Urinary Biomarkers for Lupus Nephritis: A Systems Biology Approach

Systemic lupus erythematosus (SLE) is the prototypical systemic autoimmune disorder. Kidney involvement, termed lupus nephritis (LN), is seen in 40-60% of patients with systemic lupus erythematosus (SLE). After the diagnosis, serial measurement of proteinuria is the most common method of monitoring treatment response and progression. However, present treatments for LN-corticosteroids and immunosuppressants-target inflammation, not proteinuria. Furthermore, subclinical renal inflammation can persist despite improving proteinuria. Serial kidney biopsies-the gold standard for disease monitoring-are also not feasible due to their inherent risk of complications. Biomarkers that reflect the underlying renal inflammatory process and better predict LN progression and treatment response are urgently needed. Urinary biomarkers are particularly relevant as they can be measured non-invasively and may better reflect the compartmentalized renal response in LN, unlike serum studies that are non-specific to the kidney. The past decade has overseen a boom in applying cutting-edge technologies to dissect the pathogenesis of diseases at the molecular and cellular levels. Using these technologies in LN is beginning to reveal novel disease biomarkers and therapeutic targets for LN, potentially improving patient outcomes if successfully translated to clinical practice.

OLDER ADULTS' SUBJECTIVE WELL-BEING EXPERIENCING THE EXERGAME "I AM DOLPHIN"

The objective of this study was to understand older adults' perceptions of the connections between an exergame intervention, "I Am Dolphin," and their subjective well-being. Researchers conducted three focus groups with 14 older adults who participated in the exergame feasibility study. The semi-structured focus groups were transcribed, coded, and analysed using deductive and inductive techniques. Three themes were constructed related to playing the exergame and participants' subjective well-being: 1) elevated mood (through scheduled activity, immersion, and socialization), 2) feelings of achievement (especially following frustration and competition), and 3) perceived cognitive or physical changes. These findings will help researchers better understand how exergames may relate to the well-being of older adults. Future investigators could use these findings to create and implement new exergame interventions.

Clinical Impact of CDK4/6 Inhibitors in De Novo or PR- or Very Elderly Post-Menopausal ER+/HER2- Advanced Breast Cancers

The CDK4/6 inhibitors significantly increase progression-free survival (PFS) in ER+/HER2- advanced breast cancer patients. In clinical trials, overall survival (OS) improvement has been demonstrated for ribociclib and abemaciclib but not for palbociclib. We undertook a real-world evaluation of PFS and OS in 227 post-menopausal patients who received first-line CDK4/6 inhibitors. There is no significant difference in median PFS (27.5 months vs. 25.7 months, p = 0.3) or median OS (49.5 months vs. 50.2 months, p = 0.67) in patients who received either palbociclib or ribociclib, respectively. De novo disease is significantly associated with prolonged median PFS and median OS compared with recurrence disease (47.1 months vs. 20.3 months (p = 0.0002) and 77.4 months vs. 37.3 months (p = 0.0003), respectively). PR- tumours have significantly reduced median PFS and OS compared with PR+ disease (19.2 months vs. 38 months (p = 0.003) and 34.3 months vs. 62.6 months (p = 0.02), respectively). In the very elderly (>80 years), median PFS and OS are significantly shorter compared with patients who are 65 years or below (14.5 months vs. 30.2 months (p = 0.01), and 77.4 months vs. 29.6 months (p = 0.009), respectively) in the palbociclib group. Our data suggest that the benefit in the very elderly is limited, and PR+/de novo disease obtains the maximum survival benefit.

Bispecific Antibodies in Hematological Malignancies: A Scoping Review

Bispecific T-cell engagers (BiTEs) and bispecific antibodies (BiAbs) have revolutionized the treatment landscape of hematological malignancies. By directing T cells towards specific tumor antigens, BiTEs and BiAbs facilitate the T-cell-mediated lysis of neoplastic cells. The success of blinatumomab, a CD19xCD3 BiTE, in acute lymphoblastic leukemia spearheaded the expansive development of BiTEs/BiAbs in the context of hematological neoplasms. Nearly a decade later, numerous BiTEs/BiAbs targeting a range of tumor-associated antigens have transpired in the treatment of multiple myeloma, non-Hodgkin's lymphoma, acute myelogenous leukemia, and acute lymphoblastic leukemia. However, despite their generally favorable safety profiles, particular toxicities such as infections, cytokine release syndrome, myelosuppression, and neurotoxicity after BiAb/BiTE therapy raise valid concerns. Moreover, target antigen loss and the immunosuppressive microenvironment of hematological neoplasms facilitate resistance towards BiTEs/BiAbs. This review aims to highlight the most recent evidence from clinical trials evaluating the safety and efficacy of BiAbs/BiTEs. Additionally, the review will provide mechanistic insights into the limitations of BiAbs whilst outlining practical applications and strategies to overcome these limitations.

The Long and Winding Road: 25 Years of the National Advanced Driving Simulator

The National Advanced Driving Simulator is a high-fidelity motion-base simulator owned by the National Highway Transportation Safety Administration and managed and operated by the University of Iowa. Its 25-year history has intersected with some of the most significant developments in automotive history, such as advanced driver assistance systems like stability control and collision warning systems, and highly automated vehicles. The simulator is an application of immersive virtual reality that uses multiprojection instead of head-mounted displays. A large-excursion motion system provides realistic acceleration and rotation cues to the driver. Due to its level of immersion and realism, drivers respond to events in the simulator the same way they would in their own vehicle. We document the history and technology behind this national facility.

Older Adults and Three-Dimensional Exergaming: Motivators and Barriers to Participation and Retention

Background: Cognitive and physical activity are important for daily functioning. However, limited research exists on the motivators and barriers associated with older adults participating and adhering to exergame studies that promote physical and cognitive activity. Our objective was to examine older adults' motivators and barriers to joining and completing a three-dimensional exergame study. Methods: Fourteen older adults who participated in the exergame study contributed to one of three focus group discussions. Inductive and deductive methods were used to analyze the qualitative data. Results: Motivators for joining were generativity, peer referrals, self-improvement, and curiosity. Accomplishment, immersion, and exercise were motivators for retention. Participants also cited the structured schedule and adaptive difficulty features as motivators for retention. Barriers to participation included frustration due to lack of level advancement and fatigue/pain during gameplay. Some (n = 3) reported camera tracking issues as a barrier. Unanticipated gender-based trends arose when examining perceptions of the study team's role and motivators for retention. Conclusion: These findings will inform future research strategies for participant recruitment, enrollment, and retention, in addition to providing insights into the design of motivating, enjoyable, and sustainable exergames for older adults.

INCLUDING FEEDBACK FROM OLDER ADULTS WITH VARYING HEALTH CONDITIONS TO INFORM EXERGAME DESIGNS

Exergames are emerging technologies that combine “exercise” and “video games” to promote enjoyable cognitive and physical activities. Exergame studies often exclude individuals at greatest risk for adverse health outcomes (e.g., oldest-old, living with chronic conditions, comorbidities, or functional limitations). Thus, it is important to 1) understand motivators and barriers for joining and adhering to exergame studies and 2) capture perspectives from individuals commonly excluded from these studies. We conducted three focus groups among 14 older adults (mean age=79±9 years) with varying health conditions who participated in a novel three-dimensional exergame feasibility study. Data were analyzed using the “Sort and Sift, Think and Shift” approach. Motivators for joining were generativity, peer referrals, self-improvement, and curiosity. Motivators for retention were accomplishment, enjoyability, and exercise. Barriers to participation included frustration and pain/fatigue. We also discuss how participants’ feedback influenced future exergame design. Findings will aid in promoting scalable, enjoyable, and accessible exergame interventions for all.

SARS-CoV-2 epitopes inform future vaccination strategies

All currently approved COVID-19 vaccines utilize the spike protein as their immunogen. SARS-CoV-2 variants of concern (VOCs) contain mutations in the spike protein, enabling them to escape infection- and vaccination-induced immune responses to cause reinfection. New vaccines are hence being researched intensively. Studying SARS-CoV-2 epitopes is essential for vaccine design, as identifying targets of broadly neutralizing antibody responses and immunodominant T-cell epitopes reveal candidates for inclusion in next-generation COVID-19 vaccines. We summarize the major studies which have reported on SARS-CoV-2 antibody and T-cell epitopes thus far. These results suggest that a future of pan-coronavirus vaccines, which not only protect against SARS-CoV-2 but numerous other coronaviruses, may be possible. The T-cell epitopes of SARS-CoV-2 have gotten less attention than neutralizing antibody epitopes but may provide new strategies to control SARS-CoV-2 infection. T-cells target many SARS-CoV-2 antigens other than spike, recognizing numerous epitopes within these antigens, thereby limiting the chance of immune escape by VOCs that mainly possess spike protein mutations. Therefore, augmenting vaccination-induced T-cell responses against SARS-CoV-2 may provide adequate protection despite broad antibody escape by VOCs.

Unmasking of Brugada syndrome by lamotrigine in a patient with pre-existing epilepsy: A case report with review of the literature

Brugada syndrome is an inherited cardiac channelopathy arising from mutations in voltage-gated cardiac sodium channels. Idiopathic epilepsy portrays a coalescent underlying pathophysiological mechanism pertaining to the premature excitation of neuronal voltage-gated ion channels resulting in the disruption of presynaptic neurons and the unregulated release of excitatory neurotransmitters. The coexistence of epilepsy and Brugada syndrome may be explained by mutations in voltage-gated ion channels, which are coexpressed in cardiac and neural tissue. Moreover, the incidence of sudden unexpected death in epilepsy has been associated with malignant cardiac arrhythmias in the presence of mutations in voltage-gated ion channels. Lamotrigine is an antiepileptic drug that inhibits neuronal voltage-gated sodium channels, thus stabilizing neural impulse propagation and controlling seizure activity in the brain. However, lamotrigine has been shown to inhibit cardiac voltage-gated sodium channels resulting in a potential arrhythmogenic effect and the ability to unmask Brugada syndrome in genetically susceptible individuals. We are reporting a case of a 27-year-old male patient with a background of presumed idiopathic epilepsy who was initiated on lamotrigine therapy resulting in the unmasking of Brugada syndrome and the onset of syncopal episodes. This case provides further evidence for the arrhythmogenic capacity of lamotrigine and highlights the relationship between epilepsy and Brugada syndrome. In this report, we aim to review the current literature regarding the associations between epilepsy and Brugada syndrome and the impact of lamotrigine therapy on such patients.

Abstract LB565: Efficacy of a highly potent and selective KIT V654A inhibitor for treatment of imatinib resistant GIST

Gastrointestinal stromal tumor (GIST) is the most common type of sarcoma, with approximately 5,000 patients diagnosed per year in the US. Approximately 80% of patients with GIST present with mutations in the c-KIT oncogene at exon 9 or 11, which leads to constitutive, ligand-independent activation of the KIT receptor tyrosine kinase. For patients with metastatic GIST, frontline therapy with imatinib is effective, with a response rate of approximately 51-54% and median progression-free survival (PFS) of 19-23 months, in a molecularly unselected population. Other agents are approved for advanced GIST, without molecular selection, after progression on imatinib, including sunitinib, regorafenib, and ripretinib; however, response rates are less than 10% with PFS of approximately 5-6 months. Notably, patients who progress on imatinib and other tyrosine kinase inhibitors may develop a variety of on-target resistance mutations in the KIT oncogene, such as those in exon 17 (including at amino acids D816 and D820, activation loop mutation), exon 13 (V654A, ATP-binding region mutation), and less frequently in exon 14 (T670I, gatekeeper mutation). Several KIT inhibitors have been developed to potently target the exon 17 resistance mutations (avapritinib and ripretinib); however, there remains an important medical need in 2nd- and 3rd-line therapy in a molecularly unselected population of imatinib-resistant GIST. This suggests more broad-spectrum KIT inhibition is likely required, a hypothesis supported by the observation of large inter- and intra-patient heterogeneity of KIT secondary mutations across hundreds of samples obtained from patients with GIST treated with avapritinib. Sequencing data from the NAVIGATOR phase 1 trial (NCT02508532) revealed that patients with KIT mutant GIST and with the KIT V654A secondary resistance mutation had a poor response to treatment with avapritinib. To address this, we developed a highly potent and selective inhibitor of KIT V654A. This inhibitor showed dose-dependent modulation of downstream pharmacodynamic markers and induced tumor regression in a mastocytoma xenograft model driven by an exon 11 plus 13 V654A resistance mutation. Importantly, this inhibitor was generally well-tolerated and showed high selectivity over wild-type KIT. These findings suggest this novel KIT inhibitor has the potential to be used as a single agent or combination therapy for patients with imatinib-resistant GIST harboring the KIT V654A mutation.

Citation Format: Alexandra R. Grassian, Joseph Kim, Omar Ahmad, Kevin Barvian, Alison Davis, Tom Dineen, Wei Hu, Ebby Job, Ludivine Moine, Kate Newberry, Maria Roche, Doug Shorten, Yeon Sook Choi, Francis Wolenski, Sebastian Bauer, Cesar Serrano, Jonathan Trent, Suzanne George. Efficacy of a highly potent and selective KIT V654A inhibitor for treatment of imatinib resistant GIST [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 LB565.

Answer ALS, a large-scale resource for sporadic and familial ALS combining clinical and multi-omics data from induced pluripotent cell lines

Answer ALS is a biological and clinical resource of patient-derived, induced pluripotent stem (iPS) cell lines, multi-omic data derived from iPS neurons and longitudinal clinical and smartphone data from over 1,000 patients with ALS. This resource provides population-level biological and clinical data that may be employed to identify clinical-molecular-biochemical subtypes of amyotrophic lateral sclerosis (ALS). A unique smartphone-based system was employed to collect deep clinical data, including fine motor activity, speech, breathing and linguistics/cognition. The iPS spinal neurons were blood derived from each patient and these cells underwent multi-omic analytics including whole-genome sequencing, RNA transcriptomics, ATAC-sequencing and proteomics. The intent of these data is for the generation of integrated clinical and biological signatures using bioinformatics, statistics and computational biology to establish patterns that may lead to a better understanding of the underlying mechanisms of disease, including subgroup identification. A web portal for open-source sharing of all data was developed for widespread community-based data analytics.

Abstract 1262: BLU-701 is a highly potent, brain-penetrant and WT-sparing next-generation EGFR TKI for the treatment of sensitizing (ex19del, L858R) and C797S resistance mutations in metastatic NSCLC

BACKGROUND: Non-small cell lung cancer (NSCLC) represents 80% of lung cancers, the second leading cause of cancer deaths globally. Mutations in the kinase domain of the epidermal growth factor receptor (EGFR) are genomic drivers in a molecular sub-type of NSCLC that is sensitive to tyrosine kinase inhibitors (TKIs). Third-generation, irreversible TKIs, such as osimertinib and lazertinib, have become standard of care and are now widely used as first-line therapy in EGFR-driven metastatic NSCLC. However, resistance invariably arises during treatment. The C797S mutation is the most frequent on-target resistance mechanism in response to third-generation TKIs when used in the first-line setting. There are currently no approved therapies for patients who progress with a C797S mutation. Although first-generation TKIs inhibit EGFR with a C797S mutation, they carry liabilities of 1) insufficient selectivity over wild-type (WT) EGFR, which precludes maximal target coverage and results in dose-limiting adverse events; and 2) limited brain penetration.

METHODS: BLU-701 activity was tested in biochemical assays for EGFR mutants and EGFR WT. Cellular activity was evaluated by a phosphorylation specific EGFR AlphaLisa assay in WT cell lines or those expressing EGFR mutations. The in vivo antitumor activity of BLU-701 was assessed in a PC9 ex19del cell line-derived tumor xenograft (CDX) model.

RESULTS: We have developed an orally available, single-digit nanomolar, brain-penetrant, WT-sparing, reversible EGFR inhibitor that is active against the C797S resistance mutation. BLU-701 is equally potent against both the sensitizing mutations ex19del and L858R, and the resistance double mutants ex19del/C797S and L858R/C797S. BLU-701 is brain penetrant (Kpu,u >0.9) and demonstrates a selectivity over WT EGFR that compares favorably with osimertinib. Oral administration of BLU-701 to PC9 ex19del tumor-bearing mice resulted in strong and prolonged pathway suppression and tumor regression at tolerated doses.

CONCLUSION: Due to its potent pharmacological activity and selectivity for mutant EGFR, BLU-701 has the potential to demonstrate activity in first-line and resistance settings as a single agent and in combination therapy, addressing potential tumor heterogeneity. The pre-clinical data described here supports the clinical development of BLU-701 in EGFR-driven NSCLC.

Citation Format: Chiara Conti, John Campbell, Rich Woessner, Jian Guo, Yoav Timsit, Maria Iliou, Scott Wardwell, Alison Davis, Sharon Chicklas, John Hsieh, Meredith Eno, Omar Ahmad, Dilinie Fernando, Kevin Barvian, Joseph Kim, Steven Kazmirski, Emanuele Perola, Tom Dineen, Victoria Brown, Timothy Guzi, Ayşegül Özen, Faith Stevison, Caitlin Utt, Clare Medendorp, Robert Meissner, Marion Dorsch, Klaus Hoeflich. BLU-701 is a highly potent, brain-penetrant and WT-sparing next-generation EGFR TKI for the treatment of sensitizing (ex19del, L858R) and C797S resistance mutations in metastatic NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1262.

Comparing a Novel Neuroanimation Experience to Conventional Therapy for High-Dose Intensive Upper-Limb Training in Subacute Stroke: The SMARTS2 Randomized Trial

BACKGROUND

Evidence from animal studies suggests that greater reductions in poststroke motor impairment can be attained with significantly higher doses and intensities of therapy focused on movement quality. These studies also indicate a dose-timing interaction, with more pronounced effects if high-intensity therapy is delivered in the acute/subacute, rather than chronic, poststroke period.

OBJECTIVE

To compare 2 approaches of delivering high-intensity, high-dose upper-limb therapy in patients with subacute stroke: a novel exploratory neuroanimation therapy (NAT) and modified conventional occupational therapy (COT).

METHODS

A total of 24 patients were randomized to NAT or COT and underwent 30 sessions of 60 minutes time-on-task in addition to standard care. The primary outcome was the Fugl-Meyer Upper Extremity motor score (FM-UE). Secondary outcomes included Action Research Arm Test (ARAT), grip strength, Stroke Impact Scale hand domain, and upper-limb kinematics. Outcomes were assessed at baseline, and days 3, 90, and 180 posttraining. Both groups were compared to a matched historical cohort (HC), which received only 30 minutes of upper-limb therapy per day.

RESULTS

There were no significant between-group differences in FM-UE change or any of the secondary outcomes at any timepoint. Both high-dose groups showed greater recovery on the ARAT (7.3 ± 2.9 points; P = .011) but not the FM-UE (1.4 ± 2.6 points; P = .564) when compared with the HC.

CONCLUSIONS

Neuroanimation may offer a new, enjoyable, efficient, and scalable way to deliver high-dose and intensive upper-limb therapy.

Integrative molecular characterization of pediatric spinal ependymoma: the UK Children's Cancer and Leukaemia Group study

Background

Pediatric spinal ependymomas (SP-EPNs) are rare primary central nervous system tumors with heterogeneous clinical course. Considering that ependymomas in children are biologically distinct from their adult counterparts, this study aimed to define the molecular landscape of SP-EPNs in children.

Methods

In this retrospective study, we have collected tumor samples from 27 SP-EPN patients younger than 18 years and carried out the histological review, DNA methylation, and gene expression profiling.

Results

Unsupervised analyses with methylation profiles revealed 2 subgroups where all grade I tumors (n = 11) were in Group 1, but the grade II/III tumors split into 2 groups (n = 7 in Group 1 and n = 9 in Group 2). The Heidelberg classifier assigned Group 1 tumors as spinal myxopapillary ependymomas (SP-MPEs), 5 Group 2 tumors as SP-EPNs, and failed to classify 4 Group 2 tumors. Copy numbers derived from DNA methylation arrays revealed subgroup-specific genetic alterations and showed that SP-EPN tumors lack MYCN amplification. Gene expression profiling revealed distinct transcriptomic signatures, including overexpression of genes involved in oxidative phosphorylation in SP-MPEs that were validated by Western blot analysis. We discovered widespread decreases in DNA methylation at enhancer regions that are associated with the expression of oncogenic signaling pathways in SP-MPEs. Furthermore, transcription factor motifs for master regulators, including HNF1B, PAX3, and ZIC3, were significantly overrepresented in probes specific to distal regulatory regions in SP-MPEs.

Conclusion

Our findings show substantial heterogeneity in pediatric SP-EPN and uncover novel enhancers and transcriptional pathways specific to the SP-MPE subgroup, providing a foundation for future therapeutic strategies.

Laboratory markers predictive of fulminant Clostridioides difficile infection refractory to fluid resuscitation

Background

Old age, leucocytosis, hypoalbuminemia, and elevated creatinine have been identified as risk factors for fulminant Clostridioides difficile infection (CDI). High ATLAS scores have also been linked to fatal disease. The affiliated studies, however, involved patients prescribed metronidazole - a regimen no longer standard of care. The variables were thus reassessed in patients prescribed optimal therapy.

Methods

Adults hospitalized with CDI at University of Kentucky Medical Center were retrospectively reviewed. Enrolled subjects were separated according to disease classification i.e. non-severe/severe versus fulminant CDI. Fulminant patients were further subdivided into hypotensive persons responsive to fluid resuscitation, and those with sequent shock, ileus, or megacolon. Following partition, the cohorts underwent correlation analysis.

Findings

Forty-five subjects had non-severe/severe disease. Thirteen fulminant CDI patients responded to fluid resuscitation. Seventeen fulminant CDI patients developed shock, ileus, or megacolon. Median WBC counts, albumin values, and ATLAS scores varied among the cohorts. Although WBC counts were similar among the fulminant subsets, declining albumin values and increasing ATLAS scores mirrored disease worsening. Logistic regression revealed albumin values < 20 g/L (odds ratio [OR] 3.91) and ATLAS scores ≥ 6 (OR 5.03) to predict critical illness in hypotensive persons.

Conclusion

Median WBC counts, albumin values, and ATLAS scores differed in patients separated by CDI severity. A notable variance in albumin values and ATLAS scores between fluid responsive fulminant disease and critical illness was moreover seen. The finding suggests hypoalbuminemia and high ATLAS scores in hypotensive CDI patients may herald shock, ileus, or megacolon.

Echocardiographic features and behavior of cardiac structural abnormalities in mucopolysaccharidosis

Funding Acknowledgements

Type of funding sources: None.

Mucopolysaccharidosis (MPS) is a rare genetic lysosomal storage disorder with a wide variability of phenotype. A systematic descriptive study dealing with the echocardiographic (E) features of valvular involvement and their evolution over the time in adolescent and adult patients, whose number is growing up in adult echocardiographic laboratory, is lacking in the medical literature.

Purpose

To detect the E features of valvular involvement and their evolution in adolescent and adult patients.

Method

Study design: observational descriptive retrospective. Study group: 142 E studies in 17 adolescent and adult patients with diagnosis of MPS from 2001 until 2020. Mitral (M), aortic (A), tricuspid (T) valves (V) E features (thickness, mobility, calcification, and function), their evolution over the time and the behaviour with Enzyme replacement therapy (ERT) or bone marrow transplant (BMT) were assessed.

Result

52% male, mean age 21 yrs ranges 16 to 48 yrs. 5% of the patient had MPS type I, 11% MPS type II, 29% MPS type IV, and 52% MPS type VI. 70% received ERT and 11% BMT.

In the severe case all the valves were involved (panel A, B, C; white arrows point to valve leaflets; yellow arrows MV apparatus) the whole MV apparatus was involved since the earlier stage and in the latest stage the calcification was massive (panel C). The predominant valvular dysfunction was the regurgitation followed by mixed disorder while the most frequent severe lesion was the stenosis; the echocardiographic pattern differs from the classical hockey stick appearance of the early phase of rheumatic MV and the thickening is different from the myxomatous MV for the reduced mobility and the presence of calcification. The reduced mobility of the TV (panel C) also differs from the Loeffler syndrome because of the restriction of the leaflets and the association with thickening and calcification. Under treatment, the MV thickening was found to have a slow progression of less than 1 mm yearly in 61% cases.

Conclusion

Our results showed that all the valves are affected mainly the MV; the echocardiographic pattern of MPS, different from other valvular diseases of adolescent and adult age, can help in avoiding misdiagnose. Our observations also suggest that the cardiac involvement show slow rate of progression after the initiation of the therapy. Further studies are required to confirm our results.

Type of valve % of valve thickness % of reduced mobility % calcification diffuse % valve lesion Mitral valve 88% 65% 47% 75% Aortic valve 76% 23% 41% 57% Tricuspid valve 82% 47% 17% 52% Abstract Figure. Echocardiographic features

Regioselective Cross-Electrophile Coupling of Epoxides and (Hetero)aryl Iodides via Ni/Ti/Photoredox Catalysis

A cross-electrophile coupling reaction of epoxides and (hetero)aryl iodides that operates via the merger of three catalytic cycles involving a Ni-, Ti-, and organic photoredox catalyst has been developed. Three distinct classes of epoxides, styrene oxides, cyclic epoxides, and terminal aliphatic epoxides, all undergo coupling in moderate to good yield and high regioselectivity with the use of three different nitrogen-based ligands for Ni under otherwise identical reaction conditions. The mild reaction conditions accommodate a broad scope of abundant and complex coupling partners. Mechanistic studies suggest that when styrene oxides are employed radical intermediates are involved via Ti-radical ring-opening of the epoxide. Conversely, for terminal aliphatic epoxides, involvement of an iodohydrin intermediate enables the formation of the unexpected linear product.

Comparing the Outcomes of Ceftaroline Plus Vancomycin or Daptomycin Combination Therapy Versus Monotherapy in Adults with Complicated and Prolonged Methicillin-Resistant Staphylococcus Aureus Bacteremia Initially Treated with Supplemental Ceftaroline

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia confers considerable morbidity and mortality. Although vancomycin or daptomycin monotherapy is usually curative, prolonged bacteremia necessitating supplemental ceftaroline has occurred. The practice has led to the question of whether to continue with ceftaroline following bacteremia resolution.

METHODS

Adult patients hospitalized with MRSA bacteremia at the University of Kentucky Medical Center between January 2015 and December 2017 were retrospectively reviewed. Study subjects required supplemental ceftaroline due to 4 or more days of bacteremia despite vancomycin or daptomycin. They additionally had accompanying native valve infective endocarditis, osteomyelitis, or brain abscess. Patients were divided into two cohorts. One group continued with ceftaroline plus vancomycin or daptomycin following bacteremia resolution (combination therapy group). The other group received vancomycin or daptomycin alone (monotherapy group). All involved received 6-8 weeks of therapy. Patients' Pitt bacteremia score (PBS) and Charlson comorbidity index (CCI) values were calculated. Treatment outcomes of inpatient mortality, recurrence of bacteremia, 30-day readmission, acute kidney injury, and leukopenia were recorded and compared.

RESULTS

A total of 30 patients comprised the study population. 15 patients were assigned to each cohort. The median PBS value of the combination therapy group was 2, compared with 1 among the monotherapy group. The median CCI score of both groups was 0. No statistically significant difference in the aforementioned treatment outcomes was seen between the two groups.

CONCLUSION

In subjects with complicated and prolonged MRSA bacteremia requiring supplemental ceftaroline, clinical outcomes did not differ among patients prescribed vancomycin or daptomycin alone following bacteremia resolution versus patients who continued combination therapy.

TMOD-11. CHARACTERISATION OF THE POST-SURGICAL INVASIVE TUMOUR NICHE USING ASTROCYTE-GLIOBLASTOMA ORGANOIDS AND DECELLULARISED HUMAN BRAIN

Glioblastoma therapeutic challenges are in considerable part due to myriad survival mechanisms which allow malignant cells to repurpose signalling pathways within discreet microenvironments. These Darwinian adaptations facilitate invasion into brain parenchyma and perivascular space. We hypothesised that pre-clinical modelling of glioma invasion by recapitulating early events occurring immediately after surgery at the glioblastoma invasive margin, could reveal the cross-talk between malignant cells and surrounding healthy astrocytes. We first generated transgenic H1-derived neural stem cells using CRISPR/Cas9-mediated knock-in of the YFP reporter gene under the control of the GFAP promoter at the AAVS1 safe harbour locus. Reproducible ultrahigh-throughput AggreWells™ (7200 mini-wells per plate) were used to create astrocyte-glioblastoma organoids, which we term ‘Gliomasphere Matrices’. YFP-labelled astrocytes were co-cultured with 10 treatment-naïve patient-derived cell lines isolated from the 5-aminolevulinic (5ALA)-determined glioblastoma invasive margin. Co-cultures were seeded upon a sequentially constructed, time-of-flight secondary ion mass spectrometry (ToF-SIMS)-characterised decellularised human brain extract. YFP-astrocytes were purified from each of the 10 Gliomasphere Matrices using fluorescence-activated cell sorting (FACS) after 6- and 10-days co-culture. RNA-sequencing of the putatively reprogrammed YFP-astrocytes showed the characteristic expression of canonical key regulators of multiple malignant diseases including high-grade glioma such as SND1 and EFNB2 in addition to the identification of a single novel marker located at chromosome 1 (C1orf61), highly expressed in malignant glioma when compared to somatic cancers according to TCGA RNA-sequencing data. Differentiated YFP-astrocytes also overexpressed IFITM2 and IFITM10, known to be involved in priming resistance against pathogenic microorganisms. This ultimately suggests a fluctuating state between malignant transformation imposed by the highly infiltrative glioma cells and the counter-action of the normal astrocytes to these deleterious invasive cells. This multi-faceted model offers a unique opportunity to recapitulate early molecular cross-talk which facilitates glioblastoma recurrence and may be utilised for high-throughput drug screening.

DNA methylation and transcriptomic alterations define distinct groups in pediatric spinal ependymoma

In contrast, compared to adults, spinal ependymomas (SEPN) are less common in childhood and adolescents. Children with these tumours are likely to experience a more aggressive disease course, with a higher rate of local failure, and a higher rate of metastasis. Presently the molecular basis of SEPN is poorly characterized. Therefore, we have analyzed 29 SEPN tumour samples from pediatric patients (female: 11, male: 15; age range: 4 – 21 years) and performed DNA methylation (n=28) and transcriptome profiling (n=29). Unsupervised analysis of methylation data reliably separated these tumours into two distinct groups: one group covering all myxopapillary ependymomas (MPE) and a second group dominated by grade II SPENs (SP-EPN). We identified 242 differentially methylated regions between these two groups, of which 56% showed high methylation levels in MPE, including 22 regions localized on chromosome 6. Genome-wide copy number analysis using methylation data showed differences in numbers and pattern of DNA copy number alterations between these groups. Gain of chromosome 20 (39%) followed by loss of chromosomes 6 (28%), 10 (28%), and 13 (28%) were detected in the MPE group, whereas loss of chromosome 22 was frequent (60%) in the SP-EPN group. Transcriptomic analysis showed that genes associated with oxidative phosphorylation, TCA cycle components, electron transport, and Interferon-gamma production characterize the MPE group whereas potassium ion import and regulation of astrocyte differentiation characterize the SP-EPN group. Taken together, this data suggest that mitochondrial oxidative phosphorylation may drive the regulation of energy metabolism of MPE tumours.

Analyzing progression of motor and speech impairment in ALS

Amyotrophic lateral sclerosis (ALS) is a degenerative disease which causes death of neurons controlling voluntary muscles. It is currently assessed with subjective clinical measurements, but it would benefit from alternative surrogate biomarkers that can better estimate disease progression. This work analyzes speech and fine motor coordination of subjects recruited by the Answer ALS foundation using data from a mobile app. In addition, clinical variables such as speech, writing and total ALSFRS-R scores are also acquired along with forced and slow vital capacity. Cross-sectional and longitudinal analyses were performed using speech and fine motor features. Results show that both types of features are useful to infer clinical variables especially for males (R²=0.79 for ALSFRS-R total score), but their initial values are not helpful to predict speech and motor decline. However, we found that longitudinal progression for bulbar and spinal ALS onset are different and they can be identified with high accuracy by the extracted features.

Artificial intelligence for the real-time classification of intrapapillary capillary loop patterns in the endoscopic diagnosis of early oesophageal squamous cell carcinoma: A proof-of-concept study

Background

Intrapapillary capillary loops (IPCLs) represent an endoscopically visible feature of early squamous cell neoplasia (ESCN) which correlate with invasion depth - an important factor in the success of curative endoscopic therapy. IPCLs visualised on magnification endoscopy with Narrow Band Imaging (ME-NBI) can be used to train convolutional neural networks (CNNs) to detect the presence and classify staging of ESCN lesions.

Methods

A total of 7046 sequential high-definition ME-NBI images from 17 patients (10 ESCN, 7 normal) were used to train a CNN. IPCL patterns were classified by three expert endoscopists according to the Japanese Endoscopic Society classification. Normal IPCLs were defined as type A, abnormal as B1-3. Matched histology was obtained for all imaged areas.

Results

This CNN differentiates abnormal from normal IPCL patterns with 93.7% accuracy (86.2% to 98.3%) and sensitivity and specificity for classifying abnormal IPCL patterns of 89.3% (78.1% to 100%) and 98% (92% to 99.7%), respectively. Our CNN operates in real time with diagnostic prediction times between 26.17 ms and 37.48 ms.

Conclusion

Our novel and proof-of-concept application of computer-aided endoscopic diagnosis shows that a CNN can accurately classify IPCL patterns as normal or abnormal. This system could be used as an in vivo, real-time clinical decision support tool for endoscopists assessing and directing local therapy of ESCN.

Impact of donor lung pathogenic bacteria on patient outcomes in the immediate post-transplant period

BACKGROUND

Patient outcomes post-lung transplant remain inferior to other types of solid organ transplantation. We investigated whether the presence of potentially pathogenic bacteria (PPB) in donor lung bronchial cultures was associated with adverse outcomes postoperatively.

METHODS

All patients who underwent lung transplantation between August 2015 and April 2017 at the University of Kentucky Medical Center were retrospectively reviewed. Retransplants, patients with bronchiectasis (including cystic fibrosis), and individuals who received organs from donation after cardiac death (DCD) donors were excluded. The remaining subjects were separated into two groups: individuals whose donor bronchial cultures grew PPB, and those whose cultures either returned negative for PPB or were sterile. 30-day mortality rates as well as the incidence of grade 3 primary graft dysfunction (PGD) and acute kidney injury (AKI) at both 24 and 72 hours post-transplant were calculated. The duration of mechanical ventilation postoperatively was also recorded.

RESULTS

Thirty two subjects comprised the study population. 20 patients (63%) had growth of PPB on donor cultures, while 12 (37%) did not. Patients with PPB had a significantly greater number of days on the ventilator postoperatively compared to those with no PPB (mean = 11.3 and median = 5.0 vs mean = 5.8 and median = 3.0, respectively, P = 0.0232). Subsequent regression analysis revealed this association to not be influenced by recipient lung allocation score (LAS), donor age, donor smoking history, recipient mean pulmonary artery pressure (mPAP) value, and/or use of cardiopulmonary bypass at the time of transplantation. Neither 30-day survival nor incidence of Grade 3 PGD and AKI at 24 or 72 hours post-transplant differed between the two groups (P > 0.05).

CONCLUSION

The recovery of PPB in donor lung cultures was associated with a longer duration of mechanical ventilation postoperatively in lung transplant recipients.

Feasibility of Ultrasound-Based Computational Fluid Dynamics as a Mitral Valve Regurgitation Quantification Technique: Comparison with 2-D and 3-D Proximal Isovelocity Surface Area-Based Methods

Current Doppler echocardiography quantification of mitral regurgitation (MR) severity has shortcomings. Proximal isovelocity surface area (PISA)-based methods, for example, are unable to account for the fact that ultrasound Doppler can measure only one velocity component: toward or away from the transducer. In the present study, we used ultrasound-based computational fluid dynamics (Ub-CFD) to quantify mitral regurgitation and study its advantages and disadvantages compared with 2-D and 3-D PISA methods. For Ub-CFD, patient-specific mitral valve geometry and velocity data were obtained from clinical ultrasound followed by 3-D CFD simulations at an assumed flow rate. We then obtained the average ratio of the ultrasound Doppler velocities to CFD velocities in the flow convergence region, and scaled CFD flow rate with this ratio as the final measured flow rate. We evaluated Ub-CFD, 2-D PISA and 3-D PISA with an in vitro flow loop, which featured regurgitation flow through (i) a simplified flat plate with round orifice and (ii) a 3-D printed realistic mitral valve and regurgitation orifice. The Ub-CFD and 3-D PISA methods had higher precision than the 2-D PISA method. Ub-CFD had consistent accuracy under all conditions tested, whereas 2-D PISA had the lowest overall accuracy. In vitro investigations indicated that the accuracy of 2-D and 3-D PISA depended significantly on the choice of aliasing velocity. Evaluation of these techniques was also performed for two clinical cases, and the dependency of PISA on aliasing velocity was similarly observed. Ub-CFD was robustly accurate and precise and has promise for future translation to clinical practice.

Biology and treatment of metastasis of sarcoma to the brain

Sarcomas are rare tumors with devastating clinical consequences, often affecting children as well as adults. Brain metastasis in sarcoma is frequently preceded by lung metastasis. Common offenders include Ewing sarcoma, osteosarcoma and leiomyosarcoma. Although our understanding of sarcoma metastasis remains limited, several cellular factors and signaling pathways appear to play regulatory roles and/or exhibit prognostic values in sarcoma metastasis. In addition, MicroRNAs have been shown to have either positive or negative impact on sarcoma biology and metastasis. Sarcoma is considered one of the classic radio- and chemo-resistant brain metastasis, hence the use of multiple modalities in order to improve the therapeutic ratio and overcome the inherent resistance. Treatment modalities include surgical resection, chemotherapy, gamma knife radiosurgery and/or fractionated whole-brain radiotherapy. The efficacy of chemotherapy is limited by the ability of the drug(s) to cross the blood-brain barrier (BBB), and the chemosensitivity of the tumor to the chemotherapeutic agent. In this review, we discuss the pathology, biology and therapy for sarcoma brain metastasis.

Creating pedestrian crash scenarios in a driving simulator environment

OBJECTIVE

In 2012 in the United States, pedestrian injuries accounted for 3.3% of all traffic injuries but, disproportionately, pedestrian fatalities accounted for roughly 14% of traffic-related deaths (NHTSA 2014 ). In many other countries, pedestrians make up more than 50% of those injured and killed in crashes. This research project examined driver response to crash-imminent situations involving pedestrians in a high-fidelity, full-motion driving simulator. This article presents a scenario development method and discusses experimental design and control issues in conducting pedestrian crash research in a simulation environment. Driving simulators offer a safe environment in which to test driver response and offer the advantage of having virtual pedestrian models that move realistically, unlike test track studies, which by nature must use pedestrian dummies on some moving track.

METHODS

An analysis of pedestrian crash trajectories, speeds, roadside features, and pedestrian behavior was used to create 18 unique crash scenarios representative of the most frequent and most costly crash types. For the study reported here, we only considered scenarios where the car is traveling straight because these represent the majority of fatalities. We manipulated driver expectation of a pedestrian both by presenting intersection and mid-block crossing as well as by using features in the scene to direct the driver's visual attention toward or away from the crossing pedestrian. Three visual environments for the scenarios were used to provide a variety of roadside environments and speed: a 20-30 mph residential area, a 55 mph rural undivided highway, and a 40 mph urban area.

RESULTS

Many variables of crash situations were considered in selecting and developing the scenarios, including vehicle and pedestrian movements; roadway and roadside features; environmental conditions; and characteristics of the pedestrian, driver, and vehicle. The driving simulator scenarios were subjected to iterative testing to adjust time to arrival triggers for the pedestrian actions. This article discusses the rationale behind creating the simulator scenarios and some of the procedural considerations for conducting this type of research.

CONCLUSIONS

Crash analyses can be used to construct test scenarios for driver behavior evaluations using driving simulators. By considering trajectories, roadway, and environmental conditions of real-world crashes, representative virtual scenarios can serve as safe test beds for advanced driver assistance systems. The results of such research can be used to inform pedestrian crash avoidance/mitigation systems by identifying driver error, driver response time, and driver response choice (i.e., steering vs. braking).

Assessment of point-of-care measurement of international normalised ratio using the CoaguChek XS Plus system in the setting of acute ischaemic stroke

BACKGROUND AND AIMS

Thrombolysis with alteplase (recombinant tissue plasminogen activator) is accepted hyperacute therapy for acute ischaemic stroke. Clotting must be normal before this can be administered safely. Laboratory testing of international normalised ratio (INR) takes 30-60 min, which can significantly delay administration of recombinant tissue plasminogen activator. Previous studies have suggested that point-of-care testing is useful in patients presenting with stroke and improves door-to-needle time. We performed a prospective study of point-of-care testing in patients presenting with acute ischaemic stroke.

METHODS

Fifty patients were entered into the study to compare point-of-care testing using the CoaguChek XS system with laboratory testing of INR.

RESULTS

Point-of-care testing correlated well with laboratory levels (R = 0.93, P < 0.0001). The standard deviation of difference between the two was 0.115. Overall, point-of-care testing tended to underestimate INR slightly, meaning that an INR value of 1.1 or less was required to be 95% certain that the laboratory value was 1.3 or below. Simultaneous testing using blood from a syringe was more consistent with laboratory results than testing capillary blood through finger prick.

CONCLUSION

Point-of-care INR testing correlates well with laboratory values. The results in this study mostly relate to values in the normal range. We suggest that it can be used to try to shorten door-to-needle time.

A survey of benthic assemblages of foraminifera in tropical coastal waters of pulau pinang, malaysia

The distribution of benthic Foraminifera throughout the coastal waters of Taman Negara Pulau Pinang (Penang National Park), Malaysia was studied to assess the impact of various anthropogenic activities, such as fishing, ecotourism and floating cage culture. Samples were obtained at 200 m intervals within the subtidal zone, extending up to 1200 m offshore at Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh. The depth within coastal waters ranged between 1.5 m and 10.0 m, with predominantly muddy substrate at most stations. Water quality analysis showed little variation in micronutrient (nitrite, NO2; nitrate, NO3; ammonia, NH4 and orthophosphate, PO4) concentrations between sampling stations. Temperature (29.6±0.48°C), salinity (29.4±0.28 ppt), dissolved oxygen content (5.4±0.95 mg/l) and pH (8.5± 0.13) also showed little fluctuation between stations. A total of nine genera of foraminifera were identified in the study (i.e., Ammonia, Elphidium, Ammobaculites, Bigenerina, Quinqueloculina, Reopax, Globigerina, Textularia and Nonion). The distribution of benthic foraminifera was dominated by opportunistic groups that have a high tolerance to anthropogenic stressors. Ammonia had the highest frequency of occurrence (84.7%), followed by Bigenerina (50%), Ammobaculites (44.2%) and Elphidium (38.9%). The Ammonia-Elphidium Index (AEI) was used to describe the hypoxic condition of benthic communities at all sites. Teluk Bahang had the highest AEI value. The foraminiferal assemblages and distribution in Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh showed no correlation with physical or chemical environmental parameters.

Sudden suffocation with cancer of unknown primary: a case report and review of diagnostic approach

A case of a 31-year-old woman with sudden respiratory distress is presented. Preliminary evaluations and imaging studies did not reveal the underlying cause. Workup during hospital stay showed advanced metastatic cancer of unknown primary origin. This is an unusual presentation of cancer of an unknown primary involving the thyroid with sudden suffocation. It suggests that malignancies involving the thyroid gland should be considered in patients with abrupt onset of respiratory distress. Also, this case shows the application of fine needle aspiration in diffuse thyroid enlargements mimicking thyroiditis without nodules. Diagnostic approach to cancer of unknown primary origin (CUP) is reviewed in further detail.

An in vivo comparison of hip structure analysis (HSA) with measurements obtained by QCT

SUMMARY

In a population of elderly women, bone cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z), femoral neck axis length (FNAL), and width measured with hip structure analysis (HSA) on dual-energy x-ray absorptiometry (DXA) images in the femoral neck and trochanteric regions are highly correlated to quantitative computed tomography (QCT) measurements.

INTRODUCTION

HSA is a method of obtaining measurements of proximal femur structure using 2D DXA technology. This study was designed to examine the correlations between HSA measurements and 3D QCT.

METHODS

Forty-one women (mean age, 82.8 ± 2.5 years) were measured using DXA and a 64-slice CT scanner (1 mm slice thickness, 0.29 mm in plane resolution). HSA parameters were calculated at the narrow neck (NN) and trochanteric (IT) regions on the DXA image. These regions were then translated to anatomically equivalent regions on the QCT dataset by co-registering the DXA image and QCT dataset using four DXA images acquired at different angles.

RESULTS

At the NN and IT regions, high linear correlations were measured between HSA and QCT for CSA r = 0.95 and 0.93, CSMI r = 0.94 and 0.93, and Z r = 0.93 and 0.89, respectively. All correlations were highly significant (p < 0.001), but there were differences in slope and offset between the two techniques, at least in part due to differences in calibration between the two techniques. FNAL and width of the bone at the NN and IT regions, physical measurements independent of the calibration, were highly correlated (r = 0.90-0.95, p < 0.001) and had slopes close to 1.0 (range, 0.978 to 1.003).

CONCLUSION

CSA, CSMI, Z, FNAL, and width measured by HSA correlate highly to high-resolution QCT.

Volumetric DXA (VXA): A new method to extract 3D information from multiple in vivo DXA images

Three-dimensional geometric and structural measurements of the proximal femur are of considerable interest in understanding the strength of the femur and its susceptibility to fracture. Quantitative computed tomography (QCT) with a small voxel size (≤1 mm per side) is the current "gold standard" to examine the macrostructure of the femur, but it has a high effective radiation dose (approximately 2 to 5 mSv) and cost. Volumetric dual-energy X-ray absorptiometry (VXA) uses a commercially available DXA system (Hologic Discovery A) to reconstruct the proximal femur from four DXA scans delivering an effective radiation dose of 0.04 mSv. VXA was compared with QCT (voxel size of 0.29 × 0.29 × 1 mm) in 41 elderly women (age 82 ± 2.4 years) at slices located at the femoral neck and trochanteric regions of interest. For parameters of shape, the femoral neck axis length (FNAL) and the cross-sectional slice area (SA), accuracy and strong linear correlations (r = 0.84 to 0.98) were demonstrated. Similar correlations (r = 0.81 to 0.97) were observed for the density parameters, the cross-sectional bone area (CSA) and volumetric bone mineral density (vBMD). VXA also demonstrated strong correlations (r = 0.76 to 0.99) for the engineering parameters of the minimum, maximum, and polar cross-sectional moments of inertia (CSMIs) and the section modulus (Z). We conclude that VXA is capable of generating a variety of 3D geometric and structural measurements that are highly correlated with QCT in elderly subjects in vivo. Moreover, the VXA measurements can be made with a commercially available DXA device at a very low radiation dose.

Rhabdoid meningioma presenting with subependymal and diffuse meningeal involvement but no mass lesion

Rhabdoid meningiomas are rare, aggressive tumours of the meninges that have a generally poor prognosis. We report a 49-year-old man with a background history of sarcoidosis who presented with nausea and vomiting. Imaging showed generalised leptomeningeal and subependymal enhancement suggestive of chronic meningitis. He had multiple lumbar punctures and a brain biopsy, none of which led to a pathological diagnosis. He died within months, and a postmortem examination was performed. At this stage, a diagnosis of rhabdoid meningioma was made. The clinical and radiological presentation of rhabdoid meningioma as a diffuse leptomeningeal process without a mass lesion is unique. All other published cases of rhabdoid meningioma have been of a discrete lesion. This highlights the importance of a tissue diagnosis in patients where the imaging is non-specific. A brief review of rhabdoid meningioma follows.

Atrial fibrillation and anticoagulation in a stroke unit population

BACKGROUND

Atrial fibrillation (AF) is an important predisposing factor for ischaemic stroke. There is evidence to suggest that even in appropriate candidates warfarin therapy is underutilized. We assessed the prevalence of AF in an Australian stroke unit to determine the degree of undertreatment at presentation.

METHODS

A retrospective analysis of all patients admitted to our Stroke Unit between October 2004 and September 2006 was carried out. All patients with a diagnosis of AF, either new or old, were then selected from this group to determine the overall prevalence and anticoagulation status. Data regarding prior stroke, stroke severity and discharge anticoagulation status were also determined.

RESULTS

Data from a total of 500 patients were analysed. Our results showed that AF-related strokes accounted for a large proportion (28%) of all admissions and were associated with a larger neurological deficit. Most patients (68%) with a prior diagnosis of AF without having obvious contraindications were either not anticoagulated or under-anticoagulated when presenting with an ischaemic stroke or transient ischaemic attack.

CONCLUSION

Our results stress the importance of initiating and maintaining anticoagulation in patients with AF and without obvious contraindications to minimize the risk of subsequent stroke.

Echocardiography in the detection of cardioembolism in a stroke population

Both transthoracic (TTE) and transoesophageal (TOE) echocardiography are used routinely to investigate ischaemic stroke. We retrospectively assessed the incidence of abnormalities on TTE/TOE and whether an abnormal TTE/TOE result could have been predicted on the basis of ancillary tests and clinical cardiological examination. Data from 428 patients were analysed. The diagnostic yield of TTE was 12%. For TOE there was a diagnostic yield of 40% in tests actually performed. Overall, echocardiography altered management in 5% of patients. A significant correlation was found between clinical cardiac disease, stroke subtype and the diagnostic yield of TTE. We conclude that the vast majority of abnormal findings occur in patients who already have clinical evidence of cardiac disease. This suggests that the use of these tests should not be "routine", but determined on an individual patient basis.

The photoreceptor-specific nuclear receptor Nr2e3 interacts with Crx and exerts opposing effects on the transcription of rod versus cone genes

Nr2e3 is an orphan nuclear receptor expressed specifically by retinal photoreceptor cells. Mutations in Nr2e3 result in syndromes characterized by excess blue cones and loss of rods: enhanced S-cone syndrome (ESCS) in humans and rd7 in mice. Using yeast two-hybrid screens with Nr2e3 as bait, the cone-rod homeobox protein Crx was identified as an interacting partner of Nr2e3. Immunoprecipitation assays confirmed this Nr2e3-Crx interaction and identified the DNA-binding domain of each protein as the interaction motif. Immunohistochemistry demonstrated that Crx and Nr2e3 are co-expressed by rod photoreceptors and their precursors. Chromatin immunoprecipitation assays on mouse retina demonstrated that Nr2e3 and Crx co-occupy the promoter/enhancer region of several rod and cone genes in the rod photoreceptor cells. The promoter/enhancer occupancy of Nr2e3 is Crx-dependent, suggesting that Nr2e3 is associated with photoreceptor gene targets by interacting with Crx. Transient transfection assays in HEK293 cells demonstrated that Nr2e3 enhances rhodopsin, but represses S- or M-cone opsin transcription when interacting with Crx. Quantitative real-time RT-PCR analysis on postnatal day 28 (P28) retina of the rd7 mouse, which lacks Nr2e3 protein, revealed an up-regulation of cone genes, but down-regulation of rod genes. Several mutant forms of human Nr2e3 identified from ESCS patients showed defects in interacting with Crx and/or in transcriptional regulatory function. Altogether, our findings suggest that Nr2e3 is a dual-function transcriptional regulator that acts in concert with Crx to promote and maintain the function of rod photoreceptors.