Intravesical ethanol as quantitative measure of bladder hyperpermeability

Enhancement of transduction efficiency using Adeno-associated viral vectors by chemical pretreatment to mice bladder urothelium

Adeno-associated virus (AAV) vectors have been recognized as promising tools for gene delivery. The bladder is a seemingly ideal organ for virus transfer, with easy access through the urethra enabling organ-specific delivery. However, achieving adequate transduction efficiency in the urothelium has been a major challenge because of the barrier function of the glycosaminoglycan (GAG) layer. We investigated optimal pretreatments of the bladder urothelium to maximize transduction efficiency by AAV vectors in vivo. Murine bladders were pretreated with five different chemical agents followed by transurethral instillation with an AAV2 vector encoding a tdTOMATO reporter. After 7 days, transduction efficiency of the urothelium was evaluated. Bladder urothelia pretreated with HCl showed clear evidence of AAV infection and gene delivery. Mice treated with 0.1 N HCl for 4 min showed significantly higher survival rates (nearly 80 %) compared with mice receiving other pretreatment regimens. AAV vector transduction in the urothelium was observed in seven of 20 mice (35 %), and the mean transduction efficiency in these mice was 14.5 %. Thus, HCl pretreatment enhanced transduction efficiency of the mice bladder urothelium by an AAV vector in vivo. Pretreatment with 0.1 N HCl for 4 min was the optimal condition to maximize survival and transduction efficiency of the urothelium.

Interstitial cystitis: Modern tools for an accurate diagnosis

Interstitial cystitis (IC) is a disease defined by a constellation of signs and symptoms; its etiology is not well understood. There are multiple theories regarding the cause of IC; however, no one cause has been proven conclusively. In the meantime, physicians are trying to accurately diagnose a disease that has no identified definitive cause. There have been multiple tests designed to aid in the diagnosis of IC and there are new tests on the horizon that appear promising. However, the diagnosis of IC still is one of exclusion and based primarily on clinical findings. The most useful tests are described in this article, which may make diagnosis a more accurate, less arduous process.

Intravesical ethanol test: an ineffective measure of bladder hyperpermeability

OBJECTIVES

To evaluate the intravesical ethanol test as a quantitative measure of bladder hyperpermeability in patients with interstitial cystitis.

METHODS

Patients with a clinical diagnosis of interstitial cystitis and a positive result on the Parsons potassium test were enrolled in the study. The intravesical ethanol test was conducted after completion of the Parsons potassium test. Dose escalation (10% to 20% ethanol) was performed in an attempt to achieve detectable levels of ethanol. Breathalyzer data were recorded in 5-minute intervals for 30 minutes using a calibrated Intox Breathalyzer Model IV Alcosensor. The bladder was then drained, and volume recovered was recorded. The breathalyzer data were recorded for an additional 30 minutes after removal of the catheter at 5-minute intervals.

RESULTS

The 3 patients studied demonstrated significant qualitative evidence of bladder hyperpermeability, with pain and urgency scores ranging from 4 to 5 on the Parsons potassium test. No detectable levels of ethanol were identified in any of the 3 patients after the intravesical ethanol test, with up to 50 mL of 20% ethanol instilled for 30 minutes. Intravesical ethanol instillation was not associated with significant pain or irritative voiding symptoms.

CONCLUSIONS

The intravesical ethanol test did not prove to be a useful clinical adjunct in the diagnosis and management of interstitial cystitis. The evaluation of higher concentrations of ethanol may be warranted.

Interstitial cystitis: an update

PURPOSE OF REVIEW

Interstitial cystitis is a chronically progressive, severely debilitating, heterogeneous syndrome affecting the urinary bladder, mainly associated with urgency, frequency and pain. Though known for over a century, its etiology is poorly understood and universally effective treatments are lacking. This review focuses on recently published literature on the disorder.

RECENT FINDINGS

Appropriate diagnostic tests for interstitial cystitis remain uncertain. The diagnostic criteria developed by the US National Institutes of Health represent research definitions which are subject to controversial debate for their overenthusiastic clinical application. The diagnosis is made clinically and by cystoscopy with hydrodistention and sometimes biopsy when other pathologies have been excluded. In symptomatic patients, glomerulations upon bladder distension are indicative but not pathognomonic for nonulcerative interstitial cystitis. Patients with ulcerative disease represent a separate subgroup with distinct characteristics and treatment implications. The role of bladder permeability tests remains controversial. Promising noninvasive markers for interstitial cystitis have been described but are not yet clinically available. Validated symptom scores are appropriate to assist in diagnostics and to monitor disease course and treatment efficacy. Lately investigated hypotheses for causative factors include occult or resistant microorganisms, urothelial hyperpermeability, neurogenic or hormonal pathomechanisms, and mast cell activation. Increasing evidence for a genetic susceptibility is emerging.

SUMMARY

Among the multitude of oral, intravesical, interventional and complementary treatments suggested few studies have high levels of evidence. Newly proposed agents must await further controlled studies. Treatment remains empiric until radical surgical procedures should ultimately be considered for severe refractory cases.