Delineation of blacktip shark (Carcharhinus limbatus) nursery habitats in the north-western Gulf of Mexico

Coevolution with predators leads to the use of low-risk habitats by many prey species, which promotes survival during early developmental phases. These nurseries are valued by conservation and management agencies because of their contributions to adult populations. However, the physical and geographic characteristics, like shallow depths and isolation from other marine habitats, that restrict access to predators and thereby reduce risk to juvenile animals can also limit scientific research. Consequently, many nursery habitats are still unidentified and understudied. Here we used gillnet monitoring from 1982 to 2018 to delineate blacktip shark (Carcharhinus limbatus) nurseries in the north-western Gulf of Mexico and elucidated their physical, environmental and biological characteristics. Nursery habitats within estuaries (<2% of spatial area) were proximate to the Gulf of Mexico and exhibited significantly lower variability in salinity than non-nurseries. However, relative abundances of predators and prey were not significant delineators of nursery habitats. As such, food and risk may not influence juvenile blacktip habitat use as expected. Alternatively, reduced osmoregulatory stress attributed to predictable environments likely provides advantageous conditions for blacktips to develop foraging and antipredator tactics, which is vital prior to the winter migration of juvenile sharks into the Gulf of Mexico.

AB0093 MODELING OF ANTIGEN-COLLAGEN-INDUCED ARTHRITIS IN BALB/c MICE

Background

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases. Currently, disease-modifying drugs and biological agents are used to treat RA [1]. The available drugs are not perfect: they have serious side effects and do not always cause a stable improvement or remission [2]. The above sets the task of finding new approaches to treatment that will be effective, more specific and safe. In this connection, it is necessary to develop and apply experimental models as close as possible in pathogenesis to rheumatoid arthritis. One such model, rarely used at present, is the combined antigen-collagen-induced arthritis [3].

Objectives

To show immunological and histological changes similar to RA in the AIA/CIA model and the validity of its application in research activities.

Methods

Experimental AIA/CIA was induced according to 2 different protocols in 50 BALB/c mice. Clinical assessment of arthritis was made by measuring the swelling of the paws with a caliper at different times. The assessment of immunological changes included the analysis of the content of antibodies to type II collagen by ELISA, the content of T-regulatory cells by flow cytometry. Also, a histological analysis of the obtained data was carried out.

Results

On the 10th day, a significant increase in paw thickness was recorded in animals induced both according to the first and second protocols. The intensity of swelling subsided by the 23rd day. A significant increase in the content of antibodies to type II collagen was observed in all experimental groups, but in animals from Protocol No. 1, the amount of antibodies to type II collagen was significantly higher. A high level of T-regulatory cells was registered only in mice induced according to the first protocol on the 10th day. Histological changes in the form of synovial hyperplasia, pannus, usurations were observed to varying degrees in all experimental groups, but the most pronounced changes were in animals from the first protocol.

Conclusion

In experimental animals, in all the presented protocols, changes were observed that were closest to RA, when compared with classical models of experimental arthritis induction. Based on the fact that protocol 1 animals showed an increase in the content of T-regulatory cells, the levels of antibodies to type 2 collagen were consistently high, and the histological changes were the most pronounced, it can be assumed that protocol 1 of the combined AIA/CIA model on the line of Balb/c mice, is the most suitable for testing and developing new methods of RA therapy.

References

[1]Abbasi M, Mousavi MJ, Jamalzehi S, Alimohammadi R, Bezvan MH, Mohammadi H, Aslani S. Strategies toward rheumatoid arthritis therapy; the old and the new. J Cell Physiol. 2019 Jul;234(7):10018-10031. doi: 10.1002/jcp.27860. Epub 2018 Dec 7. PMID: 30536757.

[2]Greenberg JD, Reed G, Kremer JM, Tindall E, Kavanaugh A, Zheng C, Bishai W, Hochberg MC; CORRONA Investigators. Association of methotrexate and tumour necrosis factor antagonists with risk of infectious outcomes including opportunistic infections in the CORRONA registry. Ann Rheum Dis. 2010 Feb;69(2):380-6. doi: 10.1136/ard.2008.089276. Epub 2009 Apr 8. PMID: 19359261; PMCID: PMC2861900.

[3]Baddack U, Hartmann S, Bang H, Grobe J, Loddenkemper C, Lipp M, Müller G. A chronic model of arthritis supported by a strain-specific periarticular lymph node in BALB/c mice. Nat Commun. 2013;4:1644. doi: 10.1038/ncomms2625. PMID: 23552059; PMCID: PMC3644064

Disclosure of Interests

None declared

Current Practices in Dorsal Augmentation Rhinoplasty

BACKGROUND

Dorsal augmentation rhinoplasty addresses the aesthetic and functional impairments caused by a deficient nasal dorsum. Augmentation rhinoplasty can be performed using a variety of different surgical techniques and grafting materials that all have distinct advantages and disadvantages.

METHODS

Grafting materials have unique characteristics, uses, and safety profiles. A detailed overview of various grafting materials and their uses, risks, and benefits is provided.

RESULTS

Autologous grafting materials include septal cartilage, auricular cartilage, and costal cartilage. These donor sites can provide various amounts of en bloc or diced cartilage. Alternatively, bone may be used when strong structural stability is required, and soft tissue may be used to fill mild to moderate defects. Homologous grafts (e.g., irradiated and nonirradiated rib) and acellular dermal matrices are alternatives to autologous graft with many similar advantages and no need for an additional surgical site. Lastly, alloplastic implants may be successfully used for dorsal augmentation if both patient and surgeon understand their associated risks.

CONCLUSION

To perform successful dorsal augmentation, surgeons should be familiar with the wide variety of operative approaches and augmentation materials that are currently available and understand their risks, benefits, and uses.

Magnetic Resonance Imaging Findings in High School Football Players: Brain and Cervical Spine

Football exposes its players to traumatic brain, neck, and spinal injury. It is unknown whether the adolescent football player develops imaging abnormalities of the brain and spine that are detectable on magnetic resonance imaging (MRI). The objective of this observational study was to identify potential MRI signatures of early brain and cervical spine (c-spine) injury in high school football players. Eighteen football players (mean age, 17.0 ± 1.5 years; mean career length, 6.3 ± 4.0 years) had a baseline brain MRI, and 7 had a follow-up scan 9–42 months later. C-spine MRIs were performed on 11 of the 18 subjects, and 5 had a follow-up scan. C-spine MRIs from 12 age-matched hospital controls were also retrospectively retrieved. Brain MRIs were reviewed by a neuroradiologist, and no cerebral microbleeds were detected. Three readers (a neuroradiologist, a neurosurgeon, and an orthopedic spine surgeon) studied the cervical intervertebral discs at six different cervical levels and graded degeneration using an established five-grade scoring system. We observed no statistically significant difference in disc degeneration or any trend toward increased disc degeneration in the c-spine of football players as compared with age-matched controls. Further research is needed to validate our findings and better understand the true impact of contact sports on young athletes.

Examining the trajectory and predictors of post-concussion sleep quality in children and adolescents

OBJECTIVES

This study aimed to 1) determine if post-concussion sleep quality of children and adolescents differed from healthy sleep estimates; 2) describe the trajectory of parameters of sleep quality; 3) determine factors that predict sleep quality outcomes; and 4) compare sleep parameter outcomes between asymptomatic and symptomatic participants at 4 weeks post-concussion.

METHODS

Nightly actigraphy estimates of sleep in 79 children and adolescents were measured throughout 4 weeks post-concussion. Total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), number of arousals (NOA), and average arousal length (AAL) were measured.

RESULTS

Child and adolescent participants experienced significantly poorer SE and longer WASO duration throughout 4 weeks of recovery and adolescents experienced significantly longer TST. SE significantly improved with time post-injury (p = .047). Older age was associated with longer TST (p = .003) and female sex was associated with longer WASO (p = .025) and AAL duration (p = .044). Week 4 sleep parameter outcomes were not significantly different between asymptomatic and symptomatic participants.

CONCLUSIONS

The sleep quality of youth is adversely affected by concussion, particularly in females. Sleep quality appears to improve with time but may require more than 4 weeks to return to normal.

Abstract WP262: Three-dimensional Characterization Of Cerebral Microvasculature And Microhemorrhages

Introduction: Cerebral microhemorrhages (CMH) are the pathologic substrate of MRI-demonstrable cerebral microbleeds, and are thought to occur when integrity of cerebral microvessels is compromised, leading to deposits of hemosiderin/iron accumulating within brain tissue. The presence of CMH is associated with cognitive decline and ischemic and hemorrhagic stroke. Hypertension (HTN) is a major risk factor for cerebral microbleeds and has been linked to a more significant microbleed burden in patients. Despite the clinical significance of HTN and cerebral microbleeds, our understanding of HTN-induced microbleed formation remains limited, and the vascular origin of CMH remains obscure.

Methods: We used a perfusion-based vascular label with tissue clearing to enable three-dimensional visualization of CMH with the surrounding microvascular network. Adult (18-month-old) C57BL/6J mice were administered angiotensin II to induce HTN (n=10) or PBS (n=10). Lectin-DyLight-649 was injected retro-orbitally to bind to the endothelial walls of all blood vessels in a mouse. Brains were cut into 1-mm thick sections, stained with Prussian blue to label CMH, cleared using iDISCO, and imaged via confocal microscopy. MATLAB and neuTube were used to quantify vessel diameters.

Results: Using this methodology, we were able to collect three-dimensional transmission images of CMH that were colocalized with three-dimensional fluorescence images of the surrounding microvasculature. The average vessel diameter of the 5 nearest vessels to 17 different CMH was found to be 4.22±0.81 μm, which corresponds to capillary-size vessels.

Conclusions: These data support a capillary origin for cerebral microhemorrhages in this mouse model. The capillary origin implies a role for the blood-brain barrier in the development of CMH and cerebral microbleeds in this model of HTN and aging. Three-dimensional imaging has substantial utility for improved understanding of CMH origin.

Abstract TP127: Hypertension Provokes Development Of Cerebral Microhemorrhages In A Mouse Model

Introduction: Cerebral microhemorrhages (CMH) are the pathological substrate for cerebral microbleeds, represent focal hemosiderin deposits on MRI, and are associated with increased risk of cognitive impairment and ischemic and hemorrhagic stroke. Aging and hypertension are the most common risk factors for cerebral microbleeds. In this study, we analyzed the effect of hypertension on the development of CMH in a mouse model of aging.

Methods: Hypertension was induced in aged (17 months old) female and male C57BL/6J mice, via infusion of angiotensin II (ATII) at 1000 ng/kg/min via Alzet pump over four weeks. We further examined underlying mechanism by inhibiting ATII type 1 receptor (AT1R) with telmisartan, via drinking water for 4 weeks. We collected mouse brains and performed standard histology using Prussian blue staining to detect CMH formation at 20x magnification. We also examined correlations between CMH burden and systolic (SBP) and diastolic (DPB) blood pressures.

Results: ATII infusion induced significant increases in SBP (121±4 mmHg to 159±6 mmHg; p<0.001) and DBP (94±4 mmHg to 129±7 mmHg; p<0.001). Telmisartan completely blocked ATII-induced blood pressure elevation. Hypertension increased the number of CMH (p=0.01) in male and female mice. In animals with ATII infusion, number of CMH were positively correlated with SBP (r=0.45, p=0.02) and DBP (r=0.47, p=0.01). Telmisartan reduced by 55% the number of ATII-induced CMH, but compared to controls, CMH number remained elevated (p=0.03) in telmisartan-treated animals.

Conclusions: ATII-induced hypertension promotes the development of CMH in aged mice in a manner that appears dependent on the extent of hypertension. However, in the presence of ATII with ATIR blockade, CMH develops even in the absence of hypertension. These findings emphasize the importance of presence and extent of hypertension in development of CMH in aging, as well as the significance of non-AT1R-mediated pathways independent of hypertension in ATII-induced CMH.

Abstract 87: Chronic Kidney Disease Induces Cerebral Microhemorrhages In Aged Mice

Introduction: Chronic kidney disease (CKD) is increasingly recognized as a risk factor of cerebral microvascular disease, but its association with common neuropathologic changes is not well understood. We investigated the relationship between CKD and development of cerebral microhemorrhages (CMH) in a mouse model of aging. We also examined the effect of CKD on endothelial cell function in an in vitro blood-brain barrier (BBB) model.

Methods: CKD was produced in aged C57BL/6J mice using an adenine-induced tubulointerstitial nephritis model. We performed standard histology using Prussian blue staining to examine CMH formation. Correlations between CMH burden and serum creatinine levels were assessed. In cell culture studies, human brain microvascular endothelial cells (ihBMECs) derived from induced pluripotent stem cell line IMR90-4 were treated with serum from healthy or CKD patient donors for up to 3 days. Transendothelial electrical resistance (TEER) and tracer (sodium fluorescein) permeability across the ihBMEC monolayer were measured to assess the integrity of the in vitro BBB.

Results: CKD induction in aged C57BL/6J mice caused a significant increase in both serum creatinine level (0.09±0.01 mg/dL to 0.43±0.03 mg/dL, p<0.001) and CMH number (p<0.05), without alteration of systolic or diastolic blood pressure. Number of CMH was positively correlated with serum creatinine level (r=0.41, p<0.001). Incubation of CKD serum with ihBMECs significantly reduced TEER by 26% (p<0.05) and increased sodium fluorescein permeability by 100% (p<0.01) across the ihBMEC monolayer.

Conclusions: Adenine-induced CKD promotes the development of CMH in aged C57BL/6J mice independent of blood pressure, and extent of CMH development is directly proportional to degree of renal insufficiency. Moreover, serum-derived factors in CKD disrupt BBB integrity in vitro. These findings suggest CKD provokes microvascular injury at the capillary level, leading to CMH formation in this model.

644. Phenotypic and Genomic Analysis of Novel, Fastidious, Gram-negative Bacilli Isolated from Clinical Wound Specimens

Background

Animal bites are considered the thirteenth leading cause of nonfatal ED visits. Epidemiology studies have shown a rise in dog bites during the COVID-19 pandemic in the U.S. In Oct. 2020, we received a facultatively anaerobic, non-hemolytic Gram-negative rod (OL1) from a dog bite wound for identification. 16S rRNA gene sequencing showed OL1 was 95.9% identical to Ottowia pentelensis in the family Comamonadaceae. Our historical sequence database revealed 8 additional isolates (OL2-OL9) from hand wounds/abscesses (including 3 dog bites) since 2012 that had ⩾ 99.8% identity with OL1. Most other Ottowia sp. have been isolated from industrial and food sources, with no reports from patient samples. As these clinical isolates likely represent a novel Ottowia species, we aimed to characterize them using both phenotypic and genomic approaches.

Methods

The OL isolates were tested in API 20 NE panels (8 conventional and 12 assimilation tests) for 4 d. Paired-end genomic DNA libraries (Nextera DNA Flex Library Prep, Illumina) were sequenced as 150 nt reads by Illumina NovaSeq. De novo assembly, annotation, functional prediction, and phylogenetic analyses were performed with Geneious, PATRIC, and web-prediction databases. Strain comparison was done with StrainTypeMer.

Results

All 9 OL isolates were negative for indole, urea, arginine, esculin, PNPG, glucose fermentation and carbohydrate assimilation tests. Potassium gluconate assimilation and gelatin hydrolysis were positive for 5 and 4 isolates, respectively. StrainTypeMer showed the isolates from different patients were not closely related, but 2 from the same patient were indistinguishable. The estimated genome size was ~3.1 Mbp, with 66.1% G/C, and ~3523 coding genes. Potential virulence factors (BrkB and MviM), multidrug efflux systems (MdtABC-TolC and Bcr/CflA), and 1-2 intact prophages were identified. Genomic phylogenetic analysis with RAxML showed the OL isolates clustered separately from all known Ottowia spp.

Conclusion

These OL isolates are fastidious, Gram-negative bacilli from clinical wound specimens, and are associated with dog bites. Genomic and 16S rRNA gene sequence analysis suggests these isolates constitute a novel species within the family Comamonadaceae.

Disclosures

All Authors: No reported disclosures

Guiding principles for rewilding

There has been much recent interest in the concept of rewilding as a tool for nature conservation, but also confusion over the idea, which has limited its utility. We developed a unifying definition and 10 guiding principles for rewilding through a survey of 59 rewilding experts, a summary of key organizations' rewilding visions, and workshops involving over 100 participants from around the world. The guiding principles convey that rewilding exits on a continuum of scale, connectivity, and level of human influence and aims to restore ecosystem structure and functions to achieve a self-sustaining autonomous nature. These principles clarify the concept of rewilding and improve its effectiveness as a tool to achieve global conservation targets, including those of the UN Decade on Ecosystem Restoration and post-2020 Global Biodiversity Framework. Finally, we suggest differences in rewilding perspectives lie largely in the extent to which it is seen as achievable and in specific interventions. An understanding of the context of rewilding projects is the key to success, and careful site-specific interpretations will help achieve the aims of rewilding.

Prevalence of cerebral small vessel disease in a Fabry disease cohort

Objective

To characterize the prevalence of brain ischemia and cerebral small vessel disease in a cohort of patients with Fabry disease (FD) seen at an academic medical center.

Background

FD is an inherited X-linked lysosomal storage disorder with central nervous system involvement. Limited data are available in the literature on the cerebrovascular neuroimaging findings in FD, and the reported prevalence of stroke symptoms and cerebral small vessel disease has varied widely.

Design/methods

Brain MRI was performed in 21 patients with FD followed at University of California Irvine Medical Center. Stroke symptoms were assessed and quantification of cerebral microvascular disease was performed using small vessel disease (SVD) score. Lacunes and deep white matter hyperintensities were scored on a four-point scale of 0 (absent) and 1–3 to account for increasing severity; microbleeds were scored 0 (absent) or 1 (present). The total SVD score is the sum of the three components and ranges from 0 to 7.

Results

Nearly 43% (9/21) of our FD cohort (aged 32–81 years, mean = 50) had a SVD score of one or higher, all of whom were aged 50 or more years. The most common MRI-defined SVD was white matter hyperintensities (9/9, 100%), followed by microbleeds (6/9, 66%), and lacunes (3/9, 33%). The three patients with previous strokes had some of the highest SVD scores reported in the cohort (scores 3–5).

Conclusions

In this cohort, the prevalence of SVD (43%) was three times higher than prevalence of stroke symptoms. SVD score was highest in the those who had experienced a stroke. These findings emphasize the importance of routine MRI screening of patients with FD in order to identify and treat high risk patients.

Grow fast, die young: Does compensatory growth reduce survival of juvenile blacktip sharks (Carcharhinus limbatus) in the western Gulf of Mexico?

Effective conservation and management necessitate an understanding of the ecological mechanisms that shape species life histories in order to predict how variability in natural and anthropogenic impacts will alter growth rates, recruitment, and survival. Among these mechanisms, the interaction between parturition timing and prey availability frequently influences offspring success, particularly when postnatal care is absent. Here, we assess how parturition timing and nursery conditions, including prey abundance and environmental conditions, influence the growth and potential survival of blacktip sharks (Carcharhinus limbatus) in western Gulf of Mexico (GOM) estuaries over their first year. Catch data from long-term gillnet monitoring allowed for clear delineation of cohorts based on size frequency distribution plots, and showed that late parturition cohorts born in estuaries with fewer prey resources exhibited more rapid growth than early parturition cohorts that experienced more abundant prey. Compensatory behaviors that promoted accelerated growth led to reduced second year residency, likely due to reduced survival resultant from greater risk taking and potentially due to reduced site fidelity attributed to larger body size. Water temperatures influenced blacktip growth rates through physiological increases in metabolism and potential premigratory foraging cues associated with cooling temperatures. Gradual warming of the GOM (0.03°C year-1) was also correlated with earlier parturition across the study period (1982-2017), similar to other migratory species. Considering current trends in climate and associated phenological shifts in many animals, testing hypotheses assessing compensatory growth-risk trade-offs is important moving forward to predict changes in life histories and associated recruitment in concert with current and future conservation actions, like wildlife management.

Management of gout in chronic kidney disease: a G-CAN Consensus Statement on the research priorities

Gout and chronic kidney disease (CKD) frequently coexist, but quality evidence to guide gout management in people with CKD is lacking. Use of urate-lowering therapy (ULT) in the context of advanced CKD varies greatly, and professional bodies have issued conflicting recommendations regarding the treatment of gout in people with concomitant CKD. As a result, confusion exists among medical professionals about the appropriate management of people with gout and CKD. This Consensus Statement from the Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) discusses the evidence and/or lack thereof for the management of gout in people with CKD and identifies key areas for research to address the challenges faced in the management of gout and CKD. These discussions, which address areas for research both in general as well as related to specific medications used to treat gout flares or as ULT, are supported by separately published G-CAN systematic literature reviews. This Consensus Statement is not intended as a guideline for the management of gout in CKD; rather, it analyses the available literature on the safety and efficacy of drugs used in gout management to identify important gaps in knowledge and associated areas for research.

Kidney Function Is Not Related to Brain Amyloid Burden on PET Imaging in The 90+ Study Cohort

Cognitive decline is common in chronic kidney disease (CKD). While the evidence of vascular cognitive impairment in this population is robust, the role of Alzheimer's pathology is unknown. We evaluated serum cystatin C-estimated glomerular filtration rate (eGFR), brain amyloid-β positron emission tomography (PET) imaging, and cognitive function in 166 participants from The 90+ Study. Mean age was 93 years (range 90-107) and 101 (61%) were women; 107 participants had normal cognitive status while 59 participants had cognitive impairment no dementia (CIND) or dementia. Mean ± standard deviation cystatin C was 1.59 ± 0.54 mg/L with eGFR 40.7 ± 18.7 ml/min/1.73m2. Higher amyloid-β burden was associated with dementia, but not with age, diabetes, hypertension, or cardiovascular disease. We found no association between brain amyloid-β burden and cystatin C eGFR. We previously reported that kidney function was associated with cognition and cerebral microbleeds in the same cohort of oldest-old adults (90+ years old). Collectively, these findings suggest that microvascular rather than Alzheimer's pathology drives CKD-associated cognitive dysfunction in this population.

Kwasowy komunizm. Nieukończone wprowadzenie

Artykuł stanowi nieukończone przez autora wprowadzenie do książki, którą zmarły filozof Mark Fisher projektował pod koniec życia i której nigdy nie napisał. Przedstawia w nim zarys koncepcji kwasowego komunizmu, czyli myślowej prowokacji wskazującej na potrzebę przemyślenia dziedzictwa kultury radykalnych ruchów lat 60. i 70., zwłaszcza istniejącego w nich napięcia między indywidualizmem a kolektywizmem. Istotną inspiracją myśli Fishera pozostają zwłaszcza prace Herberta Marcusego.

Spectroscopic and deep learning-based approaches to identify and quantify cerebral microhemorrhages

Cerebral microhemorrhages (CMHs) are associated with cerebrovascular disease, cognitive impairment, and normal aging. One method to study CMHs is to analyze histological sections (5-40 μm) stained with Prussian blue. Currently, users manually and subjectively identify and quantify Prussian blue-stained regions of interest, which is prone to inter-individual variability and can lead to significant delays in data analysis. To improve this labor-intensive process, we developed and compared three digital pathology approaches to identify and quantify CMHs from Prussian blue-stained brain sections: (1) ratiometric analysis of RGB pixel values, (2) phasor analysis of RGB images, and (3) deep learning using a mask region-based convolutional neural network. We applied these approaches to a preclinical mouse model of inflammation-induced CMHs. One-hundred CMHs were imaged using a 20 × objective and RGB color camera. To determine the ground truth, four users independently annotated Prussian blue-labeled CMHs. The deep learning and ratiometric approaches performed better than the phasor analysis approach compared to the ground truth. The deep learning approach had the most precision of the three methods. The ratiometric approach has the most versatility and maintained accuracy, albeit with less precision. Our data suggest that implementing these methods to analyze CMH images can drastically increase the processing speed while maintaining precision and accuracy.

A Systematic Approach to Comparing Thermal Activity of the Thoracic Region and Saddle Pressure Distribution beneath the Saddle in a Group of Non-Lame Sports Horses

Simple Summary

Thermography is a non-invasive method for measuring surface temperatures. Due to its ease of use, it may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified temperatures at specific locations (left/right) of the thoracic region at three-time points; a Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) during a period of exercise. Differences between saddle widths in the cranial/caudal mean and peak saddle pressures were found. The maximum thermal temperatures increased post lunge and post ridden compared to the baseline. No difference between post lunge and post ridden exercise were found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.

Abstract

Thermography is a non-invasive method for measuring surface temperatures and may be a convenient way of identifying hypo/hyperthermic areas under a saddle that may be related to saddle pressures. A thermal camera quantified minimum/maximum/mean temperatures at specific locations (left/right) of the thoracic region at three-time points: (1) baseline; (2) post lunging; (3) post ridden exercise in eight non-lame sports horses ridden by the same rider. A Pliance (Novel) pressure mat determined the mean/peak saddle pressures (kPa) in the cranial and caudal regions. General linear mixed models with the horse as the random factor investigated the time point (fixed factor: baseline; lunge; ridden) and saddle fit (fixed factor: correct; wide; narrow) on thermal parameters with Bonferroni post hoc comparison. The saddle pressure data (grouped: saddle width) were assessed with an ANOVA and Tukey post hoc comparison (p ≤ 0.05). Differences between the saddle widths in the cranial/caudal mean (p = 0.05) and peak saddle pressures (p = 0.01) were found. The maximum temperatures increased post lunge (p ≤ 0.0001) and post ridden (p ≤ 0.0001) compared to the baseline. No difference between post lunge and post ridden exercise (all p ≥ 0.51) was found. The thermal activity does not appear to be representative of increased saddle pressure values. The sole use of thermal imaging for saddle fitting should be applied with caution.

Stroke Preventability in Large Vessel Occlusion Treated With Mechanical Thrombectomy

Objective: The preventability of strokes treated by mechanical thrombectomy is unknown. The purpose of this study was to analyze stroke preventability for patients treated with mechanical thrombectomy for large vessel occlusion.

Methods: We conducted retrospective analyses of 300 patients (mean ± SE age 69 ± 0.9 years, range 18–97 years; 53% male) treated with mechanical thrombectomy for large vessel occlusion from January 2008 to March 2019. We collected data including demographics, NIH Stroke Scale (NIHSS) at onset, and (beginning in 2015) classified 90-day outcome by modified Rankin Scale (mRS). Patients were evaluated using a Stroke Preventability Score (SPS, 0 to 10 points) based on how well patients had been treated given their hypertension, hyperlipidemia, atrial fibrillation, and prior stroke history. We examined the relationship of SPS with NIHSS at stroke onset and with mRS outcome at 90 days.

Results: SPS was calculated for 272 of the 300 patients, with mean ± SE of 2.1 ± 0.1 (range 0–8); 89 (33%) had no preventability (score 0), 120 (44%) had low preventability (score 1–3), and 63 (23%) had high preventability (score 4 or higher). SPS was significantly correlated with age (r = 0.32, p < 0.0001), while NIHSS (n = 267) was significantly higher (p = 0.03) for patients with high stroke preventability vs. low/no preventability [18.8 ± 0.92 (n = 62) vs. 16.5 ± 0.51 (n = 205)]. Among 118 patients with mRS, outcome was significantly worse (p = 0.04) in patients with high stroke preventability vs. low/no preventability [4.7 ± 0.29 (n = 28) vs. 3.8 ± 0.21 (n = 90)]. The vast majority of patients with high stroke preventability had inadequately treated atrial fibrillation (85%, 53/62).

Conclusions: Nearly one quarter of stroke patients undergoing mechanical thrombectomy had highly preventable strokes. While stroke preventability showed some relationship to stroke severity at onset and outcome after treatment, preventability had the strongest association with age. These findings emphasize the need for improved stroke prevention in the elderly.

A comprehensive, contemporary assessment of the association between hepatosteatosis and coronary artery calcium scoring

Funding Acknowledgements

Type of funding sources: None.

onbehalf

Liverpool Multiparametric Imaging Collaboration

Background

Coronary artery calcium (CAC) score is a well-established technique for stratifying an individual’s cardiovascular disease (CVD) risk. Several well-established registries have incorporated CAC scoring into CVD risk prediction models to enhance accuracy. Hepatosteatosis (HS) has been shown to be an independent predictor of CVD events and can be measured on non-contrast computed tomography (CT). We sought to undertake a contemporary, comprehensive assessment of the influence of HS on CAC score alongside traditional CVD risk factors. In patients with HS it may be beneficial to offer routine CAC screening to evaluate CVD risk to enhance opportunities for earlier primary prevention strategies.

Methods

We performed a retrospective, observational analysis at a high-volume cardiac CT centre analysing consecutive CT coronary angiography (CTCA) studies. All patients referred for investigation of chest pain over a 28-month period (June 2014 to November 2016) were included. Patients with established CVD were excluded. The cardiac findings were reported by a cardiologist and retrospectively analysed by two independent radiologists for the presence of HS. Those with CAC of zero and those with CAC greater than zero were compared for demographic and cardiac risks. A multivariate analysis comparing the risk factors was performed to adjust for the presence of established risk factors. A binomial logistic regression model was developed to assess the association between the presence of HS and increasing strata of CAC.

Results

In total there were 1499 patients referred for CTCA without prior evidence of CVD. The assessment of HS was completed in 1195 (79.7%) and CAC score was performed in 1103 (92.3%). There were 466 with CVD and 637 without CVD. The prevalence of HS was significantly higher in those with CVD versus those without CVD on CTCA (51.3% versus 39.9%, p = 0.007). Male sex (50.7% versus 36.1% p= &lt;0.001), age (59.4 ± 13.7 versus 48.1 ± 13.6, p= &lt;0.001) and diabetes (12.4% versus 6.9%, p = 0.04) were also significantly higher in the CAC group compared to the CAC score of zero.

HS was associated with increasing strata of CAC score compared with CAC of zero (CAC score 1-100 OR1.47, p = 0.01, CAC score 101-400 OR:1.68, p = 0.02, CAC score &gt;400 OR 1.42, p = 0.14). This association became non-significant in the highest strata of CAC score.

Conclusion

We found a significant association between the increasing age, male sex, diabetes and HS with the presence of CAC. HS was also associated with a more severe phenotype of CVD based on the multinomial logistic regression model. Although the association reduced for the highest strata of CAC (CAC score &gt;400) this likely reflects the overall low numbers of patients within this group and is likely a type II error.

Based on these findings it may be appropriate to offer routine CVD risk stratification techniques in all those diagnosed with HS.

New insights into the trophic ecology of blacktip sharks (Carcharhinus limbatus) from a subtropical estuary in the western Gulf of Mexico

As environmental change persists, understanding resource use patterns is of value to predict the consequences of shifting trophic structures. While many sharks are opportunistic predators, some exhibit prey selectivity, putting them at higher risk compared to species with greater trophic plasticity. In the Gulf of Mexico (GOM), Clupeids and Sciaenids comprise 69% of blacktip shark (Carcharhinus limbatus) diets, which is consequential considering potential responses of these prey groups to disturbance and over harvesting. We assessed if blacktips exhibit selectivity for Clupeids and Sciaenids in the western GOM based on stomach contents from sharks in coastal Texas. Clupeids comprised <2% of diets, while striped mullet (Mugil cephalus) and red drum (Sciaenops ocellatus) comprised >70% of identifiable prey. Ontogenetic shifts from smaller (Clupeids, small Sciaenids) to larger, higher trophic level (Ariidae, Elasmobranchii) prey fits our understanding of foraging among coastal sharks, and suggests our regional understanding of blacktip trophic ecology may be limited by the sizes of sampled sharks. Observed increases in blacktip densities coupled with declines in prey (Mugilids, Sciaenids) is concerning if blacktips have limited diet plasticity. Yet GOM blacktips may be more generalized than previously thought, which is promising for conservation and management.

Efficacy and safety of urate-lowering therapy in people with kidney impairment: a GCAN-initiated literature review

OBJECTIVES

The aim was to evaluate the efficacy, defined as achieving target serum urate <6.0 mg/dl, and safety of urate-lowering therapies (ULTs) for people with gout and chronic kidney disease (CKD) stages 3-5.

METHODS

PubMed, The Cochrane Library and EMBASE were searched from 1 January 1959 to 31 January 2018 for studies that enrolled people with gout, who had an estimated glomerular filtration rate (eGFR) or creatinine clearance (CrCl) of <60 ml/min and exposure to allopurinol, febuxostat, probenecid, benzbromarone, lesinurad or pegloticase. All study designs other than case reports were included, except for people on dialysis, for whom we did include case reports.

RESULTS

There were 36 reports with an analysis of efficacy and/or safety based upon renal function: allopurinol (n = 12), febuxostat (n = 10), probenecid (n = 3), benzbromarone (n = 5), lesinurad (n = 5) and pegloticase (n = 1). There were 108 reports that involved people with gout and renal impairment but did not contain any analysis on efficacy and/or safety based upon renal function: allopurinol (n = 84), febuxostat (n = 14), benzbromarone (n = 1), lesinurad (n = 3) and pegloticase (n = 6). Most studies excluded people with more severe degrees of renal impairment (eGFR or CrCl of <30 ml/min). For allopurinol, in particular, there was significant variability in the dose of drug used and the efficacy in terms of urate lowering, across all levels of renal impairment.

CONCLUSION

There is a lack of evidence regarding the efficacy and/or safety of currently used ULTs according to different levels of renal function. Future studies should include patients with CKD and should report study outcomes stratified by renal function.