Beaver-related restoration: An opportunity for sandy lowland streams in a human-dominated landscape.

The expansion of beavers into human-dominated landscapes can help improve the ecological status of degraded streams. This study aimed to assess the changes in the ecological status of a degraded sandy-bottom stream under the influence of processes generated by the activity of a European beaver. We assumed that the processes in the beaver dam-and-pond complex significantly improved the physical, chemical, and bacteriological properties of water and improved the ecological status of a small lowland stream in a human-dominated landscape. To achieve these objectives, water for quality assessment, benthic invertebrates, and fish samples were collected, and the forms of land use and the natural values of the stream were analysed. In the upstream zone of the sandy-bottom stream flowing in a human-dominated landscape, the inflow of pollutants caused a significant reduction in water quality. The amount of nutrients was high and the amount of dissolved oxygen was low. Similarly, the number of meso- and psychrophilic bacteria was significantly higher than in the reference stream. The building activity of beavers initiated a series of positive environmental changes, and beaver ponds improved the self-purification of water in a polluted stream. In the lower part of the studied stream, after the stream passed through the beaver wetland system, the water quality improved, which was indicated by a significant improvement in physicochemical, microbiological, and biotic indicators, that is based on macrozoobenthos and fish. By constructing dams, beavers flooded large areas and created habitats for plant and animal species associated with wetlands, including amphibians, birds, and mammals. The improvement of the ecological status of the stream, combined with the preservation and restoration of wetland habitats in the catchment area, enables the use of ecosystem services provided by the streams in the human-dominated landscape and their surroundings.

Long-term follow-up and safety assessment of angiogenic gene therapy trial VIF-CAD: Transcatheter intramyocardial administration of a bicistronic plasmid expressing VEGF-A165/bFGF cDNA for the treatment of refractory coronary artery disease.

There have been a number of angiogenic gene therapy trials, yielding mixed results as to efficacy, but demonstrating uniform short-term treatment safety. Data regarding long-term safety of angiogenic gene therapy are limited. Double-blind VIF-CAD trial (NCT00620217) assessed myocardial perfusion and clinical data in 52 refractory coronary artery disease (CAD) patients randomized into treatment (VIF; n = 33) and Placebo (n = 19) arms. VIF group received electromechanical system NOGA-guided intramyocardial injections of VEGF-A165/bFGF plasmid (VIF) into ischemic regions, while the Placebo group-placebo plasmid injections. Full 1-year follow-up data have been published. This study presents the results of over 10-year (median 133 months, range 95-149) safety follow-up of VIF-CAD patients. Overall, 12 (36.4%) patients died in VIF and 8 (42.1%) in Placebo group (P = .68). Cardiovascular mortality was 12/33 (36.4%) in the VIF group and 6/19 (31.6%) in Placebo group (P = .73). Two Placebo patients died due to malignancies, but no VIF patients (P = .17). The Kaplan-Meier curves of combined endpoint: cardiovascular mortality, myocardial infarction and stroke were similar for both patient groups (P = .71). Odds ratio of Placebo group increasing (reaching a worse) their CCS class versus VIF was non-significant (OR 1.28, 95% CI = 0.66-2.45; P = .47). However, CCS class improved in time irrespectively of treatment-OR of reaching a less favorable CCS class per each year of follow-up was 0.74 (95% CI 0.685-0.792; P < .0001, pooled data). There were no differences in readmission rates. Intramyocardial VEGF-A165/bFGF plasmid administration appears safe, with no evidence of an increase in the incidence of death, malignancy, myocardial infarction or stroke during 10-year follow-up in this limited patient population.

The retrospective study of 93 patients with transmigration of mandibular canine and a comparative analysis with a control group.

OBJECTIVES: The aim of this study was to evaluate characteristics of patients with unilateral transmigration of a mandibular canine in the largest study group presented until now. MATERIALS AND METHODS: The study group consisted of 93 patients with unilateral transmigration of mandibular canine; the control group included 85 non-affected patients. Type of transmigration, status of deciduous and permanent canines, prevalence of missing teeth, class of occlusion, and space conditions were assessed to draw comparisons between groups. RESULTS: In this study, 64.5 per cent patients presented type 1 of transmigration; types 2, 3, 4, and 5 were present in, respectively, 23.7, 5.4, 4.3, and 2.1 per cent patients. There was a clear, statistically significant difference (P < 0.0001) between the mean crown and apex migration and angulation for the three groups of canines (transmigrated, contralateral, and control), whereas no differences were observed for the total number of permanent teeth present. In the study group, 73.1 per cent patients retained their primary canine on the affected side and 18.3 per cent on the contralateral side; in the control group, 22.3 per cent subjects had at least one primary canine. There was a statistically significant difference in the distribution of types of malocclusion between the study and the control groups. CONCLUSIONS: Transmigration of mandibular canine was associated with the presence of retained primary canine on the affected side, higher mesial tilting of contralateral mandibular canine when compared to the canines in the control group. Additionally, higher prevalence of Angle's Class I occlusion in patients with canine transmigration was recorded.

Analysis of complications in transfemoral transcatheter aortic valve implantation: a single-center study.

INTRODUCTION: Transfemoral access is a prevailing approach for transcatheter aortic valve implantation (TAVI) in contemporary practice, with a shift from surgical arteriotomy to a percutaneous arterial approach. OBJECTIVES: This study assessed long- and short­term mortality, along with Valve Academic Research Consortium-2-defined complications in percutaneous transfemoral approach (PTA) TAVI. Furthermore, it explored the impact of a learning curve on procedural outcomes. PATIENTS AND METHODS: The study included 600 patients undergoing PTA TAVI at the National Institute of Cardiology, Warsaw, Poland, from January 2009 to September 2020. Retrospective data comparison involved 2 groups: early experience (first 200 patients) and late experience (next 400 patients). RESULTS: The primary end point (composite of life­threatening bleeding, major vascular complication, or death at 30 days) occurred less often in the late experience group (28% vs 17.5%; P = 0.003). The late experience group also showed fewer cases of vascular complications (19% vs 10.7%; P = 0.005) and major bleeding (17.5% vs 8.5%; P = 0.001). Propensity matching yielded similar trends, including reduced frequency of pacemaker implantation (22.8% vs 10.9%; P = 0.03) and shorter median (interquartile range) hospitalization (11 [8-18] vs 7 [6-12] days; P <0.001) in the late experience group. CONCLUSIONS: The late experience group rated with PTA TAVI exhibited significantly reduced periprocedural complications, indicating a positive impact of accumulated expertise.

Assessment of the viable effects of structural reconstruction of habitats in a mountain stream: A long-term study.

The Carpathians are biodiversity hotspots in Europe. However, transformations resulting from human activity have affected stream catchments where forest management is carried out. Numerous anti-rubble weirs and other low-head barriers disrupt the continuity of many streams. New requirements for human interference in stream channels were formulated. Measures are urgently needed to restore the ecological continuity and mosaicism of semi-natural habitats in mountain streams. Recently, small streams have been restored in mountainous areas. To assess the viable effects of stream restoration, analyses of in-stream habitats and fish communities, which are excellent bioindicators, were performed. This study aimed to assess the effects of structural reconstruction of habitats in a mountain stream (Eastern Carpathians, Poland). The analyses were based on a long-term assessment of fish responses to barrier removal and habitat changes following stream restoration measures. The research was conducted from 2009 to 2022. Our study indicates numerous positive and viable effects of using boulder ramps as technical solutions for restoring small mountain streams. Restored ecological continuity and in-stream habitats provide fish with adequate feeding grounds, spawning grounds, and fry-growth places. On the other hand, we indicated that the assessment of the effects of mountain stream restoration should be carried out over a long-term period, in three stages after the completion of work: early, medium, and late. This may allow for the most reliable assessment of the effects of restoration measures and the early detection of the need for corrections. It is also necessary to monitor possible changes that may occur in new hydrotechnical objects, such as boulder ramps, due to natural hydro-morphodynamic processes in the stream bed.

Comparisons of Dental Anomalies in Orthodontic Patients with Impacted Maxillary and Mandibular Canines.

To assess the presence and possible associations between the type of dental anomalies and maxillary and mandibular canine impactions in orthodontic patients treated for canine impaction, panoramic radiographs of orthodontic patients treated for canine impaction were assessed for the presence of associated dental anomalies. A random sample of orthodontic patients without canine impaction matched for age and gender served as controls. Descriptive and exact inferential statistics were implemented in order to assess potential associations between canine impaction and dental anomalies. A total of 102 orthodontic patients with 70 maxillary (MaxCI) and 32 mandibular (ManCI) canine impactions were assessed. The control group included 117 orthodontic patients. Dental anomalies were present in more than 50% of patients with impacted canines and in 20% of the controls. Tooth agenesis was significantly more common in the MaxCI group when compared to the ManCI group, while supernumerary teeth and canine transmigration were registered more often in the ManCI group. When compared to the control group, peg-shaped maxillary lateral incisors and tooth agenesis were significantly more prevalent in the MaxCI group, while canine transmigration, supernumerary teeth, the agenesis of mandibular incisors and tooth transpositions were significantly more prevalent in the ManCI group. The impaction of other teeth was significantly more common in both canine impaction groups when compared to the controls. The prevalence of dental anomalies in orthodontic patients with impacted canines was higher than in orthodontic patients without canine impaction. Different types of tooth anomalies were found in the MaxCI and ManCI groups.

Pulp Revascularization After Autotransplantation of the Mandibular Canines With Partially Resected Roots: Report of 5 Cases With Follow-ups Between 26 and 80 Months.

INTRODUCTION: Transmigrated (migrated through the midline) mandibular canines constitute a treatment challenge. Advanced transmigration can be successfully treated by autotransplantation. In developing canines, pulp revascularization is typical after transplantation. On the contrary, the pulp of teeth with completed apex formation does not undergo revascularization. In this case, root canal treatment becomes compulsory and decreases the success of autotransplantation. The aim of this observational retrospective study was to evaluate whether partial resection of the root (performed during the autotransplantation of mature canines) would enable revascularization of the pulp after the surgery. METHODS: Five transmigrated mandibular canines with complete apex formation before the surgery were evaluated. During the autotransplantation surgery, the resection of 2 to 4 mm of the root apex was performed to open the path for revascularization of the pulp after surgery. The transplanted teeth were observed during healing after the surgery for the presence of pulp obliteration. Clinical and radiographic examinations were performed. RESULTS: All treated canines survived the minimum observation period of 2 years (ranging from 26 to 80 months, mean: 55 months) without pulp healing complications. The survival was 100%, and the success was 80%. In one canine, the external cervical root resorption was diagnosed and treated 1 year after the surgery. At the final examination, transplanted canines presented radiographic features of pulp obliteration, normal mobility, and healthy periodontal tissues. CONCLUSIONS: The surgical protocol proved to be successful in promoting revascularization to maintain pulp vitality, in all cases. The outcomes confirm that autotransplantation, combined with the resection of the root, constitutes a valid treatment for mature ectopic canines.

Impact of fine-grained sediment on mountain stream macroinvertebrate communities: Forestry activities and beaver-induced sediment management.

Fine-grained sediments are a natural component of river systems. Human activities generate additional sources of fine sediment. In mountainous areas, the anthropogenic inputs of fine sediments are associated with forestry. The aim of this study was to analyse the differences in the macroinvertebrate communities between the reference and caused by forest harvesting activities increased influx of fine-sediment to mountain streams. The tested hypothesis was that the macroinvertebrate communities will differ depending on the intensity of forest harvesting practices in the stream catchment that causes excessive influx of fine sediment into the stream. The reintroduction of beavers in the study area, and the formation of in-stream beaver dams, contribute the accumulation of sediments in stream sections with slower water. Thus, it was also assumed that by capturing and storing fine sediments, may contribute to the restoration of the natural structure of the benthic communities downstream of the ponds. The study was carried out in a mountain stream catchment area (Carpathians, Poland), in which inflow of fine sediments in the stream sections varied in intensity. The study was conducted over three years (2018-2020). The extensive use of forest roads, timber skidding trails, and timber storage areas produced fine sediments that clogged the interstitial spaces between the stones in the riffles, limiting the presence of rheophilic taxa associated with coarse-grained substrates. The reduction of the number of scrapers and shredders (i.e. primary consumers) associated with the influx of fine sediments may significantly affect the entire food-web structure in stream ecosystems. The capture and deposition of fine sediments in beaver ponds may accelerate the revitalisation of the flowing sections of the stream. Beaver-induced sediment management is strongly recommended as a beneficial practice that could contribute to ecological preservation and the potential of streams, particularly in mountain areas.

Barrier removal and dynamics of intermittent stream habitat regulate persistence and structure of fish community.

Barrier effects observed in the presence of weirs are exacerbated by low water levels. We conducted a 10-year study to assess the ecological effects of stream restoration while analysing the possibility of a seasonal lack of hydrological continuity, with multiple measurements before and after restoring stream structural continuity. The research hypothesis assumes that in intermittent streams, there would be little or no change in the fish community downstream the barrier before vs. after barrier removal, and a significant change upstream the barrier before vs. after. Our results indicate, that by removing small barriers, their detrimental effects on the longitudinal passage of riverine fishes and fish assemblages can be rehabilitated. In the wet season, fish migrants from the mainstem river appeared in the downstream section of the stream. Stream intermittency, however, placed a habitat filter over the assemblage. Thus, after barrier removal, only two small-bodied fish species that tolerate periodic oxygen deficiencies and rising water temperatures gradually shifted upstream and formed stable populations. We emphasize, that we should not refrain from restoring the longitudinal continuity of intermittent streams, because they periodically provide fish valuable refugia and can also be a source of new generations and strengthen fish populations in mainstem river.

Sudden Cardiac Death Risk over Time in HCM Patients with Implantable Cardioverter-Defibrillator.

Background: In patients with HCM at high risk of SCD, an ICD should be considered as a standard of care. Current risk approximation algorithms recommended by ESC 2014 criteria indicate that SCD risk is not stable. The aim of the study was to investigate how the calculated SCD risk in HCM patients with an ICD implanted in the past changed over time. Methods: We analyzed 64 HCM patients with ICD for primary prevention, referred for ICD re-implantation, and 32 HCM patients referred for a first-time ICD placement during the same period. The 5-year-SCD risk was assessed for suitable patients using the recommended ESC calculator. Results: The first-time group had a higher 5-year-SCD risk than those referred for ICD re-implantation: 7.50 (IQR 5.98−10.46) vs. 4.88 (IQR 3.42−7.25), p < 0.05. Out of the patients with an initial calculated risk below 4%, the risk increased in 22% of cases, reaching the 4−6% range. In 78% of patients, the risk remained stable and low. In 31% of patients with an initial calculated SCD risk ≥ 6%, the risk decreased over time to below 6%, and in 14% of the cases, below 4%. Conclusions: SCD risk in HCM patients is usually stable or gets lower. Our data suggest it is important to re-evaluate the risk profile for patients with HCM when ICD re-implantation is considered.

Small stream catchments in a developing city context: The importance of land cover changes on the ecological status of streams and the possibilities for providing ecosystem services.

Urban expansion and the transformation of rural areas into suburban areas along with increasing human pressure can cause major changes in the environment. Typical effects of urbanization include degradation of aquatic ecosystems. However, urban expansion is often accompanied by an effort to provide residents with some contact with nature in the city. Natural waterbodies are the elements of the environment predestined to ensure appropriate conditions for recreation and other ecosystem services key to human well-being. In this study, the changes in the forms of development of a submontane stream catchment area (Carpathians, Poland) against the background of the gradual extension of city boundaries were analysed. In addition, the impact of urbanization on the ecological conditions of the urban stream, and therefore the potential ecosystem to provide ecosystem services, was assessed. Although the extension of the city entailed the development of settlements, it was accompanied by the expansion of the municipal sewage infrastructure, thus improving sewage management. The disappearance of arable lands from the stream catchment due to the decline in agricultural activities initiated the spontaneous process of buffer restoration along the stream. All the biotic indices such as Shannon diversity index, Margalef species richness index and BMWP-PL index, based on macroinvertebrate communities increased, and the fish were more numerous in the late stage of city development compared with the early (rural) stage. Surprisingly, the system has rehabilitated well with no revitalisation actions. It is necessary, however, to improve morphological in-stream conditions, and to make further efforts to improve water quality for the system to develop a semi-natural state. Only reaching full ecological potential can lead to an increase in the ecosystem capacity to provide ecosystem services. The studied ecosystem may provide many different services simultaneously, but their availability depends on the protection of the ecosystem's functioning as a whole.

Intramyocardial plasmid-encoding human vascular endothelial growth factor A165/basic fibroblast growth factor therapy using percutaneous transcatheter approach in patients with refractory coronary artery disease (VIF-CAD).

BACKGROUND: VIF-CAD randomized, placebo-controlled, double-blind trial was an attempt to induce therapeutic angiogenesis by percutaneous intramyocardial transfer of bicistronic (vascular endothelial growth factor/fibroblast growth factor [VEGF/FGF]) plasmid (pVIF) in patients with refractory heart ischemia. Myocardial perfusion, clinical symptoms, exercise tolerance, left ventricular function, and safety were assessed. METHODS: Fifty-two patients with refractory coronary artery disease were randomized to receive VEGF/FGF plasmid (n = 33) or placebo plasmid (n = 19) into myocardial region showing stress-induced perfusion defects. Repeat stress and rest technetium Tc 99m sestamibi single-photon emission computed tomography at 5 months was the primary efficacy measure. Secondary assessment included Canadian Cardiovascular Society class and exercise tolerance at 5 and 12 months. RESULTS: Rest- and stress-induced perfusion defects did not differ between groups. Canadian Cardiovascular Society functional class improved after 5 (P = .0210) and 12 months (P = .0607) in the treatment group. The exercise tolerance of treated patients improved: total exercise time increased marginally (P = .0541); maximum workload (P = .0419) and total test distance (P = .0473) increased significantly, compared to placebo. CONCLUSION: Bicistronic VEGF/FGF plasmid therapy did not improve myocardial perfusion measured by single-photon emission computed tomography. However, treated patients experienced improvement with respect to exercise tolerance and clinical symptoms. Intramyocardial VEGF/FGF bicistronic plasmid transfer seemed safe throughout the follow-up period of 1 year.

Senescence as a trade-off between successful land colonisation and longevity: critical review and analysis of a hypothesis.

BACKGROUND: Most common terrestrial animal clades exhibit senescence, suggesting strong adaptive value of this trait. However, there is little support for senescence correlated with specific adaptations. Nevertheless, insects, mammals, and birds, which are the most common terrestrial animal clades that show symptoms of senescence, evolved from clades that predominantly did not show symptoms of senescence. Thus, we aimed to examine senescence in the context of the ecology and life histories of the main clades of animals, including humans, and to formulate hypotheses to explain the causes and origin of senescence in the major clades of terrestrial animals. METHODOLOGY: We reviewed literature from 1950 to 2020 concerning life expectancy, the existence of senescence, and the adaptive characteristics of the major groups of animals. We then proposed a relationship between senescence and environmental factors, considering the biology of these groups of animals. We constructed a model showing the phylogenetic relationships between animal clades in the context of the major stages of evolution, distinguishing between senescent and biologically 'immortal' clades of animals. Finally, we synthesised current data on senescence with the most important concepts and theories explaining the origin and mechanisms of senescence. Although this categorisation into different senescent phenotypes may be simplistic, we used this to propose a framework for understanding senescence. RESULTS: We found that terrestrial mammals, insects, and birds show senescence, even though they likely evolved from non-senescent ancestors. Moreover, secondarily aquatic animals show lower rate of senescence than their terrestrial counterparts. Based on the possible life histories of these groups and the analysis of the most important factors affecting the transition from a non-senescent to senescent phenotype, we conclude that aging has evolved, not as a direct effect, but as a correlated response of selection on developmental strategies, and that this occurred separately within each clade. Adoption of specific life history strategies could thus have far-reaching effects in terms of senescence and lifespan. CONCLUSIONS: Our analysis strongly suggests that senescence may have emerged as a side effect of the evolution of adaptive features that allowed the colonisation of land. Senescence in mammals may be a compromise between land colonisation and longevity. This hypothesis, is supported by palaeobiological and ecological evidence. We hope that the development of new research methodologies and the availability of more data could be used to test this hypothesis and shed greater light on the evolution of senescence.

Comparisons of different treatment methods and their outcomes for impacted maxillary and mandibular canines: A retrospective study.

BACKGROUND: Impacted canines may pose a functional and an esthetic problem for patients and can affect neighboring incisors. The aim of the study was to compare different treatment methods and their outcomes for impacted maxillary and mandibular canines. METHODS: The authors included 102 patients with 118 impacted canines (82 maxillary and 36 mandibular canines). Impacted canine were confirmed during clinical and radiologic examinations. Eighty-five patients (83%) with 97 impacted canines started the treatment. The authors analyzed treatment types and outcomes. Two maxillary and 4 mandibular canines were scheduled for extraction. RESULTS: Orthodontic extrusion was used most frequently to treat impacted maxillary canines (89%), whereas orthodontic extrusion and transalveolar transplantation were performed most frequently in impacted mandibular canines (33% and 37.5%, respectively). The treatment was successful in 96% of the maxillary and 95% of the impacted mandibular canines. CONCLUSIONS: Different methods were used for impacted maxillary and mandibular canines, but their overall success rate was high. PRACTICAL IMPLICATIONS: Successful outcome is determined via a well-planned and carefully executed orthodontic and surgical treatment. Early diagnosis is pivotal in facilitating spontaneous canine eruption and implementing transalveolar transplantation in a timely way.

Comparison of transcatheter aortic valve implantation outcomes in patients younger than 85 years and those aged 85 years or older: a single-center study.

INTRODUCTION: The number of elderly patients requiring treatment of aortic stenosis is expected to grow steadily due to increasing lifespan. Transcatheter aortic valve implantation (TAVI) is an alternative treat­ ment for patients with aortic stenosis considered nonoptimal candidates for surgical valve replacement. OBJECTIVES: We aimed to assess age­related differences in 30­day and 1­year cardiovascular mortality, Valve Academic Research Consortium­2 (VARC­2)-defined complications in patients undergoing TAVI, by comparing outcomes in patients younger than 85 years and those aged 85 years or older. PATIENTS AND METHODS: The study group included patients who underwent TAVI at the Institute of Cardiology, Warsaw from January 2009 to July 2019. Clinical, procedural, and follow­up data were retrospectively collected and compared in 2 groups defined according to age: group 1, younger than 85 years (417) and group 2, aged 85 or older (200). RESULTS: The surgical risk profile assessed by the EuroSCORE II was significantly higher in the group of older patients (median [interquartile range], 6.5% [3.5%-17.3%] vs 7.2% [3.4%-18.1%]; P = 0.002); 30­day and 1­year cardiovascular mortality was 4.3% in group 1 as compared with 5% in group 2 (P = 0.69) and 10.8% in group 1 as compared with 9.4% in group 2 (P = 0.51), respectively. The rate of VARC­2­defined complications was similar in both groups, with the exception of major vascular com­ plications (3.12% vs 8.5%; P = 0.004) and major bleeding (10.8% vs 18.5%; P = 0.008), which were more prevalent in older patients. CONCLUSION: Cardiovascular mortality at 1 month and 1 year following TAVI is similar in patients aged 85 years or older and in those younger than 85 years.

Geomorphological effects of animals in mountain streams: Impact and role.

Elucidating the impact of faunal activity on stream channels is an emerging field wherein ecologists, fluvial geomorphologists, and engineers collaborate to research and manage fluvial ecosystems. Here, we focused on the geomorphological effects of animals in mountain streams. This ecosystem merits conservation measures as it furnishes cold-water refugia. We searched literature addressing the impact of various animal taxa on the river/stream bed structure. The citation sources were the Web of Science, Scopus, and ScienceDirect databases covering 1975-early 2020. We examined all animal taxa with documented or potential zoogeomorphological effects upon streams and assigned spatiotemporal scales to their impacts. Interpreting the literature was challenging due to a lack of uniformity in data treatment between species groups and over time. Though human interactions prevail in stream channels, animals also have a substantial effect on a spatial scale and their modifications are more durable. In general, animals markedly influence aquatic habitats. This literature compilation revealed much information about the geomorphological effects of beavers, redd-building fish, and large bottom-dwelling fish. The scale of impact of invertebrates such as crayfish or case-building caddisfly larvae on stony-gravel bottoms has previously been demonstrated. However, previous research has concentrated on only one taxon and has not demonstrated the bioaccumulation effect of multiple taxa. Quantitative data have been presented only for large terrestrial mammals crossing streams. There was comparatively little information on the impact of other terrestrial taxa on stream geomorphology. There were also few or no quantitative data on the impacts of aquatic fauna on mountain stream channels. Much has been reported about the effects of burying invertebrates but relatively little is known about the impacts of burying fish such as lamprey larvae. The present review highlights numerous outstanding information gaps. It is hoped that this review will facilitate ongoing zoogeomorphological research.

Synergistic impacts of sediment generation and hydrotechnical structures related to forestry on stream fish communities.

The increase in anthropogenic sediment has become the most significant factor responsible for degrading flowing waters, preventing them from attaining the good ecological state of rivers requested by Water Framework Directive. After agriculture and mining, forest exploitation is a major source of mineral suspension. The accumulation of fine sediments may reduce fish spawning effectiveness, inhibit migration, and interfere with feeding. Streams degraded by the influx of anthropogenic sediments may be recolonised provided that ecological continuity of the dendritic river network is maintained. The present study focused on mountain stream fish communities whose catchments have undergone natural and intensified soil erosion. We tested the hypothesis that forestry practices transforming the stream habitats combined with the discontinuities created by hydrotechnical structures have had negative impacts on the entire catchment and adversely altered fish communities. The research was carried out in two catchments: i) in the national park, and ii) outside the national park, in an area with forest exploitation. It was observed that the negative effects of the dramatic increases in mineral suspension loads were synergistically aggravated by the presence of objects disturbing fluvial system continuity. The consequences of the synergy between these two factors were evident in local brown trout populations. Sites formerly inhabited by brown trout lacked downstream barriers during our study. After eliminating this parameter, our analysis revealed that channel silting also reduced brown trout abundance downstream from the barrier. The weir in the Muczny Stream inhibited ichthyofaunal re-establishment in streams prone to enhanced mineral suspension input. Forest mountain streams must be preserved also as cold water refugia, hence our results are of significance for forest management. Based on our results, the complete removal of the barrier in Muczny Stream is planned for 2020, and a substantial reduction in the inflow of mineral suspension to stream channels is strongly recommended.

Transcatheter aortic valve replacement in patients with previous mitral valve replacement. A systematic study.

INTRODUCTION: Severe aortic stenosis (AS) is an ever-growing healthcare problem in ageing populations. Transcatheter aortic valve implantation (TAVI) has revolutionized the treatment of AS. However, TAVI in patients who have undergone mitral valve replacement (MVR) is associated with increased risk of mitral valve damage. Limited data exist on TAVI in patients with AS who underwent MVR in the past. AIM: To retrospectively assess the clinical characteristics, detailed echocardiographic and computed tomography measurements, procedural and in-hospital outcome as well as any valve intervention or major adverse cardiovascular events according to VARC-2 criteria at follow-up of patients with a history of MVR, who underwent TAVI. MATERIAL AND METHODS: Seventeen patients with a history of mitral valve operation, in whom TAVI was performed between 2010 and 2018, were identified. Of these, 15 underwent previous MVR. RESULTS: Overall, TAVI resulted in a decrease of mean transaortic gradient by 38.3 ±14 mm Hg (p < 0.001) and a decrease of maximal transaortic gradient by 58.6 ±27.6 mm Hg (p < 0.001). A successful immediate result was obtained in 14 (93.3%) patients. One tamponade occurred during TAVI, which was successfully treated with pericardiocentesis. Post-procedurally, no significant changes in transmitral gradients or mitral regurgitations were observed. Two patients died after hospital discharge, one due to possible internal bleeding and the other due to infection. CONCLUSIONS: TAVI in patients after MVR is feasible. Meticulous preinterventional echocardiographic and computed tomography planning is essential. Although recommended in previous reports, TEE guidance may not necessarily be obligatory during the procedure.