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M Turina

Publications and source records attributed to M Turina.

At least 37 records · Page 2Linked to original sources
PubMed2001

Chronic beta-blocker therapy improves outcome and reduces treatment costs in chronic type B aortic dissection.

OBJECTIVES: To compare the medical treatment of chronic type B aortic dissection with beta-blockers versus other antihypertensive treatments in terms of their requirement for surgical intervention and treatment costs. METHODS: Case records of the 130 patients treated for aortic dissection type B in this unit between 1988 and 1997 were reviewed. Seventy-eight of 130 patients with chronic dissection have received isolated medical treatment. Seventy-one of 78 patients were discharged alive. Fifty-one of 71 received beta-blocker treatment, 20/71 were treated with other antihypertensive drugs. RESULTS: Surgery for aortic dissection became necessary in 20/71 patients (28%) during follow-up (mean, 4.2 years): 10/51 in the beta-blocker group and 9/20 in the other antihypertensive drug group. The freedom from subsequent aortic operation was 80 and 47%, respectively (P=0.001). Indications for emergency surgery were increased aortic diameter (79%), symptomatic aortic aneurysm (11%), and renal artery hypoperfusion (5%). The median hospitalization time during follow-up (dissection-related) was 2 days for patients who received beta-blockers and 16 days for patients who received other antihypertensive drug treatments (P=0.001). The cost of treatment/patient per year amounted to 644 and 12748 euros, respectively. CONCLUSIONS: A substantial proportion of patients with chronic type B dissection who receive initial medical management will later need surgery. Long-term treatment with beta-blockers reduces the progression of aortic dilatation, the incidence of subsequent hospital admissions, as well as the incidence of late dissection-related aortic procedures and the cost of treatment. Patients with chronic type B dissection need, in addition to frequent follow-up of aortic diameter, continuous treatment with beta-blocking agents.

Adrenergic beta-Antagonists↗
PubMed2001

Genetic predisposition in patients undergoing cardiopulmonary bypass surgery is associated with an increase of inflammatory cytokines.

OBJECTIVE: Cardiopulmonary bypass (CPB) surgery induces a transient rise in pro-inflammatory cytokines typically released by activated monocytes. The E4 variant of apolipoprotein E is a recognized risk factor for atherosclerosis. It has recently been shown that apolipoprotein E affects monocyte functions in vitro and leads to higher levels of median lipoprotein (a) in humans. The aim of the study is to investigate if the E4 genetic variant of apolipoprotein E affects cytokine release after CPB surgery. METHODS: 22 patients were operated on with standard coronary artery bypass grafting. Concentrations of interleukin 8 (IL-8) and tumor necrosis factor (TNF-alpha) were measured by automated Immulite immunoassay at regular intervals within 48 h after surgery. Total apparent cytokine outputs were calculated as area under the curve. Results are expressed as mean+/-standard deviation and compared by unpaired t-test. RESULTS: In the presented patient population 6 (27%) carried the E4 allele. Sixteen (63%) showed no E4 allele. Mean cross clamp time (CCT) was 56.2+/-13.5 min versus 55.7+/-12.1 min and CPB time was 91.8+/-17.5 versus 93.5+/-15.7 min. No statistical difference between E4-carriers and E4 non-carriers regarding CCT and CPB was observed. The total amount of IL-8 and TNF-alpha was higher in patients carrying the E4 genetic variant of apolipoprotein E in comparison to E4 non-carriers (P<0.08, P<0.039). CONCLUSION: The presence of the E4 allele is associated with increased release of IL-8 and TNF-alpha after CBP surgery. The preoperative determination of E4 in patients undergoing cardiac surgery may lead to additional perioperative measures for the treatment of an increased systemic inflammatory response.

Aged↗
PubMed2001

Surgical management of retro-aortic left renal vein in combined abdominal aortic and coronary surgery.

Although generally retro-aortic left renal vein is a rare anatomic finding, it occurs in 0.8% of the patients admitted for abdominal aortic aneurysm surgery. Surgeons fear fatal bleeding during clamping of the aorta, caused by a more caudal insertion of the retro-aortic left renal vein and a greater vulnerability of the anomalous tissue. Once such a complication occurs, a reconstruction of the retro-aortic left renal vein using a synthetic graft should be performed to obtain adequate renal venous flow and maintain renal function.

Aged↗
PubMed2001

Successful endovascular repair of a leaking abdominal aortic aneurysm under local anesthesia.

UNLABELLED: Local anesthesia is a safe and less invasive anesthetic management for the endovascular approach to elective aortic aneurysm. We have successfully extended the indication of local anesthesia to a high-risk patient with leaking aneurysm and stable hemodynamics. PATIENT AND METHODS: A 86 year old patient with renal insufficiency due to longstanding hypertension, coronary artery and chronic obstructive lung disease was transferred to our hospital with a leaking abdominal aortic aneurysm. Stable hemodynamics allowed to perform a fast CT scan, that confirmed the feasibility of endovascular repair. A bifurcated endograft (24 mm x 12 mm x 153 mm) was implanted under local anesthesia. RESULTS: The procedure was completed within 85 minutes without problems. The complete sealing of the aneurysm was confirmed by CT scan on the third postoperative day. Twenty months later, the patient is doing well and radiological control confirmed complete exclusion of the aneurysm. DISCUSSION: The endoluminal treatment is a minimally invasive technique. It's feasibility can be rapidly assessed by CT scan. The transfemoral implantation can be performed under local anesthesia provided that hemodynamics are stable. This anesthetic management seems to be particularly advantageous for leaking abdominal aortic aneurysm since it doesn't change the hemodynamic situation in contrast to general anesthesia. Hemodynamic instability, abdominal distension or tenderness may indicate intraperitoneal rupture and conversion to open graft repair should be performed without delay.

Aged↗
PubMed2001

Predictors of long-term survival after valve replacement for chronic aortic regurgitation; is M-mode echocardiography sufficient?

AIMS: The clinical importance of pre-operative and follow-up echocardiographic studies in patients operated on for chronic severe aortic valve regurgitation is still a matter of debate. The prognostic significance of M-mode echocardiography has never been directly compared with clinical and angiographic data. METHODS AND RESULTS: Univariate and multivariate analyses of cumulative survival were performed for clinical, echocardiographic and angiographic data of 125 patients operated on between 1975 and 1983, and followed for 13.3+/-6.4 years. Ten and 20 year survival rates were 77% and 48%, respectively. Age, NYHA class, angiographic volumes, ejection fraction, as well as M-mode echocardiographic end-systolic dimension and shortening fraction were the main pre-operative prognostic parameters for long-term survival. In a multivariate analysis the angiographic end-systolic volume index, age and preoperative NYHA class were independent pre-operative prognostic variables of long-term survival. A postoperative reduction in end-diastolic dimension of >20% predicted a significantly better late survival (74% vs 44% after 20 years, P<0.001). CONCLUSIONS: Age, pre-operative NYHA class and left ventricular systolic function are the main determinants of long-term survival after valve replacement for chronic aortic regurgitation. Despite a slightly lower predictive value of echocardiography when compared to angiography, it appeared sufficient for everyday clinical decision making for valve replacement. Echocardiography within 6 months postoperatively is able to detect recovery of left ventricular function, and enables additional risk-stratification, regardless of pre-operative findings.

Adolescent↗
PubMed2001

Optimal cell source for cardiovascular tissue engineering: venous vs. aortic human myofibroblasts.

Arterial vascular cells have been successfully utilized for tissue engineering in human cardiovascular structures, such as heart valves. The present study evaluates saphenous vein-derived myofibroblasts as an alternative, easy-to-access cell source for human cardiovascular tissue engineering. Biodegradable polyurethane scaffolds were seeded with human vascular myofibroblasts. Group A consisted of scaffolds seeded with cells from ascending aortic tissue; in group B, saphenous vein-derived cells were used. Analysis included histology, electron microscopy, mechanical testing, and biochemical assays for cell proliferation (DNA) and extracellular matrix (collagen). DNA content was comparable in both groups. Collagen and stress at maximum load was significantly higher in group B. Morphology showed viable, layered cellular tissue in all samples, with collagen fibrils most pronounced in group B. In conclusion, saphenous vein myofibroblasts cultured on biodegradable scaffolds showed excellent in vitro tissue generation. Collagen formation and mechanical properties were superior to aortic tissue derived constructs. Therefore, the easy-to-access vein cells represent a promising alternative cell source for cardiovascular tissue engineering.

Aorta↗
PubMed2001

Does the morphology of mitral paravalvular leaks influence symptoms and hemolysis?

BACKGROUND AND AIM OF THE STUDY: Prosthetic mitral valve replacement (MVR) is associated with paravalvular leak in up to 12.5% of patients. The influence of the morphology and location of paravalvular leaks on clinical symptoms and degree of leak-related hemolysis is unknown. METHODS: Morphology, size, location and number of paravalvular leaks were analyzed in 96 consecutive patients with primary mitral paravalvular leaks. RESULTS: Mitral leak was diagnosed a median of 119 days after primary MVR. A small (1-2 mm) paravalvular leak was found in 41 patients (43%), an intermediate leak (3-5 mm) in 26 (27%), and a large leak (6-15 mm) in 29 (30%). Single leaks were observed in 70 patients (73%), whilst 26 (27%) had multiple leaks. Paravalvular leaks occurred around the entire prosthetic circumference, but were seen predominantly around the mitral commissural areas (76%). The larger the size of the leak, the more symptomatic the patient (p = 0.006); 80% of patients with small leaks were in NYHA classes I and II, whilst 62% with intermediate/large leaks were in NYHA classes III and IV. The number of leaks was not correlated with severity of clinical symptoms. Multiple leaks were more likely to cause significant hemolysis. Patients with preoperative chronic renal insufficiency, postoperative infection or large (>5 cm) left atria were more likely to develop multiple leaks. The size and location of the leaks was surgeon-dependent. CONCLUSION: Intraoperative transesophageal echocardiography is mandatory to detect possible small leaks and technical errors. Strict monitoring of all MVR patients is necessary for prolonged periods, as the appearance of paravalvular leaks is not necessarily correlated with clinical symptoms. Small paravalvular leaks, in particular, may go unnoticed. As the location and size of the leaks were significantly surgeon-dependent, self-monitoring should be mandatory for all surgeons.

Adult↗
PubMed2000

[R-hirudin (lepirudin, refludan) as an alternative anticoagulant in heparin-induced thrombocytopenia during cardiopulmonary bypass connection].

A 72-year-old patient with heparin-induced thrombocytopenia (HIT) and global cardiac decompensation underwent cardiac surgery using an extracorporeal circuit (ECC). For systemic anticoagulation r-Hirudin (lepirudin, Refludan) was administered as a heparin substitute during extracorporeal circuit. During cardiopulmonary bypass (100 min) the concentration of r-Hirudin was between 2.9 and 4.6 mcg/ml under continuous infusion of r-Hirudin at between 1.5 and 4.5 mcg/kg/min. The operation was successful and during its course no abnormal bleeding or fibrin formation in the extracorporeal circuit was observed. One hour after operation haemorrhage occurred and rethoracotomy was performed without discovering the cause of the surgical bleeding. After substitution with fresh frozen plasma, thrombocytes and Prothromblex the bleeding stopped on the operation day. The further postoperative course was uncomplicated. After 3 days the patient came to nursing station and was discharged from hospital to a rehabilitation centre after 13 days. After a further 3 weeks he went home in a good general condition.

Aged↗
PubMed2000

Incidence, progression and functional significance of cardiac allograft vasculopathy after heart transplantation.

BACKGROUND: Cardiac allograft vasculopathy after heart transplantation leads to an accelerated form of atherosclerosis with marked and often diffuse vessel wall changes that limit long-term survival. Previous studies showed contradictory results relating vessel wall changes to endothelial vasodilator response. METHODS: A total of 30 cardiac transplant recipients were studied 3, 12, and 24 months after heart transplantation. Coronary angiography was performed at rest, during supine bicycle ergometry, and after 1.6 mg sublingual nitroglycerin. Coronary cross-sectional area (biplane coronary angiography) and coronary artery wall changes (intravascular ultrasound) were assessed and extent of intimal changes correlated to vasodilator responses to nitroglycerine and bicycle ergometry. RESULTS: Intravascular ultrasound showed significant intimal thickening in 43, 64, and 58% of patients at 3, 12, and 24 months. Intimal thickening 3 months after transplantation was related to donor age (r=0.70, P<0.01) but did not predict progression of disease that manifested itself angiographically as a decrease in coronary cross-sectional area at 12 and 24 months (P<0.005) and significant coronary stenosis in 12% of patients after 24 months. Endothelium-independent vasodilatation after nitroglycerin (33+/-15, 44+/-20, and 43+/-24%) was normal. Endothelium-dependent, flow-induced vasodilatation during exercise was decreased (14+/-11, 18+/-14, and 16+/-17%) but did not correlate to intimal changes assessed by ultrasound. CONCLUSIONS: The study confirms the high incidence of intimal thickening after heart transplantation as assessed by intravascular ultrasound. Impaired exercise-induced vasodilatation suggests diminished bioavailability of endothelium-derived nitric oxide to physiological stimulation but the lack of relationship between coronary wall changes and this functional impairment suggests intermittent and presumably reversible endothelial injury in graft atherosclerosis.

Adolescent↗
PubMed2000

A gene cluster encoded by panicum mosaic virus is associated with virus movement.

A subgenomic RNA (sgRNA) of about 1500 nucleotides has been detected in millet plants and protoplasts infected with panicum mosaic virus (PMV). This sgRNA expressed p8, p6.6, p15, and the 26-kDa capsid protein (CP) genes during in vitro translation assays, as determined by using mutants inactivated for expression of each open reading frame. Abolishing expression of p8 and p6.6, the two 5'-proximal genes on the sgRNA, did not affect the replication of PMV in millet protoplasts, but obstructed spread in plants. As predicted for a typical cell-to-cell movement protein, p8 localized to the cell wall fraction of PMV-infected millet plants. The introduction of premature stop codons downstream of the PMV p15 start codon (p15*) abolished infectivity in planta, but did not impair replication in protoplasts. However, a delayed systemic infection in millet plants was supported by the p15aug(-) start codon mutant, which may reflect very low levels of expression from a suboptimal start codon context and/or leaky scanning to a second inframe AUG codon to express the C-terminal portion of the 15-kDa protein. PMV CP mutants had little effect on sgRNA accumulation, but were correlated with a reduction of the gRNA and the decreased expression of the 8-kDa protein in protoplasts as well as abolishment of cell-to-cell spread in plants. These results imply that the successful establishment of a PMV systemic infection in millet host plants appears to be dependent on the concerted expression of the p8, p6.6, p15, and CP genes.

Capsid↗
PubMed2000

Genetic dissection of tomato bushy stunt virus p19-protein-mediated host-dependent symptom induction and systemic invasion.

The plus-sense single-stranded RNA of tomato bushy stunt virus (TBSV) encodes a 19-kDa protein, which is translated from a 3' proximal open reading frame (p19) that is entirely nested within the cell-to-cell movement gene (p22). Expression of the cytosolic p19-protein induces either a systemic lethal collapse in Nicotiana benthamiana and N. clevelandii, or necrotic local lesions on resistant N. tabacum. In spinach, the p19-protein is required at high abundance for efficient systemic invasion. This study aimed to determine whether these seemingly different host-dependent biological activities are governed by the same or separate regions on the 172 amino acid p19-protein. For this purpose, codons for charged amino acids predicted to be exposed on the surface of the polypeptide and presumably available for host-specific interactions, were targeted for mutagenesis. A total of 12 mutants were generated, which had no deficiencies in replication or cell-to-cell movement, and substitution of amino acids at the extreme N-terminal end or within the carboxyl 70 amino acids failed to cause a noticeable biological effect on plants. However, mutations dispersed between positions 43 and 85 on the N-terminal half prevented the onset of a systemic lethal necrosis on N. benthamiana and N. clevelandii. With one exception, the same mutants elicited mostly chlorotic, rather than necrotic, local lesions on N. tabacum. Mutations in the central region, which substituted Arg with Gly at positions 72 or 75-78, impaired the ability of TBSV to systemically invade spinach plants. However, substitution with Ala instead of Gly at position 72 had minimal effects on systemic spread in spinach, suggesting the possible influence of protein structure effects. The implications are that regions on the N-terminal portion of the p19-protein mediate interactions in a host-dependent manner and that a central region is required for all activities either by a direct effect of the amino acids or through maintenance of structural integrity.

Mutagenesis, Site-Directed↗
PubMed2000

[Proximal anastomoses of aortocoronary bypasses. Evaluation with ECG-triggered single-slice computerized tomography].

PURPOSE: Assessment of coronary artery bypass graft (CABG) patency with computed tomography methods has been demonstrated as an alternative to coronary angiography. The evaluation of the bypass anastomoses is still of limited success. Prospective ECG triggering of conventional CT scanners allows heart phase-triggered single-slice acquisition in the sub-second range. The goal of this study was to evaluate whether the use of ECG triggering can optimize the evaluation of proximal CABG anastomoses. MATERIALS AND METHODS: In ten patients after CABG surgery, ECG-triggered CT with thin (2 mm), contiguous slices was performed in the region of the proximal bypass anastomoses in the ascending aorta. The data evaluation was done on axial images and on reconstructed 2D and 3D data sets. RESULTS: The applied technique demonstrated good imaging quality, which allowed evaluation of the CABG anastomoses in all cases. Overall 18 CABG anastomoses could be visualized; 17 anastomoses could be assessed as normal, non-stenotic and patent. DISCUSSION: ECG-triggered thin-slice CT permits reliable assessment of proximal CABG anastomoses and expands the usage of CT in the evaluation of CABG.

Adult↗
PubMed2000

Tissue engineering in cardiovascular surgery: new approach to develop completely human autologous tissue.

OBJECTIVE: In cardiovascular tissue engineering, three-dimensional scaffolds serve as physical supports and templates for cell attachment and tissue development. Currently used scaffolds are still far from ideal, they are potentially immunogenic and they show toxic degradation and inflammatory reactions. The aim of this study is to develop a new method for a three-dimensional completely autologous human tissue without using any scaffold materials. METHODS: Human aortic tissue is harvested from the ascending aorta in the operation room and worked up to pure human myofibroblasts cultures. These human aortic myofibroblasts cultures (1.5x10(6) cells, passage 3) were seeded into 15-cm culture dishes. Cells were cultured with Dulbecco' s modified Eagle's medium supplemented with 1 mM L-ascorbic acid 2-phosphate for 4 weeks to form myofibroblast sheets. The harvested cell sheets were folded to form four-layer sheets. The folded sheets were then framed up and cultured for another 4 weeks. Tissue development was evaluated by biochemical assay and light and electron microscopy. RESULTS: After 4 weeks of culture in ascorbic acid supplemented medium, myofibroblasts formed thin cell sheets in culture dishes. The cell sheets presented in a multi-layered pattern surrounded by extracellular matrices. Cultured for additional 4 weeks on the frames, the folded sheets further developed into more solid and flexible tissues. Light microscopy documented a structure resembling to a native tissue with confluent extracellular matrix. Under transmission electron microscope, viable cells and confluent bundles of striated mature collagen fibers were observed. Hydroxyproline assays showed significant increase of collagen content after culturing on the frames and were 80.5% of that of natural human pericardium. CONCLUSIONS: Improved cell culture technique may render human aortic myofibroblasts to a native tissue-like structure. A three-dimensional completely autologous human tissue may be further developed on the base of this structure with no show toxic degradation or inflammatory reactions.

Analysis of Variance↗
PubMed2000

Fibrin gel as a three dimensional matrix in cardiovascular tissue engineering.

OBJECTIVE: In tissue engineering, three-dimensional biodegradable scaffolds are generally used as a basic structure for cell anchorage, cell proliferation and cell differentiation. The currently used biodegradable scaffolds in cardiovascular tissue engineering are potentially immunogenic, they show toxic degradation and inflammatory reactions. The aim of this study is to establish a new three-dimensional cell culture system within cells achieve uniform distribution and quick tissue development and with no toxic degradation or inflammatory reactions. METHODS: Human aortic tissue is harvested from the ascending aorta in the operation room and worked up to pure human myofibroblasts cultures. These human myofibroblasts cultures are suspended in fibrinogen solution and seeded into 6-well culture plates for cell development for 4 weeks and supplemented with different concentrations of aprotinin. Hydroxyproline assay and histological studies were performed to evaluate the tissue development in these fibrin gel structures. RESULTS: The light microscopy and the transmission electron microscopy studies for tissue development based on the three-dimensional fibrin gel structures showed homogenous cell growth and confluent collagen production. No toxic degradation or inflammatory reactions could be detected. Furthermore, fibrin gel myofibroblasts structures dissolved within 2 days in medium without aprotinin, but medium supplemented with higher concentration of aprotinin retained the three-dimensional structure and had a higher collagen content (P<0.005) and a better tissue development. CONCLUSIONS: A three-dimensional fibrin gel structure can serve as a useful scaffold for tissue engineering with controlled degradation, excellent seeding effects and good tissue development.

Aorta↗
PubMed2000

Expression of adhesion molecules and cytokines after coronary artery bypass grafting during normothermic and hypothermic cardiac arrest.

OBJECTIVE: Cardiac surgery with cardiopulmonary bypass (CPB) results in vascular injury and tissue damage which involves leukocyte-endothelial interactions mediated by cytokines and adhesion molecules. This study was designed to demonstrate the effect of normothermic and hypothermic CPB to cytokine and soluble adhesion molecule levels in adults and to determine whether these levels correlate to the patients postoperative course. DESIGN AND PATIENTS: In 25 patients after normothermic and in 25 patients after hypothermic coronary artery bypass grafting with cardiopulmonary bypass (CPB), blood samples for cytokine and soluble adhesion molecule analysis were taken preoperatively, 24, 36, 48 h, and 6 days postoperatively. Soluble adhesion molecules (sE-selectin, sICAM-1) were measured by ELISA and cytokines (TNF-alpha, IL-6, IL-8) by chemilumenscent-immunoassay. Clinical data were collected prospectively. RESULTS: Postoperatively, adhesion molecule and cytokine levels were significantly elevated after CPB. Mean plasma levels of sICAM-1 was 2.4-fold higher after 6 days. Mean plasma concentration of sE-selectin peaked after 48 h with a 2-fold increase compared to normothermic conditions. In the hypothermia group sICAM-1, sE-selectin, IL-6, and IL-8 showed significantly higher levels (P<0.0057, P<0.0012, P<0.0419, P<0.0145) after 24 h compared to the normothermia group. No clinical differences were seen. CONCLUSION: Adhesion molecules and cytokines are elevated after CPB. Patients after hypothermic CPB show significant higher sICAM-1, sE-selectin, IL-6, and IL-8 levels after 24 h compared to normothermic conditions. These results are mainly due to longer CPB and crossclamp times but do not alter the patient's postoperative course.

Adult↗