83 CHANGES IN BLASTOCYST LINEAGE DIFFERENTIATION AND NUTRIENT SENSING ARE MEMORIZED IN RESPONSE TO MATERNAL LOW-PROTEIN DIET

Studies have consistently shown that conditions experienced during the periconceptional period including culture in vitro and maternal diet composition can profoundly alter the development of the embryo/fetus and can result in adult diseases such as obesity, hypertension, and cardiovascular disease. This programming occurs during the pre-implantation period. Here, we have examined blastocyst phenotype changes in response to maternal protein undernutrition during the pre-implantation period and determined whether such adaptations are stable through a change in environment. Embryos were flushed at Day 3.25 to 3.75 from naturally mated MF1 mice fed either a control (NPD) or low-protein diet (LPD) from day of plug. Blastocysts were differentially labeled using the TNBS-anti-DNP-complement method with propidium iodide and Hoechst, and cells were counted on z-series with overlays using Metamorph software (Molecular Devices, Sunnyvale, CA). For outgrowths, blastocysts flushed from LPD or NPD mothers were placed into KSOM supplemented with 10% FCS and amino acids at uterine fluid concentrations (Porter et al. 2003 Pediatr. Res. 53, 46A abst). Outgrowths were cultured for an additional 96 h and scored daily with final 4′,6-diamidino-2-phenylindole (DAPI) nuclei counts. Neither total cell numbers nor lineage divergence was affected by maternal diet until just before implantation (Day 3.75) when blastocysts from LPD mothers had significantly more total cells due to an increase in trophectoderm (TE) compared with NPD blastocysts (ANOVA; Table 1). Upon outgrowth, LPD embryos spread over a greater area although with similar nuclei numbers compared with NPD blastocysts. Moreover, inhibition of the mTOR signaling pathway with rapamycin (rapa) showed the expected dose-responsive decrease of spreading in NPD but not in LPD outgrowths (Table 1). Our data suggest a compensatory upregulation of the TE lineage after mild maternal protein undernutrition. This response becomes evident just before implantation and is, together with altered nutrient sensing and signaling sensitivity, sustained throughout peri-implantation development in vitro regardless of culture environment. Thus, we show that adaptations evident by the blastocyst stage and induced by maternal environment can subsequently be memorized and are likely to contribute to long-term programming of phenotype independent of that environment. Table 1.Blastocyst and peri-implantation development respond to maternal diet Funding by DOHaD, Gerald Kerkut Trust, and NICHD are gratefully acknowledged.

The inability to ignore: distractibility in women with restricting anorexia nervosa

BACKGROUND

Attentional difficulties reported in individuals with anorexia nervosa (AN) may be due to preferential processing of disease-salient stimuli at a pre-attentive or at a conscious level or to a general problem in attention. Attentional difficulties may be associated with duration of illness.

METHOD

Female participants with AN (restricting subtype; n=24) and healthy comparison women (n=24) were randomly allocated to subliminal or supraliminal exposure to visual stimuli (food, neutral and aversive images) while performing the 1-back and 2-back working-memory tasks.

RESULTS

Participants with AN made fewer errors than the healthy comparison group in the subliminal condition but significantly more errors in the supraliminal condition [condition x group interaction, F(1, 44)=6.82, p<0.01]: this was irrespective of stimulus type (food, neutral and aversive) and task (1-back or 2-back). The total number of errors made correlated positively with the duration of the AN for both the 1-back task (rs=0.46, p<0.05) and for the 2-back task (rs=0.53, p<0.01).

CONCLUSIONS

Decreased ability to concentrate in the presence of explicit distracters is a feature of AN and is associated with longer duration of illness. This phenomenon could be addressed in psychological interventions.

114 SPECIFIC AMINO ACIDS INFLUENCE LINEAGE DIFFERENTIATION IN MOUSE BLASTOCYSTS AND OUTGROWTHS

Blastocyst biogenesis and cell lineage differentiation into inner cell mass and trophectoderm (TE) are highly regulated processes initiated during cleavage. Cell positioning and contact patterns are well-accepted broad extrinsic factors involved in regulating blastocyst formation; however, subtle changes in the chemical composition of culture media, similarly extrinsic, may exert significant consequences for differentiation. In this study, we have examined whether, when, and how the lack of branched chain amino acids impacts on blastocyst differentiation and TE development. Using superovulated MF1 mice, embryos were flushed at 50 (2 cell) or 75 (8 cell) h after hCG and cultured in mKSOM with 0.6% BSA and amino acids at uterine fluid concentrations (Porter et al. 2003 Pediatr. Res. 53, 46A) with (all) or without (–br) the branched-chain amino acids valine, leucine, and isoleucine. Blastocysts (60 or 36 h after culture onset) were differentially labeled using the TNBS-anti-DNP-complement method with propidium iodide and Hoechst, and cells were counted on z-series with overlays using Metamorph software. For outgrowths, blastocysts developed with all aa or –br from 8 cells for 36 h were placed into KSOM supplemented with 10% FCS and either all aa or –br and cultured for an additional 120 h, scored daily, and 4′,6-diamidino-2-phenylindole nuclei counts were made at 120 h. Lack of branched amino acids from the 2-cell stage onwards caused a significant increase in total blastocyst cells with predominantly higher TE numbers, whereas, when exposed to –br from the 8 cell stage onwards, the outcome was reversed (ANOVA; Table 1). Upon outgrowth, prior amino acid composition was relatively less influential in determining spreading pattern and rate over time compared to outgrowth amino acid conditions (ANOVA; Table 1). Our data indicate that lineage development in the blastocyst is sensitive to small changes in free amino acids available and responds differently according to exposure time and duration. Subsequent development predominantly depends upon outgrowth conditions, irrespective of earlier experiences, suggesting that a similar capability for adaptive changes in response to different outgrowth media is maintained. These findings may help understand developmental plasticity and consider dynamic and potential longer-term responses to minor culture changes. Table 1. Blastocyst differentiation and outgrowth Funding by DOHaD, Gerald Kerkut Trust, and NIH are gratefully acknowledged.

Brain gene expression correlates with changes in behavior in the R6/1 mouse model of Huntington's disease

Huntington's disease (HD) is an inherited neurodegeneration that causes a severe progressive illness and early death. Several animal models of the disease have been generated carrying the causative mutation and these have shown that one of the earliest molecular signs of the disease process is a substantial transcriptional deficit. We examined the alterations in brain gene expression in the R6/1 mouse line over the course of the development of phenotypic signs from 18 to 27 weeks. Changes in R6/1 mice were similar to those previously reported in R6/2 mice, and gene ontology analysis shows that pathways related to intracellular and electrical signaling are altered among downregulated genes and lipid biosynthesis and RNA processes among upregulated genes. The R6/1 mice showed deficits in rotarod performance, locomotor activity and exploratory behavior over the time-course. We have correlated the alterations in gene expression with changes in behavior seen in the mice and find that few alterations in gene expression correlate with all behavioral changes but rather that different subsets of the changes are uniquely correlated with one behavior only. This indicates that multiple behavioral tasks assessing different behavioral domains are likely to be necessary in therapeutic trials in mouse models of HD.

Long-term cardiac outcomes following low-dose anthracycline exposure

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Background: Pediatric cancer survivors treated with moderate-high dose (=250mg/m2) anthracycline therapy are known to be at risk for cardiac toxicity. It remains unclear what cardiac risk exists for survivors who received a low dose (<250mg/m2) therapy. Methods: Cardiac MRI and maximal VO2max testing were performed on young adult survivors of childhood acute lymphoblastic leukemia (ALL). MRI measurements included ejection fraction (EF), left ventricular (LV) mass, end diastolic volume (EDV), end systolic volume (ESV), and concentricity (LV mass/EDV). Survivors who were treated with low dose anthracycline (< 250mg/m2) were compared to those without anthracycline exposure. Spearman correlations and multivariable linear regression were used to examine the relationship between anthracycline dose and measures of cardiac function and cardiorespiratory fitness. Results: Sixty-seven survivors (mean age 23.9 ±5 years) participated, including 39 (58.2%) females. The mean interval from cancer diagnosis to study was 17.4 ± 6.6 years. The number of participants by cumulative anthracycline dose were 19 (28.4%) with no exposure, 28 (41.8%) with doses of 1–249mg/m2, and 20 (29.8%) with doses of =250mg/m2. When adjusted for age and race, there was not a significant difference in the cardiac MRI outcomes and VO2max levels between participants who received 1- 249mg/m2 of anthracycline versus those without anthracycline exposure. Conclusions: With continued use of anthracyclines at cumulative low doses, particularly in ALL standard risk trials, it is important to determine if there is a long-term cardiotoxicity. With a mean follow-up of 17 years, our data support the safety of low cumulative dose anthracycline.

[Table: see text]

No significant financial relationships to disclose.

Acquired haemophilia masked by warfarin therapy

Acquired haemophilia is a rare phenomenon and prompt diagnosis is essential for successful treatment. Early laboratory detection could minimize its potentially devastating consequences and reduce mortality but when a masking element such as anticoagulant therapy is present, delay in diagnosis is not uncommon. A prolonged activated partial thromboplastin time (APTT) may be falsely attributed to warfarin alone, particularly when it is associated with oral anticoagulant overdose. We describe two patients on treatment with warfarin who presented with a bleeding diathesis and disproportionately prolonged APTT, which led to the diagnosis of antibodies directed against factor VIII.

Short course continuous, hyperfractionated, accelerated radiation therapy (CHART) as preoperative treatment for rectal cancer

Determine feasibility and toxicity of preoperative short course pelvic CHART (25 Gy in 15 fractions over 5 days) for treatment of clinically resectable primary rectal tumours. Between 1998 and 2004, 20 patients with clinically staged T3 resectable rectal carcinoma were treated in this prospective pilot study with preoperative short course CHART to their pelvis. The aim was for total mesorectal excision within 7 days. Radiation toxicity, surgical morbidity, locoregional control (LRC), overall (OS), cause specific (CSS) and disease free survival (DFS) outcomes were documented. Nineteen of the 20 patients completed planned radiotherapy. One discontinued radiotherapy due to toxicity. All patients underwent potentially curative radical surgery. One patient developed grade 3, and three patients grade 2 gastrointestinal toxicity. With a median follow-up of 31 months (range 0.9-88), there is no grade 3, 4 or 5 late toxicity. Two patients experienced grade 2, and three patients grade 1 late bowel toxicity. Two patients died from postoperative complications, and two developed grade 2 abdominal wound infections. At 3 years LRC is 95% (95% CI 83-100), OS 72% (95% CI 51-94), CSS 86% (95% CI 68-100) and DFS 80% (95% CI 60-100). Two patients died from metastatic disease, one patient from a second primary and one patient is alive after successful resection of hepatic metastases. This small study suggests preoperative short course CHART for clinically resectable rectal carcinoma is feasible with acceptable compliance and tolerable side effects.

Recovery of the red-finned blue-eye: an endangered fish from springs of the Great Artesian Basin

The red-finned blue-eye (Scaturiginichthys vermeilipinnis) is endemic to a single complex of springs emanating from the Great Artesian Basin, Australia. The species has been recorded as naturally occurring in eight separate very shallow (generally <20 mm) springs, with a combined wetland area of ~0.3 ha. Since its discovery in 1990, five red-finned blue-eye (RFBE) populations have been lost and subsequent colonisation has occurred in two spring wetlands. Current population size is estimated at <3000 individuals. Artesian bores have reduced aquifer pressure, standing water levels and spring-flows in the district. There is evidence of spatial separation within the spring pools where RFBE and the introduced fish gambusia (Gambusia holbrooki) co-occur, although both species are forced together when seasonal extremes affect spring size and water temperature. Gambusia was present in four of the five springs where RFBE populations have been lost. Four out of the five remaining subpopulations of RFBE are Gambusia free. Circumstantial evidence suggests that gambusia is a major threat to red-finned blue-eyes. The impact of Gambusia is probably exacerbated by domestic stock (cattle and sheep), feral goats and pigs that utilise the springs and can negatively affect water quality and flow patterns. Three attempts to translocate RFBE to apparently suitable springs elsewhere within the complex have failed. Opportunities to mitigate threats are discussed, along with directions for future research to improve management of this extremely threatened fish and habitat.

Evaluation for cardiac toxicity with MRI in young adult survivors of acute lymphoblastic leukemia (ALL)

18604

Background: Long-term survivors of childhood cancer treated with a moderate to high cumulative dose (≥300mg/m2) an anthracycline are known to be at risk for cardiac toxicity. It remains unclear what cardiac risk exists for survivors who received a low cumulative dose (<300mg/m2) of an anthracycline. Methods: We are conducting an NIH sponsored trial in 120 young adult survivors of ALL to determine the prevalence of cardiovascular risk factors and to determine the effectiveness of an exercise intervention. As part of their cardiovascular risk assessment, participants undergo cardiac MRI, a tool with excellent reproducibility in assessing left ventricular (LV) size and function. The aim of this component of the study is to determine the prevalence of cardiac toxicity in survivors treated with low dose anthracycline in comparison to those who did not receive any anthracycline. Descriptive statistics, chi-square analysis, and spearman correlation coefficients were used to examine the relationship between anthracycline dose and measures of cardiac function. Results: This study represents a work in progress. Preliminary results from the first 22 participants who have had a cardiac MRI do not show a significant difference in ejection fraction, LV mass, cardiac output, or mass to volume ratio between those treated with low cumulative dose anthracycline versus no anthracycline. Available cardiac MRI data for all participants will be presented at the meeting. Conclusions: With the continued use of an anthracycline at cumulative low doses, particularly in upcoming ALL standard risk trials, it is particularly important to determine if there is a risk of cardiac toxicity after low doses with aging.

No significant financial relationships to disclose.

The management of scaphoid fractures

Appropriate management of scaphoid fractures is important because of the risk of long-term complications such as delayed or non-union, pain and disability. Up to 25% of scaphoid fractures are not visible on the initial radiographs. Consequently, all clinically suspected scaphoid fractures are treated as fractures with cast immobilisation until cause of the symptoms is clarified. The diagnosis often utilises a number of second line investigations that are generally performed 10-14 days after the injury. Bone scintigraphy is currently the most commonly used of these as it rarely misses a fracture. However, it does not visualise anatomical structure and therefore alternative diagnoses are difficult. Magnetic resonance imaging (MRI) is at least as sensitive and more specific than bone scanning and has the advantages of being able to identify other lesions and not expose the patient to any radiation. Furthermore, the scan may be performed as early as 2.8 days following an injury rather than 10 days later in the case of a bone scan. Although the cost of MRI is higher than other imaging modalities, it may be cost-effective in the overall management of patients with occult scaphoid fractures since it may prevent unnecessary cast immobilisation in active people. The most appropriate method of cast immobilisation is presently unclear but evidence exists for improved clinical outcomes in those that have both the thumb and elbow immobilised for the first six weeks.

Cost effectiveness of adding magnetic resonance imaging to the usual management of suspected scaphoid fractures

OBJECTIVE

To determine the cost effectiveness of a magnetic resonance imaging scan (MRI) within 5 days of injury compared with the usual management of occult scaphoid fracture.

METHODS

All patients with suspected scaphoid fractures in five hospitals were invited to participate in a randomised controlled trial of usual treatment with or without an MRI scan. Healthcare costs were compared, and a cost effectiveness analysis of the use of MRI in this scenario was performed.

RESULTS

Twenty eight of the 37 patients identified were randomised: 17 in the control group, 11 in the MRI group. The groups were similar at baseline and follow up in terms of number of scaphoid fractures, other injuries, pain, and function. Of the patients without fracture, the MRI group had significantly fewer days immobilised: a median of 3.0 (interquartile range 3.0-3.0) v 10.0 (7-12) in the control group (p = 0.006). The MRI group used fewer healthcare units (median 3.0, interquartile range 2.0-4.25) than the control group (5.0, 3.0-6.5) (p = 0.03 for the difference). However, the median cost of health care in the MRI group (594.35 dollars AUD, 551.35-667.23 dollars) was slightly higher than in the control group (428.15 dollars, 124.40-702.65 dollars) (p = 0.19 for the difference). The mean incremental cost effectiveness ratio derived from this simulation was that MRI costs 44.37 dollars per day saved from unnecessary immobilisation (95% confidence interval 4.29 dollars to 101.02 dollars). An illustrative willingness to pay was calculated using a combination of the trials measure of the subjects' individual productivity losses and the average daily earnings.

CONCLUSIONS

Use of MRI in the management of occult scaphoid fracture reduces the number of days of unnecessary immobilisation and use of healthcare units. Healthcare costs increased non-significantly in relation to the use of MRI in this setting. However, when productivity losses are considered, MRI may be considered cost effective, depending on the individual case.