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Background: Uveitis is common in horses, potentially turning chronic (persistent or recurrent) resulting in impaired vision or blindness. All mainstay therapeutics aims at controlling inflammation, but long‐term or lifelong treatment is often needed with possibly severe side effects. Therefore, intravitreal injections with low‐dose gentamicin (IVGI) have been used in attempt to give a long‐lasting result with potentially less side effects. Objectives: To retrospectively assess outcome and long‐term complications following one or two low‐dose IVGI in Swedish horses with chronic uveitis. Study design: Retrospective case series. Methods: Medical records of horses diagnosed with uveitis examined at the Equine Clinic of the University Animal Hospital of Sweden between 2016 and 2021 were reviewed. Inclusion criteria were horses with a diagnosis of chronic uveitis that were treated with 4 mg IVGI. After injection, tapering doses of anti‐inflammatory medications were administered. Due to persistence or recurrence of uveitis despite IVGI, some horses received a second injection. A positive outcome was defined as controlled uveitis, despite no or minimal anti‐inflammatory medication. Results: 32 eyes (29 horses) were included. Based on clinical evaluation, uveitis was classified as anterior (91%) or panuveitis (9%). 10 eyes were treated with IVGI twice. A positive outcome was observed in 13/32 eyes (41%). Inflammation in 9/32 eyes was controlled after the first, and in 4/10 eyes after the second IVGI treatment. Long‐term complications included retinal degeneration in seven eyes, and mature cataracts in five eyes. Enucleations were performed in 14/32 eyes, due to lack of favourable response of IVGI, or due to complications, that is, glaucoma, corneal ulceration, and/or corneal mineralisation. One horse was euthanised due to painful bouts of inflammation in both eyes despite treatment. Main limitations: Small sample size, retrospective design with no control group, no histopathology performed, infrequent sampling for Leptospira and no standardised treatment protocol after the IVGI. Conclusions: In this group of Swedish horses, predominantly diagnosed clinically with anterior uveitis, a positive outcome was observed in 41% of eyes following one or two low‐dose IVGI. Retinal degeneration in the visual streak was observed in 22% of eyes, which is a higher proportion of this complication than previously described. [ABSTRACT FROM AUTHOR]

Objective The purpose of this study was to evaluate the effectiveness of postoperative beta-irradiation with strontium-90 as an adjunctive treatment to superficial keratectomy and permanent bulbar conjunctival graft for removal of equine corneolimbal squamous cell carcinoma (SCC), in decreasing recurrence rate. Study The retrospective case study included 38 horses diagnosed and treated for SCC of the eye that involved the limbus and/or cornea. The patients were treated between 1990 and 2002, with strontium-90 irradiation immediately after corneal and conjunctival graft surgery. Recurrence was defined as the postoperative and postirradiation regrowth of SCC in the same site and globe that was previously treated. Results The Appaloosa was the most commonly represented breed and horses that had more than one base coat color represented the majority of the cases (53%). The coat colors of white, chestnut/sorrel and gray were the most commonly represented colors of the horses treated. Eight horses (21%) could not be assessed for tumor recurrence due to lack of two or more post-treatment examinations, and another horse was enucleated 6 days postoperatively due to progressive corneal ulceration. Twenty-four horses (63% of the entire study population; 83% of the followed cases) had a mean ± SD of 1754 ± 1319 days without tumor recurrence, ranging from 14 days to 5110 days. Five horses (13% of the entire study population; 17% of the assessed horses) had tumor recurrence at a mean ± SD of 449 ± 339 days with a range of 29 days to 900 days. For the five recurrences, treatment included local excision ( n = 1), enucleation ( n = 2), and additional strontium-90 therapy ( n = 3). Conclusions The combination of superficial keratectomy, β-irradiation and permanent bulbar conjunctival grafts for limbal, corneal or corneolimbal SCC in horses is effective in at least 83% of the horses. Recurrence occurred in about 17% of the horses. Multiple biannual re-examinations are recommended to observe for tumor recurrence. [ABSTRACT FROM AUTHOR]

The phenomenon of ‘eye-shine’ is seen in a variety of animal species, and is generally thought to be related to the presence of an intraocular reflecting structure, the tapetum lucidum. The tapetum lucidum is a biologic reflector system that is a common feature in the eyes of vertebrates. It normally functions to provide the light-sensitive retinal cells with a second opportunity for photon-photoreceptor stimulation, thereby enhancing visual sensitivity at low light levels. The tapetum lucidum is presented here according to a classification based on the location, as well as the composition, of this reflective layer. Finally, the physical and chemical properties, as well as the origins of the different tapeta lucida, are discussed and compared. The anatomic and biochemical aspects of the tapetum lucidum in various vertebrates are examined. Morphologic observations were made from paraffin and plastic embedded specimens. Specimens were treated with traditional stains and observed by light and transmission electron microscopy. Some species (primates, squirrels, birds, red kangaroo and pig) do not have this structure and they usually are diurnal animals. In vertebrates, the tapetum lucidum exhibits diverse structure, organization and composition. Therefore, the retinal tapetum (teleosts, crocodilians, marsupials, fruit bat), the choroidal guanine tapetum (elasmobranchs), the choroidal tapetum cellulosum (carnivores, rodents, cetacea), and the choroidal tapetum fibrosum (cow, sheep, goat, horse) are described. The tapetum lucidum represents a remarkable example of neural cell and tissue specialization as an adaptation to a dim light environment and, despite these differences, all tapetal variants act to increase retinal sensitivity by reflecting light back through the photoreceptor layer. These variations regarding both its location and structure, as well as the choice of reflective material, may represent selective visual adaptations associated with their feeding behavior, in response to the use of specific wavelengths and amount of reflectance required. [ABSTRACT FROM AUTHOR]

Abstract Background Mass spectrometry has become a standard method by which the proteomic profile of cell or tissue samples is characterized. To fully take advantage of tandem mass spectrometry (MS/MS) techniques in large scale protein characterization studies robust and consistent data analysis procedures are crucial. In this work we present a machine learning based protocol for the identification of correct peptide-spectrum matches from Sequest database search results, improving on previously published protocols. Results The developed model improves on published machine learning classification procedures by 6% as measured by the area under the ROC curve. Further, we show how the developed model can be presented as an interpretable tree of additive rules, thereby effectively removing the 'black-box' notion often associated with machine learning classifiers, allowing for comparison with expert rule-of-thumb. Finally, a method for extending the developed peptide identification protocol to give probabilistic estimates of the presence of a given protein is proposed and tested. Conclusions We demonstrate the construction of a high accuracy classification model for Sequest search results from MS/MS spectra obtained by using the MALDI ionization. The developed model performs well in identifying correct peptide-spectrum matches and is easily extendable to the protein identification problem. The relative ease with which additional experimental parameters can be incorporated into the classification framework, to give additional discriminatory power, allows for future tailoring of the model to take advantage of information from specific instrument set-ups.

Background: Previous step studies have shown mechanical variances across steps in descent; however, muscle activity differences have not been examined across steps in a staircase. The purpose of this study was to quantify differences in muscle activity during step descent between step strategies (step-over-step and step-match) and across steps., Methods: Twenty-five individuals descended a seven-step staircase at self-selected pace (rise: 15.5 cm) in both descent types. Muscle activity was recorded with bipolar electrodes placed on the right tibialis anterior, peroneals, medial gastrocnemius, rectus femoris, and biceps femoris. Two-way Repeated Measures ANOVA tests were conducted for co-activation (ankle: tibialis anterior/medial gastrocnemius; knee: rectus femoris/biceps femoris) and integrated EMG in the lead and trail limbs., Results: Results showed muscle activity is dependent on the step number for both descent strategies., Conclusions: Between strategies, lead limb step-match co-activation began the staircase high then decreased for both ankle and knee, while step-over-step activity was the opposite. Trail limb co-activation was more similar beginning high for both joints in step-over-step and the knee in step-match. Across steps, this study supports previous findings of differences between entry and exit steps compared to middle stairs. Additionally, differences were found between mid-staircase steps. These differences in both descent strategies counters previous assumptions of 'steady-state' step descent, which may have implications for individuals dealing with lower extremity musculoskeletal issues. Patients may benefit by training on their most encountered staircase length, and researchers must recognize the challenge of generalizing across step studies of varying step number., Competing Interests: Declaration of competing interest The authors do not have any conflicts of interest in this manuscript., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

An approximately 2-year-old female Doberman Pinscher was referred for the evaluation of bilateral, chronic proliferative conjunctivitis. Ophthalmic examination revealed bilateral thick, opaque pseudomembranes originating from the conjunctivae that prevented visualization of the cornea and interior structures of the eye. Histopathological findings of biopsies of the pseudomembranes were consistent with ligneous conjunctivitis. Serum plasminogen activity levels were within the normal range. Treatment with topical and systemic anti-inflammatory and immunosuppressive drugs did not improve the conjunctival lesions. The pseudomembranes were surgically excised, and the conjunctival surfaces were reconstructed with amniotic membrane. At final re-examination two years postsurgery, there was no evidence of recurrence of the pseudomembranes. To the authors' knowledge, this is the first reported case of the successful treatment of canine ligneous conjunctivitis with amniotic membrane transplantation., (© 2018 American College of Veterinary Ophthalmologists.)

Amniotic membrane transplantation (AMT) is an effective clinical therapy for reconstruction of the ocular surface in human and veterinary patients. Amnion is avascular and strong, contains antiangiogenic and antiinflammatory properties and growth factors, and has properties that prevent or decrease fibrosis in healing tissue. Indications for its use are steadily growing and include grafting to replace diseased, missing or excised tissue, patching to support diseased tissue during the healing process and as a substrate for the expansion of epithelial cells for transplantation to the cornea. AMT through a combination of mechanical and biologic factors can preserve the integrity of the globe, optimize the visual outcome, and minimize scarring in severely diseased corneas.