Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Unmasking the Confounder: The Inherent Physiologic Variability of Swine During an Automated Experimental Model of Ischemia-Reperfusion Injury

BACKGROUND

We sought to determine the magnitude of the inherent inter-animal physiologic variability by automating a porcine Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) protocol to minimize external influences that might alter physiology and confound experimental results.

METHODS

Swine (n = 42) underwent a controlled 30% blood volume hemorrhage followed by 30 minutes of REBOA (ie, ischemic phase). The animals were weaned from REBOA autonomously over 15 minutes, beginning the reperfusion phase, while continuing to provide partial flow balloon support to maintain a target proximal mean arterial pressure (pMAP) of 65 mmHg. Simultaneously, shed blood was re-transfused as part of the resuscitation efforts. Physiologic data were continuously recorded, and serum samples were serially collected. Baseline characteristics, variance in vital signs, and 8-isoprostane levels were quantified during hemorrhage, REBOA, and reperfusion phases.

RESULTS

There was no significant difference in baseline physiology across animals (P > .05). Hemodynamic variability was highest for pMAP during the ischemic phase (P = .001) and for distal mean arterial pressure (dMAP) during the weaning/reperfusion phase (P = .001). The latter finding indicated the variable physiologic response to ischemia-reperfusion injury, as the automated balloon support required by each animal to maintain pMAP was highly variable. Circulating 8-isoprostane variance was significantly higher following the start of reperfusion compared to baseline levels (P = .001).

DISCUSSION

Despite subjecting animals to a highly consistent ischemia-reperfusion injury through automation, we noted significant variability in the hemodynamic and biochemical response. These findings illustrate the inherent physiologic variability and potential limitations of porcine large animal models for the study of shock.

POS1026 PREDICTORS FOR ACHIEVEMENT OF LOW DISEASE ACTIVITY AT WEEK 56 IN PATIENTS WITH PSORIATIC ARTHRITIS WHO RECEIVED UPADACITINIB 15 MG ONCE DAILY: POOLED ANALYSIS OF TWO PHASE 3 STUDIES

Background

Upadacitinib (UPA) 15 mg once daily (QD) has demonstrated efficacy and safety in patients with psoriatic arthritis (PsA) for up to 56 weeks in the Phase 3 SELECT-PsA 1 and 2 trials.1,2

Objectives

This post hoc analysis of these studies explored the association of baseline characteristics and short-term responses with achievement of minimal disease activity (MDA) and Disease Activity Index for Psoriatic Arthritis (DAPSA) low disease activity (LDA).

Methods

Data were pooled from patients with prior inadequate response or intolerance to ≥1 non-biologic (b) DMARDs (SELECT-PsA 1) or ≥1 bDMARDs (SELECT-PsA 2) originally randomized to UPA 15 mg QD. Logistic regression models were used to assess the association between baseline characteristics and short-term (Week 12) responses with achieving MDA or DAPSA LDA at 56 weeks, sustained MDA (MDA at Weeks 36 and 56), or sustained DAPSA LDA (DAPSA LDA at Weeks 36, 44, and 56). Each predictor was evaluated separately in an initial model that included effects for study and concurrent non-bDMARD use. Odds ratios and concordance (c-)statistics were used to determine the predictive accuracy. Statistically significant predictors were then evaluated simultaneously using stepwise logistic regression with the Akaike Information Criterion for model-building.

Results

Of 640 patients included in the analysis, 40% and 47% achieved MDA and DAPSA LDA, respectively, at 56 weeks. Evaluated separately, younger age, sex (male), geographic region, lower weight, lower body mass index, the presence of dactylitis or enthesitis, and lower scores of Patient’s Assessment of Pain (Pt-Pain), Patient’s Global Assessment (PtGA), tender joint count in 68 joints, and Health Assessment Questionnaire-Disability Index (HAQ-DI) were significant baseline predictors for achieving MDA and DAPSA LDA at Week 56. Lower Pt-Pain (Weeks 12–24) and PtGA (Weeks 16–24) scores were strongly predictive (c-statistics >0.8) of achieving MDA at Week 56, and both measures (from Week 8) were moderately predictive (c-statistics >0.7) of achieving DAPSA LDA. Evaluated simultaneously with several baseline characteristics, lower Pt-Pain and HAQ-DI scores at Week 12 were included in models strongly predictive of achieving MDA (c-statistic=0.850; Figure 1) and DAPSA LDA (c-statistic=0.840; Figure 2) at Week 56. For each 1-point increase in Pt-Pain or HAQ-DI scores at Week 12 (after adjusting for other effects in the model), patients were less likely to achieve MDA (by 32% or 56%, respectively) or DAPSA LDA (by 23% or 31%, respectively) at Week 56. Predictors for achieving sustained MDA and sustained DAPSA LDA were generally similar to those identified for achieving MDA and DAPSA LDA, respectively.

Conclusion

In patients with PsA receiving UPA 15 mg, baseline characteristics and early responses strongly predicted achievement of MDA or DAPSA LDA at Week 56. This may guide considerations of treatment targets in clinical trials and encourage physicians to further optimize treatment of their patients in clinical practice.

References

[1]McInnes IB, et al. Ann Rheum Dis 2020;79:16–7.

[2]Mease PJ, et al. Rheumatol Ther 2021 [Epub ahead of print].

Acknowledgements

AbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, review, and approval of the abstract. No honoraria or payments were made for authorship. Medical writing support was provided by Hilary Wong, PhD, of 2 the Nth (Cheshire, UK), which was funded by AbbVie.

Disclosure of Interests

Daniel Aletaha Consultant of: AbbVie, Grünenthal, Janssen, Medac, Merck, Mitsubishi/Tanabe, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, Grünenthal, Janssen, Medac, Merck, Mitsubishi/Tanabe, Pfizer, Roche, and UCB, Philip J Mease Speakers bureau: AbbVie, Amgen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Eli Lilly, Galapagos, Genentech, Gilead, and Janssen, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Eli Lilly, Galapagos, Genentech, Gilead, and Janssen, Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lilly, and Janssen, Ralph Lippe Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Frank Behrens Speakers bureau: AbbVie, Amgen, Boehringer Ingelheim, Celgene, Chugai, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Celgene, Chugai, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, and UCB, Grant/research support from: Chugai, GlaxoSmithKline, Janssen, Pfizer, and Roche, Derek Haaland Speakers bureau: AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, Eli Lilly, GlaxoSmithKline, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, Takeda, and UCB, Consultant of: AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, Eli Lilly, GlaxoSmithKline, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, Takeda, and UCB, Grant/research support from: AbbVie, Adiga Life Sciences, Amgen, Bristol-Myers Squibb, Can-Fite BioPharma, Celgene, Eli Lilly, Gilead, GlaxoSmithKline, Janssen, Novartis, Pfizer, Regeneron, Sanofi, and UCB, Penelope Palominos Speakers bureau: AbbVie, Janssen, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Janssen, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Janssen, Novartis, Pfizer, and UCB, Apinya Lertratanakul Shareholder of: formerly of AbbVie, Employee of: former employee of AbbVie, Michael Lane Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Kevin Douglas Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Peter Nash Speakers bureau: AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, and UCB, Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, and UCB, Grant/research support from: AbbVie, Bristol-Myers Squibb, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi, and UCB, Arthur Kavanaugh Speakers bureau: AbbVie, Amgen, Janssen, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Janssen, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, Janssen, Novartis, Pfizer, and UCB

POS1030 EFFICACY OF UPADACITINIB IN PATIENTS WITH PSORIATIC ARTHRITIS STRATIFIED BY BASELINE SKIN SEVERITY: A SUBGROUP ANALYSIS OF TWO PHASE III TRIALS

Background:

In the SELECT-PsA 1 and 2 clinical trials, upadacitinib (UPA) demonstrated efficacy and safety in patients (pts) with active psoriatic arthritis (PsA).1,2 PsA is associated with varying degrees of psoriatic symptoms; however, the impact of skin severity on treatment outcomes is not well understood.

Objectives:

This post-hoc analysis assessed the effects of baseline skin severity on UPA efficacy.

Methods:

SELECT-PsA 1 and SELECT-PsA 2 enrolled pts with PsA and prior inadequate response (IR) or intolerance to ≥1 non-biologic disease-modifying antirheumatic drug (DMARD)1 or ≥1 biologic DMARD2, respectively. In both trials, pts received once daily UPA 15 mg or UPA 30 mg or placebo (switched at Wk 24 to either UPA 15 mg or 30 mg); SELECT-PsA 1 also included the active comparator adalimumab (ADA). Only continuous UPA 15 mg and ADA are presented here. In this analysis, pts were divided into subgroups based on the extent of psoriasis at baseline (body surface area [BSA] of ≥3%-<10% or BSA ≥10%); efficacy endpoints were analyzed at Wk 56. Results for binary endpoints are based on non-responder imputation; continuous endpoints are based on mixed model repeated measures analysis with as-observed data.

Results:

In the UPA 15 mg and ADA groups, respectively, 32% (138/429) and 31% (132/429) of pts had a BSA ≥3-<10% at baseline in SELECT-PsA 1; 18% (76/429) in each treatment group had a BSA ≥10%. In SELECT-PsA 2, 38% (80/211) had a BSA ≥3-<10% and 24% (50/211) had a BSA ≥10% at baseline in the UPA 15 mg group. Across pt populations (non-biologic DMARD-IR and biologic DMARD-IR), generally consistent results were observed between patients in both skin severity subgroups (Figure 1). In non-biologic DMARD-IR pts, a numerically greater proportion of UPA 15 mg pts with lower skin involvement compared with higher skin involvement achieved PASI100 and PASI≤1, two more stringent skin endpoints. The achievement of MDA was generally consistent across skin severity subgroups; when pts were required to achieve the skin component of MDA, results were numerically better in the ≥3-<10% skin severity group (Table 1). In non-biologic DMARD-IR pts, results were similar between UPA 15 mg and ADA.

Conclusion:

UPA is a viable treatment option for pts with active PsA regardless of the extent of psoriasis at baseline. Although these results are of interest and hypothesis-generating, they should be interpreted with caution due to low sample size.

References:

[1]McInnes IB et al. Ann Rheum Dis, 2020; 79:12

[2]Mease PJ et al. Ann Rheum Dis, 2020; doi: 10.1136/annrheumdis-2020-218870

Table 1.

Additional Efficacy Outcomes at Week 56 Stratified by Severity of Skin Involvement at Baseline

SELECT-PsA 1n/N (%) [95% CI]UPA 15 mgADAsIGA 0/1 w/at least 2 point improvement from BLa ≥3%-<10%71/128 (55.5) [46.9, 64.1]53/124 (42.7) [34.0, 51.4] ≥10%29/76 (38.2) [27.2, 49.1]33/77 (42.9) [31.8, 53.9]MDA + skinb ≥3%-<10%58/138 (42.0) [33.8, 50.3]56/132 (42.4) [34.0, 50.9] ≥10%19/76 (25.0) [15.3, 34.7]28/79 (35.4) [24.9, 46.0]SELECT-PsA 2n/N (%) [95% CI]UPA 15 mgsIGA 0/1 w/at least 2 point improvement from BLa ≥3%-<10%24/71 (33.8) [22.8, 44.8] ≥10%18/50 (36.0) [22.7, 49.3] MDA + skinb ≥3%-<10%22/80 (27.5) [17.7, 37.3] ≥10%9/50 (18.0) [7.4, 28.6]

a defined as achieving an sIGA score of 0 or 1 and at least a 2 point improvement from BL, evaluated in pts with BL sIGA ≥2.

b defined as achieving 5 of the 7 criteria, with PASI ≤1 or BSA-psoriasis ≤3 as a required component.

ADA, adalimumab; BL, baseline; CI, confidence interval; MDA, minimal disease activity; sIGA, Static Investigator Global Assessment of psoriasis; UPA, upadacitinib

Acknowledgements:

AbbVie and the authors thank the patients, study sites, and investigators who participated in this clinical trial. AbbVie, Inc was the study sponsor, contributed to study design, data collection, analysis & interpretation, and to writing, reviewing, and approval of final version. No honoraria or payments were made for authorship. Medical writing support was provided by Ramona Vladea, PhD and Jamie Urbanik, PharmD both of AbbVie Inc.

Disclosure of Interests:

Joseph F. Merola Consultant of: Merck, Bristol-Myers Squibb, AbbVie, Dermavant, Eli Lilly, Novartis, Janssen, UCB, Celgene, Sanofi, Regeneron, Arena, Sun Pharma, Biogen, Pfizer, EMD Sorono, Avotres and Leo Pharma, Pascal Richette Consultant of: AbbVie, Biogen, Janssen, BMS, Roche, Pfizer, Amgen, Sanofi-Aventis, UCB, Lilly, Novartis, and Celgene, Ennio Lubrano Speakers bureau: AbbVie, Celgene, Janssen, MSD, Novartis, and Pfizer, Consultant of: AbbVie, Celgene, Janssen, MSD, Novartis, and Pfizer, Grant/research support from: AbbVie, Celgene, Janssen, MSD, Novartis, and Pfizer, Edit Drescher: None declared, Lilian Soto: None declared, Charles Lovan Shareholder of: AbbVie, Employee of: AbbVie, Koji Kato Shareholder of: AbbVie, Employee of: AbbVie, Ralph Lippe Shareholder of: AbbVie, Employee of: AbbVie, Michael Lane Shareholder of: AbbVie, Employee of: AbbVie, Mitsumasa Kishimoto Consultant of: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Celgene, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma.

AB0547 ASSOCIATION BETWEEN ACHIEVEMENT OF LOW DISEASE ACTIVITY OR REMISSION WITH IMPROVEMENT IN QUALITY OF LIFE IN UPADACITINIB-TREATED PATIENTS IN THE PHASE 3 SELECT-PsA 1 AND 2 STUDIES

Background:

The efficacy and safety of upadacitinib (UPA) in patients (pts) with active psoriatic arthritis (PsA) was demonstrated in the phase 3 SELECT-PsA 1 and SELECT-PsA 2 clinical trials.1,2

Objectives:

To explore the relationship between achievement of low disease activity (LDA) or remission (REM) and pt-reported outcomes (PROs) in SELECT-PsA 1 and 2.

Methods:

The SELECT-PsA program enrolled pts with prior inadequate response or intolerance to ≥1 non-biologic disease-modifying antirheumatic drug (DMARD; SELECT-PsA 1) or ≥1 biologic DMARD (SELECT-PsA 2). Pts were randomized to 56 weeks (wks) of blinded treatment with UPA 15 or 30 mg once daily (QD), placebo switched to UPA 15 or 30 mg QD at Wk 24, or adalimumab (SELECT-PsA 1 only) 40 mg every other wk. LDA and REM were evaluated using the minimal disease activity (MDA; fulfillment of 5 out of 7) criteria and the Disease Activity index for Psoriatic Arthritis (DAPSA; cutoff ≤4), respectively. PROs assessed included Health Assessment Questionnaire-Disability Index (HAQ-DI), 36-Item Short-Form Survey physical component summary (SF-36 PCS), 5-Level EuroQol 5-Dimension (EQ-5D-5L) Index, and EQ-5D-5L Visual Analog Scale (VAS). Integrated data through Wk 56 from SELECT-PsA 1 and 2 from the full analysis set with both continuous UPA 15 mg and 30 mg groups were analyzed by responder status at Wks 24 and 56. Changes from baseline (BL) in PROs were analyzed using mixed effects repeated measures models (fixed effects for study, current use of non-biologic DMARDs, treatment group, visit, responder status, and continuous BL PROs). As-observed data were used in the models.

Results:

A total of 1281 pts were included in the analysis (UPA 15 mg, n=640; UPA 30 mg, n=641). MDA was achieved by 33% (UPA 15 mg) and 40% (UPA 30 mg) of patients at

Wk 24, and 40% (UPA 15 mg) and 43% (UPA 30 mg) at Wk 56; and DAPSA-REM by 10% (UPA 15 mg) and 17% (UPA 30 mg) at Wk 24, and 16% (UPA 15 mg) and 18% (UPA 30 mg) at Wk 56. Pts who achieved MDA or DAPSA-REM (responders) at Wk 56 achieved larger reductions in HAQ-DI and larger increases in SF-36 PCS, EQ-5D-5L Index and EQ-5D-5L VAS compared with non-responders (Table 1) (all p<0.0001; statistical significance was exploratory in nature). MDA or DAPSA-REM response at Wk 24 was also associated with greater PRO improvements at Wk 56 (Figure 1). Consistent with the results presented for MDA and DAPSA-REM, patients who achieved Very Low Disease Activity or DAPSA-LDA also experienced greater improvements in PROs than those who did not.

Table 1.

Change from BL in PROs at Wk 56 by MDA and DAPSA-REM responder status at Wk 56

UPA 15 mg QD(n=640)UPA 30 mg QD(n=641)Least squares mean change from BL(95% CI), unless stated otherwiseNon-responderResponderNon-responderResponderMDA, na386254368273HAQ-DI−0.26 (−0.30, −0.22)−0.61* (−0.66, −0.56)−0.27 (−0.31, −0.23)−0.69* (−0.74, −0.64)SF-36 PCS5.25 (4.60, 5.90)12.63* (11.84, 13.41)5.09 (4.42, 5.75)13.84* (13.08,14.59)EQ-5D-5L Index0.11 (0.09, 0.12)0.25* (0.23, 0.26)0.10 (0.09, 0.12)0.27* (0.25, 0.28)EQ-5D-5L VAS9.3 (7.8, 10.9)23.3* (21.4, 25.1)9.0 (7.4, 10.5)26.1* (24.4, 27.9)DAPSA-REM, na539101526115HAQ-DI−0.36 (−0.39, −0.32)−0.63* (−0.71, −0.55)−0.39 (−0.43, −0.35)−0.71* (−0.78, −0.63)SF-36 PCS6.99 (6.39, 7.59)14.54* (13.22, 15.86)7.43 (6.82, 8.03)15.16* (13.91, 16.40)EQ-5D-5L Index0.14 (0.13, 0.15)0.27* (0.24, 0.30)0.15 (0.14, 0.16)0.29* (0.26, 0.31)EQ-5D-5L VAS12.7 (11.3, 14.0)26.7* (23.7, 29.8)13.3 (11.9, 14.7)30.0* (27.1, 32.8)

*p<0.0001 vs non-responder (statistical significance was exploratory in nature)

an may vary by PRO assessed

Conclusion:

Among UPA-treated pts with PsA, improvements in quality of life and physical function were greater in pts who achieved MDA or DAPSA-REM than in those who did not. Despite DAPSA-REM being a more stringent measure (achieved by a smaller proportion of patients), these improvements were similar between MDA and DAPSA-REM responders.

References:

[1]McInnes I, et al. Ann Rheum Dis 2020;79(Suppl 1):16–7; 2. Mease PJ, et al. Ann Rheum Dis 2020

Figure 1.

Acknowledgements:

AbbVie funded this study; contributed to its design; participated in data collection, analysis, and interpretation of the data; and participated in the writing, review, and approval of the abstract. No honoraria or payments were made for authorship. Medical writing support was provided by Laura Chalmers, PhD, of 2 the Nth (Cheshire, UK), and was funded by AbbVie.

Disclosure of Interests:

Arthur Kavanaugh Grant/research support from: Research grants and/or personal fees from AbbVie, Amgen, Bristol-Myers Squibb, Eli Lilly, Janssen, Novartis, and Pfizer, Philip J Mease Grant/research support from: Research grants and personal fees from AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lilly, and Janssen; and personal fees from Boehringer Ingelheim, Galapagos, Genentech, and Gilead, Kevin Douglas Employee of: Employee of AbbVie and may own stock or options, Frank Behrens Grant/research support from: Research grants from Celgene, Chugai, Janssen, Pfizer, and Roche; personal fees from AbbVie, Boehringer Ingelheim, Celgene, Chugai, Eli Lilly, Genzyme, Janssen, MSD, Novartis, Pfizer, Roche, and Sanofi; and investigator fees from Eli Lilly, Derek Haaland Speakers bureau: Advisory board/speaker bureau membership for AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, GSK, Janssen, Novartis, Pfizer, Roche, Sanofi, and Takeda, Consultant of: Honoraria or other fees from AbbVie, Amgen, AstraZeneca, Bristol-Myers Squibb, Eli Lilly, GSK, Janssen, MSD, Novartis, Pfizer, Roche, Sanofi, Takeda, and UCB, Grant/research support from: Research grants from AbbVie, Adiga Life Sciences, Amgen, Bristol-Myers Squibb, Can-Fite Biopharma, Celgene, Eli Lilly, Gilead, GSK, Janssen, Novartis, Pfizer, Regeneron, Sanofi Genzyme, and UCB, Penelope Palominos Speakers bureau: Advisory board/speaker bureau membership for Janssen and Novartis, Consultant of: Personal fees from AbbVie, Grant/research support from: Research support from Novartis, Pfizer, and Roche, Apinya Lertratanakul Employee of: Employee of AbbVie and may own stock or options, Michael Lane Employee of: Employee of AbbVie and may own stock or options, Ralph Lippe Employee of: Employee of AbbVie and may own stock or options, Daniel Aletaha Consultant of: AbbVie, Grünenthal, Janssen, Medac, Mitsubishi Tanabe, MSD, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, Grünenthal, Janssen, Medac, Mitsubishi Tanabe, MSD, Pfizer, Roche, and UCB, Peter Nash Grant/research support from: Received honoraria and research support from AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Eli Lilly, Gilead/Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, Samsung, Sanofi, and UCB.

Selective Lobe Ventilation and a Novel Platform for Pulmonary Drug Delivery

The current methods of mechanical ventilation and pulmonary drug delivery do not account for the heterogeneity of acute respiratory distress syndrome or its dependence on gravity. The severe lung disease caused by severe acute respiratory distress syndrome coronavirus 2, coronavirus disease 2019, is one of the many causes of acute respiratory distress syndrome. Severe acute respiratory distress syndrome coronavirus 2 has caused more than three million deaths worldwide and has challenged all therapeutic options for mechanical ventilation. Thus, new therapies are necessary to prevent deaths and long-term complications of severe lung diseases and prolonged mechanical ventilation. The authors of the present report have developed a novel device that allows selective lobe ventilation and selective lobe recruitment and provides a new platform for pulmonary drug delivery. A major advantage of separating lobes that are mechanically heterogeneous is to allow for customization of ventilator parameters to match the needs of segments with similar compliance, a better overall ventilation perfusion relationship, and prevention of ventilator-induced lung injury of more compliant lobes. This device accounts for lung heterogeneity and is a potential new therapy for acute lung injury by allowing selective lobe mechanical ventilation using two novel modes of mechanical ventilation (differential positive end-expiratory pressure and asynchronous ventilation), and two new modalities of alveolar recruitment (selective lobe recruitment and continuous positive airway pressure of lower lobes with continuous ventilation of upper lobes). Herein the authors report their initial experience with this novel device, including a brief overview of device development; the initial in vitro, ex vivo, and in vivo testing; layout of future research; potential benefits and new therapies; and expected challenges before its uniform implementation into clinical practice.

IL-1α Modulates IFN-γ-Induced Production of CXCL9/MIG during Herpes Simplex Virus Type-1 Corneal Infection

PURPOSE

Investigating the modulation of neutrophil production of MIG and IP-10 during the inflammatory response to HSV-1 infection.

MATERIALS AND METHODS

An ex vivo model of human corneal infection by HSV-1 was used for this study. This model permits the study of cytokine production by human corneal buttons in the presence, or absence, of gradient purified human neutrophils, under conditions of HSV-1 infection. All experimental samples were stimulated with a baseline concentration of recombinant human IFN-γ at 1 ng/mL. The relative levels of production for 12 pro-inflammatory mediators were screened using a multi-analyte ELISA assay. Neutrophil production of chemokines MIG and IP-10, under conditions of IFN-γ and/or HSV-1 stimulation were measured by quantitative ELISA. Lastly, antibody neutralization (goat IgG anti-human IL-1α, 2 µg/mL) of de novo production of IL-1α by corneal tissue was performed to investigated the effect on MIG and IP-10 production in the ex vivo model for HSV-1 infection.

RESULTS

Four of the 12 pro-inflammatory mediators screened (IL-8, IL-6, IL-1α and IL-1β) demonstrated elevated levels of production during corneal cell infection with HSV-1 and communication with neutrophils. Neutrophils were demonstrated to produce significant levels of both MIG and IP-10 under conditions of IFN-γ stimulation, and production of MIG was further upregulated by co-stimulation with IFN-γ and HSV-1. Neutralization of de novo IL-1α production in the model resulted in increased production of the chemokine production MIG but had no observable effect on IP-10 production.

CONCLUSIONS

Our data provide evidence demonstrating the potential for expression patterns of MIG and IP-10 to be modulated by IL-1α, during the inflammatory response to HSV-1 corneal infection. Both corneal cells and neutrophils contribute to the production of T cell recruiting chemokines. However, IL-1α has the potential to upregulate MIG production by corneal cells while down-regulating MIG production by neutrophils.

AB0323 DEMYELINATING DISEASE AFTER EXPOSURE TO TUMOR NECROSIS FACTOR ALPHA INHIBITORS (TNFI): LONG-TERM OUTCOMES FROM A SINGLE CENTER

Background:

TNFi are effective treatments for multiple immune-mediated inflammatory diseases. There are five TNFi’s approved for clinical use. Despite their acceptable safety/efficacy profile, serious side effects have been reported, including central and peripheral nervous system demyelinating diseases (DD).ͥ Causation remains controversial and there is a paucity of data on the long-term outcomes in these patients.

Objectives:

To assess long term outcomes in patients with DD related to TNFi use.

Methods:

We conducted a database search and then retrospective chart review to identify patients with potential TNFi related neurologic events at a university medical center between 2006 and 2016. 15 total patients (13 living, 2 deceased) were ultimately identified. Six were able to be contacted by phone to assess their current status. Four of these patients were able to attend a one time-visit to complete a neurologic assessment and musculoskeletal examination. Interviews over the phone or in person were used to complete multiple assessments for disability.

Results:

15 patients with DD were identified from among 4600 patients on TNFi’s for various indications (0.3%). Mean duration of follow-up was 6.8 years. Neurologic symptoms occurred >12 months after starting a TNFi in 8/15 (53%) patients. 47% of patients had been exposed to two or more TNFi’s. 40% received some form of treatment for their DD, including MS disease modifying therapies, IVIG and immunosuppression. No patients experienced worsening DD after stopping their TNFi except for one patient with MS who experienced a repeat flare. Two of three patients diagnosed with MS after TNFi had a first degree relative with MS. 3/15 (20%) experienced complete resolution of their symptoms. Two patients were deceased; cause of death was thought not directly related to DD on chart review.

Conclusion:

Prevalence of DD after TNFi exposure was low at our center, consistent with previously published data. Presentations included both central and peripheral demyelinating events. With the exception of one patient who developed MS, withdrawal of TNFi’s appeared to halt further progression or development of new neurologic symptoms. It is unclear if treatment for DD is beneficial after diagnosis and TNFi withdrawal.

Patient Data:

Table.

Baseline characteristics and 6-month outcome of patients who have switched from originator to ABP 501

AgeSexIndicationTNFi at time of eventNeurologic Presentation/DiagnosisDuration of follow-up, yearsDD status at last follow-up32FJIAEAtaxia, paresthesias, dysarthria, nystagmus, tetraparesis11Persistent despite tx58MPsAGParesthesias9Improved no tx38FASANumbness and weakness5Resolved, no tx54MPsAEParesthesias, cognitive impairment10Persistent, no tx51FASAIncontinence, paresthesias10Persistent, no tx26FCrohn’sAOptic neuritis11Resolved, no tx49MPsAAMultifocal motor neuropathy3Resolved after tx37MPsAAWeakness, spasticity, paresthesias, optic neuritis9Persistent, on tx33FPsAAOptic neuritis, transverse myelitis (MS)5Flared, no tx59FPsAETransverse myelitis (MS)9Deceased45FASITransverse myelitis7Deceased70MRAACIDP1Received treatment but lost to follow-up34FCrohn’sASmall fiber neuropathy11Persistent, no tx62FRAEOptic neuritis<1Lost to follow-up after initial visit42MUveitis, retinal vasculitisAParesthesias (MS)1Persistent, on tx

Juvenile idiopathic arthritis (JIA), Psoriatic arthritis (PsA), Ankylosing spondylitis (AS), Rheumatoid Arthritis (RA)

Adalimumab (A), Etanercept (E), Golimumab (G), Infliximab (I)

Treatment (tx)

References:

[1]ͥKemanetzoglou E, Andreadou E. CNS Demyelination with TNF-α Blockers.Curr Neurol Neurosci Rep. 2017;17(4):36. doi:10.1007/s11910-017-0742-1

Disclosure of Interests:

Nicholas Stienstra: None declared, Michael Lane: None declared, Joel Horton: None declared, Anand Kumthekar: None declared, Nishad Sathe: None declared, Christy Sunny: None declared, Vijayshree Yadav Consultant of: Alexion (one time consulting fee), Atul Deodhar Grant/research support from: AbbVie, Eli Lilly, GSK, Novartis, Pfizer, UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB

Abstract P3-02-02: Targeting the tumor microenvironment: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with breast cancer (BC) at high risk for recurrence

Background: Bone marrow derived VEGFR2+ endothelial progenitor cells (EPCs) and copper-dependent pathways, including lysyl oxidase (LOX), are critical components to remodeling the tumor microenvironment and establishing the pre-metastatic niche. In preclinical models, it has been well established that copper depletion (CD) inhibits tumor progression. We hypothesized that TM-associated CD would reduce EPCs and other copper dependent processes in the pre-metastatic niche in BC pts at high risk for relapse. We investigated the relationship between CD and its effect on EPCs and other components of the tumor microenvironment including LOX, an enzyme critical for cross-linkage of collagen and priming the pre-metastatic niche.

Methods: In this single arm, phase II study, BC pts at high risk for recurrence, defined as node+ triple negative (TN), stage 3 and 4 with no evidence of disease (NED) were enrolled on a trial of CD with TM. Pts received oral TM to maintain ceruloplasmin (Cp) between 5-17 mg/dl for 2 years on the primary study. The primary endpoint was change in EPCs measured by flow cytometry before and during treatment with TM. Secondary endpoints included tolerability, safety and effect of copper depletion on other markers including LOX, quantified by ELISA.

Results: We enrolled 75 pts. The study treatment duration was 24 cycles (each cycle is 28 days). Over 2200 cycles have been administered. The median age is 51 (range 29-66). 45 pts have Stage 2/3 BC and 30 are Stage 4 NED. TNBC pts represent 48%, and 40% of pts are Stage 4 NED. Median Cp level decreased from 28 at baseline to 15.5 (p&lt;0.0001) after one cycle. Copper depletion was most efficient in TNBC, with 91% achieving a target CP within 4 weeks. TM was well tolerated and the only grade 3/4 toxicities were reversible neutropenia (3.2%) and anemia (0.0005%). CD was associated with a significant decrease in EPCs (p=0.0014) and LOX (p&lt;0.001). At a median follow-up of 5.4 years, the PFS for all 75 pts from the start of TM treatment was 71%, including a PFS of 90% for all stage 2/3 pts with TNBC. The overall survival of all patients enrolled in the trial is 86%. Relapse after two years is a rare event. Conclusions: TM is safe, well tolerated and appears to affect multiple copper dependent biologic processes in the tumor microenvironment known to be important for tumor progression. This seems to be most striking in TNBC. We believe, further phase III trials in a high risk for relapse population are warranted.

Citation Format: Nackos E, Willis A, Kornhauser N, Ward M, Andreopoulou E, Cigler T, Moore A, Fitzpatrick V, Cobham M, Schneider S, Wiener A, Guillaume-Abraham J, Warren JD, Rubinchik A, Lane M, Mittal V, Vahdat L. Targeting the tumor microenvironment: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with breast cancer (BC) at high risk for recurrence. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-02-02.

When two obese parents are worse than one! Impacts on embryo and fetal development

The prevalence of overweight and obesity in reproductive-age adults is increasing worldwide. While the effects of either paternal or maternal obesity on gamete health and subsequent fertility and pregnancy have been reported independently, the combination of having both parents overweight/obese on fecundity and offspring health has received minimal attention. Using a 2 × 2 study design in rodents we established the relative contributions of paternal and maternal obesity on fetal and embryo development and whether combined paternal and maternal obesity had an additive effect. Here, we show that parental obesity reduces fetal and placental weights without altering pregnancy establishment and is not dependent on an in utero exposure to a high-fat diet. Interestingly combined parental obesity seemed to accumulate both the negative influences of paternal and maternal obesity had alone on embryo and fetal health rather than an amplification, manifested as reduced embryo developmental competency, reduced blastocyst cell numbers, impaired mitochondrial function, and alterations to active and repressive embryonic chromatin marks, resulting in aberrant placental gene expression and reduced fetal liver mtDNA copy numbers. Further understanding both the maternal cytoplasmic and paternal genetic interactions during this early developmental time frame will be vital for understanding how developmental programming is regulated and for the proposition of interventions to mitigate their effects.

Correction: X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function

Correction for 'X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function' by M. J. Ceko et al., Metallomics, 2014, DOI: .

X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function

Studies of selenium (Se) status indicate that Se is necessary for fertility but how precisely is not known. We aimed to show that Se was important in bovine female reproductive function. The elemental distribution in the bovine ovary (n = 45 sections) was identified by X-ray fluorescence (XRF) imaging. Se was consistently localized to the granulosa cell layer of large (>10 mm) healthy follicles. Inductively Coupled Plasma - Mass Spectrometry revealed tenfold higher Se in the bovine follicle wall compared to corpora lutea. Gene expression analysis of selenoprotein genes GPX1, GPX3, VIMP and SELM in bovine granulosa cells revealed that only GPX1 was significantly up-regulated in large healthy follicles compared to the small healthy or atretic follicles (P < 0.05). Western immunoblotting identified GPX1 protein in bovine granulosa cells of large healthy follicles, but not of small healthy follicles. To assess if GPX1 was important in human follicles, cumulus cells from women undergoing IVF/ICSI with single embryo transfer were collected. Oocytes and embryos were cultured and transferred independently in 30 patients undergoing elective single embryo transfer. Gene expression of GPX1 was significantly higher in human cumulus cells from cumulus-oocyte complexes yielding a pregnancy (P < 0.05). We present the first XRF imaging of mammalian ovaries showing that Se is consistently localized to the granulosa cells of large healthy follicles. We conclude that Se and selenoproteins are elevated in large healthy follicles and may play a critical role as an antioxidant during late follicular development.

Assessing the function of homologous recombination DNA repair in malignant pleural effusion (MPE) samples

Background:

Patients with malignant pleural effusions (MPEs) generally have advanced disease with poor survival and few therapeutic options. Cells within MPEs may be used to stratify patients for targeted therapy. Targeted therapy with poly(ADP ribose) polymerase inhibitors (PARPi) depends on identifying homologous recombination DNA repair (HRR)-defective cancer cells. We aimed to determine the feasibility of assaying HRR status in MPE cells.

Methods:

A total of 15 MPE samples were collected from consenting patients with non-small-cell lung cancer (NSCLC), mesothelioma and ovarian and breast cancer. Primary cultures were confirmed as epithelial by pancytokeratin, and HRR status was determined by the detection of γH2AX and RAD51 foci following a 24-h exposure to rucaparib, by immunofluorescence microscopy. Massively parallel next-generation sequencing of DNA repair genes was performed on cultured MPE cells.

Results:

From 15 MPE samples, 13 cultures were successfully established, with HRR function successfully determined in 12 cultures. Four samples – three NSCLC and one mesothelioma – were HRR defective and eight samples – one NSCLC, one mesothelioma, one sarcomatoid, one breast and four ovarian cancers – were HRR functional. No mutations in DNA repair genes were associated with HRR status, but there was probable loss of heterozygosity of FANCG, RPA1 and PARP1.

Conclusions:

HRR function can be successfully detected in MPE cells demonstrating the potential to stratify patients for targeted therapy with PARPi.

210 FACTORS AFFECTING SUPEROVULATION RESPONSE IN CATTLE: A RETROSPECTIVE STUDY

Superovulation, embryo collection, and transfer allow for genetic improvement resulting in more rapid enhancement of production traits. Despite these advantages, variability in the response to superovulation has been observed between and within individual animals, becoming a costly inconvenience of these techniques. The purpose of this study was to evaluate the factors that influenced the superovulatory response and the resulting quantity and quality of the ova/embryos collected during embryo flushing in the study group, with cow as the experimental unit. A retrospective study was conducted, evaluating superovulation records from 794 embryo donors collected for the first time. Individual information was classified as breed (Angus or Holstein), parity (heifers or dry cow), body condition score (BCS; 5, 6, or 7 was considered optimal and BCS <5 or >7 was considered not optimal; in a 1 to 9 scale), hormonal dose used (375 or 500 IU of FSH), ovarian response (presence of more than one corpus luteum), collection (abnormal: blood or <80% fluid recovered or normal: bicornual >80% fluid recovered) and season at collection (summer, fall, winter, spring) to determine their predictive value for the total number of ova/embryos collected: number of transferable embryos, degenerated embryos, and unfertilized oocytes (UFOs) according to the IETS standards for classification. Variables were evaluated and transformed when needed to establish normality. Binary logistic regression was used to identify predictors of ovarian response or nonresponse. A model was built for each of these dependent variables using a general linear model (GLM). Tukey's post hoc test was used to compare adjusted means between groups when there were significant factors identified by the GLM. The study found a significant difference (P = 0.024) in the percentage of cows responding to superovulation treatment in summer compared with spring (91.5% v. 98.4%). From the 755 donors that responded, the mean number (±s.e.m.) of ova/embryos collected from donors with optimal BCS was higher (P = 0.052) than those from donors with nonoptimal BCS (9.8 ± 0.37 v. 8.4 ± 0.42). The mean numbers of total ova/embryos obtained from normal collections was higher (P < 0.001) than the mean from those collections classified as abnormal (10.25 ± 0.30 v. 6.60 ± 0.62). The mean number of viable embryos from responding donors was 5.66 ± 0.18 per collection. Donors with BCS classified as optimal had significantly higher (P = 0.034) mean number (±s.e.m.) of viable embryos compared with donors with nonoptimal BCS (5.95 ± 0.23 v. 5.18 ± 0.29). For the present study, the percentage of cows treated that responded and were collected decreased in summer. The effect of ambient temperature may be reduced by evaporative cooling of donors or by avoiding collections during the hottest days of the summer. Complications during the collection are rare and can be partially avoided by using experienced technicians only. Results may improve when donors are in an appropriate nutrition status, either by supplementing those animals with low body scores or by restricting diets for those that are overweight, to improve the efficiency of the technique.

Carboxypeptidase E protects hippocampal neurons during stress in male mice by up-regulating prosurvival BCL2 protein expression

Prolonged chronic stress causing elevated plasma glucocorticoids leads to neurodegeneration. Adaptation to stress (allostasis) through neuroprotective mechanisms can delay this process. Studies on hippocampal neurons have identified carboxypeptidase E (CPE) as a novel neuroprotective protein that acts extracellularly, independent of its enzymatic activity, although the mechanism of action is unclear. Here, we aim to determine if CPE plays a neuroprotective role in allostasis in mouse hippocampus during chronic restraint stress (CRS), and the molecular mechanisms involved. Quantitative RT-PCR/in situ hybridization and Western blots were used to assay for mRNA and protein. After mild CRS (1 h/d for 7 d), CPE protein and mRNA were significantly elevated in the hippocampal CA3 region, compared to naïve littermates. In addition, luciferase reporter assays identified a functional glucocorticoid regulatory element within the cpe promoter that mediated the up-regulation of CPE expression in primary hippocampal neurons following dexamethasone treatment, suggesting that circulating plasma glucocorticoids could evoke a similar effect on CPE in the hippocampus in vivo. Overexpression of CPE in hippocampal neurons, or CRS in mice, resulted in elevated prosurvival BCL2 protein/mRNA and p-AKT levels in the hippocampus; however, CPE(-/-) mice showed a decrease. Thus, during mild CRS, CPE expression is up-regulated, possibly contributed by glucocorticoids, to mediate neuroprotection of the hippocampus by enhancing BCL2 expression through AKT signaling, and thereby maintaining allostasis.

Brain lesions associated with clostridium perfringens type D epsilon toxin in a Holstein heifer calf

A 6-month-old dairy heifer calf with no premonitory signs was acutely down after the morning feeding and could not rise. On presentation, the heifer was in right lateral recumbency and moribund with opisthotonus and left hind limb paddling. Following euthanasia, gross examination of the brain revealed multifocal loss of gray-white matter distinction and extensive petechiae throughout the brainstem. On histopathological examination, there was striking white matter edema and marked perivascular proteinaceous edema surrounding many arterioles and venules (microangiopathy), mainly in the white matter of the internal capsule, thalamus, midbrain, cerebellum, and cerebellar peduncles. The perivascular neuropil was strongly positive for Alzheimer precursor protein A4. Clostridium perfringens epsilon toxin was detected in the intestinal contents. This is the first report of microangiopathy in postneonatal cattle associated with the detection of epsilon toxin in the intestinal contents.

Abstract P1-15-07: Ixabepilone-associated peripheral neuropathy in metastatic breast cancer patients and its effects on the ultrastructure of neurons

Background: Peripheral neuropathy is a dose-limiting toxicity of most microtubule-stabilizing chemotherapeutic agents. Ixabepilone, a semisynthetic analog of the natural epothilone B, has activity in a wide range of tumors including taxane-resistant disease. In this study, we sought to understand the effect of ixabepilone on the development of peripheral neuropathy both clinically and its effect at the ultrastructural level of the peripheral nerves and circulating factors over time. Parallel studies in animal models of neuropathy were performed at the same time (Proc AACR 2010 Abstract 4184).

Methods: This open-label, non-randomized phase II study enrolled 14 patients with metastatic breast cancer. Ixabepilone was administered by 2 schedules: the FDA approved dose of 40 mg/m2 every 3 weeks (q3w) and 16 mg/m2 on day 1, 8, and 15 of a 28-day cycle (weekly). Five controls, 2 with residual taxane-associated peripheral neuropathy and 3 with no prior chemotherapy or peripheral neuropathy, were also accrued. The primary objectives were to characterize the natural history of ixabepilone-associated peripheral neuropathy using the Total Neuropathy Score Clinical (TNSc) assessment tool prior to each cycle and to correlate changes in the ultrastructure of dermal myelinated nerve fibers via a 3 mm punch biopsy of an area 10 cm above the lateral malleolus every 2 cycles with electron microscopy (EM), as well as circulating factors (both inflammatory and neurotrophic) considered to be important in the pathogenesis of chemotherapy-induced peripheral neuropathy. Secondary objectives included progression-free survival (PFS) and non-neurologic toxicity.

Results: 14 patients were enrolled and were equally divided between the 2 schedules of ixabepilone chemotherapy. There were no differences in baseline characteristics between the two groups. Mean age was 54 years (range 32–71). Mean number of previous chemotherapy regimens was 3.5 (range 0–8). 57% of patients had received a taxane in the adjuvant setting and 64% in the metastatic setting. The mean neuropathy score (TNSc) at baseline was 4.6 (range 1–11). At a mean cumulative dose of 185 mg/m2, the TNSc with ixabepilone q3w schedule was 3.7 points higher/worse (95% CI: 2.2–5.3, p = 0.03) than the mean score observed in patients on the weekly schedule. The sensory component was most significantly affected, predominantly numbness. In 3 patients, the chemotherapy schedule was changed from every 3 weeks to weekly due to &gt; grade 2 toxicity at a mean cumulative dose of 107 mg/m2, and TNSc decreased/improved by 2.7 points. PFS in patients on q3w ixabepilone was 133 days (range 28–280) and in patients on weekly ixabepilone was 179 days (range 66–336), nonsignificant. Evaluation of EM and circulating factors is ongoing.

Conclusions: Weekly ixabepilone appears to have a more favorable neurotoxicity profile compared to the standard q3w schedule. Integration of the EM data and the circulating factor data are underway and will be presented. Ixabepilone-associated peripheral neuropathy may improve in patients switched to weekly ixabepilone without compromising efficacy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-15-07.

MDM2 overexpression in benign and malignant lesions of the human breast

MDM2 overexpression has been detected in women with benign or cancerous lesions of the breast. Immunohistochemical methods were used to identify overexpression in 11 of 27 benign cases (41%) and 15 of 22 (68%) cancer cases. MDM2 overexpression correlated well with immunohistochemically detected estrogen receptor (ER), suggesting that expression of these proteins was coordinately regulated. To test this, the MCF-10A human breast cell line, negative for both ER and MDM2 expression, was transfected with a wild-type ER. Following transfection, both ER and MDM2 were strongly expressed in two independent clones. Expression of both was reduced in the presence of increasing concentrations of estradiol (10(-10)-10(-8) M) thus, estrogen may be involved in regulation of MDM2 expression in proliferative breast lesions.

Diet-induced paternal obesity in the absence of diabetes diminishes the reproductive health of two subsequent generations of mice

BACKGROUND

Obesity and related conditions, notably subfertility, are increasingly prevalent. Paternal influences are known to influence offspring health outcome, but the impact of paternal obesity and subfertility on the reproductive health of subsequent generations has been overlooked.

METHODS

A high-fat diet (HFD) was used to induce obesity but not diabetes in male C57Bl6 mice, which were subsequently mated to normal-weight females. First-generation offspring were raised on a control diet and their gametes were investigated for signs of subfertility. Second-generation offspring were generated from both first generation sexes and their gametes were similarly assessed.

RESULTS

We demonstrate a HFD-induced paternal initiation of subfertility in both male and female offspring of two generations of mice. Furthermore, we have shown that diminished reproductive and gamete functions are transmitted through the first generation paternal line to both sexes of the second generation and via the first generation maternal line to second-generation males. Our previous findings that founder male obesity alters the epigenome of sperm, could provide a basis for the developmental programming of subfertility in subsequent generations.

CONCLUSIONS

This is the first observation of paternal transmission of diminished reproductive health to future generations and could have significant implications for the transgenerational amplification of subfertility observed worldwide in humans.

Simulated physiological oocyte maturation (SPOM): a novel in vitro maturation system that substantially improves embryo yield and pregnancy outcomes

BACKGROUND

Oocyte in vitro maturation (IVM) reduces the need for gonadotrophin-induced ovarian hyperstimulation and its associated health risks but the unacceptably low conception/pregnancy rates have limited its clinical uptake. We report the development of a novel in vitro simulated physiological oocyte maturation (SPOM) system.

METHODS AND RESULTS

Bovine or mouse cumulus-oocyte complexes (COCs) were treated with cAMP modulators for the first 1-2 h in vitro (pre-IVM), increasing COC cAMP levels ∼100-fold. To maintain oocyte cAMP levels and prevent precocious oocyte maturation, COCs were treated during IVM with an oocyte-specific phosphodiesterase inhibitor and simultaneously induced to mature with FSH. Using SPOM, the pre-IVM and IVM treatments synergized to increase bovine COC gap-junctional communication and slow meiotic progression (both P < 0.05 versus control), extending the normal IVM interval by 6 h in bovine and 4 h in mouse. FSH was required to complete maturation and this required epidermal growth factor signalling. These effects on COC had profound consequences for oocyte developmental potential. In serum-free conditions, SPOM increased bovine blastocyst yield (69 versus 27%) and improved blastocyst quality (184 versus 132 blastomeres; both P < 0.05 versus standard IVM). In mice, SPOM increased (all P < 0.05) blastocyst rate (86 versus 55%; SPOM versus control), implantation rate (53 versus 28%), fetal yield (26 versus 8%) and fetal weight (0.9 versus 0.5 g) to levels matching those of in vivo matured oocytes (conventional IVF).

CONCLUSIONS

SPOM is a new approach to IVM, mimicing some characteristics of oocyte maturation in vivo and substantially improving oocyte developmental outcomes. Adaption of SPOM for clinical application should have significant implications for infertility management and bring important benefits to patients.

Oxygen consumption and ROS production are increased at the time of fertilization and cell cleavage in bovine zygotes

BACKGROUND

Oxygen consumption is a key indicator of metabolic activity within embryos. Increased oxidative activity and REDOX changes at the time of fertilization have been suggested to signal Ca(2+) oscillations after sperm penetration. The objective of the present study was to determine the oxygen consumption and the REDOX status of zygotes and early embryos at the time of sperm penetration and cell cleavage and to investigate how metabolism relates to key temporal events and developmental competence.

METHODS

Individual oxygen-consumption rates of bovine in vitro matured oocytes and presumptive zygotes (n = 101) were measured using the Nanorespirometer at 0, 7, 12, 17 and 24 h after IVF. Using the Embryoscope, oxygen-consumption profiles of individual oocytes and embryos (n = 75) were recorded repeatedly from 6 h until 30 h after IVF and time-lapse images were acquired, at intervals of ∼36 min. Oocytes and embryos were stained with Hoechst 33342 and visualization of nuclear stage was performed by fluorescence microscopy. To determine the REDOX status, cohorts of oocytes and zygotes (n = 55) were individually stained with REDOX-Sensor Red CC-1 and Hoechst 33342 at 0, 7, 12, 17 and 24 h after IVF and subsequently imaged by confocal microscopy.

RESULTS

A peak of oxygen consumption was observed at the time of fertilization and a smaller rise and fall in oxygen consumption could be detected prior to the first cell cleavage. Increased reactive oxygen species production was also observed at 7 h and then at 24 h after IVF, just preceding the first embryonic cleavage.

CONCLUSIONS

There are specific events during embryo development that appear to be associated with a change in oxygen consumption and REDOX state, indicating that both have a role in sperm-mediated oocyte activation and cell cleavage in bovine embryos.

The effect of paternal diet-induced obesity on sperm function and fertilization in a mouse model

Although obvious effects of obesity on female reproduction and oocytes are emerging, the effects on male fertility and sperm quality are less clear with studies reporting conflicting results. We hypothesize that male obesity affects sperm function and physiology probably as a result of elevated oxidative stress in spermatozoa and therefore elevated levels of sperm DNA damage and loss of function. Six-week-old C57/Bl6 male mice (n = 36) were randomly allocated to two groups: group 1 (n = 18) received a control diet, whereas group 2 (n = 18) received a high-fat diet (HFD). At the completion of a 9-week period, mice were sacrificed and spermatozoa were obtained. Sperm motility, concentration, intracellular reactive oxygen species (ROS) production and sperm DNA damage were measured. The ability of the sperm to undergo capacitation, acrosome reaction, sperm binding and ability to fertilize an oocyte were also assessed. The percentage of motile spermatozoa was decreased in the HFD group compared with controls (36 ± 2% vs. 44 ± 4%; p < 0.05). Intracellular ROS was elevated (692 ± 83 vs. 409 ± 22 units; p < 0.01) in the HFD group compared with controls. Sperm DNA damage was also increased (1.64 ± 0.6% vs. 0.17 ± 0.06%; p < 0.05) in the HFD group compared with the control group. Furthermore, the percentage of non-capacitated sperm was significantly lower compared with controls (12.34% vs. 21.06%; p < 0.01). The number of sperm bound to each oocyte was significantly lower (41.14 ± 2.5 vs. 58.39 ± 2.4; p < 0.01) in the HFD group compared with that in controls and resulted in significantly lower fertilization rates (25.9% vs. 43.9%; p < 0.01). This report provides evidence that obesity may induce oxidative stress and sperm DNA damage as well as decreased fertilizing ability. This is important as DNA damage in the sperm as a result of oxidative stress has been linked to poor reproductive outcomes.

337. DIETARY OMEGA-3 FATTY ACID SUPPLEMENTATION ALTERS EMBRYO DEVELOPMENT AND METABOLISM IN SOWS

The long-chain omega-3 polyunsaturated fatty acids (LCPUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have diverse biological effects, including the improvement of cardiovascular health and asthma. The aim of this study was to examine how dietary LCPUFA supplementation of sows influenced follicular dynamics, embryo development and metabolism. A total of 30 sows per treatment were fed a control diet (CD: standard commercial ration) or an omega-3 supplemented diet (O-3: diet formulated with 3 g fish oil/kg) for 6 weeks. Ovaries were collected at slaughter and weighed 3–5 days post-weaning. Oocytes were aspirated and counted from 3 different follicle size groups (1–4mm, 4–8mm and 8+ mm) and matured in vitro for 44–46 h, prior to (a) fertilization using IVF and analysis of subsequent embryo development in culture, (b) assessment of embryo respiration rate (EmbryoScope technology, UniSense, Denmark) and glucose metabolism (radiolabelled glucose technique). Granulosa cells collected at aspiration were analysed for gene expression using q-PCR. Despite no effect of O-3 supplementation on ovary weight nor the proportion of oocytes that were fertilised and cleaved, there tended to be more medium and large follicles for the O-3 fed group. Significantly more embryos from sows fed O-3 diets developed to blastocyst stage (P < 0.05) and these tended to have an increased number of cells (P = 0.06). At the zygote stage, diet didn’t influence embryo respiration rate but glucose utilisation by blastocysts was significantly lower for O-3 treatment compared to CD (P < 0.006). Gene expression of the ER2-α, FSH-receptor, or the prostaglandin receptors EP2 and EP4 did not differ, but there tended to be reduced expression of progesterone receptor (PR) and cycloxygenase-2 (COX-2) in granulosa cells from O-3 sows (P < 0.07). In summary, O-3 dietary supplementation changed follicular growth, embryo development and blastocyst metabolism. Further studies are ongoing to determine the effect of supplementation on embryo survival and litter size.

123. THE EFFECT OF PATERNAL DIET INDUCED OBESITY ON SPERM CAPACITATION, ACROSOME REACTION, BINDING AND FERTILISATION IN MOUSE MODEL

While the effects of obesity on male fertility are emerging, the direct effects on sperm function are less clear. The aim of this study was to determine the effects of diet-induced obesity on sperm capacitation, acrosome reaction, oocyte binding and fertilisation. C57/Bl6 male mice (n = 12) were randomly allocated to two groups; group 1 received a control diet (6% fat) while group 2 received a high fat diet (HFD, 22% fat) for up to 14 weeks. Mice were sacrificed and spermatozoa obtained. Capacitation and acrosome reaction were measured using Arachis hypogaea (peanut) agglutinin. Sperm binding to oocytes was assessed by co-incubation of sperm with superovulated cumulus-enclosed oocytes for 4 hrs. Fertilisation rates were expressed as the percentage of oocytes with 2 pronuclei from the total number inseminated 6 hrs post insemination. The percentage of non-capacitated sperm in males fed a high fat diet was significantly lower compared to males fed a control diet (12.3% vs 21.1%; P < 0.01). The percentage of acrosome reacted sperm did not differ between the groups. Following 4 hrs of co-incubation with cumulus-enclosed oocytes, the number of sperm bound to each oocyte was significantly lower in the HFD group compared to controls (41.14±2.5 vs 58.39±2.4; P < 0.01). Moreover, the percentage of fertilized oocytes was significantly lower in the HFD group compared to controls (25.9% vs 43.9; P < 0.01). This study demonstrates that males fed a HFD to induce obesity have impaired spermatozoa as evidenced by lower levels of capacitation and reduced ability to bind and fertilise an oocyte. These data therefore provide direct evidence that the metabolic health of the male can have a significant impact on sperm function parameters that are associated with infertility.

181. SIRT6 PROTEIN IS REDUCED IN TESTES AND SPERM FROM OBESE MALE MICE

Obesity in males is associated with altered hormone levels, reduced sperm function and increased sperm DNA damage. However, the underlying molecular mechanism has not been identified. Mammalian SIRT6 protein exhibits caloric intake dependant DNA damage repair in other tissue types. However, a possible role for SIRT6 in male obesity and subfertility has not been considered. Therefore, the aim of this study was to assess the effects of male obesity on SIRT6 in testes and mature sperm. Five week old C57BL6 male mice (n =10 per diet) were fed either a control diet (CD) (6% fat) or a high fat diet (HFD) (21% fat) for 16 weeks before collection of sperm and testes. There was no difference in Sirt6 mRNA levels as determined by qPCR in testes from HFD males. Immunohistochemistry showed SIRT6 localised to the nucleus of transitioningspermatids from late round spermatidsuntil early elongating spermatids. SIRT6 relative fluorescence of these positive cell types was significantly decreased by 22% in males fed the HFD compared to CD (P < 0.05). This was confirmed by a decrease in total SIRT6 protein in testes from HFD males as detected by an immunoabsorbance assay (P < 0.05). Surprisingly, SIRT6 was only present in the acrosome of mature sperm. Acrosomal localisation was confirmed by the loss of SIRT6 staining after an induced acrosome reaction. SIRT6 levels in the acrosome of mature sperm was decreased by 11% in males fed the HFD (P < 0.05). This is the first study to show that SIRT6 is located to the acrosome of mature sperm, specific cells within the testes and is reduced in an obese state. Furthermore, this study suggests a possible role for SIRT6 in the acrosomal reaction and therefore potentially fertilisation, processes which are known to be reduced by male obesity.

131. SIRT3 IN OVARIAN CELLS IS ALTERED BY MATERNAL AGE AND OVARIAN RESERVE

Maternal age and reduced AMH levels affect the follicular environment and consequently oocyte viability. The Sirtuin family of protein deacetylases are able to regulate various cellular functions involved in the ageing process in other tissues. In particular, SIRT3 is related to longevity in several cell types and regulates mitochondrial function, however, its presence and role in ovarian cells remains unknown. This study therefore, investigated the presence of SIRT3 in granulosa and cumulus cells, from patients undergoing IVF, and determined the impact of maternal age and low AMH on SIRT3 levels. Granulosa and cumulus cells were collected from women (n = 36), after informed consent, and classified into 3 groups; A (<35 years, normal AMH), B (>40 years (advanced maternal age), normal AMH) and C (<35 years, low AMH). The presence of SIRT3 was determined by q-PCR (expressed as fold-change) or immunohistochemistry. SIRT3 was present in the ovarian cells of all patients analysed. SIRT3 gene expression was reduced in granulosa cells from women with low AMH (0.67 ± 0.17) compared to women with normal AMH (1.00 ± 0.23; P < 0.05). In cumulus cells, levels were reduced with advanced maternal age (0.81 ± 0.08) compared to women <35 years (1.00 ± 0.22; P < 0.05). SIRT3 protein co-localised with mitochondria in the ovarian cells, confirming previous findings for other cell types. In comparison to women <35 years with normal AMH, image analysis determined that SIRT3 protein levels were significantly reduced in the granulosa and cumulus cells from women of advanced maternal age by 21.4% and 31.8% and in women with low AMH by 34.1% and 47.2% respectively. This is the first study to demonstrate SIRT3 presence in human ovarian cells. The observation that SIRT3 levels are altered by advanced maternal age or low AMH (reduced ovarian reserve) implicate its role in ovarian ageing and plausibly in the decrease in oocyte viability observed in these women.

103. THE EFFECT OF PATERNAL OBESITY IN MICE ON REPRODUCTIVE AND METABOLIC FITNESS OF F1 MALE OFFSPRING

We know relatively little of the consequences of male obesity for reproductive success compared to female obesity. Conflicting evidence exists in both humans and rodents regarding whether paternal obesity alters sperm motility and concentration. However, we have described impaired embryo and fetal development, and implantation, in rodents as a consequence of paternal obesity. This study investigated whether founder male obesity influenced the reproductive and metabolic fitness of males of the subsequent F1 generation. C57BL/6 founder male mice were fed a standard chow (CD) or a high-fat diet (HF) for 8wks. This increases adiposity in the absence of changes in fasting glucose levels. Males were mated to female C57BL/6 mice, and subsequent m ale F1 offspring from HF (HF-F1) or CD (CD-F1) founders were weighed weekly and maintained on standard chow. At 8 weeks and 14 weeks glucose tolerance tests were performed and following euthanasia, tissues and sperm collected. Sperm reactive oxygen species (ROS) and DNA damage levels were determined, and various organs weighed. HF-F1 male pups were significantly heavier relative to CD-F1 males (P < 0.05) although adult bodyweight did not differ significantly. Despite this, liver, pancreas, testes and epididymis weight was significantly elevated for HF-F1 males at 17wks of age (P < 0.05). At both 8wks and 14wks of age HF-F1 males were hypoglycaemic and had impaired glucose metabolism. Sperm analysis of HF-F1 males indicated a significant increase in ROS levels (P < 0.05), DNA damage (P < 0.05) and a decrease in fertilization rates in vitro (P < 0.05). This data indicates significant physiological changes and perturbed sperm parameters in F1 males as a consequence of founder male obesity. It supports further interrogation of male and female F1 offspring, and warrants examination of potential effects for a subsequent F2 population.

A Phase II Trial Tetrathiomolybdate (TM), a Copper Depleting Compound, and Its Effect on Circulating Endothelial Progenitor Cells (EPCs) in Patients with Breast Cancer (BC) at High Risk of Recurrence

Background: EPCs are critical to tumor angiogenesis, are increased in BC patients (pts) and are probably an early marker for paclitaxel response. Copper is required for angiogenesis, and pre-clinical data suggest that TM, a copper-depleting compound, inhibits angiogenesis and maintains tumor dormancy. We sought to measure the effect of TM on circulating endothelial progenitor cells (EPCs) in pts at high risk of BC recurrence and to evaluate the effect of copper depletion on EPCs. Methods: This analysis is part of an ongoing phase II study of TM in BC pts at high risk of recurrence defined as any node positive triple negative (TN) BC, Stage III or IV with no evidence of disease (NED). All therapy other than hormonal was completed at least 6 weeks prior to study. Treatment: TM 180 mg daily to achieve a target ceruloplasmin (Cp) level of 5-15 mg/dL (copper depletion), and then 100 mg daily. We monitored levels of EPCs (CD45dim, CD133+, VEGFR2+), CEA, CA15-3, and Cp at baseline and monthly. Imaging studies are done every 6 months (mos). Results: 28 pts are enrolled and 304 cycles of TM have been administered. Adjuvant: 20 pts, Stage 4 NED: 8 pts, Triple negative: 8 pts (5 stage IV NED, 3 Adjuvant) The median age is 51 years (range: 29-64), median number of positive lymph nodes among Stage III patients is 7 (4-42). The median baseline Cp level was 28 mg/dL (21-43). Among 21 patients who have reached target Cp, the median time to target is 6 weeks (2-16 weeks). Two pts discontinued treatment before reaching target. The median baseline EPCs is 17.38 cells/ml (0.0-286.1) Although there was a trend toward increased EPCs at month 1, this was not statistically significant (p=0.8964) and the majority of pts EPCs were maintained below baseline over time when Cp levels were below target (ie. copper depleted). Toxicity: Grade 3/4 neutropenia occurred in 3 patients (0.02%) with 1 pt with febrile neutropenia. All resolved 5-13 days later with TM held and resumed at a lower dose in 2 patients. No other grade 3/4 toxicity was observed. Three patients were diagnosed with recurrent breast cancer at 1, 9 and 10 mos. An EPC rise preceded an abnormal marker or overt relapse by 3-5 months in 2 of 3 pts. Conclusions: TM is well tolerated in breast cancer patients. TM might contribute to maintaining EPCs below baseline in pts who are copper depleted. We postulate that the increased EPCs noted in both patients with recurrent disease 2-4 months prior to overt relapse could represent the turning on of an angiogenic switch, resulting in an outpouring of CEPCs to the new site of metastasis. Other studies geared toward understanding the mechanism for metastases are underway. The trial continues to accrue.Supported by the Susan B Komen for the Cure, NY Community Trust, Breast Cancer Alliance of Greenwich and the Madeline and Stephen Anbinder Foundation.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6090.

The Diplomatic Service Under William III

The Revolution of 1688 marks the beginning of an era of great importance in our foreign policy. This fact, together with the close personal supervision of foreign affairs by William III., makes the study of the diplomatic service in that reign peculiarly interesting. The following sketch does not pretend to be complete, but it is the fruit of much miscellaneous research.

128. A ROLE FOR SIRTUIN 3 IN THE DEVELOPING MAMMALIAN EMBRYO

Pre-implantation embryo development relies critically on the balance between cytoplasmic and mitochondrial metabolism for the generation of metabolic intermediates such as NAD+. SIRT3 is a mitochondrial sirtuin with NAD+-dependant deacetylase activity that, targets glutamate dehydrogenase (GDH). In this study we characterised SIRT3 mRNA, protein and activity through pre-implantation development and determined whether modulation of SIRT3 activity influenced GDH activity. Embryos (zygotes, 2-cell, 8-cell and blastocyst stages) were recovered from female CBA/C57Bl6 mice following ovarian stimulation and mating with CBA/C57Bl6 males. Expression of SIRT3 mRNA was measured using real-time RTPCR, protein localisation examined using immunohistochemistry and SIRT3 activity measured using a Fluor-de-Lys SIRT3 fluorescentassay. Functional GDH activity was assessed in 2-cell embryos indirectly by measuring glutamine oxidation, following culture from zygote to 2-cell in the presence of nicotinamide, (a sirtuin inhibitor), G1.2 media, or simpleG1 media, compared to in vivo controls. SIRT3 mRNA was detected at all stages of development, with significantly greater levels expressed in the blastocyst. SIRT3 protein was localised predominantly around the nucleus of zygote and 2-cell embryos, and was mainly cytoplasmic in 8-cell embryos and blastocysts. SIRT3 activity remained constant throughout pre-implantation development, and tended to increase at the blastocyst stage. Glutamine oxidation was reduced for embryos cultured in G1.2 media relative to in vivo controls (0.14 pmol/e/hr vs 0.21pmol/e/hr), and this was further reduced by the addition of nicotinamide (0.07pmol/e/hr). Embryo culture in perturbing simpleG1 increased glutamine metabolism (0.33pmol/e/hr). In conclusion, SIRT3 mRNA, protein and activity was detected throughout pre-implantation development. Modulation of sirtuins by nicotinamide decreased glutamine metabolism, likely as a result of decreased deacetylation, thus decreased activity of GDH. SIRT3 can translocate to the mitochondria during cellular stress, thus the increased glutamine metabolism in simpleG1 conditions may be caused by translocation of SIRT3 to mitochondria, potentially increasing GDH deacetylation and enzymatic activity.

The prevalence and workplace costs of adult attention deficit hyperactivity disorder in a large manufacturing firm

BACKGROUND

Little is known about the effects of adult attention deficit hyperactivity disorder (ADHD) on work performance or accidents-injuries.MethodA survey was administered in 2005 and 2006 to employees of a large manufacturing firm to assess the prevalence and correlates of adult ADHD. Respondents (4,140 in 2005, 4,423 in 2006, including 2,656 in both surveys) represented 35-38% of the workforce. ADHD was assessed with the World Health Organization (WHO) Adult ADHD Self-Report Scale (ASRS), a validated screening scale for DSM-IV adult ADHD. Sickness absence, work performance and workplace accidents-injuries were assessed with the WHO Health and Work Performance Questionnaire (HPQ).

RESULTS

The estimated current prevalence (standard error) of DSM-IV ADHD was 1.9% (0.4). ADHD was associated with a 4-5% reduction in work performance (chi12=9.1, p=0.001), a 2.1 relative-odds of sickness absence (chi12=6.2, p=0.013), and a 2.0 relative-odds of workplace accidents-injuries (chi12=5.1, p=0.024). The human capital value (standard error) of the lost work performance associated with ADHD totaled USD 4,336 (676) per worker with ADHD in the year before interview. No data were available to monetize other workplace costs of accidents-injuries (e.g. destruction of equipment). Only a small minority of workers with ADHD were in treatment.

CONCLUSIONS

Adult ADHD is a significantly impairing condition among workers. Given the low rate of treatment and high human capital costs, in conjunction with evidence from controlled trials that treatment can reduce ADHD-related impairments, ADHD would seem to be a good candidate for workplace trials that evaluate treatment cost-effectiveness from the employer's perspective.

102. THE EFFECT OF INSULIN ON EMBRYONIC STEM CELL PROGENITOR CELLS IN THE MOUSE BLASTOCYST

Human ESCs are produced from embryos donated at the mid-stage of pre-implantation development. This cryostorage reduced viability. However, it has been shown that this can be improved by the addition of growth factors to culture medium. The aim of the present study was to examine whether the addition of insulin to embryo culture medium from the 8-cell stage of development increases the number of ES cell progenitor cells in the epiblast in a mouse model. In vivo produced mouse zygotes (C57Bl6 strain) were cultured in G1 medium for 48h to the 8-cell stage, followed by culture in G2 supplemented with insulin (0, 0.17, 1.7 and 1700pM) for 68h, at 37 o C , in 5% O2, 6%CO2, 89% N2 . The number of cells in the inner cell mass (ICM) and epiblast was determined by immunohistochemical staining for Oct4 and Nanog. ICM cells express Oct4, epiblast cells express both Oct4 and Nanog. The addition of insulin at the concentrations examined did not increase the ICM. However, at 1.7pM insulin increased the number of epiblast cells (6.6±0.5 cells vs 4.1±0.5, P=0.001) in the ICM, which increased the proportion of the ICM that was epiblast (38.9±3.7% compared to 25.8±3.4% in the control P=0.01). This indicates that the increase in the epiblast is brought about by a shift in cell fate as opposed to an increase in cell division. The effect of insulin on the proportion of cells in the epiblast was investigated using inhibitors of phosphoinositide3-kinase (PI3K) (LY294002, 50µM); one of insulin's main second messengers, and p53 (pifithrin-α, 30µg/ml); a pro-apoptotic protein inactivated by PI3K. Inhibition of PI3K eliminated the increase caused by insulin (4.5±0.3 cells versus 2.2±0.3 cells, P<0.001), while inhibition of p53 increased the epiblast cell number compared to the control (7.1±0.8 and 4.1±0.7 respectively P=0.001). This study shows that insulin increases epiblast cell number through the activation of PI3K and the inhibition of p53, and may be a strategy for improving ESC isolation from human embryos.