Speciation within the Anopheles gambiae complex: high-throughput whole genome sequencing reveals evidence of a putative new cryptic taxon in 'far-west' Africa

The two main Afrotropical malaria vectors - Anopheles coluzzii and An. gambiae - are genetically distinct and reproductively isolated across West Africa. However, populations at the western extreme of their range are assigned as "intermediate" between the two species by whole genome sequence (WGS) data, and as hybrid forms by conventional molecular diagnostics. By exploiting WGS data from 1,190 specimens collected across west Africa via the Anopheles gambiae 1000 Genomes network, we identify a novel putative taxon in the far-west (provisionally named Bissau molecular form), which did not arise by admixture but rather originated at the same time as the split between An. coluzzii and An. gambiae. Intriguingly, these populations lack insecticide resistance mechanisms commonly observed in the two main species. These findings lead to a change of perspective on malaria vector species in the far-west region with potential for epidemiological implications, and a new challenge for genetic-based mosquito control approaches.

Risk of Pneumococcal Disease in US Adults by Age and Risk Profile

Background

Older age and certain medical conditions are known to modify the risk of pneumococcal disease among adults. We quantified the risk of pneumococcal disease among adults with and without medical conditions in the United States between 2016 and 2019.

Methods

This retrospective cohort study used administrative health claims data from Optum's de-identified Clinformatics Data Mart Database. Incidence rates of pneumococcal disease-all-cause pneumonia, invasive pneumococcal disease (IPD), and pneumococcal pneumonia-were estimated by age group, risk profile (healthy, chronic, other, and immunocompromising medical condition), and individual medical condition. Rate ratios and 95% CIs were calculated comparing adults with risk conditions with age-stratified healthy counterparts.

Results

Among adults aged 18-49 years, 50-64 years, and ≥65 years, the rates of all-cause pneumonia per 100 000 patient-years were 953, 2679, and 6930, respectively. For the 3 age groups, the rate ratios of adults with any chronic medical condition vs healthy counterparts were 2.9 (95% CI, 2.8-2.9), 3.3 (95% CI, 3.2-3.3), and 3.2 (95% CI, 3.2-3.2), while the rate ratios of adults with any immunocompromising condition vs healthy counterparts were 4.2 (95% CI, 4.1-4.3), 5.8 (95% CI, 5.7-5.9), and 5.3 (95% CI, 5.3-5.4). Similar trends were observed for IPD and pneumococcal pneumonia. Persons with other medical conditions, such as obesity, obstructive sleep apnea, and neurologic disorders, were associated with increased risk of pneumococcal disease.

Conclusions

The risk of pneumococcal disease was high among older adults and adults with certain risk conditions, particularly immunocompromising conditions.

Abstract 1660: Comparison between surgical and ultrasound-guided orthotopic implantation of hepatocellular carcinoma models in mice using ultrasound and bioluminescence imaging

Introduction: Orthotopic tumour mouse models are often preferred to subcutaneous models due to their increased clinical relevance and pathophysiological features, as the tumour microenvironment can influence stromal interaction, immune response, angiogenesis, tumour growth and progression as well as response to treatment. Orthotopic implantation of liver cancer cell lines can be time consuming and inefficient due to the surgical procedures involved to establish the tumour. This study assesses the benefits of replacing traditional invasive surgical orthotopic implantation of two hepatic tumour cell lines with a minimally invasive ultrasound guided approach. Tumour growth of both implantation methods were assessed using ultrasound and bioluminescence, as well as duration of surgery and animal recovery time. In addition, the immune landscape of both implantation methods was assessed using flow cytometry.

Methods: Hep3B and Hepa 1-6 cells were transfected with luciferase for bioluminescence imaging. Hep3B-luc or Hepa 1-6-luc cells were orthotopically injected into the left liver lobe of C57BL/6 mice via either conventional surgery or ultrasound guided injection. Tumour growth was measured using both Ultrasound (Fujifilm Vevo 3100 imaging system, Visualsonics) and bioluminescence (IVIS® Spectrum in vivo imaging system, Perkin Elmer). Surgery times were recorded as the duration each animal was under anaesthesia. Recovery times were reported as the time animals were held in recovery before returning to their cage. An in house validated flow cytometry T cell panel was used to assess T cell infiltration in the Hepa1-6 syngeneic model.

Results: A comparison of tumour volume versus tumour associated bioluminescence demonstrated good correlation between both methods for each cell line. The duration of surgery and post implantation recovery times were significantly reduced for mice that underwent ultrasound-guided implantation compared to surgery, as well as fewer post-operative clinical observations. No significant difference in body weight was observed throughout the study. T cell infiltration by flow cytometry assessment enabled further evaluation of potential differences in the immune landscape of Hepa 1-6 tumours.

Conclusion: Ultrasound guided implantation of orthotopic hepatic tumours is a minimally invasive technique that leads to improved recovery times for animals, which adheres to the principles of the 3R’s. The time taken for ultrasound guided implantation compared to traditional surgical methods was also significantly reduced, enabling a higher throughput of animals on study. Tumour growth kinetics in both Hep3B and Hepa 1-6 models were comparable between the 2 methods.

Citation Format: Chris Payne, Yasmin Amer, Ruth Storer, Ganisha Hutchinson, Lucy Harris, Amanda Miles, Yinfei Yin. Comparison between surgical and ultrasound-guided orthotopic implantation of hepatocellular carcinoma models in mice using ultrasound and bioluminescence imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1660.

Aligned Poly-l-lactic Acid Nanofibers Induce Self-Assembly of Primary Cortical Neurons into 3D Cell Clusters

Relative to two-dimensional (2D) culture, three-dimensional (3D) culture of primary neurons has yielded increasingly physiological responses from cells. Electrospun nanofiber scaffolds are frequently used as a 3D biomaterial support for primary neurons in neural tissue engineering, while hydrophobic surfaces typically induce aggregation of cells. Poly-l-lactic acid (PLLA) was electrospun as aligned PLLA nanofiber scaffolds to generate a structure with both qualities. Primary cortical neurons from E18 Sprague-Dawley rats cultured on aligned PLLA nanofibers generated 3D clusters of cells that extended highly aligned, fasciculated neurite bundles within 10 days. These clusters were viable for 28 days and responsive to AMPA and GABA. Relative to the 2D culture, the 3D cultures exhibited a more developed profile; mass spectrometry demonstrated an upregulation of proteins involved in cortical lamination, polarization, and axon fasciculation and a downregulation of immature neuronal markers. The use of artificial neural network inference suggests that the increased formation of synapses may drive the increase in development that is observed for the 3D cell clusters. This research suggests that aligned PLLA nanofibers may be highly useful for generating advanced 3D cell cultures for high-throughput systems.

MiR-423-5p prevents MALAT1-mediated proliferation and metastasis in prostate cancer

BACKGROUND

The long non-coding RNA (lncRNA), MALAT1, plays a key role in the development of different cancers, and its expression is associated with worse prognosis in patients. However, its mechanism of action and its regulation are not well known in prostate cancer (PCa). A general mechanism of action of lncRNAs is their interaction with other epigenetic regulators including microRNAs (miRNAs).

METHODS

Using lentiviral stable miRNA transfection together with cell biology functional assays and gene expression/target analysis, we investigated the interaction between MALAT1 and miR-423-5p, defined as a target with in silico prediction analysis, in PCa.

RESULTS

Through bioinformatic analysis of data available from TCGA, we have found that MALAT1 expression correlates with high Gleason grade, metastasis occurrence, and reduced survival in PCa patients. These findings were validated on a TMA of PCa showing a significant correlation between MALAT1 expression with both stage and grading. We report that, in PCa cells, MALAT1 expression and activity is regulated by miR-423-5p that binds MALAT1, downregulates its expression and inhibits its activity in promoting proliferation, migration, and invasion. Using NanoString analysis, we unraveled downstream cell pathways that were affected by miR-423-5p expression and MALAT1 downregulation and identified several alterations in genes that are involved in metastatic response and angiogenic pathways. In addition, we showed that the overexpression of miR-423-5p increases survival and decreases metastases formation in a xenograft mouse model.

CONCLUSIONS

We provide evidence on the role of MALAT1 in PCa tumorigenesis and progression. Also, we identify a direct interaction between miR-423-5p and MALAT1, which results in the suppression of MALAT1 action in PCa.

Usher syndrome type 1-associated gene, pcdh15b, is required for photoreceptor structural integrity in zebrafish

Blindness associated with Usher syndrome type 1 (USH1) is typically characterized as rod photoreceptor degeneration, followed by secondary loss of cones. The mechanisms leading to blindness are unknown because most genetic mouse models only recapitulate auditory defects. We generated zebrafish mutants for one of the USH1 genes, protocadherin-15b (pcdh15b), a putative cell adhesion molecule. Zebrafish Pcdh15 is expressed exclusively in photoreceptors within calyceal processes (CPs), at the base of the outer segment (OS) and within the synapse. In our mutants, rod and cone photoreceptor integrity is compromised, with early and progressively worsening abnormal OS disc growth and detachment, in part due to weakening CP contacts. These effects were attenuated or exacerbated by growth in dark and bright-light conditions, respectively. We also describe novel evidence for structural defects in synapses of pcdh15b mutant photoreceptors. Cell death does not accompany these defects at early stages, suggesting that photoreceptor structural defects, rather than overt cell loss, may underlie vision deficits. Thus, we present the first genetic animal model of a PCDH15-associated retinopathy that can be used to understand the aetiology of blindness in USH1.

This article has an associated First Person interview with the first author of the paper.

Summary: We present one of the first genetic animal mutants for PCDH15 that displays a severe, early retinopathy and suggests that zebrafish could be a useful model for PCDH15-associated retinal phenotypes.

The psychological impact of food allergy and undergoing a food challenge test in adult age

Summary

Introduction. Despite an increasing number of adults being affected by food allergy, there is currently limited research regarding the psychological impact of living with this condition in this age group and the effect of undergoing food challenge testing - the gold standard for diagnosis - on health-related quality of life (HRQoL). Objective. To assess whether ruling out a food allergy using an open food challenge could improve HRQoL and emotional well-being. To evaluate whether HRQoL gains are higher among people testing negative for food allergy and whether people higher on health anxiety would be less reassured by a negative food challenge. Methods. A cross-sectional study (n = 276) and a prospective study (n = 53) were performed. Adults with a positive (n = 34), or negative food challenge (n = 34), or with an allergy confirmed via other means (No challenge, n = 208), completed the Food Allergy Quality of Life Questionnaire-Adult Form, General Health Questionnaire-12, State-Trait Anxiety Inventory short form, Positive and Negative Affect Schedule, shortened version of the Health Anxiety Questionnaire in addition to clinical and demographic variables. A prospective study examined these measures before and three months after a food challenge (negative, n = 45; positive, n = 8). Results. Adults with a negative food challenge outcome had better HRQoL than those with a food allergy confirmed via other means (No challenge), with no differences between the two allergy positive groups (food challenge vs no challenge). No group differences in emotional distress, health anxiety or mood were found. The prospective study showed HRQoL significantly improved following a food challenge (F_(1,39) = 16.868; p minor 0.001; Intention-to-treat F_(1,52) = 15.346; p minor 0.001). High health anxiety was not associated with lower reassurance following a negative test. Conclusions. People who have a food allergy excluded following a food challenge have better HRQoL. There was a significant improvement in HRQoL following an open food challenge which supports the need to increase provision of food challenge testing in this age group.

Evaluation of COVID-19 vaccine breakthrough infections among immunocompromised patients fully vaccinated with BNT162b2

OBJECTIVE

To evaluate COVID-19 vaccine breakthrough infections among immunocompromised (IC) individuals.

METHODS

Individuals vaccinated with BNT162b2 were selected from the US HealthVerity database (10 December 2020 to 8  July 2021). COVID-19 vaccine breakthrough infections were examined in fully vaccinated (≥14 days after 2nd dose) IC individuals (IC cohort), 12 mutually exclusive IC condition groups, and a non-IC cohort. IC conditions were identified using an algorithm based on diagnosis codes and immunosuppressive (IS) medication usage.

RESULTS

Of 1,277,747 individuals ≥16 years of age who received 2 BNT162b2 doses, 225,796 (17.7%) were identified as IC (median age: 58 years; 56.3% female). The most prevalent IC conditions were solid malignancy (32.0%), kidney disease (19.5%), and rheumatologic/inflammatory conditions (16.7%). Among the fully vaccinated IC and non-IC cohorts, a total of 978 breakthrough infections were observed during the study period; 124 (12.7%) resulted in hospitalization and 2 (0.2%) were inpatient deaths. IC individuals accounted for 38.2% (N = 374) of all breakthrough infections, 59.7% (N = 74) of all hospitalizations, and 100% (N = 2) of inpatient deaths. The proportion with breakthrough infections was 3 times higher in the IC cohort compared to the non-IC cohort (N = 374 [0.18%] vs. N = 604 [0.06%]; unadjusted incidence rates were 0.89 and 0.34 per 100 person-years, respectively. Organ transplant recipients had the highest incidence rate; those with >1 IC condition, antimetabolite usage, primary immunodeficiencies, and hematologic malignancies also had higher incidence rates compared to the overall IC cohort. Incidence rates in older (≥65 years old) IC individuals were generally higher versus younger IC individuals (<65).

LIMITATIONS

This retrospective analysis relied on coding accuracy and had limited capture of COVID-19 vaccine receipt.

CONCLUSIONS

COVID-19 vaccine breakthrough infections are rare but are more common and severe in IC individuals. The findings from this large study support the FDA authorization and CDC recommendations to offer a 3rd vaccine dose to increase protection among IC individuals.

Patient deprivation and perceived scan burden negatively impact the quality of whole-body MRI

AIM

To evaluate the association between the image quality of cancer staging whole-body magnetic resonance imaging (WB-MRI) and patient demographics, distress, and perceived scan burden.

MATERIALS AND METHODS

A sample of patients recruited prospectively to multicentre trials comparing WB-MRI with standard scans for staging lung and colorectal cancer were invited to complete two questionnaires. The baseline questionnaire, administered at recruitment, collated data on demographics, distress and co-morbidity. The follow-up questionnaire, completed after staging investigations, measured perceived WB-MRI scan burden (scored 1 low to 7 high). WB-MRI anatomical coverage, and technical quality was graded by a radiographic technician and grading combined to categorise the scan as "optimal", "sub-optimal" or "degraded". A radiologist categorised 30 scans to test interobserver agreement. Data were analysed using the chi-square, Fisher's exact, t-tests, and multinomial regression.

RESULTS

One hundred and fourteen patients were included in the study (53 lung, 61 colorectal; average age 65.3 years, SD=11.8; 66 men [57.9%]). Overall, 45.6% (n=52), scans were classified as "optimal" quality, 39.5% (n=45) "sub-optimal", and 14.9% (n=17) as "degraded". In adjusted analyses, greater deprivation level and higher patient-reported scan burden were both associated with a higher likelihood of having a sub-optimal versus an optimal scan (odds ratio [OR]: 4.465, 95% confidence interval [CI]: 1.454 to 13.709, p=0.009; OR: 1.987, CI: 1.153 to 3.425, p=0.013, respectively). None of the variables predicted the likelihood of having a degraded scan.

CONCLUSIONS

Deprivation and patients' perceived experience of the WB-MRI are related to image quality. Tailored protocols and individualised patient management before and during WB-MRI may improve image quality.

Analysing the impacts of air quality policies on ecosystem services; a case study for Telemark, Norway

There is an increasing interest in considering the effects of air pollution on ecosystem services supply in order to enhance cost-benefit analyses of air pollution policies. This paper presents a generic, conceptual approach that can be used to link atmospheric deposition of air pollutants to ecosystem services supply and societal benefits. The approach is applied in a case study in the Telemark county of Norway. First, we examine the potential effects of four European air quality policy scenarios on N deposition in the ecosystems of this county. Second, we analyse the subsequent impacts on the supply of three ecosystem services: carbon sequestration, timber production and biodiversity. Changes in the supply of the first two services are analysed in both physical and monetary units, biodiversity effects are only analysed in physical terms. The scenarios derive from work conducted in the context of the European National Emissions Ceilings Directive. In the 2010 base case the benefits of carbon sequestration are estimated at 13 million euro per year and the value of timber harvesting at 2.9 million euro per year. Under the examined policy scenarios aiming to reduce nitrogen emissions the societal benefits resulting from these two ecosystem services in Telemark are found to be reduced; the scenarios have little effect on terrestrial biodiversity. Such results cannot be scaled up, individual ecosystem services respond differently to changes in air pollution depending upon type of pollutant, type of ecosystem, type of service, and the magnitude of change. The paper further presents an analysis of the uncertainties that need to be considered in linking air pollution and ecosystem services including those in deposition rates, ecosystem responses, human responses and in the values of ecosystem services. Our conceptual approach is also useful for larger scale analysis of air pollution effects on ecosystem services, for example at national or potentially European scale.

Comparative analyses of whole genome sequences of Leishmania infantum isolates from humans and dogs in northeastern Brazil

The genomic sequences of 20 Leishmania infantum isolates collected in northeastern Brazil were compared with each other and with the available genomic sequences of 29 L. infantum/donovani isolates from Nepal and Turkey. The Brazilian isolates were obtained in the early 1990s or since 2009 from patients with visceral or non-ulcerating cutaneous leishmaniasis, asymptomatic humans, or dogs with visceral leishmaniasis. Two isolates were from the blood and bone marrow of the same visceral leishmaniasis patient. All 20 genomic sequences display 99.95% identity with each other and slightly less identity with a reference L. infantum genome from a Spanish isolate. Despite the high identity, analysis of individual differences among the 32 million base pair genomes showed sufficient variation to allow the isolates to be clustered based on the primary sequence. A major source of variation detected was in chromosome somy, with only four of the 36 chromosomes being predominantly disomic in all 49 isolates examined. In contrast, chromosome 31 was predominantly tetrasomic/pentasomic, consistent with its regions of synteny on two different disomic chromosomes of Trypanosoma brucei. In the Brazilian isolates, evidence for recombination was detected in 27 of the 36 chromosomes. Clustering analyses suggested two populations, in which two of the five older isolates from the 1990s clustered with a majority of recent isolates. Overall the analyses do not suggest individual sequence variants account for differences in clinical outcome or adaptation to different hosts. For the first known time, DNA of isolates from asymptomatic subjects were sequenced. Of interest, these displayed lower diversity than isolates from symptomatic subjects, an observation that deserves further investigation with additional isolates from asymptomatic subjects.

Use of a computerised decision aid (DA) to inform the decision process on adjuvant chemotherapy in patients with stage II colorectal cancer: development and preliminary evaluation

OBJECTIVES

To develop a computerised decision aid (DA) to inform the decision process on adjuvant chemotherapy in patients with stage II colorectal cancer, and examine perceived usefulness, acceptability and areas for improvement of the DA.

DESIGN

Mixed methods.

SETTING

Single outpatient oncology department in central London.

PARTICIPANTS

Consecutive recruitment of 13 patients with stage II colorectal cancer, 12 of whom completed the study. Inclusion criteria were: age >18 years; complete resection for stage II adenocarcinoma of the colon or rectum; patients within 14-56 days after surgery; no contraindication to adjuvant chemotherapy; able to give written informed consent. Exclusion criterion: previous chemotherapy.

PRIMARY OUTCOMES

Patient perceived usefulness (assessed by the PrepDM questionnaire) and acceptability of the DA.

RESULTS

PrepDM scores, measuring the perceived usefulness of the DA in preparing the patient to communicate with their doctor and make a health decision, were above those reported in other patient groups. Patient acceptability scores were also high; however, interviews showed that there was evidence of a lack of understanding of key information among some patients, in particular their baseline risk of recurrence, the net benefit of combination chemotherapy and the rationale for having chemotherapy when cancer had apparently gone.

CONCLUSIONS

Patients found the DA acceptable and useful in supporting their decision about whether or not to have adjuvant chemotherapy. Suggested improvements for the DA include: sequential presentation of treatment options (eg, no treatment vs 1 drug, 1 drug vs 2 drugs) to enhance patient understanding of the difference between combination and single therapy, diagrams to help patients understand the rationale for chemotherapy to prevent a recurrence and inbuilt checks on patient understanding of baseline risk of recurrence and net benefit of chemotherapy.

G9a and ZNF644 Physically Associate to Suppress Progenitor Gene Expression during Neurogenesis

Proliferating progenitor cells undergo changes in competence to give rise to post-mitotic progeny of specialized function. These cell-fate transitions typically involve dynamic regulation of gene expression by histone methyltransferase (HMT) complexes. However, the composition, roles, and regulation of these assemblies in regulating cell-fate decisions in vivo are poorly understood. Using unbiased affinity purification and mass spectrometry, we identified the uncharacterized C2H2-like zinc finger protein ZNF644 as a G9a/GLP-interacting protein and co-regulator of histone methylation. In zebrafish, functional characterization of ZNF644 orthologs, znf644a and znf644b, revealed complementary roles in regulating G9a/H3K9me2-mediated gene silencing during neurogenesis. The non-overlapping requirements for znf644a and znf644b during retinal differentiation demarcate critical aspects of retinal differentiation programs regulated by differential G9a-ZNF644 associations, such as transitioning proliferating progenitor cells toward differentiation. Collectively, our data point to ZNF644 as a critical co-regulator of G9a/H3K9me2-mediated gene silencing during neuronal differentiation.

Coordinating progenitor cell cycle exit and differentiation in the developing vertebrate retina

The proper development of the vertebrate retina relies heavily on producing the correct number and type of differentiated retinal cell types. To achieve this, proliferating retinal progenitor cells (RPCs) must exit the cell cycle at an appropriate time and correctly express a subset of differentiation markers that help specify retinal cell fate. Homeobox genes, which encode a family of transcription factors, have been accredited to both these processes, implicated in the transcriptional regulation of important cell cycle components, such as cyclins and cyclin-dependent kinases, and proneural genes. This dual regulation of homeobox genes allows these factors to help co-ordinate the transition from the proliferating RPC to postmitotic, differentiated cell. However, understanding the exact molecular targets of these factors remains a challenging task. This commentary highlights the current knowledge we have about how these factors regulate cell cycle progression and differentiation, with particular emphasis on a recent discovery from our lab demonstrating an antagonistic relationship between Vsx2 and Dmbx1 to control RPC proliferation. Future studies should aim to further understand the direct transcriptional targets of these genes, additional co-factors/interacting proteins and the possible recruitment of epigenetic machinery by these homeobox genes.

Mutual antagonism of the paired-type homeobox genes, vsx2 and dmbx1, regulates retinal progenitor cell cycle exit upstream of ccnd1 expression

Understanding the mechanisms that regulate the transition between the proliferative and a post-mitotic state of retinal progenitor cells (RPCs) is key to advancing our knowledge of retinal growth and maturation. In the present study we determined that during zebrafish embryonic retinal neurogenesis, two paired-type homeobox genes - vsx2 and dmbx1 - function in a mutually antagonistic manner. We demonstrate that vsx2 gene expression requires active Fgf signaling and that this in turn suppresses dmbx1 expression and maintains cells in an undifferentiated, proliferative RPC state. This vsx2-dependent RPC state can be prolonged cell-autonomously by knockdown of dmbx1, or it can be suppressed prematurely by the over-expression of dmbx1, which we show can inhibit vsx2 expression and lead to precocious neuronal differentiation. dmbx1 loss of function also results in altered expression of canonical cell cycle genes, and in particular up-regulation of ccnd1, which correlates with our previous finding of a prolonged RPC cell cycle. By knocking down ccnd1 and dmbx1 simultaneously, we show that RPCs can overcome this phenotype to exit the cell cycle on time and differentiate normally into retinal neurons. Collectively, our data provide novel insight into the mechanism that enables RPCs to exit the cell cycle through a previously unrecognized antagonistic interaction of two paired-type homeobox genes that are central regulators of an Fgf-vsx2-dmbx1-ccnd1 signaling axis.

The neural basis of involuntary episodic memories

Voluntary episodic memories require an intentional memory search, whereas involuntary episodic memories come to mind spontaneously without conscious effort. Cognitive neuroscience has largely focused on voluntary memory, leaving the neural mechanisms of involuntary memory largely unknown. We hypothesized that, because the main difference between voluntary and involuntary memory is the controlled retrieval processes required by the former, there would be greater frontal activity for voluntary than involuntary memories. Conversely, we predicted that other components of the episodic retrieval network would be similarly engaged in the two types of memory. During encoding, all participants heard sounds, half paired with pictures of complex scenes and half presented alone. During retrieval, paired and unpaired sounds were presented, panned to the left or to the right. Participants in the involuntary group were instructed to indicate the spatial location of the sound, whereas participants in the voluntary group were asked to additionally recall the pictures that had been paired with the sounds. All participants reported the incidence of their memories in a postscan session. Consistent with our predictions, voluntary memories elicited greater activity in dorsal frontal regions than involuntary memories, whereas other components of the retrieval network, including medial-temporal, ventral occipitotemporal, and ventral parietal regions were similarly engaged by both types of memories. These results clarify the distinct role of dorsal frontal and ventral occipitotemporal regions in predicting strategic retrieval and recalled information, respectively, and suggest that, although there are neural differences in retrieval, involuntary memories share neural components with established voluntary memory systems.

Fluorometric techniques for the detection of nitric oxide and metabolites

Recently fluorometric techniques have been developed to determine NO and S-nitrosothiols with improved sensitivity over spectrophotometric techniques based on similar chemistry. This unit contains protocols for detection and quantification of NO from chemical reactions and from cellular systems, and of S-nitrosothiols in chemical, biochemical, and cellular experiments.

Functional neuroimaging of emotionally intense autobiographical memories in post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) affects regions that support autobiographical memory (AM) retrieval, such as the hippocampus, amygdala and ventral medial prefrontal cortex (PFC). However, it is not well understood how PTSD may impact the neural mechanisms of memory retrieval for the personal past. We used a generic cue method combined with parametric modulation analysis and functional MRI (fMRI) to investigate the neural mechanisms affected by PTSD symptoms during the retrieval of a large sample of emotionally intense AMs. There were three main results. First, the PTSD group showed greater recruitment of the amygdala/hippocampus during the construction of negative versus positive emotionally intense AMs, when compared to controls. Second, across both the construction and elaboration phases of retrieval the PTSD group showed greater recruitment of the ventral medial PFC for negatively intense memories, but less recruitment for positively intense memories. Third, the PTSD group showed greater functional coupling between the ventral medial PFC and the amygdala for negatively intense memories, but less coupling for positively intense memories. In sum, the fMRI data suggest that there was greater recruitment and coupling of emotional brain regions during the retrieval of negatively intense AMs in the PTSD group when compared to controls.

Methods for distinguishing nitrosative and oxidative chemistry of reactive nitrogen oxide species derived from nitric oxide

NO-derived intermediates formed under aerobic conditions may engage in complex chemical reactions with biologically important molecules. The outcomes of these reactions and their ultimate effect on biological systems depend on the selectivity of the species and the concentrations of different substances present and whether the reaction takes place in the gas or aqueous phase. In this unit conversion of two different compounds to fluorescent products is used to distinguish between oxidative and nitrosative chemistry of different reactive nitrogen oxide species.

The impact of experienced emotion on evaluative judgments: the effects of age and emotion regulation style

Adults aged from 24 to 79 were exposed to four commercial advertisements within the context of television programs designed to induce either a positive or negative mood. Although age was associated with memory for the content of the commercials, it did not moderate the impact of mood on evaluations of the advertised products. Instead, participants who reported engaging in expressive suppression as a common emotion regulation strategy were more likely to make evaluations that were biased by moods than those individuals who reported low use of this strategy. The results suggest that the maintenance of emotion regulation ability in later adulthood may help people control certain affective influences on thought.

Component Neural Systems for the Creation of Emotional Memories during Free Viewing of a Complex, Real-World Event

To investigate the neural systems that contribute to the formation of complex, self-relevant emotional memories, dedicated fans of rival college basketball teams watched a competitive game while undergoing functional magnetic resonance imaging (fMRI). During a subsequent recognition memory task, participants were shown video clips depicting plays of the game, stemming either from previously-viewed game segments (targets) or from non-viewed portions of the same game (foils). After an old–new judgment, participants provided emotional valence and intensity ratings of the clips. A data driven approach was first used to decompose the fMRI signal acquired during free viewing of the game into spatially independent components. Correlations were then calculated between the identified components and post-scanning emotion ratings for successfully encoded targets. Two components were correlated with intensity ratings, including temporal lobe regions implicated in memory and emotional functions, such as the hippocampus and amygdala, as well as a midline fronto-cingulo-parietal network implicated in social cognition and self-relevant processing. These data were supported by a general linear model analysis, which revealed additional valence effects in fronto-striatal-insular regions when plays were divided into positive and negative events according to the fan's perspective. Overall, these findings contribute to our understanding of how emotional factors impact distributed neural systems to successfully encode dynamic, personally-relevant event sequences.

Immunity to tumour antigens

During the last decade, a large number of human tumour antigens have been identified. These antigens are classified as tumour-specific shared antigens, tissue-specific differentiation antigens, overexpressed antigens, tumour antigens resulting from mutations, viral antigens and fusion proteins. Antigens recognised by effectors of immune system are potential targets for antigen-specific cancer immunotherapy. However, most tumour antigens are self-proteins and are generally of low immunogenicity and the immune response elicited towards these tumour antigens is not always effective. Strategies to induce and enhance the tumour antigen-specific response are needed. This review will summarise the approaches to discovery of tumour antigens, the current status of tumour antigens, and their potential application to cancer treatment.

Survey of paediatric case management practices in Australia for children and young people with acquired brain injury (ABI)

AIM

To investigate the characteristics of paediatric acquired brain injury (ABI) case managers and their organizations in Australia, and to determine the ways in which case managers deliver their service, maintain professional development and evaluate outcomes.

METHODS

Postal survey of 57 known paediatric ABI case managers working at 24 separate organizations in Australia.

RESULTS

Out of 40 questionnaires returned (70%), the majority of respondents had been providing case management for over 5 years (55%). Co-ordination of services was ranked the most important component of case management, with services most frequently delivered by telephone. Evaluation of case management outcomes was reported by only 52% of the case managers. Whilst the majority of case managers had received some form of training (83%), this varied widely from informal in-house training, to workshops run by insurance companies and government agencies.

DISCUSSION

This survey provides information about current case management practices for children with ABI in Australia. Detailing what case managers do is a first step towards developing controlled research designs which are required to demonstrate whether case management is effective in terms of clinical outcomes and cost-benefit.

Adverse psychological outcomes in colorectal cancer screening: does health anxiety play a role?

People who are anxious about their health are more likely to misinterpret health information as personally threatening and less likely to be reassured by medical investigations that show they are free from disease. Consequently, health anxious people would be expected to react more adversely to cancer screening, but this possibility has rarely been explored. The moderating role of health anxiety on the psychological impact of participating in colorectal cancer screening was examined among a sub-sample of 3535 participants in a large, community-based trial of colorectal cancer screening in the UK. The screening modality was flexible sigmoidoscopy, which examines the bowel for pre-cancerous polyps. It was predicted that health anxiety would be associated with more worry about cancer before screening, a greater increase in worry if polyps were detected, and less reassurance after a clear result. As expected, health anxious participants were more anxious and more worried about bowel cancer both before and after screening. However, they experienced greater reductions in anxiety and worry about cancer following the examination. They reported lower levels of reassurance following screening, but also expressed more positive reactions to the experience. The positive psychological benefits of attending medical investigations should be examined in future work, because this may go some way towards explaining why health anxious people repeatedly seek medical interventions.

SunSmart? Skin cancer knowledge and preventive behaviour in a British population representative sample

The incidence of skin cancer has risen rapidly in the UK over the last 20 years, prompting public health organizations to try and raise awareness of the dangers of sun exposure and the need to practice sun-safe behaviour. This study aimed to assess baseline levels of sun-safe knowledge and behaviour in a British population-representative sample, prior to the launch of Cancer Research UK's 'SunSmart' campaign. A face-to-face survey was conducted through the Office for National Statistics as part of their Omnibus survey. In total, 1848 men and women aged 18 and over were interviewed. Knowledge of what to do to reduce skin cancer risk was modest. Two-thirds mentioned avoiding the sun by seeking shade, 50% mentioned covering up and only 43% said to use high factor sunscreen. Practice of sun-safe behaviours was also poor, with only one-third saying they sought shade, covered up or used high factor sunscreen to protect themselves from the sun. Men and those from lower socioeconomic groups were least informed and least likely to report using sun-protective behaviours. Increases in both knowledge and use of appropriate sun-protective behaviours are needed if skin cancer incidence rates are to decrease.

Managing constraint: the experience of people with chronic pain

This study describes the experience of people with chronic pain. Using the method of grounded theory, 29 chronic pain sufferers were interviewed at an outpatient pain clinic. A model depicting the basic social psychological process of maintaining a normal life through constraint was developed. This process revolved around people's perception of the constraints imposed by pain: bodily constraint (constraint on the body and its relationship to the environment); activity constraint (the constraint on what people could do); and identity constraint (the constraint on what people could be). The degree to which pain had challenged what people had previously accepted as 'normal' was illustrated through their evaluation of the impact of pain. The conclusion of this process of evaluation reflected how people coped with the constraints of pain-whether they were assimilated, accommodated, confronted or subverted. In assimilation, the constraints were absorbed and normal life maintained. In accommodation, the constraints were accepted and normal life re-defined. In confrontation, the constraints were rejected and pre-pain identities and activities pursued despite leading to increased pain levels. In subversion, attempts were made to retain pre-pain identities, and although pain levels were minimized, activities were altered to a significant degree. The limitations imposed by pain often form the focus of people's coping efforts, rather than the pain per se. The desire to retain pre-pain 'normal' lifestyles may underlie people's use of coping strategies that exacerbate pain intensity and pain-related disability. Future research needs to explore both the relationship between adjustment to pain and adjustment to the restrictions associated with ageing, and the role of body techniques and identity management in adjustment to pain in order to understand factors which may promote pain acceptance.

Gender differences in utilization of colorectal cancer screening

OBJECTIVES

To assess the demographic and psychological mediators of gender differences in uptake of flexible sigmoidoscopy (FS) screening for colorectal cancer.

SETTING

A subsample (n=5462) from a large community trial of FS in the UK.

METHODS

Men and women randomized to screening as part of the UK Flexible Sigmoidoscopy Trial were sent a postal questionnaire assessing demographic characteristics and attitudes to screening six months before their screening appointment. Attendance at screening was recorded by the screening centres.

RESULTS

More men than women attended screening (73% versus 67%). The higher male attendance was partially explained by their lower levels of socioeconomic deprivation, higher levels of marital status and lower perceived barriers to screening.

CONCLUSIONS

Contrary to expectations, men were more likely than women to attend FS screening. This was partially explained by socioeconomic and attitudinal differences to screening, but additional research is needed to understand the key aspects of FS screening that will maximize screening uptake in men and women.

Identification of tumour antigens by serological analysis of cDNA expression cloning

The identification of antigens that distinguish normal cells from cancer cells is an important challenge in the field of tumour immunology and immunotherapy. The immunoscreening of cDNA expression libraries constructed from human tumour tissues with antibodies in sera from cancer patents (SEREX: serological identification of antigens by recombinant expression cloning) provides a powerful approach to identify immunogenic tumour antigens. To date, over 2,000 tumour antigens have been identified from a variety of malignancies using SEREX. These antigens can be classified into several categories, of which the cancer/testis (CT) antigens appear to be the most attractive candidates for vaccine development. The SEREX-defined tumour antigens facilitate the identification of epitopes (antigenic peptides) recognised by antigen-specific cytotoxic T lymphocytes (CTLs) and provide a basis for peptide vaccine and gene therapy in a wide variety of human cancers. Moreover, some of these antigens seem to play a functional role in the pathogenesis of cancer.

The factor structure of the BDI in facial pain and other chronic pain patients: a comparison of two models using confirmatory factor analysis

OBJECTIVES

1) To compare two measurement models of the BDI in chronic pain sufferers to see which provides the better fit; 2) to assess whether model fit differs for a facial pain sample compared to a sample of pain sufferers attending a multidisciplinary pain clinic; and 3) to establish which affective and somatic sub-scales of the BDI could be used in chronic pain research.

DESIGN

Two groups of chronic pain sufferers, a facial pain group, and a group attending a multidisciplinary pain clinic completed self-report questionnaires on pain (Multidimensional Pain Inventory), depression (BDI), and measures of anxiety and depression-related pain cognitions (the Spielberger State-Trait Anxiety Inventory and the Pain Cognitions Questionnaire). The measurement models of the BDI were tested using LISREL structural equation modelling and their construct validity examined using partial correlation analysis.

METHOD

A total of 173 people attending a multidisciplinary pain clinic and 157 patients attending a facial pain clinic completed self-report measures of pain and mood prior to their respective clinical consultations.

RESULTS

The model offered by Novy et al. (containing one affective factor 'Negative-attitude suicide' and two somatic factors 'Performance difficulty' and 'Physiological manifestations') fitted both pain groups better than the model offered by Williams and Richardson (containing one affective factor 'Self-reproach', one somatic factor 'Somatic disturbance' and one factor with a mixture of both affective and somatic items 'Sadness about health'). However, when the factors were allowed to correlate in the latter model, both models were broadly equivalent.

CONCLUSIONS

The two measurement models adequately fitted data in both pain samples when the factors were allowed to intercorrelate in the Williams and Richardson model. Both the affective scales offered by both models could be used in future research, although the somatic factor offered by the Williams and Richardson model offered much higher levels of internal reliability than either of those offered in the Novy et al. model. The findings are discussed in relation to the issue of depression in chronic pain.

Agonist binding to peptide hormone receptors

A fundamental issue in molecular pharmacology is to define how agonist-receptor interaction differs from that of antagonist-receptor interaction. The V(1a) vasopressin receptor (V(1a)R) is a member of a family of related G-protein-coupled receptors (GPCRs) that are activated by vasopressin, oxytocin (OT) and related peptides. A segment of the N-terminus that was required for agonist binding, but not antagonist binding, was identified by characterizing truncated V(1a)R constructs. Site-directed mutagenesis revealed that a single residue (Arg(46)) was critical for agonist binding and receptor activation. The N-terminus of the related OT receptor (OTR) could recover agonist binding in a chimaeric OTR(N)-V(1a)R construct. Furthermore, Arg(34) of the human OTR, which corresponds to Arg(46) of the rat V(1a)R, provided agonist-specific binding epitopes in the OTR, indicating a conserved function of this locus throughout this GPCR subfamily. Mutation of Arg(46) revealed that high-affinity agonist binding had an absolute requirement for arginine at this position.

Venous thromboembolism and pregnancy

Venous thromboembolism remains a major cause of maternal morbidity and mortality. Pregnancy is a thrombogenic state; therefore, clinicians must be familiar with the diagnosis and treatment of acute VTE. It is of paramount importance when caring for pregnant women to understand which patients are at risk for VTE and to use thromboprophylactic heparin accordingly.

Mass education for obesity prevention: the penetration of the BBC's 'Fighting Fat, Fighting Fit' campaign

The study aimed to evaluate the BBC's 'Fighting Fat, Fighting Fit' campaign's success in achieving public awareness of the need for obesity prevention, and putting over its message of healthy eating and increased physical activity. Demographic factors associated with awareness of the campaign were assessed. Data were collected from a national representative British sample as part of the ONS Omnibus survey in March 1999. Questions included weight and height, recognition of the campaign name, recall of the content of the campaign, and participation in the campaign registration scheme. More than half of the respondents had heard of the campaign and 30% recalled the healthy lifestyle messages, although fewer than 1% registered to participate in the scheme. Awareness of the campaign was high in all socio-economic groups, but memory for the healthy lifestyle message was significantly poorer in those with lower levels of education and from ethnic minority groups. Disappointingly, awareness was also no higher in overweight than normal weight respondents. The results strongly support the effectiveness of the campaign in publicizing the issue of increasing prevalence of obesity and the need for lifestyle change, but suggest that different approaches might be needed to maximize participation from groups most in need of lifestyle change.