Patient and public involvement in the development of health services: Engagement of underserved populations in a quality improvement programme for inflammatory bowel disease using a community-based participatory approach

INTRODUCTION

Involving people with lived experience is fundamental to healthcare development and delivery. This is especially true for inflammatory bowel disease (IBD) services, where holistic and personalised models of care are becoming increasingly important. There is, however, a significant lack of representation of underserved and diverse groups in IBD research, and there are significant barriers to healthcare access and utilisation among minority groups in IBD. IBD centres need to be aware of these experiences to address barriers via service changes, improve interactions with local communities and promote meaningful engagement for improved health outcomes.

METHODS

A pragmatic community-based approach was taken to engage with leaders and members of underserved groups across 11 workshops representing Roma, Afro-Caribbean, people of African descent and the wider black, Asian and minority ethnic (BAME) communities, Muslim women, refugee community members, deprived areas of South Yorkshire, LGBTQ+ and deaf populations. Thematic analysis of field notes identified patterns of attention across the community groups and where improvements to services were most frequently suggested.

RESULTS

Findings demonstrated several barriers experienced to healthcare access and utilisation, including language accessibility, staff attitudes and awareness, mental health and stigma, continuity of support, and practical factors such as ease of service use and safe spaces. These barriers acted as a lever to co-producing service changes that are responsive to the health and social care needs of these groups.

CONCLUSIONS

Engaging with people from a range of communities is imperative for ensuring that service improvements in IBD are accessible and representative of individual needs and values.

PATIENT OR PUBLIC CONTRIBUTION

Local community leaders and members of community groups actively participated in the co-design and development of improvements to the IBD service for a local hospital. Their contributions further informed a pilot process for quality improvement programmes in IBD centres.

Quality improvement exercises in Inflammatory Bowel Disease (IBD) services: A scoping review

OBJECTIVE

Quality Improvement initiatives aim to improve care in Inflammatory Bowel Disease (IBD). These address a range of aspects of care including adherence to published guidelines. The objectives of this review were to document the scope and quality of published quality improvement initiatives in IBD, highlight successful interventions and the outcomes achieved.

DESIGN/METHOD

We searched MEDLINE, EMBASE, CINAHL and Web of Science. Two reviewers independently screened and extracted data. We included peer reviewed articles or conference proceedings reporting initiatives intended to improve the quality of IBD care, with both baseline and prospectively collected follow-up data. Initiatives were categorised based on problems, interventions and outcomes. We used the Quality Improvement Minimum Quality Criteria Set instrument to appraise articles. We mapped the focus of the articles to the six domains of the IBD standards.

RESULTS

100 studies were identified (35 full text; 65 conference abstracts). Many focused on vaccination, medication, screening, or meeting multiple quality measures. Common interventions included provider education, the development of new service protocols, or enhancements to the electronic medical records. Studies principally focused on areas covered by the IBD standards 'ongoing care' and 'the IBD service', with less focus on standards 'pre-diagnosis', 'newly diagnosed', 'flare management', 'surgery' or 'inpatient care'.

CONCLUSION

Good quality evidence exists on approaches to improve the quality of a narrow range of IBD service functions, but there are many topic areas with little or no published quality improvement initiatives. We highlight successful quality improvement interventions and offer recommendations to improve reporting of future studies.

Service user involvement in mental health service commissioning, development and delivery: A systematic review of service level outcomes

INTRODUCTION

Service user involvement is increasingly considered essential in mental health service development and delivery. However, the impact of this involvement on services is not well documented. We aimed to understand how user involvement shapes service commissioning, development and delivery, and if/how this leads to improved service-level outcomes.

METHODS

A systematic review of electronic databases (MEDLINE, PsycINFO, CINAHL and EMBASE databases) was undertaken in June and November 2022 for studies that incorporated patient involvement in service development, and reported service-level outcomes. Included studies were synthesised into a logic model based on inputs (method of involvement), activities (changes to service) and outputs (indicators of improvement). PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines were followed when conducting this review.

RESULTS

From 10,901 records identified, nine studies were included, of which six were judged to have used co-production or co-design approaches. Included studies described service user involvement ranging from consultation to co-production. We identified a range of outputs associated with service user involvement in service planning and delivery, and reported these in the form of a logic model. These service-level outputs included improved treatment accessibility, increased referrals and greater service user satisfaction. Longer-term outcomes were rarely reported and hence it was difficult to establish whether outputs are sustained.

CONCLUSION

More extensive forms of involvement, namely, co-design and co-production, were associated with more positive and substantial outputs in regard to service effectiveness than more limited involvement methods. However, lived experience contributions highlighted service perception outputs may be valued more highly by service users than professionals and therefore should be considered equally important when evaluating service user involvement. Although evidence of longer term outcomes was scarce, meaningful involvement of service users in service planning and delivery appeared to improve the quality of mental health services.

PATIENT OR PUBLIC CONTRIBUTION

Members of a lived experience advisory panel contributed to the review findings, which were co-authored by a peer researcher. Review findings were also presented to stakeholders including service users and mental health professionals.

Prognostic accuracy of emergency department triage tools for adults with suspected COVID-19: the PRIEST observational cohort study

BACKGROUND

The WHO and National Institute for Health and Care Excellence recommend various triage tools to assist decision-making for patients with suspected COVID-19. We aimed to compare the accuracy of triage tools for predicting severe illness in adults presenting to the ED with suspected COVID-19.

METHODS

We undertook a mixed prospective and retrospective observational cohort study in 70 EDs across the UK. We collected data from people attending with suspected COVID-19 and used presenting data to determine the results of assessment with the WHO algorithm, National Early Warning Score version 2 (NEWS2), CURB-65, CRB-65, Pandemic Modified Early Warning Score (PMEWS) and the swine flu adult hospital pathway (SFAHP). We used 30-day outcome data (death or receipt of respiratory, cardiovascular or renal support) to determine prognostic accuracy for adverse outcome.

RESULTS

We analysed data from 20 891 adults, of whom 4611 (22.1%) died or received organ support (primary outcome), with 2058 (9.9%) receiving organ support and 2553 (12.2%) dying without organ support (secondary outcomes). C-statistics for the primary outcome were: CURB-65 0.75; CRB-65 0.70; PMEWS 0.77; NEWS2 (score) 0.77; NEWS2 (rule) 0.69; SFAHP (6-point rule) 0.70; SFAHP (7-point rule) 0.68; WHO algorithm 0.61. All triage tools showed worse prediction for receipt of organ support and better prediction for death without organ support. At the recommended threshold, PMEWS and the WHO criteria showed good sensitivity (0.97 and 0.95, respectively) at the expense of specificity (0.30 and 0.27, respectively). The NEWS2 score showed similar sensitivity (0.96) and specificity (0.28) when a lower threshold than recommended was used.

CONCLUSION

CURB-65, PMEWS and the NEWS2 score provide good but not excellent prediction for adverse outcome in suspected COVID-19, and predicted death without organ support better than receipt of organ support. PMEWS, the WHO criteria and NEWS2 (using a lower threshold than usually recommended) provide good sensitivity at the expense of specificity.

TRIAL REGISTRATION NUMBER

ISRCTN56149622.

Prevalence and risk factors for mental health problems in university undergraduate students: A systematic review with meta-analysis

BACKGROUND

Effective targeting of services requires that we establish which undergraduates are at increased risk of mental health problems at university. We aimed to conduct a systematic review and meta-analysis of the prevalence and risk factors for mental health problems in undergraduates.

METHODS

We searched MEDLINE, PsycInfo, EMBASE and the Cochrane Central Register. Eligible studies were assessed using the Quality of Prognostic Studies checklist and narratively synthesised. Pooled prevalence of depression and suicide-related outcomes, and associated risk factors (odds ratios) were estimated using random-effects meta-analyses.

RESULTS

Sixty-six eligible studies of varying quality were included in a narrative synthesis. The pooled prevalence of depression (eight studies; 13,790 participants) was 25% (95% CI 17%, 35%) and the pooled prevalence of suicide-related outcomes (four studies; 2,586 participants) was 14% (95% CI 0%, 44%). Thirteen studies contributed to meta-analytic syntheses of 12 depression-related and four suicide-related risk factors. Presenting with a current mental health problem, negative rumination, parent separation, experiences of sexual harassment and parental depression significantly predicted depression outcomes. Childhood adversity, baseline mental health problems and financial difficulties significantly predicted suicide-related outcomes.

LIMITATIONS

Student mental health is a heterogeneous research area and is hampered by the use of imprecise terms, both for describing risk factors and mental health outcomes. These inconsistencies limit the extent to which datasets can be meaningfully synthesised.

CONCLUSIONS

This review evidences the importance of a range of risk factors for poor undergraduate mental health. Interventions should be developed to target modifiable risk factors and prevent poor mental health outcomes. Systematic review registration: PROSPERO registration CRD42019144927.

Dark Energy Survey Year 1 Results: Cosmological Constraints from Cluster Abundances, Weak Lensing, and Galaxy Correlations

We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.

Post-exertion oxygen saturation as a prognostic factor for adverse outcome in patients attending the emergency department with suspected COVID-19: a substudy of the PRIEST observational cohort study

BACKGROUND

Measurement of post-exertion oxygen saturation has been proposed to assess illness severity in suspected COVID-19 infection. We aimed to determine the accuracy of post-exertional oxygen saturation for predicting adverse outcome in suspected COVID-19.

METHODS

We undertook a substudy of an observational cohort study across 70 emergency departments during the first wave of the COVID-19 pandemic in the UK. We collected data prospectively, using a standardised assessment form, and retrospectively, using hospital records, from patients with suspected COVID-19, and reviewed hospital records at 30 days for adverse outcome (death or receiving organ support). Patients with post-exertion oxygen saturation recorded were selected for this analysis. We constructed receiver-operating characteristic curves, calculated diagnostic parameters, and developed a multivariable model for predicting adverse outcome.

RESULTS

We analysed data from 817 patients with post-exertion oxygen saturation recorded after excluding 54 in whom measurement appeared unfeasible. The c-statistic for post-exertion change in oxygen saturation was 0.589 (95% CI 0.465 to 0.713), and the positive and negative likelihood ratios of a 3% or more desaturation were, respectively, 1.78 (1.25 to 2.53) and 0.67 (0.46 to 0.98). Multivariable analysis showed that post-exertion oxygen saturation was not a significant predictor of adverse outcome when baseline clinical assessment was taken into account (p=0.368). Secondary analysis excluding patients in whom post-exertion measurement appeared inappropriate resulted in a c-statistic of 0.699 (0.581 to 0.817), likelihood ratios of 1.98 (1.26 to 3.10) and 0.61 (0.35 to 1.07), and some evidence of additional prognostic value on multivariable analysis (p=0.019).

CONCLUSIONS

Post-exertion oxygen saturation provides modest prognostic information in the assessment of selected patients attending the emergency department with suspected COVID-19.

TRIAL REGISTRATION NUMBER

ISRCTN Registry (ISRCTN56149622) http://www.isrctn.com/ISRCTN28342533.

Derivation and validation of a clinical severity score for acutely ill adults with suspected COVID-19: The PRIEST observational cohort study

OBJECTIVES

We aimed to derive and validate a triage tool, based on clinical assessment alone, for predicting adverse outcome in acutely ill adults with suspected COVID-19 infection.

METHODS

We undertook a mixed prospective and retrospective observational cohort study in 70 emergency departments across the United Kingdom (UK). We collected presenting data from 22445 people attending with suspected COVID-19 between 26 March 2020 and 28 May 2020. The primary outcome was death or organ support (respiratory, cardiovascular, or renal) by record review at 30 days. We split the cohort into derivation and validation sets, developed a clinical score based on the coefficients from multivariable analysis using the derivation set, and the estimated discriminant performance using the validation set.

RESULTS

We analysed 11773 derivation and 9118 validation cases. Multivariable analysis identified that age, sex, respiratory rate, systolic blood pressure, oxygen saturation/inspired oxygen ratio, performance status, consciousness, history of renal impairment, and respiratory distress were retained in analyses restricted to the ten or fewer predictors. We used findings from multivariable analysis and clinical judgement to develop a score based on the NEWS2 score, age, sex, and performance status. This had a c-statistic of 0.80 (95% confidence interval 0.79-0.81) in the validation cohort and predicted adverse outcome with sensitivity 0.98 (0.97-0.98) and specificity 0.34 (0.34-0.35) for scores above four points.

CONCLUSION

A clinical score based on NEWS2, age, sex, and performance status predicts adverse outcome with good discrimination in adults with suspected COVID-19 and can be used to support decision-making in emergency care.

REGISTRATION

ISRCTN registry, ISRCTN28342533, http://www.isrctn.com/ISRCTN28342533.

Detection of Cross-Correlation between Gravitational Lensing and γ Rays

In recent years, many γ-ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of matter in the Universe has been shown to be a promising tool. We report here the first identification of a cross-correlation signal between γ rays and the distribution of mass in the Universe probed by weak gravitational lensing. We use data from the Dark Energy Survey Y1 weak lensing data and the Fermi Large Area Telescope 9-yr γ-ray data, obtaining a signal-to-noise ratio of 5.3. The signal is mostly localized at small angular scales and high γ-ray energies, with a hint of correlation at extended separation. Blazar emission is likely the origin of the small-scale effect. We investigate implications of the large-scale component in terms of astrophysical sources and particle dark matter emission.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Wide-Field Lensing Mass Maps from Dark Energy Survey Science Verification Data

We present a mass map reconstructed from weak gravitational lensing shear measurements over 139  deg2 from the Dark Energy Survey science verification data. The mass map probes both luminous and dark matter, thus providing a tool for studying cosmology. We find good agreement between the mass map and the distribution of massive galaxy clusters identified using a red-sequence cluster finder. Potential candidates for superclusters and voids are identified using these maps. We measure the cross-correlation between the mass map and a magnitude-limited foreground galaxy sample and find a detection at the 6.8σ level with 20 arc min smoothing. These measurements are consistent with simulated galaxy catalogs based on N-body simulations from a cold dark matter model with a cosmological constant. This suggests low systematics uncertainties in the map. We summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.

A randomized phase II study of ganetespib, a heat shock protein 90 inhibitor, in combination with docetaxel in second-line therapy of advanced non-small cell lung cancer (GALAXY-1)

BACKGROUND

This trial was designed to evaluate the activity and safety of ganetespib in combination with docetaxel in advanced non-small cell lung cancer (NSCLC) and to identify patient populations most likely to benefit from the combination.

PATIENTS AND METHODS

Patients with one prior systemic therapy for advanced disease were eligible. Docetaxel (75 mg/m(2) on day 1) was administered alone or with ganetespib (150 mg/m(2) on days 1 and 15) every 3 weeks. The primary end points were progression-free survival (PFS) in two subgroups of the adenocarcinoma population: patients with elevated lactate dehydrogenase (eLDH) and mutated KRAS (mKRAS).

RESULTS

Of 385 patients enrolled, 381 were treated. Early in the trial, increased hemoptysis and lack of efficacy were observed in nonadenocarcinoma patients (n = 71); therefore, only patients with adenocarcinoma histology were subsequently enrolled. Neutropenia was the most common grade ≥3 adverse event: 41% in the combination arm versus 42% in docetaxel alone. There was no improvement in PFS for the combination arm in the eLDH (N = 114, adjusted hazard ratio (HR) = 0.77, P = 0.1134) or mKRAS (N = 89, adjusted HR = 1.11, P = 0.3384) subgroups. In the intent-to-treat adenocarcinoma population, there was a trend in favor of the combination, with PFS (N = 253, adjusted HR = 0.82, P = 0.0784) and overall survival (OS) (adjusted HR = 0.84, P = 0.1139). Exploratory analyses showed significant benefit of the ganetespib combination in the prespecified subgroup of adenocarcinoma patients diagnosed with advanced disease >6 months before study entry (N = 177): PFS (adjusted HR = 0.74, P = 0.0417); OS (adjusted HR = 0.69, P = 0.0191).

CONCLUSION

Advanced lung adenocarcinoma patients treated with ganetespib in combination with docetaxel had an acceptable safety profile. While the study's primary end points were not met, significant prolongation of PFS and OS was observed in patients >6 months from diagnosis of advanced disease, a subgroup chosen as the target population for the phase III study.

In a randomized, double-blinded, placebo-controlled trial, the single oral dose typhoid vaccine, M01ZH09, is safe and immunogenic at doses up to 1.7 x 10(10) colony-forming units

M01ZH09, S. Typhi (Ty2 Delta aroC Delta ssaV) ZH9, is a single oral dose typhoid vaccine with independently attenuating deletions. A phase II randomized, double-blind, placebo-controlled, dose-escalating trial evaluated the safety and immunogenicity of M01ZH09 to 1.7 x 10(10) colony-forming units (CFU). 187 Healthy adults received vaccine or placebo in four cohorts. Serologic responses and IgA ELISPOT were measured. At all doses, the vaccine was well tolerated and without bacteremias. One subject had a transient low-grade fever. 62.2-86.1% of subjects seroconverted S. Typhi-specific LPS IgG and 83.3-97.4% IgA; 92.1% had a positive S. Typhi LPS ELISPOT. M01ZH09 is safe and immunogenic up to 1.7 x 10(10)CFU. Efficacy testing of this single-dose oral typhoid vaccine is needed.

Efficacy and safety of rofecoxib 12.5 mg and celecoxib 200 mg in two similarly designed osteoarthritis studies

OBJECTIVE

To compare the lower osteoarthritis (OA) dose of rofecoxib to the recommended dose of celecoxib in two identically designed studies.

METHODS

Patients with knee OA were randomized (2:2:1 ratio: rofecoxib 12.5 mg once daily (qd), celecoxib 200 mg qd, or placebo, respectively). The primary endpoint was patient global assessment of response to therapy (PGART) averaged over 6 weeks on a five-point scale. Rofecoxib would be declared at least as effective as celecoxib if the lower bound of the 95% confidence interval (95% CI) for difference in means was no lower than -0.5. Additional endpoints included Pain and Physical Function subscales of the Western Ontario and McMaster (WOMAC) OA Index. Adverse experiences (AEs) were recorded and combined from the two studies for analysis.

RESULTS

Study 1 enrolled 395 patients (rofecoxib, n = 160; celecoxib, n = 157; placebo, n = 78). Study 2 enrolled 413 patients (rofecoxib, n = 159; celecoxib, n = 169; placebo, n = 85). Rofecoxib 12.5 mg was at least as effective as celecoxib 200 mg by PGART (Study 1 difference -0.09 [95% CI: -0.32, 0.14] and Study 2 difference 0.02 [95% CI: -0.20, 0.24]), and both were significantly (p < 0.001) more effective than placebo. Comparable efficacy was also seen for WOMAC Pain and Physical Function subscales with the active treatments. There was a significantly higher (p < 0.05) incidence of serious AEs with celecoxib than rofecoxib or placebo, none of which was drug-related. There were no significant differences in the pre-specified measurements of safety including drug-related AEs or discontinuations due to AEs, and the medications demonstrated similar safety as assessed by spontaneous reporting.

CONCLUSIONS

Rofecoxib 12.5 mg and celecoxib 200 mg provided comparable efficacy over 6 weeks, and both were significantly more efficacious than placebo. The medications demonstrated similar safety compared to one another and placebo. The primary limitations of these studies were that they were only 6 weeks long and were powered for efficacy. Therefore, conclusions about long-term safety cannot be inferred.

Weak Gravitational Lensing by the Nearby Cluster Abell 3667

We present two weak lensing reconstructions of the nearby (zcl=0.055) merging cluster Abell 3667, based on observations taken approximately 1 yr apart under different seeing conditions. This is the lowest redshift cluster with a weak lensing mass reconstruction to date. The reproducibility of features in the two mass maps demonstrates that weak lensing studies of low-redshift clusters are feasible. These data constitute the first results from an X-ray luminosity-selected weak lensing survey of 19 low-redshift (z<0.1) southern clusters.

Amyloid precursor proteins protect neurons of transgenic mice against acute and chronic excitotoxic injuries in vivo

The beta-amyloid protein precursor (APP) is well conserved across different species and may fulfill important physiological functions within the CNS. While high-level neuronal expression of amyloidogenic forms of human APP results in beta-amyloid production and neurodegeneration, lower levels of neuronal human APP expression in neurons of transgenic mice may primarily accentuate physiological functions of this molecule. To assess the neuroprotective potential of human APP in vivo, mice from seven distinct transgenic lines expressing different human APP isoforms from the neuron-specific enolase promoter were challenged with systemic kainate injections (n=30) or transgene-mediated glial expression of gp120 (n=32), an HIV-1 protein capable of inducing excitotoxic neuronal damage. To quantitate human APP-mediated neuroprotection. the area of neuropil occupied by presynaptic terminals and neuronal dendrites in the neocortex and hippocampus of each mouse was determined using laser scanning confocal microscopy of double-immunolabelled brain sections and computer-aided image analysis. Compared with gp120 singly transgenic controls, mice from three of three human APP751gp120 bigenic lines expressing the 751 amino acid form of human APP at low levels showed significant protection against degeneration of presynaptic terminals; two of these lines also showed significantly less damage to neuronal dendrites. Two of three human APP695/gp120 bigenic lines expressing human APP695 at low levels were protected against presynaptic and dendritic damage, whereas one low expressor line and a human APP695/gp120 bigenic line expressing human APP695 at higher levels showed no significant protection. In the corresponding human APP singly transgenic lines, overexpressing only specific human APP isoforms, significant protection against kainate-induced degeneration of presynaptic terminals and neuronal dendrites was found in two of three human APP751 lines and not in any of the four human APP695 lines tested. These results indicate that human APP can protect neurons against chronic and acute excitotoxic insults in vivo and that human APP isoforms differ in their neuroprotective potential, at least with respect to specific forms of neural injury. It is therefore possible that impairments of neuroprotective human APP functions or aberrant shifts in human APP isoform ratios could contribute to neurodegeneration.

Nonisotopic M13 probes for detecting the beta-globin gene: application to diagnosis of sickle cell anemia

M13 DNA probes labeled with biotinylated psoralen and a streptavidin-horseradish peroxidase conjugate provide nonradioactive detection of the sickle cell and normal alleles of the beta-globin locus. The two biotinylated probes contain single-stranded sequences complementary to two different Sau3AI restriction fragments from the 5' region of the beta-globin gene and double-stranded M13 vector sequences. These probes are labeled with biotinylated psoralen photochemically linked to DNA. After hybridization, the presence of biotinylated probe bound to target DNA is detected in 3 h by using a streptavidin-horseradish peroxidase conjugate and the substrate, 3,3',5,5'-tetramethylbenzidine. Digestion of the normal (beta A) allele of the beta-globin gene with MstII (or isoschizomers) yields a 1.14-kb restriction fragment, while digestion of the mutant beta S allele yields a 1.34-kb fragment. These fragments can be resolved by gel electrophoresis and detected by Southern blot hybridization. The nonradioisotopic probe system can detect the beta-globin restriction fragment in as little as 0.5 microgram of human DNA and can distinguish heterozygotes (beta A beta S) from homozygotes (beta A beta A or beta S beta S) in 2.0 micrograms of human DNA.

Nonisotopic M13 probes for detecting the beta-globin gene: application to diagnosis of sickle cell anemia

M13 DNA probes labeled with biotinylated psoralen and a streptavidin-horseradish peroxidase conjugate provide nonradioactive detection of the sickle cell and normal alleles of the beta-globin locus. The two biotinylated probes contain single-stranded sequences complementary to two different Sau3AI restriction fragments from the 5' region of the beta-globin gene and double-stranded M13 vector sequences. These probes are labeled with biotinylated psoralen photochemically linked to DNA. After hybridization, the presence of biotinylated probe bound to target DNA is detected in 3 h by using a streptavidin-horseradish peroxidase conjugate and the substrate, 3,3',5,5'-tetramethylbenzidine. Digestion of the normal (beta A) allele of the beta-globin gene with MstII (or isoschizomers) yields a 1.14-kb restriction fragment, while digestion of the mutant beta S allele yields a 1.34-kb fragment. These fragments can be resolved by gel electrophoresis and detected by Southern blot hybridization. The nonradioisotopic probe system can detect the beta-globin restriction fragment in as little as 0.5 microgram of human DNA and can distinguish heterozygotes (beta A beta S) from homozygotes (beta A beta A or beta S beta S) in 2.0 micrograms of human DNA.

Cloning and sequence analysis reveal structural variation among related zein genes in maize

We have isolated a gene encoding one of the 19,000 dalton zein proteins from a maize genomic library constructed in Charon 4A. This gene occurs on a 7.7 kb Eco RI fragment, and based on Southern hybridization analysis, represents one of several homologous sequences present in the maize genome. The nucleotide sequence of the gene predicts a protein composed of 235 amino acids, including a signal peptide of 21 amino acids. There are no intervening sequences in the gene. By comparing the nucleotide sequence of this gene with that of a homologous cDNA clone, we have identified a basis for microheterogeneity within the gene family. The 5' nucleotide sequences of the genomic and cDNA clones are identical, but they differ in the center of the protein, where repeated amino acid sequences occur. A nucleotide sequence encoding a conserved peptide of 20 amino acids is repeated nine times in the center of both of these clones.