Bioefficacy of a mono-component protease in the diets of pigs and poultry: a meta-analysis of effect on ileal amino acid digestibility

A meta-analysis of the effect of a mono-component bacterial protease (RONOZYME® ProAct) on the apparent ileal digestibility of amino acids in poultry and swine diets was conducted to examine functional patterns, mean effects and variability of response. A total of 25 independently-conducted experiments were included comprising a total of 804 datapoints. The mean response to protease was +3.74% (SE 1.1%, P0.05). However, the inherent digestibility of amino acids in the control diet as a single explanatory term explained around 47% of the variance (P<0.001) in effect. When the inherent digestibility of amino acids in the control diet was less than 70% protease addition improved amino acid digestibility in 90% of cases with a mean improvement of around 10%. When the inherent digestibility of amino acids in the control diet was more than 90% there was a protease-mediated improvement in digestibility in only 60% of cases with a mean improvement of around 2%. It can be concluded that the inherent digestibility of amino acids in the diet without protease supplementation is the primary explanatory term for the efficacy of this exogenous protease, demonstrating that it is highly effective in improving the digestibility of amino acids across a wide range of feed ingredients. Benchmarking diets or feed ingredients as to their relative nutritional value would enhance the ability of nutritionists to determine the likely return on investment on use of bacterial proteases in their operatio

United we stand: combining structural methods

Structural biologists benefit enormously by combining structural approaches to tackle biological systems. This is evident in the increasing use of complementary methods combined with the traditional structural biology techniques of macromolecular X-ray crystallography (MX), nuclear magnetic resonance (NMR) and electron microscopy (EM) to generate structural information

Basal endogenous losses of amino acids in protein nutrition research for swine and poultry

AbstractIn this review, the definition and terminology of amino acid (AA) digestibility and ileal endogenous losses of AA (IAAend) in poultry and swine nutrition are discussed. Compared with apparent (AID) and true (TID) ileal digestibility, standardised ileal digestibility (SID) of AA is recommended for the expression of digestible AA contents of feed ingredients and for describing nutritional requirements of poultry and swine. To determine the SID of AA, total ileal flow of AA should be corrected for basal IAAend. Therefore, the measurement of basal IAAend is of great importance for the accuracy of the SID estimation in feed ingredients. The techniques for measuring basal IAAend in poultry and swine include the use of a nitrogen-free diet (NFD), a highly digestible or enzyme hydrolyzed protein diet, and the regression method. The classic method for basal IAAend determination involves the feeding of a NFD to experimental animals and measuring the ileal AA flow. This IAAend output is considered as basal IAAend, and it is assumed that the excretion of basal IAAend depends only on DM intake, regardless of dietary composition. There are criticisms with the NFD method about the abnormal physiological state induced by severe AA deficiency. Although this AA deficiency may affect the estimate of basal IAAend for dispensable AA, especially proline and glycine because of the degradation of body protein, the NFD method is still the most widely used method for basal IAAend measurements. According to the definition of basal IAAend, the NFD should be the preferred methodology in SID determination, because the basal IAAend should be only related to dry matter intake. Additionally, the SID coefficients in feed ingredients generated by NFD method are considered to be additive in a complete diet. However, the results generated from NFD method can vary among studies due to the variance in the experimental animals and diet composition. To improve the accuracy of estimating the SID of AA in feed ingredients, it is suggested that a mandatory NFD be included in individual studies to generate basal IAAend for correcting total ileal amino acid flow in determining SID of AA. In addition, research is needed to investigate the standard diet formulation of NFD

An isothermal titration calorimetry study of phytate binding to lysozyme: A multisite electrostatic binding reaction

Isothermal titration calorimetry (ITC) was used to detect phytate binding to the protein lysozyme. This binding interaction was driven by electrostatic interaction between the positively charged protein and negatively charged phytate. When two phytate molecules bind to the protein, the charge on the protein is neutralised and no further binding occurs. The stoichiometry of binding provided evidence of phytate–lysozyme complex formation that was temperature dependent, being most extensive at lower temperatures. The initial stage of phytate binding to lysozyme was less exothermic than later injections and had a stoichiometry of 0.5 at 313 K, which was interpreted as phytate crosslinking two lysozyme molecules with corresponding water displacement. ITC could make a valuable in vitro assay to understanding binding interactions and complex formation that normally occur in the stomach of monogastric animals and the relevance of drinking water temperature on the extent of phytate–protein interaction. Interpretation of ITC data in terms of cooperativity is also discussed

The Epidemiology of Pediatric Autoimmune Hepatitis in Scotland:A National Cohort Study

OBJECTIVES: Autoimmune hepatitis (AIH) is a rare, but potentially severe, cause of liver disease in children. We aimed to summarize how children with AIH in Scotland presented, were investigated and managed in addition to producing novel epidemiological data and outcomes.METHODS: All prevalent pediatric patients with AIH cared for in pediatric services between January 2013 and September 2018 were included. Individual patient data were obtained from electronic patient records in the 3-main academic pediatric centers in Scotland covering the entire population.RESULTS: Thirty-eight patients were included (25 female) with median follow-up of 33 months (range, 2-145 mo) and 136 total patient years. The incidence between 2014 and 2017 was 0.49/100 000/y (95% confidence interval, 0.29-0.78) and point prevalence between 2013 and 2018 was 1.75/100 000 (95% confidence interval, 1.42-2.13). Thirty-five (92%) patients were autoantibody positive, most commonly anti-nuclear antibody (63%) and anti-smooth muscle antibody (42%). Thirty-seven (97%) patients had induction therapy with oral corticosteroids, 30 (79%) required maintenance treatment with azathioprine, and 23 (61%) received ursodeoxycholic acid. There were 1.4 disease flares per 10 patient years and 3 patients required liver transplantation with an overall 5-year survival rate without the need for transplantation of 95%.CONCLUSIONS: We calculated a novel incidence and prevalence rate for pediatric AIH in Scotland. Nearly all were invariably treated initially with corticosteroids with most placed-on azathioprine as maintenance therapy. Outcomes were generally favorable with low rates of disease flares and the need for transplantation being rare.</p

The Epidemiology of Pediatric Autoimmune Hepatitis in Scotland:A National Cohort Study

OBJECTIVES: Autoimmune hepatitis (AIH) is a rare, but potentially severe, cause of liver disease in children. We aimed to summarize how children with AIH in Scotland presented, were investigated and managed in addition to producing novel epidemiological data and outcomes.METHODS: All prevalent pediatric patients with AIH cared for in pediatric services between January 2013 and September 2018 were included. Individual patient data were obtained from electronic patient records in the 3-main academic pediatric centers in Scotland covering the entire population.RESULTS: Thirty-eight patients were included (25 female) with median follow-up of 33 months (range, 2-145 mo) and 136 total patient years. The incidence between 2014 and 2017 was 0.49/100 000/y (95% confidence interval, 0.29-0.78) and point prevalence between 2013 and 2018 was 1.75/100 000 (95% confidence interval, 1.42-2.13). Thirty-five (92%) patients were autoantibody positive, most commonly anti-nuclear antibody (63%) and anti-smooth muscle antibody (42%). Thirty-seven (97%) patients had induction therapy with oral corticosteroids, 30 (79%) required maintenance treatment with azathioprine, and 23 (61%) received ursodeoxycholic acid. There were 1.4 disease flares per 10 patient years and 3 patients required liver transplantation with an overall 5-year survival rate without the need for transplantation of 95%.CONCLUSIONS: We calculated a novel incidence and prevalence rate for pediatric AIH in Scotland. Nearly all were invariably treated initially with corticosteroids with most placed-on azathioprine as maintenance therapy. Outcomes were generally favorable with low rates of disease flares and the need for transplantation being rare.</p

Multimodal Control of Liquid Crystalline Mesophases from Surfactants with Photoswitchable Tails

Non-invasive manipulation of the hierarchical structure of functional materials is a key challenge in the advancement of optoelectronics, energy conversion and storage devices and drug delivery systems. Here, using a combination of small-angle X-ray scattering and polarised optical microscopy, we decipher the various structure/self- assembly relationships of neutral surfactants bearing photoswitchable tails, which self-organise into a rich variety of lyotropic liquid crystalline mesophases. Facile, multimodal control of the nanoscale morphology of these single-component systems is achieved through: i) molecular structure, via careful selection of the alkyl tail/ethylene oxide headgroup lengths; ii) concentration; iii) temperature; and iv) photoisomerisation. The nanoscale architectures range from the weakly concentrated hyperswollen lamellar phases, the more common lyotropic lamellar and hexagonal phases, to pure thermotropic liquid crystals; all of which are accessible at room temperature. Photoisomerisation with UV light leads to the reversible destruction of the liquid crystalline phase, which can be spatially controlled through the use of a mask. This extensive study demonstrates the versatility of neutral photosurfactants and paves the way for them to be investigated for new applications, such as photoresponsive templates or drug delivery systems.Isaac Newton Trust/University of Cambridge Early Career Support Scheme grant. Irish Research Council EU COST action MP120

Controlling the properties of the micellar and gel phase by varying the counterion in functionalised-dipeptide systems

The micellar aggregates formed at high pH for dipeptide-based gelators can be varied by using different alkali metal salts to prepare the solutions. The nature of the micellar aggregates directly affects the properties of the resulting gels