المؤلفون: Luke Lemmerman, Hallie Harris, Maria Balch, Maria Rincon-Benavides, Natalia Higuita-Castro, W. Arnold, Daniel Gallego-Perez

المصدر: Bio-Protocol, Vol 12, Iss 3 (2022)

مصطلحات موضوعية: Biology (General), QH301-705.5

الوصف: Ischemic stroke is a leading cause of mortality and chronic disability worldwide, underscoring the need for reliable and accurate animal models to study this disease’s pathology, molecular mechanisms of injury, and treatment approaches. As most clinical strokes occur in regions supplied by the middle cerebral artery (MCA), several experimental models have been developed to simulate an MCA occlusion (MCAO), including transcranial MCAO, micro- or macro-sphere embolism, thromboembolisation, photothrombosis, Endothelin-1 injection, and – the most common method for ischemic stroke induction in murine models – intraluminal MCAO. In the intraluminal MCAO model, the external carotid artery (ECA) is permanently ligated, after which a partially-coated monofilament is inserted and advanced proximally to the common carotid artery (CCA) bifurcation, before being introduced into the internal carotid artery (ICA). The coated tip of the monofilament is then advanced to the origin of the MCA and secured for the duration of occlusion. With respect to other MCAO models, this model offers enhanced reproducibility regarding infarct volume and cognitive/functional deficits, and does not require a craniotomy. Here, we provide a detailed protocol for the surgical induction of unilateral transient ischemic stroke in mice, using the intraluminal MCAO model.Graphic abstract: Overview of the intraluminal monofilament method for transient middle cerebral artery occlusion (MCAO) in mouse.

وصف الملف: electronic resource

العلاقة: https://bio-protocol.org/en/bpdetail?id=4305&type=0Test; https://doaj.org/toc/2331-8325Test

الوصول الحر: https://doaj.org/article/d911aa777cfa4e528c94372212e0de3cTest

المؤلفون: W. Arnold

المصدر: Animal, Vol 14, Iss , Pp s124-s132 (2020)

مصطلحات موضوعية: seasonal acclimatization, metabolic rate, thermoregulation, digestion, organ size, Animal culture, SF1-1100

الوصف: Ruminants living in seasonal environments face a two-fold challenge during winter. The energetic cost of maintaining a high body temperature is higher at lower ambient temperatures, and this is compounded by poor availability and quality of feed. Wild ruminants acclimatize to this energetic challenge by hypothermia, that is, reduced endogenous heat production and abandoning the maintenance of a high body temperature, particularly in peripheral body parts. Further but lesser contributions to lower energy expenditure during winter are reduced foraging activity; lower heat increment of feeding; and reduced maintenance cost of size-reduced organs. Altogether, metabolic rate, estimated by the continuous measurement of heart rate, during winter is downregulated to more than half of the summer level, as is voluntary food intake, even in animals fed ad libitum. The transformation from the summer into the thrifty winter phenotype is also evident in the physiology of digestion. Microbial protein synthesis is less facilitated by diminished phosphorus secretion into the shrunk rumen during winter. In line with this result, the concentration of ammonia, the end-product of protein digestion in the rumen, peaks in rumen liquid in spring, whereas the molar proportion of acetate, an indicator of fermentation of a diet rich in fiber, peaks in winter. In contrast to reduced stimulation of growth of ruminal microbes during winter, active transport of nutrients across the intestinal epithelium is increased, resulting in more efficient exploitation of the lower amount and quality of ingested winter feed. Nevertheless, the energy balance remains negative during winter. This is compensated by using fat reserves accumulated during summer, which become a major metabolic fuel during winter.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S1751731119003240Test; https://doaj.org/toc/1751-7311Test

الوصول الحر: https://doaj.org/article/8088255b24c84e4d9391da67392d5ae7Test

المؤلفون: W. Arnold, Vicki L. McGovern, Benjamin Sanchez, Jia Li, Kaitlyn M. Corlett, Stephen J. Kolb, Seward B. Rutkove, Arthur H. Burghes

المصدر: Neurobiology of Disease, Vol 87, Iss , Pp 116-123 (2016)

مصطلحات موضوعية: Spinal muscular atrophy, Biomarker, Survival motor neuron, Antisense oligonucleotide, Electrical impedance myography, Motor unit number estimation, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571

الوصف: Background: Significant advances in the development of SMN-restoring therapeutics have occurred since 2010 when very effective biological treatments were reported in mouse models of spinal muscular atrophy. As these treatments are applied in human clinical trials, there is pressing need to define quantitative assessments of disease progression, treatment stratification, and therapeutic efficacy. The electrophysiological measures Compound Muscle Action Potential and Motor Unit Number Estimation are reliable measures of nerve function. In both the SMN∆7 mouse and a pig model of spinal muscular atrophy, early SMN restoration results in preservation of electrophysiological measures. Currently, clinical trials are underway in patients at post-symptomatic stages of disease progression. In this study, we present results from both early and delayed SMN restoration using clinically-relevant measures including electrical impedance myography, compound muscle action potential, and motor unit number estimation to quantify the efficacy and time-sensitivity of SMN-restoring therapy. Methods: SMA∆7 mice were treated via intracerebroventricular injection with antisense oligonucleotides targeting ISS-N1 to increase SMN protein from the SMN2 gene on postnatal day 2, 4, or 6 and compared with sham-treated spinal muscular atrophy and control mice. Compound muscle action potential and motor unit number estimation of the triceps surae muscles were performed at day 12, 21, and 30 by a single evaluator blinded to genotype and treatment. Similarly, electrical impedance myography was measured on the biceps femoris muscle at 12 days for comparison. Results: Electrophysiological measures and electrical impedance myography detected significant differences at 12 days between control and late-treated (4 or 6 days) and sham-treated spinal muscular atrophy mice, but not in mice treated at 2 days (p

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0969996115301170Test; https://doaj.org/toc/1095-953XTest

الوصول الحر: https://doaj.org/article/1eec81c24bdf4b9b92474f62e1ddd94bTest

المؤلفون: H. Krüger, H.-H. Fischer, M. Knapmeyer, W. Arnold

المصدر: Proceedings of Symposium on Ultrasonic Electronics. 2018, 39:1

المؤلفون: W. Arnold Hoppe, Dr.

المصدر: Revista Médica Clínica Las Condes, Vol 21, Iss 2, Pp 160-165 (2010)

مصطلحات موضوعية: Muerte encefálica /di (diagnóstico), muerte encefálica /pp (fisiopatología), muerte encefálica /lj (legislación & jurisprudencia), trasplante de órganos /lj (legislación & jurisprudencia), examen neurológico/ st (normas) examen neurológico/ mt (métodos), apnea /di (diagnóstico), actitud frente a la muerte, actitud del personal de salud, características culturales, Chile, Medicine

الوصف: Temor y ambivalencia son aspectos centrales en la matriz sociocultural relacionada con la muerte encefálica. Para el médico que debe evaluar pacientes y certificar el diagnóstico de muerte encefálica es crucial contar con una sólida comprensión de la fisiopatología, los criterios diagnósticos y de los exámenes complementarios. La existencia de un marco legal coherente y completo para el diagnóstico de muerte encefálica, independiente de la potencial donación de órganos, es ciertamente crucial para el médico. La relevancia que tiene en este sentido el fallo del Tribunal Constitucional de Chile del 13 de agosto de 1995 se analiza en profundidad.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0716864010705204Test; https://doaj.org/toc/0716-8640Test

الوصول الحر: https://doaj.org/article/cb02b185201c4238bbe9b06ab9de4685Test

المؤلفون: M. Kopycinska, S. Hirsekorn, U. Rabe, W. Arnold

المصدر: Proceedings of the Asian Pacific Conference on Fracture and Strength and International Conference on Advanced Technology in Experimental Mechanics. 2001, :41

المؤلفون: Rachel Bernard, Muhammad B. Hammami, Forest W. Arnold, Brian Mcgrath, Alieysa Patel, Brandon Wuerth, Maribeth R. Nicholson, Krishna Rao, Dejan Micic

المصدر: Gut Pathogens, Vol 14, Iss 1, Pp 1-6 (2022)

مصطلحات موضوعية: Inflammatory bowel disease, Clostridium difficile, Colitis, Diseases of the digestive system. Gastroenterology, RC799-869

الوصف: Abstract Introduction Clostridioides difficile infection (CDI) rates and outcomes can vary based on differences in testing strategy. Our aim was to assess the prevalence of toxin detection in inflammatory bowel disease (IBD) when compared to those without IBD. Secondly, the clinical outcomes of CDI in IBD were assessed using two-step testing strategies. Methods We included patients undergoing CDI testing from four academic centers in the United States between January 1, 2018 and June 30, 2020. First the prevalence of toxin detection was compared between individuals with IBD and those without IBD. Secondly, among patients with IBD a primary composite outcome of abdominal colectomy, admission to an intensive care unit (ICU) or death within 30 days of C. difficile testing was assessed across the three categorical groups (screen positive/toxin positive, screen positive/toxin negative and screen negative assay) resulting from the two-step testing strategy. Results When comparing individuals with a positive screening assay, patients with IBD were less likely to have toxin detected by enzyme immunoassay (EIA) as compared to the non-IBD population (22/145 (15.2%) vs. 413/1144 (36.1%), p

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1757-4749Test

الوصول الحر: https://doaj.org/article/2bd22a2a46d94e3790b2a3ac2db62499Test

المؤلفون: Robert W. Arnold, MD

المصدر: Ophthalmology Science, Vol 3, Iss 2, Pp 100307- (2023)

مصطلحات موضوعية: Ophthalmology, RE1-994

العلاقة: http://www.sciencedirect.com/science/article/pii/S2666914523000398Test; https://doaj.org/toc/2666-9145Test; https://doaj.org/article/bcc97683d61f4eeaa09a6f57d88e4a15Test

الإتاحة: https://doi.org/10.1016/j.xops.2023.100307Test
https://doaj.org/article/bcc97683d61f4eeaa09a6f57d88e4a15Test

المؤلفون: Julio A. Ramirez, Frederick J. Angulo, Ruth M. Carrico, Stephen Furmanek, Senén Peña Oliva, Joann M. Zamparo, Elisa Gonzalez, Pingping Zhang, Leslie A. Wolf Parrish, Subathra Marimuthu, Michael W. Pride, Sharon Gray, Cátia S. Matos Ferreira, Forest W. Arnold, Raul E. Istúriz, Nadia Minarovic, Jennifer C. Moïsi, Luis Jodar

المصدر: Emerging Infectious Diseases, Vol 29, Iss 5, Pp 919-928 (2023)

مصطلحات موضوعية: Clostridioides difficile, misdiagnosis, bacteria, infections, clinical laboratory techniques, standard-of-care specimen collection, Medicine, Infectious and parasitic diseases, RC109-216

الوصف: Although Clostridioides difficile infection (CDI) incidence is high in the United States, standard-of-care (SOC) stool collection and testing practices might result in incidence overestimation or underestimation. We conducted diarrhea surveillance among inpatients >50 years of age in Louisville, Kentucky, USA, during October 14, 2019–October 13, 2020; concurrent SOC stool collection and CDI testing occurred independently. A study CDI case was nucleic acid amplification test‒/cytotoxicity neutralization assay‒positive or nucleic acid amplification test‒positive stool in a patient with pseudomembranous colitis. Study incidence was adjusted for hospitalization share and specimen collection rate and, in a sensitivity analysis, for diarrhea cases without study testing. SOC hospitalized CDI incidence was 121/100,000 population/year; study incidence was 154/100,000 population/year and, in sensitivity analysis, 202/100,000 population/year. Of 75 SOC CDI cases, 12 (16.0%) were not study diagnosed; of 109 study CDI cases, 44 (40.4%) were not SOC diagnosed. CDI incidence estimates based on SOC CDI testing are probably underestimated.

العلاقة: https://wwwnc.cdc.gov/eid/article/29/5/22-1618_articleTest; https://doaj.org/toc/1080-6040Test; https://doaj.org/toc/1080-6059Test; https://doaj.org/article/3ace3b17f58345e78c03bef3512d31eeTest

الإتاحة: https://doi.org/10.3201/eid2905.221618Test
https://doaj.org/article/3ace3b17f58345e78c03bef3512d31eeTest

المؤلفون: Jody L Gookin, Ashley N Hartley, Kathleen M Aicher, Kyle G Mathews, Rachel Cullen, John M Cullen, Benjamin J Callahan, Devorah M Stowe, Gabriela S Seiler, Megan E Jacob, Jason W Arnold, M Andrea Azcarate-Peril, Stephen H Stauffer

المصدر: PLoS ONE, Vol 18, Iss 2, p e0281432 (2023)

مصطلحات موضوعية: Medicine, Science

الوصف: To date studies have not investigated the culture-independent microbiome of bile from dogs, a species where aseptic collection of bile under ultrasound guidance is somewhat routine. Despite frequent collection of bile for culture-based diagnosis of bacterial cholecystitis, it is unknown whether bile from healthy dogs harbors uncultivable bacteria or a core microbiota. The answer to this question is critical to understanding the pathogenesis of biliary infection and as a baseline to exploration of other biliary diseases in dogs where uncultivable bacteria could play a pathogenic role. A pressing example of such a disease would be gallbladder mucocele formation in dogs. This prevalent and deadly condition is characterized by excessive secretion of abnormal mucus by the gallbladder epithelium that can eventually lead to rupture of the gallbladder or obstruction of bile flow. The cause of mucocele formation is unknown as is whether uncultivable, and therefore unrecognized, bacteria play any systematic role in pathogenesis. In this study we applied next-generation 16S rRNA gene sequencing to identify the culture-negative bacterial community of gallbladder bile from healthy dogs and gallbladder mucus from dogs with mucocele formation. Integral to our study was the use of 2 separate DNA isolations on each sample using different extraction methods and sequencing of negative control samples enabling recognition and curation of contaminating sequences. Microbiota findings were validated by simultaneous culture-based identification, cytological examination of bile, and fluorescence in-situ hybridization (FISH) performed on gallbladder mucosa. Using culture-dependent, cytological, FISH, and 16S rRNA sequencing approaches, results of our study do not support existence of a core microbiome in the bile of healthy dogs or gallbladder mucus from dogs with mucocele formation. Our findings further document how contaminating sequences can significantly contribute to the results of sequencing analysis when performed on samples with ...

العلاقة: https://doi.org/10.1371/journal.pone.0281432Test; https://doaj.org/toc/1932-6203Test; https://doaj.org/article/8c90be6704e840ada1ef73ac803e39d2Test

الإتاحة: https://doi.org/10.1371/journal.pone.0281432Test
https://doaj.org/article/8c90be6704e840ada1ef73ac803e39d2Test