Model Selection for the Preclinical Development of New Drug-Radiotherapy Combinations

Radiotherapy plays an essential role in the treatment of more than half of all patients with cancer. In recent decades, advances in devices that deliver radiation and the development of treatment planning software have helped radiotherapy attain precise tumour targeting with minimal toxicity to surrounding tissues. Simultaneously, as more targeted drug therapies are being brought into the market, there has been significant interest in improving cure rates for cancer by adding drugs to radiotherapy to widen the therapeutic window, the difference between normal tissue toxicity and treatment efficacy. The development of new combination therapies will require judicious adaptation of preclinical models that are routinely used for traditional drug discovery. Here we highlight the strengths and weaknesses of each of these preclinical models and discuss how they can be used optimally to identify new and clinically beneficial drug-radiotherapy combinations.

Genetic correlations between wool traits and meat quality traits in Merino sheep

Genetic correlations between 29 wool production and quality traits and 25 meat quality and nutritional value traits were estimated for Merino sheep from an Information Nucleus (IN). Genetic correlations among the meat quality and nutritional value traits are also reported. The IN comprised 8 flocks linked genetically and managed across a range of sheep production environments in Australia. The wool traits included over 5,000 yearling and 3,700 adult records for fleece weight, fiber diameter, staple length, staple strength, fiber diameter variation, scoured wool color, and visual scores for breech and body wrinkle. The meat quality traits were measured on samples from the and included over 1,200 records from progeny of over 170 sires for intramuscular fat (IMF), shear force of meat aged for 5 d (SF5), 24 h postmortem pH (pHLL; also measured in the , pHST), fresh and retail meat color and meat nutritional value traits such as iron and zinc levels, and long-chain omega-3 and omega-6 polyunsaturated fatty acid levels. Estimated heritabilities for IMF, SF5, pHLL, pHST, retail meat color lightness (), myoglobin, iron, zinc and across the range of long-chain fatty acids were 0.58 ± 0.11, 0.10 ± 0.09, 0.15 ± 0.07, 0.20 ± 0.10, 0.59 ± 0.15, 0.31 ± 0.09, 0.20 ± 0.09, 0.11 ± 0.09, and range of 0.00 (eicosapentaenoic, docosapentaenoic, and arachidonic acids) to 0.14 ± 0.07 (linoleic acid), respectively. The genetic correlations between the wool production and meat quality traits were low to negligible and indicate that wool breeding programs will have little or no effect on meat quality. There were moderately favorable genetic correlations between important yearling wool production traits and the omega-3 fatty acids that were reduced for corresponding adult wool production traits, but these correlations are unlikely to be important in wool/meat breeding programs because they have high SE, and the omega-3 traits have little or no genetic variance. Significant genetic correlations among the meat quality traits included IMF with SF5 (-0.76 ± 0.24), fresh meat color * (0.50 ± 0.18), and zinc (0.41 ± 0.19). Selection to increase IMF will improve meat tenderness and color which may address some of the issues with Merino meat quality. These estimated parameters allow Merino breeders to combine wool and meat objectives without compromising meat quality.

Genetic parameters for wool traits, live weight, and ultrasound carcass traits in Merino sheep

Genetic correlations between 29 wool production and quality traits and live weight and ultrasound fat depth (FAT) and eye muscle depth (EMD) traits were estimated from the Information Nucleus (IN). The IN comprised 8 genetically linked flocks managed across a range of Australian sheep production environments. The data were from a maximum of 9,135 progeny born over 5 yr from 184 Merino sires and 4,614 Merino dams. The wool traits included records for yearling and adult fleece weight, fiber diameter (FD), staple length (SL), fiber diameter CV (FDCV), scoured color, and visual scores for breech and body wrinkle. We found high heritability for the major yearling wool production traits and some wool quality traits, whereas other wool quality traits, wool color, and visual traits were moderately heritable. The estimates of heritability for live weight generally increased with age as maternal effects declined. Estimates of heritability for the ultrasound traits were also higher when measured at yearling age rather than at postweaning age. The genetic correlations for fleece weight with live weights were positive (favorable) and moderate (approximately 0.5 ± 0.1), whereas those with FD were approximately 0.3 (unfavorable). The other wool traits had lower genetic correlations with the live weights. The genetic correlations for FAT and EMD with FD and SL were positive and low, with FDCV low to moderate negative, but variable with wool weight and negligible for the other wool traits. The genetic correlations for FAT and EMD with postweaning weight were positive and high (0.61 ± 0.18 to 0.75 ± 0.14) but were generally moderate with weights at other ages. Selection for increased live weight will result in a moderate correlated increase in wool weight as well as favorable reductions in breech cover and wrinkle, along with some unfavorable increases in FD and wool yellowness but little impact on other wool traits. The ultrasound meat traits, FAT and EMD, were highly positively genetically correlated (0.8), and selection to increase them would result in a small unfavorable correlated increase in FD, moderately favorable reductions in breech cover and wrinkle, but equivocal or negligible changes in other wool traits. The estimated parameters provide the basis for calculation of more accurate Australian Sheep Breeding Values and selection indexes that combine wool and meat objectives in Merino breeding programs.

Ewe culling and retention strategies to increase reproductive rates in Merino sheep

The present empirical study of data from three Merino resource flocks of varying genetic backgrounds run in different environments investigated the impact of various selection strategies aimed at culling poor performers (‘passengers’) or retaining good doers (‘performers’) longer, or both, on the flock reproductive performance. Four strategies were investigated and applied either individually or in combination, to quantify their impact on the litter size, rearing type and breeding efficiency (number of lambs weaned per ewe per year) of the whole flock. The main benefit from implementing any of the strategies was a decrease in the proportion of dry ewes in each flock (1–7%). There was little difference between the single strategies of culling twice-dry ewes or culling ewes that twice lambed and lost their lambs. When retaining a cohort of older ewes, it was more efficient to select these on the basis of their lifetime reproductive performance. There was only a marginal benefit gained by combining strategies and, in some cases, a single strategy was still better in terms of breeding efficiency. Commercial producers can improve the reproductive rate of these flocks by culling twice-dry ewes on the basis of their pregnancy scan data.

Genetic correlations between wool traits and carcass traits in Merino sheep

Genetic correlations between 29 wool production and quality traits and 14 whole carcass measures and carcass component traits were estimated from the Information Nucleus of 8 flocks managed across a range of Australian sheep production environments and genetically linked. Wool data were from over 5,000 Merino progeny born over 5 yr, whereas carcass data were from over 1,200 wether progeny of over 176 sires, slaughtered at about 21 kg carcass weight, on average. Wool traits included yearling and adult records for wool weight, fiber diameter, fiber diameter variation, staple strength, scoured color, and visual scores for breech and body wrinkle. Whole carcass measures included HCW, dressing percentage (DP), and various measures of fat depth and eye muscle dimensions. Carcass components were obtained by dissection, and lean meat yield (LMY) was predicted. Heritability estimates for whole carcass measures ranged from 0.12 ± 0.08 to 0.35 ± 0.10 and ranged from 0.17 ± 0.10 to 0.46 ± 0.10 for carcass dissection traits, with no evidence of important genotype × environment interactions. Genetic correlations indicated that selection for increased clean wool weight will result in reduced carcass fat (-0.17 to -0.34) and DP (-0.48 ± 0.15), with little effect on carcass muscle. Selection for lower fiber diameter will reduce HCW (-0.48 ± 0.15) as well as carcass fat (0.14 to 0.27) and muscle (0.21 to 0.50). There were high genetic correlations between live animal measures of fat and muscle depth and the carcass traits (generally greater than 0.5 in size). Selection to increase HCW (and DP) will result in sheep with fewer wrinkles on the body (-0.57 ± 0.10) and barer breeches (-0.74 ± 0.12, favorable), with minor deterioration in scoured wool color (reduced brightness and increased yellowness). Selection for reduced fat will also result in sheep with fewer body wrinkles (-0.42 to -0.79). Increasing LMY in Merinos through selection would result in a large reduction in carcass fat and DP (-0.66 to -0.84), with a smaller increase in carcass muscle and some increase in wool weight and wrinkles. Although no major antagonisms are apparent between the wool and carcass traits, developing selection indexes for dual-purpose wool and meat breeding objectives will require accurate estimates of genetic parameters to ensure that unfavorable relationships are suitably considered. The findings will aid development of dual-purpose wool and meat breeding objectives.

The repeatability of textural wool handle

Merino breeders use textural greasy wool handle in ram buying and breeding decisions. The effectiveness of the current wool handle scoring system has not been objectively evaluated. The assessor repeatability of textural wool handle was quantified using three different methods of assessment (on the live animal, as a greasy wool mid-side sample, and as a clean (scoured) wool mid-side sample). The aim of the study was to determine which method of assessment is the most repeatable. Three separately defined repeatability estimates were calculated based on knowledge about the operator. The first estimate was based on the assessor repeatability from the operators used in this study. The second estimate was calculated using replicate values obtained from the same random assessor and the third estimate was based on two results from independent random assessors. The results demonstrated that the assessor repeatability was the greatest when handle was assessed on the clean wool mid-side method, followed by the greasy wool mid-side assessment, and least in the live-animal assessment. However, there was significant variation in the repeatability estimates between the four assessors used in the study. Accounting for fixed effects such as sex, sire group, birth type and rearing type, decreased the variation observed and thus had a negative impact on the assessor repeatability of textural wool handle. The results in this study indicate that non-wool constituents negatively impact on the ability of an assessor to consistently assign a score for textual handle in the greasy wool mid-side method. It is likely that the added cost and time required for scouring to assess handle in the clean state may not be economically viable in most situations. However, the increase in repeatability by assessing handle in greasy wool mid-side method compared with the live-animal assessment indicates that sheep producers should use this strategy when evaluating the trait on-farm.

Abstract 1476: A therapeutic antibody that inhibits CD73 activity by dual mechanisms

CD73 has a central role in dictating the adenosine concentration within the tumor as it is the final step in converting extracellular ATP to adenosine. Thus, substantial reduction of CD73 enzymatic activity has the potential to reduce immunosuppression of effector immune cells within the tumor. We present data describing an anti-human CD73 antibody that suppresses CD73 by two mechanisms: 1. direct inhibition of enzymatic activity upon binding to CD73 and 2. rapid, near-complete internalization of the enzyme. Durable reduction of cell-surface CD73 was observed in multiple tumor cell lines both in vitro and in vivo. The unique properties of this antibody are a result of the use of a human IgG2-IgG1 hybrid antibody with effector function eliminated by specific mutations of the Fc. The IgG2 sequence of this antibody drives superior internalization of CD73 and enhanced CD73 inhibition. Syngeneic tumor models demonstrate that CD73 contributes to resistance to anti-tumor therapy. Combination therapy with PD-1 blockade and a surrogate anti-mouse-CD73 antibody resulted in a better anti-tumor efficacy than either treatment alone. Finally, we demonstrate a novel technique for assessing CD73 enzymatic activity in situ that has potential for clinical application. These data support antibody-based anti-CD73 therapy in cancer and highlight a novel mechanism for inhibition of CD73 enzymatic activity.

Citation Format: Bryan C. Barnhart, Emanuela Sega, Aaron Yamniuk, Sandra Hatcher, Ming Lei, Haben Ghermazien, Anne Lewin, Xi-Tao Wang, Haichun Huang, Pingping Zhang, Alan Korman. A therapeutic antibody that inhibits CD73 activity by dual mechanisms. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1476.

Effect of fitting sheep covers and injection of a mineral supplement on the brightness, clean colour and photostability of wool grown by grazing Merino sheep

Wethers sourced from a Merino genetic resource flock, selected on the basis of their measured wool clean colour at 2 years of age, were stratified on the basis of clean colour and allocated to one of four treatment groups in a 2 × 2 factorial design. The aim was to investigate the effect of coating the fleece and administration of a commercial mineral supplement on brightness, clean colour and photostability over a 12-month period when run on the Central Tablelands of New South Wales. Coating the fleece significantly improved both the brightness and clean colour of the fleece (P<0.001, by 4 and 0.5 T units, respectively), but had no effect on the photostability of the two traits. The mineral supplement had no significant impact on the colour or photostability traits and there was no evidence of an interaction between coating the fleece and the mineral supplement. Although the improvements in brightness and colour arising from coating the fleece complemented the predicted responses to genetic selection for these two traits, the combined effect would not be sufficient to replace the routine use of oxidative bleaching during processing.

Season and reproductive status rather than genetic factors influence change in ewe weight and fat over time. 4. Genetic relationships of ewe weight and fat score with fleece, reproduction and milk traits

The profitability of a sheep enterprise is greatly influenced by the ability of the ewe to produce a lamb annually. This paper examines the between- and within-breed association between the liveweight and fat score of the adult ewe and key fleece, reproduction and milk production traits. The study analysed the performance of 2846 first-cross Merino and Corriedale ewes from the maternal central progeny test (MCPT) over their first three production cycles. Breed (9 sire breeds) and within-breed (91 sires) correlations were calculated from bivariate correlations of adult liveweight and fat score with fleece, reproduction and milk production traits. The mean liveweight and fatness of the breeds were low to moderately negatively correlated with greasy fleece weight (–0.55 and –0.25, respectively) and moderate to strongly positively correlated with fibre diameter (0.88 and 0.41, respectively). However, the within-breed correlations were generally low to negligible. The genetic relationships between ewe fat score and reproductive traits at the breed and within-breed level was generally low to negligible and, in some cases, negative under production conditions where the ewes were well managed and averaged a fat score of 3.5 pre-joining and became too fat across the production cycle. Strong breed correlations between ewe fat score and milk fat concentration (0.88) suggest that selection of fatter sire breeds will lead to increased fat in their progenies’ milk, which was associated with larger lambs. The potential advantages of selecting for more fat to improve the maternal performance of the ewe seem to be limited in enterprises where the production system can easily be adjusted to restrict the influence of temporary and long-term feed deficiencies, as was achieved within the MCPT research flocks.

Fabric and greasy wool handle, their importance to the Australian wool industry: a review

Handle-related properties of woollen fabrics have been demonstrated to be major factors affecting consumer buying attitudes. Handle is the combination of both textural and compressional attributes. Compressional handle has demonstrated processing advantages in woven and knitted fabrics. The handle of processing lots can be manipulated using a variety of technologies but direct manipulation of textural greasy wool handle pre-processing is still crude. On-farm, there is documented evidence that including handle assessment in a selection index provides additional improvements in genetic gain. However, the assessment of greasy wool handle is based on a tactile evaluation of the wool staple by sheep and wool classers, and its application is affected by a lack of framework that instructs assessors on a standard method of assessment. Once a reliable and repeatable protocol is developed, further understanding of the effect greasy wool handle has on final garment quality will be possible.

Monitoring liveweight in sheep is a valuable management strategy: a review of available technologies

Liveweight is a widely accepted proxy for the energy status of sheep at a particular point in time. Fleece- and conceptus-free ewe liveweight and liveweight change influence the productivity of the ewe and optimisation may increase whole-farm profitability. Despite this, it is uncommon for producers to monitor ewe liveweight regularly and objectively. The current review discusses why ewe liveweight is important, identifies and assesses available technologies for monitoring sheep liveweight, and highlights future research priorities. The common theme in the literature is that while there are options that could possibly be used to monitor the liveweight of sheep in extensive grazing systems, few of them offer realistic solutions, especially in regard to timeliness of data collection. Thermal and stereo imaging, body measurements and plasma hormonal assays are unlikely to be commercially viable, while visual assessment, although widely practised, offers a surprisingly poor indication of sheep liveweight. Alternatively, assessment of body condition (condition scoring) or fat (fat scoring) offers viable methods of assessing sheep energy status; however, like conventional static weighing, they are performed infrequently and therefore contribute little to the day-to-day tactical management of sheep flocks. Walk-over weighing systems offer a feasible alternative for regular monitoring of sheep liveweight. Such systems are fully automated, and may be operated remotely. Currently, there are challenges associated with monitoring the liveweight of individual animals using such systems and hence there is little commercial opportunity for individual animal management. Mob-based walk-over weighing, which generates flock average liveweight estimates, offers greater potential in the short term, although the technology would benefit from further research and development, primarily to increase the frequency and repeatability of liveweight capture.

Season and reproductive status rather than genetics factors influence change in ewe weight and fat over time. 1. Analysis of crossbred ewes

The Australian sheep industry has historically made rapid advances in the quality and quantity of meat and wool through genetic improvement, but unfortunately, maternal performance, i.e. number of lambs weaned, is well below desired levels. The aim of the present paper is to investigate the potential to select for increased weight and fat across the production cycle to improve maternal performance. The analysis explores the potential to improve the weight and fat score of breeding ewes during ‘tough’ periods (i.e. when nutrient requirements are not met by the pasture), preparing the breeding ewe for the upcoming mating without an increase in overall ewe size. The 2846 ewes within the maternal central progeny test were weighed and scored for fatness 12 times across three production cycles. Low to moderate heritability estimates for weight (0.04–0.23) and fat (0.02–0.06) changes across the production cycle provide little hope for selection against weight loss during tough periods. The analysis showed very strong genetic correlations between time-points across multiple production cycles for both weight (0.99–0.93) and fat score (0.88–0.98). The very strong correlations between measurements suggest that weight and fat score are genetically the same trait throughout the ewe’s adult life. With 74% and 77% of the genetic variation in weight and fat, respectively, constant across the production cycle, there is little opportunity to select against the natural fluctuations in weight and fat reserves. In conclusion, selection for increased fat can be made at any time and it will result in more fat during tough times.

Season and reproductive status rather than genetic factors influence change in ewe weight and fat over time 2. Spline analysis of crossbred ewes

The success of slaughter lamb enterprises is heavily influenced by the ability of the breeding ewe to produce a lamb annually across variable environments. It has been shown that by maintaining heavier weight and condition across the annual production cycle producers can make significant improvements in maternal performance. This paper follows on from a previous analysis of crossbred ewes within the Maternal Central Progeny Test and examines the potential to select for reduced fluctuation in weight and fat across the production cycle. A cubic spline model was fitted to the weight and fat score data from the first three parities of 2688 first-cross ewes. The analysis partitioned the influence of environment, reproduction and genetic effects on the shape of the weight and fat score splines across three parities. Yearly and seasonal variation in feed supply and the demands of raising a lamb are the major influences on fluctuations in the weight and fat score of the breeding ewe. The genetic effects were constant across time with 98 and 92% of the genetic variation for weight and fat, respectively, associated with the spline’s intercept. In agreement with the findings of the first paper of the series it can be concluded that genetic lines do not re-rank for weight or fat score over time. The influence of sire breed on weight and fat score was constant across time with sire breeds fluctuating in parallel across time. As a result it is concluded that to avoid low fat reserves and the subsequent low fertility during the ‘tough’ periods, selection to improve ewe body condition could be made at any time and under any environmental conditions.

Using partial records to identify productive older ewes to retain in the breeding flock to increase the flock net reproduction rate

The reproductive performance of 7286 ewes from three Merino genetic resource flocks maintained in the central-western region of New South Wales was used to compare the use of fertility and fecundity information and net reproduction information whether recorded early (at 2 and 3 years of age) or later in life (at 4 and 5 years of age) with lifetime performance (at 2–6 years of age) as alternative selection criteria to identify productive older ewes to retain in the breeding flock. While the lifetime net reproduction rate is the best indicator of a ewe’s reproductive performance in later life, producers basing their selection decisions on pregnancy scanning data, which provides information on both fertility and fecundity, can improve the net reproduction rate of their flock by 2% regardless of the base reproduction rate. Despite little difference in likely flock reproduction rates between using early or later life scanning information as the selection criteria, early life performance is the best choice for commercial producers because it provides scope for eliminating twice-dry ewes from the breeding flock early in life, especially when combined with udder examination at marking.

Effects of site of assessment and variation in wool quality traits on the tactile assessment of textural greasy wool handle

Variation in textural greasy wool handle across the fleece of Merino sheep was explored. Results demonstrate that there were significant differences across nine sites on the fleece. The inclusion of the covariates fibre diameter, fibre diameter co-efficient of variation, staple length, dust penetration, staple structure, greasy wool colour and resistance to compression, helped to explain some of the variation in textural greasy wool handle between sites such that site of assessment was no longer a significant factor (P = 0.065). However, in practice, those involved with clip preparation or sheep selection based on textural greasy wool handle assessment are unlikely to have these measurements available. The results highlight the importance of nominating a site of assessment when recording textural greasy wool handle.

Effects of three whole-farmlet management systems on Merino ewe fat scores and reproduction

As part of the Cicerone Project’s whole-farmlet experiment on the Northern Tablelands of New South Wales, Australia, the fat scores and reproductive performance of ewes were measured to assess the effect of different management systems on these important production parameters over time. The three farmlets (each of 53 ha) included one (farmlet B) subjected to ‘typical’ district management consisting of moderate levels of inputs and a target stocking rate of 7.5 dse/ha, with flexible grazing management across eight paddocks. A second farmlet (A) was managed in a similar fashion to farmlet B with respect to number of paddocks and grazing management, but modified by high rates of pasture renovation and higher levels of soil fertility, with a target stocking rate of 15 dse/ha. The third farmlet (C) was managed at the same level of moderate inputs as farmlet B but employed intensive rotational grazing over 37 paddocks and also had a high target stocking rate of 15 dse/ha. The experiment was conducted over 6.5 years from July 2000 to December 2006. In spite of the fact that target levels of stocking rate were chosen at the beginning of the experiment, stocking rate, together with fat scores and reproduction were treated as emergent properties of each farmlet system. Joining took place in April–May and lambing occurred in September–October of each year. Over the first 2 years of the experiment, there were few differences among farmlets in ewe fat scores or reproductive performance. From 2003 onwards, while the percentage of ewes pregnant was similar between farmlets, the average proportion of multiple births (ewes scanned in late July, with twins) was 30%, 16% and 12%, respectively, on farmlets A–C. However, lamb losses were greater on farmlet A, with average lamb mortalities recorded on farmlets A–C of 29%, 10% and 19%, respectively. Over the duration of the experiment, ewes on farmlets A and B were more often above a fat score level of 3, and less often below 2.5, than were ewes from farmlet C. Differences among farmlet ewes in fat score were found to be significant in 7 of the total of 13 assessments over the duration of the experiment. A generalised additive model applied to whole-farmlet data showed that green digestible herbage, legume herbage, stocking rate, the amount of supplement fed and especially the proportion of each farmlet grazed at any one time all influenced fat scores of ewes. While fat scores and conception rates tended to be highest on farmlet A, farmlet B had slightly better reproductive outcomes due to less lambing losses, whereas ewes on farmlet C tended to have somewhat lower fat scores and levels of reproduction. These farmlet-scale findings highlighted the importance for livestock managers to focus not only on grazing management, stocking rate and stock density during lambing, but also on the availability of sufficient green, and especially legume herbage, and the difficulty of overcoming a deficit in quality herbage with supplementation.

Livestock weights in response to three whole-farmlet management systems

This paper reports changes in livestock weights recorded in a whole-farmlet experiment, which aimed to examine the profitability and sustainability of three different pasture and grazing management strategies. The assessment of liveweights was considered a key component of measuring the integrated effects of the farmlet-scale treatments. The three farmlets comprised a typical management regime, which employed flexible rotational grazing over eight paddocks with moderate soil fertility (farmlet B), a system based on the same grazing management and paddock number but with higher levels of sown pasture and soil fertility (farmlet A) and a farmlet with moderate soil fertility and intensive rotational grazing over 37 paddocks (farmlet C). Early in the experimental period, there were no significant differences between farmlets in the liveweight of any class of livestock. However, from the second year onwards, as the pasture renovation, soil fertility and grazing management treatments took effect, differences in liveweight between farmlets became more apparent and significant. The stocking rate, which was treated as an emergent property of each farmlet, reached a maximum annual average value after 5 years of 12.6, 8.5 and 7.7 dry sheep equivalents (dse)/ha on farmlets A, B and C representing 84, 113 and 51% of their respective target stocking rates which were 15, 7.5 and 15 dse/ha. The liveweights of ewes, both before joining and during pregnancy, varied with year and farmlet with those on farmlets A and B tending to be significantly heavier than those on farmlet C. From 2003 to 2006, liveweights were significantly (P < 0.001) affected by a wide array of factors and their interactions including: date, ewe age, green digestible herbage, legume herbage mass, proportion of farmlet grazed, stocking rate and level of supplementary feeding. The weights of lambs/weaners/hoggets, both pre- and post-weaning, were at times also higher on farmlets A and B compared with those on farmlet C and were affected by a similar range of factors to those which affected ewe weights. Similar relative differences also applied to the liveweights of the other livestock run on the farmlets, namely wethers and non-reproductive cattle. The results suggest that stocking rate was able to be increased towards the higher target of farmlet A due to the higher level of pasture renovation and soil fertility on that farmlet, which led to high liveweights per head as well as the higher stocking rate. However, as the stocking rate increased on farmlet A, the differences between farmlets in liveweight per head diminished and the need for supplementary feeding increased. In contrast, the intensive rotational grazing practised on farmlet C did not allow the farmlet to increase its stocking rate towards its higher target. It appears that the higher proportion of each of farmlets A and B grazed at any one time allowed all classes of livestock to reach higher liveweights per head than on farmlet C, due presumably to the greater proportion of those two farmlets grazed at any one time.

Managing the weaning transition of Merino lambs by promoting positive growth rates and increasing survival – is yard weaning a viable option?

The effectiveness of yard weaning to manage the weaning transition period for Merino sheep was investigated on three commercial properties in the New South Wales Central Tablelands. Three experiments were conducted, Experiment 1 investigated the duration of yard weaning, Experiment 2 compared two alternative rations provided to yard-weaned animals, while Experiment 3 compared yard weaning with paddock weaning. The ‘Control’ for each of the three experiments was each producers’ normal paddock-weaning strategy with comparisons based on post-weaning growth rates and weaner survival. Liveweights were recorded at weaning and at 15, 50 and 180 days post-weaning. Growth rates were calculated from liveweight measurements. Survival was determined by the continuing presence of an individual animal at subsequent measurements. Compared with the paddock-weaned Control group, variable responses in liveweight, growth rates and weaner survival to 50 and 180 days post-weaning occurred in the three experiments. Yard weaning was not superior to any of the producers’ normal paddock-weaning practices, however, favourable seasonal conditions in early 2010 prompted high growth rates in the paddock-weaned Control animals relative to those achieved by the yard-weaned animals. Further research is required to determine the optimum duration of confinement and ration (including composition and method of delivery). This work should include comparisons of the behaviour of paddock- and yard-weaned animals and model production benefits versus economic costs for a range of production systems and market scenarios.

Genetic variation in sulfur, calcium, magnesium, manganese and trace metal content of Merino wool and correlations with brightness, yellowness and photostability

Genetic parameters (heritability, phenotypic and genetic correlations) were estimated for sulfur (S), calcium (Ca), magnesium (Mg), manganese (Mn) and trace metal content (i.e. Cu, copper; Fe, iron; Zn, zinc) of yearling (11 months, n = 387) and adult (23 months, n = 274) fleeces from the 2007 and 2008 cohorts of Merino progeny (including both ewes and wethers) born into the Sheep CRC Information Nucleus. There was significant genetic variation in S and all metals. Ninety percent of the variation in S and Zn content of yearling wool was genetic, while heritability estimates for the remaining metals were all higher than 0.28 except for Cu (h2 = 0.17 ± 0.11) and Mn (h2 = 0.03 ± 0.12) in yearling fleeces and Cu (h2 = 0.14 ± 0.18) in adult fleeces. Ca and Mg were very highly correlated both phenotypically (0.95 ± 0.01 as yearlings and adults) and genetically (0.95 ± 0.07 as yearlings). There were also strong genetic correlations between yearling and adult Ca and adult Mn (0.85 ± 0.22 and 0.88 ± 0.10), Mg and Mn (0.92 ± 0.10) and between yearling S and adult Zn (0.67 ± 0.22) and adult S and adult Zn (0.60 ± 0.22) suggesting similar genetic mechanisms controlling the biochemical pathways of incorporation of each pair of elements into the fibre. There were significant phenotypic correlations between certain elements and the brightness, yellowness and photostability of wool. Taken together across the yearling and adult measurements, the phenotypic and genetic correlations suggest that wool with higher concentrations of Ca and Mg would tend to be less bright, yellower and less photostable than wool with lower concentrations of these metals. Wool with higher concentrations of Mn would tend to have a similar impact to Ca and Mg on brightness, clean colour and photostability. Fe was also associated with less bright wool, however wool with a high Fe content would tend to be whiter but with a propensity to yellow following UVB exposure.

High Merino weaner survival rates are a function of weaning weight and positive post-weaning growth rates

Survival and subsequent productivity of Merino ewe weaners (weaned in 2006 and 2007, respectively) on commercial properties in the New South Wales Central Tablelands were monitored through routine liveweight measurement until weaning of their own progeny from their maiden joining. Growth rates were calculated from the regular liveweight measurements with survival determined by the continuing presence of an individual animal at subsequent measurements. This study demonstrates that high weaner survival rates are a function of both weaning weight and post-weaning growth rates. Importantly, it indicates that low post-weaning growth rates can negate the survival benefit conferred by a high weaning weight such that weaners who were unable to sustain positive post-weaning growth rates were at high risk of death. Furthermore, classification of weaners into liveweight profile groups based on their weaning weight and post-weaning growth rates identified another group of weaners that are also at high risk of death. These weaners (14% of the mob) had above average weaning weights but low post-weaning growth rates and a mortality rate nearly 1.5 times that of the lightest cohort of weaners. High weaner survival rates about the 95% industry benchmark are possible if weaners show positive growth rates post weaning. Weaning weight continues to have a residual influence on the subsequent productivity of ewe weaners until they wean their first lambs. Maiden ewes that were heavier at weaning tend to have higher scanning percentages and are more likely to successfully rear their progeny to marking than their lighter weight counterparts. This finding should be taken into account when economic analyses of the benefits of alternative management strategies to promote weaner survival are undertaken.

Fat depth, muscle depth, fat score and wool growth in Merino dams selected for high or low clean fleece weight and bodyweight

Concerns exist that selection for increased clean fleece weight (CFW) is expected to reduce body fatness. Such an effect is likely to impact on reproduction; however, all previous studies have examined non-reproductive yearlings or hoggets. The present study, using adult reproductive dams examined the impact of phenotype [based on high or low phenotypic CFW and bodyweight (BWT) performance], stocking rate (high or low) and litter size on body composition and wool traits. High CFW dams were heavier (P < 0.01) with lower fat depth (P < 0.01) and muscle depth (P < 0.05). The high CFW twin-weaning dams had a lower fat score from lamb marking to pre-joining (P < 0.05), but tended to replete fat reserves faster (P < 0.1) between weaning and pre-joining. At these times of repletion these animals grew longer wool staples (P < 0.05). High BWT ewes had reduced staple length (P < 0.01), and when adjusted for maternal liveweight also reduced fat depth (P < 0.001) and muscle depth (P < 0.05). We conclude that the CFW phenotype impacts on fat reserves but that management of dams in groups according to their CFW performance is not warranted.

Can we breed Merino sheep with softer, whiter, more photostable wool?

Genetic parameters (heritability, phenotypic and genetic correlations) were estimated for a range of visual and measured wool traits recorded from the 2008 shearing of the initial cohort of Merino progeny born into the Sheep CRC’s Information Nucleus Flock. The aim of this initial analysis was to determine the feasibility of selectively breeding Merino sheep for softer, whiter, more photostable wool and to quantify the likely impact on other wool production and quality traits. The estimates of heritability were high for handle and clean colour (0.86 and 0.70, respectively) and moderate for photostability (0.18), with some evidence of maternal effects for both handle and photostability. The phenotypic correlations between handle and clean colour and between handle and photostability were close to zero, indicating that achieving the ‘triple’ objective of softer, whiter, more photostable wool in the current generation through phenotypic selection alone would be difficult. There was evidence of an antagonistic relationship between handle and photostability (–0.36), such that genetic selection for softer wool will produce less photostable wool that will yellow on exposure to UV irradiation. However genetic selection for whiter wool is complementary to photostability and will result in whiter wool that is less likely to yellow. Genetic selection to improve handle, colour and photostability can be achieved with few detrimental effects on other visual and measured wool traits, particularly if they are included in an appropriate selection index.

Comparison of manual assessments of ewe fat reserves for on-farm use

The two systems currently used in Australia for assessing the body reserves of live sheep (fat and condition scoring) were evaluated for their ability to quantify the range of scores within a mob and their ability to discriminate between sheep of varying fatness. Three ewe genotypes (fine Merino, medium Merino and first-cross Border Leicester × Merino) were independently assessed by four assessors experienced in each system (i.e. eight assessors). Twenty-four hours after assessment the ewes were slaughtered in a commercial abattoir and hot carcass measures of tissue depth at the GR site (thickness of tissue over the 12th rib, 110mm from the midline) taken to allow correlation with the assessed live scores. There was at least three times more phenotypic variation in fat score assessment compared with condition score as the fat score assessors used a wider range of scores. Despite this the average repeatability of fat scoring (0.73–0.85) was greater than condition scoring (0.64–0.84) particularly within the fine Merino genotype. Although there was a strong linear relationship between assessments of fat and condition scoring, the regression coefficients comparing the two scoring systems indicated a greater discrimination among animals on fat score across all three genotypes. Furthermore the fat scores had a significantly higher correlation with GR tissue depth measured on the carcass than condition scores. These data indicate that both systems will similarly assess the average body fat reserves of a mob or animals; however, fat scoring achieves greater discrimination when the goal is to identify individuals that are lower or higher than the mob average.

Heritability of feed intake in grazing Merino ewes and the genetic relationships with production traits

The feed intake of 1279 mature non-pregnant and non-lactating Merino ewes grazing pasture was estimated by faecal marker dilution methods using rumen controlled-release devices containing chromium sesquioxide capsules. The ewes were from two genetic resource flocks (QPLU$ flock at Trangie in NSW and a Western Australia flock at Katanning) that are representative of the major bloodlines and strains in the Australian Merino population. Pedigree information over several generations was used to genetically link other animals from the resource flocks that had additional production data to allow estimation of genetic correlations between feed intake and production traits with greater accuracy. Data were available for over 16 000 records for growth, wool and reproduction traits from the ewes and their relatives, together with carcass and meat quality traits from over 4000 rams that were slaughtered at ~18 months of age. Feed intake of the ewes was significantly affected by the reproductive status of the ewes at their previous lambing and feed intake, expressed as relative digestible dry matter intake (rDDMI), had an estimated heritability of 0.32 ± 0.08. The genetic correlations between rDDMI and growth traits were positive and larger than their standard error for birth (0.24 ± 0.12) and hogget (0.20 ± 0.09) weight, although inclusion of ewe liveweight as a covariate in the model reduced the correlations to close to zero. Generally, the genetic correlations between rDDMI and the wool, reproduction, carcass and meat quality traits were close to zero and smaller than their standard errors, with little effect of including ewe liveweight as a covariate. The results suggest that feed requirements of ewes could be reduced by selection, although ewe weight and growth would also decline unless accounted for in the model. Practical and cost effective methods of measurement of intake under grazing conditions need to be developed.

Higher weaning weight improves postweaning growth and survival in young Merino sheep

Two monitoring projects were conducted to investigate weaner mortality in commercial Merino flocks in the Yass and the Central Tablelands Rural Lands Protection Boards located in the Southern Tablelands agricultural region of New South Wales. The projects were conducted in Yass in 2005 and in the Central Tablelands in 2006. A random sample of weaners from four flocks in the Yass board and 11 flocks in the Central Tablelands board were regularly weighed, growth rates were calculated after weaning and survival was determined by the continuing presence of an individual weaner at subsequent weighing activities. Weaning weight was the most important factor in determining postweaning liveweight, growth rates and survival with the significant impact of weaning weight on liveweight persisting for up to 6 months after weaning. Despite the lightest weaners being capable of considerable compensatory growth given sufficient postweaning nutrition, the lightest 25% of weaners were more than twice as likely to die as heavier weaners. A focus on ewe nutrition and parasite control during late pregnancy and lactation will allow Merino producers to achieve higher weaning weights that will set their weaners up for strong postweaning growth with a decreased likelihood of mortality.

WITHDRAWN: Antidepressants for depression in medical illness

BACKGROUND

Depression in the physically unwell is common and an important cause of morbidity. There are problems with diagnosing depression in the physically ill which may lead to under-recognition and under-treatment. In clinical practice antidepressants are available and a feasible option for treating depressive disorders. Therefore we thought it would be a reasonable first step in addressing this problem to describe the literature of randomised controlled trials in this area.

OBJECTIVES

To determine whether antidepressants are clinically effective and acceptable for the treatment of depression in people who also have a physical illness.

SEARCH STRATEGY

MEDLINE, Cochrane Library Trials Register and Cochrane Depression and Neurosis Group Trials Register were all systematically searched, supplemented by hand searches of two journals and reference searching.

SELECTION CRITERIA

All relevant randomised trials comparing any antidepressant drug (as defined in the British National Formulary) with placebo or no treatment, in patients of either sex over 16, who have been diagnosed as depressed by any criterion, and have a specified physical disorder (for example cancer, myocardial infarction). "Functional" disorders where there is no generally agreed physical pathology (e.g. irritable bowel syndrome) were excluded. The main outcome measures are numbers of individuals who recover/improve at the end of the trial and, as a proxy for treatment acceptability, numbers who complete treatment.

DATA COLLECTION AND ANALYSIS

Data was extracted independently by the reviewers onto data collection forms and differences settled by discussion.

MAIN RESULTS

18 studies were included, covering 838 patients with a range of physical diseases (cancer 2, diabetes 1, head injury 1, heart 1, HIV 5, lung 1, multiple sclerosis 1, renal 1, stroke 3, mixed 2). Depression was diagnosed clinically in 3 studies, otherwise by structured interview or checklist. Only 5 studies described how they performed randomisation. 1 study compared drug with no treatment, and the rest with placebo: all of the latter said they were double blind.6 studies used SSRIs, 3 atypical antidepressants, and the remainder tricyclics.Patients treated with antidepressants were significantly more likely to improve than those given placebo (13 studies, OR 0.37, 95% CI 0.27-0.51) or no treatment (1 study, OR 3.45, 95% CI 11.1-1.10). About 4 patients would need to be treated with antidepressants to produce one recovery from depression which would not have occurred had they been given placebo (NNT 4.2, 95% CI 3.2-6.4). Most antidepressants (tricyclics and SSRIs together, 15 trials ) produced a small but significant increase in dropout (OR 1.66, 95% CI 1.14-2.40. NNH 9.8, 95% CI 5.4-42.9). The "atypical" antidepressant mianserin produced significantly less dropout than placebo. Only 2 studies used numerical scales designed to measure effects on function and quality of life; in HIV (Karnofsky scale), drug was better than no treatment; in lung disease (Sickness Impact Profile), drug was not significantly different from placebo. Only 7 studies reported looking for changes in the physical disease. Antidepressants produced no change in immune function in HIV relative to placebo (2 studies) or no treatment (1 study). Relative to placebo, antidepressants produced no change in cardiovascular function in heart disease, in respiratory function in lung disease, or in vital signs or laboratory tests in cancer (1 study each). Nortriptyline produced worse control in diabetes. Trends towards tricyclics being more effective than SSRIs, but also more likely to produce dropout were noted, but these are based on non-randomised comparisons between trials.

AUTHORS' CONCLUSIONS

The review provides evidence that antidepressants, significantly more frequently than either placebo or no treatment, cause improvement in depression in patients with a wide range of physical diseases. About 4 patients would need to be treated with antidepressants to produce one recovery from depression which would not have occurred had they been given placebo (NNT 4.2, 95% CI 3.2-6.4). Antidepressants seem reasonably acceptable to patients, in that about 10 patients would need to be treated with antidepressants to produce one dropout from treatment which would not have occurred had they been given placebo (NNH 9.8, 95% CI 5.4-42.9).The evidence is consistent across the trials, apart from 2 trials in cancer, where the "atypical" antidepressant mianserin produced significantly less dropout than placebo. Trends towards tricyclics being more effective than SSRIs, but also more likely to produce dropout were noted, but these are based on non-randomised comparisons between trials. Problems with the evidence include most of the trials' use of observers, rather than patients, to decide on improvement, and concentration mainly on symptoms rather than function and quality of life. There is also a possibility of undetected negative trials.Nevertheless, the review provides evidence that use of antidepressants should at least be considered in those with both physical illness and depression. Regarding diagnosis, the existence of a cheap and readily available treatment for depression should encourage detailed assessment of persistent low mood in the physically ill.

Aprotinin and epsilon aminocaproic acid are effective in reducing blood loss after primary total hip arthroplasty--a prospective randomized double-blind placebo-controlled study

A prospective randomized double-blind placebo-controlled study was undertaken to determine the efficacy and mechanism of action of two antifibrinolytic drugs aprotinin and epsilon aminocaproic acid (EACA) in reducing blood loss in primary unilateral total hip arthroplasty (THA). Aprotinin was administered as a bolus of 2 x 10(6) kallikrein inhibitor units (KIU) followed by 0.5 x 10(6) KIU h(-1) for 3 h, EACA was given as 10 g over 30 min followed by 5 g over 3 h. The median postoperative blood loss 24 h postoperatively was reduced from 450 mL in the placebo group to 180 mL for aprotinin (60% reduction, P < 0.001) and to 210 mL for EACA (53% reduction, P < 0.01). In this population, there was no reduction in the perioperative transfusion requirements. The mechanism of both drugs was independent of platelets as indicated by flow cytometric measurement of change of their expression of P-selectin, platelet-monocyte aggregates, V/Va and CD40 ligand. There were no thrombotic or infective complications and no adverse events were attributable to use of either drug. Infusion of either aprotinin or EACA at the doses described is a safe and effective means of reducing blood loss after THA. These therapies provide a means of reducing blood loss in THA patients.

Carcass traits, meat quality and muscle enzyme activity in strains of Merino wether hoggets

The carcass characteristics, meat quality and specific muscle enzyme activity were studied in 342 Merino wether hoggets representing 7 bloodlines comprising 2 superfine lines, 2 fine wool lines, 2 medium wool lines and 1 broad wool line over 2 years. All animals were supplemented at pasture for 5 weeks before slaughter with high energy pellets. Fat levels in the superfine bloodlines based on total tissue depth over the 12th rib, 110 mm from the midline were much greater than in other lines. This also applied to fat depth measured over the longissimus thoracis et lumborum (LL) muscle for one of the superfine bloodlines when adjusted to the same carcass weight. Differences in LL muscle dimensions were minor, although the broad wool bloodline had a lower depth which translated into a smaller cross-sectional area. Significant differences were detected between bloodlines for muscle pH with superfine animals having the highest values for the LL. The differences for the semitendinosus muscle were less consistent between bloodlines, but of the bloodlines the broad wool line had the lowest pH levels in both muscles. There were few differences between bloodlines for the meat colour parameters measured on the LL. In the second year, muscle samples were taken to determine the activity of fructose 1,6-bis-phosphatase, lactate dehydrogenase (LDH), isocitrate dehydrogenase (ICDH) and the concentration of myoglobin, indicators of anaerobic and aerobic metabolism. Samples from 50 carcasses were selected from a medium wool and a superfine bloodline (2 × 25) based on LL muscle pH values. Of the enzymes, only ICDH activity was different between the 2 bloodlines, with muscle from the medium wool bloodline having a significantly higher activity than muscle from the superfine bloodline. This indicates a greater aerobic capacity in the muscle of the medium wool bloodline. The significantly lower muscle pH for medium wool bloodline was mirrored by a lower glycolytic capacity expressed as the LDH/ICDH ratio with a correlation of 0.46. Thus in this dataset, a high pH is related to a change in energy metabolism as reflected by the aerobic/anaerobic capacity of the muscle and this may be a reflection of a change in fibre type frequency, but this remains to be validated.

Feasibility of using the TOSCA telescreening procedures for diabetic retinopathy

AIMS

The TOSCA project was set up to establish a tele-ophthalmology service to screen for diabetic retinopathy (DR) in Europe. The aim of this study was to determine the feasibility of establishing telemedicine-based digital screening for detecting DR and to evaluate the satisfaction of both patients and healthcare professionals with the screening procedures used within the TOSCA project.

METHODS

The study was a non-randomized, multicentre study carried out in four different countries over a period of 3 months. Patients (n = 390) with diabetes aged > 12 years were included. Two digital retinal images per eye (macular and nasal) were taken and exported to a central server. Patients were asked to complete a questionnaire to assess satisfaction. Accredited graders carried out grading remotely and the results were reported back to the referring centre. Previously graded patient data chosen randomly to represent examples of both DR and no DR were also sent anonymously to the grading centre at a frequency of approximately every 10 patients.

RESULTS

Most (99%) of the images were assessable enabling a retinopathy grade to be assigned to the patient. Patients found the retinal photography procedures acceptable; only 6% in one centre would not recommend the procedure. Healthcare professionals (photographers and graders) were also satisfied with the overall procedures. The average time taken to grade each patient was approximately 5 min.

CONCLUSIONS

This study demonstrated that it is feasible to electronically transmit and grade retinal images remotely using the TOSCA process. Built-in quality assurance procedures proved acceptable.

Blastic mantle cell lymphoma developing concurrently in a patient with chronic myelogenous leukemia and a review of the literature

Non-Hodgkin's lymphoma (NHL) occurring as a synchronous malignancy with chronic myelogenous leukemia (CML) is rare. To our knowledge, this is the first case reported of a patient who developed mantle cell lymphoma (MCL) after therapy with imatinib mesylate for CML. After a 3-year history of CML, the patient developed a lymphocytosis associated with diarrhea, anorexia, and weight loss. Imaging studies revealed abdominal adenopathy and extensive lymphomatous infiltration of the liver, stomach, pancreas, and kidneys. Flow cytometric and cytogenetic studies were consistent with MCL. Fluorescence in situ hybridization (FISH) of the bone marrow revealed a genetically distinct lymphoid neoplasm rather than an extramedullary blast crisis of CML. The development of lung cancer, prostate cancer, CML and MCL in this patient suggests a genetic predisposition, although other factors, including environmental exposures and therapy with imatinib mesylate could have had a contributory or synergistic role in the development of MCL.

Allele-specific Holliday junction formation: a new mechanism of allelic discrimination for SNP scoring

We report here a new mechanism for allelic discrimination--allele-specific Holliday Junction formation. The Holliday Junction (HJ) is a unique DNA structure that can be formed in a sequence-nonspecific manner by routine PCR. To cause the PCR-based HJ formation to occur in an allele-specific manner, the PCR primers are manipulated such that an extra mismatch next to a SNP of interest is introduced between a target and a reference amplicon and a GC-clamp is added. Based on this new mechanism, novel SNP genotyping methods were developed, including a homogeneous fluorescence polarization (FP) competition assay that requires neither labeled primers/probes nor expensive enzymes/substrates. Using this novel genotyping technology, we were able to convert >95% of SNP sequences into genotyping assays that work well under a universal set of assay conditions and achieved 100% accuracy in clinical samples.

Physical activity and exercise training prescriptions for patients

The dominant outcome from exercise prescription is an increase in various markers of exercise capacity. A very large group of studies have demonstrated that the VO2max is increased in response to exercise performed according to well-accepted principles of exercise prescription. Other markers of exercise capacity, such as the VT, also improve substantially following exercise training. Finally, improvement in exercise capacity is generally related to improved quality of life, particularly in patients with exercise capacity limited by various disease processes. Beyond the specific physiologic gains from training, exercise contributes to a better overall clinical outcome. Although there are few data conclusively demonstrating that exercise independently causes favorable changes in other risk factors, it should be recognized that exercise can contribute indirectly to modulation of other risk factors. Exercise represents positive health advice. Since most of our other recommendations to patients are in the nature of negative advice (e.g., don't smoke, don't eat high-fat foods), and since people are infamous for ignoring negative advice, the value of using a positive recommendation that may indirectly lead the patient to discontinue bad behaviors can hardly be overstated.

T-cell lymphoproliferative disorder in an aged rhesus macaque

A CD8+ T-cell leukemia was diagnosed in an aged female rhesus macaque. Although leukemia and lymphoma in nonhuman primates are commonly associated with simian T-lymphotropic virus, gibbon ape leukemia virus, oncogenic herpesviruses, and types C, D, and E retroviruses, this monkey was not infected with any of these viruses. However, the monkey did have antibodies against herpesvirus saimiri. This likely represents cross-reactivity of the herpesvirus saimiri assay with rhesus monkey rhadinovirus (RRV) antibodies; RRV was first described in rhesus macaques that were identified as having antibodies against herpesvirus saimiri. Rhesus rhadinovirus is a gamma herpesvirus, related antigenically to herpesvirus saimiri and Kaposi's sarcoma-associated herpesvirus (KSHV), which have been linked to lymphoproliferative disorders in primates and humans, respectively. Moreover, an oncogene has been recently identified in the RRV genome that is equivalent in position to the herpesvirus saimiri and KSHV oncogenes. Presently, the association of RRV infection with disease in nonhuman primates is unknown.

Biphenotypic sarcoma with characteristics of both a Ewing sarcoma and a desmoplastic small round cell tumor

BACKGROUND

The EWS gene, a transcription factor of unknown function, is involved in chromosomal translocations associated with a wide variety of tumors, particularly small round blue cell tumors such as Ewing sarcoma. It has previously been reported that desmoplastic small round blue cell tumor (DSRBCT) frequently has an associated t(11;22) abnormality resulting from fusion of the EWS and WT-1 genes.

PROCEDURE

We report a case of a small round blue cell tumor with characteristics of both Ewing sarcoma and DSRBCT with a t(11;22) translocation leading to fusion of the EWS and FLI1genes.

RESULTS

The translocation point and fusion products were confirmed by polymerase chain reaction amplification and restriction fragment mapping of the products.

CONCLUSIONS

The biphenotypic nature of this case and the apparent promiscuity of the EWS gene in tumor-associated translocations coupled with other reports of biphenotypic childhood sarcomas has potential implications for the relationship between small round blue cell tumors and the mechanism of EWS/FLI1 oncogenesis.