Validation of Distinct Bladder Pain Phenotypes Utilizing the MAPP Research Network Cohort

INTRODUCTION AND HYPOTHESIS

As interstitial cystitis/bladder pain syndrome (IC/BPS) likely represents multiple pathophysiologies, we sought to validate three clinical phenotypes of IC/BPS patients in a large, multi-center cohort using unsupervised machine learning (ML) analysis.

METHODS

Using the female Genitourinary Pain Index and O'Leary-Sant Indices, k-means unsupervised clustering was utilized to define symptomatic phenotypes in 130 premenopausal IC/BPS participants recruited through the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) research network. Patient-reported symptoms were directly compared between MAPP ML-derived phenotypic clusters to previously defined phenotypes from a single center (SC) cohort.

RESULTS

Unsupervised ML categorized IC/BPS participants into three phenotypes with distinct pain and urinary symptom patterns: myofascial pain, non-urologic pelvic pain, and bladder-specific pain. Defining characteristics included presence of myofascial pain or trigger points on examination for myofascial pain patients (p = 0.003) and bladder pain/burning for bladder-specific pain patients (p < 0.001). The three phenotypes were derived using only 11 features (fGUPI subscales and ICSI/ICPI items), in contrast to 49 items required previously. Despite substantial reduction in classification features, unsupervised ML independently generated similar symptomatic clusters in the MAPP cohort with equivalent symptomatic patterns and physical examination findings as the SC cohort.

CONCLUSIONS

The reproducible identification of IC/BPS phenotypes, distinguishing bladder-specific pain from myofascial and genital pain, using independent ML analysis of a multicenter database suggests these phenotypes reflect true pathophysiologic differences in IC/BPS patients.

Constraints on cosmological parameters from the analysis of the cosmic lens all sky survey radio-selected gravitational lens statistics

We derive constraints on cosmological parameters and the properties of the lensing galaxies from gravitational lens statistics based on the final Cosmic Lens All Sky Survey data. For a flat universe with a classical cosmological constant, we find that the present matter fraction of the critical density is Omega(m)=0.31(+0.27)(-0.14) (68%)+0.12-0.10 (syst). For a flat universe with a constant equation of state for dark energy w=p(x)(pressure)/rho(x)(energy density), we find w<-0.55(+0.18)(-0.11) (68%).

The relationship between blood glucose excursions and painful diabetic peripheral neuropathy: a pilot study

AIMS

Peripheral neuropathy affects 30% of Type 1 diabetic patients. Unfortunately, 10-20% of affected patients have disabling symptoms. The aim of this study was to examine the relationship between blood glucose excursions and pain in patients with symptomatic diabetic neuropathy.

METHODS

Twenty Type 1 diabetic patients with peripheral neuropathy (10 painful and 10 painless) wore a continuous glucose monitoring system for 3 days. Symptomatic patients kept a daily pain score diary. The mean amplitude of glycaemic excursions (MAGE) and the M-values (measure of glucose deviations from an arbitrarily selected point) were calculated.

RESULTS

Groups were matched for (mean +/- sd) age: 52.0 +/- 11.1 years; duration of diabetes: 24.8 +/- 10.7 years; HbA1c: 9.7 +/- 2.3%; duration of neuropathy: 5.6 +/- 2.6 years; and CGMS performance. The painful group had a greater mean glucose (12.1 +/- 2.9 mmol/l vs. 9.3 +/- 1.9 mmol/l, P = 0.02), a greater M-value (68.4 vs. 31.1, P = 0.02) and more glycaemic excursions (13 vs. 10, P < 0.01), compared with the painless group. However, there was no difference in the MAGE between both groups, and no correlation between the number of glycaemic excursions and the number of painful episodes in the painful group.

CONCLUSIONS

Patients with painful neuropathy have greater glucose flux and possibly poorer diabetes control, compared with patients with painless neuropathy.

Care of the diabetic foot

An update on the assessment and treatment of foot lesions in people with diabetes

Chemoneurolysis of the canine gastric submucosa: effects of surgically induced gastric hypersecretion in the Pavlov pouch

Innervated (Pavlov) gastric fundic pouches were constructed in dogs. One group of dogs served as controls, and another group of dogs had their pouch submucosa infiltrated with 25 per cent ethyl alcohol. The alcohol infiltration of the gastric pouch submucosa eliminated the gastric secretory responses to histamine, pentagastrin, a meat meal, and insulin-induced hypoglycemia. The alcohol infusion of the gastric pouch submucosa did not modify the elevated serum gastrin levels to a meat meal, alter the basal or stimulated mean splenic arterial blood flow to the pouch, nor alter the histologic appearance of the pouch with hematoxylin and eosin or histochemical fluorescence of catecholamines. Transplantation of 75 per cent of the gastric antrum into the colon caused a basal and a meal-augmented hypergastrinemia in all dogs. In the control Pavlov pouches the hypergastrinemia induced elevated gastric secretory responses to histamine, pentagastrin, and insulin-induced hypoglycemia. In those Pavlov pouches in which the submucosa had been infiltrated with alcohol, the hypergastrinemia could not induce any gastric secretory response to histamine, pentagastrin, or insulin-induced hypoglycemia.

Chemoneurolysis of the canine gastric submucosa: modification of surgically-induced peptic ulcer formation

Chemoneurolysis of the canine antral submucosa with 25% ethyl alcohol solutions reduced ulcer formation and increased the survival times in animals subjected to the Exalto-Mann-Williamson ulcer-producing procedure.

Effect of gastrin on the exocrine pancreas. A review

Studies in animals demonstrate a gastric hormonal phase of pancreatic exocrine secretion. Endogenous or exogenous gastrin causes a marked elevation in the pancreatic enzymes and a lesser increase in the pancreatic volume and bicarbonate. It is possible that these "gastrin" effects may be the basis of a "cephalic" phase of pancreatic secretion. These observations have been only partially confirmed in human subjects with and without the Zollinger-Ellison syndrome. The physiologic importance of these ecbolic actions as well as a possible trophic effect remains to be elucidated.

Chemoneurolysis of the canine gastric submucosa. Effects on surgically-induced gastric hypersecretion on the Heidenhain pouch

Double denervated gastric pouches were constructed in dogs. One gastric pouch served as a control, and the other gastric pouch had its submucosa infiltrated with 25% ethyl alcohol, (submucosal chemoneurolysis). Neurolysis of these gastric pouches eliminated their gastric secretory responses to histamine, meat and pentagastrin without altering their histological appearance. Transplantation of 75% of the gastric antrum into the colon caused a hypergastrinemia and increased the sensitivity of the control gastric pouches to the various stimuli but had no such effect on those gastric pouches infiltrated with ethyl alcohol.

Chemoneurolysis of the canine gastric submucosa. Effects on Heidenhain pouch secretion

Double denervated gastric pouches were constructed in dogs. One gastric pouch served as a control, and the other gastric pouch had its submucosa infiltrated with 25% ethyl alcohol (submucosal chemoneurolysis). Neurolysis of these gastric pouches did not alter their histological appearance but did eliminate their gastric secretory responses to histamine, meat and pentagastrin. The dogs exhibited elevated serum gastrin levels after feeding.

Submucosal vagotomy of the canine gastric fundus

Ethyl alcohol infiltration of the submucosa of canine denervated gastric pouches markedly reduced the gastric secretory responses to histamine and food without changing the histologic appearance. It is postulated that the ethyl alcohol destroyed the submucosal nerve plexus which regulates the parietal cells.