Recent advances and current challenges in CAR-T cell therapy

Rapid advancements in the field of immunotherapy have significantly improved cancer treatments. Specifically, an individualized cell-based modality which involves the removal of some of the patient's own white blood cells, including T cells, has revolutionized research in this field. This study focuses on the recent advances and current challenges of Chimeric Antigen Receptor- T (CAR-T) cell therapy and its regulations in the United States (US) and European Union (EU). Understanding the regulatory regimes of CAR-T cell therapy is critical for researchers and manufacturers as they navigate the hurdles of bringing CAR-T cell therapy to the global market. Benefits of CAR-T cell therapy include high response rates and the potential of long-term remissions in some haematological malignancies. However, the drawbacks are still evident including high costs, adverse reactions, and limited efficacy to solid tumours. CAR-T cell therapy is rapidly advancing, with 1231 clinical trials launched globally according to www.clinicalTrial.gov . The future of CAR-T cell therapy holds enormous promise but improving its safety, effectiveness, and availability are still barriers to its successful implementation.

SARS-CoV-2 Testing and Patient Waiting Times in the Emergency Department

Aim Emergency Departments (EDs) were impacted early in the coronavirus disease 2019 (COVID-19) pandemic, with high attendance numbers. EDs relied upon SARS-CoV-2 reverse-transcriptase polymerase chain reaction (RT-PCR) tests to triage patients and facilitate admission to appropriate wards, meaning positive patients were isolated as early as possible. In October 2020, we introduced a 24-hour SARS-CoV-2 testing service. We examined the impact of this on patient experience times (PETs) in the ED, and on healthcare-associated (HA) COVID-19 infections. Methods Data on PETs before and after the introduction of 24-hour testing were available from the ED. HA COVID-19 infections were reported weekly to the Health Services Executive as a key performance indicator. Results Mean PET prior to the pandemic was 20 hours and dropped to 10 and 13 hours respectively in the first and second wave. A surge in case numbers and ED attendances during the third wave was not reflected in a rise in PETs, with a mean PET of 11 hours, significantly below pre-pandemic levels. HA-COVID-19 infections remained stable between wave one and three (83 v 92). Conclusion The introduction of 24-hour SARS-CoV-2 testing in our ED contributed to a reduction in PETs, facilitated appropriate patient placement at ward level, and kept HA-COVID-19 infections at acceptably low levels.

Current trends in biopharmaceuticals production in Escherichia coli

Since the manufacture of the first biotech product for a fledgling biopharmaceutical industry in 1982, Escherichia coli, has played an important role in the industrial production of recombinant proteins. It is now 40 years since the introduction of Humulin® for the treatment of diabetes. E. coli remains an important production host, its use as a cell factory is well established and it has become the most popular expression platform particularly for non-glycosylated therapeutic proteins. A number of significant inherent obstacles in the use of prokaryotic expression systems to produce biologics has always restricted production. These include codon usage, the absence of post-translational modifications and proteolytic processing at the cell envelope. In this review, we reflect on the contribution that this model organism has made in the production of new biotech products for human medicine. This will include new advancements in the E. coli expression system to meet the biotechnology industry requirements, such as novel engineered strains to glycosylate heterologous proteins, add disulphide bonds and express complex proteins. The biopharmaceutical market is growing rapidly, with two production systems competing for market dominance: mammalian cells and microorganisms. In the past 10 years, with increased growth of antibody-based therapies, mammalian hosts particularly CHO cells have dominated. However, with new antibody like scaffolds and mimetics emerging as future proteins of interest, E. coli has again the opportunity to be the selected as the production system of choice.

Use of powered air-purifying respirators during surgical interventions

This clinical study confirms user acceptability of PAPR during surgery both at operating room team level as well as by groups of surgeons, anaesthesiologists and nursing level. While some care is needed in the use of this equipment, surgery can be performed safely with satisfactory user experience.

Therefore PAPR is useable for surgery but scope exists for improvement.

Live predator stress in adolescence results in distinct adult behavioral consequences and dorsal diencephalic brain activation patterns

Exposure to traumatic events during childhood increases the risk of adult psychopathology, including anxiety, depression, alcohol use disorders and their co-morbidity. Early life trauma also results in increased symptom complexity, treatment resistance and poor treatment outcomes. The purpose of this study was to establish a novel rodent model of adolescent stress, based on an ethologically relevant life-threatening event, live predator exposure. Rats were exposed to a live predator for 10 min. at three different time points (postnatal day (PND)31, 46 and 61). Adult depression-, anxiety-like behaviors and ethanol consumption were characterized well past the last acute stress event (two weeks). Behavioral profiles across assessments were developed to characterize individual response to adolescent stress. CNS activation patterns in separate groups of subjects were characterized after the early (PND31) and last predator exposure (PND61). Subjects exposed to live-predator adolescent stress generally exhibited less exploratory behavior, less propensity to venture into open spaces, a decreased preference for sweet solutions and decreased ethanol consumption in a two-bottle preference test. Additional studies demonstrated blunted cortisol response and CNS activation patterns suggestive of habenula, rostromedial tegmental (RMTg), dorsal raphe and central amygdala involvement in mediating the adult consequences of adolescent stress. Thus, adolescent stress in the form of live-predator exposure results in significant adult behavioral and neurobiological disturbances. Childhood trauma, its impact on neurodevelopment and the subsequent development of mood disorders is a pervasive theme in mental illness. Improving animal models and our neurobiological understanding of the symptom domains impacted by trauma could significantly improve treatment strategies.

The rostromedial tegmental nucleus modulates the development of stress-induced helpless behavior

A growing body of clinical and preclinical research suggests that structural and functional changes in the habenula, a component of the epithalamus, are associated with major depressive disorder. A major excitatory, efferent projection from the habenula targets the rostromedial tegmentum (RMTg), a mesopontine region that provides significant input to the ventral tegmentum and raphe nuclei. While the RMTg contributes to monoaminergic responses to aversive events, its role in stress-based animal models of depression has yet to be determined. In the present study, we test the hypothesis that the RMTg is a component of the circuitry mediating the development of a maladaptive behavior in which rats repeatedly exposed to inescapable footshock, fail to avoid or escape the same stressor when subsequently given the opportunity to do so. Excitotoxic lesions of the RMTg significantly diminished the frequency of these escape failures 24 h after exposure to inescapable footshock. Conversely, electrical stimulation of the Hb during the initial uncontrollable aversive event, a manipulation that enhances excitatory input to the RMTg, increased the number of trials in which subjects failed to escape an aversive stimulus when presented the option 24 h later. These complementary results provide evidence supporting a role for the RMTg in the expression of stress-induced helpless phenotype and are an important step in understanding the contribution made by this region to the development of depression-related maladaptive behaviors.

Large Metasurface Aperture for Millimeter Wave Computational Imaging at the Human-Scale

We demonstrate a low-profile holographic imaging system at millimeter wavelengths based on an aperture composed of frequency-diverse metasurfaces. Utilizing measurements of spatially-diverse field patterns, diffraction-limited images of human-sized subjects are reconstructed. The system is driven by a single microwave source swept over a band of frequencies (17.5–26.5 GHz) and switched between a collection of transmit and receive metasurface panels. High fidelity image reconstruction requires a precise model for each field pattern generated by the aperture, as well as the manner in which the field scatters from objects in the scene. This constraint makes scaling of computational imaging systems inherently challenging for electrically large, coherent apertures. To meet the demanding requirements, we introduce computational methods and calibration approaches that enable rapid and accurate imaging performance.

Hydrolysis of nitriles by soil bacteria: variation with soil origin

AIMS

The aim of this study was to explore bacterial soil diversity for nitrile biocatalysts, in particular, those for hydrolysis of β-substituted nitriles, to the corresponding carboxamides and acids that may be incorporated into peptidomimetics. To achieve this, we needed to compare the efficiency of isolation methods and determine the influence of land use and geographical origin of the soil sample.

METHODS AND RESULTS

Nitrile-utilizing bacteria were isolated from various soil environments across a 1000 km long transect of South Africa, including agricultural soil, a gold mine tailing dam and uncultivated soil. The substrate profile of these isolates was determined through element-limited growth studies on seven different aliphatic or aromatic nitriles. A subset of these organisms expressing broad substrate ranges was evaluated for their ability to hydrolyse β-substituted nitriles (3-amino-3-phenylpropionitrile and 3-hydroxy-4-phenoxybutyronitrile) and the active organisms were found to be Rhodococcus erythropolis from uncultivated soil and Rhodococcus rhodochrous from agricultural soils.

CONCLUSIONS

The capacity for hydrolysis of β-substituted nitriles appears to reside almost exclusively in Rhodococci. Land use has a much greater effect on the biocatalysis substrate profile than geographical location.

SIGNIFICANCE AND IMPACT OF THE STUDY

Enzymes are typically substrate specific in their catalytic reactions, and this means that a wide diversity of enzymes is required to provide a comprehensive biocatalysis toolbox. This paper shows that the microbial diversity of nitrile hydrolysis activity can be targeted according to land utilization. Nitrile biocatalysis is a green chemical method for the enzymatic production of amides and carboxylic acids that has industrial applications, such as in the synthesis of acrylamide and nicotinamide. The biocatalysts discovered in this study may be applied to the synthesis of peptidomimetics which are an important class of therapeutic compounds.

Influence of sweet whey protein concentrate and its hydrolysates on host-pathogen interactions in the emerging foodborne pathogen Cronobacter sakazakii

AIMS

Antimicrobial resistance poses a significant global healthcare predicament. An attractive approach to the dilemma of drug-resistant bacteria is the development and use of agents that interfere with the ability of pathogens to adhere to human tissue. The influence of sweet whey protein concentrate (SWPC), and selected hydrolysates of this material, on host-pathogen interactions of Cronobacter sakazakii (ATCC 29544) was investigated.

METHODS AND RESULTS

CaCo-2 cell line was selected as a suitable model for the human intestinal epithelium. Cronobacter sakazakiiATCC 29544 was identified as the strain with the highest adhesion efficiency. SWPC reduced its association by 80% (P < 0·01), invasion 35% (P < 0·01), and translocation >95% (P < 0·001). SWPC enzymatically modified with lipase, trypsin and pepsin had variable effects on these behaviours with the most significant effect exhibited with the lipase treatment. SWPC produced an almost total inhibition of translocation of C. sakazakii across a CaCo-2 cell monolayer. Lipase and pepsin treated SWPC also reduced translocation by 75% and 90% respectively. However, trypsin treatment nullified the effect SWPC had on translocation. The presence of viable bacterial cells and SWPC both increased expression of IL-8 following Cronobacter invasion into CaCo-2 cells.

CONCLUSIONS

Factors governing adherence, invasion and translocation of Cronobacter spp. to human intestinal cells are multi-factorial and digested milk products exhibit varying effects dependant on their enzyme modification and protein lipid content.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings contribute to our, as yet, incomplete understanding of Cronobacter pathogenesis, and suggest that SWPC in whole and enzymatically hydrolysed forms, may provide a cost-effective source of bioactive materials with inhibitory effects on bacterial virulence.

Range performance of the DARPA AWARE wide field-of-view visible imager

In a prior paper, we described a new imaging architecture that addresses the need for wide field-of-view imaging combined with the resolution required to identify targets at long range. Over the last two years substantive improvements have been made to the system, both in terms of the size, weight, and power of the camera as well as to the optics and data management software. The result is an overall improvement in system performance, which we demonstrate via a maritime target identification experiment.

SU-E-I-77: X-Ray Coherent Scatter Diffraction Pattern Modeling in GEANT4

PURPOSE

To model X-ray coherent scatter diffraction patterns in GEANT4 for simulating experiments involving material detection through diffraction pattern measurement. Although coherent scatter cross-sections are modeled accurately in GEANT4, diffraction patterns for crystalline materials are not yet included. Here we describe our modeling of crystalline diffraction patterns in GEANT4 for specific materials and the validation of the results against experimentally measured data.

METHODS

Coherent scatter in GEANT4 is currently based on Hubbell's non-relativistic form factor tabulations from EPDL97. We modified the form-factors by introducing an interference function that accounts for the angular dependence between the Rayleigh-scattered photons and the photon wavelength. The modified form factors were used to replace the inherent form-factors in GEANT4. The simulation was tested using monochromatic and polychromatic x-ray beams (separately) incident on objects containing one or more elements with modified form-factors. The simulation results were compared against the experimentally measured diffraction images of corresponding objects using an in-house x-ray diffraction imager for validation. The comparison was made using the following metrics: number of diffraction rings, radial distance, absolute intensity, and relative intensity.

RESULTS

Sharp diffraction pattern rings were observed in the monochromatic simulations at locations consistent with the angular dependence of the photon wavelength. In the polychromatic simulations, the diffraction patterns exhibited a radial blur consistent with the energy spread of the polychromatic spectrum. The simulated and experimentally measured patterns showed identical numbers of rings with close agreement in radial distance, absolute and relative intensities (barring statistical fluctuations). No significant change was observed in the execution time of the simulations.

CONCLUSIONS

This work demonstrates the ability to model coherent scatter diffraction in GEANT4 in an accurate and efficient manner without compromising the accuracy or runtime of the simulation. This work was supported by the Department of Homeland Security under grant DHS (BAA 10-01 F075), and by the Department of Defense under award W81XWH-09-1-0066.

Terahertz interferometric synthetic aperture tomography for confocal imaging systems

Terahertz (THz) interferometric synthetic aperture tomography (TISAT) for confocal imaging within extended objects is demonstrated by combining attributes of synthetic aperture radar and optical coherence tomography. Algorithms recently devised for interferometric synthetic aperture microscopy are adapted to account for the diffraction-and defocusing-induced spatially varying THz beam width characteristic of narrow depth of focus, high-resolution confocal imaging. A frequency-swept two-dimensional TISAT confocal imaging instrument rapidly achieves in-focus, diffraction-limited resolution over a depth 12 times larger than the instrument's depth of focus in a manner that may be easily extended to three dimensions and greater depths.

Design and characterization of thin multiple aperture infrared cameras

We describe a multiple-aperture long-wave infrared camera built on an uncooled microbolometer array with the objective of decreasing camera thickness. The 5 mm thick optical system is an f/1.2 design with a 6.15 mm effective focal length. An integrated image is formed from the subapertures using correlation-based registration and a least gradient reconstruction algorithm. We measure a 131 mK NETD. The system's spatial frequency is analyzed with 4 bar targets. With proper calibration, our multichannel interpolation results recover contrast for targets at frequencies beyond the aliasing limit of the individual subimages.

Discovery of a novel carboxylesterase through functional screening of a pre-enriched environmental library

AIMS

The aim of this study was to demonstrate the application of environmental sample pre-enrichment to access novel carboxylesterases from environmental genomes, along with subsequent heterologous expression and characterization of the discovered enzyme(s).

METHODS AND RESULTS

A positive recombinant clone (UVCL29), conferring an esterase phenotype was identified from a shotgun gene library. The complete sequence of the 3.0 kb DNA insert from the pUVCL29 recombinant plasmid was obtained using primer-walking strategies. Nucleotide sequence analysis revealed a complete 945 bp open reading frame (ORF1). Translational analysis of the ORF1 showed a protein of 314 amino acids (named EstAM) with a predicted molecular weight of 34 kDa. EstAM's primary structure showed a classical (-G-D-S-A-G-) motif, corresponding with the generally conserved (G-x-S-x-G) esterase signature motif. Identity searches indicated that EstAM has high sequence similarity with esterases from family IV. EstAM was successfully expressed in Escherichia coli in a biologically active form. Partial purification was achieved using a one-step Pro-PurTM IMAC column. Biochemical characterization revealed that EstAM has a temperature optimum of 40 degrees C.

CONCLUSION

Based on its substrate profile, EstAM was classified as a carboxylesterase because of its preference for short p-nitrophenyl ester substrates.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is a demonstration of the successful application of environmental sample pre-enrichment technology in accessing novel esterases from a mining environment.

Measurement-efficient optical wavemeters

We describe a method for efficiently determining the wavelength of a monochromatic source and provide an experimental proof-of-concept. The photomeasurement efficiency for a wavemeter can be written as eta(N,q) = (1 + logqN)/m, where N is the number of spectral channels, q is the number of distinguishable output levels per photodetector, and m is the actual number of photomeasurements made. An implementation is developed that achieves a theoretical efficiency of eta(N,q) = 1. The proof-of-concept experiment achieves efficiencies eta = O(1), where the deviation from theory is attributable to well-known optical effects and should be correctable in future versions.

Characterisation of nitrilase and nitrile hydratase biocatalytic systems

Biocatalytic transformations converting aromatic and arylaliphatic nitriles into the analogous related amide or acid were investigated. These studies included synthesis of the beta-substituted nitrile 3-hydroxy-3-phenylpropionitrile, subsequent enrichment and isolation on this substrate of nitrile-degrading microorganisms from the environment, and a comparative study of enzymatic reactions of nitriles by resting cell cultures and enzymes. Each biocatalyst exhibited a distinctive substrate selectivity profile, generally related to the length of the aliphatic chain of the arylaliphatic nitrile and the position of substituents on the aromatic ring or aliphatic chain. Cell-free nitrilases generally exhibited a narrower substrate range than resting whole cells of Rhodococcus strains. The Rhodococcus strains all exhibited nitrile hydratase activity and converted beta-hydroxy nitriles (but did not demonstrate enantioselectivity on this substrate). The biocatalysts also mediated the synthesis of a range of alpha-hydroxy carboxylic acids or amides from aldehydes in the presence of cyanide. The use of an amidase inhibitor permits halting the nitrile hydratase/amidase reaction at the amide intermediate.

Coded apertures for efficient pyroelectric motion tracking

Coded apertures may be designed to modulate the visibility between source and measurement spaces such that the position of a source among N resolution cells may be discriminated using logarithm of N measurements. We use coded apertures as reference structures in a pyroelectric motion tracking system. This sensor system is capable of detecting source motion in one of the 15 cells uniformly distributed over a 1.6m x 1.6m domain using 4 pyroelectric detectors.

Thyroid hormone regulation of N-methyl-D-aspartic acid receptor subunit mRNA expression in adult brain

Thyroid hormone is an essential modulator of brain development, but little is known about its actions in the adult brain. Hypothyroidism is associated with gene expression changes in both central and peripheral nervous tissue. Functional consequences of adult-onset hypothyroidism include an inability to produce long-term potentiation in rat hippocampus and impaired learning and memory in both rats and man. Long-term potentiation is a form of learning that is dependent on functional N-methyl-d-aspartic acid (NMDA)-preferring ionotropic glutamate receptors. This work examines the expression of ionotropic glutamate receptor subunit mRNA following surgical thyroidectomy with or without thyroid hormone replacement. In situ hybridization histochemistry was used to determine the mRNA levels of the NMDA receptor subunits NR1, NR2A, NR2B, the AMPA receptor subunit GluR1, and the kainate receptor subunit KA2. Reducing circulating concentrations of thyroid hormone by surgical removal of the thyroid gland 2 weeks before sacrifice decreased the expression of NR1 mRNA exclusively in the hippocampus. Conversely, hyperthyroidism selectively reduced NR2B mRNA expression in the dorsal hippocampus. Altering thyroid hormone status had no effect on the expression of KA2 or GluR1 subunit mRNA. The regulation of expression of NR1 and NR2B mRNA by thyroid hormone is a novel mechanism for explaining the relationship between thyroid hormone and cognitive function.

Altered hypothalamic cholinergic responses in patients with nonulcer dyspepsia: a study of pyridostigmine-stimulated growth hormone release

OBJECTIVE

Acetylcholine plays a central and peripheral role in regulating gastric motility. In the hypothalamus, it is a key neuroendocrine modulator; acting through somatostatin, it brings about the release of growth hormone (GH). We measured hypothalamic cholinergic receptor sensitivity in patients with nonulcer dyspepsia (NUD) by examining GH release in response to cholinergic challenge.

METHODS

Forty patients with NUD and 40 healthy comparison subjects were administered pyridostigmine (the acetylcholinesterase inhibitor, 120 mg), and GH release over a 3-h period was monitored.

RESULTS

Calculating response as the maximum GH relative to baseline (delta GH), the mean +/- SEM response in the patients was 11.9 +/- 1.9 U/L and in the healthy subjects 6.7 +/- 0.7 mU/L (t = 2.1, df = 78, p = 0.03). Helicobacter pylori status had no appreciable impact on GH response with H. pylori-positive patients having a mean response of 10.5 +/- 2.1 mU/L and negative patients a mean response of 13.2 +/- 3.4 mU/L. Overall, patients with NUD release more GH in response to pyridostigmine challenge than healthy subjects.

CONCLUSIONS

Patients with NUD may have a pathophysiological disturbance involving central cholinergic systems.

High depth of field microscopic imaging using an interferometric camera

We describe the design of a microscope combining rotational shear interferometer (RSI)-based coherence imaging with an objective lens to simultaneously obtain high numerical aperture and high depth of field imaging. We present experimental results showing the operation of this instrument.

A maximum-likelihood base caller for DNA sequencing

The procedures used to sequence the human genome involve the electrophoretic separation of mixtures of dioxyribonucleic acid (DNA) fragments tagged with reporting groups, usually fluorescent dyes. Each fluorescent pulse which arrives from an optical detector corresponds to a nucleotide (base) in the DNA sequence, and the subsequent process of base detection is known as base calling. Generating longer and more accurate sequences in the base-calling process will reduce the high cost of DNA sequencing. This paper presents an automated base-calling algorithm, referred to as maximum-likelihood base caller (MLB), which is based on maximum likelihood equalization for digital communication channels. Based on 125 experimental datasets, MLB averaged up to 40% fewer errors than the widely used ABI base caller from the Applied Biosystems Division of PE Corporation. MLB's accuracy rivaled that of another well-known base caller, Phred, surpassing it on datasets with high background noise.

Tomographic imaging of foam

The morphology of three-dimensional foams is of interest to physicists, engineers, and mathematicians. It is desired to image the 3-dimensional structure of the foam. Many different techniques have been used to image the foam, including magnetic resonance imaging, and short-focal length lenses. We use a camera and apply tomographic algorithms to accurately image a set of bubbles. We correct for the distortion of a curved plexiglas container using ray-tracing.

Incidence of BRCA1/2 germ line alterations in a high risk cohort participating in a phase II chemoprevention trial

It is unknown what proportion of women at high risk for breast cancer, entering phase II chemoprevention trials, have BRCA1/2 alterations, and whether their initial biomarker patterns or response to preventive interventions will differ between carriers and non-carriers. As part of a 6-month phase II chemoprevention trial of diflouromethlyornithine (DFMO), high-risk subjects (family history, prior precancerous breast disease or prior breast cancer), who had random peri-areolar fine needle evidence of epithelial hyperplasia with or without atypia, were offered genetic counselling and testing at the completion of their study participation. 97% of the 119 women eligible for testing underwent BRCA1/2 gene sequencing, 3 declined. 26 (22%) of the 116 women had an alteration in BRCA1/2. Known deleterious mutations were present in 3 (3%), uncertain significance mutations in 19 (16%), and probable polymorphisms in 6 (5%). There does not appear to be a difference in initial biomarker distribution between participants with and without germ line alterations.

Fabrication of thin-film micropolarizer arrays for visible imaging polarimetry

We describe a microfabrication process for fabricating micropolarizer devices with polarization thin film. The polarization film is less than a 0.5 microm thick and can have a polarization extinction ratio of approximately 330 in the visible wavelength range. A single-state micropolarizer array with polarizing pixels as small as 5 microm x 5 microm has been fabricated. A multilayer spatially multiplexed three-state micropolarizer line array with a 14.4-microm resolution has also been fabricated for visible imaging polarimetry application.

The dying cancer patient

Cancer patients often die with serious unrelieved symptoms causing a distressing death for them and needless added suffering for their families. Many physicians have not been trained to care for the dying patient. This chapter reviews the common symptoms and describes the methods to control them and support the patient and family through this difficult time. These symptoms are so characteristic of the dying process that all physicians should recognize them, be skilled in providing appropriate care, and prepare for problems that may arise.

Alternatives in screening at school entry: comparison of the childhood middle ear disease and hearing questionnaire (CMEDHQ) and the pure tone sweep test

Some health authorities in the UK are discontinuing hearing screening at school entry, mainly because the pure tone sweep test is under-specific (i.e. fails too many children) and thus leads to unnecessary and costly, but unproductive, follow-up assessment. A screening method with different properties such as a questionnaire could be a more cost-effective method of mass screening children. The MRC Institute of Hearing Research has developed and evaluated through several stages such a screening questionnaire (the Childhood Middle Ear Disease and Hearing Questionnaire (CMEDHQ), containing 11 scored questions under two broad headings: history and presentation of the disease, and consultation/treatment history. In a service-based evaluation, 2860 mainstream reception-year school children from two consecutive years, attending schools in south west Cumbria in the North-West Regional Health Authority received the sweep test and the CMEDHQ. (Although predominantly designed to detect middle ear problems, the questionnaire also has some potential to detect permanent hearing loss; thus providing a useful backstop for detection of permanent losses either missed or not present in earlier infancy.) The screening CMEDHQ obtained a very high response rate (90%). Follow-up included 235 control cases as well as all pure tone sweep test failures. Analysis, by use of a definition of cases conservative with respect to the sensitivity of the questionnaire, showed that the CMEDHQ has better specificity, but slightly lower sensitivity, than the pure tone sweep test for composite system decision (where 'case' = treated at ENT; 'non-case' = pass at whatever stage was reached before discharge). Follow-up indicated that the limited method available for assessing sensitivity might give an over-favourable view of the pure tone sweep test. Possible improvement of questionnaire sensitivity by further refinements is under examination. The findings show that it is worth conducting a fully parallel multi-district cost-effectiveness comparison of the pure tone sweep test versus the CMEDHQ.