Climate change and mental health: risks, impacts and priority actions.

BACKGROUND: This article provides an overview of the current and projected climate change risks and impacts to mental health and provides recommendations for priority actions to address the mental health consequences of climate change. DISCUSSION AND CONCLUSION: The authors argue the following three points: firstly, while attribution of mental health outcomes to specific climate change risks remains challenging, there are a number of opportunities available to advance the field of mental health and climate change with more empirical research in this domain; secondly, the risks and impacts of climate change on mental health are already rapidly accelerating, resulting in a number of direct, indirect, and overarching effects that disproportionally affect those who are most marginalized; and, thirdly, interventions to address climate change and mental health need to be coordinated and rooted in active hope in order to tackle the problem in a holistic manner. This discussion paper concludes with recommendations for priority actions to address the mental health consequences of climate change.

Evaluation of vegetable protein in canine diets: Assessment of performance and apparent ileal amino acid digestibility using a broiler model.

Recent technological advances in the human food industry with respect to meat processing have decreased the availability of animal proteins to the pet food industry which typically formulates diets with an excess of animal protein. In the long term, this is not sustainable; thus, alternative protein sources need to be investigated. This study examined three canine diets, comparing a typical animal protein-based diet (control) with two experimental diets where the animal protein was substituted in part with vegetable protein (formulated based either on total protein or amino acid content) using a broiler model. Each diet was fed to six cages each containing two birds from day 15, 18 cages in total (36 birds). Excreta were collected from days 19 to 21. On day 23, birds were euthanized and weighed, and their ileal digesta were collected and pooled for each cage. In addition, one leg per cage was collected for evaluation of muscle mass. Results showed no significant difference in animal performance (feed intake or live weight gain) or muscle to leg proportion across the diets. Birds fed the control diet and the diet balanced for amino acid content exhibited the greatest coefficients of apparent metabolizability for nitrogen (p < .001). Birds fed the diets that contained partial replacement of animal with vegetable protein generally had greater ileal digestibility of amino acids compared to birds fed the control (animal protein) diet. Analysis of excreta showed no dietary difference in terms of dry matter content; however, birds fed the diet balanced for total protein and the diet balanced for amino acid content had significantly greater excreta nitrogen than the control (p = .038). Overall, the study suggests vegetable proteins when formulated based on amino acid content are a viable alternative to animal proteins in canine diets.

Investigations of the nutritive value of meals of double-low rapeseed and its influence on growth performance of broiler chickens.

Four experiments were carried out to study the possible differences in metabolizable energy (ME) of meals (RSM) or expeller meals (RSE) from double-low rapeseed (Expt. 1), the influence of processing on ME (Expt. 2) and on relative phosphorus (P) bioavailability (Expt. 3) in RSM, and effect of RSM inclusion on growth performance of broilers (Expt. 4). For Expt. 1, diets with 300 g/kg RSM from 11 RSM and 4 RSE varieties were fed to broilers from d 14 to 21, with excreta collection on d 19 to 21. Each treatment had 8 replicates and 3 birds per replicate. Energy metabolizability of RSM of a specialized high glucosinolate variety (V275OL) was greater (P < 0.05) than all the other varieties. In Expt. 2, two RSM varieties were processed with mild or conventional processing condition. There were no variety effects on ME, but ME and MEn were greater (P < 0.01) for RSM processed by mild processing condition. In Expt. 3, P bioavailability of RSM was determined, relative to MSP, using growth performance and tibia ash as responses. Phosphorus relative bioavailability values were greater (P < 0.05) in RSM of DK Cabernet variety processed using the mild processing condition. In Expt. 4, two RSM varieties were added to wheat-soybean meal-based diet at the rates of 50, 100, 150, or 200 g/kg and fed to broilers from d 0 to 42. Inclusion of 150 and 200 g/kg of RSM resulted in reduced weight gain and increased feed conversion ratio (FCR) compared (P < 0.01) with the lower inclusion levels during the starter phase. For the entire trial (d 0 to 42), weight gain was greater (P < 0.01) for birds receiving diets with RSM from PR46W21 variety. It was concluded from the experiments that apart from the residual ether extract content, variety differences had no impact on ME of RSM, conventional processing reduced ME and relative bio-availability of P; and that the maximum level of RSM inclusion depends on maximum growth performance level desired.

Rapeseed napin and cruciferin are readily digested by poultry.

Rapeseed proteins have been considered as being poorly digestible in the gut of non-ruminants. The aim of the study was to assess the digestibility of napin and cruciferin in ileal digesta of broiler chickens, testing sixteen samples of rapeseed co-products with protein levels ranging from 293 g/kg to 560 g/kg dry matter. Each sample was included into a semi-synthetic diet at a rate of 500 g/kg and evaluated with broiler chickens in a randomised design. Dietary and ileal digesta proteins were extracted and identified by gel-based liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three isomers of napin (a 2S albumin) and nine cruciferins (an 11S globulin) were identified in the rapeseed co-products, whereas six endogenous enzymes such as trypsin (I-P1, II-P29), chymotrypsin (elastase and precursor), carboxypeptidase B and α-amylase were found in the ileal digesta. It is concluded that as none of the rapeseed proteins were detected in the ileal digesta, rapeseed proteins can be readily digested by broiler chickens, irrespective of the protein content in the diet.

Assessment of caecal parameters in layer hens fed on diets containing wheat distillers dried grains with solubles.

There is much interest in quantifying the nutritional value of UK wheat distillers dried grains with solubles (W-DDGS) for livestock species. A study was designed to evaluate caecal parameters (pH, short chain fatty acids (SCFAs) and bacterial diversity) in layer hens fed on balanced diets containing graded concentrations of W-DDGS. A total of 32 layer hens (Bovans Brown strain at 27 weeks of age) were randomly allocated to one of 4 dietary treatments containing W-DDGS at 0, 60, 120 or 180 g/kg. Each treatment was fed to 8 replicate individually housed layer hens over a 5-d acclimatisation period, followed by a 4-week trial. Individual feed intakes were monitored and all eggs were collected daily for weeks 2, 3 and 4 of the trial, weighed and an assessment of eggshell "dirtiness" made. All hens were culled on d 29 and caecal pH and SCFAs measured. Polymerase chain reaction denaturing gradient gel electrophoresis of the bacterial 16 S rDNA gene was used to assess total bacterial diversity of luminal caecal content from hens fed the 0 and 180 g W-DDGS/kg diets. Unweighted pair group method with arithmetic mean (UPGMA) dendrograms were generated from DGGE banding patterns. Increasing W-DDGS dietary concentrations resulted in a more acidic caecal environment. Caecal SCFAs were unaffected by diet aside from a quadratic effect for molar proportions of isobutyric acid. Diversity profiles of the bacterial 16S rRNA gene from luminal caecal contents were unaffected by W-DDGS inclusion. The results of the current study suggest that W-DDGS can be successfully formulated into nutritionally balanced layer diets (supplemented with xylanase and phytase) at up to 180 g/kg with no detrimental effects to the caecal environment.

Influence of the in vivo method and basal dietary ingredients employed in the determination of the amino acid digestibility of wheat distillers dried grains with solubles in broilers.

As distillers dried grains with solubles (DDGS) become increasingly available, it is important to determine their nutritional value for precise feed formulation. The accurate determination of digestibility is crucial, and it is known that the methods used will affect the values obtained. An experiment was designed to determine and compare the standardized ileal digestibility (SID) of amino acids from wheat DDGS using a semisynthetic diet and a difference method using 4 further diets based on corn, wheat, corn DDGS, and wheat DDGS. Eighty 1-d-old male broilers were fed a commercial starter diet until d 21. Between d 21 and 23, they were fed test diets in order to adapt to those diets before the trial took place between d 24 and 27. The trial period took place between d 24 and 27. Feed intake was measured, excreta collected, and at d 27, all birds were culled and ileal digesta was collected for the determination of apparent ileal digestibility and SID of amino acids. Values determined were similar to those reported elsewhere in the literature, although SID values for lysine were particularly low, being 0.26, 0.27, or 0.32, measured in semisynthetic, corn, or wheat diet backgrounds, respectively. It appeared that diet type employed was influential in the values obtained. The SID values for methionine, cysteine, methionine plus cysteine, and arginine were significantly lower (P < 0.05) when measured in semisynthetic diet backgrounds than wheat- or corn-based diets. It appears that dextrose and possibly purified starch have a detrimental impact on the broiler digestive tract. This may affect all digestibility methodologies in which such a diet base is used.

Uptake of tamoxifen in consecutive premenopausal women under surveillance in a high-risk breast cancer clinic.

BACKGROUND: Randomised trials of tamoxifen versus placebo indicate that tamoxifen reduces breast cancer risk by approximately 33%, yet uptake is low. Approximately 10% of women in our clinic entered the IBIS-I prevention trial. We assess the uptake of tamoxifen in a consecutive series of premenopausal women not in a trial and explore the reasons for uptake through interviews. METHODS: All eligible women between 33 and 46 years at ≥17% lifetime risk of breast cancer and undergoing annual mammography in our service were invited to take a 5-year course of tamoxifen. Reasons for accepting (n=15) or declining (n=15) were explored using semi-structured interviews. RESULTS: Of 1279 eligible women, 136 (10.6%) decided to take tamoxifen. Women >40 years (74 out of 553 (13.4%)) and those at higher non-BRCA-associated risk were more likely to accept tamoxifen (129 out of 1109 (11.6%)). Interviews highlighted four themes surrounding decision making: perceived impact of side effects, the impact of others' experience on beliefs about tamoxifen, tamoxifen as a 'cancer drug', and daily reminder of cancer risk. CONCLUSIONS: Tamoxifen uptake was similar to previously ascertained uptake in a randomised controlled trial (IBIS-I). Concerns were similar in women who did or did not accept tamoxifen. Decision making appeared to be embedded in the experience of significant others.

Predicting the environmental impacts of chicken systems in the United Kingdom through a life cycle assessment: broiler production systems.

The aim of this study was to apply the life cycle assessment (LCA) method, from cradle to gate, to quantify the environmental burdens per 1,000 kg of expected edible carcass weight in the 3 main broiler production systems in the United Kingdom: 1) standard indoor, 2) free range, and 3) organic, and to identify the main components of these burdens. The LCA method evaluates production systems logically to account for all inputs and outputs that cross a specified system boundary, and it relates these to the useful outputs. The analysis was based on an approach that applied a structural model for the UK broiler industry and mechanistic submodels for animal performance, crop production, and major nutrient flows. Simplified baseline feeds representative of those used by the UK broiler industry were used. Typical UK figures for performance and mortality of birds and farm energy and material use were applied. Monte Carlo simulations were used to quantify the uncertainties in the outputs. The length of the production cycle was longer for free-range and organic systems compared with that of the standard indoor system, and as a result, the feed consumption and manure production per bird were higher in the free-range and organic systems. These differences had a major effect on the differences in environmental burdens between the systems. Feed production, processing, and transport resulted in greater overall environmental impacts than any other components of broiler production; for example, 65 to 81% of the primary energy use and 71 to 72% of the global warming potential of the system were due to these burdens. Farm gas and oil use had the second highest impact in primary energy use (12-25%) followed by farm electricity use. The direct use of gas, oil, and electricity were generally lower in free-range and organic systems compared with their use in the standard indoor system. Manure was the main component of acidification potential and also had a relatively high eutrophication potential. The LCA method allows for comparisons between systems and for the identification of hotspots of environmental impacts that could be subject to mitigation.

Predicting the environmental impacts of chicken systems in the United Kingdom through a life cycle assessment: egg production systems.

The aim of this study was to apply a life cycle assessment (LCA) method, from cradle to gate, to quantify the environmental burdens per 1,000 kg of eggs produced in the 4 major hen-egg production systems in the United Kingdom: 1) cage, 2) barn, 3) free range, and 4) organic. The analysis was based on an approach that applied a structural model for the industry and mechanistic submodels for animal performance, crop production, and nutrient flows. Baseline feeds representative of those used by the UK egg production industry were used. Typical figures from the UK egg production industry, feed intake, mortality of birds, farm energy, and material use in different systems were applied. Monte Carlo simulations were used to quantify the uncertainties in the outputs and allow for comparisons between the systems. The number of birds required to produce 1,000 kg of eggs was highest in the organic and lowest in the cage system; similarly, the amount of feed consumed per bird was highest in the organic and lowest in the cage system. These general differences in productivity largely affected the differences in the environmental impacts between the systems. Feed production, processing, and transport caused greater impacts compared with those from any other component of production; that is, 54 to 75% of the primary energy use and 64 to 72% of the global warming potential of the systems. Electricity (used mainly for ventilation, automatic feeding, and lighting) had the second greatest impact in primary energy use (16-38%). Gas and oil (used mainly for heating in pullet rearing and incineration of dead layer birds) used 7 to 14% of the total primary energy. Manure had the greatest impact on the acidification and eutrophication potentials of the systems because of ammonia emissions that contributed to both of these potentials and nitrate leaching that only affected eutrophication potential. The LCA method allows for comparisons between systems and for the identification of hotspots of environmental impacts that could be subject to mitigation.

Effect of compensatory growth on forms of glycogen, postmortem proteolysis, and meat quality in pigs.

The current experiment was designed to examine if a compensatory feed regimen influenced storage of glycogen forms, activity of proteolytic systems, and meat quality. Female pigs (Large White × Landrace × Duroc cross) with an initial age of 74 d were allocated to 6 feeding treatment groups (n=8 for each group). Groups then consumed feed ad libitum for 40 (A40), 42 (A42), or 82 d (A82). The compensatory growth groups were fed 0.70 of ad libitum intake for 40 d (R40) followed by refeeding for ad libitum intake for 2 (R40A2) or 42 d (R40A42). Pigs were slaughtered at the end of the restriction period (SL1), then after refeeding for 2 (SL2) and 42 d (SL3). The feeding regimen caused restricted animals at SL2 to have a decreased BW (P=0.039), with the refed animals undergoing compensatory growth by SL3 so BW was not different (P=0.829). At SL1 there was a trend for the R40 pigs to have less intramuscular fat than A40 (P=0.084). There was a trend for macroglycogen (MG; P=0.051) and a significant effect for proglycogen (ProG; P=0.014) to be greater at slaughter in R40 than A40, along with a greater postmortem decline in both MG (P=0.033) and ProG (P=0.022) over the first 2 h in R40, which was associated with the R40 having a lower pH at 24 h postmortem (P=0.043). After refeeding for 2 d (SL2), only MG of R40A2 was greater (P=0.030) than A42 and had a trend for a greater difference of decline at 24 h postmortem (P=0.091), which was associated with lower pH at 24 h (P=0.012). The data suggest that the concentrations of ProG are more labile and recovered to the concentrations of pigs fed for ad libitum intake sooner than MG. After full compensation in SL3, there was no difference for MG content (at 0 h, P=0.721; at 2 h, P=0.987; at 24 h, P=0.343), ProG content (at 0 h, P=0.879; at 2 h, P=0.946; at 24 h, P=0.459), and muscle pH (at 45 min, P=0.373; at 24 h, P=0.226). At all slaughter points, there was no difference in shear force (at SL1, P=0.101; at SL2, P=0.420; at SL3, P=0.167). There were no significant effects of the feeding regimen on micro- and milli-calpain large subunit gene expression (for micro-calpain at SL1, P=0.450; at SL2, P=0.171; at SL3, P=0.281; for milli-calpain at SL1, P=0.666; at SL2, P=0.123; at SL3, P=0.617) or the activity of the 2 proteolytic enzymes at any of the slaughter dates (for micro-calpain at SL1, P=0.238; at SL2, P =0.238; at SL3, P=0.222; for milli-calpain at SL1, P=0.296; at SL2, P=0.230; at SL3, P=0.615). In R40 there was a trend (P=0.070) for greater gene expression of caspase 3, whereas in R40A2 the increase was significant (P=0.009) relative to pigs consuming feed ad libitum. However, gene expression of the E3 ligase, MuRF1, at SL3 was less in R40A42 (P=0.019). Although compensatory growth does appear to influence the expression of various proteolytic systems, the changes do not appear to be associated with meat quality as measured by shear force.

Effect of compensatory growth on performance, carcass composition and plasma IGF-1 in grower finisher pigs.

A total of 48 female pigs (Large White × Landrace × Duroc cross) were used to determine whether a compensatory feed regime influenced performance, carcass composition and the level of plasma IGF-1. Pigs of initial age 73 days were fed a commercial diet at 0.70 of ad libitum (R) for 40 days followed by a return to ad libitum feeding for a further 42 days. The control group was fed ad libitum (A) throughout. Groups of animals on R and A feed regimes were slaughtered at the end of restriction period (SL1), 2 days after refeeding ad libitum (SL2) to establish the more immediate effects of refeeding on IGF levels, and after 42 days refeeding (SL3; n = 8 for each group). As expected, during the restriction period, average daily live weight gain in all the slaughter groups of R pigs was significantly lower than A pigs (P < 0.01); there was no significant difference in feed conversion ratios. In the re-alimentation period of SL3, R pigs grew 12.9% faster (P = 0.033), indicating compensatory growth. At SL1, there was a trend for carcass weight (P = 0.108) of A pigs to be higher than R pigs, but at SL2 live weight and carcass weight of A pigs were significantly heavier than R pigs (P < 0.05), but not at SL3. For killing-out percentage, there was no difference in SL1. After refeeding for 2 days (SL2) and 42 days (SL3), R pigs had significantly lower killing-out percentage than A pigs (P < 0.05). As a proportion of live weight, R pigs had smaller heart, kidney and liver (P < 0.05) than A pigs at SL1. At SL2, only the kidney was smaller in the restricted group (P < 0.05) and there were no significant differences in SL3. As a proportion of carcass weight, Longissimus dorsi was heavier in the R pigs at SL1 (P = 0.108) and SL2 (P < 0.05), but not at SL3. At SL1, there was a trend for intramuscular fat of A pigs to be higher than R pigs. The plasma IGF-1 level was lower in R pigs than A pigs (P = 0.010) at SL1, and slightly lower at SL2 (P = 0.110), with no significant differences at SL3. Dietary restriction period influenced plasma IGF-1 levels, which returned to the ad libitum group levels when animals were refed, as did live weight and carcass weight. It appears that the internal organs and possibly fat, but not muscles, underwent a compensatory response when animals were refed.

The consequences of non-starch polysaccharide solubility and inclusion level on the health and performance of weaned pigs challenged with enterotoxigenic Escherichia coli.

The inclusion of insoluble NSP (iNSP) in weaner pig diets has been reported to decrease post-weaning colibacillosis (PWC). Conversely, soluble NSP (sNSP) have been shown to exacerbate PWC. The present study investigated the effect of NSP solubility and inclusion level on the health and performance of newly weaned pigs challenged with enterotoxigenic Escherichia coli (ETEC), using NSP sources known not to affect digesta viscosity, in a 2 x 2 x 2 factorial combination of NSP solubility (iNSP v. sNSP), inclusion level (low (L; 50 g/kg) v. high (H; 150 g/kg)) and ETEC challenge (infected v. sham). Infection had no effect on pig health, but reduced performance to a larger extent in pigs on the L diets compared with those on the H diets. The inclusion of sNSP significantly decreased the occurrence of diarrhoea (P < 0.001) and improved gut health, as indicated by a lower caecal digesta pH (P = 0.008) and increased (P = 0.002) Lactobacillus:coliform ratio, when compared with the iNSP diet on day 14 post-weaning. There was no effect of NSP solubility on ETEC shedding, digesta viscosity or pig performance. Pigs on the H diets had fewer cases of diarrhoea and shed fewer ETEC than those on the L diets. Increasing NSP inclusion significantly increased colonic Lactobacillus:coliform ratio, volatile fatty acid concentration and caecal digesta viscosity, but decreased performance. These results suggest that sNSP per se are not detrimental to pig health and that increasing the concentration of NSP in weaner diets that do not increase digesta viscosity may have a beneficial effect on gut health and protect against PWC.

Physicochemical properties and nutritional quality of raw cereals for newly weaned piglets.

The digestibility of the starch component of raw cereals in newly weaned piglets is highly variable. Reasons for this must be elucidated if the most suitable cereals are to be used. A novel approach was employed, which consisted of assessing the physicochemical properties (rapid visco analysis, water absorption and solubility indices, particle size distribution and in vitro amylolytic digestion) of eight raw cereals contained within piglet diets and subsequently relating this in vitro data to the biological responses of weaned piglets. Trial 1 examined soft and hard wheat, trial 2 - soft wheat, barley, rye and triticale, and trial 3 - soft wheat, naked oats, whole oats and maize. The initial observation was that in vitro testing prior to animal trials is recommended in nutritional evaluation since it indicated fundamental differences between raw cereals, such as for example the levels of endogenous amylase in wheat. Starch and nitrogen digestibility differed between cereals (apparent digestibility coefficients at the 0.5 site of the small intestine ranged from 0.10 to 0.69 for starch and from 0.17 to 0.68 for nitrogen). There is also a probable relationship between the coefficients of ileal apparent starch digestibility, at approximately halfway from the gastric pylorus to the ileocaecal valve, and the presence of endogenous amylase (mean values of 0.53 and 0.62 in trials 2 and 3, respectively, for the higher amylase wheat; 0.38 for the low-amylase wheat used in trial 1). This additional variable (i.e. the unforeseen presence of endogenous amylase) in wheat made it more difficult to draw a firm conclusion about the nutritional suitability of the different cereals. All raw-cereal diets caused atrophy of the villi during the initial week following weaning, but the soft wheat was associated with the highest comparative villi height and might therefore be considered the best of all raw cereals in minimising the post-weaning growth check. For wheat, this might also suggest a possible interaction between villus architecture and endosperm texture in the immediate post-weaning period.

Physicochemical changes to starch granules during micronisation and extrusion processing of wheat, and their implications for starch digestibility in the newly weaned piglet.

Two trials were performed to assess changes in the physicochemical properties of precisely processed (micronised v. extruded) wheats, prior to inclusion in piglet diets. The in vitro data obtained were subsequently related to biological responses of newly weaned piglets over 14 days. The effects of the severity of micronisation (Trial 1) or extrusion (Trial 2) on the nutritional value of two wheats (varying in endosperm texture) were examined. Extrusion, in contrast to micronisation, drastically disrupted the structural properties of wheat starch granules through melting of crystallites and macromolecular degradation of starch polysaccharides. These structural changes strongly improved the hydration characteristics of starch and its digestibility. The amount of starch digested in vitro was approximately 0.20, 0.70 and 0.90 for the unprocessed, micronised and extruded samples, respectively. This enhanced in vitro digestibility correlated well with, and helped to explain, the significant improvement in the apparent digestibility of starch at both the 0.5 region (mean coefficients for extruded wheat were 0.869 and 0.959 v. raw 0.392; P = 0.017) and 0.75 region (extruded 0.973 v. raw 0.809; P = 0.009) of the small intestine, when compared with piglets fed an unprocessed wheat diet. Extrusion and, to a lesser extent, micronisation lessened the reduction in apparent starch digestibility on day 4 post-weaning, typically seen at the 0.5 intestinal region in piglets fed an unprocessed wheat diet. Processing variables influenced both in vitro and in vivo data, with for instance, a positive relationship between specific mechanical energy (SME) input during extrusion and starch digestibility at the 0.5 region. The higher digestibility coefficient observed at the 0.5 region for the high SME diet suggests enhanced digestion and more rapid release of starch. However, it remains to be seen whether a diet containing rapidly digestible, as opposed to slowly digestible, starch is more beneficial for piglets. This rate of starch breakdown in the piglet is an important finding, which may have implications in helping to alleviate the post-weaning growth check, particularly in the absence of in-feed antibiotic growth promoters. Processing did not appear to offer any benefit over unprocessed wheat with regard to daily live-weight gain or the apparent digestibility of nitrogen in the small intestine over the 14-day period. Based on the enhanced in vivo starch digestibility, performance might be improved over a longer period, although future studies are required to confirm this. Precise processing variables for raw materials must be stated in all animal trials.

Effects of extrusion conditions on trypsin inhibitor activity of full fat soybeans and subsequent effects on their nutritional value for young broilers.

1. Increasing proportions of soybeans in poultry diets have highlighted the importance of correct processing to inactivate the anti-nutritional factors present whilst maintaining protein quality. 2. Ground full fat soybeans (FFSB) were extruded using a Clextral laboratory model twin-screw extruder with 0.75 l/h of water and end barrel temperatures of 90, 110, 130 and 160 degrees C resulting in trypsin inhibitor activities (TIA) of 14.8, 9.6, 4.5 and 1.9 mg/g sample. 3. The 4 extrudates were used at three different inclusion levels: 200, 400 and 600 g/kg semi-synthetic diet and fed to male Ross broiler chicks from d 19 to d 26. Digesta samples were taken for measurement of coefficient of ileal apparent amino acid digestibility (CIAD) and both pancreas and whole bird weights were measured. 4. Concentration of ileal apparent digestible lysine was increased from 10.53 to 17.63 g/kg FFSB by increasing extrusion temperature from 90 to 160 degrees C. CIAD of lysine was also improved from 0.58 to 0.86. Other amino acids showed similar improvements in both their ileal apparent digestible concentration and CIAD. 5. Mean weight gain over 3 d increased linearly from 42 to 95 g per bird with increasing extrusion temperatures of FFSB. Pancreatic enlargement was evident after 6 d of feeding with FFSB processed at lower temperatures, even when the TIA level was at the recommended threshold of 4 mg/g. 6. The results emphasise the importance of controlled conditions during processing of FFSB for poultry diets and suggest that processing of FFSB in order to reduce TIA levels below 4 mg/g may provide significant benefits for broiler chicks.

Allele frequency and likely impact of the glycogen branching enzyme deficiency gene in Quarter Horse and Paint Horse populations.

Glycogen Branching Enzyme Deficiency (GBED), a fatal condition recently identified in fetuses and neonatal foals of the Quarter Horse and Paint Horse lineages, is caused by a nonsense mutation in codon 34 of the GBE1 gene, which prevents the synthesis of a functional GBE protein and severely disrupts glycogen metabolism. The aims of this project were to determine the mutant GBE1 allele frequency in random samples from the major relevant horse breeds, as well as the frequency with which GBED is associated with abortion and early neonatal death using the tissue archives from veterinary diagnostic laboratories. The mutant GBE1 allele frequency in registered Quarter Horse, Paint Horse, and Thoroughbred populations was 0.041, 0.036, and 0.000, respectively. Approximately 2.5% of fetal and early neonatal deaths in Quarter Horse-related breeds submitted to 2 different US diagnostic laboratories were homozygous for the mutant GBE1 allele, with the majority of these being abortions. Retrospective histopathology of the homozygotes detected periodic acid Schiff's (PAS)-positive inclusions in the cardiac or skeletal muscle, which is characteristic of GBED, in 8 out of the 9 cases. Pedigree and genotype analyses supported the hypothesis that GBED is inherited as a simple recessive trait from a single founder. The frequency with which GBED is associated with abortion and neonatal mortality in Quarter Horse-related breeds makes the DNA-based test valuable in determining specific diagnoses and designing matings that avoid conception of a GBED foal.

A comparison of linear and branched polyethylenimine (PEI) with DCChol/DOPE liposomes for gene delivery to epithelial cells in vitro and in vivo.

Polyethylenimine (PEI), a polycation with high ionic charge density, has recently been used as a gene therapy delivery agent. We have defined the optimal conditions for PEI-based transfection of airway epithelial cells in vitro and in vivo and used these conditions to restore Cl(-) channel activity in a CF mouse model. Three forms of PEI, a linear 22 kDa (ExGen 500) form and branched 25 or 50 kDa forms were evaluated. All forms of PEI significantly increased luciferase reporter gene expression compared to the liposome DCChol/DOPE in a human bronchial epithelial cell line (16HBE) irrespective of the extent of cell confluency. With subconfluent cells, gene expression was around 1000-, 200- and 25-fold higher than liposomes using linear 22, 25 and 50 kDa PEI, respectively. The transfection efficiency was reduced in confluent and polarized epithelial cells but linear 22 kDa PEI showed the smallest decrease and gave 8000-fold better transfection in polarized cells compared to liposomes. A comparison of linear 22 or 25 kDa PEI with DCChol/DOPE for airway delivery in vivo via intranasal instillation was also performed. Linear 22 kDa PEI gave significantly better luciferase reporter gene expression of 350-fold in the lung, 180-fold in the nose and 85-fold in the trachea compared to liposome. In contrast, the 25 kDa form of PEI was no better than DCChol/DOPE. Repeat dosing with linear 22 kDa PEI failed to give reporter gene delivery comparable to the initial dose. To establish that PEI can be used to deliver a physiologically relevent gene in vivo, we used it to restore Cl(-) secretion by CFTR gene delivery in the airways of a CF mouse model.

The evaluation of rhytidectomy flap healing after CO2 laser resurfacing in a pig model.

OBJECTIVE: This study was conducted to determine when it becomes safe to perform laser resurfacing after rhytidectomy flap elevation. STUDY DESIGN: Eighty-four sites on 12 domestic Yorkshire pigs were selected; 4 x 10-cm skin flaps were elevated in 72 of the 84 sites and shortened 10%. The 12 remaining sites (controls) were treated with laser resurfacing alone. Laser resurfacing was also performed at days 0, 7, 14, 21, and 28 after closing the skin flaps. The healing time for the laser-resurfaced sites without flap elevation were compared to that of the skin flaps treated with the laser at days 0, 7, 14, 21, and 28. Twelve "skin flap" controls were elevated, shortened 10%, and closed without laser treatment. Resurfacing was performed using 2 passes with the Sharplan Silk Touch CO(2) laser. RESULTS: The average healing time for the skin flaps treated with the laser at day 0 was 23.9 days. All of these flaps showed skin slough with delayed healing followed by scar formation. The areas treated with the laser alone (controls), and the subsequent skin flaps treated with the laser postoperatively at days 7, 14, 21, and 28 days completely re-epithelialized in an average of 7.8, 8.1, 7.3, 7.4, and 7.3 days, respectively. There were no statistically significant differences in healing time between the controls and flaps treated with the laser on or after 7 days (P > 0.05). However, there were statistically significant differences in healing time between the laser-treated skin flaps at day 0 and the controls, between the laser-treated flaps on day 0 and day 7, and between the laser-treated flaps on day 0 and day 14 (P < 0.001). Because there was little difference in healing time after 14 days, only the healing times for laser-treated skin flaps up to 14 days were compared using paired t tests. CONCLUSIONS: From our observations using a pig model, we conclude that skin flaps may be safely laser resurfaced about 1 week postoperatively. On the other hand, simultaneous flap elevation and laser resurfacing results in delayed healing with subsequent scar formation.

Reduction of glial glutamate transporters in the parietal cortex and hippocampus of the EL mouse.

There is extensive experimental evidence indicating a crucial role for glutamate in epileptogenesis and epileptic activity. The glial glutamate transporters GLT1 and GLAST are proposed to account for the majority of extracellular glutamate re-uptake. In the present study, polyclonal antibodies specific to GLT1 and GLAST were generated and characterized, revealing distribution patterns for the two transporters confirming those previously reported. In situ hybridization and immunoblotting were then used to compare levels of these two transporters in the parietal cortex and hippocampus of unstimulated and stimulated EL mice with DDY control mice. Additionally, HPLC determined tissue glutamate concentrations in the same regions of these animals. These experiments revealed reductions in GLT1 mRNA and protein in the parietal cortex of unstimulated and stimulated EL mice compared with DDY controls, accompanied by an increase in tissue glutamate concentration in the stimulated EL mice group. GLT1 mRNA was also reduced in the CA3 hippocampal subfield of both unstimulated and stimulated EL mice. GLAST protein was reduced in the hippocampus of the stimulated EL mice group, while no changes in GLAST mRNA or protein were detected in the parietal cortex of EL mice when compared with DDY controls. The glial glutamate transporter down-regulation reported here may play a role in seizure initiation, spread and maintenance in the EL mouse.