Abstracts from the 2022 European Association for Vision and Eye Research Festival, 13-15 October 2022, Valencia

PURPOSE

Albinism refers to a group of genetic disorders typically characterized by a loss/reduction of melanin in the hair, skin and eyes of affected patients. Apart from pigment changes, all albinism patients present with foveal hypoplasia and optic nerve misrouting, and have blurred vision. The molecular mechanisms that link this lack of pigment with neural retinal development are poorly understood, with foveal and optic tract development being difficult to model. To advance our knowledge, we developed a novel retinal organoid model of albinism, and characterized the development and outgrowth of retinal ganglion cells affected during albinism as a model for future studies.

METHODS

Human oculocutaneous albinism 1 (OCA1) patient-derived stem cells were differentiated alongside controls into retinal organoids, as published previously^1,2 . Early retinal ganglion cells develop in the first 4 weeks of differentiation, at which point whole organoids could be plated to allow for optic nerve-like outgrowth. Whole organoids were also fixed and analysed with immunohistochemistry (IHC) to visualize contralateral and ipsilateral ganglion cells present in the organoid.

RESULTS

IHC analysis showed differences in the number of ipsilateral and contralateral retinal ganglion cells between the healthy control and albinism organoids, in line with in vivo observations. Further, optic nerve-like outgrowth could be achieved with both models, allowing for future research into optic nerve misrouting in albinism.

CONCLUSIONS

We generated a novel retinal organoid model of oculocutaneous albinism, and characterized the retinal ganglion cell development and outgrowth. This will allow us in the future to study a different and sometimes overlooked aspect of albinism; optic nerve misrouting. References 1. Wagstaff, P. E., Ten Asbroek, A., Ten Brink, J. B., Jansonius, N. M. & Bergen, A. A. B. An alternative approach to produce versatile retinal organoids with accelerated ganglion cell development. Sci Rep 11, 1101, doi:10.1038/s41598-020-79651-x (2021). 2. Ohlemacher, S. K. et al. Stepwise Differentiation of Retinal Ganglion Cells from Human Pluripotent Stem Cells Enables Analysis of Glaucomatous Neurodegeneration. Stem Cells 34, 1553-1562, doi:10.1002/stem.2356 (2016).

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

Rev-Erbα and Photoreceptor Outer Segments modulate the Circadian Clock in Retinal Pigment Epithelial Cells

Retinal photoreceptor outer segments (POS) are renewed daily through phagocytosis by the adjacent retinal pigment epithelial (RPE) monolayer. Phagocytosis is mainly driven by the RPE circadian clock but the underlying molecular mechanisms remain elusive. Using ARPE-19 (human RPE cell-line) dispersed and monolayer cell cultures, we investigated the influence of cellular organization on the RPE clock and phagocytosis genes. PCR analysis revealed rhythmic expression of clock and phagocytosis genes in all ARPE-19 cultures. Monolayers had a tendency for higher amplitudes of clock gene oscillations. In all conditions ARNTL, CRY1, PER1-2, REV-ERBα, ITGB5, LAMP1 and PROS1 were rhythmically expressed with REV-ERBα being among the clock genes whose expression showed most robust rhythms in ARPE-19 cells. Using RPE-choroid explant preparations of the mPer2^Luc knock-in mice we found that Rev-Erbα deficiency induced significantly longer periods and earlier phases of PER2-bioluminescence oscillations. Furthermore, early phagocytosis factors β₅-Integrin and FAK and the lysosomal marker LAMP1 protein levels are rhythmic. Finally, POS incubation affects clock and clock-controlled phagocytosis gene expression in RPE monolayers in a time-dependent manner suggesting that POS can reset the RPE clock. These results shed some light on the complex interplay between POS, the RPE clock and clock-controlled phagocytosis machinery which is modulated by Rev-Erbα.

Design and validation of a large-format transition edge sensor array magnetic shielding system for space application

The paper describes the development and the experimental validation of a cryogenic magnetic shielding system for transition edge sensor based space detector arrays. The system consists of an outer mu-metal shield and an inner superconducting niobium shield. First, a basic comparison is made between thin-walled mu-metal and superconducting shields, giving an off-axis expression for the field inside a cup-shaped superconductor as a function of the transverse external field. Starting from these preliminary analytical considerations, the design of an adequate and realistic shielding configuration for future space flight applications (either X-IFU [D. Barret et al., e-print arXiv:1308.6784 [astro-ph.IM] (2013)] or SAFARI [B. Jackson et al., IEEE Trans. Terahertz Sci. Technol. 2, 12 (2012)]) is described in more detail. The numerical design and verification tools (static and dynamic finite element method (FEM) models) are discussed together with their required input, i.e., the magnetic-field dependent permeability data. Next, the actual manufacturing of the shields is described, including a method to create a superconducting joint between the two superconducting shield elements that avoid flux penetration through the seam. The final part of the paper presents the experimental verification of the model predictions and the validation of the shield's performance. The shields were cooled through the superconducting transition temperature of niobium in zero applied magnetic field (<10 nT) or in a DC field with magnitude ∼100 μT, applied either along the system's symmetry axis or perpendicular to it. After cool-down, DC trapped flux profiles were measured along the shield axis with a flux-gate magnetometer and the attenuation of externally applied AC fields (100 μT, 0.1 Hz, both axial and transverse) was verified along this axis with superconducting quantum interference device magnetometers. The system's measured on-axis shielding factor is greater than 10⁶, well exceeding the requirement of the envisaged missions. Following field-cooling in an axial field of 85 μT, the residual internal DC field normal to the detector plane is less than 1 μT. The trapped field patterns are compared to the predictions of the dynamic FEM model, which describes them well in the region where the internal field exceeds 6 μT.

Ophthalmic epidemiology in Europe: the "European Eye Epidemiology" (E3) consortium

The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 European participants. The aim of the consortium is to promote and sustain collaboration and sharing of data and knowledge in the field of ophthalmic epidemiology in Europe, with particular focus on the harmonization of methods for future research, estimation and projection of frequency and impact of visual outcomes in European populations (including temporal trends and European subregions), identification of risk factors and pathways for eye diseases (lifestyle, vascular and metabolic factors, genetics, epigenetics and biomarkers) and development and validation of prediction models for eye diseases. Coordinating these existing data will allow a detailed study of the risk factors and consequences of eye diseases and visual impairment, including study of international geographical variation which is not possible in individual studies. It is expected that collaborative work on these existing data will provide additional knowledge, despite the fact that the risk factors and the methods for collecting them differ somewhat among the participating studies. Most studies also include biobanks of various biological samples, which will enable identification of biomarkers to detect and predict occurrence and progression of eye diseases. This article outlines the rationale of the consortium, its design and presents a summary of the methodology.

Cyclosporine A Treatment Inhibits Abcc6-Dependent Cardiac Necrosis and Calcification following Coxsackievirus B3 Infection in Mice

Coxsackievirus type B3 (CVB3) is a cardiotropic enterovirus. Infection causes cardiomyocyte necrosis and myocardial inflammation. The damaged tissue that results is replaced with fibrotic or calcified tissue, which can lead to permanently altered cardiac function. The extent of pathogenesis among individuals exposed to CVB3 is dictated by a combination of host genetics, viral virulence, and the environment. Here, we aimed to identify genes that modulate cardiopathology following CVB3 infection. 129S1 mice infected with CVB3 developed increased cardiac pathology compared to 129X1 substrain mice despite no difference in viral burden. Linkage analysis identified a major locus on chromosome 7 (LOD: 8.307, P<0.0001) that controlled the severity of cardiac calcification and necrosis following infection. Sub-phenotyping and genetic complementation assays identified Abcc6 as the underlying gene. Microarray expression profiling identified genotype-dependent regulation of genes associated with mitochondria. Electron microscopy examination showed elevated deposition of hydroxyapatite-like material in the mitochondrial matrices of infected Abcc6 knockout (Abcc6-/-) mice but not in wildtype littermates. Cyclosporine A (CsA) inhibits mitochondrial permeability transition pore opening by inhibiting cyclophilin D (CypD). Treatment of Abcc6 -/- mice with CsA reduced cardiac necrosis and calcification by more than half. Furthermore, CsA had no effect on the CVB3-induced phenotype of doubly deficient CypD-/-Abcc6-/- mice. Altogether, our work demonstrates that mutations in Abcc6 render mice more susceptible to cardiac calcification following CVB3 infection. Moreover, we implicate CypD in the control of cardiac necrosis and calcification in Abcc6-deficient mice, whereby CypD inhibition is required for cardioprotection.

Expanded clinical spectrum of enhanced S-cone syndrome

IMPORTANCE

New funduscopic findings in patients with enhanced S-cone syndrome (ESCS) may help clinicians in diagnosing this rare autosomal recessive retinal dystrophy.

OBJECTIVE

To expand the clinical spectrum of ESCS due to mutations in the NR2E3 gene.

DESIGN

Retrospective, noncomparative case series of 31 patients examined between 1983 and 2012.

SETTING

Academic and private ophthalmology practices specialized in retinal dystrophies.

PARTICIPANTS

A cohort of patients diagnosed with ESCS and harboring known NR2E3 mutations.

INTERVENTION

Patients had ophthalmic examinations including visual function testing that led to the original diagnosis.

MAIN OUTCOMES AND MEASURES

New fundus features captured with imaging modalities.

RESULTS

New clinical observations in ESCS include (1) torpedo-like, deep atrophic lesions with a small hyperpigmented rim, variably sized and predominantly located along the arcades; (2) circumferential fibrotic scars in the posterior pole with a spared center and large fibrotic scars around the optic nerve head; and (3) yellow dots in areas of relatively normal-appearing retina.

CONCLUSIONS AND RELEVANCE

Enhanced S-cone syndrome has more pleiotropy than previously appreciated. While the nummular type of pigmentation at the level of the retinal pigment epithelium and cystoid or schisis-like maculopathy with typical functional findings remain classic hallmarks of the disease, changes such as circumferential fibrosis of the macula or peripapillary area and "torpedo-like" lesions along the vascular arcades may also direct the clinical diagnosis and focus on screening the NR2E3 gene for a molecular diagnosis.

Union makes strength: a worldwide collaborative genetic and clinical study to provide a comprehensive survey of RD3 mutations and delineate the associated phenotype

Leber congenital amaurosis (LCA) is the earliest and most severe retinal degeneration (RD), and the most common cause of incurable blindness diagnosed in children. It is occasionally the presenting symptom of multisystemic ciliopathies which diagnosis will require a specific care of patients. Nineteen LCA genes are currently identified and three of them account for both non-syndromic and syndromic forms of the disease. RD3 (LCA12) was implicated as a LCA gene based on the identification of homozygous truncating mutations in two LCA families despite the screening of large cohorts of patients. Here we provide a comprehensive survey of RD3 mutations and of their clinical expression through the screening of a cohort of 852 patients originating worldwide affected with LCA or early-onset and severe RD. We identified three RD3 mutations in seven unrelated consanguineous LCA families - i.e., a 2 bp deletion and two nonsense mutations – predicted to cause complete loss of function. Five families originating from the Southern Shores of the Mediterranean segregated a similar mutation (c.112C>T, p.R38*) suggesting that this change may have resulted from an ancient founder effect. Considering the low frequency of RD3 carriers, the recurrence risk for LCA in non-consanguineous unions is negligible for both heterozygote and homozygote RD3 individuals. The LCA12 phenotype in our patients is highly similar to those of patients with mutant photoreceptor-specific guanylate cyclase (GUCY2D/LCA1). This observation is consistent with the report of the role of RD3 in trafficking of GUCYs and gives further support to a common mechanism of photoreceptor degeneration in LCA12 and LCA1, i.e., inability to increase cytoplasmic cGMP concentration in outer segments and thus to recover the dark-state. Similar to LCA1, LCA12 patients have no extraocular symptoms despite complete inactivation of both RD3 alleles, supporting the view that extraocular investigations in LCA infants with RD3 mutations should be avoided.

Circadian expression of clock genes and clock-controlled genes in the rat retina

The circadian expression patterns of genes encoding for proteins that make up the core of the circadian clock were measured in rat retina using real-time quantitative PCR (qPCR). Transcript levels of several genes previously used for normalization of qPCR assays were determined and the effect of ischemia-reperfusion on the expression of clock genes was studied. Statistically significant circadian changes in transcript levels were found for: Per2, Per3, Cry2, Bmal1, Rora, Rorb, and Rorc with changes ranging between 1.6- and 2.6-fold. No changes were found for Per1, Cry1, Clock, Rev-erb alpha, and Rev-erb beta. Significant differences in transcript levels were observed for several candidate reference genes: HPRT, GAPDH, rhodopsin, and Thy1 and, consequently, the use of these genes for normalization purposes in qPCR or Northern blots may lead to erroneous conclusions. Ischemia-reperfusion leads to a persistent decrease of Per1 and Cry2, which may be related to the selective degeneration of amacrine and ganglion cells. We conclude that while all clock genes are expressed in the retina, only a few show a clear circadian pattern.

Naked Amoebas and Bacteria in an Oil-Impacted Salt Marsh Community

Populations of soil amoebas were monitored in two salt marshes in Staten Island, NY for 2 years. One site, Gulfport Reach on the Arthur Kill, has been highly impacted by numerous oil spills. In particular, in 1990 a massive no. 2 fuel oil spill from a ruptured pipe flooded the area; its sediments had total petroleum hydrocarbon (TPH) concentrations in the range 800-46,000 ppm. A reference site 11 km away, on the Atlantic coast, had low TPH levels. Amoeba population densities were in general higher in the impacted sediments. In laboratory microcosm experiments, sediment samples from unimpacted sites were treated with added fresh (unweathered) hydrocarbons (no. 2 fuel oil) and cultured; these also yielded higher amoeba numbers than untreated controls. Four distinct amoeba morphotypes were monitored. Changes in population levels of total amoebas were correlated in the two sites, particularly for morphotype 2 (r = 0.83). The ratios of total amoebas to total bacterial numbers were also correlated (r = 0.85) between the sites. This suggests the amoebas may function as generalists, and that their trophic relation to bacterial prey is not much affected by the presence of petroleum hydrocarbons, but rather may reflect regional parameters such as ambient temperature or other physical factors.

Generalising to theory: the use of a multiple case study design to investigate needs assessment and quality of care in community nursing

This paper outlines the detail of the case study method used in a project commissioned by the English National Board for Nursing, Midwifery and Health Visiting (ENB) to investigate the changing educational needs of community nurses with regard to needs assessment and quality of care in the context of the NHS and Community Care Act, 1990. It explains the methodological procedures and analytic processes which led to integration of data across the whole study, focusing on the role of a prior theoretical framework in case study design. Recently qualified practitioners (health visitors and district nurses) were observed during a regular shift (N=134 visits), concentrating on their practice of assessing needs, and on liaison and collaboration within teams and across sectors. They were interviewed after the observation period (N=33 practitioners), to determine the extent of formality they attached to each assessment, and elicit information about aspects which may be embedded in everyday practice as well as those recorded for explicit requirements.The preliminary analysis resulted in the modification of a model for assessing service quality, and identified various points where a 'policy-practice gap' might arise between policies and practice in both the health service and education. The practicalities of operationalising a multiple case study design into research are highlighted, and the mechanism for 'generalising to theory' illustrated.

A case for case studies: exploring the use of case study design in community nursing research

The case study has become an accepted vehicle for conducting research in a variety of disciplines. However, the meaning behind the term is not always made explicit by researchers and this has given rise to a number of assumptions which are open to challenge, and to questions about the robustness of the method. This paper explores some of the issues arising from one particular definition of case study research, used in a study by Yin which examined the practice of case management in community nursing. Four main areas are discussed. First, defining 'case' is seen to pose questions about the relationship of the phenomenon to its context, the degree of researcher control over case definition, the limits to what may constitute a 'case' and what is meant by the term 'unit of analysis'. Second, the relevance of external validity to case study research is supported through the use of a number of tactics, in particular Yin's concept of replication logic, which involves generalizing to theory, rather than to empirical data. Third, the use of method triangulation (multiple methods of data collection) is advanced as a means of enhancing construct validity in research where data converge around a particular theory. Finally, the relationship of the case study to theory construction, through the prior development of 'propositions' is discussed. Each of these issues is applied to the design and conduct of a research study based closely on Yin's multiple case study framework. Thirteen 'cases' were selected of case management practice and data were collected through interviews and examination of literature and documentation, to explore the suitability of community nurses for the role. It is concluded that, given the appropriate subject matter, context and research aims, the case study method may be seen as a credible option in nursing research.

Using language intensity to increase the success of a family intervention to protect children from ultraviolet radiation: predictions from language expectancy theory

BACKGROUND

Even though people are informed about skin cancer prevention, they do not always comply with prevention advice. From Language Expectancy Theory, it was predicted that messages with high language intensity would improve compliance with sun safety recommendations and that this effect would be enhanced with deductive argument style.

METHODS

Parents (N = 841) from a pediatric clinic and elementary schools received sun safety messages (newsletters, brochures, tip cards) by mail that varied in language intensity and logical style. Effects on attitudes and behavior were tested in a pretest-posttest factorial design.

RESULTS

As hypothesized, parents receiving messages with high- as opposed to low-intensity language complied more with sun safety advice. Messages with highly intense language were more persuasive when the arguments were formatted in a deductive style; low language intensity was more persuasive in inductively styled messages.

CONCLUSIONS

By carefully adjusting messages features, health professionals can obtain further compliance beyond that produced by educating people about health risks and creating favorable attitudes and self-efficacy expectations. Highly intense language may be a good general strategy in prevention messages and works better when conclusions and recommendations are offered explicitly to recipients, especially when advice is aimed at reducing their personal risk.

A taxonomy of needs assessment, elicited from a multiple case study of community nursing education and practice

The role and expectations of community nurses in carrying out needs assessments changed when an internal quasi-market was introduced to the British health service under the National Health Service (NHS) & Community Care Act 1990. This paper reports on a study commissioned by the English National Board for Nursing, Midwifery and Health Visiting (ENB) to investigate the changing educational needs of community nurses with regard to needs assessment in the context of this legislation. A multiple case study design was utilized and four cases identified, incorporating the geographical variation in England. Recently qualified practitioners (health visitors and district nurses) were observed during a regular shift (n=134 visits), concentrating on their practice of assessing needs, and on liaison and collaboration within teams and across sectors. Participants were interviewed after the observation period (n=33 practitioners), to determine the extent of formality they attached to each assessment, and to elicit information about aspects which may be embedded in everyday practice. Single and multiple case analyses across the four cases used an iterative process of pattern-matching, replication logic and explanation building. The preliminary analysis yielded a descriptive 'taxonomy' which could serve as a basis for classifying the variants of needs assessment and help to clarify the whole phenomenon. When applied further to the data, this revealed the complex interactions between the different ideals (relating to policy, nursing and ascribed worth), the various types (purpose, formality/specificity and complexity) and timing (in relation to client, service and practice issues) within needs assessment.

Identification of four variants in the tryptophan hydroxylase promoter and association to behavior

One of the most replicated findings in biological psychiatry is the observation of lower 5-hydroxyindoleacetic acid concentrations, the major metabolite of serotonin, in the brain and cerebrospinal fluid of subjects with impulsive aggression. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the synthesis of serotonin, however functional variants have not been reported from the coding sequence of this gene. Therefore, we screened the human TPH promoter (TPH-P) for genetic variants which could modulate TPH gene transcription. The TPH-P (2093 nucleotides) was screened for sequence variation by SSCP analysis of 260 individuals from Finnish, Italian, American Caucasian, and American Indian populations. Four common polymorphisms were identified: -7180T>G, -7065C>T, -6526A>G, and -5806G>T (designated as nucleotides upstream of the translation start site). In the Finns, the four polymorphisms had a minor allele frequency of 0.40 and in this population linkage disequilibrium between the four loci was complete. In the other populations the minor allele frequencies ranged from 0.40 to 0.45. TPH -6526A>G genotype was determined in 167 unrelated Finnish offenders and 153 controls previously studied for the TPH IVS7+779C>A polymorphism. A significant association was observed between -6526A>G and suicidality in the offenders. TPH -6526A>G and the previously reported intron seven polymorphism, TPH IVS7+779C>A, exhibited a normalised linkage disequilibrium of 0.89 in Finns. Normalized linkage disequilibrium was reduced in other populations, being 0.49 and 0.21 in Italians and American Indians, respectively. In conclusion, four TPH-P variants were identified which can be used for haplotype-based analysis to localize functional TPH alleles influencing behavior.

Ancestral Asian source(s) of new world Y-chromosome founder haplotypes

Haplotypes constructed from Y-chromosome markers were used to trace the origins of Native Americans. Our sample consisted of 2,198 males from 60 global populations, including 19 Native American and 15 indigenous North Asian groups. A set of 12 biallelic polymorphisms gave rise to 14 unique Y-chromosome haplotypes that were unevenly distributed among the populations. Combining multiallelic variation at two Y-linked microsatellites (DYS19 and DXYS156Y) with the unique haplotypes results in a total of 95 combination haplotypes. Contra previous findings based on Y- chromosome data, our new results suggest the possibility of more than one Native American paternal founder haplotype. We postulate that, of the nine unique haplotypes found in Native Americans, haplotypes 1C and 1F are the best candidates for major New World founder haplotypes, whereas haplotypes 1B, 1I, and 1U may either be founder haplotypes and/or have arrived in the New World via recent admixture. Two of the other four haplotypes (YAP+ haplotypes 4 and 5) are probably present because of post-Columbian admixture, whereas haplotype 1G may have originated in the New World, and the Old World source of the final New World haplotype (1D) remains unresolved. The contrasting distribution patterns of the two major candidate founder haplotypes in Asia and the New World, as well as the results of a nested cladistic analysis, suggest the possibility of more than one paternal migration from the general region of Lake Baikal to the Americas.

Mutation screening of the 5-hydroxytryptamine7 receptor gene among Finnish alcoholics and controls

Impaired central serotonin neurotransmission has been associated with increased aggression, impaired impulse control and diurnal activity rhythm disturbances among humans. Neuroanatomic distribution and pharmacological properties of the serotonin 5-HT7 receptor suggest that it may play a role in psychiatric disorders and in circadian rhythm regulation. In this study a point mutation causing proline279 --> leucine amino acid substitution in the 5-hydroxytryptamine7 (5-HT7) receptor gene was discovered. This 5-HT7Leu279 variant was observed in six of 825 individuals, all of whom are heterozygous for the substitution. Three of them are alcoholic offenders (3/255), two are relatives of an offender without the 5-HT7Leu279 allele (2/255) and one is a healthy control without any psychiatric diagnosis (1/248). The allele frequency of the 5-HT7Leu279 variant is 0.004 (6/758) among Finns. Although the 5-HT7Leu279 variant is approximately three times more common among alcoholic offenders than among healthy controls, it is not significantly associated with alcoholism or impulsivity in the present study. The 5-HT7Leu279 allele may, however, be a predisposing allele in a subgroup of alcoholic offenders with multiple behavioral problems.

Identification of a Ser857-Asn857 substitution in DRK1 (KCNB1), population frequencies and lack of association to the low voltage alpha EEG trait

A nonconservative amino acid substitution (Ser857Asn) in the human delayed-rectifier potassium channel DRK1 (KCNB1 locus), a candidate gene for the low voltage alpha electroencephalogram (EEG) trait locus (LVEEG1) at 20q13.2, and its frequency in ethnic population samples are described. The frequency of Asn857 in seven different ethnic population samples, totalling more than 1600 individuals, ranged from zero to greater than 3%. However, no association was found between Asn857 and the low voltage alpha EEG trait (LVA) in a population of 105 subjects assessed for the EEG, 24 of whom actually had LVA.

The telephone survey method: a discussion paper

The telephone survey method is discussed in the light of the experiences of one research team investigating case management practices among nurses working in the community using a multiple-method design. An account is given of the strategies employed to recruit a study sample, minimize non-response and bias and ensure the use of sound practices during data collection. The findings highlight the benefits of using the telephone survey method when recruiting respondents across a wide geographical area and/or working within a continually changing environment. However, the findings also highlight the challenge of non-response caused by non-contact and the resource implications of 'doing more' to recruit key informants via the telephone.

Establishing a framework for research: the example of needs assessment

This paper explains the early planning stage of a study commissioned by the English National Board which will investigate the changing educational needs of community nurses with regard to needs assessment and quality of care in the context of the NHS and Community Care Act 1990. Two focus groups, comprising 22 participants altogether, generated data which were used to augment and clarify issues explored in an initial literature review. Some of the methodological issues are explained. Traditional community nursing approaches to needs assessment appeared to value process and integration, while the new legislation emphasizes the separateness of assessment; there is a danger that it may be seen as a single event. The consumer views were both supportive and critical about each of the approaches; some important insights were gained, and a confident basis from which to launch the study identified. The approach offers one possible way to clarify the starting point of a project when carrying out a standard literature review seems insufficient. This may occur with under-researched or rapidly changing phenomena, or if a field of interest is the subject of multiple interpretations or lack of consensus.

Mass allele detection (MAD) of rare 5-HT1A structural variants with allele-specific amplification and electrochemiluminescent detection

A strategy is described that exploits allele-specific amplification (ASA-PCR) and electrochemiluminescence (ECL) detection technology to rapidly and cheaply screen large numbers of DNAs arranged in pooled matrices in order to identify individual nucleotide sequence variants. To demonstrate this strategy, a large genomic DNA collection was screened for two nucleotide variants in the 5-HT1A serotonin receptor gene and individual heterozygotes were identified. Conversion of two SSCP variants to allele-specific PCR polymorphisms was accomplished, and PCR product capture and ECL detection were enabled by the covalent addition of biotin to allele-specific PCR primers and ruthenium to the nonspecific PCR primer. A two-level DNA pooling strategy was used to reduce the number of individual PCR reactions required. Pooling experiments established that ASA-PCR with ECL detection is sufficiently sensitive to reproducibly detect a single specific allele in the presence of a 40-fold excess of genomic DNA from individuals negative for the specific allele. The detection sensitivity of the ECL device and the design of the pooled DNA arrays reduced the number of PCRs required to detect the rare individuals with the variant sequences by approximately 90%. This strategy is called mass allele detection (MAD).

Case management in the community: identifying a role for nursing

This paper describes the findings of a questionnaire survey designed to create a picture of current case management practices as they relate to community nursing. Eighty-three questionnaires were analysed in order to identify client groups, nurse details, functions of case management adopted, other services involved, titles used and advantages and disadvantages of the ways of working adopted. Findings suggest that interpretation of, and involvement in, case management is variable and that the practice potential for this model of care warrants further research.

Characterization of a gene coamplified with Ki-ras in Y1 murine adrenal carcinoma cells that codes for a putative membrane protein

We report the sequence and genomic organization of a gene linked to Ki-ras in the mouse and coamplified in Y1 murine adrenal carcinoma cells. The entire 4.4-kb cDNA sequence as well as promoter and splice sites for each of the three exons was determined. The gene, designated KRAG (Ki-ras-associated gene) has a CG-rich first exon and promoter region and a long 3' untranslated region and encodes 216 amino acids. The putative 23.9-kDa protein has four potential transmembrane hydrophobic domains. The hydropathy plot resembles that of certain tumor-associated antigens, including CO-029 and ME491. A potential human homologue, EST05985, was identified and provisionally mapped to human chromosome 12, a chromosome syntenic to mouse chromosome 6, the previously mapped location of KRAG.

Exploring consumer views of care provided by the Macmillan nurse using the critical incident technique

This study focuses on descriptive accounts of one Macmillan nurse's work, as provided by key individuals coming into contact with this specialist professional service. Twenty respondents (eight patients, five carers, five district nurses and two general practitioners) were interviewed using a variation of the critical incident technique. Data were analysed in terms of meaningful observed events (critical happenings) that were perceived as effective or ineffective with respect to the delivery of high-quality nursing care. Some variations were found between groups of respondents in their perception of the nurse's role. However, there was a general emphasis on the possession of specialist knowledge of terminal cancer care and the positive impact of interventions to both the patient and to lay and professional carers. The critical incident technique was found to be a valuable method for eliciting detailed accounts of the work of the nurse in this specialized field of practice.

Case management in community care: concepts, practices and implications for nursing

Case management has recently become a prominent issue in British community policy and practice, but one which, at the same time, has been subjected to a variety of interpretations. For this reason, it is considered useful to analyse it in terms of a framework embracing conceptual and operational components rather than within the more limiting confines of conventional definitions. A review, within this framework, of initial research projects suggests case management to be a viable mode of community care, with generally favourable outcomes. It also suggests a potentially significant role for community nurses as case managers, although several issues need to be considered when implementing these practices. Finally, a number of questions emerge which should be the focus of future research in the area.

Evaluating nursing care of the terminally ill in the community: a case study approach

A multiple case study approach was used to evaluate the care of terminally ill people in the community of one Health Authority. Nine patients, and their visiting district and continuing care nurses, were interviewed to determine their different perspectives on need identification and resolution, using the Standard on Care of the Dying as a framework. Data were subjected to content analysis and categorized in relation to theory emerging from the literature. Needs were felt to be generally well met by the nurses, and patients indicated no serious areas of omission. However, a number of recurrent problems and issues were highlighted and recommendations put forward to redress them.

Nurses caring for the terminally ill in the community: a review of the literature

The review considers the literature covering both general district nursing and specialist nursing provision for the terminally ill in the community over the last 10 years in the United Kingdom. It looks at the theoretical and methodological issues associated with research in this area and offers critiques of a number of individual studies in the light of these issues. Research findings are subject to limited comparative analysis and tentative conclusions are drawn regarding the model of care best suited to the needs of those dying at home. Recommendations for future areas of nursing research are made.