Tumor-Targeted Perfluorinated Micelles as Efficient Theranostic Agents Combining Positron Emission Tomography and Radiosensitization

We report the synthesis of biocompatible perfluorinated micelles designed to improve radiotherapeutic efficacy in a radioresistant tumor environment. In vitro and in vivo behaviors of perfluorinated micelles were assessed at both cellular and tissular levels. The micellar platform offers key advantages as theranostic tool: (i) small size, allowing deep tissue penetration; (ii) oxygen transport to hypoxic tissues; (iii) negligible toxicity in the absence of ionizing radiation; (iv) internalization into cancer cells; (v) potent radiosensitizing effect; and (vi) excellent tumor-targeting properties, as monitored by positron emission tomography. We have demonstrated strong in vitro radiosensitizing effects of the micelle and in vivo tumor targeting, making this nanometric carrier a promising tool for the potentiation of focused radiotherapy.

Effects of tryptophan and probiotic supplementation on growth and behavior in quail

In laying hens, a diet supplemented with tryptophan (Trp) has been shown to affect their pecking behavior. However, unlike this positive effect, Trp is also involved in negative effects on behavior and stress through indolic pathways. Indole production can be reduced by probiotics (Pro), thus we hypothesized that Pro may prevent negative effects of Trp and increase beneficial effects on behavior in birds. Combined effects of Pro and Trp were also expected. To investigate the effects on behavior in birds of supplementing with a high level of Trp with or without Pro, Japanese quail were used because their behavior can be influenced by Pediococcus acidilactici, and they can be highly aggressive. Quails (n = 120) were assigned to 4 groups in a 2 × 2 factorial design for 55 d: C-C (control diet with usual Trp level, 0.3%; without Pro; n = 30), Trp-C (Trp: 2%; without Pro; n = 30), C-Pro (control diet; with Pro: 1 x 10⁹ CFU/L P. acidilactici in drinking water; n = 30), and Trp-Pro (Trp 2%; with Pro; n = 30). Body weight was measured every week, and different tests were conducted to investigate behavioral characteristics of each quail. Contrary to our hypothesis, there was almost no interaction between Trp and Pro treatments. Tryptophan supplementation significantly (P < 0.05) reduced live weight up to 27 d, whereas Pro treatment had no effect. There was no significant difference between groups for tonic immobility variables (P > 0.05). The birds fed the high Trp diet spent significantly less time in the periphery of the open field than those fed the control diet and moved less in the arena during the social isolation test. Interindividual distances were significantly lower in males fed with Trp 2% than with the control diet, whereas Trp and Pro supplements interacted in females. The treatments did not affect sexual motivation in males. These results indicate that a high level of Trp reduced growth and appeared to enhance emotional reactivity in quails and that supplementing with Pro did not reduce these effects. In conclusion, feeding high Trp for 55 d cannot be recommended as a strategy to improve social behavior unlike effects observed in laying hens.

Formation of Imidazolones by Ring Closure of α-Isocyanoamides: Exploring New Reactivities

Base-mediated ring closure of α,α-disubstituted α-isocyanoamides with further electrophilic trapping has previously been explored, but with limited applications. In this work, we wished to unravel the reactivities of these compounds and, in particular, to allow palladium-catalyzed coupling at the C2 position.

Omega-3 polyunsaturated fatty acids provided during embryonic development improve the growth performance and welfare of Muscovy ducks (Cairina moschata)

The welfare of ducks can be affected by unwanted behaviors such as excessive reactivity and feather pecking. Providing long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) during gestation and early life has been shown to improve the brain development and function of human and rodent offspring. The aim of this study was to test whether the pecking behavior of Muscovy ducks during rearing could be reduced by providing LC n-3 PUFA during embryonic and/or post-hatching development of ducklings. Enrichment of eggs, and consequently embryos, with LC n-3 PUFA was achieved by feeding female ducks (n-3F) a diet containing docosahexaenoic (DHA) and linolenic acids (microalgae and linseed oil). A control group of female ducks (CF) was fed a diet containing linoleic acid (soybean oil). Offspring from both groups were fed starter and grower diets enriched with DHA and linolenic acid or only linoleic acid, resulting in four treatment groups with 48 ducklings in each. Several behavioral tests were performed between 1 and 3 weeks of age to analyze the adaptation ability of ducklings. The growth performance, time budget, social interactions, feather growth, and pecking behavior of ducklings were recorded regularly during the rearing period. No significant interaction between maternal and duckling feeding was found. Ducklings from n-3F ducks had a higher body weight at day 0, 28, and 56, a lower feed conversion ratio during the growth period, and lower reactivity to stress than ducklings from CF ducks. Ducklings from n-3F ducks also exhibited a significantly reduced feather pecking frequency at 49 and 56 days of age and for the whole rearing period. Moreover, consumption of diets enriched with n-3 PUFA during the starter and grower post-hatching periods significantly improved the tibia mineralization of ducklings and the fatty acid composition of thigh muscles at 84 days of age by increasing the n-3 FA content.

The European experience in poultry welfare--a decade ahead

Farm animal welfare is a major issue in Europe, which resulted in regulations and development of research dedicated to animal welfare, especially on standard poultry production, which is often considered as resulting in very poor welfare. The effect of selection is also often questioned. Indeed, capacities of adaptation have been very little considered during the first years of commercial selection and thus have been reduced. Nowadays, a much greater importance is given to welfare-related traits and genomic selection should alleviate the need for their measurements in the short-term. However, the choice of the fittest selection criteria is still to be made. Because behavioral traits are highly dependent on environment, general reactivity may be more efficient. For example, selection against undesirable behavior such as feather pecking has been proven to be efficient, but selection for reduced mortality rates in collective cages proved to be preferable. Most often, selection should not exacerbate extreme values, which are most often detrimental, as in the case of social motivation, which, when increased to too large of an extent, results in increased aggressivity. Moreover, a general propensity will not result in overall improvement; for example, reducing fearfulness has positive effects but does not modify response to social stress. Detrimental effects on other traits may also be observed: although genetic resistance to diseases should increase animal welfare, it may also result in increased frequency of silent carriers and in turn to human transmission. Indeed, an optimum must be found. Studying lines selected for or against these traits will be of great help to choose the best strategy of selection. Another and longer term concern should be on links with other production traits but also on sustainability, which will probably be of greater importance in the coming years.

Genetic selection on a behavioural fear trait is associated with changes in heart rate variability in quail

This study investigated whether genetic selection on a divergent behavioural trait of fearfulness (tonic immobility duration) was related to changes in the nervous control of the heart. Quail selected for either long or short tonic immobility (LTI or STI, respectively) duration was compared with an unselected control line (CTI). The autonomic control of the heart was assessed by heart rate variability analysis and pharmacological blockades. Quail were surgically fitted with a telemetric device. Heart rate before injection did not differ between the three lines. The vagal-sympathetic effect (VSE) at rest differed significantly from 1 in CTI and STI quail, suggesting that parasympathetic activity was dominant. In LTI quail, VSE did not differ from 1, suggesting a balance between parasympathetic and sympathetic activities. The intrinsic heart rate reached after the successive injections of propranolol and atropine did not differ between lines and was higher than the heart rate at rest in STI, which was in line with results of VSE at rest. After atropine injection, the sympathetic activity indicated by the low-frequency power was lower in CTI than in the two selected quail. After propranolol injection, the parasympathetic activity indicated by the root of the mean squares of successive differences and the high-frequency power was higher in STI than in CTI and LTI quail. Selection on tonic immobility duration thus appears to be associated with changes in the sympathovagal control of the heart, which may influence behavioural responses to stressful situations.

Emotional reactivity modulates autonomic responses to an acoustic challenge in quail

Emotional reactivity modulates autonomic responses to an acoustic challenge in quail. Physio Behav 00(0) 000-000, 2006. This study investigated the relationship between emotional reactivity and behavioral and autonomic responses to an acoustic stimulus in quail. It was hypothesized that birds with high emotional reactivity would have higher motor inhibition combined with higher sympathetic activation than birds with low emotional reactivity. Two experiments were performed. The first looked for correlations between emotional reactivity, evaluated by a tonic immobility test, and motor and Heart Rate Variability in relation to an acoustic stimulus. The second experiment compared the motor and autonomic responses to the acoustic stimulus of quail selected on either long (LTI) or short (STI) duration of tonic immobility. The first experiment showed that the acoustic stimulation induced motor inhibition and cardiac activation. Correlations were found between tonic immobility duration and both autonomic activity before stimulation and sympathovagal balance after stimulation. In the second experiment, LTI quail showed strong sympathetic activation, whereas STI quail showed parasympathetic and sympathetic activation. The activation of the parasympathetic system induced by the noise in STI quail can be explained by the predominance of this system at rest in this line. In conclusion, both the basal autonomic activity and the autonomic responses differed according to the emotional reactivity, and changes in autonomic activity appear to be related to the genetic selection process.

Sequential Feeding Programs for Broiler Chickens: Twenty-Four- and Forty-Eight-Hour Cycles

Sequential feeding programs (Seq) of 2 feeds, 1 protein rich-energy poor and 1 energy rich-protein poor, during the same day or every other day were compared with a control complete diet for male broiler growth and body composition from 15 d to market weight. In experiment 1, BW gain and breast meat yield were significantly lower than those of controls for 24-h-cycle Seq with extreme protein content difference between the 2 feeds. BW gain and breast meat yield were higher than those of controls when feeds with moderate differences [feed moderately rich in protein (PM) = 26% CP; feed moderately rich in energy (EM) = 16% CP] were fed. Feeding periods that were half as long but changed twice as frequently gave less favorable results. In experiment 2, effects of allowing access to feed for different lengths of time were measured. The treatments in a 24-h cycle were a constant control diet, 50% PM-50% EM, 40% PM-60% EM, or 80% PM-20% EM decreasing to 40% PM-60% EM. Chickens fed 40% PM-60% EM had a 6% lower BW gain and a 3% higher feed/gain ratio and were fatter than those from other treatments. In experiment 3, male chickens fed a 48-h-cycle Seq of EM and PM every other day had the same BW gain, feed intake, and feed/gain ratio as controls. In experiment 4, five 48-h-cycle Seq with varying differences of energy and protein contents between EM and PM gave similar or slight reduction of performances compared with controls. A field trial with 8 flocks of broilers confirmed that feeding high and low protein feeds on alternate days resulted in performance similar to that from feeding a complete feed despite large day-to-day variations in lysine intake. Converse to shorter phases, Seq for 48-h cycles offers new opportunities for practical application and also for studies of short-term regulation of protein and lipid metabolism in chickens.

Factorial correspondence analysis of fear-related behaviour traits in Japanese quail

Factorial correspondence analysis was performed on 341 quails from a F2 cross between two lines divergently selected on the duration of tonic immobility over 29 generations. Several fear- or stress-related traits were recorded, i.e. tonic immobility duration, number of inductions needed to induce tonic immobility, open-field behaviour (time spent walking, latency before first movement and number of defecations), asymmetry of tibia lengths and corticosterone concentration after restraint stress. Variables were categorised in classes and analysed by factorial correspondence analysis. The first axis was mostly described by open-field behaviour, and the second by tonic immobility traits (duration of tonic immobility and number of inductions), which showed that these behaviours were almost independent. No relationship was found between axes of the factorial correspondence analysis and corticosterone concentration or asymmetry of tibia lengths, showing that these variables reflected other characteristics of stress susceptibility than those described by tonic immobility and open-field behaviour. These results show that reaction to stress of quails is a multidimensional trait and cannot be summarised by one trait.

Sequential feeding can increase activity and improve gait score in meat-type chickens

This study investigated the short- and long-term effects of sequential feeding by alternating low-and high-lysine diets during the day on growth, gait score (GS), and behavior in broilers. From Days 2 to 12, 6 pens of 10 birds were assigned to control treatment and fed a standard normal lysine diet (NL) (ME = 3,250 kcal/kg, CP = 23%, Lys = 1.19%) and six pens of 10 birds were assigned to the sequential treatment and fed a low-lysine diet (LL) (Lys = 0.85%) for half of the day and NL for the other half of the day. From Days 13 to 21, all groups were fed NL, and from Days 21 to 42, they were fed a grower diet. Sequential (S) chicks were lighter than Control chicks at Days 13 (304 +/- 6 vs. 378 +/- 7 g) and 42 (2,588 +/- 31 vs. 2,714 +/- 10 g) and had better leg condition at Day 42 (mean GS = 1.6 +/- 0.1 vs. 2.1 +/- 0.1, P < or = 0.05). During a day of S feeding, S birds ate less and wasted more LL than NL. Sequential birds spent less time standing and more time lying idle when fed LL than when fed NL. Sequential birds spent more time eating than Control birds, and they gradually increased the number of pecks in the litter during a sequential feeding day. The results suggest a major effect of food composition on behavior. Sequential feeding could be a means of decreasing leg problems in broilers.

Influence of increased environmental complexity on leg condition, performance, and level of fearfulness in broilers

We hypothesized that increased distance between resources and stimulation of foraging behavior, through altering the degree of environmental complexity by using moving lights and scattering whole wheat in the litter, would improve physical activity of broiler chickens. Increased activity may potentially improve leg condition and performance and decrease the level of fearfulness in broilers. To test this hypothesis, 1,800 1-d-old male broilers were divided into 40 groups of 45 birds each (10 birds/m2). Each group was assigned to one of four treatments (10 replicates) as follows: barrier treatment (B) contained three barriers placed between the drinker line and the feeder. The light treatment (L) consisted of brightly colored moving lights projected on the pen floor for four 1-h periods/d throughout rearing. For the wheat treatment (W) wheat was dispersed on the floor from Days 8 to 17. Control birds (C) were maintained under standard management. Body weights and consumption were obtained throughout the rearing period. Gait score (GS), tibia length and diameter, fluctuating asymmetry (FA), bone ash, tibial dyschondroplasia (TD), bone breaking strength, and tonic immobility (TI) were measured at slaughter age. Mortality, body weight, feed conversion, FA, bone ash, TD, bone breaking strength, and TI duration did not differ significantly among groups. L birds had a higher GS than C and B birds and W birds had a higher GS than C birds (P < 0.05). Provision of barriers significantly increased the diameter of the tibia diaphysis (P = 0.05), which is a promising result for further studies to improve leg condition.

Typology of activity bouts and effect of fearfulness on behaviour in meat-type chickens

Increased physical exercise is known to prevent leg problems in meat-type chickens. Our aims were to study in detail the organisation of general and locomotor activity, to determine how physical exercise could be promoted and to investigate the effects of tonic immobility (TI) duration on spontaneous activity. Chicks were allocated to two groups according to their TI duration at 3 and 20 days (fearful birds, HF, n=11; non-fearful birds, LF, n=14). The behaviour patterns expressed by awake birds were recorded as 'activity bouts'. Activity bouts were then classified into five classes according to the most long-lasting activity in the bout. The behaviour patterns were similar in both groups. The FORAGING class contained long-lasting bouts with high levels of locomotor activity which decreased considerably with age, when bouts of EATING and DRINKING classes became more and more numerous. Bouts in the PREENING and NONE classes contained low activity. In conclusion, the level of activity in home pens was poorly related to TI. Categorisation of bouts into five classes is valuable to understand the general organisation of activity in chickens. The FORAGING class included bouts with high levels of locomotion and it could thus be used as a general indicator of activity.

Effect of genotype, sex and rearing temperature on carcase and meat quality of guinea fowl

1. The aim of our study was to analyse the effect of genotype (label and standard), sex and rearing temperature (simulating daily outdoor in the summer or winter) on the carcase and meat quality of guinea fowl. Using 20 animals per treatment, slaughtered at 96 d of age we measured the breast angle and the thickness of the skin on the wing membrane. Carcases were weighed and cut into parts according to a standardised procedure to determine the percentages of abdominal fat, breasts, wings and thighs with shanks. 2. At slaughter, standard guinea fowl were heavier than label guinea fowl and for both genotypes, the females were heavier than the males (+5.6%). The mean value of breast angle was 85 degrees. This value was significantly higher for the standard guinea fowls and for the females of both genotypes compared with males. Thus, female carcases, particularly standard females, were more compact. The skin was thicker for the standard guinea fowls (0.84 mm vs 0.77 mm) which could be due to more subcutaneous fat. 3. Carcase yield was higher for the males (68.7% vs 68.2%). The percentage of abdominal fat was higher for the standard guinea fowls (2.8% vs 2.4%) and for the females of both genotypes compared with males. The label guinea fowls had higher yields of breasts and thighs with shanks. For both lines, the breast and thigh meat of females was judged more tender and less stringy. 4. Low rearing temperature decreased growth performance but had no significant effect on carcase quality.

Early bone growth in chickens genetically selected for a high and low growth rate

Male chickens from lines divergently selected for fast (FGL) and slow (SGL) growth were compared for the growth of cortical bone. Morphology, histomorphometric, compositional and biomechanical properties of the tibiotarsi were analysed in both lines at 1, 8, 15 and 22 d of age. Tibial morphology (length, volume, cross-section and diameters) was similar in FGL and SGL chickens when compared at an equal body weight. Cortical area was also similar in both lines at an equal body weight but cortex porosity was higher in FGL. Tibial mineral density (ash:volume) was higher in FGL than in SGL at hatching and at 8 d of age. Biomechanical properties were lower in SGL than in FGL at 8 d of age, but then became higher in this line when compared at equal body weight. The very slow growth rate in SGL did not modify bone size when chickens were compared at equal body weight. Bone quality was modified in various ways: in SGL bone structure was strengthened by a lower porosity of the cortex while bone tissue was less mineralized up to 22 d of age. In both lines, cortical growth was slower than in commercial cross-breeds and bone quality (structure and composition) was improved compared to broilers.

Reducing growth rate of broiler chickens with a low energy diet does not improve cortical bone quality

1. Reducing growth rate is often supposed to allow better skeletal development and improve bone quality. In order to test this assumption, flocks of broiler chickens fed on a diet containing 13.31 MJ ME/kg (H) were compared with flocks in which the growth rate was reduced by feeding birds with a low energy diet (L, 9.62 MJ ME/kg). 2. Bone growth was studied in 2 experiments in order to identify any changes in bone tissue of slow-growing chickens that might explain why they are less predisposed to varus-valgus deformities (3.1% vs 19.9%). 3. In experiment 1, the morphology, composition and histomorphometry of the tibiotarsi were analysed in both groups at 1, 12, 26, 42 and 46 d of age. Tibial variables (weight, volume, length, cortex size and structure, dry content and ash percentage) were always reduced in slow-growing birds except at 42 d of age, when tibial weight and cortex areas were similar in both groups. 4. Every variable was similar in both groups, or even higher in H birds, when chickens were compared at similar body weight, suggesting that the low growth rate did not improve bone quantity or quality of the tibiae. 5. In experiment 2, the composition of the tibiotarsi was compared every 2 days during the first week and twice a week until 36 d of age, in H and L birds. Weight and composition of the tibiotarsi did not differ between groups when compared at equal body weight, as also shown in experiment 1. 6. The reduced occurrence of varus-valgus deformities in slow-growing chicks cannot be related to an improvement in the structure and the composition of their bone tissue.

Influence of treadmill running on femoral bone in young orchidectomized rats

Forty 6-wk-old male Wistar rats weighing 308 +/- 24 g were divided into two groups. On day 0, the 20 animals in one group were surgically castrated and the other group was sham operated. Within each group, 10 rats were selected for treadmill running (60% maximal O2 consumption, 1 h/day, 6 days/wk for 15 wk). The 20 sedentary rats were used as controls. At the time the rats were killed (day 105), running had no significant effect on femoral mechanical properties either in castrated or in sham-operated rats. Femoral bone density was lower in orchidectomized than in sham-operated rats. Nevertheless, it was higher in exercised than in sedentary rats. Femoral Ca content paralleled changes in bone density. Treadmill running had no significant effect on plasma osteocalcin concentration but inhibited the increase in urinary deoxypyridinoline excretion observed in castrated rats. Image analysis (measured at the distal femoral diaphysis) revealed that these effects mainly resulted from decreased trabecular bone resorption in castrated exercised rats.

Composition, cortical structure and mechanical properties of chicken tibiotarsi: effect of growth rate

1. Comparisons of tibial growth in slowly (X) and rapidly (F) growing chicks were carried out weekly until the birds weighed 500 g. 2. Bone volume and percentage of ash per dry weight increased with age and were similar at equal body weights between crossbreeds. In birds of the same age, the ratio of tibial dry weight to hydrated weight was greater in crossbreed X as compared with crossbreed F. Consequently, the tibial density and the mineral content per volume were higher, at equal body weights, in crossbreed X. 3. Cortical cross-sectional area was greater in crossbreed F at the different ages, but was similar in both crossbreeds at equal body weights. A peripheral active zone of greater porosity was predominantly characterised by radial fibrolamellar tissue in fast growing birds and covered a larger area in crossbreed F than in crossbreed X. 4. Biomechanical properties of the tibiotarsi were evaluated in a three-point flexure test. The area moment of inertia was equal at similar body weights in both crossbreeds, but the yield or maximal forces and stiffness of tibiotarsi were lower in the rapidly growing crossbreed F compared with crossbreed X. 5. It is concluded that an increased rate of growth is associated with a lower mineral density and higher porosity of the tibial cortices resulting in reduced bending resistance.

Dietary phosphorus and food allowance of dwarf breeders affect reproductive performance of hens and bone development of their progeny

1. An experiment was conducted with 144 caged hens to study the effects of different dietary concentrations of phosphorus and of food restriction on the reproductive performance of dwarf breeder hens and on the growth and the bone development of their progeny. 2. Severe food restrictions at 105 g/hen day compared to 115 g/hen day, decreased hen body weight and hen day egg production. Fertility was unaffected and hatchability slightly depressed by the more severe restriction. 3. Egg and one-day-old chick weights were decreased by limiting the food intake of the breeders but the negative effect disappeared at slaughter (7 weeks). 4. Shell quality decreased as the dietary phosphorus increased and was not affected by food allowance. Albumen quality was slightly impaired in severely restricted hens. 5. Serum inorganic phosphorus in hens and yolk phosphorus increased with increasing dietary phosphorus. Tibial breaking strength and tibial percentage ash of the progeny at hatching was markedly improved in proportion to maternal phosphorus and food intake. This improvement in bone quality was not maintained at 7 weeks. 6. The number of chicks affected by twisted legs (valgus) and dyschondroplasia were similar whatever the maternal diet. The frequency of valgus was higher in males than in females. 7. It is concluded that maternal food intake and phosphorus supply are of importance for the initial bone development of the progeny.

Maternal body weight and feed allowance of breeders affect performance of dwarf broiler breeders and tibial ossification of their progeny

Four hundred and eight dwarf broiler breeder hens were raised collectively in a floor pen to 21 wk of age. At this age they were classified into four groups with reference to their individual BW as heavy (1.95 +/- .1 kg), medium (1.80 +/- .1 kg), light (1.69 +/- .1 kg), and ultralight (1.57 +/- .1 kg). All groups were individually caged at 23 wk of age. During the reproductive period, each group was divided into three subgroups fed on liberal, intermediate, or severe feed restriction (reaching up to 135, 125, and 115 g of daily feed allowance at 29 wk of age, respectively). Intergroup differences in BW were maintained throughout the experiment (21 to 61 wk) but tended to decrease with age. Hen-day egg production was depressed by the lower feed allowance. Fertility and hatchability were impaired when hens received the largest quantities of food. Hen size influenced female breeder performance only slightly. Shell quality and albumen quality were affected by the level of feed consumption. Egg weights as well as BW of the progeny at hatching were enhanced by increased maternal BW and feed allowance. This positive maternal effect was still present at 40 days of age. Despite better overall BW performances of the male versus female broilers, the abdominal fat pad of female broilers was heavier than that of males and tended to increase with breeder size and breeder feed allowance. Accordingly, tibial breaking strength and percentage ash of the progeny at hatching were markedly improved in proportion to the breeders' BW and to their feed allowance. The effect of breeder size on broiler tibial quality was maintained up to 40 days of age but the effect of breeder feed intake tended to disappear with increasing age of the broilers. Tibial strength and mineralization were higher in male than in female broilers at 40 days of age. Dyschondroplasia was higher in broilers hatched from heavier breeder hens, but was not influenced by breeder feed intake. The incidence of varus and valgus in progeny was similar whatever the breeders' treatment. It is concluded that performance of dwarf breeders in a given flock depends mainly upon breeder feed allowance but that broiler performance and, especially, tibial ossification of broilers is greatly influenced by maternal size and, to a lesser extent, by maternal feed intake.