HSF-1 enhances cardioprotective potential of stem cells via exosome biogenesis and their miRNA cargo enrichment.

Stem cell therapy provides a hope to no option heart disease patient group. Stem cells work via different mechanisms of which paracrine mechanism is reported to justify most of the effects. Therefore, identifying the control arms for paracrine cocktail production is necessary to tailor stem cell functions in disease contextual manner. In this study, we describe a novel paracrine cocktail regulatory axis, in stem cells, to enhance their cardioprotective abilities. We identified that HSF1 knockout resulted in reduced cardiac regenerative abilities of mesenchymal stem cells (MSCs) while its overexpression had opposite effects. Altered exosome biognesis and their miRNA cargo enrichment were found to be underlying these altered regenerative abilities. Decreased production of exosomes by MSCs accompanied their loss of HSF1 and vice versa. Moreover, the exosomes derived from HSF1 depleted MSCs showed significantly reduced candidate miRNA expression (miR-145, miR-146, 199-3p, 199b and miR-590) compared to those obtained from HSF1 overexpressing MSCs. We further discovered that HSF1 mediates miRNAs' enrichment into exosomes via Y binding protein 1 (YBX1) and showed, by loss and gain of function strategies, that miRNAs' enrichment in mesenchymal stem cell derived exosomes is deregulated with altered YBX1 expression. It was finally demonstrated that absence of YBX1 in MSCs, with normal HSF1 expression, resulted in significant accumulation of candidate miRNAs into the cells. Together, our data shows that HSF1 plays a critical role in determining the regenerative potential of stem cells. HSF1 does that by affecting exosome biogenesis and miRNA cargo sorting via regulation of YBX1 gene expression.

Safety and efficacy of transcoronary transfer of human neonatal stem cells to ischemic myocardium using a novel cell-delivery system (CIRCULATE catheter) in swine model of acute myocardial infarction.

Introduction: Stem cell-based therapies have shown promise in adults with ischemic cardiomyopathy and children with congenital heart diseases, especially those without available therapeutic options. Human neonatal mesenchymal stem cells (nMSCs) have greater regenerative potential than adult stem cells. Aim: To describe our experience with a novel catheter system for transcoronary delivery of cell-based therapies (CIRCULATE catheter) in the intra-coronary delivery of nMSCs in a swine acute myocardial infarct model. Material and methods: A newly developed catheter system (CIRCULATE catheter) with several unique features, including an expandable intra-coronary reservoir with spirally placed side holes of varying diameter, was used. nMSCs together with their secretome were used for the treatment. Pigs underwent myocardial infarction by inflating a 2.5 mm angioplasty balloon in the left anterior descending artery for 60 min. After reperfusion, stem cell therapy or placebo was administered via the novel catheter. TTE was performed at baseline, 1 h after the procedure, and before the euthanasia. Troponin blood concertation was evaluated at baseline, and after 48 h. The heart was harvested, sliced, and stained with triphenyl tetrazolium chloride (TTC). Infarct size to area-at-risk ratio was calculated. Troponin was assessed at baseline and after 48 h. Results: Thirty-nine pigs were operated with the mortality rate of 5.13% (exclusively malignant arrhythmia). Infarct size to area-at-risk ratio was significantly lower in the treatment group. Treated animals had higher ejection fraction than controls. Conclusions: Intra-coronary delivery of neonatal mesenchymal stem cells reduces the infarct size and restores myocardial function in a swine model. The novel catheter system (CIRCULATE catheter) tested in this study was safe and effective in transcoronary cell delivery of human neonatal mesenchymal stem cells.

Stem cell therapy for single ventricle congenital heart disease - current state and future directions.

Hypoplastic left heart syndrome (HLHS) is one of the most complex forms of congenital heart disease, characterized by an underdeveloped left ventricle, outflow tract and aorta. Current surgical and medical treatment for this disease remains palliative. As a result of the multi-step surgery, the right ventricle plays the role of the systemic ventricle, which inevitably leads to its failure. There is an urgent need to develop new treatments to ameliorate the right ventricle failure. Stem cell therapy may represent a new approach to single ventricle pathology. Great numbers of small and large animal studies have proven this therapy to be safe and effective in hypoplastic left heart syndrome. Several clinical trials have been designed to investigate the potential of mesenchymal stem cells in univentricular heart physiology. With increasing evidence, understanding of the mechanism of stem cells' action has shifted from the concept of differentiation into various heart cell types to paracrine activity playing the major role. The secretome of stem cells has been identified as their functional unit. In this review, we present different types of stem cells used in single ventricle diseases in children as well as their preclinical investigations. We also summarize clinical applications of stem cells in children with HLHS.

Safety and performance of a novel transventricular beating heart mitral valve repair system: 1-year outcomes.

OBJECTIVES: The objective of this study was to evaluate the safety and performance of a novel, beating heart procedure that enables echocardiographic-guided beating heart implantation of expanded polytetrafluoroethylene (ePTFE) artificial cords on the posterior mitral leaflet of patients with degenerative mitral regurgitation. METHODS: Two prospective multicentre studies enrolled 13 (first-in-human) and 52 subjects, respectively. Patients were treated with the HARPOON beating heart mitral valve repair system. The primary (30-day) end point was successful implantation of cord(s) with mitral regurgitation reduction to ≤moderate. An independent core laboratory analysed echocardiograms. RESULTS: Of 65 patients enrolled, 62 (95%) achieved technical success, 2 patients required conversion to open surgery and 1 procedure was terminated. The primary end point was met in 59/65 (91%) patients. Among the 62 treated patients, the mean procedural time was 2.1 ± 0.5 h. Through discharge, there were no deaths, strokes or renal failure events. At 1 year, 2 of the 62 patients died (3%) and 8 (13%) others required reoperations. At 1 year, 98% of the patients with HARPOON cords were in New York Heart Association class I or II, and mitral regurgitation was none/trace in 52% (n = 27), mild in 23% (n = 12), moderate in 23% (n = 12) and severe in 2% (n = 1). Favourable cardiac remodelling outcomes at 1 year included decreased end-diastolic left ventricular volume (153 ± 41 to 119 ± 28 ml) and diameter (53 ± 5 to 47 ± 6 mm), and the mean transmitral gradient was 1.4 ± 0.7 mmHg. CONCLUSIONS: This initial clinical experience with the HARPOON beating heart mitral valve repair system demonstrates encouraging early safety and performance. CLINICAL REGISTRATION NUMBERS: NCT02432196 and NCT02768870.

Final 5-year outcomes following aortic valve replacement with a RESILIA™ tissue bioprosthesis.

OBJECTIVES: Long-term durability of bioprosthetic valves is predominantly limited by structural valve deterioration. RESILIA™ tissue has exhibited reduced calcification in pre-clinical and early clinical studies. This study evaluated the 5-year clinical and haemodynamic outcomes of an aortic valve with this tissue. METHODS: This was a prospective, non-randomized, single-arm study of 133 patients implanted with a RESILIA aortic bioprosthesis between July 2011 and February 2013 at 2 sites in Poland. Clinical outcomes and haemodynamic performance were assessed annually for 5 years post-implant. Safety events were adjudicated by a Clinical Events Committee and echocardiographic data were assessed by an independent core laboratory. RESULTS: Mean patient age was 65.3 ± 13.5 years, with 34 patients (25.6%) ≤60. The mean follow-up was 4.2 ± 1.5 years. Early (≤30 days) and late (>30 days) all-cause mortality were 2.3% (N = 3) and 3.2%/late patients-years (N = 18) respectively. Early events included thromboembolism in 3 patients (2.3%). Late valve-related events included endocarditis in 1 patient, which led to explant, and valve thrombosis in another patient. There were no events of structural valve deterioration throughout the study. At 5 years, mean gradient was 14.8 ± 7.6 mmHg and effective orifice area was 1.4 ± 0.5 cm2, a marked improvement over baseline values. All New York Heart Association class III patients and most class II patients at baseline had improved classifications at 5 years. CONCLUSIONS: The bioprosthesis with RESILIA tissue demonstrated a good safety profile with excellent haemodynamic performance over 5 years of follow-up. These encouraging outcomes warrant additional investigation of this novel tissue. CLINICAL TRIAL REGISTRATION NUMBER: NCT01651052.

Intermediate-term outcomes after aortic valve replacement with a novel RESILIATM tissue bioprosthesis.

BACKGROUND: The durability of bioprosthetic heart valves is limited by structural valve deterioration (SVD) due to long-term calcification. A novel bioprosthetic tissue (RESILIATM) has been developed which, in preclinical studies, has shown reduced calcification. The purpose of this study was to evaluate the intermediate-term clinical outcomes and hemodynamic performance of this tissue. METHODS: A prospective, single-arm, observational trial was conducted in patients who required surgical aortic valve replacement (AVR). Between July 2011 and February 2013, 133 patients were implanted at two sites in Poland. Hemodynamic performance and clinical outcomes were assessed annually through 4 years of follow-up. All safety events were adjudicated by an independent Clinical Events Committee, and echocardiographic data were evaluated by a core laboratory. RESULTS: Patients were 65.3±13.5 years old and 26% were ≤60 years old. The average follow-up was 3.8±1.1 (median: 4.1; IQR, 4.0-4.3) years. Early (≤30 day) and late (>30 day) all-cause mortality rates were 2.3% (n=3) and 3.2% late patient-years (n=16), respectively. There were no cases of early or late SVD. There was one early case of major paravalvular leak (0.8%), and no late cases. At 4 years, the mean gradient was 14.5±7.4 mmHg and the effective orifice area was 1.6±0.4 cm2, both markedly improved from baseline. At 4 years, the New York Heart Association functional class had improved from baseline in 54.5% of patients. CONCLUSIONS: The aortic bioprosthesis with novel RESILIATM tissue demonstrated excellent hemodynamic performance and safety outcomes over 4 years. Longer follow-up will be important to confirm the durability of this bioprosthesis.

Primary safety and effectiveness feasibility study after surgical aortic valve replacement with a new generation bioprosthesis: one-year outcomes.

BACKGROUND: Structural valve deterioration (SVD) is a major obstacle to lifetime durability for bioprosthetic heart valves. A bio-prosthetic valve created with RESILIA™ tissue was designed to produce long-term resistance to SVD. AIM: The objective of this study was to evaluate the safety and performance of this new class of RESILIA™ tissue aortic bio-prosthesis. METHODS: A nonrandomised, prospective, multi-centre, single-arm, observational study was performed in 133 patients who underwent surgical aortic valve replacement between July 2011 and February 2013. Patients were assessed at 3-6 months and one year for haemodynamic performance, clinical outcomes, and functional improvement. RESULTS: The mean age was 65.3 ± 13.5 years, with 34 (25.6%) of patients < 60 years of age. Early (≤ 30 day) and late (> 30 day) all-cause mortality rates were 2.3% (n = 3) and 4.5% (n = 6), respectively. Early events included thromboembolism in three (2.3%) patients and major bleeding events requiring transfusion in six (4.5%) patients. Late events included one endocarditis leading to explant. Mean gradients were reduced across all valve sizes and were maintained at one year of follow-up. The mean effective orifice area and effective orifice area index increased across all valve sizes postoperatively and were maintained at one year. The rates of paravalvular leak (> 2+) at 3-6 months and one-year follow-up were 0.7% and 0.7%, respectively. CONCLUSIONS: The new generation RESILIA™ tissue aortic valve bioprosthesis demonstrated excellent haemodynamic per-formance and safety outcomes at one year of follow-up. Longer follow-up of these patients will provide further insight on long-term durability.

Beating-Heart Mitral Valve Repair Using a Novel ePTFE Cordal Implantation Device: A Prospective Trial.

BACKGROUND: Conventional mitral valve (MV) operations allow direct anatomic assessment and repair on an arrested heart, but require cardiopulmonary bypass, aortic cross-clamping, sternotomy or thoracotomy, and cardioplegic cardiac arrest, and are associated with significant perioperative disability, and risks of morbidity and mortality. OBJECTIVES: This study evaluated safety and performance of a transesophageal echocardiographic-guided device designed to implant artificial expanded polytetrafluoroethylene (ePTFE) cords on mitral leaflets in the beating heart. METHODS: In a prospective multicenter study, 30 consecutive patients with severe degenerative mitral regurgitation (MR) were treated with a mitral valve repair system (MVRS) via small left thoracotomy. The primary (30-day) endpoint was successful implantation of cords with MR reduction to moderate or less. RESULTS: The primary endpoint was met in 27 of 30 patients (90%). Three patients required conversion to open mitral surgery. There were no deaths, strokes, or permanent pacemaker implantations. At 1 month, MR was mild or less in 89% (24 of 27) and was moderate in 11% (3 of 27). At 6 months, MR was mild or less in 85 % (22 of 26), moderate in 8% (2 of 26), and severe in 8% (2 of 26). Favorable cardiac remodeling at 6 months included decreases in end-diastolic (161 ± 36 ml to 122 ± 30 ml; p < 0.001) and left atrial volumes (106 ± 36 ml to 69 ± 24 ml; p < 0.001). The anterior-posterior mitral annular dimension decreased from 34.7 ± 5.8 mm to 28.2 ± 5.1 mm; p < 0.001 as did the mitral annular area (10.0 ± 2.7 cm2 vs. 6.9 ± 2.0 cm2; p < 0.0001). CONCLUSIONS: MVRS ePTFE cordal implantation can reduce the invasiveness and morbidity of conventional MV surgery. The device's safety profile is promising and prospective trials comparing the outcomes of the MVRS to conventional MV repair surgery are warranted. (CE Mark Study for the Harpoon Medical Device [TRACER]; NCT02768870).

Transapical Beating-Heart Mitral Valve Repair With an Expanded Polytetrafluoroethylene Cordal Implantation Device: Initial Clinical Experience.

BACKGROUND: Degenerative mitral valve (MV) disease is a common cause of severe mitral regurgitation (MR) and accounts for the majority of MV operations. Conventional MV surgery requires cardiopulmonary bypass, aortic cross-clamping, cardioplegia, and a thoracotomy or sternotomy and, therefore, is associated with significant disability, risks, and unpredictable rates of MV repair. Transesophageal echocardiography-guided beating-heart MV repair with expanded polytetrafluoroethylene cordal insertion has the potential to significantly reduce surgical morbidity. We report the first-in-human clinical experience with a novel preformed expanded polytetrafluoroethylene knot implantation device (Harpoon TSD-5) designed to treat degenerative MR. METHODS: Through a small left thoracotomy, the device was inserted into the heart and guided by transesophageal echocardiography to the ventricular surface of the prolapsed leaflet. Multiple expanded polytetrafluoroethylene cords were anchored in the leaflet and then adjusted to the correct length to restore MV leaflet coaptation and secured at the epicardium. RESULTS: Eleven patients with posterior leaflet prolapse and severe MR, with mean±SD age of 65±13 years and mean ejection fraction of 69±7%, were treated with 100% procedural success. Immediate postprocedural mean MR grade was trace. At 1 month, the mean MR grade was mild with significant decreases in end-diastolic volume (139 to 107 mL; P=0.03) and left atrial volume (118 to 85 mL; P=0.04). CONCLUSIONS: A novel device used for beating-heart image-guided MV repair demonstrates a significant reduction in MR with favorable left ventricular and left atrial reverse remodeling. This approach has the potential to decrease invasiveness and surgical morbidity. Further follow-up is necessary to assess long-term efficacy. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT02432196.

[The correlation between phenotypes and genotypes of macrolides, lincosamides and streptogramins B resistance in Staphylococcus aureus]. / Korelacja genotypów i fenotypów opornoscina makrolidy, linkozamidy i streptograminy B u Staphylococcus aureus.

For 31 clinical strains of S. aureus the correlation between phenotype and genotype of resistance to macrolides, lincosamides and streptogramins B (MLSB) was established.. Phenotypes were determined on the basis of: susceptibility to erythromycin and clindamycin and the ability to an induction of the resistance (phenotypes S, susceptible; R , constitutive resistant, D, resistant after induction with erythromycin, D+, resistant after induction with erythromycin and with a presence of the small colonies inside inhibition zone between erythromycin and clindamycin discs), and on the basis of the resistance to spectinomycin (spR, resistant, spS, susceptible). Among examined S. aureus strains eight phenotypes of resistance to MLSB were recognized (the corresponding genotypes are given in brackets). Six phenotypes were typical: SspS (lack of MLS-B resistance genes), NEGspS (msrA/B, 1 strain), D+spS (ermCi, 4 strains),. DspR (ermAi, 11 strains and ermAi + msrA/B, 2 strains), RspR (ermAc, 4 strains and ermA + msrA/B,1 strain and ermA + ermC, 1 strain) and RspS (ermCc, 6 strains and ermB, 1 strain). Two rare phenotypes in two single strains were observed: SspR (ermAi, the strain with altered inducibility, inductor other than erythromycin) and DspS (ermAi, presumably mutation or lack of spc in Tn554).

[Antibmicrobial susceptibility of Serratia marcescens isolated from hospitalized patients in 2003 - 2005]. / Wrazliwosc na antybiotyki szczepów Serratia marcescens izolowanych od chorych hospitalizowanych w latach 2003 - 2005.

500 strains of Serratia marcescens isolated in 2003-2005 were examined for drug susceptibility. By using several phenotypic methods it was shown that 67.6% of these strains produced ESBLs. Strains ESBL(-) and ESBL(+) were compared, paying special attention to their susceptibility to various antibiotics. It was revealed that strains ESBL(+) were much more resistant to majority of the investigated drugs. The biggest differences were in the case of amikacin and gentamicin, sensitive about 50% of ESBL(-) and 10% of ESBL(+), ciprofloxacin, sensitive 42% of ESBL(-) and 6.3% of ESBL(+) and trimethoprim/ sulphametoxazole, sensitive 45.8% of ESBL(-) and 9.4% of ESBL(+). Strains ESBL(-) retained a high susceptibility to ceftazidime (68.9%) and cefepime (71%). All strains ESBL(-) as well as ESBL(+) were susceptible to imipenem and meropenem. 78.9% of ESBL(-) and 67.3% of investigated ESBL(+) were susceptible to piperacillin/ tazobactam.

[High effectiveness of the method with cefpirome in detection of extended-spectrum beta-lactamases in different species of gram-negative bacilli]. / Ocena przydatnosci testu z cefpiromem do wykrywania beta-laktamaz o rozszerzonym spektrum u róznych gatunków paleczek gram-ujemnych.

Gram-negative bacilli were examined for ESBL production by using four methods: double-disc synergy diffusion test (DDST), and three tests of combined discs with cefpodoxime, ceftazidime and cefotaxime alone and the same cephalosporins with clavulanic acid. Strains determined as ESBL-negative with all these tests were examined by using fifth method with cefpirome. 47,5% from 178 negative in other methods strains, appeared ESBL-positive in this test. The examined strains belonged to 16 different species. Most of them were Enterobacter cloaceae, Serratia marcescens, Pseudomonas aeruginosa and Acinetobacter baumanii. It seems that the combined discs method with cefpirome may be usefull for phenotypic detection of ESBL producing bacteria also in the case of strains where ESBL production is camouflaged with derepressed chromosomal AmpC beta-lactamases.

[MIC and MBC of quinupristin/dalfopristin of erythromycin-resistant MRSA strains isolated from clinical specimens]. / Aktywnosc chinupristiny/dalfopristiny wobec erytromycyno-opornych szczepów MRSA izolowanych z materialu klinicznego.

The MICs and MBCs of quinupristin/dalfopristin were determined for 22 clinical strains MRSA with inducible type of resistance to MLS-B and for 15 of their derivatives with constitutive resistance to MLS-B. For MRSA strains with inducible resistance to MLS-B the obtained results for quinupristin/ dalfopristin were: MIC50 = 0.25, MIC90 = 0.5, MBC50 = 1.0 and MBC90 = 1.0. Mutants of the same strains characterized with the following values for quinopristin/dalfopristin: MIC50 = 0.5, MIC90 = 1.5, MBC50 = 4.0 and MTC90 = 8.0.