The psychological impact of predictive genetic testing for Huntington's disease: a systematic review of the literature

Huntington's disease (HD) is a neurodegenerative genetic condition for which a predictive genetic test by mutation analysis has been available since 1993. However, whilst revealing the future presence of the disease, testing may have an adverse psychological impact given that the disease is progressive, incurable and ultimately fatal. This review seeks to systematically explore the psychological impact of genetic testing for individuals undergoing pre-symptomatic mutation analysis. Three databases (Medline, PsycInfo and Scopus) were interrogated for studies utilising standardised measures to assess psychological impact following predictive genetic testing for HD. From 100 papers initially identified, eight articles were eligible for inclusion. Psychological impact of predictive genetic testing was not found to be associated with test result. No detrimental effect of predictive genetic testing on non-carriers was found, although the process was not found to be psychologically neutral. Fluctuation in levels of distress was found over time for carriers and non-carriers alike. Methodological weaknesses of published literature were identified, notably the needs of individuals not requesting genetic testing, as well as inadequate support for individuals registering elevated distress and declining post-test follow-up. Further assessment of these vulnerable individuals is warranted to establish the extent and type of future psychological support.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Inhibition of carbonic anhydrase activity modifies the toxicity of doxorubicin and melphalan in tumour cells in vitro

Carbonic anhydrase IX (CA IX) is a hypoxia-regulated enzyme, overexpressed in many types of human cancer. CA IX is involved in pH homeostasis, contributing to extracellular acidification and tumourigenesis. Acidification of the extracellular milieu can impact upon cellular uptake of chemotherapeutic drugs by favouring weak acids (e.g. melphalan), but limiting access of weak bases (e.g. doxorubicin). We investigated whether alterations of CA IX activity affected anti-cancer drug uptake and toxicity. CA inhibitor acetazolamide (AZM) enhanced doxorubicin toxicity but reduced melphalan toxicity in cell lines that highly expressed CA IX under anoxic conditions (HT29 and MDA435 CA9/18). The toxicity changes reflected modification of passive drug uptake. AZM did not alter toxicity or uptake in cells with low CA IX activity (HCT116 and MDA435 EV1). AZM lowered intracellular pH in HT29 and MDA435 CA9/18 cells under anoxic conditions. CA IX activity has chemomodulatory properties and is an attractive target for anti-cancer therapy.

Reduction in overweight and obesity from a 3-year community-based intervention in Australia: the 'It's Your Move!' project

'It's Your Move!' was a 3-year intervention study implemented in secondary schools in Australia as part of the Pacific Obesity Prevention In Communities Project. This paper reports the outcome results of anthropometric indices and relevant obesity-related behaviours. The interventions focused on building the capacity of families, schools and communities to promote healthy eating and physical activity. Baseline response rates and follow-up rates were 53% and 69% respectively for the intervention group (n=5 schools) and 47% and 66% respectively for the comparison group (n=7 schools). Statistically significant relative reductions in the intervention versus comparison group were observed: weight (-0.74 kg, P < 0.04), and standardized body mass index (-0.07, P<0.03), and non-significant reductions in prevalence of overweight and obesity (0.75 odds ratio, P=0.12) and body mass index (-0.22, P=0.06). Obesity-related behavioural variables showed mixed results with no pattern of positive intervention outcomes. In conclusion, this is the first study to show that long-term, community-based interventions using a capacity-building approach can prevent unhealthy weight gain in adolescents. Obesity prevention efforts in this important transitional stage of life can be successful and these findings need to be translated to scale for a national effort to reverse the epidemic in children and adolescents.

The prevalence of neuromyelitis optica in South East Wales

BACKGROUND AND PURPOSE

Neuromyeltis optica (NMO) is a neuroinflammatory disorder considered rare in Caucasian populations. However, accurate population-based epidemiological data for NMO and NMO spectrum disorder (NMO-SD) from Western populations employing validated diagnostic criteria remain limited. We sought therefore to estimate the prevalence and clinical features of NMO in a north European Caucasian population in South East Wales.

METHODS

Patients were identified by a comprehensive, multistage ascertainment strategy employing a regional neuroinflammatory disease register, hospital diagnostic databases personal physician referrals and regional requests for anti-aquaporin-4 antibodies (anti-AQP4).

RESULTS

Fourteen Caucasian patients (11 patients with NMO and three with NMO-SD) were identified in a population of 712,572 (19.6/million; 95% CIs: 12.2-29.7). There was an excess of females (female:male 12:2), 11/14 were anti-AQP4 positive and 5/14 had disease onset under the age of 20 years.

CONCLUSION

This study suggests that NMO and related spectrum disorders are at least as frequent in Northern European populations as in non-Caucasian populations and that the demographic profile of prevalent patients differs from clinic-based cohorts.

Evidence for significant heritability of apoptotic and cell cycle responses to ionising radiation

Genetic factors are likely to affect individual cancer risk, but few quantitative estimates of heritability are available. Public health radiation protection policies do not in general take this potentially important source of variation in risk into account. Two surrogate cellular assays that relate to cancer susceptibility have been developed to gain an insight into the role of genetics in determining individual variation in radiosensitivity. These flow cytometric assays for apoptosis induction and cell cycle delay following radiation are sufficiently sensitive to distinguish lymphocytes from a healthy donor population from those of a sample of obligate carriers of ATM mutations (P = 0.01 and P = 0.02, respectively). Analysis of 54 unselected twin pairs (38 dizygotic, 16 monozygotic) indicated much greater intrapair correlation in response in monozygotic than in dizygotic pairs. Structural equation modelling indicated that models including unique environmental factors only fitted the data less well than those incorporating two or more of additive genetic factors, common environmental factors and unique environmental factors. A model incorporating additive genetic factors and unique environmental factors yielded estimates of heritability for the two traits of 68% (95% CI 40-82%, cell cycle) and 59% (95% CI 22-79%, apoptosis). Thus, these data suggest that genetic factors contribute significantly to human variation in these two measures of radiosensitivity that relate to cancer susceptibility.

Psychological morbidity and illness appraisals of patients with cardiac and non-cardiac chest pain attending a rapid access chest pain clinic: a longitudinal cohort study

OBJECTIVES

To assess the psychological morbidity and illness beliefs in newly referred patients with chest pain, and to compare the psychological morbidity of patients with pain of cardiac origin with that of patients with pain of non-cardiac origin.

DESIGN

Longitudinal cohort study.

SETTING

Rapid Access Chest Pain Clinic in a tertiary referral centre in Leicester, United Kingdom.

PARTICIPANTS

246 patients with acute, undifferentiated, chest pain followed up 1 week and 2 months subsequent to clinic attendance.

MAIN OUTCOME MEASURES

Levels of affective disturbance, health anxiety and illness perception.

RESULTS

Levels of anxiety before clinic attendance exceeded community norms but did not differentiate the two groups. However, after clinic attendance levels of anxiety for those with a non-cardiac diagnosis significantly exceeded those of patients whose pain was of cardiac origin and remained above community norms 2 months hence. Non-cardiac patients viewed their condition as significantly less controllable and less understandable than those whose pain was cardiac in origin. Levels of depression for those with cardiac pain also significantly increased to above community norms after clinic attendance.

CONCLUSIONS

Clinical levels of psychological morbidity are evident in the immediate and long-term aftermath of a visit to a Rapid Access Chest Pain Clinic, despite early access and provision of reassurance. More structured interventions appear necessary to deal with both distress and illness beliefs that may influence future healthcare use.

Basilar tip aneurysm - adenosine induced asystole for the treatment of a basilar tip aneurysm following failure of temporary clipping

We report on a giant basilar tip aneurysm in a 48-year-old woman that could not be clipped despite temporary occlusion of the basilar trunk. Adenosine induced cardiac asystole reduced the aneurysm's wall tension and coupled with increased exposure resulting from brain relaxation allowed for the aneurysm to be satisfactorily occluded via an extended right pterional craniotomy. In difficult vascular cases, adenosine induced cardiac standstill is a useful technique which may allow for technical success when other methods such as temporary clipping fail. It acts to both reduce aneurysm wall tension and increase operative exposure by reducing vascular, and hence brain volume.

Psychological morbidity and problems of daily living in people with visual loss and diabetes: do they differ from people without diabetes?

AIMS

To examine psychological adjustment and changes in the activities of daily living in relation to visual loss in diabetes.

METHODS

This was an incident cohort, longitudinal, observational study contrasting the adjustment of individuals with visual loss associated with diabetes and those whose visual loss arose from other conditions; in the year subsequent to registration for blindness and 12 months later, 124 individuals participated in the study (51 with diabetes and 73 without). Participants provided demographic and biomedical information, and completed the Brief COPE, Hospital Anxiety and Depression Scale, SF-36, Instrumental Activities of Daily Living scale and Social Avoidance and Distress Scale via interview. People with diabetes were compared with those without.

RESULTS

Both diabetic and non-diabetic groups showed elevated and comparable levels of psychological morbidity, sustained over time. Significant differences in functional adjustment were found at initial interview: people with diabetes having more problems coping but these were no longer present 1 year later.

CONCLUSIONS

There was a significant and enduring elevation of anxiety and depression in those who were newly registered blind or visually handicapped. Taking these findings into account, psychological assessment should be developed for all those experiencing visual loss.

Preparation of tumor homogenates for subsequent preparation of cytosols, membrane fractions, RNA, and DNA

This chapter outlines methods for the preparation of several different cellular fractions from whole samples of tumor and normal tissue.

Isolation of DNA from tumor samples

A method for producing high-molecular-weight DNA from pulverized tissue, nuclear fractions, or cultured cells. This isolation method relies on the powerful proteolytic activity of proteinase K combined with the denaturing ability of the ionic detergent sodium dodecyl sulfate. Ethylenediaminetetraacetic acid is included in the lysis buffer to inhibit DNases.

cisRED: a database system for genome-scale computational discovery of regulatory elements

We describe cisRED, a database for conserved regulatory elements that are identified and ranked by a genome-scale computational system (www.cisred.org). The database and high-throughput predictive pipeline are designed to address diverse target genomes in the context of rapidly evolving data resources and tools. Motifs are predicted in promoter regions using multiple discovery methods applied to sequence sets that include corresponding sequence regions from vertebrates. We estimate motif significance by applying discovery and post-processing methods to randomized sequence sets that are adaptively derived from target sequence sets, retain motifs with p-values below a threshold and identify groups of similar motifs and co-occurring motif patterns. The database offers information on atomic motifs, motif groups and patterns. It is web-accessible, and can be queried directly, downloaded or installed locally.

Isolation of RNA from tumor samples: single-step guanidinium acid-phenol method

The guanidinium acid-phenol method of RNA extraction is relatively fast (4 h) and is useful for the processing of large numbers of samples, without the need for ultracentrifugation. This protocol produces total RNA that includes ribosomal, transfer, and messenger RNA. This high-quality RNA is suitable for Northern blot analysis, dot-blot hybridization, poly (A) RNA selection, in vitro translation, cDNA library construction, reverse transcriptase-polymerase chain reaction, ribonuclease protection assay, and primer extension experiments.

Tailored interventions to overcome identified barriers to change: effects on professional practice and health care outcomes

BACKGROUND

Strategies to implement change in health professional performance have variable impact. A potential explanation is that the barriers to implementation are different in different settings and at different times. Change may be more likely if the strategies were specifically chosen to address the identified barriers.

OBJECTIVES

To assess the effectiveness of strategies tailored to address specific, identified barriers to change in professional performance.

SEARCH STRATEGY

We searched the Cochrane Effective Practice and Organisation of Care Group (EPOC) specialised register and pending files until end of December 2002. English language articles only were included.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that reported objectively measured professional practice or health care outcomes in which at least one group received an intervention designed (or tailored) to address prospectively identified barriers to change.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed quality. We also contacted study authors to obtain any missing information. Quantitative and qualitative analyses were undertaken.

MAIN RESULTS

We included 15 studies. For Comparison 1 (an intervention tailored to address identified barriers to change compared to no intervention or an intervention(s) not tailored to the barriers), there was no consistency in the results and the effect sizes varied both across and within studies.A meta-regression of a subset of the included studies, using a classical approach estimated a combined OR of 2.18 (95% CI: 1.09, 4.34), p = 0.026 in favour of tailored interventions. However, when a Bayesian approach was taken, meta-regression gave a combined OR of 2.27 (95% Credible Interval: 0.92, 4.75), which was not statistically significant.

AUTHORS' CONCLUSIONS

Interventions tailored to prospectively identify barriers may improve care and patient outcomes. However, from the studies included in this review, we were unable to determine whether the barriers were valid, which were the most important barriers, whether all barriers were identified and if they had been addressed by the intervention chosen. Based on the evidence presented in this review, the effectiveness of tailored interventions remains uncertain and more rigorous trials (including process evaluations) are needed. Further research needs to address explicitly the questions of identifying and addressing barriers.

Role of carbonic anhydrase IX in human tumor cell growth, survival, and invasion

Carbonic anhydrase IX (CAIX) is a membrane-associated carbonic anhydrase (CA), strongly induced by hypoxia. CAIX is overexpressed in a variety of tumor types and associated with increased metastasis and poor prognosis. An inhibitor of CAs, acetazolamide has been reported to inhibit invasion. We used RNA interference (RNAi) to examine the function of CAIX in MDA468 and MDA231 breast carcinoma cells, which express high levels of CAIX under hypoxia. Hypoxia-induced CA activity was completely blocked by specific RNAi (P < 0.01). RNAi-treated cells showed growth delay in dense monolayer culture and a 50% reduction in clonogenic survival under hypoxia. In the MDA468 cells, there was no effect of RNAi treatment on invasion. In a cell line that did not induce CAIX under hypoxia, RT112, we found no effect on the ability of cells transfected with CAIX to invade or migrate. Thus, CAIX plays an important role in the growth and survival of tumor cells under normoxia and hypoxia, making it a potential target for cancer therapy, but is not involved in invasion.

Anti-reflux surgery for the neonatal intensive care-dependent infant

AIM

The benefit of anti-reflux surgery for gastro-oesophageal reflux (GOR) in early infancy is uncertain. The aim of this study was to assess the value of Nissen fundoplication in a group of infants with severe GOR.

METHODS

10 infants underwent Nissen fundoplication for gastro-oesophageal reflux following a failure of medical management. All had suffered life-threatening respiratory episodes as a consequence of gastro-oesophageal reflux, and were neonatal intensive care-dependent. Median (range) birth weight was 1.26 kg (0.48-3.8 kg), gestation 30 weeks (25-38 weeks); at surgery, weight was 3.25 kg (2.5-6.1 kg) at a corrected age of 11.5 weeks (term-22) weeks. For each infant, the success of enteral feeding and the level of support required pre- and post-operatively was compared, and where appropriate, the facilitation of palliative feeding was assessed. Median follow-up was 14 (3-36) months.

RESULTS

No infant suffered intra-operative morbidity or mortality. One infant died within 1 month of surgery from a collapse unrelated to surgery. Eight of nine surviving infants were discharged from intensive care following extubation and the establishment of enteral feeding. One patient died of severe bronchopulmonary dysplasia 3 months post-surgery. One infant developed a gastrostomy site infection, and two required gastrostomy tube replacement within 6 months of surgery. All were thriving at follow-up. Two infants with a congenital myopathy died as a result of their muscle disease at 9 and 11 months post-operatively.

CONCLUSIONS

Nissen fundoplication is a feasible, effective and safe operation in severe gastro-oesophageal reflux unresponsive to medical treatment in term and pre-term infants. It has an additional important role in facilitating safe palliative enteral feeding in infants with a diagnosis incompatible with survival into adulthood.