Biomedical subjects

Susan K Keay

Publications and source records attributed to Susan K Keay.

9 recordsLinked to original sources

PubMed2007

Changes in urine markers and symptoms after bladder distention for interstitial cystitis.

PURPOSE: We evaluated changes in urine markers and symptom scores after bladder distention in patients with interstitial cystitis. MATERIALS AND METHODS: Study subjects were 33 new patients who had undergone no prior interstitial cystitis treatment. Urine specimens were taken before and 1 month after bladder distention. University of Wisconsin symptom scores were done the same day as the urine specimen collection. Urine marker levels and symptom scores before and after distention were compared. Changes in markers were tested for associations with changes in symptom scores and other markers. Markers and specific symptoms before distention were tested for their association with post-distention symptom improvement. RESULTS: After distention the median total University of Wisconsin score decreased significantly (28.5 before, 20 after, p <0.001). A total of 12 patients (36%) had at least 30% improvement in University of Wisconsin score, and 8 patients (24%) had at least 50% improvement. No pre-distention markers or symptoms predicted which patients would have a good response. There were 2 urine markers that improved significantly after distention: anti-proliferative factor activity (median -96% before, -17% after, p <0.001) and heparin-binding epidermal growth factor-like growth factor levels (median 0.34 ng/mg creatinine before, 4.1 after, p <0.001). None of the changes in urine markers associated with changes in symptom scores. CONCLUSIONS: The median symptom score for newly diagnosed patients with interstitial cystitis decreased after distention, but only a minority of patients had at least 30% symptom improvement. Bladder distention altered urine anti-proliferative factor activity and heparin-binding epidermal growth factor-like growth factor levels toward normal, but the mechanism of symptom relief after distention is still unknown.

Adult↗

PubMed2006

CKAP4/p63 is a receptor for the frizzled-8 protein-related antiproliferative factor from interstitial cystitis patients.

Antiproliferative factor (APF) is a low molecular weight sialoglycopeptide that is secreted by bladder cells from interstitial cystitis patients and is a potent inhibitor of both normal bladder epithelial and bladder carcinoma cell proliferation. We hypothesized that APF may produce its antiproliferative effects by binding to a transmembrane receptor. This study demonstrates that cytoskeleton-associated protein 4/p63 (CKAP4/p63), a type II transmembrane receptor, binds with high affinity to APF. The antiproliferative activity of APF is effectively inhibited by preincubation with anti-CKAP4/p63-specific antibodies, as well as by short interfering RNA knockdown of CKAP4/p63. Immunofluorescent confocal microscopy showed co-localization of anti-CKAP4/p63 and rhodamine-labeled synthetic APF binding in both cell membrane and perinuclear areas. APF also inhibits the proliferation of HeLa cervical carcinoma cells that are known to express CKAP4/p63. These data indicate that CKAP4/p63 is an important epithelial cell receptor for APF.

Amino Acid Sequence↗

PubMed2005

Do the National Institute of Diabetes and Digestive and Kidney Diseases cystoscopic criteria associate with other clinical and objective features of interstitial cystitis?

PURPOSE: We compared urine markers, bladder biopsy findings and clinical features of patients with symptoms of interstitial cystitis (IC) who did or did not meet the cystoscopic criteria defined by the National Institute of Diabetes and Digestive and Kidney Diseases. MATERIALS AND METHODS: Urine markers and symptom questionnaires were measured before and 1 month after bladder distention for IC. Bladder biopsies were taken at the time of distention. At distention patients were defined as meeting or not meeting the National Institute of Diabetes and Digestive and Kidney Diseases established cystoscopic criteria for IC. The 2 patient groups were compared. RESULTS: Urine marker levels were similar for the 2 groups, including antiproliferative factor, epidermal growth factor, heparin binding epidermal growth factor-like growth factor, cyclic guanosine monophosphate, interleukins 6 and 8, and methylhistamine. Bladder biopsy features were similar for the 2 groups. Bladder capacity with the patients under anesthesia was higher in those who did not meet the criteria (median 750 vs 1,000 ml, p = 0.005). Median age at symptom onset was 26 years in both groups. On the University of Wisconsin symptom scale patients who met the criteria had higher scores for daytime frequency (p = 0.002) and nocturia (p = 0.01). Symptom characteristics and symptom response after bladder distention were similar for the 2 groups. CONCLUSIONS: Patients who met the cystoscopic criteria had worse daytime frequency and nocturia, and lower bladder capacity under anesthesia. However, the 2 groups had similar urine markers and bladder biopsy findings. The cystoscopic criteria do not appear to identify a distinct pathophysiological subset of patients with IC symptoms.

Adult↗

PubMed2004

An antiproliferative factor from interstitial cystitis patients is a frizzled 8 protein-related sialoglycopeptide.

Approximately 1 million people in the United States suffer from interstitial cystitis, a chronic painful urinary bladder disorder characterized by thinning or ulceration of the bladder epithelial lining; its etiology is unknown. We have identified a glycosylated frizzled-related peptide inhibitor of cell proliferation that is secreted specifically by bladder epithelial cells from patients with this disorder. This antiproliferative factor (APF) profoundly inhibits bladder cell proliferation by means of regulation of cell adhesion protein and growth factor production. The structure of APF was deduced by using ion trap mass spectrometry (MS), enzymatic digestion, lectin affinity chromatography, and total synthesis, and confirmed by coelution of native and synthetic APF derivatives on microcapillary reversed-phase liquid chromatography (microRPLC)/MS. APF was determined to be an acidic, heat-stable sialoglycopeptide whose peptide chain has 100% homology to the putative sixth transmembrane domain of frizzled 8. Both synthetic and native APF had identical biological activity in normal bladder epithelial cells and T24 bladder cancer cells. Northern blot analysis indicated binding of a probe containing the sequence for the frizzled 8 segment with mRNA extracted from cells of patients with interstitial cystitis but not controls. APF is therefore a frizzled-related peptide growth inhibitor shown to contain exclusively a transmembrane segment of a frizzled protein and is a potential biomarker for interstitial cystitis.

Antineoplastic Agents↗

PubMed2004

Interstitial cystitis antiproliferative factor (APF) as a cell-cycle modulator.

BACKGROUND: Interstitial cystitis (IC) is a chronic bladder disorder of unknown etiology. Antiproliferative factor (APF), a peptide found in the urine of IC patients, has previously been shown to decrease incorporation of thymidine by normal bladder epithelial cells. This study was performed to determine the effect of APF on the cell cycle of bladder epithelial cells so as to better understand its antiproliferative activity. METHODS: Explant cultures from normal bladder biopsy specimens were exposed to APF or mock control. DNA cytometry was performed using an automated image analysis system. Cell cycle phase fractions were calculated from the DNA frequency distributions and compared by two-way analysis of variance (ANOVA). RESULTS: APF exposure produced statistically significant increases in the proportion of tetraploid and hypertetraploid cells compared to mock control preparations, suggesting a G2 and/or M phase cell cycle block and the production of polyploidy. CONCLUSIONS: APF has a specific effect on cell cycle distributions. The presence of a peptide with this activity may contribute to the pathogenesis of interstitial cystitis through disruption of normal urothelial proliferation and repair processes.

Adult↗

PubMed2002

Is interstitial cystitis an infectious disease?

Interstitial cystitis (IC) is a chronic bladder disorder of unknown aaetiology. Although several investigators have attempted to identify an infectious cause for IC, none has yet been found. Our own studies to search for an infectious cause discovered instead, a toxic factor in the urine of approximately 95% of IC patients that is made by and inhibits, the normal proliferation of bladder epithelial cells. Additional research is necessary to determine whether this factor is encoded by the eucaryotic cells themselves or an unidentified intracellular microorganism.

Bacteria↗

PubMed2002

Interstitial cystitis.

Appropriate diagnostic tests for interstitial cystitis remain uncertain. One or more promising markers for this disease have been described which may provide a noninvasive means for diagnosis as well as clues to pathogenesis of this disease. Treatment remains empiric.

Bacterial Infections↗

PubMed2002

A comparison of multiple urine markers for interstitial cystitis.

PURPOSE: We measured several urine markers in 24-hour specimens from patients with interstitial cystitis and healthy controls. For each marker we determined whether the urine level was significantly different in interstitial cystitis and control cases, and whether the marker level correlated with the symptom score. MATERIALS AND METHODS: Study participants included 36 female patients with interstitial cystitis and 36 age matched female volunteers. Multiple urine aliquots were obtained to measure the various markers. RESULTS: Certain markers were significantly increased in interstitial cystitis, including anti-proliferative factor, epidermal growth factor, insulin-like growth factor (IGF) binding protein-3 and interleukin (IL)-6. Markers significantly decreased in interstitial cystitis were heparin-binding epidermal growth factor-like growth factor, cyclic guanosine monophosphate and methylhistamine. Other markers were not significantly different in the interstitial cystitis and control groups, including total glycosaminoglycans, epitectin, hyaluronic acid, IL-8, IL-1 and nitrates plus nitrites. IGF-1 was undetectable in 24-hour urine samples but spot voided samples from the same interstitial cystitis population had IGF-1 levels similar to previously reported levels. The only significant association of marker with symptom score was a positive correlation of IL-6 with nocturia. For all markers the conclusions were the same whether the marker was normalized to creatinine or to 24 hours. CONCLUSIONS: This study confirmed several previously reported urine alterations in interstitial cystitis, including increased anti-proliferative factor, epidermal growth factor, IGF binding protein-3 and IL-6, and decreased heparin-binding epidermal growth factor-like growth factor and cyclic guanosine monophosphate. Of all markers studied anti-proliferative factor had the least overlap in the interstitial cystitis and control groups, and so it is the most likely candidate to become a diagnostic test.

Adult↗

PubMedDate not supplied

The use of urine proteomic and metabonomic patterns for the diagnosis of interstitial cystitis and bacterial cystitis.

The advent of systems biology approaches that have stemmed from the sequencing of the human genome has led to the search for new methods to diagnose diseases. While much effort has been focused on the identification of disease-specific biomarkers, recent efforts are underway toward the use of proteomic and metabonomic patterns to indicate disease. We have developed and contrasted the use of both proteomic and metabonomic patterns in urine for the detection of interstitial cystitis (IC). The methodology relies on advanced bioinformatics to scrutinize information contained within mass spectrometry (MS) and high-resolution proton nuclear magnetic resonance (1H-NMR) spectral patterns to distinguish IC-affected from non-affected individuals as well as those suffering from bacterial cystitis (BC). We have applied a novel pattern recognition tool that employs an unsupervised system (self-organizing-type cluster mapping) as a fitness test for a supervised system (a genetic algorithm). With this approach, a training set comprised of mass spectra and 1H-NMR spectra from urine derived from either unaffected individuals or patients with IC is employed so that the most fit combination of relative, normalized intensity features defined at precise m/z or chemical shift values plotted in n-space can reliably distinguish the cohorts used in training. Using this bioinformatic approach, we were able to discriminate spectral patterns associated with IC-affected, BC-affected, and unaffected patients with a success rate of approximately 84%.

Bacterial Infections↗