Cat Kidney Research Articles

Potential applications and effects of silymarin in domestic animals – a review

Silymarin is a mixture of flavonolignan fractions from the medicinal plant milk thistle, which is primarily used as a hepatoprotector in humans and animals, and acts as an antioxidant, anti-inflammatory, antifibrotic, and antiapoptotic agent. As a dietary supplement, it is increasingly used to treat various liver diseases, some intoxications, prevent side effects of chemotherapy and protect the kidneys in dogs, birds, poultry, rabbits, cats, horses and other animals. The use of silymarin in dairy cows showed an improved biochemical profile of cows, reduced occurrence of ketosis and increased milk production. In pigs, nutrient digestibility, total average daily feed intake, and average daily weight gain improved, while in sport horses, silymarin supplementation accelerated the return of cortisol levels to pre-exercise levels. Lipidosis of the liver or fatty liver disease is a common disorder among captive parrots. After long-term administration of 100–150 mg/kg silymarin in food every 8–12 hours, the health condition improved significantly according to the testimonies of parrot owners and veterinarians. In intensive poultry production systems, silymarin is used in broilers as a hepatotonic, to improve carcass characteristics, to boost the immune system and intestinal health, and as a growth promoter, and in laying hens to improve egg quality. In addition, it mitigated the negative effects of mycotoxins in broilers,chickens and Japanese quails. Although numerous studies are known about the effect of milk thistle and silymarin, their use on animals is not yet widespread.

Species-specific histological characterizations of renal tubules and collecting ducts in the kidneys of cats and dogs.

The histomorphological features of normal kidneys in cats and dogs have been revealed despite the high susceptibility of cats to tubulointerstitial damage. Herein, the histological characteristics of the two species were compared. Cytoplasmic lipid droplets (LDs) were abundant in the proximal convoluted tubules (PCTs) of cats aged 23-27 months but scarce in dogs aged 24-27 months. LDs were rarely observed in the distal tubules (DTs) and collecting ducts (CDs) of either species, as visualized by the expression of Tamm-Horsfall protein 1, calbindin-D28K, and aquaporin 2. The occupational area ratio of proximal tubules (PTs) in the renal cortex was higher, but that of DTs or CDs was significantly lower in adult cats than in dogs. Single PT epithelial cells were larger, but PCT, DT, and CD lumens were significantly narrower in adult cats than in dogs. Unlike adults, young cats at 6 months exhibited significantly abundant cytoplasmic LDs in proximal straight tubules, indicating lipid metabolism-related development. Histochemistry of the 21 lectins also revealed variations in glycosylation across different renal tubules and CDs in both species. Sodium-glucose cotransporter 2 was expressed only in PTs, excluding the proximal straight tubules with few LDs in adult cats or the PCTs of young cats and adult dogs. These findings are crucial for understanding species-specific characteristics of renal histomorphology and pathogenesis.

Investigation of Functional Cytochrome P450 4A Enzymes in Liver and Kidney of Pigs, Cats, Tree Shrews, and Dogs in Comparison with the Metabolic Capacity of Human P450 4A11.

Pigs are sometimes used in preclinical drug metabolism studies, with growing interest, and thus their drug-metabolizing enzymes, including the cytochromes P450 (P450 or CYP; EC 1.14.14.1), need to be examined. In the present study, novel CYP4A cDNAs were isolated and characterized, namely, pig CYP4A23 and CYP4A90; cat CYP4A37 and CYP4A106; and tree shrew CYP4A11a, CYP4A11d, CYP4A11e, CYP4A11f, and CYP4A11g. For comparison, the following known CYP4A cDNAs were also analyzed: pig CYP4A21 and dog CYP4A37, CYP4A38, and CYP4A39. These CYP4A cDNAs all contained open reading frames of 504-513 amino acids and had high amino acid sequence identity (74%-80%) with human CYP4As. Phylogenetic analysis of amino acid sequences revealed that these CYP4As were clustered in each species. All CYP4A genes contained 12 coding exons and formed a gene cluster in the corresponding genomic regions. A range of tissue types were analyzed, and these CYP4A mRNAs were preferentially expressed in liver and/or kidney, except for pig CYP4A90, which showed preferential expression in lung and duodenum. CYP4A enzymes, heterologously expressed in Escherichia coli, preferentially catalyzed lauric acid 12-hydroxylation and arachidonic acid 20-hydroxylation, just as human CYP4A11 does, with the same regioselectivity (i.e., at the ω-position of fatty acids). These results imply that dog, cat, pig, and tree shrew CYP4As have functional characteristics similar to those of human CYP4A11, with minor differences in lauric acid 12-hydroxylation. SIGNIFICANCE STATEMENT: Cytochrome P450 (P450, CYP) 4As are important P450s in human biological processes because of their fatty acid-metabolizing ability. Pig CYP4A21, CYP4A23, and CYP4A90; cat CYP4A37 and CYP4A106; tree shrew CYP4A11a, CYP4A11d, CYP4A11e, CYP4A11f, and CYP4A11g; and dog CYP4A37, CYP4A38, and CYP4A39 cDNAs were isolated and analyzed. These CYP4A cDNAs shared relatively high sequence identities with human CYP4A11 and CYP4A22. Pig, cat, tree shrew, and dog CYP4As in the liver and kidneys are likely to catalyze the ω-hydroxylation of fatty acids.

Accumulation of persistent organic pollutants in the kidneys of pet cats (Felis silvestris catus) and the potential implications for their health

Persistent organic pollutants (POPs), such as polychlorinated diphenyls (PCBs) and brominated diphenyl ethers (PBDEs), are ubiquitous in the pet cat's living environment and are ingested through dietary intake and environmental exposure such as house dust. Cats are known to be susceptible to chronic kidney disease (CKD) and exposure to POPs may be associated with CKD. However, no studies have been conducted on the renal accumulation and health effects of POPs in cats. The objective of this study was to elucidate the accumulation of PCBs, PBDEs, and organochlorine pesticides (OCPs) in the kidneys of domestic cats and discuss their potential impact on feline health.We report here that cats specifically accumulate POPs in their kidneys. Tissue samples were collected from the kidneys, livers, and muscles of cats and the concentrations of POPs in these tissues were analyzed in this study. The results showed that these compounds accumulated significantly higher in the kidney compared to other tissues. In addition, the ability to accumulate in the kidney was higher in cats than in other animals, suggesting that cats have a unique pattern of POPs accumulation in their kidneys, which is thought to occur because cats store a significant number of lipid droplets in the proximal tubules of the kidneys. This unique feature suggests that lipophilic POPs may accumulate in these lipid droplets during the excretory process. Accumulation of certain POPs in the kidneys causes necrosis and sloughing of renal tubular epithelial cells, which may be associated with CKD, a common disease in cats. This study provides valuable insight into understanding the renal accumulation and risk of POPs in cats and provides essential knowledge for developing strategies to protect the health and welfare of domestic cats.

PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts

Background Polycystic kidney disease (PKD) has a complex phenotype partly explained by genetic variants related to this disease. Ultrasonography is a promising approach for defining clinical signs. This study aimed to assess kidney characteristics in cats with Polycystin-1 (PKD1) gene mutations and wild-type cats. Kidney characteristics were identified by ultrasonography. Methods A total of 108 cats of variable breeds aged an average of 37.01±3.50 months were included. Blood examination and biochemical tests were evaluated. For cystic formation, renal ultrasound was performed. The PKD1 gene mutation was identified via polymerase chain reaction (PCR) and DNA sequencing. Matrix correlation and effectiveness of ultrasound for PKD1 mutation detection were determined. Results The results showed that 19.44% of cats had PKD1 mutations, a high prevalence in Persian and Persian-related breed cats. Our results demonstrated the characteristics of kidneys in wild-type cats and cats with gene mutations. Based on ultrasonography results, there was an association between cats with gene mutations and cyst formation. The findings indicated that ultrasound did not detect cysts in cats aged 4-36 months, supporting the evidence that PKD1 gene mutations may not be present. This study found high sensitivity and renal specificity ultrasound for PKD1 heterozygous mutation. Moreover, cystic formation via renal ultrasound showed an increased risk for PKD1 mutation 2,623 times compared to normal kidneys. Conclusions Ultrasonographic examination, coupled with genetic investigations, may help to clarify the phenotypic variability of PKD1. The phenotypic profile of PKD1 will guide therapeutic outcomes and reduce the prevalence of PKD morbidity and mortality in cats.

Criteria for evaluation of the kidneys in dogs and cats using B-mode ultrasound ...

Criteria for evaluation of the kidneys in dogs and cats using B-mode ultrasound ...

PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts.

Polycystic kidney disease (PKD) has a complex phenotype partly explained by genetic variants related to this disease. Ultrasonography is a promising approach for defining clinical signs. This study aimed to assess kidney characteristics in cats with Polycystin-1 (PKD1) gene mutations and wild-type cats. Kidney characteristics were identified by ultrasonography. A total of 108 cats of variable breeds aged an average of 37.01±3.50 months were included. Blood examination and biochemical tests were evaluated. For cystic formation, renal ultrasound was performed. The PKD1 gene mutation was identified via polymerase chain reaction (PCR) and DNA sequencing. Matrix correlation and effectiveness of ultrasound for PKD1 mutation detection were determined. The results showed that 19.44% of cats had PKD1 mutations, a high prevalence in Persian and Persian-related breed cats. Our results demonstrated the characteristics of kidneys in wild-type cats and cats with gene mutations. Based on ultrasonography results, there was an association between cats with gene mutations and cyst formation. The findings indicated that ultrasound did not detect cysts in cats aged 4-36 months, supporting the evidence that PKD1 gene mutations may not be present. This study found high sensitivity and renal specificity ultrasound for PKD1 heterozygous mutation. Moreover, cystic formation via renal ultrasound showed an increased risk for PKD1 mutation 2,623 times compared to normal kidneys. Ultrasonographic examination, coupled with genetic investigations, may help to clarify the phenotypic variability of PKD1. The phenotypic profile of PKD1 will guide therapeutic outcomes and reduce the prevalence of PKD morbidity and mortality in cats.

Immunohistochemical analysis of renal oxidative damage in senior and geriatric cats with chronic kidney disease

Oxidative stress is a well-known cause of chronic kidney disease (CKD). In this study, renal oxidative damage in azotaemic and non-azotaemic aged cats with naturally occurring CKD was investigated using immunohistochemistry for 8-hydroxy-2′-deoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE) as markers of oxidative tissue damage. Kidneys were obtained from aged (>10 years old) azotaemic (n = 13) and non-azotaemic (n = 7) cats. Immunoreactivity for 8-OHdG was found in the nuclei of glomeruli, proximal and distal tubules, loops of Henle and collecting ducts, whereas 4-HNE-positive signals were detected in the cytoplasm of distal nephrons in azotaemic and non-azotaemic cats. Quantitative analysis did not identify any significant differences between the azotaemic and non-azotaemic groups for any of the parameters examined. These results indicate that renal oxidative damage occurs in the kidneys of aged cats with CKD, regardless of whether they are azotaemic or non-azotaemic, emphasizing the importance of oxidative stress during early-stage CKD in senior and geriatric cats.

Assessing the safety and suitability of using silver vine as an olfactory enrichment for cats

Olfactory enrichment is a strategy that can improve welfare among animals managed in captivity, such as household domestic cats. Catnip (Nepeta cataria) and silver vine (Actinidia polygama) that produce iridoids are used as olfactory enrichments for cats, but little is known about the safety or the best plant resources to use that maximize positive cat responses. We report physiological effects and suitable harvest and drying methods for using silver vine as olfactory enrichment. Continuous exposure of cats to silver vine showed no hallmarks of addictive behavior, while blood indicators of stress and hepatic or renal injury showed no increase in cats stimulated with it. Drying the leaves changed the iridoid profile, enhancing the feline response. In conclusion, dried silver vine leaves are the most suitable resource for developing olfactory enrichment that maximizes feline typical response, which would not result in dependence, stress, or toxicity to the liver or kidneys in cats.

Results of ultrasonic study of chronic kidney disease in domestic cats in the territory of the capital megapolis

Kidney disease in pets is the most common problem that pet owners come to the veterinary clinic for. With age, the likelihood of kidney disease in domestic cats increases. It has been found that 20 to 50% of household cats older than 15 suffer from chronic renal failure. The authors studied chronic kidney disease of domestic cats in the metropolitan metropolis at the Monino veterinary clinic. The total sample consisted of 85 cats, of which, after clarification of the diagnosis (biochemical tests), experimental (n = 37) and control groups (n = 37) were formed. According to clinical analysis, the latter was assigned to a conditionally healthy group. The mean age of healthy cats in the control group was 4.95±0.22 years (median five years), and that of cats in the experimental group with renal insufficiency was 8.92±0.53 (median nine years). Ultrasound examination of the kidneys of domestic cats with chronic renal failure revealed diseases such as nephritis with a frequency of 32.4%, glomerulonephritis - 27.1, urolithiasis - 21.6 and pyelonephritis - 18.9%. Frequent clinical symptoms in domestic cats were: loss or lack of appetite - 54.1%, vomiting - 32.4%, pollakiuria with strangiuria - 10.8%, and lethargy - 10.8%. Thus, ultrasound diagnostics showed high information content in detecting renal failure in domestic cats. The diagnostic efficiency reached 97%. The ultrasound method has established itself as safe, painless and comfortable for a pet when examining the abdominal organs.

PKD1 gene mutation and ultrasonographic characterization in cats with renal cysts

Background: Polycystic kidney disease (PKD) has a complex phenotype partly explained by genetic variants related to this disease. Ultrasonography is a promising approach for defining clinical signs. This study aimed to assess kidney characteristics in cats with Polycystin-1 (PKD1) gene mutations and wild-type cats. Kidney characteristics were identified by ultrasonography. Methods: A total of 108 cats of variable breeds aged an average of 37.01±3.50 months were included. Blood examination and biochemical tests were evaluated. For cystic formation, renal ultrasound was performed. The PKD1 gene mutation was identified via polymerase chain reaction (PCR) and DNA sequencing. Matrix correlation and effectiveness of ultrasound for PKD1 mutation detection were determined. Results: The results showed that 19.44% of cats had PKD1 mutations, a high prevalence in Persian and Persian-related breed cats. Our results demonstrated the characteristics of kidneys in wild-type cats and cats with gene mutations. Based on ultrasonography results, there was an association between cats with gene mutations and cyst formation. The findings indicated that ultrasound did not detect cysts in cats aged 4-36 months, supporting the evidence that PKD1 gene mutations may not be present. This study found high sensitivity and renal specificity ultrasound for PKD1 heterozygous mutation. Moreover, cystic formation via renal ultrasound showed an increased risk for PKD1 mutation 2,623 times compared to normal kidneys. Conclusions: Ultrasonographic examination, coupled with genetic investigations, may help to clarify the phenotypic variability of PKD1. The phenotypic profile of PKD1 will guide therapeutic outcomes and reduce the prevalence of PKD morbidity and mortality in cats.

Relationship between kidney ultrasound data and blood creatinine and urea levels in cats with autosomal dominant polycystic kidney disease

The results of studying the influence of structural changes in the kidneys on their filtration in cats with polycystic kidney disease are given. The study was conducted on 10 domestic cats, which were divided into two experimental groups based on the results of creatinine determination according to the IRIS (International Renal Interest Society) classification – 5 animals with moderate renal azotemia (group 1) and 5 animals with severe renal azotemia (group 2). Ultrasound examination of the kidneys of cats in both groups was performed using a Mindray device with a microconvection transducer with a frequency of 7.5–10 MHz in B-mode. Both kidneys were examined in each animal. Scanning was performed in the sagittal plane so that the kidney gate was visible. The length, width of the kidney, and thickness of the cortical layer, as well as the number of cysts and their diameter, were counted. The renal area (RA), cyst area (CA), and the ratio of cyst area to renal area (RA/Cyst) were calculated. According to the results of the study of serum creatinine and urea content, the animals were divided into two groups depending on the level of azotemia. 5 cats with stage III chronic renal failure (CRF), serum creatinine levels were 326.40 ± 23.59 μmol/l, and 5 animals with stage IV chronic renal failure serum creatinine – 887.00 ± 61.81 µmol/l, which is 2.7 times higher (P ≤ 0.001) than the creatinine level in cats with stage III CKD. The urea content in the serum was significantly increased compared to the norm and amounted to 22.82 ± 2.09 mol/l in cats with stage III CKD and 42.45 ± 1.05 mol/l in cats with stage IV CKD, which was 2.2 times higher (P ≤ 0.01) compared to stage III. In animals with polycystic kidney disease and stage IV chronic renal failure according to the results of ultrasound examination an increase in the length of the kidney by 6.5 mm (p≤0.001) and a thickening of the cortical layer by 0.8 mm (P ≤ 0.01) was revealed, compared to animals with polycystic kidney disease and stage III chronic renal failure. There was no correlation between the area of cysts in the kidneys and the level of creatinine in the blood serum of animals. Ultrasound signs of chronic renal failure in cats of stage III are enlargement of the kidney in the length of more than 51 mm and cortical thickness of more than 5.5 mm, of stage IV is an increase in kidney length of more than 59 mm and cortical thickness of more than 6.0 mm. According to the results of ultrasonography, the number of cysts or their area cannot be used to assess the degree of renal functional failure.

Assessment of peritubular capillary rarefaction in kidneys of cats with chronic kidney disease.

Hypoxia is a key driver of fibrosis and is associated with capillary rarefaction in humans. Characterize capillary rarefaction in cats with chronic kidney disease (CKD). Archival kidney tissue from 58 cats with CKD, 20 unaffected cats. Cross-sectional study of paraffin-embedded kidney tissue utilizing CD31 immunohistochemistry to highlight vascular structures. Consecutive high-power fields from the cortex (10) and corticomedullary junction (5) were digitally photographed. An observer counted and colored the capillary area. Image analysis was used to determine the capillary number, average capillary size, and average percent capillary area in the cortex and corticomedullary junction. Histologic scoring was performed by a pathologist masked to clinical data. Percent capillary area (cortex) was significantly lower in CKD (median 3.2, range, 0.8-5.6) compared to unaffected cats (4.4, 1.8-7.0; P= <.001) and was negatively correlated with serum creatinine concentrations (r= -.36, P= .0013), glomerulosclerosis (r= -0.39, P= <.001), inflammation (r= -.30, P= .009), and fibrosis (r= -.30, P= .007). Capillary size (cortex) was significantly lower in CKD cats (2591 pixels, 1184-7289) compared to unaffected cats (4523 pixels, 1801-7618; P= <.001) and was negatively correlated with serum creatinine concentrations (r= -.40, P= <.001), glomerulosclerosis (r= -.44, P< .001), inflammation (r= -.42, P= <.001), and fibrosis (r= -.38, P= <.001). Capillary rarefaction (decrease in capillary size and percent capillary area) is present in kidneys of cats with CKD and is positively correlated with renal dysfunction and histopathologic lesions.

Ethylene glycol intoxication in a pregnant cat and a tomcat

Clinical cases of two cats, poisoned with ethylene glycol: one tomcat and a pregnant female in the last quarter of gestation, are presented. Cats were reared outdoor. The history included a sudden weakness, inappetence, lethargy and repeated vomiting in both animals. Physical examination showed reduced skin elasticity, hypothermia (37.3 С° and 37.8 С°), hyporeflexia, pale mucous coats. Blood biochemical changes comprised hyperglycaemia (7.74 and 10.1 mmol/L), hyperphosphataemia (6.3 and 5.67 mmol/L), increased urea (66.6 and 68.2 mmol/L) and creatinine concentrations (1408 and 918 µmol/L). Ultrasound examination showed severely increased corticomedullary echogenicity of kidneys, including foetal kidneys. Blood sample obtained post mortem from foetuses was characterised with dramatically increased phosphate (11.3 mmol/L), urea (66.2 mmol/L) and creatinine concentrations (642 µmol/L). Foetal urine had abundant calcium oxalate monohydrate crystals. Such crystals were present also in histological preparations from kidneys of both adult cats and foetuses.

Intra- and Inter-Observer Variability of Quantitative Parameters Used in Contrast-Enhanced Ultrasound of Kidneys of Healthy Cats.

Contrast-enhanced ultrasound (CEUS) is a non-invasive imaging technique which allows qualitative and quantitative assessment of tissue perfusion. Although CEUS offers numerous advantages, a major challenge remains the variability in tissue perfusion quantification. This study aimed to assess intra- and inter-observer variability for quantification of renal perfusion. Two observers with different levels of expertise performed a quantitative analysis of 36 renal CEUS studies, twice. The CEUS data were collected from 12 healthy cats at 3 different time points with a 7-day interval. The inter- and intra-observer agreement was assessed by the intraclass correlation coefficient. Within and between observers, a good agreement was demonstrated for intensity-related parameters in the cortex, medulla, and interlobular artery. For some parameters, ICCinter was considerably lower than ICCintra, mostly when the ROI encompassed the entire kidney or medulla. With the exception of time to peak (TTP) and mean transit time (mTTI), time-related and slope-related parameters showed poor agreement among observers. In conclusion, it may be advised against having the quantitative assessment of renal perfusion performed by different observers, especially if their experience levels differ. The cortical mTTI seemed to be the most appropriate parameter as it showed a favorable inter-observer agreement and inter-period agreement.

Frequency of histologic lesions in the kidneys of cats without kidney disease.

In humans, renal aging is associated with an increased frequency of glomerulosclerosis, interstitial fibrosis, inflammation and tubular atrophy. The purpose of this study was to describe the frequency of renal histopathologic lesions in cats without kidney disease. A cross-sectional study of archival kidney tissue from 74 cats without kidney disease (serum creatinine <1.6 mg/dl; urine specific gravity >1.035) was carried out: 0-4 years (young, n = 18); 5-9 years (mature, n = 16); 10-14 years (senior, n = 34), 15+ years (geriatric, n = 6). Glomerulosclerosis, tubular atrophy, interstitial inflammation and fibrosis, and the presence or absence of lipid in the interstitium and tubules were scored by a pathologist masked to clinical data. Statistical analyses were performed as appropriate. Geriatric cats had significantly more glomerulosclerosis than mature (P = 0.01) and young cats (P = 0.004). Senior cats had significantly more glomerulosclerosis than young cats (P = 0.006). Glomerulosclerosis was weakly positively correlated with age (r = 0.48; P <0.0001). Geriatric cats had significantly more tubular atrophy than mature (P = 0.02) and young cats (P <0.0001). Senior cats had significantly more tubular atrophy than young cats (P <0.0001). Geriatric cats had significantly more inflammation than senior cats (P = 0.02), mature cats (P = 0.01) and young cats (P <0.0001). Senior cats had significantly more inflammation than young cats (P = 0.004). Geriatric and senior cats had significantly more fibrosis than young cats (P = 0.01 and P = 0.04, respectively). Frequency of tubular lipid increased with age (young: 28%; mature: 56%; senior: 79%; geriatric: 100%) as did the frequency of interstitial lipid (young: 22%, mature: 56%, senior: 85%, geriatric: 100%). Evidence of renal aging exists in cats. These changes imply that the aging kidney may be more susceptible to injury and impaired healing.

Nehemiah Grew, the illustrator

The literature on seventeenth-century Royal Society member Nehemiah Grew's artistic production has been sparse and tentative. Although his publication record includes five illustrated books, some of which feature quite elaborate illustrative programmes, it has been challenging to credit any of this visual production directly to the books’ author. In this article, I aim to both contribute to the growing interest in Grew's illustrations, and to provide a corrective to this gap in the literature, presenting Grew for the first time as an active illustrator and arguing for the importance of Grew's visual production during his career with the Royal Society. I will discuss his visual archive and his relationship with his engravers and will also present evidence of his regular use of illustrated figures in lectures he presented throughout the 1670s. This includes attributing two original drawings to Grew that are still present in the Royal Society's collections—two dissected cat's kidneys—that are associated with a lecture he gave on animal anatomy in 1679.

FeMV is a cathepsin-dependent unique morbillivirus infecting the kidneys of domestic cats

Feline morbillivirus (FeMV) is a recently discovered pathogen of domestic cats and has been classified as a morbillivirus in the Paramyxovirus family. We determined the complete sequence of FeMVUS5 directly from an FeMV-positive urine sample without virus isolation or cell passage. Sequence analysis of the viral genome revealed potential divergence from characteristics of archetypal morbilliviruses. First, the virus lacks the canonical polybasic furin cleavage signal in the fusion (F) glycoprotein. Second, conserved amino acids in the hemagglutinin (H) glycoprotein used by all other morbilliviruses for binding and/or fusion activation with the cellular receptor CD150 (signaling lymphocyte activation molecule [SLAM]/F1) are absent. We show that, despite this sequence divergence, FeMV H glycoprotein uses feline CD150 as a receptor and cannot use human CD150. We demonstrate that the protease responsible for cleaving the FeMV F glycoprotein is a cathepsin, making FeMV a unique morbillivirus and more similar to the closely related zoonotic Nipah and Hendra viruses. We developed a reverse genetics system for FeMVUS5 and generated recombinant viruses expressing Venus fluorescent protein from an additional transcription unit located either between the phospho-protein (P) and matrix (M) genes or the H and large (L) genes of the genome. We used these recombinant FeMVs to establish a natural infection and demonstrate that FeMV causes an acute morbillivirus-like disease in the cat. Virus was shed in the urine and detectable in the kidneys at later time points. This opens the door for long-term studies to address the postulated role of this morbillivirus in the development of chronic kidney disease.

PSXI-2 Circulating Mirnas as non-Invasive Biomarkers of Chronic Kidney Disease and Calcium Oxalate Uroliths in Felines

Abstract Chronic kidney disease (CKD), characterized by progressive loss of kidney function, is a major cause of mortality in cats. Another complication is the formation of calcium oxalate (CaOx) uroliths in the bladder and kidneys of cats, where inflammation has a role in its pathogenesis. MicroRNAs (miRNAs) are small non-coding RNAs which bind to the target mRNA to reduce its function. Depending on the target mRNA, they regulate transcription of several pro-inflammatory genes. We assessed the expression profiles of circulating miRNAs in blood, collected at the natural end-of-life in colony cats, in a retrospective study, in healthy (n=10; 5.9-16 yr), CaOx (n=10, 8.6-13.4 yr), and CKD (n=10; 8.3-15.4 yr). Circulating concentrations of creatinine, symmetric dimethylarginine, and blood urea nitrogen were significantly greater in CaOx and CKD cats compared with controls, indicating kidney dysfunction. Expression of miRNAs, measured by qRT-PCR, was analyzed using the ΔΔCt method and normalized to U6. There was a significant upregulation of miR-155 in CaOx stone formers compared with controls (p&amp;lt; 0.05). miR-155 is increased in the serum and urine of human patients with nephrolithiasis. miR-155 can also promote oxalate-induced renal oxidative stress by suppressing MGP expression. In humans, miR-155 concentrations are negatively correlated with cytokines including IL-1β, IL-6, and TNF-α, suggesting the involvement of inflammation in nephrolithiasis. However, miR-155 was downregulated in CKD compared with controls. miR-16 was also downregulated in CKD cats. Consistent with this, there is downregulation of both the miRNAs in human patients with Stage 4 CKD. Further, miRNAs downregulated in CaOx, but not in CKD, included miR-17, miR-19b, miR-27a, and miR-27b, whereas let-7a, miR-15a, miR-16, miR-29b, and miR-200a were downregulated only in CKD cats. Taken together, the profile of circulating miRNAs in CaOx and CKD cats may serve as important biomarkers in the initiation and progression of renal dysfunction in cats.

Evaluation of a Low-cost Renal Simulator for the Diagnostic Ultrasound Training of Veterinary Medicine Students.

The acquisition of ultrasound diagnostic skills via training is important for undergraduate veterinary medical students. Unfortunately, commercial simulators are costly, which limits their use and makes it necessary to develop low-cost simulators for training purposes. The aim of this study was to evaluate the efficacy of an easily constructed, low-cost, high-fidelity renal simulator for use in diagnostic ultrasound training of veterinary medical students. To construct the simulators, donated cat kidneys were embedded in a prepared agar matrix. The echogenicity of ultrasound scans obtained on the kidney simulator was assessed by the subject lecturers and compared with images acquired during clinical routine diagnostic procedures. Five students with no prior experience of the technique, under the direct supervision of a lecturer, performed five B-mode ultrasound examinations of the renal structure of the simulator. The structure of the kidney was assessed, and its length, width and thickness were measured. Three lecturers performed the same procedure as the students, and their results were used for comparison. Appropriate anatomical and ultrasonographic realism was achieved for each of the three layers of the kidney (cortex, medulla and pelvis), and similar pixel values were obtained with the simulator model and actual clinical diagnostic ultrasounds. In addition, the kidney dimensions acquired by the students were consistent with those acquired by the lecturers. Thus, the proposed kidney simulator can be used for the training of veterinary medicine students in ultrasonographic diagnostic techniques.