r = 0.25) with heparin need in CCHD group but no correlation was found in RHD group.

Over the past 15 years 23 patients, aged 14-50, with aortic sinus-cardiac chamber fistulous communication have been operated upon. All were symptomatic and had angiographic evaluation before surgery. The last 5 were diagnosed by two-dimensional echocardiography. The origin of the fistula was the right aortic sinus in 22 and the non-coronary sinus in 1. The involved cardiac chamber was the right ventricle in 18, right atrium in 3 and left ventricle in 2. Associated lesions were ventricular septal defect (VSD) in 9, ventricular septal defect + atrial septal defect (VSD + ASD) in 1, ventricular septal defect + pulmonary stenosis (VSD + PS) in 1, atrial septal defect (ASD) in 3 and congenital aortic stenosis (AS) in 1. At surgery both the aorta and involved cardiac chamber were opened. No recurrence was encountered when the fistula was repaired using teflon felts on both ends. Three patients, 2 of whom had been operated upon before the use of cardioplegic arrest, died (13%).