Phenytoin enzyme induction for management of supratherapeutic tacrolimus levels due to drug-drug interaction with nirmatrelvir/ritonavir: Case series and discussion.

PURPOSE: Nirmatrelvir/ritonavir is one of few options for outpatient treatment of COVID-19, but its use has been limited in transplant recipients due to significant drug interactions with immunosuppressants. Tacrolimus toxicity is possible when the drug is coadministered with nirmatrelvir/ritonavir and may require urgent reduction of tacrolimus levels. This case series describes the use of phenytoin for enzyme induction in 5 adult solid organ transplant recipients with supratherapeutic tacrolimus levels resulting from coadministration with nirmatrelvir/ritonavir. SUMMARY: Solid organ transplant recipients are at high risk for complications related to COVID-19. Outpatient treatment options are limited, and therapeutic drug monitoring is complex in patients requiring quarantine. The 5 solid organ transplant recipients described herein were initiated on nirmatrelvir/ritonavir in the outpatient setting and subsequently presented with supratherapeutic tacrolimus concentrations greater than 59 ng/mL and developed signs and symptoms of tacrolimus toxicity. In all patients, nirmatrelvir/ritonavir and tacrolimus were discontinued, and oral phenytoin (200-400 mg/day) was given for 2 to 4 days. Tacrolimus was resumed once tacrolimus levels decreased to appropriate levels. CONCLUSION: These observations demonstrate that metabolism induction using phenytoin may be a useful strategy in the setting of supratherapeutic tacrolimus levels resulting from concomitant administration with nirmatrelvir/ritonavir.

In vivo mitochondria-targeted protection against uterine artery vascular dysfunction and remodelling in rodent hypoxic pregnancy.

Gestational hypoxia adversely affects uterine artery function, increasing complications. However, an effective therapy remains unidentified. Here, we show in rodent uterine arteries that hypoxic pregnancy promotes hypertrophic remodelling, increases constrictor reactivity via protein kinase C signalling, and triggers compensatory dilatation via nitric oxide-dependent mechanisms and stimulation of large conductance Ca2+ -activated K+ -channels. Maternal in vivo oral treatment with the mitochondria-targeted antioxidant MitoQ in hypoxic pregnancy normalises uterine artery reactivity and prevents vascular remodelling. From days 6-20 of gestation (term ∼22 days), female Wistar rats were randomly assigned to normoxic or hypoxic (13-14% O2 ) pregnancy ± daily maternal MitoQ treatment (500 µm in drinking water). At 20 days of gestation, maternal, placental and fetal tissue was frozen to determine MitoQ uptake. The uterine arteries were harvested and, in one segment, constrictor and dilator reactivity was determined by wire myography. Another segment was fixed for unbiased stereological analysis of vessel morphology. Maternal administration of MitoQ in both normoxic and hypoxic pregnancy crossed the placenta and was present in all tissues analysed. Hypoxia increased uterine artery constrictor responses to norepinephrine, angiotensin II and the protein kinase C activator, phorbol 12,13-dibutyrate. Hypoxia enhanced dilator reactivity to sodium nitroprusside, the large conductance Ca2+ -activated K+ -channel activator NS1619 and ACh via increased nitric oxide-dependent mechanisms. Uterine arteries from hypoxic pregnancy showed increased wall thickness and MitoQ treatment in hypoxic pregnancy prevented all effects on uterine artery reactivity and remodelling. The data support mitochondria-targeted therapy against adverse changes in uterine artery structure and function in high-risk pregnancy. KEY POINTS: Dysfunction and remodelling of the uterine artery are strongly implicated in many pregnancy complications, including advanced maternal age, maternal hypertension of pregnancy, maternal obesity, gestational diabetes and pregnancy at high altitude. Such complications not only have immediate adverse effects on the growth of the fetus, but also they can also increase the risk of cardiovascular disease in the mother and offspring. Despite this, there is a significant unmet clinical need for therapeutics that treat uterine artery vascular dysfunction in adverse pregnancy. Here, we show in a rodent model of gestational hypoxia that in vivo oral treatment of the mitochondria-targeted antioxidant MitoQ protects against uterine artery vascular dysfunction and remodelling, supporting the use of mitochondria-targeted therapy against adverse changes in uterine artery structure and function in high-risk pregnancy.

In vivo measurement of mitochondrial ROS production in mouse models of photoreceptor degeneration.

Retinitis pigmentosa (RP) is a disease characterised by photoreceptor cell death. It can be initiated by mutations in a number of different genes, primarily affecting rods, which will die first, resulting in loss of night vision. The secondary death of cones then leads to loss of visual acuity and blindness. We set out to investigate whether increased mitochondrial reactive oxygen species (ROS) formation, plays a role in this sequential photoreceptor degeneration. To do this we measured mitochondrial H2O2 production within mouse eyes in vivo using the mass spectrometric probe MitoB. We found higher levels of mitochondrial ROS that preceded photoreceptor loss in four mouse models of RP: Pde6brd1/rd1; Prhp2rds/rds; RPGR-/-; Cln6nclf. In contrast, there was no increase in mitochondrial ROS in loss of function models of vision loss (GNAT-/-, OGC), or where vision loss was not due to photoreceptor death (Cln3). Upregulation of Nrf2 transcriptional activity with dimethylfumarate (DMF) lowered mitochondrial ROS in RPGR-/- mice. These findings have important implications for the mechanism and treatment of RP.

Telerehabilitation for people with physical disabilities and movement impairment: development and evaluation of an online toolkit for practitioners and patients.

PURPOSE: Telerehabilitation has increasingly been used since the COVID-19 pandemic but with limited guidance available on undertaking physical assessments using remote methods. We aimed to provide such guidance by developing a Telerehab Toolkit, an online information and training resource for practitioners, patients, and carers on telerehabilitation for people with physical disabilities and movement impairment. MATERIALS AND METHODS: Development and evaluation of the toolkit were informed by the Knowledge to Action framework and took place iteratively in two phases-knowledge creation and action. Information was collated from various sources including literature review, online survey, service evaluation, and focus group discussions. The toolkit has been evaluated using think-aloud interviews, e-mail and social media feedback from users, and analytics data on user engagement with the website. RESULTS: The Telerehab Toolkit focuses on remote physical assessments, and contains information on technology, digital skills, remote assessment tools, information governance, and safety for telerehabilitation. Resources include top tips from practitioners and patients, how-to guides, checklists, videos, and links to evidence. CONCLUSIONS: The Telerehab Toolkit has been well-received by practitioners, healthcare students, patients, and carers, is being disseminated widely, and is freely available (www.plymouth.ac.uk/research/telerehab). IMPLICATIONS FOR REHABILITATIONTelerehabilitation has been increasingly used since the COVID-19 pandemic, but with limited guidance and training for practitioners on undertaking safe and effective remote physical assessments.The Telerehab Toolkit has been developed iteratively using the Knowledge to Action framework; it is a free online resource for practitioners and patients with specific guidance on telerehabilitation for physical disabilities and movement impairment.It is anticipated that the resource will help to improve the knowledge, skills, and confidence of the current and future rehabilitation workforce.

Rapid and selective generation of H2S within mitochondria protects against cardiac ischemia-reperfusion injury.

Mitochondria-targeted H2S donors are thought to protect against acute ischemia-reperfusion (IR) injury by releasing H2S that decreases oxidative damage. However, the rate of H2S release by current donors is too slow to be effective upon administration following reperfusion. To overcome this limitation here we develop a mitochondria-targeted agent, MitoPerSulf that very rapidly releases H2S within mitochondria. MitoPerSulf is quickly taken up by mitochondria, where it reacts with endogenous thiols to generate a persulfide intermediate that releases H2S. MitoPerSulf is acutely protective against cardiac IR injury in mice, due to the acute generation of H2S that inhibits respiration at cytochrome c oxidase thereby preventing mitochondrial superoxide production by lowering the membrane potential. Mitochondria-targeted agents that rapidly generate H2S are a new class of therapy for the acute treatment of IR injury.

Native chemical ligation approach to sensitively probe tissue acyl-CoA pools.

During metabolism, carboxylic acids are often activated by conjugation to the thiol of coenzyme A (CoA). The resulting acyl-CoAs comprise a group of ∼100 thioester-containing metabolites that could modify protein behavior through non-enzymatic N-acylation of lysine residues. However, the importance of many potential acyl modifications remains unclear because antibody-based methods to detect them are unavailable and the in vivo concentrations of their respective acyl-CoAs are poorly characterized. Here, we develop cysteine-triphenylphosphonium (CysTPP), a mass spectrometry probe that uses "native chemical ligation" to sensitively detect the major acyl-CoAs present in vivo through irreversible modification of its amine via a thioester intermediate. Using CysTPP, we show that longer-chain (C13-C22) acyl-CoAs often constitute ∼60% of the acyl-CoA pool in rat tissues. These hydrophobic longer-chain fatty acyl-CoAs have the potential to non-enzymatically modify protein residues.

Telerehabilitation for physical disabilities and movement impairment: A service evaluation in South West England.

RATIONALE, AIMS AND OBJECTIVES: Telerehabilitation was used to ensure continued provision of care during the COVID-19 pandemic, but there was a lack of guidance on how to use it safely and effectively for people with physical disabilities and movement impairment. In this service evaluation, we aimed to collate information on practitioner and patient experiences, challenges and facilitators, and examples of best practice to inform the development of an online toolkit and training package. METHODS: Guided discussions were carried out with 44 practitioners, 7 patients and 2 carers from five health and social care organisations in South West England, and analysed thematically. RESULTS: Practitioners and patients had positive experiences of telerehabilitation and were optimistic about its future use. Recognized benefits for people with physical disabilities included greater flexibility, reduced travel and fatigue, having appointments in a familiar environment and ease of involving family members. Challenges encountered were: technological (usability issues, access to technology and digital skills); difficulties seeing or hearing patients; the lack of 'hands-on' care; and safety concerns. Facilitators were supported by colleagues or digital champions, and family members or carers who could assist patients during their appointments. Key themes in best practice were: person-centred and tailored care; clear and open communication and observation and preparation and planning. Practitioners shared tips for remote physical assessments; for example, making use of patient-reported outcomes, and asking patients to wear bright and contrasting coloured clothing to make it easier to see movement. CONCLUSION: Telerehabilitation holds promise in health and social care, but it is necessary to share good practice to ensure it is safe, effective and accessible. We collated information and recommendations that informed the content of the Telerehab Toolkit (https://www.plymouth.ac.uk/research/telerehab), a practical resource for practitioners, patients and carers, with a focus on remote assessment and management of physical disabilities and movement impairment.

Functional standing frame programme early after severe sub-acute stroke (SPIRES): a randomised controlled feasibility trial.

BACKGROUND: Early mobilisation (> 24 h post-stroke) is recommended for people with stroke. However, there is a paucity of evidence about how to implement early mobilisation for people who have had a severe stroke. Prolonged standing and task-specific training (sit-to-stand repetitions) have separately been evaluated in the literature; however, these functionally linked tasks have not been evaluated in combination for people with severe sub-acute stroke. METHODS: The objective was to determine the feasibility of conducting a randomised controlled trial (RCT) of a functional standing frame programme compared with usual physiotherapy for people with severe sub-acute stroke. An assessor-blinded feasibility RCT with nested qualitative component (interviews and focus group) and process evaluation was adopted. Participants were aged ≥ 18 years with new diagnosis of severe sub-acute stroke (modified Rankin Scale (mRS) 4/5) from four Stroke Rehabilitation Units across South West England. Participants were randomised to receive either: (1) functional standing frame programme (30 min. standing plus sit-to-stand repetitions) plus 15 min of usual physiotherapy daily (intervention); (2) usual physiotherapy (45 min) daily (control). Both programmes were protocolised to be undertaken a minimum of five sessions per week for 3 weeks. Feasibility indicators included process, resource, management, and safety. Adherence, fidelity, and acceptability of the trial and intervention were evaluated using data recorded by therapists, observation of intervention and control sessions, interviews and one focus group. Patient measures of motor impairment, activities/participation, and quality of life were carried out by blinded assessors at baseline, 3, 15, 29, and 55 weeks post-randomisation. RESULTS: Forty-five participants (51-96 years; 42% male, mRS 4 = 80% 5 = 20%) were randomised (n = 22 to intervention). Twenty-seven (60%) participants were followed-up at all time points. Twelve participants (27%) died during the trial; no deaths were related to the trial. Adherence to the minimum number of sessions was low: none of the participants completed all 21 sessions, and only 8 participants (18%) across both groups completed ≥ 15 sessions, over the 3 weeks; 39% intervention; 51% control sessions were completed; mean session duration 39 min (SD 19) control, 37 min intervention (SD 11). Intervention group: mean standing time 13 min (SD 9); mean sit-to-stand repetitions/session 5 (SD 4). Interviews were conducted with 10 participants, four relatives and six physiotherapists. Five physiotherapists attended a focus group. CONCLUSIONS: The majority of progression criteria for this feasibility trial were met. However, adherence to the interventions was unacceptably low. This aspect of the trial design needs to be addressed prior to moving to a definitive RCT of this standing frame intervention in people with severe sub-acute stroke. Solutions have been identified to address these concerns. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number ISRCTN15412695 . Registration 19 December 2016.

Telerehabilitation for People With Physical Disabilities and Movement Impairment: A Survey of United Kingdom Practitioners.

BACKGROUND: Telerehabilitation is a feasible and potentially effective alternative to face-to-face rehabilitation. However, specific guidance, training, and support for practitioners who undertake remote assessments in people with physical disabilities and movement impairment are limited. OBJECTIVE: The aims of this survey of United Kingdom-based health and social care practitioners were to explore experiences, assess training needs, and collate ideas on best practices in telerehabilitation for physical disabilities and movement impairment. The aim will be to use the findings to inform a practical tool kit and training package for telerehabilitation use. METHODS: UK rehabilitation practitioners were invited to complete an online questionnaire from November to December 2020. Opportunity and snowball sampling were used to recruit participants from professional and educational networks, special interest groups, and via social media. Closed questionnaire items were analyzed using descriptive statistics. Qualitative inductive analysis using NVivo was used for open responses. RESULTS: There were 247 respondents, of which 177 (72%) were physiotherapists and occupational therapists. Most (n=207, 84%) had used video-based consultations (typically supported by telephone and email), and the use of this method had increased in frequency since the COVID-19 pandemic. Practitioners perceived telerehabilitation positively overall and recognized benefits for patients including a reduced infection risk, convenience and flexibility, and reduced travel and fatigue. Common obstacles were technology related (eg, internet connection), practical (eg, difficulty positioning the camera), patient related (eg, health status), practitioner related (eg, lack of technical skills), and organizational (eg, lack of access to technology). Support from family members or carers was a major facilitator for successful remote consultations. Of the 207 respondents who had used video-based consultations, 103 (50%) had assessed physical impairments using this method, 107 (52%) had assessed physical function, and 121 (59%) had used patient-reported outcome measures. Although practitioners generally felt confident in delivering video-based consultations, they felt less proficient in undertaking remote physical assessments, expressing concerns about validity, reliability, and safety. Only 46 of the 247 (19%) respondents had received any training in telerehabilitation or video consultations, and some felt they were "feeling their way in the dark." Practitioners desired training and guidance on physical assessment tools suitable for remote use, when to use video-based consultations or alternative methods, governance issues, digital platforms, and signposting to digital skills training for themselves and their patients. CONCLUSIONS: In response to the COVID-19 pandemic, practitioners rapidly adopted telerehabilitation for people with physical disabilities and movement impairment. However, there are technical, practical, and organizational obstacles to overcome, and a clear need for improved guidance and training in remote physical assessments. The findings of this survey will inform the development of a tool kit of resources and a training package for the current and future workforce in telerehabilitation.

Ester Prodrugs of Malonate with Enhanced Intracellular Delivery Protect Against Cardiac Ischemia-Reperfusion Injury In Vivo.

PURPOSE: Mitochondrial reactive oxygen species (ROS) production upon reperfusion of ischemic tissue initiates the ischemia/reperfusion (I/R) injury associated with heart attack. During ischemia, succinate accumulates and its oxidation upon reperfusion by succinate dehydrogenase (SDH) drives ROS production. Inhibition of succinate accumulation and/or oxidation by dimethyl malonate (DMM), a cell permeable prodrug of the SDH inhibitor malonate, can decrease I/R injury. However, DMM is hydrolysed slowly, requiring administration to the heart prior to ischemia, precluding its administration to patients at the point of reperfusion, for example at the same time as unblocking a coronary artery following a heart attack. To accelerate malonate delivery, here we developed more rapidly hydrolysable malonate esters. METHODS: We synthesised a series of malonate esters and assessed their uptake and hydrolysis by isolated mitochondria, C2C12 cells and in mice in vivo. In addition, we assessed protection against cardiac I/R injury by the esters using an in vivo mouse model of acute myocardial infarction. RESULTS: We found that the diacetoxymethyl malonate diester (MAM) most rapidly delivered large amounts of malonate to cells in vivo. Furthermore, MAM could inhibit mitochondrial ROS production from succinate oxidation and was protective against I/R injury in vivo when added at reperfusion. CONCLUSIONS: The rapidly hydrolysed malonate prodrug MAM can protect against cardiac I/R injury in a clinically relevant mouse model.

Scope, context and quality of telerehabilitation guidelines for physical disabilities: a scoping review.

OBJECTIVE: To identify the available guidance and training to implement telerehabilitation movement assessments for people (adults and children) with a physical disability, including those recovering from COVID-19. DESIGN: Rapid scoping review. INCLUDED SOURCES AND ARTICLES: PubMed, CINAHL, PsychInfo, Cochrane, Embase, Web of Science, PEDro, UK Health Forum, WHO, National Archives and NHS England were searched using the participant-concept-context framework from 2015 to August 2020. Primary studies that recruited individuals with physical disabilities and guidance documents aimed at providers to implement movement-related telerehabilitation were included. RESULTS: 23 articles (11 primary research studies, 3 systematic reviews and 9 guidance documents) were included out of 7857 that were identified from the literature search. Two main issues were found: (1) telerehabilitation guidance (from both research studies and guidance documents) was not specific to movement-related assessment and (2) most primary research studies provided neither guidance nor training of movement-specific assessment to practitioners. Of the COVID-19 related guidance, two articles reported COVID-19 management that only referred to identifying COVID-19 status without references to specific movement-related guidance. CONCLUSIONS: Telerehabilitation guidance and training have existed pre-COVID-19, yet the lack of specific movement-related information and provider support is surprising. This gap must be addressed to optimise effective implementation of remote assessments for those with physical disabilities. REVIEW REGISTRATION: Open Science Framework: osf.io/vm6sp.

Outcomes of hepatitis C virus nucleic acid testing positive donors in aviremic recipients with delayed direct-acting antiviral initiation.

The use of allografts from hepatitis C virus (HCV) Nucleic Acid Testing (NAT)+ donors into HCV NAT- recipients has been reported to be efficacious in a handful of studies. However, these studies have not reflected real-world practice where the initiation of direct-acting antivirals (DAA) is dependent on insurance coverage. A single-center, retrospective chart review of HCV NAT- recipients who underwent solid organ transplantation (SOT) from a HCV NAT+ donor between April 1, 2019 and May 27, 2020 was conducted. Sixty-one HCV NAT- patients underwent SOT with a HCV NAT+ organ, with 59 transplant recipients included for evaluation: 22 kidney (KT), 18 liver (LiT), 10 heart (HT), nine lung (LuT). HCV transmission occurred in 100% of recipients. Average time to DAA initiation was POD 46.3 ± 25 days. SVR12 was achieved in 98% (56/57; two patients ineligible for analysis). Treatment failure occurred in one LuT on glecaprevir/pibrentasvir with P32del and Q80K mutations. No patients developed fibrosing cholestatic hepatitis. Two patients died, secondary to anastomotic complication (LuT) and pulmonary embolism (HT). Clinically significant rejection was diagnosed and treated in two HT (one patient with ACR2 and one with ACR2/pAMR2) and one LiT (RAI 5/9). Six patients (10.2%) had documented adverse effects attributed to DAA therapy, primarily gastrointestinal.

Mitochondria antioxidant protection against cardiovascular dysfunction programmed by early-onset gestational hypoxia.

Mitochondria-derived oxidative stress during fetal development increases cardiovascular risk in adult offspring of pregnancies complicated by chronic fetal hypoxia. We investigated the efficacy of the mitochondria-targeted antioxidant MitoQ in preventing cardiovascular dysfunction in adult rat offspring exposed to gestational hypoxia, integrating functional experiments in vivo, with those at the isolated organ and molecular levels. Rats were randomized to normoxic or hypoxic (13%-14% O2 ) pregnancy ± MitoQ (500 µM day-1 ) in the maternal drinking water. At 4 months of age, one cohort of male offspring was chronically instrumented with vascular catheters and flow probes to test in vivo cardiovascular function. In a second cohort, the heart was isolated and mounted onto a Langendorff preparation. To establish mechanisms linking gestational hypoxia with cardiovascular dysfunction and protection by MitoQ, we quantified the expression of antioxidant system, ß-adrenergic signaling, and calcium handling genes in the fetus and adult, in frozen tissues from a third cohort. Maternal MitoQ in hypoxic pregnancy protected offspring against increased α1 -adrenergic reactivity of the cardiovascular system, enhanced reactive hyperemia in peripheral vascular beds, and sympathetic dominance, hypercontractility and diastolic dysfunction in the heart. Inhibition of Nfe2l2-mediated oxidative stress in the fetal heart and preservation of calcium regulatory responses in the hearts of fetal and adult offspring link molecular mechanisms to the protective actions of MitoQ treatment of hypoxic pregnancy. Therefore, these data show the efficacy of MitoQ in buffering mitochondrial stress through NADPH-induced oxidative damage and the prevention of programmed cardiovascular disease in adult offspring of hypoxic pregnancy.

Technologies to Support Assessment of Movement During Video Consultations: Exploratory Study.

BACKGROUND: Understanding and assessing patients' body movements is essential for physical rehabilitation but is challenging in video consultations, as clinicians are frequently unable to see the whole patient or observe the patient as they perform specific movements. OBJECTIVE: The objective of this exploratory study was to assess the use of readily available technologies that would enable remote assessment of patient movement as part of a video consultation. METHODS: We reviewed the literature and available technologies and chose four technologies (Kubi and Pivo desktop robots, Facebook Portal TV, wide-angle webcam), in addition to help from a friend or a simple mobile phone holder, to assist video consultations. We used 5 standard assessments (sit-to-stand, timed "Up & Go," Berg Balance Test, ankle range of motion, shoulder range of motion) as the "challenge" for the technology. We developed an evaluation framework of 6 items: efficacy, cost, delivery, patient setup, clinician training and guidance, and safety. The coauthors, including 10 physiotherapists, then took the roles of clinician and patient to explore 7 combinations of 5 technologies. Subsequently, we applied our findings to hypothetical patients based on the researchers' family members and clinical experience. RESULTS: Kubi, which allowed the clinician to remotely control the patient's device, was useful for repositioning the tablet camera to gain a better view of the patient's body parts but not for tracking movement. Facebook Portal TV was useful, but only for upper body movement, as it functions based on face tracking. Both Pivo, with automated full body tracking using a mobile phone, and the wide-angle webcam for a laptop or desktop computer show promise. Simple solutions such as having a friend operate a mobile phone and use of a mobile phone holder also have potential. The setup of these technologies will require better instructions than are currently available from suppliers, and successful use will depend on the technology readiness of patients and, to some degree, of clinicians. CONCLUSIONS: Technologies that may enable clinicians to assess movement remotely as part of video consultations depend on the interplay of technology readiness, the patient's clinical conditions, and social support. The most promising off-the-shelf approaches seem to be use of wide-angle webcams, Pivo, help from a friend, or a simple mobile phone holder. Collaborative work between patients and clinicians is needed to develop and trial technological solutions to support video consultations assessing movement.

Early detection of doxorubicin-induced cardiotoxicity in rats by its cardiac metabolic signature assessed with hyperpolarized MRI.

Doxorubicin (DOX) is a widely used chemotherapeutic agent that can cause serious cardiotoxic side effects culminating in congestive heart failure (HF). There are currently no clinical imaging techniques or biomarkers available to detect DOX-cardiotoxicity before functional decline. Mitochondrial dysfunction is thought to be a key factor driving functional decline, though real-time metabolic fluxes have never been assessed in DOX-cardiotoxicity. Hyperpolarized magnetic resonance imaging (MRI) can assess real-time metabolic fluxes in vivo. Here we show that cardiac functional decline in a clinically relevant rat-model of DOX-HF is preceded by a change in oxidative mitochondrial carbohydrate metabolism, measured by hyperpolarized MRI. The decreased metabolic fluxes were predominantly due to mitochondrial loss and additional mitochondrial dysfunction, and not, as widely assumed hitherto, to oxidative stress. Since hyperpolarized MRI has been successfully translated into clinical trials this opens up the potential to test cancer patients receiving DOX for early signs of cardiotoxicity.

Confirmation of the Cardioprotective Effect of MitoGamide in the Diabetic Heart.

PURPOSE: HFpEF (heart failure with preserved ejection fraction) is a major consequence of diabetic cardiomyopathy with no effective treatments. Here, we have characterized Akita mice as a preclinical model of HFpEF and used it to confirm the therapeutic efficacy of the mitochondria-targeted dicarbonyl scavenger, MitoGamide. METHODS AND RESULTS: A longitudinal echocardiographic analysis confirmed that Akita mice develop diastolic dysfunction with reduced E peak velocity, E/A ratio and extended isovolumetric relaxation time (IVRT), while the systolic function remains comparable with wild-type mice. The myocardium of Akita mice had a decreased ATP/ADP ratio, elevated mitochondrial oxidative stress and increased organelle density, compared with that of wild-type mice. MitoGamide, a mitochondria-targeted 1,2-dicarbonyl scavenger, exhibited good stability in vivo, uptake into cells and mitochondria and reactivity with dicarbonyls. Treatment of Akita mice with MitoGamide for 12 weeks significantly improved the E/A ratio compared with the vehicle-treated group. CONCLUSION: Our work confirms that the Akita mouse model of diabetes replicates key clinical features of diabetic HFpEF, including cardiac and mitochondrial dysfunction. Furthermore, in this independent study, MitoGamide treatment improved diastolic function in Akita mice.

Targeting succinate dehydrogenase with malonate ester prodrugs decreases renal ischemia reperfusion injury.

Renal ischemia reperfusion (IR) injury leads to significant patient morbidity and mortality, and its amelioration is an urgent unmet clinical need. Succinate accumulates during ischemia and its oxidation by the mitochondrial enzyme succinate dehydrogenase (SDH) drives the ROS production that underlies IR injury. Consequently, compounds that inhibit SDH may have therapeutic potential against renal IR injury. Among these, the competitive SDH inhibitor malonate, administered as a cell-permeable malonate ester prodrug, has shown promise in models of cardiac IR injury, but the efficacy of malonate ester prodrugs against renal IR injury have not been investigated. Here we show that succinate accumulates during ischemia in mouse, pig and human models of renal IR injury, and that its rapid oxidation by SDH upon reperfusion drives IR injury. We then show that the malonate ester prodrug, dimethyl malonate (DMM), can ameliorate renal IR injury when administered at reperfusion but not prior to ischemia in the mouse. Finally, we show that another malonate ester prodrug, diacetoxymethyl malonate (MAM), is more potent than DMM because of its faster esterase hydrolysis. Our data show that the mitochondrial mechanisms of renal IR injury are conserved in the mouse, pig and human and that inhibition of SDH by 'tuned' malonate ester prodrugs, such as MAM, is a promising therapeutic strategy in the treatment of clinical renal IR injury.

Effectiveness of non-pharmacological interventions to treat orthostatic hypotension in elderly people and people with a neurological condition: a systematic review.

OBJECTIVE: The objective of this review was to summarize the best available evidence regarding the effectiveness of non-pharmacological interventions to treat orthostatic hypotension (OH) in elderly people and people with a neurological condition. INTRODUCTION: Orthostatic hypotension is common in elderly people and people with a neurological condition and can interfere with or limit rehabilitation. Non-pharmacological interventions to treat OH could allow for longer and earlier mobilization, which is recommended in national clinical guidelines for rehabilitation in the acute or sub-acute phase following stroke or other neurological conditions. INCLUSION CRITERIA: The review considered people aged 50 years and older, and people aged 18 years and elderly people with a neurological condition. Non-pharmacological interventions to treat OH included compression garments, neuromuscular stimulation, physical counter-maneuvers, aerobic or resistance exercises, sleeping with head tilted up, increasing fluid and salt intake, and timing and size of meals. The comparator was usual care, no intervention, pharmacological interventions, or other non-pharmacological interventions. Outcome measures included systolic blood pressure, diastolic blood pressure, heart rate, cerebral blood flow, observed/perceived symptoms, duration of standing or sitting in minutes, tolerance of therapy, functional ability, and adverse events/effects. METHODS: Databases for published and unpublished studies available in English up to April 2018 with no lower date limit were searched. Critical appraisal was conducted using standardized instruments from JBI. Data were extracted using standardized tools designed for quantitative studies. Where appropriate, studies were included in a meta-analysis; otherwise, data were presented in a narrative form due to heterogeneity. RESULTS: Forty-three studies - a combination of randomized controlled trials (n = 13), quasi-experimental studies (n = 28), a case control study (n = 1), and a case report (n = 1) - with 1069 participants were included. Meta-analyses of three interventions (resistance exercise, electrical stimulation, and lower limb compression bandaging) showed no significant effect of these interventions. Results from individual studies indicated physical maneuvers such as leg crossing, leg muscle pumping/contractions, and bending forward improved orthostatic hypotension. Abdominal compression improved OH. Sleeping with head up in combination with pharmacological treatment was more effective than sleeping with head up alone. Eating smaller, more frequent meals was effective. Drinking 480 mL of water increased blood pressure. CONCLUSIONS: The review found mixed results for the effectiveness of non-pharmacological interventions to treat OH in people aged 50 years and older, and people with a neurological condition. There are several non-pharmacological interventions that may be effective in treating OH, but not all have resulted in clinically meaningful changes in outcome. Some may not be suitable for people with moderate to severe disability; therefore, it is important for clinicians to consider the patient's abilities and impairments when considering which non-pharmacological interventions to implement.

Isolating adverse effects of glucocorticoids on the embryonic cardiovascular system.

Antenatal glucocorticoid therapy reduces mortality in the preterm infant, but evidence suggests off-target adverse effects on the developing cardiovascular system. Whether deleterious effects are direct on the offspring or secondary to alterations in uteroplacental physiology is unclear. Here, we isolated direct effects of glucocorticoids using the chicken embryo, a model system in which the effects on the developing heart and circulation of therapy can be investigated, independent of effects on the mother and/or the placenta. Fertilized chicken eggs were incubated and divided randomly into control (C) or dexamethasone (Dex) treatment at day 14 out of the 21-day incubation period. Combining functional experiments at the isolated organ, cellular and molecular levels, embryos were then studied close to term. Chicken embryos exposed to dexamethasone were growth restricted and showed systolic and diastolic dysfunction, with an increase in cardiomyocyte volume but decreased cardiomyocyte nuclear density in the left ventricle. Underlying mechanisms included a premature switch from tissue accretion to differentiation, increased oxidative stress, and activated signaling of cellular senescence. These findings, therefore, demonstrate that dexamethasone treatment can have direct detrimental off-target effects on the cardiovascular system in the developing embryo, which are independent of effects on the mother and/or placenta.

A sensitive mass spectrometric assay for mitochondrial CoQ pool redox state in vivo.

Coenzyme Q (CoQ) is an essential cofactor, primarily found in the mitochondrial inner membrane where it functions as an electron carrier in the respiratory chain, and as a lipophilic antioxidant. The redox state of the CoQ pool is the ratio of its oxidised (ubiquinone) and reduced (ubiquinol) forms, and is a key indicator of mitochondrial bioenergetic and antioxidant status. However, the role of CoQ redox state in vivo is poorly understood, because determining its value is technically challenging due to redox changes during isolation, extraction and analysis. To address these problems, we have developed a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay that enables us to extract and analyse both the CoQ redox state and the magnitude of the CoQ pool with negligible changes to redox state from small amounts of tissue. This will enable the physiological and pathophysiological roles of the CoQ redox state to be investigated in vivo.