Molecular mechanisms of amyloid disaggregation.

Introduction: Protein aggregation and deposition of uniformly arranged amyloid fibrils in the form of plaques or amorphous aggregates is characteristic of amyloid diseases. The accumulation and deposition of proteins result in toxicity and cause deleterious effects on affected individuals known as amyloidosis. There are about fifty different proteins and peptides involved in amyloidosis including neurodegenerative diseases and diseases affecting vital organs. Despite the strenuous effort to find a suitable treatment option for these amyloid disorders, very few compounds had made it to unsuccessful clinical trials. It has become a compelling challenge to understand and manage amyloidosis with the increased life expectancy and ageing population. Objective: While most of the currently available literature and knowledge base focus on the amyloid inhibitory mechanism as a treatment option, it is equally important to organize and understand amyloid disaggregation strategies. Disaggregation strategies are important and crucial as they are present innately functional in many living systems and dissolution of preformed amyloids may provide a direct benefit in many pathological conditions. In this review, we have compiled the known amyloid disaggregation mechanism, interactions, and possibilities of using disaggregases as a treatment option for amyloidosis. Methods: We have provided the structural details using protein-ligand docking models to visualize the interaction between these disaggregases with amyloid fibrils and their respective proposed amyloid disaggregation mechanisms. Results: After reviewing and comparing the different amyloid disaggregase systems and their proposed mechanisms, we presented two different hypotheses for ATP independent disaggregases using L-PGDS as a model. Conclusion: Finally, we have highlighted the importance of understanding the underlying disaggregation mechanisms used by these chaperones and organic compounds before the implementation of these disaggregases as a potential treatment option for amyloidosis.

In vivo liquid-liquid phase separation protects amyloidogenic and aggregation-prone peptides during overexpression in Escherichia coli.

Studying pathogenic effects of amyloids requires homogeneous amyloidogenic peptide samples. Recombinant production of these peptides is challenging due to their susceptibility to aggregation and chemical modifications. Thus, chemical synthesis is primarily used to produce amyloidogenic peptides suitable for high-resolution structural studies. Here, we exploited the shielded environment of protein condensates formed via liquid-liquid phase separation (LLPS) as a protective mechanism against premature aggregation. We designed a fusion protein tag undergoing LLPS in Escherichia coli and linked it to highly amyloidogenic peptides, including ß amyloids. We find that the fusion proteins form membraneless organelles during overexpression and remain fluidic-like. We also developed a facile purification method of functional Aß peptides free of chromatography steps. The strategy exploiting LLPS can be applied to other amyloidogenic, hydrophobic, and repetitive peptides that are otherwise difficult to produce.

Factor analysis demonstrates a symptom cluster related to methane and non-methane production in irritable bowel syndrome.

INTRODUCTION: Irritable bowel syndrome (IBS) is a chronic disorder often subdivided into constipation-predominant and diarrhea-predominant forms. Earlier studies have shown that IBS patients with methane detected on lactulose breath test (LBT) are more likely to have constipation. The goal of this study was to conduct a factor analysis to determine whether there is a cluster of symptoms associated with methane production. METHODS: Patients with IBS referred for a LBT completed a questionnaire assessing 31 symptoms. The degree of each symptom was graded on a visual analog scale of 0 to 5. Exploratory factor analysis was carried out separately in methane and nonmethane patients. A score was determined for each symptom cluster by summing across the related variables. The cluster scores were compared between the 2 groups by the Wilcoxon rank-sum test. RESULTS: A total of 459 IBS patients (72 with methane, 387 with nonmethane) were evaluated. On the basis of factor analysis results, 3 symptom clusters (bloating weighted, pain weighted, and constipation weighted) were created in methane-producing patients. Two symptom clusters (bloating weighted and diarrhea weighted) were created in the nonmethane group. The groups did not differ significantly on the methane-derived bloating score (P=0.24) or the pain score (P=0.15). However, the methane-derived constipation score was significantly higher in the methane group, 15.3 ± 4.9 versus 13.4 ± 4.9, P=0.002. The constipation-weighted cluster included the following symptoms: constipation, lack of milk intolerance, lack of weight loss, small bowel movements, and straining. The diarrhea cluster score was significantly higher in the nonmethane group, 14.2 ± 8.0 versus 11.3 ± 6.5, P=0.005. The diarrhea cluster included the following symptoms: diarrhea, pain with bowel movements, pain after bowel movements, foul-smelling bowel movements, and large bowel movements. The groups did not differ significantly on the nonmethane-derived bloating cluster, P=0.11. CONCLUSIONS: Methane-producing IBS patients have a unique cluster of symptoms related to constipation.

Importance of diarrhea in evaluating constipation in irritable bowel syndrome clinical studies.

BACKGROUND: Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by alterations in bowel function, abdominal discomfort, and bloating. The symptoms of IBS vary widely between constipation and diarrhea predominance. In this study, we examine "constipation minus diarrhea" score (C-D) to account for the contribution of diarrhea and to create a reliable method for predicting constipation predominance in IBS. METHODS: A nested study was conducted in participants with IBS by Rome I criteria. After consent, they completed a daily stool diary for 1 week. This included recording frequency of bowel movements and describing consistency of stool using the Bristol stool scale. After submitting their diaries, participants rated their bowel symptoms using a visual analog score (VAS) scale from 0 to 100 mm, with 100 mm representing maximum severity. VAS scores for C, D, and C-D were subsequently compared with the true stool events of the previous week by stool diary to validate the potential usefulness of the simple C-D method. RESULTS: Eighty-four participants with IBS completed stool diaries and VAS surveys for bowel symptoms, from which C-D scores were compiled. By correcting for the predominance of constipation compared with diarrhea, C-D scores predicted constipation based on the frequency of bowel movements and Bristol stool score. Furthermore, a second method was used to validate the C-D technique by comparing the mean C-D score in participants with constipation (≤3 d with bowel movement in previous week). In this case, the mean C-D score was 74.1 ± 3.8 compared with -3.0 ± 5.9 for patients with >3 days with bowel movement in that week (P<0.001). Although the constipation severity alone also distinguished these 2 groups, the difference was less impressive (P<0.01). In participants with mean Bristol stool scores of ≤2 in the preceding week, the C-D mean score was 25.4 ± 6.1 compared with participants having mean Bristol stool score of >2 where the C-D was -11.1 ± 5.9 (P<0.01). Using constipation severity by VAS alone, there was no significant difference between these same 2 Bristol stool categories (P=0.29). CONCLUSIONS: IBS patients' self-assessment of constipation and diarrhea severity using the C-D score is an effective predictor of C-IBS and constipation severity. The C-D score may be a useful tool in future IBS constipation trials, as it seems to predict constipation and it correlates well with stool diaries.

Apple sauce improves detection of esophageal motor dysfunction during high-resolution manometry evaluation of dysphagia.

BACKGROUND: Esophageal manometry utilizes water swallows to evaluate esophageal motor abnormalities in patients with dysphagia, chest pain, or reflux symptoms. Although manometry is the gold standard for evaluation of these symptoms, patients with dysphagia often have normal results in manometry studies. AIM: The objective of this work was to test the hypothesis that challenging the esophagus with viscous apple sauce boluses uncovers motor abnormalities in patients with dysphagia not seen when using water swallows. METHODS: High-resolution esophageal manometry was performed using ten water swallows followed by ten apple sauce swallows in consecutive subjects presenting with dysphagia. Subjects with grossly abnormal water swallow evaluations were excluded. Each swallow was categorized as normal, hypotensive (distal isobaric contour plots of < 30 mmHg over >5 cm), or simultaneous (distal esophageal velocity ≥ 8.0 cm/s). Ineffective esophageal motility (IEM) was defined as ≥ 30% hypotensive swallows, and pressurization was defined as ≥ 20% simultaneous pressure waves. RESULTS: Data from 41 subjects was evaluated. Overall, 96.3% of water swallows were normal, 2.9% hypotensive, and 0.7% simultaneous. Only 70.3% of viscous swallows were normal; 16.7% were hypotensive and 13.0% were simultaneous (P < 0.001 all groups). Seven (17.1%) met criteria for IEM, and pressurization with viscous swallows was observed for nine (22.0%). Fourteen subjects (34.1%) had abnormal results from viscous studies. The presence of any abnormal water swallows was predictive of abnormal viscous swallows (OR = 9.00, CI = 2.15-80.0), although the presence of hypotensive or simultaneous water swallows was not associated with IEM (OR = 0.63, CI = 0.16-2.17) or pressurization (OR = 7.00, CI = 0.90-315.4) with viscous apple sauce. CONCLUSIONS: Apple sauce challenge increased identification of classifiable motor disorders in patients with dysphagia and may be preferred to alternative bolus materials.

Acute and chronic histological changes of the small bowel secondary to C. jejuni infection in a rat model for post-infectious IBS.

BACKGROUND: Campylobacter jejuni has been implicated in the pathogenesis of post-infectious irritable bowel syndrome (PI-IBS) in humans, effects which may be because of cytolethal distending toxin (CDT). In this study, we characterized both acute and chronic-phase histological changes of the small bowel in rats exposed to wild-type C. jejuni 81-176, or a strain that does not produce CDT, by using a validated rat model of PI-IBS. METHODS: Sprague-Dawley rats were given 1.0 × 10(8) CFU of either wild-type C. jejuni 81-176 (C+, PI/C+) or the CDT-negative strain (CDT-), or vehicle alone (Control). Acute-phase rats (C+, CDT-) were euthanized on days 2, 4, 8, 16, and 32. Chronic-phase rats (PI/C+, Control) were euthanized 3 months after clearing the initial infection. Segments of duodenum, jejunum, and ileum were resected and the contents plated for C. jejuni culture, and tissue sections were stained for histology. RESULTS: We observed preferential infection of the ileum and jejunum by Campylobacter jejuni. Compared with controls, epithelial cell basal membrane ballooning, villous tip disruption, and reduced villous-to-crypt ratios were observed for both C+ and CDT- rats. Villous widening, the only result significantly different in C+ vs. CDT- rats, was greatest at day 4 (134.1 ± 21.12 µm vs. 109.9 ± 10.6 µm for CDT-, P < 0.01). Little or no cellular inflammatory changes were seen during acute C. jejuni infection. Three months after clearing the initial infection, no histological changes remained. CONCLUSION: Significant histological changes, with the absence of inflammatory cells, are seen in the duodenum, jejunum, and ileum of rats during acute infection with C. jejuni. These changes occurred irrespective of the presence or absence of the CDT toxin.

Antibiotic prophylaxis prevents the development of a post-infectious phenotype in a new rat model of post-infectious IBS.

BACKGROUND: A recent post-infectious rat model with Campylobacter jejuni 81-176 has replicated the events noted in humans with post-infectious irritable bowel syndrome (IBS). In this study, we test whether prophylactic treatment with the antibiotic rifaximin will prevent the development of long-term altered bowel function in this model. METHODS: Sprague-Dawley rats were divided into two groups. Both groups were gavaged with a 1 mL solution of 10(8) cfu/mL of C. jejuni. However, one group was also prophylactically gavaged with a solution of rifaximin 200 mg per day for 3 days (the day before gavage, the day of gavage, and the day after gavage with C. jejuni). Fresh stool was collected from rats daily until two consecutive stool cultures were negative for C. jejuni. The rats were then housed for 3 months. At the end of 3 months, fresh stool was collected on three consecutive days to determine stool % wet weight and stool consistency on a stool score. RESULTS: Rats that received rifaximin antibiotic prophylaxis had a greater rate of stool shedding of C. jejuni. However, the mean duration of colonization was shorter in the rifaximin-treated group (10.3 ± 7.1 days) compared to rats receiving no prophylaxis (12.6 ± 5.9 days) (P < 0.01). After 3 months, rats that did not receive rifaximin had a greater variability in stool % wet weight (P < 0.01). Furthermore, the average stool consistency over 3 days of measurement was closer to normal in the rifaximin-treated rats, with a consistency of 1.1 ± 0.3, compared to 1.5 ± 0.4 in rats receiving no prophylaxis (P < 0.00001). CONCLUSIONS: Prophylactic treatment of rats with the antibiotic rifaximin in a new animal model of post-infectious IBS with C. jejuni mitigated the development of long-term altered stool form and function.

Liquid-Liquid Phase Separation of Short Histidine- and Tyrosine-Rich Peptides: Sequence Specificity and Molecular Topology.

The increasing realization of the prevalence of liquid-liquid phase separation (LLPS) across multiple length scales of biological constructs, from intracellular membraneless organelles to extracellular load-bearing tissues, has raised intriguing questions about intermolecular interactions regulating LLPS at the atomic level. Squid-beak derived histidine (His)- and tyrosine (Tyr)-rich peptides (HBpeps) have recently emerged as suitable short model peptides to precisely assess the roles of peptide motifs and single residues on the phase behavior and material properties of microdroplets obtained by LLPS. In this study, by systematically introducing single mutations in an HBpep, we have identified specific sticker residues that attract peptide chains together. We find that His and Tyr residues located near the sequence termini drive phase separation, forming interaction nodes that stabilize microdroplets. Combining quantum chemistry simulations with NMR studies, we predict atomic-level bond geometries and uncover inter-residue supramolecular interactions governing LLPS. These results are subsequently used to propose possible topological arrangements of the peptide chains, which upon expansion can help explain the three-dimensional network of microdroplets. The stability of the proposed topologies carried out through all-atom molecular dynamics simulations predicts chain topologies that are more likely to stabilize the microdroplets. Overall, this study provides useful guidelines for the de novo design of peptide coacervates with tunable phase behavior and material properties. In addition, the analysis of nanoscale topologies may pave the way to understand how client molecules can be trapped within microdroplets, with direct implications for the encapsulation and controlled release of therapeutics for drug delivery applications.

A combination of rifaximin and neomycin is most effective in treating irritable bowel syndrome patients with methane on lactulose breath test.

AIM: There is a growing interest in methane and its association with constipation in functional bowel disease. Neomycin-based treatment of methane-positive subjects has resulted in improvement of constipation. Rifaximin, although superior for the treatment of irritable bowel syndrome compared with other antibiotics, seems less effective in methane-positive subjects. In this study, we evaluate 3 different antibiotic treatments in patients who have a methane-positive breath test: rifaximin only, neomycin only, and the combination of neomycin and rifaximin. METHODS: A retrospective chart review was conducted on patients with methane on their lactulose breath test (> or =3 ppm of methane) who received one of the following antibiotic treatments: 500 mg b.i.d. for 10 days of neomycin alone, 400 mg t.i.d. for 10 days of rifaximin alone, or a combination of both rifaximin and neomycin for 10 days. All patients must have received antibiotic treatment after their initial consultation at the medical center and, in addition, had at least 1 follow-up to evaluate the effects of the treatment. After inclusion/exclusion criteria were met, all charts were evaluated to determine if the subject was a responder to the antibiotic therapy. This included clinical symptom improvement and eradication of methane on their breath test. RESULTS: Of the subjects receiving the treatment of rifaximin and neomycin (n=27), 85% had a clinical response, compared with 63% of subjects in the neomycin only group (n=8) (P=0.15) and 56% of subjects in the rifaximin only group (n=39) (P=0.01). When comparing the neomycin group with the rifaximin group, the difference was nonsignificant. When evaluating methane eradication results, 87% of subjects taking the rifaximin and neomycin combination eradicated the methane on their breath test. This is compared with 33% of subjects in the neomycin group that eradicated the methane (P=0.001), and only 28% of subjects in the rifaximin group (P=0.001). Of the patients who did not eliminate the methane with only rifaximin treatment, 66% of those who subsequently used the rifaximin and neomycin treatment were able to normalize their breath test. CONCLUSIONS: The combination of rifaximin and neomycin is more effective in treating methane-producing subjects-in both clinical response and methane elimination.

Polycystic ovary syndrome is associated with an increased prevalence of irritable bowel syndrome.

INTRODUCTION: Polycystic ovary syndrome (PCOS) affects 5-10% of reproductive-aged women. Irritable bowel syndrome (IBS) is a chronic intestinal disorder that affects up to 20% of adults, more often women. We evaluate if there is a relationship between these common conditions. METHODS: Polycystic ovary syndrome and control subjects were prospectively recruited. A questionnaire was given to determine their gastrointestinal symptoms. Body mass index (BMI) and percent body fat were also calculated. RESULTS: About 65 female subjects completed the study. Among the 36 PCOS patients, 15 subjects (42%) had IBS, compared to 3 subjects (10%) among controls (p < 0.01). Control subjects were leaner (BMI: 27.5 +/- 1.1 vs. 31.4 +/- 1.2 kg/m(2), p < 0.05) than PCOS patients. Among women with PCOS, those with IBS had a higher BMI (32.9 +/- 2.0 kg/m(2)) compared to those with PCOS but no IBS (30.3 +/- 1.6 kg/m(2)) and controls (27.5 +/- 1.1 kg/m(2); p < 0.05). This difference was true even after correcting for BMI and age (p < 0.01). CONCLUSIONS: Women with PCOS have a higher prevalence of IBS compared to healthy controls. When IBS is present with PCOS, a higher BMI and percent body fat is seen compared to PCOS alone.

Evaluating breath methane as a diagnostic test for constipation-predominant IBS.

Studies suggest that subjects with IBS have altered gut flora. Among these findings, methane production is more commonly associated with constipation-predominant symptoms. In this study, we prospectively evaluated the role of methane as a diagnostic test. Consecutive Rome I positive IBS patients referred for a lactulose breath test were eligible to participate. After exclusion criteria, subjects completed a symptom questionnaire grading bloating, diarrhea, and constipation on a VAS scale (0-100 mm). Once completed, a physician interviewed the subjects and rated the subject accordingly, and also determined whether the patient had C-IBS, D-IBS, or neither. Subjects and physicians were blinded to the results of the breath test. The presence of methane in the breath test was compared to the results of the scoring by subjects and physicians. A total of 56 Rome I positive IBS subjects were enrolled. During breath testing, 28 subjects produced methane. Good agreement between physician's evaluation and the patient's was seen (diarrhea = 0.69; constipation = 0.69; bloating = 0.62). The severity of constipation was noted to be greater in the methane group (49.3 +/- 28.7) than in the non-methane group (25.3 +/- 31.47) (P < 0.01). In contrast, diarrhea was less severe in the methane group (12.3 +/- 21.0) than the non-methane group (36.7 +/- 32.4) (P < 0.01). Out of the 56 patients, 23 C-IBS subjects were identified by the physician. When methane was used to predict the assignment of C-IBS compared to non-C-IBS, it had a sensitivity of 91.7% and a specificity of 81.3% (OR = 47.7, CI = 9.4-232, P < 0.00001). In conclusion, methane is a potential diagnostic test for the identification of C-IBS and may guide treatment.

New clinical method for distinguishing D-IBS from other gastrointestinal conditions causing diarrhea: the LA/IBS diagnostic strategy.

Modern methods of diagnosing diarrhea-predominant irritable bowel syndrome (D-IBS) require a "diagnosis of exclusion" approach. In this study we aim to test the diagnostic ability of using the fluctuation of frequency and consistency of bowel patterns in IBS to discriminate it from other causes of diarrhea. Eligible subjects were asked to complete a questionnaire on the changes in form and frequency of bowel habits by time. The primary endpoint was to evaluate the diagnostic effectiveness of having irregularly irregular bowel function and form as more characteristic of IBS versus non-IBS causes. Patients were prospectively recruited from a tertiary care GI clinic. Subjects had to have diarrhea as their primary complaint. In the case of IBS, D-IBS subjects were recruited. Subjects with celiac disease, Crohn's and ulcerative colitis were recruited for comparison and were categorically called "non-IBS." Non-IBS subjects could not have a recent history of blood in stool or a history of bowel surgery, fistulae or narcotic use. Sixty-two IBS and 37 non-IBS subjects were recruited. Among the 62 IBS subjects, 49 (79%) stated that their bowel habits varied in form and frequency on a daily basis compared to 35% in non-IBS subjects (OR = 8.9, CI = 3.5-22.5, P < 0.00001). When subjects were compared by the number of different stool forms they had witnessed in the prior week, IBS subjects noted 3.58 +/- 0.19 types and non-IBS reported 2.35 +/- 0.16 (P < 0.00001). Using > or = 3 stool forms per week as a method of discriminating IBS from non-IBS, 50 out of 62 subjects with IBS (81%) reported this greater number of forms compared to 15 out of 37 (41%) non-IBS subjects (sensitivity = 0.81; specificity = 0.60). The use of this simple tool that identifies an irregularly irregular bowel form and function is successful in separating D-IBS from non-IBS subjects.

Anticholinergic Drugs Interact With Neuroprotective Chaperone L-PGDS and Modulate Cytotoxicity of Aß Amyloids.

Anticholinergic drugs can be used as a treatment for many diseases. However, anticholinergic drugs are also known for their cognition-related side effects. Recently, there has been an increasing number of reports indicating a positive association between exposure to anticholinergic drugs and Alzheimer's disease (AD). Our novel study provides evidence of interactions between two representative anticholinergic drugs [Chlorpheniramine (CPM), a common antihistamine, and Trazodone (TRD), an antidepressant] with neuroprotective amyloid-beta (Aß) chaperone, lipocalin-type prostaglandin D synthase (L-PGDS) and the amyloid beta-peptide (1-40). Here, we demonstrate that CPM and TRD bind to L-PGDS with high affinity where chlorpheniramine exhibited higher inhibitory effects on L-PGDS as compared to Trazodone. We also show that the interactions between the drug molecules and Aß(1-40) peptides result in a higher fibrillar content of Aß(1-40) fibrils with altered fibril morphology. These altered fibrils possess higher cytotoxicity compared to Aß(1-40) fibrils formed in the absence of the drugs. Overall, our data suggest a mechanistic link between exposure to anticholinergic drugs and increased risk of Alzheimer's disease via inhibition of the neuroprotective chaperone L-PGDS and direct modification of Aß amyloid morphology and cytotoxicity.

Adherence and Outcomes with Urate-Lowering Therapy: A Site-Randomized Trial.

PURPOSE: The purpose of this study was to test a pharmacist-led intervention to improve gout treatment adherence and outcomes. METHODS: We conducted a site-randomized trial (n=1463 patients) comparing a 1-year, pharmacist-led intervention to usual care in patients with gout initiating allopurinol. The intervention was delivered primarily through automated telephone technology. Co-primary outcomes were the proportion of patients adherent (proportion of days covered ≥0.8) and achieving a serum urate <6.0 mg/dl at 1 year. Outcomes were reassessed at year 2. RESULTS: Patients who underwent intervention were more likely than patients of usual care to be adherent (50% vs 37%; odds ratio [OR] 1.68; 95% confidence interval [CI] 1.30, 2.17) and reach serum urate goal (30% vs 15%; OR 2.37; 95% CI 1.83, 3.05). In the second year (1 year after the intervention ended), differences were attenuated, remaining significant for urate goal but not for adherence. The intervention was associated with a 6%-16% lower gout flare rate during year 2, but the differences did not reach statistical significance. CONCLUSIONS: A pharmacist-led intervention incorporating automated telephone technology improved adherence and serum urate goal in patients with gout initiating allopurinol. Although this light-touch, low-tech intervention was efficacious, additional efforts are needed to enhance patient engagement in gout management and ultimately to improve outcomes.

Interrater and intrarater reliability of the wheelchair skills test version 4.2 for power wheelchair users.

PURPOSE: The purpose of this study is to estimate the interrater and intrarater reliability of the Wheelchair Skills Test (WST) Version 4.2 for powered wheelchairs operated by adult users. MATERIALS AND METHODS: Cohort study with a convenience sample of occupational therapists (n = 10). For the main outcome measure, participants viewed and scored eight videos of adult power wheelchair users completing the 30 skills of the WST Version 4.2 on two occasions, a minimum of two weeks apart. Using these scores, we calculated intraclass correlation coefficients to estimate interrater and intrarater reliability. RESULTS: The interrater reliability intraclass correlation coefficient was 0.940 (95%CI 0.862-0.985). Intrarater reliability intraclass correlation coefficients ranged from 0.923 to 0.998. CONCLUSIONS: The WST Version 4.2 has excellent interrater and intrarater reliability and is a reliable tool for use in clinical and research practice to evaluate a power wheelchair user's skill capacity. Implications for Rehabilitation The Wheelchair Skills Test for Powered Wheelchair Users (WST-P 4.2) is a useful addition to the clinical tools available for clinicians who assess and train for powered wheelchair use. The WST-P 4.2 has excellent reliability and potential for clinical use as a pre-post measure of powered wheelchair skills. Clinicians using the WST-P 4.2 should attempt to maintain consistent scoring procedures, particularly for those skills that may require subjective assessment of skill safety.

Rationale and design of the randomized evaluation of an Ambulatory Care Pharmacist-Led Intervention to Optimize Urate Lowering Pathways (RAmP-UP) Study.

BACKGROUND: Despite the availability of effective therapies, most gout patients achieve suboptimal treatment outcomes. Current best practices suggest gradual dose-escalation of urate lowering therapy and serial serum urate (sUA) measurement to achieve sUA<6.0mg/dl. However, this strategy is not routinely used. Here we present the study design rationale and development for a pharmacist-led intervention to promote sUA goal attainment. METHODS: To overcome barriers in achieving optimal outcomes, we planned and implemented the Randomized Evaluation of an Ambulatory Care Pharmacist-Led Intervention to Optimize Urate Lowering Pathways (RAmP-UP) study. This is a large pragmatic cluster-randomized trial designed to assess a highly automated, pharmacist-led intervention to optimize allopurinol treatment in gout. Ambulatory clinics (n=101) from a large health system were randomized to deliver either the pharmacist-led intervention or usual care to gout patients over the age of 18years newly initiating allopurinol. All participants received educational materials and could opt-out of the study. For intervention sites, pharmacists conducted outreach primarily via an automated telephone interactive voice recognition system. The outreach, guided by a gout care algorithm developed for this study, systematically promoted adherence assessment, facilitated sUA testing, provided education, and adjusted allopurinol dosing. The primary study outcomes are achievement of sUA<6.0mg/dl and treatment adherence determined after one year. With follow-up ongoing, study results will be reported subsequently. CONCLUSION: Ambulatory care pharmacists and automated calling technology represent potentially important, underutilized resources for improving health outcomes for gout patients.

Identification and evaluation of risk factors in patients with continuously uncontrolled hypertension.

An aggressive strategy to manage hypertension in a large integrated healthcare organization achieved blood pressure control in 82% of hypertensive patients, as compared with 52% nationwide. It is unknown why the remaining 18% is uncontrolled. The objective of this study was to identify characteristics associated with patients whose blood pressure remains continuously uncontrolled. This nested case-control study included 1583 continuously uncontrolled cases and 7901 matched controls. Univariate analysis revealed patients who visited their primary care provider frequently (odds ratio, 0.42; 95% confidence interval, 0.39-0.46) were adherent to antihypertensive medications (odds ratio, 0.12; 95% confidence interval, 0.10-0.14), and dispensed more medications (odds ratio, 0.86; 95% confidence interval, 0.85-0.87) were less likely to be continuously uncontrolled. Patient characteristics that were associated with continuously uncontrolled hypertension were the Patient Health Questionnaire-9 score and higher body mass index. Since patients with controlled hypertension visited their provider more often, patients with continuously uncontrolled hypertension may benefit from more interaction with their healthcare system.

Intestinal methane production in obese individuals is associated with a higher body mass index.

BACKGROUND: Obesity is an epidemic that affects 1 in 3 individuals in the United States, and recent evidence suggests that enteric microbiota may play a significant role in the development of obesity. This study evaluated the association between methanogenic archaea and obesity in human subjects. METHODS: Subjects with a body mass index (BMI) of 30 kg/m² or higher were prospectively recruited from the weight loss program of a tertiary care medical center. Subjects who met the study's inclusion criteria were asked to complete a questionnaire that included a series of visual analogue scores for bowel symptom severities. Subjects then provided a single end-expiratory breath sample to quantitate methane levels. Bivariate and multivariate analyses were used to determine associations with BMI. RESULTS: A total of 58 patients qualified for enrollment. Twenty percent of patients (n = 12) had breath test results that were positive for methane (>3 parts per million [ppm]), with a mean breath methane concentration of 12.2±3.1 ppm. BMI was significantly higher in methane-positive subjects (45.2±2.3 kg/m²) than in methane-negative subjects (38.5±0.8 kg/m²; P=.001). Methane-positive subjects also had a greater severity of constipation than methane-negative subjects (21.3±6.4 vs 9.5±2.4; P=.043). Multiple regression analysis illustrated a significant association between BMI and methane, constipation, and antidepressant use. However, methane remained an independent predictor of elevated BMI when controlling for antidepressant use (P<.001) and when controlling for both constipation and antidepressant use (6.55 kg/m² greater BMI; P=.003). CONCLUSION: This is the first human study to demonstrate that a higher concentration of methane detected by breath testing is a predictor of significantly greater obesity in overweight subjects.

Role of Cytolethal Distending Toxin in Altered Stool Form and Bowel Phenotypes in a Rat Model of Post-infectious Irritable Bowel Syndrome.

BACKGROUND/AIMS: Campylobacter jejuni infection is a leading cause of acute gastroenteritis, which is a trigger for post-infectious irritable bowel syndrome (PI-IBS). Cytolethal distending toxin (CDT) is expressed by enteric pathogens that cause PI-IBS. We used a rat model of PI-IBS to investigate the role of CDT in long-term altered stool form and bowel phenotypes. METHODS: Adult Sprague-Dawley rats were gavaged with wildtype C. jejuni (C+), a C. jejunicdtB knockout (CDT-) or saline vehicle (controls). Four months after gavage, stool from 3 consecutive days was assessed for stool form and percent wet weight. Rectal tissue was analyzed for intraepithelial lymphocytes, and small intestinal tissue was stained with anti-c-kit for deep muscular plexus interstitial cells of Cajal (DMP-ICC). RESULTS: All 3 groups showed similar colonization and clearance parameters. Average 3-day stool dry weights were similar in all 3 groups, but day-to-day variability in stool form and stool dry weight were significantly different in the C+ group vs both controls (P < 0.01) and the CDT- roup (P < 0.01), but were not different in the CDT- vs controls. Similarly, rectal lymphocytes were significantly higher after C. jejuni (C+) infection vs both controls (P < 0.01) and CDT-exposed rats (P < 0.05). The counts in the latter 2 groups were not significantly different. Finally, c-kit staining revealed that DMP-ICC were reduced only in rats exposed to wildtype C. jejuni. CONCLUSIONS: In this rat model of PI-IBS, CDT appears to play a role in the development of chronic altered bowel patterns, mild chronic rectal inflammation and reduction in DMP-ICC.

ICC density predicts bacterial overgrowth in a rat model of post-infectious IBS.

AIM: To investigate the interstitial cells of Cajal (ICC) number using a new rat model. METHODS: Sprague-Dawley rats were assigned to two groups. The first group received gavage with Campylobacter jejuni (C. jejuni) 81-176. The second group was gavaged with placebo. Three months after clearance of Campylobacter from the stool, precise segments of duodenum, jejunum, and ileum were ligated in self-contained loops of bowel that were preserved in anaerobic bags. Deep muscular plexus ICC (DMP-ICC) were quantified by two blinded readers assessing the tissue in a random, coded order. The number of ICC per villus was compared among controls, Campylobacter recovered rats without small intestinal bacterial overgrowth (SIBO), and Campylobacter recovered rats with SIBO. RESULTS: Three months after recovery, 27% of rats gavaged with C. jejuni had SIBO. The rats with SIBO had a lower number of DMP-ICC than controls in the jejunum and ileum. Additionally there appeared to be a density threshold of 0.12 DMP-ICC/villus that was associated with SIBO. If ileal density of DMP-ICC was < 0.12 ICC/villus, 54% of rats had SIBO compared to 9% among ileal sections with > 0.12 (P < 0.05). If the density of ICC was < 0.12 DMP-ICC/villus in more than one location of the bowel, 88% of these had SIBO compared to 6% in those who did not (P < 0.001). CONCLUSION: In this post-infectious rat model, the development of SIBO appears to be associated with a reduction in DMP-ICC. Further study of this rat model might help understand the pathophysiology of post-infectious irritable bowel syndrome.