Autophagy counters inflammation-driven glycolytic impairment in aging hematopoietic stem cells

Autophagy is central to the benefits of longevity signaling programs and to hematopoietic stem cell (HSC) response to nutrient stress. With age, a subset of HSCs increases autophagy flux and preserves regenerative capacity, but the signals triggering autophagy and maintaining the functionality of autophagy-activated old HSCs (oHSCs) remain unknown. Here, we demonstrate that autophagy is an adaptive cytoprotective response to chronic inflammation in the aging murine bone marrow (BM) niche. We find that inflammation impairs glucose uptake and suppresses glycolysis in oHSCs through Socs3-mediated inhibition of AKT/FoxO-dependent signaling, with inflammation-mediated autophagy engagement preserving functional quiescence by enabling metabolic adaptation to glycolytic impairment. Moreover, we show that transient autophagy induction via a short-term fasting/refeeding paradigm normalizes glycolytic flux and significantly boosts oHSC regenerative potential. Our results identify inflammation-driven glucose hypometabolism as a key driver of HSC dysfunction with age and establish autophagy as a targetable node to reset oHSC regenerative capacity.

Validity of the Bern Score as a Surrogate Marker of Clinical Severity in Patients with Spontaneous Intracranial Hypotension

BACKGROUND AND PURPOSE

The Bern score is a quantitative scale characterizing brain MR imaging changes in spontaneous intracranial hypotension. Higher scores are associated with more abnormalities on brain MR imaging, raising the question of whether the score can serve as a measure of disease severity. However, the relationship between clinical symptom severity and the Bern score has not been evaluated. Our purpose was to assess correlations between Bern scores and clinical headache severity in spontaneous intracranial hypotension.

MATERIALS AND METHODS

This study was a single-center, retrospective cohort of patients satisfying the International Classification of Headache Disorders-3 criteria for spontaneous intracranial hypotension. Fifty-seven patients who completed a pretreatment headache severity questionnaire (Headache Impact Test-6) and had pretreatment brain MR imaging evidence of spontaneous intracranial hypotension were included. Pearson correlation coefficients (ρ) for the Headache Impact Test-6 and Bern scores were calculated. Receiver operating characteristic curves were used to assess the ability of Bern scores to discriminate among categories of headache severity.

RESULTS

We found low correlations between clinical headache severity and Bern scores (ρ = 0.139; 95% CI, -0.127-0.385). Subgroup analyses examining the timing of brain MR imaging, symptom duration, and prior epidural blood patch showed negligible-to-weak correlations in all subgroups. Receiver operating characteristic analysis found that the Bern score poorly discriminated subjects with greater headache severity from those with lower severity.

CONCLUSIONS

Pretreatment Bern scores show a low correlation with headache severity in patients with spontaneous intracranial hypotension. This finding suggests that brain imaging findings as reflected by Bern scores may not reliably reflect clinical severity and should not replace clinical metrics for outcome assessment.

Autophagy counters inflammation-driven glycolytic impairment in aging hematopoietic stem cells

Aging of the hematopoietic system promotes various blood, immune and systemic disorders and is largely driven by hematopoietic stem cell (HSC) dysfunction ( 1 ). Autophagy is central for the benefits associated with activation of longevity signaling programs ( 2 ), and for HSC function and response to nutrient stress ( 3,4 ). With age, a subset of HSCs increases autophagy flux and preserves some regenerative capacity, while the rest fail to engage autophagy and become metabolically overactivated and dysfunctional ( 4 ). However, the signals that promote autophagy in old HSCs and the mechanisms responsible for the increased regenerative potential of autophagy-activated old HSCs remain unknown. Here, we demonstrate that autophagy activation is an adaptive survival response to chronic inflammation in the aging bone marrow (BM) niche ( 5 ). We find that inflammation impairs glucose metabolism and suppresses glycolysis in aged HSCs through Socs3-mediated impairment of AKT/FoxO-dependent signaling. In this context, we show that inflammation-mediated autophagy engagement preserves functional quiescence by enabling metabolic adaptation to glycolytic impairment. Moreover, we demonstrate that transient autophagy induction via a short-term fasting/refeeding paradigm normalizes glucose uptake and glycolytic flux and significantly improves old HSC regenerative potential. Our results identify inflammation-driven glucose hypometabolism as a key driver of HSC dysfunction with age and establish autophagy as a targetable node to reset old HSC glycolytic and regenerative capacity.

One-Sentence Summary

Autophagy compensates for chronic inflammation-induced metabolic deregulation in old HSCs, and its transient modulation can reset old HSC glycolytic and regenerative capacity.

The effect of standing posture on amplitude and variability of postural tremor in Parkinson’s disease

INTRODUCTION

This study examined whether altering body position (i.e., sitting or standing) affected the dynamics of physiological tremor for healthy older adults and persons with Parkinson's disease (PD). It was also of interest to determine how consistent the tremor was for both groups as determined by examining changes in within-subject variability of tremor amplitude, regularity and frequency.

METHODS

Ten Parkinsonian participants (65.1±3.2 yrs.) and twelve elderly persons (71.2±2.6 yrs.) participated in this study. Tremor was collected from the index finger and hand segments using lightweight accelerometers during the performance of a bilateral pointing task. Persons performed the pointing task in a standing or sitting position.

RESULTS

As expected, the tremor for the PD persons was greater in magnitude (mean RMS, peak power), more regular (lower SampEn), and more inconsistent from trial-to-trial (increased intra-individual variability, IIV) than the tremor recorded for the elderly. Further, when assessed during standing, the magnitude of the tremor for all individuals (elderly and PD) was greater, more variable, and less complex compared to the tremor when assessed during the sitting posture. The only measure which did not change within each group was the frequency of the major tremor peak which remained consistent, showing no significant change between limbs or as a function of the posture adopted.

CONCLUSION

The findings revealed that tremor increased in amplitude and decreased in regularity for all individuals was assessed when standing compared to sitting. It is likely that these increases were task-related, reflecting the increased physical demands of performing the task when standing rather than being driven by specific age- or disease-related changes in the mechanisms underlying tremorgenesis. Further, the tremor for the PD individuals tended to be more variable from trial-by-trial in terms of both amplitude and regularity as compared to the elderly persons. Interestingly, the only tremor metric which showed no change within each group was the frequency of the major tremor peak which was consistent within both groups irrespective of the posture adopted.

Abstract PR003: OXPHOS impairing mitochondrial DNA mutations suppress melanoma growth and metastatic progression

Cancers acquire somatic mitochondrial DNA (mtDNA) mutations undetected in surrounding tissues. Cancer-specific mtDNA mutations primarily constitute variants of unknown significance whose oncogenic consequences are poorly understood. Analysis of large-scale sequencing datasets suggests that human cancers generally select against severe mtDNA mutations; however, the presence of selective pressure on the mtDNA genome has yet to be experimentally demonstrated. Here we optimized a FACS-based protocol to reconstitute the highly metastatic human melanoma cell line A375 with exogenous mtDNA, thereby generating nuclear-isogenic cytoplasmic hybrid (cybrid) lines. Homoplasmic cybrids were generated exclusively harboring either exogenous wildtype mtDNA, mtDNA with partial loss of OXHPHOS function (SNPs in mt.ND1 (of Complex I) or mt.ATP6 (of Complex V)), or mtDNA with complete loss of OXPHOS function (derived from a human melanoma harboring a truncating frameshift mutation in mt.CO1 (of Complex IV)). Compared to wildtype cybrids, subcutaneous xenografts of ND1 and ATP6 cybrids into NOD–SCID Il2rg−/− (NSG) mice had elevated primary tumor ROS levels and similar primary tumor growth rates. Xenografts of our most dysfunctional OXPHOS cybrid, CO1, formed tumors albeit with lowered growth rates. Uniquely, the ND1 and CO1 xenografts respectively exhibited diminished metastatic burden and no metastatic burden. Our results suggest that OXPHOS impairing mtDNA mutations are tolerable during primary tumor growth but reduce the severity and incidence of metastasis. Lastly, we generated heteroplasmic A375 cybrids, harboring both wild-type and mutant alleles, and developed a ddPCR method to characterize allelic frequency with single-cell precision. Extended in vitro passage of the heteroplasmic cybrids failed to significantly shift the heteroplasmic mtDNA allelic frequency. However, following subcutaneous xenografting of the heteroplasmic cybrids, primary tumors significantly shifted their variant allele frequency to favor the wildtype allele. In summary, these results indicate that a functional mtDNA haplotype is not absolutely required for tumorigenesis but contributes to metastatic efficiency. In addition, we experimentally demonstrated the existence of selective pressure in favor of functional mtDNA during tumorigenesis.

Citation Format: Spencer Shelton, Sara House, Vijayashree Ramesh, Zhengkang Chen, Claire Llamas, Alpaslan Tasdogan, Ralph DeBerardinis, Sean Morrison, Prashant Mishra. OXPHOS impairing mitochondrial DNA mutations suppress melanoma growth and metastatic progression [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR003.

THE EFFECT OF DISRUPTIVE MEDICAL EVENTS ON MORTALITY IN PEOPLE WITH AND WITHOUT DEMENTIA

Disruptive medical events such as pneumonia and hip fracture occur more frequently among older adults with dementia than those without dementia. It is not well-understood whether these events increase the risk of mortality to a greater extent for people with dementia (PWD) compared to people without dementia (PWoD). Using data from the Health and Retirement Study linked to Medicare claims, we estimated the impact of hip fracture and pneumonia on risk of mortality among 700 PWD and 12,438 PWoD using a Cox proportional hazards model. PWD had a higher risk of mortality both in the case of hip fracture (HR 1.64, 95% CI 1.31, 1.96) and pneumonia (HR 1.21 95% CI 1.09, 1.34) compared to PWoD who experienced those events. This study provides evidence that dementia may increase mortality after a disruptive medical event and suggests that the clinical course of dementia may not always be slow and gradual.

THE WIDOWHOOD EFFECT IN COMPLEX SERIOUS ILLNESS: THE IMPACT OF SPOUSAL DEATH ON MORTALITY IN DEMENTIA

Numerous studies suggest that there is an association between widowhood and mortality. This “widowhood effect” may be heightened in patients with dementia, who have high support needs and for whom spouses typically provide extensive caregiving support. Yet there are limited data on widowhood and mortality that account for dementia status. To determine the relative mortality risk of widowhood among those with and without dementia, we conducted a retrospective cohort study among community-dwelling, married/partnered persons, ≥65 years, enrolled in the Health and Retirement Study, 2000-2018. Among the 12,308 persons (n=390 with dementia), widowhood was not associated with increased mortality, after adjusting for age and dementia status, in men or women (adjusted HR 1.04; 95%C.I.(0.95-1.13); HR 0.96; 95%C.I.(0.87-1.95), respectively). These findings suggest that dementia, age, or other unmeasured confounding variables may account for the previous finding of increased mortality following spousal death. Further research is needed to confirm these findings in diverse populations.

Caught in a Loop with Advance Care Planning and Advance Directives: How to Move Forward?

Completion of an advance care planning (ACP) process and/or an advance directive should result in patients receiving the care they desire at the end of life. However, three decades of research have shown that is just not the case. ACP has been a front runner in developing the science within palliative care. Some positive outcomes such as lowering levels of surrogate grief may be associated with ACP. Yet, it does not appear that further ACP research will ensure that seriously ill patients will get goal-concordant care. An unfortunate consequence of palliative care research and advocacy so far is the misguided notion of many hospital systems trying to solve their palliative care problems by only implementing an ACP initiative. At best, ACP is but one tool in the collective palliative care toolbox. New tools are needed. Given that we have finite resources, future research should focus more on tools to improve symptom management, better models of care, and systems that will ensure goal-concordant care that meet the needs of the population that the health care system is designed to meet.

Physiological tremor is suppressed and force steadiness is enhanced with increased availability of serotonin regardless of muscle fatigue

Although there is evidence that 5-HT acts as an excitatory neuromodulator to enhance maximal force generation, it is largely unknown how 5-HT activity influences the ability to sustain a constant force during steady-state contractions. A total of 22 healthy individuals participated in the study, where elbow flexion force was assessed during brief isometric contractions at 10% maximal voluntary contraction (MVC), 60% MVC, MVC, and during a sustained MVC. The selective serotonin reuptake inhibitor, paroxetine, suppressed physiological tremor and increased force steadiness when performing the isometric contractions. In particular, a main effect of drug was detected for peak power of force within the 8-12 Hz range (P = 0.004) and the coefficient of variation (CV) of force (P < 0.001). A second experiment was performed where intermittent isometric elbow flexions (20% MVC sustained for 2 min) were repeatedly performed so that serotonergic effects on physiological tremor and force steadiness could be assessed during the development of fatigue. Main effects of drug were once again detected for peak power of force in the 8-12 Hz range (P = 0.002) and CV of force (P = 0.003), where paroxetine suppressed physiological tremor and increased force steadiness when the elbow flexors were fatigued. The findings of this study suggest that enhanced availability of 5-HT in humans has a profound influence of maintaining constant force during steady-state contractions. The action of 5-HT appears to suppress fluctuations in force regardless of the fatigue state of the muscle.NEW & NOTEWORTHY Converging lines of research indicate that enhanced serotonin availability increases maximal force generation. However, it is largely unknown how serotonin influences the ability to sustain a constant force. We performed two experiments to assess physiological tremor and force steadiness in unfatigued and fatigued muscle when serotonin availability was enhanced in the central nervous system. Enhanced availability of serotonin reduced physiological tremor amplitude and improved steadiness regardless of muscle fatigue.

1631 The Pen is Mightier than the Sword; but the Keyboard may be Better

Introduction

Operation notes ensure patient safety through continuity of care, and act as reliable treatment records. Notes must be legible, accessible, and contain all relevant information. Specific standards are outlined in the Good Surgical Practice Guidelines (2014) by the Royal College of Surgeons of England. Audits in the UK show poor adherence to these standards. Online operative note systems are becoming more common, but variety still exists in operations notes. This work assessed operative note standards in an orthopaedic department and assessed the utility of electronic operative note systems.

Method

This was a prospective quality improvement project. Operation notes for all emergency orthopaedic operations were audited against national standards. An online operation note system was introduced and re-audit carried out following implementation.

Results

Initial audit noted poor adherence to standards. An online operative note system was introduced. A second audit with 96 patients was undertaken. Uptake of the software was low, with 10% of notes being online. 19 of 21 information points showed improved standards adherence with the online system versus other methods. In the remaining 2 areas 100% of notes adhered to standards in both methods. The online system had 100% adherence in 19 data points, and 90% in the remaining 2.

Conclusions

Online note softwares have various benefits, including improved adherence to standards. Other benefits exist, such as databasing of operations for review and audit. These systems appear reliable and beneficial for operative documentation and are easily implemented; however, some work is still required to change old habits and improve uptake.

A humeral intracondylar repair system for the management of humeral intracondylar fissure and humeral condylar fracture

OBJECTIVES

To report complications, clinical outcomes and CT-imaging outcomes of a surgical system designed for the management of humeral intracondylar fissures and humeral condylar fractures.

MATERIALS AND METHODS

Retrospective review of fracture healing from medical records, direct owner contact and an online data-submission service. Follow-up included CT scans and a calculated "bone-opacity continuity index" to quantify bone healing.

RESULTS

There was one major surgical complication and one major medical complication out of 34 fissure cases, and two major surgical and one major medical complication out of 14 fractures. Follow-up times ranged from 29 to 1268 days. All cases with CT follow-up had some continuity of bone opacity across the condyle.

CLINICAL SIGNIFICANCE

In the cases included in this study, this repair system was associated with low complication rates and favourable healing rates, particularly for humeral intracondylar fissure.

Regional anesthesia combined with virtual reality hypnosis for extended orthopedic surgery: two case reports

Background : Virtual reality hypnosis is a combination of visual immersion in a virtual reality environment and clinical hypnosis. It can be used in addition to conventional techniques, for sedation and pain management during wound care. Patients undergoing painful and long-lasting procedures under regional anesthesia could also benefit, from this technique alleviating the need for sedative-hypnotic medication. Case presentation : Two patients with relative contra- indications for general anesthesia underwent lengthy orthopedic surgery of the upper limbs under regional anesthesia with additional virtual reality hypnosis. Written informed consent was obtained from both patients before surgery. A 69-year-old man, with a previous medical history of severe symptomatic aortic valve stenosis (ѳ 0.69cm2, max/mean gradient of 91/58mmHg) sustained a proximal humerus fracture-dislocation and was scheduled to undergo shoulder hemi-arthroplasty. Anesthesia was provided with ultrasound-guided continuous interscalene block at the C5-C6 level (11mL levobupivacaine 0.5%) combined with a single-shot superficial cervical plexus block (6mL levobupivacaine 0.5%). The second case was a 56-year-old man suffering from rheumatoid arthritis with severe restrictive lung function due to interstitial lung disease and bilateral bronchiectasis. He received a unilateral elbow prosthesis. Continuous infra-clavicular brachial plexus block, per- formed under ultrasound guidance was provided (20 mL mepivacaine 1.5%). Both patients required prolonged immobilization on the operating table. We used virtual reality hypnosis to induce sedation and improve comfort without using medication. This was provided by headphones and head-mounted goggles, showing computer generated images of underwater scenes (Aqua module, Oncomfort ™). Both surgeries were uneventful during which time cardiorespiratory stability was maintained. Patients were comfortable during and satisfied after surgery. No sedative drugs were given before nor during the procedures. Conclusion : Non-pharmacological sedation can be achieved with virtual reality hypnosis. When com- bined with regional anesthesia, this technique provides satisfactory sedation when pharmacological methods may be hazardous.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Assessment of the gait-related acceleration patterns in adults with autism spectrum disorder

Individuals with autism spectrum disorder (ASD) can exhibit a range of movement issues, which are often characterized by a general slowing of movement responses that can extend to walking speed. The current study was designed to examine the spatio-temporal features and pattern of acceleration for the trunk, neck and head during walking for a cohort of adults with ASD compared to neurotypical individuals. Twenty young adults with ASD and 20 age-matched neurotypical adults participated in this study. Participants performed five walking trials across a 20ft Protokinetics pressure sensitive surface at their preferred walking speed. Accelerations were collected using three triaxial accelerometers affixed to the head, neck, and lower trunk. Comparisons of acceleration amplitude (i.e., RMS), frequency, segmental gain and regularity (i.e., SampEn) during the walking tasks were performed. Results revealed that the adults with ASD walked slower than the neurotypical persons with a greater proportion of time spent in double stance. Despite walking at a slower pace overall, the adults with ASD exhibited a decreased ability to attenuate gait-related oscillations from the trunk to the head. Overall, these findings suggest that adults with ASD exhibited a decreased ability to accommodate and dampen those accelerations related to walking. As declines in gait speed are often linked with loss of head control, one suggestion is that the inability to appropriately compensate for gait-related oscillations may, in part, explain why persons with ASD walk slower.

Short-term comparison between preperitoneal and intraperitoneal onlay mesh placement in robotic ventral hernia repair

PURPOSE

The aim of this study was to compare perioperative results of robotic IPOM (r-IPOM) and robotic TAPP (r-TAPP) in ventral hernia repair, and to identify risk factors associated with postoperative complications.

METHODS

After obtaining balanced groups with propensity score matching, the comparative analysis was performed in terms of perioperative and early outcomes. All variables were also examined in a subset analysis in patients with and without complications. Multivariable regression analysis was used to identify independent risk factors associated with the development of complications.

RESULTS

Of 305 r-IPOM and r-TAPP procedures, 104 patients were assigned to each group after propensity score matching. There was no difference in operative times between two groups. Although postoperative complications were largely minor (Clavien-Dindo grade-I and II), the rate of complications was higher in the r-IPOM group within the first 3-weeks (33.3% in r-IPOM vs. 20% in r-TAPP, p = 0.039). At the 3-month visit, outcomes between groups were not different (p = 0.413). Emergency department re-visits within 30-days and surgical site events were also higher in the IPOM group (p = 0.028, p = 0.042, respectively). In regression analysis, the development of complications was associated with incisional hernias (p = 0.040), intraperitoneal mesh position (p = 0.046) and longer procedure duration (p = 0.049).

CONCLUSION

Our data suggest r-IPOM may be associated with increased complication rates in the immediate postoperative period when compared to r-TAPP. However, at 3 months, outcomes are comparable. More investigation is needed in this area, specifically with regards to long-term follow-up and multicenter data, to determine the true value of extra-peritoneal mesh placement.

Robotic retromuscular ventral hernia repair and transversus abdominis release: short-term outcomes and risk factors associated with perioperative complications

BACKGROUND

Retromuscular ventral hernia repairs have become increasingly popular, both with and without transversus abdominis release. We aim to describe our 90-day outcomes in patients who underwent robotic retromuscular ventral hernia repair (RRVHR).

METHODS

All patients were subcategorized into those who underwent a TAR (TAR+) as part of their repair, and those who did not (TAR-). Patient demographics, comorbidities, hernia characteristics, and LOS were studied. Perioperative complications were reviewed in four different time frames up to 90 days. All hernias and complications were classified using the recommended classification systems. Appropriate univariate analyses and multivariate regression analyses were performed to determine the hernia characteristics which required a TAR technique, and risk factors which associated with the development of complications.

RESULTS

Of 454 robotic ventral hernia repairs, 101 patients who underwent RRVHR were included into the study. Of these, 54 patients underwent RRVHR with TAR while the remaining 47 patients underwent repair without TAR. Incisional hernias, off-midline locations, and larger size defects were factors that required the addition of a TAR. In 9.9% patients, an unplanned TAR was performed. Postoperative pain assessment was similar in both groups. LOS was significantly longer for TAR + group (p < 0.001). The median Comprehension Complication Index^® score was 8.7 (range: 0-42.4) for all patients and was significantly higher for TAR+ group (p = 0.014). Complications were higher in the TAR+ group as compared to the TAR- group (p = 0.028), though this difference did not persist in follow-up. Most complications were minor (Clavien-Dindo grade-I and -II). The development of complications was only associated with the presence of an incarcerated hernia at repair.

CONCLUSION

RRVHR is safe and feasible. 9.9% of our cohort required a TAR that was unplanned, particularly incisional hernias. TAR patients may be more prone to complications in the immediate post-operative period, however, the difference between patients with and without TAR adjuncts resolved at 90 days.

Blood immune transcriptome analysis of artificially fed dairy calves and naturally suckled beef calves from birth to 7 days of age

Neonatal calves possess a very immature and naïve immune system and are reliant on the intake of maternal colostrum for passive transfer of immunoglobulins. Variation in colostrum management of beef and dairy calves is thought to affect early immune development. Therefore, the objective of this study was to examine changes in gene expression and investigate molecular pathways involved in the immune-competence development of neonatal Holstein dairy calves and naturally suckled beef calves using next generation RNA-sequencing during the first week of life. Jugular whole blood samples were collected from Holstein (H) dairy calves (n = 8) artificially fed 5% B.W. colostrum, and from beef calves which were the progenies of Charolais-Limousin (CL; n = 7) and Limousin-Friesian beef suckler cows (LF; n = 7), for subsequent RNA isolation. In dairy calves, there was a surge in pro-inflammatory cytokine gene expression possibly due to the stress of separation from the dam. LF calves exhibited early signs of humoral immune development with observed increases in the expression genes coding for Ig receptors, which was not evident in the other breeds by 7 days of age. Immune and health related DEGs identified as upregulated in beef calves are prospective contender genes for the classification of biomarkers for immune-competence development, and will contribute towards a greater understanding of the development of an immune response in neonatal calves.

A meta-analysis of the efficacy of allopurinol in reducing the incidence of myocardial infarction following coronary artery bypass grafting

Background

The xanthine oxidase inhibitor allopurinol that is commonly used to treat gout, has been suggested to have pleiotropic effects that are likely to reduce the incidence of myocardial infarction (MI) in at risk individuals. The aim of this meta-analysis was to assess the efficacy of allopurinol treatment in reducing the incidence of MI.

Method

MEDLINE, Scopus, Web of Science, and Cochrane Library databases were searched for randomised controlled trials examining the efficacy of allopurinol in reducing the incidence of MI. The quality of study methodology was assessed by two independent reviewers using the Cochrane Collaboration’s tool for assessing risk of bias. This meta-analysis was conducted using a fixed-effects model, and heterogeneity was assessed with the I² index.

Results

One thousand one hundred twenty-three citations were screened and only six studies satisfied the inclusion criterion. Published between 1988 and 1995, all studies examined the cardioprotective efficacy of allopurinol in the setting of coronary artery bypass graft (CABG). From a total pooled sample size of 229, MI was reported in 2 (1.77%) allopurinol and 14 (12.07%) control patients. A fixed-effects meta-analysis (I² = 0%) identified a statistically significant reduced incidence of myocardial infarction (RR 0.21, 95% CI: 0.06, 0.70, p = 0.01) in patients allocated to allopurinol. However, in the leave-one-out sensitivity analyses, the treatment effect became non-significant with the removal of one of the studies.

Conclusion

Based on the limited evidence available, allopurinol appears to reduce the incidence of perioperative MI following CABG. Further research is required to confirm these findings.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0881-6) contains supplementary material, which is available to authorized users.

L-18F-DOPA-PET bei Parkinson-Plus-Syndromen zum Nachweis einer gestörten präsynaptischen dopaminergen Funktion

Bei 14 Patienten mit Parkinson-Plus-Syndromen (PPLUS) wurden PET-Unter- suchungen mittels L-18F-DOPA unter Verwendung einer arteriellen Inputfunktion durchgeführt. Aufgrund von Modellannahmen konnte für den radioaktiven Tracer die Influxkonstante Ki in Abhängigkeit von Korrekturen der unspezifischen Aktivität im Kortex oder Zerebellum bestimmt werden. Die Ergebnisse wurden mit denen von 20 gesunden Kontrollen verglichen und im Hinblick auf die Intra- und Interuntersucher-Variabilität ausgewertet. Bei Patienten mit Parkinson-Plus-Syndromen war in allen Fällen die Influxkonstante Ki erniedrigt. Ihr Mittelwert betrug 0,154 (ml/Striatum/min) bei PPLUS gegenüber 0,690 (ml/ Striatum/min) bei Gesunden. Der Korrelationskoeffizient war für die Intraunter- sucher-Variabilität r = 0,973 und die Interuntersucher-Variabilität r = 0,879 bei Gesunden bzw. 0,989 und 0,973 bei PPLUS nach Korrektur der unspezifischen Aktivität über eine kortikale Region. Weder bei Gesunden noch bei PPLUS waren nach Korrektur der unspezifischen Aktivität über eine zerebellare Region Unterschiede der gemessenen Werte für Ki nachweisbar (p = 0,1). PET- Untersuchungen mittels L-18F-DOPA können das Ausmaß der nigrostriatalen Degeneration in vivo sicher erfassen. Aufgrund der irreversiblen Bindung von L-18F-DOPA innerhalb des Striatums läßt sich durch PET eine untersucherunabhängige Quantifizierung der gestörten präsynaptischen dopaminergen Funktion vornehmen.

Upper body accelerations during walking are altered in adults with ACL reconstruction

This study was designed to assess and compare the pattern of acceleration from the lower trunk, neck and head regions for individuals with reconstructed ACL compared to healthy controls during walking. Participants with unilateral ACL reconstruction and matched control persons participated in the study. Accelerations were collected using three triaxial accelerometers attached to the head, neck, and lower trunk. Measures of amplitude and signal regularity of the acceleration data were performed. Similarities were seen between both groups with regards to the general acceleration patterns in all three axes. However, the results also revealed that the individuals with ACL reconstruction had significantly greater peak power in the AP direction at higher frequencies, indicating a reduced ability to attenuate frequency signals. Further, the ACL group had a reduced ability to control head motion during gait, as indicated by reduced regularity in VT. Both groups demonstrated a similar pattern of gait-related oscillations across the head, neck and trunk segments. However, adults with a reconstructed ACL demonstrated a reduced capacity to compensate for the higher frequency components of the gait signal, which may have led to a decline in head control. Overall, these findings indicate that previous damage to the ACL is not simply localized to the knee joint, but influences upper body control, too.

Estimation of the future remnant liver function is a better tool to predict post-hepatectomy liver failure than platelet-based liver scores

INTRODUCTION

Recently, there has been increasing interest in the preoperative prediction and prevention of post-hepatectomy liver failure (PHLF). This is a particular concern in colorectal liver metastases (CRLM), when surgery follows potentially hepatotoxic chemotherapy. Platelet-based liver scores (PBLS) such as APRI and FIB-4 are predictive of chemotherapy-associated liver injury (CALI) and PHLF. Estimation of the future liver remnant function (eFLRF) by combining ^99mTc-Mebrofenin Hepatobiliary Scintigraphy (HBS^BSA) with future liver remnant volume ratio (FLRV%), is predictive of PHLF and related mortality. We hypothesized that a HBS^BSA based formula was a better predictor for PHLF than PBLS in chemotherapy-pretreated CRLM.

METHODS

Between 2012 and 2016, 140 patients underwent liver resection for CRLM following systemic therapy. HBS^BSA, FLRV%, eFLRF and PBLS were calculated and compared for their value in predicting PHLF.

RESULTS

eFLRF and FLRV% had a better predictive value for PHLF than HBS^BSA alone and APRI and FIB-4 (AUC = 0.800, 0.843 versus 0.652, 0.635 and 0.658 respectively). In a subgroup analysis (Oxaliplatin all, Oxaliplatin ≥ 6 cycles, Irinotecan all and Irinotecan ≥ 6 cycles), eFLRF was the only factor predictive for PHLF in all subgroups (all: p ≤ 0.05). Prediction of HBS^BSA for chemotherapy associated steato-hepatitis (CASH) reached almost significance (p = 0.06). FIB-4 was predictive for sinusoidal obstruction syndrome (SOS) (p = 0.011). Only weak correlation was found between HBS^BSA and PBLS.

CONCLUSION

eFLRF is a better predictor of PHLF than PBLS or HBS^BSA alone. PBLS seem to measure other aspects of liver function or damage than HBS^BSA.

Glucosylceramide and Glucosylsphingosine Quantitation by Liquid Chromatography-Tandem Mass Spectrometry to Enable In Vivo Preclinical Studies of Neuronopathic Gaucher Disease

Gaucher disease (GD) is caused by mutations in the GBA1 gene that encodes the lysosomal enzyme acid β-glucosidase (GCase). Reduced GCase activity primarily leads to the accumulation of two substrates, glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph). Current treatment options have not been shown to ameliorate the neurological pathology observed in the most severe forms of GD, clearly representing an unmet medical need. To better understand the relationship between GlcCer and GlcSph accumulation and ultimately their connection with the progression of neurological pathology, we developed LC-MS/MS methods to quantify GlcCer and GlcSph in mouse brain tissue. A significant challenge in developing these methods was the chromatographic separation of GlcCer and GlcSph from the far more abundant isobaric galactosyl epimers naturally occurring in white matter. After validation of both methods, we evaluated the levels of both substrates in five different GD mouse models, and found significant elevation of brain GlcSph in all five, while GlcCer was elevated in only one of the five models. In addition, we measured GlcCer and GlcSph levels in the brains of wild-type mice after administration of the GCase inhibitor conduritol β-epoxide (CBE), as well as the nonlysosomal β-glucosidase (GBA2) inhibitor N-butyldeoxygalactonojirimycin (NB-DGJ). Inhibition of GCase by CBE resulted in elevation of both sphingolipids; however, inhibition of GBA2 by NB-DGJ resulted in elevation of GlcCer only. Taken together, these data support the idea that GlcSph is a more selective and sensitive biomarker than GlcCer for neuronopathic GD in preclinical models.

Deficits in medio-lateral balance control and the implications for falls in individuals with multiple sclerosis

A major health concern faced by individuals with Multiple Sclerosis (MS) is the heightened risk of falling. Reasons for this increased risk can often be traced back to declines in neurophysiological mechanisms underlying balance control and/or muscular strength. The aim of this study was to assess differences between persons with MS and age-matched healthy adults in regards to their falls risk, strength, reactions and directional control of balance. Twenty-two persons with multiple sclerosis (mean age 56.3±8.9 years) and 22 age-matched healthy adults (mean age 59.1±7.1 years) participated in the study. Assessments of falls risk, balance, fear of falling, lower limb strength, and reaction time were performed. Balance control was assessed under four conditions where the combined effects of vision (eyes open/closed) and standing surface (firm/pliable surface) were evaluated. Results demonstrated that, in comparison to healthy older adults, persons with MS had a significantly higher falls risk, slower reaction times, and weaker lower- limb strength. For balance, persons with MS exhibited greater overall COP motion in both the medio-lateral (ML) and anterior-posterior (AP) directions compared to older adults. Additionally, during more challenging balance conditions, persons from the MS group exhibited greater ML motion compared to sway in the AP direction. Overall, the results confirm that persons with MS are often at a heightened risk of falling, due to the multitude of neuromuscular changes brought about by this disease process. However, the increased ML sway for the MS group could reflect a decreased ability to control side-to-side motion in comparison to controlling AP sway.

Abstract 2806: Oxidative stress limits metastasis of human melanoma cells

Solid cancer cells commonly enter the blood and disseminate systemically, but are highly inefficient at forming distant metastases for poorly understood reasons. We studied the complex and poorly understood process of metastasis by using a clinically relevant model of melanoma metastasis: patient-derived xenografts (PDX) that differ in their capacity to metastasize in NOD-SCID-Il2rg−/− (NSG) mice, mirroring their metastasis histories in the patients from which they were derived. We systematically dissected distinct steps of the metastatic cascade in vivo to show that melanomas had high frequencies of cells that formed subcutaneous tumours, but much lower percentages of cells that formed tumours after intravenous or intrasplenic transplantation, particularly among inefficiently metastasizing melanomas. Using Liquid Chromatography-Mass Spectrometry (LC-MS) and flow cytometry, we discovered that melanoma cells in the blood and visceral organs experienced high levels of oxidative stress not observed in subcutaneous tumours. This work demonstrates that successfully metastasizing melanomas undergo reversible functional and metabolic changes during metastasis that increases their capacity to withstand oxidative stress through an increased dependence on NADPH-generating enzymes in the folate pathway. Chronic antioxidant treatment promotes circulating melanoma cell survival and distant metastases in NSG mice. Folate pathway inhibition, using low-dose methotrexate or depletion of several NADPH-regenerating enzymes, inhibits distant metastases without significantly affecting the growth of subcutaneous tumours in the same mice. We are currently investigating the role of other NADPH-regenerating pathways such as the pentose phosphate pathway in metastasis of human melanoma cells. Finally, we hypothesize that other stress types may also play a role in limiting metastasis in vivo and we are looking for additional metabolic adaptations that may increase stress-resistance of metastasizing melanoma cells and represent novel therapeutic targets in metastatic disease.

Citation Format: Elena Piskounova, Michail Agathocleous, Malea Murphy, Zeping Hu, Ralph DeBerardinis, Sean Morrison. Oxidative stress limits metastasis of human melanoma cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2806.

Abstract LB-061: Bmi1 is required for the initiation of pancreatic cancer through an Ink4a-independent mechanism

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer related death in the United States. Many characteristic mutations in PDAC are known, but this information has so far failed to produce the development of effective treatments, highlighting the need for deeper understanding of the processes that drive tumorigenesis.

B-cell specific Moloney murine leukemia virus insertion site 1 (Bmi1), a Polycomb repressive group protein, is upregulated in PDAC and associated with poor prognosis. Our lab has shown that despite an oncogenic K-ras mutation, mice with pancreas specific loss of Bmi1 do not develop precancerous lesions, termed PanINs (Pancreatic Intraepithelial Neoplasia). This lack of PanIN development was also seen in the presence of pancreatitis, which is usually known to synergize with oncogenic K-ras to speed PanIN development. In other cancer types, Bmi1's effect on tumorigenesis was mechanistically linked to its regulation of the Ink4a/ARF genetic locus. However, we found that in PDAC, PanIN initiation was independent of Bmi1 control this locus. Further, impairment in the regulation of ROS generation was seen in vitro in pancreatic cancer cell lines lacking Bmi1. Regulating ROS generation is a vital step in the neoplastic process and has been shown in other systems to be controlled by Bmi1.

Overall, in this work we have shown that expression of the Polycomb group protein Bmi1 is necessary for the initiation of pancreatic precancerous lesions, and that the mechanism of Bmi1 requirement is independent of its repression of the Ink4a/ARF genetic locus. Given the recent pre-clinical development of a Bmi1 inhibitor, this work could provide rationale for future treatment of pancreatic cancer, a truly devastating disease.

Citation Format: Heather Schofield, Filip Bednar, Meredith Collins, Wei Yan, Yaqing Zhang, Nikhil Shyam, Jaime Eberle, Kenneth Olive, Nabeel Bardeesy, Daisuke Nakada, Diane Simeone, Sean Morrison, Marina Pasca di Magliano. Bmi1 is required for the initiation of pancreatic cancer through an Ink4a-independent mechanism. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-061. doi:10.1158/1538-7445.AM2015-LB-061

Bracing of the trunk and neck has a differential effect on head control during gait

During gait, the trunk and neck are believed to play an important role in dissipating the transmission of forces from the ground to the head. This attenuation process is important to ensure head control is maintained. The aim of the present study was to assess the impact of externally restricting the motion of the trunk and/or neck segments on acceleration patterns of the upper body and head and related trunk muscle activity. Twelve healthy adults performed three walking trials on a flat, straight 65-m walkway, under four different bracing conditions: 1) control-no brace; 2) neck-braced; 3) trunk-braced; and 4) neck-trunk braced. Three-dimensional acceleration from the head, neck (C7) and lower trunk (L3) were collected, as was muscle activity from trunk. Results revealed that, when the neck and/or trunk were singularly braced, an overall decrease in the ability of the trunk to attenuate gait-related oscillations was observed, which led to increases in the amplitude of vertical acceleration for all segments. However, when the trunk and neck were braced together, acceleration amplitude across all segments decreased in line with increased attenuation from the neck to the head. Bracing was also reflected by increased activity in erector spinae, decreased abdominal muscle activity and lower trunk muscle coactivation. Overall, it would appear that the neuromuscular system of young, healthy individuals was able to maintain a consistent pattern of head acceleration, irrespective of the level of bracing, and that priority was placed over the control of vertical head accelerations during these gait tasks.

Abstract 3999: Characterization of the limiting steps in the melanoma metastatic cascade

Metastasis is a complex multistep process: cancer cells have to detach from the bulk of the primary tumor, intravasate into the blood, survive anoikis and high shear forces in the blood stream while existing as single cells, extravasate into a distal site, and finally proliferate to form metastatic nodules. Each of these steps requires distinctive capabilities, which must either be intrinsic or gained.

We have used a melanoma xenograft model to define three major limiting steps of the metastatic cascade: intravasation into the blood, survival in circulation/extravasation into organs, and proliferation at distal sites. In our model, melanoma tumors that have previously been shown to efficiently metastasize to distal organs when grown subcutaneously (efficient metastasizers), are also capable of overcoming each of these three bottlenecks of metastasis. On the contrary, cells that are not able to metastasize when grown subcutaneously (inefficient metastasizers), are also inefficient at each of these limiting steps. This suggests that there are significant intrinsic differences between these two classes of tumors that determine the capacity of melanoma cells to grow at each step of the metastatic cascade.

To gain mechanistic insight into these differences, we have analyzed genomic mutations, gene expression and metabolomic profiles, comparing human melanomas with varying metastatic potential. Using our xenograft model we are currently investigating the role of select pathways in driving melanoma metastasis, which will ultimately lead to improved therapeutic options for patients with aggressive cancers.

Citation Format: Elena Piskounova, Sean Morrison. Characterization of the limiting steps in the melanoma metastatic cascade. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3999. doi:10.1158/1538-7445.AM2014-3999

Abstract 4435: Deubiquitinases Usp9x and Usp5 control tumorigenicity and apoptotic responsiveness in malignant melanoma

Melanoma is an aggressive skin cancer characterized by gene mutations, high metastatic potential and few clinically effective systemic therapies. BRAF, MEK1 kinase inhibitors and CTLA4 antagonist have improved patient survival, but only a subset of patients respond or derived long-lasting clinical benefit, illustrating the need for discovery of additional targets and pathways that may be inhibited with small molecules. Given the clinical impact of inhibitors of the ubiquitin-proteasome system in other cancers, we explored the potential for aberrant deubiquitinase (DUB) activity to play a role in the tumorigenic properties of melanoma. We also assessed whether specific DUBs play a role in apoptotic responsiveness and resistance to kinase inhibitors. Initially, we noted that the activity of several DUBs, including Usp9x and Usp5, was elevated in melanoma compared to normal melanocytes. Further, Usp9x and Usp5 expression and activity were up-regulated by expression of BRAFV600E in 293T cells and kinase inhibition partially suppressed both Usp9x and Usp5 activity in vemurafenib sensitive, but not resistant cells. Usp9x knockdown (KD) in BRAF mutant or wild-type melanoma did not affect 2-dimensional cell growth or survival but significantly amplified the apoptotic activity of BRAF or MEK1 inhibitors, respectively. Usp5 KD in melanoma suppressed cell growth by reinforced the S/G2-M checkpoint, enhanced extrinsic caspase activation through modulation of p53 and FAS levels and amplified the apoptotic activity of kinase inhibitors (and other chemotherapeutic agents) and overcame vemurafenib resistance in A375R cells. To further assess the clinical relevance of activated DUBs in melanoma, primary human melanoma explants characterized for their metastatic efficiency in patients and NSG mice demonstrated that Usp9x and Usp5 expression and activity were elevated in efficient metastasizers, but only a subset of inefficient metastasizers, suggesting a potential role for DUBs in the regulation of metastatic potential. To investigate that possibly, control and Usp9x KD cells were grown in Matrigel or suspension culture and colony growth and survival, as well as Usp9x activity were examined. Usp9x KD significantly suppressed melanoma colony growth and fully reduced survival of highly metastatic SK-Mel147 cells in 3D culture. Growth in 3D conditions resulted in activation of Usp9x, but also increased their sensitivity (IC50 &lt;400 nM) to our partially selective Usp9x inhibitor, EOAI3402143 (G9). G9 inhibits both Usp9x and Usp5 activity and phenocopied the activities of both Usp9x and Usp5 KD cells. G9 was safely administered to NSG mice, with complete block of melanoma growth. We conclude that targeted inhibition of specific DUBs will suppress metastatic melanoma and amplify existing melanoma therapies.

Citation Format: Harish Potu, Anupama Pal, Hanshi Sun, Luke Peterson, Moshe Talpaz, Monique Verhaegen, Juxiang Cao, Ugur Eskiocak, Sean Morrison, Nicholas J. Donato. Deubiquitinases Usp9x and Usp5 control tumorigenicity and apoptotic responsiveness in malignant melanoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4435. doi:10.1158/1538-7445.AM2014-4435

The pattern of coupling dynamics between postural motion, isotonic hand movements and physiological tremor

This study was designed to examine differences in the coupling dynamics between upper limb motion, physiological tremor and whole body postural sway in young healthy adults. Acceleration of the hand and fingers, forearm EMG activity and postural sway data were recorded. Estimation of the degree of bilateral and limb motion-postural sway coupling was determined by cross correlation, coherence and Cross-ApEn analyses. The results revealed that, under postural tremor conditions, there was no significant coupling between limbs, muscles or sway across all metrics of coupling. In contrast, performing a rapid alternating flexion/extension movement about the wrist joint (with one or both limbs) resulted in stronger coupling between limb motion and postural sway. These results support the view that, for physiological tremor responses, the control of postural sway is maintained independent to tremor in the upper limb. However, increasing the level of movement about a distal segment of one arm (or both) leads to increased coupling throughout the body. The basis for this increased coupling would appear to be related to the enhanced neural drive to task-specific muscles within the upper limb.