Metabolic mitochondrial alterations prevail in the female rat heart 8 weeks after exercise cessation.

BACKGROUND: The consumption of high-caloric diets strongly contributes to the development of non-communicable diseases (NCDs), including cardiovascular disease, the leading cause of mortality worldwide. Exercise (along with diet intervention) is one of the primary non-pharmacological approaches to promote a healthier lifestyle and counteract the rampant prevalence of NCDs. The present study evaluated the effects of exercise cessation after a short period training on the cardiac metabolic and mitochondrial function of female rats. METHODS: Seven-week-old female Sprague-Dawley rats were fed a control or a high-fat, high-sugar (HFHS) diet and, after 7 weeks, the animals were kept on a sedentary lifestyle or submitted to endurance exercise for 3 weeks (6 days per week, 20-60 min/day). The cardiac samples were analysed 8 weeks after exercise cessation. RESULTS: The consumption of the HFHS diet triggered impaired glucose tolerance, whereas the HFHS diet and physical exercise resulted in different responses in plasma adiponectin and leptin levels. Cardiac mitochondrial respiration efficiency was decreased by the HFHS diet consumption, which led to reduced ATP and increased NAD(P)H mitochondrial levels, which remained prevented by exercise 8 weeks after cessation. Exercise training-induced cardiac adaptations in redox balance, namely increased relative expression of Nrf2 and downstream antioxidant enzymes persist after an eight-week exercise cessation period. CONCLUSIONS: Endurance exercise modulated cardiac redox balance and mitochondrial efficiency in female rats fed a HFHS diet. These findings suggest that exercise may elicit cardiac adaptations crucial for its role as a non-pharmacological intervention for individuals at risk of developing NCDs.

Sex-dependent vulnerability of fetal nonhuman primate cardiac mitochondria to moderate maternal nutrient reduction.

Poor maternal nutrition in pregnancy affects fetal development, predisposing offspring to cardiometabolic diseases. The role of mitochondria during fetal development on later-life cardiac dysfunction caused by maternal nutrient reduction (MNR) remains unexplored. We hypothesized that MNR during gestation causes fetal cardiac bioenergetic deficits, compromising cardiac mitochondrial metabolism and reserve capacity. To enable human translation, we developed a primate baboon model (Papio spp.) of moderate MNR in which mothers receive 70% of control nutrition during pregnancy, resulting in intrauterine growth restriction (IUGR) offspring and later exhibiting myocardial remodeling and heart failure at human equivalent ∼25 years. Term control and MNR baboon offspring were necropsied following cesarean-section, and left ventricle (LV) samples were collected. MNR adversely impacted fetal cardiac LV mitochondria in a sex-dependent fashion. Increased maternal plasma aspartate aminotransferase, creatine phosphokinase (CPK), and elevated cortisol levels in MNR concomitant with decreased blood insulin in male fetal MNR were measured. MNR resulted in a two-fold increase in fetal LV mitochondrial DNA (mtDNA). MNR resulted in increased transcripts for several respiratory chain (NDUFB8, UQCRC1, and cytochrome c) and adenosine triphosphate (ATP) synthase proteins. However, MNR fetal LV mitochondrial complex I and complex II/III activities were significantly decreased, possibly contributing to the 73% decreased ATP content and increased lipid peroxidation. MNR fetal LV showed mitochondria with sparse and disarranged cristae dysmorphology. Conclusion: MNR disruption of fetal cardiac mitochondrial fitness likely contributes to the documented developmental programming of adult cardiac dysfunction, indicating a programmed mitochondrial inability to deliver sufficient energy to cardiac tissues as a chronic mechanism for later-life heart failure.

Radiotherapy for metastatic spinal cord compression with increased radiation doses (RAMSES-01): a prospective multicenter study.

BACKGROUND: Patients with metastatic spinal cord compression (MSCC) and favorable survival prognoses can benefit from radiation doses greater than 30Gy in 10 fractions in terms of improved local progression-free survival (LPFS) and overall survival (OS). METHODS/DESIGN: This prospective study mainly investigates LPFS after precision radiotherapy (volumetric modulated arc therapy or stereotactic body radiotherapy) with 18 × 2.33Gy in 3.5 weeks. LPFS is defined as freedom from progression of motor deficits during radiotherapy and an in-field recurrence of MSCC following radiotherapy. The maximum relative dose allowed to the spinal cord is 101.5% of the prescribed dose, resulting in an equivalent dose in 2Gy-fractions (EQD2) for radiation myelopathy is 45.5Gy, which is below the tolerance dose of 50Gy according to the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC). The EQD2 of this regimen for tumor cell kill is 43.1Gy, which is 33% higher than for 30Gy in 10 fractions (EQD2 = 32.5Gy). Primary endpoint is LPFS at 12 months after radiotherapy. Secondary endpoints include the effect of 18 × 2.33Gy on motor function, ambulatory status, sensory function, sphincter dysfunction, LPFS at other follow-up times, overall survival, pain relief, relief of distress and toxicity. Follow-up visits for all endpoints will be performed directly and at 1, 3, 6, 9 and 12 months after radiotherapy. A total of 65 patients are required for the prospective part of the study. These patients will be compared to a historical control group of at least 235 patients receiving conventional radiotherapy with 10x3Gy in 2 weeks. DISCUSSION: If precision radiotherapy with 18 × 2.33Gy results in significantly better LPFS than 10x3Gy of conventional radiotherapy, this regimen should be strongly considered for patients with MSCC and favorable survival prognoses. TRIAL REGISTRATION: Clinicaltrials.gov NCT04043156. Registered 30-07-2019.

High-precision radiotherapy of motor deficits due to metastatic spinal cord compression (PRE-MODE): a multicenter phase 2 study.

BACKGROUND: For metastatic spinal cord compression (MSCC), conventional radiotherapy with 10 × 3 Gy in 2 weeks results in better local progression-free survival (LPFS) than 5 × 4 Gy in 1 week. Since patients with MSCC are often significantly impaired, an overall treatment time of 1 week would be preferable if resulting in similar outcomes as longer programs. This may be achieved with 5 × 5 Gy in 1 week, since the biologically effective dose is similar to 10 × 3 Gy. It can be expected that 5 × 5 Gy (like 10 × 3) Gy results in better LPFS than 5 × 4 Gy in 1 week. METHODS/DESIGN: This phase 2 study investigates LPFS after high-precision RT with 5 × 5 Gy in 1 week. LPFS is defined as freedom from both progression of motor deficits during RT and new or progressive motor deficits dur to an in-field recurrence of MSCC following RT. Considering the tolerance dose of the spinal cord, 5 × 5 Gy can be safely administered with high-precision radiotherapy such as volumetric modulated arc therapy (VMAT) or stereotactic body radiotherapy (SBRT). Maximum dose to the spinal cord should not exceed 101.5% of the prescribed dose to keep the risk of radiation myelopathy below 0.03%. Primary endpoint is LPFS at 6 months following radiotherapy; secondary endpoints include motor function/ability to walk, sensory function, sphincter dysfunction, LPFS directly and 1 and 3 months following radiotherapy, overall survival, pain relief, quality of life and toxicity. Follow-up visits will be performed directly and at 1, 3 and 6 months following radiotherapy. After completion of this phase 2 study, patients will be compared to a historical control group receiving conventional radiotherapy with 5 × 4 Gy in 1 week. Forty-four patients will be included assuming 5 × 5 Gy will provide the same benefit in LPFS when compared to 5 × 4 Gy as reported for 10 × 3 Gy. DISCUSSION: If superiority regarding LPFS is shown for high-precision radiotherapy with 5 × 5 Gy when compared to conventional radiotherapy with 5 × 4 Gy, patients with MSCC would benefit from 5 × 5 Gy, since high LPFS rates could be achieved with 1 week of radiotherapy instead of 2 weeks (10 × 3 Gy). TRIAL REGISTRATION: clinicaltrials.gov NCT03070431 . Registered 27 February 2017.

Quaternary ammonium surfactant structure determines selective toxicity towards bacteria: mechanisms of action and clinical implications in antibacterial prophylaxis.

OBJECTIVES: Broad-spectrum antimicrobial activity of quaternary ammonium surfactants (QAS) makes them attractive and cheap topical prophylactic options for sexually transmitted infections and perinatal vertically transmitted urogenital infections. Although attributed to their high affinity for biological membranes, the mechanisms behind QAS microbicidal activity are not fully understood. We evaluated how QAS structure affects antimicrobial activity and whether this can be exploited for use in prophylaxis of bacterial infections. METHODS: Acute toxicity of QAS to in vitro models of human epithelial cells and bacteria were compared to identify selective and potent bactericidal agents. Bacterial cell viability, membrane integrity, cell cycle and metabolism were evaluated to establish the mechanisms involved in selective toxicity of QAS. RESULTS: QAS toxicity normalized relative to surfactant critical micelle concentration showed n-dodecylpyridinium bromide (C12PB) to be the most effective, with a therapeutic index of ∼10 for an MDR strain of Escherichia coli and >20 for Neisseria gonorrhoeae after 1 h of exposure. Three modes of QAS antibacterial action were identified: impairment of bacterial energetics and cell division at low concentrations; membrane permeabilization and electron transport inhibition at intermediate doses; and disruption of bacterial membranes and cell lysis at concentrations close to the critical micelle concentration. In contrast, toxicity to mammalian cells occurs at higher concentrations and, as we previously reported, results primarily from mitochondrial dysfunction and apoptotic cell death. CONCLUSIONS: Our data show that short chain (C12) n-alkyl pyridinium bromides have a sufficiently large therapeutic window to be good microbicide candidates.

Excellent outcomes after radiotherapy alone for malignant spinal cord compression from myeloma.

BACKGROUND: Uncertainty exists whether patients with spinal cord compression (SCC) from a highly radiosensitive tumor require decompressive spinal surgery in addition to radiotherapy (RT). This study addressed the question by evaluating patients receiving RT alone for SCC from myeloma. PATIENTS AND METHODS: Data of 238 patients were retrospectively analyzed for response to RT and local control of SCC. In addition, the effect of RT on motor function (improvement, no further progression, deterioration) was evaluated. Overall response was defined as improvement or no further progression of motor dysfunction. Prior to RT, patients were presented to a neurosurgeon for evaluation whether upfront decompressive surgery was indicated (e.g. vertebral fracture or unstable spine). RESULTS: In the entire cohort, the overall response rate was 97% (53% improvement plus 44% no further progression). Following RT, 88% of the patients were able to walk. Of the 69 non-ambulatory patients 44 patients (64%) regained the ability to walk. Local control rates at 1, 2 and 3 years were 93%, 82% and 82%, respectively. A trend towards better local control was observed for patients who were ambulatory before starting RT (p = 0.08) and those with a more favorable performance status (p = 0.07). CONCLUSIONS: RT alone provided excellent response rates, functional outcomes and local control in patients with SCC from myeloma. These results should be confirmed in a prospective randomized trial.

Effects of moderate global maternal nutrient reduction on fetal baboon renal mitochondrial gene expression at 0.9 gestation.

Early life malnutrition results in structural alterations in the kidney, predisposing offspring to later life renal dysfunction. Kidneys of adults who were growth restricted at birth have substantial variations in nephron endowment. Animal models have indicated renal structural and functional consequences in offspring exposed to suboptimal intrauterine nutrition. Mitochondrial bioenergetics play a key role in renal energy metabolism, growth, and function. We hypothesized that moderate maternal nutrient reduction (MNR) would adversely impact fetal renal mitochondrial expression in a well-established nonhuman primate model that produces intrauterine growth reduction at term. Female baboons were fed normal chow diet or 70% of control diet (MNR). Fetal kidneys were harvested at cesarean section at 0.9 gestation (165 days gestation). Human Mitochondrial Energy Metabolism and Human Mitochondria Pathway PCR Arrays were used to analyze mitochondrially relevant mRNA expression. In situ protein content was detected by immunohistochemistry. Despite the smaller overall size, the fetal kidney weight-to-body weight ratio was not affected. We demonstrated fetal sex-specific differential mRNA expression encoding mitochondrial metabolite transport and dynamics proteins. MNR-related differential gene expression was more evident in female fetuses, with 16 transcripts significantly altered, including 14 downregulated and 2 upregulated transcripts. MNR impacted 10 transcripts in male fetuses, with 7 downregulated and 3 upregulated transcripts. The alteration in mRNA levels was accompanied by a decrease in mitochondrial protein cytochrome c oxidase subunit VIc. In conclusion, transcripts encoding fetal renal mitochondrial energy metabolism proteins are nutrition sensitive in a sex-dependent manner. We speculate that these differences lead to decreased mitochondrial fitness that contributes to renal dysfunction in later life.

Doxorubicin-induced cardiotoxicity: from bioenergetic failure and cell death to cardiomyopathy.

Doxorubicin (DOX) is an anticancer anthracycline that presents a dose-dependent and cumulative cardiotoxicity as one of the most serious side effects. Several hypotheses have been advanced to explain DOX cardiac side effects, which culminate in the development of life-threatening cardiomyopathy. One of the most studied mechanisms involves the activation of DOX molecule into a more reactive semiquinone by mitochondrial Complex I, resulting in increased oxidative stress. The present review describes and critically discusses what is known about some of the potential mechanisms of DOX-induced cardiotoxicity including mitochondrial oxidative damage and loss of cardiomyocytes. We also discuss alterations of mitochondrial metabolism and the unique characteristics of DOX delayed toxicity, which can also interfere on how the cardiac muscle handles a "second-hit stress." We also present pharmaceutical and nonpharmaceutical approaches that may decrease DOX cardiac alterations in animal models and humans and discuss the limitations of each strategy.

Exercise mitigates diclofenac-induced liver mitochondrial dysfunction.

BACKGROUND: Several strategies have been developed to counteract liver injury as a consequence of nonsteroid anti-inflammatory drugs toxicity. Here, we aimed to determine whether physical exercise results in liver mitochondrial protection against in vitro diclofenac toxicity. MATERIAL AND METHODS: Male adult Sprague-Dawley rats were divided into sedentary, 12-week endurance training (ET) and voluntary activity (VPA). In vitro liver mitochondrial function as assessed by oxygen consumption, transmembrane electric potential (ΔΨ) and susceptibility to the mitochondrial permeability transition pore (MPTP) was evaluated in the absence and presence of diclofenac. Mitochondrial oxidative stress markers [MnSOD, aconitase, -SH and MDA, SIRT3, p66shc(Ser36)/p66shc ratio] and apoptotic signalling (caspases 3, 8 and 9, Bax, Bcl-2 and CypD) were assessed. Content of OXPHOS components and qualitative liver morphological evaluation were assessed. RESULTS: Despite no effects of ET and VPA on basal liver mitochondrial oxygen consumption or ΔΨ endpoints, exercised animals showed lower susceptibility to MPTP. Diclofenac-induced decrease in ΔΨ, increased state 4 respiration and susceptibility to MPTP opening were all prevented by exercise. Under untreated conditions, VPA group showed higher aconitase activity, while ET decreased MDA and increased Bax content. VPA decreased p66shc(Ser36), complex III and V OXPHOS subunits. Both ET and VPA increased complex IV OXPHOS subunit, and SIRT3 and Bcl-2 content and decreased caspase 9 activity. Unexpectedly, ET and VPA decreased ANT. CONCLUSIONS: Both chronic physical exercise models augmented the resistance to in vitro diclofenac-induced mitochondrial alterations, including increased MPTP susceptibility, possibly by modulating oxidative stress and MPTP regulators.

A Phase II Trial of Stereotactic Body Radiation Therapy and Androgen Deprivation for Oligometastases in Prostate Cancer (SBRT-SG 05).

PURPOSE: SBRT-Spanish Group-05 (ClinicalTrials.gov.Identifier: NCT02192788) is a collaborative (SBRT-SG, Grupo de Investigación Clínica en Oncología Radioterápica, and Sociedad Española de Oncología Radioterápica) prospective multicenter phase II trial testing stereotactic body radiation therapy (SBRT) and androgen deprivation therapy (ADT) in patients with oligorecurrent prostate cancer. METHODS AND MATERIALS: Two cohorts of patients with prostate cancer in an oligorecurrent stage (hormone-sensitive in the principal cohort and castration-resistant in the exploratory cohort) were assigned to receive ADT and SBRT for at least 24 months from the time of the enrollment. Concomitant treatment with chemotherapy, abiraterone, or enzalutamide was not allowed. Oncologic outcomes were assessed in both cohorts. Toxicity was prospectively analyzed. RESULTS: From 2014 to 2019, 81 patients with a total of 126 lesions from 14 centers met the inclusion criteria, 14 of whom were castration-resistant. With a median follow-up of 40 months (12-58 months), 3-year local recurrence-free survival was 92.5% (95% CI, 79.9%-96.3%) and 85.7% (95% CI, 48.2%-95.6%) in the principal and exploratory cohorts, respectively. In the principal cohort, biochemical relapse-free survival and metastasis progression-free survival at 1, 2, and 3 years were 91% (95% CI, 81%-95.8%), 73.7% (95% CI, 61.1%-82.8%), 50.6% (95% CI, 36.2%-63.3%), and 92% (95% CI, 83%-97%), 81% (95% CI, 70%-89%), and 67% (95% CI, 53%-77%), respectively. In the exploratory cohort, metastasis progression-free survival at 1, 2, and 3 years was 64% (95% CI, 34%-83%), 43% (95% CI, 18%-66%), and 26% (95% CI, 7%-51%), respectively. None of the patients developed grade III or higher toxicity or symptoms related to local progression, and only 2 (2.4%) patients developed grade II toxicity. CONCLUSIONS: The combination of SBRT and ADT is safe and shows favorable clinical outcomes in patients with hormone-sensitive and castration-resistant prostate cancer. Validation studies are needed in patients with castration-resistant prostate cancer.

Mitochondrial dysfunction is the focus of quaternary ammonium surfactant toxicity to mammalian epithelial cells.

Surfactants have long been known to have microbicidal action and have been extensively used as antiseptics and disinfectants for a variety of general hygiene and clinical purposes. Among surfactants, quaternary ammonium compounds (QAC) are known to be the most useful antiseptics and disinfectants. However, our previous toxicological studies showed that QAC are also the most toxic surfactants for mammalian cells. An understanding of the mechanisms that underlie QAC toxicity is a crucial first step in their rational use and in the design and development of more effective and safer molecules. We show that QAC-induced toxicity is mediated primarily through mitochondrial dysfunction in mammalian columnar epithelial cell cultures in vitro. Toxic effects begin at sublethal concentrations and are characterized by mitochondrial fragmentation accompanied by decreased cellular energy charge. At very low concentrations, several QAC act on mitochondrial bioenergetics through a common mechanism of action, primarily by inhibiting mitochondrial respiration initiated at complex I and, to a lesser extent, by slowing down coupled ADP phosphorylation. The result is a reduction of cellular energy charge which, when reduced below 50% of its original value, induces apoptosis. The lethal effects are shown to be primarily a result of this process. At higher doses (closer to the critical micellar concentration), QAC induce the complete breakdown of cellular energy charge and necrotic cell death.

Mechanism of inhibition of mitochondrial ATP synthase by 17ß-estradiol.

17ß-estradiol (E2) is considered to modulate the ATP synthase activity through direct binding to the oligomycin sensitive-conferring protein. We have previously demonstrated that E2 increases the amplitude of depolarization associated with the addition of ADP to energized mitochondria (i.e., to initiate a phosphorylative cycle) suggesting a direct action on the phosphorylative system of mitochondria. The purpose of the present study was to investigate the underlying mechanisms responsible for this effect. We show here that E2 modulates the activity of mitochondrial ATP synthase by promoting the intrinsic uncoupling ("slipping") of the ATP synthase. E2 depressed RCR, ADP/O ratio and state 3 respiration, whereas state 4 respiration was increased and VFCCP (uncoupled respiration) remained unaltered. In contrast to the stimulatory effect on state 4 respiration, state 2 respiration and Volig were not affected by E2. The effect of E2 appeared to be directed towards ATP synthase, since glutamate/malate respiration, uncoupled from the electron transport chain, was unaffected by E2. Apparently, E2 allows a proton back-leak through the Fo component of ATP synthase. This action of E2 is dependent on the presence of ATP, is more pronounced at high membrane potentials, and it is reversed by oligomycin (a Fo-ATP synthase inhibitor) but not by resveratrol (a F1-ATP synthase inhibitor). Altogether, our data provide a mechanistic explanation for the effect of E2 at the level of mitochondrial ATP synthase.

A New and Easy-to-Use Survival Score for Patients Irradiated for Metastatic Epidural Spinal Cord Compression.

PURPOSE: A survival score was created in 2008 to improve treatment personalization of patients irradiated for metastatic epidural spinal cord compression (MESCC). Since then, targeted therapies improved survival of patients with cancer, which may decrease this score's predictive value. A new score appears necessary. METHODS AND MATERIALS: Two hundred sixty-four patients receiving radiation therapy without surgery in prospective trials (2010-2021) were included. A dose-fractionation regimen plus 15 factors were analyzed: age, sex, tumor type, interval tumor diagnosis to MESCC, MESCC sites, affected vertebrae, additional bone lesions, other distant lesions (yes or no), number of organs involved by metastases, time developing motor deficits, ambulatory status, sensory function, sphincter dysfunction, pain, and distress. Six-month survival rates (%) of independent prognostic factors were divided by 10 and summed for each patient. The score was compared with the previous tool for predicting death ≤6 months and survival ≥6 months. RESULTS: In a multivariate analysis, tumor type (P = .001), other distant lesions (P < .001), and ambulatory status (P < .001) were significant. Based on 6-month survival rates, 4 groups (8-9, 10-13, 14-17, and 18 points) were created with 6-month survival rates of 12.8%, 34.7%, 62.8%, and 90.0%, respectively (version A). For version B, "other distant lesions" was replaced by "number of organs involved by metastases." Version B included 4 groups (8-10, 11-14, 15-16, and 17 points) with 6-month survival rates of 11.1%, 42.0%, 68.6%, and 91.7%, respectively. Positive predictive values to predict death ≤6 months were 87.2% (version A) and 88.9% (version B) versus 76.6% (3 groups) and 84.6% (5 groups) for the previous score. Positive predictive values to predict survival ≥6 months were 90.0% and 91.7% versus 59.0% and 64.3%. CONCLUSIONS: Both versions of the new score were more precise than the previous tool. Version B appears slightly superior to version A but requires more extensive diagnostic staging that may not be readily available when emergently treating.

A New Clinical Instrument for Estimating the Ambulatory Status after Irradiation for Malignant Spinal Cord Compression.

Estimating post-treatment ambulatory status can improve treatment personalization of patients irradiated for malignant spinal cord compression (MSCC). A new clinical score was developed from data of 283 patients treated with radiotherapy alone in prospective trials. Radiotherapy regimen, age, gender, tumor type, interval from tumor diagnosis to MSCC, number of affected vertebrae, other bone metastases, visceral metastases, time developing motor deficits, ambulatory status, performance score, sensory deficits, and sphincter dysfunction were evaluated. For factors with prognostic relevance in the multivariable logistic regression model after backward stepwise variable selection, scoring points were calculated (post-radiotherapy ambulatory rate in % divided by 10) and added for each patient. Four factors (primary tumor type, sensory deficits, sphincter dysfunction, ambulatory status) were used for the instrument that includes three prognostic groups (17-21, 22-31, and 32-37 points). Post-radiotherapy ambulatory rates were 10%, 65%, and 97%, respectively, and 2-year local control rates were 100%, 75%, and 88%, respectively. Positive predictive values to predict ambulatory and non-ambulatory status were 97% and 90% using the new score, and 98% and 79% using the previous instrument. The new score appeared more precise in predicting non-ambulatory status. Since patients with 32-37 points had high post-radiotherapy ambulatory and local control rates, they may not require surgery.

Exposure to marine benthic dinoflagellate toxins may lead to mitochondrial dysfunction.

Even though marine dinoflagellates are important primary producers, many toxic species may alter the natural equilibrium of aquatic ecosystems and even generate human intoxication incidents, as they are the major causative agents of harmful algal blooms. In order to deepen the knowledge regarding benthic dinoflagellate adverse effects, the present study aims to clarify the influence of Gambierdiscus excentricus strain UNR-08, Ostreopsis cf. ovata strain UNR-03 and Prorocentrum lima strain UNR-01 crude extracts on rat mitochondrial energetic function and permeability transition pore (mPTP) induction. Our results, expressed in number of dinoflagellate cell toxic compounds tested in a milligram of mitochondrial protein, revealed that 934 cells mg prot-1 of G. excentricus, and 7143 cells mg prot-1 of both O. cf. ovata and P. lima negatively affect mitochondrial function, including by decreasing ATP synthesis-related membrane potential variations. Moreover, considerably much lower concentrations of dinoflagellate extracts (117 cells mg prot-1 of G. excentricus, 1429 cells mg prot-1 of O. cf. ovata and 714 cells mg prot-1 of P. lima) produced mPTP-induced swelling in Ca2+-loaded isolated mitochondria. The present study clearly demonstrates the toxicity of G. excentricus, O. cf. ovata and P. lima extracts at the mitochondrial level, which may lead to mitochondrial failure and consequent cell toxicity, and that G. excentricus always provide much more severe effects than O. cf. ovata and P. lima.

Comparison of 5 × 5 Gy and 10 × 3 Gy for metastatic spinal cord compression using data from three prospective trials.

BACKGROUND: In a palliative situation like metastatic spinal cord compression (MSCC), overall treatment time of radiotherapy should be as short as possible. This study compared 5 × 5 Gy in 1 week to 10 × 3 Gy in 2 weeks in a prospective cohort. METHODS: Forty patients receiving 5 × 5 Gy in a phase II trial were matched 1:2 to 213 patients receiving 10 × 3 Gy in two previous prospective studies for tumor type, ambulatory status, time developing motor deficits, interval between tumor diagnosis and MSCC and visceral metastases. These factors were consistent in all three patients (triple) used for each 1:2 matching. Groups were compared for local progression-free survival (LPFS), motor function, ambulatory status, and overall survival (OS). RESULTS: After matching, 32 triples remained for analyses (N = 96 in total). Six-month LPFS-rates were 94% after 5 × 5 Gy and 87% after 10 × 3 Gy (p = 0.36), 6-month OS-rates 43% and 35% (p = 0.74). Improvement of motor function was achieved in 59% and 34% of patients (p = 0.028); overall response rates (improvement or no further progression of motor deficits) were 94% and 89% (p = 0.71). Post-treatment ambulatory rates were 81% after 5 × 5 Gy and 85% after 10 × 3 Gy (p = 0.61). Of non-ambulatory patients, 50% (6/12) and 46% (11/24) regained the ability to walk (p = 1.00). CONCLUSIONS: 5 × 5 Gy in 1 week appeared similarly effective as 10 × 3 Gy in 2 weeks. These results may not be applicable to long-term survivors and should be confirmed in a randomized trial directly comparing 5 × 5 Gy and 10 × 3 Gy. Trial registration clinicaltrials.gov NCT03070431. Registered 27 February 2017.

Proton leak modulation in testicular mitochondria affects reactive oxygen species production and lipid peroxidation.

Mitochondrial proton leak can account for almost 20% of oxygen consumption and it is generally accepted that this process contributes to basal metabolism. In order to clarify the role of basal proton leak in testicular mitochondria, we performed a comparative study with kidney and liver mitochondrial fractions. Proton leak stimulated by linoleic acid and inhibited by guanosine diphosphate (GDP) was detected, in a manner that was correlated with protein levels for uncoupling protein 2 (UCP2) in the three fractions. Modulation of proton leak had an effect on reactive oxygen species production as well as on lipid peroxidation, and this effect was also tissue-dependent. However, a possible role for the adenine nucleotide transporter (ANT) in testicular mitochondria proton leak could not be excluded. The modulation of proton leak appears as a possible and attractive target to control oxidative stress with implications for male gametogenesis.

Mitochondrial impairment and cytotoxicity effects induced by the marine epibenthic dinoflagellate Coolia malayensis.

Mitochondria was used to clarify the effects of Coolia malayensis strain UNR-02 crude extract by studying mitochondrial membrane potential (ΔΨm) generation and the fluctuations of ΔΨm associated with the induction of mitochondrial permeability transition (MPT). The cytoxicity of C. malayensis was also determined using both HepG2 and H9c2(2-1) cells. C. malayensis extract significantly depressed the oxidative phosphorylation efficiency, as was inferred from the perturbations in ΔΨm and in the phosphorylative cycle induced by ADP. Increased susceptibility to Ca2+-induced MPT was also observed. At the cellular level, the extract significantly decreased cell mass of both cell lines.

Radiotherapy-related skin toxicity (RAREST-02): A randomized trial testing the effect of a mobile application reminding head-and-neck cancer patients to perform skin care (reminder app) on radiation dermatitis.

BACKGROUND: Radiotherapy of head-and-neck cancer can be associated with significant toxicities including dermatitis and oral mucositis. Severe toxicities may require interruptions of the radiation treatment associated with impairment of the patients' prognoses. This study will investigate whether the addition of a reminder app to standard care can reduce dermatitis and oral mucositis rates during radiotherapy in these patients. METHODS: This randomized trial compares standard care supported by a reminder app (Arm A) to standard care alone (Arm B) with respect to grade ≥ 2 radiation dermatitis and oral mucositis at 60 Gy of radiotherapy, the minimum planned dose for patients receiving definitive or adjuvant radiotherapy for locally advanced head- and-neck cancer. Moreover, radiation-induced dermatitis and oral mucositis grade ≥ 3 at 60 Gy and both grade ≥ 2 and grade ≥ 3 at the end of radiation treatment (EOT) will be evaluated, as well as quality of life and pain. According to sample size calculations, 80 patients are required per arm within the full analysis set. Taking into account that 5% of patients will not qualify for full analysis set, 168 patients should be randomized. The impact of the reminder app will be considered clinically relevant, if the rates of grade ≥ 2 radiation dermatitis (primary endpoint) and oral mucositis (secondary endpoint) can be reduced by 20%. DISCUSSION: If the addition of a reminder app to standard care will lead to a significant reduction of radiation dermatitis and oral mucositis, it could become a helpful tool for patients with head-and-neck cancer during radiotherapy. TRIAL REGISTRATION: clinicaltrials.gov (NCT04110977). Registered on September 27, 2019. First patient is planned to be included in December 2019.

Precision Radiation Therapy for Metastatic Spinal Cord Compression: Final Results of the PRE-MODE Trial.

OBJECTIVE: To investigate precision radiation therapy for metastatic spinal cord compression and compare it to conventional radiation therapy. METHODS AND MATERIALS: In a multicenter phase 2 study, 40 patients received 5 Gy × 5 fractions of precision radiation therapy (38 volume modulated arc therapy, 2 intensity modulated radiation therapy) for metastatic spinal cord compression and were evaluated for local progression-free survival (LPFS), motor function, ambulatory status, sensory function, sphincter dysfunction, pain, distress, overall survival (OS), and toxicity. Maximum spinal cord dose was 101.5% (myelopathy risk, <0.03%) of the prescription dose. Patients were compared with a historical control group conventionally irradiated with 4 Gy × 5 fractions (propensity score analysis). The equivalent dose in 2 Gy-fractions of 5 Gy × 5 fractions is similar to 3 Gy × 10 fractions, which results in better LPFS than 4 Gy × 5 fractions. It was assumed that 5 Gy × 5 fractions is also superior to 4 Gy × 5 fractions for LPFS. (ClinicalTrials.gov-identifier: NCT03070431) RESULTS: Six-month rates of LPFS and OS were 95.0% and 42.6%, respectively. Improvement of motor function occurred in 24 patients (60%). Thirty-three patients (82.5%) were ambulatory after radiation therapy. Eight of 16 patients (50.0%) with sensory deficits improved. Pain and distress relief were reported by 61.9% and 54.2% of patients 1 month after radiation therapy. Grade 3 toxicities occurred in 1 patient and grade 2 toxicities in another 3 patients. Of the control group, 664 patients qualified for the propensity score analysis; 5 Gy × 5 fractions was significantly superior to 4 Gy × 5 fractions with regard to LPFS (P = .026) but not motor function (P = .51) or OS (P = .82). CONCLUSIONS: Precision radiation therapy with 5 Gy × 5 fractions was well tolerated and effective and appeared superior to 4 Gy × 5 fractions in terms of LPFS. The retrospective nature of the historic control group, which might have led to a hidden selection bias, needs to be considered when interpreting the results.