Statin administration ameliorates ischemia-induced overactive bladder with improvement of blood flow and anti-inflammatory effects in rats

AIMS

Statins are widely used to treat dyslipidemia and have been shown to reduce the risk of ischemic heart disease and cerebrovascular disease. The effects of statins on ischemia-induced overactive bladder (OAB) and the associated mechanisms were investigated in a rat model of chronic pelvic ischemia.

METHODS

A pelvic ischemia model was created by iliac arterial injury (AI) and a high-fat diet using male Sprague-Dawley rats. Rats were assigned to 3 groups: control group, AI group, and AI + statin group. The control group underwent sham operation and was fed a normal diet. The AI group underwent AI surgery and was fed a high-cholesterol diet. The AI + statin group was administered a statin for 4 weeks. Cystometry was performed for 8 weeks after surgery. Blood flow was evaluated by laser meter. Thickness of the iliac arteries was measured, and microvascular density in the lamina propria was evaluated by immunostaining for CD31. Expressions of inflammatory cytokines in the bladder were measured by real-time PCR.

RESULTS

Cystometry showed a significantly shorter voiding interval and lower bladder capacity in the AI group than in the control group. The AI + statin group showed improvement of these findings. The AI group showed decreased bladder blood flow, increased iliac arterial wall thickening, and decreased microvascular density compared to the control group. Statin administration improved blood flow. Iliac arterial wall thickening was suppressed, and microvascular density was increased by statin administration, though not significantly. Real-time PCR showed significantly higher expressions of inflammatory cytokines (IL-6, IL-8, and TNF-α) in the AI group than in the control group, and IL-6 and IL-8 expressions were lower in the AI + statin group than in the AI group.

CONCLUSIONS

The present results suggest that statins are effective in OAB caused by arteriosclerosis and ischemia. The mechanism of their effects involves improved bladder blood flow and decreased bladder inflammation.

Neurogenic Bladder in Dogs, Cats and Humans: A Comparative Review of Neurological Diseases

Lower urinary tract disease (LUTD) includes abnormalities in the structure and function of the bladder and the urethra. LUTD caused by neurological disease is defined neurogenic bladder (NB). The integrity of the central nervous system (CNS) and peripheral nervous system (PNS) is required to explicate normal micturition, maintaining the proper function of bladder and urethra. The location and type of neurological lesions influence the pattern of clinical manifestations, potential treatment, and prognosis. Though, in dogs and cats, spinal cord injury is considered mainly responsible for bladder and/or urethra incompetence, other disorders, congenital or acquired, involving CNS or PNS, could play a role in NB. In veterinary medicine, the information about the epidemiology, prevalence, etiopathogenesis, diagnosis and treatment of NB are scattered. The aim of this study is to provide an overview of the epidemiology, prevalence, clinical findings, diagnosis and prognosis for NB in dogs and cats compared with humans.

Development of an ultrasound-guided transgluteal injection of the pudendal nerve in cats: a cadaveric study

OBJECTIVE

To develop an ultrasound-guided interfascial plane technique for injection of the pudendal nerve near its sacral origin in cats.

STUDY DESIGN

Prospective, randomized, anatomical study.

ANIMALS

A group of 12 feline cadavers.

METHODS

Gross and ultrasound anatomy of the ischiorectal fossa, the pudendal nerve relationship with parasacral structures, and the interfascial plane were described. Computed tomography was employed to describe a cranial transgluteal approach to the pudendal nerve. Bilateral ultrasound-guided injections were performed in eight cadavers using low [(LV) 0.1 mL kg^-1] or high volume [(HV) 0.2 mL kg^-1] of ropivacaine-dye solution. Dissections were performed to determine successful staining of the pudendal nerve (>1 cm) and inadvertent staining of the sciatic nerve, and any rectal, urethral, or intravascular puncture. Pudendal nerve staining in groups LV and HV were compared using Fisher's exact and Wilcoxon rank-sum test as appropriate (p = 0.05).

RESULTS

The pudendal nerve and its rectal perineal and sensory branches coursed through the ischiorectal fossa, dorsomedial to the ischiatic spine. The pudendal nerve was not identified ultrasonographically, but the target plane was identified between the sacral transverse process, the ischiatic spine, the pelvic fascia and the rectum, and it was filled with dye solution. Both branches of the pudendal nerve were completely stained 75% and 87.5% in groups LV and HV, respectively (p = 1.00). The dorsal aspect of the sciatic nerve was partially stained in 37% of injections in group HV. Rectal or urethral puncture and intravascular injection were not observed.

CONCLUSIONS AND CLINICAL RELEVANCE

In cats, ultrasound-guided cranial transgluteal injection successfully stained the pudendal nerve in at least 75% of attempts, regardless of injectate volume. Group HV had a greater probability of sciatic nerve staining.

Frequency of bacteriuria in dogs with chronic kidney disease: A retrospective study of 201 cases

Background

Studies have shown an increased prevalence of positive urine culture (PUC) in cats with chronic kidney disease (CKD); no information is available in dogs.

Objectives

To document the PUC frequency in a cohort of dogs with CKD, determine risk factors for PUC, and identify associations between clinicopathologic data and PUC.

Animals

Two hundred one client‐owned dogs with CKD.

Methods

Retrospective, observational study. Dogs recruited from 2 veterinary teaching hospitals were included if they were diagnosed with CKD and had a culture performed on urine collected by cystocentesis. The PUC frequency was calculated, multivariate analysis was performed to identify risk factors, and associations with clinicopathologic data were investigated.

Results

Sixty‐five dogs (32%) with CKD had PUC, including 8 (28%) in International Renal Interest Society (IRIS) stage 1; only 8% showed signs of a urinary tract infection. Escherichia coli was the most common isolate (67%). A PUC was more likely in females (odds ratio [OR], 3.22; 95% confidence interval [CI], 1.67‐6.37; P < .001) than males and in dogs with isosthenuria (OR, 2.48; 95% CI, 1.24‐5.03; P = .01) than in dogs with urine‐specific gravity 1.013‐1.024. A positive leukocyte esterase test and microorganisms found by urine sediment analysis were significantly associated with PUC (both P < .001).

Conclusions and Clinical Importance

Dogs with CKD, even IRIS stage 1, have a high frequency of PUC and most cases are asymptomatic. A urine culture could be considered in the routine evaluation of dogs with CKD, but the clinical relevance of a PUC remains unknown and needs further evaluation.

Clinical, histopathologic, cystoscopic, and fluorescence in situ hybridization analysis of proliferative urethritis in 22 dogs

Background

Proliferative urethritis (PU) is a lower urinary tract disease of dogs characterized by frond‐like lesions in the urethra. The etiology of PU is unknown, although an association with bacterial cystitis is reported.

Objectives

Deep‐seated bacterial cystitis is associated with PU, particularly in dogs with neutrophilic or granulomatous inflammation.

Animals

Twenty‐two client‐owned dogs with PU and 5 control dogs euthanized for non‐urinary disease.

Methods

In retrospective analysis, medical records of dogs with PU from 1986 to 2016 were reviewed. Signalment, clinical signs, cystoscopic findings, antimicrobial use, and results of urine, bladder, or urethral tissue cultures, if available, were recorded. Histopathology was reviewed and classified as lymphocytic‐plasmacytic (LP), neutrophilic, LP‐neutrophilic (LPN), granulomatous, or pleocellular. Eubacterial fluorescence in situ hybridization (FISH) was performed on 18 tissue samples (13 cases, 5 controls), with subsequent evaluation of bacterial species.

Results

Of the 22 dogs, 9 had LP urethritis, 6 had LPN, 4 had pleocellular, and 3 had neutrophilic urethritis. Of note, 7 of 13 PU samples were FISH+ for adherent or invasive bacteria; 1 of 5 controls were FISH+ for adherent bacteria. Five dogs had negative urine and tissue cultures when FISH was positive. There was no association detected between the type of urethral inflammation and the results of urine and tissue culture or FISH.

Conclusions and Clinical Importance

The type of inflammation varied widely in these 22 PU cases. Deep‐seated bacterial urethritis could be contributing to the inflammatory process in some dogs, regardless of the inflammation type. Urine and tissue cultures likely underestimate bacterial colonization of the urethra in dogs.

Use of the MALDI BioTyper system and rapid BACpro with MALDI-TOF MS for rapid identification of microorganisms causing bacterial urinary tract infection in feline urine samples

With the increasing number of cats kept as pets, opportunities to treat cats with lower urinary tract disease (LUTD) have recently increased in the clinical veterinary field. Urine samples collected from 50 cats with bacterial cystitis brought to Maeda Veterinary Hospital between August 10, 2015 and March 31, 2017 were used in the study. Sample preparation of the urine was performed using a MALDI Sepsityper kit and rapid BACpro. To identify the isolates, MALDI-TOF MS was performed on an AutoFlex TOF/TOF mass spectrometer. MALDI-TOF MS using rapid BACpro for pretreatment was found to be a quick and reliable method for identification of bacteria from infected urine, with a shortened analysis time enabling earlier and more accurate selection of antibiotics for treatment of feline LUTD.

Urinary Nerve Growth Factor Levels in Urinary Tract Diseases With or Without Frequency Urgency Symptoms

OBJECTIVES

To measure urinary nerve growth factor (NGF) levels in patients with several urinary tract diseases under different conditions and compare with NGF levels in patients with overactive bladder (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS).

METHODS

Urinary NGF levels were measured using enzyme-linked immunosorbent assay (ELISA) and normalized by urinary creatinine concentration. Patients with acute bacterial cystitis, urinary tract stone, urothelial cell carcinoma, and OAB patients after antimuscarinic therapy were evaluated. The urinary NGF levels of OAB, IC/PBS and controls from previous studies were used for comparison. NGF levels were compared among subgroups and between urinary tract diseases with or without associated OAB symptoms. The urinary NGF levels were also compared among natural filling, after normal saline filling and after potassium chloride test in a group of OAB and IC/PBS patients.

RESULTS

Patients with acute bacterial cystitis, urinary tract stones or urothelial cell carcinoma had elevated NGF levels that were not associated with the presence of OAB symptoms. Symptomatic cystitis patients who had resolved OAB symptoms after antibiotic treatment had a significant decrease in urinary NGF levels. The urinary NGF levels decreased significantly in OAB patients with effective antimuscarinic treatment for 6 months, but remained stationary and higher than the controls for up to 12 months after treatment.

CONCLUSION

Urinary NGF is not produced solely in patients with OAB or IC/PBS. Acute bacterial cystitis, urinary tract stones and urothelial cell carcinoma can have high urinary NGF production.