Decellularised heart valve roots offer a promising option for heart valve replacement in young patients, having the potential to remodel and repair. Replacement heart valves have to undergo billions ...of opening and closing cycles throughout the patient's lifetime. Therefore, understanding the effect of cyclic loading on decellularised heart valve roots is important prior to human implantation. The aim of this preliminary study was to investigate the influence of low concentration sodium dodecyl sulphate (SDS) decellularisation treatment on the in vitro real time mechanical fatigue of porcine aortic heart valve roots under physiological real time cyclic loading conditions. This required a specific real time in vitro method to be developed, since previous methods relied on accelerated testing, which is non-physiological, and not appropriate for valve replacement materials that exhibit time dependent characteristics. The effects of the real time fatigue on hydrodynamic function and mechanical properties of the heart valve roots were assessed. The mechanical fatigue of decellularised porcine aortic heart valve roots (n = 6) was assessed and compared to cellular porcine aortic heart valve roots (n = 6) in a modified Real time Wear Tester (RWT) at a physiological frequency and under cyclic pressure conditions for a maximum of 1.2 million cycles. Periodically, the heart valve roots were removed from the RWT to assess the influence of cyclic loading on valve competency (static leaflet closure). At the end of testing further hydrodynamic performance parameters were ascertained, along with determination of leaflet material properties. A real time mechanical fatigue assessment method was developed and applied; with two cellular and two decellularised porcine aortic leaflets in different heart valve roots showing tears in the belly region. The decellularised aortic heart valve roots exhibited comparative functionality to the cellular heart valve roots under in vitro static and pulsatile hydrodynamic conditions. However, the material properties of the decellularised aortic leaflets were significantly altered following cyclic fatigue assessment and showed increases in elastin and collagen phase slopes and ultimate tensile strength compared to the cellular porcine aortic leaflets in the circumferential direction. This preliminary study demonstrated that low concentration SDS decellularised porcine aortic heart valve roots can withstand physiological cyclic deformations up to 1.2 million cycles in a RWT whilst maintaining their overall hydrodynamic function and leaflet mechanical properties. This is the first full report of preclinical mechanical fatigue assessment of decellularised porcine aortic heart valve roots under physiological real time conditions.
The primary objective was to evaluate performance of low concentration SDS decellularised porcine pulmonary roots in the right ventricular outflow tract of juvenile sheep. Secondary objectives were ...to explore the cellular population of the roots over time. Animals were monitored by echocardiography and roots explanted at 1, 3, 6 (n = 4) and 12 months (n = 8) for gross analysis. Explanted roots were subject to histological, immunohistochemical and quantitative calcium analysis (n = 4 at 1, 3 and 12 months) and determination of material properties (n = 4; 12 months). Cryopreserved ovine pulmonary root allografts (n = 4) implanted for 12 months, and non-implanted cellular ovine roots were analysed for comparative purposes. Decellularised porcine pulmonary roots functioned well and were in very good condition with soft, thin and pliable leaflets. Morphometric analysis showed cellular population by 1 month. However, by 12 months the total number of cells was less than 50% of the total cells in non-implanted native ovine roots. Repopulation of the decellularised porcine tissues with stromal (α-SMA+; vimentin+) and progenitor cells (CD34+; CD271+) appeared to be orchestrated by macrophages (MAC 387+/ CD163low and CD163+/MAC 387−). The calcium content of the decellularised porcine pulmonary root tissues increased over the 12-month period but remained low (except suture points) at 401 ppm (wet weight) or below. The material properties of the decellularised porcine pulmonary root wall were unchanged compared to pre-implantation. There were some changes in the leaflets but importantly, the porcine tissues did not become stiffer. The decellularised porcine pulmonary roots showed good functional performance in vivo and were repopulated with ovine cells of the appropriate phenotype in a process orchestrated by M2 macrophages, highlighting the importance of these cells in the constructive tissue remodelling of cardiac root tissues.
IntroductionThe improvements in short-term outcome after severe trauma achieved through early resuscitation and acute care can be offset over the following weeks by an acute systemic inflammatory ...response with immuneparesis leading to infection, multiorgan dysfunction/multiorgan failure (MOF) and death. Serum levels of the androgen precursor dehydroepiandrosterone (DHEA) and its sulfate ester DHEAS, steroids with immune-enhancing activity, are low after traumatic injury at a time when patients are catabolic and immunosuppressed. Addressing this deficit and restoring the DHEA(S) ratio to cortisol may provide a range of physiological benefits, including immune modulatory effects.ObjectiveOur primary objective is to establish a dose suitable for DHEA supplementation in patients after acute trauma to raise circulating DHEA levels to at least 15 nmol/L. Secondary objectives are to assess if DHEA supplementation has any effect on neutrophil function, metabolic and cytokine profiles and which route of administration (oral vs sublingual) is more effective in restoring circulating levels of DHEA, DHEAS and downstream androgens.Methods and analysisA prospective, phase II, single-centre, cross-sectional, randomised study investigating Dehydroepiandrosterone supplementation and its profile in trauma, with a planned recruitment between April 2019 and July 2021, that will investigate DHEA supplementation and its effect on serum DHEA, DHEAS and downstream androgens in trauma. A maximum of 270 patients will receive sublingual or oral DHEA at 50, 100 or 200 mg daily over 3 days. Females aged ≥50 years with neck of femur fracture and male and female major trauma patients, aged 16–50 years with an injury severity score ≥16, will be recruited.Ethics and disseminationThis protocol was approved by the West Midlands – Coventry and Warwickshire Research Ethics Committee (Reference 18/WM/0102) on 8 June 2018. Results will be disseminated via peer-reviewed publications and presented at national and international conferences.Trial registrationThis trial is registered with the European Medicines Agency (EudraCT: 2016-004250-15) and ISRCTN (12961998). It has also been adopted on the National Institute of Health Research portfolio (CPMS ID:38158).Trial progressionThe study recruited its first patient on 2 April 2019 and held its first data monitoring committee on 8 November 2019. DHEA dosing has increased to 100 mg in both male cohorts and remains on 50 mg in across all female groups.
Objectives
To assess cabazitaxel versus docetaxel re‐challenge for the treatment of metastatic castrate refractory prostate cancer (CRPC) patients previously treated with docetaxel at inception of ...primary hormone therapy.
Patients and Methods
The CANTATA trial was a prospective, two‐arm, open‐label, phase II study conducted in eight UK centres. Patients over the age of 18, with histologically proven, metastatic prostate cancer who had been previously treated with up to 6 cycles of docetaxel as part of the STAMPEDE trial (or treated with the same drug outside of the trial at primary diagnosis) and had a performance status (PS) of 0–2, were eligible. Patients who progressed during primary treatment with docetaxel or had received prior systemic chemotherapy were excluded. Cabazitaxel (25 mg/m2) or docetaxel (75 mg/m2) was administered via intravenous infusion every 3 weeks with oral prednisolone (10 mg) for up to 10 cycles, until disease progression, death or unacceptable toxicity. The primary outcome was clinical progression‐free survival (PFS) as defined by either date of pain progression, date of a cancer‐related skeletal‐related event, or date of death from any cause. Analyses were by intention to treat. EudraCT number: 2012‐003835‐40
Results
Between 7 March 2013 and 4 January 2016, 15 patients with a median age of 70 years (range 54–76) were recruited; seven received cabazitaxel, eight docetaxel. The study was halted due to slow accrual. The median clinical PFS time in the cabazitaxel group was 6.2 months compared with 8.4 for the docetaxel group (95% confidence intervals were not reached due to the small number of patients). A total of 13 serious adverse events were reported.
Conclusion
Due to the low number of patients recruited, meaningful comparisons could not be made. However, toxicity was in line with known outcomes for these agents, demonstrating it is feasible and safe to deliver chemotherapy to men relapsing with CRPC after upfront chemotherapy.
Background
The treatment of traumatic haemorrhagic shock has been transformed through better haemorrhage control, use of tranexamic acid and use of blood products. The improved survival seen from ...these strategies has stimulated an interest in pre-hospital transfusion.
Objectives
To determine if the clinical effectiveness of resuscitation with red blood cells and lyophilised plasma was superior to 0.9% saline for improving tissue perfusion and reducing mortality in adults with haemorrhagic shock following major trauma.
Design
A multi-centre, allocation concealed, open-label, parallel group, randomised controlled trial (with internal pilot).
Setting
The trial was conducted in four civilian pre-hospital critical care services who operated within the National Health Service (NHS) England Major Trauma Networks.
Participants
Adults (aged ≥16 years) who had sustained traumatic injuries, were attended by a pre-hospital emergency medical team and were hypotensive (systolic blood pressure <90 mmHg or absence of radial pulse) as a consequence of traumatic haemorrhage were eligible for inclusion. The exclusion criteria were known or apparently <16 years, blood administered on scene prior to arrival of the RePHILL team, traumatic cardiac arrest where (1) the arrest occurred prior to arrival of the team and/or (2) the primary cause is not hypovolaemia, refusal of blood product administration, known Jehovah’s Witness, pregnancy, isolated head injury without evidence of external haemorrhage, prisoners in the custody of HM Prison and Probation Service.
Interventions
Participants were randomised to receive up to either two units each of red blood cells and lyophilised plasma or up to 1 L 0.9% saline. Treatment was administered through the intravenous or intraosseous route.
Main outcome measures
The primary outcome was a composite of episode mortality and/or impaired lactate clearance. The secondary outcomes included the individual components of the primary outcome.
Results
From 6 December 2016 to 2 January 2021, pre-hospital medical teams randomised 432 participants to red blood cell/lyophilised plasma (
n
= 209) or 0.9% saline (
n
= 223) out of a target sample size of 490. Most participants were white (62%), males (82%), median age 38 (interquartile range 26 to 58), involved in a road traffic collision (62%) with severe injuries (median injury severity score 36, interquartile range 25 to 50). Prior to randomisation participants had received on average 430 ml crystalloid fluids and tranexamic acid (90%). The primary outcome occurred in 128/199 (64.3%) of participants randomised to red blood cell/lyophilised plasma and 136/210 (64.8%) randomised to 0.9% saline adjusted risk difference –0.025% (95% confidence interval –9.0% to 9.0%),
p
= 0.996. The event rates for the individual components of the primary outcome, episode mortality and lactate clearance were not statistically different between groups adjusted average differences −3% (−12% to 7%);
p
= 0.57 and −5% (−14% to 5%),
p
= 0.33, respectively.
Limitations
Recruitment stopped prematurely due to disruption caused by the COVID-19 pandemic.
Future work
Identify the characteristics of patients who may benefit from pre-hospital blood products and whether alternative transfusion regimens are superior to standard care.
Conclusions
The trial did not demonstrate that pre-hospital red blood cell/lyophilised plasma resuscitation was superior to 0.9% saline for trauma-related haemorrhagic shock.
Trial registration
This trial is registered as ISRCTN62326938.
Funding
This award was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation Programme (NIHR award ref: 14/152/14) and is published in full in
Efficacy and Mechanism Evaluation
; Vol. 11, No. 2. See the NIHR Funding and Awards website for further award information.
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