LiverZap: a chemoptogenetic tool for global and locally restricted hepatocyte ablation to study cellular behaviours in liver regeneration.

The liver restores its mass and architecture after injury. Yet, investigating morphogenetic cell behaviours and signals that repair tissue architecture at high spatiotemporal resolution remains challenging. We developed LiverZap, a tuneable chemoptogenetic liver injury model in zebrafish. LiverZap employs the formation of a binary FAP-TAP photosensitiser followed by brief near-infrared illumination inducing hepatocyte-specific death and recapitulating mammalian liver injury types. The tool enables local hepatocyte ablation and extended live imaging capturing regenerative cell behaviours, which is crucial for studying cellular interactions at the interface of healthy and damaged tissue. Applying LiverZap, we show that targeted hepatocyte ablation in a small region of interest is sufficient to trigger local liver progenitor-like cell (LPC)-mediated regeneration, challenging the current understanding of liver regeneration. Surprisingly, the LPC response is also elicited in adjacent uninjured tissue, at up to 100 µm distance to the injury. Moreover, dynamic biliary network rearrangement suggests active cell movements from uninjured tissue in response to substantial hepatocyte loss as an integral step of LPC-mediated liver regeneration. This precisely targetable liver cell ablation tool will enable the discovery of key molecular and morphogenetic regeneration paradigms.

Emerging From the Haze: A Multicenter, Controlled Pilot Study of a Multidimensional, Psychoeducation-Based Cognitive Rehabilitation Intervention for Breast Cancer Survivors Delivered With Telehealth Conferencing.

OBJECTIVE: To quantify the effect of a psychoeducation-based cognitive rehabilitation intervention on breast cancer survivors' self-report of cognitive function and investigate the feasibility of accrual, adherence, and multisite program delivery using secure telehealth conferencing. DESIGN: Prospective, nonblinded, wait-list controlled pilot study. SETTING: Nonprofit academic medical center and university medical center with associated community practice affiliates. PARTICIPANTS: Adult female survivors of stage I-III breast cancer reporting cognitive complaints 2 months to 5 years after chemotherapy (N=61). Ongoing endocrine and/or anti-HER-2 therapy was allowed. Patients were excluded for history of other conditions involving impaired cognitive function. Combination referred and volunteered sample. In total, 107 women were screened, 61 consented, and 52 analyzed. No attrition due to adverse events. Group allocation was based on consent timing and next scheduled cohort to minimize wait time for wait-list controls. INTERVENTION: Psychoeducation-based cognitive rehabilitation intervention delivered in a group setting during 6 weekly 2.5-hour classes. Included presentation, class exercises, discussion, and homework exercises. Provided in-person and virtually by Health Insurance Portability and Accountability Act compliant and encrypted telehealth conferencing. MAIN OUTCOME MEASURES: Primary: self-report of perceived cognitive function (PCF) was compared between the intervention group (n=27) and wait-list controls (n=28) with the Functional Assessment of Cancer Therapy-Cognition perceived cognitive impairment subscale. Secondary: feasibility for multisite delivery via teleconferencing was measured by total accrual, percent adherence to 4 of the 6 weeks of content, and participant satisfaction ratings. RESULTS: The intervention group demonstrated improvement in PCF both at the conclusion of the intervention and 1 month later (P<.01). Within-group improvement in PCF was maintained at 6 and 12 months (P<.01). CONCLUSION: These study results provide further preliminary evidence of the efficacy of psychoeducation-based cognitive rehabilitation as an intervention for decreased PCF in breast cancer survivors with cognitive complaints after chemotherapy. Feasibility for accrual, adherence, and participant satisfaction with secure telehealth conferencing was demonstrated. These positive pilot study results will inform future work.

Inflammation and blood-brain barrier breach remote from the primary injury following neurotrauma.

BACKGROUND: Following injury to the central nervous system, increased microglia, secretion of pro- and anti-inflammatory cytokines, and altered blood-brain barrier permeability, a hallmark of degeneration, are observed at and immediately adjacent to the injury site. However, few studies investigate how regions remote from the primary injury could also suffer from inflammation and secondary degeneration. METHODS: Adult female Piebald-Viral-Glaxo (PVG) rats underwent partial transection of the right optic nerve, with normal, age-matched, unoperated animals as controls. Perfusion-fixed brains and right optic nerves were harvested for immunohistochemical assessment of inflammatory markers and blood-brain barrier integrity; fresh-frozen brains were used for multiplex cytokine analysis. RESULTS: Immediately ventral to the optic nerve injury, immunointensity of both the pro-inflammatory biomarker inducible nitric oxide synthase (iNOS) and the anti-inflammatory biomarker arginase-1 (Arg1) increased at 7 days post-injury, with colocalization of iNOS and Arg1 immunoreactivity within individual cells. CD11b+ and CD45+ cells were increased 7 days post-injury, with altered BBB permeability still evident at this time. In the lower and middle optic tract and superior colliculus, IBA1+ resident microglia were first increased at 3 days; ED1+ and CD11b+ cells were first increased in the middle and upper tract and superior colliculus 7 days post-injury. Increased fibrinogen immunoreactivity indicative of altered BBB permeability was first observed in the contralateral upper tract at 3 days and middle tract at 7 days post-injury. Multiplex cytokine analysis of brain homogenates indicated significant increases in the pro-inflammatory cytokines, IL-2 and TNFα, and anti-inflammatory cytokine IL-10 1 day post-injury, decreasing to control levels at 3 days for TNFα and 7 days for IL-2. IL-10 was significantly elevated at 1 and 7 days post-injury with a dip at 3 days post-injury. CONCLUSIONS: Partial injury to the optic nerve induces a complex remote inflammatory response, characterized by rapidly increased pro- and anti-inflammatory cytokines in brain homogenates, increased numbers of IBA1+ cells throughout the visual pathways, and increased CD11b+ and ED1+ inflammatory cells, particularly towards the synaptic terminals. BBB permeability can increase prior to inflammatory cell infiltration, dependent on the brain region.

Prostate Specific Antigen Density as a Predictor of Clinically Significant Prostate Cancer When the Prostate Specific Antigen is in the Diagnostic Gray Zone: Defining the Optimum Cutoff Point Stratified by Race and Body Mass Index.

PURPOSE: We assessed the predictive value of prostate specific antigen density to detect clinically significant prostate cancer, defined as prostate cancer grade group 2 or greater, in a series of men undergoing prostate biopsy with prostate specific antigen 4 to 10 ng/ml. We sought to define an optimum cutoff point for prostate specific antigen density and assess how race and body mass index affects prostate specific antigen density performance. MATERIALS AND METHODS: We analyzed data on 2,162 men, of whom 56% were African American, with serum prostate specific antigen 4 to 10 ng/ml who underwent prostate biopsy. We compared the AUC between prostate specific antigen and prostate specific antigen density to predict clinically significant and any prostate cancer vs no cancer. We calculated the negative predictive value of prostate specific antigen density cutoff points ranging from 0.05 to 0.15 by every 0.01 step. We a priori defined the optimal cutoff point of prostate specific antigen density as a negative predictive value of 95% and tested whether the cutoff was sensitive to body mass index and race by comparing the negative predictive value across strata. RESULTS: Median prostate specific antigen was 5.6 ng/ml (IQR 4.8-7) and median prostate specific antigen density was 0.15 ng/ml/cc (IQR 0.1-0.22). Prostate specific antigen density improved the performance of prostate specific antigen to detect significant cancer (AUC 0.58 to 0.68) and any cancer (AUC 0.55 to 0.69, each p <0.001). We identified a prostate specific antigen density cutoff point of less than 0.08 ng/ml/cc with a 96% negative predictive value for grade group 2 or greater. This was largely unchanged among different races and body mass indexes. CONCLUSIONS: Regardless of race or body mass index men with prostate specific antigen density less than 0.08 were unlikely to harbor grade group 2 or greater disease when prostate specific antigen was 4 to 10 ng/ml. If validated, prostate specific antigen density is a simple inexpensive and available tool that can be used to identify men who can likely forego prostate biopsies, thus reducing the over detection and morbidity of unnecessary biopsies.

The Drosophila MAST kinase Drop out is required to initiate membrane compartmentalisation during cellularisation and regulates dynein-based transport.

Cellularisation of the Drosophila syncytial blastoderm embryo into the polarised blastoderm epithelium provides an excellent model with which to determine how cortical plasma membrane asymmetry is generated during development. Many components of the molecular machinery driving cellularisation have been identified, but cell signalling events acting at the onset of membrane asymmetry are poorly understood. Here we show that mutations in drop out (dop) disturb the segregation of membrane cortical compartments and the clustering of E-cadherin into basal adherens junctions in early cellularisation. dop is required for normal furrow formation and controls the tight localisation of furrow canal proteins and the formation of F-actin foci at the incipient furrows. We show that dop encodes the single Drosophila homologue of microtubule-associated Ser/Thr (MAST) kinases. dop interacts genetically with components of the dynein/dynactin complex and promotes dynein-dependent transport in the embryo. Loss of dop function reduces phosphorylation of Dynein intermediate chain, suggesting that dop is involved in regulating cytoplasmic dynein activity through direct or indirect mechanisms. These data suggest that Dop impinges upon the initiation of furrow formation through developmental regulation of cytoplasmic dynein.

Spatiotemporal oscillations of Notch1, Dll1 and NICD are coordinated across the mouse PSM.

During somitogenesis, epithelial somites form from the pre-somitic mesoderm (PSM) in a periodic manner. This periodicity is regulated by a molecular oscillator, known as the 'segmentation clock', that is characterised by an oscillatory pattern of gene expression that sweeps the PSM in a caudal-rostral direction. Key components of the segmentation clock are intracellular components of the Notch, Wnt and FGF pathways, and it is widely accepted that intracellular negative-feedback loops regulate oscillatory gene expression. However, an open question in the field is how intracellular oscillations are coordinated, in the form of spatiotemporal waves of expression, across the PSM. In this study, we provide a potential mechanism for this process. We show at the mRNA level that the Notch1 receptor and Delta-like 1 (Dll1) ligand vary dynamically across the PSM of both chick and mouse. Remarkably, we also demonstrate similar dynamics at the protein level; hence, the pathway components that mediate intercellular coupling themselves exhibit oscillatory dynamics. Moreover, we quantify the dynamic expression patterns of Dll1 and Notch1, and show they are highly correlated with the expression patterns of two known clock components [Lfng mRNA and the activated form of the Notch receptor (cleaved Notch intracellular domain, NICD)]. Lastly, we show that Notch1 is a target of Notch signalling, whereas Dll1 is Wnt regulated. Regulation of Dll1 and Notch1 expression thus links the activity of Wnt and Notch, the two main signalling pathways driving the clock.

The role of physical rehabilitation in stem cell transplantation patients.

The purpose of this paper is to review the evidence for the role of physical rehabilitation in stem cell transplantation patients. We will also review the literature and discuss professional experiences on how rehabilitation can play a role in stem cell transplant care and survivorship. Hematopoietic stem cell transplantation (HCT) is a procedure that has evolved substantially over the years to help treat multiple conditions, particularly hematologic malignancies. HCT can be very stressful on the body and can leave patients weakened and sometimes quite debilitated. Supportive care measures have advanced to improve the quality of life and overall survival of HCT survivors. One key component of improved supportive care is gaining increased attention, and that is physical medicine and rehabilitation. Its role in HCT survivorship care is expanding, and new insight and research within the discipline have focused on fatigue, inflammation, exercise, and the development of structured rehabilitation programs to improve the musculoskeletal sequelae of transplantation. This literature review has demonstrated the utility of physical rehabilitation in HCT, its impact on cancer-related fatigue, and to outline the current state of the literature on these topics. The paper delves into a background of HCT. Cancer-related fatigue in HCT is then discussed and summarized, and the role that exercise plays in modifying such fatigue is outlined. We then outline the models and the impact that physical rehabilitation may play in HCT recipients.

National Benchmarks to Understand how Doctor of Physical Therapy Learners from Minoritized Race and Ethnicity Groups Perceive their Physical Therapist Education Program.

OBJECTIVE: The demographic homogeneity of the physical therapist workforce and its educational pathway may undermine the profession's potential to improve the health of society. Building academic environments that support the development of all learners is fundamental to building a workforce to meet societal health care needs. The Benchmarking in Physical Therapy Education study uses the Physical Therapy Graduation Questionnaire to comprehensively assess learner perceptions of the physical therapist academic environment. The present report examined whether racial and ethnic minoritized (REM) physical therapist learners perceive their Doctor of Physical Therapy (DPT) education differently from their non-REM peers. METHODS: Five thousand and eighty graduating DPT learners in 89 institutions provided demographic data and perceptions of a range of learning environment domains. Analyses included REM versus non-REM comparisons as well as comparisons among individual race and ethnicity groups. RESULTS: Compared to their non-minoritized peers, REM respondents expressed less satisfaction with their education and lower confidence in their preparedness for entry-level practice. REM respondents observed more faculty professionalism disconnects and demonstrated less agreement that their program had fostered their overall psychological well-being. REM respondents experienced higher rates of mistreatment than their peers and reported higher rates of exhaustion and disengagement, the 2 axes of academic burnout. Black/African American and Hispanic/Latino/a/x (Hispanic, Latino, Latina, and/or Latinx) respondents incurred significantly more educational debt than Asian and White respondents. REM respondents reported greater empathy and greater interest in working in underserved communities. CONCLUSION: REM respondents perceived the physical therapist learning environment more negatively than their non-minoritized peers but expressed strong interest in serving people from underserved communities. These national benchmarks offer academic institutions the opportunity to self-assess their own environment and to work to improve the quality of the educational experience for all learners. IMPACT: In a nationwide benchmarking study, learners from minoritized race and ethnicity backgrounds reported more negative experiences and outcomes during physical therapist education than their non-minoritized peers. These same learners demonstrated high empathy and interest in serving people from underserved (under-resourced) communities. Learning environments that permit all individuals to thrive may be an essential avenue to improve the health of a rapidly diversifying society.

Wearable sensor-based performance status assessment in cancer: A pilot multicenter study from the Alliance for Clinical Trials in Oncology (A19_Pilot2).

Clinical performance status is designed to be a measure of overall health, reflecting a patient's physiological reserve and ability to tolerate various forms of therapy. Currently, it is measured by a combination of subjective clinician assessment and patient-reported exercise tolerance in the context of daily living activities. In this study, we assess the feasibility of combining objective data sources and patient-generated health data (PGHD) to improve the accuracy of performance status assessment during routine cancer care. Patients undergoing routine chemotherapy for solid tumors, routine chemotherapy for hematologic malignancies, or hematopoietic stem cell transplant (HCT) at one of four sites in a cancer clinical trials cooperative group were consented to a six-week prospective observational clinical trial (NCT02786628). Baseline data acquisition included cardiopulmonary exercise testing (CPET) and a six-minute walk test (6MWT). Weekly PGHD included patient-reported physical function and symptom burden. Continuous data capture included use of a Fitbit Charge HR (sensor). Baseline CPET and 6MWT could only be obtained in 68% of study patients, suggesting low feasibility during routine cancer treatment. In contrast, 84% of patients had usable fitness tracker data, 93% completed baseline patient-reported surveys, and overall, 73% of patients had overlapping sensor and survey data that could be used for modeling. A linear model with repeated measures was constructed to predict the patient-reported physical function. Sensor-derived daily activity, sensor-derived median heart rate, and patient-reported symptom burden emerged as strong predictors of physical function (marginal R2 0.429-0.433, conditional R2 0.816-0.822). Trial Registration: Clinicaltrials.gov Id NCT02786628.

Cancer-Related Cognitive Impairment: Retrospective Analyses of a Multidimensional, Psychoeducation-Based Cognitive Rehabilitation Intervention.

BACKGROUND: Managing cancer-related cognitive impairment (CRCI) is a vital component of optimal cancer survivorship care. Results from several small studies indicate growing support for the use of cognitive rehabilitation and training strategies. OBJECTIVES: This study aimed to retrospectively analyze the effects of a six-week standardized, multidimensional, psychoeducation-based group cognitive rehabilitation intervention for CRCI. METHODS: Retrospective analyses were conducted for data collected for 20 cohorts who received the intervention in groups of about six participants. Changes in cognitive function and health-related quality of life (HRQOL) were compared. FINDINGS: 85 of 110 participants completed pre- and postintervention assessments. A significant improvement for self-reported cognitive function and HRQOL was demonstrated and sustained over time. Program satisfaction was high.

Emerging From the Haze: A Pilot Study Evaluating Feasibility of a Psychoeducational Intervention to Improve Cancer-Related Cognitive Impairment in Gynecologic Cancer Survivors.

PURPOSE:: The objective of this pilot study is to evaluate the (1) applicability of a 15-hour attending-taught psychoeducational intervention in a retrospective cohort and (2) feasibility of a trainee-taught intervention in a prospective cohort of patients with gynecologic cancer to help manage cancer-related cognitive impairment (CRCI). METHODS:: Adults with any stage gynecologic cancer who completed chemotherapy and reported cognitive complaints were eligible. Additionally, the screening criteria of Functional Assessment of Cancer Therapy-Cognition (FACT-Cog) perceived cognitive impairment (PCI) subscale score <59 was used in the prospective cohort. Validated patient-reported outcomes including FACT-Cog and Patient-Reported Outcomes Measurement Information System (PROMIS) Applied Cognition Abilities and General Concerns were measured before and after the intervention. RESULTS:: Twelve patients underwent an attending-taught intervention between 2011 and 2014. Significant improvements in mean FACT-Cog PCI (+6.1, P < .048), quality of life (+2.4, P = .04), and total score (+9.8, P = .03) were demonstrated, while there was no significant change in mean FACT-Cog perceived cognitive abilities. Ten patients underwent a trainee-taught intervention in 2017. No significant changes in mean FACT-Cog subscale or total scores were seen. Significant improvements in PROMIS Applied Cognition Abilities (+8.2, P = .01) and PROMIS Applied Cognition General Concerns were demonstrated (-8.0, P < .01). CONCLUSIONS:: Our psychoeducational intervention demonstrates applicability to patients with gynecologic cancer reporting CRCI and supports the feasibility of more widespread training based on improvements in validated patient-reported outcomes related to cognition.

Early-Life Alcohol Intake and High-Grade Prostate Cancer: Results from an Equal-Access, Racially Diverse Biopsy Cohort.

Epidemiologic evidence for an association between alcohol and prostate cancer is mixed. Moreover, there is a lack of research investigating early-life alcohol intake as a risk factor for either overall or high-grade prostate cancer. We examined lifetime alcohol intake in association with prostate cancer diagnosis in an equal-access, racially diverse prostate biopsy cohort. Men undergoing prostate biopsy at the Durham Veterans Affairs Medical Center from 2007 to 2018 completed a survey indicating average number of alcoholic beverages consumed per week [categorized as none (ref), 1-6, ≥7] during each decade of life. Multivariable logistic regression was used to test the association between alcohol intake across decades and diagnosis of overall, low-grade [grade group (GG) 1-2] and high-grade prostate cancer (GG 3-5). Of 650 men ages 49-89 who underwent biopsy, 325 were diagnosed with prostate cancer, 238 with low-grade and 88 with high-grade disease. Relative to nondrinkers, men who consumed ≥7 drinks/week at ages 15 to 19 had increased odds of high-grade prostate cancer diagnosis (OR = 3.21, P trend = 0.020), with similar findings for ages 20 to 29, 30 to 39, and 40 to 49. Consistent with these results, men in the upper tertile of cumulative lifetime intake had increased odds of high-grade prostate cancer diagnosis (OR = 3.20, P trend = 0.003). In contrast, current alcohol intake was not associated with prostate cancer. In conclusion, among men undergoing prostate biopsy, heavier alcohol intake earlier in life and higher cumulative lifetime intake were positively associated with high-grade prostate cancer diagnosis, while current intake was unrelated to prostate cancer. Our findings suggest that earlier-life alcohol intake should be explored as a potential risk factor for high-grade prostate cancer. Cancer Prev Res; 11(10); 621-8. ©2018 AACR.

The Effects of Exercise on Patient-Reported Outcomes and Performance-Based Physical Function in Adults With Acute Leukemia Undergoing Induction Therapy: Exercise and Quality of Life in Acute Leukemia (EQUAL).

INTRODUCTION: Fatigue is a distressing symptom for adults with acute leukemia, often impeding their ability to exercise. OBJECTIVES: 1) Examine effects of a 4-week mixed-modality supervised exercise program (4 times a week, twice a day) on fatigue in adults with acute leukemia undergoing induction chemotherapy. 2) Evaluate effects of exercise program on cognition, anxiety, depression, and sleep disturbance. 3) Evaluate effect of intervention on adherence to exercise. METHODS: 17 adults (8 intervention, 9 control), aged 28-69 years, newly diagnosed with acute leukemia were recruited within 4 days of admission for induction treatment. Patient-reported outcomes (PROs) (fatigue, cognition, anxiety, depression, sleep disturbance, mental health, and physical health) and fitness performance-based measures (Timed Up and Go [TUG], Karnofsky Performance Status, and composite strength scoring) were assessed at baseline and at discharge. Changes in PRO and performance-based physical function measures from baseline to time of discharge were compared between groups using Wilcoxon Rank Sum tests. RESULTS: With PROMIS (Patient-Reported Outcomes Measurement Information System) Fatigue, we found a median change in fatigue (-5.95) for the intervention group, which achieved a minimally important difference that is considered clinically relevant. Intervention group reduced their TUG performance by 1.73 seconds, whereas the control group remained fairly stable. A concerning finding was that cognition decreased for both groups during their hospitalization. 80% adherence of visits completed with a mean of 6 sessions attended per week. CONCLUSIONS: Our study provides information on the impact of exercise on symptomatology, with focus on fatigue and other psychosocial variables in acute leukemia.

Bace1-dependent amyloid processing regulates hypothalamic leptin sensitivity in obese mice.

Obesity places an enormous medical and economic burden on society. The principal driver appears to be central leptin resistance with hyperleptinemia. Accordingly, a compound that reverses or prevents leptin resistance should promote weight normalisation and improve glucose homeostasis. The protease Bace1 drives beta amyloid (Aß) production with obesity elevating hypothalamic Bace1 activity and Aß1-42 production. Pharmacological inhibition of Bace1 reduces body weight, improves glucose homeostasis and lowers plasma leptin in diet-induced obese (DIO) mice. These actions are not apparent in ob/ob or db/db mice, indicating the requirement for functional leptin signalling. Decreasing Bace1 activity normalises hypothalamic inflammation, lowers PTP1B and SOCS3 and restores hypothalamic leptin sensitivity and pSTAT3 response in obese mice, but does not affect leptin sensitivity in lean mice. Raising central Aß1-42 levels in the early stage of DIO increases hypothalamic basal pSTAT3 and reduces the amplitude of the leptin pSTAT3 signal without increased inflammation. Thus, elevated Aß1-42 promotes hypothalamic leptin resistance, which is associated with diminished whole-body sensitivity to exogenous leptin and exacerbated body weight gain in high fat fed mice. These results indicate that Bace1 inhibitors, currently in clinical trials for Alzheimer's disease, may be useful agents for the treatment of obesity and associated diabetes.

Perceived Benefits and Barriers to Exercise for Recently Treated Adults With Acute Leukemia

PURPOSE/OBJECTIVES: To explore perceived exercise benefits and barriers in adults with acute leukemia who recently completed an inpatient exercise intervention during induction therapy.
. RESEARCH APPROACH: Descriptive, exploratory design using semistructured interviews.
. SETTING: Inpatient hematology/oncology unit at North Carolina Cancer Hospital in Chapel Hill.
. PARTICIPANTS: 6 adults with acute leukemia aged 35-67 years.
. METHODOLOGIC APPROACH: Content analyses of semistructured interviews that were conducted with each participant prior to hospital discharge.
. FINDINGS: Most participants were not meeting the recommended physical activity levels of 150 minutes of moderate-intensity exercise per week before their diagnosis. Patients were highly pleased with the exercise intervention and the overall program. Common barriers to exercise were anxiety and aches and pains.
. INTERPRETATION: Overall, participants experienced physical and psychological benefits with the exercise intervention with no adverse events from exercising regularly during induction chemotherapy. Referrals for cancer rehabilitation management will lead to prolonged recovery benefits.
. IMPLICATIONS FOR NURSING: Findings inform the nurses' role in encouraging and supporting adults with acute leukemia to exercise and be physically active during their hospitalization. Nurses should also be responsible for assisting patients with physical function activities to increase mobility and enhance overall health-related quality of life.

Temporal Ordering of Dynamic Expression Data from Detailed Spatial Expression Maps.

During somitogenesis, pairs of epithelial somites form in a progressive manner, budding off from the anterior end of the pre-somitic mesoderm (PSM) with a strict species-specific periodicity. The periodicity of the process is regulated by a molecular oscillator, known as the "segmentation clock," acting in the PSM cells. This clock drives the oscillatory patterns of gene expression across the PSM in a posterior-anterior direction. These so-called clock genes are key components of three signaling pathways: Wnt, Notch, and fibroblast growth factor (FGF). In addition, Notch signaling is essential for synchronizing intracellular oscillations in neighboring cells. We recently gained insight into how this may be mechanistically regulated. Upon ligand activation, the Notch receptor is cleaved, releasing the intracellular domain (NICD), which moves to the nucleus and regulates gene expression. NICD is highly labile, and its phosphorylation-dependent turnover acts to restrict Notch signaling. The profile of NICD production (and degradation) in the PSM is known to be oscillatory and to resemble that of a clock gene. We recently reported that both the Notch receptor and the Delta ligand, which mediate intercellular coupling, themselves exhibit dynamic expression at both the mRNA and protein levels. In this article, we describe the sensitive detection methods and detailed image analysis tools that we used, in combination with the computational modeling that we designed, to extract and overlay expression data from distinct points in the expression cycle. This allowed us to construct a spatio-temporal picture of the dynamic expression profile for the receptor, the ligand, and the Notch target clock genes throughout an oscillation cycle. Here, we describe the protocols used to generate and culture the PSM explants, as well as the procedure to stain for the mRNA or protein. We also explain how the confocal images were subsequently analyzed and temporally ordered computationally to generate ordered sequences of clock expression snapshots, hereafter defined as "kymographs," for the visualization of the spatiotemporal expression of Delta-like1 (Dll1) and Notch1 throughout the PSM.

Fatigue among patients with brain tumors.

Fatigue is a ubiquitous and an extremely distressing symptom among patients with brain tumors (BT), particularly those with high-grade gliomas. The pathophysiology of cancer-related fatigue (CRF) in the context of patients with BT is multifactorial and complex, involving biological, behavioral, medical and social factors. The etiology of CRF in the general oncology population is pointing to the role of inflammatory cytokines as a key factor in the genesis of CRF, but this research is currently limited in the setting of BT. CRF should be screened, assessed and managed according to clinical practice guidelines. Fatigue has recently emerged as a strong, independent prognostic factor for survival that provides incremental prognostic value to the traditional markers of prognosis in recurrent high-grade gliomas. Therefore, strategies to treat fatigue warrant investigation, not only to improve the QOL of a group of patients with often limited life expectancy, but also possibly to optimize survival.

Comparison of Methods for Determining Aerobic Exercise Intensity Using Heart Rate in Acute Leukemia Patients Prior to Induction Chemotherapy.

INTRODUCTION: Cardiopulmonary exercise testing (CPET), the gold standard of cardiopulmonary evaluation, is used to determine VO2 levels at different aerobic exercise training intensities; however, it may not be feasible to conduct CPET in all clinical settings. AIMS: To compare the heart rate reserve (HRR) and percent of 220-age methods for prescribing cycle ergometry exercise intensity using heart rate (HR) against the HRs obtained during a CPET in adults undergoing treatment for acute leukemia (AL). METHODS: In this exploratory study, part of a larger randomized controlled trial, 14 adults with AL completed CPET on a cycle ergometer with indirect calorimetry within 96 hr of admission to a cancer hospital to determine VO2peak and HR corresponding to low (40% VO2peak), moderate (60% VO2peak), and high (75% VO2peak) exercise intensities. Analyses of variance were used to compare estimated HR for each intensity level using the HRR and percent of 220-age methods with HR determined via VO2peak. RESULTS: HR corresponding to low-intensity exercise differed significantly across all three methods (p ≤ .05). No significant differences were observed between HR estimated via the percent of 220-age method and determined via VO2peak at moderate (100 ± 8 and 113 ± 24 bpm, p = .122) or high intensities (125 ± 10 and 123 ± 25 bpm, p = .994). CONCLUSION: In adults with AL, HR-based methods for defining aerobic exercise intensities should be used with caution. At low intensity, neither should be used, while at moderate and high intensities, the percent of 220-age equation might serve as an adequate substitute for CPET.

Retinoic Acid Signaling in B Cells Is Required for the Generation of an Effective T-Independent Immune Response.

Retinoic acid (RA) plays an important role in the balance of inflammation and tolerance in T cells. Furthermore, it has been demonstrated that RA facilitates IgA isotype switching in B cells in vivo. However, it is unclear whether RA has a direct effect on T-independent B cell responses in vivo. To address this question, we generated a mouse model where RA signaling is specifically silenced in the B cell lineage. This was achieved through the overexpression of a dominant negative receptor α for RA (dnRARα) in the B cell lineage. In this model, we found a dramatic reduction in marginal zone (MZ) B cells and accumulation of transitional 2 B cells in the spleen. We also observed a reduction in B1 B cells in the peritoneum with a defect in the T-independent B cell response against 2,4,6-trinitrophenyl. This was not a result of inhibited development of B cells in the bone marrow, but likely the result of both defective expression of S1P1 in MZ B cells and a defect in the development of MZ and B1 B cells. This suggests that RARα expression in B cells is important for B cell frequency in the MZ and peritoneum, which is crucial for the generation of T-independent humoral responses.

An Unexpected Transient Breakdown of the Blood Brain Barrier Triggers Passage of Large Intravenously Administered Nanoparticles.

The highly restrictive blood-brain barrier (BBB) plays a critically important role in maintaining brain homeostasis and is pivotal for proper neuronal function. The BBB is currently considered the main limiting factor restricting the passage of large (up to 200 nm) intravenously administered nanoparticles to the brain. Breakdown of the barrier occurs as a consequence of cerebrovascular diseases and traumatic brain injury. In this article, we report that remote injuries in the CNS are also associated with BBB dysfunction. In particular, we show that a focal partial transection of the optic nerve triggers a previously unknown transient opening of the mammalian BBB that occurs in the visual centres. Importantly, we demonstrate that this transient BBB breakdown results in a dramatic change in the biodistribution of intravenously administered large polymeric nanoparticles which were previously deemed as BBB-impermeable.