Dysfunctional Bladder Morphology and Functional Impairments Are Identified in the Alzheimer's Disease APPNL-G-F/NL-G-F Murine Model

BACKGROUND

While symptoms related to lower urinary tract dysfunction (LUTD) are common in individuals with Alzheimer's disease (AD), pathophysiological links between AD and LUTD remain unclear.

OBJECTIVE

This study aimed to investigate whether AD neuropathology would cause autonomic dysfunction along the spinal cord-bladder axis, which could result in alterations in bladder muscle kinetics.

METHODS

We utilized APPNL-G-F/NL-G-F knock-in (APP KI) and APPwt/wt (wild-type) mice at two different ages, 4- and 10-month-old, to investigate how AD impacts bladder tissue function by immunohistochemistry, western blotting, and pharmacomyography.

RESULTS

We showed that the mucosal layer partially separated from the detrusor in 10-month-old APP KI mouse bladders. Although there was no detectable amyloid deposition in the APP KI bladder, we found amyloid plaques in APP KI lumbar spinal cord. Further immunoblot analysis revealed that tyrosine hydroxylase protein levels were significantly reduced in both 4- and 10-month-old bladder tissues, suggesting reduction of norepinephrine synthesis in APP KI mouse bladders. In contrast, the level of β2 adrenergic receptor was increased in 4-month-old but not 10-month-old APP KI bladders. In bladder strips, the adrenergic agonist isoproterenol induced increased relaxation in 4- but not 10-month-old APP KI bladders. With 10 Hz electrical field stimulation, 10-month-old APP KI bladder strips were more responsive than wild-type controls, with no differences observed in 4-month-old APP KI bladders.

CONCLUSIONS

APP KI mice exhibit LUTD, which is likely arising from amyloid pathology in the spinal cord, and results in maturational declines in presynaptic activity combined with compensatory postsynaptic upregulation.

Loss of resilience contributes to detrusor underactivity in advanced age

Volume hyposensitivity resulting from impaired sympathetic detrusor relaxation during bladder filling contributes to detrusor underactivity (DU) associated with aging. Detrusor tension regulation provides an adaptive sensory input of bladder volume to the brainstem and is challenged by physiological stressors superimposed upon biological aging. We recently showed that HCN channels have a stabilizing role in detrusor sympathetic relaxation. While mature mice maintain homeostasis in the face of stressors, old mice are not always capable. In old mice, there is a dichotomous phenotype, in which resilient mice adapt and maintain homeostasis, while non-resilient mice fail to maintain physiologic homeostasis. In this DU model, we used cystometry as a stressor to categorize mice as old-responders (old-R, develop a filling/voiding cycle) or old-non-responders (old-NR, fail to develop a filling/voiding cycle; fluctuating high pressures and continuous leaking), while also assessing functional and molecular differences. Lamotrigine (HCN activator)-induced bladder relaxation is diminished in old-NR mice following HCN-blockade. Relaxation responses to NS 1619 were reduced in old-NR mice, with the effect lost following HCN-blockade. However, RNA-sequencing revealed no differences in HCN gene expression and electrophysiology studies showed similar percentage of detrusor myocytes expressing HCN (I_h) current between old-R and old-NR mice. Our murine model of DU further defines a role for HCN, with failure of adaptive recalibration of HCN participation and intensity of HCN-mediated stabilization, while genomic studies show upregulated myofibroblast and fibrosis pathways and downregulated neurotransmitter-degradation pathways in old-NR mice. Thus, the DU phenotype is multifactorial and represents the accumulation of age-associated loss in homeostatic mechanisms.

Alzheimer's disease amyloidogenesis is linked to altered lower urinary tract physiology

AIMS

While most Alzheimer's disease (AD) research emphasizes cognitive and behavioral abnormalities, lower urinary tract symptoms (LUTS) are observed in a third of AD patients, contributing to morbidity, poor quality of life, and need for institutionalization. Alzheimer's disease-associated urinary dysfunction (ADUD) has been assumed to be due to cognitive decline alone. While mouse studies have suggested that bladder innervation and voiding behavior may be altered in AD models, technical challenges precluded voiding reflex assessments. This study seeks to establish a mouse model of ADUD, and it seeks to characterize the noncognitive sequelae involved in AD-pathology associated alterations in the voiding reflex.

METHODS

Having developed techniques permitting the assessment of bladder volume, pressure, and flow in mice, we now provide evidence of alterations in involuntary bladder control and increased response heterogeneity in a transgenic amyloidosis mouse model of AD using cystometry and tissue pharmacomyography. Tg-APP/PS1DE9 (PA) mice and their wild-type (WT) littermates (n = 6-8 per group) were used before plaque onset in the PA mice (4-6 months) and after plaque accumulation in the PA mice (8-10 months) in comparison to their WT control littermates.

RESULTS

Novel findings include data suggestive of sphincteric discoordination, with pharmacological evidence of altered adrenergic mechanisms.

CONCLUSIONS

Together, these data highlight the importance of addressing noncognitive sequelae of AD and offer novel translational insights into the debilitating impact of AD on LUTS and incontinence.

The hyperpolarization-activated, cyclic nucleotide-gated channel resides on myocytes in mouse bladders and contributes to adrenergic-induced detrusor relaxation

Control of urinary continence is predicated on sensory signaling about bladder volume. Bladder sensory nerve activity is dependent on tension, implicating autonomic control over detrusor myocyte activity during bladder filling. Hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channels are known contributors to bladder control, but their mechanism of action is not well understood. The lack of a definitive identification of cell type(s) expressing HCN in the bladder presents a significant knowledge gap. We recently reported a complete transcriptomic atlas of the C57BL/6 mouse bladder showing the dominant HCN paralog in mouse bladder, Hcn1, is limited to a subpopulation of detrusor smooth myocytes (DSMs). Here, we report details of these findings, along with results of patch-clamp experiments, immunohistochemistry, and functional myobath/tension experiments in bladder strips. With the use of a transgenic mouse expressing fluorescence-tagged α-smooth muscle actin, our data confirmed location and function of DSM HCN channels. Despite previous associations of HCN with postulated bladder interstitial cells, neither evidence of specific interstitial cell types nor an association of nonmyocytes with HCN was discovered. We confirm that HCN activation participates in reducing sustained (tonic) detrusor tension via cAMP, with no effect on intermittent (phasic) detrusor activity. In contrast, blockade of HCN increases phasic activity induced by a protein kinase A (PKA) blocker or a large-conductance Ca²⁺-activated K⁺ (BK) channel opener. Our findings, therefore, suggest a central role for detrusor myocyte HCN in regulating and constraining detrusor myocyte activity during bladder filling.

Cuprizone-mediated demyelination reversibly degrades voiding behavior in mice while sparing brainstem reflex

Multiple sclerosis (MS) is a chronic, progressively debilitating demyelinating disease of the central nervous system (CNS). Nearly 80% of MS patients experience lower urinary tract dysfunction early in their diagnosis. This significantly affects the quality of life, and in latter stages of disease is a leading cause of hospitalization. Previously, animal models have shown that inflammatory demyelination in the CNS causes profound bladder dysfunction, but the confounding influence of systemic inflammation limits the potential interpretation of the contribution of CNS demyelination to bladder dysfunction. Since the micturition circuit has myelinated neuronal connections in the cortex, brainstem, and spinal cord, we examined alterations in bladder function in the cuprizone model characterized by demyelinating lesions in the cortex and corpus callosum that are independent of T-cell-mediated autoimmunity. Herein, we report that a 4-week dietary cuprizone treatment in C57Bl/6J mice induced alterations in voiding behavior with increased micturition frequency and reduced volume voided, similar to human MS bladder dysfunction. Subsequently, recovery from cuprizone treatment restored normal bladder function. Demyelination and remyelination were confirmed by Luxol Fast Blue staining of the corpus callosum. Additionally, we also determined that an 8-week cuprizone treatment, resulting in chronic demyelination lacking spontaneous remyelination potential, is associated with an exacerbated voiding phenotype. Interestingly, while cuprizone-induced CNS demyelination severely affected conscious (cortical) urinary behavior, the brainstem and spinal cord reflex remained unchanged, as confirmed by urethane-anesthetized cystometry. This is the first study to show that cortical demyelination independent of inflammation can negatively impact urinary function.

Blocking peripheral drive from colorectal afferents by subkilohertz dorsal root ganglion stimulation

ABSTRACT

Clinical evidence indicates dorsal root ganglion (DRG) stimulation effectively reduces pain without the need to evoke paresthesia. This paresthesia-free anesthesia by DRG stimulation can be promising to treat pain from the viscera, where paresthesia usually cannot be produced. Here, we explored the mechanisms and parameters for DRG stimulation using an ex vivo preparation with mouse distal colon and rectum (colorectum), pelvic nerve, L6 DRG, and dorsal root in continuity. We conducted single-fiber recordings from split dorsal root filaments and assessed the effect of DRG stimulation on afferent neural transmission. We determined the optimal stimulus pulse width by measuring the chronaxies of DRG stimulation to be below 216 µs, indicating spike initiation likely at attached axons rather than somata. Subkilohertz DRG stimulation significantly attenuates colorectal afferent transmission (10, 50, 100, 500, and 1000 Hz), of which 50 and 100 Hz show superior blocking effects. Synchronized spinal nerve and DRG stimulation reveals a progressive increase in conduction delay by DRG stimulation, suggesting activity-dependent slowing in blocked fibers. Afferents blocked by DRG stimulation show a greater increase in conduction delay than the unblocked counterparts. Midrange frequencies (50-500 Hz) are more efficient at blocking transmission than lower or higher frequencies. In addition, DRG stimulation at 50 and 100 Hz significantly attenuates in vivo visceromotor responses to noxious colorectal balloon distension. This reversible conduction block in C-type and Aδ-type afferents by subkilohertz DRG stimulation likely underlies the paresthesia-free anesthesia by DRG stimulation, thereby offering a promising new approach for managing chronic visceral pain.

PART 2: Mouse models for multiple sclerosis research

Lower urinary tract symptoms and dysfunction (LUTS/LUTD) contribute to loss of quality of life, morbidity, and need for medical intervention in most patients with multiple sclerosis (MS). Although MS is an inflammatory neurodegenerative disease, clinical manifestations including continence control disorders have traditionally been attributed to the loss of neural signaling due to neurodegeneration. Clinical approaches to MS-LUTS/LUTD have focused on addressing symptoms in the context of urodynamic dysfunctions as pathophysiologic understandings are incomplete. The mouse model provides a useful research platform for discovery of more detailed molecular, cellular, and tissue-level knowledge of the disease and its clinical manifestations. The aim of this two-part review is to provide a state-of-the-art update on the use of the mouse model for MS research, with a focus on lower urinary tract symptoms. Part I presents a summary of current understanding of MS pathophysiology, the impact on lower urinary tract symptoms, and briefly introduces the types of mouse models available to study MS. Part II presents the common animal models that are currently available to study MS, their mechanism, relevance to MS-LUTS/LUTD and their urinary pathophysiology, advantages and disadvantages.

Animal modeling of lower urinary tract dysfunction associated with multiple sclerosis: Part I: Justification of the mouse model for MS research

Lower urinary tract symptoms and dysfunction (LUTS/LUTD) contribute to loss of quality of life, morbidity, and need for medical intervention in most patients with multiple sclerosis (MS). Although MS is an inflammatory neurodegenerative disease, clinical manifestations including continence control disorders have traditionally been attributed to the loss of neural signaling due to neurodegeneration. Clinical approaches to MS-LUTS/LUTD have focused on addressing symptoms in the context of urodynamic dysfunctions as pathophysiologic understandings are incomplete. The mouse model provides a useful research platform for the discovery of more detailed molecular, cellular, and tissue-level knowledge of the disease and its clinical manifestations. The aim of this two-part review is to provide a state-of-the-art update on the use of the mouse model for MS research, with a focus on lower urinary tract symptoms. Part I presents a summary of the current understanding of MS pathophysiology, the impact on lower urinary tract symptoms, and briefly introduces the types of mouse models available to study MS. Part II presents the common animal models that are currently available to study MS, their mechanism, relevance to MS-LUTS/LUTD and their urinary pathophysiology, advantages, and disadvantages.

Aging Changes in Bladder Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels Are Associated With Increasing Heterogeneity of Adrenergic/Mucosal Influence on Detrusor Control in the Mouse

A geroscience-informed approach to the increasing prevalence of bladder control problems in older adults requires understanding the impact of aging on dynamic mechanisms that ensure resilience in response to stressors challenging asymptomatic voluntary control over urine storage and voiding. Bladder control is predicated on sensory neural information about bladder volume. Modulation of volume-induced bladder wall tensions by autonomic and mucosal factors controls neural sensitivity to bladder volume. We hypothesized that hyperpolarization-activated cyclic nucleotide-gated (HCN) channels integrate these factors and thereby mediate adrenergic detrusor tension control. Furthermore, loss of HCN expression compromises that integration and could result in loss of precision of detrusor control. Using a life-span mouse model, reverse transcription quantitative real-time PCR and pharmacologic studies in pretensioned intact and mucosa-denuded bladder strips were made. The dominant hcn1 expression declines with maturation and aging; however, aging is also associated with increased variance around mean values. In strips from Mature animals, isoproterenol had less effect in denuded muscle strips than in intact strips, and HCN blockade diminished isoproterenol responsiveness. With aging, variances about mean response values significantly increased, paralleling hcn1 expression. Our findings support a role for HCN in providing neuroendocrine/paracrine integration and suggest an association of increased heterogeneity of HCN expression in aging with reductions in response precision to neuroendocrine control. The functional implication is an increased risk of dysfunction of brainstem/bladder regulation of neuronal sensitivity to bladder volume. This supports the clinical model of the aging bladder phenotype as an expression of loss of resilience, and not as emerging bladder pathology with aging.

Cervical dilatation and preparation prior to outpatient hysteroscopy: a systematic review and meta-analysis

BACKGROUND

There are uncertainties about the benefit of routine cervical preparation and/or cervical dilatation before outpatient hysteroscopy.

OBJECTIVE

To determine if cervical preparation and/or routine mechanical dilatation reduces pain during outpatient hysteroscopy.

SEARCH STRATEGY

MEDLINE, EMBASE, CINAHL and CENTRAL were searched on 19 October 2020, using keywords 'hysteroscopy', 'cervical preparation', 'cervical ripening', 'cervical dilatation', 'outpatient', 'office' and/or 'ambulatory' and associated medical subject headings.

SELECTION CRITERIA

Randomised controlled trials investigating the benefit of cervical preparation and/or cervical dilatation on pain in women undergoing outpatient hysteroscopy were included.

DATA COLLECTION AND ANALYSIS

Two independent reviewers selected eligible trials and extracted data on pain, feasibility, adverse events and satisfaction/acceptability for meta-analysis.

MAIN RESULTS

The literature search yielded 807 records, of which 24 were included for review and 19 provided data for meta-analysis. No trials investigated the role of routine mechanical cervical dilatation. Cervical preparation significantly reduced pain during outpatient hysteroscopy; standard mean difference (SMD) -0.67, 95% confidence interval (CI) -1.05 to -0.29. Feasibility also improved as priming provided significantly easier hysteroscopic entry (SMD 0.89, 95% CI 0.32-1.46), greater cervical dilatation (SMD 0.81, 95% CI 0.08-1.53) and shorter procedural times (SMD -0.51, 95% CI -0.88 to -0.13). Cervical preparation, however, incurred significantly more adverse effects, mainly comprising genital tract bleeding, abdominal pain and gastrointestinal symptoms (odds ratio 2.94, 95% CI 1.58-5.47). There were limited data regarding satisfaction, acceptability and complications.

CONCLUSIONS

Cervical preparation reduces pain and improves feasibility associated with outpatient hysteroscopy but increases the risk of adverse effects.

TWEETABLE ABSTRACT

Cervical preparation before outpatient hysteroscopy reduces pain, enhances feasibility but increases adverse effects.

Should we routinely assess psychological morbidities in idiopathic lower urinary tract dysfunction: ICI-RS 2019?

AIMS

Psychological morbidities play a major role in idiopathic lower urinary tract dysfunction (iLUTD). The aim of the Think Tank (TT) was to discuss the relevance of psychological morbidities in idiopathic LUTD over the life span, including overactive bladder (OAB) or dysfunctional voiding (DV) and methods of assessment.

METHODS

The paper is based on a selective review of the literature and in-depth discussions, leading to research recommendations regarding the assessment of psychological morbidities in iLUTD on children and adults held during the TT of the International Consultation on Incontinence Research Society in 2019.

RESULTS

Psychological comorbidities affect the health behaviors and treatment outcomes in patients with iLUTD. Both clinically relevant comorbid mental disorders, as well as subclinical psychological symptoms have a major impact and negatively influence incontinence treatment. Research is needed to elucidate mechanisms underlying iLUTD and psychological comorbidities. Clinical studies are needed to determine how perception generation and cognition impacts on the relationship of urinary perceptions, symptoms, and objective urodynamic function. Due to high psychological comorbidity rates, screening with validated, generic questionnaires for emotional and behavioral disorders in children with nocturnal enuresis, daytime urinary incontinence, and fecal incontinence is recommended. Brief screening is recommended for all adults with iLUTD, especially with OAB and DV, who are refractory to treatment.

CONCLUSIONS

Due to the high rate and relevance in clinical practice, screening for psychological comorbidities is recommended for all age groups. The research recommendations of this TT may be followed to improve the assessment of psychological morbidities in iLUTD.

Best practices for cystometric evaluation of lower urinary tract function in muriform rodents

AIMS

Rodent cystometry has provided valuable insights into the impact of the disease, injury, and aging on the cellular and molecular pathways, neurologic processes, and biomechanics of lower urinary tract function. The purpose of this white paper is to highlight the benefits and shortcomings of different experimental methods and strategies and to provide guidance on the proper interpretation of results.

METHODS

Literature search, selection of articles, and conclusions based on discussions among a panel of workers in the field.

RESULTS

A range of cystometric tests and techniques used to explore biological phenomena relevant to the lower urinary tract are described, the advantages and disadvantages of various experimental conditions are discussed, and guidance on the practical aspects of experimental execution and proper interpretation of results are provided.

CONCLUSIONS

Cystometric evaluation of rodents comprises an extensive collection of functional tests that can be performed under a variety of experimental conditions. Decisions regarding which approaches to choose should be determined by the specific questions to be addressed and implementation of the test should follow standardized procedures.

HCN as a Mediator of Urinary Homeostasis: Age-Associated Changes in Expression and Function in Adrenergic Detrusor Relaxation

The Hyperpolarization activated, cyclic nucleotide gated (HCN) channel is a candidate mediator of neuroendocrine influence over detrusor tonus during filling. In other tissues, HCN loss with aging is linked to declines in rhythmicity and function. We hypothesized that HCN has an age-sensitive expression profile and functional role in adrenergic bladder relaxation. HCN was examined in bladders from young (2-6 months) and old (18-24 months) C57BL/6 female mice, using qRT-PCR, RNAScope, and Western blots. Isometric tension studies were conducted using bladder strips from young wild-type (YWT), old wild-type (OWT), and young HCN1 knock-out (YKO) female mice to test the role HCN in effects of β-adrenergic stimulation. Hcn1 is the dominant HCN isoform RNA in the mouse bladder wall, and is diminished with age. Location of Hcn RNA within the mouse bladder wall is isoform-specific, with HCN1 limited to the detrusor layer. Passively-tensioned YWT bladder strips are relaxed by isoproterenol in the presence of HCN function, where OWT strips are relaxed only in the presence of HCN blockade. HCN has an age-specific expression and function in adrenergic detrusor relaxation in mouse bladder strips.

Can we improve our diagnosis of impaired detrusor contractility in women? An ICI-RS 2019 proposal

INTRODUCTION

Widely accepted consensus terminology and calculations of detrusor contractility in females do not exist but may be useful. We report the output of a proposal session at the International Consultation on Incontinence Research Society meeting 2019, addressing the title topic.

METHODS

Three formal presentations and a lively discussion addressed several questions including: which is the optimal cutoff value of female bladder voiding efficiency during uroflow to suspect obstruction or detrusor underactivity? Is there a definition of pure underactive and pure obstructed voiding in females? Is there a place to distinguish those relatively obstructed from those relatively underactive females especially in those cases of equivocal obstruction? Current measures of contractility were reviewed for their usefulness in women.

RESULTS

No recommendation for a specific index or calculation can be made based on current knowledge. "Contractility" may be context-dependent regarding clinical care, clinical prognostication, and physiologic research.

CONCLUSIONS

This group proposes that context-sensitive definitions of "Contractility" deserve attention by international leadership. Cooperative clinical and physiologic expertise will be needed to achieve this goal. Following initial recommendations based on expert opinion, the development of final definitions and measures of contractility should be iterative, based upon validation studies to be considered as part of the definitional process.

The aging bladder phenotype is not the direct consequence of bladder aging

AIMS

The prevalence of urinary dysfunction increases with age, yet therapies are often suboptimal. Incomplete understanding of the linkages between system, organ, and tissue domains across lifespan remains a knowledge gap. If tissue-level changes drive the aging bladder phenotype, parallel changes should be observed across these domains. In contrast, a lack of inter-domain correlation across age groups would support the hypothesis that urinary performance is a measure of the physiologic reserve, dependent on centrally-mediated adaptive mechanisms in the aging system.

METHODS

Male and female mice across four age groups underwent sequential voiding spot assays, pressure/flow cystometry, bladder strip tension studies, histology, and quantitative PCR analyses. The primary objective of this study was to test the impact of age on the cortical, autonomic, tissue functional and structural, and molecular domains, and identify inter-domain correlations among variables showing significant changes with age within these domains.

RESULTS

Behavior revealed diminished peripheral voiding and spot size in aged females. Cystometry demonstrated increased postvoid residual and loss of volume sensitivity, but the preservation of voiding contraction power, with almost half of oldest-old mice failing under cystometric stress. Strip studies revealed no significant differences in adrenergic, cholinergic, or EFS sensitivity. Histology showed increased detrusor and lamina propria thickness, without a change in collagen/muscle ratio. Adrb2 gene expression decreased with age. No consistent inter-domain correlations were found across age groups.

CONCLUSIONS

Our findings are consistent with a model in which centrally-mediated adaptive failures to aging stressors are more influential over the aging bladder phenotype than local tissue changes.

Vaginoscopy Against Standard Treatment: a randomised controlled trial

OBJECTIVE

To evaluate whether vaginoscopy or standard hysteroscopy was more successful in the outpatient setting.

DESIGN

Randomised controlled multicentre trial.

SETTING

Outpatient hysteroscopy clinics at two UK hospitals.

POPULATION

1597 women aged 16 or older undergoing an outpatient hysteroscopy.

METHODS

Women were allocated to vaginoscopy or standard hysteroscopy using third party randomisation stratified by menopausal status with no blinding of participants or clinicians.

MAIN OUTCOME MEASURES

The primary outcome was 'success', a composite endpoint defined as: a complete procedure, no complications, a level of pain acceptable to the patient, and no sign of genitourinary tract infection 2 weeks after the procedure.

RESULTS

Vaginoscopy was significantly more successful than standard hysteroscopy [647/726 (89%) versus 621/734 (85%), respectively; relative risk (RR) 1.05, 95% CI 1.01-1.10; P = 0.01]. The median time taken to complete vaginoscopy was 2 minutes compared with 3 minutes for standard hysteroscopy (P < 0.001). The mean pain score was 42.7 for vaginoscopy, which was significantly less than standard hysteroscopy 46.4 (P = 0.02). Operative complications occurred in five women receiving vaginoscopy and 19 women receiving standard hysteroscopy (RR 0.26, 95% CI 0.10-0.69).

CONCLUSIONS

Vaginoscopy is quicker to perform, less painful, and more successful than standard hysteroscopy and therefore should be considered the technique of choice for outpatient hysteroscopy.

TWEETABLE ABSTRACT

Vaginoscopy is quicker to perform, less painful, and more successful than standard hysteroscopy.

Outcomes in prevention and management of miscarriage trials: a systematic review

BACKGROUND

There is a substantial body of research evaluating ways to prevent and manage miscarriage, but all studies do not report on the same outcomes.

OBJECTIVE

To review systematically, outcomes reported in existing miscarriage trials.

SEARCH STRATEGY

MEDLINE, Embase, CINAHL, and Cochrane were searched from inception until January 2017.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting prevention or management of miscarriage. Miscarriage was defined as a pregnancy loss in the first trimester.

DATA COLLECTION AND ANALYSIS

Data about the study characteristics, primary, and secondary outcomes were extracted.

MAIN RESULTS

We retrieved 1553 titles and abstracts, from which 208 RCTs were included. For prevention of miscarriage, the most commonly reported primary outcome was live birth and the top four reported outcomes were pregnancy loss/stillbirth (n = 112), gestation of birth (n = 68), birth dimensions (n = 65), and live birth (n = 49). For these four outcomes, 58 specific measures were used for evaluation. For management of miscarriage, the most commonly reported primary outcome was efficacy of treatment. The top four reported outcomes were bleeding (n = 186), efficacy of miscarriage treatment (n = 105), infection (n = 97), and quality of life (n = 90). For these outcomes, 130 specific measures were used for evaluation.

CONCLUSIONS

Our review found considerable variation in the reporting of primary and secondary outcomes along with the measures used to assess them. There is a need for standardised patient-centred clinical outcomes through the development of a core outcome set; the work from this systematic review will form the foundation of the core outcome set for miscarriage.

TWEETABLE ABSTRACT

There is disparity in the reporting of outcomes and the measures used to assess them in miscarriage trials.

Report and Research Agenda of the American Geriatrics Society and National Institute on Aging Bedside-to-Bench Conference on Urinary Incontinence in Older Adults: A Translational Research Agenda for a Complex Geriatric Syndrome

The American Geriatrics Society, with support from the National Institute on Aging and other funders, held its ninth Bedside-to-Bench research conference, entitled "Urinary Incontinence in the Older Adult: A Translational Research Agenda for a Complex Geriatric Syndrome," October 16 to 18, 2016, in Bethesda, Maryland. As part of a conference series addressing three common geriatric syndromes-delirium, sleep and circadian rhythm disturbance, and urinary incontinence-the series highlighted relationships and pertinent clinical and pathophysiological commonalities between these conditions. The conference provided a forum for discussing current epidemiology, basic science, and clinical and translational research on urinary incontinence in older adults; for identifying gaps in knowledge; and for developing a research agenda to inform future investigative efforts. The conference also promoted networking involving emerging researchers and thought leaders in the field of incontinence, aging, and other fields of research, as well as National Institutes of Health program personnel.

Pathophysiology of the Underactive Bladder: Evolving New Concepts

PURPOSE OF REVIEW

Underactive Bladder (UAB) is an emerging concept of voiding dysfunction, building on a tradition of often overlapping and confusing terminologies describing the patient experience, urodynamic function, and pathophysiology. This confusion of symptoms with function with pathology has hampered development of an effective disease model.

RECENT FINDINGS

As with other urinary symptoms, the relationship of voiding symptoms to urodynamic dysfunction is variable. Efforts are underway to formally define UAB as a collection of symptoms related to voiding. Defined as voiding symptoms, UAB cannot be reliably linked to detrusor underactivity (DU) nor to detrusor weakness.

SUMMARY

Progress will be made by characterizing the functional disorders underlying UAB symptoms, examining the biology of these linkages, re-conceptualizing urinary control as one part of a more global biologic adaptive physiology, and determining the relationships of central and peripheral pathologies leading to disrupted control mechanisms.

Global Genome Biodiversity Network: saving a blueprint of the Tree of Life - a botanical perspective

BACKGROUND

Genomic research depends upon access to DNA or tissue collected and preserved according to high-quality standards. At present, the collections in most natural history museums do not sufficiently address these standards, making them often hard or impossible to use for whole-genome sequencing or transcriptomics. In response to these challenges, natural history museums, herbaria, botanical gardens and other stakeholders have started to build high-quality biodiversity biobanks. Unfortunately, information about these collections remains fragmented, scattered and largely inaccessible. Without a central registry or even an overview of relevant institutions, it is difficult and time-consuming to locate the needed samples.

SCOPE

The Global Genome Biodiversity Network (GGBN) was created to fill this vacuum by establishing a one-stop access point for locating samples meeting quality standards for genome-scale applications, while complying with national and international legislations and conventions. Increased accessibility to genomic samples will further genomic research and development, conserve genetic resources, help train the next generation of genome researchers and raise the visibility of biodiversity collections. Additionally, the availability of a data-sharing platform will facilitate identification of gaps in the collections, thereby empowering targeted sampling efforts, increasing the breadth and depth of preservation of genetic diversity. The GGBN is rapidly growing and currently has 41 members. The GGBN covers all branches of the Tree of Life, except humans, but here the focus is on a pilot project with emphasis on 'harvesting' the Tree of Life for vascular plant taxa to enable genome-level studies.

CONCLUSION

While current efforts are centred on getting the existing samples of all GGBN members online, a pilot project, GGI-Gardens, has been launched as proof of concept. Over the next 6 years GGI-Gardens aims to add to the GGBN high-quality genetic material from at least one species from each of the approx. 460 vascular plant families and one species from half of the approx. 15 000 vascular plant genera.

Predicting the chance of live birth for women undergoing IVF: a novel pretreatment counselling tool

STUDY QUESTION

Which pretreatment patient variables have an effect on live birth rates following assisted conception?

SUMMARY ANSWER

The predictors in the final multivariate logistic regression model found to be significantly associated with reduced chances of IVF/ICSI success were increasing age (particularly above 36 years), tubal factor infertility, unexplained infertility and Asian or Black ethnicity.

WHAT IS KNOWN ALREADY

The two most widely recognized prediction models for live birth following IVF were developed on data from 1991 to 2007; pre-dating significant changes in clinical practice. These existing IVF outcome prediction models do not incorporate key pretreatment predictors, such as BMI, ethnicity and ovarian reserve, which are readily available now.

STUDY DESIGN, SIZE, DURATION

In this cohort study a model to predict live birth was derived using data collected from 9915 women who underwent IVF/ICSI treatment at any CARE (Centres for Assisted Reproduction) clinic from 2008 to 2012. Model validation was performed on data collected from 2723 women who underwent treatment in 2013. The primary outcome for the model was live birth, which was defined as any birth event in which at least one baby was born alive and survived for more than 1 month.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were collected from 12 fertility clinics within the CARE consortium in the UK. Multivariable logistic regression was used to develop the model. Discriminatory ability was assessed using the area under receiver operating characteristic (AUROC) curve, and calibration was assessed using calibration-in-the-large and the calibration slope test.

MAIN RESULTS AND THE ROLE OF CHANCE

The predictors in the final model were female age, BMI, ethnicity, antral follicle count (AFC), previous live birth, previous miscarriage, cause and duration of infertility. Upon assessing predictive ability, the AUROC curve for the final model and validation cohort was (0.62; 95% confidence interval (CI) 0.61-0.63) and (0.62; 95% CI 0.60-0.64) respectively. Calibration-in-the-large showed a systematic over-estimation of the predicted probability of live birth (Intercept (95% CI) = -0.168 (-0.252 to -0.084), P < 0.001). However, the calibration slope test was not significant (slope (95% CI) = 1.129 (0.893-1.365), P = 0.28). Due to the calibration-in-the-large test being significant we recalibrated the final model. The recalibrated model showed a much-improved calibration.

LIMITATIONS, REASONS FOR CAUTION

Our model is unable to account for factors such as smoking and alcohol that can affect IVF/ICSI outcome and is somewhat restricted to representing the ethnic distribution and outcomes for the UK population only. We were unable to account for socioeconomic status and it may be that by having 75% of the population paying privately for their treatment, the results cannot be generalized to people of all socioeconomic backgrounds. In addition, patients and clinicians should understand this model is designed for use before treatment begins and does not include variables that become available (oocyte, embryo and endometrial) as treatment progresses. Finally, this model is also limited to use prior to first cycle only.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first study to present a novel, up-to-date model encompassing three readily available prognostic factors; female BMI, ovarian reserve and ethnicity, which have not previously been used in prediction models for IVF outcome. Following geographical validation, the model can be used to build a user-friendly interface to aid decision-making for couples and their clinicians. Thereafter, a feasibility study of its implementation could focus on patient acceptability and quality of decision-making.

STUDY FUNDING/COMPETING INTEREST

None.

Characterization of the role of HCN channels in β3-adrenoceptor mediated rat bladder relaxation

Objective

The second messenger cAMP is involved in both β3 adrenoceptor (β3-AR) mediated detrusor relaxation and the kinetics of Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Here we characterized the effect HCN channel activation and possible interaction with β3-AR in bladder.

Materials and Methods

Bladder tissues from Sprague-Dawley rats and Human organ donors were obtained for studying species-specific expression of HCN channels by real-time qPCR and Western Blot. Effect of β3-agonist on rat bladder strips (0.5 × 0.5 × 7 mm in size) was studied during activation and blockade of HCN channels by Lamotrigine and ZD7288, respectively.

Results

Expression of all four genes encoding for HCN channels (HCN1-4) was detected separately in bladder mucosa and detrusor from human and rat bladders. Species based differences were evident from relatively higher expression of HCN4 isoform in human bladder and that of HCN1 in rat bladder. Western blot confirmed the findings at mRNA level. Cumulative application β3-AR agonist CL316,243 produced a concentration dependent decrease in resting tension of rat bladder strips expressed as integral of mechanical activity. Pre-incubation of HCN channel blocker ZD 7288 opposed the relaxant effect of CL316,243, whereas co-administration of lamotrigine with CL316,243 at equal molar concentrations caused an additive decrease in resting tension. Cumulative addition of ZD7288 and lamotrigine in absence of CL316,243 showed opposing effects on detrusor contractility.

Conclusions

Species-specific differences were noted in expression of HCN channels in bladder. Opposing effects ZD7288 and Lamotrigine in the action of β3-AR agonist demonstrate possible functional interaction of HCN channels and β3-AR in detrusor contractility.

Overactive bladder in the vulnerable elderly

Overactive bladder (OAB) is a common problem that may occur in individuals of all ages. It has a considerable impact on patient quality of life, and although moderately effective management strategies do exist, this condition often remains undiagnosed and untreated. OAB needs to be viewed as a symptom complex. Its presentation and management are complicated in the vulnerable elderly by the presence of baseline frailty and multiple coexisting chronic conditions. Furthermore, and beyond a simple understanding of symptomatology, providers must address patient goals and motivations as well as the expectations of caretakers. These multiple levels of perception, function, expectations, and treatment efficacy/risks must be tailored to the individual patient. While the vulnerable elderly patient may often have evidence of urinary tract dysfunction, OAB and urge urinary incontinence in this population must be understood as a multifactorial geriatric syndrome and viewed in the context of medical and functional baseline and precipitating risk factors. Expectations and goals must be tailored to the resources of vulnerable elderly patients and their caregivers, and care must be coordinated with other medical care providers. The management of OAB in the vulnerable elderly often poses significant management challenges. Nonetheless, with a thoughtful approach and an aim towards future research specifically for this population, significant reductions in morbidity and mortality long with enhancement in health-related quality of life are possible.

Pathophysiology and animal modeling of underactive bladder

While the symptomology of underactive bladder (UAB) may imply a primary dysfunction of the detrusor muscle, insights into pathophysiology indicate that both myogenic and neurogenic mechanisms need to be considered. Due to lack of proper animal models, the current understanding of the UAB pathophysiology is limited, and much of what is known about the clinical etiology of the condition has been derived from epidemiological data. We hereby review current state of the art in the understanding of the pathophysiology of and animal models used to study the UAB.

Does defective volume sensation contribute to detrusor underactivity?

AIMS

The urodynamic finding of detrusor underactivity (DU) in neurologically intact unobstructed patients may relate to impaired volume sensations rather than detrusor contractile defects. We hypothesized that DU patients would demonstrate higher volumes but similar wall stress at sensation thresholds, and similar voiding contractility, compared to other groups.

METHODS

Chart review of urodynamic studies in neurologically normal, nonobstructed symptomatic patients. Urodynamic studies having the primary findings of DU, stress urinary incontinence (SUI), detrusor overactivity (DO), and increased sensations without detrusor overactivity (IS) were abstracted. Age, gender, and pressure/volume data associated with sensations and voiding parameters were collected. Wall stress at sensations was calculated. Urodynamic variables at standard sensations and progression across standard sensations were compared among the four groups.

RESULTS

Fifty-one urodynamic studies were analyzed for comparison. Mean age did not differ between groups. The DU group was predominantly male versus the other groups. DU, SUI, and DO had higher volume thresholds for strong desire than did IS. DU and DO demonstrated higher wall stress at strong desire than did IS and SUI. Watts factor was not significantly different between groups, however, DU had a smaller voided volumes and a higher post-void residuals.

CONCLUSION

Increased volume and wall stress at strong desire, and similar contractility but the smaller voided volumes and elevated PVRs in DU suggest that diminished central sensitivity to volume afferent activity contributes to DU in nonobstructed, non-neurogenic symptomatic patients.

Acute lower urinary tract dysfunction (LUTD) following traumatic brain injury (TBI) in rats

AIMS

The aim of this study was to assess experimental traumatic brain injury (TBI)-induced lower urinary tract dysfunction (LUTD) by monitoring systemic and urodynamic parameters using an implantable telemetry system.

METHODS

A single lateral fluid percussion TBI (FP-TBI; 3.4 atm) was administered to 10 female rats. Pressure micro-catheters were implanted in the abdominal aorta and bladder dome for simultaneous data recording. Hemodynamic and urodynamic variables recorded 24 hr before and 24 hr after injury were analyzed and compared.

RESULTS

TBI in the acute phase resulted in LUTD affecting bladder emptying, characterized by failure of voiding reflex, high capacity bladder, increased voided volume, prolonged intermicturition intervals, and loss of compliance. The dominant symptom was urinary retention (100%) and incontinence (60%). The effects followed a pattern of initial loss of bladder function followed by either altered recovery of reflex micturition or a period of incontinence. With a moderate injury symptoms were temporary in 90% of animals and permanent in 10% of animals. Injury produced only transient hypertension (≤1 hr) with a maximum systolic pressure of 172.64 ± 14.53 mmHg (70% of animals).

CONCLUSIONS

The results demonstrate that experimental FP-TBI causes temporary bladder dysfunction that in more severe cases becomes permanent. Telemetry recordings revealed a sequence of events following injury that establishes moderate TBI as a risk factor for neurogenic bladder disorder. Results also suggest a correlation between lateral FP-TBI and incontinence.

Pseudoreflux and detrusor overactivity due to accidental ureteral catheterization during cytometry in a pediatric patient

We present the case of a 9-year-old girl with a neurogenic bladder who had accidental ureteral cannulation with the vesical catheter during cytometry. This is the first reported pediatric case described of this complication, the four prior cases all being in adults. The signs and symptoms of ureteral catheterization differed significantly in this patient from the adult cases. In our patient, malpositioning of the vesical catheter yielded a misleading pressure profile of primarily rhythmic pressure increases suggestive of severe detrusor overactivity and vesicoureteral reflux on fluoroscopy. The reading, however, actually reflected ureteric filling and peristalsis, and these findings resolved when the catheter was properly repositioned. This case highlights the possibility of inadvertent ureteral catheterization, and that, while rare, this complication should be kept in mind when new or unexpected DO or VUR is observed upon filling cystometry.

Detrusor expulsive strength is preserved, but responsiveness to bladder filling and urinary sensitivity is diminished in the aging mouse

The prevalence of urinary symptoms increases with age and is a significant source of distress, morbidity, and expense in the elderly. Recent evidence suggests that symptoms in the aged may result from sensory dysfunction, rather than abnormalities of detrusor performance. Therefore, we employed a pressure/flow multichannel urethane-anesthetized mouse cystometry model to test the hypothesis that in vivo detrusor performance does not degrade with aging. Secondarily, we sought to evaluate sensory responsiveness to volume using pressure-volume data generated during bladder filling. Cystometric data from 2-, 12-, 22-, and 26-mo-old female C57BL6 mice were compared. All 2- and 12-mo-old mice, 66% of 22-mo-old mice, and 50% of 26-mo-old mice responded to continuous bladder filling with periodic reflex voiding. Abdominal wall contraction with voiding had a minimal contribution to expulsive pressure, whereas compliance pressure was a significant contributor. Maximum bladder pressure, estimated detrusor pressure, detrusor impulse (pressure-time integral), as well as indices of detrusor power and work, did not decrease with aging. Bladder precontraction pressures decreased, compliance increased, and nonvoiding contraction counts did not change with increasing age. Intervoid intervals, per-void volumes, and voiding flow rates increased with age. Calculations approximating wall stress during filling suggested loss of bladder volume sensitivity with increasing age. We conclude that aging is associated with an impaired ability to respond to the challenge of continuous bladder filling with cyclic voiding, yet among responsive animals, voiding detrusor contraction strength does not degrade with aging in this murine model. Furthermore, indirect measures suggest that bladder volume sensitivity is diminished. Thus, changes in homeostatic reserve and peripheral and/or central sensory mechanisms may be important contributors to aging-associated changes in bladder function.

Evidence of a functional effect of transient transurethral catheterization on micturition in women

INTRODUCTION AND HYPOTHESIS

The objective of this study is to evaluate the effect of transient catheterization on uroflow parameters.

METHODS

Consenting women (ages 18-90) provided an uninstrumented uroflow pre- and post-indicated in urodynamic procedures. Voided volume, Qmax, and Qave were recorded for both uninstrumented uroflows. Uroflow curves were classified as "normal" or "abnormal." Pre- and post-urodynamic uroflow data were compared.

RESULTS

Thirty-five patients were included in the study. There was a statistically significant decrease in Qave from the pre- to the post-urodynamic uroflows from 14.71 to 10.55 ml/s (p = 0.012). Additionally, 28.6% of uroflow tracing patterns changed from "normal" to "abnormal," whereas only one (2.9%) changed from "abnormal" to "normal" (p = 0.031).

CONCLUSIONS

This study showed a degradative effect of transient catheterization on uroflow parameters, suggesting that catheterization may cause more than simply a passive obstructive effect. Urethral stimulation due to catheterization may perturb detrusor urethral function, altering voiding and possibly filling performance.

Evidence of central modulation of bladder compliance during filling phase

AIMS

Bladder compliance is one expression of the pressure and volume relationship as the bladder fills. In addition to passive elements, autonomous micromotional detrusor activity contributes to this relationship. In the mouse cystometric model, compliance pressure contributes to voiding expulsive pressure. During attempts to isolate the detrusor contractile component of this filling pressurization, we found that compliance reversibly diminishes under conditions which remove central control from the micturition cycle.

METHODS

Ten mature female mice underwent constant infusion pressure/flow cystometry under urethane anesthesia, and five awake mature female mice underwent constant infusion pressure cystometry. Following baseline cystometry, all mice were anesthetized with isoflurane to abolish the micturition reflex, and cystometry conducted with manual emptying of the bladders. Animals were then allowed to recover from isoflurane to re-establish the micturition reflex, and cystometry again conducted. The urethane group was also studied immediately post-mortem. Repeated measures comparisons of cystometric parameters were made across conditions.

RESULTS

Compliance reversibly decreased in all mice with the abolishment of micturition responses by isoflurane anesthesia. A similar decrease was observed immediately post-mortem in the urethaned mice. Bladder filling and voiding were not different between the intact micturition segments of the testing.

CONCLUSIONS

Enhanced compliance in mice with intact micturition responses suggests that autonomous micromotional activity is suppressed by central processes during normal filling. Since afferent activity during filling is also determined by the relationship between bladder pressure and volume, a feed-forward afferent signal conditioning mechanism may exist, creating novel therapeutic targets for urinary dysfunctions.

Continuous uroflow cystometry in the urethane-anesthetized mouse

PURPOSE

In vivo animal cystometry represents an accepted methodology for the study of lower urinary tract physiology. A particular advantage of the mouse model is the availability of genetically modified strains, offering the possibility of linking individual genes to relevant physiological events. However, small voided volumes complicate the ability to obtain reliable pressure-flow data by gravimetric methods, due to non-continuous drop formation and release during voiding. We investigated the feasibility of a simple non-gravimetric continuous urine collection system during cystometry under urethane anesthesia, and compared urethane-anesthetized with awake cystometry.

METHODS

Cystometry was performed in awake and urethane-anesthetized female mice using a suprapubic tube. A simple, novel non-gravimetric method of urine collection was used in urethane-anesthetized animals to assess voided volume and permit flow rate calculations. Pressure and time-related variables were compared between groups.

RESULTS

Voided urine collection appears to be complete and continuous in this model. Mean voided volume was 0.09 ± 0.020 ml, with an average flow rate of 0.029 ± 0.007 ml/sec. Urethane anesthesia delayed cystometric pressure/volume responses. However, micturition reflexes were intact and otherwise comparable between groups. Female mice void with pulsatile pressurization previously described in rats.

CONCLUSION

Suprapubic voiding cystometry using a simple and reliable urine collection method under urethane anesthesia is feasible in mice, permitting the integration of voided volumes with pressure and time data. The inclusion of volume and flow data enhances the usefulness of the mouse model for in vivo assessment of detrusor and potentially sphincteric performance.