How can the evaluation of genetic tests be enhanced? Lessons learned from the ACCE framework and evaluating genetic tests in the United Kingdom.

Advances in genetic technology are increasing the availability of genetic tests, not only for rare single gene disorders, but also for common diseases such as breast and colo-rectal cancer. Before there can be widespread uptake of these tests, they must be evaluated to confirm the benefits of their use. But how should genetic tests be evaluated, given the speed at which new tests are emerging? One highly influential approach is the analytic validity, clinical validity, clinical utility and ethical, legal and social issues (ACCE) framework, which has provided a benchmark for the evaluation of genetic tests. The approach has been adopted and adapted by the United Kingdom Genetic Testing Network, with the help of the Public Health Genetics Unit in Cambridge, to evaluate new genetic tests for use in the National Health Service. We discuss a number of conceptual, methodological, and practical issues concerning the evaluation of genetic tests, based on lessons learned from applying the ACCE framework and from the UK experience, and make a number of recommendations to further strengthen the evaluation of genetic tests.     

Size distribution and In vitro translation of the RNAs isolated from turnip yellow mosaic virus nucleoproteins

Purified preparations of TYMV contain a number of minor nucleoprotein components distinguishable on the basis of their density in CsCl gradients (R. E. F. Matthews, Virology12, 521–539, 1960). When analysed by polyacrylamide-gel eletrophoresis, the RNA from each of these various components was found to consist of a characteristic set of molecular-weight species. Full-size RNA (2 × 10⁶ daltons) was present only in nucleoproteins B₁ and B₂. Nucleoproteins B₀, B₀₀, and B₀₀₀ contained RNAs ranging in size from approx 1.3 to 0.28 × 10⁶ daltons. The 0.28 × 10⁶-dalton RNA species was detectable in all nucleoprotein fractions, but was a significant proportion of the RNAs of B₀₀₀ and B₀₀. Translation of the RNA from each of the nucleoproteins in the wheat germ cell-free protein synthesizing system yielded essentially similar patterns of polypeptides which ranged in size from 5000 to 70,000 daltons. The major radioactive product migrated on SDS-polyacrylamide gels to the same position as TYMV coat protein. The data suggest that the 0.28 × 10⁶-dalton RNA component is the cistron for coat protein, and that it and other RNAs associated with TYMV infection are encapsidated.     

Internal quality assurance in a clinical virology laboratory. I. Internal quality assessment.

AIMS--In April 1991 an internal quality assessment scheme (IQAS) was introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. The IQAS was established to identify recurring technical and procedural problems, to check the adequacy of current techniques, and to calculate the frequency of errors. METHODS--Between April 1991 and December 1993, 715 anonymous clinical serum samples were submitted to the laboratory to test 3245 individual procedures of diagnostic viral serology. RESULTS--A total of 485 (14.9%) procedural and 61 (1.9%) technical discrepancies were observed, the technical discrepancies mainly being recorded in complement fixation tests. Twenty two (0.7% of total procedures) of the technical discrepancies were diagnostically significant. CONCLUSIONS--Evaluation criteria developed with the introduction of IQAS to viral serology, and technical and procedural discrepancies are assessed. As yet, IQAS has not been introduced to other sections of the diagnostic virology laboratory (virus isolation, electron microscopy, immunofluorescence, and enzyme linked immunosorbent assays for viral and chlamydial antigens).     

Internal quality assurance in a clinical virology laboratory. II. Internal quality control.

AIMS--In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera. METHODS--From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera. RESULTS--The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests). CONCLUSIONS--The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results.     

Bronchodilator efficacy of indacaterol, a novel once-daily beta2-agonist, in patients with persistent asthma

BACKGROUND: Indacaterol is a novel once-daily inhaled beta2-agonist in development for the treatment of patients with asthma or chronic obstructive pulmonary disease. OBJECTIVE: To investigate the bronchodilator efficacy of indacaterol in patients with persistent asthma. METHODS: Patients received a randomized sequence of single doses of indacaterol, 400 microg, via single-dose dry powder inhaler (SDDPI); indacaterol, 200 microg, via multidose dry powder inhaler (MDDPI); and placebo. At each visit, the forced expiratory volume in 1 second (FEV1) was recorded at a series of time points during a 24-hour period. RESULTS: Of 33 patients screened, 25 were randomized to treatment. Adjusted mean FEV1 was significantly higher (P < or = .005) for both indacaterol doses vs placebo at most time points. The first time points at which statistically significant treatment differences were observed for indacaterol and placebo in FEV1 were 0.17 L at 5 minutes after dosing for 400 microg of indacaterol (SDDPI) and 0.21 L at 10 minutes for 200 microg of indacaterol (MDDPI) (both P < .001 vs placebo). Differences relative to placebo at the final time point, 24 hours after dosing, were 0.29 L and 0.15 L for indacaterol, 400 microg and 200 microg, respectively (both P < or = .003 vs placebo). Overall, FEV1 was significantly higher for the 400-microg dose compared with the 200-microg dose from 15 minutes to 2 hours after dosing (P < or = .013) and from 5 hours onward (P < or = .022). Indacaterol was associated with good tolerability and safety. CONCLUSIONS: Indacaterol demonstrates sustained bronchodilator efficacy throughout the full 24-hour period, with a rapid onset of action and a good overall safety profile.     

Combined finite element and multibody dynamics analysis of biting in a Uromastyx hardwickii lizard skull

Lizard skulls vary greatly in shape and construction, and radical changes in skull form during evolution have made this an intriguing subject of research. The mechanics of feeding have surely been affected by this change in skull form, but whether this is the driving force behind the change is the underlying question that we are aiming to address in a programme of research. Here we have implemented a combined finite element analysis (FEA) and multibody dynamics analysis (MDA) to assess skull biomechanics during biting. A skull of Uromastyx hardwickii was assessed in the present study, where loading data (such as muscle force, bite force and joint reaction) for a biting cycle were obtained from an MDA and applied to load a finite element model. Fifty load steps corresponding to bilateral biting towards the front, middle and back of the dentition were implemented. Our results show the importance of performing MDA as a preliminary step to FEA, and provide an insight into the variation of stress during biting. Our findings show that higher stress occurs in regions where cranial sutures are located in functioning skulls, and as such support the hypothesis that sutures may play a pivotal role in relieving stress and producing a more uniform pattern of stress distribution across the skull. Additionally, we demonstrate how varying bite point affects stress distributions and relate stress distributions to the evolution of metakinesis in the amniote skull.     

Ascertaining women's preferred mode of address and preferred choice of title during pregnancy and childbirth

To determine how women in pregnancy would like to be addressed and to ascertain their preferred choice of title during pregnancy. A questionnaire was administered to 925 antenatal women. Midwifery and medical staff (183) were invited to respond to a similar questionnaire. The response rate was 71.2% from the survey of pregnant women. The vast majority (82.1%) preferred to be addressed by their first name. Women were in favour of being called 'patient' (32.8%) as their first choice. The staff survey yielded a response rate of 77%. The majority (81.8%) of health professionals preferred to address women by their first name. 'Mother' (28.7%) was the most popular first choice. We conclude that women in pregnancy do have a preference on how they would like to be addressed and this is predominantly by first name. Health professionals also prefer to call pregnant women by their first name. The term 'patient' was the most popular first choice of title of women in pregnancy but the term 'mother' was the preferred choice of the health professionals. Medical staff were more likely to choose 'patient' than midwives.     

Pulmonary response to silica or titanium dioxide: inflammatory cells, alveolar macrophage-derived cytokines, and histopathology

We investigated the effects of silica (SiO2) and titanium dioxide (TiO2) on the pulmonary recruitment of inflammatory cells and the ability of alveolar macrophages (AMs) to release the pro-inflammatory cytokines, interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF). Rats were intratracheally instilled with 5 to 100 mg/kg of the materials, and bronchoalveolar lavage cell populations and AM cytokine release were characterized on days 1, 7, 14, and 28. Both dusts elicited dose-related increases in neutrophils, lymphocytes, and AMs; however, this response was more pronounced and persistent with SiO2. SiO2 at greater than or equal to 50 mg/kg increased AM release of IL-1 and TNF at all time points; lower SiO2 doses had either a transient or no effect on AM-derived cytokines. TiO2 did not result in AM IL-1 release and increased TNF release transiently at doses greater than or equal to 50 mg/kg. Both dusts primed AMs to release increased levels of IL-1 and TNF upon in vitro stimulation with lipopolysaccharide. Histopathology (day 28) demonstrated dose-related interstitial inflammation associated with SiO2 exposure, an effect that was less severe with TiO2. SiO2 doses of greater than or equal to 50 mg/kg elicited a granulomatous response. Development of granulomatous inflammation only at SiO2 doses for which persistent AM IL-1 release occurred suggests involvement of this cytokine in the formation of SiO2-induced granulomas. The ability of SiO2 to activate AM release of IL-1 and TNF in a more pronounced and persistent manner than TiO2 is likely responsible, at least in part, for the greater inflammation and pneumotoxicity associated with SiO2.