845 Diabetic Foot Care Services in COVID-19 Era – A University Hospital Multi specialty Team Experience

Introduction

Multidisciplinary foot care services contribute to the reduction in amputations from foot ulceration secondary to diabetes. The COVID-19 pandemic pressurised services and required a pause of elective care. This study reports the patient’s experience of foot care provision during the first wave where self-care, virtual appointments and patient directed appointments were utilised.

Method

Diabetic foot patients were retrospectively identified over a one-month period booked for MDT care (in hospital, OPD, diabetic foot clinic, community podiatry clinic or at home). All patients>16 years of age diagnosed with a new or previous diabetic foot ulcer or post-operative foot wound were included. Data was collated via a patient survey form and descriptive statistics were used to characterize the study population and responses.

Results

63 patients were identified (1/10 – 30/10) with data collated from 51 respondents (81%). 78% (40/51) were male. Median age was 69 years (IQR 59–76). 86% were comfortable attending a hospital appointment. 92% reported continuing to receive an appropriate level of care. All of the patients felt well supported and knew how to access the foot care service. 29% utilised virtual care. 82% (42/51) considered face to face appointments were more suitable for follow up rather than virtual/phone appointments.

Conclusions

It was possible to continue to provide safe diabetic foot care despite the COVID-19 pandemic but careful patient selection and communication is the key.

Microfluidic Enabling Platform for Cell-based Assays

We have developed proprietary technologies for executing continuous flow assays in biochips which mimic human capillaries. Such technologies are integral to the rapidly growing laboratory instrumentation sector for applications in drug discovery, biotechnology, medical diagnostics and environmental studies. A common link between all sectors is the movement toward miniaturization to increase throughput, accuracy and efficiency in the development of new drugs. The miniaturization process itself leads to a demand for new instruments and tools capable of handling microlitre quantities of biological fluids and reagents, thus, we present an instrument which is capable of doing so in the form of a microfluidic enabling platform.

Effect of Disease Severity in Asthma and Chronic Obstructive Pulmonary Disease on Inhaler-Specific Inhalation Profiles Through the ELLIPTA® Dry Powder Inhaler

BACKGROUND

Two studies were undertaken to characterize the maximal effort inhalation profiles of healthy subjects and patients with asthma or chronic obstructive pulmonary disease (COPD) through a moderate-resistance dry powder inhaler (DPI). Correlations between inhaler-specific inhalation characteristics and inhaler-independent lung function parameters were investigated.

METHODS

Healthy subjects (n = 15), patients with mild, moderate, or severe asthma (n = 45), and patients with mild, moderate, severe, or very-severe COPD (n = 60) were included in the studies. Inhalation pressure drop versus time profiles were recorded using an instrumented ELLIPTA® DPI or bespoke resistor component with equivalent resistivity. Inhaler-independent lung function assessments included pharyngometry, spirometry, plethysmography, and diffusion.

RESULTS

For the inhaler-specific inhalation profiles, the mean maximal effort peak inspiratory flow rates (PIFRs) varied across the subgroups from 65.8-110.6 L/min (range: 41.6-142.9). Peak pressure drop, PIFR, inhaled volume, and average inhalation flow rate (primary endpoints) did not differ markedly between healthy subjects and patients with asthma or mild COPD. Moderate, severe, and very-severe COPD patients demonstrated lower mean peak pressure drops, PIFRs and inhaled volumes, which tended to decrease with increasing COPD severity. Severe and very-severe COPD patients demonstrated shorter mean inhalation times compared with all other participants. Inhaler-independent lung function parameters were consistent with disease severity, and statistically significant (p < 0.05) strong correlations (R > 0.7) with components of the inhaler-specific inhalation profiles were observed in the COPD cohort; correlations in the asthma cohort tended to be weaker.

CONCLUSIONS

All participants achieved a maximal effort PIFR ≥ 41.6 L/min through the moderate resistance of the ELLIPTA inhaler. Patients with asthma achieved similar inhalation profiles to healthy subjects, but increasing COPD severity tended to reduce a patient's inhalation capability. Correlation analyses suggest that some lung function parameters may be a useful indicator of ability to inhale efficiently through a moderate-resistance DPI, such as the ELLIPTA inhaler.

Effect of severe renal impairment on umeclidinium and umeclidinium/vilanterol pharmacokinetics and safety: a single-blind, nonrandomized study

Background

Umeclidinium and vilanterol, long-acting bronchodilators for the treatment of chronic obstructive pulmonary disease, are primarily eliminated via the hepatic route; however, severe renal impairment may adversely affect some elimination pathways other than the kidney.

Objectives

To evaluate the effect of severe renal impairment on the pharmacokinetics of umeclidinium and umeclidinium/vilanterol.

Methods

Nine patients with severe renal impairment (creatinine clearance <30 mL/min) and nine matched healthy volunteers received a single dose of umeclidinium 125 μg; and after a 7- to 14-day washout, a single dose of umeclidinium/vilanterol 125/25 μg.

Results

No clinically relevant increases in plasma umeclidinium or vilanterol systemic exposure (area under the curve or maximum observed plasma concentration) were observed following umeclidinium 125 μg or umeclidinium/vilanterol 125/25 μg administration. On average, the amount of umeclidinium excreted in 24 hours in urine (90% confidence interval) was 88% (81%–93%) and 89% (81%–93%) lower in patients with severe renal impairment compared with healthy volunteers following umeclidinium 125 μg and umeclidinium/vilanterol 125/25 μg administration, respectively. Treatments were well tolerated in both populations.

Conclusion

Umeclidinium 125 μg or umeclidinium/vilanterol 125/25 μg administration to patients with severe renal impairment did not demonstrate clinically relevant increases in systemic exposure compared with healthy volunteers. No dose adjustment for umeclidinium and umeclidinium/vilanterol is warranted in patients with severe renal impairment.

Articulating the value of health research

Previous contributions to Quarterly Journal of Medicine have drawn attention to the work of FEAM, the Federation of European Academies of Medicine, in collaboration with others, in exploring and explaining the issues that will ensure an appropriate European Union (EU) policy framework for health research and innovation. In this article, we present a proposal for an archive of important research conducted in the EU that will act as a resource for illustrating and guiding the development of the necessary regulatory framework.

A randomized, placebo- and moxifloxacin-controlled thorough QT study of umeclidinium monotherapy and umeclidinium/vilanterol combination in healthy subjects

INTRODUCTION

The long-acting muscarinic antagonist umeclidinium (UMEC) and the combination of UMEC with the long-acting beta2 agonist vilanterol (VI) are approved maintenance treatments for chronic obstructive pulmonary disease in the US and EU.

OBJECTIVES

This study investigated the effect of UMEC and UMEC/VI on the QT interval corrected using Fridericia's correction (QTcF) following a 10-day treatment period.

METHODS

Randomized, placebo- and moxifloxacin-controlled, 4-period incomplete block crossover study of healthy non-smokers (n = 103). All treatments were double blind, except for moxifloxacin/moxifloxacin placebo controls which were single blinded. Subjects were randomized to a treatment sequence which consisted of 4 of 5 regimens. Each regimen consisted of once-daily doses on Days 1-10 via the ELLIPTA™ dry powder inhaler and a single tablet on Day 10 of the following: placebo + placebo; placebo + moxifloxacin; UMEC 500 μg + placebo; UMEC/VI 125/25 μg (delivered dose: 113/22 μg) + placebo; UMEC/VI 500/100 μg + placebo. QT interval, additional cardiac parameters, pharmacokinetics, pharmacodynamics and safety were assessed.

RESULTS

No clinically significant changes from baseline in QTcF occurred with UMEC 500 μg and UMEC/VI 125/25 μg compared with placebo, however, there was a change in QTcF from baseline of 6.4 ms (90% confidence interval [CI]: 4.3, 8.5) at 10 min and 8.2 ms (90%: 6.2, 10.2) at 30 min post dose following UMEC/VI 500/100 μg compared with placebo. On Day 10, categorical analysis demonstrated absolute QTcF values >450-480 ms for UMEC/VI 125/25 μg (1 subject) and moxifloxacin (3 subjects), and a change from baseline QTcF of >30-60 ms for UMEC/VI 125/25 μg, UMEC 500/100 μg and placebo (1 subject each) and moxifloxacin (2 subjects). On Day 10, the mean change from baseline in heart rate was increased with UMEC/VI 125/25 μg and UMEC 500/100 μg compared with placebo with the maximum increase occurring at 10 min post dose (8.4 bpm [90% CI: 7.0, 9.8] for UMEC/VI 125/25 μg; 20.3 bpm [90% CI: 18.9, 21.7] for UMEC/VI 500/100 μg); after this timepoint, heart rate rapidly returned to normal levels. UMEC and VI systemic exposures following UMEC/VI 500/100 μg were >4-fold higher than those following UMEC/VI 125/25 μg. All treatments were generally well tolerated in terms of adverse events, laboratory, vital signs and electrocardiogram data; the proportion of subjects with any adverse event was similar across treatments arms (39-59%)..

CONCLUSION

There was no clinically significant effect on QTcF observed following 10-days' treatment with inhaled UMEC/VI 125/25 μg or UMEC 500 μg compared with placebo. The supratherapeutic dose of UMEC/VI 500/100 μg prolonged QTcF by 6.4 ms (90% CI: 4.3, 8.5) at 10 min and 8.2 ms (90% CI: 6.2, 10.2) at 30 min compared with placebo, following which QTcF interval difference from placebo declined rapidly..

Effect of verapamil on systemic exposure and safety of umeclidinium and vilanterol: a randomized and open-label study

Background

The combination of umeclidinium (UMEC), a long-acting muscarinic receptor antagonist, and vilanterol (VI), a selective long-acting β₂ agonist, is in development for the treatment of chronic obstructive pulmonary disease (COPD). This study evaluated the pharmacokinetics, safety and tolerability, and pharmacodynamics of once-daily, inhaled UMEC and UMEC/VI when co-administered with oral verapamil, a moderate P-glycoprotein transporter and moderate cytochrome P450 3A4 (CYP3A4) inhibitor frequently used by patients with COPD and cardiovascular comorbidities.

Methods

Subjects were randomized to one of two 13-day treatment regimens: UMEC 500 μg or UMEC 500 μg/VI 25 μg. All subjects received a single tablet containing 240 mg verapamil on each of days 9–13.

Results

Repeat doses of UMEC and UMEC/VI in combination with and without verapamil were safe and well tolerated. There was no increase in systemic exposure of UMEC when administered in combination with VI compared to UMEC alone. UMEC maximum concentration was similar with or without verapamil; a moderate increase in UMEC area under the curve (approximately 1.4-fold) was observed with verapamil. Verapamil did not increase systemic exposure to VI following administration of the UMEC/VI combination.

Conclusion

Administration of UMEC and UMEC/VI combination was well tolerated and did not show clinically relevant increases in systemic exposure for either drug. The UMEC/VI combination is unlikely to have a clinically meaningful drug–drug interaction with moderate P-glycoprotein transporter and CYP3A4 inhibitor drugs.

Short-term gain for long-term pain? Which patients should be treated and should we ration?

Objectives:

Treatments of common conditions which do not affect mortality often become sidelined in the drive to improve efficiency and reduce costs. The rationing of patients is a divisive but crucial component to universal health care. How should this be accomplished?

Methods and Results:

In this article we examine the outcomes of various rationing methods in varicose veins.

Conclusions:

No method is perfect and treatment of symptoms and complications should remain the target for all physicians.

Venous thromboembolism in the paediatric patient

Venous thromboembolism is a concern in the paediatric population and its incidence seems to be increasing. Symptoms and signs may be subtle so a high degree of suspicion is needed. Paediatric patients represent a unique challenge in the provision of anticoagulation due to their unique physiology.

Parallel artefact rejection for epileptiform activity detection in routine EEG

The EEG signal is very often contaminated by electrical activity external to the brain. These artefacts make the accurate detection of epileptiform activity more difficult. A scheme developed to improve the detection of these artefacts (and hence epileptiform event detection) is introduced. A structure of parallel Support Vector Machine classifiers is assembled, one classifier tuned to perform the identification of epileptiform activity, the remainder trained for the detection of ocular and movement-related artefacts. This strategy enables an absolute reduction in false detection rate of 21.6% with the constraint of ensuring all epileptic events are recognized. Such a scheme is desirable given that sections of data which are heavily contaminated with artefact need not be excluded from analysis.

Treatment Options, Clinical Outcome (Quality of Life) and Cost Benefit (Quality-adjusted Life Year) in Varicose Vein Treatment

Varicose veins are an extremely common condition causing morbidity; however, with current financial pressures, treatment of such benign diseases is controversial. Many procedures allow the treatment of varicose veins with minimal cost and extensive literature supporting differing approaches. Here we explore the underlying evidence base for treatment options, the effect on clinical outcome and the cost-benefit economics associated with varicose vein treatment. The method of defining clinical outcome with quality-of-life assessment tools is also investigated to explain concepts of treatment success beyond abolition of reflux.

Pilot translational study of dietary vitamin C supplementation in Barrett's esophagus

The transcription factor Nuclear factor kappa B (NF-kappaB) is central to the regulation of genes encoding for mediators of inflammation and carcinogenesis. In the esophagus, NF-kappaB is progressively activated from inflammation to Barrett's metaplasia and adenocarcinoma. Vitamin C, an antioxidant, can inhibit NF-kappaB in in vitro models, and the aim of this study was to prospectively assess the effect of supplemental vitamin C on NF-kappaB and associated cytokines in patients with Barrett's esophagus. Twenty-five patients with long-segment Barrett's and specialized intestinal metaplasia received dietary vitamin C (1000 mg/day) orally for four weeks, and had pre- and post-vitamin C endoscopic biopsies. NF-kappaB activity (activated p50 and p65 subunits) of nuclear extracts was assessed using the Active Motif NF-kappaB assay, and cytokines and growth factors were measured using the Evidence Investigator biochip array. NF-kappaB and related pro-inflammatory cytokines and growth factors (IL-8, VEGF, IL-10) were activated in all Barrett's tissue pre-treatment. Down-regulation in activated NF-kappaB and cytokines was observed in 8/25 (35%) patients. Dietary vitamin C supplementation may down-regulate pro-inflammatory markers in a subset of Barrett's patients. Further studies with larger numbers of endpoints will be needed to further evaluate this effect.

Coeliac disease-associated risk variants in TNFAIP3 and REL implicate altered NF-kappaB signalling

OBJECTIVE

Our previous coeliac disease genome-wide association study (GWAS) implicated risk variants in the human leucocyte antigen (HLA) region and eight novel risk regions. To identify more coeliac disease loci, we selected 458 single nucleotide polymorphisms (SNPs) that showed more modest association in the GWAS for genotyping and analysis in four independent cohorts.

DESIGN

458 SNPs were assayed in 1682 cases and 3258 controls from three populations (UK, Irish and Dutch). We combined the results with the original GWAS cohort (767 UK cases and 1422 controls); six SNPs showed association with p<1 x 10(-04) and were then genotyped in an independent Italian coeliac cohort (538 cases and 593 controls).

RESULTS

We identified two novel coeliac disease risk regions: 6q23.3 (OLIG3-TNFAIP3) and 2p16.1 (REL), both of which reached genome-wide significance in the combined analysis of all 2987 cases and 5273 controls (rs2327832 p = 1.3 x 10(-08), and rs842647 p = 5.2 x 10(-07)). We investigated the expression of these genes in the RNA isolated from biopsies and from whole blood RNA. We did not observe any changes in gene expression, nor in the correlation of genotype with gene expression.

CONCLUSIONS

Both TNFAIP3 (A20, at the protein level) and REL are key mediators in the nuclear factor kappa B (NF-kappaB) inflammatory signalling pathway. For the first time, a role for primary heritable variation in this important biological pathway predisposing to coeliac disease has been identified. Currently, the HLA risk factors and the 10 established non-HLA risk factors explain approximately 40% of the heritability of coeliac disease.

Comparison of three cell fixation methods for high content analysis assays utilizing quantum dots

Semiconductor nanoparticles or quantum dots are being increasingly utilized as fluorescent probes in cell biology both in live and fixed cell assays. Quantum dots possess an immense potential for use in multiplexing assays that can be run on high content screening analysers. Depending on the nature of the biological target under investigation, experiments are frequently required on cells retaining an intact cell membrane or also on those that have been fixed and permeabilized to expose intracellular antigens. Fixation of cell lines before or after the addition of quantum dots may affect their localization, emission properties and stability. Using a high content analysis platform we perform a quantitative comparative analysis of three common fixation techniques in two different cell lines exposed to carboxylic acid stabilized CdTe quantum dots. Our study demonstrates that in prefixed and permeabilized cells, quantum dots are readily internalized regardless of cell type, and their intracellular location is primarily determined by the properties of the quantum dots themselves. However, if the fixation procedures are preformed on live cells previously incubated with quantum dots, other important factors have to be considered. The choice of the fixative significantly influences the fluorescent characteristics of the quantum dots. Fixatives, regardless of their chemical nature, negatively affected quantum dots fluorescence intensity. Comparative analysis of gluteraldehyde, methanol and paraformaldehyde demonstrated that 2% paraformaldehyde was the fixative of choice. The presence of protein in the media did not significantly alter the quantum dot fluorescence. This study indicates that multiplexing assays utilizing quantum dots, despite being a cutting edge tool for high content cell imaging, still require careful consideration of the basic steps in biological sample processing.

A calcified lung tumour and microcytic anaemia in a young woman: partial expression of the Carney triad

The Carney triad is the non-familial addociation of gastric stromal tumours (GISTs), pulmonar chondromas and extra-adrenal paragangliomas. Fewer than 100 cases of the disorder have been reported since its description in 1977. The condition has a predeliction for young women. Most patients exhibit only two of the three components. The tumours tend to be multifocal in the affected organ or system. Herein, we describe the case of a 27-year-old woman with multiple gastric GISTs and a pulmonary chondroma, partial expression of the Carney triad. It is important to be aware of the Carney triad when one of its constituent tumours is found, particularly if the patient is a young woman, so that a search can be made for and surveillance instituted for the other components. Treatment for the gastric tumours (sarcomas) and the paragangliomas (potentially malignant) is surgical. The lung chondromas are benign neoplasms and ordinarily not symptomatic. If a diagnosis of the tumour can be established by biopsy, surgical resection may not be necessary.

Characterization of tumour necrosis factor-alpha genetic variants and mRNA expression in patients with severe sepsis

Tumour necrosis factor-alpha (TNFalpha) has been implicated in the pathogenicity of severe sepsis by both genetic association studies and animal models. Conflicting functional data have emerged in relation to genetic variants and TNFalpha protein production. Therefore, we assessed the functionality of TNFalpha genetic variants in terms of mRNA production and their potential influence on outcome in the setting of severe sepsis. Sixty-two Irish Caucasian patients presenting with severe sepsis were recruited and TNFalpha mRNA and protein levels were quantified. Patient DNA was analysed for the presence of common promoter polymorphisms and haplotypes were inferred. An A allele at position -863 was associated with more TNFalpha mRNA on day 1 compared to C homozygotes (P = 0.037). There was a trend for G homozygotes at position -308 to produce more TNFalpha mRNA on day 1 than those carrying an A allele (P = 0.059). The presence of an A allele at -863 was associated with greater levels of TNFalpha mRNA in comparison with patients carrying the A allele at -308 on day 1 (P = 0.02). Patients homozygous for the A allele at position -308 had a higher mortality than those carrying the G allele (P = 0.01). Our data are consistent with recent reports suggesting that a deficient proinflammatory response may be harmful in human sepsis. This deficient inflammatory response may be mediated in part by polymorphisms in the TNFalpha promoter.

The impact of inherited prothrombotic risk factors on individuals chronically infected with hepatitis C virus from a single source

Intrahepatic thrombotic events have been postulated to play a key role in the pathogenesis of hepatic fibrosis. Genetic and acquired thrombotic risk factors may therefore contribute to the varying rates of fibrosis progression observed in patients with chronic hepatitis C virus (HCV) infection. The aim of this study was to assess the impact of inherited mutations in factor V and factor II (prothrombin) on hepatic fibrosis progression rates in individuals infected with HCV. Two hundred and ten Irish women infected with HCV genotype 1b, contracted from a single source (HCV-contaminated anti-D immunoglobulin) were genotyped for the factor V Leiden G1691A and prothrombin G20210A polymorphisms, and compared with Irish Caucasoid controls. Index and subsequent liver biopsies were scored (Ishak scoring system) by a single pathologist. Statistical analysis was performed using SPSS. Factor V Leiden and prothrombin G20210A heterozygosity were determined in 3.7% and 1.85%, respectively, of the study population. There was no association between these polymorphisms and fibrotic score on the index biopsy, or degree of change in fibrotic score on subsequent biopsies. The mean fibrotic score for factor V wild type was 1.06 vs 0.71 for the heterozygotes (P = 0.89). The mean change in fibrotic scores between subsequent biopsies was 0.72 for factor V wild type vs 0.50 for heterozygotes (P = 0.68). Similarly, there was no significant difference in fibrotic score for those with the prothrombin G20210A polymorphism (P = 0.936). Alanine aminotransferase levels for factor V wild type were significantly lower than those for the heterozygotes, 45.9 vs 57 (P = 0.032). Factor V Leiden and prothrombin G20210A heterozygosity rates were infrequently detected in this HCV cohort and were similar to rates seen in a Caucasian Irish control population. In this cohort, neither factor V Leiden nor prothrombin G20210A polymorphisms had a significant impact on fibrotic scores or degree of change between subsequent biopsies. These data do not support a key role for thrombotic risk factors in fibrogenesis in HCV-infected patients.

Levels of interpopulation differentiation among different functional classes of immunologically important genes

It has been postulated that gene function may influence the degree to which allele frequencies differ among populations. In order to evaluate this effect, genotypic data from resequencing studies of genes classified as cytokines, cytokine receptors, cell adhesion molecules, Toll-like receptors and coagulation proteins were analysed for genetic differentiation (FST) between population samples of European and African descent. FST values did not differ statistically among functional groups when all polymorphic sites were included in the analyses. However, analysis based on nonsynonymous SNPs alone suggested weak heterogeneity among functional classes (P=0.0424). Particularly high levels of differentiation were shown by individual nonsynonymous SNPs at some genes, most notably ICAM1 and some Toll-like receptors. These genes interact directly with pathogens, and may therefore have been subject to geographically localised natural selection. Such loci warrant particular attention in studies of genetic disease risk and local adaptation to environmental conditions.

Vitamin C enhances chemosensitization of esophageal cancer cells in vitro

Chemotherapy is increasingly utilised in multimodal protocols to try and improve outcomes. Cisplatin and 5-fluorouracil (5-Fu) are the mainstay of chemotherapeutic regimens, and an understanding of sensitivity and resistance of esophageal cancer to these agents is of considerable clinical importance. Antioxidants may modulate the response to chemotherapy, and in this study we examined the effect of vitamin C on 5-Fu and cisplatin cytotoxicity and related pathways in the esophageal cancer cell lines OE33 and SKGT-4. The antiproliferative effect of antitumor agents was measured by the MTT assay, and the transcription factors NF-kappaB and AP-1 pathways were assessed by electrophoretic mobility gel shift assay. 5-Fu and cisplatin demonstrated marked morphological changes and decreased cell proliferation. A combination of vitamin C with 5-Fu or cisplatin exerted a significantly enhanced cytotoxic effect compared to both drugs individually. Treatment of esophageal cancer cells with 5-Fu and cisplatin induced NF-kappaB and AP-1 activation. Pretreatment with vitamin C inhibited 5-Fu or cisplatin induced NF-kappaB nuclear translocation and DNA binding activity, but vitamin C had no effect on IkappaB-alpha protein levels. Vitamin C also inhibited 5-Fu- and cisplatin-induced AP-1 activation. Our data demonstrate that vitamin C enhances the antitumor activity of 5-Fu and cisplatin, in part by inhibiting translocation of NF-kappaB and AP-1, and sensitizes cancer cells to drug-induced cell death. The data suggest that vitamin C supplementation may improve the efficacy of chemotherapy for esophageal cancer.

Haplotypes in the CTLA4 region are associated with coeliac disease in the Irish population

Chromosomal region 2q33 encodes the immune regulatory genes, CTLA4, ICOS and CD28, which are involved in regulation of T-cell activity and has been studied as a candidate gene locus in autoimmune diseases, including coeliac disease (CD). We have investigated whether an association exists between this region and CD in the Irish population using a comprehensive analysis for genetic variation. Using a haplotype-tagging approach, this gene cluster was investigated for disease association in a case-control study comprising 394 CD patients and 421 ethnically matched healthy controls. Several SNPs, including CTLA4_CT60, showed association with disease; however, after correction for multiple-testing, CTLA4-658C/T was the only polymorphism found to show significant association with disease when allele, genotype, or carrier status frequency were analysed (carrier status (Allele C), P = 0.0016). Haplotype analysis revealed a haplotype incorporating the CD28/CTLA4 and two 5' ICOS polymorphisms to be significantly associated with disease (patients 24.1%; controls 31.5%; P = 0.035), as was a shorter haplotype composed of the CTLA4 markers only (30.9 vs 34.9%; P = 0.042). The extended haplotype incorporating CD28/CTLA4 and 5' ICOS is more strongly associated with disease than haplotypes of individual genes. This suggests a causal variant associated with this haplotype may be associated with disease in this population.

Activated nuclear factor-kappa B and cytokine profiles in the esophagus parallel tumor regression following neoadjuvant chemoradiotherapy

Esophageal adenocarcinoma is increasing in incidence; it relates to chronic gastroesophageal reflux, it is difficult to cure, and treatment modalities increasingly use chemotherapy and radiation therapy prior to resectional surgery. Nuclear factor-kappa B (NF-kappaB) is a pleiotropic transcription factor that regulates several genes for cytokines and enzymes involved in inflammation and immunity, and we have previously described sequential expression of NF-kappaB from the normal esophagus through Barrett's metaplasia to adenocarcinoma. The aim of this exploratory study was to assess the NF-kappaB status and cytokine profiles pre- and post-chemoradiotherapy for esophageal adenocarcinoma. Fresh biopsy specimens obtained from 20 patients with esophageal adenocarcinoma and normal adjacent squamous epithelium were obtained pre-, during and post-chemoradiotherapy, and NF-kappaB expression was analyzed by electrophoretic mobility shift assay. The cytokine protein content of interleukin-1 beta (IL-1beta) and interleukin-8 (IL-8) of tissue homogenates was measured using the ELISA technique. NF-kappaB was constitutively activated in tumor tissues from esophageal adenocarcinoma but was not detected in adjacent normal esophageal mucosa. Elevated levels of IL-1beta and IL-8 were significantly (P < 0.05) higher in tumor tissues compared to control tissues. Patients with a major or complete pathological response (responders) were associated with absence of activated NF-kappaB from nuclear extracts after treatment. Moreover, IL-1beta and IL-8 levels were significantly (P < 0.05) down-regulated in tumor tissues from patients who demonstrated a complete pathological response. No differences in NF-kappaB, IL-1beta and IL-8 levels were detected pre- and post-treatment in patients who did not have a major or complete pathological response (non-responders). The study suggests that monitoring of molecular and cytokine patterns in patients undergoing this neoadjuvant regimen may help subselect the cohort that derives most benefit from the multimodal approach.

The CCR5-delta32 mutation: impact on disease outcome in individuals with hepatitis C infection from a single source

BACKGROUND AND AIMS

Chemokines are small polypeptides, a major function of which is lymphocyte recruitment and trafficking. The aim of this study was to assess the involvement of inherited variations in CCR2, CCR5, and the ligand RANTES in determining disease outcome in hepatitis C virus (HCV) infected individuals.

METHODS

A total of 283 women, all exposed to HCV genotype 1b from a single donor, and including those who had spontaneously cleared the virus and those chronically infected, were genotyped for CCR2, CCR5, and RANTES polymorphisms. The frequencies of these polymorphisms were then compared with disease activity and severity.

RESULTS

CCR5, CCR2, and RANTES genotypes were compared with HCV polymerase chain reaction (PCR) status, alanine aminotransferase levels, and liver histology. There was no significant relationship between CCR2 or RANTES polymorphisms and disease outcome or severity. However, CCR5delta32 heterozygotes were more likely to have spontaneous clearance of the virus than those without the mutation (42% PCR negative v 28.3% negative; p = 0.044, odds ratio 1.83 (95% confidence interval 1.1-3.6)). Among the subgroup of DRB1*03011 negative individuals, previously found to be associated with more severe inflammation, the difference in histological inflammatory score (CCR5WT/WT = 4.9 v CCR5delta32/WT = 3.53; p = 0.043) was significant.

CONCLUSION

Heterozygosity for CCR5delta32 was shown to be significantly associated with spontaneous hepatitis C viral clearance and with significantly lower hepatic inflammatory scores in subgroups within this cohort. Both controls and the HCV population had similar heterozygosity frequencies.

Proinflammatory cytokine and nuclear factor kappa-B expression along the inflammation-metaplasia-dysplasia-adenocarcinoma sequence in the esophagus

BACKGROUND

The incidence of esophageal adenocarcinoma has increased significantly in the western world over the last 20 yr. Most cases arise in a background of chronic gastroesophageal reflux, and specialized intestinal metaplasia in Barrett's esophagus is frequently an antecedent phenotype or evident in association with adenocarcinoma. The molecular events that characterize the pathway from inflammation to metaplasia to dysplasia and adenocarcinoma are poorly understood.

AIMS

To examine the expression of the proinflammatory cytokines IL-8 and IL-1beta along the esophagitis, metaplasia, dysplasia, and adenocarcinoma pathway, and to correlate this with histological changes and expression of the transcription factor NF-kappaB.

PATIENTS AND METHODS

Fresh biopsy specimens were collected from patients with reflux esophagitis (n=15), Barrett's esophagus (n=35), Barrett's adjacent to adenocarcinoma (n=8), and esophageal adenocarcinoma (n=35). IL-8 and IL-1beta expression were measured using enzyme-linked immunosorbent assay. NF-kappaB expression was measured by electrophoretic mobility shift assay.

RESULTS

Elevated expression of NF-kappaB was found in 2 (13%) out of 15 patients with reflux esophagitis, 21 (60%) out of 35 patients with Barrett's esophagus, and 28 (80%) out of 35 patients with esophageal adenocarcinoma. All 5 patients with Barrett's esophagus and high-grade dysplasia showed elevated expression of NF-kappaB. IL-8 and IL-1beta were significantly increased in esophagitis, Barrett's, and adenocarcinoma compared with squamous epithelium, and in adenocarcinoma compared with all other groups. There was a stepwise increase in the expression of IL-8, IL-1beta, and NF-kappaB from normal through Barrett's epithelium to adenocarcinoma in eight cases of esophageal adenocarcinoma. The levels of both IL-8 and IL-1beta in adenocarcinoma patients correlated with stage of disease. Patients with adenocarcinoma who were NF-kappaB positive had significantly higher levels of both IL-8 (p=0.04) and IL-1beta (p=0.03) compared to adenocarcinoma patients who were NF-kappaB negative.

CONCLUSIONS

The proinflammatory cytokines IL-8 and IL-1beta are elevated in esophagitis and Barrett's epithelium, and markedly elevated in adenocarcinoma. NF-kappaB activation is infrequent in esophagitis, but is increased in Barrett's epithelium and adenocarcinoma. The association of NF-kappaB activation with cytokine upregulation was only evident in patients with adenocarcinoma. These patterns may play an important role in Barrett's inflammation and tumourigenesis, and inhibition of the NF-kappaB/proinflammatory cytokine pathway may be an important target for future chemoprevention strategies.

Chromosome 5q candidate genes in coeliac disease: Genetic variation at IL4, IL5, IL9, IL13, IL17B and NR3C1

Genetic predisposition to coeliac disease (CD) is determined primarily by alleles at the HLA-DQB locus, and evidence exists implicating other major histocompatibility complex-linked genes (6p21) and the CTLA4 locus on chromosome 2q33. In addition, extensive family studies have provided strong, reproducible evidence for a susceptibility locus on chromosome 5q (CELIAC2). However, the gene responsible has not been identified. We have assayed genetic variation at the IL4, IL5, IL9, IL13, IL17B and NR3C1 (GR) loci, all of which are present on chromosome 5q and have potential or demonstrated involvement in autoimmune and/or inflammatory disease, in a sample of 409 CD cases and 355 controls. Thirteen single nucleotide polymorphisms were chosen on the basis of functional relevance, prior disease association and, where possible, prior knowledge of the haplotype variation present in European populations. There were no statistically significant allele or haplotype frequency differences between cases and controls. Therefore, these results provide no evidence that these loci are associated with CD in this sample population.

Human peripheral and gastric lymphocyte responses to Helicobacter pylori NapA and AphC differ in infected and uninfected individuals

BACKGROUND

In this study, we identify the nature of the immunological response of human peripheral blood mononuclear cells (PBMC) and lamina propria gastric lymphocytes (LPL) to two Helicobacter pylori antigens, the neutrophil activating protein (NapA) and alkyl hydroperoxide reductase (AphC). These antigens were identified and selected for study based on the observation that serological recognition of these proteins was associated with H pylori negative status in humans.

AIMS

The aim was to study the serological, proliferative, and cytokine responses of PBMC and LPL, obtained from H pylori infected and uninfected individuals, to these antigens.

METHODS

Patient serum, PBMC, and LPL were used to determine antibody isotype, and proliferative and cytokine responses to recombinant forms of NapA and AphC using western blotting and ELISA.

RESULTS

Western blotting revealed antibody reactivity to recombinant NapA and AphC among the H pylori negative population studied. Both the proliferative and interferon gamma responses of PBMC and LPL to NapA and AphC were significantly higher in H pylori negative compared with H pylori positive subjects. Analysis of the IgG subclass profiles to both antigens revealed a T helper 1 associated IgG3 antibody response in uninfected individuals. However, interleukin 10 production was greater in H pylori positive individuals in response to these antigens.

CONCLUSIONS

Taken together these data are consistent with an immune response to these antigens skewed towards a T helper 1 response in the uninfected cohort.

Haplotype variation at the IBD5/SLC22A4 locus (5q31) in coeliac disease in the Irish population

In addition to the well-established association of coeliac disease (CD) with HLA-DQ (6p21) and possibly CTLA4 (2q33), there is considerable evidence for a susceptibility locus on chromosome 5q, which contains many potential candidates for inflammatory disease, including a cluster of cytokine genes in 5q31. CD cases and controls were genotyped for four single-nucleotide polymorphism (SNP) markers that together characterize >90% of the haplotype variation at the IBD5 locus encoding, among others, the SLC22A4 gene. IBD5 and SLC22A4 map to 5q31 and have recently been associated with Crohn's disease and rheumatoid arthritis. Haplotype frequencies do not differ significantly between CD cases and controls in the Irish population, and therefore the chromosome 5 CD susceptibility locus most likely lies elsewhere on 5q.

Hepatitis C among drug users: consensus guidelines on management in general practice

BACKGROUND

Hepatitis C (HCV) is a common cause of morbidity among patients who attend general practitioners (GPs) in Ireland for methadone maintenance treatment.

AIMS

To describe the development and content of guidelines for the management of HCV among current or former opiate users in the Eastern Regional Health Authority area attending GPs for methadone treatment.

METHODS

The guidelines were produced in five stages: identification of key stakeholders; development of evidence-based draft guidelines; discussion of content; determination of 'Delphi'-facilitated consensus and review by a sample of GPs for whom the guidelines would be intended.

RESULTS

The guidelines contain advice for GPs on all aspects of care of patients at risk of HCV, including general and preventative care, care of other bloodborne and hepatotoxic viruses, and the factors to be considered and appropriate evaluation prior to referring a patient for assessment at a hepatology unit.

CONCLUSIONS

GPs have an important role to play in the care of patients at risk of, or infected with, HCV.

Helicobacter pylori activates the early growth response 1 protein in gastric epithelial cells

The early growth response 1 (Egr-1) transcription factor is rapidly induced by various stimuli and is implicated in the regulation of cell growth, differentiation, and gene expression. The aim of this study was to examine the effect of Helicobacter pylori on the expression of Egr-1 and Egr-1-regulated genes in gastric epithelial AGS cells. Egr-1 expression was assayed by immunoblotting and electrophoretic mobility shift assays using H. pylori-stimulated AGS cells. Transient transfection experiments with promoter-reporter constructs of CD44, ICAM-1, and CD95L were used for expression studies. H. pylori induced the expression of Egr-1 in gastric epithelial cell lines in a dose-dependent manner, with the rapid kinetics that are typical of this class of transcription factors. Immunohistochemical studies of biopsies revealed that Egr-1 expression is more abundant in H. pylori-positive patients than in uninfected individuals. Reporter-promoter transfection studies indicated that Egr-1 binding is required for the H. pylori-induced transcriptional promoter activity of the CD44, ICAM-1, and CD95L (APO-1/Fas) constructs. The blocking of egr-1 with an antisense sequence prevented H. pylori-induced Egr-1 and CD44 protein expression. The MEK1/2 signaling cascade participates in H. pylori-mediated Egr-1 expression, but the p38 pathway does not. The data indicate that H. pylori induces Egr-1 expression in AGS cells in vitro and that the Egr-1 protein is readily detectable in biopsies from H. pylori-positive subjects. These observations suggest that H. pylori-associated Egr-1 expression may play a role, in part, in H. pylori-induced pathology.

NOD2/CARD15, TLR4 and CD14 mutations in Scottish and Irish Crohn's disease patients: evidence for genetic heterogeneity within Europe?

NOD2/caspase recruitment domain (CARD)15 variants are identified in up to 50% of Crohn's disease (CD) patients. Functional variants of toll-like receptor-4 (TLR4) and CD14 genes may also be relevant to disease pathophysiology. We aimed to assess the contribution of NOD2/CARD15, TLR4 and CD14 variants in Scottish and Irish CD patients. In all, 612 patients with well-characterised inflammatory bowel disease (252 Scottish CD, 247 Scottish UC, 113 Irish CD) and 304 controls were genotyped for variants of NOD2/CARD15 (1007fsinsC, G908R, R702W, P268S), TLR4 (A299G) and CD14 (T-159C). Genotype-phenotype analyses were performed. Variant 1007fsinsC (P=0.003) and G908R (P=0.008) but not R702W (P=0.269) alleles were more prevalent in Scottish CD (4.7, 1.8 and 7.1%, respectively) than Scottish control (2.3, 0.3 and 5.4%). CD allelic frequencies were lower than the series from Europe (P<0.00001) and North America (P<0.00001) but not Scandinavia (P<0.7). Associations were identified with age at diagnosis (P=0.002), ileal disease (P<0.02), penetrating disease (P=0.04) and inflammatory joint disease (P<0.02). TLR4 and CD14 variants did not differ between CD and controls. In conclusion, we present compelling evidence for genetic heterogeneity within Europe. These NOD2/CARD15 variants have a minor contribution in Scottish and Irish CD patients, consistent with an emerging pattern from Northern Europe.

Comparative locomotory behavior of T lymphocytes versus T lymphoma cells on flat and grooved surfaces

Locomotion is a characteristic of many cell types, including malignant cells. It is driven by a combination of interacting factors, one of which is recognized to be the surface microtopography. In this study, an in vitro analysis of cell migration was carried out to observe and quantify the differences in locomotion of two types of lymphoid cell on both flat and grooved surfaces. The cells studied were peripheral blood T lymphocytes (PBTL) and a malignant T lymphoma cell line (HUT78). It was found that, on the grooved pattern, the lymphoma HUT78 cells were more diffusive in their migration than the T lymphocyte PBTL cells whereas, on the flat surface, the T lymphocyte PBTL cells had a more diffusive response than the T lymphoma HUT78 cells. It was also found that malignant T lymphoma cells are significantly slower and less diffusive when exposed to a plane substrate than when subjected to a grooved substrate. On the contrary, PBTL cells showed only a moderate drop in cell speed and diffusion on the grooved compared to the flat substrate. PBTL cells did, however, show a general alignment to the direction of the grooves whereas HUT78 did not. Therefore, we have found that the surface topography can influence the motile response of the two different T cell types in different ways, and this can be quantified in terms of motility parameters. This difference may have exploitable applications for cell sorting.

Glucocorticoid resistance in inflammatory bowel disease

Glucocorticoids are potent inhibitors of T cell activation and proinflammatory cytokines and are highly effective treatment for active inflammatory bowel disease (IBD). However, failure to respond, acutely or chronically, to glucocorticoid therapy is a common indication for surgery in IBD, with as many as 50% of patients with Crohn's disease (CD) and approximately 20% of patients with ulcerative colitis (UC) requiring surgery in their lifetime as a result of poor response to glucocorticoids. Studies report that approximately one-third of patients with CD are steroid dependent and one-fifth are steroid resistant while approximately one-quarter of patients with UC are steroid dependent and one-sixth are steroid resistant. While the molecular basis of glucocorticoid resistance has been widely assessed in other inflammatory conditions, the pathophysiology of the glucocorticoid resistance in IBD is poorly understood. Research in IBD suggests that the phenomenon of glucocorticoid resistance is compartmentalised to T-lymphocytes and possibly other target inflammatory cells. This review focuses on three key molecular mechanisms of glucocorticoid resistance in IBD: (i) decreased cytoplasmic glucocorticoid concentration secondary to increased P-glycoprotein-mediated efflux of glucocorticoid from target cells due to overexpression of the multidrug resistance gene (MDR1); (ii) impaired glucocorticoid signaling because of dysfunction at the level of the glucocorticoid receptor; and (iii) constitutive epithelial activation of proinflammatory mediators, including nuclear factor kappa B, resulting in inhibition of glucocorticoid receptor transcriptional activity. In addition, the impact of disease heterogeneity on glucocorticoid responsiveness and recent advances in IBD pharmacogenetics are discussed.

Viral dynamics and their relations to baseline factors and longer term virologic responses in treatment-naive HIV-1-infected patients receiving abacavir in combination with HIV-1 protease inhibitors

From a study of 71 HIV-1-infected patients receiving abacavir in combination with 1 of 5 different HIV-1 protease inhibitors (indinavir, ritonavir, saquinavir, nelfinavir, or amprenavir), we found that the baseline HIV-1 RNA levels were highly predictive of the viral decay rates. The baseline HIV-1 RNA levels were negatively correlated with the first phase viral decay rates (r = -0.77, P < 0.001) and positively correlated with the second phase viral decay rates (r = 0.68, P < 0.001). In addition, the first phase viral decay rate was positively correlated with CD4+ cell increases. No significant correlation was found between viral decay rates and longer term (24 weeks) virologic responses, and no difference in viral decay rates was found among the 5 study regimens. These data suggest that the potency of the 5 treatment regimens was similar and was not predictive of long-term virologic failure.

The methylenetetrahydrofolate reductase (MTHFR) gene in colorectal cancer: role in tumor development and significance of allelic loss in tumor progression

BACKGROUND AND AIM

Folate deficiency predisposes to sporadic colorectal cancer (CRC). Methylenetetrahydrofolate reductase (MTHFR) is a critical folate-metabolising enzyme and a polymorphism at position 677 (C677T), is associated with reduced enzyme activity. We investigated whether this functional polymorphism modulates the risk of developing CRC.

METHODS

This was a retrospective case-control study. 136 unselected cases of sporadic CRC and 848 normal population controls were genotyped for the MTHFR C677T polymorphism. Tumor tissue was genotyped to assess loss of heterozygosity (LOH).

RESULTS

MTHFR CT heterozygotes had a significantly increased risk of developing CRC (53.7% of CRC cases vs 38.4% of controls), odds ratio 1.86 (95% CI 1.3-2.7, p < 0.005). No increased cancer risk was observed in TT homozygotes. The MTHFR 'T' allele frequency was significantly higher in the cancer group (0.3713) as compared to controls (0.2900, p < 0.008). LOH at the MTHFR locus was observed in 18% of informative cancers, with exclusive loss of the variant 'T' allele, in all cases.

CONCLUSION

In this study of a homogenous northern European population, MTHFR CT heterozygotes had an almost two-fold increased risk of developing sporadic CRC. The exclusive pattern of MTHFR allele loss in cases of LOH, suggest that functional MTHFR activity within a tumor might play an important role in the survival and progression of a colonic neoplasm.

A prospective study of circulating mutant KRAS2 in the serum of patients with colorectal neoplasia: strong prognostic indicator in postoperative follow up

BACKGROUND AND AIMS

Mutant tumour derived DNA has been detected in the sera of colorectal cancer patients. We investigated if mutant serum KRAS2 was detectable preoperatively in a large group of patients with colorectal neoplasia. A prospective study of 94 patients who underwent putative curative resection for colorectal carcinoma (CRC) was performed to ascertain if serum mutant KRAS2 could be used postoperatively as a disease marker.

METHODS

Preoperative sera from 78 patients were analysed (group A). Sera from 94 patients were obtained three monthly for up to three years during the postoperative period (group B). Codon 12 and 13 KRAS2 mutations were analysed in matched tumour and serum samples.

RESULTS

In the preoperative group (group A), KRAS2 mutation was found in 41/78 (53%) tumours and in 32/78 (41%) preoperative sera. Of 41 tumour KRAS2 mutation positive cases, 31/41 (76%) had an identical serum mutation detectable. In group B, the postoperative follow up group, 60/94 cases were primary tumour KRAS2 mutation positive. Of these 60, 16/60 (27%) became persistently serum mutant KRAS2 positive postoperatively. Ten of 16 (63%) of these developed a recurrence compared with only 1/44 (2%) patients who remained serum mutant negative (odds ratio 71.7 (95% confidence interval 7.7-663.9; p=0.0000). None of 34 tumour mutation negative cases became serum mutant KRAS2 positive postoperatively, despite recurrence in 9/34 patients. The relative hazard of disease recurrence in postoperative serum mutant KRAS2 positive patients was 6.37 (2.26-18.0; p=0.000).

CONCLUSIONS

Serum mutant KRAS2 can be detected preoperatively in all stages of colorectal neoplasia. Postoperatively, serum mutant KRAS2 is a strong predictor of disease recurrence, stronger even than Dukes' stage of disease, and thus shows potential for use in clinical practice as a marker of preclinical disease recurrence.

Evaluation of renal function following treatment with 5-aminosalicylic acid derivatives in patients with ulcerative colitis

BACKGROUND

A number of cases of nephrotoxicity have been reported in patients with inflammatory bowel disease taking oral 5-aminosalicylic acid (5-ASA).

AIM

To evaluate the effects of 9 months of therapy with mesalazine or olsalazine on renal function in patients with ulcerative colitis in remission.

METHODS

Forty patients with ulcerative colitis in complete remission for 6 months were randomized to either olsalazine (n=20) or mesalazine (n=20 for nine months). Thirty-six of the 40 patients were on prior salicylate therapy. Disease activity was the measure ofclinical efficacy and was assessed by the Harvey-Bradshaw Index (HBI). Laboratory efficacy measurements included glomerular filtration rate (GFR), microalbuminuria, urinary gluthathione S-transferase (GST) and serum C-reactive protein (CRP). Safety analysis consisted of documentation of adverse events and laboratory values.

RESULTS

There was no significant reduction in the GFR overall on therapy. The levels of GFR adjusted for baseline were similar in the two treatment groups after 3, 6 and 9 months. A significantly higher percentage of mesalazine-treated patients experienced drug related adverse events, all of a minor nature. The incidence of adverse events causing early withdrawal was similar in the two treatment groups.

CONCLUSION

Treatment with mesalazine or olsalazine for 9 months had no significant impact on GFR.

St Johns wort increases expression of P-glycoprotein: implications for drug interactions

AIMS

St John's Wort (SJW) is widely used in the treatment of depression but concerns have been raised about its potential to interact with other drugs. Co-administration with SJW has resulted in significant reductions in trough plasma concentrations of indinavir and cyclosporin [1, 2]. Induction of cytochrome P450 3A4 (CYP3A4) has been implicated as the most likely interaction mechanism. However, the magnitude of the interaction seen in clinical practice is greater than that predicted by in vitro studies suggesting additional interaction mechanisms may exist. As indinavir and cyclosporin are substrates for both CYP3A4 and the multi drug transporter P-glycoprotein we hypothesized that modulation of P-glycoprotein expression and function by SJW may contribute to the development of potentially harmful drug-drug interactions.

METHODS

Healthy volunteers were randomized to either SJW (0.15%) 600 mg three times daily for 16 days (n = 15) or placebo (n = 7). Blood samples were obtained for P-glycoprotein expression and function at baseline, 16 and 32 days post treatment. Peripheral blood lymphocytes (PBMCs) were isolated by Ficoll density gradient centrifugation, fixed and permeabilized. Cells were stained with a P-glycoprotein specific antibody, quantified by flow cytometry and median fluorescence intensity (MFI) values obtained. Vimentin and IE (nonsense antibody) were used as controls. The presence of the MDR 1 gene product was confirmed by RT-PCR. P-glycoprotein mediated drug efflux was determined as a function of rhodamine efflux in the absence and presence of ritonavir. Data are expressed as mean +/- s.d. and were subjected to nonparametric analysis.

RESULTS

P-glycoprotein expression increased 4.2 fold from baseline in subjects treated with SJW (7.0 +/- 1.9 vs 29.5 +/- 14.3 (MFI); P < 0.05). There was no effect with placebo (5.1 +/- 1.3 vs 6.0 +/- 1.9 MFI). SJW increased P-glycoprotein mediated rhodamine efflux (reduced ratio) compared with baseline (0.12 +/- 0.04 vs 0.24 +/- 0.18 P < 0.05). There was no change with placebo. Ritonavir (5 microm) inhibited P-glycoprotein mediated efflux in both groups producing greater intracellular accumulation of rhodamine. However, this effect was attenuated following treatment with SJW (23.9 +/- 15.3% vs 75.4 +/- 16.4% P < 0.05).

CONCLUSIONS

SJW increased expression and enhanced the drug efflux function of the multi drug transporter P-glycoprotein in PBMCs of healthy volunteers. This may represent a second mechanism for the drug-herb interactions seen in clinical practice and account for the discrepancies between in vitro and in vivo data. Since P-glycoprotein and CYP3A4 have distinct though overlapping substrates, patients receiving drugs, which are P-glycoprotein substrates should be warned against self-medication with SJW as clinically significant drug interactions may occur.