Embryo mortality in Holstein x Limousine embryos

The objective of this study was to compare the late embryo mortality (LEM) rate (losses approximately between 32 and 53 days of gestation) and Pregnancy Specific Protein B (PSPB) and progesterone (P4) concentrations on day 32 post AI in Holstein cows bred with either Holstein or Limousine semen. A sample size of 1,082 cows per group diagnosed pregnant between 28- and 35-days post breeding was calculated. The study consisted of evaluating LEM (%) in a cohort of Holstein cows bred with Holstein semen (HO x HO) or Limousine semen (HO x LM), to compare pregnancy loss from 28-35 days post breeding to 50-57 days post breeding. A logistic regression model to compare embryo losses was developed considering as main explanatory variable the cohort (HO x HO embryo vs. HO x LM embryo), correcting by lactation number, breeding season, days to breeding and AI technician. HO x HO embryos had greater LEM (15.16%) than HO x LM embryos (9.79%). Cows bred in summertime had higher LEM (15.23%) than cows bred in no-summertime (9.88%). There were no differences among AI technicians. Within summertime there was no difference in LEM (%) between groups within each lactation number; however, within no-summertime, LEM (%) was higher in HO x HO than HO x LM within each lactation number. Pregnancy SPB optical densities were significantly greater in the HO x HO than in the HO x LM (P=0.023) group; however, the concentration of P4 was not different between groups (P > 0.05).

257 The Effect of the COVID-19 Pandemic on Mental Health Associated Trauma, Admissions and Fractures at a London Major Trauma Centre

Aim

Non-injury related factors have been extensively studied in major trauma and shown to have a significant impact on patient outcomes, with mental illness and associated medication use proven to have a negative effect on bone health and fracture healing. We report the epidemiological effect of COVID-19 pandemic on mental health associated Orthopaedic trauma, fractures, and admissions to our centre.

Method

We collated data retrospectively from the electronic records of Orthopaedic inpatients in an 8-week non-COVID and COVID period analysing demographic data, referral and admission numbers, orthopaedic injuries, surgery performed and patient co-morbidities including psychiatric history.

Results

here were 824 Orthopaedic referrals and 358 admissions (6/day) in the non-COVID period with 38/358 (10.6%) admissions having a psychiatric diagnosis and 30/358 (8.4%) also having a fracture. This was compared to 473 referrals and 195 admissions (3/day) in the COVID period with 73/195 (37.4%) admissions having a documented psychiatric diagnosis and 47/195 (24.1%) a fracture. 22/38 (57.9%) and 52/73 (71.2%) patients were known to mental health services, respectively.

Conclusions

Whilst total numbers utilising the Orthopaedic service decreased, the impact of the pandemic and lockdown disproportionately affected those with mental health problems, a group already at higher risk of poorer functional outcomes and non-union. The proportion of patients with both a fracture and a psychiatric diagnosis more than doubled and the number of patients presenting due to a traumatic suicide attempt almost tripled. It is imperative that adequate support is in place for vulnerable mental health patients, particularly as we are currently experiencing the “second wave” of COVID-19.

The effect of the COVID-19 pandemic on mental health associated trauma, admissions and fractures at a London major trauma centre

INTRODUCTION

Non-injury-related factors have been extensively studied in major trauma and have been shown to have a significant impact on patient outcomes. Mental illness and associated medication use has been proven to have a negative effect on bone health and fracture healing.

MATERIALS AND METHODS

We collated data retrospectively from the records of orthopaedic inpatients in a non-COVID and COVID period. We analysed demographic data, referral and admission numbers, orthopaedic injuries, surgery performed and patient comorbidities, including psychiatric history.

RESULTS

There were 824 orthopaedic referrals and 358 admissions (six/day) in the non-COVID period, with 38/358 (10.6%) admissions having a psychiatric diagnosis and 30/358 (8.4%) also having a fracture. This was compared with 473 referrals and 195 admissions (three/day) in the COVID period, with 73/195 (37.4%) admissions having a documented psychiatric diagnosis and 47/195 (24.1%) having a fracture.

DISCUSSION

There was a reduction in the number of admissions and referrals during the pandemic, but a simultaneous three-fold rise in admissions with a psychiatric diagnosis. The proportion of patients with both a fracture and a psychiatric diagnosis more than doubled and the number of patients presenting due to a traumatic suicide attempt almost tripled.

CONCLUSION

While total numbers using the orthopaedic service decreased, the impact of the pandemic and lockdown disproportionately affects those with mental health problems, a group already at higher risk of poorer functional outcomes and non-union. It is imperative that adequate support is in place for patients with vulnerable mental health during these periods, particularly as we look towards a potential 'second wave' of COVID-19.

59 Incubation of frozen/thawed bovine embryos

High-quality, properly developed bovine embryos are crucial to the embryo transfer industry and enable cryopreservation; however, ∼30% of invivo embryos do not develop to the appropriate stage and are discarded. Currently, frozen/thawed embryos are transferred directly into a recipient, and the quality of embryos post-thaw is seldom evaluated. The objective of this experiment was to evaluate frozen/thawed bovine embryos immediately post-thaw, and again after incubation in different environments. Frozen/thawed bovine embryos (n=30/treatment) processed for direct transfer were thawed (30°C water; 30s) and graded and staged in holding medium. Embryos were then placed into either holding medium, phosphate-buffered saline supplemented with 15% fetal bovine serum (v/v) and antibiotic/antimycotic (2μL mL−1) (PBS+FBS), or a commercially available invitro culture (IVC) medium for ∼18h. Embryos in holding medium and PBS+FBS were loaded into 0.25-mL straws with the appropriate medium, and the straws were sealed and submerged in 38.5°C water. The IVC embryos were placed individually into 25-μL culture drops on tissue-coated 60-mm plastic Petri dishes overlaid with mineral oil and incubated (18h) at 38.5°C in 5% CO2 and air at 100% humidity. Embryos were then collected, regraded, and staged, and comparisons among groups were analysed via the Kruskal–Wallis H-test. Quality score of all embryos decreased by at least one-third post-thaw; however, the developmental stage was unaffected by the freeze/thaw cycle. Following incubation, all embryos suffered a significant (P<0.05) decrease in embryo quality but the IVC group demonstrated less (P<0.05) of a decline in resulting quality (Table 1). The IVC group demonstrated significant development (P<0.05) during incubation compared to the Holding and PBS+FBS groups (Table 1) indicating that on average, viability was maintained during IVC. Regardless of group, the zona pellucida was damaged during the freeze/thaw process in 31.1% of embryos. These data illuminated embryo damage after cryopreservation, and demonstrated that short-term invitro incubation of frozen/thawed embryos (IVC) facilitated continued development and may be a practical mechanism to salvage poor quality or developmentally suppressed embryos. Future research will focus on salvaging fresh embryos that are classified as degenerate and may prove useful in the bovine embryo industry, and for cattle producers alike, by ultimately increasing the number of transferable embryos that would otherwise be discarded. Table 1. Descriptive statistics (mean±s.e.m.) of bovine embryos pre-freeze and post-thaw and incubation Item Media Pre-freeze Post-thaw Post-incubation Grade Holding 1.4±0.1 1.7±0.1a 3.3±0.1b,x PBS+FBS 1.2±0.1 1.6±0.1a 3.1±0.1b,x IVC1 1.2±0.1 1.6±0.1a 2.5±0.2b,y Stage Holding 4.0±0.1 4.0±0.1 3.9±0.1x PBS+FBS 4.7±0.2 4.4±0.2 4.5±0.2y IVC 4.3±0.1 4.3±0.1a 5.8±0.2b,z a,b, x–zDifferent superscripts within row (a, b) and column (x, y, z) indicate a significant difference (P<0.05, Kruskal-Wallis H-test). 1Invitro culture medium.

72 Evaluation of digital images of bovine embryos

Bovine embryo transfer is an assisted reproductive technology that enables cattle producers to reach their reproductive, genetic, and financial goals. Proper evaluation of embryo quality and developmental stage is key to the success of the embryo transfer industry and is often acquired “on the job” as there are few embryo evaluation training opportunities. The goals of this project were to develop a bank of digital images of invivo-produced bovine embryos, and to evaluate interrater reliability and variation of grade and stage scores and the assessment of the integrity of the zona pellucida (ZP) using an online platform. Frozen/thawed bovine embryos (Day 7) were placed in a commercially available holding medium, and images were captured using a high-resolution camera (112× magnification). Survey participants (n=89) responded to questions on demographic and embryo evaluation experience and assigned grades and stages and evaluated the integrity of the ZP in 58 embryo images (the IETS embryo evaluation rubric was provided). The variation among raters within and between demographic categories was analysed using the “kappaetc” package with weights for ordinal variables (grade and stage) in Stata version 14.2 (StataCorp). The Kruskal–Wallis test was used to assess whether variation [measured as interquartile range (IQR)] in grade and stage ratings within individual were significantly different (P=0.05) by demographic factors. Overall, interrater reliability (measured by Cohen’s Kappa, κ) for stage was moderate (κ=0.57), whereas identification of grade and the ZP was substantial (κ=0.69 and 0.73, respectively). Interrater reliability for grade was significantly lower among those with ≤2 years (n=17) of experience (κ=0.44) compared with those having 3–9 years (n=29; κ=0.57) and ≥10 years (n=43; κ=0.64). Similarly, interrater agreement for stage was significantly lower for those with ≤2 years of experience (κ=0.58) compared with those having 3–9 years (κ=0.68) and ≥10 years (κ=0.75). Interrater agreement for stage was higher for those who did not use the IETS rubric compared with those who did (κ=0.73 vs. κ=0.63, respectively), and the variability was highest for Stage 6 and lowest for Stage 4 embryos. No demographic variables were significantly associated with interrater reliability for the integrity of the ZP. The variability of stage ratings (IQR) within individual significantly increased with more years of experience, with greatest IQR among those with ≥10 years of experience. The IQR within individual for grade decreased with increasing length of time rating, with the lowest IQR for the longest duration spent on rating the embryos. Overall, there was a moderate to substantial interrater agreement in embryo evaluation, which increased with experience. Further, evaluation of bovine embryo digital images may be a useful training tool instead of or in conjunction with a “hands-on” experience. Future surveys will involve multiple images of the same embryo and video to enhance the evaluation process and increase interrater reliability.

12 Artificial insemination and embryo transfer results in ewes during a long daylength period

Sheep are polyestrous, short-day breeders (∼11h of daylength), and exhibit oestrus approximately every 16–17 days during the breeding season, usually in late September to late December in the Northern Hemisphere. Progressive sheep producers often use assisted reproductive techniques such as laparoscopic AI and ovarian hyper-stimulation, embryo collection, and embryo transfer (ET) to increase genetic gain, and strive to have early December lambs to target specific show markets, which dictates AI or ET during the late summer. This field trial compared pregnancy rates following AI or ET in July and August (∼14h of daylength) in southwest Virginia (36–38′12″ N). Ewes (AI, n=83; ET recipients, n=33) were synchronized using a modified Ovsynch protocol involving intravaginal progesterone implants for 14 days, prostaglandin F2α (intramuscular) 48h before expected oestrus, and PG600 (IM) and gonadotrophin-releasing hormone (intramuscular) 52 to 54h and 16h before AI, respectively. Ewes were subjected to AI (frozen/thawed semen) regardless of whether they displayed signs of oestrus, and ewes selected as embryo recipients were subjected to a similar protocol but instead received 1 or 2 embryos (based upon the number of viable embryos produced per embryo donor) 6 days following the AI of the embryo donors. Ovarian hyper-stimulation of the embryo donors (n=13) was enabled by twice-daily FSH injections [totalling 350–455IU of Folltropin V (10–13mL)] for the 4 days before AI. Six days following AI, embryos were recovered surgically from the embryo donors (n=13) and yielded an average (±s.e.m.) of 6.6±1.2 total ova, 4.7±1.1 transferable quality embryos, and 1.9±0.8 unfertilized ova per collection. Pregnancy was detected using transrectal ultrasonography at ∼30 days of gestation and the pregnancy rates were analysed using Chi-squared. There was a tendency (P=0.092) for more pregnancies to be established following ET (22/33; 66%) compared with AI (41/83; 49%). There was no statistical relationship between AI ewes or ET recipient ewes that became pregnant relative to whether they displayed signs of oestrus or not. Embryo transfer was a more successful approach to produce pregnancies in ewes compared with AI during long daylength periods in this field trial. Further, ova from hyper-stimulated embryo donor ewes experienced a very high fertilization rate. Future studies will evaluate the ova capability directly via laparoscopic aspiration of ovarian follicles and IVF and evaluation of hyper- and non-hyper-stimulated follicular waves (using transrectal ultrasonography) and endocrine dynamics during different long and short daylength periods. Extending the opportunity to generate embryos and offspring regardless of daylength will assist aggressive sheep producers in reaching their reproductive, financial, and genetic goals.

Dairy cow trade-off preference for 2 different lying qualities: Lying surface and lying space

Lying down is an important behavior for cows, contributing to their health and welfare. With dairy cows being housed for increasingly longer periods, if not year-round, it is important to ensure that dairy cow lying comfort is not compromised when they are housed. The aim of this study was to assess cow preference for 2 different qualities of lying area that appear to be important to cows-surface type and an open lying space-to better understand how to optimize lying comfort for cows when housed. Twenty-four Holstein dairy cows were used during the study, which took place in Scotland from July to November 2018. The study consisted of 6 experimental periods, each lasting a total of 21 d. Cows were tested 4 at a time and individually housed in their own test pen. Each pen had 3 lying surfaces: sand, mattress, and straw (2.4 m × 2.4 m each) with a freestall in the middle of each, which could be removed. Cows were given access to one surface at a time (training period) with a freestall for 2 d, and then given a choice of all 3 surfaces for 2 d. When given the choice with freestalls in position, cows spent, on average, the largest amount of their lying time on straw (46.6 ± 7.8%) followed by mattress (44.3 ± 12.4%). Freestalls were then removed and the training and choice phase was repeated on the following day, with cows, on average, spending the most time lying on straw (64.4 ± 7.2%). Finally, a freestall was refitted onto each cow's most preferred surface and the cows were given a choice between lying on their most preferred surface with a freestall (P1 + freestall) or on their second or third preferred surface without a freestall (P2 + open and P3 + open, respectively) for 3 d. During this final trade-off stage, of the 19 cows for which data were available, 14 cows chose to give up the opportunity to lie down on their most preferred surface to have more space on P2 + open and P3 + open, 3 cows chose to lie down on P1 + freestall, and 2 cows made no clear choice. Overall, cows spent the largest amount of their total lying time on their second most preferred surface as an open lying space (65.7 ± 6.9%) compared with their preferred surface with a freestall (20.5 ± 5.9%) and their third preferred surface as an open lying space (13.8 ± 3.7%). The results indicate that when lying down, these dairy cows value an open lying space more than the lying surface.

Controlling spin current polarization through non-collinear antiferromagnetism

The interconversion of charge and spin currents via spin-Hall effect is essential for spintronics. Energy-efficient and deterministic switching of magnetization can be achieved when spin polarizations of these spin currents are collinear with the magnetization. However, symmetry conditions generally restrict spin polarizations to be orthogonal to both the charge and spin flows. Spin polarizations can deviate from such direction in nonmagnetic materials only when the crystalline symmetry is reduced. Here, we show control of the spin polarization direction by using a non-collinear antiferromagnet Mn₃GaN, in which the triangular spin structure creates a low magnetic symmetry while maintaining a high crystalline symmetry. We demonstrate that epitaxial Mn₃GaN/permalloy heterostructures can generate unconventional spin-orbit torques at room temperature corresponding to out-of-plane and Dresselhaus-like spin polarizations which are forbidden in any sample with two-fold rotational symmetry. Our results demonstrate an approach based on spin-structure design for controlling spin-orbit torque, enabling high-efficient antiferromagnetic spintronics.

In the typical spin-hall effect, spin-current, charge current, and spin polarisation are all mutually perpendicular, a feature enforced by symmetry. Here, using an anti-ferromagnet with a triangular spin structure, the authors demonstrate a spin-hall effect without a perpendicular spin alignment.

Field survey to evaluate space allowances for dairy cows in Great Britain

Housing conditions can affect health of cows by increasing exposure to biological, chemical, and physical hazards, resulting in increased disease. A report in 2014 indicated that 99% of UK dairy cows are housed during winter months and that an increasing number of farms are committing to year-round indoor-housing management systems. Current literature does not provide a clear understanding of the relationship between cow health, welfare, and production, and the housing environment. Loafing space, in this case defined as non-feed, non-lying, and non-high traffic areas of the housed environment, is considered an important component of housing for dairy cows; however, the scientific literature associated with this subject is sparse internationally. The aim of this research was to explore current housing of dairy cows across Great Britain, with specific focus on understanding the practices and variability associated with space allowance. A secondary aim was to explore farmer opinions and knowledge on the value of living space. A single researcher visited 53 randomly selected farms, from a representative sample group, once during the winter housing period 2017-18. Data collection consisted of 3 elements: collation of basic farm details, precise measurement of adult dairy cow accommodation, and a questionnaire to capture farmer opinions on space allowances. Statistical analysis was undertaken to assess variation among farms in total space, loafing space, and living space per cow. A new metric, termed "living space," was defined to describe the additional space availability for dairy cows above that deemed to be a baseline requirement. Large variability was identified between farms in total space available per cow, with a range from 5.4 to 12.7 m² [mean = 8.3 m², median = 8.2 m², interquartile range (IQR) = 1.9 m²]. The mean living space was 2.5 m², with a range of 0.5 m² to 6.4 m² (median = 2.4 m², IQR = 1.6 to 3.2 m²). Responses from a farmer questionnaire on importance of loafing space revealed that farmers felt it was essential for cow welfare, over half of farmers scoring this ≥8 on a 0 to 10 scale. Farmers were categorized into 4 latent classes based on their attitudes toward the importance of loafing space. In a linear model to predict the "living space" provided on each farm, geographical location and latent class of farmer attitude were covariates significantly associated with the amount of space provided. This study is the first worldwide to quantify variability in loafing and living spaces for dairy herds; further research is required to evaluate the extent to which variation in quantity and quality of space influences cow health, welfare, and productivity, as well as farm economics and emissions.

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

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Systemic Yersinia pseudotuberculosis as a Cause of Osteomyelitis in a Captive Ring-tailed Lemur (Lemur catta)

Yersinia pseudotuberculosis and Yersinia enterocolitica are ubiquitous pathogens with wildlife and domestic animal reservoirs. Outbreaks of 'non-plague' yersiniosis in man and non-human primates are reported frequently (including zoological specimens and research breeding colonies) and are usually characterized by enteritis, mesenteric lymphadenitis and occasionally organ abscessation. In people, non-septic reactive arthritis is a common sequela to yersiniosis. However, there have been rare reports in people of septic arthritis and osteomyelitis because of active systemic infection with Y. pseudotuberculosis. Osteomyelitis has also been reported rarely in historical yersiniosis outbreaks in farmed turkeys in England and the USA. This paper reports the first case of osteomyelitis caused by systemic infection with Y. pseudotuberculosis O:1 in a non-human primate, a captive ring-tailed lemur (Lemur catta). The lemur had a short clinical history of hyporexia and weight loss with reduction in mobility, especially of the left hindlimb. On post-mortem examination there was evidence of multi-organ abscessation. In addition, severe necrosis, inflammation and large bacterial colonies were present in the musculature, periosteum and bone marrow in the hip, ribs and a vertebra at the cervicothoracic junction. Osteomyelitis should be considered as a rare clinical presentation in non-human primates with systemic Y. pseudotuberculosis infection.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Producer estimates of prevalence and perceived importance of lameness in dairy herds with tiestalls, freestalls, and automated milking systems

Lameness is one of the most important welfare and productivity concerns in the dairy industry. Our objectives were to obtain producers' estimates of its prevalence and their perceptions of lameness, and to investigate how producers monitor lameness in tiestall (TS), freestall with milking parlor (FS), and automated milking system (AMS) herds. Forty focal cows per farm in 237 Canadian dairy herds were scored for lameness by trained researchers. On the same day, the producers completed a questionnaire. Mean herd-level prevalence of lameness estimated by producers was 9.0% (±0.9%; ±SE), whereas the researchers observed a mean prevalence of 22.2% (±0.9%). Correlation between producer- and researcher-estimated lameness prevalence was low (r = 0.19) and mean researcher prevalence was 1.6, 1.8, and 4.1 times higher in AMS, FS, and TS farms, respectively. A total of 48% of producers thought lameness was a moderate or major problem in their herds (TS = 34%; AMS =53%; FS = 59%). One third of producers considered lameness the highest ranked health problem they were trying to control, whereas two-thirds of producers (TS = 43%; AMS = 63%; FS = 71%) stated that they had made management changes to deal with lameness in the past 2 yr. Almost all producers (98%) stated they routinely check cows to identify new cases of lameness; however, 40% of producers did not keep records of lameness (AMS = 24%; FS = 23%; TS = 60%). A majority (69%) of producers treated lame cows themselves immediately after detection, whereas 13% relied on hoof-trimmer or veterinarians to plan treatment. Producers are aware of lameness as an issue in dairy herds and almost all monitor lameness as part of their daily routine. However, producers underestimate lameness prevalence, which highlights that lameness detection continues to be difficult in in all housing systems, especially in TS herds. Training to improve detection, record keeping, identification of farm-specific risk factors, and treatment planning for lame cows is likely to help decrease lameness prevalence.

A comparison of the pharmacokinetics and safety of enzalutamide in subjects with hepatic impairment and matched healthy subjects

WHAT IS KNOWN AND OBJECTIVE

Enzalutamide is an androgen receptor inhibitor approved for treatment of metastatic castration-resistant prostate cancer. Enzalutamide is highly protein bound and eliminated primarily by hepatic metabolism; therefore, it is important to understand whether enzalutamide pharmacokinetics is altered by hepatic impairment.

METHODS

Pharmacokinetic data were obtained from two non-randomized, open-label, single-dose, phase 1 studies conducted in patients with mild (Child-Pugh class A, n = 6) or moderate (Child-Pugh class B, n = 8) hepatic impairment (NCT01901133) or severe (Child-Pugh class C, n = 8) hepatic impairment (NCT02138162) and their corresponding matched healthy controls; data from both studies are presented here. Subjects with hepatic impairment had liver cirrhosis (n = 19) or chronic hepatitis (n = 3). All subjects received a single oral dose of 160 mg enzalutamide under fasting conditions, with blood samples collected predose and up to 49 days post-dose.

RESULTS AND DISCUSSION

Exposure to enzalutamide active moieties, based on the area under the curve of the sum of enzalutamide and N-desmethyl enzalutamide (an active metabolite with similar potency to enzalutamide), increased by 13%, 18% and 4% in subjects with mild, moderate and severe hepatic impairment, respectively, relative to matched controls. Compared with healthy controls, the mean maximum plasma concentration for enzalutamide active moieties was 24% higher in subjects with mild hepatic impairment and 11% and 41% lower in subjects with moderate and severe hepatic impairment, respectively. Enzalutamide was generally well tolerated, with no clinically significant trends in abnormal laboratory findings, vital signs or electrocardiograms.

WHAT IS NEW AND CONCLUSIONS

No major differences in single-dose pharmacokinetics were observed in subjects with hepatic impairment vs. matched healthy controls. Therefore, these studies indicate that no initial dose adjustment is necessary when administering enzalutamide to patients with hepatic impairment.

Evaluation of the usefulness at national level of the dairy cattle health and production recording systems in Great Britain

The aim of this study was to formally evaluate, qualitatively, the ability of existing recording systems to generate accurate and reliable estimates of the frequency of selected health conditions in the dairy herd of Great Britain. Fifty-nine recording systems were identified, of which 36 had their key characteristics defined through a web-based questionnaire. Nineteen of them were further assessed following the SERVAL, a SuRveillance EVALuation framework against a set of 12 attributes: benefit, bias, communication, coverage, data collection, data management, data analysis, data completeness, flexibility, multiple utility, representativeness and stability/sustainability. The evaluated systems showed considerable differences in their coverage, implementation and objectives. There were overlaps in recorded conditions, with Johne's disease, bovine viral diarrhoea, mastitis and lameness being recorded by most of the systems. Selection bias, data ownership and lack of integration of data from different systems appeared to be a key limitation on the future use of existing systems for nationwide monitoring. The results showed that even though the individual systems can provide reliable estimates of dairy health for individual farmers, none of the systems alone could provide accurate and reliable estimates for any of the conditions of interest at national level.

Upregulation of MAPK Negative Feedback Regulators and RET in Mutant ALK Neuroblastoma: Implications for Targeted Treatment

PURPOSE

Activating ALK mutations are present in almost 10% of primary neuroblastomas and mark patients for treatment with small-molecule ALK inhibitors in clinical trials. However, recent studies have shown that multiple mechanisms drive resistance to these molecular therapies. We anticipated that detailed mapping of the oncogenic ALK-driven signaling in neuroblastoma can aid to identify potential fragile nodes as additional targets for combination therapies.

EXPERIMENTAL DESIGN

To achieve this goal, transcriptome profiling was performed in neuroblastoma cell lines with the ALK(F1174L) or ALK(R1275Q) hotspot mutations, ALK amplification, or wild-type ALK following pharmacologic inhibition of ALK using four different compounds. Next, we performed cross-species genomic analyses to identify commonly transcriptionally perturbed genes in MYCN/ALK(F1174L) double transgenic versus MYCN transgenic mouse tumors as compared with the mutant ALK-driven transcriptome in human neuroblastomas.

RESULTS

A 77-gene ALK signature was established and successfully validated in primary neuroblastoma samples, in a neuroblastoma cell line with ALK(F1174L) and ALK(R1275Q) regulable overexpression constructs and in other ALKomas. In addition to the previously established PI3K/AKT/mTOR, MAPK/ERK, and MYC/MYCN signaling branches, we identified that mutant ALK drives a strong upregulation of MAPK negative feedback regulators and upregulates RET and RET-driven sympathetic neuronal markers of the cholinergic lineage.

CONCLUSIONS

We provide important novel insights into the transcriptional consequences and the complexity of mutant ALK signaling in this aggressive pediatric tumor. The negative feedback loop of MAPK pathway inhibitors may affect novel ALK inhibition therapies, whereas mutant ALK induced RET signaling can offer novel opportunities for testing ALK-RET oriented molecular combination therapies.

On the fate of particles liberated from hydroxyapatite coatings in vivo

PURPOSE

Hydroxyapatite (HA) has been used as a coating for orthopaedic implants for over 30 years to help promote the fixation of orthopaedic implants into the surrounding bone. However, concerns exist about the fate of the hydroxyapatite coating and hydroxyapatite particles in vivo, especially in the wake of recent concerns about particulates from metal-on-metal bearings.

METHODS

Here, we assess the mechanisms of particle detachment from coated orthopaedic devices as well as the safety and performance concerns and biomedical implications arising from the liberation of the particles by review of the literature.

FINDINGS

The mechanisms that can result in the detachment of the HA coating from the implant can be mechanical or biochemical, or both. Mechanical mechanisms include implant insertion, abrasion, fatigue and micro-motion. Biochemical mechanisms that contribute to the liberation of HA particles include dissolution into extra-cellular fluid, cell-mediated processes and crystallisation of amorphous phases. The form the particles take once liberated is influenced by a number of factors such as coating method, the raw powder morphology, processing parameters, coating thickness and coating structure.

CONCLUSIONS

This review summarises and discusses each of these factors and concludes that HA is a safe biomimetic material to use as a coating and does not cause any problems in particulate form if liberated as debris from an orthopaedic implant.

An assessment tool to help producers improve cow comfort on their farms

Effective management and an appropriate environment are essential for dairy cattle health and welfare. Codes of practice provide dairy producers with best practice guidance for the care and handling of their cattle. New Canadian recommendations have been established for the dairy industry. The objectives of this study were to develop an on-farm assessment tool that helps producers assess how well they are meeting their code of practice and that identifies management and environment modifications that could improve dairy cow comfort on their farms. The assessment tool addressed critical areas of dairy cow comfort, including accommodation and housing (stall design, space allowance, stall management, pen management, milking parlor, and transfer alleys), feed and water (body condition scoring, nutrition), and health and welfare (lameness, claw health, and hoof-trimming). Targets of good practices were identified from the requirements and recommendations of the code of practice. Each farm received a score for each target, ranging from 0 (target not reached) to 100 (target reached). One hundred tiestall and 110 freestall farms were surveyed in 3 provinces of Canada (Quebec, Ontario, and Alberta). The duration of the assessment, in 2 visits lasting, on average, 8 and 9h (range between freestall and tiestall farms) and 4 and 4.1h, was beyond the targeted 3 to 4h due mainly to the animal-based measures; strategies to reduce the duration of the assessment were discussed. Standard operating procedures were developed to ensure consistency in measuring and recording data. Periodical checks were conducted by trainers to ensure all 15 assessors remained above target agreement of weighted kappa ≥0.6. Average scores for all critical areas ranged from 25 to 89% for freestall farms and from 48 to 95% for tiestall farms. These scores need to be considered with caution when comparing farms because scores could not always be calculated the same way between housing systems. An evaluation report was provided and discussed with each producer, identifying strengths and areas for improvement that could benefit dairy cow comfort on their farms. The producers were convinced of the effectiveness of our tool for assessing cow comfort (freestall: 86%; tiestall: 95%) and in assisting them to make decisions for improvements (freestall: 83%; tiestall: 93%). Our cow comfort assessment tool served as background material for the Dairy Farmers of Canada animal care assessment program.

Abstract 2622: New therapeutic strategies in neuroblastoma: combined targeting of a novel tyrosine kinase inhibitor and liposomal siRNAs against ALK

The anaplastic lymphoma kinase (ALK), a tyrosine kinase receptor involved in the genesis of several human cancers, is a promising therapeutic target in Neuroblastoma (NB). Many studies on sporadic cases with advanced NB have shown ALK mutated or highly expressed independently of its genetic status (mutated, amplified, wild-type) and its pivotal role in NB growth and survival. As ALK is currently considered a master driver of NB oncogenesis, the use of therapies inhibiting ALK represents a suitable treatment option.

The ALK inhibitor Crizotinib was recently approved for the treatment of advanced NSCLC patient. However, as often observed with kinase inhibitors, some patients develop acquired resistance in part due to genetic ALK mutations. To overcome this limitation a selective and more potent ALK inhibitor, X-396, was developed that is currently in phase I clinical trial in adult patients with advanced solid tumors, but it has not been tested in preclinical animal models of NB.

We have successfully employed a RNAi-mediated therapeutic approach to selectively knockdown ALK expression by using nanoliposomes entrapping siRNA and coupled with anti-GD2 antibodies to target NB cells. Our data demonstrate for the first time a role of ALK in NB-induced angiogenesis and in tumor invasion.

Here, we aimed to test whether the combination of the novel ALK kinase inhibitor X-396 with the liposome-based silencing of ALK could represent a powerful synergistic and or additive effect in NB xenografts to promote long-term survival.

In vitro, X-396 showed to be more effective than Crizotinib in inhibiting cell proliferation and in inducing cell death in both LAN-5 (R1275Q ALK mut, Crizotinib-sensitive) and SH-SY5Y (F1174L ALK mut, Crizotinib-resistant) cells.

Pharmacokinetic profiles of X-396 after multiple PO administration in NB-xenografts revealed a good bioavailability and a moderate half-life. Biodistribution study clearly indicated that the concentration of X-396 8h post-administration was 35 fold higher in the tumor site than in plasma. X-396 reduced the tumor volume in subcutaneous SH-SY5Y NB-model in a dose-dependent manner and it was more effective than Crizotinib when administered at the same concentration. In orthotopic xenografts of SH-SY5Y and LAN-5 cells, X-396 significantly increased life span. In combination studies, all effects were significantly improved in the mice treated with targeted liposomal formulation of ALK-siRNA and X-396 compared to untreated control mice or mice receiving the single agent treatments. In the latter studies, further enhancement of life span was obtained by increasing the X-396 dose. Moreover, the combined treatment was also proven to be effective in the SH-SY5Y-pseudometastatic model in determining long-term survivors. Our findings provide a rational basis to design innovative molecular-based combination of treatments for clinical application in NB.

Citation Format: Daniela Di Paolo, Laura Emionite, George Liu, Michele Cilli, Annarita Di Fiore, Chiara Brignole, Chris Liang, Fabio Pastorino, Jay Gibbons, Mirco Ponzoni, Patrizia Perri. New therapeutic strategies in neuroblastoma: combined targeting of a novel tyrosine kinase inhibitor and liposomal siRNAs against ALK. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2622. doi:10.1158/1538-7445.AM2014-2622

Development and implementation of a training program to ensure high repeatability of body condition scoring of dairy cows

A body condition score (BCS) in dairy cattle is a subjective assessment of the proportion of body fat that she possesses and is a common measure used in animal welfare assessment. The objectives of our study were to develop and implement a training program to produce highly repeatable BCS by many assessors as part of a cross-Canada epidemiological study on dairy cow comfort and welfare. In preliminary studies, we established that without any proper standard operating procedures (SOP) to describe the practical steps of the process and good standard reference for each score, assessors provided with a BCS chart scored with each other only with substantial agreement within 0.5 points and moderate agreement on exact score (mean weighted kappa coefficient=0.79 and 0.46, respectively). Detailed SOP were developed to assess BCS in 4 locations on a dairy farm. Assessing BCS presented more challenges in some locations (when cows exited the milking parlor, when the assessor was located outside the freestall pen) than others (when cows were headlocked at the feed bunk, when assessor was located inside the freestall pen). Additionally, training material and a training procedure were developed to ensure that future assessors would achieve almost perfect repeatability with the trainer within 0.5 points (weighted kappa coefficient >0.80). Twelve trainees followed this training and their repeatability was assessed using photographs in classroom sessions and live observations on farm over a 1-wk period. Repeatability was maintained above target agreement at periodic checks over the 6 mo of on-farm data collection. Two trainers were used as a reference standard to which all trainees were compared. This study demonstrates that to obtain reliable measures, a training program must include validated procedures to help assessors cope with a variety of farm setups. Regular repeatability checks are essential to ensure that the reference standard is maintained over time and to secure high data quality. This method to develop a training program as well as the training program implemented can be used as a model to successfully train on-farm assessors.

SU-E-T-588: A Treatment Planning Comparison of Dual-Arc VMAT Vs. Helical Tomotherapy for Post-Mastectomy Radiotherapy

PURPOSE

To investigate the feasibility of volumetric modulated arc therapy (VMAT) for post-mastectomy radiotherapy (PMRT) and to compare dual- arc VMAT treatment plans to helical tomotherapy (HT) plans on the basis of dosimetric quality, radiobiological calculations and delivery efficiency.

METHODS

Dual-arc VMAT and HT treatment plans were created for fifteen patients previously treated at our clinic. Planning target volumes (PTV) included the chest wall (CW) and regional lymph nodes. The following metrics were used to compare treatment plans for each patient: dose homogeneity index (DHI) and conformity index (CI); coverage of the PTV; dose to organs at risk (OAR); tumor control probability (TCP), normal tissue complication probability (NTCP) and secondary cancer complication probability (SCCP); and treatment delivery time. Differences between treatment plans were tested for significance using the paired Student's t-test.

RESULTS

Both modalities produced clinically acceptable PMRT plans. VMAT plans showed better CI (p < 0.01), and better OAR sparing at low doses than HT plans. For example, VMAT plans showed a 26% (p < 0.01) and 9% (p < 0.01) decrease in V5Gy in the lungs and heart respectively. On the other hand, HT plans showed better DHI (p < 0.01) and PTV coverage (p < 0.01). HT plans also showed slightly better OAR sparing at higher doses, including 8% (p < 0.01) and 9% (p < 0.01) lower maximum doses to the lungs and heart, respectively. Both modalities achieved nearly 100% tumor control and approximately 1% NTCP in the lungs and heart, with VMAT showing lower SCCP (p < 0.01). VMAT plans also required 66.2% less time to deliver.

CONCLUSIONS

Both VMAT and HT are suitable treatment options for PMRT. Our study showed that VMAT"'in addition to being significantly faster'"achieved better CI and low dose OAR sparing while HT achieved better DHI. This work was supported in part by a research support from Elekta, Ltd. However, Elekta, Ltd., did not participate in the study design; in the collection, analysis, and interpretation of data; in the writing of the manuscript; or in the decision to submit.

SU-E-T-97: Intra and Inter Variability in Beam Data Commissioning among Water Phantom Scanning Systems

PURPOSE

There are many water-phantom scanning systems with advanced features to collect accurate commissioning data. However the intra- and inter-variability of commissioning data has not been reported which is attempted in this study.

METHODS

Four vendors with modern water-phantom scanning systems; PTW, Sun Nuclear (SN), Standard Imaging (SI) and IBA were invited to an institution to demonstrate beam data collection. Each system was used to collect percent depth dose (PDD) and profiles several times in a day with their choice of detector for four different machines for photon and electron beam commissioning. This provided information on intra-variability. At the end, each vendor was allowed to setup and collect data on a single unit for inter-variability. All data were sent to a central location for analysis and evaluation.

RESULTS

The depth dose and profiles for 2×2cm² and 10×10cm² fields were analyzed for intra- and inter-variability. With repeated measurements, the intra-variability provided a detailed degree of fidelity of data collection. This was shown to be with (± 0.1%) among all vendors. Ignoring data in buildup region and comparing with one system (PTW), the PDDs variability were slightly larger 0.02±0.17%, 0.14±0.21%, 0.17±0.2%, for SI, SN and IBA, respectively. The profiles inter-variability in central region were <0.1 %, however in penumbra up to ± 4.8%were observed. The polarity effect was also noted up to 3% which was depth and detector dependent.

CONCLUSIONS

Intra- and inter-variability among various scanning system are very small indicting that all modern systems if used properly could collect data within±0.2% accuracy. The selection of device should be based on institutional comfort and personal preference of software and hardware. This study provides unique opportunity to compare data among systems which is otherwise not possible.

SU-D-BRCD-06: Measurement of Elekta Electron Energy Spectra Using a Small Magnetic Spectrometer

PURPOSE

To demonstrate how a small magnetic spectrometer can measure the energy spectra of seven electron beams on an Elekta Infinity tuned to match beams on a previously commissioned machine.

METHODS

Energyspectra were determined from measurements of intensity profiles on 6″-long computed radiographic (CR) strips after deflecting a narrow incident beam using a small (28 lbs.), permanent magnetic spectrometer. CR plateexposures (<1cGy) required special beam reduction techniques and bremsstrahlung shielding. Curves of CR intensity (corrected for non- linearity and background) versus position were transformed into energy spectra using the transformation from position (x) on the CR plate to energy (E) based on the Lorentz force law. The effective magnetic field and its effective edge, parameters in the transformation, were obtained by fitting a plot of most probable incident energy (determined from practical range) to the peak position.

RESULTS

The calibration curve (E vs. x) fit gave 0.423 Tesla for the effective magnetic field. Most resulting energy spectra were characterized by a single, asymmetric peak with peak position and FWHM increasing monotonically with beam energy. Only the 9-MeV spectrum was atypical, possibly indicating suboptimal beam tuning. These results compared well with energy spectra independently determined by adjusting each spectrum until the EGSnrc Monte Carlo calculated percent depth-dose curve agreed well with the corresponding measured curve.

CONCLUSIONS

Results indicate that this spectrometer and methodology could be useful for measuring energy spectra of clinical electron beams at isocenter. Future work will (1) remove the small effect of the detector response function (due to pinhole size and incident angular spread) from the energy spectra, (2) extract the energy spectra exiting the accelerator from current results, (3) use the spectrometer to compare energy spectra of matched beams among our clinical sites, and (4) modify the spectrometer to utilize radiochromic film.

Phase I, first-in-human trial of an oral VEGFR tyrosine kinase inhibitor (TKI) x-82 in patients (pts) with advanced solid tumors

3041

Background: VEGFR TKIs have shown benefit in the treatment of various tumor types. Side effects of the TKIs have affected the duration of therapy pts can tolerate, as well as the combinability with chemotherapy. X-82 is a highly potent VEGFR/PDGFR TKI with a smaller volume of distribution and limited tissue accumulation designed to minimize side effects while maintaining target effect. Methods: Pts with advanced solid tumors were enrolled using an accelerated titration scheme followed by 3+3 dose escalation design. X-82 was administered orally once daily (QD) or twice daily (BID) every 28 days. Safety, pharmacokinetic, clinical endpoints and blood-based biomarkers were evaluated. Results: 16 pts were treated across 8 dose levels: 20 (n=1), 40 (n=1), 80 (n=1), 160 (n=1), 300 (n=2), 400 mg QD (n=3), 140 mg BID (n=3) and 200 mg BID (n=4). The most common related adverse events (AEs) by pt were fatigue (4 G1, 1 G2), nausea (3 G1, 1 G2), diarrhea (3 G1), anorexia (1 G1, 1 G2), and vomiting (2 G1). G2 hypertension, resolved with treatment, was experienced by 1 patient. No > G3 related AEs have been reported. Dose proportional exposure was observed with doses up to 160 mg QD, and BID dosing cohorts were added. At 160 mg QD X-82 has plasma concentrations >100 ng/mL for at least 12 hours, the desired exposure predicted preclinically. Preliminary blood biomarker data (n=8) shows >25% decrease in VEGFR1 in 62% of pts and in VEGFR2 in 25% of pts, including pts at 40 and 80 mg cohorts. Efficacy has also been noted, including 1 confirmed complete response lasting 24+ weeks (pancreatic adenocarcinoma), and 6 pts with stable disease lasting 8+ weeks (range 12.1+, 38.3+ weeks), including the pt at 20 mg with SCLC (25.1 weeks). Conclusions: X-82 is a well-tolerated VEGFR/PDFGR TKI designed to minimize side effects while inhibiting target receptors. No MTD has yet been defined, though preliminary biomarker data are encouraging and clinical efficacy has been noted.

105 BOVINE EMBRYO TYPE, GRADE AND RECIPIENT SYNCHRONY, BUT NOT CORPUS LUTEUM QUALITY, INFLUENCED PREGNANCY RATES IN COMMERCIAL EMBRYO TRANSFER

Embryo transfer is a tool that enables progressive cattle producers to reach their reproductive, genetic and financial goals. The complexity of pregnancy establishment increases with any reproductive technology, especially with one with many variables. This clinical analysis employed a statistical model capable of explaining factors that affect pregnancy probability resulting from over 8000 embryo transfers. These data included corpus luteum (CL) quality score, embryo stage (morula to blastocyst) and grade (1–3), recipient synchrony (relative to the embryo age) and pregnancy rate (≥45 days). The CL score was an amalgamation of the palpable diameter of the CL, whether or not a crown was present and the overall quality of the reproductive tract (size of the uterine horns and perceived patency of the cervix). Embryos produced by IVF were transferred fresh and in vivo–produced embryos were transferred fresh (VIVO FRESH) or following cryopreservation (VIVO FROZ). Statistical methods were used to compare types of embryos transferred and pregnancy rates. All data were analysed using JMP 2009 software by logistic regression with the Logit link. Analysis for the odds of pregnancy occurring among groups using contrasts was conducted. Fisher's exact test showed significant differences (P < 0.05) among groups for pregnancy rate, with the VIVO FRESH embryos group having the highest rate (68.5 ± 1.5%) and the VIVO FROZ the lowest (54.7 ± 1.6%) and the IVF embryos were intermediate (62.1 ± 3.3%). Synchrony, stage, embryo grade and CL quality were analysed for their predictive ability of pregnancy rates in the IVF, VIVO FRESH and VIVO FROZ groups using effect tests with a P < 0.05. Interestingly, the CL quality had no predictive ability for any of the groups. Effectors that had an influence on the VIVO FROZ group included synchrony, stage and embryo grade. However, for the IVF and VIVO FRESH groups, pregnancy rates were affected by only embryo grade. Retrospective, observational analysis of commercial embryo transfer data represents a challenge to meaningful interpretation. Because of the nature of the business, experimental treatments cannot always be developed and implemented. Nonetheless, valuable information is gained by using appropriate statistical methods. As anticipated, these data suggested that the type of embryo transferred, grade and synchrony of the recipient are all important factors, particularly for cryopreserved embryos. Unexpectedly, the score of the CL did not influence pregnancy outcome regardless of embryo type. Evaluation of clinical data allows adjustment of embryo transfer protocols, facilitates genetic gain via enhanced reproductive success and provides a unique opportunity to analyse large, real-world data sets.

n-Type silicon photoelectrochemistry in methanol: Design of a 10.1% efficient semiconductor/liquid junction solar cell

n-Type Si electrodes in MeOH solvent with 0.2 M (1-hydroxyethyl)ferrocene, 0.5 mM (1-hydroxyethyl)ferricenium, and 1.0 M LiClO(4) exhibit air mass 2 conversion efficiencies of 10.1% for optical energy into electricity. We observe open-circuit voltages of 0.53 V and short-circuit quantum efficiencies for electron flow of nearly unity. The fill factor of the cell does not decline significantly with increases in light intensity, indicating substantial reduction in efficiency losses in MeOH solvent compared to previous nonaqueous n-Si systems. Matte etch texturing of the Si surface decreases surface reflectivity and increases photocurrent by 50% compared to shiny, polished Si samples. The high values of the open-circuit voltage observed are consistent with the presence of a thin oxide layer, as in a Schottky metal-insulator-semiconductor device, which yields decreased surface recombination and increased values of open-circuit voltage and short-circuit current. The n-Si system was shown to provide sustained photocurrent at air mass 2 levels (20 mA/cm(2)) for charge through the interface of >2,000 C/cm(2). The n-Si/MeOH system represents a liquid junction cell that has exceeded the 10% barrier for conversion of optical energy into electricity.

Antitumor efficacy profile of PKI-402, a dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor

PKI-402 is a selective, reversible, ATP-competitive, equipotent inhibitor of class I phosphatidylinositol 3-kinases (PI3K), including PI3K-alpha mutants, and mammalian target of rapamycin (mTOR; IC(50) versus PI3K-alpha = 2 nmol/L). PKI-402 inhibited growth of human tumor cell lines derived from breast, brain (glioma), pancreas, and non-small cell lung cancer tissue and suppressed phosphorylation of PI3K and mTOR effector proteins (e.g., Akt at T308) at concentrations that matched those that inhibited cell growth. In MDA-MB-361 [breast: Her2(+) and PIK3CA mutant (E545K)], 30 nmol/L PKI-402 induced cleaved poly(ADP-ribose) polymerase (PARP), a marker for apoptosis. In vivo, PKI-402 inhibited tumor growth in MDA-MB-361, glioma (U87MG), and lung (A549) xenograft models. In MDA-MB-361, PKI-402 at 100 mg/kg (daily for 5 days, one round) reduced initial tumor volume of 260 mm(3) to 129 mm(3) and prevented tumor regrowth for 70 days. In MDA-MB-361 tumors, PKI-402 (100 mg/kg, single dose) suppressed Akt phosphorylation (at T308) and induced cleaved PARP. Suppression of phosphorylated Akt (p-Akt) was complete at 8 hours and still evident at 24 hours. Cleaved PARP was evident at 8 and 24 hours. In normal tissue (heart and lung), PKI-402 (100 mg/kg) had minimal effect on p-Akt, with no detectable cleaved PARP. Preferential accumulation of PKI-402 in tumor tissue was observed. Complete, sustained suppression of Akt phosphorylation may cause tumor regression in MDA-MB-361 and other xenograft models. We are testing whether dual PI3K/mTOR inhibitors can durably suppress p-Akt, induce cleaved PARP, and cause tumor regression in a diverse set of human tumor xenograft models. Mol Cancer Ther; 9(4); 976-84. (c)2010 AACR.

Lead optimization of N-3-substituted 7-morpholinotriazolopyrimidines as dual phosphoinositide 3-kinase/mammalian target of rapamycin inhibitors: discovery of PKI-402

Herein we describe the identification and lead optimization of triazolopyrimidines as a novel class of potent dual PI3K/mTOR inhibitors, resulting in the discovery of 3 (PKI-402). Compound 3 exhibits good physical properties and PK parameters, low nanomolar potency against PI3Kalpha and mTOR, and excellent inhibition of cell proliferation in several human cancer cell lines. Furthermore, in vitro and in vivo biomarker studies demonstrated the ability of 3 to shut down the PI3K/Akt pathway and induce apoptosis in cancer cells. In addition, 3 showed excellent in vivo efficacy in various human cancer xenografts, validating suppression of PI3K/mTOR signaling as a potential anticancer therapy.

183 EXERCISE INFLUENCES EMBRYO QUALITY IN MARES

Athletic mares are commonly utilized in an embryo transfer regimen during the breeding season, which allows owners to continue to train and compete with these animals. Exercising mares in a hot and humid environment has proven detrimental to embryo recovery rates. However, the effects of exercise under milder temperatures have not been examined. Our goal was to compare embryo recovery rates and embryo quality scores of mares under mild environmental conditions of 2 differing exercise regimens v. a single control group (n = 5). One treatment group (full exercise) consisted of mares (n = 5) exercised 6 days a week throughout the duration of the project. The partial-exercise group (n = 5) was exercised throughout the duration of the project 7 days a week, with full rest from day of detected ovulation to the proceeding embryo collection attempt. This was to limit any deleterious effects exercise may potentially have on the mare and subsequent early developing equine embryo. Exercise resumed the day after an embryo collection attempt for the partial-exercise group. Exercised mares were given a 1-month training period prior to the beginning of this project and were moderately exercised for 30 min in a mechanical exercise pen (free exerciser). Control mares were managed similarly as the other groups, however were not exercised. Mares were bred via artificial insemination and embryos were nonsurgically collected 7 d post-ovulation. Mean environmental temperature during the duration of this study was 27.1°C with average 60% humidity. Immediately following completion of exercise, mares in the full exercise group had a mean temperature increase of 1.0°C and partial-exercised mares increased 0.9°C. Exercise had a significant effect on embryo quality (P < 0.05, Table 1) but did not influence embryo recovery rate. The mean embryo quality score for the control group was 1.1, whereas the full-exercised group was 1.85 and partial-exercised group was 2.5. It appears from these data that exercise has a negative effect on embryo quality, thus lowering the availability of transferable embryos. Embryos of lower quality (≥3) have been shown to result in poor pregnancy rates in horses. Additionally, rest from ovulation to an embryo collection attempt did not improve embryo quality. Table 1.Embryo recovery rate and quality score of embryos from control and exercised mares

Abstract B142: PKI-402, a dual PI3K/mTOR inhibitor

We have developed small molecule inhibitors of the PI3K/mTOR signaling pathway. An example is PKI-402. This compound is a reversible, ATP competitive, and equipotent inhibitor of class I PI3Ks, including the E545K and H1047R mutant forms of PI3K- , and mTOR (IC50 vs PI3K- = 1nM). Selectivity of PKI-402 was established in a screen against 236 diverse human kinases. PKI-402 caused in vitro growth inhibition of human tumor cell lines derived from breast, brain (glioma), pancreas, and non small cell lung cancer (NSCLC) tissues. In many cases IC50 values were &lt;100 nM. In vitro, PKI-402 suppressed phosphorylation of PI3K and mTOR effector proteins, particularly p-Akt at threonine 308 (T308), at concentrations that closely matched those that inhibited tumor cell growth. In MDA361, a breast tumor line with elevated levels of Her2 receptor, and mutant PI3K- (E545K), 30 nM PKI-402 induced cleaved PARP, a marker for apoptosis. This occurred after an exposure time of 4 h. In vivo, PKI-402 displayed anti-tumor activity when administered by IV route in glioma (U87MG, PTEN), NSCLC (A549; K-Ras, STK11), and breast (MDA361: Her2+, PIK3CA [E545K]) xenograft models. A key question about PI3K/mTOR signaling inhibitors is: can they cause tumor regression in pre-clinical models? At 25, 50, and 100 mg/kg PKI-402 caused regression of MDA361 tumors. PKI-402 effect was most pronounced at 100 mg/kg (daily for 5 days [dx5], 1 round), which reduced an initial tumor volume of 260 mm3 to 129 mm3, and prevented tumor re-growth for 70 days. Tumor re-growth occurred between days 16–20 when PKI-402 was administered at 25 and 50 mg/kg (dx5, 2 rounds). However, when PKI-402 was re-administered at 100 mg/kg (dx3, 1 round) at day 37 (25 mg/kg group), large tumors (∼600 mm3) were reduced in volume by 69%. In MDA361 tumor tissue PKI-402 at 100 mg/kg (single dose) caused sustained suppression of Akt phosphorylation at both the T308 and S473 sites, and induced cleaved PARP. Suppression of p-Akt was complete at 8 h, and still evident at 24 h; while cleaved PARP was evident at both 8 h and 24 h. In vivo biomarker analysis of heart and lung tissue showed minimal effect on p-Akt and no induction of cleaved PARP by PKI-402 at 100 mg/kg. Preferential accumulation of PKI-402 in tumor tissue was observed. It may be that complete and sustained suppression of p-Akt is needed to cause tumor regression in the MDA361 and other tumor xenograft models. We are testing whether dual PI3K/mTOR inhibitors can durably suppress p-Akt, induce cleaved PARP, and cause tumor regression in a diverse set of human tumor xenograft models.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B142.