Statement on Meningococcal Disease and the International Traveller

BACKGROUND

Meningococcal meningitis occurs globally and the predominant serogroups vary by geographic region. Vaccines against serogroups A, B, C, Y and W-135 are available in Canada.

OBJECTIVE

To provide guidance to health care professionals for the prevention of invasive meningococcal disease in international travellers from Canada.

METHODS

This Statement was developed by the Committee to Advise on Tropical Medicine and Travel (CATMAT) to compliment the Canadian Immunization Guide. It considers the need for protection and the potential for adverse effects of vaccination.

RESULTS

Meningococcal vaccine recommendations vary by traveller characteristics and travel destination. Meningococcal meningitis occurs globally and the predominant serogroup varies by geographic region. Areas of particular risk are the "meningitis belt" in Sub-Saharan Africa, Saudi Arabia during the Hajj and Umrah pilgrimages and places with current epidemics or heightened disease activity. For healthy travellers see the Canadian Immunization Guide. Quadrivalent vaccine should be given to individuals at increased risk for invasive meningococcal disease due to medical conditions with booster doses every five years. Meningococcal B vaccine should be considered.

CONCLUSION

Vaccination is the most effective measure for preventing invasive meningococcal disease. The Government of Canada's travel health notices identify areas of new and recent meningococcal activity and are updated regularly.

Classroom conditions and CO2 concentrations and teacher health symptom reporting in 10 New York State Schools

This study assessed the relationship between teacher-reported symptoms and classroom carbon dioxide (CO2 ) concentrations. Previous studies have suggested that poor indoor ventilation can result in higher levels of indoor pollutants, which may affect student and teacher health. Ten schools (9 elementary, 1 combined middle/high school) in eight New York State school districts were visited over a 4-month period in 2010. Carbon dioxide concentrations were measured in classrooms over 48-h, and teachers completed surveys assessing demographic information and self-reported symptoms experienced during the current school year. Data from 64 classrooms (ranging from 1 to 9 per school) were linked with 68 teacher surveys (for four classrooms, two surveys were returned). Overall, approximately 20% of the measured classroom CO2 concentrations were above 1000 parts per million (ppm), ranging from 352 to 1591 ppm. In multivariate analyses, the odds of reporting neuro-physiologic (i.e., headache, fatigue, difficulty concentrating) symptoms among teachers significantly increased (OR = 1.30, 95% CI = 1.02-1.64) for every 100 ppm increase in maximum classroom CO2 concentrations and were non-significantly increased in classrooms with above-median proportions of CO2 concentrations greater than 1000 ppm (OR = 2.26, 95% CI = 0.72-7.12).

Travel-acquired infections in Canada: CanTravNet 2011-2012

BACKGROUND

Important gaps remain in our knowledge of the infectious diseases people acquire while travelling and the impact of pathogens imported by Canadian travellers.

OBJECTIVE

To provide a surveillance update of illness in a cohort of returned Canadian travellers and new immigrants.

METHODS

Data on returning Canadian travellers and new immigrants presenting to a CanTravNet site between September 2011 and September 2012 were extracted and analyzed by destination, presenting symptoms, common and emerging infectious diseases and disease severity.

RESULTS

During the study period, 2283 travellers and immigrants presented to a CanTravNet site, 88% (N=2004) of whom were assigned a travel-related diagnosis. Top three destinations for non-immigrant travellers were India (N=132), Mexico (N=103) and Cuba (N=89). Fifty-one cases of malaria were imported by ill returned travellers during the study period, 60% (N=30) of which were Plasmodium falciparum infections. Individuals travelling to visit friends and relatives accounted for 83% of enteric fever cases (15/18) and 41% of malaria cases (21/51). The requirement for inpatient management was over-represented among those with malaria compared to those without malaria (25% versus 2.8%; p<0.0001) and those travelling to visit friends and relatives versus those travelling for other reasons (12.1% versus 2.4%; p<0.0001). Nine new cases of HIV were diagnosed among the cohort, as well as one case of acute hepatitis B. Emerging infections among travellers included hepatitis E virus (N=6), chikungunya fever (N=4) and cutaneous leishmaniasis (N=16). Common chief complaints included gastrointestinal (N=804), dermatologic (N=440) and fever (N=287). Common specific causes of chief complaint of fever in the cohort were malaria (N=47/51 total cases), dengue fever (14/18 total cases), enteric fever (14/17 total cases) and influenza and influenza-like illness (15/21 total cases). Animal bites were the tenth most common diagnosis among tourist travellers.

INTERPRETATION

Our analysis of surveillance data on ill returned Canadian travellers provides a recent update to the spectrum of imported illness among travelling Canadians. Preventable travel-acquired illnesses and injuries in the cohort include malaria, enteric fever, HIV, hepatitis B, hepatitis A, influenza and animal bites. Strategies to improve uptake of preventive interventions such as malaria chemoprophylaxis, immunizations and arthropod/animal avoidance may be warranted.

Management of impacted wisdom teeth: teaching of undergraduate students in UK dental schools

INTRODUCTION

Wisdom tooth removal is one of the most common oral surgical procedures performed across the world. The aim of this study was to gauge the teaching and training of impacted wisdom teeth in undergraduate dental programmes across the UK. The objectives were to identify consistencies and variations in theoretical instructions and clinical training as well as approaches to management of impacted wisdom teeth.

METHODS

This was a cross-sectional survey utilising an online questionnaire. A purposefully designed pro forma with open- as well as closed-ended questions was used. The questionnaire was hosted online on the school's blackboard academic suite (Emily). Prior to conducting the study, approval was gained from the Research and Ethics Committee, and all the ethical principles pertaining to data protection were strictly followed. E-mail invitations were sent to oral surgery leads in all dental schools in the UK. The participants were provided with an information sheet, and an informed consent was obtained. The participants were invited by e-mail to complete the questionnaire online voluntarily.

RESULTS

A total of 16 dental schools offering an undergraduate course in dentistry in the UK, 13 responded positively. (response rate = 81.25%). In majority of dental schools, this subject is taught in the 4th and 5th years. A pre-clinical competency on phantom heads is a requirement in six schools, whilst only one school requires the students to pass a clinical competency. The clinical exposure of students to wisdom tooth surgery is quite variable. Although the dental schools are fairly consistent in their teaching with regard to the indications for surgical intervention, diagnostic/treatment modalities as well as the post-operative care, interesting variations were also observed.

CONCLUSIONS

This study, perhaps the first of its kind, provides useful insights into management of impacted wisdom teeth, as taught in the undergraduate dental programmes across the UK.

Summary of recommendations for the diagnosis and treatment of malaria by the Committee to Advise on Tropical Medicine and Travel (CATMAT)

BACKGROUND

On behalf of the Public Health Agency of Canada, the Committee to Advise on Tropical Medicine and Travel (CATMAT) developed the Canadian Recommendations for the Prevention and Treatment of Malaria Among International Travellers for Canadian health care providers who are preparing patients for travel to malaria-endemic areas and treating travellers who have returned ill. These recommendations aim to achieve appropriate diagnosis and management of malaria, a disease that is still uncommon in Canada.

OBJECTIVE

To provide recommendations on the appropriate diagnosis and treatment of malaria.

METHODS

CATMAT reviewed all major sources of information on malaria diagnosis and treatment, as well as recent research and national and international epidemiological data, to tailor guidelines to the Canadian context. The evidence-based medicine recommendations were developed with associated rating scales for the strength and quality of the evidence.

RECOMMENDATIONS

Malarial management depends on rapid identification of the disease, as well as identification of the malaria species and level of parasitemia. Microscopic identification of blood samples is both rapid and accurate but can be done only by trained laboratory technicians. Rapid diagnostic tests are widely available, are simple to use and do not require specialized laboratory equipment or training; however, they do not provide the level of parasitemia and do require verification. Polymerase chain reaction (PCR), although still limited in availability, is emerging as the gold standard for high sensitivity and specificity in identifying the species.

A novel, automated nutrition screening system as a predictor of nutritional risk in an oncology day treatment unit (ODTU)

PURPOSE

Paper-based nutrition screening tools can be challenging to implement in the ambulatory oncology setting. The aim of this study was to determine the validity of the Malnutrition Screening Tool (MST) and a novel, automated nutrition screening system compared to a 'gold standard' full nutrition assessment using the Patient-Generated Subjective Global Assessment (PG-SGA).

METHODS

An observational, cross-sectional study was conducted in an outpatient oncology day treatment unit (ODTU) within an Australian tertiary health service. Eligibility criteria were as follows: ≥ 18 years, receiving outpatient anticancer treatment and English literate. Patients self-administered the MST. A dietitian assessed nutritional status using the PG-SGA, blinded to the MST score. Automated screening system data were extracted from an electronic oncology prescribing system. This system used weight loss over 3 to 6 weeks prior to the most recent weight record or age-categorised body mass index (BMI) to identify nutritional risk. Sensitivity and specificity against PG-SGA (malnutrition) were calculated using contingency tables and receiver operating curves.

RESULTS

There were a total of 300 oncology outpatients (51.7% male, 58.6 ± 13.3 years). The area under the curve (AUC) for weight loss alone was 0.69 with a cut-off value of ≥ 1% weight loss yielding 63% sensitivity and 76.7% specificity. MST (score ≥ 2) resulted in 70.6% sensitivity and 69.5% specificity, AUC 0.77.

CONCLUSIONS

Both the MST and the automated method fell short of the accepted professional standard for sensitivity (~≥ 80%) derived from the PG-SGA. Further investigation into other automated nutrition screening options and the most appropriate parameters available electronically is warranted to support targeted service provision.

Evaluation of an innovative recruitment initiative on the attitudes of medical students

Some medical specialties struggle to recruit sufficient trainees to their postgraduate programmes. In many countries including Ireland, psychiatry is one of these specialties. A psychiatric summer school was developed by the trainee committee of the College of Psychiatry of Ireland as a recruitment initiative. All applicants were invited to complete a questionnaire prior, on the day of and three months after the summer school assessing their attitudes to a career in psychiatry. The mean score on the modified Nielson questionnaire in the pre-summer school group was 26.7 (SD +/- 3.8) and this rose significantly 28.3 (SD +/- 3.2) after completion of the summer school. 64% (n = 31) of applicants to the Summer school expressed an interest in a career in psychiatry. This rose to 88% (n = 32) of those who attended. The findings of this study have national and international interest for all specialties who are struggling to recruit to their field.

A pragmatic randomised controlled trial to compare antidepressants with a community-based psychosocial intervention for the treatment of women with postnatal depression: the RESPOND trial

OBJECTIVES

To evaluate clinical effectiveness at 4 weeks of antidepressant therapy for mothers with postnatal depression (PND) compared with general supportive care; to compare outcome at 18 weeks of those randomised to antidepressant therapy with those randomised to listening visits as the first intervention (both groups were to be allowed to receive the alternative intervention after 4 weeks if the woman or her doctor so decided); and to assess acceptability of antidepressants and listening visits to users and health professionals.

DESIGN

A pragmatic two-arm individually randomised controlled trial.

SETTING

Participants were recruited from 77 general practices: 21 in Bristol, 21 in south London and 35 in Manchester.

PARTICIPANTS

A total of 254 women who fulfilled International Classification of Diseases version 10 criteria for major depression in the first 6 postnatal months were recruited and randomised.

INTERVENTIONS

Women were randomised to receive either an antidepressant, usually a selective serotonin reuptake inhibitor prescribed by their general practitioner (GP), or non-directive counselling (listening visits) from a specially trained research health visitor (HV). The trial was designed to compare antidepressants with general supportive care for the first 4 weeks, after which women allocated to listening visits commenced their sessions. It allowed for women to receive the alternative intervention if they had not responded to their allocated intervention or wished to change to, or add in, the alternative intervention at any time after 4 weeks.

MAIN OUTCOME MEASURES

The duration of the trial was 18 weeks. Primary outcome, measured at 4 weeks and 18 weeks post randomisation, was the proportion of women improved on the Edinburgh Postnatal Depression Scale (EPDS), that is scoring < 13. Secondary outcomes were the EPDS measured as a continuous variable at 4 and 18 weeks, and scores on various other questionnaires.

RESULTS

At 4 weeks, women were more than twice as likely to have improved if they had been randomised to antidepressants compared with listening visits, which started after the 4-week follow-up, i.e. after 4 weeks of general supportive care [primary intention-to-treat (ITT), 45% versus 20%; odds ratio (OR) 3.4, 95% confidence interval (CI) 1.8 to 6.5, p < 0.001]. Explanatory analyses emphasised these findings. At 18 weeks, ITT analysis revealed that the proportion of women improving was 11% greater in the antidepressant group, but logistic regression analysis showed no clear benefit for one group over the other [62% versus 51%, OR 1.5 (95% CI 0.8 to 2.6), p = 0.19]. Overall, there was a difference between the groups in favour of the antidepressant group of about 25 percentage points at 4 weeks, which reduced at 18 weeks. No statistical support existed for a benefit of antidepressants at 18 weeks, but 95% CIs could not rule out a clinically important benefit. It was difficult for GPs not to prescribe antidepressants to women randomised to listening visits after the initial 4 weeks, so many women received both interventions in both groups by 18 weeks and consequently power was reduced. Qualitative interviews with women revealed a preference for listening visits but an acceptance that antidepressants might be necessary. They wished to be reassured that their GP and HV were offering continuity of care focusing on their particular set of circumstances. Interviews with GPs and HVs revealed lack of collaboration in managing care for women with PND; neither professional group was willing to assume responsibility.

CONCLUSIONS

At 4 weeks, antidepressants were significantly superior to general supportive care. Trial design meant that by 18 weeks many of the women initially randomised to listening visits were also receiving antidepressants, and more vice versa. The lack of evidence for differences at 18 weeks is likely to reflect a combination of reduced power and the considerable degree of switching across the two interventions. Qualitative study revealed that women found both antidepressants and listening visits effective depending on their circumstances and preferences. The trial indicates that early treatment with antidepressants leads to clinical benefit for women with PND.

Primary adenoid cystic carcinoma of the bronchus in a female teenager

Primary adenoid cystic carcinoma (ACC) of the lung is an extremely rare malignant lung neoplasm. ACC of salivary glands of the head and neck, lachrymal glands, breast, skin, vulva and trachea have been frequently reported disease patterns in the literature, but it is unique to see this rare lung tumour in a patient as young as 14 years old. No double blind placebo, multicentre treatment data are available. Surgery is considered as the cornerstone of the treatment. Prognosis is variable and adjuvant radiotherapy has been found beneficial for prolonged survival. Our report of primary lung ACC in a young girl is a complex case due to young age, a different way of presentation and staging on diagnosis. It has been a quite challenging clinical scenario for the multidisciplinary lung cancer treating team involved in the clinical care. Prognosis remains unpredictable and uncertain despite the best present day evidence-based treatment.

Pregnancy outcomes in sickle cell disease: a retrospective cohort study from two tertiary centres in the UK

The objective of this retrospective cohort study from two tertiary centres in the UK was to describe the pregnancy outcomes of women with sickle cell disease (SCD) who booked at these centres between 2004 and 2008, and to compare this with historical data. The study population comprised 122 singleton pregnancies in women with SCD: homozygous sickle cell disease 64, sickle cell haemoglobin C disease 45, sickle b plus thalassaemia 11, sickle cell haemoglobin E disease 1 and sickle cell delta disease 1 from 2004 to 2008 managed in the joint haematology/obstetric antenatal clinics in two tertiary teaching hospitals. The main outcome measures were the frequency of sickle cell crises and obstetric complications. Age and gestation at booking were 18-43 years (mean 29.7) and 9-36 weeks gestation (mean 17.3), respectively. Complications of SCD occurred in 25% of pregnancies. Fifty-four percent of women had induction of labour and 39% were delivered by emergency caesarean section. Thirty-three percent had a postpartum haemorrhage. Nineteen percent of women delivered before 37 completed weeks. Birth weight below 2500 g occurred in 20% of singleton pregnancies. Three neonates developed transient complications related to maternal opiate exposure postnatally. Three intrauterine deaths occurred at 24, 29 and 34 weeks. Two of these had congenital defects, and the other severe intrauterine growth restriction. No maternal deaths occurred. Successful pregnancy outcomes can be achieved in SCD. There has been an improvement in fetal and maternal morbidity and mortality compared with historical data. Pregnancy in women with SCD remains high risk. Early access to antenatal care and to expertise in SCD is essential. A matched control population from the same time period and prospective data collection is needed to address confounders such as ethnicity and deprivation.

Fathers’ Views and Understanding of their Roles in Families with a Child with Acute Lymphoblastic Leukaemia

This study explored how fathers of children diagnosed with acute lymphoblastic leukaemia (ALL) perceived and understood the roles they had within their family over the course of their child’s illness and treatment. In-depth semi-structured interviews were conducted with five fathers. Transcripts were analysed using interpretative phenomenological analysis (IPA). The major themes that emerged were: adjusting to the diagnosis; the experience of maternal gate-keeping; striving for normalization; experiences of giving and receiving support. Overall, the fathers perceived themselves as having significant responsibility in helping their child and family cope with the illness experience. Clinical implications, including the need for professionals to recognize and more openly acknowledge the father’s position, are considered.

Population pharmacokinetic and pharmacogenetic analysis of 6-mercaptopurine in paediatric patients with acute lymphoblastic leukaemia

AIMS

To investigate the population pharmacokinetics of 6-mercaptopurine (6-MP) active metabolites in paediatric patients with acute lymphoblastic leukaemia (ALL) and examine the effects of various genetic polymorphisms on the disposition of these metabolites.

METHODS

Data were collected prospectively from 19 paediatric patients with ALL (n = 75 samples, 150 concentrations) who received 6-MP maintenance chemotherapy (titrated to a target dose of 75 mg m(-2) day(-1)). All patients were genotyped for polymorphisms in three enzymes involved in 6-MP metabolism. Population pharmacokinetic analysis was performed with the nonlinear mixed effects modelling program (nonmem) to determine the population mean parameter estimate of clearance for the active metabolites.

RESULTS

The developed model revealed considerable interindividual variability (IIV) in the clearance of 6-MP active metabolites [6-thioguanine nucleotides (6-TGNs) and 6-methylmercaptopurine nucleotides (6-mMPNs)]. Body surface area explained a significant part of 6-TGNs clearance IIV when incorporated in the model (IIV reduced from 69.9 to 29.3%). The most influential covariate examined, however, was thiopurine methyltransferase (TPMT) genotype, which resulted in the greatest reduction in the model's objective function (P < 0.005) when incorporated as a covariate affecting the fractional metabolic transformation of 6-MP into 6-TGNs. The other genetic covariates tested were not statistically significant and therefore were not included in the final model.

CONCLUSIONS

The developed pharmacokinetic model (if successful at external validation) would offer a more rational dosing approach for 6-MP than the traditional empirical method since it combines the current practice of using body surface area in 6-MP dosing with a pharmacogenetically guided dosing based on TPMT genotype.

Early life growth and hemostatic factors: the Barry Caerphilly Growth study

Associations between early life growth trajectories and a range of adult (aged approximately 25 years) hemostatic factors were assessed in the Barry Caerphilly Growth study (N = 517) in South Wales, 1974-1999. Associations of birth weight, birth length, and weight and height velocities during three periods ("immediate": 0-<5 months, "infant": 5 months-<1 year 9 months, and "childhood": 1 year 9 months-5 years) with adult levels of hemostatic factors were assessed. Birth weight was inversely associated with fibrinogen (beta per 1-unit change in z score = -0.08, 95% confidence interval (CI): -0.15, -0.02). Immediate weight velocity was inversely associated with factor VII (beta = -1.88, 95% CI: -3.84, 0.09), factor VIII (beta = -2.58, 95% CI: -4.07, -0.45), and von Willebrand factor antigen (beta = -4.07, 95% CI: -7.25, -0.89). Birth length was inversely associated with fibrinogen (beta = -0.07, 95% CI: -0.14, -0.01). Evidence was weaker for an inverse association of immediate height velocity with factor VIII (beta = -2.16, 95% CI: -4.62, 0.29) and von Willebrand factor antigen (beta = -2.85, 95% CI: -6.52, 0.81). Childhood height velocity was positively associated with D-dimer (ratio of geometric means = 1.11, 95% CI: 1.01, 1.23). Results support the view that the immediate postnatal period may be particularly important, possibly through impaired liver development and/or infection in early life, in determining cardiovascular disease risk.

Pharmacogenomic studies of the anticancer and immunosuppressive thiopurines mercaptopurine and azathioprine

AIMS

To examine the allelic variation of three enzymes involved in 6-mercaptopurine/azathioprine (6-MP/AZA) metabolism and evaluate the influence of these polymorphisms on toxicity, haematological parameters and metabolite levels in patients with acute lymphoblastic leukaemia (ALL) or inflammatory bowel disease (IBD).

METHODS

Clinical data and blood samples were collected from 19 ALL paediatric patients and 35 IBD patients who were receiving 6-MP/AZA therapy. All patients were screened for seven genetic polymorphisms in three enzymes involved in mercaptopurine metabolism [xanthine oxidase, inosine triphosphatase (C94-->A and IVS2+21A-->C) and thiopurine methyltransferase]. Erythrocyte and plasma metabolite concentrations were also determined. The associations between the various genotypes and myelotoxicity, haematological parameters and metabolite concentrations were determined.

RESULTS

Thiopurine methyltransferase variant alleles were associated with a preferential metabolism away from 6-methylmercaptopurine nucleotides (P = 0.008 in ALL patients, P = 0.038 in IBD patients) favouring 6-thioguanine nucleotides (6-TGNs) (P = 0.021 in ALL patients). Interestingly, carriers of inosine triphosphatase IVS2+21A-->C variants among ALL and IBD patients had significantly higher concentrations of the active cytotoxic metabolites, 6-TGNs (P = 0.008 in ALL patients, P = 0.047 in IBD patients). The study confirmed the association of thiopurine methyltransferase heterozygosity with leucopenia and neutropenia in ALL patients and reported a significant association between inosine triphosphatase IVS2+21A-->C variants with thrombocytopenia (P = 0.012). CONCLUSIONS; Pharmacogenetic polymorphisms in the 6-MP pathway may help identify patients at risk for associated toxicities and may serve as a guide for dose individualization.

Estimates of maternal risks of pregnancy for women with hereditary haemorrhagic telangiectasia (Osler-Weber-Rendu syndrome): suggested approach for obstetric services

OBJECTIVES

Hereditary haemorrhagic telangiectasia (HHT) affects 1 in 5-8000 individuals. Pregnancy outcomes are rarely reported. The major reason is that most women do not have their HHT diagnosed prior to pregnancy. Using a large well-characterised series, we studied all pregnancies known to have occurred in HHT-affected women, whether or not their diagnosis was known at the time of pregnancy. Our aim was to estimate rates and types of major complications of HHT in pregnancy, to guide management decisions.

DESIGN

Cohort study, with prospective, retrospective and familial components.

SETTING/POPULATION

Tertiary referral centre population.

METHODS

All 262 pregnancies in the 111 women with HHT and pulmonary arteriovenous malformations (PAVMs) reviewed between 1999 and 2005 were studied. Eighty-two women (74%) did not have a diagnosis of HHT/PAVM at the time of pregnancy. 222 pregnancies in their 86 HHT-affected relatives were also studied.

MAIN OUTCOME MEASURES

PAVM bleed, stroke and maternal death.

RESULTS

Thirteen women experienced life-threatening events during pregnancy: 1.0% (95% CI 0.1-1.9) of pregnancies resulted in a major PAVM bleed; 1.2% (0.3-2.2%) in stroke (not all were HHT related); and 1.0% (0.13-1.9%) in maternal death. All deaths occurred in women previously considered well. In women experiencing a life-threatening event, prior awareness of HHT or PAVM diagnosis was associated with improved survival (P = 0.041, Fisher's exact test).

CONCLUSIONS

Most HHT pregnancies proceed normally. Rare major complications, and improved survival outcome following prior recognition, means that pregnancy in a woman with HHT should be considered high risk. Recommendations for pregnancy management are provided.

Prevention and management of central venous catheter occlusion and thrombosis in children with cancer

BACKGROUND

The views and clinical practice of children's cancer units were surveyed regarding management of central venous catheter (CVC) occlusion (CVC-occlusion), CVC-related thrombosis (CVC-thrombosis) and thromboembolism (CVC-thromboembolism).

PROCEDURE

A questionnaire was sent to all 22 United Kingdom Children's Cancer Study Group centres, requesting information about their views of the importance of, and their practices regarding, prophylaxis, diagnosis and treatment of CVC-occlusion/thrombosis.

RESULTS

Twenty (91%) centres responded. Eighty percent, 80% and 70%, respectively, stated that CVC-occlusion, CVC-thrombosis and CVC-thromboembolism were clinically important concerns. All centres used heparinised saline flushes as prophylaxis against CVC-occlusion, with little variation (</=30% centres) in frequency, volume and heparin concentration. Symptoms or signs suggesting partial CVC-occlusion, total CVC-occlusion, or CVC-thrombosis/thromboembolism were always investigated in 20%, 55% and 85% of centres, respectively, but with considerable variability in the nature and sequence of investigations performed, which included (depending on the clinical scenario) chest X-ray, contrast linography or venography, ultrasonography, echocardiography and magnetic resonance venography. A fibrinolytic lock was administered before investigation of CVC-occlusion in 75% of centres. Although 45%, 60% and 80%, respectively, always treated partial CVC-occlusion, total CVC-occlusion or CVC-thrombosis/thromboembolism, the type and order of treatments differed greatly between centres, especially for CVC-thrombosis/thromboembolism, in which CVC removal, systemic anticoagulation (heparin or warfarin), local or systemic fibrinolysis, or thrombectomy were performed in at least some centres.

CONCLUSIONS

The clinical practice of UKCCSG centres regarding prevention, investigation and treatment of CVC-occlusion/thrombosis varies greatly. Additional trials should facilitate development of evidence-based guidelines.

Development of the left-right axis

Left-right is not an axis in the conventional sense but rather two mirror-image proximodistal axes, upon which a quantal piece of positional information (leftness or rightness) is superimposed for laterally asymmetric organ development. We are attempting to establish the stages at which left-right is specified and determined, but this is complicated by the apparent loss of normal handed development in embryos that are cultured from pre-neural plate stages. Experiments suggest that left-right is determined by the first somite stage. The loss of normal left-right development in early cultures is probably not due to removal of some maternal signal, even though embryos do develop in vivo with their axes in a specific orientation relative to the uterus. The fact that there are two random embryonic axis orientations, 180 degrees opposed to one another, and that the axes of the two uterine horns are mirror-images of each other make it unlikely that the uterus could impart a sense of left-right to the embryo. The right ovary produces more eggs than the left one; this is reversed in iv/iv situs inversus mice. Analysis of iv/iv mice shows a correlation of left-right abnormalities with sex and close relationships between the abnormal left-right development of some organs, for example the heart and spleen, that have no obvious developmental connection.

Development of handed body asymmetry in mammals

We have proposed a three step model for the specification of left-right in mammalian embryos. The fundamental assumption is that handedness is imparted by an asymmetrical molecule. Conversion of molecular asymmetry to the cellular level gives a property to one side of the embryo to bias an otherwise random generation of an asymmetrical gradient which can be interpreted by developing organs. Rat embryos, treated at discrete stages, show a window of sensitivity for disruption of handedness, which may reflect the time of conversion/biasing. Heat shock and several chemicals cause left-right inversion in up to 50% of embryos exposed during neural groove formation. Earlier stages are less sensitive; no treatment begun after foregut pocket formation influences asymmetry. Evidence for cellular interactions in left-right specification comes from the apparent rescue of iv/iv mutant embryos in chimeras. We are looking for molecular left-right disparity before morphological asymmetry but detect no differences in two-dimensional protein profiles. Using an indirect measure, we find a right-left gradient of tissue oxygen in embryos at the 20-30 somite stage. This may reflect asymmetrical vasculature, as we have suggested to explain drug-induced asymmetrical limb malformations.

A mouse model of basal-like breast carcinoma with metaplastic elements

Breast cancers arising in carriers of germline BRCA1 mutations frequently have a basal-like phenotype. Basal-like cancers are characterized by high histological grade, central necrotic areas, foci with metaplastic differentiation, lack of hormone receptor and HER2 (ErbB2) expression, and consistent positivity for basal markers, including CK5/6, CK14, and EGFR. We have used germline manipulation to generate a conditional mouse model of Brca1 deficiency. Transgenic expression of Cre recombinase in the mammary gland of these mice results in deletion of exons encoding the C-terminus of Brca1 and leads to tumour formation when combined with heterozygosity for a p53 mutation. Histologically, these mammary gland tumours were characterized by high histological grade, central necrotic areas, and presence of homologous metaplastic elements. These metaplastic elements consisted of neoplastic spindle cells or squamous cell differentiation in the form of keratin pearls or individual cell keratinization. Immunohistochemical analysis revealed expression of basal-like markers in all cases. The tumour phenotype generated in our mouse model was compared with published data on human basal-like breast carcinomas and also with metaplastic breast cancers with a basal-like phenotype; the comparison showed that we have generated a mouse model of basal-like breast cancer, which should prove useful in testing new and targeted treatments for this type of breast cancer.

A study of idiopathic generalised epilepsy in an Irish population

Idiopathic generalised epilepsy (IGE) is subdivided into syndromes based on clinical and EEG features.

PURPOSE

The aim of this study was to characterise all cases of IGE with supportive EEG abnormalities in terms of gender differences, seizure types reported, IGE syndromes, family history of epilepsy and EEG findings. We also calculated the limited duration prevalence of IGE in our cohort.

METHODS

Data on abnormal EEGs were collected retrospectively from two EEG databases at two tertiary referral centres for neurology. Clinical information was obtained from EEG request forms, standardised EEG questionnaires and medical notes of patients.

RESULTS

two hundred twenty-three patients met our inclusion criteria, 89 (39.9%) male and 134 (60.1%) females. Tonic clonic seizures were the most common seizure type reported, 162 (72.65%) having a generalised tonic clonic seizure (GTCS) at some time. IGE with GTCS only (EGTCSA) was the most common syndrome in our cohort being present in 94 patients (34 male, 60 female), with 42 (15 male, 27 female) patients diagnosed with Juvenile myoclonic epilepsy (JME), 23 (9 male, 14 female) with Juvenile absence epilepsy (JAE) and 20 (9 male, 11 female) with childhood absence epilepsy (CAE). EEG studies in all patients showed generalised epileptiform activity.

CONCLUSIONS

More women than men were diagnosed with generalised epilepsy. Tonic clonic seizures were the most common seizure type reported. EGTCSA was the most frequent syndrome seen. Gender differences were evident for JAE and JME as previously reported and for EGTCSA, which was not reported to date, and reached statistical significance for EGTCA and JME.

Epidemiological, social, diagnostic and economic evaluation of population screening for genital chlamydial infection

OBJECTIVES

To investigate epidemiological, social, diagnostic and economic aspects of chlamydia screening in non-genitourinary medicine settings.

METHODS

Linked studies around a cross-sectional population-based survey of adult men and women invited to collect urine and (for women) vulvovaginal swab specimens at home and mail these to a laboratory for testing for Chlamydia trachomatis. Specimens were used in laboratory evaluations of an amplified enzyme immunoassay (PCE EIA) and two nucleic acid amplification tests [Cobas polymerase chain reaction (PCR), Becton Dickinson strand displacement amplification (SDA)]. Chlamydia-positive cases and two negative controls completed a risk factor questionnaire. Chlamydia-positive cases were invited into a randomised controlled trial of partner notification strategies. Samples of individuals testing negative completed psychological questionnaires before and after screening. In-depth interviews were conducted at all stages of screening. Chlamydia transmission and cost-effectiveness of screening were investigated in a transmission dynamic model.

SETTING AND PARTICIPANTS

General population in the Bristol and Birmingham areas of England. In total, 19,773 women and men aged 16-39 years were randomly selected from 27 general practice lists.

RESULTS

Screening invitations reached 73% (14,382/19,773). Uptake (4731 participants), weighted for sampling, was 39.5% (95% CI 37.7, 40.8%) in women and 29.5% (95% CI 28.0, 31.0%) in men aged 16-39 years. Chlamydia prevalence (219 positive results) in 16-24 year olds was 6.2% (95% CI 4.9, 7.8%) in women and 5.3% (95% CI 4.4, 6.3%) in men. The case-control study did not identify any additional factors that would help target screening. Screening did not adversely affect anxiety, depression or self-esteem. Participants welcomed the convenience and privacy of home-sampling. The relative sensitivity of PCR on male urine specimens was 100% (95% CI 89.1, 100%). The combined relative sensitivities of PCR and SDA using female urine and vulvovaginal swabs were 91.8% (86.1, 95.7, 134/146) and 97.3% (93.1, 99.2%, 142/146). A total of 140 people (74% of eligible) participated in the randomised trial. Compared with referral to a genitourinary medicine clinic, partner notification by practice nurses resulted in 12.4% (95% CI -3.7, 28.6%) more patients with at least one partner treated and 22.0% (95% CI 6.1, 37.8%) more patients with all partners treated. The health service and patients costs (2005 prices) of home-based postal chlamydia screening were 21.47 pounds (95% CI 19.91 pounds, 25.99) per screening invitation and 28.56 pounds (95% CI 22.10 pounds, 30.43) per accepted offer. Preliminary modelling found an incremental cost-effectiveness ratio (2003 prices) comparing screening men and women annually to no screening in the base case of 27,000 pounds/major outcome averted at 8 years. If estimated screening uptake and pelvic inflammatory disease incidence were increased, the cost-effectiveness ratio fell to 3700 pounds/major outcome averted.

CONCLUSIONS

Proactive screening for chlamydia in women and men using home-collected specimens was feasible and acceptable. Chlamydia prevalence rates in men and women in the general population are similar. Nucleic acid amplification tests can be used on first-catch urine specimens and vulvovaginal swabs. The administrative costs of proactive screening were similar to those for opportunistic screening. Using empirical estimates of screening uptake and incidence of complications, screening was not cost-effective.

Leflunomide failure to control recurrent cytomegalovirus infection in the setting of renal failure after allogeneic stem cell transplantation

Cytomegalovirus (CMV) reactivation is common in the allogeneic stem cell transplant setting but the incidence of CMV organ disease and mortality has been dramatically reduced by prophylactic or preemptive antiviral therapy. We report the case of a CMV-seropositive 46-year-old man with non-Hodgkin's lymphoma who underwent an unrelated allogeneic stem cell transplant from a CMV-seronegative HLA-matched unrelated donor. CMV encephalitis and colitis developed that was refractory to single-agent therapy. The CMV isolate demonstrated genotypic resistance to both ganciclovir and foscarnet. CMV disease was controlled by prolonged combination ganciclovir and cidofovir therapy, but severe renal dysfunction developed. Leflunomide was selected as a last resort to avoid the nephrotoxicity of cidofovir. CMV antigenemia rapidly increased following leflunomide administration, necessitating discontinuing this agent and resuming prior antiviral therapy. The pharmacokinetics of leflunomide in the setting of renal insufficiency is presented. Options for salvage therapy in refractory CMV disease in allogeneic stem cell transplant recipients are briefly reviewed.

High-throughput sample handling and data collection at synchrotrons: embedding the ESRF into the high-throughput gene-to-structure pipeline

An automatic data-collection system has been implemented and installed on seven insertion-device beamlines and a bending-magnet beamline at the ESRF (European Synchrotron Radiation Facility) as part of the SPINE (Structural Proteomics In Europe) development of an automated structure-determination pipeline. The system allows remote interaction with beamline-control systems and automatic sample mounting, alignment, characterization, data collection and processing. Reports of all actions taken are available for inspection via database modules and web services.

The care and nurture of undulator data sets

Undulator radiation is the X-ray source of choice for modern macromolecular crystallography beamlines. Here, the basic properties of undulator sources are described and it is indicated why they make such good X-ray sources for macromolecular crystallography. Collection of excellent data from these beamlines is not always straightforward; therefore, a number of rules are postulated for undulator data collection and guidelines are offered which will help to ensure a satisfactory experiment.