Relevance of dog as an animal model for urologic diseases

Study on the expression of testin in the testes of dogs

Introduction

Testin is a protein involved in cell mobility, adhesion and colony formation. In rats, testin presence has been reported in the testes, and its possible role in spermatogenesis has been suggested. Studies in humans also suggest a possible role of testin as a cancer suppressor protein. In the dog, which represents both an important pet species and a good animal model for studying biological and pathological testicular processes, the presence of testin has never been reported.

Material and Methods

In the present study, the expression of testin in foetal, prepubertal, adult and aged canine testes was investigated. Testes from 5 adult and 3 aged dogs, from 2 one-month-old puppies and from 2 foetuses miscarried at the end of pregnancy were immunohistochemically examined with a commercial antibody against testin.

Results

Testin was intensely expressed in Sertoli cells in every testis examined. Spermatids were also positive for testin in mature dogs and in the testicular areas of the aged ones which were not atrophic. Weak expression of testin was also detected in all testes examined.

Conclusion

The present study, the first demonstrating the presence of testin in canine testes, provides the basis for further dog-human comparative research and for studies on the role of this protein in canine physiology, reproduction and testicular pathologies.

The impact of urine collection method on canine urinary microbiota detection: a cross-sectional study

BACKGROUND

The urinary tract harbors unique microbial communities that play important roles in urogenital health and disease. Dogs naturally suffer from several of the same urological disorders as humans (e.g., urinary tract infections, neoplasia, urolithiasis) and represent a valuable translational model for studying the role of urinary microbiota in various disease states. Urine collection technique represents a critical component of urinary microbiota research study design. However, the impact of collection method on the characterization of the canine urinary microbiota remains unknown. Therefore, the objective of this study was to determine whether urine collection technique alters the microbial populations detected in canine urine samples. Urine was collected from asymptomatic dogs by both cystocentesis and midstream voiding. Microbial DNA was isolated from each sample and submitted for amplicon sequencing of the V4 region of the bacterial 16 S rRNA gene, followed by analyses to compare microbial diversity and composition between urine collection techniques.

RESULTS

Samples collected via midstream voiding exhibited significantly higher sequence read counts (P = .036) and observed richness (P = .0024) than cystocentesis urine. Bray Curtis and Unweighted UniFrac measures of beta diversity showed distinct differences in microbial composition by collection method (P = .0050, R2 = 0.06 and P = .010, R2 = 0.07, respectively). Seven taxa were identified as differentially abundant between groups. Pasteurellaceae, Haemophilus, Friedmanniella, two variants of Streptococcus, and Fusobacterium were over-represented in voided urine, while a greater abundance of Burkholderia-Caballeronia-Paraburkholderia characterized cystocentesis samples. Analyses were performed at five thresholds for minimum sequence depth and using three data normalization strategies to validate results; patterns of alpha and beta diversity remained consistent regardless of minimum read count requirements or normalization method.

CONCLUSION

Microbial composition differs in canine urine samples collected via cystocentesis as compared to those collected via midstream voiding. Future researchers should select a single urine collection method based on the biological question of interest when designing canine urinary microbiota studies. Additionally, the authors suggest caution when interpreting results across studies that did not utilize identical urine collection methods.

Artificial Urinary Sphincter With Bilateral Atrophic Kidneys and Accessory Renal Arteries in a Male Cadaveric Subject: A Case Report and Clinicopathological Reconciliation of Urinary Abnormalities and Embryogenetic Correlation of Vascular Aberrations

A unique combination of triple abnormality in a willed male body donor dissection, with putative clinicopathological correlations during the subject's lifetime, is described in this case report. The subject had a three-piece artificial urinary sphincter surgically implanted around the proximal corpus spongiosum, left scrotal pouch and in the lower left abdominal wall, ostensibly for urinary incontinence during his lifetime, though the etiology of the latter was not immediately obvious. He also had a total of three accessory renal arteries involving both sides, complicated by bilateral diffuse renal atrophy from presumable glomerulosclerosis or nephrosclerosis-induced nephrotic syndrome. While each entity may not be so unique per se, each is not too common either. The combination of all three findings has not been described to date in the contemporary literature in a single male cadaver dissection. Only seven reports of artificial urinary sphincter studies on human cadaver subjects could be detected in contemporary literature, this being the eighth. Finally, there were no apparent etiopathological or pathogenetic mechanisms to explain the occurrence of each or the coexistence of all of them in a single male cadaveric subject. The artificial urinary sphincter was reviewed with respect to its characteristics, placement, and efficacy. An attempt was made to establish the cause-effect relationship between the artificial sphincter and urinary incontinence that necessitated the implant. Thereafter, a clinicopathological correlation was proposed in this case report to reconcile the concomitance of urinary incontinence, bilateral accessory renal arteries, and bilateral renal atrophy. An embryogenetic mechanism of the aberrant renal arteries was also suggested. Physician awareness from the standpoint of preoperative investigation of such cases was also highlighted.

Mutations in melanocortin-4 receptor: From fish to men

Melanocortin-4 receptor (MC4R), expressed abundantly in the hypothalamus, is a critical regulator of energy homeostasis, including both food intake and energy expenditure. Shortly after the publication in 1997 of the Mc4r knockout phenotypes in mice, including increased food intake and severe obesity, the first mutations in MC4R were reported in humans in 1998. Studies in the subsequent two decades have established MC4R mutation as the most common monogenic form of obesity, especially in early-onset severe obesity. Studies in animals, from fish to mammals, have established the conserved physiological roles of MC4R in all vertebrates in regulating energy balance. Drug targeting MC4R has been recently approved for treating morbid genetic obesity. How the MC4R can be exploited for animal production is highly worthy of active investigation.