Publications by Year: 2020

BACKGROUND: Ultrasound is generally used to measure postvoid residual (PVR) in daily clinical practice for a basic assessment of voiding dysfunction. In animal research, however, PVR is measured mostly by expelling the urine with gentle squeezing of the bladder.

OBJECTIVE: To assess the translational value of measuring PVR by ultrasound in awake rats with the aim of obtaining directly comparable data sets in patients and rodent models.

DESIGN, SETTING, AND PARTICIPANTS: A prospective animal study was conducted in 10 rats with large, incomplete thoracic spinal cord injury resulting in severe bladder impairment. Lower urinary tract function was assessed by urodynamics with implanted bladder catheter and external urethral sphincter electrodes, allowing for repeated measurements over time. Immediately after the last micturition cycle in the urodynamic investigation, PVR was first assessed by ultrasound using a 7.5 MHz linear probe and then by manually expelling the urine via gentle pressure on the abdomen.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PVR was measured by ultrasound and by manually expelling the urine. Paired t test was used to analyze the difference between the two measurements 1 and 2 wk after spinal cord injury.

RESULTS AND LIMITATIONS: PVR assessed by ultrasound was equal to and not statistically different from the volumes obtained by manual expulsion in intact rats, both before injury and during the first 2 wk after spinal cord injury (intact: 0.16 ± 0.07 vs 0.14 ± 0.09 ml, p =  0.08; week 1: 1.67 ± 0.53 vs 1.71 ± 0.55 ml, p =  0.67; week 2: 1.16 ± 0.35 vs 0.98 ± 0.43 ml, p =  0.11). The main limitation of ultrasound for measuring PVR is the restricted availability of ultrasound machines in animal research laboratories.

CONCLUSIONS: Ultrasound is a valuable translational tool to measure PVR in awake rats reflecting the situation in humans.

PATIENT SUMMARY: We measured postvoid residual by ultrasound in awake rats, analogous to clinical examination in humans. Ultrasonography provided similar values to the generally used manual bladder expulsion.

BACKGROUND: The majority of eukaryotic promoters utilize multiple transcription start sites (TSSs). How multiple TSSs are specified at individual promoters across eukaryotes is not understood for most species. In Saccharomyces cerevisiae, a pre-initiation complex (PIC) comprised of Pol II and conserved general transcription factors (GTFs) assembles and opens DNA upstream of TSSs. Evidence from model promoters indicates that the PIC scans from upstream to downstream to identify TSSs. Prior results suggest that TSS distributions at promoters where scanning occurs shift in a polar fashion upon alteration in Pol II catalytic activity or GTF function.

RESULTS: To determine the extent of promoter scanning across promoter classes in S. cerevisiae, we perturb Pol II catalytic activity and GTF function and analyze their effects on TSS usage genome-wide. We find that alterations to Pol II, TFIIB, or TFIIF function widely alter the initiation landscape consistent with promoter scanning operating at all yeast promoters, regardless of promoter class. Promoter architecture, however, can determine the extent of promoter sensitivity to altered Pol II activity in ways that are predicted by a scanning model.

CONCLUSIONS: Our observations coupled with previous data validate key predictions of the scanning model for Pol II initiation in yeast, which we term the shooting gallery. In this model, Pol II catalytic activity and the rate and processivity of Pol II scanning together with promoter sequence determine the distribution of TSSs and their usage.

OBJECTIVES: To analyze factors during early stage of urinary tract infection (UTI) that are associated with development of chronic UTI.

METHODS: Mice were inoculated with Uropathogenic Escherichia coli (UPEC) 2 times 24 hours apart. At 1, 3, 7, 10, 14, 21 and 28 days post infection (dpi), urine bacterial loads and voiding behavior (voiding spot assay, VSA) were measured. At 1 and 28 dpi, 32 urine inflammatory cytokines/chemokines were measured using enzyme-linked immunosorbent assay (ELISA). Bladder and kidney cytokines/chemokines were measured on 28 dpi. Mice that had no more than 1 episode of urine bacterial load < 104 colony forming unit/ml during the entire 4 weeks were defined as susceptible to chronic UTI, otherwise, mice were considered resistant.

RESULTS: At 28 dpi, 64.3% mice developed chronic UTI (susceptible group) and 35.7% mice did not (resistant group). Factors at 1 dpi that were predictive of chronic UTI included increased urine IL-2 (OR 11.9, 95%CI 1.1-130.8, P = .043) and increased urine IL-10 (OR 14.0, 95%CI 1.0-201.2, P = .052). At 28 dpi, there were several significant differences between the susceptible vs resistant groups including urine/tissue bacterial loads and certain urine/tissue cytokines/chemokines.

CONCLUSIONS: Higher urine IL-2 and IL-10 at 1 dpi predicted chronic UTI infection in this model. There have been recent publications associating both of these cytokines to UTI susceptibility. Further explorations into IL-2 and IL-10 mediated pathways could shed light on the biology of recurrent and chronic UTI which are difficult to treat.

Diabetic bladder dysfunction is a frequent complication of diabetes. Although many mouse models of diabetes now exist, there has been little systematic effort to characterize them for the timing of onset and severity of bladder dysfunction. We monitored metabolic status and tested bladder function by void spot assay and limited anesthetized cystometry in both male and female mice of three models of obesity and diabetes: a type 1 diabetes model (the Akita mouse) and two type 2 diabetes models [the diet-induced obese (DIO) model and the ob/ob mouse]. Akita mice had insulin pellets implanted subcutaneously every 3 mo to mimic poorly controlled type 1 diabetes in humans. Mice were hyperglycemic by 48 days after implants. Female mice exhibited no bladder dysfunction at any age up to 20 mo and gained weight normally. In contrast, by 7 mo, male Akita mice developed a profound polyuria and failed to show normal weight gain. There were no observable signs of bladder dysfunction in either sex. DIO mice on high/low-fat diets for 16 mo exhibited mild hyperglycemia in female mice (not in male mice), mild weight gain, and no evidence of bladder dysfunction. Ob/ob mice were followed for 8 mo and became extremely obese. Male and female mice were glucose intolerant, insulin intolerant, and hyperinsulinemic at 4 mo. By 8 mo, their metabolic status had improved but was still abnormal. Urine volume increased in male mice but not in female mice. Bladder dysfunction was observed in the spotting patterns of female mice at 4 and 6 mo of age, resolving by 8 mo. We conclude there are dramatic sex-related differences in lower urinary tract function in these models. Male Akita mice may be a good model for polyuria-related bladder remodeling, whereas female ob/ob mice may better mimic storage problems related to loss of outlet control in a setting of type 2 diabetes complicated by obesity.

BACKGROUND: Our understanding of the neural circuits controlling micturition and continence is constrained by a paucity of techniques for measuring voiding in awake, behaving mice.

NEW METHOD: To facilitate progress in this area, we developed a new, non-invasive assay, micturition video thermography (MVT), using a down-facing thermal camera above mice on a filter paper floor.

RESULTS: Most C57B6/J mice void infrequently, with a stereotyped behavioral sequence, and usually in a corner. The timing of each void is indicated by the warm thermal contrast of freshly voided urine. Over the following 10-15 min, urine cools to ∼3 °C below the ambient temperature and spreads radially in the filter paper. By measuring the area of cool contrast comprising this "thermal void spot," we can derive the initially voided volume. Thermal videos also reveal mouse behaviors including a home-corner preference apart from void spots, and a stereotyped, seconds-long pause while voiding.

COMPARISON WITH EXISTING METHODS AND CONCLUSIONS: MVT is a robust, non-invasive method for measuring the timing, volume, and location of voiding. It improves on an existing technique, the void spot assay, by adding timing information, and unlike the cystometrogram preparation, MVT does not require surgical catheterization. Combining MVT with current neuroscience techniques will improve our understanding of the neural circuits that control continence, which is important for addressing the growing number of patients with urinary incontinence as the population ages.

The general anesthetic ketamine has been repurposed by physicians as an anti-depressant and by the public as a recreational drug. However, ketamine use can cause extensive pathological changes, including ketamine cystitis. The mechanisms of ketamine's anti-depressant and adverse effects remain poorly understood. Here we present evidence that ketamine is an effective L-type Ca2+ channel (Cav1.2) antagonist that directly inhibits calcium influx and smooth muscle contractility, leading to voiding dysfunction. Ketamine prevents Cav1.2-mediated induction of immediate early genes and transcription factors, and inactivation of Cav1.2 in smooth muscle mimics the ketamine cystitis phenotype. Our results demonstrate that ketamine inhibition of Cav1.2 signaling is an important pathway mediating ketamine cystitis. In contrast, Cav1.2 agonist Bay k8644 abrogates ketamine-induced smooth muscle dysfunction. Indeed, Cav1.2 activation by Bay k8644 decreases voiding frequency while increasing void volume, indicating Cav1.2 agonists might be effective drugs for treatment of bladder dysfunction.

INTRODUCTION: While efficacy of deep brain stimulation for motor symptoms of neurological disorders is well accepted, its effects on the autonomic system remain controversial. We aimed to systematically assess all available evidence of deep brain stimulation effects on lower urinary tract function.

METHODS: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies were identified by electronic search of Cochrane Central Register of Controlled Trials, Embase, Medline, Scopus, and Web of Science (last search July 12, 2019) and by screening of reference lists and reviews.

RESULTS: After screening 577 articles, we included 29 studies enrolling a total of 1293 patients. Deep brain stimulation of the globus pallidus internus (GPi), pedunculopontine nucleus (PPN), and subthalamic nucleus (STN) had an inhibitory effect on detrusor function, while deep brain stimulation of the ventral intermediate nucleus of the thalamus (VIM) showed an excitatory effect. In the meta-analysis, deep brain stimulation of the STN led to a significant increase in maximum bladder capacity (mean difference 124 mL, 95% confidence interval 60-187 mL, p = 0.0001) but had no clinically relevant effects on other urodynamic parameters. Adverse events (reported in thirteen studies) were most commonly respiratory issues, postural instability, and dysphagia. Risk of bias and confounding was relatively low.

CONCLUSIONS: Deep brain stimulation does not impair lower urinary tract function and might even have beneficial effects. This needs to be considered in the deep brain stimulation decision-making process helping to encourage and to reassure prospective patients.

INTRODUCTION: Neurogenic lower urinary tract dysfunction (NLUTD), including neurogenic detrusor overactivity (NDO) and detrusor sphincter dyssynergia, is one of the most frequent and devastating sequelae of spinal cord injury (SCI), as it can lead to urinary incontinence and secondary damage such as renal failure. Transcutaneous tibial nerve stimulation (TTNS) is a promising, non-invasive neuromodulatory intervention that may prevent the emergence of the C-fibre evoked bladder reflexes that are thought to cause NDO. This paper presents the protocol for TTNS in acute SCI (TASCI), which will evaluate the efficacy of TTNS in preventing NDO. Furthermore, TASCI will provide insight into the mechanisms underlying TTNS, and the course of NLUTD development after SCI.

METHODS AND ANALYSIS: TASCI is a nationwide, randomised, sham-controlled, double-blind clinical trial, conducted at all four SCI centres in Switzerland. The longitudinal design includes a baseline assessment period 5-39 days after acute SCI and follow-up assessments occurring 3, 6 and 12 months after SCI. A planned 114 participants will be randomised into verum or sham TTNS groups (1:1 ratio), stratified on study centre and lower extremity motor score. TTNS is performed for 30 min/day, 5 days/week, for 6-9 weeks starting within 40 days after SCI. The primary outcome is the occurrence of NDO jeopardising the upper urinary tract at 1 year after SCI, assessed by urodynamic investigation. Secondary outcome measures assess bladder and bowel function and symptoms, sexual function, neurological structure and function, functional independence, quality of life, as well as changes in biomarkers in the urine, blood, stool and bladder tissue. Safety of TTNS is the tertiary outcome.

ETHICS AND DISSEMINATION: TASCI is approved by the Swiss Ethics Committee for Northwest/Central Switzerland, the Swiss Ethics Committee Vaud and the Swiss Ethics Committee Zürich (#2019-00074). Findings will be disseminated through peer-reviewed publications.

TRIAL REGISTRATION NUMBER: NCT03965299.

BACKGROUND: Urodynamic investigations have a pivotal role in the diagnosis of lower urinary tract symptoms. Despite expert statements and guidelines supporting their usefulness for clinical decision making in various clinical domains, the academic debate remains controversial.

OBJECTIVE: To provide a metaepidemiological inventory of studies assessing the diagnostic properties of urodynamic investigations.

DESIGN, SETTING, AND PARTICIPANTS: Systematic searches without language restrictions were performed in (Pre-)Medline, EMBASE, and the Cochrane Library from inception until August 31, 2018. Checking of reference lists of included studies and reviews complemented searches. Records were compiled and screened for possible inclusion by reading title and abstracts by two teams of two research fellows. Inclusion criteria were as follows: prospective data collection and urodynamic investigations performed either as a diagnostic test or using a therapy monitoring instrument. No a priori selection on clinical domain was done. Double reading was performed on records marked "included." Extraction into a developed and piloted matrix was performed in duplicate and checked by a third research fellow.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Of each included article, study specifics, objective, study design, type of data collection, clinical domain, type and description of test used, and type of outcome were extracted and attributed to a framework.

RESULTS AND LIMITATIONS: Electronic searches retrieved 20 841 records. After screening, 299 abstracts were considered relevant. The main reasons for exclusion were as follows: animal studies, no primary data, editorial/opinion based on published data or reviews, primary objective of the study being not the assessment of urodynamic investigations, and post hoc (opportunistic) correlation studies.

CONCLUSIONS: To our knowledge, this is the first comprehensive collection of studies assessing the clinical usefulness of urodynamic investigations. The collection is the starting point for a series of systematic reviews assessing the diagnostic properties of urodynamic investigations.

PATIENT SUMMARY: The usefulness of urodynamic investigations for clinical decision making is under debate. We established an inventory of diagnostic studies on urodynamics to assess the value of urodynamics in various clinical applications.