The development and acceptability of an educational and training intervention for recruiters to neonatal trials: the TRAIN project

BACKGROUND

Suboptimal or slow recruitment affects 30-50% of trials. Education and training of trial recruiters has been identified as one strategy for potentially boosting recruitment to randomised controlled trials (hereafter referred to as trials). The Training tRial recruiters, An educational INtervention (TRAIN) project was established to develop and assess the acceptability of an education and training intervention for recruiters to neonatal trials. In this paper, we report the development and acceptability of TRAIN.

METHODS

TRAIN involved three sequential phases, with each phase contributing information to the subsequent phase(s). These phases were 1) evidence synthesis (systematic review of the effectiveness of training interventions and a content analysis of the format, content, and delivery of identified interventions), 2) intervention development using a Partnership (co-design/co-creation) approach, and 3) intervention acceptability assessments with recruiters to neonatal trials.

RESULTS

TRAIN, accompanied by a comprehensive intervention manual, has been designed for online or in-person delivery. TRAIN can be offered to recruiters before trial recruitment begins or as refresher sessions during a trial. The intervention consists of five core learning outcomes which are addressed across three core training units. These units are the trial protocol (Unit 1, 50 min, trial-specific), understanding randomisation (Unit 2, 5 min, trial-generic) and approaching and engaging with parents (Unit 3, 70 min, trial-generic). Eleven recruiters to neonatal trials registered to attend the acceptability assessment training workshops, although only four took part. All four positively valued the training Units and resources for increasing recruiter preparedness, knowledge, and confidence. More flexibility in how the training is facilitated, however, was noted (e.g., training divided across two workshops of shorter duration). Units 2 and 3 were considered beneficial to incorporate into Good Clinical Practice Training or as part of induction training for new staff joining neonatal units.

CONCLUSION

TRAIN offers a comprehensive co-produced training and education intervention for recruiters to neonatal trials. TRAIN was deemed acceptable, with minor modification, to neonatal trial recruiters. The small number of recruiters taking part in the acceptability assessment is a limitation. Scale-up of TRAIN with formal piloting and testing for effectiveness in a large cluster randomised trial is required.

Videolaryngoscopy in neonatal clinical care

Endotracheal intubation is a life-saving procedure for many newborns. Historically, it has been achieved by obtaining an airway view through the mouth via direct laryngoscopy. It is a skill that takes time and practice to achieve proficiency. Increasing evidence for the benefit of videolaryngoscopy in adults and the new development of technology has allowed videolaryngoscopy to become a reality in neonatal care. Studies have examined its use as both a technique to improve intubation safety and success, and as a training tool for those learning the skill in this vulnerable population. We present the current evidence for videolaryngoscopy in neonates in different settings where intubation may be required, in addition to exploring the challenges and practicalities of implementing this technique into clinical practice.

Two-Year Outcomes After Minimally Invasive Surfactant Therapy in Preterm Infants: Follow-Up of the OPTIMIST-A Randomized Clinical Trial

Importance

The long-term effects of surfactant administration via a thin catheter (minimally invasive surfactant therapy [MIST]) in preterm infants with respiratory distress syndrome remain to be definitively clarified.

Objective

To examine the effect of MIST on death or neurodevelopmental disability (NDD) at 2 years' corrected age.

Design, Setting, and Participants

Follow-up study of a randomized clinical trial with blinding of clinicians and outcome assessors conducted in 33 tertiary-level neonatal intensive care units in 11 countries. The trial included 486 infants with a gestational age of 25 to 28 weeks supported with continuous positive airway pressure (CPAP). Collection of follow-up data at 2 years' corrected age was completed on December 9, 2022.

Interventions

Infants assigned to MIST (n = 242) received exogenous surfactant (200 mg/kg poractant alfa) via a thin catheter; those assigned to the control group (n = 244) received sham treatment.

Main Outcomes and Measures

The key secondary outcome of death or moderate to severe NDD was assessed at 2 years' corrected age. Other secondary outcomes included components of this composite outcome, as well as hospitalizations for respiratory illness and parent-reported wheezing or breathing difficulty in the first 2 years.

Results

Among the 486 infants randomized, 453 had follow-up data available (median gestation, 27.3 weeks; 228 females [50.3%]); data on the key secondary outcome were available in 434 infants. Death or NDD occurred in 78 infants (36.3%) in the MIST group and 79 (36.1%) in the control group (risk difference, 0% [95% CI, -7.6% to 7.7%]; relative risk [RR], 1.0 [95% CI, 0.81-1.24]); components of this outcome did not differ significantly between groups. Secondary respiratory outcomes favored the MIST group. Hospitalization with respiratory illness occurred in 49 infants (25.1%) in the MIST group vs 78 (38.2%) in the control group (RR, 0.66 [95% CI, 0.54-0.81]) and parent-reported wheezing or breathing difficulty in 73 (40.6%) vs 104 (53.6%), respectively (RR, 0.76 [95% CI, 0.63-0.90]).

Conclusions and Relevance

In this follow-up study of a randomized clinical trial of preterm infants with respiratory distress syndrome supported with CPAP, MIST compared with sham treatment did not reduce the incidence of death or NDD by 2 years of age. However, infants who received MIST had lower rates of adverse respiratory outcomes during their first 2 years of life.

Trial Registration

anzctr.org.au Identifier: ACTRN12611000916943.

134 ADULT SAFEGUARDING, HUMAN RIGHTS AND PEOPLE LIVING WITH DEMENTIA IN NURSING HOMES: CO-PRODUCING RECOMMENDATIONS FOR BEST PRACTICE

Background

People living with dementia (PLwD) in nursing homes have the right to be safe and to live a life free from harm and abuse; all persons are entitled to this right, regardless of their circumstances or where they live. PLwD are at greater risk of abuse and neglect than those without a diagnosis. Such abuse often goes unnoticed, because dementia may affect a person’s ability to recognise abuse or to report it. In 2021, the Alzheimer Society of Ireland’s Irish Dementia Working Group (IDGW) commissioned the development of a briefing paper to outline the key issues relating to upholding the human rights and safeguarding of PLwD in nursing homes including concrete recommendations for policy and practice.

Methods

A scoping review of the existing literature on this topic was carried out. This was supplemented by adopting a snowball strategy to identify additional relevant literature. Three co-design online sessions were convened with members of the IDWG in order to discuss and agree on the general content and members also provided suggestions for additional research or policy papers that should be included. Co-design sessions were also used to brainstorm and reach a consensus as a group on recommendations.

Results

This project identified a number of specific risk factors for PLwD, including organisational abuse, the need to move towards a restraint-free environment, addressing barriers to reporting of abuse and promoting agency and autonomy within safeguarding processes. A number of policy and legislative gaps in our current adult safeguarding framework were identified making it more difficult to adequately protect PLwD in nursing homes.

Conclusion

22 recommendations for best practice were developed by the IDWG for nursing home service providers (public and private), health and social care practitioners, policymakers, the Department of Health, HIQA and political representatives in order to collectively advocate for meaningful change.

Tracheostomy stomal seeding following oral cavity resection

BACKGROUND

Tracheal stoma recurrence following oral cavity surgery is exceedingly rare. Although several different mechanisms for this have been described, the pathogenesis still remains uncertain.

METHODS

We present the case of a gentleman who presented 6-months following oral cavity SCC resection with a large fungating mass at his previous tracheostomy site, and also review the reported literature on this rare phenomenon.

RESULTS

Four weeks after diagnosis of his recurrence he underwent a total laryngectomy, wide-local skin excision and reconstruction with a pectoralis major pedicled flap. He recovered well initially following his operation, however unfortunately contracted nosocomial SARS-Cov2 and succumbed from respiratory complications during his post-operative recovery.

CONCLUSION

Stomal recurrence after temporary tracheostomy for oral cavity malignancies are very rare. Previously reported management of these can vary from surgical to palliative treatment. Methods to prevent these include delaying tracheostomy until after surgical resection, packing the pharynx during resection and adjuvant radiotherapy.

A review of the use of supraglottic airways in neonates for use during interhospital transfer

A secure and patent airway is a prerequisite to safe interhospital transfer and this has traditionally been via endotracheal tubes. Neonatal intubation success rates are falling as there is declining opportunities amongst paediatric junior doctors and consultants, therefore being able to successfully intubate an infant before or during a transfer, especially if they have an airway anomaly, may be very challenging. The use of supraglottic airways is increasingly popular in neonatology as an alternative to facemask ventilation or endotracheal intubation. This review considers the role of supraglottic airway devices during the stabilisation and transfer of neonates.

Unmasking Latent Inhibitory Connections in Human Cortex to Reveal Dormant Cortical Memories

Balance of cortical excitation and inhibition (EI) is thought to be disrupted in several neuropsychiatric conditions, yet it is not clear how it is maintained in the healthy human brain. When EI balance is disturbed during learning and memory in animal models, it can be restabilized via formation of inhibitory replicas of newly formed excitatory connections. Here we assess evidence for such selective inhibitory rebalancing in humans. Using fMRI repetition suppression we measure newly formed cortical associations in the human brain. We show that expression of these associations reduces over time despite persistence in behavior, consistent with inhibitory rebalancing. To test this, we modulated excitation/inhibition balance with transcranial direct current stimulation (tDCS). Using ultra-high-field (7T) MRI and spectroscopy, we show that reducing GABA allows cortical associations to be re-expressed. This suggests that in humans associative memories are stored in balanced excitatory-inhibitory ensembles that lie dormant unless latent inhibitory connections are unmasked.

Video Abstract

•

Associative memories can be measured in human cortex following learning

•

Over time the expression of these memories becomes silenced

•

By reducing cortical GABA with brain stimulation these memories are re-expressed

•

Cortical memories appear to be stored in balanced excitatory-inhibitory ensembles

Analysis of cerebrospinal fluid for xanthochromia versus modern computed tomography scanners in the diagnosis of subarachnoid haemorrhage: experience at a tertiary trauma referral centre

BACKGROUND

Diagnosis of subarachnoid haemorrhage, a neurosurgical emergency in patients with headache remains a logistical challenge. The rationale of the traditional pathway of cerebrospinal fluid xanthochromia analysis following negative computed tomography head scans to exclude subarachnoid haemorrhage has been challenged by the increasing accuracy of modern computed tomography scanners.

AIM

We set out to establish whether our xanthochromia service was adding value to the diagnostic pathway for subarachnoid haemorrhage or whether it was acting merely as a supportive test.

METHOD

A retrospective audit of all cerebrospinal fluid requests received since the inception of Xanthochromia service at a tertiary trauma centre. Cases interpreted as being consistent with subarachnoid haemorrhage based on cerebrospinal fluid xanthochromia analysis were selected for in-depth review from the total number of cases.

RESULTS

In total 660 requests were received for cerebrospinal fluid xanthochromia between August 2009 and July 2012. A total 28 of these were interpreted as being consistent with subarachnoid haemorrhage. Only 18 (64.3%) of requests were deemed appropriate as the clinical presentation in the remaining 10 (35.7%) was strongly suggestive of other causes of headache. A final clinical diagnosis of subarachnoid haemorrhage was made in 11 of the 18 patients who had cerebrospinal fluid xanthochromia requested appropriately. From these 11, five (45%) were deemed initially computed tomography negative and cerebrospinal fluid analysis led to final correct diagnosis of subarachnoid haemorrhage and appropriate surgical management.

CONCLUSION

Despite improved computed tomography scanning technology, cerebrospinal fluid xanthochromia interpretation aids in the definitive diagnosis of subarachnoid haemorrhage. When requested appropriately cerebrospinal fluid xanthochromia analysis remains a vital service as results impact on clinical decision making, especially when computed tomography scan results are equivocal and is also important in later presenting patients when computed tomography accuracy decreases.

What do the terms wellness and wellbeing mean in dietary practice: an exploratory qualitative study examining women's perceptions

BACKGROUND

Wellness and wellbeing are terms associated with health within dietetic discourse. More broadly, these terms are found in social discourse as represented in food and nutrition consumer communications. With the increasing requirement for evidence-based healthcare, there is an imperative to understand whether these terms are meaningful to individuals typically targeted for nutrition interventions and whether there are any implications for dietetic education.

METHODS

To explore the understanding of these terms, eight semi-structured focus groups were conducted with 32 female participants (age range 23-79 years) who were actively engaged in managing their health. Overall understanding of the terms, factors that impacted perceptions and any relationships with food behaviour were investigated with the groups. Group discussions were transcribed verbatim and each transcript was examined by two researchers. Inductive analysis linking codes into main thematic categories was conducted using the constant comparison approach across the full data set.

RESULTS

Wellness and wellbeing were identified as meaningful terms associated with health. A theoretical framework of wellness and wellbeing reflecting these meanings was developed linking four dominant thematic areas. These were Desired outcomes (most sought after result); Taking control (self management strategies); Internal influences (various personal inner factors influencing behaviours); and External influences (plethora of peripheral factors influencing behaviours).

CONCLUSIONS

Wellness and wellbeing are terms that are relevant and aspirational for individuals typically targeted for nutrition intervention. A theoretical framework of dominant areas of influence on notions of wellness and wellbeing was identified. This theoretical framework is worthy of further research to determine usefulness and effectiveness in dietetic practice settings.

Effect of prism adaptation on left dichotic listening deficit in neglect patients: glasses to hear better?

Unilateral neglect is a disabling syndrome frequently observed following right hemisphere brain damage. Symptoms range from visuo-motor impairments through to deficient visuo-spatial imagery, but impairment can also affect the auditory modality. A short period of adaptation to a rightward prismatic shift of the visual field is known to improve a wide range of hemispatial neglect symptoms, including visuo-manual tasks, mental imagery, postural imbalance, visuo-verbal measures and number bisection. The aim of the present study was to assess whether the beneficial effects of prism adaptation may generalize to auditory manifestations of neglect. Auditory extinction, whose clinical manifestations are independent of the sensory modalities engaged in visuo-manual adaptation, was examined in neglect patients before and after prism adaptation. Two separate groups of neglect patients (all of whom exhibited left auditory extinction) underwent prism adaptation: one group (n = 6) received a classical prism treatment ('Prism' group), the other group (n = 6) was submitted to the same procedure, but wore neutral glasses creating no optical shift (placebo 'Control' group). Auditory extinction was assessed by means of a dichotic listening task performed three times: prior to prism exposure (pre-test), upon prism removal (0 h post-test) and 2 h later (2 h post-test). The total number of correct responses, the lateralization index (detection asymmetry between the two ears) and the number of left-right fusion errors were analysed. Our results demonstrate that prism adaptation can improve left auditory extinction, thus revealing transfer of benefit to a sensory modality that is orthogonal to the visual, proprioceptive and motor modalities directly implicated in the visuo-motor adaptive process. The observed benefit was specific to the detection asymmetry between the two ears and did not affect the total number of responses. This indicates a specific effect of prism adaptation on lateralized processes rather than on general arousal. Our results suggest that the effects of prism adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. These findings should stimulate the development of therapeutic approaches aimed at bypassing the affected sensory processing modality by adapting other sensory modalities.

Modulation of movement-associated cortical activation by transcranial direct current stimulation

Transcranial direct current stimulation (tDCS) is currently attracting increasing interest as a tool for neurorehabilitation. However, local and distant effects of tDCS on motor-related cortical activation patterns remain poorly defined, limiting the rationale for its use. Here we describe the results of a functional magnetic resonance imaging (MRI) experiment designed to characterize local and distant effects on cortical motor activity following excitatory anodal stimulation and inhibitory cathodal stimulation. Fifteen right-handed subjects performed a visually cued serial reaction time task with their right hand in a 3-T MRI scanner both before and after 10 min of 1-mA tDCS applied to the left primary motor cortex (M1). Relative to sham stimulation, anodal tDCS led to short-lived activation increases in the M1 and the supplementary motor area (SMA) within the stimulated hemisphere. The increase in activation in the SMA with anodal stimulation was found also when directly comparing anodal with cathodal stimulation. Relative to sham stimulation, cathodal tDCS led to an increase in activation in the contralateral M1 and dorsal premotor cortex (PMd), as well as an increase in functional connectivity between these areas and the stimulated left M1. These increases were also found when directly comparing cathodal with anodal stimulation. Significant within-session linear decreases in activation occurred in all scan sessions. The after-effects of anodal tDCS arose primarily from a change in the slope of these decreases. In addition, following sham stimulation compared with baseline, a between-session decrease in task-related activity was found. The effects of cathodal tDCS arose primarily from a reduction of this normal decrease.

A comparison of blood pressure measurements in newborns

Blood pressure monitoring is an essential component of neonatal intensive care. We compared invasive and noninvasive (Dinamap, Marquette, and Dash) recordings in newborns and also noninvasive values obtained from upper and lower limbs. Infants' blood pressure was recorded every 6 hours for 72 hours using three noninvasive devices and compared with invasive readings taken simultaneously. Twenty-five babies were enrolled in the study, with birth weights of 560 to 4500 g and gestation 24 + 1 to 40 + 5 weeks. Three hundred thirty-two recordings were obtained. Comparison between invasive and noninvasive readings revealed that all three noninvasive monitors overread mean blood pressure. There was no significant difference between the cuff recordings obtained from the upper or lower limbs. All three noninvasive devices overestimated mean blood pressure values compared with invasive monitoring. Clinicians may be falsely reassured by noninvasive monitoring. Mean blood pressure values obtained from the upper and lower limb are similar.

A p74 common gamma receptor chain isoform facilitates IL-2 and IL-15 responses by the myelomonocytic cell line Tf-1beta2

Functional forms of the IL-2, IL-4, IL-7, IL-9, and IL-15 receptors require the gamma c receptor component. We have described previously a myeloid cell line called Tf-1beta, which binds IL-2 with intermediate-affinity and proliferates in response to IL-2. In this study, we characterize gamma c expression on Tf-1beta2 cells, a derivative of Tf-1beta cells stimulated exclusively with IL-2. Although Tf-1beta2 cells bind IL-2 with intermediate-affinity and proliferate in response to IL-2, this cell line does not express the p64 gamma c chain at the protein level. This result was surprising because prior studies suggest these cells should not be expected to proliferate in response to IL-2 or IL-15 in the absence of the p64 gamma c chain. A p74 protein was detected by western blot following immunoprecipitation with an anti-gamma c polyclonal antibody, and a p74 protein was identified consistently in complex with IL-2 and IL-15 on these cells. However, the gamma c gene in these Tf-1beta2 cells shows no evidence of mutation by sequence analysis. Furthermore, inhibition of glycosylation of these Tf-1beta2 cells by tunicamycin treatment yields a standard 39-kDa molecule recognized on western blot with anti-gamma c antibody, as seen for the standard 64-kDa isoform of gamma c. These results demonstrate that a 74-kDa gamma c receptor isoform was involved in the response of the Tf-1beta2 cells to cytokines which normally interact with the 64-kDa gamma c chain.

Searching for an unrelated haemopoietic stem cell donor--a United Kingdom perspective

The worldwide search for unrelated stem cell donors (now over 6 million) is one of the great success stories of international cooperation in the medical field. The initial search report from Bone Marrow Donors Worldwide estimates the chance of finding a suitably matched donor for a given patient. Registries whose donors are HLA-A, -B and -DR typed present the optimal prerequisite to identify a suitable donor for most patients. High-resolution matching HLA class I and class II alleles of the donor and recipient improves clinical outcome after unrelated donor transplantation. The clinical results of unrelated donor bone marrow transplantation are continually improving reflecting improvements in HLA matching, GvHD prophylaxis and transplantation in a favourable phase of disease. However, matching each HLA allele may or may not be critical for successful stem cell transplantation. Some degree of HLA mismatch ("permissible" mismatches) may be tolerated, especially in children. Cord blood banks provide a supplementary source of unrelated stem cell donors, in particular to patients from ethnic minority groups.

Reference strand mediated conformation analysis resolves HLA-DRB1 typing ambiguities when matching for unrelated bone marrow transplantation

We show here the use of reference strand mediated conformation analysis (RSCA) to unambiguously resolve the HLA-DRB1 typing of two individuals which were selected as potential unrelated donors for bone marrow transplantation (BMT). In the first case, both sequence-specific primer (SSP) amplification and sequence-specific oligonucleotide probing (SSO), routinely used in different tissue typing laboratories gave, for the two unrelated donors, the same ambiguous typing of HLA-DRB1*04011+*0403 or DRB1*0407+*0413. In this case sequence-based typing (SBT) was not the method of choice to resolve the situation, due to the sequence ambiguities of these two given combinations. RSCA of both samples, using homozygous typing cells (HTCs) for DRB1*04011, *0403 and *0407 as internal controls, gave the unambiguous result that both donors were HLA-DRB1*04011+*0403. In the second case, a donor was typed as DRB1*1102+1103 by SSP, while SSO excluded the DRB1*1102 allele. The patient was unambiguously typed as DRB1*1101+1103 by both techniques. RSCA, using DNA from reference cell lines as internal controls, gave the unambiguous typing that the donor was DRB1*1103 homozygous.

Cytokine regulation of IL-12 receptor beta2 expression: differential effects on human T and NK cells

The biological activities of IL-12 are mediated through a specific, high-affinity receptor composed of IL-12 receptor(R)beta1 and IL-12Rbeta2 subunits that exist primarily on T and NK cells. Remarkably, the expression of IL-12Rbeta2 on CD4(+) T cells in mouse and humans appears to be differentially regulated by IFN-gamma and IFN-alpha, respectively. Using an antibody specific for the human IL-12Rbeta2 subunit, the effect of IFN-gamma, IFN-alpha, IL-12 and IL-2 on the regulation of IL-12R expression and IL-12 responsiveness of human T and NK cells was assessed. The presence of IFN-alpha or IFN-gamma in cultures enhanced IL-12Rbeta2 expression of CD4(+) and CD8(+) T cells. The enhancing effect of IFN-alpha and IFN-gamma was independent of endogenous IL-12. Furthermore, the clearest effects of IFN-alpha and IFN-gamma on IL-12Rbeta2 expression on T cells were seen by abrograting the inhibition induced by the presence of IL-4 in cultures. In contrast to T cells, IFN-alpha and IFN-gamma had little effect on regulating IL-12Rbeta2 expression on human NK cells. Taken together, these data show that there is differential regulation of IL-12Rbeta2 expression by IFN-alpha and IFN-gamma on human T and NK cells.

IFN consensus sequence binding protein potentiates STAT1-dependent activation of IFNgamma-responsive promoters in macrophages

IFNgamma, once called the macrophage-activating factor, stimulates many genes in macrophages, ultimately leading to the elicitation of innate immunity. IFNgamma's functions depend on the activation of STAT1, which stimulates transcription of IFNgamma-inducible genes through the GAS element. The IFN consensus sequence binding protein (icsbgamma or IFN regulatory factor 8), encoding a transcription factor of the IFN regulatory factor family, is one of such IFNgamma-inducible genes in macrophages. We found that macrophages from ICSBP-/- mice were defective in inducing some IFNgamma-responsive genes, even though they were capable of activating STAT1 in response to IFNgamma. Accordingly, IFNgamma activation of luciferase reporters fused to the GAS element was severely impaired in ICSBP-/- macrophages, but transfection of ICSBP resulted in marked stimulation of these reporters. Consistent with its role in activating IFNgamma-responsive promoters, ICSBP stimulated reporter activity in a GAS-specific manner, even in the absence of IFNgamma treatment, and in STAT1 negative cells. Indicative of a mechanism for this stimulation, DNA affinity binding assays revealed that endogenous ICSBP was recruited to a multiprotein complex that bound to GAS. These results suggest that ICSBP, when induced by IFNgamma through STAT1, in turn generates a second wave of transcription from GAS-containing promoters, thereby contributing to the elicitation of IFNgamma's unique activities in immune cells.

Downregulation of JAK3 protein levels in T lymphocytes by prostaglandin E2 and other cyclic adenosine monophosphate-elevating agents: impact on interleukin-2 receptor signaling pathway

The Janus kinase, JAK3 plays an important role in interleukin-2 (IL-2)-dependent signal transduction and proliferation of T lymphocytes. Our findings show that prostaglandin E2 (PGE2) can inhibit upregulation of JAK3 protein in naive T cells and can downregulate its expression in primed cells. Reduction in JAK3 was selective because expression of other tyrosine kinases (JAK1, p56(lck), and p59(fyn)) and signal transducer and activator of transcription (STAT)5, which are linked to IL-2 receptor (IL-2R) signaling pathway, were not affected. Inhibition of JAK3 may be controlled by intracellular cyclic adenosine monophosphate (cAMP) levels, as forskolin, a direct activator of adenylate cyclase and dibutyryl cAMP (dbcAMP), a membrane permeable analogue of cAMP suppressed JAK3 expression. Moreover, 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of cAMP phosphodiesterase, potentiated PGE2-induced suppression of JAK3. In naive T cells, but not primed T cells, PGE2 and other cAMP elevating agents also caused a modest reduction in surface expression of the common gamma chain (gammac) that associates with JAK3. The absence of JAK3, but not IL-2R in T cells correlated with impaired IL-2-dependent signal transduction and proliferation. The alteration in IL-2 signaling included decreased tyrosine phosphorylation and DNA binding activity of STAT5 and poor induction of the c-Myc and c-Jun pathways. In contrast, IL-2-dependent induction of Bcl-2 was unaffected. These findings suggest that suppression of JAK3 levels may represent one mechanism by which PGE2 and other cAMP elevating agents can inhibit T-cell proliferation.

Molecular typing shows a high level of HLA class I incompatibility in serologically well matched donor/patient pairs: implications for unrelated bone marrow donor selection

In comparison with HLA-matched sibling bone marrow transplants, unrelated donor transplants are associated with increased graft-versus-host disease and graft failure. This is likely in part due to HLA incompatibilities not identified by current matching strategies. High resolution DNA-based typing methods for HLA class II loci have improved donor selection and treatment outcome in unrelated donor bone marrow transplantation. By using DNA-based typing methods for HLA-A and -B on a cohort of 100 potential bone marrow donor/patient pairs, we find that serological typing for HLA class I is limited in its ability to identify incompatibilities in unrelated pairs. Furthermore, the incompatibilities identified are associated with the presence at high frequency of alloreactive cytotoxic T-lymphocyte precursors. DNA typing also indicates that HLA-C mismatches are common in HLA-A and -B serologically matched pairs. Such mismatches appear to be significantly less immunogenic with respect to cytotoxic T-lymphocyte recognition, but are expected to influence natural killer cell activity. Thus, improved resolution of HLA class I shows many previously undisclosed mismatches that appear to be immunologically functional. Use of high resolution typing methods in routine matching is expected to improve unrelated donor selection and transplant outcome.

The use of antibodies against the IL-2 receptor in transplantation

Humanized monoclonal antibodies that recognize the alpha chain of the IL-2 receptor (e.g. daclizumab) have been used to prevent allograft rejection, since this chain is expressed by T cells participating in allograft rejection but not by resting T cells. In a randomized trial, when added to standard cyclosporin-based immunosuppression, daclizumab significantly reduced the frequency of acute rejection of renal transplants.

A high resolution HLA class I and class II matching method for bone marrow donor selection

HLA matching in bone marrow transplantation has an important role in determining successful outcome. However HLA typing of both potential related and unrelated donors can be both time-consuming and laborious, and does not always resolve accurately the true level of histocompatibility. We have utilised a method, reference strand mediated conformation analysis (RSCA), which is technically simple and allows high resolution matching for all HLA loci, for the typing of 48 patients and their potential 120 donors. The results indicate that RSCA can detect many mismatches that are not routinely identified by conventional HLA typing methods. In addition, RSCA can be applied for the simultaneous analysis of multiple potential BM donor samples in order to quickly identify the best match for each patient.

A community-based study of the epidemiology of Helicobacter pylori infection and associated asymptomatic gastroduodenal pathology

OBJECTIVES

To document the epidemiology of Helicobacter pylori infection in a normal population, to assess asymptomatic H. pylori positive individuals for the presence of gastroduodenal disease, and to compare the macroscopic and microscopic findings at endoscopy in this group with those of patients presenting with dyspepsia.

DESIGN/METHODS

Serum was collected from blood donors and assessed for the presence of anti-H. pylori IgG antibodies. A randomly selected group of asymptomatic blood donors and dyspeptic patients underwent endoscopy.

RESULTS

The seroprevalence of H. pylori in 1000 subjects was 43.0%. The prevalence of infection increased from 29% in 18-30 year olds to 62% in 46-60 year olds (P < 0.01). The infection was more prevalent in individuals from social classes IV and V (50.0%) than social classes I and II (36.9%) (P < 0.01). There was no difference between the H. pylori positive asymptomatic individuals (n = 37) and matched dyspeptic patients (n = 29) at endoscopy with regard to duodenal ulcer (13.5% vs. 17.2%) or gastroduodenal erosions (24.3% vs. 20.7%) while 5.4% of the former had gastro-oesophageal reflux compared to 27.6% of the latter. Overall, 56.8% of the H. pylori positive asymptomatic group had a normal macroscopic endoscopy compared with 31% of the dyspeptic group. Histology of the gastric mucosa did not reveal any significant differences between the two groups. In H.pylori negative asymptomatic individuals (n = 13) 92.3% had a normal endoscopy (7.7% had grade I gastro-oesophageal reflux) compared with 61.5% of a matched dyspeptic group (n = 13).

CONCLUSION

H.pylori infection, symptomatic and asymptomatic, is associated with significant pathology, and screening for the infection may be indicated for the prevention of gastroduodenal diseases.

Measurement of cytotoxic T lymphocyte precursor frequencies reveals cryptic HLA class I mismatches in the context of unrelated donor bone marrow transplantation

BACKGROUND

In this large, two-center study, 260 cytotoxic T lymphocyte precursor (CTLp) frequency assays, performed to assess patient-donor compatibility, were analyzed in relation to the degree of HLA matching.

METHODS

While the tissue-typing techniques used at the Royal Postgraduate Medical School (RPMS) and Anthony Nolan Bone Marrow Trust (ANBMT) differ, the results of the analyses on the two sites are analogous, with high CTLp frequencies (>1:100,000) in 42% and 41% of recipient-donor pairs, respectively.

RESULTS

Recipient-donor combinations with class I mismatches and class II identity were associated with high CTLp frequencies (collectively 83% vs. 17% low CTLp). This correlation was not as strong in pairs where class II mismatches were demonstrated (61% high vs. 39% low). Despite using different matching procedures, the RPMS and ANBMT both show that 32% of the "perfectly" matched pairs (i.e., where no mismatch was detected by any of the techniques used here) had high frequencies of recipient-specific CTLp.

CONCLUSIONS

The failure of conventional methods to identify such a level of histoincompatibilities indicates that the CTLp assay has an important role in the selection of unrelated donors for bone marrow transplantation.