Severe Hypomagnesemia Caused by Proton-Pump Inhibitors in a Patient With an Ostomy

Proton pump inhibitors (PPIs) are commonly used for many gastrointestinal issues, such as gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger-Ellison syndrome. Many patients are on life-long daily therapy with this class of medications. The adverse effects of long-term use of PPI have been studied, and over the last two decades, a link between hypomagnesemia and PPI has been established. In addition, other electrolyte derangements can also ensue, such as hypokalemia and hypocalcemia. Losses through the gastrointestinal or renal systems may also be responsible for this electrolyte disturbance. In this case, we present a "perfect storm" of a patient who, in addition to having ongoing gastrointestinal losses through an ostomy, had severe hypomagnesemia to less than 1 mg/dL compounded by PPI use. Through its unique mechanism of action on intestinal epithelial cells, PPI use in certain settings can potentially be catastrophic. Severe hypomagnesemia may manifest as tetany, convulsions, tremors, arrhythmias, or torsades de pointes.

Exploring the pathogenesis of osteomyelitis accompanied by diabetic foot ulcers using microarray data analysis

Although numerous studies have shown distinctive similarities between osteomyelitis and diabetic foot ulcers (DFU), the common pathogenesis of both is not fully understood. The current research focuses on an in-depth study of the molecular and pathway mechanisms involved in the complication of these 2 diseases. We downloaded clinical information on osteomyelitis (GSE30119) and DFU (GSE29221) from the GEO database, along with gene expression matrices. Differentially expressed genes (DEGs) among normal individuals and patients with osteomyelitis; normal individuals and patients with DFU were identified by R software, and thus common DEGs were confirmed. We then analyzed these differential genes, including the functional pathway analysis, protein-protein interaction (PPI), modules and hub genes establishment, and transcription factor regulatory networks. We identified 109 common DEGs (46 up-regulated and 63 down-regulated genes) for subsequent analysis. The results of PPI network and the functional pathway analysis revealed the importance of immune response and inflammatory response in both diseases. Among them, chemokines and cytokines were found to be closely related to both osteomyelitis and DFU. In addition, the tumor necrosis factor (TNF) pathway and Staphylococcus aureus infection were found to have more significant roles too. The 12 most essential key genes were later screened by cytoHubba, including matrix metalloproteinases (MMP) 1, MMP3, MMP9, IL8, C-X-C chemokine receptor (CXCR) 2, C-X-C motif chemokine ligand (CXCL) 9, CXCL10, CXCL13, FCGR3B, IL1B, LCN2, S100A12. CXCL10, and MMP1 were validated using the least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) algorithms. Osteomyelitis and DFU share similar molecular and pathway mechanisms. These common key genes and pathways may provide new directions toward the future study of osteomyelitis and DFU.

Effectiveness of Omeprazole in Acid Peptic Disease: A Real-World, Patient-Reported Outcome Measures Study

Objectives This prospective study assessed the effectiveness and patient satisfaction of four-week omeprazole therapy in acid peptic disease (APD). Methods This was an observational, post-marketing, real-world evidence, patient-reported outcome (PRO) measures study. Patients visiting the five study sites across India with symptoms of APD, and who were prescribed oral omeprazole (20/40 mg per day) for at least four weeks were enrolled after obtaining informed consent. Study assessments included frequency and severity of symptoms and overall satisfaction reported by the patients using the Patient Assessment of Gastrointestinal Disorder Symptom Severity Index (PAGI-SYM) questionnaire. The satisfaction with therapy was reported by the patients using the Treatment Satisfaction Questionnaire for Medication (TSQM) questionnaire. Both PAGI-SYM and TSQM were reported by patients on days 14 and 28. Omeprazole safety was assessed based on the adverse events reported by the patients. Results A total of 96 (62 males and 34 females) patients were included in the study, of which 38.54% had significant findings related to APD at baseline. The proportion of patients with symptoms reduced to 16.67% on day 14 and 8.33% on day 28 with omeprazole therapy. The PAGI-SYM total scores at baseline were 41.32 (15.487), which reduced to 20.86 (11.620) on day 14 (p < 0.0001), and to 8.93 (8.361) on day 28 (p < 0.0001). Significant reductions were also seen in individual symptom scores. The TSQM total scores increased to 36.67 (range: 13 to 63) on day 28 from 34.69 (range: 12 to 58) on day 14. Improvement in scores for all domains of TSQM (effectiveness, convenience, and global satisfaction) was seen on day 28. Improvement in reflux symptoms was reported by 46.74% and 68.48% of patients on day 14 and day 28, respectively. Four (4.17%) patients reported adverse events, which were of mild severity and were unrelated to omeprazole. Conclusions Omeprazole provides significant improvement in PAGI-SYM and TSQM questionnaires on day 14 and day 28. Patients reported the omeprazole-based therapy as effective, convenient, and satisfactory. Omeprazole therapy is safe and effective for the treatment of APD and shows good improvement in APD in patients suffering from duodenal ulcers, gastric ulcers, and reflux oesophagitis.

Effectiveness of Proton Pump Inhibitor Therapy in the Prevention of Bleeding After Prophylactic Endoscopic Variceal Band Ligation

Background Endoscopic variceal ligation (EVL) is a surgical intervention that can work well to curb variceal bleeding in people with liver cirrhosis. However, it could make ulcer bleeding worse and be fatal in some cases. The widespread use of proton pump inhibitors (PPI) in cirrhotic individuals with variceal bleeding is empirical rather than based on scientific data. According to many studies, PPIs reduce the size of post-EVL ulcers. This study aimed to see if PPI use could reduce rebleeding after endoscopy therapy in cirrhotic patients with variceal bleeding. Methodology A retrospective cross-sectional study was conducted at a tertiary care hospital from August 2019 to September 2021. Cirrhotic patients with bleeding gastroesophageal varices (GEVs) who had undergone EVL at the same hospital were enrolled in the study. Medical records were organized, and the sample was divided into two groups based on whether or not PPI was given. Both PPI and non-PPI patients had their endoscopic findings, initial hemostasis outcomes, rebleeding rates, bleeding-related mortality rates, and treatment-related comorbidities compared. Results A total of 46 patients were selected for the study and divided into two groups (PPI group n=28 and non-PPI group n=18). The majority of the patients were males. The PPI group had a mean age of 58.6 ±7.8 years, whereas the non-PPI group had a mean age of 53.6 ±4.4 years. Hepatitis B virus (HBV) infection was the most prevalent cause of cirrhosis in both groups. After endoscopic treatment, three patients (16%) in the non-PPI group suffered a variceal hemorrhage. Bleeding-related fatalities and the time it took for the bleeding to stop varied significantly between the two groups. History of variceal bleeding (relative risk (RR)=1.45; 95% confidence interval (CI), 1.60-7.67; p=0.02), presence of gastric varices (RR=2.23; 95% CI, 2.56-9.832; p=0.035), and not administering PPIs (RR =7.542; 95% CI, 3.98-29.13; p=0.008) were linked with rebleeding. The presence of red concurrent esophageal varices (RR=6.37; 95% CI, 0.562-15.342; p=0.002) and failure to provide PPIs (RR=2.3; 95% CI, 1.621-25.64; p=0.04) were linked with post-EVL bleeding in a multivariate analysis. Conclusions Proton pump inhibitors reduce the occurrence of early bleeding and adverse events after EVL in cirrhotic patients. Not prescribing PPIs and the presence of GEVs were substantially related to a higher risk of bleeding during preventative EVL. Not initiating PPI medication immediately was the sole predictor of bleeding complications in patients who had undergone EVL without gastric varix treatment. To lower the risk of post-EVL ulcer bleeding, we recommend PPI use in patients undergoing EVL.

The influence of pretreatment with PPI on Helicobacter pylori eradication: A systematic review and meta-analysis

BACKGROUND

In this meta-analysis, we aimed to comprehensively investigate the impact of pretreatment with proton pump inhibitor (PPI) on Helicobacter pylori (H. pylori) eradication and provide novel inspiration to clinical practice.

METHODS

Relevant studies were selected through PubMed, Embase, and Cochrane Library from inception to March 2021. Two reviewers performed the selection independently. The primary outcome of the meta-analysis was the eradication rate. A modified Jadad scale was used to evaluate literature quality quantitatively.

RESULTS

Ten studies were included in this research. The results showed no significant difference between PPI pretreatment and standard treatment on eradication of H. pylori [relative risk (RR): 1.17, 95% confidence interval (95% CI): 0.0.73-1.88]. There was no significant difference between the PPI pretreatment group and the standard therapy group for conventional triple therapy, PPI and amoxicillin and clarithromycin (RR: 1.29, 95% CI: 0.60-2.77). Similar results were obtained in the therapy strategy of PPI and amoxicillin and metronidazole (RR: 3.01, 95% CI: 0.62-14.74). Interestingly, for the therapy regimen of PPI and clarithromycin and metronidazole, PPI pretreatment indicated superiority on H. pylori eradication rate (RR: 0.48, 95% CI: 0.23-0.97, P < .05).

CONCLUSION

PPI pretreatment did not affect the H. pylori eradication rates, regardless of the various types of bacteriostatic antibiotic, except the therapy regimen of PPI and clarithromycin and metronidazole.

Plausible Role of Asthma Biological Modifiers in the Treatment of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a T-helper type-2 (Th2/T2) cell-mediated disease characterized by 15 or more eosinophils per high-powered esophageal biopsy microscopy field (eos/hpf), excluding other causes. EoE is often clinically characterized by symptoms such as dysphagia, nausea, food impaction, and chest pain that do not respond to antacids. Two-thirds of patients are unresponsive to proton pump inhibitors (PPIs). Steroids may be effective but pose long-term health risks and can lose efficacy in patients with serum eosinophilia greater than 1,500 cells/µL. Because EoE is not IgE-mediated, allergy skin testing for food may benefit a subset of patients. These therapies have shortcomings, which necessitate further investigation. Herein, we report a patient successfully treated with benralizumab (anti-IL-5Rα), demonstrating a potential solution to the lack of effective treatments for EoE.

A Retrospective Review of Upper Gastrointestinal Bleed Outcomes During Hospital Admission While on Oral Anticoagulation

Introduction

Direct-acting oral anticoagulants (DOACs) are approved for stroke prevention in non-valvular atrial fibrillation and treatment of venous thromboembolism. Most recent guidelines recommend DOACs over warfarin for most diagnoses given their predictable pharmacodynamics, lack of required monitoring, and safety profile. Specific outcomes such as shock, acute renal failure, and blood transfusion requirement while on oral anticoagulation compared to no anticoagulation remain unknown in patients with upper gastrointestinal (GI) bleeds. 

Methods

This retrospective study used the HCA Healthcare Enterprise Data Warehouse (EDW) to analyze 13,440 patients aged >18 years that were admitted with an upper GI bleed from January 2017 to December 2019. The patients were categorized based on oral anticoagulant (i.e. rivaroxaban, apixaban, dabigatran and warfarin). The control group was patients admitted with an upper GI bleed not on oral anticoagulation. We evaluated the severity of upper GI bleeds while on oral anticoagulation based on the outcomes: mortality rate, length of stay, acute renal failure, shock, and need for packed red blood cell transfusions (pRBC). Comorbid conditions assessed were coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), heart failure (HF), atrial fibrillation (AF), venous thromboembolism (VTE), peripheral vascular disease (PVD), tobacco abuse, alcohol abuse, and chronic kidney disease (CKD). Home use of proton pump inhibitors (PPI), aspirin, and P2Y12 inhibitors were also evaluated. 

Results

Patients on a DOAC without home PPI have a mortality odds ratio of 3.066 with a confidence interval (CI) greater than 95% (1.48-6.26, p<0.05) compared to patients on a DOAC and home PPI. Patients on warfarin and no home PPI have a mortality odds ratio of 5.55 (95% CI (1.02-30.35), p<0.05) compared to those on warfarin with home PPI use. In the no anticoagulation group, those not on PPI have an odds ratio of 3.28 (95% CI (2.54-4.24), p<0.05) of death compared to home PPI use. There was no statistical difference in mortality between each DOAC and warfarin. 

There was no difference in the presence of acute renal failure or shock when comparing each DOAC, warfarin, and no medication. For patients presenting with GI bleed, 0.8414 units of pRBC were transfused. Patients not on oral anticoagulation were found to have statistically significant decrease in pRBC transfusion if they did not report alcohol use, CKD, HF, AF, VTE, PVD. Patients on DOACs and alcohol use have an average pRBC transfusion count that is 0.922 units more than those without reported alcohol use (p=0.006). In the warfarin group, there was no statistical significance noted when comparing pRBC transfusions and also when comparing to baseline comorbidities.

Conclusion

The retrospective study leads us to conclude that overall, patients taking the DOACs or warfarin had no statistically significant increase in RBC transfusions, length of stay, shock, acute renal failure, or mortality rate compared to patients who were not on oral anticoagulation. Home PPI use was shown to lower odds of mortality in patients on anticoagulation who presented with upper GI bleeding. PPI use had no effect on the need for transfusion or length of stay in patients on anticoagulation. These results can help predict which patients are likely to have higher mortality based on the use of home PPIs.

A Randomized Open-Label Study of Two Methods of Proton Pump Inhibitors Discontinuation

Background

Proton pump inhibitors (PPIs) are effective in treating gastroesophageal reflux disease (GERD). Unfortunately, they are often inappropriately prescribed and long-term use has potential adverse effects. A single best method for discontinuation of PPIs does not currently exist. The objective of this study was to determine if there is a significant difference in successfully discontinuing PPI use at 12 months between patients discontinuing abruptly or tapering first.

Methodology

We conducted a randomized trial with 38 patients diagnosed with GERD. We collected six weekly and then monthly surveys of symptoms based on the Dyspepsia Symptom Severity Index. Chart review at 12 months determined whether the patient was able to discontinue PPI.

Results

A Kaplan-Meier survival analysis at 12 months did not show a statistically significant difference between the abrupt and taper groups for discontinuation of PPI medication (p = 0.75). Cox regression analysis showed no association of alcohol use, smoking, or caffeine use with failure to discontinue PPI, but H2 blocker use was associated with a 79% reduction in risk of failure to discontinue PPI (p = 0.004). The taper group had significantly less symptoms 14, 18, 22, and 30 weeks after discontinuation.

Conclusions

Our study suggests that there is no difference in successful discontinuation of PPIs between abrupt and taper methods at 12 months; however, there are less symptoms in the taper method, and H2 blocker use is associated with success. Further study is needed with larger numbers of participants and randomization of H2 blocker use.

Do the types and routes of proton pump inhibitor treatments affect clostridium difficile in ICU patients? A retrospective cohort study

Background: : Proton pump inhibitors (PPI) are associated with Clostridium difficile infection (CDI). Impact of the route of administration is unknown.Research Design and Methods: Patients in Multiparameter Intelligent Monitoring in Intensive Care II database (MIMIC-II) from 2001 to 2008, >18 years old, admitted to medical, surgical, or cardiac ICUs were included. PPI exposures were omeprazole, esomeprazole, lansoprazole, and pantoprazole. PPI administration routes were oral or intravenous. Patients who received histamine receptor antagonists (H2RA) were the control arm. CDI was identified using ICD-9 diagnostic code 008.45. Multiple logistic regression analysis was performed to calculate odds ratios (OR).Results: The study included 16,820 patients (57% male) with a mean age of 63 (SD±17) years and hospitalization duration of 10.2 days (SD±11). Pantoprazole was the most common PPI (94%). CDI occurred in 2.4% and more in patients receiving PPIs than H2RAs (3.0% vs. 0.8%, p < 0.001). CDI prevalence increased with intravenous (95%CI = 1.69-3.39, OR 2.4) and oral (95%CI = 1.59-3.27, OR 2.3) PPI use compared to H2RAs. CDI prevalence was not associated with PPI route in the multivariable model (OR 1.07, 95%CI 0.86-1.34).Conclusions: Both intravenous and oral PPI use in the ICU were independently associated with CDI.

Drug rash with eosinophilia and systemic symptoms and severe renal injury induced by proton pump inhibitor therapy: A case report

INTRODUCTION

Proton pump inhibitors (PPIs) are widely prescribed and generally well tolerated but can rarely cause severe allergic reactions, such as drug rash with eosinophilia and systemic symptoms (DRESS). We report a case of DRESS and renal injury induced by PPIs, and describe the therapeutic process.

PATIENT CONCERNS

The patient was a 66-year-old female who complained of fever, pruritus, desquamation, erythema multiforme, and anuria caused by omeprazole taken for 2 weeks to treat abdominal distention.

DIAGNOSIS

The clinical history revealed a similar episode of PPI-induced fever, eosinophilia, and acute kidney injury more than 1 year ago. The present laboratory tests revealed eosinophilia and oliguric renal failure. The renal biopsy was performed subsequently and proved the diagnosis of PPI-induced DRESS.

INTERVENTIONS

After the suspected diagnosis of PPI-induced DRESS, omeprazole was discontinued and methylprednisolone infusion (40 mg qd) was initiated. Because of oliguric renal failure, the patient received intermittent hemodialysis.

OUTCOMES

The patient initially responded to omeprazole discontinuation, hemodialysis, and glucocorticoids but later died from severe infection during the tapering of glucocorticoid therapy.

CONCLUSION

Clinicians should remain on high alert for potential life-threatening complications when prescribing PPIs. If unexplained renal injury develops in a patient taking a PPI, renal biopsy may help in identifying the pathogenesis and might facilitate timely intervention.

Fr-PPIChem: An Academic Compound Library Dedicated to Protein-Protein Interactions

Protein-protein interactions (PPIs) mediate nearly every cellular process and represent attractive targets for modulating disease states but are challenging to target with small molecules. Despite this, several PPI inhibitors (iPPIs) have entered clinical trials, and a growing number of PPIs have become validated drug targets. However, high-throughput screening efforts still endure low hit rates mainly because of the use of unsuitable screening libraries. Here, we describe the collective effort of a French consortium to build, select, and store in plates a unique chemical library dedicated to the inhibition of PPIs. Using two independent predictive models and two updated databases of experimentally confirmed PPI inhibitors developed by members of the consortium, we built models based on different training sets, molecular descriptors, and machine learning methods. Independent statistical models were used to select putative PPI inhibitors from large commercial compound collections showing great complementarity. Medicinal chemistry filters were applied to remove undesirable structures from this set (such as PAINS, frequent hitters, and toxic compounds) and to improve drug likeness. The remaining compounds were subjected to a clustering procedure to reduce the final size of the library while maintaining its chemical diversity. In practice, the library showed a 46-fold activity rate enhancement when compared to a non-iPPI-enriched diversity library in high-throughput screening against the CD47-SIRPα PPI. The Fr-PPIChem library is plated in 384-well plates and will be distributed on demand to the scientific community as a powerful tool for discovering new chemical probes and early hits for the development of potential therapeutic drugs.

Reducing the Inappropriate Use of Proton Pump Inhibitors in an Internal Medicine Residency Clinic

Introduction

Proton pump inhibitors (PPI) are commonly prescribed in the primary care setting. While generally considered to be safe, there is growing evidence suggesting that PPI misuse is associated with a variety of significant adverse outcomes and unnecessary cost. The goal of this quality improvement project was to identify patients with non-guideline recommended PPI prescriptions in our internal medicine residency clinics and implement a process to de-prescribe or reduce the dose of PPIs across this patient population.

Methods

PPI prescription rates, dosage, and indication were extracted from the medical records of all 854 patients empaneled to the internal medicine residency clinics at a multicenter closed referral military hospital system. Appropriate PPI indication was consensus based upon published guidelines, and patients without an appropriate indication were targeted for intervention. These patients were directly contacted by their primary care physicians, via phone or during a clinic visit, to discuss the risks and benefits of ongoing PPI use as well as alternative therapies or tapering regimens at the physician’s discretion. For moderate to high dose PPI, the dose was decreased by 50% every week until the lowest tolerated dose was achieved or until discontinuation. For low dose PPI, discontinuation was recommended as the initial intervention. Six months following the intervention, the empanelment was reevaluated for ongoing PPI usage, tapered dosage, or discontinuation.

Results

Of a total of 854 patient records reviewed at the initiation of the project, 322 patients were noted to be prescribed PPIs. Of this subset, 66% (217/322) did not meet a guideline recommended indication for their use. At the completion of the six-month intervention period, 44% (96/217) of patients were successfully weaned to a reduced dose or were no longer using a PPI.

Conclusions

PPIs are widely used and generally considered to be a well-tolerated therapy for acid-secretion disorders. PPI overprescription and the associated adverse effects and economic burden are increasingly recognized. We show that a simple, focused, resident-driven quality improvement intervention can be effective in de-prescribing efforts to reduce inappropriate PPI use in the outpatient primary care setting.

Proton pump inhibitors and hypomagnesemia: A meta-analysis of observational studies

BACKGROUND

Previous meta-analyses have suggested that there might be an association between the use of proton pump inhibitors (PPIs) and the development of hypomagnesemia, although the conclusions were no definitive.

METHODS

To provide an update on this topic, we performed a meta-analysis of all observational studies that examined the association between the use of PPIs and the development of hypomagnesemia. A literature search was conducted in MEDLINE, Scopus and Cochrane Central Register of Controlled Trials (January 1970 to June 2018) to identify observational studies that examined the association between the use of PPIs and the incidence and prevalence of hypomagnesemia.

STUDY ELIGIBILITY CRITERIA

In the absence of randomized controlled trials, we focused primarily on observational studies, including cross-sectional, case-control, retrospective, and prospective cohort studies. There was no limitation on sample size or study duration. Random-effect models meta-analyses were used to compute pooled unadjusted and adjusted odds ratios (ORs) for binary variables.

RESULTS

Sixteen observational studies were identified, including 13 cross-sectional studies, 2 case-control studies, and 1 cohort study, with a total of 131,507 patients. The pooled percentage of PPI users was 43.6% (95% confidence interval [CI] 25.0%, 64.0%). Among PPI users, 19.4% (95% CI 13.8%, 26.5%) had hypomagnesemia compared to 13.5% (95% CI 7.9%, 22.2%) among nonusers. By meta-analysis, PPI use was significantly associated with hypomagnesemia, with a pooled unadjusted OR of 1.83 (95% CI 1.26, 2.67; P = .002) and a pooled adjusted OR of 1.71 (95% CI 1.33, 2.19; P < .001). In subgroup analyses, high-dose PPI use was associated with higher odds for hypomagnesemia relative to low-dose PPI use (pooled adjusted OR 2.13; 95% CI 1.26, 3.59; P = .005).

CONCLUSION

Our findings are in support of the results of the previous meta-analyses. Furthermore, we found a dose-response between the PPI use and development of hypomagnesemia.

Practice styles, knowledge and attitudes of general practitioners and gastroenterology specialists who treat gastroesophageal reflux disease

As little is known on the subject, our aim was to compare practice styles, knowledge and attitudes of general practitioners (GPs), and gastroenterology specialists (GIs) regarding the treatment of gastroesophageal reflux disease (GERD).An internet survey designed by the authors was sent nationwide and randomly to 290 GIs and 1312 GPs. We assessed for the burden of GERD, indications for referral for a GI consultation, criteria for proton pump inhibitors (PPIs) selection, and main unmet treatment needs.Forty (14%) GIs and 132 (10%) GPs returned the questionnaire. Both groups treat 13 to 14 GERD patients weekly (mean age 41-50 years). The most common first and second line drug of choice in both groups was omeprazole and esomeprazole, respectively. GIs stated that the most important consideration for the selection of treatment was high safety profile, whereas GPs considered it to be a rapid symptomatic relief. In the case of first and second line PPI failures, GIs tended to prescribe a non PPI treatment, whereas GPs restarted esomeprazole. GIs stated that the most prevalent conceived limitations of PPI treatment were nighttime heartburn and undesirable side effects, whereas GPs considered treatment inflexibility and drug interactions.GIs and GPs hold different practice styles, knowledge, and attitudes on the treatment of GERD. Our findings ascertain the need for the development of updated National Clinical Guidelines focusing on GERD.

Evidence-based patient/public voice: a patient and public involvement audit in the field of sexual health

BACKGROUND

The National Health Institute constitution enshrines the central role of patient and public involvement (PPI) in order to place patients at the heart of the NHS. The sexual health field presents unique challenges for PPI in the tension between current PPI practice versus the need for confidentiality/feelings of shame/stigma. However, there is little evidence around the goals, evaluation measures or theoretical underpinnings of PPI.

OBJECTIVES

In order to improve current PPI practice in the sexual health field, audits were carried out on PPI plans in both service and research sectors.

METHODS

18 local sexual health service contacts completed the audit through snowballing. The tool was refined and five research projects completed the audit from the Health Protection Research Unit in BloodBorne and Sexually Transmitted Infections. Responses were collated and a thematic analysis by two independent researchers carried out. Common areas for improvement were identified.

RESULTS

Audit tool responses evidenced wide variability in practice. Issues included conflation of PPI work and qualitative research; limited 'patient satisfaction' approaches; lack of PPI goals; methodological reliance on 'visible' methods such as focus groups; lack of responsiveness around patient needs and poor resourcing of PPI work. Research specific issues included 'late' PPI after key decisions had been made and poor lay summary validity.

DISCUSSION

Two audits evidenced a range of areas for improvement of PPI practice in sexual health. Clear definition of 'what PPI is for' aligned with evaluation measures would begin to build an evidence base for the contribution of patient voice.

Functional connectivity in the social brain across childhood and adolescence

Previous research has characterized a collection of neural regions which support social-cognitive processes. While this 'social brain' is often described as a cohesive unit, it has been largely assessed with univariate methodologies, which cannot account for functional relationships 'between' brain regions, and therefore cannot test the idea of the social brain as a network. In the present work, we utilized a multi-method approach to empirically assess the functional architecture of the social brain. Fifty participants (ages 8-16) completed a social evaluation task during an functional imaging scan. Results from three unique functional connectivity methodologies demonstrated that social brain regions show strong functional relationships, while also interfacing with non-social regions, suggesting that future work should consider network relationships between social brain regions in addition to traditional univariate approaches. We probed, but did not find age-related differences in social brain network organization, demonstrating that this functional architecture is in place by late childhood.

Maintenance therapy with proton pump inhibitors and risk of gastric cancer: a nationwide population-based cohort study in Sweden

OBJECTIVE

Proton pump inhibitors (PPIs) are among the most commonly prescribed drugs. Concerns have been raised about a potentially increased risk of gastric cancer following long-term use. Our aim is to assess the risk of gastric cancer associated with PPI use, taking into account underlying indications.

DESIGN

This is a population-based cohort study. Standardised incidence ratios (SIRs) and 95% CIs were calculated to compare the risk of gastric cancer among long-term PPI users with the corresponding background population, while taking confounding by indication into account.

SETTING

Population-based study in Sweden (2005-2012).

PARTICIPANTS

This study included virtually all adults residing in Sweden exposed to maintenance therapy with PPIs.

EXPOSURE/INTERVENTION

Maintenance use of PPIs, defined as at least 180 days during the study period. Maintenance use of histamine 2 receptor antagonist was evaluated for comparison reasons.

OUTCOME MEASURES

Gastric cancer (cardia and non-cardia), and subgroup analysis for gastric adenocarcinoma, as defined by the Swedish Cancer Registry.

RESULTS

Among 797 067 individuals on maintenance PPI therapy, the SIR of gastric cancer was over threefold increased (SIR=3.38, 95% CI 3.23 to 3.53). Increased SIRs were found in both sexes and all age groups, but were especially increased among PPI users younger than 40 years (SIR=22.76, 95% CI 15.94 to 31.52). Increased SIRs were found for each indication studied, including those without an association with gastric cancer, for example, gastro-oesophageal reflux (SIR=3.04, 95% CI 2.80 to 3.31), and those with a supposedly decreased risk, for example, aspirin users (SIR=1.93, 95% CI 1.70 to 2.18). The association was similar for cardia and non-cardia gastric cancer. Analyses restricted to adenocarcinoma showed similar results to those for all gastric cancers. Long-term users of histamine 2 receptor antagonists, which have the same indications as PPIs, were not at any increased risk.

CONCLUSIONS

Long-term PPI use might be an independent risk factor for gastric cancer. This challenges broad maintenance PPI therapy, particularly if the indication is weak.

Pantoprazole, a proton pump inhibitor, does not prevent botulinum toxin induced disuse osteopenia in mice

OBJECTIVES

Pantoprazole is a proton pump inhibitor that has been shown to inhibit bone resorption. The aim of the study was to investigate whether pantoprazole can prevent development of botulinum toxin (BTX)-induced disuse osteopenia in mice.

METHODS

Forty-eight 16-week-old female C57BL/6J mice were randomized into 4 groups (n=12): Base, Ctrl, BTX, and BTX+Pan. The Base group was euthanized at study start. The BTX and BTX+Pan groups were immobilized by injections with BTX in one hind limb. The BTX+Pan group was injected i.p. daily with 100 mg pantoprazole per kg bodyweight. The mice were euthanized after 3 weeks of treatment. The skeletal status was investigated by DEXA, µCT, mechanical testing, dynamic bone histomorphometry, and RT-qPCR. The bone sites investigated were tibia, femur, L5 vertebra, and humerus.

RESULTS

Injections of BTX induced a pronounced and significant loss of bone density, microstructure, and strength in the immobilized hind limb. Furthermore, the localized intramuscular injections of BTX lead to a slight loss of bone and bone strength at the L5 vertebra and humerus. Treatment with pantoprazole did not have any bone protective or deleterious effects.

CONCLUSION

Pantoprazole was unable to prevent the development of BTX induced disuse osteopenia in skeletally mature female C57BL/6J mice.

Assessing the Risk of Hospital-Acquired Clostridium Difficile Infection With Proton Pump Inhibitor Use: A Meta-Analysis

BACKGROUND Clostridium difficile is the principal infectious cause of antibiotic-associated diarrhea and accounts for 12% of hospital-acquired infections. Recent literature has shown an increased risk of C. difficile infection (CDI) with proton pump inhibitor (PPI) use. OBJECTIVE To conduct a systematic assessment of the risk of hospital-acquired CDI following exposure to PPI. METHODS We searched multiple databases for studies examining the relationship between PPI and hospital-acquired CDI. Pooled odds ratios were generated and assessment for heterogeneity performed. RESULTS We found 23 observational studies involving 186,033 cases that met eligibility criteria. Across studies, 10,307 cases of hospital-acquired CDI were reported. Significant heterogeneity was present; therefore, a random effects model was used. The pooled odds ratio was 1.81 (95% CI, 1.52-2.14), favoring higher risk of CDI with PPI use. Significant heterogeneity was present, likely due to differences in assessment of exposure, study population, and definition of CDI. DISCUSSION This meta-analysis suggests PPIs significantly increase the risk of hospital-acquired CDI. Given the significant health and economic burden of CDI and the risks of PPI, optimization of PPI use should be included in a multifaceted approach to CDI prevention. Infect Control Hosp Epidemiol 2016;1408-1417.

Gating Deficit Heritability and Correlation With Increased Clinical Severity in Schizophrenia Patients With Positive Family History

OBJECTIVE

The Consortium on the Genetics of Schizophrenia Family Study evaluated 12 primary and other supplementary neurocognitive and neurophysiological endophenotypes in schizophrenia probands and their families. Previous analyses of prepulse inhibition (PPI) and P50 gating measures in this sample revealed heritability estimates that were lower than expected based on earlier family studies. Here the authors investigated whether gating measures were more heritable in multiply affected families with a positive family history compared with families with only a single affected proband (singleton).

METHOD

A total of 296 nuclear families consisting of a schizophrenia proband, at least one unaffected sibling, and both parents underwent a comprehensive endophenotype and clinical characterization. The Family Interview for Genetic Studies was administered to all participants and used to obtain convergent psychiatric symptom information for additional first-degree relatives. Among the families, 97 were multiply affected, and 96 were singletons.

RESULTS

Both PPI and P50 gating displayed substantially increased heritability in the 97 multiply affected families (47% and 36%, respectively) compared with estimates derived from the entire sample of 296 families (29% and 20%, respectively). However, no evidence for heritability was observed for either measure in the 96 singleton families. Schizophrenia probands derived from the multiply affected families also displayed a significantly increased severity of clinical symptoms compared with those from singleton families.

CONCLUSIONS

PPI and P50 gating measures demonstrate substantially increased heritability in schizophrenia families with a higher genetic vulnerability for illness, providing further support for the commonality of genes underlying both schizophrenia and gating measures.

Meclizine enhancement of sensorimotor gating in healthy male subjects with high startle responses and low prepulse inhibition

Histamine H1 receptor systems have been shown in animal studies to have important roles in the reversal of sensorimotor gating deficits, as measured by prepulse inhibition (PPI). H1-antagonist treatment attenuates the PPI impairments caused by either blockade of NMDA glutamate receptors or facilitation of dopamine transmission. The current experiment brought the investigation of H1 effects on sensorimotor gating to human studies. The effects of the histamine H1 antagonist meclizine on the startle response and PPI were investigated in healthy male subjects with high baseline startle responses and low PPI levels. Meclizine was administered to participants (n=24) using a within-subjects design with each participant receiving 0, 12.5, and 25 mg of meclizine in a counterbalanced order. Startle response, PPI, heart rate response, galvanic skin response, and changes in self-report ratings of alertness levels and affective states (arousal and valence) were assessed. When compared with the control (placebo) condition, the two doses of meclizine analyzed (12.5 and 25 mg) produced significant increases in PPI without affecting the magnitude of the startle response or other physiological variables. Meclizine also caused a significant increase in overall self-reported arousal levels, which was not correlated with the observed increase in PPI. These results are in agreement with previous reports in the animal literature and suggest that H1 antagonists may have beneficial effects in the treatment of subjects with compromised sensorimotor gating and enhanced motor responses to sensory stimuli.

Aberrant amygdala-frontal cortex connectivity during perception of fearful faces and at rest in generalized social anxiety disorder

BACKGROUND

Generalized social anxiety disorder (gSAD) is characterized by exaggerated amygdala reactivity to social signals of threat, but if and how the amygdala interacts with functionally and anatomically connected prefrontal cortex (PFC) remains largely unknown. Recent evidence points to aberrant amygdala connectivity to medial PFC in gSAD at rest, but it is difficult to attribute functional relevance without the context of threat processing. Here, we address this by studying amygdala-frontal cortex connectivity during viewing of fearful faces and at rest in gSAD patients.

METHODS

Twenty patients with gSAD and 17 matched healthy controls (HCs) participated in functional magnetic resonance imaging of an emotional face matching task and a resting state task. Functional connectivity and psychophysiological interaction analysis were used to assess amygdala connectivity.

RESULTS

Compared to HCs, gSAD patients exhibited less connectivity between amygdala and the rostral anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) while viewing fearful faces. gSAD patients also showed less connectivity between amygdala and rostral ACC at rest in the absence of fearful faces. DLPFC connectivity was negatively correlated with LSASFear (where LSAS is Liebowitz Social Anxiety Scale).

CONCLUSIONS

Task and rest paradigms provide unique and important information about discrete and overlapping functional networks. In particular, amygdala coupling to DLPFC may be a phasic abnormality, emerging only in the presence of a social predictor of threat, whereas amygdala coupling to the rostral ACC may reflect both phasic and tonic abnormalities. These findings prompt further studies to better delineate intrinsic and externally evoked brain connectivity in anxiety and depression in relation to amygdala dysfunction.

Behavioral, neurochemical and morphological changes induced by the overexpression of munc18-1a in brain of mice: relevance to schizophrenia

Overexpression of the mammalian homolog of the unc-18 gene (munc18-1) has been described in the brain of subjects with schizophrenia. Munc18-1 protein is involved in membrane fusion processes, exocytosis and neurotransmitter release. A transgenic mouse strain that overexpresses the protein isoform munc18-1a in the brain was characterized. This animal displays several schizophrenia-related behaviors, supersensitivity to hallucinogenic drugs and deficits in prepulse inhibition that reverse after antipsychotic treatment. Relevant brain areas (that is, cortex and striatum) exhibit reduced expression of dopamine D(1) receptors and dopamine transporters together with enhanced amphetamine-induced in vivo dopamine release. Magnetic resonance imaging demonstrates decreased gray matter volume in the transgenic animal. In conclusion, the mouse overexpressing brain munc18-1a represents a new valid animal model that resembles functional and structural abnormalities in patients with schizophrenia. The animal could provide valuable insights into phenotypic aspects of this psychiatric disorder.

Prepulse inhibition in patients with fragile X-associated tremor ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late onset neurodegenerative disorder that affects carriers of the fragile X premutation, typically after age 50. Common symptoms include intention tremor, ataxia, neuropathy, autonomic dysfunction, cognitive decline, and dementia. The objectives of this study were to determine if patients with FXTAS have altered prepulse inhibition (PPI; a measure of sensorimotor gating), and to study possible correlations between PPI, molecular status, and cognitive performance. A passive acoustic PPI paradigm was applied in 163 subjects; 121 carriers of the fragile X premutation, and 42 healthy controls. There were significant differences in PPI between premutation carriers with FXTAS and controls at PPI 60 ms, and at 120 ms. This effect was more prominent in the male FXTAS patients. There was a tendency to an impaired PPI in female premutation carriers at the 120 ms condition. There was a significant correlation between the PPI deficit and a higher CGG repeat number. The results show an impairment in sensorimotor gating processes in male carriers of the fragile X premutation, which is more prominent in patients with FXTAS.

Unconditioned responses and functional fear networks in human classical conditioning

Human imaging studies examining fear conditioning have mainly focused on the neural responses to conditioned cues. In contrast, the neural basis of the unconditioned response and the mechanisms by which fear modulates inter-regional functional coupling have received limited attention. We examined the neural responses to an unconditioned stimulus using a partial-reinforcement fear conditioning paradigm and functional MRI. The analysis focused on: (1) the effects of an unconditioned stimulus (an electric shock) that was either expected and actually delivered, or expected but not delivered, and (2) on how related brain activity changed across conditioning trials, and (3) how shock expectation influenced inter-regional coupling within the fear network. We found that: (1) the delivery of the shock engaged the red nucleus, amygdale, dorsal striatum, insula, somatosensory and cingulate cortices, (2) when the shock was expected but not delivered, only the red nucleus, the anterior insular and dorsal anterior cingulate cortices showed activity increases that were sustained across trials, and (3) psycho-physiological interaction analysis demonstrated that fear led to increased red nucleus coupling to insula but decreased hippocampus coupling to the red nucleus, thalamus and cerebellum. The hippocampus and the anterior insula may serve as hubs facilitating the switch between engagement of a defensive immediate fear network and a resting network.

Group II mGluR agonist LY354740 and NAAG peptidase inhibitor effects on prepulse inhibition in PCP and D-amphetamine models of schizophrenia

RATIONALE

Group II metabotropic glutamate receptor (mGluR) agonists represent a novel approach to the treatment of schizophrenia. Inasmuch as the peptide neurotransmitter N-acetylaspartylglutamate (NAAG) activates these receptors, NAAG peptidase inhibitors conceptually represent a parallel path toward development of new antipsychotic drugs. While group II agonists are effective in several animal models of schizophrenia, they are reported to lack efficacy in moderating the effects of phencyclidine (PCP) on prepulse inhibition of acoustic startle in animal models of sensory processing deficits found in this disorder.

OBJECTIVE

The objective of this study was to re-examine the efficacy of a group II metabotropic glutamate agonist and NAAG peptidase inhibitors in prepulse inhibition models of schizophrenia across two strains of mice.

METHODS

The method used was an assay to determine the efficacy of these drugs in moderating the reduction in prepulse inhibition of acoustic startle in mice treated with PCP and D: -amphetamine.

RESULTS

The group II agonist LY354740 (5 and 10 mg/kg) moderated the effects of PCP on prepulse inhibition of acoustic startle in DBA/2 but not C57BL/6 mice. In contrast, two NAAG peptidase inhibitors, ZJ43 (150 mg/kg) and 2-PMPA (50, 100, and 150 mg/kg), did not significantly affect the PCP-induced reduction in prepulse inhibition in either strain.

CONCLUSIONS

These data demonstrate that the efficacy of group II agonists in this model of sensory motor processing is strain-specific in mice. The difference between the effects of the group II agonist and the peptidase inhibitors in the DBA/2 mice may relate to the difference in efficacy of NAAG and the agonist at mGluR2.

Lack of relationship between acoustic startle and cognitive variables in schizophrenia and control subjects

Measures of acoustic startle such as prepulse inhibition (PPI) and startle latency have been found to be impaired in schizophrenia, and are commonly thought to be related to cognitive deficits in this disease. However, findings about the relationship between startle variables and cognitive performance have been equivocal. In this study, we examined correlations between startle measures (baseline startle magnitude, latency, habituation and PPI) and cognitive performance (using the Benton Visual Retention Test, Conner's Continuous Performance Test, California Verbal Learning Test, Finger Tapping Test, and Wisconsin Card Sort Test) in 107 schizophrenia patients and 94 healthy controls. Overall, there was a lack of any significant relationship between these constructs in both populations when correcting for multiple comparisons. This suggests that alterations in startle measures seen in schizophrenia may not reflect elements of information processing that cause cognitive deficits in the disease.

Serotonin1A receptor deletion does not interact with maternal separation-induced increases in startle reactivity and prepulse inhibition deficits

RATIONALE

Early life stress is a risk factor for the development of psychopathology in later life. Consequences of adverse life events, however, may depend on the genetic makeup of an individual. Reduced serotonin(1A) receptor function may predispose to the development of anxiety disorders.

OBJECTIVE

Determine susceptibility of serotonin(1A) receptor knockout (1AKO) mice on different background strains to the effects of maternal separation (MS) by assessing startle plasticity in adulthood.

METHODS

1AKO mice on a 129S6 and a Swiss Webster (SW) background were used. MS groups were separated daily from their mother for 180 min/day from postnatal days 2 to 14. Control groups underwent normal animal facility rearing. In adulthood, effects on acoustic startle response, habituation, prepulse inhibition (PPI), and foot shock sensitization were determined.

RESULTS

MS increased startle reactivity and reduced PPI in 129S6 mice. These effects of MS were independent of genotype. MS had no effect on the other readouts. In SW mice, MS had no consistent effect on startle reactivity and did not alter startle plasticity in wild type or in 1AKO mice. 1AKO mice did not differ from wild-type mice in startle plasticity.

CONCLUSION

Serotonin(1A) receptor deletion does not enhance vulnerability to the effects of MS on startle plasticity. The life-long increase in startle reactivity and PPI deficit induced by MS are strain-dependent. Further, the use of startle reactivity and plasticity may have added value in translational studies relating to early life stress.

eFIP: a tool for mining functional impact of phosphorylation from literature

Technologies and experimental strategies have improved dramatically in the field of genomics and proteomics facilitating analysis of cellular and biochemical processes, as well as of proteins networks. Based on numerous such analyses, there has been a significant increase of publications in life sciences and biomedicine. In this respect, knowledge bases are struggling to cope with the literature volume and they may not be able to capture in detail certain aspects of proteins and genes. One important aspect of proteins is their phosphorylated states and their implication in protein function and protein interacting networks. For this reason, we developed eFIP, a web-based tool, which aids scientists to find quickly abstracts mentioning phosphorylation of a given protein (including site and kinase), coupled with mentions of interactions and functional aspects of the protein. eFIP combines information provided by applications such as eGRAB, RLIMS-P, eGIFT and AIIAGMT, to rank abstracts mentioning phosphorylation, and to display the results in a highlighted and tabular format for a quick inspection. In this chapter, we present a case study of results returned by eFIP for the protein BAD, which is a key regulator of apoptosis that is posttranslationally modified by phosphorylation.

MYBBP1A: a new Ipr1's binding protein in mice

Infection with mycobacterium tuberculosis (MTB) can cause different outcomes in hosts with variant genetic backgrounds. Previously, we identified an intracellular pathogen resistance 1 (Ipr1) gene with the role of resistance of MTB infection in mice model. However, until now, its binding proteins have been little known even for its human homology, SP110. In this study, the homology for mouse Ipr1 in canines was found to have an extra domain structure, h.1.5.1. And 30 potential candidate proteins were predicted to bind canine Ipr1, which were characterized of the interacting structure with the h.1.5.1. Among them, MYBBP1A was verified to bind with both Ipr1 and eGFP-Ipr1 in mouse macrophage J774A.1 clone 21 cells using co-immunoprecipitation method. And with the constructed high-confidence Ipr1-involved network, we suggested that Ipr1 might be involved in apoptosis pathway via MYBBP1A.

Prepulse inhibition in fragile X syndrome: feasibility, reliability, and implications for treatment

Pharmacological rescue of behavioral, cognitive and synaptic abnormalities in the animal models of fragile X syndrome (FXS) has prompted the initiation of clinical trials of targeted treatments in humans with this condition. Objective, well-validated outcome measures that are reflective of FXS deficits and can be modeled similarly in animal and human studies are urgently needed. A protocol measuring prepulse inhibition (PPI) of the startle reflex, including measures of test-retest stability, was evaluated in 61 individuals with the fragile X full mutation (40 males and 21 females; 19.18 +/- 7.18 years) and 63 age-matched normal controls (35 males and 28 females; 20.83 +/- 6.96 years) across two laboratory sites with identical equipment and protocols. Relative to controls, the fragile X group had PPI impairment of 26%, 22%, and 28% for 60, 120, and 240 ms prepulse interval trial types, respectively, P = 0.000002. PPI test-retest reliability in 29 of the participants was excellent for the 120 ms prepulse interval trials (intraclass correlations: FXS, 0.85; controls, 0.88, 0.89 overall). This study demonstrates the feasibility and reliability of PPI measurement in a developmentally disabled population and highlights its potential as an outcome measure to test the efficacy of targeted neurotherapeutic agents.

Chronic reductions in serotonin transporter function prevent 5-HT1B-induced behavioral effects in mice

BACKGROUND

Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts, images, or impulses and/or repetitive stereotypical behavior. Obsessive-compulsive disorder patients exhibit reduced prepulse inhibition (PPI) and symptom exacerbation after challenge with 5-HT1B receptor agonists. Recently, gain-of-function alleles of the serotonin transporter (5-HTT) have been associated with OCD. We tested the hypothesis that reducing 5-HTT function chronically, either genetically or via serotonin reuptake inhibitor (SRI) treatment, attenuates PPI deficits and perseverative hyperlocomotion induced by 5-HT1B agonists in mice.

METHODS

Mice received subchronic or chronic pretreatment with the SRI fluoxetine and acute treatment with RU24969 (5-HT1A/1B agonist) or 8-OH-DPAT (5-HT1A agonist) and were assessed for PPI, locomotor activity, and spatial patterns of locomotion. The same measures were evaluated in 5-HTT wild-type (WT), heterozygous (HT), and knockout (KO) mice after RU24969 treatment. The effects of WAY100635 (5-HTA antagonist) or GR127935 (5-HT1B/D antagonist) pretreatment on RU24969-induced effects were evaluated. Finally, 5-HT1B binding and functional coupling were assessed in 5-HTT-WT, -HT, and -KO mice, and normal fluoxetine-treated mice.

RESULTS

Chronic, but not subchronic, fluoxetine treatment prevented RU24969-induced PPI deficits and perseverative hyperlocomotion. These RU24969-induced effects were mediated via 5-HT1B and not 5-HT1A receptors. 5-HTT-KO mice showed no effects of RU24969, and 5-HTT-HT mice exhibited intermediate phenotypes. 5-HT1B binding and functional coupling were reduced in the globus pallidus and substantia nigra of 5-HTT-KO mice.

CONCLUSIONS

Our results demonstrate that chronic, but not subchronic, fluoxetine treatment and 5-HTT knockout robustly attenuate 5-HT1B agonist-induced PPI deficits and perseverative hyperlocomotion. These results may have implications for the etiology and treatment of OCD.

Profile of auditory information-processing deficits in schizophrenia

Schizophrenia patients exhibit abnormalities in several different auditory event-related potential (ERP) measures. It is unclear how these abnormalities relate to each other, since multiple measures are rarely acquired from the same sample. This study addressed two related questions: 1) Are specific auditory ERP measures differentially impaired in schizophrenia? 2) Do abnormalities co-aggregate within the same patients? Nine auditory ERP measures were acquired in a single testing session from 23 schizophrenia patients and 22 healthy subjects. Hierarchical oblique factor analysis revealed that these measures aggregated into four factors, with each loading primarily on a single factor. Patient deficits were observed for two independent factors: N100/mismatch negativity (MMN) and P3a/P3b. N100/MMN abnormalities were associated with symptoms of alogia and formal thought disorder. P3a/P3b abnormalities were associated with avolition, attentional disturbances and delusions. We conclude that deficits in different ERP measures of early sensory processing at the level of the auditory cortex co-occur in patients. These likely represent a single differential deficit indexing the physiological abnormality underlying impaired language and verbal processing. This is relatively independent of a higher cortical deficit that mediates cognitive stimulus evaluation and underlies deficits in motivation, attention and reality testing. Such multidimensional profiling of ERP abnormalities may help to clarify the clinical and genetic heterogeneity of schizophrenia.

Prepulse inhibition of startle in adults with ADHD

Prepulse inhibition of startle (PPI) is a measure of sensorimotor gating, a pre-conscious regulator of attention. PPI is impaired in adults with schizophrenia and several other neuropsychiatric disorders associated with attentional abnormalities. The core feature of ADHD involves deficits in attention and, like schizophrenia, ADHD is associated with dysregulation of cortical-striatal circuits and dopamine transmission. Therefore, PPI may be disrupted in ADHD. While ADHD persists into adulthood in approximately half the children with ADHD, there has not been any published report of PPI in ADHD adults. In this study, PPI was measured in a sample of ADHD adults and compared to a sample of healthy comparison (HC) subjects. Twenty unmedicated adults with ADHD (11 inattentive subtype, 9 combined subtype) and 17 HC subjects were administered an eyeblink startle PPI paradigm. The PPI of ADHD adults was not significantly different from that of HC subjects in any of the PPI conditions. There was no significant effect of ADHD subtype nor of gender. The lack of PPI deficits in ADHD adults has important implications and suggests that, despite the presence of PPI dysregulation in a large number of disparate neuropsychiatric disorders, it is not a general feature of all neuropsychiatric disorders with attention abnormalities. Furthermore, the attentional deficiency in ADHD may have a neurobiological substrate somewhat distinct from schizophrenia and other neuropsychiatric disorders that are associated with PPI deficits. This distinction may be related to a relative sparing of pre-conscious attentional functions in ADHD compared to other disorders with PPI impairment.

Nicotine effect on prepulse inhibition and prepulse facilitation in schizophrenia patients

Acoustic prepulse inhibition (PPI) is considered an important biomarker in animal studies of psychosis and a number of psychiatric conditions. Nicotine has been shown to improve acoustic PPI in some animal strains and in humans. However, there is little data on effects of nicotine on acoustic PPI in schizophrenia patients using a double-blind, placebo-controlled study design. The primary aim of the current study was to test the effect of nicotine nasal spray on acoustic PPI in schizophrenia patients. The secondary aim was to test nicotine effect on prepulse facilitation (PPF). The study included 18 schizophrenia patient smokers and 12 healthy control smokers, tested in a double-blind, placebo-controlled, crossover, randomized design immediately after nicotine or saline placebo nasal sprays. PPI was tested using 120 ms prepulse-pulse interval. PPF was tested using 4500 ms prepulse-pulse interval. The results showed a significant main effect of drug on PPI in that nicotine improved PPI compared to placebo (p=0.008) with no drug by diagnosis interaction (p=0.90). Improvement in PPI in response to nicotine was significantly correlated with the baseline severity of clinical symptoms (r=0.59, p=0.02) in patients. There was no significant drug or drug by diagnosis interaction for the 4500 ms prepulse-pulse interval condition. However, nicotine improved inhibition in a subgroup of subjects exhibiting PPF (p=0.002). In conclusion, the findings confirmed that nicotine transiently improves acoustic PPI in schizophrenia patients. Additionally, schizophrenia patients with more clinical symptoms may have benefited more from nicotinic effect on PPI.

Evidence of missense mutations on the neuregulin 1 gene affecting function of prepulse inhibition

BACKGROUND

Neuregulin 1 (NRG1) is one of the leading candidate genes in schizophrenia. Rodents with NRG1 knock-out showed significantly impaired prepulse inhibition (PPI) in the original report linking NRG1 to schizophrenia. A widely used surrogate measure of psychosis in animal models, PPI is considered a schizophrenia endophenotype. We hypothesized that if NRG1 influences PPI in rodents, then it should have a similar effect on PPI in humans.

METHODS

We examined the potential neurophysiological effects of two nonsynonymous single nucleotide polymorphisms located on NRG1 (rs3924999 and rs10503929) on PPI. Genotyping was completed in 430 unrelated individuals, including 244 schizophrenia cases and 186 controls. PPI was available in a subgroup of 113 cases and 63 controls.

RESULTS

Rs3924999 genotype was significantly associated with PPI (p = .003): PPI was lowest in the subjects who were homozygous for the minor allele A/A carriers, intermediate in A/G carriers, and highest in homozygous major alleles G/G carriers. The associations persisted within cases (p = .02) and controls (p = .02) analyzed separately. An additive model suggested that rs3924999 alone contributes to 7.9% of the PPI variance. In contrast, rs10503929 genotype was not associated with PPI (p = .85). Schizophrenia patients had reduced PPI compared to control subjects (p = .04). Neither single nucleotide polymorphism was associated with schizophrenia (all p > .37). However, schizophrenia patients with abnormal PPI may be associated with rs3924999 (p = .05).

CONCLUSIONS

A missense mutation on rs3924999 of the neuregulin 1 gene may have a functional effect on prepulse inhibition in both schizophrenia and healthy control populations.

Short-term treatment of gastroesophageal reflux disease

OBJECTIVE

To investigate the efficacy of acid suppressant drugs in the empirical treatment of gastroesophageal reflux disease (GERD) and in the treatment of endoscopy-negative reflux disease (ENRD).

DESIGN

medline, embase, and the Cochrane Controlled Trials Register were searched. Bibliographies were reviewed.

SETTING

Studies were eligible that compared the short-term use of proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) with each other or with placebo in adults with GERD who were enrolled irrespective of endoscopic findings (empirical cases) or in whom endoscopy showed no signs of esophagitis (endoscopy-negative cases).

MEASUREMENTS

Of 1,408 studies, only 13 could be included for meta-analysis. Data on 3,433 patients empirically treated for GERD and 2,520 patients treated for ENRD were extracted. The primary endpoint was relief of heartburn.

MAIN RESULTS

In the empirical treatment of GERD, the summary relative risk (sRR) for symptom relief from H2RAs versus placebo was 0.77 (95% confidence interval [95% CI], 0.60 to 0.99). RR in the only placebo-controlled PPI trial was 0.35 (95% CI, 0.26 to 0.46). The sRR for standard dose PPIs versus H2RAs was 0.55 (95% CI, 0.44 to 0.68). In treatment of ENRD, both PPIs (sRR, 0.64; 95% CI, 0.52 to 0.79) and H2RAs (sRR, 0.78; 95% CI, 0.62 to 0.97) were superior to placebo, and PPIs were superior to H2RAs (sRR, 0.81; 95% CI, 0.70 to 0.95).

CONCLUSIONS

Acid suppressant therapy (with a PPI or an H2RA) is more effective than placebo for short-term relief of heartburn in patients with persistent symptoms who are treated empirically for GERD and in those in whom esophagitis was excluded after endoscopy. The benefit of PPIs compared with H2RAs is more pronounced in patients treated empirically.

Ligand-independent assembly of recombinant human CD1 by using oxidative refolding chromatography

CD1 is an MHC class I-like antigen-presenting molecule consisting of a heavy chain and beta(2)-microglobulin light chain. The in vitro refolding of synthetic MHC class I molecules has always required the presence of ligand. We report here the use of a folding method using an immobilized chaperone fragment, a protein disulphide isomerase, and a peptidyl-prolyl cis-trans isomerase (oxidative refolding chromatography) for the fast and efficient assembly of ligand-free and ligand-associated CD1a and CD1b, starting with material synthesized in Escherichia coli. The results suggest that "empty" MHC class I-like molecules can assemble and remain stable at physiological temperatures in the absence of ligand. The use of oxidative refolding chromatography thus is extended to encompass complex multisubunit proteins and specifically to members of the extensive, functionally diverse and important immunoglobulin supergene family of proteins, including those for which a ligand has yet to be identified.