Background To evaluate long-term outcome of tetralogy of Fallot repair analyzing an unbiased country-wide surgically treated population with tetralogy of Fallot. Methods and Results Retrospective analysis of consecutive patients aged <18 years who underwent tetralogy of Fallot repair at a single nationwide pediatric cardiac center. Death from any cause and need for surgical or catheter reintervention were the study end points. Cox regression analysis was used to identify related risk factors. A total of 917 patients (male, 56.3%) were analyzed. Staged repair was performed in 16.9%. Early mortality (24/917, 2.62% patients) was confined to the early surgical eras. Late mortality was 4.5% (40/893 patients). Survival probability was 95.1%, 93.8% and 91.9% at 10, 20 and 30 years after repair, respectively. Early surgical era (P=0.013) and surgical/catheter reinterventions (P<0.001) were multivariable predictors of late death. A total of 487 reinterventions were performed after initial repair in 253/917 patients (27.6%), with pulmonary artery revalvulation (196/917 patients, 21.4%) being most frequent. Probability of freedom from first reintervention was 89.0%, 73.3%, and 55.1% at 10, 20, and 30 years after primary repair, respectively. Transannular repair was associated with the need for pulmonary artery revalvulation (P<0.001). Patients who underwent staged repair were more likely to need reinterventions on pulmonary arteries (P<0.001). Conclusions In an unbiased nationwide cohort, tetralogy of Fallot repair carried a favorable survival of >90% at 30 years. Each reintervention significantly incrementally increased the risk of mortality. Type of initial repair predicted the need for specific surgical or catheter reinterventions.
- Klíčová slova
- outcome, pulmonary valve replacement, surgical repair, tetralogy of Fallot,
- MeSH
- dítě MeSH
- Fallotova tetralogie * chirurgie MeSH
- kojenec MeSH
- lidé MeSH
- následné studie MeSH
- plicní chlopeň * chirurgie MeSH
- reoperace MeSH
- retrospektivní studie MeSH
- rizikové faktory MeSH
- svoboda MeSH
- výsledek terapie MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Several studies have shown that petiole xylem structure could be an important predictor of leaf gas exchange capacity, but the question of how petiole xylem structure relates to leaf gas exchange under different environment conditions remains unresolved. Moreover, knowledge of the amount of leaf gas exchange and structural variation that exists within a single species is also limited. In this study, we investigated the intraspecies coordination of leaf gas exchange and petiole xylem traits in 2-year-old seedlings of Ulmus laevis Pall. under well-watered and drought conditions. It was found that all studied petiole xylem traits of the elm seedlings were positively correlated with each other. This shows that the development of petiole xylem structure is internally well-coordinated. Nevertheless, the lower correlation coefficients between some petiole xylem traits indicate that the coordination is also individually driven. Drought stress reduced all studied leaf gas exchange traits and significantly increased intraspecies variation. In addition, drought stress also shifted the relationships between physiological traits and exhibited more structure-function relationships. This indicates the importance of petiole xylem structure in dictating water loss during drought stress and could partly explain the inconsistencies between leaf structure-function relationships studied under optimal conditions. Although several structure-function traits were related, the wide ranges of correlation coefficients indicate that the internal coordination of these traits substantially differs between individual elm seedlings. These findings are very important in the context of expected climatic change, as some degree of intraspecies variation in structure-function relationships could ensure the survival of some individuals under different environmental conditions.
- Klíčová slova
- intraspecies variation, net photosynthesis, stomatal conductance, vessel area, water use efficiency, xylem area,
- MeSH
- listy rostlin fyziologie MeSH
- období sucha MeSH
- semenáček MeSH
- Ulmus * fyziologie MeSH
- voda * fyziologie MeSH
- xylém fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- voda * MeSH
Spring drought is becoming a frequently occurring stress factor in temperate forests. However, the understanding of tree resistance and resilience to the spring drought remains insufficient. In this study, European beech (Fagus sylvatica L.) seedlings at the early stage of leaf development were moderately and severely drought stressed for 1 month and then subjected to a 2-week recovery period after rewatering. The study aimed to disentangle the complex relationships between leaf gas exchange, vascular anatomy, tree morphology and patterns of biomass allocation. Stomatal conductance decreased by 80 and 85% upon moderate and severe drought stress, respectively, which brought about a decline in net photosynthesis. However, drought did not affect the indices of slow chlorophyll fluorescence, indicating no permanent damage to the light part of the photosynthetic apparatus. Stem hydraulic conductivity decreased by more than 92% at both drought levels. Consequently, the cambial activity of stressed seedlings declined, which led to lower stem biomass, reduced tree ring width and a lower number of vessels in the current tree ring, these latter also with smaller dimensions. In contrast, the petiole structure was not affected, but at the cost of reduced leaf biomass. Root biomass was reduced only by severe drought. After rewatering, the recovery of gas exchange and regrowth of the current tree ring were observed, all delayed by several days and by lower magnitudes in severely stressed seedlings. The reduced stem hydraulic conductivity inhibited the recovery of gas exchange, but xylem function started to recover by regrowth and refilling of embolized vessels. Despite the damage to conductive xylem, no mortality occurred. These results suggest the low resistance but high resilience of European beech to spring drought. Nevertheless, beech resilience could be weakened if the period between drought events is short, as the recovery of severely stressed seedlings took longer than 14 days.
- Klíčová slova
- chlorophyll fluorescence, embolism, hydraulic conductivity, net photosynthesis, stomatal conductance, vascular anatomy,
- MeSH
- buk (rod) * MeSH
- fotosyntéza MeSH
- listy rostlin MeSH
- období sucha * MeSH
- semenáček MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- voda MeSH
Although spine variation within cacti species or populations is assumed to be large, the minimum sample size of different spine anatomical and morphological traits required for species description is less studied. There are studies where only 2 spines were used for taxonomical comparison amnog species. Therefore, the spine structure variation within areoles and individuals of one population of Gymnocalycium kieslingii subsp. castaneum (Ferrari) Slaba was analyzed. Fifteen plants were selected and from each plant one areole from the basal, middle and upper part of the plant body was sampled. A scanning electron microscopy was used for spine surface description and a light microscopy for measurements of spine width, thickness, cross-section area, fiber diameter and fiber cell wall thickness. The spine surface was more visible and damaged less in the upper part of the plant body than in the basal part. Large spine and fiber differences were found between upper and lower parts of the plant body, but also within single areoles. In general, the examined traits in the upper part had by 8-17% higher values than in the lower parts. The variation of spine and fiber traits within areoles was lower than the differences between individuals. The minimum sample size was largely influenced by the studied spine and fiber traits, ranging from 1 to 70 spines. The results provide pioneer information useful in spine sample collection in the field for taxonomical, biomechanical and structural studies. Nevertheless, similar studies should be carried out for other cacti species to make generalizations. The large spine and fiber variation within areoles observed in our study indicates a very complex spine morphogenesis.
- Klíčová slova
- Areole, fiber, minimum sample size, spine cross-section, spine morphogenesis, spine surface,
- Publikační typ
- časopisecké články MeSH
Predicted increases in the frequency and duration of drought are expected to negatively affect tree vitality, but we know little about how water shortage will influence needle anatomy and thereby the trees' photosynthetic and hydraulic capacity. In this study, we evaluated anatomical changes in sun and shade needles of 20-year-old Norway spruce trees exposed to artificial drought stress. Canopy position was found to be important for needle structure, as sun needles had significantly higher values than shade needles for all anatomical traits (i.e., cross-sectional needle area, number of tracheids in needle, needle hydraulic conductivity, and tracheid lumen area), except proportion of xylem area per cross-sectional needle area. In sun needles, drought reduced all trait values by 10-40%, whereas in shade needles, only tracheid maximum diameter was reduced by drought. Due to the relatively weaker response of shade needles than sun needles in drought-stressed trees, the difference between the two needle types was reduced by 25% in the drought-stressed trees compared to the control trees. The observed changes in needle anatomy provide new understanding of how Norway spruce adapts to drought stress and may improve predictions of how forests will respond to global climate change.
- Klíčová slova
- Climatic change, Picea abies, drought, hydraulic conductivity, light quality, needle growth, tracheid, xylem transport,
- Publikační typ
- časopisecké články MeSH
Conifers and other trees are constantly adapting to changes in light conditions, water/nutrient supply and temperatures by physiological and morphological modifications of their foliage. However, the relationship between physiological processes and anatomical characteristics of foliage has been little explored in trees. In this study we evaluated needle structure and function in Norway spruce families exposed to different light conditions and transpiration regimes. We compared needle characteristics of sun-exposed and shaded current-year needles in a control plot and a thinned plot with 50% reduction in stand density. Whole-tree transpiration rates remained similar across plots, but increased transpiration of lower branches after thinning implies that sun-exposed needles in the thinned plot were subjected to higher water stress than sun-exposed needles in the control plot. In general, morphological and anatomical needle parameters increased with increasing tree height and light intensity. Needle width, needle cross-section area, needle stele area and needle flatness (the ratio of needle thickness to needle width) differed most between the upper and lower canopy. The parameters that were most sensitive to the altered needle water status of the upper canopy after thinning were needle thickness, needle flatness and percentage of stele area in needle area. These results show that studies comparing needle structure or function between tree species should consider not only tree height and light gradients, but also needle water status. Unaccounted for differences in needle water status may have contributed to the variable relationship between needle structure and irradiance that has been observed among conifers.
- MeSH
- aklimatizace * MeSH
- dehydratace MeSH
- dusík metabolismus MeSH
- listy rostlin anatomie a histologie metabolismus fyziologie MeSH
- půda analýza MeSH
- sluneční záření * MeSH
- smrk anatomie a histologie metabolismus fyziologie MeSH
- transpirace rostlin MeSH
- vlhkost MeSH
- voda analýza fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- dusík MeSH
- půda MeSH
- voda MeSH
We present our initial experience in 10 patients operated on using a modified Ross operation. In our modification of the Ross operation the pulmonary autograft root was inserted in the Gelweave Valsalva graft to prevent dilatation of the neoaortic root. This type of graft was selected to match the discrepancy between diameters of the annulus and the sinotubular junction of the autograft and to preserve the characteristic configuration of the native root. In our group of 10 patients operated consecutively by this technique there was no change in the geometry of the neoaortic root in the follow-up 3-19 months (mean 14.6 months).
- MeSH
- aortální chlopeň chirurgie MeSH
- cévní protézy MeSH
- chirurgická náhrada chlopně škodlivé účinky metody MeSH
- dilatace patologická prevence a kontrola MeSH
- dospělí MeSH
- lidé MeSH
- následné studie MeSH
- nemoci srdečních chlopní prevence a kontrola chirurgie MeSH
- plicní chlopeň transplantace MeSH
- šicí techniky MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
Two patients with congenital atresia of the left coronary artery ostium underwent myocardial revascularization at the age of three years and three months, respectively. The patients were admitted to the hospital with a clinical history of sudden chest pain or short apnea not necessitating resuscitation. Non-invasive examinations and hemodynamic studies revealed dysfunction of the left ventricle and ostial atresia of the left coronary artery. Surgical revascularization-bypass grafts were performed using the left internal mammary artery and saphenous vein graft in the first case and the left internal mammary artery in the second child. Both patients survived surgery and good patency of the grafts was confirmed by coronary angiograms during hospital stay. These cases are interesting because of their rarity and diagnostic and therapeutic difficulties.
- MeSH
- angina pectoris etiologie chirurgie MeSH
- anomálie koronárních cév komplikace patologie patofyziologie chirurgie MeSH
- apnoe etiologie chirurgie MeSH
- funkce levé komory srdeční MeSH
- kojenec MeSH
- koronární angiografie MeSH
- koronární bypass * MeSH
- koronární cévy patologie patofyziologie chirurgie MeSH
- lidé MeSH
- předškolní dítě MeSH
- průchodnost cév MeSH
- vena saphena transplantace MeSH
- výsledek terapie MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
