A Longitudinal Study of Adherence among Cystic Fibrosis Patients: Associations with Gratitude Over the Course of One Year.

BACKGROUND: Daily airway clearance therapy (ACT) is a critical aspect of treatment in cystic fibrosis (CF), but poor adherence is a prominent concern. Identifying factors that might enhance or diminish adherence is a priority for treatment centers. Gratitude, a generalized tendency to notice and appreciate positive facets of experience, is a psychosocial resource that has commanded growing research interest. This longitudinal study examined whether gratitude at baseline was associated with ongoing or persistent ACT adherence over the course of a year. METHODS: Trait gratitude was evaluated at baseline using a validated measure, among adults receiving care at a regional CF treatment center. Self-reported adherence to ACT was assessed at baseline, 6 months, and 12 months using the Cystic Fibrosis Treatment Questionnaire. Average age of participants was 27.2 years, 45.5% were women, and 19.7% had severe disease. RESULTS: In multivariable logistic regression models that accounted for disease severity (Forced Expiratory Volume1% predicted) and other clinical and demographic variables, individuals with higher baseline gratitude were significantly more likely to demonstrate persistent adherence over the course of the year. Gratitude remained predictive after additionally adjusting for other well-known psychosocial resource variables (social support and emotional well-being). CONCLUSION: This is among the first demonstrations that gratitude is associated with persistent self-reported adherence to treatment over time. Findings suggest that gratitude may be important psychosocial resource for adults with CF, as they contend with complex, highly burdensome treatment regimens. Further research is warranted to examine these relationships and their impact on downstream health outcomes.

Denosumab in a pediatric kidney transplant recipient with late, resistant hypercalcemia secondary to Pneumocystis jirovecii pneumonia.

Kidney transplant recipients (KTR) are at an increased risk of developing Pneumocystis jirovecii pneumonia (PCP), especially during the first year after transplantation. This is the first reported pediatric KTR, with chronic kidney disease (CKD) secondary to kidney dysplasia and vesicoureteral reflux, who developed refractory and symptomatic hypercalcemia 5 years after transplantation. The hypercalcemia was resistant to treatment with intravenous hyperhydration, furosemide, and a low-calcium diet. A respiratory tract infection due to PCP treated with trimethoprim-sulfamethoxazole did not improve calcium levels. Due to the hypercalcemic symptom burden for the patient, a single dose of subcutaneous denosumab was used to achieve sustained clinical and biochemical improvement, without any severe adverse events. This case highlights the potential use of denosumab as a treatment option in pediatric KTR with refractory hypercalcemia related to PCP. Further study of denosumab in young people with CKD or kidney transplants is needed before routine use can be recommended.

Oral antimicrobial therapy for cellulitis versus outpatient parenteral antimicrobial therapy: a single-centre audit of cellulitis outcomes.

BACKGROUND: Cellulitis is a common acute skin and soft tissue infection that causes substantial morbidity and healthcare costs. AIMS: To audit the impact on cellulitis management, regimen tolerability and outcomes of switching from outpatient parenteral antimicrobial therapy (OPAT) using intravenous (i.v.) cefazolin once daily plus probenecid to oral beta-lactam therapy (OBLT) using oral flucloxacillin plus probenecid. METHODS: We undertook a retrospective audit on cellulitis management, regimen tolerability and outcomes at the Dunedin Public Hospital Emergency Department (ED) before and after a change of the local outpatient cellulitis treatment pathway from OPAT using i.v. cefazolin once daily plus probenecid to OBLT using oral flucloxacillin plus probenecid. RESULTS: OPAT was used in 97/123 (78.9%) patients with cellulitis before compared to 1/70 (1.4%) after the pathway change (odds ratio (OR), 0.04, P < 0.01). OBLT was used in 26/123 (21.1%) patients with cellulitis before and 69/70 (98.6%) after (OR, 218.8, P < 0.01). Antimicrobial change due to intolerance occurred in 4/123 (3.2%) patients with cellulitis before and 4/70 (5.7%) after (OR, 1.8, P, not significant (NS)) the pathway change. Inpatient admission within 28 days occurred in 15/123 (12.2%) cellulitis patients before and 9/70 (12.9%) after (OR, 1.1, P, NS) the pathway change. CONCLUSIONS: Implementation of a change in outpatient cellulitis treatment pathway resulted in a significant change in prescribing practice. Our findings suggest that OBLT was both tolerable and had similar outcomes to OPAT.

Delusions of Vampirism in an Adolescent and Treatment With Clozapine: A Case Report.

This case describes delusions of vampirism among several other psychotic symptoms in a 15-year-old who has a diagnosis of schizophrenia, with these delusions first presenting when he was 13 years of age. Delusions of vampirism can be associated with a strong desire to suck human blood but these delusional beliefs were not acted upon here. This is the first report of delusions of vampirism in childhood to date. The introduction of the antipsychotic medication clozapine after failed treatment trials with two other antipsychotic agents has been associated with a significant amelioration in symptomatology and an improvement in functioning.

Controlling peripheral intravenous catheter failure by needleless connector design: A pilot randomised controlled trial.

AIM: To test the feasibility of a study protocol that compared the efficacy of neutral- and negative-pressure needleless connectors (NCs). DESIGN: A single-centre, parallel-group, pilot randomised control trial. METHODS: Our study compared neutral-(intervention) and negative-pressure (control) NCs among adult patients in an Australian hospital. The primary feasibility outcome was measured against predetermined criteria (e.g. eligibility, attrition). The primary efficacy outcome was all-cause peripheral intravenous catheter failure, analysed as time-to-event data. RESULTS: In total, 201 (100 control; 101 intervention) participants were enrolled between March 2020 and September 2020. All feasibility criteria were met except eligibility, which was lower (78%) than the 90% criterion. All-cause peripheral intravenous catheter failure was significantly higher in the intervention group (39%) compared to control (19%). CONCLUSION: With minor modifications to participant screening for eligibility, this randomised control trial is feasible for a large multicentre randomised control trial. The neutral NC was associated with an increased risk of peripheral intravenous catheter failure. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: There are several NC designs available, often identified by their mechanism of pressure (positive, negative and neutral). However, NCs can contribute to peripheral intravenous catheter failure. This is the first randomised controlled trial to compare neutral and negative NC designs. Negative pressure NCs had lower PIVC failure compared to neutral NCs, however the results might not be generalisable to other brands or treatment settings. Further high-quality research is needed to explore NC design. REPORTING METHOD: Study methods and results reported in adherence to the CONSORT Statement. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

Perforated intravenous catheter design is acceptable for the administration of contrast-enhanced computed tomography administration in cancer patients: Results of a pilot randomised controlled trial.

BACKGROUND: Optimising first time success of peripheral intravenous catheter (PIVC) insertion and reducing intravenous (IV) complications in cancer patients undergoing contrast-enhanced computed tomography (CT) is vital to ensure vascular access preservation and diagnostic accuracy. The aim of this study was to test the feasibility of a randomised controlled trial (RCT) evaluating a novel perforated PIVC compared to a standard PIVC. METHODS: A single centre, parallel-group, pilot RCT was conducted between March and May 2020. Adult participants diagnosed with cancer were randomised to a non-perforated PIVC (standard care) or a PIVC with a novel perforated design (intervention) for the administration of IV contrast. There were two primary outcomes: (1) feasibility of an adequately powered RCT with pre-established criteria; and (2) all-cause PIVC failure. Secondary outcomes included: first insertion success, modes of PIVC failure, dwell time, contrast injection parameters (volume and injection rate), contrast enhancement, radiographer satisfaction and adverse events. RESULTS: Feasibility outcomes were met, except for eligibility (⩾90%) and recruitment (⩾90%). In total, 166 participants were screened, 128 (77%) were eligible and of these 101/128 (79%) were randomised; 50 to standard care and 51 to intervention. First time insertion rate was 94% (47/50) in standard care and 90% (46/50) in intervention. The median dwell time was 37 minutes (interquartile range (IQR): 25-55) in standard care and 35 minutes (IQR: 25-60) in the intervention group. There was one PIVC failure, a contrast media extravasation, in the intervention group (1/51; 2%). The desired contrast injection rate was not achieved in 4/101 (4%) of participants; two from each group. Radiographers were satisfied with the contrast flow rate. CONCLUSIONS: This pilot RCT suggests perforated PIVCs provide expected flow rate, with no evidence of differences in contrast enhancement to non-perforated PIVCs. The feasibility of conducting a larger powered RCT was demonstrated.

Comparing the use of midline catheters versus peripherally inserted central catheters for patients requiring peripherally compatible therapies: A pilot randomised controlled trial (the compact trial).

BACKGROUND: Midline catheter (MC) use has increased in acute-care settings, particularly for patients with difficult venous access or requiring peripherally compatible intravenous therapy for up-to 14 days. Our aim was to assess feasibility and generate clinical data comparing MCs with Peripherally Inserted Central Catheters (PICCs). METHODS: A two-arm parallel group pilot randomised controlled trial (RCT), comparing MCs with PICCs, was conducted in a large tertiary hospital in Queensland between September 2020 and January 2021. The primary outcome was study feasibility, measured against rates of eligibility (>75%), consent (>90%), attrition (<5%); protocol adherence (>90%) and missing data (<5%). The primary clinical outcome was all-cause device failure. RESULTS: In total, 25 patients were recruited. The median patient age was 59-62 years; most patients were overweight/obese, with ≥2 co-morbidities. PRIMARY OUTCOMES: The eligibility and protocol adherence criteria were not met; of 159 screened patients, only 25 (16%) were eligible, and three patients did not receive their allocated intervention post-randomisation (88% adherence). All-cause failure occurred in two patients allocated to MC (20%) and one PICC (8.3%). CONCLUSIONS: Our study found that a fully powered RCT testing MCs compared with PICCs is not currently feasible in our setting. We recommend a robust process evaluation before the introduction of MCs into clinical practice.

Does longer peripheral intravenous catheter length optimise antimicrobial delivery? Protocol for the LEADER study.

BACKGROUND: Hospitalised patients receiving intravenous antimicrobial therapy require a reliable device through which this is delivered. Short peripheral intravenous catheters (PIVCs) are the default device for antimicrobial therapy but up to half fail before therapy completion, leading to suboptimal drug dosing, patient distress from repeated insertions, and increased healthcare costs. This study will investigate the use of long PIVCs to determine if they are more reliable at delivering antimicrobial therapy. METHODS: A two-arm, parallel randomised controlled trial of hospitalised adults requiring at least 3 days of peripherally compatible intravenous antimicrobials. Participants will be randomised to a short (<4 cm) or long (4.5-6.4 cm) PIVC. After interim analysis ( n=70) for feasibility and safety, 192 participants will be recruited. Primary outcome is disruption to antimicrobial administration from all-cause PIVC failure. Secondary outcomes include: number of devices to complete therapy, patient-reported pain and satisfaction, and a cost analysis. Ethical and regulatory approvals have been received.

Hope and healthy lifestyle behaviors in older adulthood.

OBJECTIVES: Hope has been associated with better health and social well-being outcomes, including emotional adjustment, positive affect, life satisfaction, reduced risk of all-cause mortality, and increased physical activity, yet how hope as a construct impacts these health benefits in older adults is not very well-understood. This study examined: (1) the relationship between hope and health behaviors in older adults; (2) how this relationship may differ across different socio-demographic groups; and (3) how hope relates to perceived future selves among older adults. METHODS: The study used cross-sectional data from 711 community-dwelling adults aged ≥55 years (280 men, 431 women). Survey measures included the Snyder Adult Dispositional Hope Scale (ADHS) and the Herth Hope Index (HHI), a health behaviors checklist, self-reported health, and a future self-scale. Data were analyzed using bivariate and multiple regressions. RESULTS: Hope was positively associated with healthy behaviors in older adults. Participants with higher levels of hope also reported more positive future selves and better health. The associations were similar across different racial/ethnic groups. CONCLUSIONS: This study fills an important gap in our understanding of hope and its association with health behaviors in community-dwelling older adults. These findings highlight a need to promote hope in older adults in order to enhance their sense of well-being.

Physical reserve: construct development and predictive utility.

BACKGROUND: Physical reserve (PR) refers to one's ability to maintain physical functioning despite age, illness, or injury. The measurement and predictive utility of PR, however, are not well established. AIMS: We quantified PR using a residual measurement approach by extracting standardized residuals from gait speed, while accounting for demographic and clinical/disease variables, and used it to predict fall-risk. METHODS: Participants (n = 510; age ≥ 70ys) were enrolled in a longitudinal study. Falls were assessed annually (in-person) and bimonthly (via structured telephone interview). RESULTS: General Estimating Equations (GEE) revealed that higher baseline PR was associated with reduced odds of reporting falls over repeated assessments in the total sample, and incident falls among those without fall's history. The protective effect of PR against fall risk remained significant when adjusting for multiple demographic and medical confounders. DISCUSSION/CONCLUSION: We propose a novel framework to assessing PR and demonstrate that higher PR is protective against fall-risk in older adults.

Safety and efficacy of midline catheters versus peripheral intravenous catheters: A pilot randomized controlled trial.

BACKGROUND: Despite pervasive need for peripheral intravenous catheters, insertion is often difficult, and approximately two thirds fail prematurely. Midline catheters are an alternative long peripheral catheter, inserted in the upper arm, ideal for patients with difficult access. AIM: The aim of this study is to test feasibility of the protocol and compare the efficacy and safety of midline catheters to peripheral intravenous catheters. DESIGN: A parallel-group, pilot randomized controlled trial of adult medical/surgical hospitalized patients, from a single Australian referral hospital. METHODS: Participants with difficult vascular access (≤2 palpable veins) and/or anticipated ≥5 days of peripherally compatible intravenous therapy were recruited between May 2019 and March 2020. Participants were randomized to (1) peripheral intravenous catheter or (2) midline catheter. Primary feasibility outcome measured eligibility, recruitment, protocol adherence, retention and attrition. Primary clinical outcomes measured device insertion failure and post-insertion failure. RESULTS: In total, n = 143 participants (71 peripheral intravenous catheters and 72 midline catheters) were recruited; n = 139 were analysed. Most feasibility criteria were met. Peripheral intravenous catheters had shorter functional dwell time, with higher incidence of post-insertion failure compared to midline catheters. CONCLUSION: Midline catheters appear to be superior for patients with difficult vascular access or receiving prolonged intravenous therapy; a large, multi-centre trial to confirm findings is feasible.

Agreement of telemetric temperature capsules ingested 48 hours apart.

Telemetric temperature capsules are frequently utilized to measure deep body temperature. Whereas most methods to measure temperature are conducted at a single site (e.g., rectal temperature), the location of ingested telemetry capsules varies. If distinct regions of the gastrointestinal tract have different temperatures, the measurements obtained using telemetry capsules will vary accordingly. This study examined the agreement of two telemetric temperature capsules in fifty-seven Army Ranger School students ingested 64 and 16 h before a cool weather waterborne movement. Twenty-one subjects (37%) (age: 25 ± 4, weight: 81±7 kg) retained both capsules. Subjects completed activities that could increase (e.g. exercise) and decrease (e.g. cold water immersion) body temperature. Agreement between the two capsules was assessed through concordance and Bland Altman analysis using a linear mixed model. Bias between the two capsules was low (0.01 °C, SE = 0.03, before a neck-deep immersion river crossing and -0.09 °C, SE = 0.08, after the river crossing), but there were large differences in the variance components (0.044 vs 0.155 total variance for the pre-crossing vs the post-crossing data). The 95% Limits of Agreement indicate that discordance between the two capsules was lower before the river crossing (-0.40 to +0.42 °C) than after (-0.86 to +0.68 °C). In summary, this study examined telemetry capsule agreement with more time between capsule ingestion (48 h) in a larger sample size than most previous studies on the topic, and found notable (95% LoA>0.4 °C) variability between the two capsules which was exacerbated after crossing a cold river. Differences in gastrointestinal location of telemetry capsules can introduce variability into the measurement of deep body temperature due to regional temperature differences. This variability may be acceptable for some study designs, but unacceptable when small changes in temperature are important to detect. If the convenience of telemetric temperature capsules is desired, an alternative is to use the capsule as a rectal suppository.

Examining the Effect of Increased Aerobic Exercise in Moderately Fit Adults on Psychological State and Cognitive Function.

Regular physical exercise can decrease the risk for obesity, diabetes, and cardiovascular disease, increase life expectancy, and promote psychological health and neurocognitive functioning. Cross-sectional studies show that cardiorespiratory fitness level (VO2 max) is associated with enhanced brain health, including improved mood state and heightened cognitive performance. Interventional studies are consistent with these cross-sectional studies, but most have focused on low-fit populations. Few such studies have asked if increasing levels of physical activity in moderately fit people can significantly enhance mood, motivation, and cognition. Therefore, the current study investigated the effects of increasing aerobic exercise in moderately fit individuals on psychological state and cognitive performance. We randomly assigned moderately fit healthy adults, 25-59 years of age, who were engaged in one or two aerobic exercise sessions per week to either maintain their exercise regimen (n = 41) or increase their exercise regimen (i.e., 4-7 aerobic workouts per week; n = 39) for a duration of 3 months. Both before and after the intervention, we assessed aerobic capacity using a modified cardiorespiratory fitness test, and hippocampal functioning via various neuropsychological assessments including a spatial navigation task and the Mnemonic Similarity Task as well as self-reported measures including the Positive and Negative Affect Scale, Beck Anxiety Inventory, State-Trait Anxiety Inventory, Perceived Stress Scale, Rumination Scale, Eating Disorders Examination, Eating Attitudes Test, Body Attitudes Test, and Behavioral Regulation of Exercise Questionnaire. Consistent with our initial working hypotheses, we found that increasing exercise significantly decreased measures of negative affect, including fear, sadness, guilt, and hostility, as well as improved body image. Further, we found that the total number of workouts was significantly associated with improved spatial navigation abilities and body image as well as reduced anxiety, general negative affect, fear, sadness, hostility, rumination, and disordered eating. In addition, increases in fitness levels were significantly associated with improved episodic memory and exercise motivation as well as decreased stress and disordered eating. Our findings are some of the first to indicate that in middle-aged moderately-fit adults, continuing to increase exercise levels in an already ongoing fitness regimen is associated with additional benefits for both psychological and cognitive health.

Securing jugular central venous access devices with dressings fixed to a liquid adhesive in an intensive care unit population: a randomised controlled trial.

BACKGROUND: Central venous access devices (CVADs) can have high rates of failure due to dressing-related complications. CVADs placed in the internal jugular vein are at particular risk of dressing failure-related complications, including catheter-associated bloodstream infection and medical adhesive-related skin injury. Application of Mastisol liquid adhesive (MLA) may reduce CVAD dressing failure and associated complications, by reducing the frequency of dressing changes. The aim of this study is to investigate whether, in an intensive care unit (ICU) population, standard dressing care with or without the addition of MLA, improves internal jugular CVAD dressing adherence. METHODS: This two-arm, parallel group randomised controlled trial will be conducted in three Australian ICUs. A total of 160 patients (80 per group) will be enrolled in accordance with study inclusion and exclusion criteria. Patients will be randomised to receive either (1) 'standard' (in accordance with local hospital policy) CVAD dressings (control) or (2) 'standard' dressings in addition to MLA (intervention). Patients will be followed from the time of CVAD insertion to 48 h after CVAD removal. The primary outcome is 'dressing failure' defined as requirement for initial CVAD dressing to be replaced prior to seven days (routine replacement). DISCUSSION: This study will be the first randomised controlled trial to evaluate the clinical effectiveness of MLA in the adult intensive care unit population and will also provide crucial data for patient-important outcomes such as infection and skin injury. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12621001012864 . Registered on 2 August 2021.

Building research capacity and culture: Exploring nurses' experience of implementing a nurse-led clinical trial.

AIM: To explore the experiences of a nursing team who implemented an international nurse-led clinical trial in practice and understand the facilitators to their involvement. BACKGROUND: The role and responsibilities of the clinical nurse are advancing to encompass research activity to help inform evidence-based practice. However, several personal and organisational challenges can inhibit nurses' capacity to implement and undertake research within clinical practice. METHODS: Three focus groups were conducted with members of a nursing team (N = 18). Thematic analysis was employed, and themes were identified and agreed upon by the research team. RESULTS: Five themes were identified: 'Previous experience of and attitudes to participation in clinical research', 'Decision-making regarding participation in the clinical trial', 'Facilitators of participation in the clinical trial', 'Challenges of research in nursing practice' and 'Future orientation towards research'. CONCLUSION: Through their experiences of implementing a nurse-led clinical trial within practice, nurses recognized a number of facilitators and challenges to their participation. The perceived relevance of the clinical trial to the nurses' practice, potential to improve patient care and appreciation of the nurse leader's expertise and understanding of their context were key motivators. Reciprocal trust with the nurse leader who was encouraging, motivating, supportive and accessible resulted in the engagement and commitment of the nursing team. IMPLICATIONS FOR NURSING MANAGEMENT: This paper offers a perspective that can inform senior nursing management teams when implementing and conducting evidence-based research amongst nursing teams and in doing so meet the needs of developing research capacity amongst clinical nurses.

N6-Methyladenosine Reader YTHDF1 Promotes ARHGEF2 Translation and RhoA Signaling in Colorectal Cancer.

BACKGROUND & AIMS: N6-methyladenosine (m6A) governs the fate of RNAs through m6A readers. Colorectal cancer (CRC) exhibits aberrant m6A modifications and expression of m6A regulators. However, how m6A readers interpret oncogenic m6A methylome to promote malignant transformation remains to be illustrated. METHODS: YTH N6-methyladenosine RNA binding protein 1 (Ythdf1) knockout mouse was generated to determine the effect of Ythdf1 in CRC tumorigenesis in vivo. Multiomic analysis of RNA-sequencing, m6A methylated RNA immunoprecipitation sequencing, YTHDF1 RNA immunoprecipitation sequencing, and proteomics were performed to unravel targets of YTHDF1 in CRC. The therapeutic potential of targeting YTHDF1-m6A-Rho/Rac guanine nucleotide exchange factor 2 (ARHGEF2) was evaluated using small interfering RNA (siRNA) encapsulated by lipid nanoparticles (LNP). RESULTS: DNA copy number gain of YTHDF1 is a frequent event in CRC and contributes to its overexpression. High expression of YTHDF1 is significantly associated with metastatic gene signature in patient tumors. Ythdf1 knockout in mice dampened tumor growth in an inflammatory CRC model. YTHDF1 promotes cell growth in CRC cell lines and primary organoids and lung and liver metastasis in vivo. Integrative multiomics analysis identified RhoA activator ARHGEF2 as a key downstream target of YTHDF1. YTHDF1 binds to m6A sites of ARHGEF2 messenger RNA, resulting in enhanced translation of ARHGEF2. Ectopic expression of ARHGEF2 restored impaired RhoA signaling, cell growth, and metastatic ability both in vitro and in vivo caused by YTHDF1 loss, verifying that ARHGEF2 is a key target of YTHDF1. Finally, ARHGEF2 siRNA delivered by LNP significantly suppressed tumor growth and metastasis in vivo. CONCLUSIONS: We identify a novel oncogenic epitranscriptome axis of YTHDF1-m6A-ARHGEF2, which regulates CRC tumorigenesis and metastasis. siRNA-delivering LNP drug validated the therapeutic potential of targeting this axis in CRC.

Cognitive Reserve Moderates the Efficiency of Prefrontal Cortex Activation Patterns of Gait in Older Adults.

BACKGROUND: Cognitive reserve (CR) protects against cognitive decline, but whether CR influences the efficiency of cortical control of gait has not been reported. The current study addressed this important gap in the literature. Specifically, we determined the role of CR in moderating the efficiency of functional near-infrared spectroscopy (fNIRS)-derived oxygenated hemoglobin (HbO2) in the prefrontal cortex (PFC) assessed during active walking. We hypothesized that higher CR would be associated with more efficient brain activation patterns. METHODS: Participants were 55 (mean age = 74.84; %female = 49.1) older adults who underwent the combined walking/fNIRS protocol and had magnetic resonance imaging data. We used an established dual-task walking paradigm that consisted of 3 task conditions: single-task walk (STW), single-task alpha (STA, cognitive task), and dual-task walk (DTW). Using the residual approach, CR was derived from a word-reading test score by removing variance accounted for by sociodemographic variables, tests of current cognitive functions, and a measure of structural brain integrity. RESULTS: CR moderated the change in fNIRS-derived HbO2 in the PFC across tasks. Higher CR was associated with smaller increases in fNIRS-derived HbO2 from the single tasks to dual-task walking (CR × DTW compared with STW: estimate = 0.183; p < .001; CR × DTW compared with STA: estimate = 0.257; p < .001). The moderation effect of CR remained significant when adjusting for multiple covariates and concurrent moderation effects of measures of gait performance, current cognitive functions, and structural integrity of the brain. CONCLUSION: The current study provided first evidence that higher CR was associated with better neural efficiency of walking in older adults.

Assessing therapy response in patient-derived xenografts.

Quantifying response to drug treatment in mouse models of human cancer is important for treatment development and assignment, yet remains a challenging task. To be able to translate the results of the experiments more readily, a preferred measure to quantify this response should take into account more of the available experimental data, including both tumor size over time and the variation among replicates. We propose a theoretically grounded measure, KuLGaP, to compute the difference between the treatment and control arms. We test and compare KuLGaP to four widely used response measures using 329 patient-derived xenograft (PDX) models. Our results show that KuLGaP is more selective than currently existing measures, reduces the risk of false-positive calls, and improves translation of the laboratory results to clinical practice. We also show that outcomes of human treatment better align with the results of the KuLGaP measure than other response measures. KuLGaP has the potential to become a measure of choice for quantifying drug treatment in mouse models as it can be easily used via the kulgap.ca website.

CRISPR screens identify cholesterol biosynthesis as a therapeutic target on stemness and drug resistance of colon cancer.

Cancer stem cells (CSCs) are responsible for tumor progression, recurrence, and drug resistance. To identify genetic vulnerabilities of colon cancer, we performed targeted CRISPR dropout screens comprising 657 Drugbank targets and 317 epigenetic regulators on two patient-derived colon CSC-enriched spheroids. Next-generation sequencing of pooled genomic DNAs isolated from surviving cells yielded therapeutic candidates. We unraveled 44 essential genes for colon CSC-enriched spheroids propagation, including key cholesterol biosynthetic genes (HMGCR, FDPS, and GGPS1). Cholesterol biosynthesis was induced in colon cancer tissues, especially CSC-enriched spheroids. The genetic and pharmacological inhibition of HMGCR/FDPS impaired self-renewal capacity and tumorigenic potential of the spheroid models in vitro and in vivo. Mechanistically, HMGCR or FDPS depletion impaired cancer stemness characteristics by activating TGF-ß signaling, which in turn downregulated expression of inhibitors of differentiation (ID) proteins, key regulators of cancer stemness. Cholesterol and geranylgeranyl diphosphate (GGPP) rescued the growth inhibitory and signaling effect of HMGCR/FDPS blockade, implying a direct role of these metabolites in modulating stemness. Finally, cholesterol biosynthesis inhibitors and 5-FU demonstrated antitumor synergy in colon CSC-enriched spheroids, tumor organoids, and xenografts. Taken together, our study unravels novel genetic vulnerabilities of colon CSC-enriched spheroids and suggests cholesterol biosynthesis as a potential target in conjunction with traditional chemotherapy for colon cancer treatment.