Genome sequencing reveals underdiagnosis of primary ciliary dyskinesia in bronchiectasis.

BACKGROUND: Bronchiectasis can result from infectious, genetic, immunological and allergic causes. 60-80% of cases are idiopathic, but a well-recognised genetic cause is the motile ciliopathy, primary ciliary dyskinesia (PCD). Diagnosis of PCD has management implications including addressing comorbidities, implementing genetic and fertility counselling and future access to PCD-specific treatments. Diagnostic testing can be complex; however, PCD genetic testing is moving rapidly from research into clinical diagnostics and would confirm the cause of bronchiectasis. METHODS: This observational study used genetic data from severe bronchiectasis patients recruited to the UK 100,000 Genomes Project and patients referred for gene panel testing within a tertiary respiratory hospital. Patients referred for genetic testing due to clinical suspicion of PCD were excluded from both analyses. Data were accessed from the British Thoracic Society audit, to investigate whether motile ciliopathies are underdiagnosed in people with bronchiectasis in the UK. RESULTS: Pathogenic or likely pathogenic variants were identified in motile ciliopathy genes in 17 (12%) out of 142 individuals by whole-genome sequencing. Similarly, in a single centre with access to pathological diagnostic facilities, 5-10% of patients received a PCD diagnosis by gene panel, often linked to normal/inconclusive nasal nitric oxide and cilia functional test results. In 4898 audited patients with bronchiectasis, <2% were tested for PCD and <1% received genetic testing. CONCLUSIONS: PCD is underdiagnosed as a cause of bronchiectasis. Increased uptake of genetic testing may help to identify bronchiectasis due to motile ciliopathies and ensure appropriate management.

Long Chain Omega-3 Fatty Acid Intervention in Ageing Adults at Risk of Dementia Following Repeated Head Trauma. Low-level Support or an Opportunity for an Unanswered Question?

Emerging evidence of brain injury on risk of neurodegenerative diseases such as Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE) have resulted in interest in therapeutic potential of omega-3 fatty acids (n-3FA). We conducted a systematic review of n-3FA therapeutic efficacy for ageing adults at risk of AD/CTE following a history of repeated head trauma. Databases for articles between 1980-June 2020 were examined for studies reporting on n-3 FAs in adults (≥ 45 years) with a history of repeated brain injury. Following an initial screen of 175 articles, 12 studies were considered but were eventually rejected, as they did not meet inclusion criteria. Our review could find no evidence to support, or disprove, effectiveness of n-3FA intervention in older adults with a history of head trauma. With animal studies showing neuro-restorative potential of n-3FA following brain injury, this review highlights the urgent need for human research in this area.

Diagnostic strategies using DNA testing for hereditary haemochromatosis in at-risk populations: a systematic review and economic evaluation.

OBJECTIVE: To evaluate DNA testing for detecting hereditary haemochromatosis (HHC) in subgroups of patients suspected of having the disorder and in family members of those diagnosed with HHC. DATA SOURCES: Major electronic databases, searched from inception to April 2007. REVIEW METHODS: A systematic review was undertaken using a priori methods and a de novo model developed to assess costs and consequences of DNA testing. RESULTS: Eleven studies were identified for estimating the clinical validity of genotyping for the C282Y mutation for the diagnosis of HHC. No clinical effectiveness studies meeting the inclusion criteria were identified. Two North American cost-effectiveness studies of reasonable quality were identified but their generalisability to the UK is not clear. Three cohort studies met the inclusion criteria for the review of psychosocial aspects. All had methodological limitations and their generalisability is difficult to determine. The clinical sensitivity of C282Y homozygosity for HHC ranged from 28.4% to 100%, or from 91.3% to 92.4% when considering only the most relevant studies. Clinical specificity ranged from 98.8% to 100%. One study found that gene testing was a cost-effective method of screening relatives of patients with haemochromatosis, whereas the other found that genotyping the spouse of a homozygote was the most cost-efficient strategy. Genetic testing for haemochromatosis appears to be well accepted, is accompanied by few negative psychosocial outcomes and may lead to reduced anxiety. The de novo economic model showed that, in people suspected of having haemochromatosis, the DNA strategy is cost saving compared with the baseline strategy using liver biopsy (cost saved per case detected 123 pounds), largely because of the reduction in liver biopsies. For family testing of siblings the DNA strategy is not cost saving because of the costs of the DNA test (additional cost per case detected 200 pounds). If the cost of the test were to reduce from 100 pounds to 60 pounds, the DNA strategy would be the cheaper one. For family testing of offspring the DNA test strategy is cheaper than the baseline biochemical testing strategy (cost saved per case detected 7982 pounds). Sensitivity analyses showed that the conclusions in each case are robust across all reasonable parameter values. CONCLUSIONS: The preferred strategy in practice is DNA testing in conjunction with testing iron parameters when there is clear clinical indication of risk for haemochromatosis because of biochemical criteria or when there is familial risk for HHC. Access to genetic testing and centralisation of test provision in expert laboratories would lower the cost of testing, improve the cost-effectiveness of the strategy and improve the quality of information provided to clinicians and patients.

A decision analysis model for diagnostic strategies using DNA testing for hereditary haemochromatosis in at risk populations.

BACKGROUND: New techniques for diagnosing hereditary haemochromatosis (HHC) have become available alongside traditional tests such as liver biopsy and serum iron studies. AIM: To evaluate DNA tests in people suspected of having haemochromatosis at clinical presentation compared to liver biopsy, and in family members of those diagnosed with haemochromatosis compared to phenotypic iron studies in UK. METHODS: Decision analytic models were constructed to compare the costs and consequences of the diagnostic strategies for a hypothetical cohort of people with suspected haemochromatosis. For each strategy, the number of cases of haemochromatosis identified and treated and the resources used were estimated. RESULTS: For diagnostic strategies in people suspected clinically of having haemochromatosis, the DNA strategy is cost saving compared to liver biopsy (cost saved per case detected, 123 pounds) and continues to be so across all ranges of parameters. For family testing, the DNA strategy is cost saving for the offspring of the proband but not for siblings. If the DNA test cost were to reduce by 40% to 60 pounds or, if in the phenotypic model, those with initially normal iron indices were retested twice instead of once, the DNA strategy would be the cheaper one. CONCLUSION: Diagnostic strategies involving DNA testing are likely to be cost saving in clinical cases with iron overload and in the offspring of index cases. This study supports the UK guideline recommendations for the use of DNA testing in UK.

A systematic review of the clinical validity and clinical utility of DNA testing for hereditary haemochromatosis type 1 in at-risk populations.

OBJECTIVE: To evaluate the clinical validity and clinical utility of DNA testing in people suspected of having hereditary haemochromatosis and in family members of those diagnosed with the disorder. DESIGN: A systematic review. METHODS: 15 electronic databases were searched up to April 2007. For assessment of the clinical validity of genotyping for the C282Y mutation in the diagnosis of hereditary haemochromatosis, studies were included if they reported the use of DNA tests in Caucasians of northern European origin with iron overload suggestive of haemochromatosis compared with a control population, and reported or allowed calculation of sensitivity and specificity. For clinical utility, studies were included if participants were Caucasians with iron overload suggestive of haemochromatosis or were relatives of suspected cases, if the study compared a diagnostic strategy incorporating DNA testing with one not incorporating DNA testing, and if the study reported patient-based outcomes or some measure of cost effectiveness. RESULTS: 11 studies that could be used to evaluate clinical validity of genotyping for the C282Y mutation in the diagnosis of hereditary haemochromatosis were identified. Clinical sensitivity of C282Y homozygosity for hereditary haemochromatosis ranged from 28.4% to 100%; when considering studies that used strict criteria to classify hereditary haemochromatosis clinical sensitivity ranged from 91.3% to 92.4%. No clinical effectiveness studies were found. Two cost effectiveness studies were identified, both of which suggested that gene testing may be cost effective. CONCLUSION: DNA testing for hereditary haemochromatosis in at-risk populations has clinical validity and may have clinical utility. The review highlights the limitations of the literature and the methodological difficulties associated with evaluating this genetic test.

Australian consumers are sceptical about but influenced by claims about fat on food labels.

OBJECTIVES: To explore the beliefs and attitudes of Australian consumers to claims about fat made on the labels of packaged food. DESIGN: Content analysis of transcripts from focus group discussions. SUBJECTS: A total of 26 female and 10 male participants aged 20-80 y, recruited by advertisement into six focus groups, stratified by age, sex and health status. RESULTS: Awareness of claims about fat was high in this sample of Australians and participants admitted that they influenced their purchase decisions. The most preferred form of claim was 'X% fat free'. Claims were considered most useful on foods that were high in fat. There was considerable scepticism about all nutrient claims, and consumers preferred to check claims about fat against the values in the nutrition information panel. Many claims were seen as advertising that could be misleading, deceptive or confusing. While claims about fat might prompt product trial, factors such as price, taste, naturalness, as well as other nutritional factors, also influenced purchase decisions. Some consumers believe low fat claims encourage over consumption of foods. CONCLUSIONS: Changes to regulations governing nutrition claims on food labels should be made to enhance their credibility and support their role in assisting consumers to make healthier food choices.

Can motivational signs prompt increases in incidental physical activity in an Australian health-care facility?

This study aimed to evaluate whether a stair-promoting signed intervention could increase the use of the stairs over the elevator in a health-care facility. A time-series design was conducted over 12 weeks. Data were collected before, during and after displaying a signed intervention during weeks 4-5 and 8-9. Evaluation included anonymous counts recorded by an objective unobtrusive motion-sensing device of people entering the elevator or the stairs. Self-report data on stair use by hospital staff were also collected. Stair use significantly increased after the first intervention phase (P = 0.02), but after the intervention was removed stair use decreased back towards baseline levels. Moreover, stair use did not significantly change after the re-introduction of the intervention. Lastly, stair use decreased below the initial baseline level during the final weeks of evaluation. Furthermore, there was no significant change in self-reported stair use by hospital staff. Therefore, the signed intervention aimed at promoting an increase in incidental physical activity produced small brief effects, which were not maintained. Further research is required to find more effective 'point of choice' interventions to increase incidental physical activity participation with more sustainable impact.

The 'new genetics' and nursing: what does it have to do with me?

Recent developments in genetics mean that this previously specialised subject is now essential knowledge for all nurses. Heather Skirton and Christine Patch describe how fundamental knowledge of the new genetics will enable nurses to help patients through the maze of choices open to them.

The application of the continuum of care model in the re-configuration of nutrition and dietetics services.

The continuum of health care model can be used to improve service delivery. Within a hospital setting, finite resources are available. Service gaps must be identified, priorities established and resources re-distributed to meet these gaps. Using Continuous Quality Improvement (CQI) tools, barriers to change were identified and a plan for improvement was formulated. Areas receiving disproportionate resources were identified and a more even resource allocation adopted. In an illustration of the success of strategic change, core services were not only maintained but also showed improved efficiency. The Department of Nutrition and Dietetics at Wollongong and Port Kembla Hospitals achieved an increase in dietetic services through a reorientation of current resources.

Recommendations for education and training of genetic nurses and counsellors in the United Kingdom.

Genetic nurses and counsellors work as part of the professional team providing clinical genetic services from regional centres in the United Kingdom. The education and training needs of genetic nurses and counsellors have not previously been formally identified. The guidelines presented have been devised to equip practitioners to fulfil their professional role as defined in a previous study, by identifying objectives, educational pathways, and means of assessment. While academic courses provide an essential framework, experiential learning in a clinical setting is also considered a vital component of the preparation for practice.

Molecular re-investigation of patients with Huntington's disease in Wessex reveals a family with dentatorubral and pallidoluysian atrophy.

Dentatorubral and pallidolysian atrophy (DRPLA), a neurological disorder thought to be rare in European populations, is caused by a triplet repeat expansion in the B37 gene on chromosome 12. This disorder can phenotypically mimic Huntington's disease (HD) which is also caused by a repeat expansion. We have analysed 139 affected individuals for the HD triplet repeat expansion and found 132 patients had one normal and one expanded allele. Two patients had an expansion on both chromosomes and five patients had two normal-size alleles. Of these five patients, two were considered to be atypical Two patients who were father and daughter were found to have an expansion of the DRPLA triplet repeat. This therefore constitutes the second such family described in the United Kingdom.

Protelomeric sequences are deleted in cases of short arm inverted duplication of chromosome 8.

We present a patient with a de novo inverted duplication of the short arm of chromosome 8. Molecular analysis confirmed the cytogenetic suspicion of a simultaneous deletion of the tip of the short arm and indicated the maternal origin of the abnormality. This deletion made no detectable contribution to the phenotype of the patient which was comparable to that of previous cases of 8p duplication. Similar investigations of inverted duplications involving other chromosomes may reveal unexpected deletions with significant phenotypic consequences.

A systematic search for uniparental disomy in carriers of chromosome translocations.

A systematic search was made for uniparental disomy in carriers of apparently balanced chromosome translocations who also had unexplained abnormalities of mental or physical development. Of 65 families studied, biparental origin of both translocated chromosomes was demonstrated in 64, and only 1 case of maternal uniparental disomy of chromosome 14 was detected in the carrier of a Robertsonian t(13q14q). We conclude that uniparental disomy is a rare occurrence in this population.

Biochemical properties of media conditioned by simian virus 40-induced hamster tumor cells: correlation with distinct cell phenotypes but not with oncogenicity.

Hamster cells, transformed in vitro by SV40, have been reported to secrete an unidentified factor(s) that inhibits thymidine uptake (TU) by various normal cell types, including activated lymphocytes. It has been postulated that this apparent antiproliferative effect may play an in vivo role in the high tumorigenic capacity of SV40-transformed hamster cells. In keeping with this hypothesis, Adenovirus type 2-transformed hamster cells, which are only weakly tumorigenic, do not inhibit TU by indicator cells in vitro. To study the biological relevance of this phenomenon, we assayed 11 cell lines derived from different fibrosarcomas, induced in Syrian hamsters by SV40, for their ability to inhibit TU by normal rabbit kidney indicator cells. In contrast to cells transformed in vitro by SV40, media conditioned by 6 of 11 tumor-derived cell lines did not inhibit TU. Our results do not support the hypothesis that an antiproliferative factor secreted by SV40-transformed cells promotes the tumor-inducing capacity of these cells. Furthermore, inhibition of TU does not appear to be due to the production of a specific antimitotic peptide, but rather to other biochemical properties of the media conditioned by transformed cells. Finally, these biochemical properties do appear to correlate with specific morphological and growth characteristics of the tumor cells, but probably as an effect and not a cause.

Mitogenic and antimitogenic transforming growth factors secreted by adenovirus 2- and simian virus 40-transformed hamster cells: possible roles in promoting tumorigenesis.

Adenovirus 2 (Ad2)- and simian virus 40 (SV40)-transformed hamster embryo cells differ markedly in a number of phenotypic properties including their potential for inducing tumors in hamsters. Both Ad2- and SV40-transformed cells are immortalized and readily induce tumors in immunoincompetent newborn syngeneic hamsters, but only SV40-transformed cells are highly oncogenic in both adult syngeneic and allogeneic immunocompetent hamsters. The reasons for the difference in the oncogenic potential of the Ad2- and SV40-transformed phenotypes remain elusive. However, recent studies with transforming growth factors (TGFs) indicate that these factors play an important role in determining many phenotypic characteristics of transformed cells. To determine whether TGFs secreted by Ad2- and SV40-transformed hamster embryo cells differ, we have examined the ability of media conditioned by these two transformed cell phenotypes to modulate thymidine uptake in quiescent, untransformed cells. We found that both transformed phenotypes secrete very similar TGF alpha-like mitogenic factors which inhibit binding of 125I-labeled epidermal growth factor to its receptor. Our results also show that SV40-transformed cells, but not Ad2-transformed cells, secrete a powerful mitogenic inhibitor (MI). The MI secreted by SV40-transformed cells is inhibitory for several transformed and untransformed cell types and exerts a cytostatic, not cytolytic, action on untransformed primary hamster embryo cells. MI elutes from size exclusion high-performance liquid chromatography columns with a molecular weight of 24,000. Although MI has about the same molecular weight as TGF beta, it differs from TGF beta in two important respects: it is heat labile and it has a different target specificity for antimitogenic activity. The MI secreted by SV40-transformed cells also inhibits thymidine uptake by concanavalin A-stimulated spleen lymphocytes. This finding suggests that MI might contribute to the extreme oncogenicity of SV40-transformed cells by inhibiting mobilization of immune effector cells at the site of tumor cell proliferation.

The level of expression of adenovirus type 2 transforming genes governs sensitivity to nonspecific immune cytolysis and other phenotypic properties of adenovirus 2-simian virus 40-transformed cell hybrids.

Syrian hamster embryo cells transformed by adenovirus type 2 (Ad2) or simian virus 40 (SV40) differ markedly in morphology, tumorigenicity, and susceptibility to in vitro lysis by nonspecific cytotoxic cells. Hybrid cells formed by fusing Ad2- and SV40-transformed Syrian hamster embryo cells may express only SV40 T antigens or both SV40 and Ad2 T antigens. Hybrids that express only SV40 T antigens are indistinguishable from the nonhybrid SV40-transformed phenotype, whereas hybrid cells that express T antigens from both viruses closely resemble the nonhybrid parental Ad2-transformed phenotype. Because these hybrid cells have been useful in the study of neoplastic transformation, we determined the amount of viral antigens that they accumulate in an attempt to correlate the level of expression of the transforming viral genes with some of their phenotypic properties. Hybrid cells that expressed proteins from both viruses showed reduced levels of SV40 T antigens compared with those of hybrid cells that did not express Ad2 T antigens. We also found that the production of several cellular proteins that influence cytomorphology was inhibited in hybrid and nonhybrid cells that expressed Ad2 T antigens, and the repression of these cellular proteins correlated with a change in cytomorphology from fibroblastic to spherical. Finally, we showed that the susceptibility of our hybrid cells to in vitro lysis by natural killer cells and activated macrophages, two putative host-effector cells involved in defense against neoplasia, correlated closely with the level of expression of a 58,000-dalton Ad2 protein. The results reported here, together with the results of previous studies, indicate that the oncogenic potential of hybrid cells that express both Ad2 and SV40 antigens is extremely sensitive to Ad2 expression, whereas other phenotypic properties depend on Ad2 expression in a dose-dependent manner.

Adenovirus 2 early gene expression promotes susceptibility to effector cell lysis of hybrids formed between hamster cells transformed by adenovirus 2 and simian virus 40.

Weakly oncogenic adenovirus 2 (Ad2)-transformed LSH hamster cells are sensitive to lysis by spontaneously cytolytic lymphoid cells and activated macrophages, whereas highly oncogenic simian virus 40 (SV40)-transformed LSH cells are relatively resistant to these nonspecific effector cells. Somatic cell hybrids formed between Ad2- and SV40-transformed hamster cells, which expressed Ad2 tumor (T) antigens, exhibited an increased cytolytic susceptibility compared to Ad2 T antigen-negative cell hybrids or nonhybrid SV40-transformed cells. No correlation was found between the expression of SV40 T antigen in hybrid cells and cytolytic susceptibility. The results suggest the existence of a novel function for early Ad2 genome-encoded polypeptides (T antigens) expressed in transformed hamster cells--the induction of susceptibility to destruction mediated by immunologically nonspecific effector cells.

Suppression of the simian virus 40 tumorigenic phenotype in hybrid cells formed from simian virus 40- and adenovirus 2-transformed hamster embryo cells.

Hamster cells transformed by adenovirus 2 (Ad2) or simian virus 40 (SV40) have different tumorigenic phenotypes. In the present study, somatic cell hybrids formed from Ad2- and SV40-transformed hamster cells were used to determine whether possible interactions between the integrated viral genomes would influence the tumorigenic phenotype of hybrid transformed cells. These somatic cell hybrids were of two types, one expressing both Ad2 and SV40 T-antigens and the other expressing only SV40 T-antigens. Tumor induction by hybrid cells that expressed both Ad2 and SV40 T-antigens was reduced in adult syngeneic hamsters and abrogated in adult allogeneic hamsters. These results indicate that the tumorigenic phenotype of transformed somatic cell hybrids that contain both the Ad2 and SV40 genome is governed by the genetic expression of Ad2. This expression may alter the ability of SV40-transformed hamster cells to resist the immunologically nonspecific defenses of the host.

Kinetics of inhibition of papovavirus DNA synthesis by superinfection with adenovirus 2 and non-defective adenovirus 2-simian virus 40 hybrid viruses.

Simian Virus 40 (SV40) DNA synthesis is inhibited in monkey cells by superinfection with adenovirus 2 (Ad2) and various non-defective Ad2-SV40 hybrid viruses. Similarly, BKV (a human papovavirus) DNA synthesis is inhibited in human cells by superinfection with Ad2. Kinetic studies indicate that inhibition begins during the early phase of the Ad2 lytic cycle. Superinfection with Ad2 does not significantly alter the formation of SV40 T antigen. Superinfection with Ad2 late in SV40 lytic cycle is less efficient in the inhibition of SV40 DNA synthesis, and the onset of Ad2 DNA synthesis is delayed, compared to superinfection early in the SV40 lytic cycle. These findings suggest that the Ad2 and SV40 genomes may compete to bind an early AD2 protein which is essential for Ad2 replication, but which blocks SV40 replication.