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Rikke Krüger Jensen,1,2 Henrik Hein Lauridsen,1 Andreas Duch Kiilerich Andresen,3 Rune Mygind Mieritz,4 Berit Schiøttz-Christensen,5,6 Werner Vach7,8 1Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; 2Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark; 3Spine Surgery and Research, Spine Centre of Southern Denmark, University Hospital Lillebaelt, Middelfart, Denmark; 4Department of Neurosurgery, University Hospital Odense, Odense, Denmark; 5Spine Centre of Southern Denmark, University Hospital Lillebaelt, Middelfart, Denmark; 6Department of Regional Health Research, University of Southern Denmark, Odense, Denmark; 7Department of Orthopaedics and Traumatology, University Hospital Basel, Basel, Switzerland; 8Basel Academy, Basel, SwitzerlandCorrespondence: Rikke Krüger JensenDepartment of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, Odense M 5230, DenmarkTel +45 40 41 97 73Email rikkekruger@nikkb.dkPurpose: To develop a self-administered diagnostic screening questionnaire for lumbar spinal stenosis (LSS) consisting of items with high content validity and to investigate the diagnostic value of the questionnaire and the items.Patients and Methods: A self-reported diagnostic LSS screening questionnaire was developed based on items from the existing literature describing key symptoms of LSS. The screening questionnaire (index test) was to be tested in a cohort of patients with persistent lumbar and/or leg pain recruited from a Danish publicly funded outpatient secondary care spine clinic with clinicians performing the reference test. However, to avoid unnecessary collection of data if the screening questionnaire proved to be of limited value, a case–control design was incorporated into the cohort design including an interim analysis. Additional cases for the case–control study were recruited at two Danish publicly funded spine surgery departments. Prevalence, sensitivity, specificity and diagnostic odds ratio (OR) were calculated for each individual item, and AUC (area under the curve) was calculated to examine the performance of the full questionnaire.Results: A 13-item Danish questionnaire was developed and tested in 153 cases and 230 controls. The interim analysis was not in favour of continuing the cohort study, and therefore, only results from the case–control study are reported. There was a positive association for all items except the presence of back pain. However, the association was only moderate with ORs up to 3.3. When testing the performance of the whole questionnaire, an AUC of 0.72 was reached with a specificity of 20% for a fixed sensitivity of 95%.Conclusion: The items were associated with LSS and therefore have some potential to identify LSS patients. However, the association was not strong enough to provide sufficient accuracy for a diagnostic tool. Additional dimensions of symptoms of LSS need identification to obtain a reliable questionnaire for screening purposes.Keywords: lumbar spinal stenosis, neurogenic claudication, diagnostic screening, questionnaire

Abstract Background The choice of an evaluative instrument has been hampered by the lack of head-to-head comparisons of responsiveness and the minimal clinically important difference (MCID) in subpopulations of low back pain (LBP). The objective of this study was to concurrently compare responsiveness and MCID for commonly used pain scales and functional instruments in four subpopulations of LBP patients. Methods The Danish versions of the Oswestry Disability Index (ODI), the 23-item Roland Morris Disability Questionnaire (RMQ), the physical function and bodily pain subscales of the SF36, the Low Back Pain Rating Scale (LBPRS) and a numerical rating scale for pain (0–10) were completed by 191 patients from the primary and secondary sectors of the Danish health care system. Clinical change was estimated using a 7-point transition question and a numeric rating scale for importance. Responsiveness was operationalised using standardardised response mean (SRM), area under the receiver operating characteristic curve (ROC), and cut-point analysis. Subpopulation analyses were carried out on primary and secondary sector patients with LBP only or leg pain +/- LBP. Results RMQ was the most responsive instrument in primary and secondary sector patients with LBP only (SRM = 0.5–1.4; ROC = 0.75–0.94) whereas ODI and RMQ showed almost similar responsiveness in primary and secondary sector patients with leg pain (ODI: SRM = 0.4–0.9; ROC = 0.76–0.89; RMQ: SRM = 0.3–0.9; ROC = 0.72–0.88). In improved patients, the RMQ was more responsive in primary and secondary sector patients and LBP only patients (SRM = 1.3–1.7) while the RMQ and ODI were equally responsive in leg pain patients (SRM = 1.3 and 1.2 respectively). All pain measures demonstrated almost equal responsiveness. The MCID increased with increasing baseline score in primary sector and LBP only patients but was only marginally affected by patient entry point and pain location. The MCID of the percentage change score remained constant for the ODI (51%) and RMQ (38%) specifically and differed in the subpopulations. Conclusion RMQ is suitable for measuring change in LBP only patients and both ODI and RMQ are suitable for leg pain patients irrespectively of patient entry point. The MCID is baseline score dependent but only in certain subpopulations. Relative change measured using the ODI and RMQ was not affected by baseline score when patients quantified an important improvement.

The evolutionary conservation of the building plan of the heart suggests this organ is under substantial form-function constraints. Its form varies to such a degree, however, that it questions whether we understand the form-function relations of the heart. A previously published image of the heart of the sunfish (Mola mola, Tetraodontiformes) indicates the presence of an exceptionally simple topology of the chambers. Here, we describe the gross morphology of the sunfish heart (N = 7) because, we assess, this expands the known spectrum of cardiac form that is compatible with function. The usual teleost piscine compartments were present, guarded by valved junctions: sinus venosus, atrium, ventricle, and bulbus arteriosus. Especially, the ventricle was much displaced ventrally and the atrium was dorso-ventrally elongate. The ventricular central cavity exhibited a simple 90-degree curve, or a-quarter circle, and opened into an almost vertical bulbus arteriosus. Overall, the normal piscine S-topology of the cardiac chambers (when seen from the left) appeared distorted to a simpler J-shape. When compared to other fish, including a tetraodontiform boxfish, these highly unusual characters appeared to have evolved recently. The distantly related spotted tinselfish (Xenolepidichthys dalgleishi) resembles sunfish in shape, its heart is almost J-shaped, but the ventricle was sac-like and typically piscine. Surprisingly, the ventricular wall had a comparatively high proportion of compact myocardium, approximately 34%. The relative mass of the sunfish heart was typically piscine, approximately 0.08% of body mass. In conclusion, the sunfish heart may be the least curved cardiac structure described for any fully formed vertebrate., (© 2024 The Author(s). Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.)

The best practice for killing decapod crustaceans lacking a centralized ganglion has been debated for a century. Currently, there is a movement away from live boiling towards electrocution and mechanical splitting or spiking, which are efficient in the large commercial setting but may be unavailable and impractical for small decapods such as shrimp and prawn in the small-scale setting of, e.g., the household. Here, using carcasses of varying sizes of prawn, crayfish, lobster and green and brown crab, we used micro-CT imaging to measure surface area and sphericity in relation to body mass. Then, we measured heating profiles at the anterior ganglion and in the core of carcasses of the same species when exposed to standardized boiling regimes. We found a relationship with positive allometry between surface area and body mass for all species and a decrease in sphericity with mass. Heating times until proposed stunning (26 °C) and killing (44 °C) varied with body size and starting temperature and exceeded minutes for larger species. For a small species like prawn, times to stunning and killing by boiling are comparable to electrocution times and within the acceptable range compared to recreational killing of other sentient beings such as game mammals.

Fluid preserved animal specimens in the collections of natural history museums constitute an invaluable archive of past and present animal diversity. Well-preserved specimens have a shelf-life spanning centuries and are widely used for e.g. anatomical, taxonomical and genetic studies. The way specimens were collected depended on the type of animal and the historical setting. As many small mammals and birds were historically collected by shooting, large quantities of heavy metal residues, primarily lead, may have been introduced into the sample in the form of lead shot pellets. Over time, these pellets may react with tissue fluids and/or the fixation and preservation agents and corrode into lead salts. As these chemicals are toxic, they could constitute a health issue to collection staff. Additionally, heavy element chemicals interfere with several imaging technologies increasingly used for non-invasive studies, and may confound anatomical and pathological investigations on affected specimens. Here we present a case-study based on platypus (Ornithorhynchus anatinus) and other small mammals containing lead pellets from the collection of The Natural History Museum of Denmark., Competing Interests: I have read the journal’s policy and the author Michiel Krols of this manuscript has the following competing interests: Employed at TESCAN XRE, a manufacture of one of the micro-CT systems used in the study (UniTOM XL Spectral). The remaining authors have declared that no competing interests exist. This does not alter our adherence to PLOS ONE policies on sharing data and materials, (Copyright: © 2024 Lauridsen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Air-breathing fish risk losing aerially sourced oxygen to ambient hypoxic water since oxygenated blood from the air-breathing organ returns through the heart to the branchial basket before distribution. This loss is thought to help drive the evolutionary reduction in gill size with the advent of air-breathing. In many teleost fish, gill size is known to be highly plastic by modulation of their anatomic diffusion factor (ADF) with inter-lamellar cell mass (ILCM). In the anoxia-tolerant crucian carp, ILCM recedes with hypoxia but regrows in anoxia. The air-breathing teleost Chitala ornata has been shown to increase gill ADF from normoxic to mildly hypoxic water by reducing ILCM. Here, we test the hypothesis that ADF is modulated to minimize oxygen loss in severe aquatic hypoxia by measuring ADF, gas-exchange, and by using computed tomography scans to reveal possible trans-branchial shunt vessels. Contrary to our hypothesis, ADF does not modulate to prevent oxygen loss and despite no evident trans-branchial shunting, C. ornata loses only 3% of its aerially sourced O 2 while still excreting 79% of its CO 2 production to the severely hypoxic water. We propose this is achieved by ventilatory control and by compensating the minor oxygen loss by extra aerial O 2 uptake.

Background: Emergency department (ED) crowding is a major patient safety concern and has a negative impact on healthcare systems and healthcare providers. We hypothesized that it would be feasible to control crowding by employing a multifaceted approach consisting of systematically fast-tracking patients who are mostly not in need of a hospital stay as assessed by an initial nurse and treated by decision competent physicians., Methods: Data from 120,901 patients registered in a secondary care ED from the 4t th quarter of 2021 to the 1st quarter of 2024 was drawn from the electronic health record's data warehouse using the SAP Web Intelligence tool and processed in the Python programming language. Crowding was compared before and after ED transformation from a uniform department into a high flow (α) and a low flow (β) section with patient placement in gurneys/chairs or beds, respectively. Patients putatively not in need of hospitalization were identified by nurse, placed in in the α setting and assessed and treated by decision competent physicians. Incidence of crowding, number of patients admitted per day and readmittances within 72 h following ED admission before and after changes were determined. Values are number of patients, mean ± SEM and mean differences with 95% CIs. Statistical significance was ascertained using Student's two tailed t-test for unpaired values., Results: Before and after ED changes crowding of 130% amounted to 123.8 h and 19.3 h in the latter. This is a difference of -104.6 ± 23.9 h with a 95% CI of -159.9 to -49.3, Δ% -84 (p = 0.002). There was the same amount of patients / day amounting to 135.8 and 133.5 patients / day Δ% = -1.7 patients 95% CI -6.3 to 1.6 (p = 0.21). There was no change in readmittances within 72 h before and after changes amounting to 9.0% versus 9.5%, Δ% = 0.5, 95%, CI -0.007 to 1.0 (p > 0.052)., Conclusion: It appears feasible to abate crowding with unchanged patient admission and without an increase in readmittances by fast-track assessment and treatment of patients who are not in need of hospitalization., (© 2024. The Author(s).)

An intricate meshwork of trabeculations lines the luminal side of cardiac ventricles. Compaction, a developmental process, is thought to reduce trabeculations by adding them to the neighboring compact wall which is then enlarged. When pig, a plausible cardiac donor for xenotransplantation, is compared to human, the ventricular walls appear to have fewer trabeculations. We hypothesized the trabecular volume is proportionally smaller in pig than in human. Macroscopically, we observed in 16 pig hearts that the ventricular walls harbor few but large trabeculations. Close inspection revealed a high number of tiny trabeculations, a few hundred, within the recesses of the large trabeculations. While tiny, these were still larger than embryonic trabeculations and even when considering their number, the total tally of trabeculations in pig was much fewer than in human. Volumetrics based on high-resolution MRI of additional six pig hearts compared to six human hearts, revealed the left ventricles were not significantly differently trabeculated (21.5 versus 22.8%, respectively), and the porcine right ventricles were only slightly less trabeculated (42.1 vs 49.3%, respectively). We then analyzed volumetrically 10 pig embryonic hearts from gestational day 14-35. The trabecular and compact layer always grew, as did the intertrabecular recesses, in contrast to what compaction predicts. The proportions of the trabecular and compact layers changed substantially, nonetheless, due to differences in their growth rate rather than compaction. In conclusion, processes that affect the trabecular morphology do not necessarily affect the proportion of trabecular-to-compact myocardium and they are then distinct from compaction., (© 2024 The Authors. Clinical Anatomy published by Wiley Periodicals LLC on behalf of American Association of Clinical Anatomists and British Association of Clinical Anatomists.)

Non-invasive computed tomography (CT) of an adult sand tiger shark Carcharias taurus Rafinesque, 1810 is used to provide an interactive three-dimensional 'general' shark (Selachimorpha) anatomy atlas. Given its post-cranial body morphology, the sand tiger shark appeared to be a well-chosen candidate and through comparison of the sand tiger shark with several other representatives of all eight established orders of sharks, we confirm that the relatively large degree of mineralization of the endoskeleton, along with the overall size, makes the sand tiger shark an ideal candidate for skeletal segmentation and construction of a skeletal atlas using conventional CT. This atlas both increases accessibility to the internal morphological features of the sand tiger shark and provides a more generalized overview of the skeletal anatomy of sharks and can aid as a supplement to destructive fresh dissection of specimens in the future and the construction of future skeletal atlases of other less mineralized sharks., Competing Interests: We declare we have no competing interests., (© 2024 The Authors.)

A focused point-of-care abdominal ultrasound is an examination performed at the patient's location and interpreted within the clinical context. This review gives an overview of this examination modality. The objective is to rapidly address predefined dichotomised questions about the presence of an abdominal aortic aneurysm, gallstones, cholecystitis, hydronephrosis, urinary retention, free intraperitoneal fluid, and small bowel obstruction. FAUS is a valuable tool for emergency physicians to promptly confirm various conditions upon the patients' arrival, thus reducing the time to diagnosis and in some cases eliminating the need for other imaging., (Published under Open Access CC-BY-NC-BD 4.0. https://creativecommons.org/licenses/by-nc-nd/4.0/.)

In hypoxia, air-breathing fish obtain O 2 from the air but continue to excrete CO 2 into the water. Consequently, it is believed that some O 2 obtained by air-breathing is lost at the gills in hypoxic water. Pangasionodon hypophthalmus is an air-breathing catfish with very large gills from the Mekong River basin where it is cultured in hypoxic ponds. To understand how P. hypophthalmus can maintain high growth in hypoxia with the presumed O 2 loss, we quantified respiratory gas exchange in air and water. In severe hypoxia (PO 2 : ≈ 1.5 mmHg), it lost a mere 4.9% of its aerial O 2 uptake, while maintaining aquatic CO 2 excretion at 91% of the total. Further, even small elevations in water PO 2 rapidly reduced this minor loss. Charting the cardiovascular bauplan across the branchial basket showed four ventral aortas leaving the bulbus arteriosus, with the first and second gill arches draining into the dorsal aorta while the third and fourth gill arches drain into the coeliacomesenteric artery supplying the gut and the highly trabeculated respiratory swim-bladder. Substantial flow changes across these two arterial systems from normoxic to hypoxic water were not found. We conclude that the proposed branchial oxygen loss in air-breathing fish is likely only a minor inefficiency.

Longitudinal animal experiments in the field of regenerative biology often require repeated use of short-term anesthesia (minutes to a few hours). Regain of consciousness limits the level of acceptable invasiveness of procedures, and it makes it difficult to untangle behavioral changes caused by injury to physiological processes involved in the regenerative response. Therefore, a method to keep a regenerative research animal in a comatose state under continuous anesthesia during regenerative experiments often spanning months, would be ethically and experimentally desirable. Here we report on a method using propofol based anesthesia in an isosmotic environment that allows for continuous anesthesia of regenerating axolotls for 60 days with a 75% survival rate, thus spanning the majority of a full regenerative cycle following limb amputation or cryoinjury to the heart. No differences were detected in the axolotl's ability to regenerate amputated limbs and cardiac cryo-injury while anesthetized, however some regenerative failures in the limb were observed in both anesthetized and unanesthetized control groups, most likely caused by prolonged fasting. Sixty days of anesthesia may be approaching a level were kidney function is affected, but the 75% surviving anesthetized animals recovered well after anesthesia and showed a full behavioral recovery within 17 days., (© 2023. Springer Nature Limited.)

The bulk of biomedical positron emission tomography (PET)-scanning experiments are performed on mammals (ie, rodents, pigs, and dogs), and the technique is only infrequently applied to answer research questions in ectothermic vertebrates such as fish, amphibians, and reptiles. Nevertheless, many unique and interesting physiological characteristics in these ectothermic vertebrates could be addressed in detail through PET. The low metabolic rate of ectothermic animals, however, may compromise the validity of physiological and biochemical parameters derived from the images created by PET and other scanning modalities. Here, we review some of the considerations that should be taken into account when PET scanning fish, amphibians, and reptiles. We present specific results from our own experiments, many of which remain previously unpublished, and we draw on examples from the literature. We conclude that knowledge on the natural history and physiology of the species studied and an understanding of the limitations of the PET scanning techniques are necessary to avoid the design of faulty experiments and erroneous conclusions., Competing Interests: Declaration of Competing Interest The authors declare no known competing financial interests or personal relationships that influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)