The structural components of the Azotobacter vinelandii iron-only nitrogenase, AnfDKG, form a protein complex within the plant mitochondrial matrix

A long-held goal of synthetic biology has been the transfer of a bacterial nitrogen-fixation pathway into plants to reduce the use of chemical fertiliser on crops such as rice, wheat and maize. There are three classes of bacterial nitrogenase, named after their metal requirements, containing either a MoFe-, VFe- or FeFe-cofactor, that converts N₂ gas to ammonia. Relative to the Mo-nitrogenase the Fe-nitrogenase is not as efficient for catalysis but has less complex genetic and metallocluster requirements, features that may be preferable for engineering into crops. Here we report the successful targeting of bacterial Fe-nitrogenase proteins, AnfD, AnfK, AnfG and AnfH, to plant mitochondria. When expressed as a single protein AnfD was mostly insoluble in plant mitochondria, but coexpression of AnfD with AnfK improved its solubility. Using affinity-based purification of mitochondrially expressed AnfK or AnfG we were able to demonstrate a strong interaction of AnfD with AnfK and a weaker interaction of AnfG with AnfDK. This work establishes that the structural components of the Fe-nitrogenase can be engineered into plant mitochondria and form a complex, which will be a requirement for function. This report outlines the first use of Fe-nitrogenase proteins within a plant as a preliminary step towards engineering an alternative nitrogenase into crops.

Job satisfaction and symptoms of depression, anxiety, stress, and burnout: A survey of Australian and New Zealand intensive care research coordinators

INTRODUCTION

Intensive care unit clinical research is often implemented by specialised research coordinators (RCs). Clinical research activity within Australian and New Zealand intensive care units has escalated, particularly during the COVID-19 pandemic. Growth of the intensive care RC workforce to match research demand is poorly understood.

AIM

The aim of this study was to repeat an Intensive Care Research Coordinator Interest Group workforce survey conducted in 2004 and 2009 to describe the current workforce and role satisfaction and also to determine reported symptoms of depression, anxiety, stress, and burnout in Australian and New Zealand intensive care RCs.

METHODS

In April 2021, an online anonymised survey was distributed to intensive care RCs to complete demographic and workforce questions, the McCloskey/Mueller Satisfaction Scale, the Depression Anxiety Stress Scales-21, and the Maslach Burnout Inventory-Human Services Survey for Medical Personnel.

RESULTS

Of 128 Intensive Care Research Coordinator Interest Group eligible members, 98 (77%) completed the survey. Respondents were mainly women (91%), the median age was 47 years, 37% have a postgraduate qualification, and a third have over 10 years of RCC experience (31%). Half do not have permanent employment (52%). The mean Depression Anxiety Stress Scales-21 scores were within the normal range, and respondents reported symptoms of depression (21 [21%]), anxiety (23 [23%]), and stress (26 [27%]). Nearly half of the respondents (44%) exhibited an early symptom of burnout by reporting problematic experiences of work. The overall role satisfaction score was 3.5/5 (neutral; neither satisfied nor dissatisfied).

CONCLUSIONS

Intensive care RCs are an experienced group of professionals with limited satisfaction in the role. One-fifth of the ICU RCs experienced depression, anxiety, or stress symptoms, with close to half reporting signs of burnout. These results highlight the need to address areas of concern to ensure retention of this specialised intensive care workforce.

A multicentre point prevalence study of delirium assessment and management in patients admitted to Australian and New Zealand intensive care units

Objective: To characterise the assessment and management of delirium in patients admitted to intensive care units (ICUs) in Australia and New Zealand. Methods: We conducted a multicentre observational point prevalence study across 44 adult Australian and New Zealand ICUs. Data were extracted for all patients in the ICU in terms of assessment and treatment of delirium. ICU-level data were collected regarding the use of explicit protocols related to delirium. Results: We studied 627 patients, with 54% (336/627) having at least one delirium screening assessment performed. The Confusion Assessment Method for the ICU (CAM-ICU) was the most frequently used tool (88%, 296/336). Of patients assessed, 20% (68) were identified to have delirium. Eighteen per cent (111) of patients were administered a drug to manage delirium, with 41% (46) of those receiving a drug having no recorded assessment for delirium on that day. Of the drugs used to treat delirium, quetiapine was the most frequently administered. Physical restraints were applied to 8% (48/626) of patients, but only 17% (8/48) of such patients had been diagnosed with delirium. Most physically restrained patients either did not have delirium diagnosed (31%, 15/48) or had no formal assessment recorded (52%, 25/48) on that day. Conclusions: On the study day, more than 50% of patients had a delirium screening assessment performed, with 20% of screened patients deemed to have delirium. Drugs that are prescribed to treat delirium and physical restraints were frequently used in the absence of delirium or the formal assessment for its presence.

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial

IMPORTANCE

Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

OBJECTIVE

To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020.

INTERVENTIONS

The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108).

MAIN OUTCOMES AND MEASURES

The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%).

RESULTS

After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial

IMPORTANCE

Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

OBJECTIVE

To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020.

INTERVENTIONS

The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108).

MAIN OUTCOMES AND MEASURES

The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%).

RESULTS

After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02735707.

Real-world systemic therapy treatment patterns for squamous cell carcinoma of the head and neck in Canada

Background

In the present study, we examined real-world treatment patterns for squamous cell carcinoma of the head and neck (scchn) in Canada, which are largely unknown.

Methods

Oncologists across Canada provided data for disease history, characteristics, and treatment patterns during May-July 2016 for 6-8 consecutive patients receiving first-line or second-line drug treatment for scchn (including locally advanced and recurrent or metastatic disease).

Results

Information from 16 physicians for 109 patients receiving drug treatment for scchn was provided; 1 patient was excluded from the treatment-pattern analysis. Median age in the cohort was 63 years [interquartile range (iqr): 57-68 years], and 24% were current smokers, with a mean exposure of 26.2 ± 12.7 pack-years. The most common tumour site was the oropharynx (48%). Most patients (84%) received platinum-based regimens as first-line treatment (44% received cisplatin monotherapy). Use of cetuximab-based regimens as first-line treatment was limited (17%). Of 53 patients receiving second-line treatment, 87% received a first-line platinum-based regimen. Median time between first-line treatment with a platinum-based regimen and initiation of second-line treatment was 55 days (iqr: 20-146 days). The most common second-line regimen was cetuximab monotherapy (43%); platinum-based regimens were markedly infrequent (13%).

Conclusions

Our analysis provides real-world insight into scchn clinical practice patterns in Canada, which could inform reimbursement decision-making. High use of platinum-based regimens in first-line drug treatment was generally reflective of treatment guidelines; cetuximab use in the second-line was higher than anticipated. Additional real-world studies are needed to understand the effect of novel therapies such as immuno-oncology agents on clinical practice and outcomes, particularly for recurrent or metastatic scchn.

Subcutaneous rather than intravenous ustekinumab induction is associated with comparable circulating drug levels and early clinical response: a pilot study

BACKGROUND

Ustekinumab (USK) is licenced for intravenous induction and subcutaneous (S/C) maintenance in Crohn's disease.

AIM

To evaluate ustekinumab trough concentrations and clinical response with exclusive subcutaneous ustekinumab induction.

METHODS

Patients with Crohn's disease who initiated treatment with subcutaneous ustekinumab at a single academic centre were included in this pilot study. A dosage of 360 mg ustekinumab was given subcutaneously in divided doses; 180 mg at Week 0, 90 mg at Week 1 and 90 mg at Week 2, with corresponding ustekinumab trough concentrations assessed to Week 8. The primary outcome measures were trough serum ustekinumab levels and clinical remission at Week 8. Secondary outcome measures were trough serum ustekinumab levels at Week 1 & 2 and changes in C-reactive protein, albumin and faecal calprotectin at Week 8.

RESULTS

Nineteen patients were included. Median Week 8 ustekinumab trough concentrations were 6.1 μg/mL (Inter-quartile range 4-9.8 μg/mL). There was a significant improvement in Harvey Bradshaw index from Week 0 (median HBI 5; interquartile range 2-8) to Week 8 (median HBI 1; interquartile range 0-3) (P = 0.002). C-reactive protein levels did not change significantly but faecal calprotectin improved significantly; median faecal calprotectin at Week 0 was 533 μg/g; at Week 8, it was 278 μg/g (P = 0.038).

CONCLUSIONS

Ustekinumab trough concentrations are comparable whether ustekinumab induction treatment was administered subcutaneously or intravenously. A significant improvement in symptoms and faecal calprotectin was noted. These results support the use of subcutaneous induction as an alternative if there are barriers to intravenous induction.

Scombrotoxic Fish Poisoning Secondary to Tuna Ingestion

Scombrotoxic poisoning results from the improper handling and refrigeration of fish containing naturally occurring histidine. Scombroid fish species such as tuna, mackerel and swordfish contain histidine, which is converted to histamine when inadequately chilled. European legislation states that scombroid fish species should be tested for the presence of histamine and mean values should be <100mg/kg1. The authors report an outbreak of scombrotoxic fish poisoning in 12 individuals following ingestion of tuna. Symptoms occurred rapidly and included flushing, headache, palpitations and diarrhoea. Fortunately, symptoms were short lived and self-limiting except in one individual, who required anti-histamine medication. Adequate refrigeration practices are crucial in preventing scombrotoxic food poisoning.

The effect of dabigatran on the kaolin-activated whole blood thromboelastogram

Dabigatran is a direct thrombin inhibitor, which is increasingly likely to be encountered in patients presenting for surgery. This study examines whether there is a consistent effect of dabigatran on the thromboelastogram (TEG) and whether this correlates with the effects of dabigatran on traditional coagulation parameters. Twenty patients taking dabigatran had blood sampled for kaolin-activated whole blood TEG analysis and routine coagulation testing. There was a statistically significant correlation between thrombin clotting time (TCT) and R-time (R=0.77, P=0.0001) and between activated partial thromboplastin time (APTT) and R-time (R=0.68, P=0.0013), but not between TCT and alpha-angle (R= -0.4232, P=0.071). Despite the moderate to high correlation between the TEG R-time and the TCT and APTT, there appeared to be no consistent effect of dabigatran on the TEG. These findings suggest that use of kaolin-activated whole blood TEG does not add additional benefit to traditional coagulation tests when monitoring the effect of dabigatran.

PCSK9 inhibitors and their role in high-risk patients in reducing LDL cholesterol levels: evolocumab

Patients with familial hypercholesterolemia or statin intolerance are especially challenging to manage since LDL cholesterol levels often remain considerably elevated despite clinicians’ best efforts. With statins regarded as first-line pharmacologic therapy by the current American College of Cardiology/American Heart Association guidelines to reduce LDL cholesterol and cardiovascular risk, there is now a critical need to determine when other agents will play a role beyond maximally tolerated statin therapy and lifestyle changes. In this review, we take a closer look at evolocumab (Repatha®), one of the new injectable human monoclonal antibodies to PCSK9 and its efficacy and safety properties from the results of various trials.

PCSK9 inhibitors and their role in high-risk patients in reducing LDL cholesterol levels: alirocumab

In this review, we examine alirocumab (Praluent(®)), a monoclonal antibody to PCSK9 and its role in reducing LDL-C levels. By comparing the results of various studies and trials we discuss the efficacy and safety of alirocumab. We aim to guide clinicians of the role of alirocumab in clinical practice. Overall, PCSK9 inhibitors are promising new agents in further reducing LDL-C levels in addition to diet and maximally tolerated statin therapy. Long-term outcome studies are currently ongoing and will further delineate the role of PCSK9 inhibitors.

Axial p-n-junctions in nanowires

The charge distribution and potential profile of p-n-junctions in thin semiconductor nanowires (NWs) were analyzed. The characteristics of screening in one-dimensional systems result in a specific profile with large electric field at the boundary between the n- and p- regions, and long tails with a logarithmic drop in the potential and charge density. As a result of these tails, the junction properties depend sensitively on the geometry of external contacts and its capacity has an anomalously large value and frequency dispersion. In the presence of an external voltage, electrons and holes in the NWs can not be described by constant quasi-Fermi levels, due to small values of the average electric field, mobility, and lifetime of carriers. Thus, instead of the classical Sah-Noice-Shockley theory, the junction current-voltage characteristic was described by an alternative theory suitable for fast generation-recombination and slow diffusion-drift processes. For the non-uniform electric field in the junction, this theory predicts the forward branch of the characteristic to have a non-ideality factor η several times larger than the values 1 < η < 2 from classical theory. Such values of η have been experimentally observed by a number of researchers, as well as in the present work.

Genomic architecture of histone 3 lysine 27 trimethylation during late ovine skeletal muscle development

The ruminant developmental transition from late foetus to lamb is associated with marked changes in skeletal muscle structure and function that reflect programming for new physiological demands following birth. To determine whether epigenetic changes are involved in this transition, we investigated the genomic architecture of the chromatin modification, histone 3 lysine 27 trimethylation (H3K27me3), which typically regulates early life developmental processes; however, its role in later life processes is unclear. Chromatin immunoprecipitation coupled with next‐generation sequencing was used to map H3K27me3 nucleosomes in ovine longissimus lumborum skeletal muscle at 100 days of gestation and 12 weeks post‐partum. In both states, H3K27me3 modification was associated with genes, transcription start sites and CpG islands and with transcriptional silencing. The H3K27me3 peaks consisted of two major categories, promoter specific and regional, with the latter the dominant feature. Genes encoding homeobox transcription factors regulating early life development and genes involved in neural functions, particularly gated ion channels, were strongly modified by H3K27me3. Gene promoters differentially modified by H3K27me3 in the foetus and lamb were enriched for gated ion channels, which may reflect changes in neuromuscular function. However, most modified genes showed no changes, indicating that H3K27me3 does not have a large role in late muscle maturation. Notably, promyogenic transcription factors were strongly modified with H3K27me3 but showed no differences between the late gestation foetus and lamb, likely reflecting their lack of involvement in the myofibre fusion process occurring in this transition. H3K27me3 is a major architectural feature of the epigenetic landscape of ruminant skeletal muscle, and it comments on gene transcription and gene function in the context of late skeletal muscle development.

The extent and nature of need for mealtime support among adults with intellectual disabilities

BACKGROUND

For many adults with an intellectual disability (ID), mealtimes carry significant health risks. While research and allied clinical guidance has focused mainly on dysphagia, adults with a range of physical and behavioural difficulties require mealtime support to ensure safety and adequate nutrition. The extent of need for and nature of such support within the wider ID population has yet to be reported.

METHODS

In this study, we have estimated the prevalence of need for mealtime support among people with ID in the UK, using a population of 2230 adults known to specialist ID services (in Cambridgeshire, UK, total population 586,900). In a sample (n = 69, aged 19 to 79 years, with mild to profound ID), we characterised the support provided, using a structured proforma to consult support workers and carers providing mealtime support, and health and social care records.

RESULTS

Mealtime support was found to be required by a significant minority of people with ID for complex and varied reasons. Prevalence of need for such support was estimated at 15% of adults known to specialist ID services or 56 per 100,000 total population. Within a sample, support required was found to vary widely in nature (from texture modification or environmental adaptation to enteral feeding) and in overall level (from minimal to full support, dependent on functional skills). Needs had increased over time in almost half (n = 34, 49.3%). Reasons for support included difficulties getting food into the body (n = 56, 82.2%), risky eating and drinking behaviours (n = 31, 44.9%) and slow eating or food refusal (n = 30, 43.5%). These proportions translate into crude estimates of the prevalence of these difficulties within the known ID population of 11.9%, 6.6% and 6.4% respectively. Within the sample of those requiring mealtime support, need for support was reported to be contributed to by the presence of additional disability or illness (e.g. visual impairment, poor dentition and dementia; n = 45, 65.2%) and by psychological or behavioural issues (e.g. challenging behaviour, emotional disturbance; n = 36, 52.2%).

CONCLUSIONS

These findings not only highlight the need for a multidisciplinary approach to mealtime interventions (paying particular attention to psychological and environmental as well as physical issues), but also signal the daily difficulties faced by carers and paid support workers providing such support and illustrate their potentially crucial role in managing the serious health risks associated with eating and drinking difficulties in this population.

Genetic structure of European sheep breeds

Large-scale evaluations of genetic diversity in domestic livestock populations are necessary so that region-specific conservation measures can be implemented. We performed the first such survey in European sheep by analysing 820 individuals from 29 geographically and phenotypically diverse breeds and a closely related wild species at 23 microsatellite loci. In contrast to most other domestic species, we found evidence of widespread heterozygote deficit within breeds, even after removing loci with potentially high frequency of null alleles. This is most likely due to subdivision among flocks (Wahlund effect) and use of a small number of rams for breeding. Levels of heterozygosity were slightly higher in southern than in northern breeds, consistent with declining diversity with distance from the Near Eastern centre of domestication. Our results highlight the importance of isolation in terms of both geography and management in augmenting genetic differentiation through genetic drift, with isolated northern European breeds showing the greatest divergence and hence being obvious targets for conservation. Finally, using a Bayesian cluster analysis, we uncovered evidence of admixture between breeds, which has important implications for breed management.

Analysis of gene expression during the onset of muscle hypertrophy in callipyge lambs

The callipyge mutation causes postnatal muscle hypertrophy in heterozygous lambs that inherit a paternal callipyge allele (+/CLPG). Our hypothesis was that the up-regulation of one or both of the affected paternally expressed genes (DLK1 or PEG11) initiates changes in biochemical and physiological pathways in skeletal muscle to induce hypertrophy. The goal of this study was to identify changes in gene expression during the onset of muscle hypertrophy to identify the pathways that are involved in the expression of the callipyge phenotype. Gene expression was analysed in longissimus dorsi total RNA from lambs at 10, 20, and 30 days of age using the Affymetrix Bovine Expression Array. An average of 40.6% of probe sets on the array was detected in sheep muscle. Data were normalized and analysed using a two-way anova for genotype and age effects with a false discovery rate of 0.10. From the anova, 13 genes were significant for the effect of genotype and 13 were significant for effect of age (P < 0.10). No significant age-by-genotype interactions were detected (P > 0.10). Of the 13 genes indicating an effect of genotype, quantitative PCR assays were developed for all of them and tested on a larger group of animals from 10 to 200 days of age. Nine genes had significantly elevated transcript levels in callipyge lambs. These genes included phosphofructokinase, a putative methyltransferase protein, a cAMP phosphodiesterase, and the transcription factor DNTTIP1.

The causes of homelessness in later life: findings from a 3-nation study

OBJECTIVE

This article presents findings from a study of the causes of homelessness among newly homeless older people in selected urban areas of the United States, England, and Australia.

METHODS

Interviews were conducted in each country with > or =122 older people who had become homeless during the last 2 years. Information was also collected from the subjects' key workers about the circumstances and problems that contributed to homelessness.

RESULT

Two-thirds of the subjects had never been homeless before. Antecedent causes were the accommodation was sold or needed repair, rent arrears, death of a close relative, relationship breakdown, and disputes with other tenants and neighbors. Contributory factors were physical and mental health problems, alcohol abuse, and gambling problems.

DISCUSSION

Most subjects became homeless through a combination of personal problems and incapacities, welfare policy gaps, and service delivery deficiencies. Whereas there are nation-specific variations, across the three countries, the principal causes and their interactions are similar.

Releases from copper smelters and refineries and zinc plants in Canada: human health exposure and risk characterization

In these assessments of releases from copper smelters and refineries and from zinc plants as Priority Substances under the Canadian Environmental Protection Act (CEPA), available data were critically evaluated to determine if environmental exposure to selected components of these releases poses a risk to human health. The data on airborne levels of a variety of toxic substances near these facilities in Canada were obtained from the companies or provinces and systematically analyzed. Monitoring of ambient air near the Canadian copper smelters and refineries and zinc plants indicates that releases from these facilities result in increased potential for inhalation exposure of local human populations to several components of releases (As, Cd, Cr, Ni, Pb, SO(2) and PM(10)). Airborne levels in the vicinity of these metal-processing operations overlap those associated with cardiorespiratory effects for PM(10), and exceed health-based guidelines for SO(2) and, near some facilities, Pb. In addition, the margin between levels of As, Cd, Cr and Ni near these facilities in Canada and carcinogenic potency for each of these metals is relatively small near copper smelters, larger near copper refineries, and intermediate near zinc plants. On this basis, the risk to human health from environmental exposure to releases from these facilities is considered to be high compared with other Priority Substances assessed under CEPA, especially for facilities where copper is smelted.

Nursing clinics in elder housing: providing access and improving health care outcomes

This article describes one approach to helping elder individuals residing in subsidized senior housing achieve better health outcomes by providing health promotion and disease prevention services at on-site student nursing clinics. Clinics operate 2 days a week in the community room at the elderly housing sites and are staffed by senior baccalaureate nursing students who are in their community health clinical rotation. The student nursing clinic outcomes demonstrate improvement in residents' health through increased access to care, better identification and management of hypertension, more involvement for residents with diabetes in monitoring and management of their conditions, and better preparation for emergency medical situations.

Establishing partnerships with social services agencies for community health education

Nursing education is currently faced with many changes in both the academic and clinical environments. A significant challenge is to provide students with meaningful clinical placements. Experiences in clinical placements allow students to test assessment, critical thinking, communication, and decision-making skills in real and culturally diverse world situations. Nursing faculties need to develop new and innovative approaches for students to gain the necessary clinical experience. This article describes a community health clinical placement designed and implemented through a partnership of academic and social service organizations. It details the conception, growth, and development of student nursing clinics based in elderly and disabled housing sites.

Intussusception in an adult patient with severe hyperglycaemia--a case report

AIMS

To report a case of adult intussusception associated with and possibly induced by acute hyperglycaemia.

METHODS

We present the first case report of adult intussusception with severe hyperglycaemia. Clinical and laboratory data together with radiological findings are presented with a brief review of the literature.

RESULTS

A 20-year-old man with no past medical history presented with abdominal pain for 2 days. The patient was severely hyperglycaemic with blood glucose of 72.7 mmol/l (normal 3.3-6.1 mmol/l), a pH of 7.2 and serum potassium of 6.5 mmol/l (normal 3.5-5.0 mmol/l). He had a computed tomography (CT) scan of the abdomen that revealed small bowel intussusception. Upon treatment of his hyperglycaemia, the patient's abdominal pain completely resolved. Follow up abdominal CT revealed complete resolution of the previously detected intussusception.

CONCLUSION

Clinicians should be aware of the potential for the occurrence of intussusception in severely hyperglycaemic patients. Correction of hyperglycaemia could lead to resolution of the intussusception without surgical intervention. Possible effects of hyperkalaemia and/or acidosis on gastrointestinal motility should also be considered.

A novel method using formamide for the elution of antibodies from erythrocytes

BACKGROUND AND OBJECTIVES

Accurate identification of antibodies that sensitize red blood cells (RBCs) involves dissociating them from RBCs using an in vitro elution method that does not alter their antigen-binding properties, and analysis of the eluates against a panel of RBCs.

MATERIALS AND METHODS

A method was developed that allowed efficient RBC antibody elution. Human polyclonal anti-D was used to sensitize Rh-positive RBCs, and known antigen-antibody disruptive reagents were tested using these RBCs. The best reagent conditions were optimized. Eluates made were tested and compared to results obtained with a glycine-acid-based commercial elution kit to determine efficacy. Patient samples that were positive with direct antiglobulin tests (DATs), and in vitro commercial antisera-sensitized RBCs representing clinically significant antibodies, were used for evaluating the new method.

RESULTS

The formamide method was efficient at removing antibodies from RBCs. The patient samples with a positive DAT had antibodies recovered with the same specificity when compared to the acid-based technique. The length of preparation time was similar for both formamide and acid-based methods. Results of testing the eluates made from reagent RBCs sensitized with commercial antisera were distinct with antigen-positive and -negative erythrocytes.

CONCLUSIONS

The formamide method compares well with acid techniques and may be an alternative choice of elution method.

In vitro RBC exposure to Plasmodium falciparum has no effect on RBC antigen expression

Severe malarial anaemia is a leading cause of death in African children younger than 3 years of age who are infected with Plasmodium falciparum. The pathogenesis of this anaemia is not understood. The purpose of this study was to determine if P. falciparum induces changes in RBC membranes that contribute to the immune destruction of RBCs. RBCs were collected from healthy subjects and tested using standard haemagglutination assays for 45 antigens representing 21 blood group systems/collections before and after exposure to P. falciparum, strain FVO. Lectins were used to determine whether crypt or neoantigens were expressed on the RBC membrane. Polybrene was used to detect changes in sialic acid. RBCs were cultured in vitro with and without the parasite, and blinded serologic studies were completed. CD35 (complement receptor 1), CD55 (decay-accelerating factor), CD59 (membrane inhibitor of reactive lysis) and CD47 (integrin-associated protein) flow cytometric assays were compared for infected and uninfected RBCs. The percentage of parasitaemia was determined using Giemsa-stained thin blood films. Two (Ch, Lub) of the 45 antigens had differing strengths of agglutination between infected and uninfected RBCs, but these differences were resolved with a second source of antisera. Forty-three antigens showed no significant differences in the strength of agglutination between the infected and uninfected RBCs. Lectin and polybrene testing showed no differences. CD35, CD55, CD59 and CD47 levels showed no significant differences. P. falciparum does not appear to alter the expression of classified immunogenic antigens on the RBC membrane in this in vitro system. The pathogenesis of the haemolytic episode that occurs in these children remains unclear.

Physical mapping of CSF2RA, ANT3 and STS on the pseudoautosomal region of bovine chromosome X

The pseudoautosomal region (PAR) of bovine chromosome X (BTA X) has a particularly low representation of genes and markers, making comparative gene mapping in this region difficult. We describe the localization of three genes, colony-stimulating factor 2 receptor alpha (CSF2RA), ADP/ATP translocase 3 (ANT3) and steroid sulphatase (STS) on PAR of BTA X using a 5000 rad whole-genome radiation hybrid panel. The relationship of these genes to a number of previously mapped simple sequence repeat (microsatellite) markers is determined by physical and radiation hybrid mapping methods. The resulting radiation hybrid map resolves a discrepancy between the two major bovine linkage maps in the PAR of BTA X.