434 research outputs found

    Multiscale analysis of human tissue engineered matrices for heart valve tissue engineering applications

    Full text link
    Human tissue-engineered matrices (hTEMs) have been proposed as a promising approach for in-situ tissue engineered heart valves (TEHVs). However, there is still a limited understanding on how ECM composition in hTEMs develops over tissue culture time. Therefore, we performed a longitudinal hTEM assessment by 1) multiscale evaluation of hTEM composition during culture time (2, 4, 6-weeks), using (immuno)histology, biochemical assays, and mass spectrometry (LC-MS/MS); 2) analysis of protein pathways involved in ECM development using gene set enrichment analysis (GSEA); and 3) assessment of hTEM mechanical characterization using uniaxial tensile testing. Finally, as proof-of-concept, TEHVs manufactured using 6-weeks hTEM samples were tested in a pulse duplicator. LC-MS/MS confirmed the tissue culture time-dependent increase in ECM proteins observed in histology and biochemical assays, revealing the most abundant collagens (COL6,COL12), proteoglycans (HSPG2,VCAN), and glycoproteins (FN,TNC). GSEA identified the most represented protein pathways in the hTEM at 2-weeks (mRNA metabolic processes), 4-weeks (ECM production), and 6-weeks (ECM organization and maturation). Uniaxial mechanical testing showed increased stiffness and stress at failure, and reduction in strain over tissue culture time. hTEM-based TEHVs demonstrated promising in vitro performance at both pulmonary and aortic pressure conditions, with symmetric leaflet coaptation and no stenosis. In conclusion, ECM protein abundance and maturation increased over tissue culture time, with consequent improvement of hTEM mechanical characterics. These findings suggest that longer tissue culture impacts tissue organization, leading to an hTEM that may be suitable for high-pressure applications. STATEMENT OF SIGNIFICANCE: : It is believed that the composition of the extracellular matrix (ECM) in the human tissue engineered matrices (hTEM) may favor tissue engineered heart valve (TEHV) remodeling upon implantation. However, the exact protein composition of the hTEM, and how this impacts tissue mechanical properties, remains unclear. Hence, we developed a reproducible rotation-based tissue culture method to produce hTEM samples. We performed a longitudinal assessment using different analytical techniques and mass spectrometry. Our data provided an in-depth characterization of the hTEM proteome with focus on ECM components, their development, and how they may impact the mechanical properties. Based on these results, we manufactured functional hTEM-based TEHVs at aortic-like condition in vitro. These outcomes pose an important step in translating hTEM-based TEHVs into clinics and in predicting their remodeling potential upon implantation

    Selective Intra-arterial Chemotherapy with Floxuridine as Second- or Third-Line Approach in Patients with Unresectable Colorectal Liver Metastases

    Get PDF
    Background: An outcome assessment was performed of patients with unresectable colorectal liver metastases (CRLM) treated in second or third line with floxuridine (FUDR)-based hepatic artery infusion (HAI). Methods: Twenty-three patients who were pretreated with systemic (immuno)chemotherapy received FUDR-HAI alone or combined with systemic chemotherapy. We reviewed patient charts and our prospective patient database for survival and associated risk factors. Results: Patients received FUDR-HAI for unresectable CRLM from January 2000 to September 2010. Twelve patients (52%) received concurrent systemic chemotherapy. Median overall survival (OS), progression-free survival (PFS), and hepatic PFS were 15.6months (range, 2.5-55.7months), 3.9months (range, 0.7-55.7months), and 5.5months (range, 1.6-55.7months), respectively. The liver resection rate after HAI was 35%. PFS was better in patients undergoing secondary resection than in patients without resection (hazard ratio [HR] 0.21; 95% confidence interval [95% CI] 0.07-0.66; P=0.0034), while OS showed a trend toward improvement (HR 0.4; 95% CI 0.13-1.2; P=0.09). No differences were observed in OS (P=0.69) or PFS (P=0.086) in patients who received FUDR-HAI alone compared with patients treated with combined regional and systemic chemotherapy. No statistically significant differences were seen in patients previously treated with one chemotherapy line compared with patients treated with two lines. Presence of extrahepatic disease was a negative risk factor for PFS (liver-only disease: HR 0.03; 95% CI 0.0032-0.28; P<0.0001). Toxicities were manageable with dose modifications and supportive measures. Conclusions: FUDR-HAI improves PFS and results in a trend toward improved OS in selected patients able to undergo liver resection after tumor is downsize

    FCET2EC (From controlled experimental trial to = 2 everyday communication): How effective is intensive integrative therapy for stroke-induced chronic aphasia under routine clinical conditions? A study protocol for a randomized controlled trial

    Full text link
    Background: Therapy guidelines recommend speech and language therapy (SLT) as the “gold standard” for aphasia treatment. Treatment intensity (i.e., ≥5 hours of SLT per week) is a key predictor of SLT outcome. The scientific evidence to support the efficacy of SLT is unsatisfactory to date given the lack of randomized controlled trials (RCT), particularly with respect to chronic aphasia (lasting for >6 months after initial stroke). This randomized waiting list-controlled multi-centre trial examines whether intensive integrative language therapy provided in routine in- and outpatient clinical settings is effective in improving everyday communication in chronic post-stroke aphasia. Methods/Design: Participants are men and women aged 18 to 70 years, at least 6 months post an ischemic or haemorrhagic stroke resulting in persisting language impairment (i.e., chronic aphasia); 220 patients will be screened for participation, with the goal of including at least 126 patients during the 26-month recruitment period. Basic language production and comprehension abilities need to be preserved (as assessed by the Aachen Aphasia Test).Therapy consists of language-systematic and communicative-pragmatic exercises for at least 2 hours/day and at least 10 hours/week, plus at least 1 hour self-administered training per day, for at least three weeks. Contents of therapy are adapted to patients’ individual impairment profiles.Prior to and immediately following the therapy/waiting period, patients’ individual language abilities are assessed via primary and secondary outcome measures. The primary (blinded) outcome measure is the A-scale (informational content, or 'understandability’, of the message) of the Amsterdam-Nijmegen Everyday Language Test (ANELT), a standardized measure of functional communication ability. Secondary (unblinded) outcome measures are language-systematic and communicative-pragmatic language screenings and questionnaires assessing life quality as viewed by the patient as well as a relative.The primary analysis tests for differences between the therapy group and an untreated (waiting list) control group with respect to pre- versus post 3-week-therapy (or waiting period, respectively) scores on the ANELT A-scale. Statistical between-group comparisons of primary and secondary outcome measures will be conducted in intention-to-treat analyses. Long-term stability of treatment effects will be assessed six months post intensive SLT (primary and secondary endpoints)

    Results of the Patient-Related Outcomes of Mechanical lead Extraction Techniques (PROMET) study: a multicentre retrospective study on advanced mechanical lead extraction techniques.

    Get PDF
    AIMS: Several large studies have documented the outcome of transvenous lead extraction (TLE), focusing on laser and mechanical methods. To date there has been no large series addressing the results obtained with rotational lead extraction tools. This retrospective multicentre study was designed to investigate the outcomes of mechanical and rotational techniques. METHODS AND RESULTS: Data were collected on a total of 2205 patients (age 66.0 ± 15.7 years) with 3849 leads targeted for extraction in six European lead extraction centres. The commonest indication was infection (46%). The targeted leads included 2879 pacemaker leads (74.8%), 949 implantable cardioverter-defibrillator leads (24.6%), and 21 leads for which details were unknown; 46.6% of leads were passive fixation leads. The median lead dwell time was 74 months [interquartile range (IQR) 41-112]. Clinical success was obtained in 97.0% of procedures, and complete extraction was achieved for 96.5% of leads. Major complications occurred in 22/2205 procedures (1%), with a peri-operative or procedure-related mortality rate of 4/2205 (0.18%). Minor complications occurred in 3.1% of procedures. A total of 1552 leads (in 992 patients) with a median dwell time of 106 months (IQR 66-145) were extracted using the Evolution rotational TLE tool. In this subgroup, complete success was obtained for 95.2% of leads with a procedural mortality rate of 0.4%. CONCLUSION: Patient outcomes in the PROMET study compare favourably with other large TLE trials, underlining the capability of rotational TLE tools and techniques to match laser methods in efficacy and surpass them in safety

    The quest for companions to post-common envelope binaries. II. NSVS14256825 and HS0705+6700

    Get PDF
    We report new mid-eclipse times of the two close binaries NSVS14256825 and HS0705+6700, harboring an sdB primary and a low-mass main-sequence secondary. Both objects display clear variations in the measured orbital period, which can be explained by the action of a third object orbiting the binary. If this interpretation is correct, the third object in NSVS14256825 is a giant planet with a mass of roughly 12 M_Jup. For HS0705+6700, we provide evidence that strengthens the case for the suggested periodic nature of the eclipse time variation and reduces the uncertainties in the parameters of the brown dwarf implied by that model. The derived period is 8.4 yr and the mass is 31 M_Jup, if the orbit is coplanar with the binary. This research is part of the PlanetFinders project, an ongoing collaboration between professional astronomers and student groups at high schools.Comment: Accepted by Astron. and Astrophy

    Epicardial catheter ablation for ventricular tachycardia on uninterrupted warfarin: A safe approach for those with a strong indication for peri-procedural anticoagulation?

    Get PDF
    BACKGROUND: Current guidelines for epicardial catheter ablation for ventricular tachycardia (VT) advocate that epicardial access is avoided in anticoagulated patients and should be performed prior to heparinisation. Recent studies have shown that epicardial access may be safe in heparinised patients. However, no data exist for patients on oral anticoagulants. We investigated the safety of obtaining epicardial access on uninterrupted warfarin. METHODS: A prospective registry of patients undergoing epicardial VT ablation over two years was analysed. Consecutive patients in whom epicardial access was attempted were included. All patients were heparinised prior to epicardial access with a target activated clotting time (ACT) of 300-350s. Patients who had procedures performed on uninterrupted warfarin (in addition to heparin) were compared to those not taking an oral anticoagulant. RESULTS: 46 patients were included of which 13 were taking warfarin. There was no significant difference in clinical and procedural characteristics (except INR and AF) between the two groups. Epicardial access was achieved in all patients. There were no deaths and no patients required surgery. A higher proportion of patients in the warfarin group had a drop in haemoglobin of >2g/dL compared to the no-warfarin group (38.5% versus 27.3%, p=0.74) and delayed pericardial drain removal (7.8% versus 3.03%, p=0.47). There was no difference in overall procedural complication rate. No patients required warfarin reversal or blood transfusion. CONCLUSION: Epicardial access can be achieved safely and effectively in patients' anticoagulated with warfarin and heparinised with therapeutic ACT. This may be an attractive option for patients with a high stroke risk

    Clinical Study Suitability, Efficacy, and Safety of Vernakalant for New Onset Atrial Fibrillation in Critically Ill Patients

    Get PDF
    Objectives. This study investigates the suitability, safety, and efficacy of vernakalant in critically ill patients with new onset atrial fibrillation (AF) after cardiac surgery. Methods. Patients were screened for inclusion and exclusion criteria according to the manufacturers&apos; recommendations. Included patients were treated with 3 mg/kg of vernakalant over 10 min and, if unsuccessful, a second dose of 2 mg/kg. Blood pressure was measured continuously for 2 hours after treatment. Results. Of the 191 patients screened, 159 (83%) were excluded, most importantly due to hemodynamic instability (59%). Vernakalant was administered to 32 (17% of the screened) patients. Within 6 hours, 17 (53%) patients converted to sinus rhythm. Blood pressure did not decrease significantly 10, 30, 60, and 120 minutes after the vernakalant infusion. However, 11 patients (34%) experienced a transient decrease in mean arterial blood pressure &lt;60 mmHg. Other adverse events included nausea ( = 1) and bradycardia ( = 2). Conclusions. Applying the strict inclusion and exclusion criteria provided by the manufacturer, only a minority of postoperative ICU patients with new onset AF qualified for vernakalant. Half of the treated patients converted to sinus rhythm. The drug was well tolerated, but close heart rate and blood pressure monitoring remains recommended

    Acceptability and feasibility of peer assisted supervision and support for intervention practitioners: a Q-methodology evaluation

    Get PDF
    Evidence-based interventions often include quality improvement methods to support fidelity and improve client outcomes. Clinical supervision is promoted as an effective way of developing practitioner confidence and competence in delivery; however, supervision is often inconsistent and embedded in hierarchical line management structures that may limit the opportunity for reflective learning. The Peer Assisted Supervision and Support (PASS) supervision model uses peer relationships to promote the self-regulatory capacity of practitioners to improve intervention delivery. The aim of the present study was to assess the acceptability and feasibility of PASS amongst parenting intervention practitioners. A Q-methodology approach was used to generate data and 30 practitioners volunteered to participate in the study. Data were analyzed and interpreted using standard Q-methodology procedures and by-person factor analysis yielded three factors. There was consensus that PASS was acceptable. Participants shared the view that PASS facilitated an environment of support where negative aspects of interpersonal relationships that might develop in supervision were not evident. Two factors represented the viewpoint that PASS was also a feasible model of supervision. However, the third factor was comprised of practitioners who reported that PASS could be time consuming and difficult to fit into existing work demands. There were differences across the three factors in the extent to which practitioners considered PASS impacted on their intervention delivery. The findings highlight the importance of organizational mechanisms that support practitioner engagement in supervision
    • …
    corecore