Photosensitizer-Amplified Antimicrobial Materials for Broad-Spectrum Ablation of Resistant Pathogens in Ocular Infections

The emergence of multidrug resistant (MDR) pathogens and the scarcity of new potent antibiotics and antifungals are one of the biggest threats to human health. Antimicrobial photodynamic therapy (aPDT) combines light and photosensitizers to kill drug-resistant pathogens; however, there are limited materials that can effectively ablate different classes of infective pathogens. In the present work, a new class of benzodiazole-paired materials is designed as highly potent PDT agents with broad-spectrum antimicrobial activity upon illumination with nontoxic light. The results mechanistically demonstrate that the energy transfer and electron transfer between nonphotosensitive and photosensitive benzodiazole moieties embedded within pathogen-binding peptide sequences result in increased singlet oxygen generation and enhanced phototoxicity. Chemical optimization renders PEP3 as a novel PDT agent with remarkable activity against MDR bacteria and fungi as well as pathogens at different stages of development (e.g., biofilms, spores, and fungal hyphae), which also prove effective in an ex vivo porcine model of microbial keratitis. The chemical modularity of this strategy and its general compatibility with peptide-based targeting agents will accelerate the design of highly photosensitive materials for antimicrobial PDT.

Validation of actigraphy sleep metrics in children aged 8 to 16 years: considerations for device type, placement and algorithms

BACKGROUND

Actigraphy is often used to measure sleep in pediatric populations, despite little confirmatory evidence of the accuracy of existing sleep/wake algorithms. The aim of this study was to determine the performance of 11 sleep algorithms in relation to overnight polysomnography in children and adolescents.

METHODS

One hundred thirty-seven participants aged 8-16 years wore two Actigraph wGT3X-BT (wrist, waist) and three Axivity AX3 (wrist, back, thigh) accelerometers over 24-h. Gold standard measures of sleep were obtained using polysomnography (PSG; Embletta MPRPG, ST + Proxy and TX Proxy) in the home environment, overnight. Epoch by epoch comparisons of the Sadeh (two algorithms), Cole-Kripke (three algorithms), Tudor-Locke (four algorithms), Count-Scaled (CS), and HDCZA algorithms were undertaken. Mean differences from PSG values were calculated for various sleep outcomes.

RESULTS

Overall, sensitivities were high (mean ± SD: 91.8%, ± 5.6%) and specificities moderate (63.8% ± 13.8%), with the HDCZA algorithm performing the best overall in terms of specificity (87.5% ± 1.3%) and accuracy (86.4% ± 0.9%). Sleep outcome measures were more accurately measured by devices worn at the wrist than the hip, thigh or lower back, with the exception of sleep efficiency where the reverse was true. The CS algorithm provided consistently accurate measures of sleep onset: the mean (95%CI) difference at the wrist with Axivity was 2 min (-6; -14,) and the offset was 10 min (5, -19). Several algorithms provided accurate measures of sleep quantity at the wrist, showing differences with PSG of just 1-18 min a night for sleep period time and 5-22 min for total sleep time. Accuracy was generally higher for sleep efficiency than for frequency of night wakings or wake after sleep onset. The CS algorithm was more accurate at assessing sleep period time, with narrower 95% limits of agreement compared to the HDCZA (CS:-165 to 172 min; HDCZA: -212 to 250 min).

CONCLUSION

Although the performance of existing count-based sleep algorithms varies markedly, wrist-worn devices provide more accurate measures of most sleep measures compared to other sites. Overall, the HDZCA algorithm showed the greatest accuracy, although the most appropriate algorithm depends on the sleep measure of focus.

Rapid Point-of-Care Identification of Aspergillus Species in Microbial Keratitis

Importance

Microbial keratitis (MK) is a common cause of unilateral visual impairment, blindness, and eye loss in low-income and middle-income countries. There is an urgent need to develop and implement rapid and simple point-of-care diagnostics for MK to increase the likelihood of good outcomes.

Objective

To evaluate the diagnostic performance of the Aspergillus-specific lateral-flow device (AspLFD) to identify Aspergillus species causing MK in corneal scrape and corneal swab samples of patients presenting with microbial keratitis.

Design, Setting, and Participants

This diagnostic study was conducted between May 2022 and January 2023 at the corneal clinic of Aravind Eye Hospital in Madurai, Tamil Nadu, India. All study participants were recruited during their first presentation to the clinic. Patients aged 15 years or older met the eligibility criteria if they were attending their first appointment, had a corneal ulcer that was suggestive of a bacterial or fungal infection, and were about to undergo diagnostic scrape and culture.

Main Outcomes and Measures

Sensitivity and specificity of the AspLFD with corneal samples collected from patients with MK. During routine diagnostic scraping, a minimally invasive corneal swab and an additional corneal scrape were collected and transferred to aliquots of sample buffer and analyzed by lateral-flow device (LFD) if the patient met the inclusion criteria. Photographs of devices were taken with a smartphone and analyzed using a ratiometric approach, which was developed for this study. The AspLFD results were compared with culture reports.

Results

The 198 participants who met the inclusion criteria had a mean (range) age of 51 (15-85) years and included 126 males (63.6%). Overall, 35 of 198 participants with corneal scrape (17.7%) and 17 of 40 participants with swab samples (42.5%) had positive culture results for Aspergillus species. Ratiometric analysis results for the scrape samples found that the AspLFD achieved high sensitivity (0.89; 95% CI, 0.74-0.95), high negative predictive value (0.97; 95% CI, 0.94-0.99), low negative likelihood ratio (0.12; 95% CI, 0.05-0.30), and an accuracy of 0.94 (95% CI, 0.90-0.97). Ratiometric analysis results for the swab samples showed that the AspLFD had high sensitivity (0.94; 95% CI, 0.73-1.00), high negative predictive value (0.95; 95% CI, 0.76-1.00), low negative likelihood ratio (0.07; 95% CI, 0.01-0.48), and an accuracy of 0.88 (95% CI, 0.73-0.96).

Conclusions and Relevance

Results of this diagnostic study suggest that AspLFD along with the ratiometric analysis of LFDs developed for this study has high diagnostic accuracy in identifying Aspergillus species from corneal scrapes and swabs. This technology is an important step toward the provision of point-of-care diagnostics for MK and could inform the clinical management strategy.

FluoroPi Device With SmartProbes: A Frugal Point-of-Care System for Fluorescent Detection of Bacteria From a Pre-Clinical Model of Microbial Keratitis

Purpose

Rapid and accurate diagnosis of microbial keratitis (MK) could greatly improve patient outcomes. Here, we present the development of a rapid, accessible multicolour fluorescence imaging device (FluoroPi) and evaluate its performance in combination with fluorescent optical reporters (SmartProbes) to distinguish bacterial Gram status. Furthermore, we show feasibility by imaging samples obtained by corneal scrape and minimally invasive corneal impression membrane (CIM) from ex vivo porcine corneal MK models.

Methods

FluoroPi was built using a Raspberry Pi single-board computer and camera, light-emitting-diodes (LEDs), and filters for white-light and fluorescent imaging, with excitation and detection of bacterial optical SmartProbes: Gram-negative, NBD-PMX (exmax 488 nm); Gram positive, Merocy-Van (exmax 590 nm). We evaluated FluoroPi with bacteria (Pseudomonas aeruginosa and Staphylococcus aureus) isolated from ex vivo porcine corneal models of MK by scrape (needle) and CIM with the SmartProbes.

Results

FluoroPi provides <1 µm resolution and was able to readily distinguish bacteria isolated from ex vivo models of MK from tissue debris when combined with SmartProbes, retrieved by both scrape and CIM. Single bacteria could be resolved within the field of view, with limits of detection demonstrated as 103 to 104 CFU/mL. Sample preparation prior to imaging was minimal (wash-free), and imaging and postprocessing with FluoroPi were straightforward, confirming ease of use.

Conclusions

FluoroPi coupled with SmartProbes provides effective, low-cost bacterial imaging, delineating Gram-negative and Gram-positive bacteria directly sampled from a preclinical model of MK.

Translational Relevance

This study provides a crucial stepping stone toward clinical translation of a rapid, minimally invasive diagnostic approach for MK.

Efficient quantitative assessment of robot swarms: coverage and targeting Lévy strategies

Biologically inspiredstrategieshave long been adapted to swarm robotic systems, including biased random walks, reaction to chemotactic cues and long-range coordination. In this paper we applyanalysis toolsdeveloped for modeling biological systems, such as continuum descriptions, to the efficient quantitative characterization of robot swarms. As an illustration, both Brownian and Lévy strategies with a characteristic long-range movement are discussed. As a result we obtain computationally fast methods for the optimization of robot movement laws to achieve a prescribed collective behavior. We show how to compute performance metrics like coverage and hitting times, and illustrate the accuracy and efficiency of our approach for area coverage and search problems. Comparisons between the continuum model and robotic simulations confirm the quantitative agreement and speed up by a factor of over 100 of our approach. Results confirm and quantify the advantage of Lévy strategies over Brownian motion for search and area coverage problems in swarm robotics.

Molecular detection of Gram-positive bacteria in the human lung through an optical fiber-based endoscope

Purpose

The relentless rise in antimicrobial resistance is a major societal challenge and requires, as part of its solution, a better understanding of bacterial colonization and infection. To facilitate this, we developed a highly efficient no-wash red optical molecular imaging agent that enables the rapid, selective, and specific visualization of Gram-positive bacteria through a bespoke optical fiber–based delivery/imaging endoscopic device.

Methods

We rationally designed a no-wash, red, Gram-positive-specific molecular imaging agent (Merocy-Van) based on vancomycin and an environmental merocyanine dye. We demonstrated the specificity and utility of the imaging agent in escalating in vitro and ex vivo whole human lung models (n = 3), utilizing a bespoke fiber–based delivery and imaging device, coupled to a wide-field, two-color endomicroscopy system.

Results

The imaging agent (Merocy-Van) was specific to Gram-positive bacteria and enabled no-wash imaging of S. aureus within the alveolar space of whole ex vivo human lungs within 60 s of delivery into the field-of-view, using the novel imaging/delivery endomicroscopy device.

Conclusion

This platform enables the rapid and specific detection of Gram-positive bacteria in the human lung.

Electronic supplementary material

The online version of this article (10.1007/s00259-020-05021-4) contains supplementary material, which is available to authorized users.

Polymyxin-based photosensitizer for the potent and selective killing of Gram-negative bacteria

The methylene blue-polymyxin conjugate demonstrated high selectivity, sensitivity and phototoxicity against Gram-negative bacteria, including in early biofilm models.

Significance of root hairs at the field scale - modelling root water and phosphorus uptake under different field conditions

ABSTRACT

BACKGROUND AND AIMS

Root hairs play a significant role in phosphorus (P) extraction at the pore scale. However, their importance at the field scale remains poorly understood.

METHODS

This study uses a continuum model to explore the impact of root hairs on the large-scale uptake of P, comparing root hair influence under different agricultural scenarios. High vs low and constant vs decaying P concentrations down the soil profile are considered, along with early vs late precipitation scenarios.

RESULTS

Simulation results suggest root hairs accounted for 50% of total P uptake by plants. Furthermore, a delayed initiation time of precipitation potentially limits the P uptake rate by over 50% depending on the growth period. Despite the large differences in the uptake rate, changes in the soil P concentration in the domain due to root solute uptake remains marginal when considering a single growth season. However, over the duration of 6 years, simulation results showed that noticeable differences arise over time.

CONCLUSION

Root hairs are critical to P capture, with uptake efficiency potentially enhanced by coordinating irrigation with P application during earlier growth stages of crops.

P30 A PRISMA systematic review and meta-analysis of open and novel ‘minimally invasive’ techniques for mesial temporal lobe epilepsy (MTLE)

Objectives

One third of patients with focal epilepsy fail to achieve seizure freedom despite best medical therapy. Surgery may provide seizure freedom if the epileptogenic zone can be safely remove. We compare the outcomes following open surgery, laser interstitial thermal therapy (LITT), radiofrequency ablation (RFA) and radiosurgery (RS).

Design

PRISMA systematic review and meta-analysis.

Subjects

MTLE

Methods

Structured searchs of PubMed, Embase and Cochrane databases. Random effects meta-analysis to calculate effects sizes and a pooled estimate of the probability of remaining seizure free at one year following intervention.

Results

From 1212 screened publications, 57 articles were included in the quantitative analysis. Open surgery included anterior temporal lobectomy as well as transcortical, subtemporal and transsylvian selective amygdalohippocampectomy. The probability of remaining seizure free at one year was 0.89 (95% CI 0.83–0.93) with open surgery based on Level 1 and 2 evidence. RS resulted in 0.88 (95% CI 0.84–0.90) probability and a single RCT revealed RS was less efficacious than open surgery. Follow up duration and study sizes were limited with LITT and RFA providing a probability of remaining seizure free at one year of 0.71 (95% CI 0.65–0.76) and 0.86 (95% CI 0.76–0.92) respectively.

Conclusions

There is no evidence supporting novel ‘minimally invasive’ approaches as being as efficacious as open surgery. Secondary outcome measures such as neuropsychological outcome and intervention morbidity are poorly reported.

TP3-4 Changes in whole brain connectomes with simulated laser interstitial thermal therapy (LITT) using seizure free and non-seizure free ablation cavities in mesial temporal sclerosis: a graph theory approach

Objectives

LITT is a novel means of focal lesioning. Improved seizure free outcome has been associated with the extent to which the mesial hippocampal head is ablated, but not overall ablation volume. We question whether specific changes in structural network connectivity exist in patients that achieve seizure freedom.

Design

Retrospective

Subjects

25 MTS patients after LITT with 2 year outcome.

Methods

Ablation cavities from 11 seizure free and 14 non-seizure free patients were combined to generate group masks. In 12 separate pre-operative patients with MTS (6 right), weighted normalized connectomes were generated with 1 × 10^7 streamlines. To simulate ablations the group cavity masks were excluded from the connectomes prior to normalization. Differences in connectomes were assessed by graph theory metrics.

Results

Greater node strength (str) in non-seizure free patients were present in the ipsilateral basal temporo-occipital cortices in both right and left MTS. Str and local efficiency were relatively maintained in the ipsilateral thalamus of seizure free cavities. Betweenness centrality in non-seizure free cavities were greater in ipsilateral temporal poles in right and left MTS.

Conclusions

Differences in network connectivity are present following simulated LITT for MTS between seizure free and non-seizure free ablation cavities. LiTT ablation cavities may be pre-operatively modelled to ensure the ablation cavity includes important structures and non-essential or inhibitory connectivity is spared. Prospective validation is required.

Concurrent femoral head reduction and periacetabular osteotomies for the treatment of severe femoral head deformities

AIMS

The aims of this study were to review the surgical technique for a combined femoral head reduction osteotomy (FHRO) and periacetabular osteotomy (PAO), and to report the short-term clinical and radiological results of a combined FHRO/PAO for the treatment of selected severe femoral head deformities.

PATIENTS AND METHODS

Between 2011 and 2016, six female patients were treated with a combined FHRO and PAO. The mean patient age was 13.6 years (12.6 to 15.7). Clinical data, including patient demographics and patient-reported outcome scores, were collected prospectively. Radiologicalally, hip morphology was assessed evaluating the Tönnis angle, the lateral centre to edge angle, the medial offset distance, the extrusion index, and the alpha angle.

RESULTS

The mean follow-up was 3.3 years (2 to 4.6). The modified Harris Hip Score improved by 33.0 points from 53.5 preoperatively to 83.4 postoperatively (p = 0.03). The Western Ontario McMasters University Osteoarthritic Index score improved by 30 points from 62 preoperatively to 90 postoperatively (p = 0.029). All radiological parameters showed significant improvement. There were no long-term disabilities and none of the hips required early conversion to total hip arthroplasty.

CONCLUSION

FHRO combined with a PAO resulted in clinical and radiological improvement at short-term follow-up, suggesting it may serve as an appropriate salvage treatment option for selected young patients with severe symptomatic hip deformities.

Ym1 induces RELMα and rescues IL-4Rα deficiency in lung repair during nematode infection

Ym1 and RELMα are established effector molecules closely synonymous with Th2-type inflammation and associated pathology. Here, we show that whilst largely dependent on IL-4Rα signaling during a type 2 response, Ym1 and RELMα also have IL-4Rα-independent expression patterns in the lung. Notably, we found that Ym1 has opposing effects on type 2 immunity during nematode infection depending on whether it is expressed at the time of innate or adaptive responses. During the lung migratory stage of Nippostrongylus brasiliensis, Ym1 promoted the subsequent reparative type 2 response but once that response was established, IL-4Rα-dependent Ym1 was important for limiting the magnitude of type 2 cytokine production from both CD4+ T cells and innate lymphoid cells in the lung. Importantly, our study demonstrates that delivery of Ym1 to IL-4Rα deficient animals drives RELMα production and overcomes lung repair deficits in mice deficient in type 2 immunity. Together, Ym1 and RELMα, exhibit time and dose-dependent interactions that determines the outcome of lung repair during nematode infection.

Measurement of micro-scale soil deformation around roots using four-dimensional synchrotron tomography and image correlation

This study applied time lapse (four-dimensional) synchrotron X-ray computed tomography to observe micro-scale interactions between plant roots and soil. Functionally contrasting maize root tips were repeatedly imaged during ingress into soil columns of varying water content and compaction. This yielded sequences of three-dimensional densiometric data, representing time-resolved geometric soil and root configurations at the micronmetre scale. These data were used as inputs for two full-field kinematic quantification methods, which enabled the analysis of three-dimensional soil deformation around elongating roots. Discrete object tracking was used to track rigid mineral grains, while continuum digital volume correlation was used to track grey-level patterns within local sub-volumes. These techniques both allowed full-field soil displacements to be quantified at an intra-rhizosphere spatial sampling scale of less than 300 µm. Significant differences in deformation mechanisms were identified around different phenotypes under different soil conditions. A uniquely strong contrast was observed between intact and de-capped roots grown in dry, compacted soil. This provides evidence that functional traits of the root cap significantly reduce the amount of soil disturbance per unit of root elongation, with this effect being particularly significant in drier soil.

High prevalence of anti-hepatitis A IgG in a cohort of UK HIV-negative men who have sex with men: implications for local hepatitis A vaccine policy

BASHH guidelines recommend that ‘the hepatitis A virus total antibody test can be offered to at-risk patients whose immune status is unknown … depending on local funding arrangements’. We sought to measure the local prevalence of anti-hepatitis A (HAV) IgG in HIV-negative men who have sex with men (MSM), to inform the utility of pre-vaccination screening. We assessed the prevalence of anti-HAV IgG in HIV-negative MSM who attended sexual health services in County Durham and Darlington, UK, from March to August 2017. Data were extracted from electronic patient records and analysed in Excel. Our study was granted local Caldicott approval. Seventy four per cent of 244 HIV-negative MSM who attended for review were screened. Anti-HAV IgG was detected in 42% who did not report definite previous infection or vaccination; not detected in 57.4%; and was equivocal in 0.6%. Vaccine was administered to 48% of eligible patients. The estimated financial costs of universal vaccination of MSM (£4235.40) and pre-vaccination screening with vaccination of susceptible patients (£4188.13) are similar. Pre-vaccination screening and vaccination of susceptible patients does not save resources compared to a policy of universal vaccination of MSM in our setting. Universal vaccination of MSM attending genitourinary medicine clinics may improve vaccine uptake.

A systematic review of immunosuppressant adherence interventions in transplant recipients: Decoding the streetlight effect

Non-adherence to immunosuppressant medications is an important risk factor for graft dysfunction. To evaluate the effectiveness of adherence-enhancing interventions, we reviewed adherence intervention studies in solid organ transplant recipients (all ages). Using the following databases: PsycINFO, PubMed, Scopus, and ScienceDirect, we identified 41 eligible studies. Only three non-randomized trials showed a possible positive effect on objective indicators of transplant outcomes (such as rejection, liver enzyme levels, kidney function). None of the 21 RCTs showed an improvement in transplant outcomes. Three studies showed a higher rate of adverse events in the intervention group as compared with controls, although this may be related to ascertainment bias. Improvement in adherence as measured indirectly (eg, with electronic monitoring devices) was not aligned with effects on transplant outcomes. We conclude that adherence interventions, to date, have largely been ineffective in improving transplant outcomes. To improve this track record, intervention efforts may wish to concentrate on non-adherent patients (rather than use convenience sampling, which excludes many of the patients who need the intervention), use direct measures of adherence to guide the interventions, and employ strategies that are intensive and yet engaging enough to ensure that non-adherent patients are able to participate.

IL-33 delivery induces serous cavity macrophage proliferation independent of interleukin-4 receptor alpha

IL‐33 plays an important role in the initiation of type‐2 immune responses, as well as the enhancement of type 2 effector functions. Engagement of the IL‐33 receptor on macrophages facilitates polarization to an alternative activation state by amplifying IL‐4 and IL‐13 signaling to IL‐4Rα. IL‐4 and IL‐13 also induce macrophage proliferation but IL‐33 involvement in this process has not been rigorously evaluated. As expected, in vivo delivery of IL‐33 induced IL‐4Rα‐dependent alternative macrophage activation in the serous cavities. IL‐33 delivery also induced macrophages to proliferate but, unexpectedly, this was independent of IL‐4Rα signaling. In a filarial nematode infection model in which IL‐4Rα‐dependent alternative activation and proliferation in the pleural cavity is well described, IL‐33R was essential for alternative activation but not macrophage proliferation. Similarly, during Alternaria alternata induced airway inflammation, which provokes strong IL‐33 responses, we observed that both IL‐4Rα and IL‐33R were required for alternative activation, while macrophage proliferation in the pleural cavity was still evident in the absence of either receptor alone. Our data show that IL‐33R and IL‐4Rα promote macrophage proliferation independently of each other, but both are essential for induction of alternative activation.

Epilepsy and Pregnancy: For healthy pregnancies and happy outcomes. Suggestions for service improvements from the Multispecialty UK Epilepsy Mortality Group

Between 2009 and 2012 there were 26 epilepsy-related deaths in the UK of women who were pregnant or in the first post-partum year. The number of pregnancy-related deaths in women with epilepsy (WWE) has been increasing. Expert assessment suggests that most epilepsy-related deaths in pregnancy were preventable and attributable to poor seizure control. While prevention of seizures during pregnancy is important, a balance must be struck between seizure control and the teratogenic potential of antiepileptic drugs (AEDs). A range of professional guidance on the management of epilepsy in pregnancy has previously been issued, but little attention has been paid to how optimal care can be delivered to WWE by a range of healthcare professionals. We summarise the findings of a multidisciplinary meeting with representation from a wide group of professional bodies. This focussed on the implementation of optimal pregnancy epilepsy care aiming to reduce mortality of epilepsy in mothers and reduce morbidity in babies exposed to AEDs in utero. We identify in particular -What stage to intervene - Golden Moments of opportunities for improving outcomes -Which Key Groups have a role in making change -When - 2020 vision of what these improvements aim to achieve. -How to monitor the success in this field We believe that the service improvement ideas developed for the UK may provide a template for similar initiatives in other countries.

Precision Medicine at the University of Alabama at Birmingham: Laying the Foundational Processes Through Implementation of Genotype-Guided Antiplatelet Therapy

Precision medicine entails tailoring treatment based on patients' unique characteristics. As drug therapy constitutes the cornerstone of treatment for most chronic diseases, pharmacogenomics (PGx), the study of genetic variation influencing individual response to drugs, is an important component of precision medicine. Over the past decade investigations have identified genes and single-nucleotide polymorphisms (SNPs) and quantified their effect on drug response. Parallel development of point-of-care (POC) genotyping platforms has enabled the interrogation of the genes/SNPs within a timeline conducive to the provision of care. Despite these advances, the pace of integration of genotype-guided drug therapy (GGTx) into practice has faced significant challenges. These include difficulty in identifying SNPs with sufficiently robust evidence to guide clinical decision making, lack of clinician training on how to order and use genotype data, lack of clinical decision support (CDS) to guide treatment, and limited reimbursement. The University of Alabama at Birmingham's (UAB) efforts in precision medicine were initiated to address these challenges and improve the health of the racially diverse patients we treat.

Macrophage origin limits functional plasticity in helminth-bacterial co-infection

Rapid reprogramming of the macrophage activation phenotype is considered important in the defense against consecutive infection with diverse infectious agents. However, in the setting of persistent, chronic infection the functional importance of macrophage-intrinsic adaptation to changing environments vs. recruitment of new macrophages remains unclear. Here we show that resident peritoneal macrophages expanded by infection with the nematode Heligmosomoides polygyrus bakeri altered their activation phenotype in response to infection with Salmonella enterica ser. Typhimurium in vitro and in vivo. The nematode-expanded resident F4/80high macrophages efficiently upregulated bacterial induced effector molecules (e.g. MHC-II, NOS2) similarly to newly recruited monocyte-derived macrophages. Nonetheless, recruitment of blood monocyte-derived macrophages to Salmonella infection occurred with equal magnitude in co-infected animals and caused displacement of the nematode-expanded, tissue resident-derived macrophages from the peritoneal cavity. Global gene expression analysis revealed that although nematode-expanded resident F4/80high macrophages made an anti-bacterial response, this was muted as compared to newly recruited F4/80low macrophages. However, the F4/80high macrophages adopted unique functional characteristics that included enhanced neutrophil-stimulating chemokine production. Thus, our data provide important evidence that plastic adaptation of MΦ activation does occur in vivo, but that cellular plasticity is outweighed by functional capabilities specific to the tissue origin of the cell.

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.

ID: 87: TRANSCRIPTION FACTOR CREB3L3 IS A NOVEL REGULATOR FOR ADIPOCYTE BIOLOGY AND METABOLISM

The presence of differential metabolic risks between the metabolically-protective subcutaneous adipose tissue (SAT) and the disease-associated visceral adipose tissue (VAT) is well established, but the mechanisms that cause these differences are not well understood. Cyclic AMP responsive element binding protein 3-like 3 (CREB3L3), a previously characterized liver-specific ER-bound transcription factor, was found to be expressed in murine SAT and VAT. In obese human subjects and an obese mouse model, we found that CREB3L3 is downregulated in SAT, but not in VAT. To examine the role of CREB3L3 in adipocyte biology and metabolism, we created a fat-specific CREB3L3 knockout (KO) mouse using the AdipoQ-Cre mouse. To establish a potential role for CREB3L3 in adipocytes, we examined in vitro differentiated adipocytes from isolated WT and KO primary stromal vascular fraction. We observed that ablation of CREB3L3 in SAT adipocytes significantly upregulated expression of both lipogenic and lipolytic markers. At the same time, we also observed significantly increased expression of thermogenic markers like PGC1α and Cox8b. Taken together our data suggest potential upregulation of the fat futile cycle in SAT upon deletion of CREB3L3. Surprisingly, we found that CREB3L3 KO tends to downregulate expression of markers of both lipogenesis and lipolysis in VAT adipocytes. This observation could potentially be contributed by the tendency of CREB3l3 KO VAT to have inhibited differentiation. To investigate the in vivo function of CREB3L3, we challenged WT and KO mice with high fat diet with weekly body weight assessment. We observed that CREB3L3 ablation in adipose tissues promotes significant weight gain in mice on HFD. Unexpectedly, despite being heavier, the KO mice are not more glucose intolerant or insulin resistant. These data together suggest that ablation of CREB3L3 could potentially promote fat storage in adipose tissues to prevent metabolic diseases caused by ectopic fat deposition.

The impact of the 2011 UK post-exposure prophylaxis for HIV following sexual exposure guidelines: a regional retrospective audit

A re-audit of prescribing of post-exposure prophylaxis for HIV following sexual exposure in the Thames Valley demonstrated that an updated proforma has led to significant improvements in clinician-led outcomes, but had no impact on completion or follow-up rates.

IL-4 directly signals tissue-resident macrophages to proliferate beyond homeostatic levels controlled by CSF-1

Macrophages (MΦs) colonize tissues during inflammation in two distinct ways: recruitment of monocyte precursors and proliferation of resident cells. We recently revealed a major role for IL-4 in the proliferative expansion of resident MΦs during a Th2-biased tissue nematode infection. We now show that proliferation of MΦs during intestinal as well as tissue nematode infection is restricted to sites of IL-4 production and requires MΦ-intrinsic IL-4R signaling. However, both IL-4Rα-dependent and -independent mechanisms contributed to MΦ proliferation during nematode infections. IL-4R-independent proliferation was controlled by a rise in local CSF-1 levels, but IL-4Rα expression conferred a competitive advantage with higher and more sustained proliferation and increased accumulation of IL-4Rα(+) compared with IL-4Rα(-) cells. Mechanistically, this occurred by conversion of IL-4Rα(+) MΦs from a CSF-1-dependent to -independent program of proliferation. Thus, IL-4 increases the relative density of tissue MΦs by overcoming the constraints mediated by the availability of CSF-1. Finally, although both elevated CSF1R and IL-4Rα signaling triggered proliferation above homeostatic levels, only CSF-1 led to the recruitment of monocytes and neutrophils. Thus, the IL-4 pathway of proliferation may have developed as an alternative to CSF-1 to increase resident MΦ numbers without coincident monocyte recruitment.

Hypophosphataemia with non-tenofovir-containing antiretroviral therapy

Hypophosphataemia with tenofovir (TDF) treatment has been well described. The role of HIV infection and of other antiretroviral (ART) agents in hypophosphataemia has received less attention. The aim of this study was to determine the prevalence of hypophosphataemia in HIV-positive adults. We measured the fasting plasma phosphate level and estimated glomerular filtration rate (eGFR) in 123 HIV-positive patients. A total of 26% had hypophosphataemia and 11% had hypophosphataemia of grades 2-4 (0.65 mmol/L or less). Hypophosphataemia of any grade was more frequent in those who were ART-treated than ART-naive (35% versus 10%; P = 0.0001). Multiple linear regression analysis showed no significant association between phosphate level and gender, TDF status, duration of ART, duration of HIV infection and eGFR. Increasing age was significantly associated with a very small rise in phosphate level. Isolated hypophosphataemia was significantly more frequent in HIV-positive subjects receiving ART than ART-naive individuals, irrespective of the drug regimen.

Effect of abomasal ferrous lactate infusion on phosphorus absorption in lactating dairy cows

The objective of this study was to evaluate the effect of ferrous lactate infusion on postruminal P absorption in lactating dairy cows. Four ruminally cannulated lactating cows were used in a 4×4 Latin square design with 14 d per period. Cows were fed a basal diet containing 0.39% P, providing 100% of the calculated P requirement. On d 8 to 14 of each period, each cow was infused with 0, 200, 500, or 1,250mg of Fe/d in the form of ferrous lactate solution (ferrous lactate in 1L of double-distilled water) into the abomasum. Infusate was formulated to approximate 0, 2, 5, or 12.5mg of Fe/L in drinking water with 100L of water intake/d. Total fecal collection was conducted in the last 4 d of each period to measure nutrient digestion and excretion. Dry matter intake, milk yield, and milk composition were not affected by treatment. Digestibility of DM, NDF, and nitrogen decreased linearly with increasing ferrous lactate infusion. Infusion of ferrous lactate did not affect intake and digestibility of total P, inorganic P, or phytate P. In lactating cows, P absorption was not negatively influenced by abomasally infused ferrous lactate up to 1,250mg of Fe/d.

Managing HIV in pregnancy in a community-based sexual health clinic: a decade in review

The management of HIV in pregnancy has evolved significantly over the past 10 years as our experience of combination antiretroviral therapy (ART) has grown. We reviewed 109 pregnancies which were managed at our community-based integrated HIV and sexual health clinic to investigate preconception and antenatal care, and trends in ART over time. We document an increasing proportion of pregnancies in which the mother was aware of her HIV status pre-conception and conception on ART. Pre-conception care was sought in a minority of cases, and many women did not present for first antenatal review until the end of the second trimester. Of 108 live births, there was one case of vertical transmission (0.93%). While our study demonstrates the efficacy of current strategies to prevent mother to child transmission of HIV infection, more could be done to encourage HIV-positive women to seek preconception advice and to attend for early review in the first trimester.

Epilepsy health consumer groups and charities; how representative of patients are they? The results of a pilot study

PURPOSE

In the United Kingdom all health care providers are encouraged to consult with user groups. The submissions of charities and patient advocacy groups to NICE and SIGN are considered reflective of the patient groups they purport to represent, yet little is known about how representative they are. This pilot study was designed to ascertain how many patients attending a hospital based epilepsy clinic were members of such advocacy groups.

METHODS

Patients were asked to complete a brief 9-question questionnaire before they left the clinic.

RESULTS

One hundred and twenty-five questionnaires were distributed, of which 101 were returned. Seventeen percent of patients were members of advocacy groups, with several being members of more than one charity/group. Only seven percent of the respondents had ever been contacted by an advocacy group to canvass their opinions. Seventy percent of patients questioned stated they thought a frank discussion with their physician, or specialist nurse was more likely to influence patient services. Patients with long duration of disease and taking multiple anti-epileptic drugs were more likely to be members of charity/advocacy groups.

CONCLUSIONS

As patient charities in the U.K. are often in receipt of public funds, and actively seek to influence public policy this raises the question of whether they should be required to consult more widely with the people they claim to represent.

The Peroxisomal 3-keto-acyl-CoA thiolase B Gene Expression Is under the Dual Control of PPARα and HNF4α in the Liver

PPARα and HNF4α are nuclear receptors that control gene transcription by direct binding to specific nucleotide sequences. Using transgenic mice deficient for either PPARα or HNF4α, we show that the expression of the peroxisomal 3-keto-acyl-CoA thiolase B (Thb) is under the dependence of these two transcription factors. Transactivation and gel shift experiments identified a novel PPAR response element within intron 3 of the Thb gene, by which PPARα but not HNF4α transactivates. Intriguingly, we found that HNF4α enhanced PPARα/RXRα transactivation from TB PPRE3 in a DNA-binding independent manner. Coimmunoprecipitation assays supported the hypothesis that HNF4α was physically interacting with RXRα. RT-PCR performed with RNA from liver-specific HNF4α-null mice confirmed the involvement of HNF4α in the PPARα-regulated induction of Thb by Wy14,643. Overall, we conclude that HNF4α enhances the PPARα-mediated activation of Thb gene expression in part through interaction with the obligate PPARα partner, RXRα.