The effects of short-term, progressive exercise training on disease activity in smouldering multiple myeloma and monoclonal gammopathy of undetermined significance: a single-arm pilot study

BACKGROUND

High levels of physical activity are associated with reduced risk of the blood cancer multiple myeloma (MM). MM is preceded by the asymptomatic stages of monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) which are clinically managed by watchful waiting. A case study (N = 1) of a former elite athlete aged 44 years previously indicated that a multi-modal exercise programme reversed SMM disease activity. To build from this prior case study, the present pilot study firstly examined if short-term exercise training was feasible and safe for a group of MGUS and SMM patients, and secondly investigated the effects on MGUS/SMM disease activity.

METHODS

In this single-arm pilot study, N = 20 participants diagnosed with MGUS or SMM were allocated to receive a 16-week progressive exercise programme. Primary outcome measures were feasibility and safety. Secondary outcomes were pre- to post-exercise training changes to blood biomarkers of MGUS and SMM disease activity- monoclonal (M)-protein and free light chains (FLC)- plus cardiorespiratory and functional fitness, body composition, quality of life, blood immunophenotype, and blood biomarkers of inflammation.

RESULTS

Fifteen (3 MGUS and 12 SMM) participants completed the exercise programme. Adherence was 91 ± 11%. Compliance was 75 ± 25% overall, with a notable decline in compliance at intensities > 70% V̇O2PEAK. There were no serious adverse events. There were no changes to M-protein (0.0 ± 1.0 g/L, P =.903), involved FLC (+ 1.8 ± 16.8 mg/L, P =.839), or FLC difference (+ 0.2 ± 15.6 mg/L, P =.946) from pre- to post-exercise training. There were pre- to post-exercise training improvements to diastolic blood pressure (- 3 ± 5 mmHg, P =.033), sit-to-stand test performance (+ 5 ± 5 repetitions, P =.002), and energy/fatigue scores (+ 10 ± 15%, P =.026). Other secondary outcomes were unchanged.

CONCLUSIONS

A 16-week progressive exercise programme was feasible and safe, but did not reverse MGUS/SMM disease activity, contrasting a prior case study showing that five years of exercise training reversed SMM in a 44-year-old former athlete. Longer exercise interventions should be explored in a group of MGUS/SMM patients, with measurements of disease biomarkers, along with rates of disease progression (i.e., MGUS/SMM to MM).

REGISTRATION

https://www.isrctn.com/ISRCTN65527208 (14/05/2018).

DNA methylation is associated with codon degeneracy in a species of bumblebee

Social insects display extreme phenotypic differences between sexes and castes even though the underlying genome can be almost identical. Epigenetic processes have been proposed as a possible mechanism for mediating these phenotypic differences. Using whole genome bisulfite sequencing of queens, males, and reproductive female workers we have characterised the sex- and caste-specific methylome of the bumblebee Bombus terrestris. We have identified a potential role for DNA methylation in histone modification processes which may influence sex and caste phenotypic differences. We also find differentially methylated genes generally show low levels of DNA methylation which may suggest a separate function for lowly methylated genes in mediating transcriptional plasticity, unlike highly methylated genes which are usually involved in housekeeping functions. We also examined the relationship between the underlying genome and the methylome using whole genome re-sequencing of the same queens and males. We find DNA methylation is enriched at zero-fold degenerate sites. We suggest DNA methylation may be acting as a targeted mutagen at these sites, providing substrate for selection via non-synonymous changes in the underlying genome. However, we did not see any relationship between DNA methylation and rates of positive selection in our samples. In order to fully assess a possible role for DNA methylation in adaptive processes a specifically designed study using natural population data is needed.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

POS0888 NON-SURGICAL LOCAL TREATMENTS FOR DIGITAL ULCERS IN SYSTEMIC SCLEROSIS: A SYSTEMATIC LITERATURE REVIEW

Background

Digital ulcers(DUs) in systemic sclerosis(SSc) represent a major clinical challenge. There are no recommendations for the local management of SSc-DUs. Systemic therapy is considered the standard of care. However, there is a strong rationale for local approaches to DU by avoiding side effects from systemic therapies. The World Scleroderma Foundation DU Working Group intends to develop evidence-based recommendations for DU management including local, non-surgical treatment(ln-sT).

Objectives

To summarise the literature on the safety and efficacy of ln-sT for SSc-DUs.

Methods

A systematic literature review(SLR) of papers describing the use of ln-sT for DU in SSc was performed up to May 2021 according to the PICO framework. References were independently screened by two reviewers who independently assessed the full text of eligible articles and extracted data.

Results

Among 790 retrieved references, 12 were included. Median(range) number of patients per study was 9(7–84), mean age ranging from 37 to 62.5 years. In 5(41%) studies a control group was included. Background systemic therapies are summarized in Table 1. The most studied treatment was botulin toxin A(BTA). It was used as hand injection in 3 studies (median dose ranging from 90 to 150 U) and as 50 U single finger injection in 1 study. Healing rate after a median time of 8-49 weeks ranged from 71% to 100%. In 2 studies a reduction in VAS pain was observed from 20% to 100%. Transient muscle weakness was the most common side effect in 10% of patients. Amniotic(Am) and hydrocolloid membranes(HyM) were used in 1 study each. They were associated with a good healing rate, statistically significant for the HyM. Tadalafil 2% cream was studied in 1 study and was associated with a reduction in the median DU number from 1.6 to 1 per patient after a median time of 4 weeks and a reduction by 1.4 point in the 10-mm VAS scale. Vitamin E gel was shown to be associated with a statistically significant reduction in the healing time compared to SoC alone in 1 RCT(13.2 ± 2.7 versus 20.9 ± 3.6 weeks, P=<0.001). Low-level light therapy, hydrodissection and corticosteroid injection and extracorporeal shock wave(ESW) were evaluated in 1 study each. They were all associated with positive outcomes which was statistically significant only for the ESW. The only negative trial examined dimethyl sulfoxide and was associated with local toxicity.

Table 1.

Characteristics of the studies.

TreatmentType of studyPatientsBaseline DUBackground therapy (%) ETA CCB APA PG ARB ACE-I PDE-5i ISFollow-up (weeks)Healing rate(%)*Pain Reduction (VAS/10)ComparatorHydrodissection and corticosteroid injectionP1202334.4Rheumatoid ArthritisTadalafil 2% Vitamin E gelRRCT15131.6(1)3.5±2.30462700130704 241(1)Reduced time to heal**1.4SoCAmHyMRP67310001002800002817033143810090**SoCBTAMedian 90 U per handHigh-concentration hand100 U non-dominant handSingle finger 50 URRPP772010314571140718558551008514201001414718 4981277717510020%100%Untreated CHLow-level light therapyP8102537025378100ESWP9493355661144441**1.31Dimethyl sulfoxideDBRCT84No change, skin toxicity with 70% formulation

*Unless otherwise stated. **Statistically significant. ARB= angiotensin receptor antagonist. ACEi= ACE inhibitors. APA= anti-platelet agents. CCB= calcium channel blockers. CH= contralateral hand. DBRCT= double blind randomized-controlled trial. ETA = endothelin antagonist. IS= immunosuppression. PG= prostaglandins. PDE-5i= Phosphodiesterase type-5 inhibitors. P = prospective. R = retrospective. SoC= standard of care (as per local protocol).

Conclusion

Our SLR supports interest to develop ln-sTs for SSc-DUs. The number of studies is limited and mainly case reports and small single studies are present. Treatments were well tolerated and there was evidence of efficacy for BTA, vitamin E, ESW and HyM in refractory DUs. The evidence is not robust and confounding factors (vasodilators background therapies) could impact on the findings. Future research is indicated to conduct larger, well-designed studies.

Disclosure of Interests

Corrado Campochiaro: None declared, Yossra A. Suliman: None declared, Michael Hughes Speakers bureau: Actelion pharmaceuticals, Eli Lilly, and Pfizer, outside of the submitted work., Jan Schoones: None declared, Dilia Giuggioli: None declared, Pia Moinzadeh Speakers bureau: speaking fees from Actelion pharmaceuticals and Boehringer Ingelheim, Nancy Maltez: None declared, Laura Ross: None declared, Murray Baron: None declared, Lorinda Chung: None declared, Yannick Allanore: None declared, Christopher P Denton: None declared, Oliver Distler Speakers bureau: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Tracy Frech: None declared, Daniel Furst: None declared, Dinesh Khanna Speakers bureau: Janssen and Eicos Sciences, Inc., Thomas Krieg: None declared, Masataka Kuwana Speakers bureau: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Marco Matucci-Cerinic: None declared, Janet Pope: None declared, Alessia Alunno: None declared

POS0898 SURGICAL MANAGEMENT OF DIGITAL ULCERS IN SYSTEMIC SCLEROSIS: A SYSTEMATIC LITERATURE REVIEW

Background

Management of digital ulcers (DUs) in systemic sclerosis (SSc) is a major clinical challenge. To date, systemic therapy is generally considered as the ‘standard of care’ for significant SSc-DUs. However, there is a strong rationale to develop local approaches to DUs, to avoid side effects from systemic therapies. World Scleroderma Foundation DU Working Group intends to develop practical, evidence-based recommendations for DU management including local, Surgical Treatment (L-ST).

Objectives

To summarize the literature on the safety and efficacy of L-ST for SSc-DUs.

Methods

A systematic literature review (SLR) was conducted up to May 2021. According to the PICO framework, eligibility criteria were defined and original research articles about surgical treatment of SSc DUs in adult patients were included. References were independently screened by 2 reviewers who assessed the full text of eligible articles and extracted data.

Results

Thirteen eligible articles out of 790 total publications were identified (Table 1). Due to the paucity of randomized controlled trials of surgical treatments for SSc-DU, we included retrospective studies and case series with at least 4 patients. Autologous fat (adipose tissue AT) grafting was the surgical modality mostly identified (7 studies of which 1 RCT and 6 prospective open label single arm). The healing rate (HR) with autologous fat grafting (4 studies) ranged from 66-100 %. In the RCT, two age and sex matched groups were included, adipose tissue (AT)group (n=25 pts) and sham procedure (SP) group (n=13), DU healing was reported in 23/25 in AT group versus 1/13 in the SP group in 8 wks, (p<0.0001), 12 pts in the SP group, received rescue AT injection, all of them healed after 8 wks. Three studies reported autologous adipose-derived stromal vascular fraction(SVF) grafting and the HR ranged from 32-60%, followed up to 12 months. Transient edema and paresthesia were reported in 2 studies, and amputation in 2 ulcers in 1 study, and no complications were reported in other studies. Surgical sympathectomy was reported in 3 studies, with a median healing rate of 81%. Bone marrow derived cell transplantation in a single study showed 87% healing rate over (4-24 wks). Two surgical studies (of direct microsurgical revascularization N=4, and microsurgical arteriolysis, N=6), showed 100% healing of ulcers, no complications reported.

Table 1.

Characteristics of the extracted studies.

StudydesignPatients (n)Baseline DU (n)Background therapy (%)Follow-upOutcomeHealed ulcers(%) Adipose tissue graftAutologous fat graftp9.15PG, CCB—100ETA 26PDE-5i 138-12 wks66Adipose tissue graftingRCT25 case13- Ctr25-case13- CtrPG- 100CCB 1008 wks92-case7-CtrAdipose tissue implantp1515no therapy7 wks100Adipose tissue graftp129PG,CCB-100ETA6 month88adipose derived SVFp1215PDE-5i, ccb, PG allowed22m6Adipose derived SVFp1215CCB 50ETA166 m63 Adipose derived SVFp1819CCB 50PG 27ETA 5IS 7124 wks32SympathectomySympathectomyR611CCB-10020 m81SympathectomyR1335PGCCBAPA35Sympathectomy, vascular bypass (+vein graftR1726Ccb 35APA 47PDE-i5 589 m100Bone marrow derived cells transplantation)p88PG-6236 m87Direct microsurgical revascularizationR44m100Limited microsurgical arteriolysisR61712 m100

SVF =stromal vascular fraction P = prospective. R = retrospective. RCT= double blind randomized-controlled trial. ETA = endothelin antagonist. CCB= calcium channel blockers. APA= anti-platelet agents. PG= prostaglandins. ARB= angiotensin receptor antagonist. ACEi= ACE inhibitors. PDE-5i= PDE-5 inhibitors. IS= immunosuppression. M=median. SoC= standard of care. HR= healing rate

Conclusion

Our SLR has identified several surgical modalities for SSc-DUs. L-STseemed generally effective and safe for DU healing, thus Significant methodological issues emerged including small numbers of pts, lack of comparator, failure to report confounders such as background therapies and variable follow up. Future research is warranted to rigorously investigate surgical interventions for Dus.

Disclosure of Interests

Yossra A. Suliman: None declared, Corrado Campochiaro: None declared, Michael Hughes Speakers bureau: speaking fees from Actelion pharmaceuticals, Eli Lilly, and Pfizer, outside of the submitted work, Jan Schoones: None declared, Dilia Giuggioli: None declared, Nancy Maltez: None declared, Pia Moinzadeh Speakers bureau:: speaking fees from Actelion pharmaceuticals and Boehringer Ingelheim, Laura Ross: None declared, Lorinda Chung: None declared, Yannick Allanore: None declared, Murray Baron: None declared, Christopher P Denton: None declared, Oliver Distler Shareholder of: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Speakers bureau: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Consultant of: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Grant/research support from: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Tracy Frech: None declared, Daniel Furst: None declared, Dinesh Khanna Speakers bureau: Janssen and Eicos Sciences, Inc., Paid instructor for: Janssen and Eicos Sciences, Inc., Consultant of: Janssen and Eicos Sciences, Inc., Thomas Krieg: None declared, Masataka KUWANA Speakers bureau: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Paid instructor for: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Consultant of: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Marco Matucci-Cerinic: None declared, Janet Pope: None declared, Alessia Alunno: None declared

POS0900 SYSTEMIC PHARMACOLOGICAL TREATMENT OF DIGITAL ULCERS IN SYSTEMIC SCLEROSIS: A SYSTEMATIC LITERATURE REVIEW

Background

Digital ulcers (DU) are common in systemic sclerosis (SSc) and associated with reduced survival, high morbidity and poor quality of life. Recommendations have previously been proposed for DU management yet there remains significant unmet patient need. Therefore the World Scleroderma Foundation DU Working Group intends to develop practical evidence based recommendations for DU management.

Objectives

To summarise data on efficacy and safety of systemic treatments for SSc DU.

Methods

A systematic literature review to May 2021 was performed. PubMed, MEDLINE, Embase, Web of Science, Cochrane Library, Emcare (OVID) and Academic Search Premier databases were searched for original studies on adult patients with SSc DU treated with systemic pharmacological treatment. Based on the PICO framework, eligibility criteria were defined and references were independently screened by two reviewers. Reviewers independently assessed the full text of eligible articles. Owing to interstudy heterogeneity narrative summaries were used to present data.

Results

The search strategy identified 1271 references of which 45 eligible articles were included. Seventeen studies were randomised placebo controlled trials (RCT) pertaining to PDE5 antagonists (PDE5i) (n=3), endothelin receptor antagonists (ERA) (n=3), prostanoids (n=7), antiplatelet agents (n=1) and other (n=3) (Table 1). No head to head RCT was retrieved. All other studies were observational studies (OBS). Studies were highly heterogeneous with application of differing definition of DU, variable study eligibility criteria, clinical endpoints and follow up periods. This limited the calculation of effect size and comparison across studies.

Table 1.

Characteristics of placebo controlled randomised controlled trials

Author YearInterventionnFollow upOutcomeFavours interventionHachulla 2016Sildenafil8312 weeksTime to DU healing-Andrigueti 2017Sildenafil4112 weeksDU healing+Shenoy 2010Tadalafil246 weeksNew DU+Khanna 2016Macitentan55416 weeksNew DU-Matucci-Cerinic 2011Bosentan18832 weeksNew DU Time to healing of DU+-Korn 2004Bosentan12212 weeksNew DU+Kawald 2008IV iloprost5012 monthsDU healing-Wigley 1992IV iloprost3510 weeksDU healing+Wigley 1994IV iloprost739 weeks50% reduction in DU score-Seibold 2017Treprostinil14820 weeksNet DU burden-Vayssairat 1999Beraprost10725 weeks% patients with new DU-Denton 2017Selexipag7412 weeksNumber of new DU DU healing-Lau 1993Cicaprost334 weeksNumber of DU-Abou-Raya 2008Atorvastatin844 monthsNumber of DU+Au 2010Cyclophosphamide15812 monthsNumber of patients with DU-Beckett 1984Dipyridamole / aspirin412 yearsChange in general SSc-Nagaraja 2019Riociguat1732 weeksNet DU burden-

+ significantly superior to comparator

- non significantly different from comparator

DU: digital ulcers IV: intravenous SSc: systemic sclerosis

Several RCT found improved DU healing with treatment: two with PDE5i, one with iloprost and one showed improved DU healing and prevention with atorvastatin. Two RCT demonstrated effective prevention of new DU with bosentan. OBS studies with a total of 621 patients showed variable improvements in the healing of DU with CCB, PDE5i, ERA, statins, N-acetylcysteine, prostanoids and ketanserin and prevention of new DU with ERA.

Regarding safety, all treatments were generally tolerated with few serious adverse events. Treatment was ceased in 6.25-17.5% of patients in RCT due to treatment related side effects.

Conclusion

Despite several studies assessing the efficacy and safety of systemic pharmacological treatment of SSc DU, it is not possible to draw solid conclusions due to study heterogeneity. Small RCT have shown treatment benefit with PDE5i, iloprost and atorvastatin. Large studies demonstrated effective prevention of new DU with bosentan. Our results highlight the urgent need for improved clinical trial design to generate more robust evidence and novel therapies to guide the management SSc DU.

Acknowledgements

This work was supported by the World Scleroderma Foundation.

Disclosure of Interests

Nancy Maltez: None declared, Laura Ross: None declared, Michael Hughes Speakers bureau: Actelion Pharmaceuticals, Eli Lilly and Pfizer outside of the submitted work., Jan Schoones: None declared, Murray Baron: None declared, Lorinda Chung Consultant of: Eicos, Corrado Campochiaro: None declared, Yossra A. Suliman: None declared, Dilia Giuggioli: None declared, Pia Moinzadeh Speakers bureau: Actelion Pharmaceuticals, Boehringer Ingelheim, Yannick Allanore: None declared, Christopher P Denton: None declared, Oliver Distler Speakers bureau: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur., Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur., Grant/research support from: Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143), Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur., Tracy Frech: None declared, Daniel Furst: None declared, Dinesh Khanna Consultant of: Eicos Sciences Inc, Janssen, Thomas Krieg: None declared, Masataka Kuwana Speakers bureau: Speaker fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and consultancy fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida outside of the submitted work., Marco Matucci-Cerinic: None declared, Janet Pope: None declared, Alessia Alunno: None declared

Intragenic complementation at the Lotus japonicus CELLULOSE SYNTHASE-LIKE D1 locus rescues root hair defects

Root hair cells form the primary interface of plants with the soil environment, playing key roles in nutrient uptake and plant defense. In legumes, they are typically the first cells to become infected by nitrogen-fixing soil bacteria during root nodule symbiosis. Here, we report a role for the CELLULOSE SYNTHASE-LIKE D1 (CSLD1) gene in root hair development in the legume species Lotus japonicus. CSLD1 belongs to the cellulose synthase protein family that includes cellulose synthases and cellulose synthase-like proteins, the latter thought to be involved in the biosynthesis of hemicellulose. We describe 11 Ljcsld1 mutant alleles that impose either short (Ljcsld1-1) or variable (Ljcsld1-2 to 11) root hair length phenotypes. Examination of Ljcsld1-1 and one variable-length root hair mutant, Ljcsld1-6, revealed increased root hair cell wall thickness, which in Ljcsld1-1 was significantly more pronounced and also associated with a strong defect in root nodule symbiosis. Lotus japonicus plants heterozygous for Ljcsld1-1 exhibited intermediate root hair lengths, suggesting incomplete dominance. Intragenic complementation was observed between alleles with mutations in different CSLD1 domains, suggesting CSLD1 function is modular and that the protein may operate as a homodimer or multimer during root hair development.

Lotus japonicus Nuclear Factor YA1, a nodule emergence stage-specific regulator of auxin signalling

Organogenesis of legume root nodules begins with the nodulation factor-dependent stimulation of compatible root cells to initiate divisions, signifying an early nodule primordium formation event. This is followed by cellular differentiation, including cell expansion and vascular bundle formation, and we previously showed that Lotus japonicus NF-YA1 is essential for this process, presumably by regulating three members of the SHORT INTERNODES/STYLISH (STY) transcription factor gene family. In this study, we used combined genetics, genomics and cell biology approaches to characterize the role of STY genes during root nodule formation and to test a hypothesis that they mediate nodule development by stimulating auxin signalling. We show here that L. japonicus STYs are required for nodule emergence. This is attributed to the NF-YA1-dependent regulatory cascade, comprising STY genes and their downstream targets, YUCCA1 and YUCCA11, involved in a local auxin biosynthesis at the post-initial cell division stage. An analogous NF-YA1/STY regulatory module seems to operate in Medicago truncatula in association with the indeterminate nodule patterning. Our data define L. japonicus and M. truncatula NF-YA1 genes as important nodule emergence stage-specific regulators of auxin signalling while indicating that the inductive stage and subsequent formation of early nodule primordia are mediated through an independent mechanism(s).

Bridging the Expertise of Advocates and Academics to Identify Reproductive Justice Learning Outcomes

Phenomenon: Reproductive justice (RJ) is defined by women of color advocates as the right to have children, not have children and parent children while maintaining reproductive autonomy. In the United States, physicians have been complicit in multiple historical reproductive injustices, involving coercive sterilization of thousands of people of color, low income, and disabilities. Currently, reproductive injustices continue to occur; however, physicians have no formal RJ medical education to address injustices. The objective of this study was to engage leading advocates within the movement using a Delphi method to identify critical components for such a curriculum. Approach: In 2016, we invited 65 RJ advocates and leaders to participate in an expert panel to design RJ medical education. A 3-round Delphi survey was distributed electronically to identify content for inclusion in an RJ curriculum. In the next 2 survey rounds, experts offered feedback and revisions and rated agreement with including content recommendations in the final curriculum. We calculated descriptive statistics to analyze quantitative data. A team with educational expertise wrote learning outcomes based on expert content recommendations. Findings: Of the 65 RJ advocates and leaders invited, 41 participated on the expert panel of the Delphi survey. In the first survey, the expert panel recommended 58 RJ content areas through open-ended response. Over the next 2 rounds, there was consensus among the panel to include 52 of 58 of these areas in the curriculum. Recommended content fell into 11 broad domains: access, disparities, and structural competency; advocacy; approaches to reproductive healthcare; contemporary law and policy; cultural safety; historical injustices; lesbian, gay, bisexual, transgender, queer/questioning, and intersex health; oppression, power, and bias training; patient care; reproductive health; and RJ definitions. The 97 learning outcomes created from this process represented both unique and existing educational elements. Insights: A collaborative methodology infused with RJ values can bridge experts in advocacy and academics. New learning outcomes identified through this process can enhance medical education; however, it is just as important to consider education in RJ approaches to care as it is knowledge about that care. We must explore the pedagogic process of RJ medical education while considering that expertise in this area may exist outside of the medical community and thus there is a need to partner with RJ advocates. Finally, we expect to use innovative teaching methods to transform medical education and achieve an RJ focus.

Validation of alternative behavioral observation methods in young broiler chickens

Continuous sampling provides the most complete data set for behavioral research; however, it often requires a prohibitive investment of time and labor. The objectives of this study were to validate behavioral observation methods of young broiler chickens using 1) 7 scan sampling intervals (0.5, 1, 3, 5, 10, 15, and 30 min) and 2) an automated tracking software program (EthoVision XT 14) compared to continuous behavioral observation, considered the gold standard for behavior observation. Ten 19-day-old Ross 708 broiler cockerels were included in this study. All behavior was video recorded over an 8-h period, and data were collected using a continuous sampling methodology. The same video files were utilized for analysis for scan sampling and automated tracking software analysis. For both analyses, the following criteria were used to identify which method accurately reflected the true duration and frequency for each behavior, as determined by continuous observation: R² ≥ 0.9, slope was not different from 1 (P > 0.05), and intercept was not different from 0 (P > 0.05). Active, eating, drinking, and maintenance behaviors were accurately estimated with 0.5-min scan sample intervals. Active, inactive, eating, and maintenance behaviors were accurately estimated with 1-min scan sample intervals. Inactive behavior was accurately estimated with 5-min scan sample intervals. The remainder of sampling intervals examined did not provide accurate estimates, and no scan sampling interval accurately estimated the number of behavior bouts. The automated tracking software was able to accurately detect true duration of inactive behavior but was unable to accurately detect activity. The results of this study suggest that high-frequency behaviors can be accurately observed with instantaneous scan sampling up to 1-min intervals. Automated tracking software can accurately identify inactivity in young broiler chickens, but further behavior identification will require refinement.

Determination of Chlormequat and Mepiquat in Foods by Liquid Chromatography/Mass Spectrometry or Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Study

Interlaboratory validation studies have been performed on 2 methods for the determination of chlormequat (CLQ) and mepiquat (MPQ). Both methods used identical extraction procedures and stable isotope internal standardization but differed in the use of liquid chromatography/mass spectrometry (LC/MS) or LC/tandem mass spectrometry (LC/MS/MS) for the determination, the amount of internal standard used, and the expected limit of detection. After addition of deuterated internal standards, CLQ and MPQ were extracted with methanol–water and determined by LC/MS or LC/MS/MS with positive electrospray ionization. Eight European laboratories participated in the LC/MS method study, analyzing mushroom, pear, wheat flour, and fruit puree with residues of CLQ in the range 0.040–1.19 mg/kg and of MPQ in the range 0.041–0.39 mg/kg. For CLQ, the Horwitz ratio (HoRat) values for individual test materials/levels were in the range 0.85–1.13 with amean of 1.00, showing good method performance. For MPQ, the Ho values for mushroom, pear (both levels), and wheat flour were in the range 0.83–0.94, again indicating good method performance. For the determination of MPQ in infant food (fruit puree) at 0.041 mg/kg, the Ho was 1.7 when a value of 0 reported by one participant was excluded. In the LC/MS/MS study, in which 11 laboratories participated, a separate sample set was analyzed with residues of CLQ in the range 0.007–1.03 mg/kg and of MPQ in the range 0.008–0.72 mg/kg. Ho values for CLQ were in the range 0.27–1.36 and for MPQ in the range 0.51–2.10, all corresponding to acceptable method performance.

Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14-8.23; P<0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19-3.77; P=0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08-3.47; P=0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10-5.50; P=0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30-0.72; P=0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01-1.04; P<0.001) and age (OR, 1.17; 95% CI, 1.08-1.26; P<0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54-0.69) and a specificity of 0.63 (95% CI, 0.59-0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study.

Inside out: root cortex-localized LHK1 cytokinin receptor limits epidermal infection of Lotus japonicus roots by Mesorhizobium loti

During Lotus japonicus-Mesorhizobium loti symbiosis, the LOTUS HISTIDINE KINASE1 (LHK1) cytokinin receptor regulates both the initiation of nodule formation and the scope of root infection. However, the exact spatiotemporal mechanism by which this receptor exerts its symbiotic functions has remained elusive. In this study, we performed cell type-specific complementation experiments in the hyperinfected lhk1-1 mutant background, targeting LHK1 to either the root epidermis or the root cortex. We also utilized various genetic backgrounds to characterize expression of several genes regulating symbiotic infection. We show here that expression of LHK1 in the root cortex is required and sufficient to regulate both nodule formation and epidermal infections. The LHK1-dependent signalling that restricts subsequent infection events is triggered before initial cell divisions for nodule primordium formation. We also demonstrate that AHK4, the Arabidopsis orthologue of LHK1, is able to regulate M. loti infection in L. japonicus, suggesting that an endogenous cytokinin receptor could be sufficient for engineering nitrogen-fixing root nodule symbiosis in nonlegumes. Our data provide experimental evidence for the existence of an LHK1-dependent root cortex-to-epidermis feedback mechanism regulating rhizobial infection. This root-localized regulatory module functionally links with the systemic autoregulation of nodulation (AON) to maintain the homeostasis of symbiotic infection.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Do stroke patients screened as lower-nutritional-risk still receive dietitian assessment if indicated? A retrospective evaluation of two dietetic models of care for adult stroke patients

BACKGROUND

Dietetic models of care at Logan Hospital changed from all patients with a confirmed stroke receiving dietitian assessment (Old pathway) to only those patients screened as high-nutritional-risk (Modified pathway). However, it was unknown whether all low-nutritional-risk patients who were indicated for dietitian assessment for nutrition support actually received assessment. This pre-post retrospective study evaluated whether the Old pathway and the Modified pathway were equally effective in identifying low-nutritional-risk stroke patients who were indicated for dietitian assessment and compared the time spent providing Dietetic care.

METHODS

For both pathways, medical charts were reviewed for low-nutritional-risk patients admitted between December 2012 and November 2017 with a confirmed stroke, who were given a standard food and fluid diet code and scored MST < 2 (Malnutrition Screening Tool) on admission. Data collected included demographics, anthropometrics, malnutrition assessment, dietetic intervention and time spent caring for patients. Malnutrition-related clinical indicators were used to classify patients as either Dietitian Assessment for Nutrition Support Indicated or Not Indicated.

RESULTS

Low-nutritional-risk patients were similar on the Old (n = 180) and Modified (n = 206) pathways [mean (SD) 66 (13) years, 63% male, 4% malnutrition]. Those classified as Dietitian Assessment for Nutrition Support Indicated (n = 61 of 180) were older, had a longer length of stay (P < 0.05), and were all identified by the Dietitian on both pathways. Ten minutes less dietetic time per patient was required on the Modified pathway (P < 0.001).

CONCLUSIONS

The Modified Nutrition Stroke pathway performed more efficiently than the Old pathway and was equally effective at ensuring that stroke patients who were determined as being low-nutritional-risk received dietitian assessment during admission if indicated.

Fish consumption is associated with a decreased risk of death among adults with diabetes: 18-year follow-up of a national cohort

BACKGROUND

There is a paucity of studies examining the beneficial effects of fish consumption on cardiovascular diseases (CVDs) among adults with diabetes, who experience a substantially high risk of CVDs.

METHODS AND RESULTS

We analyzed the data of 1136 adults with diabetes mellitus aged 18 years and older who participated in the National Health and Nutrition Examination Survey, 1988-1994, and were followed up through December 31, 2010. We used Cox regression to estimate the adjusted hazard ratios (HRs) for the relative risk across the levels of fish consumption. A total of 698 deaths were recorded at the end of 11,465 person-years follow-up with a mortality rate of 60.88 per 1000 person-years. CVDs were listed as a contributing cause for 326 deaths, thus accounting for 46.4% of total deaths. Stroke-specific mortality rate among patients who ate fish less than once a week was more than twice as high as that among patients who ate fish more than twice a week, 6.23 vs. 2.36 per 1000 person-years, respectively. The corresponding CVD-specific rate was 34.38 vs. 22.99 per 1000 person-years, respectively. The adjusted HRs of death due to stroke were 1.00 (reference), 0.55 (95% confidence interval = 0.28-1.07), and 0.30 (0.11-0.80) among patients who ate fish <1, 1-2, and 2 + times a week, and the corresponding HRs of death due to CVDs were 1.00 (reference), 0.78 (0.60-1.02), and 0.69 (0.50-0.96), respectively.

CONCLUSIONS

A high consumption of fish was associated with a low risk of death due to CVDs, especially stroke, among adults with diabetes.

Lotus japonicus NF-YA1 Plays an Essential Role During Nodule Differentiation and Targets Members of the SHI/STY Gene Family

Legume plants engage in intimate relationships with rhizobial bacteria to form nitrogen-fixing nodules, root-derived organs that accommodate the microsymbiont. Members of the Nuclear Factor Y (NF-Y) gene family, which have undergone significant expansion and functional diversification during plant evolution, are essential for this symbiotic liaison. Acting in a partially redundant manner, NF-Y proteins were shown, previously, to regulate bacterial infection, including selection of a superior rhizobial strain, and to mediate nodule structure formation. However, the exact mechanism by which these transcriptional factors exert their symbiotic functions has remained elusive. By carrying out detailed functional analyses of Lotus japonicus mutants, we demonstrate that LjNF-YA1 becomes indispensable downstream from the initial cortical cell divisions but prior to nodule differentiation, including cell enlargement and vascular bundle formation. Three affiliates of the SHORT INTERNODES/STYLISH transcription factor gene family, called STY1, STY2, and STY3, are demonstrated to be among likely direct targets of LjNF-YA1, and our results point to their involvement in nodule formation.

Into the Root: How Cytokinin Controls Rhizobial Infection

Leguminous plants selectively initiate primary responses to rhizobial nodulation factors (NF) that ultimately lead to symbiotic root nodule formation. Functioning downstream, cytokinin has emerged as the key endogenous plant signal for nodule differentiation, but its role in mediating rhizobial entry into the root remains obscure. Nonetheless, such a role is suggested by aberrant infection phenotypes of plant mutants with defects in cytokinin signaling. We postulate that cytokinin participates in orchestrating signaling events that promote rhizobial colonization of the root cortex and limit the extent of subsequent infection at the root epidermis, thus maintaining homeostasis of the symbiotic interaction. We further argue that cytokinin signaling must have been crucial during the evolution of plant cell predisposition for rhizobial colonization.

Evolutionary problems in centrosome and centriole biology

Centrosomes have been an enigma to evolutionary biologists. Either they have been the subject of ill-founded speculation or they have been ignored. Here, we highlight evolutionary paradoxes and problems of centrosome and centriole evolution and seek to understand them in the light of recent advances in centrosome biology. Most evolutionary accounts of centrosome evolution have been based on the hypothesis that centrosomes are replicators, independent of the nucleus and cytoplasm. It is now clear, however, that this hypothesis is not tenable. Instead, centrosomes are formed de novo each cell division, with the presence of an old centrosome regulating, but not essential for, the assembly of a new one. Centrosomes are the microtubule-organizing centres of cells. They can potentially affect sensory and motor characters (as the basal body of cilia), as well as the movements of chromosomes during cell division. This latter role does not seem essential, however, except in male meiosis, and the reasons for this remain unclear. Although the centrosome is absent in some taxa, when it is present, its structure is extraordinarily conserved: in most taxa across eukaryotes, it does not appear to evolve at all. And yet a few insect groups display spectacular hypertrophy of the centrioles. We discuss how this might relate to the unusual reproductive system found in these insects. Finally, we discuss why the fate of centrosomes in sperm and early embryos might differ between different groups of animals.

Recombination, chromosome number and eusociality in the Hymenoptera

Extraordinarily high rates of recombination have been observed in some eusocial species. The most popular explanation is that increased recombination increases genetic variation among workers, which in turn increases colony performance, for example by increasing parasite resistance. However, support for the generality of higher recombination rates among eusocial organisms remains weak, due to low sample size and a lack of phylogenetic independence of observations. Recombination rate, although difficult to measure directly, is correlated with chromosome number. As predicted, several authors have noted that chromosome numbers are higher among the eusocial species of Hymenoptera (ants, bees and wasps). Here, we present a formal comparative analysis of karyotype data from 1567 species of Hymenoptera. Contrary to earlier studies, we find no evidence for an absolute difference between chromosome number in eusocial and solitary species of Hymenoptera. However, we find support for an increased rate of chromosome number change in eusocial taxa. We show that among eusocial taxa colony size is able to explain some of the variation in chromosome number: intermediate-sized colonies have more chromosomes than those that are either very small or very large. However, we were unable to detect effects of a number of other colony characteristics predicted to affect recombination rate - including colony relatedness and caste number. Taken together, our results support the view that a eusocial lifestyle has led to variable selection pressure for increased recombination rates, but that identifying the factors contributing to this variable selection will require further theoretical and empirical effort.

Lotus japonicus SUNERGOS1 encodes a predicted subunit A of a DNA topoisomerase VI that is required for nodule differentiation and accommodation of rhizobial infection

A symbiotic mutant of Lotus japonicus, called sunergos1-1 (suner1-1), originated from a har1-1 suppressor screen. suner1-1 supports epidermal infection by Mesorhizobium loti and initiates cell divisions for organogenesis of nodule primordia. However, these processes appear to be temporarily stalled early during symbiotic interaction, leading to a low nodule number phenotype. This defect is ephemeral and near wild-type nodule numbers are reached by suner1-1 at a later point after infection. Using an approach that combined map-based cloning and next-generation sequencing we have identified the causative mutation and show that the suner1-1 phenotype is determined by a weak recessive allele, with the corresponding wild-type SUNER1 locus encoding a predicted subunit A of a DNA topoisomerase VI. Our data suggest that at least one function of SUNER1 during symbiosis is to participate in endoreduplication, which is an essential step during normal differentiation of functional, nitrogen-fixing nodules.

The evolution of genomic imprinting: theories, predictions and empirical tests

The epigenetic phenomenon of genomic imprinting has motivated the development of numerous theories for its evolutionary origins and genomic distribution. In this review, we examine the three theories that have best withstood theoretical and empirical scrutiny. These are: Haig and colleagues' kinship theory; Day and Bonduriansky's sexual antagonism theory; and Wolf and Hager's maternal–offspring coadaptation theory. These theories have fundamentally different perspectives on the adaptive significance of imprinting. The kinship theory views imprinting as a mechanism to change gene dosage, with imprinting evolving because of the differential effect that gene dosage has on the fitness of matrilineal and patrilineal relatives. The sexual antagonism and maternal–offspring coadaptation theories view genomic imprinting as a mechanism to modify the resemblance of an individual to its two parents, with imprinting evolving to increase the probability of expressing the fitter of the two alleles at a locus. In an effort to stimulate further empirical work on the topic, we carefully detail the logic and assumptions of all three theories, clarify the specific predictions of each and suggest tests to discriminate between these alternative theories for why particular genes are imprinted.

Serum 25-hydroxy vitamin D concentrations are more deficient/insufficient in peritoneal dialysis than haemodialysis patients in a sunny climate

BACKGROUND

Research has identified associations between serum 25(OH)D and a range of clinical outcomes in chronic kidney disease and wider populations. The present study aimed to investigate vitamin D deficiency/insufficiency in dialysis patients and the relationship with vitamin D intake and sun exposure.

METHODS

A cross-sectional study was used. Participants included 30 peritoneal dialysis (PD) (43.3% male; 56.87 ± 16.16 years) and 26 haemodialysis (HD) (80.8% male; 63.58 ± 15.09 years) patients attending a department of renal medicine. Explanatory variables were usual vitamin D intake from diet/supplements (IU day(-1) ) and sun exposure (min day(-1) ). Vitamin D intake, sun exposure and ethnic background were assessed by questionnaire. Weight, malnutrition status and routine biochemistry were also assessed. Data were collected during usual department visits. The main outcome measure was serum 25(OH)D (nm).

RESULTS

Prevalence of inadequate/insufficient vitamin D intake differed between dialysis modality, with 31% and 43% found to be insufficient (<50 nm) and 4% and 33% found to be deficient (<25 nm) in HD and PD patients, respectively (P < 0.001). In HD patients, there was a correlation between diet and supplemental vitamin D intake and 25(OH)D (ρ = 0.84, P < 0.001) and average sun exposure and 25(OH)D (ρ = 0.50, P < 0.02). There were no associations in PD patients. The results remained significant for vitamin D intake after multiple regression, adjusting for age, gender and sun exposure.

CONCLUSIONS

The results highlight a strong association between vitamin D intake and 25(OH)D in HD but not PD patients, with implications for replacement recommendations. The findings indicate that, even in a sunny climate, many dialysis patients are vitamin D deficient, highlighting the need for exploration of determinants and consequences.

Lotus japonicus cytokinin receptors work partially redundantly to mediate nodule formation

Previous analysis of the Lotus histidine kinase1 (Lhk1) cytokinin receptor gene has shown that it is required and also sufficient for nodule formation in Lotus japonicus. The L. japonicus mutant carrying the loss-of-function lhk1-1 allele is hyperinfected by its symbiotic partner, Mesorhizobium loti, in the initial absence of nodule organogenesis. At a later time point following bacterial infection, lhk1-1 develops a limited number of nodules, suggesting the presence of an Lhk1-independent mechanism. We have tested a hypothesis that other cytokinin receptors function in at least a partially redundant manner with LHK1 to mediate nodule organogenesis in L. japonicus. We show here that L. japonicus contains a small family of four cytokinin receptor genes, which all respond to M. loti infection. We show that within the root cortex, LHK1 performs an essential role but also works partially redundantly with LHK1A and LHK3 to mediate cell divisions for nodule primordium formation. The LHK1 receptor is also presumed to partake in mediating a feedback mechanism that negatively regulates bacterial infections at the root epidermis. Interestingly, the Arabidopsis thaliana AHK4 receptor gene can functionally replace Lhk1 in mediating nodule organogenesis, indicating that the ability to perform this developmental process is not determined by unique, legume-specific properties of LHK1.

Lotus japonicus cytokinin receptors work partially redundantly to mediate nodule formation

Previous analysis of the Lotus histidine kinase1 (Lhk1) cytokinin receptor gene has shown that it is required and also sufficient for nodule formation in Lotus japonicus. The L. japonicus mutant carrying the loss-of-function lhk1-1 allele is hyperinfected by its symbiotic partner, Mesorhizobium loti, in the initial absence of nodule organogenesis. At a later time point following bacterial infection, lhk1-1 develops a limited number of nodules, suggesting the presence of an Lhk1-independent mechanism. We have tested a hypothesis that other cytokinin receptors function in at least a partially redundant manner with LHK1 to mediate nodule organogenesis in L. japonicus. We show here that L. japonicus contains a small family of four cytokinin receptor genes, which all respond to M. loti infection. We show that within the root cortex, LHK1 performs an essential role but also works partially redundantly with LHK1A and LHK3 to mediate cell divisions for nodule primordium formation. The LHK1 receptor is also presumed to partake in mediating a feedback mechanism that negatively regulates bacterial infections at the root epidermis. Interestingly, the Arabidopsis thaliana AHK4 receptor gene can functionally replace Lhk1 in mediating nodule organogenesis, indicating that the ability to perform this developmental process is not determined by unique, legume-specific properties of LHK1.

Fewer invited talks by women in evolutionary biology symposia

Lower visibility of female scientists, compared to male scientists, is a potential reason for the under-representation of women among senior academic ranks. Visibility in the scientific community stems partly from presenting research as an invited speaker at organized meetings. We analysed the sex ratio of presenters at the European Society for Evolutionary Biology (ESEB) Congress 2011, where all abstract submissions were accepted for presentation. Women were under-represented among invited speakers at symposia (15% women) compared to all presenters (46%), regular oral presenters (41%) and plenary speakers (25%). At the ESEB congresses in 2001–2011, 9–23% of invited speakers were women. This under-representation of women is partly attributable to a larger proportion of women, than men, declining invitations: in 2011, 50% of women declined an invitation to speak compared to 26% of men. We expect invited speakers to be scientists from top ranked institutions or authors of recent papers in high-impact journals. Considering all invited speakers (including declined invitations), 23% were women. This was lower than the baseline sex ratios of early-mid career stage scientists, but was similar to senior scientists and authors that have published in high-impact journals. High-quality science by women therefore has low exposure at international meetings, which will constrain Evolutionary Biology from reaching its full potential. We wish to highlight the wider implications of turning down invitations to speak, and encourage conference organizers to implement steps to increase acceptance rates of invited talks.

SYK regulates mTOR signaling in AML

Spleen Tyrosine Kinase (SYK) was recently identified as a new target in acute myeloid leukemia (AML); however, its mechanistic role in this disease is poorly understood. Based on the known interaction between SYK and mTOR signaling in lymphoma, we hypothesized that SYK may regulate mTOR signaling in AML. Both small-molecule inhibition of SYK and SYK-directed shRNA suppressed mTOR and its downstream signaling effectors, as well as its upstream activator, AKT. Moreover, the inhibition of multiple nodes of the PI3K signaling pathway enhanced the effects of SYK suppression on AML cell viability and differentiation. Evaluation of the collateral MAPK pathway revealed a heterogeneous response to SYK inhibition in AML with down-regulation of MEK and ERK phosphorylation in some AML cell lines but a paradoxical increase in MEK/ERK phosphorylation in RAS-mutated AML. These studies reveal SYK as a regulator of mTOR and MAPK signaling in AML and demonstrate that inhibition of PI3K pathway activity enhances the effects of SYK inhibition on AML cell viability and differentiation.

Abstract P4-07-01: The Class I Selective PI3K Inhibitor GDC-0941 Enhances the Efficacy of Docetaxel in Human Breast Cancer Models by Increasing the Rate of Apoptosis

Docetaxel (DTX) is commonly used as a front-line treatment option for breast cancer but many patients ultimately relapse and succumb to disease progression. Phosphatidylinositol 3-kinases (PI3K) are lipid kinases that regulate breast tumor cell growth, migration and survival. Given that phosphatidylinositol 3-kinase (PI3K) is frequently activated in breast cancer and induces chemo-resistance, it is an attractive target for combination therapy with standard of care drugs such as DTX. The current study was intended to determine if GDC-0941, an orally bioavailable class I selective PI3K inhibitor, enhances the anti-tumor activity of DTX in human breast cancer models in vitro and in vivo. A panel of 25 breast tumor cell lines representing luminal, HER2+ and basal sub-types were treated with GDC-0941, DTX or the combination of both drugs and assayed for cellular viability, modulation of PI3K pathway markers and apoptosis induction. The combination of GDC-0941 and DTX decreased the cellular viability of breast tumor cell lines in vitro but with variable drug synergy. The addition of both drugs resulted in stronger synergistic effects in a sub-set of tumor cell lines that was not predicted by breast cancer sub-type or mutations within the PI3K pathway. Human xenografts of breast cancer cell lines and patient-derived tumors were utilized to assess efficacy of GDC-0941 and DTX in vivo. In these models, the best combination efficacy was detected when the two drugs were dosed within 1 hour of each other. We also observed that GDC-0941 increased the rate of apoptosis in cells arrested in mitosis upon co-treatment with DTX. Our data provides a preclinical rationale for evaluating GDC-0941 in combination with DTX for breast cancer treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-07-01.