Oral graft-versus-host disease

OBJECTIVE

Graft-versus-host disease (GVHD) is a leading cause of morbidity and mortality in patients receiving hematopoietic cell transplant. It is estimated that 40-70% of engrafted patients surviving the initial transplant eventually develop chronic GVHD (cGVHD), which can persist for months to years and require long-term management from multiple disciplines. This review describes the oral component of this transplant complication.

DESIGN

The search related to GVHD patho-biology, salivary gland disease after hematopoietic cell transplant and treatments for oral GVHD encompassed literature from 1966 through 2008. Searches were limited to the MEDLINE/PubMed database and English language literature in peer-reviewed journals.

RESULTS

Our understanding of the patho-biology of oral cGVHD is based on studies of other affected tissues. It is difficult to determine the prevalence and incidence of salivary gland disease after transplant because there is no universally accepted case definition. In general, clinical trials for treatment of oral cGVHD have been too small to make strong recommendations for use in clinical practice.

CONCLUSIONS

Larger well-designed clinical studies are needed to understand the patho-biology of oral cGVHD and determine best treatments for this disease.

Optimizing the encounter rate in biological interactions: Ballistic versus Lévy versus Brownian strategies

Bartumeus et al. [Phys. Rev. Lett. 88, 097901 (2002)] compared the efficiency of a Lévy random walk predator strategy with a Brownian random walk strategy in a periodic one-dimensional domain with nonrevisitable moving targets. Their findings from numerical simulations conclude that "a Lévy search strategy is the best option in some, but not all, cases for a random search process." Using the same methodology, we show that the simplest random search strategy of all, ballistic motion in a random direction, outperforms a Lévy strategy in almost every case. We further show that, in the small set of cases where the ballistic strategy is not optimal, the periodic model does not capture the more realistic nonperiodic case. In the nonperiodic case, the ballistic strategy again outperforms the Lévy strategy.

Acquired Brown's syndrome associated with preseptal cellulitis

We describe a patient who developed vertical diplopia, a left head tilt and restriction of right eye on elevation in adduction during preseptal cellulitis. Pathways of inflammatory preseptal conditions in association with acquired Brown's syndrome are being reviewed.

Donor HLA-C genotype has a profound impact on the clinical outcome following liver transplantation

Late allograft dysfunction is a significant problem following liver transplantation and its pathogenesis is uncertain. HLA-C is the major inhibitory ligand for killer immunoglobulin-like receptors (KIRs) that regulate the cytotoxic activity of natural killer (NK) cells. HLA-C alleles can be allocated into two groups, termed HLA-C1 and HLA-C2, based on their KIR specificity. HLA-C2 interactions are more inhibiting to NK cell activation. We studied the clinical importance of HLA-C genotype in a large liver transplant cohort and found that possession of at least one HLA-C2 allele by the donor allograft was associated with less histological evidence of chronic rejection and graft cirrhosis, a 16.2% reduction in graft loss (p = 0.003) (hazard ratio: 2.7, 95% CI 1.4-5.3) and a 13.6% improvement in patient survival (p = 0.01) (hazard ratio: 1.9, 95% CI 1.1-3.3) at 10 years. Transplantation of an HLA-C2 homozygous allograft led to a particularly striking 26.5% reduction in graft loss (p < 0.001) (hazard ratio: 7.2, 95% CI 2.2-23.0) at 10 years when compared to HLA-C1 homozygous allografts. Donor HLA-C genotype is therefore a major determinant of clinical outcome after liver transplantation and reveals the importance of NK cells in chronic rejection and graft cirrhosis. Modulation of HLA-C and KIR interactions represents an important novel approach to promote long-term graft and patient survival.

Sci-Thurs PM: Delivery-05: One year of learning from incidents

The aim of this study is to quantify the effect of an incident learning system in radiation therapy. The system is designed to detect all occurrences of "an unwanted or unexpected change from a normal system behaviour that causes or has the potential to cause an adverse effect to persons or equipment". Our application to radiation therapy defines 5 incident types, four levels of severity and four work domains where errors discovered during routine quality assurance within each domain were not classified as incidents. During 2007, we recorded, corrected, investigated, determined root cause and learned from 657 incidents. The vast majority of these incidents were classified as potential minor clinical incidents having little or no impact on patient treatment. The value of the system lies in the application of the learning portion of the investigation. We demonstrated a dramatic reduction in the rate of more severe incidents by the implementation of several simple tools. Our results also show a reduction of incidents on accelerators treating essentially a single disease site. The only treatment unit treating with both image guidance and intensity modulation recorded the fewest incidents while the cobalt unit with the least technological assistance recorded three times the average treatment unit incidents with a higher severity. Additionally, although the rate of incidents at the point of treatment delivery was low, the impact of those incidents was substantially higher than that of incidents originating during treatment planning. This system has proven to be a powerful program management tool.

The 'omics' tools: genomics, proteomics, metabolomics and their potential for solving the aflatoxin contamination problem

Aflatoxins are highly carcinogenic secondary metabolites produced primarily by the fungi Aspergillus flavus and Aspergillus parasiticus. Aflatoxin contamination of food and feed is an age old problem of particular concern over the last four decades. Now, for the first time control measures for this problem appear within reach. For practical and sustainable control of aflatoxin contamination to be realised, however, additional information is needed rather rapidly, particularly for understanding the specific molecular factors (both in the plant and the fungus) involved during host plant-fungus interaction. The information derived from the use of novel tools such as genomics, proteomics and metabolomics provides us with the best and the quickest opportunity to achieve a clear understanding of the survival of toxigenic fungi in the field, the ability of the fungus to invade crops, and the process of toxin contamination under various environmental conditions. Significant progress has been made recently in understanding the genomic makeup of the most significant aflatoxin producing field fungus, namely Aspergillus flavus. Progress also has been made in the study of host crop resistance to fungal invasion through the use of proteomics. The information available on production of aflatoxin and other metabolites by Aspergillus flavus is reasonably extensive, although the application of metabolomics as a tool in this study is relatively new. In this review there is a discussion of the use of genomics, proteomics and metabolomics in deriving the requisite information for developing effective strategies to interrupt the machinery in the fungus for production of these toxins, as well as to assist in the development of host-resistance against fungal invasion and aflatoxin contamination of crops.

Double superior vena cava with a persistent left superior vena cava: an incidental finding during peripherally inserted central catheter placement

We describe a case of double superior vena cava with a persistent left-sided superior vena cava discovered at the time of peripherally inserted central catheter (PICC) placement. The diagnosis was suggested by fluoroscopy and confirmed by venography. The relevance of the diagnosis with respect to PICC placement is discussed.

Congenital desmoplastic trichoepithelioma

Desmoplastic trichoepithelioma (DT) is a rare benign adnexal neoplasm considered to have follicular differentiation. It usually presents as an asymptomatic, firm, annular plaque with a raised border. The most common site of occurrence is the face, usually on the cheek. Females are more often affected than males and the age range of patients previously reported is 8-79 years. We present a case of congenital desmoplastic trichoepithelioma. A girl was born at term to a healthy mother after an uneventful pregnancy and was noted to have widespread erythematous plaques with milia-like lesions over the right scalp, face and neck, with some areas of atrophic scarring. Histology and immunohistochemistry of incisional biopsies of the lesions were consistent with a diagnosis of DT. To our knowledge, this is the first reported case of congenital DT.

The clinical effectiveness and cost of repetitive transcranial magnetic stimulation versus electroconvulsive therapy in severe depression: a multicentre pragmatic randomised controlled trial and economic analysis

OBJECTIVE

To investigate if repetitive transcranial magnetic stimulation (rTMS) was as effective as electroconvulsive therapy (ECT) in treating major depressive episodes and to perform a cost-effectiveness analysis.

DESIGN

A single-blind pragmatic multicentre randomised controlled trial (RCT) with 6 months of follow-up to test equivalence of rTMS with ECT.

SETTING

The South London and Maudsley NHS Trust and Pembury Hospital in the Invicta Mental Health Trust in Kent.

PARTICIPANTS

Right-handed adult patients referred for ECT for treatment of a major depressive episode (DSM-IV) were assessed. During the 2.5-year trial period, 260 patients were referred for ECT, of whom 46 entered the trial. The main reason for not entering the trial was not consenting to ECT while being formally treated under the UK Mental Health Act 1983.

INTERVENTIONS

Patients were randomised to receive a 15-day course of rTMS of the left dorsolateral prefrontal cortex (n = 24) or a course of ECT (n = 22).

MAIN OUTCOME MEASURES

Patients were assessed before randomisation, at end of treatment and at the 6-month follow-up. Primary outcome measures were the 17-item Hamilton Rating Scale for Depression (HRSD) and proportion of remitters (defined as HRSD score <or=8) at the end-of-treatment time point. Secondary outcomes included self-ratings for mood on the Beck Depression Inventory-II (BDI-II) and visual analogue mood scales (VAMS), the Brief Psychiatric Rating Scale (BPRS), plus subjective and objective side-effects. Low scores on the BDI-II, VAMS and BPRS are positive in terms of health. The results were analysed on an intention-to-treat basis. Cost data were collected using the Client Service Receipt Inventory and the Short Form with 36 Items was used to obtain quality of life measures. Health economic outcomes were cost of treatments, costs incurred during the 6-month follow-up period and gains in quality-adjusted life-years (QALYs).

RESULTS

One patient was lost to follow-up at end of treatment and another eight at 6 months. The end-of-treatment HRSD scores were lower for ECT, with 13 (59%) achieving remission compared with four (17%) in the rTMS group. However, HRSD scores did not differ between groups at 6 months. BDI-II, VAMS and BPRS scores were lower for ECT at end of treatment and remained lower after 6 months. Improvement in subjective reports of side-effects following ECT correlated with antidepressant response. There was no difference between the two groups before or after treatment on global measures of cognition. Although individual treatment session costs were lower for rTMS than ECT, the cost for a course of rTMS was not significantly different from that for a course of ECT as more rTMS sessions were given per course. Service costs were not different between the groups in the subsequent 6 months but informal care costs were significantly higher for the rTMS group and contributed substantially to the total cost for this group during the 6-month follow-up period. There also was no difference in gain in QALYs for ECT and rTMS patients. Analysis of cost-effectiveness acceptability curves demonstrated that rTMS has very low probability of being more cost-effective than ECT.

CONCLUSIONS

ECT is a more effective and potentially cost-effective antidepressant treatment than 3 weeks of rTMS as administered in this study. Optimal treatment parameters for rTMS need to be established for treating depression. More research is required to refine further the administration of ECT in order to reduce associated cognitive side-effects while maintaining its effectiveness. There is a need for large-scale, adequately powered RCTs comparing different forms of ECT. The next generation of randomised trials of rTMS should also seek to compare treatment variables such as stimulus intensity, number of stimuli administered and duration of treatment, with a view to quantifying an effect size for antidepressant action.

Morphoproteomic depiction of constitutively activated mTOR and ERK pathways in adenocarcinoma of the large intestine: A pilot study

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Background: Preclinical studies have demonstrated a role for the mammalian target of rapamycin (mTOR) pathway in intestinal tumorigenesis. However, the mTOR and its related ERK pathway in human adenocarcinoma of the large intestine (ALI) have been little examined. Methods: To assess morphoproteomic alterations of ALI, tissue materials from three patients with ALI were analyzed in the present study. Antibody probes used included phosphorylated (p)-mTOR (Ser-2448) and one of its downstream effectors, p-p70S6K (Thr-389); bcl-2, which undergoes mTOR-dependent phosphorylative inactivation; and p-extracellular signal-regulated kinase (ERK)1/2 (Thr-202/Tyr-204), a co-activator of p-p70S6K. The intensity of the chromogenic signal and the cellular compartmentalization (plasmalemmal, cytoplasmic, and/or nuclear) were assessed and scored on a scale of 0–3+. Results: Moderate to strong (up to 2+ or 3+) expression of p-mTOR and its substrate, p-p70S6K, and p-ERK1/2 was present in all three cases. We also found plasmalemmal translocation of p-mTOR and nuclear translocation of p-p70S6K and p-ERK1/2, indicating constitutive activation of these protein analytes and their corresponding signal transduction pathways. We did not detect bcl-2 expression in any of these cases. Conclusions: Morphoproteomic analysis reveals constitutive activation of the mTOR and ERK pathways in ALI as evidenced by the collective commonalities of expression of p-mTOR, p-p70S6K, and p- ERK1/2 and the plasmalemmal translocation of p-mTOR and nuclear translocation of p-p70S6K and p-ERK1/2. The absence of bcl-2 expression in this context is noteworthy. These findings coincide with the preclinical data on the efficacy of rapamycin and a rapamycin analogue against colon cancer cell lines and xenograft models. Although preliminary, these observations of morphoproteomic alterations represent the first in primary human ALI specimens according to a review of the literature. The present pilot study offers a starting point for further studies (we are currently conducting a confirmatory study with larger series of cases) and the design of clinical trials using such small molecule inhibitors(e.g. rapamycin, RAD001) in a combinational strategy against ALI.

No significant financial relationships to disclose.

The risk of hepatocellular carcinoma in patients with previous malignancy

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Background: Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. Its incidence has doubled over the past 20 years in the United States. Determination of the pattern of occurrence of HCC as a second primary malignancy might give clues for new risk factors for HCC, or may reveal common genetic or environmental risks. Methods: We identified patients with a diagnosis of a second primary HCC between 1973 and 2002 using the Surveillance, Epidemiology, and End-Results Program (SEER) a compilation of population-based cancer registries in the United States, to calculate the observed to expected (O/E) frequency of second primary HCC after a different primary cancer. We stratified by ethnicity, latency from the year of diagnosis of primary cancer to HCC diagnosis, and period of diagnosis of primary cancer as early (1973–1987) or late (1987–2002). Results: We reviewed 1,931,911 subjects with cancer, and identified 1,185 second primary HCC cases. Overall, a second primary HCC after any primary cancer was less frequent than expected (O/E=0.82, 95% CI=0.77–0.87). We found positive associations with head and neck cancers (oral cavity/pharynx O/E=2.1, 95% CI=1.7–2.5), Kaposi's sarcoma (O/E=3.3, 95% CI=1.2–7.1) and Hodgkin's disease (O/E=2.3, 95% CI=1.2–4.0). Negative associations were seen for breast cancer (O/E=0.7, 95% CI=0.6–0.8), colorectal cancer (O/E=0.6, 95% CI=0.6–0.8), and prostate cancer (O/E=0.7, 95%CI=0.6–0.8). Overall, lower O/E ratios were seen in whites, while in African Americans and those of other races, the O/E ratios were close to one. Latency times were relatively short for head and neck cancers and Kaposi's sarcoma (most within 12–59 months), and greater than 120 months for most cases of HCC after Hodgkin's disease. All cases of Kaposi's sarcoma were seen in the later time period. Conclusions: These results highlight possible shared risk factors of alcohol ingestion and viral exposures which may predispose to second primary HCC after other primary malignancies. Providers should maintain heightened alertness for second primary HCC in these patients, especially those with head and neck cancers and HIV.

No significant financial relationships to disclose.

Loss of bacterial diversity during antibiotic treatment of intubated patients colonized with Pseudomonas aeruginosa

Management of airway infections caused by Pseudomonas aeruginosa is a serious clinical challenge, but little is known about the microbial ecology of airway infections in intubated patients. We analyzed bacterial diversity in endotracheal aspirates obtained from intubated patients colonized by P. aeruginosa by using 16S rRNA clone libraries and microarrays (PhyloChip) to determine changes in bacterial community compositions during antibiotic treatment. Bacterial 16S rRNA genes were absent from aspirates obtained from patients briefly intubated for elective surgery but were detected by PCR in samples from all patients intubated for longer periods. Sequencing of 16S rRNA clone libraries demonstrated the presence of many orally, nasally, and gastrointestinally associated bacteria, including known pathogens, in the lungs of patients colonized with P. aeruginosa. PhyloChip analysis detected the same organisms and many additional bacterial groups present at low abundance that were not detected in clone libraries. For each patient, both culture-independent methods showed that bacterial diversity decreased following the administration of antibiotics, and communities became dominated by a pulmonary pathogen. P. aeruginosa became the dominant species in six of seven patients studied, despite treatment of five of these six with antibiotics to which it was sensitive in vitro. Our data demonstrate that the loss of bacterial diversity under antibiotic selection is highly associated with the development of pneumonia in ventilated patients colonized with P. aeruginosa. Interestingly, PhyloChip analysis demonstrated reciprocal changes in abundance between P. aeruginosa and the class Bacilli, suggesting that these groups may compete for a similar ecological niche and suggesting possible mechanisms through which the loss of microbial diversity may directly contribute to pathogen selection and persistence.

Neural Probes for Concurrent Detection of Neurochemical and Electrophysiological Signals in vivo

Electrochemical sensing with microelectrode arrays provides a means for monitoring neurotransmitter dynamics across multiple locations within a micro-scale region of brain tissue. Here we present a multi-modal neural probe design for concurrent recording of neurochemical and electrophysiological signals in vivo. Prior to implantation, platinum sites on each array underwent platinum-black electroplating and Nafion electropolymerization, which increased sensitivity to dopamine by 74% and decreased sensitivity to common interferents by at least 89%. In a series of three rats, we applied various electrochemical waveforms to platinum sites and monitored neural activity on adjacent iridium sites. We found that chronoamperometry and constant-potential amperometry did not alter firing rates at +0.25, +0.50, and +0.75 V. In addition, we have demonstrated multi-modal recordings of striatal neurons in response to medial forebrain bundle stimulation.

Cost-effectiveness of omalizumab in patients with severe persistent allergic asthma

BACKGROUND

The health, economic and societal burden of asthma is considerable, and is greatest in patients with severe asthma, particularly when inadequately controlled. Real-life studies that assess the effectiveness of treatment are of particular interest.

METHODS

We determined the incremental cost-effectiveness ratio (ICER) of adding omalizumab to standard therapy using data from the real-life 1-year randomized open-label study (ETOPA) and using Canada as a reference country. Only patients receiving high-dose ICS plus LABA were included in the analysis, reflecting the EU label for omalizumab. Costs and quality-adjusted life years (QALYs) gained were used to calculate the ICER for omalizumab (cost/QALY). Probabilistic sensitivity analysis was performed to determine the 95% confidence interval and one-sided sensitivity analyses were performed.

RESULTS

The base case lifetime analysis of standard therapy vs standard therapy plus add-on omalizumab for the first 5 years, gave an ICER of 31,209 Euro. Probabilistic sensitivity analysis indicated that the 95% confidence interval around the ICER was 27,739-40,840 Euro. The ICER range for one-way sensitivity analyses was 23,762 Euro without discounting to 66,443 Euro without inclusion of asthma-related mortality.

CONCLUSIONS

This study demonstrates that add-on omalizumab therapy is cost-effective in patients with severe persistent allergic asthma.

Pediatric pancreatic trauma: predictors of nonoperative management failure and associated outcomes

BACKGROUND

Nonoperative management (NOM) is an accepted treatment of pediatric solid organ injuries and is typically successful. Blunt pancreatic trauma tends to require operative intervention more frequently. We sought to identify predictors of failure of NOM and compare the outcome of operative management against NOM.

METHODS

A retrospective analysis was performed from January 1993 to December 2002 of all children with blunt pancreatic injuries from the trauma registries of 7 designated level 1 pediatric trauma centers. Failure of NOM was defined as the need for intraabdominal operative intervention. Injuries were graded I to V, and ductal injury was defined as grades III to V. Parameters included mechanism of injury, injury severity score (ISS), organ grade, Glasgow Coma Scale score, and outcome. Data were analyzed by Fisher exact test and Mann-Whitney U test, with mean values +/- SD and significance of P < .05.

RESULTS

Pancreatic injuries were present in 173 (9.2%) of 1823 patients. Of these, 43 (26.0% [43/173]) required an operation. Valid morbidity data was obtained in 118 of 173 patients. ISS was significantly higher in all patients treated operatively. Patients with an injury of grade III to V failed NOM more frequently than all patients with pancreatic injury (P =.0169). Length of stay was longer, and the incidence of pseudocysts, drainage procedures, and pancreatitis was higher in NOM patients, although not significant.

CONCLUSIONS

Patients with pancreatic injuries had a NOM failure rate of 26.0%. ISS and injury grades III to V were predictors of NOM failure. Patients with pancreatic ductal injury require more aggressive management.

Integration, Coordination and Multidisciplinary Care: What can These Approaches Offer to Australian Primary Health Care?

Australia's population is ageing and the consequential burden of chronic disease increasingly challenges the health system. This has raised interest in, and awareness of, approaches built on multidisciplinary teams and integrated and coordinated care in managing the complex care needs of patient groups such as the chronically ill or frail aged. A systematic investigation of the literature relating to these approaches provided the opportunity to explore the meaning of these terms and their potential application and relevance to the Australian primary health care setting. Five systematic reviews of a sentinel condition and an exemplar approach to coordinated and multidisciplinary care were completed. Common learnings from the individual reviews were identified. The literature suggests that approaches encouraging a coordinated and multidisciplinary plan of care for individual patients and/or particular populations may improve a variety of outcomes. There are many methodological considerations in conducting reviews of complex interventions and in assessing their applicability to the Australian health system.

Use of the recto-sigmoid index to diagnose Hirschsprung's disease

The recto-sigmoid index on barium enema may aid in the diagnosis of Hirschsprung's disease. However, data on its reliability in different age groups are sparse. The recto-sigmoid index and transitional zone were evaluated blindly in 107 patients with diagnostic rectal suction biopsies. Patients were divided into 3 groups: neonates, infants older than 1 month, and children. The recto-sigmoid index and transitional zone agreed with the histopathologic diagnosis in 79% and 87% of the cases, respectively. Their negative predictive values reached clinical significance in infants and children but not in neonates. Their positive predictive values were not significant in any age group. The recto-sigmoid index identified 4 patients with recto-sigmoid Hirschsprung's disease whose diagnosis was missed by evaluating the transitional zone alone.

Assessing procedural skills in context: Exploring the feasibility of an Integrated Procedural Performance Instrument (IPPI)

BACKGROUND

The assessment of clinical procedural skills has traditionally focused on technical elements alone. However, in real practice, clinicians are expected to be able to integrate technical with communication and other professional skills. We describe an integrated procedural performance instrument (IPPI), where clinicians are assessed on 12 clinical procedures in a simulated clinical setting which combines simulated patients (SPs) with inanimate models or items of medical equipment. Candidates are observed remotely by assessors whose data are fed back to the clinician within 24 hours of the assessment. This paper describes the feasibility of IPPI.

RESULTS

A full-scale IPPI and 2 pilot studies with trainee and qualified health care professionals has yielded an extensive data set including 585 scenario evaluations from candidates, 60 from clinical assessors and 31 from simulated patients (SPs). Interview and questionnaire data showed that for the majority of candidates IPPI provided a powerful and valuable learning experience. Realism was rated highly. Remote and real-time assessment worked effectively, although for some procedures limited camera resolution affected observation of fine details.

DISCUSSION

IPPI offers an innovative approach to assessing clinical procedural skills. Although resource-intensive, it has the potential to provide insight into individual's performance over a spectrum of clinical scenarios and at no risk to the safety of patients. Additional benefits of IPPI include assessment in real time from experts (allowing remote rating by external examiners) as well as provision of feedback from simulated patients.

The usefulness of bone marrow aspiration in the diagnosis of Niemann-Pick disease type C in infantile liver disease

BACKGROUND

Niemann-Pick disease type C (NPC) is a fatal, autosomal recessive lysosomal storage disease which may present in infancy with cholestatic jaundice and/or hepatosplenomegaly. In cholestatic patients with splenomegaly, a bone marrow aspirate has been advocated as a relatively accessible tissue to demonstrate storage phenomena. Typically in patients with NPC, macrophages with abnormal cholesterol storage, so called foam cells, can be detected in the bone marrow.

AIM

To review our experience of bone marrow aspiration in children with NPC presenting with infantile liver disease.

METHODS

A retrospective analysis of 11 consecutive children (8 males) from Birmingham Children's Hospital with NPC presenting with infantile liver disease was undertaken. The diagnosis of NPC was confirmed in all cases by demonstrating undetectable or low rates of cholesterol esterification and positive filipin staining for free cholesterol in cultured fibroblasts.

RESULTS

The median age at presentation was 1.5 months (range 0.5-10). Bone marrow aspirates showed storage cells in only 7/11 cases. Bone marrow aspirates which had storage cells were undertaken at a median age of 11 months while those with no storage cells were undertaken at median age 2.3 months. The overall sensitivity of bone marrow aspirates for detecting storage cells in children presenting with infantile liver disease was 64%; however, for children who had bone marrow aspirates in the first year of life it was only 57%.

CONCLUSIONS

The sensitivity of bone marrow aspirate for the diagnosis of NPC disease in patients presenting with infantile liver disease was lower than previously reported. Where NPC is suspected clinically, definitive investigations should be undertaken promptly. There is a need to develop sensitive screening methods for NPC in children presenting with infantile liver disease.

Evidence for a Polar Ethane Cloud on Titan

Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal the presence of a vast tropospheric cloud on Titan at latitudes 51 degrees to 68 degrees north and all longitudes observed (10 degrees to 190 degrees west). The derived characteristics indicate that this cloud is composed of ethane and forms as a result of stratospheric subsidence and the particularly cool conditions near the moon's north pole. Preferential condensation of ethane, perhaps as ice, at Titan's poles during the winters may partially explain the lack of liquid ethane oceans on Titan's surface at middle and lower latitudes.

Epigenetics as a mechanism driving polygenic clinical drug resistance

Aberrant methylation of CpG islands located at or near gene promoters is associated with inactivation of gene expression during tumour development. It is increasingly recognised that such epimutations may occur at a much higher frequency than gene mutation and therefore have a greater impact on selection of subpopulations of cells during tumour progression or acquisition of resistance to anticancer drugs. Although laboratory-based models of acquired resistance to anticancer agents tend to focus on specific genes or biochemical pathways, such ‘one gene : one outcome’ models may be an oversimplification of acquired resistance to treatment of cancer patients. Instead, clinical drug resistance may be due to changes in expression of a large number of genes that have a cumulative impact on chemosensitivity. Aberrant CpG island methylation of multiple genes occurring in a nonrandom manner during tumour development and during the acquisition of drug resistance provides a mechanism whereby expression of multiple genes could be affected simultaneously resulting in polygenic clinical drug resistance. If simultaneous epigenetic regulation of multiple genes is indeed a major driving force behind acquired resistance of patients' tumour to anticancer agents, this has important implications for biomarker studies of clinical outcome following chemotherapy and for clinical approaches designed to circumvent or modulate drug resistance.

Gender differences among medical students in attitudes to learning about complementary and alternative medicine

OBJECTIVES

To explore gender differences in attitudes to CAM among Year 1, 2 and 3 medical students.

DESIGN

Survey; seven-item self-administered questionnaire.

SETTING

Plenary lectures at the start of semester 2 of the academic year at the University of Birmingham Medical School.

RESULTS

35.6% of 662 students were male and 64.4% female. Females were more likely than males to feel CAM has an important role in healthcare (p < 0.001). This difference increased through the medical course (p < 0.05). Females gave a more positive rating than males to the use of five therapies in healthcare (p < 001). Females were more positive than males about learning the theory (p < 0.001) and practice (p < 0.001) of CAM and a greater amount of CAM curriculum time (p < 0.001).

CONCLUSIONS

If CAM teaching is optional females may be more likely to choose it. An unexpected consequence of more women than men entering medical school may be a positive impact on the development of integrated medicine.

A comparison of the effects of A1 and A2 β-casein protein variants on blood cholesterol concentrations in New Zealand adults

Beta-casein is a cow's milk protein that occurs predominantly in two forms, A1 and A2. Epidemiological evidence suggests that per capita consumption of beta-casein A1 is associated with national mortality rates from ischaemic heart disease. A biological mechanism was proposed after rabbits fed diets containing beta-casein A2 had lower serum cholesterol concentrations and less aortic intimal thickening than rabbits fed beta-casein A1. We tested whether beta-casein A1 and A2 variants differentially affect plasma cholesterol concentrations in humans. In a randomised crossover trial of two four-and-a-half week periods without washout, 62 participants replaced all dairy products in their diet with 500 mL of low-fat milk and 28 g of full-fat cheese that differed in the proportion of beta-casein A1 and A2 variants. Duplicate blood samples were taken on non-consecutive days at the end of each treatment period from 55 people who completed the study. Mean (S.D.) plasma total, low-density and high-density lipoprotein cholesterol concentrations were 5.60 (0.77), 3.73 (0.70) and 1.26 (0.34) mmol/L after the A1 diet and 5.63 (0.81), 3.75 (0.75) and 1.27 (0.37) mmol/L after the A2 diets. We found no evidence that dairy products containing beta-casein A1 or A2 exerted differential effects (P > 0.05) on plasma cholesterol concentrations in humans.

Contribution of adenosine receptors in the control of arteriolar tone and adenosine–angiotensin II interaction

Adenosine (Ado) mediates vasoconstriction via A(1)-Ado receptors and vasodilation via A(2)-Ado receptors in the kidney. It interacts with angiotensin II (Ang II), which is important for renal hemodynamics and tubuloglomerular feedback (TGF). The aim was to investigate the function of Ado receptors in the Ado-Ang II interaction in mouse microperfused, afferent arterioles. Ado (10(-11)-10(-4) mol/l) caused a biphasic response: arteriolar diameters were reduced (-7%) at Ado 10(-11)-10(-9) mol/l and returned to control values at higher concentrations. Treatment with Ang II (10(-10) mol/l) transformed the response into a concentration-dependent constriction. N(6)-cyclopentyladenosine (A(1)-Ado receptor agonist) reduced diameters (12% at 10(-6) mol/l). Application of CGS21680 (10(-12)-10(-4) mol/l, A(2A) receptor agonist) increased the diameter by 13%. Pretreatment with ZM241385 (A(2A)-Ado receptor antagonist) alone or in combination with MRS1706 (A(2B)-Ado receptor antagonist) resulted in a pure constriction upon Ado, whereas 8-cyclopentyltheophylline (CPT) (A(1)-Ado receptor antagonist) inhibited the constrictor response. Afferent arterioles of mice lacking A(1)-Ado receptor did not show constriction upon Ado. Treatment with Ado (10(-8) mol/l) increased the response upon Ang II, which was blocked by CPT. Ado (10(-5) mol/l) did not influence the Ang II response, but an additional blockade of A(2)-Ado receptors enhanced it. The action of Ado on constrictor A(1)-Ado receptors and dilatory A(2)-Ado receptors modulates the interaction with Ang II. Both directions of Ado-Ang II interaction, which predominantly leads to an amplification of the contractile response, are important for the operation of the TGF.

Relations among questionnaire and laboratory measures of rhinovirus infection

Due to high incidence and quality-of-life impact, upper respiratory infection substantially impacts on population health. To test or compare treatment effectiveness, a well-designed and validated illness-specific quality-of-life instrument is needed. Data reported in the current study were obtained from a trial testing echinacea for induced rhinovirus infection. Laboratory-assessed biomarkers included interleukin (IL)-8, nasal neutrophil count (polymorphonuclear neutrophils (PMN)), mucus weight, viral titre and seroconversion. The questionnaires used included the general health short form (SF)-8 (24-h recall version), the eight-item Jackson cold scale, and the 44-item Wisconsin Upper Respiratory Symptom Survey (WURSS). In total, 399 participants were inoculated with rhinovirus and monitored over 2,088 person-days. Statistically significant associations were found among nearly all variables. Between-questionnaire correlations were: WURSS-Jackson = 0.81; WURSS-SF-8 = 0.62; and Jackson-SF-8 = 0.60. Correlations with laboratory values were as follows: WURSS-mucus weight = 0.53; Jackson-mucus weight = 0.55; WURSS-viral titre = 0.37; Jackson-viral titre = 0.46; WURSS-IL-8 = 0.31; Jackson-IL-8 = 0.36; WURSS-PMN = 0.31; and Jackson-PMN = 0.28. Neither WURSS nor Jackson yielded satisfactory cut-off scores for diagnosis of infection. Symptomatic and biological outcomes of upper respiratory infection are highly variable, with only modest associations. While Wisconsin Upper Respiratory Symptom Survey and Jackson questionnaires both correlate with biomarkers, neither is a good predictor of induced infection. The inclusion of functional and quality-of-life items in the Wisconsin Upper Respiratory Symptom Survey does not significantly decrease the strength of association with laboratory-assessed biomarkers.

Factors influencing p53 expression in ovarian cancer as a biomarker of clinical outcome in multicentre studies

The prognostic impact of p53 immunostaining in a large series of tumours from epithelial ovarian cancer patients in a two-centre study was analysed. The study population (n=476) comprised of a retrospective series of 188 patients (Dutch cohort) and a prospective series of 288 patients (Scottish cohort) enrolled in clinical trials. P53 expression was determined by immunohistochemistry on tissue microarrays. Association with progression-free survival (PFS) and overall survival (OS) was analysed by univariate and multivariate Cox regression analysis. Aberrant p53 overexpression was significantly associated with PFS in the Dutch and Scottish cohorts (P=0.001 and 0.038, respectively), but not with OS in univariate analysis. In multivariate analysis, when the two groups were combined and account taken of clinical factors and country of origin of the cohort, p53 expression was not an independent prognostic predictor of PFS or OS. In this well-powered study with minimal methodological variability, p53 immunostaining is not an independent prognostic marker of clinical outcome in epithelial ovarian cancer. The data demonstrate the importance of methodological standardisation, particularly defining patient characteristics and survival end-point data, if biomarker data from multicentre studies are to be combined.

Prognostic impact of MAD1L1 promoter hypermethylation in advanced ovarian cancer

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Background: Aberrant methylation of GC-rich gene promoters is a frequent epigenetic event in ovarian cancer leading to silencing of tumor suppressor genes. Identification of methylation biomarkers holds promise for impacting patient survival. Methods: High-throughput screening of hypermethylated CpG islands was conducted by differential methylation hybridization on stage III and IV epithelial ovarian carcinomas. Tumor DNA methylation status was interrogated by methylation-sensitive restriction enzymes, followed by co-hybridization on a custom promoter CpG island array with pooled normal ovarian surface epithelial cell (nOSE) DNA. Microarray findings were validated by quantitative methylation-specific PCR (qMSP) on 55–79 tumor samples. Results: Methylation levels of 6 novel genes (CYP39A1, EBP, FOXD4b, GTF2A1, MAD1L1 and YY1AP1) functioning in cell cycle control, transcription and drug metabolism/transport were identified as hypermethylated in ovarian cancer versus nOSE (nonparametric Wilcoxon rank sum test, p < 0.005). Using Fisher’s exact test, patients with shorter progression-free survival (PFS) (≤18 months) had higher methylation levels compared to those with longer PFS (p = 0.015) for the gene MAD1L1, a mitotic checkpoint protein and antagonist of c-myc that regulates cell proliferation and differentiation. Cox regression analysis of methylation levels and PFS identified a negative correlation for MAD1L1. This correlation achieved statistical significance when MAD1L1 methylation levels combined with chemotherapy response was tested against PFS (p = 0.021), suggesting an interaction of this gene in patient response to chemotherapy. Conclusions: Induced overexpression of MAD1L1 has been shown to delay cell proliferation and inhibit growth. Downregulation via hypermethylation of this gene results in cell cycle dysregulation, a pathway for disease progression. This epigenetic modification in MAD1L1 renders it a potential target for intervention therapies that could improve patient survival.

No significant financial relationships to disclose.