Multimodal testing reveals subclinical neurovascular dysfunction in prediabetes, challenging the diagnostic threshold of diabetes.

AIM: To explore if novel non-invasive diagnostic technologies identify early small nerve fibre and retinal neurovascular pathology in prediabetes. METHODS: Participants with normoglycaemia, prediabetes or type 2 diabetes underwent an exploratory cross-sectional analysis with optical coherence tomography angiography (OCT-A), handheld electroretinography (ERG), corneal confocal microscopy (CCM) and evaluation of electrochemical skin conductance (ESC). RESULTS: Seventy-five participants with normoglycaemia (n = 20), prediabetes (n = 29) and type 2 diabetes (n = 26) were studied. Compared with normoglycaemia, mean peak ERG amplitudes of retinal responses at low (16-Td·s: 4.05 µV, 95% confidence interval [95% CI] 0.96-7.13) and high (32-Td·s: 5·20 µV, 95% CI 1.54-8.86) retinal illuminance were lower in prediabetes, as were OCT-A parafoveal vessel densities in superficial (0.051 pixels/mm2 , 95% CI 0.005-0.095) and deep (0.048 pixels/mm2 , 95% CI 0.003-0.093) retinal layers. There were no differences in CCM or ESC measurements between these two groups. Correlations between HbA1c and peak ERG amplitude at 32-Td·s (r = -0.256, p = 0.028), implicit time at 32-Td·s (r = 0.422, p < 0.001) and 16-Td·s (r = 0.327, p = 0.005), OCT parafoveal vessel density in the superficial (r = -0.238, p = 0.049) and deep (r = -0.3, p = 0.017) retinal layers, corneal nerve fibre length (CNFL) (r = -0.293, p = 0.017), and ESC-hands (r = -0.244, p = 0.035) were observed. HOMA-IR was a predictor of CNFD (ß = -0.94, 95% CI -1.66 to -0.21, p = 0.012) and CNBD (ß = -5.02, 95% CI -10.01 to -0.05, p = 0.048). CONCLUSIONS: The glucose threshold for the diagnosis of diabetes is based on emergent retinopathy on fundus examination. We show that both abnormal retinal neurovascular structure (OCT-A) and function (ERG) may precede retinopathy in prediabetes, which require confirmation in larger, adequately powered studies.

Genetic-interaction screens uncover novel biological roles and regulators of transcription factors in fission yeast.

In Schizosaccharomyces pombe, systematic analyses of single transcription factor deletion or overexpression strains have made substantial advances in determining the biological roles and target genes of transcription factors, yet these characteristics are still relatively unknown for over a quarter of them. Moreover, the comprehensive list of proteins that regulate transcription factors remains incomplete. To further characterize Schizosaccharomyces pombe transcription factors, we performed synthetic sick/lethality and synthetic dosage lethality screens by synthetic genetic array. Examination of 2,672 transcription factor double deletion strains revealed a sick/lethality interaction frequency of 1.72%. Phenotypic analysis of these sick/lethality strains revealed potential cell cycle roles for several poorly characterized transcription factors, including SPBC56F2.05, SPCC320.03, and SPAC3C7.04. In addition, we examined synthetic dosage lethality interactions between 14 transcription factors and a miniarray of 279 deletion strains, observing a synthetic dosage lethality frequency of 4.99%, which consisted of known and novel transcription factor regulators. The miniarray contained deletions of genes that encode primarily posttranslational-modifying enzymes to identify putative upstream regulators of the transcription factor query strains. We discovered that ubiquitin ligase Ubr1 and its E2/E3-interacting protein, Mub1, degrade the glucose-responsive transcriptional repressor Scr1. Loss of ubr1+ or mub1+ increased Scr1 protein expression, which resulted in enhanced repression of flocculation through Scr1. The synthetic dosage lethality screen also captured interactions between Scr1 and 2 of its known repressors, Sds23 and Amk2, each affecting flocculation through Scr1 by influencing its nuclear localization. Our study demonstrates that sick/lethality and synthetic dosage lethality screens can be effective in uncovering novel functions and regulators of Schizosaccharomyces pombe transcription factors.

Community oncologists' perceptions and utilization of large-panel genomic tumor testing.

PURPOSE: Large-panel genomic tumor testing (GTT) is an emerging technology with great promise but uncertain clinical value. Previous research has documented variability in academic oncologists' perceptions and use of GTT, but little is known about community oncologists' perceptions of GTT and how perceptions relate to clinicians' intentions to use GTT. METHODS: Community oncology physicians (N = 58) participating in a statewide initiative aimed at improving access to large-panel GTT completed surveys assessing their confidence in using GTT, attitudes regarding the value of GTT, perceptions of barriers to GTT implementation, and future intentions to use GTTs. Descriptive and multivariable regression analyses were conducted to characterize these perceptions and to explore the relationships between them. RESULTS: There was substantial variability in clinicians' perceptions of GTT. Clinicians generally had moderate confidence in their ability to use GTT, but lower confidence in patients' ability to understand test results and access targeted treatment. Clinicians had positive attitudes regarding the value of GTT. Clinicians' future intentions to use GTT were associated with greater confidence in using GTT and greater perceived barriers to implementing GTT, but not with attitudes about the value of GTT. CONCLUSIONS: Community oncologists' perceptions of large-panel genomic tumor testing are variable, and their future intentions to use GTT are associated with both their confidence in and perceived barriers to its use, but not with their attitudes towards GTT. More research is needed to understand other factors that determine how oncologists perceive and use GTT in clinical practice.

Patients' Expectations of Benefits From Large-Panel Genomic Tumor Testing in Rural Community Oncology Practices.

Large-panel genomic tumor testing (GTT) is an emerging technology that promises to make cancer treatment more precise. Because GTT is novel and complex, patients may have unrealistic expectations and limited knowledge of its benefits. These problems may limit the clinical value of GTT, but their prevalence and associated factors have not been explored. METHODS: Patients with cancer enrolled in a large initiative to disseminate GTT in community oncology practices completed surveys assessing their expectations, knowledge, and attitudes about GTT. The study sample (N = 1,139) consisted of patients with a range of cancer types (22% gynecologic, 14% lung, 10% colon, 10% breast, and 46% other malignancies) and cancer stages (4% stage I, 3% stage II, 15% stage III, and 74% stage IV). Mean age was 64 years (standard deviation = 11); 668 (59%) were women; 71% had no college degree; 57% came from households with less than $50,000 US dollars household income; and 73% lived in a rural area. RESULTS: Generally, patients had high expectations that they would benefit from GTT (M = 2.81 on 0-4 scale) and positive attitudes toward it (M = 2.98 on 0-4 scale). Patients also had relatively poor knowledge about GTT (48% correct answers on an objective test of GTT knowledge). Greater expectations for GTT were associated with lower knowledge (b = -0.46; P < .001), more positive attitudes (b = 0.40; P < .001), and lower education (b = -0.53; P < .001). CONCLUSION: This research suggests patients have high expectations that they will benefit from GTT, which is associated with low knowledge, positive attitudes, and low education. More research is needed to understand the concordance between expectations and actual clinical outcomes.

African Americans With p16+ and p16- Oropharyngeal Squamous Cell Carcinomas Have Distinctly Poor Treatment Outcomes Independent of Medical Care Access.

PURPOSE: Human papilloma virus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC), diagnosed with p16 immunohistochemistry, is associated with favorable prognosis; however, this connection was established using European American (EA)-skewed populations. The impact of p16/human papillomavirus status on outcomes in African American (AA) OPSCC patients remains to be settled. In this study, we determine the association between cancer disparity and p16 status in an OPSCC cohort controlling for time to treatment initiation (TTI), a surrogate for medical care access. MATERIALS AND METHODS: We analyzed data from all patients diagnosed with OPSCC (N = 440) between 2010 and 2017, who received treatment at our academic medical center. Associations between age, disease stage, sex, p16 status, race, TTI, and overall survival (OS) were investigated. RESULTS: TTI was similar between AA and EA OPSCC patients in our p16+ (P = .291) or p16- (P = .715) cohorts. Among p16+ OPSCC patients, the median OS was > 8.65 years for EA patients compared with 5.038 years (95% CI, 2.019 to 5.30; P = .003, log-rank) for AA patients. For p16- patients, the median OS was 5.74 years (95% CI, 3.32 to 6.99) for EA patients and 1.85 years (95% CI, 0.978 to 4.50; P = .03, log-rank) for AA patients. Multivariate Cox regression analysis showed that race was an independent prognostic biomarker and the most impactful co-variate for OS (hazard ratio, 0.40; 95% CI, 0.00 to 0.69; P = .001). CONCLUSION: Our work showed that AAs with p16+ OPSCC have surprisingly poor clinical outcomes and are thus poor candidates for treatment de-escalation regimens. Caution should be exercised when extending clinical guidelines based on EA-majority studies to non-EA populations.

Ensuring best practice in genomics education and evaluation: reporting item standards for education and its evaluation in genomics (RISE2 Genomics).

PURPOSE: Widespread, quality genomics education for health professionals is required to create a competent genomic workforce. A lack of standards for reporting genomics education and evaluation limits the evidence base for replication and comparison. We therefore undertook a consensus process to develop a recommended minimum set of information to support consistent reporting of design, development, delivery, and evaluation of genomics education interventions. METHODS: Draft standards were derived from literature (25 items from 21 publications). Thirty-six international experts were purposively recruited for three rounds of a modified Delphi process to reach consensus on relevance, clarity, comprehensiveness, utility, and design. RESULTS: The final standards include 18 items relating to development and delivery of genomics education interventions, 12 relating to evaluation, and 1 on stakeholder engagement. CONCLUSION: These Reporting Item Standards for Education and its Evaluation in Genomics (RISE2 Genomics) are intended to be widely applicable across settings and health professions. Their use by those involved in reporting genomics education interventions and evaluation, as well as adoption by journals and policy makers as the expected standard, will support greater transparency, consistency, and comprehensiveness of reporting. Consequently, the genomics education evidence base will be more robust, enabling high-quality education and evaluation across diverse settings.

"Why didn't we do it"? Reproductive loss and the problem of post-mortem consent.

Informed consent has been a much debated topic within the social sciences. It often forms a central feature of discussions on research in medical settings and in social research methods more broadly. While sympathetic to its' underlying principles of autonomy and choice, social scientists have tended to argue that these are seldom enacted in research or clinical practice. Rather, such principles are often circumscribed by wider social structures and by a culture of medical dominance. Drawing on data from a qualitative study on perinatal post-mortem, this paper explores informed consent in the emotionally charged clinical arena of perinatal pathology. Our in-depth analysis will provide fresh insight into post-mortem decision-making in the sensitive arena of baby loss. Our findings show how parents often found it difficult to give consent for post-mortem, and also for professionals to take consent from parents. It was also not uncommon for parents to experience regret over non-consent later on. One of our key findings, however, related to the sense of emotional and diagnostic closure often afforded by post-mortem when consent had been given. We conclude by arguing that, although we cannot resolve the tension between the principles of consent and their enactment in practice, we can develop a reflexive approach with which to navigate the process. In doing so, the paper contributes to wider sociological discussions on the meaning and use of informed consent in various settings beyond medical contexts.

cfDNA detection for HPV+ squamous cell carcinomas.

High-risk human papillomavirus (HPV) is an etiologic factor in a spectrum of squamous cell carcinomas including anal, cervical, and oropharyngeal. HPV cell free DNA (cfDNA) is shed from the primary tumor into systemic circulation and can be detected using several platforms including quantitative PCR, digital droplet PCR, or next generation sequencing. Levels of HPV cfDNA at time of initial presentation is associated with known poor prognostic clinicopathologic variables, such as advanced stage and, locoregional and distant metastases. Moreover, longitudinal sampling revealed that persistent or increasing HPV cfDNA levels are indicative of treatment relapse and, in some studies, HPV cfDNA detection predicted treatment failures prior to routine post-treatment clinical imaging. A liquid biopsy platform using HPV cfDNA offers unique advantages over traditional approaches and may have clinical utility for detection of minimum residual disease, treatment response, and disease progression in patients with HPV+ cancers.

Do Black and Asian individuals wait longer for treatment? A survival analysis investigating the effect of ethnicity on time-to-clinic and time-to-treatment for diabetic eye disease.

AIMS/HYPOTHESIS: This study explored the impact of ethnicity on time-to-clinic, time-to-treatment and rates of vision loss in people referred to hospital with diabetic eye disease. METHODS: A survival analysis was performed on all referrals from an inner-city diabetic eye screening programme to a tertiary hospital eye service between 1 October 2013 and 31 December 2017. Exclusion criteria were failure to attend hospital, distance visual acuity in both eyes too low to quantify with the Early Treatment Diabetic Retinopathy Study (ETDRS) letter chart and treatment received prior to referral. Demographic and screening grade data were collected at the point of referral. Small-area statistics and census data were used to calculate indices of multiple deprivation. The main outcome measures were time taken from the date of referral for an individual to achieve the following: (1) attend the first hospital clinic appointment; (2) receive the first macular laser, intravitreal anti-vascular endothelial growth factor injection or pan-retinal photocoagulation treatment, in either eye; and (3) lose at least ten ETDRS letters of distance visual acuity, in either eye. RESULTS: Of 2062 referrals, 1676 individuals were included. Mean age (± SD) was 57.6 ± 14.7 years, with 52% male sex and 86% with type 2 diabetes. The ethnicity profile was 52% Black, 30% White, 10% Asian and 9% mixed/other, with similar disease severity at the time of referral. Time-to-clinic was significantly longer for Asian people than for Black people (p = 0.03) or White people (p = 0.001). Time-to-treatment was significantly longer for Black people than for White people (p = 0.02). Social deprivation did not significantly influence time-to-treatment. There were no significant differences in the rates of vision loss between ethnic groups. CONCLUSIONS/INTERPRETATION: Black people wait longer for hospital eye treatment compared with their White counterparts. The reasons for this delay in treatment warrant further investigation.

Differences in cancer patients' and clinicians' preferences for disclosure of uncertain genomic tumor testing results.

OBJECTIVE: To compare clinicians' and patients' preferences for disclosure of genomic tumor testing (GTT) results; to determine the sensitivity of these disclosure preferences to uncertainty about the actionability of results; and to explore factors associated with disclosure preferences. METHODS: Community-based oncology clinicians (n = 94) and patients (n = 1121) were surveyed about their preferences for disclosing GTT results with varying levels of uncertainty (Tiers 1, 2, 3). Descriptive and multivariable regression analyses were used to compare clinicians' and patients' disclosure preferences and their sensitivity to uncertainty, and to explore associations between disclosure preferences and sociodemographic, clinical, and psychological factors. RESULTS: Relatively more patients than clinicians preferred disclosure, and their preferences were less sensitive to the uncertainty of GTT results. For patients and clinicians, lower uncertainty sensitivity was associated with positive GTT attitudes; for patients it was also associated with greater uncertainty tolerance and knowledge of uncertainty in GTT. CONCLUSION: Relatively more cancer patients than clinicians prefer disclosure of GTT results, and their preferences are less sensitive to result uncertainty. Uncertainty sensitivity in disclosure preferences is associated with GTT-related attitudes and uncertainty tolerance. PRACTICE IMPLICATIONS: Differences in cancer patients' and clinicians' preferences for disclosure of uncertain GTT results warrant greater attention in cancer care.

The influence of uncertainty and uncertainty tolerance on attitudes and self-efficacy about genomic tumor testing.

Novel medical technologies, like large-panel genomic tumor testing (GTT), offer great promise but also substantial uncertainty regarding their clinical value and appropriate use. The goal of this study was to understand how clinicians' perceived uncertainty about GTT, and uncertainty tolerance (UT), a construct that describes trait-level differences in individuals' responses to uncertainty, influence attitudes and self-efficacy regarding GTT. Community-based oncologists participating in a study of large-panel GTT completed surveys assessing their perceptions of uncertainty about GTT, and their attitudes and self-efficacy regarding GTT. Multivariable regression analyses examined the relationship between oncologists' perceived uncertainty of GTT and their GTT-related attitudes and self-efficacy, and the potential moderating effect of individual differences in UT. Fifty-seven oncologists completed surveys. Greater perceived uncertainty about GTT was associated with more negative attitudes towards it. This association was moderated by UT, such that lower UT was associated with a stronger negative relationship between perceived uncertainty and attitudes. That is, oncologists who perceive GTT as uncertain, tended to have more negative attitudes, particularly if they were low in the trait of uncertainty tolerance. More research is warranted to understand how uncertainty and uncertainty tolerance influence clinicians' responses to GTT and other novel medical interventions.

Physiological and Perceptual Demands of Running on a Curved Nonmotorized Treadmill Compared With Running on a Motorized Treadmill Set at Different Grades.

Schoenmakers, PPJM, Crisell, JJ, and Reed, KE. Physiological and perceptual demands of running on a curved nonmotorized treadmill compared with running on a motorized treadmill set at different grades. J Strength Cond Res 34(5): 1197-1200, 2020-The current study compared the physiological and perceptual demands of running on a commercially available curved nonmotorized treadmill (cNMT) with different incline grades on a motorized treadmill (MT). Ten male team-sport athletes completed, after a familiarization session, a 6-minute run at a target velocity of 2.78 m·s on the cNMT (cNMTrun). The mean individual running velocity of cNMTrun was then used as warm-up and experimental running velocity in 3 subsequent visits, in which subjects ran for 6 minutes on the MT set at different grades (4, 6, or 8%). In all experimental trials (cNMTrun, 4MTrun, 6MTrun, and 8MTrun) and in the warm-up of the subjects' third visit (1MTrun), oxygen consumption (V[Combining Dot Above]O2) and heart rate (HR) were monitored, and ratings of perceived exertion (RPE) were obtained. The HR in cNMTrun was significantly higher compared with all MT trials. V[Combining Dot Above]O2 and RPE were significantly higher in cNMTrun compared with 1MTrun and 4MTrun, but not different from 6MTrun and 8MTrun. The relationship between V[Combining Dot Above]O2 and MT grades was highly linear (V[Combining Dot Above]O2 = 34.36 + 1.7 MT grade; r = 0.99), and using linear interpolation, the concave curved design of the cNMT was estimated to mimic a 6.9 ± 3% MT grade. On matched running velocities, V[Combining Dot Above]O2 and RPE responses while running on the cNMT are similar to a 6-8% MT grade. These findings can be used as a reference value by athletes and coaches in the planning of cNMT training sessions and amend running velocities accordingly. Future studies are needed to determine whether this estimate is similar for female runners, or those of a lower body mass.

p53 functional states are associated with distinct aldehyde dehydrogenase transcriptomic signatures.

p53 and aldehyde dehydrogenase (ALDH) have been implicated in key tumorigenesis processes including cancer initiating cell (CIC) maintenance; however, the relationship between these two mediators remains poorly defined. In this study, ALDH isoform expression diversity was revealed in CICs with disparate p53 functional states: gain of function, high risk p53 mutation (p53HRmut) and wildtype p53 (p53WT) inactivated by the human papillomavirus 16 (HPV16) E6 oncogene. Interrogation of head and neck squamous cell carcinoma (HNSCC) cell lines and patient tumors showed that HPV16+/p53WT cases have higher ALDH variance score (AVS), a measure of tumor ALDH isoform expression diversity, compared to HPV-/p53HRmut cases (p = 0.03). AVS and several individual ALDH isoforms were associated with prognosis in HPV16+/p53WT HNSCC but not in HPV-/p53HRmut HNSCC. Knockdown of the dominant ALDH isoform in high AVS HNSCC depleted the CIC pool in vitro and in vivo. Our results demonstrate that p53 functional states are associated with distinct ALDH isoform transcriptomic signatures. Moreover, tumor ALDH profiling may provide insight on which ALDH isoform to target in high AVS HNSCC tumors to deplete the CIC population.

HPV33+ HNSCC is associated with poor prognosis and has unique genomic and immunologic landscapes.

OBJECTIVE: To determine the influence of high-risk HPV genotype on outcomes in HNSCC patients. MATERIALS AND METHODS: This is a retrospective analysis of The Cancer Genome Atlas HNSCC cohort. RESULTS: Using multivariate Cox regression analysis, we revealed that HPV33+ HNSCC patients have inferior overall survival compared to HPV16+ HNSCC patients independent of anatomical site (HR 3.59, 95% CI 1.58-8.12; p = 0.002). A host anti-viral immune response, apolipoprotein B mRNA editing enzyme, and catalytic polypeptide-like mutational signature, was under represented and, aneuploidy and 3p loss were more frequent in HPV33+ tumors. A deconvolution RNA-Seq algorithm to infer immune cell fractions revealed that CD8+ cytotoxic T-cell infiltration was reduced in HPV33+ compared to HPV16+ tumors (1.3% vs. 2.7%, p = 0.007). TGFB1, a negative modulator of T-cell infiltration and function, showed expression and pathway enrichment in HPV33+ tumors. CONCLUSIONS: Our work reveals that HPV genotype, in particular HPV33, has a powerful impact on HNSCC patient survival. We argue that p16 immunohistochemistry as a surrogate biomarker for HPV+ status will lead to sub-optimal risk stratification and advocate HPV genotype testing as standard of care.

Sustainable access to appropriate opioids for palliative care patients in Australia-preventing the need for crisis management.

The main goal of palliative care is to relieve suffering. Opioids are an essential part of the pharmacological options required to address suffering by helping to relieve the pain and chronic breathlessness that may be experienced by someone with a life-limiting illness. This paper considers the recent history and current issues of the 'opioid crisis' providing recommendations to which regulatory and peak bodies can work with the Australian government, ensuring consistent adherence to WHO guidelines maintaining access to evidence based opioid management for palliative care patients whilst actively avoiding unintended suffering restricted access can cause. The recommendations are as follows:Review of the Palliative Care schedule of the Pharmaceutical Benefit SchemeSupport of prescribers with current evidence, clinical practice guidelines and regulatory frameworksNational opioid prescribing policies promoting linkages between palliative care and pain and addiction specialists.National real time monitoring of all opioid prescriptionsPalliative care involvement in all opioids stewardship programs in acute services.Reform Medical Benefits Schedule to improve access for primary and other speciality practitioners to provide palliative care services.Compulsory palliative care education in undergraduate medical, nursing and allied health tertiary courses.Adequate, consistent stock of evidence based opioids for palliative care in community pharmacies and residential aged care facilities.These recommendations provide the regulatory guidance required to ensure persons with life limiting illness have continued access to safe and effective medication that can relieve suffering.

Quantifying adherence to antihypertensive medication for chronic hypertension during pregnancy.

Estimates of adherence to antihypertensive treatment in pregnancy are limited; identifying non-adherence could facilitate intervention and optimise blood pressure control. This study aimed to evaluate adherence to antihypertensive treatment amongst pregnant women with chronic hypertension using high-performance liquid chromatography-tandem mass spectrometry instrumentation. Spot urine samples collected from women who were randomised to labetalol or nifedipine were assessed. Samples from 74 women were included; documented prescribing and urine metabolite detection were concordant in 88% (n = 65). Evidence of self-administration of alternative treatment was observed in 8% (n = 6). Measurement of urinary antihypertensive metabolites in pregnancy provides insight into treatment adherence.

The Moderating Role of Recovery Durations in High-Intensity Interval-Training Protocols.

Purpose: Over recent years, multiple studies have tried to optimize the exercise intensity and duration of work intervals in high-intensity-interval training (HIIT) protocols. Although an optimal work interval is of major importance to facilitate training adaptations, an optimal HIIT protocol can only be achieved with an adequate recovery interval separating work bouts. Surprisingly, little research has focused on the acute responses and long-term impact of manipulating recovery intervals in HIIT sessions. This invited commentary therefore aimed to review and discuss the current literature and increase the understanding of the moderating role of recovery durations in HIIT protocols. Conclusion: The acute responses to manipulations in recovery durations in repeated-sprint training (RST), sprint interval training (SIT), and aerobic interval training (AIT) protocols have recently begun to receive scientific interest. However, limited studies have manipulated only the recovery duration in RST, SIT, or AIT protocols to analyze the role of recovery durations on long-term training adaptations. In RST and SIT, longer recovery intervals (≥80 s) facilitate higher workloads in subsequent work intervals (compared with short recovery intervals), while potentially lowering the aerobic stimulus of the training session. In AIT, the total physiological strain endured per training protocol appears not to be moderated by the recovery intervals, unless the recovery duration is too short. This invited commentary highlights that further empirical evidence on a variety of RST, SIT, and AIT protocols and in exercise modalities other than cycling is needed.

Using a Chemical Genetic Screen to Enhance Our Understanding of the Antimicrobial Properties of Gallium against Escherichia coli.

The diagnostic and therapeutic agent gallium offers multiple clinical and commercial uses including the treatment of cancer and the localization of tumors, among others. Further, this metal has been proven to be an effective antimicrobial agent against a number of microbes. Despite the latter, the fundamental mechanisms of gallium action have yet to be fully identified and understood. To further the development of this antimicrobial, it is imperative that we understand the mechanisms by which gallium interacts with cells. As a result, we screened the Escherichia coli Keio mutant collection as a means of identifying the genes that are implicated in prolonged gallium toxicity or resistance and mapped their biological processes to their respective cellular system. We discovered that the deletion of genes functioning in response to oxidative stress, DNA or iron⁻sulfur cluster repair, and nucleotide biosynthesis were sensitive to gallium, while Ga resistance comprised of genes involved in iron/siderophore import, amino acid biosynthesis and cell envelope maintenance. Altogether, our explanations of these findings offer further insight into the mechanisms of gallium toxicity and resistance in E. coli.

The effects of recovery duration on physiological and perceptual responses of trained runners during four self-paced HIIT sessions.

OBJECTIVES: This study aimed to examine the effects of different recovery durations on self-selected running velocities, physiological responses, and ratings of perceived exertion (RPE) in a commonly used high intensity interval training (HIIT) protocol. DESIGN & METHODS: Twelve trained runners performed an incremental treadmill exercise test to determine maximal oxygen uptake (V˙O2max) and heart rate (HRmax). In four subsequent visits, participants performed a HIIT session comprising six 4-min work intervals, in which the recovery duration between work intervals equalled either a fixed (1MIN, 2MIN, 3MIN) or a self-selected duration (ssMIN). HIIT sessions were run on a non-motorized treadmill, and were performed under isoeffort conditions. RESULTS: Mean running velocity was significantly higher in 3MIN compared with all other protocols, and higher in ssMIN compared with 2MIN. No significant differences in time spent ≥90% and 95% V˙O2max, or ≥90% and 95% HRmax were evident between the four protocols. RPE responses were similar across and within the protocols showing a gradual increase with each progressive interval. CONCLUSION: In a self-paced HIIT session of six 4-min work intervals, the length of recovery durations had a limited effect on the total physiological strain endured in the training. However, running velocities were higher when participants received the longest recovery period (3MIN). Longer recovery durations may facilitate a higher external training load (faster running), whilst maintaining a similar internal training load (physiological stimulus), and may therefore allow for greater training adaptations.