Establishing an infrastructure to optimize the integration of genomics into research: Results from a precision health needs assessment

Researchers across the translational research continuum have emphasized the importance of integrating genomics into their research program. To date capacity and resources for genomics research have been limited; however, a recent population-wide genomic screening initiative launched at the Medical University of South Carolina in partnership with Helix has rapidly advanced the need to develop appropriate infrastructure for genomics research at our institution. We conducted a survey with researchers from across our institution (n = 36) to assess current knowledge about genomics health, barriers, and facilitators to uptake, and next steps to support translational research using genomics. We also completed 30-minute qualitative interviews with providers and researchers from diverse specialties (n = 8). Quantitative data were analyzed using descriptive analyses. A rapid assessment process was used to develop a preliminary understanding of each interviewee's perspective. These interviews were transcribed and coded to extract themes. The codes included types of research, alignment with precision health, opportunities to incorporate precision health, examples of researchers in the field, barriers, and facilitators to uptake, educational activity suggestions, questions to be answered, and other observations. Themes from the surveys and interviews inform implementation strategies that are applicable not only to our institution, but also to other organizations interested in making genomic data available to researchers to support genomics-informed translational research.

178 A RETROSPECTIVE EVALUATION OF PROCESS OUTCOMES OF OLDER ADULTS REFERRED TO A COMMUNITY RE-ENABLEMENT TEAM FROM THE EMERGENCY DEPARTMENT

Background

Emergency Departments (ED) are complex and challenging environments to provide care to older adults. There is currently a paucity of high quality methodological research investigating the effectiveness of interventions focused on transitions of care from the ED to primary care services (Hughes et al, 2019). This study aims to evaluate the impact of a collaborative model of care between primary and secondary care services for older adults discharged home following ED index visit.

Methods

This was an observational retrospective study. Participants aged ≥65 years discharged home from the ED of a University Teaching Hospital and referred to a Multidisciplinary Community Intervention Team (MDCIT) were included. Referral pathways were via the OPTIMEND team (Cassarino et al, 2021) and MDCIT, which is a rapid access re-enablement team based in the community and compromises nursing staff, an occupational therapist, physiotherapist, therapy and healthcare assistants. Descriptive statistics were used to profile the baseline characteristics of study participants and to summarise data related to process outcomes. Ethical approval was granted for this study (020/2021).

Results

In the study period, January—December 2020, 54 patients were referred to the MDCIT. The mean age of participants was 80.1 years (SD 8.2), 57% were female, and the most common Manchester Triage System presenting complaint was ‘limb problems’. The median Patient Experience Time within the ED was 7.4 hours (IQR 13.1); 55% of participants were seen in their home within 24 hours of discharge. A mean of 10 interventions were delivered by the MDCIT. A 9.1% incidence rate of 30 day unscheduled hospital readmission was recorded.

Conclusion

Integrated care programmes have been advocated to improve the continuum of care from the ED into the community. This evaluation has demonstrated the feasibility of implementing such a model of care. However, further methodologically robust research is required to advance the evidence base and should also focus on patient outcomes.

Virtual fracture liaison clinics in the COVID era: an initiative to maintain fracture prevention services during the pandemic associated with positive patient experience

We introduced virtual fracture liaison clinics during the COVID-19 pandemic in order to support clinical care while DXA services were down-turned. We observed that virtual FLS clinics are effective in delivering fracture risk assessment, health promotion, and clinical management and are well received by patients with positive patient experience.

INTRODUCTION

We examined the impact of virtual FLS telephone clinics, as an alternative to face-to-face clinics during the COVID-19 lockdown.

METHODS

Patients presenting with low trauma fracture were recruited according to standard criteria. A structured telephone clinic appointment was offered, which included fracture risk and health promotion assessment and a treatment plan. Risk factors, demographics, fracture type, FRAX scores, and outcomes were analysed. We assessed patient experience with an anonymised patient survey.

RESULTS

Clinical outcomes from virtual clinics were assessed (77F/33M; mean age 65.7 years). The mean 10-year observed fracture risk for major osteoporotic fracture was 18.2% and 7.0% for hip fracture. We observed high 'attendance' rates at 79%; however, a significant number were still not available for telephone review (11%) or cancelled their appointment (10%). A recommendation for bisphosphonate treatment was made in 54% of the cohort based on National Osteoporosis Guidelines Group (NOGG) criteria. Follow-up DXA assessment is planned for 64%, according to fracture risk and NOGG guidance. We received 60 responses from the initial patient survey. Ninety percent rated their overall experience of service at 4 or 5 (very good to excellent). Ninety-eight indicated they would recommend the service to others.

CONCLUSIONS

Virtual clinics are effective in delivery of fracture risk assessment and clinical management with positive patient experience. While a significant proportion will require DXA follow-up to complete the clinical assessment, virtual clinics have mitigated delays in fracture prevention interventions during the COVID-19 pandemic.

Nutritional requirements for reproduction and survival in the blowfly Lucilia sericata

Insects with access to finite energy resources must allocate these between maintenance and reproduction in a way that maximizes fitness. This will be influenced by a range of life-history characteristics and the environment in which any particular insect species lives. In the present study, females of the blowfly Lucilia sericata (Diptera: Calliphoridae) were fed diets differing in protein and carbohydrate (sucrose) content and the allocation of lipid to reproduction was quantified using a spectrophotometric method of analysis. Immediately after adult emergence, total body lipid, scaled for differences in body size, showed an initial decline as it was utilized to meet the metabolic demands of cuticle deposition, muscle maturation and then flight. When flies were denied access to sucrose, stored lipid then continued to decrease until flies died, usually within 4 days of emergence. However, flies given access to sucrose were able to increase body lipid content, demonstrating that carbohydrate is essential for homeostasis and that it can be used to synthesize lipid. Nevertheless, female flies fed sucrose only were unable to synthesize egg yolk. Only flies provided with protein were able to mature eggs. However, the rate of egg maturation and number and size of eggs matured were greater for female flies given liver compared with flies provided with pure whey protein powder. The results demonstrate the importance of different dietary components for different elements of the life-history of L. sericata, namely survival and reproduction.

SAT-026 Association of Inflammatory Markers with Depressive Symptoms Across the Perinatal Period

Perinatal depression (PND) is a mood disorder affecting 10-15% of women during pregnancy and postpartum. Its aetiology is complex with contribution from both genetic background and psychosocial as well as environmental stressors that determine individual responses shaped by chronic and acute disease burden (1). It is thought that the molecular basis of PND involves dysregulation of the HPA axis associated with neurotransmitter and neuroactive steroids imbalance. Inflammation appears to be a contributing mechanism, with increased levels of cytokines exerting adverse effects on serotonin metabolism, neuroplasticity and HPA hyperactivity (2). With only 50% of women detected through current screening strategies, there is an urgent unmet need for the development of biomarker-based strategies to identify women at risk of PND. In this study we used data and blood samples from the prospective Coventry and Warwickshire PND study; we investigated for inflammatory markers associated with depressive symptoms, assessed using the Edinburgh Postnatal Depression Score (EPDS) questionnaire between 24-29 weeks of gestation and again 6-10 weeks postpartum. A cut-off score of 10 categorize ‘high’ or ‘low’ risk for depression. Blood samples collected at 28 weeks of gestation were profiled for either IL-6 and IL-10 levels or a panel of 92 inflammatory markers. Individual inflammatory markers were compared across groups using Welch’s ANOVA. Results suggest that IL-10 levels were significantly correlated with EPDS score, exerting a protective effect (r= -.10), with reduced levels in the highest severity category (EPDS ≥ 15). The IL-6/IL-10 ratio was also associated with a raised EPDS score (r=.10, p=.01), as well as delivery complications (r=.09). The highest IL-6/IL-10 ratio is observed in women who had emergency caesarean section. Bayes’ theorem analysis suggested that IL-6/IL-10 ratio could be used as a negative screen to rule out low risk pregnancies. From the 92 inflammatory markers, 14 analytes were below the limit of detection for more than 50% of samples and so were excluded from further analysis. Upon comparison of groups determined by antenatal and postnatal EPDS scores, 29 markers displayed a significance value of P<0.05. Upon the application of post hoc tests, 8 markers including: STAM-BP, SIRT2, CD40, CASP8 and ADA, all associated with apoptotic processes, remained statistically significant in pregnant women with raised antenatal EPDS scores. This data support an association between inflammatory markers and perinatal depression and adverse pregnancy outcomes. Detailed quantitative analysis of such biomarker signatures at different stages of pregnancy, might lead to early detection of disease and application of targeted treatment. (1) Pariante, C. M. & Lightman, S. L. (2008) Trends Neurosci, 31 (9): 464-468. (2) Raison et al., (2006) Trends Immunol, 27 (1): 24-31.

Detection of vertebral fracture in an acute hospital setting: an intervention to reduce future fracture risk through fracture liaison service intervention?

We introduced a standardised reporting system in the radiology department to highlight vertebral fractures and to signpost fracture prevention services. Our quality improvement project achieved improved fracture reporting, access to the FLS service, bone density assessment and anti-fracture treatment.

PURPOSE

Identification of vertebral fragility fractures (VF) provides an opportunity to identify individuals at high risk who might benefit from secondary fracture prevention. We sought to standardise VF reporting and to signpost fracture prevention services. Our aim was to improve rates of VF detection and access to our fracture liaison service (FLS).

METHODS

We introduced a standardised reporting tool within the radiology department to flag VFs with signposting for referral for bone densitometry (DXA) and osteoporosis assessment in line with Royal Osteoporosis Society guidelines. We monitored uptake of VF reporting during a quality improvement phase and case identification within the FLS service.

RESULTS

Recruitment of individuals with VF to the FLS service increased from a baseline of 63 cases in 2017 (6%) to 95 (8%) in 2018 and 157 (8%) in 2019 and to 102 (12%) in the first 6 months of 2020 (p = 0.001). One hundred fifty-three patients with VFs were identified during the QI period (56 males; 97 females). Use of the terminology 'fracture' increased to 100% (mean age 70 years; SD 13) in computed tomography (n = 110), plain X-ray (n = 37) or magnetic resonance imaging (n = 6) reports within the cohort. Signposting to DXA and osteoporosis assessment was included in all reports (100%). DXA was arranged for 103/153; 12 failed to attend. Diagnostic categories were osteoporosis (31%), osteopenia (36%) or normal bone density (33%). A new prescription for bone protection therapy was issued in 63/153. Twelve of the series died during follow-up.

CONCLUSIONS

Standardisation of radiology reporting systems facilitates reporting of prevalent vertebral fractures and supports secondary fracture prevention strategies.

Real World Experience of Denosumab Treatment in the Belfast Osteoporosis Service

Osteoporosis is a significant global health and economic burden associated with bone fracture, morbidity and mortality. Denosumab, a novel human monoclonal antibody second-line treatment, inhibits osteoclast-mediated bone resorption and increases bone mineral density (BMD). Treatment achieves reductions in vertebral, non-vertebral and hip fracture risk. We undertook a service evaluation to review clinical outcomes of patients treated with denosumab in an osteoporosis department that provides regional services. We identified 529 patients (95% female; mean age 72.8 years; 35-98 years), who had at least one dose of denosumab administered for the treatment of osteoporosis. The mean number of denosumab doses administered was 4.9 (range: 1 to 12). 330/529 patients had completed a baseline and post-treatment bone densitometry scan (DXA). The mean observed BMD change at around 18 months at the lumbar spine was +8.4% and at the hip was +3.5%. While the majority have transitioned to shared care administration of treatment within primary care (53%), 20% continue to attend hospital clinics to receive treatment. During follow-up, there were 66 deaths (12%). 15% switched to an alternative treatment or were discharged. This retrospective cohort study demonstrates the clinical effectiveness of denosumab in improving bone mineral density in a real life setting in an ageing, co-morbid population. There has been recent progress with adoption of shared care administration in primary care. As part of a quality improvement programme we have recently developed a dedicated denosumab database and day-case treatment clinic for those receiving treatment in secondary care.

Modelling of psychosocial and lifestyle predictors of peripartum depressive symptoms associated with distinct risk trajectories: a prospective cohort study

Perinatal depression involves interplay between individual chronic and acute disease burdens, biological and psychosocial environmental and behavioural factors. Here we explored the predictive potential of specific psycho-socio-demographic characteristics for antenatal and postpartum depression symptoms and contribution to severity scores on the Edinburgh Postnatal Depression Scale (EPDS) screening tool. We determined depression risk trajectories in 480 women that prospectively completed the EPDS during pregnancy (TP1) and postpartum (TP2). Multinomial logistic and penalised linear regression investigated covariates associated with increased antenatal and postpartum EPDS scores contributing to the average or the difference of paired scores across time points. History of anxiety was identified as the strongest contribution to antenatal EPDS scores followed by the social status, whereas a history of depression, postpartum depression (PPD) and family history of PPD exhibited the strongest association with postpartum EPDS. These covariates were the strongest differentiating factors that increased the spread between antenatal and postpartum EPDS scores. Available covariates appeared better suited to predict EPDS scores antenatally than postpartum. As women move from the antenatal to the postpartum period, socio-demographic and lifestyle risk factors appear to play a smaller role in risk, and a personal and family history of depression and PPD become increasingly important.

Prevalence and risk factor analysis for feline haemoplasmas in cats from Northern Serbia, with molecular subtyping of feline immunodeficiency virus

Objectives

The objectives of this study were to estimate the prevalence of feline haemoplasma infections in Northern Serbia, identify potential risk factors and perform molecular subtyping of feline immunodeficiency virus (FIV).

Methods

PCR analysis for feline haemoplasmas was performed on surplus EDTA blood samples from 373 cats from the Belgrade region, Serbia. An ELISA was used to determine the prevalence of feline leukaemia virus (FeLV) and FIV; PCR was performed on a subpopulation of these cats. FIV subtyping was performed using PCR.

Results

Within this population, 64/373 cats (17.2%) were infected with one or more haemoplasma species. Mycoplasma haemofelis was detected in 20/373 cats (5.4%), ‘Candidatus Mycoplasma haemominutum’ in 47/373 cats (12.6%) and ‘Candidatus Mycoplasma turicensis’ in 23/373 cats (6.2%). Coinfections were observed in 21/373 cats (5.6%). Based on ELISA serological retroviral testing, 4/310 cats (1.3%) were infected with FeLV, whereas 78/331 (23.6%) were infected with FIV. Multivariable analysis identified significant associations between haemoplasma infection and anaemia (anaemic/non-anaemic, odds ratio [OR] 2.7, 95% confidence interval [CI] 1.04–7.1; P = 0.041]), male gender (male/female, OR 4.5, 95% CI 2.22–9.03; P <0.0005), outdoor access (yes/no, OR 5.2, 95% CI 2.28–11.92; P <0.0005), non-pedigree breed (non-pedigree/pedigree, OR 5.5, 95% CI 1.24–24.84; P = 0.025) and FIV seropositive status (positive/negative, OR 2.4, 95% CI 1.21–4.83; P = 0.012). PCR analysis of the FIV ELISA-positive samples revealed clade D as being the most prevalent.

Conclusions and relevance

All three known species of feline haemoplasma were detected, confirming their presence in Serbia; ‘Candidatus Mycoplasma haemominutum’ was the most prevalent. We found a high prevalence of FIV-infected cats and FIV clade D was most prevalent.

Increased food availability raises eviction rate in a cooperative breeding mammal

In group-living mammals, the eviction of subordinate females from breeding groups by dominants may serve to reduce feeding competition or to reduce breeding competition. Here, we combined both correlational and experimental approaches to investigate whether increases in food intake by dominant females reduces their tendency to evict subordinate females in wild meerkats (Suricata suricatta). We used 20 years of long-term data to examine the association between foraging success and eviction rate, and provisioned dominant females during the second half of their pregnancy, when they most commonly evict subordinates. We show that rather than reducing the tendency for dominants to evict subordinates, foraging success of dominant females is positively associated with the probability that pregnant dominant females will evict subordinate females and that experimental feeding increased their rates of eviction. Our results suggest that it is unlikely that the eviction of subordinate females serves to reduce feeding competition and that its principal function may be to reduce reproductive competition. The increase in eviction rates following experimental feeding also suggests that rather than feeding competition, energetic constraints may normally constrain eviction rates.

Cytomegalovirus Infection and Rates of Antiviral Resistance Following Intestinal and Multivisceral Transplantation

BACKGROUND

Cytomegalovirus (CMV) disease is a common and clinically significant complication following intestinal or multivisceral transplantation. CMV disease is more common in cases of serologic mismatch between donor and recipient. Though in some cases it may be asymptomatic, in the immunosuppressed population it often manifests with evidence of systemic infection or end-organ disease.

METHODS

We conducted a retrospective review of all patients undergoing intestinal or multivisceral transplantation over 8 years at our institution.

RESULTS

Forty-eight transplantations were performed, with 40% of the patients (19/48) having ≥1 episode of CMV viremia, which rose to 90% in the "donor-positive, recipient-negative" (DPRN) serologic mismatch group. The median time to 1st episode following transplantation was 22.3 weeks (range, 1-78) and median duration of each episode was 4.9 weeks (range, 1.6-37.4). Six of the 19 viremic patients (31.6%) developed virologic resistance with 4 of these occurring in the DPRN group. Four of the 6 patients with drug-resistant CMV died with CMV viremia. All patients with drug resistance acquired ganciclovir resistance; these patients were more challenging to manage with second-line toxicity-limited treatments, including foscarnet, cidofovir, and leflunomide. CMV immunoglobulin has been used and we briefly discuss the use of CMV-specific adoptive T-lymphocyte transfer in the management of 1 case.

CONCLUSIONS

Post-transplantation CMV disease continues to be challenging to manage, and there is little consensus on optimal management strategies in this patient group, with a significant requirement for novel therapies; these may be pharmacologic or cell based. Extensive multidisciplinary discussion is important for most cases, but particularly for those patients who acquire virologic resistance.

The Need for Electronic Health Records in Long-Term Care

Long-term care (LTC) settings serve an important proportion of seniors and vulnerable populations that require 24-hour nursing care. Deployment of interoperable electronic health records (iEHRs) to these settings lag. There is little evidence on the availability of patient information from across the continuum of care. To fill this knowledge gap this study examines the prevalence and nature of information gaps experienced in LTC during patient encounters (n=1050). Overall, more than one-third (34%) of all LTC patient encounters were missing at least one item of information that was needed for the encounter. Approximately 59% of missing information during patient encounters was documented or ordered by a clinician external to the LTC facility; 41% were within the LTC facility itself. These information gaps have an adverse consequence for nearly 3 out of every 10 (31%) patient encounters in LTC. Extending iEHRs to LTC has the potential to support timely, appropriate, and better quality of patient care and improve provider experience.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Phenolic Composition of Bud Exudates of Populus deltoides

Bud exudate of Populus deltoides clones originating from six central and eastern American states was examined by gas chromatography/mass spectrometry and the components were identified. The principal components of the bud exudate were the flavone galangin, the flavanone pinocembrin and the flavanonol pinobanksin, together with the related compounds pinocembrin chalcone, pinobanksin methyl ether and pinobanksin-3-acetate. The bud exudate composition was very different from that seen in a North American poplar of the section Tacamahaca, P. balsamifera.

The bud exudates from all P. deltoides specimens were similar excepting that from Vermont.

Cooperative personalities and social niche specialization in female meerkats

The social niche specialization hypothesis predicts that group-living animals should specialize in particular social roles to avoid social conflict, resulting in alternative life-history strategies for different roles. Social niche specialization, coupled with role-specific life-history trade-offs, should thus generate between-individual differences in behaviour that persist through time, or distinct personalities, as individuals specialize in particular nonoverlapping social roles. We tested for support for the social niche specialization hypothesis in cooperative personality traits in wild female meerkats (Suricata suricatta) that compete for access to dominant social roles. As cooperation is costly and dominance is acquired by heavier females, we predicted that females that ultimately acquired dominant roles would show noncooperative personality types early in life and before and after role acquisition. Although we found large individual differences in repeatable cooperative behaviours, there was no indication that individuals that ultimately acquired dominance differed from unsuccessful individuals in their cooperative behaviour. Early-life behaviour did not predict social role acquisition later in life, nor was cooperative behaviour before and after role acquisition correlated in the same individuals. We suggest that female meerkats do not show social niche specialization resulting in cooperative personalities, but that they exhibit an adaptive response in personality at role acquisition.

Weak evidence for anticipatory parental effects in plants and animals

The evolution of adaptive phenotypic plasticity relies on the presence of cues that enable organisms to adjust their phenotype to match local conditions. Although mostly studied with respect to nonsocial cues, it is also possible that parents transmit information about the environment to their offspring. Such 'anticipatory parental effects' or 'adaptive transgenerational plasticity' can have important consequences for the dynamics and adaptive potential of populations in heterogeneous environments. Yet, it remains unknown how widespread this form of plasticity is. Using a meta-analysis of experimental studies with a fully factorial design, we show that there is only weak evidence for higher offspring performance when parental and offspring environments are matched compared with when they are mismatched. Estimates of heterogeneity among studies suggest that effects, when they occur, are subtle. Study features, environmental context, life stage and trait categories all failed to explain significant amounts of variation in effect sizes. We discuss theoretical and methodological reasons for the limited evidence for anticipatory parental effects and suggest ways to improve our understanding of the prevalence of this form of plasticity in nature.

Electron Emission Properties of Si Field Emitter Arrays Coated With Nanocrystalline Diamond From Fullerene Precursors

In this paper, we report on a substantial lowering of the threshold field for electron field emission from Si field emitter arrays (FEA), which have been coated with a thin layer of nanocrystalline diamond by microwave plasma-assisted chemical vapor deposition (MPCVD) from fullerene (C60) and methane (CH4) precursors. The field emission characteristics were investigated and the emission sites imaged using photoelectron emission microscopy (PEEM). Electron emission from these Si FEAs coated with nanocrystalline diamond was observed at threshold fields as low as 3 V/μm, with effective work functions as low as 0.59 eV.

Posterior knee pain

Posterior knee pain is a common patient complaint. There are broad differential diagnoses of posterior knee pain ranging from common causes such as injury to the musculotendinous structures to less common causes such as osteochondroma. A precise understanding of knee anatomy, the physical examination, and of the differential diagnosis is needed to accurately evaluate and treat posterior knee pain. This article provides a review of the anatomy and important aspects of the history and physical examination when evaluating posterior knee pain. It concludes by discussing the causes and management of posterior knee pain.

Escalated conflict in a social hierarchy

Animals that live in cooperative societies form hierarchies in which dominant individuals reap disproportionate benefits from group cooperation. The stability of these societies requires subordinates to accept their inferior status rather than engage in escalated conflict with dominants over rank. Applying the logic of animal contests to these cases predicts that escalated conflict is more likely where subordinates are reproductively suppressed, where group productivity is high, relatedness is low, and where subordinates are relatively strong. We tested these four predictions in the field on co-foundress associations of the paper wasp Polistes dominulus by inducing contests over dominance rank experimentally. Subordinates with lower levels of ovarian development, and those in larger, more productive groups, were more likely to escalate in conflict with their dominant, as predicted. Neither genetic relatedness nor relative body size had significant effects on the probability of escalation. The original dominant emerged as the winner in all except one escalated contest. The results provide the first evidence that reproductive suppression of subordinates increases the threat of escalated conflict, and hence that reproductive sharing can promote stability of the dominant-subordinate relationship.

Feasibility and assessment of non-invasive in vivo redox status using electron paramagnetic resonance imaging

PURPOSE

To test the feasibility of electron paramagnetic resonance imaging (EPRI) to provide non-invasive images of tissue redox status using redox-sensitive paramagnetic contrast agents.

MATERIAL AND METHODS

Nitroxide free radicals were used as paramagnetic agents and a custom-built 300 MHz EPR spectrometer/imager was used for all studies. A phantom was constructed consisting of four tubes containing equal concentrations of a nitroxide. Varying concentrations of hypoxanthine/xanthine oxidase were added to each tube and reduction of the nitroxide was monitored by EPR as a function of time. Tumor-bearing mice were intravenously infused with a nitroxide and the corresponding reduction rate was monitored on a pixel-by-pixel basis using 2D EPR of the tumor-bearing leg and normal leg serving as control. For animal studies, nitroxides were injected intravenously (1.25 mmol/kg) and EPR projections were collected every 3 min after injection using a magnetic field gradient of 2.5 G/cm. The reduction rates of signal intensity on a pixel-by-pixel basis were calculated and plotted as a redox map. Redox maps were also collected from the mice treated with diethylmaleate (DEM), which depletes tissue thiols and alters the global redox status.

RESULTS

Redox maps obtained from the phantoms were in agreement with the intensity change in each of the tubes where the signals were decreasing as a function of the enzymatic activity, validating the ability of EPRI to accurately access changes in nitroxide reduction. Redox imaging capability of EPR was next evaluated in vivo. EPR images of the nitroxide distribution and reduction rates in tumor-bearing leg of mice exhibited more heterogeneity than in the normal tissue. Reduction rates were found to be significantly decreased in tumors of mice treated with DEM, consistent with the depletion of thiols and the consequent alteration of the redox status.

CONCLUSION

Using redox-sensitive paramagnetic contrast agents, EPRI can non-invasively discriminate redox status differences between normal tissue and tumors.

Feasibility and assessment of non-invasive in vivo redox status using electron paramagnetic resonance imaging

PURPOSE

To test the feasibility of electron paramagnetic resonance imaging (EPRI) to provide non-invasive images of tissue redox status using redox-sensitive paramagnetic contrast agents.

MATERIAL AND METHODS

Nitroxide free radicals were used as paramagnetic agents and a custom-built 300 MHz EPR spectrometer/imager was used for all studies. A phantom was constructed consisting of four tubes containing equal concentrations of a nitroxide. Varying concentrations of hypoxanthine/xanthine oxidase were added to each tube and reduction of the nitroxide was monitored by EPR as a function of time. Tumor-bearing mice were intravenously infused with a nitroxide and the corresponding reduction rate was monitored on a pixel-by-pixel basis using 2D EPR of the tumor-bearing leg and normal leg serving as control. For animal studies, nitroxides were injected intravenously (1.25 mmol/kg) and EPR projections were collected every 3 min after injection using a magnetic field gradient of 2.5 G/cm. The reduction rates of signal intensity on a pixel-by-pixel basis were calculated and plotted as a redox map. Redox maps were also collected from the mice treated with diethylmaleate (DEM), which depletes tissue thiols and alters the global redox status.

RESULTS

Redox maps obtained from the phantoms were in agreement with the intensity change in each of the tubes where the signals were decreasing as a function of the enzymatic activity, validating the ability of EPRI to accurately access changes in nitroxide reduction. Redox imaging capability of EPR was next evaluated in vivo. EPR images of the nitroxide distribution and reduction rates in tumor-bearing leg of mice exhibited more heterogeneity than in the normal tissue. Reduction rates were found to be significantly decreased in tumors of mice treated with DEM, consistent with the depletion of thiols and the consequent alteration of the redox status.

CONCLUSION

Using redox-sensitive paramagnetic contrast agents, EPRI can non-invasively discriminate redox status differences between normal tissue and tumors.

Decrease in cardiac output and muscle sympathetic activity during vasovagal syncope

The importance of cardiac output (CO) to blood pressure level during vasovagal syncope is unknown. We measured thermodilution CO, mean blood pressure (MBP), and leg muscle mean sympathetic nerve activity (MSNA) each minute during 60 degrees head-up tilt in 26 patients with recurrent syncope. Eight patients tolerated tilt (TT) for 45 min (mean age 60 +/- 5 yr) and 15 patients developed syncope during tilt (TS) (mean age 58 +/- 4 yr, mean tilt time 15.4 +/- 2 min). In TT patients, CO decreased during the first minute of tilt (from 3.2 +/- 0.2 to 2.5 +/- 0.3 l x min(-1) x m(-2), P = 0.001) and thereafter remained stable between 2.5 +/- 0.3 (P = 0.001) and 2.4 +/- 0.2 l x min(-1) x m(-2) (P = 0.004) at 5 and 45 min, respectively. In TS patients, CO decreased during the first minute (from 3.3 +/- 0.2 to 2.7 +/- 0.1 l x min(-1) x m(-2), P = 0.02) and was stable until 7 min before syncope, falling to 2.0 +/- 0.2 at syncope (P = 0.001). Regression slopes for CO versus time during tilt were -0.01 min(-1) in TT versus -0.1 l x min(-1) x m(-2) x min(-1) in TS (P = 0.001). However, MBP was more closely correlated to total peripheral resistance (R = 0.56, P = 0.001) and MSNA (R = 0.58, P = 0.001) than CO (R = 0.32, P = 0.001). In vasovagal reactions, a progressive decline in CO may contribute to hypotension some minutes before syncope occurs.

Reversible glutathionylation regulates actin polymerization in A431 cells

In response to growth factor stimulation, many mammalian cells transiently generate reactive oxygen species (ROS) that lead to the elevation of tyrosine-phosphorylated and glutathionylated proteins. While investigating EGF-induced glutathionylation in A431 cells, paradoxically we found deglutathionylation of a major 42-kDa protein identified as actin. Mass spectrometric analysis revealed that the glutathionylation site is Cys-374. Deglutathionylation of the G-actin leads to about a 6-fold increase in the rate of polymerization. In vivo studies revealed a 12% increase in F-actin content 15 min after EGF treatment, and F-actin was found in the cell periphery suggesting that in response to growth factor, actin polymerization in vivo is regulated by a reversible glutathionylation mechanism. Deglutathionylation is most likely catalyzed by glutaredoxin (thioltranferase), because Cd(II), an inhibitor of glutaredoxin, inhibits intracellular actin deglutathionylation at 2 microM comparable with its IC(50) in vitro. Moreover, mass spectral analysis showed efficient transfer of GSH from immobilized S-glutathionylated actin to glutaredoxin. Overall, this study revealed a novel physiological relevance of actin polymerization regulated by reversible glutathionylation of the penultimate cysteine mediated by growth factor stimulation.

Representations of knowledge about dominoes in demented and normal elderly players

1. Dementia patients who retain musical and game-playing skills exhibit impaired performance on explicit memory tests of knowledge about their retained skill. 2. Dementia patients who retain skill at playing dominoes can answer complex questions about the play of the game almost as well as normal elderly domino players when the questions are presented with real dominoes. 3. The aim of this study was to determine if skilled dementia patients could answer questions about domino play when the stimuli were two-dimensional drawings of dominoes. 4. Seventeen dementia patients and eight normal elderly domino players were tested on two forms of the Domino Quiz: first with real dominoes, then with two-dimensional drawings; other neuropsychological tests were given at the same time. 5. Fourteen of the 17 patients and all of the controls showed no decline in answering questions about domino play when two-dimensional drawings were used. These patients showed retained symbolic processing of information about dominoes despite declines in overall mental status, generation of words from specific semantic categories, and recognition memory for domino terminology. 6. Because the 14 patients with retained domino skill performed as accurately as controls on both administrations of a letter cancellation task, the ability to process familiar symbols may be important to their game-playing skill.

Long-lived picture priming in normal elderly persons and demented patients

Normal elderly control participants showed short-term (10-min delay) and long-term (12 months delay) priming on the Gollin Figures Test. Nearly all patients with Alzheimer's disease or vascular dementia showed short-term priming, but the magnitude of their priming was less than that of controls. Significant long-term priming was not observed for the dementia groups. Differences between controls and dementia patients on the short-term priming test may depend upon structural-perceptual processes that are intact in dementia patients and controls and explicit memory functions available only to controls. The same model could account for differences between normal elderly and dementia patients on the long-term priming test, but several other explanations are also plausible.

Expression of game-related and generic knowledge by dementia patients who retain skill at playing dominoes

Patients with dementia who remain skilled at musical performance or playing bridge fail explicit memory tests for information related to their skills, suggesting that implicit memory mediates their preserved skills. To reexamine this issue, 23 dementia patients and 15 elderly controls of comparable domino-playing skill were compared on tests of naming, verbal fluency, and domino knowledge. On an explicit test of domino knowledge, the patients scored well below the elderly controls, performing no better than students who were unfamiliar with the game. But when game-like situations were created with real dominoes, both the skilled controls and the patients with dementia chose optimal moves and verbally explained their choices equally well. On naming and fluency tests, the skilled patients showed no advantage over patients of comparable dementia severity who had no retained skill. In dementia, some complex knowledge seems intact but is accessible only in particular contexts.

Changes in the management of benign prostatic hyperplasia

The dilemma facing urologists dealing with patients complaining of a poor urinary stream and nocturia is whom to treat and how to treat. For the last few decades, most men complaining of these symptoms underwent a prostatectomy, as it was presumed that their symptoms were caused by an enlarged prostate obstructing the bladder outlet. Since "prostatism" was thought to be a progressive disease, related to the inexorable progression of prostatic size, once a man presented to his urologist with symptoms, treatment often followed. The rate of prostatectomy in the United States increased from 30% of men with urinary symptoms in the haven of 1960 to nearly 60% in 1990 and 1991 according to Medicare data. More recently, it has been recognized that 25-30% of men with prostatic symptoms do not actually have outflow obstruction. Even those patients who do have very severe symptoms and what appears to be outflow obstruction, may not need surgery as their symptoms may wax and wane, or they may be satisfactorily relieved with conservative management. Thus, the risk of benefit ratio for prostatectomy for males with symptoms with no clear relationship to bladder outlet obstruction is a problem.

Stimulation of bicarbonate secretion by alpha- and beta-adrenoceptor agonists in rat caecum in vitro

This study examines the effects of adrenergic drugs on bicarbonate secretion by the rat caecum in vitro. Noradrenaline, phenylephrine but not clonidine, stimulated secretion in a concentration-related manner. Noradrenaline responses were antagonised by alprenolol (20 microM) but not phentolamine (10 microM) whilst phenylephrine was antagonised by phentolamine (10 microM), prazosin (5 microM) but not yohimbine (5 microM), alprenolol or tetrodotoxin (1 microM). Replacement of mucosal Cl- abolished the phenylephrine response. Combined stimulation with maximum concentrations of phenylephrine and isoprenaline gave a response which was not greater than that to either agonist alone but it did involve both alpha- and beta-adrenoceptors as judged from the effects of alprenolol and phentolamine either alone or combined. Submaximum concentrations of the two agonists did show additive responses. The results show that alpha 1- but not alpha 2-adrenoceptor agonists stimulate bicarbonate secretion and may act on the same transport mechanism as beta-adrenoceptor agonists. Noradrenaline stimulates via beta-adrenoceptors.

Analysis of Phenolics of Bud Exudate of Populus tristis by GC/MS

Analysis of bud exudate of Populus tristis by GC/MS revealed 61 phenolic components representing 55 phenolic compounds. Caffeic acid esters and chalcones made up the bulk of the exudate.

Analysis of Phenolics of Bud Exudates of Populus koreana, Populus maximowiczii and Populus suaveolens by GC-MS

Analysis of GC-MS data revealed 76 components of bud exudates from Populus koreana, P. maximowiczii and P. suaveolens (Section Tacamahaca), of which 49 were phenolics. The bulk of the exudates were composed of phenones, pinobanksin-3-acetate and aliphatic esters of caffeic acid. Bud exudates of P. koreana and P. m aximowiczii were virtually identical in composition and closely resembled those of P. suaveolens. The three poplars were alike in having as major com ponents of their bud exudate pentanophenones, which do not occur in the bud exudates of most other poplars. These three Asiatic poplars appear more closely related chemotaxonomically to Section Aigeiros poplars than to those of Section Tacamahaca.

Analysis of Phenolics of Bud Exudates of Populus cathayana and Populus szechuanica by GC-MS

Analysis of GC-MS data revealed 58 com ponents of bud exudate from P. cathayana (Section Tacamahaca) and 40 components of bud exudate from P. szechuanica (Section Tacamahaca) of which 47 and 35 respectively were phenolics. The bud exudates were very similar in composition, containing flavanones and chalcones (61% and 51% respectively), flavones (15% and 12%) and pentenyl caffeates (11% and 6%). The major single component of the exudate of both poplars was pinobanksin- 3-acetate (26% and 33%). The bud exudates of P. cathayana and P. szechuanica are similar to those of European and American Section Aigeiros poplars and unlike those of North American Section Tacamahaca poplars.

Relationships of Populus × acuminata and Populus × generosa with their parental species examined by gas chromatography – mass spectrometry of bud exudates

Analysis by gas chromatography – mass spectrometry of bud exudates of Populus deltoides and Populus trichocarpa showed that they each contained a number of different compounds. Exudates of P. trichocarpa contained dihydrochalcones and sesquiterpenols, which were absent from the exudate of P. deltoides, but lacked the flavones, flavanones, and flavanonols present in the exudate of P. deltoides. Exudates of their hybrid, P. × generosa (P. × interamericana), contained compounds typical of both parent plants. Bud exudates of Populus angustifolia and Populus sargentii were qualitatively similar in their flavonoid composition but the exudate of P. angustifolia contained in addition caffeate esters, which were absent from P. sargentii. The exudate from the hybrid P. × acuminata was intermediate. Bud exudates of P. angustifolia and P. × acuminata were more like those of P. deltoides and P. sargentii (section Aigeiros) than they were to those of P. trichocarpa (section Tacamahaca). It is therefore suggested that P. angustifolia and P. × acuminata might be more correctly classified together with P. sargentii and P. deltoides within the section Aigeiros. Key words: Populus, bud exudate, chemotaxonomy, gas chromatography – mass spectrometry.

Interrelationships of poplars in a hybrid swarm as studied by gas chromatography – mass spectrometry

Analysis of bud exudate by gas chromatography-mass spectrometry (GC–MS) of 14 clones belonging to a natural hybrid swarm involving Populus angustifolia, P. balsamifera, and P. deltoides produced results consistent with those obtained by previous analysis of leaf characteristics. Specimens that had leaves most characteristic of a pure species also produced bud exudate GC–MS profiles which were characteristic of those species. GC–MS profiles of interspecific hybrid clones were intermediate between the parental species. This demonstrates the usefulness of GC–MS analysis of bud exudate as a chemo-taxonomic method for the study of intersecific poplar hybrids and also supports the accuracy of analysis of foliar morphology for taxonomic assessment. Key words: Populus, bud exudate, gas chromatography – mass spectrometry.

Variation in Bud Exudate Composition of Populus nigra Assessed by Gas Chromatography-Mass Spectrometry

Bud Exudate, GC-MS Bud exudates from twelve clones of Populus nigra originating from seven countries were analyzed by gas chromatography-mass spectrometry and the principal compounds identified. Specimens of P. nigra var betulifolia differed in bud exudate com position from the other specimens analyzed, and were more similar in exudate com position to P. deltoides than were the other specimens. The range of bud exudate com position was greater than that which would be expected to occur within a single coherent species.