The bladder mucus (glycosaminoglycan) layer in interstitial cystitis

Hyaluronic acid and chondroitin sulphate treatment for recurrent severe urinary tract infections due to multidrug-resistant gram-negative bacilli in a patient with multiple sclerosis: case report and literature review

Urinary tract infections (UTIs) are the most common bacterial infections in patients with neurogenic lower urinary tract dysfunction. Antibiotic options for prophylaxis or curative treatment in case of recurrent UTIs, especially due to multidrug-resistant organisms (MDRO), are scarce. We present the case of a 72-year-old man with neurogenic lower urinary tract dysfunction and history of frequent recurrent UTIs due to multiple MDROs who was successfully treated with hyaluronic acid (HA) and chondroitin sulfate (CS) bladder instillations. We also provide a literature review on the efficacy of HA-CS intravesical instillations for prevention of UTI among this population.

Recent advances and prospects of hyaluronan as a multifunctional therapeutic system

Hyaluronan (HA) is a naturally occurring non-sulfated glycosaminoglycan (GAG), cell-surface-associated biopolymer and is the key component of tissue extracellular matrix (ECM). Along with remarkable physicochemical properties, HA also has multifaceted biological effects that include but not limited to ECM organization, immunomodulation, and various cellular processes. Environmental cues such as tissue injury, infection or cancer change downstream signaling functionalities of HA. Unlike native HA, the fragments of HA have diversified effects on inflammation, cancer, fibrosis, angiogenesis and autoimmune response. In this review, we aim to discuss HA as a therapeutic delivery system development process, source, biophysical-chemical properties, and associated biological pathways (especially via cell surface receptors) of native and fragmented HA. We also tried to address an overview of the potential role of HA (native HA vs fragments) in the modulation of inflammation, immune response and various cancer targeting delivery applications. This review will also highlight the HA based therapeutic systems, medical devices and future perspectives of various biomedical applications were discussed in detail.

A high molecular weight hyaluronic acid biphasic dispersion as potential therapeutics for interstitial cystitis

Interstitial cystitis (IC) is a progressive bladder disease characterized by increased urothelial permeability, inflammation of the bladder with abdominal pain. While there is no consensus on the etiology of the disease, it was believed that restoring the barrier between urinary solutes and (GAG) urothelium would interrupt the progression of this disease. Currently, several treatment options include intravesical delivery of hyaluronic acid (HA) and/or chondroitin sulfate solutions, through a catheter to restore the urothelial barrier, but have shown limited success in preclinical, clinical trials. Herein we report for the first time successful engineering and characterization of biphasic system developed by combining cross‐linked hyaluronic acid and naïve HA solution to decrease inflammation and permeability in an in vitro model of interstitial cystitis. The cross‐linking of HA was performed by 4‐arm‐polyethyeleneamine chemistry. The HA formulations were tested for their viscoelastic properties and the effects on cell metabolism, inflammatory markers, and permeability. Our study demonstrates the therapeutic effects of different ratios of the biphasic system and reports their ability to increase the barrier effect by decreasing the permeability and alteration of cell metabolism with respect to relative controls. Restoring the barrier by using biphasic system of HA therapy may be a promising approach to IC.

Urine and serum glycosaminoglycan levels in the diagnosis of urological diseases and conditions: A narrative review of the literature

Glycosaminoglycans (GAGs) are sulfated, negatively charged polysaccharides produced in almost every cell of the human body. As GAGs are extracellularly localized, the changes in body fluids such as blood and urine may reflect pathological changes in the urinary system as observed in other pathologies. In this review, we determined the potential of urinary and/or serum GAG levels as a marker for kidney and urothelial system diseases. We performed a search in the PubMed, MEDLINE, and ScienceDirect databases until September 30, 2019. A number of studies reported changes in the urinary and/or plasma GAG levels or composition in urological diseases and conditions, such as renal cell carcinoma, kidney stone, bladder carcinoma, and overactive bladder. GAGs were found to have a predictive biomarker potential that could be limited by generalizability concerns.

Advances in Understanding the Human Urinary Microbiome and Its Potential Role in Urinary Tract Infection

Recent advances in the analysis of microbial communities colonizing the human body have identified a resident microbial community in the human urinary tract (UT). Compared to many other microbial niches, the human UT harbors a relatively low biomass. Studies have identified many genera and species that may constitute a core urinary microbiome. However, the contribution of the UT microbiome to urinary tract infection (UTI) and recurrent UTI (rUTI) pathobiology is not yet clearly understood. Evidence suggests that commensal species within the UT and urogenital tract (UGT) microbiomes, such as Lactobacillus crispatus, may act to protect against colonization with uropathogens. However, the mechanisms and fundamental biology of the urinary microbiome-host relationship are not understood. The ability to measure and characterize the urinary microbiome has been enabled through the development of next-generation sequencing and bioinformatic platforms that allow for the unbiased detection of resident microbial DNA. Translating technological advances into clinical insight will require further study of the microbial and genomic ecology of the urinary microbiome in both health and disease. Future diagnostic, prognostic, and therapeutic options for the management of UTI may soon incorporate efforts to measure, restore, and/or preserve the native, healthy ecology of the urinary microbiomes.

Electron microscopic characteristics of interstitial cystitis/bladder pain syndrome and their association with clinical condition

Background

Electron microscopy (EM) characteristics of the urothelium in interstitial cystitis/bladder pain syndrome (IC/BPS) and their association with clinical condition are unclear.

Methods

Ten IC/BPS patients who were admitted for hydrodistention and 5 patients with stress urinary incontinence (control patients) were enrolled. All patients provided detailed clinical histories and underwent urodynamic studies. Cystoscopic bladder biopsies were obtained and processed for transmission EM (TEM) and scanning EM (SEM). The severity of the urothelium findings was graded on a 4-point scale (0: none, 1: mild, 2: moderate, and 3: severe). The EM findings between IC/BPS and control patients were compared; the results were analyzed using the chi-square test.

Results

Compared with the urothelium of control patients, the urothelium of IC/BPS patients had more severe defects of the urothelial cell layers and integrity of umbrella cells in TEM (p = 0.045 and 0.01, respectively). In SEM, umbrella cell pleomorphism increased and microplicae of the cell membrane decreased in the IC/BPS group, and both were more severe than in the control group (p = 0.022 and 0.007, respectively). The patients with moderate to severe defects of umbrella cell integrity had more severe bladder pain and smaller maximal bladder capacity (MBC) (both p = 0.010). Patients with moderate to severe defects in microplicae of the cell membrane had smaller cystometric bladder capacity and MBC (p = 0.037 and 0.047, respectively).

Conclusions

The results revealed significant urothelium defects in IC/BPS, especially in the umbrella cells. Defects of umbrella cells may play an important role in the pathogenesis of IC/BPS.

Botulinum Toxin A and Lower Urinary Tract Dysfunction: Pathophysiology and Mechanisms of Action

The use of onabotulinumtoxinA (BoNT-A) for the treatment of lower urinary tract diseases (LUTD) has increased markedly in recent years. The indications for BoNT-A treatment of LUTD now include neurogenic or idiopathic detrusor overactivity, interstitial cystitis/bladder pain syndrome and voiding dysfunction. The mechanisms of BoNT-A action on LUTDs affect many different aspects. Traditionally, the effects of BoNT-A were believed to be attributable to inhibition of acetylcholine release from the presynaptic efferent nerves at the neuromuscular junctions in the detrusor or urethral sphincter. BoNT-A injection in the bladder also regulated sensory nerve function by blocking neurotransmitter release and reducing receptor expression in the urothelium. In addition, recent studies revealed an anti-inflammatory effect for BoNT-A. Substance P and nerve growth factor in the urine and bladder tissue decreased after BoNT-A injection. Mast cell activation in the bladder also decreased. BoNT-A-induced improvement of urothelium function plays an important mitigating role in bladder dysfunction. Vascular endothelial growth factor expression in urothelium decreased after BoNT-A injection, as did apoptosis. Studies also revealed increased apoptosis in the prostate after BoNT-A injection. Although BoNT-A injection has been widely used to treat different LUTDs refractory to conventional treatment, currently, onabotulinumtoxinA has been proven effective only on urinary incontinence due to IDO and NDO in several large-scale clinical trials. The effects of onabotulinumtoxinA on other LUTDs such as interstitial cystitis, benign prostatic hyperplasia, dysfunctional voiding or detrusor sphincter dyssynergia have not been well demonstrated.

Evaluation of the metabolism of glycosaminoglycans in patients with interstitial cystis

INTRODUCTION

Painful bladder syndrome/interstitial cystitis (PBS/IC) pathogenesis is not fully known, but evidence shows that glycosaminoglycans (GAG) of bladder urothelium can participate in its genesis. The loss of these compounds facilitates the contact of urine compounds with deeper portions of bladder wall triggering an inflammatory process. We investigated GAG in urine and tissue of PBS/IC and pure stress urinary incontinence (SUI) patients to better understand its metabolism.

MATERIALS AND METHODS

Tissue and urine of 11 patients with PBS/IC according to NIDDK criteria were compared to 11 SUI patients. Tissue samples were analyzed by histological, immunohistochemistry and immunofluorescence methods. Statistical analysis were performed using t Student test and Anova, considering significant when p < 0.05.

RESULTS

PBS/IC patients had lower concentration of GAG in urine when compared to SUI (respectively 0.45 ± 0.11 x 0.62 ± 0.13 mg/mg creatinine, p < 0.05). However, there was no reduction of the content of GAG in the urothelium of both groups. Immunofluorescence showed that PBS/IC patients had a stronger staining of TGF-beta, decorin (a proteoglycan of chondroitin/dermatan sulfate), fibronectin and hyaluronic acid.

CONCLUSION

the results suggest that GAG may be related to the ongoing process of inflammation and remodeling of the dysfunctional urothelium that is present in the PBS/IC.

Estrogen affects the glycosaminoglycan layer of the murine bladder

OBJECTIVES

Urinary tract infections (UTIs), commonly caused by uropathogenic Escherichia coli (UPEC), confer significant morbidity among postmenopausal women. Glycosaminoglycans (GAGs) comprise the first line of defense at the bladder's luminal surface. Our objective was to use a murine model of menopause to determine whether estrogen status affects the GAG layer in response to UPEC infection.

METHODS

Adult female mice underwent sham surgery (SHAM, n = 18) or oophorectomy (OVX, n = 66) to establish a murine model of menopause. A subset of oophorectomized mice underwent hormone therapy (HT, n = 33) with 17β-estradiol. Mice were inoculated with UPEC and killed at various time points; bladders were collected and GAG layer thickness was assessed in multiple bladder sections. Sixteen measurements were made per bladder. A repeated-measures 2-way analysis of variance was performed to determine the effect of time after infection and hormonal condition on GAG thickness. We also investigated the molecular underpinnings of GAG biosynthesis in response to alterations in estrogen status and infection.

RESULTS

We did not observe significant difference of GAG thickness among the 3 hormonal conditions; however, the time course of GAG thickness was significantly different (P < 0.05). The OVX mice demonstrated significantly greater thickness at 72 hours after infection (P = 0.0001), and this effect was shifted earlier (24 hours after infection) on the addition of HT (P = 0.001). At 2 to 4 weeks after infection, GAG thickness among all cohorts was not significantly different from baseline. In addition, quantitative reverse transcription-polymerase chain reaction analysis revealed that GAG biosynthesis is altered by estrogen status at basal level and on infection.

CONCLUSIONS

The GAG layer is dynamically altered during the course of UTI. Our data show that HT positively regulates GAG layer thickness over time, as well as the composition of the GAGs. In addition, the GAG sulfation status can be influenced by estrogen levels in response to UPEC infection. The protective effects of the GAG layer in UTI may represent pharmacologic targets for the treatment and prevention of postmenopausal UTI.

Long-term efficacy and tolerability of pentosan polysulphate sodium in the treatment of bladder pain syndrome

OBJECTIVE

The primary objective of this study is to report on the long-term efficacy and tolerability of pentosan polysulphate sodium (PPS) in patients with bladder pain syndrome (BPS). The secondary objective is to find the predictors of the long-term outcome.

METHODS

This is a single institution, retrospective study. The study period was from 1994 to 2008. All patients fulfilled the clinical criteria of BPS, as suggested by European Society for the Study of Interstitial Cystitis. We included only patients with de novo BPS diagnosis and no previous PPS or other treatment. The efficacy of PPS was measured with the global response assessment scale (GRA). Patients were stratified into 2 groups based on the duration of the treatment. Group 1 took the drug for less than 12 months. Group 2 took the drug for more than 12 months.

RESULTS

There were 271 patients eligible for the study. Most of the patients were female (90%), with the mean age at presentation of 45.5 years. The average duration of symptoms was 28.5 months. The mean follow-up was 22 months (range 3-130). Out of all the patients, 147 patients (54.2%) reported over 50% improvement using the GRA. The reported efficacy was higher in Group 2 (60%). Ninety-three patients (34.3%) decided to stop taking the medication for various reasons. The most common reasons to stop the medication were poor outcome (16.6% of patients) and side effects (11.1% of patients). Poor outcome was associated with nocturia, smoking and detrusor overactivity. Good outcome was associated with longer PPS intake (>12 months) and severe cystoscopic findings of glomerulation.

CONCLUSION

Pentosan polysulphate sodium is an effective oral therapy to control the symptoms of BPS with good long-term efficacy and tolerability.

Prevention of recurrent urinary tract infections by intravesical administration of hyaluronic acid and chondroitin sulphate: a placebo-controlled randomised trial

BACKGROUND

Urinary tract infection (UTI) is a prevalent condition in women during their lifetime with a high rate of recurrence within 3-6 mo.

OBJECTIVES

Our aim was to investigate the efficacy and tolerability of the intravesical administration of combined hyaluronic acid (HA) and chondroitin sulphate (CS) in female patients with a history of recurrent UTI.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a prospective, randomised, double-blind, placebo-controlled study comparing the intravesical instillation of HA-CS with placebo in women with recurrent UTI.

INTERVENTION

Participants were randomised to receive 50 ml of sterile sodium HA 1.6% and CS 2.0% solution (IALURIL(®)) weekly for 4 wk and then monthly for 5 mo.

MEASUREMENTS

The primary end point of the study was defined as the mean number of UTI per patient per year. Participants were evaluated addressing UTI status/urinary symptoms and with a general health-related quality-of-life (QoL) questionnaire at baseline and after 3, 6, 9, and 12 mo.

RESULTS AND LIMITATIONS

In the intention-to-treat analysis, 57 women were randomly allocated to HA-CS (n=28) or placebo (n=29). The UTI rate per patient per year at the end of the study (12 mo) (mean±SD: -86.6%±47.6 vs -9.6%±24.6; mean difference: 77%; 95% confidence interval, 72.3-80.8; p=0.0002) and the mean time to UTI recurrence (52.7±33.4 vs 185.2±78.7 d; p<0.001) were significantly reduced after treatment with HA-CS compared with placebo. Overall urinary symptoms and QoL measured by questionnaires significantly improved compared with placebo (Pelvic Pain and Urgency/Frequency questionnaire symptom score: 14.53±4.32 vs 9.88±6.77; p=0.004; SF-36 QoL score: 78.6±6.44 vs 53.1±4.72; p<0.001). No serious adverse event was reported.

CONCLUSIONS

Compared with placebo, HA-CS intravesical instillations significantly reduced UTI rate without severe side effects while improving symptoms and QoL over a 12-mo period in patients with recurrent UTI.

TRIAL REGISTRATION

ISRCTN 76354426.

Bacterial interference for the prevention and treatment of infections

Bacterial interference refers to the antagonism between bacterial species during the process of surface colonisation and acquisition of nutrients. The clinical evidence on the potential applications of microorganisms for the prevention and/or treatment of infections in the upper respiratory, urogenital and gastrointestinal tracts was reviewed through the PubMed and Scopus databases. Data regarding factors that may affect the human microflora, thus contributing to tissue colonisation from potential pathogens, were also retrieved. The clinical evidence for application of the interfering ability of non-virulent bacteria to prevent or treat infections has been rather limited, although promising for certain purposes. A number of relevant preliminary trials suggest that in the upper respiratory tract the rate of recurrence of otitis media or streptococcal pharyngotonsillitis appears to decrease using selected bacteria with inhibitory ability against common pathogens of upper respiratory tract in combination with appropriate antibiotic treatment. Regarding the urogenital tract, specific non-pathogenic strains of Escherichia coli and probiotic organisms were successfully applied to decrease the recurrence of local infections. The interfering ability of specific probiotic organisms (strains of Lactobacilli and Bifidobacteria) within the gastrointestinal tract against common pathogens was also demonstrated. In conclusion, randomised controlled trials are warranted to investigate the effectiveness and safety of potential applications of the principle of bacterial interference in the prevention and treatment of infections of various sites. Such trials should initially employ selected strains of probiotics for which there are preliminary data regarding their effectiveness and lack of common or serious toxicity.

Prevention of recurrent bacterial urinary tract infections by intravesical instillation of hyaluronic acid

OBJECTIVE

To evaluate the efficacy of vesical instillation of hyaluronic acid against recurrent urinary tract infections.

METHODS

Twenty women with a history of recurrent urinary tract infections each received 9 intravesical instillations of hyaluronic acid over 6 months. Their status was assessed prospectively over 47.6 weeks and compared with a retrospective review of patient charts covering 36.2+/-6.2 weeks.

RESULTS

The total numbers of urinary tract infections were 67 before and 10 after treatment (p<0.001). Thirteen patients (65%) were free of recurrences until the end of the study. One had a recurrence during treatment, and 6 (30%) during follow-up. The number of infections per year per patient was reduced from 4.99+/-0.92 to 0.56+/-0.82 (p<0.001). In women with recurrences, time to recurrence was 178.3+/-25.5 days, compared with 76.7+/-24.6 days before treatment (p<0.001).

CONCLUSION

Intravesical instillation of hyaluronic acid is effective in preventing recurrent urinary tract infections.

Urinary and Serologic Markers forInterstitial Cystitis: An Update

This update reviews the published literature from the past 2 years pertaining to urinary and serum markers for interstitial cystitis (IC). Literature on markers described before 2004 also is included when needed to provide background information for the current literature. The markers that have been the focus of the most research in the recent literature are antiproliferative factor, epidermal growth factor, heparin-binding epidermal growth factor-like growth factor, glycosaminoglycans, and bladder nitric oxide. These markers are discussed in consideration of their three different possible roles: 1) as diagnostic markers of IC; 2) distinguishing relevant subsets of IC patients; and 3) measuring disease activity and objectively following treatment response.

THE BLADDER DOES NOT APPEAR TO HAVE A DYNAMIC SECRETED CONTINUOUS MUCOUS GEL LAYER

PURPOSE

We determined whether the nature of any protective barrier in the bladder is composed of a secreted mucous gel layer.

MATERIALS AND METHODS

We collected 24-hour urine samples for analysis from 8 healthy 22 to 49-year-old volunteers and 5, 19 to 59-year-old patients treated with bladder reconstruction, in addition to scrapings from 100 freshly slaughtered pig bladders. Samples were subjected to homogenization, dialysis, freeze-drying, papain digestion, gel chromatography, equilibrium density gradient centrifugation, periodic acid-Schiff assay and amino acid analysis. Normal human bladder, pig bladder, normal ileum and transposed intestinal segments were studied for the presence of a mucous layer using a new method of histological analysis.

RESULTS

Mucin content in normal urine is 2.7 mg/24 hours, meaning that less than 0.6% of nondialyzable material in normal urine is mucin. The mucin content of urine from reconstructed bladders amounted to 86 mg/24 hours (5.2% of nondialyzable material). We observed that glycosaminoglycans accounted for 41% of the peak total elution volume of PAS positive material in normal urine. Mucin estimation in urine can be grossly overestimated if contaminating glycoconjugates are not removed. Biochemical analysis of material scraped off the pig bladder surface demonstrated that the maximum thickness of a continuous layer that could be achieved was 13.6 mum. While we could visualize an obvious mucous layer on control ileal samples and biopsies of transposed ileal segments from patients with bladder reconstruction, we were unable to note a distinct, measurable mucous layer lining the bladder surface in humans or pigs.

CONCLUSIONS

Mucin levels in normal human and pig urine would be enough for slow turnover of a thin barrier but the large increase in mucin in the urine of patients with transposed intestinal segments demonstrates that any layer in normal bladder is much different than that lining the transposed intestinal segment. The most likely constituents of this barrier are membrane bound rather than secreted mucins along with the proteoglycan components of the glycocalix.

INTRAVESICAL POTASSIUM CHLORIDE SENSITIVITY TEST IN MEN WITH CHRONIC PELVIC PAIN SYNDROME

PURPOSE

Intravesical potassium chloride has been reported to cause pain in patients with interstitial cystitis and male chronic prostatitis (CP)/chronic pelvic pain syndrome (CPPS). We performed the potassium chloride sensitivity test (PST) in subjects with CP/CPPS and healthy men without pelvic pain.

MATERIALS AND METHODS

We recruited 40 men with CP/CPPS and 63 healthy men. The National Institutes of Health CPPS symptom index was used to measure the severity of symptoms. We instilled 100 ml physiological saline (NaCl 0.9%) intravesically. The bladder was emptied and 100 ml potassium chloride solution (KCl 40 mEq) were instilled. The subjects were asked to score urgency (0 to 10) and pain (0 to 10) sensations after each instillation. A positive PST was defined by 5 different cut-off points as the difference in score between KCl and NaCl instillations. Logistic regression analyses and area under the receiver operating characteristics curve were used to determine the predictive power of PST in CP/CPPS.

RESULTS

There was no difference in pain and urgency scores between the men with CP/CPPS and controls (p >0.05 for each). Men with CP/CPPS had higher pain and urgency scores with KCl than with NaCl (p = 0.011 and 0.033, respectively). The rates of positive PST were 50% and 36.5% in the CP/CPPS and control groups, respectively (p = 0.160). There was no significant correlation of potassium chloride sensitivity scores with National Institutes of Health symptom scores (p >0.05 for each). The sensitivity, specificity, and positive predictive and negative predictive values of PST were 50%, 63.5%, 46.5% and 66.7%, respectively.

CONCLUSIONS

Although there was a significant increase in pain and urgency scores following KCl instillation in patients with CP/CPPS, these scores and the rate of positive PST were not statistically different from those of healthy subjects. Thus, PST does not have a good predictive value in the diagnosis of CP/CPPS.

Prevention of recurrent bacterial cystitis by intravesical administration of hyaluronic acid: a pilot study

OBJECTIVES

To assess the effect of bladder instillations of hyaluronic acid (HA) on the rate of recurrence of urinary tract infection (UTI).

PATIENTS AND METHODS

Forty women (mean age 35 years) with a history of recurrent UTI received intravesical instillations of HA (40 mg in 50 mL phosphate-buffered saline) once weekly for 4 weeks then once monthly for 4 months. The UTI status was assessed over a prospective follow-up of 12.4 months and compared with the rates of UTI before instillation, determined by a retrospective review of patient charts covering 15.8 months.

RESULTS

After HA treatment no patients had a UTI during the 5-month treatment phase and 28 (70%) were recurrence-free at the end of the follow-up. The mean (sd) rate of UTI per patient-year was 4.3 (1.55) before treatment and 0.3 (0.55) afterward (P < 0.001). The median time to recurrence after HA treatment was 498 days, compared with 96 days beforehand (P < 0.001). The tolerability was excellent, as side-effects were limited to nine patients who reported mild bladder irritation; no patient interrupted the treatment.

CONCLUSIONS

In this preliminary study, bladder instillations of HA had a significant effect on the rate of UTI in women with a history of recurrent UTIs. The bladder instillation of HA is an acceptable and promising therapeutic alternative in patients with recurrent UTI. Expanded placebo controlled clinical trials examining this application of HA are currently underway.

The correlation between zeta potential and mucoadhesion strength on pig vesical mucosa

The detachment forces of various polymers are frequently measured to determine their mucoadhesion strength. As the process of mucoadhesion is a consequence of interactions between the mucus layer on mucosa and mucoadhesive polymers, it is greatly dependent on mucus and polymer structure including their charge. It is also known that the glycosaminoglycan layer, which covers the urinary bladder mucosa surface, is highly negatively charged. Therefore, by measuring the zeta potential of polymer dispersions and mucosal homogenates an insight into electrostatic interactions during mucoadhesion can be obtained. In our experiments we chose three polymers, two anionic (polycarbophil, PC; sodium carboxymethyl cellulose, CMCNa) and one cationic (chitosan hydrochloride, CH), for which we expected different zeta potential values and different mucoadhesion strengths. The correlation between the zeta potential and the detachment force was determined. In addition to that, the zeta potential of the scraped surface layer of pig urinary bladders was measured to confirm its negative value. The mucoadhesion strength decreased in the following order: CH>CMCNa=PC. The zeta potentials for all three polymers and for porcine vesical mucosal homogenates were measured in Tyrode solution and two NaCl solutions with different ionic strengths. The lower values of the detachment force correlated well with the more negative zeta potential of the polymer, which might be a consequence of the greater repulsion between negative charges of polymers and glycosaminoglycans.

Pathophysiology of interstitial cystitis

Despite being described over 80 years ago, interstitial cystitis remains a disease of undetermined aetiology and poor treatment outcomes. Generally agreed diagnostic criteria of this condition, which occurs primarily in females, are frequency, urgency and pain, a low-capacity hypersensitive bladder, and mucosal haemorrhages and tearing on bladder distention. Although current theories of pathophysiology are predominantly conjecture, important elements of the disease process are increased afferent and efferent neuronal activity, an excess of inflammatory mediators, increased epithelial permeability and possibly reduced bladder vascularity. Improved treatment outcome will follow a better understanding of pathophysiology.

Glycosaminoglycan content of human bladders. a method of analysis using cold-cup biopsies

A glycocalyx layer composed of glycosaminoglycans (GAGs) and other molecules lines the transitional epithelium of the urinary bladder. This layer forms a barrier between the transitional cells and urinary bladder environment and is believed to help prevent the adherence of bacteria, minerals and carcinogens. Investigators postulate that quantitative and/or qualitative defects in the GAG component may be responsible for a spectrum of acute and chronic disease processes ranging from urinary tract infections to cancer. While the presence of epithelium GAGs has been confirmed biochemically and histochemically, few rigorous characterizations have been performed. This study establishes the methodology and feasibility of using routine cold-cup biopsies from cadaveric human bladders for GAG analysis and establishes baseline contents of the sulfated and non-sulfated GAGs in the urinary bladder glycocalyx. Using detergent extraction, the GAGs from cold-cup biopsies (n = 34) from four cadaveric bladders were isolated. The isolates were subjected to two colorimetric assays to quantify both sulfated and non-sulfated GAGs. The nonsulfated GAG content of the bladder epithelium ranged from 2.15 x 10(-4) to 5.50 x 10(-4) mmol/kg of dry, defatted bladder. The sulfated GAG content ranged from 2.00 x 10(-1) to 7.40 x 10(-1) mmol/kg of dry, defatted bladder. These values are consistent with reports found in the literature using electrophoresis on full-thickness human bladder specimens. The GAG content of human bladder epithelium can be readily and accurately characterized from cold-cup biopsy samples. Our future plans involve using this routinely used technique to analyze samples from live control and disease-state bladders thereby demonstrating any quantitative and/or qualitative differences in GAG constituents.

Treatment of refractory interstitial cystitis

Interstitial cystitis is the most therapeutically frustrating condition of the urinary tract. The vast array of treatments available clearly indicates that none is particularly effective. As the majority of patients fail to experience a significant and prolonged response to standard treatments, new options are frequently being developed. These include the oral administration of cimetidine, the intravesical use of hyaluronic acid and BCG, and total cystectomy with the formation of a continent urinary diversion. Unfortunately, the acceptance of many new treatments is based on incomplete evaluation, and this has resulted in a confusing array of disparate alternatives. Effective and durable treatment will not be available until the nature of the disease is better understood and the mechanisms of action of current therapies are elucidated.

Urodynamics in acetone-induced cystitis of anesthetized rats

We examined the bladder function of cystitis models induced by intravesical acetone instillation in urethane-anesthetized rats. Acetone (0.35 ml) at 10, 30, or 50% concentration or deionized water (sham-treatment) was instilled into the bladder via the cannula which was inserted into the lumen. Acetone was withdrawn 90 sec after instillation and the bladder lumen was washed with saline after 15 min. One hour later, the cystometrogram induced by transvesical infusion of saline (3.3 ml/hr) was measured. During cystometrography of normal (non-treated) or sham-treated group, the time required to cause micturition, reflecting bladder capacity, was 9.6 +/- 0.9 (n = 7) or 10.0 +/- 0.8 min (n = 6), respectively. In the 10% acetone-treated group, the bladder capacity was similar to that in the normal or sham group. In the 30% acetone group, the time to micturition was 4.4 +/- 0.4 min (n = 7), indicating decreased bladder capacity, although the micturition pressure and the threshold pressure were not significantly different from those in the normal or sham group. However, in the 50% acetone group, the micturition reflex disappeared. In isolated rat bladder strips, contractile responses to carbachol or electrical field stimulation in the sham and 30% acetone group were similar. While, both responses in isolated strips from the 50% acetone group were reduced. The degree of damage from degeneration and desquamation of epithelium and hemorrhage in the bladder tissue from the 30% acetone group was less prominent than in the 50% acetone group. Additionally, some tissue from the 50% acetone group showed degeneration of muscle layer. The effects of three drugs were investigated in the 30% acetone group which showed increased urinary frequency. Baclofen (100 microg/kg, i.v.) and morphine (100 microg/kg, i.v.) increased significantly the bladder capacity and the threshold pressure. Atropine (10 microg/kg, i.v.) decreased the micturition pressure. These results suggest that cystitis models induced by intravesical instillation of 30% acetone may be valuable for evaluating drugs for the treatment of urinary frequency.

Interstitial cystitis and the gynecologist

Interstitial cystitis (IC) is a predominantly female condition with the presenting symptoms of frequency of micturition and pain. The diagnosis is confirmed by bladder visualization at cystoscopy during filling, emptying, and redistension. The epidemiology, proposed etiologies, and current therapies for interstitial cystitis are discussed. The condition of IC is poorly understood and has no specific histological characteristics. However, there is much that can be offered to the IC sufferer to relieve or cure her symptoms. It is hoped that the recent decade of increasing research activity will be fruitful in answering questions of etiology and pathogenesis, and offering hope for new therapies and ultimately cure.

Long-term experience with pentosanpolysulfate in interstitial cystitis

OBJECTIVES

An oral preparation of pentosanpolysulfate sodium (PPS) was recently approved by the Food and Drug Administration for interstitial cystitis (IC). Previously published articles have documented improvement in symptoms in 28% to 63% of patients, but no long-term studies have been published. No unique characteristics except for Hunner's ulcer have been found in patients experiencing relief from PPS. We report our experience with PPS following patients up to 116 months and analyze baseline parameters in an attempt to characterize long-term responders.

METHODS

Baseline and follow-up data from 97 patients with IC and enrolled in a compassionate use study with PPS at the University of Wisconsin from 1987 to 1995 are analyzed. Previous treatments had failed, and patients had to pay for PPS. Patients continuing treatment with PPS were monitored every 3 months with questionnaires and laboratory tests. In 1996 an update on medication and a questionnaire developed by the National Institutes of Health Interstitial Cystitis Database were sent to patients who had discontinued treatment.

RESULTS

By the end of the study period 11 (11.3%) of the patients were still taking PPS, with 6 (6.2%) doing so continuously for more than 18 months. Three (3%) patients who discontinued PPS were in long-term remission. An additional 15% had remission for a substantial period. Except for a weak correlation between less constant pain (P = 0.0439), no correlations were found between baseline parameters and duration of treatment with PPS.

CONCLUSIONS

On a long-term basis, between 6.2% and 18.7% of patients with IC benefit from PPS. The only baseline factor predicting response to PPS was less constant pain.

Intravesical hyaluronic acid in the treatment of refractory interstitial cystitis

OBJECTIVES

On the assumption that interstitial cystitis (IC) is the result of a defective mucous lining of the bladder epithelium, a study was carried out to investigate the activity of hyaluronic acid (HA) in the treatment of IC. HA is an important glycosaminoglycan (GAG) present in all connective tissues, including the GAG layer of the vesical mucosa. It exhibits a variety of pharmacologic properties that enhance its appeal for the therapy of IC.

METHODS

A total of 25 patients, with the characteristic picture of IC and refractory to other medical treatments, participated in a trial of HA. Patients received 40 mg of HA intravesically on a weekly basis for 4 weeks, then monthly. Response to therapy was evaluated by symptom score, voiding diaries, and visual analog scales.

RESULTS

An initial positive (complete+partial) response of 56% at week 4 increased to 71% by week 12. This response was maintained until week 20; beyond week 24 there appears to be a moderate decrease in the effectiveness of the medication. There was no significant toxicity attributable to the presence of HA in the bladder.

CONCLUSIONS

The response of refractory IC patients to the intravesical administration of HA was gratifying. In the past, many therapies for IC that were initially considered promising failed the test of a controlled study. Further studies will establish the effectiveness of this particular preparation of HA in the treatment of IC.

Interstitial cystitis: a critique of current concepts with a new proposal for pathologic diagnosis and pathogenesis

Interstitial cystitis (IC) has continued to be an unresolved problem in clinical urology despite intense investigation over the past 16 or more years. Its etiology and pathogenesis are still undetermined, and its pathologic diagnosis is essentially one of exclusion, with no specific or clear criteria. In this review, current concepts of the etiology/pathogenesis and pathology are critically analyzed, new pathologic observations summarized, and a proposal of neurogenic inflammation as the primary pathogenetic factor is presented in the context of all currently available information. The popular postulate attributing IC to a deficient or defective glycosaminoglycan urothelial surface layer is not substantiated by morphologic, experimental, clinical, or therapeutic observations. Although the consensus seems to discount an infectious etiology, there is sufficient evidence that a microbial factor-short of a bona fide clinical infection-may have a role. Both autoimmunity and mast cell infiltration also appear to have a role, despite the lack of evidence that either is involved as the primary etiologic factor. Claims that the so-called feline urologic syndrome may represent a natural animal model of IC are shaky. As it now stands, there is no natural or induced animal model that duplicates IC as it occurs in humans. No specific or diagnostic light microscopic pathologic features are provided by either routine histopathology or immunohistochemistry. Increasingly, it has been recognized that detrusor mast cell count has little or no diagnostic value. On the other hand, electron microscopy has provided important new observations: (a) presence of mast cells, activated by piecemeal degranulation, in close proximity to intrinsic nerves-particularly in suburothelium: (b) distinctive pathologic changes in urothelium, suburothelium, and muscularis in biopsy samples obtained after diagnostic bladder hydrodistension; (c) constant associated changes in venules, capillaries, and neural elements in the same biopsy samples; and (d) diffuse involvement of bladder wall, with the most evident and profound pathologic changes in posthydrodistension biopsy samples obtained from cystoscopically obvious lesions (glomerulations). These features are sufficiently distinctive to allow definitive pathologic diagnosis of IC, and provide a firm basis for primary involvement of neurogenic inflammation in its pathogenesis. A proposal is presented regarding the mechanisms invoked by neurogenic inflammation. This proposal revolves around sensory nerve excitation, the release of neuropeptides, and activated differential secretion of potent mast cell mediators. This proposal can account for the heterogeneity and variability of observed pathologic features, and upholds the tacit acceptance of IC as a disease of pluricausal etiology and multifactorial pathogenesis.

Bladder permeability in interstitial cystitis is similar to that of normal volunteers: direct measurement by transvesical absorption of 99mtechnetium-diethylenetriaminepentaacetic acid

Bladder permeability was directly measured with the radionuclide used clinically for detecting vesicoureteral reflux (99mtechnetium-diethylenetriaminepentaacetic acid, 99mTc-DTPA) in 10 interstitial cystitis patients diagnosed according to National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases criterion and compared to 9 sex matched, symptom-free, normal volunteers. After functional bladder capacity was determined (capacity at which the patient demands fluid inflow to stop), the bladder was emptied and 5 mCi. 99mTc-DTPA in 10 ml. of saline were infused followed by normal saline to 80% of functional capacity. This was done to normalize the patients to the same low bladder pressure, since previous studies of rabbits indicated that bladder permeability is low and not significantly different at 20% and 60% of anesthetized bladder capacity (defined as the volume producing an intravesical pressure of 20 cm. water). Radioactivity of 1 ml. serum specimens taken at 0, 2, 15 and 30 minutes after radionuclide infusion was determined in a gamma counter, corrected for radioactive decay and converted to per cent of instilled dose per whole body based on blood volume estimated from body weight for each individual. There was considerable interindividual variability in the absorption between the patients and the volunteers. Analysis of variance of these data showed no statistically significant difference between the patients and controls at any time sampled. These results indicate that while some interstitial cystitis patients have a more permeable bladder than others, the same is true for normal, symptom-free volunteers. Thus, the concept of increased bladder permeability in interstitial cystitis is not supported by this direct measurement of bladder permeability.