ANTAGONISTIC PLEIOTROPIC EFFECT OF SECOND-CHROMOSOME INVERSIONS ON BODY SIZE AND EARLY LIFE-HISTORY TRAITS IN DROSOPHILA BUZZATII

A simple way to think of evolutionary trade-offs is to suppose genetic effects of opposed direction that give rise to antagonistic pleiotropy. Maintenance of additive genetic variability for fitness related characters, in association with negative correlations between these characters, may result. In the cactophilic species Drosophila buzzatii, there is evidence that second-chromosome polymorphic inversions affect size-related traits. Because a trade-off between body size and larval developmental time has been reported in Drosophila, we study here whether or not these inversions also affect larva-adult viability and developmental time. In particular, we expect that polymorphic inversions make a statistically significant contribution to the genetic correlation between body size (as measured by thorax length) and larval developmental time. This contribution is expected to be in the direction predicted by the trade-off, namely, those flies whose karyotypes cause them to be genetically larger should also have a longer developmental time than flies with other karyotypes. Using two different experimental approaches, a statistically significant contribution of the second-chromosome inversions to the phenotypic variances of body size and developmental time in D. buzzatii was found. Further, these inversions make a positive contribution to the total genetic correlation between the traits, as expected by the suggested trade-off. The data do not provide evidence as to whether the genetic correlation is due to antagonistic pleiotropic gene action or to gametic disequilibrium of linked genes that affect one or both traits. The results do suggest, however, a possible explanation for the maintenance of inversion polymorphism in this species.

Serum hepatitis B core-related antigen is more accurate than hepatitis B surface antigen to identify inactive carriers, regardless of hepatitis B virus genotype

OBJECTIVES

To investigate whether hepatitis B surface antigen (HBsAg) and hepatitis B core-related antigen (HBcrAg) levels are useful to identify inactive carriers among HBeAg-negative patients infected by different hepatitis B virus (HBV) genotypes.

METHODS

In all, 202 consecutive HBeAg-negative patients with chronic hepatitis B, 135 inactive carriers and 67 with HBV activity, were prospectively followed for 1 year.

RESULTS

In HBeAg-negative patients, HBsAg levels differed across the different genotypes (p <0.001). The highest levels were observed in genotypes F or H (4.2 ± 0.6 logIU/mL), followed by genotype E (3.4 ± 1.1 logIU/mL), genotype A (3.4 ± 0.8 logIU/mL), and the lowest in genotype D (2.7 ± 1.1 logIU/mL). Variations in HBsAg levels were similar in inactive carriers and patients with HBV activity. HBsAg <3 logIU/mL showed good performance for identifying genotype D inactive carriers: 76% of genotype D inactive carriers met this cut-off versus ≤31% for genotypes A, E, F or H. However, in patients with genotype A, HBsAg levels ≤3.7 logIU/mL better classified inactive carriers. The combination of a single measurement of HBcrAg ≤3 logU/mL plus HBV DNA ≤2000 IU/mL yielded a positive predictive value and diagnostic accuracy >85% in all HBV genotypes, except genotype H or F, with values of 62.5% and 72.7%, respectively, for the two parameters.

CONCLUSIONS

HBsAg levels varied across genotypes in HBeAg-negative patients. HBsAg levels <3 logIU/mL were only useful for identifying genotype D inactive carriers. A single HBcrAg measurement ≤3 logU/mL plus HBV DNA ≤2000 IU/mL was highly accurate for identifying inactive carriers, regardless of their HBV genotype.

Longitudinal changes in fetal biometry and cerebroplacental hemodynamics in fetuses with congenital heart disease

OBJECTIVES

To determine the longitudinal behavior of fetal biometric measures and cerebroplacental hemodynamics throughout gestation in fetuses with congenital heart disease (CHD).

METHODS

Fetal biometry and Doppler hemodynamics (uterine artery (UtA), umbilical artery (UA) and fetal middle cerebral artery (MCA)) were measured serially in a cohort of consecutive fetuses diagnosed with CHD. Evaluations were made at various time points, from diagnosis (20-25 weeks) to delivery, with at least two measurements per fetus that were at least 2 weeks apart. Fetuses were classified into three groups according to the pattern of blood supply to the brain (placental vs systemic) that would be expected on the basis of the type of CHD. All parameters were transformed into Z-scores. A linear mixed model to analyze repeated measurements was constructed for each parameter to assess its behavior throughout gestation.

RESULTS

Four hundred and forty-four ultrasound examinations were performed in 119 CHD fetuses, with a median of two measurements per fetus. The fetuses presented a small head at diagnosis (biparietal diameter (BPD) Z-score, -1.32 ± 0.99; head circumference (HC) Z-score, -0.79 ± 1.02), which remained small throughout gestation. UtA and UA pulsatility indices (PI) showed a significant increase towards the end of pregnancy, whereas no significant changes were observed in MCA-PI or cerebroplacental ratio (CPR) with gestational age. Both MCA and CPR presented significant differences in longitudinal behavior between CHD groups, while BPD and HC did not.

CONCLUSIONS

CHD fetuses have a relatively small head from the second trimester of pregnancy, regardless of the type of CHD anomaly, and increasing resistance in the UtA and UA as pregnancy progresses, suggestive of increasing degree of placental impairment. Our findings indicate the early onset of mechanisms that could lead to poorer neurodevelopment later in life. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Abstract P4-22-10: Evaluation of the effects of palbociclib (PAL) + letrozole (LET) on QTc

Background: PAL , an oral cyclin dependent kinase (CDK) 4/6 inhibitor, is under investigation in multiple oncologic clinical trials and is currently approved for use in multiple countries in patients with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2–) advanced breast cancer (ABC).

International Conference on Harmonization guidance recommends that all new drugs be evaluated for effects on cardiac repolarization in a well-controlled clinical study. For drugs for which such evaluation cannot be conducted in healthy volunteers (eg, most non-adjuvant anticancer agents), collection of robust corrected QT (QTc) interval data from a dedicated QTc study (hybrid thorough QT/QTc study) in patients [pts] is required in the registration dossier. The phase 3 PALOMA-2 study (N=666) confirmed the superior clinical benefit of PAL+LET vs placebo (P) + LET in postmenopausal women with estrogen receptor positive/HER2– ABC who have not received any prior systemic anticancer therapies for ABC. One of the secondary objectives of the study was to evaluate the effects of PAL+LET on QTc.

Methods: 12 lead (with a 10 second rhythm strip) tracings were performed in triplicate ∼2 min apart but within 10 min for all 3 ECGs. On the day preceding the initiation of treatment (Day 0), triplicate ECGs were obtained at time 0, 2, 4, 6, and 8 hrs (baseline). On Cycle 1 Day 14, when PAL concentrations were at steady-state, triplicate ECGs time-matched to baseline ECGs collected on Day 0 (±35 min) were obtained following PAL or P dosing. All ECGs were sent to a central laboratory for blinded manual adjudication and these data were used for analysis. ECG measurements included PR interval, QT interval, RR interval and QRS complex. The QT interval was corrected for the effect of heart rate using Fridericia's correction (QTcF), Bazett's correction (QTcB), and a study-specific correction factor (QTcS).

Approximately 60 pts were to be included for QTc evaluation to ensure 40 evaluable pts in the PAL+LET arm (2:1 randomization) of PALOMA-2 and thus, to establish noninferiority between post-baseline and baseline (ΔQTc) at all 5 QTc sampling timepoints on Cycle 1 Day 14 with 90% power. The test was based on a 1-sided difference in means t test for paired ΔQTc (α= 0.05). The difference in means between ΔQTc under the alternative hypothesis is 10 ms, assuming a noninferiority margin of 20 ms and the standard deviation of the paired differences equal to 16 ms based on PALOMA-1 study. If the upper bounds (UB) of 1-sided 95% confidence intervals (CI) of ΔQTc for all 5 QTc time points were &lt;20 ms, the post-baseline QTc will be considered noninferior to baseline and PAL+LET effect on QTc will be concluded to be not of clinical relevance.

Results: A total of 77 pts were enrolled for intensive QTc assessment in PAL+LET arm. No pts had a post-baseline absolute maximum QTcF, QTcS or QTcB ≥500 ms or a ΔQTc ≥60 ms during the intensive QTc assessment period. A random effect analysis of the mean ΔQTc data demonstrated that the UB of the 1-sided 95% CI for QTcF, QTcS, and QTcB were &lt;8 ms at all 5 QTc sampling time points.

Conclusion: PAL+LET does not have a clinically relevant effect on QTc.

Sponsor: Pfizer

Citation Format: Ruiz A, Gauthier E, Durairaj C, Huang X, Hoffman J, Finn RS, Moulder S, Joy AA, Ettl J, Rugo HS, Wang D. Evaluation of the effects of palbociclib (PAL) + letrozole (LET) on QTc [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-10.

103 INFLUENCE OF ESTRUS EXPRESSION AND TREATMENT WITH GONADOTROPIN-RELEASING HORMONE ON PREGNANCY RATES IN RECIPIENTS SYNCHRONIZED WITH PROGESTERONE DEVICES AND ESTRADIOL AND TRANSFERRED AT A FIXED TIME

An experiment was designed to evaluate whether expression of oestrus in recipients synchronized with progesterone devices and oestradiol affects pregnancy rates to a fixed-time embryo transfer (FTET). A secondary objective was to determine whether administration of gonadotropin-releasing hormone (GnRH) to those recipients not showing oestrus by 48 h after device removal had an effect on pregnancy rates. Mature, non-lactating beef recipients (Bonsmara, Brangus, and Braford; n = 729), with a corpus luteum (CL) or a follicle ≥8 mm in diameter detected by ultrasonography (Mindray DP 30, Shenzhen, China) and body condition score 2 to 4 (1 to 5 scale) were synchronized in 7 replicates. On Day 0, recipients received a progesterone device (DIB 0.5 g, Zoetis, Buenos Aires, Argentina) and 2 mg of oestradiol benzoate (Gonadiol, Zoetis). On Day 8, DIB were removed and recipients received 400 IU eCG (Novormon 5000, Zoetis) plus 0.5 mg of oestradiol cypionate (Cipiosyn, Zoetis) and 500 μg of cloprostenol (Cyclase, Zoetis). In addition, all cows were tail-painted on the sacrococcygeal area (CeloTest, Biotay, Buenos Aires, Argentina) at DIB removal and were observed to determine the expression of oestrus, according to the percentage of paint loss 48 h later. The animals that showed oestrus (paint loss >30%) were recorded, and those with paint loss ≤30% (not in oestrus) were randomly allocated to receive 100 μg of gonadorelin (GnRH; Gonasyn, Zoetis) or no treatment. On Day 17, all recipients were examined by ultrasonography and those with a CL ≥18 mm (G1), ≥16 and <18 mm (G2), or ≥14 and <16 mm (G3) in diameter received in vivo-produced frozen-thawed embryos by direct transfer or fresh in vitro-produced embryos. Pregnancy was diagnosed by ultrasonography at 23 days after FTET, and data were analysed by logistic regression. There were no differences between replicates, in vivo- and in vitro-produced embryos, or operators (P > 0.2). However, the proportion of recipients transferred and pregnant (P/FTET) was higher (P < 0.05) for those that showed oestrus at 48 h after DIB removal (422/454, 93.0% and 227/471, 48.2%) than those that did not show oestrus (109/211, 51.7% and 45/120, 37.5%). Within the recipients not showing oestrus, P/FTET was significantly higher (P < 0.05) in those that received GnRH (34/74, 45.9%) than in those that did not receive GnRH (12/46, 26.1%). There was a significant interaction (P < 0.05) between CL diameter and expression of oestrus. When recipients had CL ≥18 mm in diameter (G1), P/FTET did not differ (oestrus: 164/338, 48.5% v. no oestrus 30/65, 46.2%); however, when CL diameter was <18 mm and ≥14 mm (G2 and G3), P/FTET was higher (P < 0.05) in those that showed oestrus (37/85, 43.5%) than in those that did not show oestrus (11/43, 25.6%). Finally, P/FTET was higher (P < 0.05) in recipients with a CL (268/573, 46.8%) on Day 0 than in those with follicles >8 mm in diameter (4/18, 22.2%). In conclusion, the expression of oestrus significantly affected the percentage of recipients selected for embryo transfer and P/FTET. Furthermore, treatment of recipients not showing oestrus by 48 h after DIB removal with GnRH at that time increased P/FTET.

Palm oil and cardiovascular disease: a randomized trial of the effects of hybrid palm oil supplementation on human plasma lipid patterns

This study examines, for the first time, the effect of hybrid Elaeis oleifera × E. guineensis palm oil supplementation on human plasma lipids related to CVD risk factors. One hundred sixty eligible participants were randomized and assigned to one of the two treatments: 25 mL hybrid palm oil (HPO group) or 25 mL extra virgin olive oil (EVOO group) daily for 3 months. Fasting venous samples were obtained at baseline and after 1, 2 and 3 months for measurement of plasma lipids (TC, LDL-C, HDL-C and TAGs). Changes in body mass index and waist circumference were also assessed. Although there was an overall reduction in TC (7.4%, p < 0.001) and in LDL-C (15.6%, p < 0.001), no significant differences were found between the treatment groups in a repeated measures analysis of variance for TC (p = 0.0525), LDL-C (p = 0.2356), HDL-C (p = 0.8293) or TAGs (p = 0.3749). Furthermore, HPO consumption had similar effects on plasma lipids to EVOO, thus providing additional support for the concept that hybrid Elaeis oleifera × E. guineensis palm oil can be seen as a "tropical equivalent of olive oil".