Inhibition of chromatin condensation disrupts planar cell migration

Cell migration involves the actin cytoskeleton, and recently recognized nuclear involvement. In this study, we explore the impact of chromatin remodeling on cell migration using NIH 3T3 cells and a scratch wound assay subjected to pharmacological interventions. We inhibit histone deacetylases (HDACs) with Trichostatin A (TSA) and methyltransferase EZH2 with GSK126 to modulate chromatin compaction. Our results indicate that chromatin modifications impair wound closure efficiency, reduce individual cell migration speed, and disrupt migration persistence. Live-cell imaging reveals dynamic intranuclear chromatin remodeling and nuclear shape parameters during migration, influenced by both small- and large-scale chromatin remodeling. The altered nuclear shape is associated with disrupted cell and nuclear mechanics, suggesting a crucial interplay between chromatin remodeling, nuclear mechanics and migration. These findings shed light on the intricate connection between intranuclear chromatin dynamics, nuclear mechanics, and cell migration, providing a basis for further investigations into the molecular mechanisms governing these processes.

High-Throughput Multiparametric Quantification of Mechanics Driven Heterogeneity in Mesenchymal Stromal Cell Population

Mesenchymal stromal or stem cells (MSCs) are one of the most promising candidates for a myriad of cell therapy applications. Despite showing promise in numerous preclinical and clinical studies, MSC-based therapy is not yet a reality for regenerative medicine due to its suboptimal outcome at the clinical endpoint. The mechanical environment is a critical determinant of MSC gene expression and function. This study reports that MSC population becomes phenotypically heterogenous and commits to an unwanted osteoprogenitor pathway when it experiences an abnormal mechanically stiff environment, compared to its native softer environment. A method is developed to measure the heterogeneity using nuclear shape, chromatin state, and CD73 marker. Heterogeneity is shown to be associated with a larger spread in the nuclear shape parameters and a smaller spread in the chromatin openness. Subsequently, intervention strategies are investigated to create a more homogeneous MSC population. Culturing MSCs on soft surfaces or inhibiting actomyosin on stiff surfaces can make them more homogeneous, while inhibiting YAP, Runx2, and actin polymerization helps maintain but does not fully homogenize them. This study offers insights for cell and tissue engineers, aiding in the design of optimal conditions and materials for MSC culture, ultimately enhancing their therapeutic potential.

Residual inflammatory risk appeared related to weight, atherogenic lipid profile and biomarkers of inflammation, but not to glycaemic control in type 1 diabetes

Background

Mortality associated with atherosclerotic cardiovascular disease reduces average life expectancy by more than a decade in type 1 diabetes. Systemic inflammation drives atherosclerosis, and the concept of residual inflammatory risk (defined by high-sensitivity C-reactive protein (hsCRP) ≥2 mg/l) poses a potential, new therapeutic target for lowering residual cardiovascular risk in type 1 diabetes. However, the characteristics of individuals with residual inflammatory risk in type 1 diabetes are unknown.

Purpose

Identify differences in relevant demographics, clinical and paraclinical parameters for individuals with residual inflammatory risk as compared to those without in type 1 diabetes.

Methods

Baseline characteristics as stratified for CRP ≥2 mg/l were analysed in 105 patients with type 1 diabetes participating in a previously published clinical trial. The study population was sampled to represent the broad background population struggling with glycaemic control and with a high cardiovascular risk.

Results

Residual inflammatory risk was seen in 39.1% of the study population. Compared to individuals without residual inflammatory risk, individuals with residual inflammatory risk were more frequently women, had increased body weight, body mass index and dual-energy X-ray absorptiometry (DXA)-assessed fat mass and exhibited elevated levels of low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) and total cholesterol as well as triglycerides, interleukin 6 and tumour necrosis factor alpha (Table 1). Glycated haemoglobin, blood pressure and markers of renal function were similar between groups (Table 1).

Conclusion

In the present cohort of individuals with type 1 diabetes, residual inflammatory risk was seen in 39.1% (similar to what is observed outside of type 1 diabetes) and appeared related to overweight/obesity, an atherogenic lipid profile and circulating biomarkers of inflammation but not to glycaemic control, blood pressure or renal function.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): AstraZenecaHerlev Gentofte Hospital

Obstetric and perinatal risks in 4601 singletons and 884 twins conceived after fresh blastocyst transfers: a Nordic study from the CoNARTaS group

STUDY QUESTION

Are obstetric and perinatal outcomes in pregnancies after fresh blastocyst transfer (BT) comparable with those born after fresh cleavage stage transfer (CT) and spontaneous conception (SC)?

SUMMARY ANSWER

Fresh BT is associated with a higher risk of placental and perinatal complications.

WHAT IS KNOWN ALREADY

BT optimizes the selection of top-quality embryos and increases pregnancy and live birth rates per transfer compared to CT. However, concerns have been raised as extended culture duration may increase obstetric complications and impair perinatal outcomes. Previous studies have shown a higher risk of preterm birth (PTB) among infants born after BT compared with CT. Pregnancies after BT are also prone to a higher risk of same-sex twins after single embryo transfer (SET).

STUDY DESIGN, SIZE, DURATION

A retrospective register-based cohort study used data from Denmark, Norway and Sweden including three cohorts: 56 557 singletons and 16 315 twins born after fresh IVF/ICSI cycles and 2 808 323 SC singletons in Denmark (birth years 1997-2014), Norway (2010-2015) and Sweden (2002-2015). Of the fresh IVF/ICSI singletons, 4601 were born after BT and 51 956 after CT. The twin cohort consisted of 884 fresh IVF/ICSI children born after BT and 15 431 fresh IVF/ICSI children born after CT.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were obtained from a large Nordic cohort of children born after ART and SC initiated by the Committee of Nordic ART and Safety (CoNARTaS). The CoNARTaS cohort was established by cross-linking National ART-, Medical Birth-, and National Patients Registers using the unique personal identification number, allocated to every citizen in the Nordic countries. Obstetric and perinatal outcomes after BT, CT and SC were compared using logistic regression analysis. For perinatal outcomes, we calculated gestational age based on the date of oocyte pick-up (OPU) and in sensitivity analyses on data from Denmark and Norway, we also calculated gestational age based on the second-trimester ultrasonography (US) scan. Risk of pregnancies with same-sex twins after SET was used as a proxy for risk of monozygotic twins. Adjustments were made for child's sex, birth year, parity (0 or >1), maternal age, body mass index, smoking, educational level, fertilization method (IVF/ICSI), the number of aspirated oocytes, SET and country. Information on educational level and the number of aspirated oocytes was not available for Norway. Children born after frozen embryo transfer were not included. The birth cohorts were restricted according to the year in which BT was introduced in the different countries.

MAIN RESULTS AND THE ROLE OF CHANCE

A higher risk of placenta previa was found in singleton pregnancies after BT compared with CT (adjusted odds ratio [aOR] 2.11 [95% CI 1.76; 2.52]). Singletons born after BT had a higher risk of PTB (aOR 1.14 [95% CI 1.01; 1.29]) compared with CT singletons, when estimated based on OPU. Furthermore, an altered male/female ratio (aOR 1.13 [95% CI 1.06; 1.21]) with more males following BT compared with CT was seen. Risk of same-sex twins after SET was higher after single BT compared with single CT (aOR 1.94 [95% CI 1.42; 2.60]).

LIMITATIONS, REASONS FOR CAUTION

Residual confounding cannot be excluded, in particular related to duration and cause of infertility that we could not adjust for due to lack of reliable data.

WIDER IMPLICATIONS OF THE FINDINGS

Extended embryo culture to the blastocyst stage has the potential to compromise obstetric and perinatal outcomes in fresh cycles. These results are important since an increasing number of IVF/ICSI treatments are performed as BT.

STUDY FUNDING/COMPETING INTEREST(S)

NORDFORSK (project no: 71450). The Research Fund of Rigshospitalet, Copenhagen University Hospital. ReproUnion Collaborative study, co-financed by the European Union, Interreg V ÖKS. Grants from Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (LUA/ALF 70940), Hjalmar Svensson Research Foundation. The Research Council of Norway through its Centres of Excellence funding scheme, project number 262700. None of the authors has any conflicts of interests to declare regarding this study.

TRIAL REGISTRATION NUMBER

ISRCTN11780826.

Cumulative live birth rate prognosis based on the number of aspirated oocytes in previous ART cycles

STUDY QUESTION

Is the number of aspirated oocytes in the first ART cycle associated with the cumulative live birthrates (CLBR) in subsequent cycles?

SUMMARY ANSWER

The number of aspirated oocytes in the first cycle was associated with CLBR in subsequent cycles. Previous treatment response predicts outcome in future cycles.

WHAT IS KNOWN ALREADY

Previous reports have shown a positive association between the number of retrieved oocytes and live birthrate per fresh treatment cycle. This has also been shown for the CLBR in one complete ART-cycle, including possible subsequent frozen-thawed transfers (FER). It has been shown that women with less than five oocytes in the first cycle have poorer outcome within six complete cycles than women with more than 12 oocytes, suggesting that the number of aspirated oocytes in the first cycle may be reproduced in later cycles. However, other studies have shown that an initial low treatment response may be improved with increased gonadotrophin start-dose.

STUDY DESIGN, SIZE, DURATION

The Danish National IVF-registry includes all ART treatments in public and private clinics since 1994. Treatment-cycles were cross-linked with the Medical Birth Registry, identifying treatment-related births and natural conception births. This national cohort study includes all women starting ART treatments with homologous eggs between 2002 and 2011, N = 30 486. Subjects were followed for up to four fresh ART-cycles including subsequent FER-cycles (=four complete cycles), until the first livebirth, or until December 2011.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The CLBR within 1-4 complete ART-cycles were calculated as the proportion of women with a livebirth, out of all women initiating ART-treatment, including drop-outs (no livebirth or no continued treatment within follow-up). In women with one year follow-up from last treatment, multivariate logistic regression analysis assessed impact of retrieved oocytes on CLBR, adjusting results for female age and cause of infertility. Hospital admission due to ovarian hyperstimulation syndrome (OHSS) was reported.

MAIN RESULTS AND THE ROLE OF CHANCE

After one, two and three complete ART-cycles, the CLBRs attributable to ART treatment were 26.4% [95%CI 25.9-26.9], 42.6% [42.0-43.1] and 51.3% [50.7-51.9], respectively. The CLBR attributable to non-ART related conception (natural conception or intrauterine insemination) were 5.3% [5.0-5.6], 8.3% [8.0-8.7] and 10.6% [10.3-11.0], after one, two and three complete cycles. In women without a live birth in the first complete cycle, the number of aspirated oocytes predicted the outcome in the second and third cycle: When compared to women with 0-3 aspirated oocytes in the first cycle, the odds for live birth in the second and third cycle was 1.18 [1.07-1.30] for women with 4-9 aspirated oocytes in the first cycle, 1.41 [1.27-1.57] for women with 10-15 aspirated oocytes and 1.63 [1.42-1.88] for women with more than 15 aspirated oocytes. For women without a livebirth in the first and second cycle, the sum of aspirated oocytes predicted outcome in the third complete cycle. Women with a sum larger than six aspirated oocytes, had marked increased odds ratios for livebirth in the third complete cycle, compared to women with a sum of 0-6 oocytes in the first and second fresh cycle. Incidence of hospital-admission due to OHSS was 1.7% in the first cycle, decreasing to 1.3% and 1.0% in the second and third cycles.

LIMITATIONS, REASONS FOR CAUTION

Although mandatory, there may be treatment-cycles not registered in the IVF-registry. Missing information in number of aspirated oocytes are most likely random losses of information. There were few observations in women with more than 15 aspirated oocytes and these birthrates should be interpreted cautiously. Information on gonadotrophin dose used for stimulation was not available, nor was information on dose adjustments in subsequent cycles.

WIDER IMPLICATIONS OF THE FINDINGS

With these results we can counsel couples returning for fertility treatments, providing an age-stratified revised prognosis for chances of live birth and risk of OHSS, reflecting prior failed attempts and previous ovarian response.

STUDY FUNDING/COMPETING INTEREST(S)

This study was unconditionally funded by Ferring Pharmaceuticals and ReproUnion. The funders had no role in the study design, data collection and interpretation, or decision to submit the work for publication. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

The study was approved by the Danish Data Protection Agency (J.nr. 2012-41-1330).

DTL-RnB: Algorithms and Tools for Summarizing the Space of DTL Reconciliations

Phylogenetic tree reconciliation is an important technique for reconstructing the evolutionary histories of species and genes and other dependent entities. Reconciliation is typically performed in a maximum parsimony framework and the number of optimal reconciliations can grow exponentially with the size of the trees, making it difficult to understand the solution space. This paper demonstrates how a small number of reconciliations can be found that collectively contain the most highly supported events in the solution space. While we show that the formal problem is NP-complete, we give a approximation algorithm, experimental results that indicate its effectiveness, and the new DTL-RnB software tool that uses our algorithms to summarize the space of optimal reconciliations (www.cs.hmc.edu/dtlrnb).

Obstetric and neonatal complications in pregnancies conceived after oocyte donation: a systematic review and meta-analysis

BACKGROUND

Approximately 50 000 oocyte donation (OD) treatment cycles are now performed annually in Europe and the US.

OBJECTIVES

To ascertain whether the risk of adverse obstetric and perinatal/neonatal outcomes is higher in pregnancies conceived by OD than in pregnancies conceived by conventional in-vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) or spontaneously.

SEARCH STRATEGY

A systematic search was performed in the PubMed, Cochrane and Embase databases from 1982-2016. Primary outcomes were hypertensive disorders of pregnancy, pre-eclampsia (PE), gestational diabetes mellitus, postpartum haemorrhage, caesarean section, preterm birth, low birthweight and small for gestational age.

SELECTION CRITERIA

Inclusion criteria were original studies including at least five OD pregnancies with a control group of pregnancies conceived by conventional IVF/ICSI or spontaneous conception, and case series with >500 cases reporting one or more of the selected complications. Studies not adjusting for plurality were excluded.

DATA COLLECTION AND ANALYSIS

Thirty-five studies met the inclusion criteria. A random-effects model was used for the meta-analyses.

MAIN RESULTS

For OD pregnancies versus conventional IVF/ICSI pregnancies the risk of PE was adjusted odds ratio (AOR) 2.11 (95% CI, 1.42-3.15) in singleton and AOR 3.31 (95% CI, 1.61-6.80) in multiple pregnancies. The risks of preterm birth and low birthweight in singletons were AOR 1.75 (95% CI, 1.39-2.20) and 1.53 (95% CI, 1.16-2.01), respectively.

CONCLUSIONS

OD conceptions are associated with adverse obstetric and neonatal outcomes. To avoid the additional increase in risk from multiplicity, single-embryo transfer should be the choice of option in OD cycles.

TWEETABLE ABSTRACT

Oocyte donation pregnancies have increased risk of a range of obstetric and neonatal complications.

Academic performance in adolescents born after ART-a nationwide registry-based cohort study

STUDY QUESTION

Is academic performance in adolescents aged 15-16 years and conceived after ART, measured as test scores in ninth grade, comparable to that for spontaneously conceived (SC) adolescents?

SUMMARY ANSWER

ART singletons had a significantly lower mean test score in the adjusted analysis when compared with SC singletons, yet the differences were small and probably not of clinical relevance.

WHAT IS KNOWN ALREADY

Previous studies have shown similar intelligence quotient (IQ) levels in ART and SC children, but only a few have been on adolescents. Academic performance measured with standardized national tests has not previously been explored in a complete national cohort of adolescents conceived after ART.

STUDY DESIGN, SIZE, DURATION

A Danish national registry-based cohort including all 4766 ART adolescents (n = 2836 singletons and n = 1930 twins) born in 1995-1998 were compared with two SC control cohorts: a randomly selected singleton population (n = 5660) and all twins (n = 7064) born from 1995 to 1998 in Denmark. Nine children who died during the follow-up period were excluded from the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Mean test scores on a 7-point-marking scale from -3 to 12 were compared, and adjustments were made for relevant reproductive and socio-demographic covariates including occupational and educational level of the parents.

MAIN RESULTS AND THE ROLE OF CHANCE

The crude mean test score was higher in both ART singletons and ART twins compared with SC adolescents. The crude mean differences were +0.41 (95% CI 0.30-0.53) and +0.45 (95% CI 0.28-0.62) between ART and SC singletons and between ART and SC twins, respectively. However, the adjusted mean overall test score was significantly lower for ART singletons compared with SC singletons (adjusted mean difference -0.15 (95% CI -0.29-(-0.02))). For comparison, the adjusted mean difference was +2.05 (95% CI 1.82-2.28) between the highest and the lowest parental educational level, suggesting that the effect of ART is weak compared with the conventional predictors. The adjusted analyses showed significantly lower mean test scores in mathematics and physics/chemistry for ART singletons compared with SC singletons. Comparing ART twins with SC twins yielded no difference in academic performance in the adjusted analyses. Similar crude and adjusted overall mean test scores were found when comparing ART singletons and ART twins.

LIMITATIONS, REASONS FOR CAUTION

Missing data on educational test scores occurred in 6.6% of adolescents aged 15-16 years for the birth cohorts 1995-1997, where all of the children according to their age should have passed the ninth grade exam at the time of data retrieval. As sensitivity analyses yielded no significant difference in the adjusted risk of having missing test scores between any of the groups, it is unlikely that this should bias our results. Adjustment for body mass index and smoking during pregnancy was not possible.

WIDER IMPLICATIONS OF THE FINDINGS

As our results are based on national data, our findings can be applied to other populations. The findings of this paper suggest that a possible small negative effect of parental subfertility or ART treatment is counterbalanced by the higher educational level in the ART parents.

STUDY FUNDING/COMPETING INTERESTS

The Danish Medical Association in Copenhagen (KMS) funded this study with a scholarship grant. None of the authors had any competing interests.

TRIAL REGISTRATION NO STATISTICS DENMARK

704676.

Large baby syndrome in singletons born after frozen embryo transfer (FET): is it due to maternal factors or the cryotechnique?

STUDY QUESTION

Are singletons born after frozen embryo transfer (FET) at increased risk of being born large for gestational age (LGA) and if so, is this caused by intrinsic maternal factors or related to the freezing/thawing procedures?

SUMMARY ANSWER

Singletons after FET have an increased risk of being born LGA. This cannot solely be explained by intrinsic maternal factors as it was also observed in sibling pairs, where the sibling conceived after FET had an increased risk of LGA compared with the sibling born after Fresh embryo transfer.

WHAT IS KNOWN ALREADY

FET singletons have a higher mean birthweight than singletons born after transfer of fresh embryos, and FET singletons may be at an increased risk of being born LGA.

STUDY DESIGN, SIZE, DURATION

The national register-based controlled cohort study involves two populations of FET singletons. The first population (A: total FET cohort) consisted of all FET singletons (n = 896) compared with singletons born after Fresh embryo transfer (Fresh) (n = 9480) and also with that born after natural conception (NC; n = 4510) in Denmark from 1997 to 2006. The second population (B: Sibling FET cohort) included all sibling pairs, where one singleton was born after FET and the consecutive sibling born after Fresh embryo transfer or vice versa from 1994 to 2008 (n = 666). The sibling cohort included n = 550 children with the sibling combination first child Fresh/second child FET and n = 116 children with the combination first child FET/second child Fresh.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Main outcome measures were LGA defined as birthweight of >2 SD from the population mean (z-score >2) according to Marsáls curves. Macrosomia was defined as birthweight of >4500 g. Crude and adjusted odds ratios (AORs) of LGA and macrosomia were calculated for FET versus Fresh and versus NC singletons in the total FET cohort. Similarly, AOR was calculated for FET versus Fresh in the sibling cohort. Adjustments were made for maternal age, parity, child sex, year of birth and birth order in the sibling analyses. Meta-analyses were performed by pooling our data with the previously published cohort studies on LGA and macrosomia.

MAIN RESULTS AND THE ROLE OF CHANCE

The AORs of LGA (z-score >2) and macrosomia in FET singletons versus singletons conceived after Fresh embryo transfer were 1.34 [95% confidence interval (95% CI) 0.98-1.80] and 1.91 (95% CI 1.40-2.62), respectively. The corresponding risks for FET versus NC singletons were 1.41 (95% CI 1.01-1.98) for LGA and 1.67 (95% CI 1.18-2.37) for macrosomia. The increased risk of LGA and macrosomia in FET singletons was confirmed in the sibling cohort also after adjustment for birth order. Hence, the increased risk of LGA in FET singletons cannot solely be explained by being the second born or by intrinsic maternal factors, but may also partly be related to freezing/thawing procedures per se. In the meta-analysis, the summary effects of LGA and macrosomia in FET versus singletons conceived after Fresh embryo transfer were AOR 1.54 (95% CI 1.31-1.81) and AOR 1.64 (95% CI 1.26-2.12), respectively. The corresponding figures for FET versus NC singletons were for LGA AOR 1.32 (95% CI 1.07-1.61) and macrosomia AOR 1.41 (95% CI 1.11-1.80), respectively.

LIMITATIONS, REASONS FOR CAUTION

Adjustment for body mass index as a possible confounder was not possible. The size of the FET/Fresh sibling cohort was limited; however, the complete sibling cohort was sufficiently powered to explore the risk of LGA. A bias is very unlikely as data coding was based on national registers.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings are consistent with the previous Nordic studies and thus can be generalized to the Nordic countries. The causes for LGA in FET singletons should be further explored.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this project. None of the authors have any conflict of interest to declare.

Abstract OT1-4-03: Phase I study of erlotinib and metformin in triple negative breast cancer

Background: Triple negative breast cancers (TNBC) are enriched for increased phosphorylated EGFR expression and decreased expression of PTEN. We found that combined treatment of metformin and erlotinib induces cell death in a subset of TNBC cell lines with evidence of combined enhanced reduction of EGFR, AKT, S6 and 4EBP1 phosphorylation. Analysis of TNBC cell line alterations led to the hypothesis that loss of PTEN sensitized cells to the drug combination, which was confirmed using isogenic cell line models with and without PTEN expression. The inhibitory effects of combined erlotinib and metformin were confirmed in mouse xenografts of PTEN null TNBC breast cancer cell lines. These data provided a rationale for clinical translation and testing in advanced TNBC patients.

Trial Design: Single institution expanded Phase I design in patients with advanced TNBC. Erlotinib dosing will start and remain at 150 mg. Due to frequent GI upset in patients starting metformin, the dose of metformin will be titrated up to the assigned dose level over 2 weeks. The first metformin dose level will be 850 mg twice daily and will be escalated to its maximum FDA approved dose of 850 mg three times daily. Dose escalation will follow the standard 3 + 3 design. Dose limiting toxicities will be determined during the first 5 weeks of therapy. One metformin dose de-escalation level to 500 mg twice daily is allowed. Cycles will be defined as three weeks of treatment, and response assessments will be performed after every three cycles.

Main Eligibility Criteria:

1. Pathologic diagnosis of TNBC.

2. Measurable or non-measurable disease.

3. At least one prior treatment for metastatic disease.

4. ECOG PS = 0-2.

5. Prior metformin or EGFR targeted therapy.

6. Fasting blood glucose level < 126 mg/dl.

7. Normal renal function.

8. Available archived tumor tissue.

Specific Aims: The primary endpoints are defining the maximum tolerated dose (MTD) of metformin in combination with 150 mg erlotinib, and for the extended phase, determining the potential for clinical benefit by treating 14 patients at the MTD with the goal of rejecting the null hypothesis that the regimen is futile. Clinical benefit is defined as either partial response or lack of progression after 18 weeks of therapy (stable disease). Secondary endpoints include: 1) progression free survival, and 2) pharmacodynamic assessment of the phosphorylation status of AMPK and EGFR from pre- and on-treatment skin biopsies. The exploratory endpoint will be assessment of the status of EGFR, PTEN, LKB1, and 4EBP1 from available patient tumor samples to correlate against treatment response.

Statistical Methods: If one patient meets the primary endpoint, among the 14 patients treated at the MTD, then the regimen will be considered worthy of further investigation.

Target Accrual: 17-20 patients. Four patients accrued as of June 2013. Accrual completion expected June 2015.

Contact: Matthew Maurer, Columbia University Medical Center, mm2058@columbia.edu.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-4-03.

Diet and trophic niche of Antarctic silverfish Pleuragramma antarcticum in the Ross Sea, Antarctica

The diet of Antarctic silverfish Pleuragramma antarcticum was evaluated by examining stomach contents of specimens collected in the Ross Sea (71°-77° S; 165°-180° E) in January to March 2008. Pleuragramma antarcticum (50-236 mm standard length, L(S)) and prey items were analysed for stable-isotopic composition of carbon and nitrogen. According to index of relative importance (I(RI) ), which incorporates frequency of occurrence, mass and number of prey items, the most important prey items were copepods (81%I(RI) over all specimens), predominantly Metridia gerlachei and Paraeuchaeta sp., with krill and fishes having low I(RI) (2·2 and 5·6%I(RI) overall). According to mass of prey (M) in stomachs, however, fishes (P. antarcticum and myctophids) and krill dominated overall diet (48 and 22%M, respectively), with copepods being a relatively minor constituent of overall diet by mass (9·9%M). Piscivory by P. antarcticum occurred mainly in the extreme south-west of the region and near the continental slope. Krill identified to species level in P. antarcticum stomachs were predominantly Euphausia superba (14·1%M) with some Euphausia crystallophorias (4·8%M). Both DistLM modelling (PRIMER-permanova+) on stomach contents (by I(RI)) and stepwise generalized linear modelling on stable isotopes showed that L(S) and location were significant predictors of P. antarcticum diet. Postlarval P. antarcticum (50-89 mm L(S)) consumed exclusively copepods. Juvenile P. antarcticum (90-151 mm L(S)) consumed predominantly krill and copepods by mass (46 and 30%M, respectively). Small adult P. antarcticum (152-178 mm L(S)) consumed krill, fishes and copepods (37, 36 and 15%M, respectively). Large adult P. antarcticum (179-236 mm L(S)) consumed predominantly fishes and krill (55 and 17%M, respectively), especially in the north (near the Ross Sea slope) and in the SW Ross Sea. Amphipods were occasionally important prey items for P. antarcticum (western Ross Sea, 39%M). General concordance between stomach contents and trophic level of P. antarcticum and prey based on δ(15) N was demonstrated. Pleuragramma antarcticum trophic level was estimated as 3·7 (postlarval fish) and 4·1 (fish aged 3+ years).

OT3-01-13: Phase One Trial of Combined Temsirolimus, Erlotinib, and Cisplatin in Advanced Solid Tumors

Background: A large subset of triple negative breast cancers (TNBC) are driven in part by a combination of activated growth factor signaling and downstream constitutive activation of the PI3K pathway. One therapeutic strategy is to target each driver simultaneously, requiring an understanding of drug interactions and combined toxicities. There is a strong correlation between loss of PTEN and both expression of EGFR and mutation of p53 in a subset of TNBC. Single agent trials targeting EGFR in breast cancer have been a disappointment likely, in part, due to constitutive downstream activation of PI3K, AKT and mTOR signaling, mainly through loss of PTEN expression. Preclinical studies have demonstrated 1) that resistance to EGFR-targeted therapy in the setting of an activated PI3K pathway can be overcome with rapamycin (which inhibits the TORC1 mTOR complex), and 2) that a subset of TNBC cells with p53 mutations are particularly sensitive to the DNA damaging agent cisplatin due to their high expression of p63 and p73. We have hypothesized that targeting the EGFR, PTEN and DNA damage pathways simultaneously with the rapalog temsirolimus, the EGFR inhibitor erlotinib, and cisplatin will provide therapeutic benefit in a definable subset of TNBC patients.

Design: Single institution phase one dose escalation trial of combined temsirolimus, erlotinib, and cisplatin in advanced solid tumor patients. Cisplatin and temsirolimus are given on day 1 and day 8 of 21 day cycles and erlotinib is taken daily without interruption. Patients are dose escalated using a standard 3+3 design. Cisplatin is given at a fixed dose of 30 mg/m2. Erlotinib was started at 100 mg and will be escalated to 150 mg. Temsirolimus was started at 15 mg, and after erlotinib escalation, will be escalated to 25 mg. The objectives of the study are: 1) characterize toxicity of the regimen and establish combined maximal tolerated dosing, 2) measure drug target inhibition by assessing EGFR, AKT, and mTOR activation in serial assessments of peripheral blood mononuclear cells and skin biopsies, 3) measure the pharmacokinetics of all three drugs in combination, and 4) exploratory assessment of molecular measures of PTEN, EGFR, and p53 status, and markers of activated downstream pathways in patient's archived pathology specimens to assess feasibility of identifying candidate biomarkers in future trials involving patients with TNBC. Eligibility criteria include one prior treatment for advanced disease, ECOG PS=0-1, measurable or non-measurable disease, available archived tumor sample, non-smoking, normal renal function, and lack of concurrent use of strong CYP3A4 inhibitors or inducers. Because of significant rash encountered in prior combination trials of EGFR and TORC1 inhibitors, a prophylactic oral doxycycline strategy supported by randomized trials is being employed. Current accrual is 6 out of a possible 18 patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-01-13.

Pressure waves in the aorta during isolated abdominal belt loading: the magnitude, phasing, and attenuation

While rupture of the aorta is a leading cause of sudden death following motor vehicle crashes, the specific mechanism that causes this injury is not currently well understood. Aortic ruptures occurring in the field are likely due to a complex combination of contributing factors such as acceleration, compression of the chest, and increased pressure within the aorta. The objective of the current study was to investigate one of these factors in more detail than has been done previously; specifically, to investigate the in situ intra-aortic pressure generated during isolated belt loading to the abdomen. Ten juvenile swine were subjected to dynamic belt loads applied to the abdomen. Intraaortic pressure was measured at multiple locations to assess the magnitude and propagation of the resulting blood pressure wave. The greatest average peak pressure (113.6 +/- 43.5 kPa) was measured in the abdominal aorta. Pressures measured in the thoracic aorta and aortic arch were 70 per cent and 50 per cent, respectively, that measured in the abdominal aorta. No macroscopic aortic trauma was observed. To the authors' knowledge the present study is the first one to document the presence, propagation, and attenuation of a transient pressure wave in the aorta generated by abdominal belt loading. The superiorly moving wave is sufficient to generate hydrostatic and intimal shear stress in the aorta, possibly contributing to the hypothesized mechanisms of traumatic aortic rupture.

Feeding habits of alfonsino Beryx splendens

The diet of the alfonsino Beryx splendens was determined from examination of stomach contents of 287 specimens of 17 to 48 cm fork length (L(F)) sampled by bottom trawl on the Chatham Rise to the east of New Zealand. Prey items were predominantly crustaceans and mesopelagic fishes. The most important prey species by mass was Sergestes spp. prawns, followed by the myctophid Lampanyctodes hectoris, and then Pasiphaea spp. prawns. Multivariate analyses indicated that small crustaceans (euphausiids and amphipods) were most important in the diet of smaller B. splendens (100-424 g, 17-26.5 cm), with larger prawn species and mesopelagic fishes most important for larger fish (425-2070 g, 27-46 cm). Moon phase and bottom temperature also explained some of the variability in diet, but the moon phase effect was difficult to explain, and the bottom temperature effect may have been confounded, to some extent, with L(F). The results indicated that B. splendens were moderately selective feeders that foraged primarily in the mesopelagic layers. The diet of New Zealand B. splendens is generally similar to those reported from other areas, i.e. dominated by mesopelagic crustaceans and fishes, and with a transition from small crustaceans to fishes with increasing predator size.

The role of the champion in infection prevention: results from a multisite qualitative study

BACKGROUND

Although 20% or more of healthcare-associated infections can be prevented, many hospitals have not implemented practices known to reduce infections. We explored the types and numbers of champions who lead efforts to implement best practices to prevent hospital-acquired infection in US hospitals.

METHODS

Qualitative analyses were conducted within a multisite, sequential mixed methods study of infection prevention practices in Veteran Affairs and non-Veteran Affairs hospitals in the USA. The first phase included telephone interviews conducted in 2005-2006 with 38 individuals at 14 purposively selected hospitals. The second phase used findings from phase 1 to select six hospitals for site visits and interviews with another 48 individuals in 2006-2007.

RESULTS

It was possible for a single well-placed champion to implement a new technology, but more than one champion was needed when an improvement required people to change behaviours. Although the behavioural change itself may appear to be an inexpensive and simple solution, implementation was often more complicated than changing technology because behavioural changes required interprofessional coalitions working together. Champions in hospitals with low-quality working relationships across units or professions had a particularly challenging time implementing behavioural change. Merely appointing champions is ineffective; rather, successful champions tended to be intrinsically motivated and enthusiastic about the practices they promoted. Even when broad implementation is stymied, champions can implement change within their own sphere of influence.

CONCLUSIONS

The types and numbers of champions varied with the type of practice implemented and the effectiveness of champions was affected by the quality of organisational networks.

The role of the champion in infection prevention: results from a multisite qualitative study

BACKGROUND

Although 20% or more of healthcare-associated infections can be prevented, many hospitals have not implemented practices known to reduce infections. We explored the types and numbers of champions who lead efforts to implement best practices to prevent hospital-acquired infection in US hospitals.

METHODS

Qualitative analyses were conducted within a multisite, sequential mixed methods study of infection prevention practices in Veteran Affairs and non-Veteran Affairs hospitals in the USA. The first phase included telephone interviews conducted in 2005-2006 with 38 individuals at 14 purposively selected hospitals. The second phase used findings from phase 1 to select six hospitals for site visits and interviews with another 48 individuals in 2006-2007.

RESULTS

It was possible for a single well-placed champion to implement a new technology, but more than one champion was needed when an improvement required people to change behaviours. Although the behavioural change itself may appear to be an inexpensive and simple solution, implementation was often more complicated than changing technology because behavioural changes required interprofessional coalitions working together. Champions in hospitals with low-quality working relationships across units or professions had a particularly challenging time implementing behavioural change. Merely appointing champions is ineffective; rather, successful champions tended to be intrinsically motivated and enthusiastic about the practices they promoted. Even when broad implementation is stymied, champions can implement change within their own sphere of influence.

CONCLUSIONS

The types and numbers of champions varied with the type of practice implemented and the effectiveness of champions was affected by the quality of organisational networks.

Phase II trial of oral capecitabine (C) and weekly docetaxel (D) in patients with metastatic androgen independent prostate cancer (AIPC)

5121

Background: Due to demonstrated synergistic anti-tumor effect of D and C related to docetaxel-mediated up-regulation of thymidine phosphorylase (TP), a phase II trial with weekly D and C in metastatic AIPC was performed. Endpoints of response and survival were correlated with biomarker levels of TP, dihydropyrimidine dehydrogenase (DPD), thymidylate synthase (TS) in tumor tissue and DPD in serum Methods: Patients with metastatic AIPC, with no prior chemotherapy for metastatic disease were eligible to receive D 36 mg/m2/week IV on days 1,8, and 15 and C 1,250 mg/m2 /day in two divided doses on days 5–18. Cycles were repeated every 28 days and response was assessed every 2 cycles. Biomarker correlative study for Serum DPD and TP/DPD ratio and TS/DPD ratio on tissue were performed using mouse anti-TP, rat anti-DPD and mouse anti-TS monoclonal antibodies Results: 30 patients enrolled with median age of 69 years, median pretherapy PSA of 110 ng/ml (range 1.2 to 3716.9). 21(70%) had bone pain, Gleason score ≥ 8 in 18 (61%) patients; measurable disease progression in 9, bone scan progression in 18 patients and PSA only progression noted in 22 patients. 144 cycles have been administered (range 0–10 cycles). Grade 3 or 4 neutropenia seen in 3 patients and Grade 3 hand-foot syndrome in 2 patients. No treatment related deaths seen. PSA response (≥50% decline) noted in 22 (73.3%) with ≥90% PSA decline in 9 (30%) pts. Measurable disease PR noted in 5 of 9 patients (56 %). Median follow-up is 11 months (range 2.1 to 30.4). Median time to progression is 9.1 months (90% CI 6.2–15.1 months), and the median overall survival (OS) is 18.9 months (90% CI 14.9–26.4 months). 1 year PFS and OS is 44% and 84% respectively. Samples for DPD were available for 25 patients and pre-therapy tumor tissue for 23 patients. Quantitative fluorescence IHC has been performed on available samples, the final analysis is ongoing. Conclusions: The combination is well tolerated and demonstrates favorable and durable remission and survival outcomes. Correlation with biomarker analysis will be reported. This may help in selecting patients more likely to derive benefit from combination of D and C. Supported in part by Aventis Inc.

No significant financial relationships to disclose.

Phase II trial of weekly docetaxel and oral capecitabine in metastatic hormone-refractory prostate cancer

4634

Background: Docetaxel based chemotherapy for hormone-refractory prostate cancer (HRPC) has demonstrated survival benefit. The combination of docetaxel-capecitabine has demonstrated synergistic anti-tumor effect, which is attributable to docetaxel-mediated up-regulation of thymidine phosphorylase (TP). Hence, a phase II trial is being conducted to assess efficacy and tolerability of weekly docetaxel and capecitabine in metastatic HRPC. Methods: Patients with metastatic HRPC, who have not received prior chemotherapy for metastatic disease were eligible to receive docetaxel 36 mg/m2/week IV on days 1,8, and 15 and Capecitabine 1250 mg/m2 /day in two divided doses on days 5–18. Cycles were repeated every 28 days and response was assessed every 2 cycles. The primary end point was response rate. A two stage Simon study design required 15 patients to be accrued in first stage and additional 13 patients in second stage. Results: First stage was completed and response was adequate to proceed to second stage. 21 patients have been registered to this ongoing trial. Baseline characteristics included median age of 71 (range 47–80 years); median performance status of 1; median PSA at study entry of 60.6 ng/ml (range 1.2–3716.9); Of the 21 patients, 16 had bone pain pretherapy, Gleason score ≥ 8 in 14; 8 had measurable disease; 8 had new bone metastases and 14 had PSA progression. 83 cycles have been administered (median 4, range 1–10 cycles). To date 18 patients were assessable for toxicity and response. Grade 3 and 4 neutropenia was noted in 3 patients and Grade 3 hand-foot syndrome in 2 patients. There were no treatment related deaths. A PSA partial response (PR) defined as ≥ 50% decline sustained for ≥ 4 weeks was observed in 14/18 (77%) with ≥90% PSA decline in 7/18 (39%) patients. PR noted in 5/8 measurable disease patients. Stable disease by bone metastases in 15/18. Median time to PSA progression was 5 months (95% CI of 3.5–7.2+ month). Conclusions: The combination of capecitabine and weekly docetaxel demonstrated encouraging activity and acceptable toxicity profile.

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