The effect of polypropylene on the formation of byssal threads produced by Dreissena polymorpha (zebra mussels)

The presence of microfibers and microplastics in the environment is an ever-growing ecological concern. Accumulation of microplastics (plastic particles smaller than 5 mm) in aquatic environments and the subsequent exposure of these particles to organisms have been shown to have negative effects on aquatic biota. As an invasive, filter-feeding bivalve found across Indiana freshwater ecosystems, the zebra mussel (Dreissena polymorpha) serves as a good model organism for studying microplastics’ effects on physiological and behavioral functions of affected organisms. We have studied the impacts of microplastic exposure on a freshwater mollusk, the zebra mussel. We collected zebra mussels from Stone Lake, Indiana, in late fall of 2019. Individual zebra mussels were exposed to polypropylene rope fibers (concentration of rope fibers in the environment of one zebra mussel was ~400 microfibers per L) for 24-hour trials and assessed the effects by production of byssal threads, which are produced by the zebra mussel for anchorage and in response to predation threats. Results from a comparison between unexposed control mussels (n=70) and mussels exposed to rope fibers (n=70) revealed no significant difference in motility nor the number of byssal threads produced. Despite using microplastic concentrations that were higher than that found in the Great Lakes, a 24 hour exposure time may still not have been enough to significantly impact the animals. Continued research on the attachment strength of Dreissena polymorpha exposed to rope fibers will provide clearer evidence of any direct effect of these microplastics on the ecologically important mussel species

Focused cardiac ultrasound examination in the emergency and critical care horse: Training for non‐specialist veterinarians and evaluation of proficiency

Background: Focused cardiac ultrasound examination (FoCUS) is rapidly emerging for point-of-care cardiac assessment using hand-carried ultrasound (HCU) devices. A specific FoCUS protocol for horses and adequate training guidelines currently are not available. Hypothesis: To gain knowledge about the training necessary to become proficient in performing FoCUS using a HCU device. Animals: Three healthy Warmblood horses were used for practical training of veterinarians and veterinary students in equine focused cardiac ultrasound (eFoCUS). Methods: Prospective educational study. An eFoCUS protocol and 1-day training course were developed. Pre- and post-course written tests were administered to participants to evaluate proficiency in knowledge of echocardiography and echocardiographic pathology. A post-course practical examination involved performing eFoCUS and storage of representative images. Images were evaluated using an image quality score and compared between participants with some practical experience and participants with no practical experience. Results: Participants' knowledge of echocardiography increased significantly. Recognition of echocardiographic pathology pre-course ranged from 40% to 90% (mean score, 65.7%) and post-course from 85% to 100% (mean score, 92%). Eighteen of 21 participants were proficient in performing eFoCUS with a median image quality score of 79% (range, 42%-95%). Image quality did not differ between participants with some practical experience compared to participants with no experience. Conclusions and clinical importance: Veterinarians and veterinary students independent of previous experience can become proficient in performing eFoCUS after completion of a 1-day training course

Die Bedeutung der Müllerzelle für die Pathogenese der equinen rezidivierenden Uveitis und Etablierung einer equinen Müllerzelllinie

Die equine rezidivierende Uveitis (ERU) stellt weltweit die häufigste Ursache für eine erworbene Blindheit bei Pferden dar. Diese spontan auftretende, autoimmun-mediierte Augenentzündung tritt in der Pferdepopulation mit einer Prävalenz von 10% auf. Die ERU ist zudem das einzige spontane Tiermodell für die autoimmune Uveitis, dessen Erforschung einen wertvollen Beitrag für die humane Uveitisforschung leistet. Ablaufende Pathogenese-assoziierte Vorgänge in der Retina, dem Zielorgan der ERU, sind bisher noch weitgehend ungeklärt, tragen jedoch zu einer fortwährenden Schädigung der retinalen Gewebearchitektur, sowie der physiologischen Funktion der Retina bei. Die Müllerzellen, die retinalen Gliazellen, sind durch ihre besonderen strukturellen und funktionellen Glia-Neuron-Interaktionen von entscheidender Bedeutung für die Aufrechterhaltung der retinalen Struktur, sowie der Physiologie. Gliose bezeichnet eine bekannte Reaktion der Müllerzellen auf nahezu alle beschriebenen pathologischen Bedingungen und hat einen fundamentalen Einfluss auf den Verlauf einer Netzhauterkrankung. Die neuroprotektive Wirksamkeit steht dabei den für die Retina schädlichen Auswirkungen der Gliose gegenüber. Das Ziel dieser Studie war die Verifizierung und nähere Charakterisierung der bei der ERU auftretenden Gliose, um die Bedeutung der Müllerzelle bei der autoimmunen Uveitis zu bemessen und somit ein besseres Verständnis der Pathogenese-assoziierten Vorgänge im Zielorgan dieser Erkrankung zu ermöglichen. Dies wurde durch die Untersuchung der Expression von Müllerzell-spezifischen Membranproteinen, welche maßgeblich an der Regulation der retinalen Ionen- und Wasserhomöostase beteiligt sind, in gesunden im Vergleich zu uveitischen Retinae erzielt. Die Regulation der retinalen Kalium- und Wasserhomöostase ist eine der wichtigsten Müllerzellfunktionen und wird durch die einwärtsgleichrichtenden Kaliumkanäle Kir2.1 und Kir4.1, sowie dem Wasserkanal Aquaporin 4 (AQP4) bewerkstelligt. Gesunde Pferderetinae zeigten im Gegensatz zu anderen Spezies ein gleichmäßiges Verteilungsmuster von Kir4.1 entlang der Müllerzelle, dessen Expression bei der ERU signifikant vermindert war. Hingegen war die Expression von Kir2.1 in uveitischen Retinae signifikant erhöht, welche auch ein verändertes Expressionsmuster für Kir2.1 von Müllerzellfortsätzen hin zu den Zellkörpern der inneren Körnerschicht aufwiesen. Diese Befunde deuten auf eine gestörte Kaliumpermeabilität der Müllerzellmembran hin, die eine Beeinträchtigung der retinalen Kaliumhomöostase, sowie weiterer Funktionen der Müllerzelle zur Folge haben könnte. AQP4 war signifikant erhöht exprimiert und zeigte eine massive Re-Lokalisation in uveitischen Retinae im Vergleich zu Kontrollen. Während gesunde Retinae eine AQP4 Expression vor allem in Stammfortsätzen der Müllerzelle aufwiesen, wurde ein kreisförmiges Expressionsmuster in der äußeren Körnerschicht von uveitischen Retinae detektiert. Dies könnte möglicherweise in Verbindung mit der Entstehung eines retinalen Ödems stehen, einer der Hauptursachen für den Verlust der Sehfähigkeit bei Uveitis. In der vorliegenden Studie wurde zudem das Verteilungsmuster eins weiteren Mitglieds der Aquaporin-Familie (AQP5) charakterisiert und erstmalig dessen Expression in der Müllerzelle beschrieben. Außerdem wurde eine signifikant verminderte Expression bei der autoimmun-mediierten Uveitis gefunden und damit erstmals eine Beteiligung dieses Membranproteins bei einer retinalen Erkrankung dokumentiert. Die in dieser Studie gewonnenen Ergebnisse deuten daraufhin, dass die Müllerzelle von entscheidender Bedeutung für die Pathogenese der ERU ist, da die auftretende Gliose schädliche Auswirkungen auf die physiologische Funktion der Retina zu haben scheint. Weitere funktionelle Untersuchungen der Müllerzelle sind zukünftig notwendig, um ein besseres Verständnis der Physiologie der Müllerzelle und ihrer Beeinträchtigung bei der ERU zu erlangen. Durch die Etablierung der ersten equinen Müllerzelllinie eqMC-7 wurde mit dieser Studie die Grundvoraussetzung für dieses Vorhaben geschaffen

Osteopontin and Fibronectin Levels Are Decreased in Vitreous of Autoimmune Uveitis and Retinal Expression of Both Proteins Indicates ECM Re-Modeling

Autoimmune uveitis is an intraocular inflammation that arises through autoreactive T-cells attacking the inner eye, eventually leading to blindness. However, the contributing molecular pathomechanisms within the affected tissues remain as yet elusive. The extracellular matrix (ECM) is a highly dynamic structure that varies tremendously and influences the encompassing tissue. In order to assess ECM re-modeling in autoimmune uveitis, we investigated the expression of ECM molecules fibronectin and osteopontin in vitreous and retina samples. This was carried out in the only spontaneous animal model for human autoimmue uveitis, namely equine recurrent uveitis (ERU) that resembles the human disease in clinical as well as in immunopathological aspects. ERU is a naturally occurring autoimmune disease in horses that develops frequently and has already proved its value to study disease-related pathomechanisms. Western blot analysis of fibronectin and osteopontin in healthy and uveitic vitreous revealed significant reduction of both proteins in uveitis. Immunohistochemical expression of fibronectin in healthy retinas was restricted to the inner limiting membrane abutting vimentin positive Müller cell endfeet, while in uveitic sections, a disintegration of the ILM was observed changing the fibronectin expression to a dispersed pattern extending toward the vitreous. Retinal expression of osteopontin in control tissue was found in a characteristic Müller cell pattern illustrated by co-localization with vimentin. In uveitic retinas, the immunoreactivity of osteopontin in gliotic Müller cells was almost absent. The ability of Müller cells to express fibronectin and osteopontin was additionally shown by immunocytochemistry of primary cultured equine Müller cells and the equine Müller cell line eqMC-7. In conclusion, severe ECM re-modeling in autoimmune uveitis reported here, might affect the adhesive function of fibronectin and thus the anchoring of Müller cell endfeet to the ILM. Furthermore, the absence of osteopontin in gliotic Müller cells might represent reduced neuroprotection, an osteopontin attribute that is intensively discussed

Quantification of left atrial contractile function using two-dimensional speckle tracking echocardiography in horses after conversion of atrial fibrillation to sinus rhythm

Introduction/objectives: In horses, persistent atrial dysfunction is a prognostic indicator of recurrence of atrial fibrillation (AF). The objective of this study was to quantify left atrial (LA) contractile function in Warmblood horses after successful cardioversion of AF to sinus rhythm, using standard two-dimensional echocardiography (2DE) and two-dimensional speckle tracking (2DST) analyses, and to provide proof-of-concept for use of 2DST to detect LA contractile dysfunction in horses. Animals, materials, and methods: Nineteen Warmblood horses with AF and successful transvenous electrical cardioversion (TVEC) or medical cardioversion using quinidine sulfate (QS) were included. Echocardiography was performed at 24 hr, 72 hr, and 1-6 months after cardioversion. Conventional 2DE-derived indices of LA size and function and global longitudinal strain (SL) and longitudinal strain rate (SRL) during LA contractile function were measured to detect differences in LA size and function over time and between treatment modalities. The association between 2DE-derived indices and global SL and SRL, respectively, and the agreement of the variables to detect LA dysfunction were assessed. Results: Global SL and SRL, as well as active LA fractional area change (FAC) identified cases with LA dysfunction after TVEC and QS cardioversion and proved useful to demonstrate LA functional recovery over time. Agreement between active LA FAC and SL and SRL, respectively, to diagnose atrial dysfunction was substantial to fair at 24 hr after cardioversion and decreased with time. Conclusion: This study shows that 2DST is useful to quantify LA contractile dysfunction in horses after cardioversion of AF

Focused cardiac ultrasound examination in the emergency and critical care equine patient : training for non-specialist veterinarians and evaluation of proficiency

SUPPORTING INFORMATION : DATA S1. Equine focused cardiac ultrasound (eFoCUS): The course. DATA S2. Equine focused cardiac ultrasound (eFoCUS): Practical test—scoring sheet. DATA S3. Representative questions. VIDEO S1. Right-parasternal left ventricular outflow tract view: Thickening of the tricuspid and aortic valves. VIDEO S2. Right-parasternal left ventricular outflow tract view: Enlargement of the pulmonary artery (PA). The diameter of the PA appears larger compared to the diameter of the aorta indicating pulmonary hypertension. VIDEO S3. Right-parasternal short axis view of the left ventricle. Focal hyperechogenic lesion in the septum. VIDEO S4. Right-parasternal short axis view at the level of the aortic valve: Enlargement of the left atrium (LA). LA area: aortic area ratio > 3:1.BACKGROUND : Focused cardiac ultrasound examination (FoCUS) is rapidly emerging for point-of-care cardiac assessment using hand-carried ultrasound (HCU) devices. A specific FoCUS protocol for horses and adequate training guidelines currently are not available. HYPOTHESIS : To gain knowledge about the training necessary to become proficient in performing FoCUS using a HCU device. ANIMALS : Three healthy Warmblood horses were used for practical training of veterinarians and veterinary students in equine focused cardiac ultrasound (eFoCUS). METHODS : Prospective educational study. An eFoCUS protocol and 1-day training course were developed. Pre- and post-course written tests were administered to participants to evaluate proficiency in knowledge of echocardiography and echocardiographic pathology. A post-course practical examination involved performing eFoCUS and storage of representative images. Images were evaluated using an image quality score and compared between participants with some practical experience and participants with no practical experience. RESULTS : Participants' knowledge of echocardiography increased significantly. Recognition of echocardiographic pathology pre-course ranged from 40% to 90% (mean score, 65.7%) and post-course from 85% to 100% (mean score, 92%). Eighteen of 21 participants were proficient in performing eFoCUS with a median image quality score of 79% (range, 42%-95%). Image quality did not differ between participants with some practical experience compared to participants with no experience. CONCLUSIONS AND CLINICAL IMPORTANCE : Veterinarians and veterinary students independent of previous experience can become proficient in performing eFoCUS after completion of a 1-day training course.http://wileyonlinelibrary.com/journal/jvimhj2023Companion Animal Clinical Studie

κ Light-chain monoclonal gammopathy and cast nephropathy in a horse with multiple myeloma

CASE DESCRIPTION A 27-year-old Dutch Warmblood mare was evaluated because of a history of lethargy, reluctance to move, weight loss, persistent hyperproteinemia, and recurrent episodes of mild lameness. CLINICAL FINDINGS Hematologic evaluation revealed anemia (RBC concentration, 3.84 × 106 cells/μL), thrombocytopenia (47 × 103 thrombocytes/μL), and hyperproteinemia (total protein concentration, 11.2 g/dL) with hyperglobulinemia and hypoalbuminemia. Results of protein electrophoresis of serum and urine samples indicated a monoclonal gammopathy; the paraprotein was identified as a κ light chain. On abdominal ultrasonographic examination, hypoechoic nodules were visualized in the spleen. Results of cytologic examination of a splenic fine-needle aspirate and histologic examination of a bone marrow biopsy sample were consistent with plasma cell myeloma. TREATMENT AND OUTCOME Treatment was declined owing to the age of the horse and poor prognosis. The horse was discharged from the hospital, and the owner was given palliative care instructions. The horse was euthanized 2 weeks later because of recurrent episodes of lethargy, anorexia, and signs of colic. Necropsy confirmed the diagnosis of multiple (plasma cell) myeloma. Plasma cell aggregates in the liver, spleen, bone marrow, and kidney and the presence of cast nephropathy were identified on histologic examination. CLINICAL RELEVANCE Multiple myeloma is rarely reported in horses. A monoclonal peak on serum protein electrophoresis should raise the suspicion of neoplasia, specifically multiple myeloma. The findings for this patient confirmed the importance of considering neoplasia in horses with nonspecific clinical signs

Chilaiditi Syndrome: A Case Report Highlighting the Intermittent Nature of the Disease

Background. Chilaiditi syndrome is a phenomenon where there is an interposition of the colon between the liver and the abdominal wall leading to clinical symptoms. This is distinct from Chilaiditi sign for which there is radiographic evidence of the interposition, but is asymptomatic. Case Presentation. Here, we present the case of a patient who, despite having clinical symptoms for a decade, had a delayed diagnosis presumably due to the interposition being intermittent and episodic. Conclusions. This case highlights the fact that Chilaiditi syndrome may be intermittent and episodic in nature. This raises an interesting question of whether previous case reports, which describe complete resolution of the syndrome after nonsurgical intervention, are perhaps just capturing periods of resolution that may have occurred spontaneously. Because the syndrome may be intermittent with spontaneous resolution and then recurrence, patients should have episodic follow-up after nonsurgical intervention