Inhibition of Mast Cell Degranulation by Novel Small Molecule MRGPRX2 Antagonists.

BACKGROUND: Mas-related G-protein coupled receptor X2 (MRGPRX2) is a promiscuous receptor on mast cells that mediates IgE-independent degranulation and has been implicated in multiple mast cell-mediated disorders, including chronic urticaria, atopic dermatitis, and pain disorders. Although it is a promising therapeutic target, few potent, selective, small molecule antagonists have been identified, and functional effects of human MRGPRX2 inhibition have not been evaluated in vivo. OBJECTIVE: We identified and characterized novel, potent, and selective orally active small molecule MRGPRX2 antagonists for potential treatment of mast cell-mediated disease. METHODS: Antagonists were identified using multiple functional assays in cell lines overexpressing human MRGPRX2, LAD2 mast cells, human peripheral stem cell-derived mast cells, and isolated skin mast cells. Skin mast cell degranulation was evaluated in Mrgprb2em(-/-) knockout (KO) and Mrgprb2em(MRGPRX2) transgenic human MRGPRX2 knock-in (KI) mice by assessment of agonist-induced skin vascular permeability. Ex vivo skin mast cell degranulation and associated histamine release was evaluated by microdialysis of human skin tissue samples. RESULTS: MRGPRX2 antagonists potently inhibited agonist-induced MRGPRX2 activation and mast cell degranulation in all mast cell types tested, in an IgE-independent manner. Orally administered MRGPRX2 antagonists also inhibited agonist-induced degranulation and resulting vascular permeability in MRGPRX2 KI mice. In addition, antagonist treatment dose dependently inhibited agonist-induced degranulation in ex vivo human skin. CONCLUSION: MRGPRX2 small molecule antagonists potently inhibited agonist-induced mast cell degranulation in vitro and in vivo as well as ex vivo in human skin, supporting potential therapeutic utility as a novel treatment for multiple human diseases involving clinically relevant mast cell activation.

The molecular evolution of cancer associated genes in mammals.

Cancer is a disease that many multicellular organisms have faced for millions of years, and species have evolved various tumour suppression mechanisms to control oncogenesis. Although cancer occurs across the tree of life, cancer related mortality risks vary across mammalian orders, with Carnivorans particularly affected. Evolutionary theory predicts different selection pressures on genes associated with cancer progression and suppression, including oncogenes, tumour suppressor genes and immune genes. Therefore, we investigated the evolutionary history of cancer associated gene sequences across 384 mammalian taxa, to detect signatures of selection across categories of oncogenes (GRB2, FGL2 and CDC42), tumour suppressors (LITAF, Casp8 and BRCA2) and immune genes (IL2, CD274 and B2M). This approach allowed us to conduct a fine scale analysis of gene wide and site-specific signatures of selection across mammalian lineages under the lens of cancer susceptibility. Phylogenetic analyses revealed that for most species the evolution of cancer associated genes follows the species' evolution. The gene wide selection analyses revealed oncogenes being the most conserved, tumour suppressor and immune genes having similar amounts of episodic diversifying selection. Despite BRCA2's status as a key caretaker gene, episodic diversifying selection was detected across mammals. The site-specific selection analyses revealed that the two apoptosis associated domains of the Casp8 gene of bats (Chiroptera) are under opposing forces of selection (positive and negative respectively), highlighting the importance of site-specific selection analyses to understand the evolution of highly complex gene families. Our results highlighted the need to critically assess different types of selection pressure on cancer associated genes when investigating evolutionary adaptations to cancer across the tree of life. This study provides an extensive assessment of cancer associated genes in mammals with highly representative, and substantially large sample size for a comparative genomic analysis in the field and identifies various avenues for future research into the mechanisms of cancer resistance and susceptibility in mammals.

Unlicensed antiviral products used for the at-home treatment of feline infectious peritonitis contain GS-441524 at significantly different amounts than advertised.

OBJECTIVE: To analyze the content of unlicensed GS-441524-like products being used as a largely successful at-home treatment for cats suspected to have FIP. The remdesivir content and pH were also measured. SAMPLE: 127 injectable and oral samples from 30 of the most popular brands of black market producers. METHODS: Unlicensed GS-441524-like products were procured through donations and tested for GS-441524 and remdesivir content by liquid chromatography with tandem mass spectrometry. A pH meter measured the pH of injectable samples. RESULTS: Of the 87 injectable formulations, 95% contained more (on average 39% more) GS-441524 than expected based on the producer's marketed concentrations. The average pH (1.30 pH) was well below the physiologic pH conditions recommended for SC injections. The oral formulations were more variable, with 43% containing more GS-441524 (on average 75% more) than expected and 58% containing less (on average 39% less) than the expected content. There was minimal variability in GS-441524 content between replicate samples in the injectables formulations (measured by coefficient of variation). One injectable and 2 oral samples additionally contained remdesivir. CLINICAL RELEVANCE: All unlicensed products used for the at-home treatment of FIP that we tested contain GS-441524. The injectables generally contain significantly more drug than advertised at a below-physiologic pH. Unlicensed oral products vary more widely in drug content and suffer from unconventional dosing and labeling. These data should highlight the need for regulation of these products and the development of legal pathways to procure GS-441524.

Glycine supplementation can partially restore oxidative stress-associated glutathione deficiency in ageing cats.

Intracellular levels of glutathione, the major mammalian antioxidant, are reported to decline with age in several species. To understand whether ageing affects circulating glutathione levels in cats, blood was sampled from two age groups, < 3 years and > 9 years. Further, to determine whether dietary supplementation with glutathione precursor glycine (GLY) affects glutathione concentrations in senior cats (> 8 years), a series of free GLY inclusion level dry diets were fed. Subsequently, a 16-week GLY feeding study was conducted in senior cats (> 7 years), measuring glutathione, and markers of oxidative stress. Whole blood and erythrocyte total, oxidised and reduced glutathione levels were significantly decreased in senior cats, compared with their younger counterparts (P ≤ 0·02). The inclusion level study identified 1·5 % free GLY for the subsequent dry diet feeding study. Significant increases in erythrocyte total and reduced glutathione were observed between senior cats fed supplemented and control diets at 4 weeks (P ≤ 0·03; maximum difference of 1·23 µM). Oxidative stress markers were also significantly different between groups at 8 (P = 0·004; difference of 0·68 nG/ml in 8-hydroxy-2'-deoxyguanosine) and 12 weeks (P ≤ 0·049; maximum difference of 0·62 nG/mG Cr in F2-isoprostane PGF2α). Senior cats have lower circulating glutathione levels compared with younger cats. Feeding senior cats a complete and balanced dry diet supplemented with 1·5 % free GLY for 12 weeks elevated initial erythrocyte glutathione and altered markers of oxidative stress. Dietary supplementation with free GLY provides a potential opportunity to restore age-associated reduction in glutathione in cats.

An Aptamer-Based Proteomic Analysis of Plasma from Cats (Felis catus) with Clinical Feline Infectious Peritonitis.

Feline infectious peritonitis (FIP) is a systemic disease manifestation of feline coronavirus (FCoV) and is the most important cause of infectious disease-related deaths in domestic cats. FIP has a variable clinical manifestation but is most often characterized by widespread vasculitis with visceral involvement and/or neurological disease that is typically fatal in the absence of antiviral therapy. Using an aptamer-based proteomics assay, we analyzed the plasma protein profiles of cats who were naturally infected with FIP (n = 19) in comparison to the plasma protein profiles of cats who were clinically healthy and negative for FCoV (n = 17) and cats who were positive for the enteric form of FCoV (n = 9). We identified 442 proteins that were significantly differentiable; in total, 219 increased and 223 decreased in FIP plasma versus clinically healthy cat plasma. Pathway enrichment and associated analyses showed that differentiable proteins were related to immune system processes, including the innate immune response, cytokine signaling, and antigen presentation, as well as apoptosis and vascular integrity. The relevance of these findings is discussed in the context of previous studies. While these results have the potential to inform diagnostic, therapeutic, and preventative investigations, they represent only a first step, and will require further validation.

Guidelines for resident training in veterinary clinical pathology. IV: Laboratory quality management-Teaching domains, competencies, and suggested learning outcomes.

BACKGROUND: The 2019 ASVCP Education Committee Forum for Discussion, presented at the annual ASVCP/ACVP meeting, identified a need to develop recommendations for teaching laboratory quality management principles in veterinary clinical pathology residency training programs. OBJECTIVES: To present a competency-based framework for teaching laboratory quality management principles in veterinary clinical pathology residency training programs, including entrustable professional activities (EPAs), domains of competence, individual competencies, and learning outcomes. METHODS: A joint subcommittee of the ASVCP Quality Assurance and Laboratory Standards (QALS) and Education Committees executed this project. A draft guideline version was reviewed by the ASVCP membership and shared with selected ACVP committees in early 2022, and a final version was voted upon by the full QALS and Education Committees in late 2022. RESULTS: Eleven domains of competence with relevant individual competencies were identified. In addition, suggested learning outcomes and resource lists were developed. Domains and individual competencies were mapped to six EPAs. CONCLUSIONS: This guideline presents a framework for teaching principles of laboratory quality management in veterinary clinical pathology residency training programs and was designed to be comprehensive yet practical. Guidance on pedagogical terms and possible routes of implementation are included. Recommendations herein aim to improve and support resident training but may require gradual implementation, as programs phase in necessary expertise and resources. Future directions include the development of learning milestones and assessments and consideration of how recommendations intersect with the American College of Veterinary Pathologists training program accreditation and certifying examination.

AN OUTBREAK OF FELINE INFECTIOUS PERITONITIS IN THREE RELATED SAND CATS (FELIS MARGARITA) IN HUMAN CARE.

Feline infectious peritonitis (FIP) is a systemic disease in felid species caused by infection with mutated forms of feline coronavirus (FCoV), and outbreaks can devastate exotic felid populations in human care. Feline infectious peritonitis was diagnosed in three of four related juvenile sand cats (Felis margarita) from a single institution over a 6-wk period. Case 1 was a 7-mon-old male found deceased with no premonitory signs. Case 2, an 8-mon-old male (littermate to Case 1), and Case 3, a 6-mon-old male (from a different litter with identical parentage), were evaluated for lethargy and anorexia 1 mon after Case 1. Both exhibited transient anisocoria and progressive lethargy, anorexia, and dehydration despite antibiotic and supportive treatment. Approximately 1 wk after initial presentation, Case 2 was humanely euthanized, and Case 3 was found deceased. Necropsy findings included intrathoracic and/or intra-abdominal lymphadenopathy (3/3 cases), bicavitary effusion (2/3), multifocal tan hepatic and intestinal nodules (1/3), and multifocal yellow renal nodules (1/3). Histologically, all cats had severe pyogranulomatous vasculitis in multiple organs, and the presence of FCoV antigen was confirmed using immunohistochemical staining. Next-generation sequencing of the virus from Case 3's affected kidney demonstrated ∼93% homology to the UG-FH8 virus, a serotype 1 feline alphacoronavirus isolated from Denmark. Future research will focus on comparative viral genomic sequencing with the goals of identifying potential sources of FCoV infection and identifying features that may have contributed to the development of FIP in this species.

The Late Asymptomatic and Terminal Immunodeficiency Phases in Experimentally FIV-Infected Cats-A Long-Term Study.

Feline immunodeficiency virus (FIV) is a lentivirus in the family Retroviridae that infects domestic cats resulting in an immunodeficiency disease featuring a progressive and profound decline in multiple sets of peripheral lymphocytes. Despite compelling evidence of FIV-associated immunopathology, there are conflicting data concerning the clinical effects of FIV infection on host morbidity and mortality. To explore FIV-associated immunopathogenesis and clinical disease, we experimentally inoculated a cohort of four specific pathogen-free kittens with a biological isolate of FIV clade C and continuously monitored these animals along with two uninfected control animals for more than thirteen years from the time of inoculation to the humane euthanasia endpoint. Here, we report the results obtained during the late asymptomatic and terminal phases of FIV infection in this group of experimentally FIV-infected cats.

Flow Cytometry in Veterinary Practice.

This article summarizes the current applications of flow cytometry in clinical veterinary medicine, which is largely restricted to the diagnosis of hematopoietic neoplasms (lymphomas and leukemias) of domestic dogs, cats, and horses. A brief background on the technique of flow cytometry and fundamentals of data interpretation are included. Major emphasis is placed on clinical indications for flow cytometry, principles of sample collection and submission, and awareness of diagnostic and prognostic utility. Expectations regarding both the benefits and limitations of flow cytometry in a clinical setting, and its complementary nature with other types of testing, are also reviewed.

Multiple Myeloma with Aberrant CD3 Expression in a Red-Lored Amazon Parrot (Amazona autumnalis).

A 20-year-old, female, red-lored Amazon parrot (Amazona autumnalis) was presented for a 2-week history of weakness. On physical examination, the bird was quiet, fluffed, weak, and had a distended coelom. Radiographic and ultrasound imaging revealed coelomic distention, increased pulmonary parenchymal opacity, renomegaly, dilated intestines, and a thickened ventricular wall. The results of a complete blood cell count indicated the patient was anemic (28%) and had intermediate to large lymphocytes with immature chromatin that were suspected to be neoplastic. Immunocytochemistry on peripheral blood determined that the suspected circulating neoplastic cells were cluster of differentiation (CD) 3+ and occasionally expressed multiple myeloma oncogene 1 (MUM1). Abnormalities from a plasma biochemistry panel were moderate hyperphosphatemia (6.8 mg/dL), marked hyperproteinemia (13.6 g/L), analbuminemia (0 g/dL), and marked hyperglobulinemia (13.6 g/dL). Agarose gel plasma protein electrophoresis documented the presence of albumin (1.2 g/dL) and monoclonal bands which, on reduced lithium dodecyl sulfate polyacrylamide gel electrophoresis, resolved as 60-kd and ∼25-kd bands consistent with immunoglobulin Y heavy and light chains. On the basis of these findings, multiple myeloma was diagnosed. Because of a poor prognosis, the bird was euthanized for postmortem examination. Bone marrow cytology from samples collected during the postmortem examination revealed 17.4% plasma cells and 24% large immature cells with occasional plasmacytoid features. Histopathologic findings included aggregates of neoplastic plasma cells in the bone marrow, spleen, kidney, liver, gastrointestinal tract, muscle, ovary, and brain. The neoplastic cells were strongly immunoreactive for MUM1 and cluster of differentiation 3 (CD3), but negative for CD79a, paired box protein 5, and CD20. This confirmed the clinical diagnosis of multiple myeloma. This report describes an avian immunoglobulin Y-secreting multiple myeloma with aberrant CD3 expression and pseudoanalbuminemia. Aberrant CD3 expression by avian multiple myeloma may explain previously published cases of birds with a monoclonal gammopathy and apparent T-cell lymphoma diagnosed by CD3 immunoreactivity.

Unlicensed Molnupiravir is an Effective Rescue Treatment Following Failure of Unlicensed GS-441524-like Therapy for Cats with Suspected Feline Infectious Peritonitis.

Feline infectious peritonitis (FIP) is a complex and historically fatal disease, though recent advances in antiviral therapy have uncovered potential treatments. A newer therapeutic option, unlicensed molnupiravir, is being used as a first-line therapy for suspect FIP and as a rescue therapy to treat cats who have persistent or relapsed clinical signs of FIP after GS-441524 and/or GC376 therapy. Using owner-reported data, treatment protocols for 30 cats were documented. The 26 cats treated with unlicensed molnupiravir as a rescue therapy were treated with an average starting dosage of 12.8 mg/kg and an average ending dosage of 14.7 mg/kg twice daily for a median of 12 weeks (IQR = 10-15). In total, 24 of 26 cats were still living disease-free at the time of writing. One cat was euthanized after completing treatment due to a prolonged seizure, and the other cat underwent retreatment for relapsed clinical signs. Few adverse effects were reported, with the most notable-folded ears (1), broken whiskers (1), and severe leukopenia (1)-seen at dosages above 23 mg/kg twice daily. This study provides a proof of principle for the use of molnupiravir in cats and supports the need for future studies to further evaluate molnupiravir as a potentially safe and effective therapy for FIP.

Diagnostic accuracy of cytology for the detection of bacterial infection in fluid samples from veterinary patients.

BACKGROUND: Bacterial sepsis is a relatively common, life-threatening condition with a high case fatality rate. The current primary diagnostic tools for detecting bacterial infection in fluids are bacterial culture and fluid cytology. While culture is the gold standard, it can take up to several days for results to be made available to clinicians, which can delay recognition of bacterial sepsis and negatively impact patient outcomes. OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy of cytology for detecting bacterial infection in body fluids. METHODS: We retrospectively reviewed 10 years of medical records at the Ohio State University's Veterinary Medical Center for mammalian patients with both cytology and bacterial culture of fluid samples, including body cavity fluids (abdominal and thoracic effusion), blood, joint fluid, and CSF. The overall sensitivity and specificity of cytology relative to the reference method of bacterial culture was recorded, as well as among the subcategories of fluid type. RESULTS: The overall sensitivity and specificity of cytology for the diagnosis of sepsis were 42.6% and 93.0%, respectively. Individual sensitivities and specificities were also calculated for each fluid type. Thoracic fluid cytology had relatively high sensitivity and low specificity, in contrast to the other fluid types analyzed. CONCLUSIONS: Overall, cytology is poorly sensitive but highly specific for the detection of bacterial infection in fluid samples. The results from this study will allow a better comparison between the diagnostic accuracy of cytology and emerging diagnostic tests for the detection of bacterial sepsis in mammalian patients.

American Society for Veterinary Clinical Pathology-Recommended Clinical Pathology Competencies for Graduating Veterinarians.

Given the move toward competency-based veterinary education and the subsequent reevaluation of veterinary curricula, there is a need for specialties to provide guidance to veterinary college administrators and educators on the core knowledge and skills pertaining to their specialty to ensure their inclusion in revised or redesigned curricula. The American Society for Veterinary Clinical Pathology (ASVCP) Education Committee sought to create a list of competencies specific to clinical pathology expected of graduating veterinarians. The stimulus for this project was the American Veterinary Medical Association Council on Education Standards of Accreditation for Colleges of Veterinary Medicine, further driven by the 2018 publication of the Association of American Veterinary Medical Colleges Competency-Based Veterinary Education Working Group framework. The recommendations made in this document are the culmination of the 2016 ASVCP Education Forum for Discussion, multiple remote subcommittee communications, and feedback obtained from ASVCP membership. The final framework includes 8 clinical pathology-focused domains of competence with 20 clinical pathology competencies and 61 clinical pathology illustrative sub-competencies. The clinical pathology-focused domains of competence are: the pre-analytical phase of testing, laboratory medicine and instrumentation, principles of test selection and interpretation, hematology and hemostasis, chemistry, endocrinology, urinalysis, and cytology. These are not intended to replace the nine established AAVMC domains of competence with supportive competencies and illustrative sub-competencies but to guide institutions for how clinical pathology aligns within the competency-based veterinary education (CBVE) framework for the practice-ready veterinary graduate. This clinical pathology competency framework may prove useful and empowering during discussions of curriculum revisions and redesigns.

Novel Multicentric Hepatic Lymphoma with Extrahepatic Biliary Obstruction Associated with Duodenal Perforation in a Cat.

An 11-year-old male castrated domestic shorthair cat was presented for evaluation due to clinical deterioration and potential extrahepatic biliary obstruction (EHBO). Further investigations confirmed EHBO and revealed severe and previously unreported comorbidities. On initial examination, the cat was markedly icteric with a poor body condition score and severe muscle wasting. Serum chemistry and complete blood count showed evidence of cholestasis and anemia. Primary diagnostics and therapeutics targeted these abnormalities. Abdominal ultrasound revealed peritoneal effusion, multifocal mixed echogenic hepatic and splenic foci, small intestinal thickening, cholelithiasis, choledocholithiasis, and common bile duct and pancreatic duct dilation with evidence of obstruction. Peritoneal effusion cytology confirmed septic peritonitis. Hepatic and splenic cytology was consistent with lymphoma. Based on these results, euthanasia was elected by the owners of the animal. Necropsy confirmed the ultrasound diagnoses, septic peritoneal effusion associated with a duodenal perforation, multiorgan lymphoma, and common bile duct carcinoma. Flow cytometry classified the lymphoma as a double-negative phenotype of T-cell lymphoma (CD3+ and CD5+, but CD4- and CD8-) present in the duodenum and liver and suspected in the spleen which has previously not been reported in cats. This case report documents a cat with EHBO caused by multiple disease processes including a novel T-cell lymphoma phenotype, biliary carcinoma, duodenal perforation and septic abdomen, and choleliths, as well as inflammatory hepatobiliary disease.

Unlicensed GS-441524-Like Antiviral Therapy Can Be Effective for at-Home Treatment of Feline Infectious Peritonitis.

The goal of this study was to formally evaluate the administration of unlicensed, crowd-sourced antiviral GS-441524-like therapy for cats suspected to have feline infectious peritonitis (FIP), a previously fatal disease. Members of a large social media support and GS-441524-like drug distribution group were surveyed via the Internet. The survey was targeted toward owners who had treated their cats for at least 12 weeks with unlicensed GS-441524-like drugs. Of the 393 analyzed surveys which met inclusion criteria, 73.7% of owners utilizing this therapy were from the United States. Only 8.7% of owners reported receiving help from their veterinarian in administering the treatment to their cat. The mean cost of treatment was USD 4920. A majority of owners (88.2%) reported noticeable improvement in clinical signs within one week of initiating therapy. At the time of the survey, 96.7% (380 cats) were alive, with 54.0% of them considered cured and another 43.3% being monitored in the 12-week observation period. A total of 12.7% of the cats suffered a relapse of clinical signs of FIP, and 3.3% of the cats died despite GS-441524-like therapy. Reported complications were mostly related to owner administration of subcutaneous injections of the acidic GS-441525-like therapy, such as vocalization, pain, struggling, and injection-site wounds. Limitations of this study include a retrospective design, bias in case selection, reliance on owner-reported data, and inability to confirm the contents of unlicensed pharmaceuticals; however, important lessons can be learned from the experiences of these owners. While unconventional, and certainly not free from medical and legal risks, unlicensed, at-home GS-441524-like therapy, according to owner reports, can apparently offer benefits in the treatment of cats suspected of FIP.

Presentation, management and outcomes of ileoanal pouch cancer: a single-centre experience.

AIM: This study aimed to determine the clinical presentation, management and outcomes for patients with ileoanal pouch cancer. METHOD: Patients who were diagnosed with ileoanal pouch cancer were identified from our polyposis registry (1978-2019) and operative and referral records (2006-2019). Details of presentation, endoscopic surveillance, cancer staging and management were retrieved from hospital records. RESULTS: Eighteen patients were identified (12 with ulcerative colitis, one with Crohn's disease, three with familial adenomatous polyposis [FAP], two with dual diagnosis of FAP and inflammatory bowel disease). The median time from pouch formation to cancer diagnosis was 16.5 years (range 5-34 years) and the median age of the patient at pouch cancer diagnosis was 54 years (range 35-71 years). Eleven of the 18 patients were undergoing surveillance. Four of five FAP patients developed pouch cancer whilst on surveillance. Eight patients were asymptomatic at the time of pouch cancer diagnosis. Two patients had complete clinical response following chemoradiotherapy. Fourteen patients underwent pouch excision surgery (eight with exenteration). Median survival was 54 months; however, only eight patients had outcomes available beyond 24 months follow-up. CONCLUSIONS: Pouch cancer can occur in patients despite routine surveillance and without symptoms, and survival is poor. Centralization of 'high-risk' patients who require surveillance is recommended and a low threshold for referral to centres that can provide expert investigation and management is advised.

Comparison of pathologist review protocols for cytologic detection of prostatic and urothelial carcinomas in canines: A bi-institutional retrospective study of 298 cases.

Urothelial carcinoma, also known as transitional cell carcinoma, is the most common primary bladder tumour in dogs, and can also involve the prostate gland. Cytology is a common diagnostic tool utilized for dogs with bladder or prostate gland lesions. The objectives of this retrospective study were to compare the sensitivity and specificity of cytologic evaluation for urothelial or prostatic carcinoma between two institutions with different cytology review protocols as well as determine if certain collection methods resulted in higher cytologic accuracy. A total of 298 cases met inclusion criteria. The overall sensitivity and specificity for institution 1 were 91.8% and 50%, respectively, compared to 31.1% and 97.4%, respectively, for institution 2. When the urine sample review protocol at institution 2 was matched to that of institution 1, sensitivity and specificity were more similar to institution 1 (71.2% and 88.9%, respectively). Our results show that the sensitivity and specificity of cytology are affected by screening and review protocols implemented by different institutions. The data also demonstrate that sensitivity and specificity vary by collection method. Diagnostic catheterization had the highest performance: of the 11 cases between two institutions, it had 100% sensitivity and specificity. In contrast, examination of urine sediment not collected via diagnostic catheterization had low sensitivity and specificity that varied greatly by institution. In summary, cytologic interpretation should be undertaken with consideration given to both processing and collection protocols.

Formulae to correct sodium concentrations for serum water fraction in cases of hypo- and hyperproteinemia in cats.

BACKGROUND: Biochemistry analyzers in many high-throughput laboratories use indirect potentiometry to determine serum electrolyte concentrations, which involves a pre-analytical dilution step that may be associated with artifactual increases or decreases in electrolyte concentrations under circumstances of altered serum water fraction (SWF). Severe hypo- and hyperproteinemia, conditions that cause altered SWF, are recognized but under-emphasized causes of falsely measured serum sodium concentrations. OBJECTIVES: The goals of this study were to determine the average actual SWF (SWFA ) and establish formulae to correct serum sodium concentration measured by indirect potentiometry in hypo- and hyperproteinemic cats. METHODS: Serum samples from 112 feline patients were analyzed for electrolytes (measured by both indirect and direct potentiometry), total protein, albumin, triglycerides, and cholesterol. Each serum sample was also lyophilized to determine the SWFA . A feline-specific formula to estimate SWF (SWFE-FEL ) was developed and evaluated with a multivariable linear model. RESULTS: The mean SWFA in this population of cats was 91.2%, which was significantly different (P < .0001) than the mean (93.9%) calculated using the human estimated formula (SWFE-HUM ). The formula devised for the SWFE-FEL better recapitulated the SWFA than did the SWFE-HUM , and the corrected sodium concentrations calculated using the feline formula were better correlated with serum sodium measured by direct potentiometry than those determined using the human formula. CONCLUSIONS: Application of feline-specific formulae is expected to limit the misinterpretation of electrolyte data from indirect potentiometry when altered SWF occurs. To demonstrate this, a case example of a hypoproteinemic cat is provided.

Virtual Microscopy Is More Effective Than Conventional Microscopy for Teaching Cytology to Veterinary Students: A Randomized Controlled Trial.

Virtual microscopy (VM) using scanned slides and imaging software is increasingly used in medical curricula alongside instruction in conventional microscopy (CM). Limited reports suggest that VM is useful in the veterinary education setting, and generally well-received by students. Whether students can apply knowledge gained through VM to practical use is unknown. Our objective was to determine whether instruction using VM, compared to CM, is a successful method of training veterinary students for the application of cytology in practice (i.e., using light microscopes). Seventy-one veterinary students from Colorado State University who attended a voluntary 3-hour cytology workshop were randomized to receive the same instruction with either VM (n = 35) or CM (n = 36). We compared these students to a control group (n = 22) of students who did not attend a workshop. All students took a post-workshop assessment involving the interpretation of four cases on glass slides with CM, designed to simulate the use of cytology in general practice. Students also took an 18-question survey related to the effectiveness of the workshop, providing their opinions on cytology instruction in the curriculum and their learning preference (VM or CM). The mean assessment score of the VM group (14.18 points) was significantly higher than the control group (11.33 points, p = .003), whereas the mean of the CM group (12.77 points) was not statistically significantly different from controls (p = .170). Not only is VM an effective method of teaching cytology to veterinary students that can be translated to a real-world case scenario, but it outperformed CM instruction in this study.