No genetic erosion after five generations for Impatiens glandulifera populations across the invaded range in Europe.

BACKGROUND: The observation that many alien species become invasive despite low genetic diversity has long been considered the 'genetic paradox' in invasion biology. This paradox is often resolved through the temporal buildup genetic diversity through multiple introduction events. These temporal dynamics in genetic diversity are especially important for annual invasive plants that lack a persistent seed bank, for which population persistence is strongly dependent on consecutive seed 're-establishment' in each growing season. Theory predicts that the number of seeds during re-establishment, and the levels of among-population gene flow can strongly affect recolonization dynamics, resulting in either an erosion or build-up of population genetic diversity through time. This study focuses on temporal changes in the population genetic structure of the annual invasive plant Impatiens glandulifera across Europe. We resampled 13 populations in 6 regions along a 1600 km long latitudinal gradient from northern France to central Norway after 5 years, and assessed population genetic diversity with 9 microsatellite markers. RESULTS: Our study suggests sufficiently high numbers of genetically diverse founders during population re-establishment, which prevent the erosion of local genetic diversity. We furthermore observe that I. glandulifera experiences significant among-population gene flow, gradually resulting in higher genetic diversity and lower overall genetic differentiation through time. Nonetheless, moderate founder effects concerning population genetic composition (allele frequencies) were evident, especially for smaller populations. Despite the initially low genetic diversity, this species seems to be successful at persisting across its invaded range, and will likely continue to build up higher genetic diversity at the local scale.

Comparative anatomy and morphology of the knee in translational models for articular cartilage disorders. Part II: Small animals.

BACKGROUND: Small animal models are critical to model the complex disease mechanisms affecting a functional joint leading to articular cartilage disorders. They are advantageous for several reasons and significantly contributed to the understanding of the mechanisms of cartilage diseases among which osteoarthritis. METHODS: Literature search in Pubmed. RESULTS AND DISCUSSION: This narrative review summarizes the most relevant anatomical structural and functional characteristics of the knee (stifle) joints of the major small animal species, including mice, rats, guinea pigs, and rabbits compared with humans. Specific characteristics of each species, including kinematical gait parameters are provided and compared with the human situation. When placed in a proper context respecting their challenges and limitations, small animal models are important and appropriate models for articular cartilage disorders.

Comparative anatomy and morphology of the knee in translational models for articular cartilage disorders. Part I: Large animals.

BACKGROUND: The human knee is a complex joint, and affected by a variety of articular cartilage disorders. Large animal models are critical to model the complex disease mechanisms affecting a functional joint. Species-dependent differences highly affect the results of a pre-clinical study and need to be considered, necessitating specific knowledge not only of macroscopic and microscopic anatomical and pathological aspects, but also characteristics of their individual gait and joint movements. METHODS: Literature search in Pubmed. RESULTS AND DISCUSSION: This narrative review summarizes the most relevant anatomical structural and functional characteristics of the knee (stifle) joints of the major translational large animal species, comprising dogs, (mini)pigs, sheep, goats, and horses in comparison with humans. Specific characteristics of each species, including kinematical gait parameters are provided. Considering these multifactorial dimensions will allow to select the appropriate model for answering the research questions in a clinically relevant fashion.

Sex differences in outcomes following less-invasive left ventricular assist device implantation.

BACKGROUND: Worse outcomes in women compared to men undergoing left ventricular assist device (LVAD) implantation remain an underestimated problem in heart failure (HF) patients. With device miniaturization, less-invasive LVAD implantation techniques have gained relevance, but their impact on outcomes in women is unknown. This study investigates sex-related differences in patients undergoing LVAD implantation through less-invasive procedures. METHODS: This retrospective single-center cohort study included patients who underwent isolated LVAD implantation between 2011 and 2018 through less-invasive techniques. Propensity score matching (PSM) was utilized to balance preoperative heterogeneity. Primary endpoint was two-year survival, and secondary endpoints included long-term survival, surgical outcomes and postoperative adverse events. RESULTS: Baseline analysis of 191 patients (females 18.3%) showed differences in terms of age [female (median, 52; IQR, 47-61); male (median, 58.5; IQR, 49-66); P=0.005], underlying diagnosis (P<0.001), INTERMACS profile (P=0.009), history of previous cardiac surgery (P=0.049) and preoperative creatinine values [female (median, 110; IQR, 71-146); male (median, 126; IQR, 9-168); P=0.049]. Over a follow-up of 460.68 patient-years, Kaplan-Meyer analysis showed better survival in females (P=0.027) and a similar probability of cardiac transplantation (P=0.288). After PSM, females showed higher needs for intraoperative fresh frozen plasma (P=0.044) and platelets (P=0.001) but comparable postoperative outcomes. No sex-related differences were noticed regarding two-year outcomes, long-term survival and adverse events. LVAD-related infections remained the most common complication with males experiencing more pump infections than women (P=0.050). CONCLUSIONS: Patients receiving less-invasive LVAD implantation do not show significant sex-related differences in short and long-term outcomes and survival. Prospective studies are needed to evaluate the role of less-invasive techniques in reducing sex-based disparities after LVAD implantation.

Biased niches - Species response curves and niche attributes from Huisman-Olff-Fresco models change with differing species prevalence and frequency.

The study aimed to examine the effects of different numbers of presences and frequencies (proportions) of occurrences of species in a plot data set of forest vegetation on the species response curves and their niche attributes, based on Huisman-Olff-Fresco models (HOF). We modeled responses of 72 to 105 herbaceous forest species along a pH gradient under 14 different random sampling scenarios by varying the number of presences and absences used for model fitting. Mean niche attributes were calculated from 100 repetitive runs for each scenario and species. Re-prediction success of HOF models among the repetitive runs was highest when the total number of plots was high and the frequency of occurrences was low. With low plot numbers and high frequencies, less complicated model types (no response or monotonically increasing/decreasing responses) predominate. Measures of species niche boundaries (limits & borders) and niche width were strongly influenced by changes in sampling characteristics. With an increasing number of presences and an increasing frequency, limits and borders shifted to more extreme values, leading to wider niches. In contrast, species optima showed almost no change between the scenarios. Thus, the detected ecological response of a species often depends on the size of the data set and the relation between presences and absences of a species. In general, high data quantities are required for reliable response curve modeling with HOF models, which prevents the assessment of the responses of many rare species. To avoid undesired bias by differing sampling characteristics when comparing niches between different species or between data sets, the data basis used for model fitting should be adjusted according to the niche attribute in question, for example by keeping the frequency of the species constant.

First series of left ventricular assist device exchanges to HeartMate 3.

OBJECTIVES: Left ventricular assist device (LVAD) exchange is becoming a standard surgical procedure. The exchange procedure is an opportunity to upgrade patients to a new generation pump that offers advanced reduction of adverse events or longer battery hours. METHODS: We performed an analysis of 6 consecutive patients who underwent LVAD exchange to HeartMate 3 either from a HeartWare or HeartMate (HM) II device. Minimally invasive operations were performed through a lateral thoracotomy. Follow-up time was 6 months after LVAD exchange. RESULTS: We present 4 patients with the HM II and 2 patients with the HeartWare ventricular assist device (HVAD) who underwent LVAD exchange to HM III. The average age was 57.5 years. At the time of the LVAD exchange, all patients were classified as Interagency Registry for Mechanically Assisted Circulatory Support level 3. In 5 cases, LVAD infection led to LVAD exchange (83%, 5/6). The remaining patient underwent LVAD exchange due to pump thrombosis (16%, 1/6). The 6-month survival rate after LVAD exchange was 100% (6/6). None of the patients was postoperatively supported by extracorporeal membrane oxygenation. No patient experienced postoperative relevant bleeding. One patient suffered minor cerebral bleeding (16.6%, 1/6). At the 6-month follow-up examination, 1 patient reported a single syncope and several low-flow alarms (1/6). The remaining 5 patients showed no adverse events or technical malfunctions of the VAD (5/6). CONCLUSIONS: LVAD exchanges from HM II as well from HVAD to HM 3 are proven to be technically feasible. Due to the advantages and technical improvements of the new-generation pumps, this procedure is an excellent opportunity to give patients access to a superior generation of assist device.