Browsing by Subject "MAGNETIC-RESONANCE"

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  • Kaipainen, Aku L.; Pitkänen, Johanna; Haapalinna, Fanni; Jääskeläinen, Olli; Jokinen, Hanna; Melkas, Susanna; Erkinjuntti, Timo; Vanninen, Ritva; Koivisto, Anne M.; Lötjönen, Jyrki; Koikkalainen, Juha; Herukka, Sanna-Kaisa; Julkunen, Valtteri (2021)
    Purpose Automated analysis of neuroimaging data is commonly based on magnetic resonance imaging (MRI), but sometimes the availability is limited or a patient might have contradictions to MRI. Therefore, automated analyses of computed tomography (CT) images would be beneficial. Methods We developed an automated method to evaluate medial temporal lobe atrophy (MTA), global cortical atrophy (GCA), and the severity of white matter lesions (WMLs) from a CT scan and compared the results to those obtained from MRI in a cohort of 214 subjects gathered from Kuopio and Helsinki University Hospital registers from 2005 - 2016. Results The correlation coefficients of computational measures between CT and MRI were 0.9 (MTA), 0.82 (GCA), and 0.86 (Fazekas). CT-based measures were identical to MRI-based measures in 60% (MTA), 62% (GCA) and 60% (Fazekas) of cases when the measures were rounded to the nearest full grade variable. However, the difference in measures was 1 or less in 97-98% of cases. Similar results were obtained for cortical atrophy ratings, especially in the frontal and temporal lobes, when assessing the brain lobes separately. Bland-Altman plots and weighted kappa values demonstrated high agreement regarding measures based on CT and MRI. Conclusions MTA, GCA, and Fazekas grades can also be assessed reliably from a CT scan with our method. Even though the measures obtained with the different imaging modalities were not identical in a relatively extensive cohort, the differences were minor. This expands the possibility of using this automated analysis method when MRI is inaccessible or contraindicated.
  • Melcr, Josef; Martinez-Seara, Hector; Nencini, Ricky; Kolafa, Jiri; Jungwirth, Pavel; Ollila, O. H. Samuli (2018)
    Binding affinities and stoichiometries of Na+ and Ca2+ ions to phospholipid bilayers are of paramount significance in the properties and functionality of cellular membranes. Current estimates of binding affinities and stoichiometries of cations are, however, inconsistent due to limitations in the available experimental and computational methods. In this work, we improve the description of the binding details of Na+ and Ca2+ ions to a 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayer by implicitly including electronic polarization as a mean field correction, known as the electronic continuum correction (ECC). This is applied by scaling the partial charges of a selected state-of-the-art POPC lipid model for molecular dynamics simulations. Our improved ECC-POPC model reproduces not only the experimentally measured structural parameters for the ion-free membrane, but also the response of lipid headgroup to a strongly bound cationic amphiphile, as well as the binding affinities of Na+ and Ca2+ ions. With our new model, we observe on the one side negligible binding of Na+ ions to POPC bilayer, while on the other side stronger interactions of Ca2+ primarily with phosphate oxygens, which is in agreement with the previous interpretations of the experimental spectroscopic data. The present model results in Ca2+ ions forming complexes with one to three POPC molecules with almost equal probabilities, suggesting more complex binding stoichiometries than those from simple models used to interpret the NMR data previously. The results of this work pave the way to quantitative molecular simulations with realistic electrostatic interactions of complex biochemical systems at cellular membranes.
  • Takatalo, Jani; Karppinen, Jaro; Taimela, Simo; Niinimaki, Jaakko; Laitinen, Jaana; Sequeiros, Roberto Blanco; Paananen, Markus; Remes, Jouko; Nayha, Simo; Tammelin, Tuija; Korpelainen, Raija; Tervonen, Osmo (2013)
  • Heise, Katje; Delepierre, Gwenn; King, Alistair; Kostiainen, Mauri; Zoppe, Justin; Weder, Christoph; Kontturi, Eero (2021)
    Native plant cellulose has an intrinsic supramolecular structure. Consequently, it can be isolated as nanocellulose species, which can be utilized as building blocks for renewable nanomaterials. The structure of cellulose also permits its end-wise modification, i.e., chemical reactions exclusively on one end of a cellulose chain or a nanocellulose particle. The premises for end-wise modification have been known for decades. Nevertheless, different approaches for the reactions have emerged only recently, because of formidable synthetic and analytical challenges associated with the issue, including the adverse reactivity of the cellulose reducing end and the low abundance of newly introduced functionalities. This Review gives a full account of the scientific underpinnings and challenges related to end-wise modification of cellulose nanocrystals. Furthermore, we present how the chemical modification of cellulose nanocrystal ends may be applied to directed assembly, resulting in numerous possibilities for the construction of new materials, such as responsive liquid crystal templates and composites with tailored interactions.
  • Valiev, Rashid R.; Fliegl, Heike; Sundholm, Dage (2017)
    Magnetizabilities and magnetically induced ring-current strength susceptibilities have been calculated at the Hartree-Fock, density functional theory and second order Moller-Plesset levels for a number of antiaromatic closed-shell carbaporphyrins, carbathia-porphyrins and isophlorins. The calculations yield a linear relation between magnetizabilities and ring-current strength susceptibilities. The calculations show that the porphyrinoids with the largest ring-current strength susceptibility are closed-shell paramagnetic molecules with positive magnetizabilities. The closed-shell paramagnetism is due to the large paramagnetic contribution to the magnetizability originating from the strong paratropic ring current in the antiaromatic porphyrinoids.
  • Jalanko, Mikko; Väänänen, Heikki; Tarkiainen, Mika; Sipola, Petri; Jääskeläinen, Pertti; Lauerma, Kirsi; Laitinen, Tiina; Laitinen, Tomi; Laine, Mika; Heliö, Tiina; Kuusisto, Johanna; Viitasalo, Matti (2018)
    Background Hypertrophic cardiomyopathy (HCM) is characterized by ventricular repolarization abnormalities and risk of ventricular arrhythmias. Our aim was to study the association between the phenotype and ventricular repolarization dynamics in HCM patients. Methods Results HCM patients with either the MYBPC3-Q1061X or TPM1-D175N mutation (n = 46) and control subjects without mutation and hypertrophy (n = 35) were studied with 24-hr ambulatory ECG recordings by measuring time intervals of rate-adapted QT (QTe), maximal QT, and T-wave apex to wave end (TPE) intervals and the QTe/RR slope. Findings were correlated to specified echocardiographic and cardiac magnetic resonance imaging (CMRI) findings. Rate-adapted QTe interval was progressively longer in HCM patients with decreasing heart rates compared to control subjects (p = 0.020). The degree of hypertrophy correlated with measured QTe values. HCM patients with maximal wall thickness higher than the mean (20.6 mm) had longer maximum QTe and median TPE intervals compared to control subjects and HCM patients with milder hypertrophy (p p = 0.014, respectively). HCM patients with late gadolinium enhancement (LGE) on CMRI had steeper QTe/RR slopes compared to HCM patients without LGE and control subjects (p = 0.044 and p = 0.001, respectively). LGE was an independent predictor of QTe/RR slope (p = 0.023, B = 0.043). Conclusion Dynamics of ventricular repolarization in HCM are affected by hypertrophy and fibrosis. LGE may confer an independent effect on QT dynamics which may increase the arrhythmogenic potential in HCM.
  • Jiang, Ping; Vuontela, Virve; Tokariev, Maksym; Lin, Hai; Aronen, Eeva T.; Ma, YuanYe; Carlson, Synnöve (2018)
    Earlier studies on adults have shown that functional connectivity (FC) of brain networks can vary depending on the brain state and cognitive challenge. Network connectivity has been investigated quite extensively in children in resting state, much less during tasks and is largely unexplored between these brain states. Here we used functional magnetic resonance imaging and independent component analysis to investigate the functional architecture of large-scale brain networks in 16 children (aged 7-11 years, 11 males) and 16 young adults (aged 22-29 years, 10 males) during resting state and visual working memory tasks. We identified the major neurocognitive intrinsic connectivity networks (ICNs) in both groups. Children had stronger FC than adults within the cingulo-opercular network in resting state, during task performance, and after controlling for performance differences. During tasks, children had stronger FC than adults also within the default mode (DMN) and right frontoparietal (rFPN) networks, and between the anterior DMN and the frontopolar network, whereas adults had stronger coupling between the anterior DMN and rFPN. Furthermore, children compared to adults modulated the FC strength regarding the rFPN differently between the brain states. The FC within the anterior DMN correlated with age and performance in children so that the younger they were, the stronger was the FC, and the stronger the FC within this network, the slower they performed the tasks. The group differences in the network connectivity reported here, and the observed correlations with task performance, provide insight into the normative development of the preadolescent brain and link maturation of functional connectivity with improving cognitive performance.
  • FinHCM Study Grp; Jääskeläinen, Pertti; Vangipurapu, Jagadish; Raivo, Joose; Kuulasmaa, Teemu; Helio, Tiina; Aalto-Setala, Katriina; Kaartinen, Maija; Ilveskoski, Erkki; Vanninen, Sari; Hämäläinen, Liisa; Melin, John; Kokkonen, Jorma; Nieminen, Markku S.; Laakso, Markku; Kuusisto, Johanna; Kervinen, Helena; Mustonen, Juha; Juvonen, Jukka; Niemi, Mari; Uusimaa, Paavo; Junttila, Juhani; Kotila, Matti; Pietila, Mikko; Jyrkila, Heini; Mahonen, Ilkka; Vartia, Paula (2019)
    Aims Nationwide large-scale genetic and outcome studies in cohorts with hypertrophic cardiomyopathy (HCM) have not been previously published. Methods and results We sequenced 59 cardiomyopathy-associated genes in 382 unrelated Finnish patients with HCM and found 24 pathogenic or likely pathogenic mutations in six genes in 38.2% of patients. Most mutations were located in sarcomere genes (MYBPC3, MYH7, TPM1, and MYL2). Previously reported mutations by our study group (MYBPC3-Gln1061Ter, MYH7-Arg1053Gln, and TPM1-Asp175Asn) and a fourth major mutation MYH7-Val606Met accounted for 28.0% of cases. Mutations in GLA and PRKAG2 were found in three patients. Furthermore, we found 49 variants of unknown significance in 31 genes in 20.4% of cases. During a 6.7 +/- 4.2 year follow-up, annual all-cause mortality in 482 index patients and their relatives with HCM was higher than that in the matched Finnish population (1.70 vs. 0.87%; P <0.001). Sudden cardiac deaths were rare (n = 8). Systolic heart failure (hazard ratio 17.256, 95% confidence interval 3.266-91.170, P = 0.001) and maximal left ventricular wall thickness (hazard ratio 1.223, 95% confidence interval 1.098-1.363, P <0.001) were independent predictors of HCM-related mortality and life-threatening cardiac events. The patients with a pathogenic or likely pathogenic mutation underwent an implantable cardioverter defibrillator implantation more often than patients without a pathogenic or likely pathogenic mutation (12.9 vs. 3.5%, P <0.001), but there was no difference in all-cause or HCM-related mortality between the two groups. Mortality due to HCM during 10 year follow-up among the 5.2 million population of Finland was studied from death certificates of the National Registry, showing 269 HCM-related deaths, of which 32% were sudden. Conclusions We identified pathogenic and likely pathogenic mutations in 38% of Finnish patients with HCM. Four major sarcomere mutations accounted for 28% of HCM cases, whereas HCM-related mutations in non-sarcomeric genes were rare. Mortality in patients with HCM exceeded that of the general population. Finally, among 5.2 million Finns, there were at least 27 HCM-related deaths annually.
  • Hatton, Sean N.; Panizzon, Matthew S.; Vuoksimaa, Eero; Hagler, Donald J.; Fennema-Notestine, Christine; Rinker, Daniel; Eyler, Lisa T.; Franz, Carol E.; Lyons, Michael J.; Neale, Michael C.; Tsuang, Ming T.; Dale, Anders M.; Kremen, William S. (2018)
    Two basic neuroimaging-based characterizations of white matter tracts are the magnitude of water diffusion along the principal tract orientation (axial diffusivity, AD) and water diffusion perpendicular to the principal orientation (radial diffusivity, RD). It is generally accepted that decreases in AD reflect disorganization, damage, or loss of axons, whereas increases in RD are indicative of disruptions to the myelin sheath. Previous reports have detailed the heritability of individual AD and RD measures, but have not examined the extent to which the same or different genetic or environmental factors influence these two phenotypes (except for corpus callosum). We implemented bivariate twin analyses to examine the shared and independent genetic influences on AD and RD. In the Vietnam Era Twin Study of Aging, 393 men (mean age = 61.8 years, SD = 2.6) underwent diffusion-weighted magnetic resonance imaging. We derived fractional anisotropy (FA), mean diffusivity (MD), AD, and RD estimates for 11 major bilateral white matter tracts and the mid-hemispheric corpus callosum, forceps major, and forceps minor. Separately, AD and RD were each highly heritable. In about three-quarters of the tracts, genetic correlations between AD and RD were >.50 (median = .67) and showed both unique and common variance. Genetic variance of FA and MD were predominately explained by RD over AD. These findings are important for informing genetic association studies of axonal coherence/damage and myelination/demyelination. Thus, genetic studies would benefit from examining the shared and unique contributions of AD and RD.
  • Vähämurto, L.; Juonala, M.; Ruohonen, S.; Hutri-Kähönen, N.; Kähönen, M.; Laitinen, T.; Tossavainen, P.; Jokinen, E.; Viikari, J.; Raitakari, O. T.; Pahkala, K. (2018)
    Aims: Eastern Finns have higher risk of coronary heart disease (CHD) and carotid intima-media thickness than western Finns although current differences in CHD risk factors are minimal. Left ventricular (LV) mass and diastolic function predict future cardiovascular events but their east-west differences are unknown. We examined the association of eastern/western baseline origin with LV mass and diastolic function. Methods : The study population included 2045 subjects of the Cardiovascular Risk in Young Finns Study with data from the baseline survey (1980) and the latest follow-up (2011) when echocardiography was performed at the age of 34-49 years. Results: Subjects with eastern baseline origin had in 2011 higher LV mass (139 +/- 1.0 vs. 135 +/- 1.0 g, p=0.006) and E/e-ratio indicating weaker LV diastolic function (4.86 +/- 0.03 vs. 4.74 +/- 0.03, p=0.02) than western subjects. Results were independent of age, sex, area of examination and CHD risk factors such as blood pressure and BMI (LV mass indexed with height: p
  • Xia, Ming-Feng; Yki-Jarvinen, Hannele; Bian, Hua; Lin, Huan-Dong; Yan, Hong-Mei; Chang, Xin-Xia; Zhou, You; Gao, Xin (2016)
    Objectives Presence of non-alcoholic fatty liver disease (NAFLD) can predict risks for diabetes, cardiovascular disease and advanced liver disease in the general population. We aimed to establish a non-invasive score for prediction of NAFLD in Han Chinese, the largest ethnic group in the world, and detect whether ethnicity influences the accuracy of such a score. Methods Liver fat content (LFAT) was measured by quantitative ultrasound in 3548 subjects in the Shanghai Changfeng Community and a Chinese score was created using multivariate logistic regression analyses. This new score was internally validated in Chinese and externally in Finns. Its diagnostic performance was compared to the NAFLD liver fat score, fatty liver index (FLI) and hepatic steatosis index (HSI) developed in Finns, Italians and Koreans. We also analyzed how obesity related to LFAT measured by H-1-MRS in 79 Finns and 118 Chinese with type 2 diabetes (T2D). Results The metabolic syndrome and T2D, fasting serum insulin, body mass index (BMI) and AST/ALT ratio were independent predictors of NAFLD in Chinese. The AUROC in the Chinese validation cohort was 0.76 (0.73-0.78) and in Finns 0.73 (0.68-0.78) (p Conclusion The predictors of NAFLD in Han Chinese are as in Europids but the Chinese have more LFAT for any given degree of obesity than Europids. Ethnicity needs to be considered when NAFLD is predicted using risk scores.
  • Bacle, Amelie; Buslaev, Pavel; Garcia-Fandino, Rebeca; Favela-Rosales, Fernando; Ferreira, Tiago Mendes; Fuchs, Patrick F. J.; Gushchin, Ivan; Javanainen, Matti; Kiirikki, Anne M.; Madsen, Jesper J.; Melcr, Josef; Rodriguez, Paula Milan; Miettinen, Markus S.; Ollila, O. H. Samuli; Papadopoulos, Chris G.; Peon, Antonio; Piggot, Thomas J.; Pineiro, Angel; Virtanen, Salla (2021)
    Interest in lipid interactions with proteins and other biomolecules is emerging not only in fundamental biochemistry but also in the field of nanobiotechnology where lipids are commonly used, for example, in carriers of mRNA vaccines. The outward-facing components of cellular membranes and lipid nanoparticles, the lipid headgroups, regulate membrane interactions with approaching substances, such as proteins, drugs, RNA, or viruses. Because lipid headgroup conformational ensembles have not been experimentally determined in physiologically relevant conditions, an essential question about their interactions with other biomolecules remains unanswered: Do headgroups exchange between a few rigid structures, or fluctuate freely across a practically continuous spectrum of conformations? Here, we combine solid-state NMR experiments and molecular dynamics simulations from the NMRlipids Project to resolve the conformational ensembles of headgroups of four key lipid types in various biologically relevant conditions. We find that lipid headgroups sample a wide range of overlapping conformations in both neutral and charged cellular membranes, and that differences in the headgroup chemistry manifest only in probability distributions of conformations. Furthermore, the analysis of 894 protein-bound lipid structures from the Protein Data Bank suggests that lipids can bind to proteins in a wide range of conformations, which are not limited by the headgroup chemistry. We propose that lipids can select a suitable headgroup conformation from the wide range available to them to fit the various binding sites in proteins. The proposed inverse conformational selection model will extend also to lipid binding to targets other than proteins, such as drugs, RNA, and viruses.
  • Catte, Andrea; Girych, Mykhailo; Javanainen, Matti; Loison, Claire; Melcr, Josef; Miettinen, Markus S.; Monticelli, Luca; Maatta, Jukka; Oganesyan, Vasily S.; Ollila, O. H. Samuli; Tynkkynen, Joona; Vilov, Sergey (2016)
    Despite the vast amount of experimental and theoretical studies on the binding affinity of cations -especially the biologically relevant Na+ and Ca2+ - for phospholipid bilayers, there is no consensus in the literature. Here we show that by interpreting changes in the choline headgroup order parameters according to the 'molecular electrometer' concept [Seelig et al., Biochemistry, 1987, 26, 7535], one can directly compare the ion binding affinities between simulations and experiments. Our findings strongly support the view that in contrast to Ca2+ and other multivalent ions, Na+ and other monovalent ions (except Li+) do not specifically bind to phosphatidylcholine lipid bilayers at sub-molar concentrations. However, the Na+ binding affinity was overestimated by several molecular dynamics simulation models, resulting in artificially positively charged bilayers and exaggerated structural effects in the lipid headgroups. While qualitatively correct headgroup order parameter response was observed with Ca2+ binding in all the tested models, no model had sufficient quantitative accuracy to interpret the Ca2+: lipid stoichiometry or the induced atomistic resolution structural changes. All scientific contributions to this open collaboration work were made publicly, using nmrlipids. as the main communication platform.
  • Javanainen, Matti; Martinez-Seara, Hector; Vattulainen, Ilpo (2017)
    Biological membranes generate specific functions through compartmentalized regions such as cholesterol-enriched membrane nanodomains that host selected proteins. Despite the biological significance of nanodomains, details on their structure remain elusive. They cannot be observed via microscopic experimental techniques due to their small size, yet there is also a lack of atomistic simulation models able to describe spontaneous nanodomain formation in sufficiently simple but biologically relevant complex membranes. Here we use atomistic simulations to consider a binary mixture of saturated dipalmitoylphosphatidylcholine and cholesterol - the "minimal standard" for nanodomain formation. The simulations reveal how cholesterol drives the formation of fluid cholesterol-rich nanodomains hosting hexagonally packed cholesterol-poor lipid nanoclusters, both of which show registration between the membrane leaflets. The complex nanodomain substructure forms when cholesterol positions itself in the domain boundary region. Here cholesterol can also readily flip-flop across the membrane. Most importantly, replacing cholesterol with a sterol characterized by a less asymmetric ring region impairs the emergence of nanodomains. The model considered explains a plethora of controversial experimental results and provides an excellent basis for further computational studies on nanodomains. Furthermore, the results highlight the role of cholesterol as a key player in the modulation of nanodomains for membrane protein function.
  • Rosenblatt, Alana Jayne; Lappalainen, Anu Katriina; James, Nina Alice; Webster, Natalie Siu Ling; Caraguel, Charles Gregoire Benedict (2018)
    BackgroundThe Dachshund is a chondrodystrophic breed of dog predisposed to premature degeneration and calcification, and subsequent herniation, of intervertebral discs (IVDs). This condition is heritable in Dachshunds and breeding candidates are screened for radiographically detectable intervertebral disc calcification (RDIDC), a feature of advanced disc degeneration and a prognostic factor for clinical disease. RDIDC scoring has been previously shown to be consistent within scorers; however, strong scorer effect (subjectivity) was also reported. The aim of this study was to estimate the within- and between-scorer agreement (repeatability and reproducibility, respectively) of computed tomography (CT) scanning and magnetic resonance imaging (MRI) for scoring IVD calcification, and to compare these modalities with radiographic scoring.ResultsTwenty-one Dachshund dogs were screened for IVD calcification using the three imaging modalities. Three scorers scored each case twice, independently. Repeatability was highest for radiography (95.4%), and significantly higher than for CT (90.4%) but not MRI (93.8%). Reproducibility was also highest for radiography (92.9%), but not significantly higher than for CT or MRI (89.4% and 86.4%, respectively). Overall, CT scored IVDs differently than radiography and MRI (64.8% and 62.7% agreement, respectively), while radiography and MRI scored more similarly (85.7% agreement).ConclusionsDespite high precision for radiography, previous evidence of scorer subjectivity was confirmed, which was not generally observed with CT and MRI. The increased consistency of radiography may be related to prior scorer experience with the modality and RDIDC scoring. This study does not support replacing radiography with CT or MRI to screen for heritable IVD calcification in breeding Dachshunds; however, evaluation of dog-level precision and the accuracy of each modality is recommended.
  • Ylanen, Kaisa; Eerola, Anneli; Vettenranta, Kim; Poutanen, Tuija (2016)
    Longitudinal motion significantly contributes to the contraction of the ventricles. We studied the left (LV) and right ventricular (RV) longitudinal functions in 75 anthracycline-exposed, long-term childhood cancer survivors and 75 healthy controls with conventional echocardiography, tissue Doppler imaging (TDI), speckle tracking echocardiography (STE) of the mitral and tricuspid annular motion, and real-time three-dimensional echocardiography (RT-3DE). Cardiac magnetic resonance (CMR) imaging was performed on 61 of the survivors. The survivors had lower systolic myocardial velocities in the LV and lower diastolic velocities in both ventricles by TDI than did their healthy peers. The STE-based tissue motion annular displacement (TMAD) values describing the LV and RV systolic longitudinal function (MAD and TAD mid%, respectively) were also lower among the survivors (15.4 +/- 2.4 vs. 16.1 +/- 2.2 %, p = 0.049 and 22.5 +/- 3.0 vs. 23.5 +/- 3.0 %, p = 0.035). MAD and TAD mid in millimeters correlated with the respective ventricular volumes measured with RT-3DE or CMR. Conclusion: Childhood cancer survivors exposed to low to moderate anthracycline doses had decreased longitudinal systolic and diastolic functions (TDI or STE) compared with healthy controls. The STE-based TMAD is a fast and reproducible method to assess cardiac longitudinal function.
  • Suominen, Pertti K.; Keski-Nisula, Juho; Ojala, Tiina; Rautiainen, Paula; Jahnukainen, Timo; Hastbacka, Johanna; Neuvonen, Pertti J.; Pitkanen, Olli; Niemela, Jussi; Kaskinen, Anu; Salminen, Jukka; Lapatto, Risto (2017)
    Background. Corticosteroids can improve the hemodynamic status of neonates with postoperative low cardiac output syndrome after cardiac operations. This study compared a prophylactically administered stress-dose corticosteroid (SDC) regimen against placebo on inflammation, adrenocortical function, and hemodynamic outcome. Methods. Forty neonates undergoing elective open heart operations were randomized into two groups. The SDC group received perioperatively 2 mg/kg methylprednisolone, and 6 hours after the operation, a hydrocortisone infusion (0.2 mg/kg/h) was started with tapering doses for 5 days. Placebo was administered in a similar fashion. An adrenocorticotropic hormone stimulation test was performed after the therapy. The primary endpoint of the study was plasma concentration of interleukin (IL-6). Secondary clinical outcomes included plasma cortisol, IL-10, C-reactive protein, echocardiographic systemic ventricle contractility evaluated by the Velocity Vector Imaging program, the inotropic score, and time of delayed sternal closure. Results. The IL-6 values of the SDC group were significantly lower postoperatively than in the placebo group. Significantly lower inotropic scores (p <0.05), earlier sternal closure (p = 0.03), and less deterioration in the systemic ventricle mean delta strain values between the preoperative and the first postoperative assessment (p = 0.01) were detected for the SDC group. The SDC therapy did not suppress the hypothalamic-pituitary-adrenal axis more than placebo. The mean plasma cortisol level did not decline in the placebo group after the operation. Conclusions. The SDC regimen for 5 days post-operatively in neonates was safe and did not cause suppression of the hypothalamic-pituitary-adrenal axis. Furthermore, the open heart operation per se did not lead to adrenal insufficiency in neonates. (C) 2017 by The Society of Thoracic Surgeons
  • Kandolin, Riina M.; Wiefels, Christiane C.; Mesquita, Claudio Tinoco; Chong, Aun-Yeong; Boland, Paul; Glineur, David; Sun, Louise; Beanlands, Rob S.; Mielniczuk, Lisa M. (2019)
    This review describes the current evidence and controversies for viability imaging to direct revascularization decisions and the impact on patient outcomes. Balancing procedural risks and possible benefit from revascularization is a key question in patients with heart failure of ischemic origin (IHF). Different stages of ischemia induce adaptive changes in myocardial metabolism and function. Viable but dysfunctional myocardium has the potential to recover after restoring blood flow. Modern imaging techniques demonstrate different aspects of viable myocardium; perfusion (single-photon emission computed tomography [SPECT], positron emission tomography [PET], cardiovascular magnetic resonance [CMR]), cell metabolism (PET), cell membrane integrity and mitochondrial function (201Tl and 99mTc-based SPECT), contractile reserve (stress echocardiography, CMR) and scar (CMR). Observational studies suggest that patients with IHF and significant viable myocardium may benefit from revascularization compared with medical treatment alone but that in patients without significant viability, revascularization appears to offer no survival benefit or could even worsen the outcome. This was not supported by 2 randomized trials (Surgical Treatment for Ischemic Heart Failure [STICH] and PET and Recovery Following Revascularization [PARR] -2) although post-hoc analyses suggest that benefit can be achieved if decisions had been strictly based on viability imaging recommendations. Based on current evidence, viability testing should not be the routine for all patients with IHF considered for revascularization but rather integrated with clinical data to guide decisions on revascularization of high-risk patients with comorbidities.
  • Kuusisto, Jouni K.; Järvinen, Vesa M.; Sinisalo, Juha P. (2018)
    Background: Left atrial volume is a prognostic factor in cardiac pathologies. We aimed to validate left atrial volume detection with 3D and 2D echocardiography (3DE and 2DE) by human cadaveric casts. 3DE facilitates measurement of atrial volume without geometrical assumptions or dependence on imaging angle in contrast to 2DE methods. Methods: For method validation, six water-filled balloons were submerged in a 20-l water tank and their volumes were measured with 3DE. Seven human cadaveric left atrial casts were prepared of silicone and were transformed into ultrasound-permeable casts. Casts were imaged in the same setting, so that 3DE and 2DE of casts represented transthoracic apical view. Left ventricle analysis softwares GE 4D Auto LVQ and TomTec 4D LV-Function were used for 3DE volumetry. Results; Balloon volumes ranged 37 to 255ml (mean 126 ml). 3DE resulted in an excellent volumetric agreement with balloon volumes, absolute bias was -3.7 ml (95% CI -5.9 to -1.4). Atrial cast volumes were 38 to 94 ml (mean 56.6 ml). 3DE and 2DE volumes were excellently correlated with cast volumes (r = 0.96 to 0.99). Biases were for GE 4D LVQ - 0.7 ml (95% CI -6.1 to 4.6), TomTec 4D LV-Function 3.3 ml (-1.9 to 8.5) and 2DE 2.9 ml (-4.0 to 9.9). 3DE resulted in lower limits of agreement and showed no volume-related bias in contrast to area-length method. Conclusions: We conclude that measurement of human cadaveric left atrial cast volumes by 3DE is in excellent agreement with true cast volumes.