| 1. |
- Tamás, Éva, et al.
(författare)
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Exercise radionuclide ventriculography for predicting postoperative left ventricular function in chronic aortic regurgitation
- 2009
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Ingår i: JACC: Cardiovascular Imaging. - : Elsevier. - 1936-878X. ; 2:1, s. 48-55
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Ejection fraction (EF) reaction upon exercise by radionuclide ventriculography and standard echocardiographic parameters was evaluated as predictors for post-operative left ventricular (LV) function in chronic aortic regurgitation (AR). Background: The optimal timing of surgery for chronic AR is when the left ventricle is still compensating for the volume and pressure overload without irreversible dysfunction. For asymptomatic patients when EF is normal and LV diameters are borderline, exercise testing is recommended by present guidelines. However, only a limited number of studies have been performed, and data are scarce on this subject. Methods: Radionuclide ventriculography with multiple gated acquisition at rest and during exercise was performed in 29 consecutive patients with severe chronic aortic regurgitation pre-operatively and 6 months post-operatively. Patient subgroups were formed based on pre-operative EF exercise response (ΔEF) and were categorized as decreasing (ΔEF <−5%), unaltered (−5% ≤ ΔEF ≤ 5%), and increasing (ΔEF > 5%). A 5% or higher increase was considered normal. The LV diameters and mass were measured by echocardiography. Results: Pre-operative LV diameters were markedly elevated before surgery and diminished significantly after surgery. Left ventricular diameters, LV mass, EF at rest (EFrest), and EF change from rest to exercise (ΔEF) were independent of New York Heart Association functional class. Pre-operative end-diastolic diameter proved to be a predictor for pre- and post-operative ΔEF (p = 0.003; p = 0.04) but not for the nature of the exercise response post-operatively. Patients with decreasing and unaltered EF pre-operatively presented a significantly higher but still abnormal ΔEF post-operatively. Those with increasing EF pre-operatively had a similar response and a normal ΔEF post-operatively. Pre-operative ΔEF was not only a predictor for post-operative ΔEF (p = 0.02) but also classified patients into post-operative subgroups (EF decreasing, p = 0.03; unaltered, p = 0.02; increasing, p = 0.0008). Conclusions: An abnormal EF response to exercise may also occur in patients who do not fulfill criteria for surgery based on LV dimensions or EF. A follow-up of exercise LV function and adjusting the timing of surgery according to the nature of exercise response could, therefore, be beneficial.
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| 2. |
- Nilsson, Jessica, et al.
(författare)
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Bis- and tris(pyridyl)amine-oxidovanadium complexes: characteristics and insulin-mimetic potential.
- 2009
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9234 .- 1477-9226. ; :38, s. 7902-7911
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Tidskriftsartikel (refereegranskat)abstract
- Two novel vanadium complexes, [V(IV)O(bp-O)(HSO4)] (1) and [V(IV)O(bp-OH)Cl2] x CH3OH (2 x CH3OH), where bp-OH is 2-{[bis(pyrid-2-yl)methyl]amine}methylphenol, were prepared and structurally characterised. EPR spectra of methanol solutions of 2 suggest exchange of Cl- for CH3OH and partial conversion to [VO(bp-OH)(CH3OH)3]2+. Speciation studies on the VO2+-bpOH system in a water/dmso mixture (4:1 v/v) revealed [VO(bp-O)(H2O)n]+ as the dominating species in the pH range 2-7. The insulin-mimetic properties of 1 and 2, [V(IV)O(SO4)tpa] (3), [V(IV)O(pic-trpMe)2] (5) and the new mixed-ligand complexes [V(V)O(pic-trpH)tpa]Cl2 (4Cl2) and [V(V)O(pic-OEt)tpa]Cl2 (6Cl2), tpa = tris(pyrid-2-yl)methylamine, picH-trpH = 2-carboxypyridine-5-(L-tryptophan)carboxamide (picH-trpMe is the respective tryptophanmethyl ester), pic-OEt = 5-carboethoxypyridine-2-carboxylic acid, were evaluated with rat adipocytes, employing two lipolysis assays (release of glycerol and free fatty acids (FFA)), respectively and a lipogenesis assay (incorporation of glucose into lipids). The IC50 values for the inhibition of lipolysis in the FFA assay vary between 0.41 (+/-0.03) (5) and 21.2 (+/-0.6) mM (2), as compared to 0.81 (+/-0.2) mM for VOSO4.
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| 3. |
- Szabó, Zoltán, et al.
(författare)
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Kiegészítő klinikai módszer a nyitott szívműtéteknél fellépő légembolisatio csökkentésére : [A complementary clinical method to minimize air embolism during open-heart surgery]
- 2008
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Ingår i: Magyar Sebeszet. - : Akademiai Kiado. - 0025-0295 .- 1789-4301. ; 61, s. 57-59
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Tidskriftsartikel (refereegranskat)abstract
- Air from the left heart is ejected even up to several hours after cardiopulmonary bypass (CPB) despite the use of CO 2 . The following method is complementary in addition to surgical de-airing in order to further reduce the chance of air embolism, especially from the pulmonary veins. After re-expanding the lungs with standard bag inflation, the ventilation is restarted in consultation with the surgeon. The ventilator is set to the respiratory minute volume used before the CPB but at a respiratory frequency of 10/minutes whereas the regularly beating heart is filled from the heart lung machine. Transoesophageal echocardiography (TEE) reliably controls the effect.
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| 4. |
- Tamás, Éva, et al.
(författare)
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Are patients with isolated chronic aortic regurgitation operated in time? : Analysis of survival data over a decade
- 2005
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289 .- 1932-8737. ; 28:7, s. 329-332
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients suffering from chronic isolated aortic regurgitation have a less favorable outcome than patients with aortic stenosis. According to international recommendations, these patients should undergo surgery as soon as left ventricular function begins to deteriorate, that is, surgery is not to be postponed until clinical symptoms become relevant. Hypothesis: The study was undertaken to evaluate how satisfactory our timing of surgery was, as reflected by survival data. Methods: Survival was studied retrospectively in a consecutive series of patients undergoing surgery for chronic isolated aortic regurgitation during a 10-year period in our institution. Results were compared with data from the literature. By excluding patients with aortic aneurysms and acute endocarditis, we formed a homogeneous patient group of 88 subjects. Results: Thirty-day mortality was 1% and late mortality after a mean follow-up period of 6 years was 11%. Compared with survival data from an earlier study in which the patient population was similar and resided in the same geographic area, the results in our patient group seem to be better. It is noteworthy that despite a strong effort to recommend surgery at an earlier stage of the disease than previously, 35% of the patients had moderate or severe left ventricular dysfunction pre-operatively because of late referrals. Conclusion: This stresses the importance of early detection and careful preoperative follow-up with noninvasive methods in patients with aortic regurgitation.
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| 5. |
- Tamás, Éva, et al.
(författare)
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Echocardiographic Description of the Anatomic Relations within the Normal Aortic Root
- 2007
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Ingår i: The Journal of Heart Valve Disease. - 0966-8519. ; 16:3, s. 240-246
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Tidskriftsartikel (refereegranskat)abstract
- Background and aim of the study: Diagnostic procedures continue to contain much hidden information that may substantially improve the understanding of the mechanisms of aortic valve disease and its treatment planning. The study aim, using transesophageal echocardiography (TEE), was to describe in detail the anatomical and physiological properties of the normal human aortic root in vivo. Methods: The study included 32 patients referred for TEE for suspected cardiac sources of emboli, but diagnosed as normal. Images of the aortic valve in long axis (100-120∞) and short-axis (45-60∞) views were recorded in mid-systole and end-diastole. Parameters of the aortic root (subaortic diameter, sinotubular junction (STJ), maximal sinus diameter, sinus height, cusp diameter, cusp height, opening, coaptation and intercommissural distance) were measured. For repeatability and reliability, two investigators performed the same series of measurements on a subgroup of 11 patients. Results: Aortic valve parameters proved to be independent of age, gender, body weight and height, and also of body mass index and body surface area. The subaortic diameter showed no statistically significant connection to maximal sinus diameter or to STJ. No connection was found between STJ and cusp or sinus length in the long-axis view. A simplified regression equation describes the STJ as being three-quarters of the maximal sinus diameter. The valve opening was found to be ca. 80% of the subaortic diameter in systole. Length of coaptation proved to be independent of aortic diameters, but was approximately half of the left coronary (LC) and right coronary (RC) cusp height in diastole. This measurement model proved to be both reliable and reproducible. Conclusion: This reliable description of normal anatomic and geometric relations within the aortic root, through extended examination of the aortic root by echocardiography, may facilitate a better planning of aortic valve-preserving interventions.
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| 6. |
- Tamás, Éva, et al.
(författare)
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Measurement of physical work capacity in patients with chronic aortic regurgitation : A potential improvement in patient management
- 2009
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 29:6, s. 453-457
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Timing of surgery in aortic regurgitation (AR) is important. Exercise testing is recommended upon uncertainty about functional limitations but reports on cardiopulmonary exercise testing (CPET) in populations with pure chronic AR are scarce. METHOD: Twenty-eight patients referred for surgery because of chronic AR (13 in NYHA I, 10 in NYHA II and five in NYHA III) were tested by CPET pre- and 6 months postoperatively. Echocardiography, with measurement of left ventricular ejection fraction (LVEF), diameters (LVED, LVES) and volumes (LVEDV, LVESV) was also performed. RESULTS: The patients had normal LVEF pre- and postoperatively. LV diameters and volumes diminished significantly postoperatively (LVED from 67 to 57, LVES from 49 to 41 mm; P < 0.001). The majority of the patients had a 'low' physical work capacity, none of them performed better than 'average' according to Astrand's classification preoperatively and there was no significant postoperative improvement. The mean peak oxygen uptake (VO(2peak)) was 25 ml kg(-1) min(-1) both pre- and postoperatively, and six of the 28 patients had a VO(2peak) of less than 20 ml kg(-1) min(-1). VO(2peak) was not significantly related to NYHA class. CONCLUSION: LVEF, diameters and volumes at rest did not fulfil the criteria for surgery in most of our AR patients, of whom 46% were asymptomatic. However, many had a remarkably low work capacity, which was neither improved 6 months postoperatively nor correlated to echocardiographic LV dimensions. CPET predicted the postoperative work capacity and may, therefore, be a useful complement for timing of surgery in patients with chronic AR.
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| 7. |
- Tamas, Eva, et al.
(författare)
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[Simple surgical method for intraoperative evaluation of adequacy of tricuspid annuloplasty].
- 2008
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Ingår i: Magyar sebészet. - 0025-0295. ; 61:1, s. 49-52
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Tidskriftsartikel (refereegranskat)abstract
- In tricuspid annuloplasty intraoperative "real time" evaluation using transoesophageal echocardiography requires normal flow to get reliable result. It means that the patient has to be already weaned from the cardiopulmonary bypass by the time of evaluation. In the authors' experience a well functioning tricuspid annuloplasty prevents back-flow through the valve. It can be observed on on-pump beating heart. If the tricuspid valve is competent, it is unnecessary to suck the blood flowing back through the coronary sinus while closing the right atrium. This observation seems to correlate well with post cardiopulmonary bypass transoesophageal echocardiography measurements and the control transthoracic echocardiography right before discharging the patients. These statements are based on a group of 72 patients. Sixty-nine patients (95.8%) were discharged (early mortality 4.2%). Only in one case we could observe a discrepancy between the intraoperative surgical observation and the postoperative echocardiographic finding. Development of functional tricuspid regurgitation in left-sided heart disease is a warning sign for myocardial impairment, which is an indication for surgery. Tricuspid annuloplasty can be performed even with moderate to medium grade regurgitation because it improves the early and late outcome. The described method is an adequate method for intraoperative evaluation of the repaired tricuspid valve competency.
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| 8. |
- Tamás, Éva, 1968-
(författare)
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Surgical treatment in chronic aortic regurgitation : Timing, results, prognosis and left ventricular function
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chronic aortic regurgitation (AR) of varying degree affects 13% of men and 8.5% of women. In persons with severe AR, the expected length of life and its quality are influenced. Some individuals remain asymptomatic for a long period, due to effective compensatory mechanisms, but dysfunction of the left ventricle (LV) usually begins before symptoms appear and can be irreversible by then. This thesis addresses questions of LV function and optimal time for operation of patients suffering from chronic AR. Moreover, detailed echocardiographic studies of the anatomy of the normal aortic valve have been performed to obtain a better understanding of the in vivo anatomic relations within the aortic root.Patients with chronic AR, without concomitant cardiac disease, were studied both retrospectively (n=88) and prospectively (n=29) and the aortic valves of persons (n=32) free from cardiac disease were investigated.For the retrospectively studied patients, survival was 82% at 10 years which is an improvement compared with previously published results. The majority of the patients, however, had LV dysfunction preoperatively. By studying patients prospectively by echocardiography, radionuclide ventriculography (MUGA) and cardiopulmonary exercise testing (CPET) our aim was to evaluate the predictive value of measurements of LV function at rest and during exercise for postoperative outcome. LV diameters were markedly elevated prior to and diminished significantly after surgery. Patients with an abnormal exercise ejection fraction (EF) response by MUGA preoperatively, presented the same reaction postoperatively. This could not be predicted by LV function determination at rest, or by NYHA functional class. In spite of median NYHA class II, these patients had a low work capacity on CPET, which was neither improved 6 months postoperatively nor correlated to echocardiographic LV dimensions. Thus, both MUGA and CPET may be useful complements for timing of surgery in patients with chronic AR.Assuming that patients would benefit from preservation of their native valves the normal aortic valve was studied to gain detailed information about the echocardiographic anatomy and relations within the normal aortic root. This extended examination of the aortic root may facilitate a better planning of aortic valve‐preserving interventions in the future.
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| 9. |
- Freyhult, Eva, et al.
(författare)
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Fisher: a program for the detection of H/ACA snoRNAs using MFE secondary structure prediction and comparative genomics - assessment and update
- 2008
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Ingår i: BMC Research Notes. - : Springer Science and Business Media LLC. - 1756-0500. ; 1:49, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe H/ACA family of small nucleolar RNAs (snoRNAs) plays a central role in guiding the pseudouridylation of ribosomal RNA (rRNA). In an effort to systematically identify the complete set of rRNA-modifying H/ACA snoRNAs from the genome sequence of the budding yeast, Saccharomyces cerevisiae, we developed a program - Fisher - and previously presented several candidate snoRNAs based on our analysis [1]. FindingsIn this report, we provide a brief update of this work, which was aborted after the publication of experimentally-identified snoRNAs [2] identical to candidates we had identified bioinformatically using Fisher. Our motivation for revisiting this work is to report on the status of the candidate snoRNAs described in [1], and secondly, to report that a modified version of Fisher together with the available multiple yeast genome sequences was able to correctly identify several H/ACA snoRNAs for modification sites not identified by the snoGPS program [3]. While we are no longer developing Fisher, we briefly consider the merits of the Fisher algorithm relative to snoGPS, which may be of use for workers considering pursuing a similar search strategy for the identification of small RNAs. The modified source code for Fisher is made available as supplementary material. ConclusionOur results confirm the validity of using minimum free energy (MFE) secondary structure prediction to guide comparative genomic screening for RNA families with few sequence constraints.
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| 10. |
- Kurucz, Eva, et al.
(författare)
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Nimrod, a putative phagocytosis receptor with EGF repeats in Drosophila plasmatocytes.
- 2007
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Ingår i: Curr Biol. - 0960-9822. ; 17:7, s. 649-54
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Tidskriftsartikel (refereegranskat)abstract
- The hemocytes, the blood cells of Drosophila, participate in the humoral and cellular immune defense reactions against microbes and parasites [1-8]. The plasmatocytes, one class of hemocytes, are phagocytically active and play an important role in immunity and development by removing microorganisms as well as apoptotic cells. On the surface of circulating and sessile plasmatocytes, we have now identified a protein, Nimrod C1 (NimC1), which is involved in the phagocytosis of bacteria. Suppression of NimC1 expression in plasmatocytes inhibited the phagocytosis of Staphylococcus aureus. Conversely, overexpression of NimC1 in S2 cells stimulated the phagocytosis of both S. aureus and Escherichia coli. NimC1 is a 90-100 kDa single-pass transmembrane protein with ten characteristic EGF-like repeats (NIM repeats). The nimC1 gene is part of a cluster of ten related nimrod genes at 34E on chromosome 2, and similar clusters of nimrod-like genes are conserved in other insects such as Anopheles and Apis. The Nimrod proteins are related to other putative phagocytosis receptors such as Eater and Draper from D. melanogaster and CED-1 from C. elegans. Together, they form a superfamily that also includes proteins that are encoded in the human genome.
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