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Objectives There is an ongoing debate as to what extent antimicrobial resistance (AMR) can be transmitted from animals to humans via the consumption of animal products. Because epidemiological data on the role of diet in AMR in humans are lacking, we investigated this association between diet and AMR for different antimicrobial drugs in Escherichia coli (E. coli) in urinary tract infections (UTIs). Methods Susceptibility of E. coli in urinary cultures and information on diet (with food frequency questionnaires) were obtained from participants of the Rotterdam study, a population-based prospective cohort study. The association between intake of several food groups (meat, seafood, eggs, dairy products, crops) and resistance of E. coli to several antimicrobial drugs (amoxicillin, amoxicillin-clavulanic acid, trimethoprim, sulfamethoxazole-trimethoprim, first-generation cephalosporins, cefotaxime, nitrofurantoin, norfloxacin) was studied. Results Urinary cultures with E. coli were obtained from 612 individuals, of whom 481 (78.6%) were women. Resistance rates varied from 246/611 (40.3%) for amoxicillin and 167/612 (27.3%) for trimethoprim to only 29/612 (4.7%) for nitrofurantoin and 16/462 (3.5%) for cefotaxime. A higher intake of chicken was associated with cefotaxime resistance (OR 2.18; 95% CI 1.05–4.51 per tertile increase); a higher intake of pork was associated with norfloxacin resistance (OR 1.42; 95% CI 1.04–1.95 per quartile increase). In contrast, a higher intake of cheese was associated with lower AMR to amoxicillin (OR 0.84; 95% CI 0.72–0.99 per quartile increase) and amoxicillin-clavulanic acid (OR 0.67; 95% CI 0.53–0.86 per quartile increase). Conclusions These findings support the hypothesis that diet may play a role in the AMR of E. coli in UTIs.

Background:Pain is a major debilitating symptom of knee osteoarthritis (OA). However, the extent of joint damage in OA does not correlate well with the severity of pain. The mechanisms that govern OA pain are poorly understood. Immune cells infiltrating nervous tissue may contribute to pain maintenance.Objectives:Here we investigated the role of macrophages in the initiation and maintenance of OA pain.Methods:Knee joint damage was induced by an unilateral injection of mono-iodoacetate (MIA) or after application of a groove at the femoral condyles of rats fed on high fat diet. Pain-like behaviors were followed over time using von Frey test and dynamic weight bearing. Joint damage was assessed by histology. Dorsal root ganglia (DRG) infiltrating immune cells were assessed over time using flow cytometry. To deplete monocytes and macrophages, Lysmcrex Csfr1-Stop-DTR were injected intrathecal or systemically with diptheria toxin (DT).Results:Intraarticular monoiodoacetate injection induced OA and signs of persistent pain, such as mechanical hyperalgesia and deficits in weight bearing. The persisting pain-like behaviors were associated with accumulation of F4/80+macrophages with an M1-like phenotype in the lumbar DRG appearing from 1 week after MIA injection, and that persisted till at least 4 weeks after MIA injection. Macrophages infiltrated DRG were also observed in the rat groove model of OA, 12 weeks after application of a groove at the femoral condyles. Systemic or local depletion of DRG macrophages during established MIA-induced OA completely ablated signs of pain, without affecting MIA-induced knee pathology. Intriguingly when monocytes/macrophages were depleted prior to induction of osteoarthritis, pain-like behaviors still developed, however these pain-like behaviors did not persist over time.In vitro,sensory neurons innervating the affected OA joint programmed macrophages into a M1 phenotype. Local repolarization of M1-like DRG macrophages towards M2 by intrathecal injection of M2 macrophages or anti-inflammatory cytokines resolved persistent OA-induced pain.Conclusion:Overall we show that macrophages infiltrate the DRG after knee damage and acquire a M1-like phenotype and maintain pain independent of the lesions in the knee joint. DRG-infiltrating macrophages are not required for induction of OA pain. Reprogramming M1-like DRG-infiltrating macrophages may represent a potential strategy to treat OA pain.Acknowledgments:This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreements No 814244 and No 642720. Dutch Arthritis SocietyDisclosure of Interests:Ramin Raoof: None declared, Christian Martin: None declared, Huub de Visser: None declared, Judith Prado: None declared, Sabine Versteeg: None declared, Anne Heinemans: None declared, Simon Mastbergen: None declared, Floris Lafeber Shareholder of: Co-founder and shareholder of ArthroSave BV, Niels Eijkelkamp: None declared

A robotic testing facility for the measurement of joint mechanics was used to determine the significance of tears in the intervertebral disc on the mechanics of the spinal joint. Ten lumbar joints of sheep were dynamically loaded and manipulated. Comparisons were made between the behaviour of the intervertebral disc in flexion and extension at two test speeds. The influence of the posterior elements and of rim lesions was assessed by testing the joint immediately before and after removal of the posterior elements and after the creation of a 40 N mm × 10 mm rim lesion in the disc. Stiffness of the spinal joint dropped significantly upon removal of the posterior elements, from 0.81 to 0.23 N m/deg for flexion and from 0.65 to 0.40 N m/deg for extension. Maximum moments dropped 37 per cent for flexion and 63 per cent for extension. The rim lesion caused a further significant stiffness reduction to 0.21 and 0.31 N m/deg respectively. Maximum moments reduced a further 12 per cent and 16 per cent respectively. A higher test speed (2 deg/s instead of 0.5 deg/s) usually did not change these results significantly. The novel six-degrees-of-freedom robotic testing facility used in this study was demonstrated to be an effective system for studying the mechanics of complex biological joints.

International audience; Venous thromboembolism (VTE), the third leading cause of cardiovascular mortality, is a complex thrombotic disorder with environmental and genetic determinants. Although several genetic variants have been found associated with VTE, they explain a minor proportion of VTE risk in cases. We undertook a meta-analysis of genome-wide association studies (GWASs) to identify additional VTE susceptibility genes. Twelve GWASs totaling 7,507 VTE case subjects and 52,632 control subjects formed our discovery stage where 6,751,884 SNPs were tested for association with VTE. Nine loci reached the genome-wide significance level of 5 × 10(-8) including six already known to associate with VTE (ABO, F2, F5, F11, FGG, and PROCR) and three unsuspected loci. SNPs mapping to these latter were selected for replication in three independent case-control studies totaling 3,009 VTE-affected individuals and 2,586 control subjects. This strategy led to the identification and replication of two VTE-associated loci, TSPAN15 and SLC44A2, with lead risk alleles associated with odds ratio for disease of 1.31 (p = 1.67 × 10(-16)) and 1.21 (p = 2.75 × 10(-15)), respectively. The lead SNP at the TSPAN15 locus is the intronic rs78707713 and the lead SLC44A2 SNP is the non-synonymous rs2288904 previously shown to associate with transfusion-related acute lung injury. We further showed that these two variants did not associate with known hemostatic plasma markers. TSPAN15 and SLC44A2 do not belong to conventional pathways for thrombosis and have not been associated to other cardiovascular diseases nor related quantitative biomarkers. Our findings uncovered unexpected actors of VTE etiology and pave the way for novel mechanistic concepts of VTE pathophysiology.

Grass samples were harvested during the 1993 growing season after a precut on April 27, 1993 and were stored frozen or left to ensile in 30-L buckets. Effects on chemical composition and fermentation kinetics of the maturation of the grass and of ensiling were investigated. Chemical composition and fermentation kinetics were determined using the gas production technique, in vitro techniques, and the nylon bag technique. Two silage samples were also investigated in vivo. Maturation caused a decrease in crude protein content and organic matter degradability and an increase in neutral detergent fiber, acid detergent fiber, and lignin contents. Degradation rates were highest for the youngest samples and decreased as grass and silage matured. This result could be observed from the first derivative of the cumulative gas production curves (i.e., the rate of gas production) and from the gas production parameters. The rate of degradation of the nonsoluble fraction of the young samples, determined using the gas production technique, was relatively higher in rumen fluid from a cow fed silage from grass cut at a young stage. More mature samples were degraded relatively faster in rumen fluid from a cow fed mature grass silage, suggesting a specific adaptation of the rumen microorganisms to the grass properties. There was a good relationship among the second phase of gas production (i.e., fermentation of the nonsoluble fraction), maturity of the grass and grass silage samples, degradability determined with the Tilley and Terry technique, and degradability determined after 46 h of incubation in rumen fluid. Results obtained with both of the different in vitro techniques and the nylon bag technique were confirmed by the in vivo experiments involving the two silage samples.

We studied the presence of bacterial antigens in rat tissues. We produced a monoclonal antibody (MAb 2E9) directed against intestinal flora-derived peptidoglycan-polysaccharide complexes from human and rat feces. With several immunological techniques, the specificity of 2E9 for this bacterial product was demonstrated. Using 2E9 in an immunohistological assay, we were able to show the presence of bacterial products in macrophages in the red pulp of spleens of conventional Lewis rats. However, we found no correlation between the development of the intestinal flora and positive spleen staining with MAb 2E9. The results were confirmed by immunohistology with a previously described MAb 2-4 directed to muramyl dipeptide. Other lymphoid organs did not stain positively with 2E9 and 2-4. Neonatal and young rats showed no staining of the spleen, but positivity could be induced by injecting peptidoglycan-polysaccharide complexes systemically. We conclude that bacterial fragments are present in splenic macrophages of conventional rats.

Interestingly, using a monoclonal antibody, peptidoglycan-polysaccharide complexes (PPC) were detected intracellularly in the mucosa and submucosa of the bowel wall of Crohn's disease (CD) patients. PPC are the main constituents of the gram-positive bacterial cell wall. These PPC were however detected in the normal bowel wall also. Therefore, in this study the hypothesis that an enhanced immune responsiveness to bacterial antigens plays a pivotal role in the induction or the chronicity of CD was tested. As antigens, the peptidoglycan structures of intestinal bacteria (Eubacterium aerofaciens or fecal PPC) or of Streptococcus pyogenes, the 65-kDa heat shock protein and muramyl dipeptide (MDP), the smallest bioactive subunit of peptidoglycan, were used. The proliferative responses of peripheral blood (PB) mononuclear cells (MNC) of healthy subjects and patients in a remissive stage of CD or an active CD stage were examined. Of this last patient group the MNC responses of the mesenterial lymph nodes that drain the inflamed gut area were measured also. The responses of PB-MNC of the healthy subjects and the patients in a remissive CD stage were not different. Compared to the responses in remissive CD, the PB-MNC responses in active CD to the eubacterial cell wall and streptococcal cell wall antigen were significantly higher. At the inflammation site in active CD, the lymph nodes, the responses to most of the bacterial antigens were significantly higher than in the PB. In summary, the results show the presence of bacterial peptidoglycan in the bowel wall and the immune responsiveness, especially at the inflammation site, to these antigens in active CD and therefore present suggestive evidence for the role of peptidoglycan in the etiology and/or pathogenesis of CD.

A series of experiments have been conducted to determine the flexural and torsional rigidity of an Olympus colonoscope CF-140S and torsional rigidity of a Pentax colonoscope EC-3870 and the dependency of these properties on temperature and on the presence of loops. Along the length of the colonoscope, the flexural rigidity of the Olympus colonoscope varied between 260 and 400 Ncm2 and the torsional rigidity varied between 68 and 88 Ncm2/deg, with an average of 76 Ncm2/deg for tests involving 0.86 Nm of anticlockwise torque. Results show a significant decrease of 10 per cent in torsional rigidity between clockwise and anticlockwise torque. For the Pentax colonoscope flexural rigidity was not tested; its torsional rigidity varied between 34 and 76 Ncm2/deg, with an average of 46 Ncm2/deg for tests involving 0.43 Nm of anticlockwise torque. An increase in temperature of the Olympus colonoscope from 24 to 37 °C reduced the flexural rigidity by an average of 17 per cent and torsional rigidity by an average of 7 per cent. A right-handed loop caused a significant increase in flexural rigidity, but other looping configurations had no significant influence.

Three rumen fermentation studies in combination with three feeding trials were carried out to investigate the effect of partial replacement of heavily fertilized perennial ryegrass by low protein feedstuffs on pH and concentrations of VFA and NH3 N in the rumen and on N excretion in milk, urine, and feces by dairy cows. Feedstuffs tested were high fiber concentrate mixtures based on sugar beet pulp and soybean hulls and high starch concentrate mixtures based on corn (Experiments 1 and 2), corn silage (Experiment 1), dried and ensiled pressed sugar beet pulp and high moisture ear corn silages with or without husks (Experiment 3). In the fermentation studies, N intake ranged between .43 and .57 kg/d. Partial replacement often increased DMI (maximal by 2.6 kg), resulting in minor effects on N intake. Urinary N excretion ranged between 30 and 58% of N intake and decreased by 30 to 40% when grass was partially replaced. Fecal N output was between 25 and 30% of N intake and tended to increase with the low protein feed. The reduction in urinary N excretion corresponded to a decrease of rumen NH3 N. Replacement by concentrate mixtures based on corn reduced milk fat content; for mixtures based on beet pulp, milk fat content was not changed.

In a 4 x 4 Latin square experiment the effects of DM content and/or the extent of fermentation in grass silages on the pattern of rumen fermentation and rumen kinetics were studied. In a separate study two cows were used to measure the rate of degradation using the dacron bag technique. Four rumen cannulated dairy cows were used to measure rumen fermentation pattern, rumen kinetics were measured in three of these animals. Basal diets (70% of total DM) consisted of maize silage, moist ensiled beet pulp, moist ensiled maize gluten feed, moist ensiled brewers' grains and a concentrate mixture. The remainder of the diet (30% of total DM) was wilted grass silage (WGS), high moisture grass silage with molasses (MGS), high moisture silage with formic acid (FGS) or wilted grass silage with additional water (WW). All diets were fed as complete feeds. pH of the rumen fluid was lower on the MGS and FGS diets. Concentrations of total VFA, acetic acid, ammonia and branched-chain fatty acids (BCFA) were highest on high moisture diets (MGS and FGS). Rates of clearance and digestion of the organic matter (OM) fractions were or showed tendencies towards being negatively influenced by both MGS and FGS, but remained unaffected by WGS and WW. Degradability of the grass silages was influenced by fermentation in the silo (lower digestible fractions and higher soluble fractions), as were rates of degradation (higher). Results of the degradability measured on the basal diet ingredients were in agreement with published literature and showed a strong correlation between OM digestibility in vitro and the undigestible fraction.

Effects of carbohydrates in concentrate mixtures (starch vs. cell wall constituents) and in rate of rumen degradation (rapid vs. slow) on rumen fermentation and rumen kinetics were studied using a 4 x 4 Latin square design. The basal diets, which comprised 75% of total DM, consisted of wilted grass silage, maize silage and concentrates. The remainder consisted of barley (B), maize (M), pressed ensiled beet pulp (P) or moist ensiled maize bran (MB). All diets were fed as totally mixed rations (TMR). The pH of the rumen fluid and the total concentration of volatile fatty acids (tVFA) did not differ among diets. The major volatile fatty acids did differ between diets and were expressed as the non-glucogenic:glucogenic ratio (NGR), being lowest for B and highest for P. Differences in NGR could be explained by differences in the rate of degradation of starch and/or NDF, using nylon bag incubations. Concentrations of ammonia and branched chain fatty acids (BCFA) were higher for diet MB and corresponded with the availability of nitrogen and energy for microbial protein synthesis, which was also reflected in the amount of bacterial protein in the rumen. Degradability was lower for maize starch compared with starch from barley. The rates of digestion measured in sacco and from rumen evacuations were similar for organic matter and N, but the nylon bag method showed a lower estimate for starch and NDF. The large particle fraction of mean total rumen contents consisted mainly of cell wall constituents and did not differ between diets. (Abstract retrieved from CAB Abstracts by CABI’s permission)

A feeding trial was carried out with 64 multiparous dairy cows, in which the effect of type of carbohydrate in concentrate mixtures (starch vs. cell wall constituents) and differences in rumen degradation (fast vs. slow) on feed intake and milk yield were studied. The experiment started immediately after parturition and lasted for 15 wk. The basal diet, which comprised 75% of the total DM intake, consisted of wilted grass silage, maize silage and concentrates. The remaining part of the diet consisted of barley (B), maize (M), pressed ensiled beet pulp (P) or moist ensiled maize bran (MB). All diets were given as totally mixed rations. Total intake of DM and net energy did not differ between diets, but differences were found in energy partition. There was a tendency for cows given diet B to show increased liveweight gain, while cows given P mobilized more body reserves compared with the other treatments. Milk yield did not differ between diets, but milk fat content was higher for diet P. Milk protein content was higher for diets B and M compared with P and MB. The lower protein content of the milk of treatment P can be explained by a longer period of negative energy balance, while the lower milk protein in cows given diet MB probably resulted from reduced microbial protein synthesis. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Dutch Landrace X Large White pigs 14 to 15 weeks old and about 45 kg were fed on low-protein diets (16.1%) and supplemented with lysine, orally, by slow or rapid jugular infusion or by slow portal/caval infusion in order to evaluate the bioavailability of lysine with type of treatment. Elimination rate after intravenous treatment had a half-life of 2.0+or-1.6 h (after bolus injection) or 3.7+or-1.9 h (after slow infusion). Absorption of an oral dose of lysine from the intestine (half-life of 3.6+or-0.9 h) was slower than elimination rate (half-life of 0.9+or-0.3 h). No significant liver first-pass effects could be detected and bioavailability of lysine after enteral intake was 82+or-6%. Analysis of plasma kinetics of amino acids may provide a valuable tool to evaluate bioavailability of dietary amino acids. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Prior studies have found that primary rotations in the lumbar spine are accompanied by coupled out-of-plane rotations. However, it is not clear whether these accompanying rotations are primarily due to passive (discs, ligaments, and facet joints) or active (muscles) spinal anatomy. The aim of this study was to use a finite element model of the lumbar spine to predict three-dimensional coupled rotations between the lumbar vertebrae, due to passive spinal structures alone. The finite element model was subjected to physiologically observed whole lumbar spine rotations about in vivo centres of rotation. Model predictions were validated by comparison of intra-discal pressures and primary rotations with in vivo measurements and these showed close agreement. Predicted coupled rotations matched in vivo measurements for all primary motions except lateral bending. We suggest that coupled rotations accompanying primary motions in the sagittal (flexion/extension) and transverse (axial rotation) planes are primarily due to passive spinal structures. For lateral bending the muscles most likely play a key role in the coupled rotation of the spine.

Introduction It is important to understand the mechanics of the lumbar spine, as it has been shown that much low back pain is attributable to mechanical factors. One important aspect of spinal mechanics is the neutral zone, defined as a region of little or no resistance to motion on either side of the neutral position for a motion segment. If the neutral zone is a significant feature of intervertebral joint mechanics then the spinal joints will have little intrinsic stability and rely on muscles to control their movement around the neutral position. This has significant implications for our understanding of how degenerative changes to the spinal joints might destabilise the spine. This study was performed to characterise the size of the neutral zone and the effect of axial preload for different spinal motions. Methods Using a 6 degree-of-freedom (DOF) ABB industrial robot incorporating a 6-DOF JR3 force sensor, six isolated ovine lumbar joint segments were subjected to 5 repetitive movements in 3 directions (6° extension / 15° flexion, +/- 7° lateral bend, +/- 3° axial twist) with 4 different preloads (0, 150, 300, 450N) under 2 conditions (facet joints intact and facets removed). For each direction, the fixed axis about which the joint would rotate with a minimal motion-opposing moment was determined in advance. In accordance with a previous study by this group, the neutral zone was defined as the region where absolute rotational stiffness is less than 0.05 Nm/°. Results When moving from 6° of extension to -15° (flexion) a neutral zone was usually observed starting around 0° and continuing as far as -8 or -9°. The neutral zone was in the same region when moving in the opposite direction, except when the specimen showed a considerable amount of hysteresis, in which case the neutral zone could start as early as -11° or -12° and usually continued to -2°or -3°. Increasing preload usually made the joint stiffer in the regions outside the neutral zone, but did not affect the neutral zone itself. If present without preload, hysteresis usually increased with increasing preload. In lateral bend and axial twist no neutral zone was generally observed. In lateral bend the stiffness gradually increased with rotation, whereas in axial twist the stiffness was usually constant over the range of movement. For all movements, the only effect of facet removal was a constant reduction in stiffness over the whole movement. For lateral bend this meant that the stiffness around 0° usually would drop below the threshold of 0.05Nm/°, hence creating a neutral zone extending over a couple of degrees. Discussion Ovine spinal joints have a region where there is little to no resistance to flexion/extension. This region can be in excess of 10°. This means in their neutral position, the individual spinal joints have virtually no stability and the spine depends on other measures such as muscle activation to maintain stability in the sagittal plane. For lateral bend there is a region of little resistance as well, but it is not nearly as profound as in flexion/extension.

This paper presents the design of a body-powered voluntary closing prosthetic hand. It is argued that the movement of the fingers before establishing a grip is much less relevant for good control of the object held than the distribution of forces once the object has been contacted. Based on this notion, the configurations of forces on the fingers and the force transmission through the whole mechanism were taken as a point of departure for the design, rather than movement characteristics. For a good distribution of pinching forces on the object and a natural behavior, the prosthesis is made adaptive and flexible. To achieve good force feedback, the disturbing influences of the cosmetic glove are strongly reduced by a compensation mechanism. To further improve the transmission of forces, friction is reduced by furnishing the whole mechanism with rolling links. This force-directed design approach has led to a simple mechanism with low operating force and good feedback of the pinching force.

The interaction between the quality of grass silage and starch supplementation on ruminal digestion was studied in an experiment with a 2 x 2 factorial design using four dairy cows. Treatment factors were grass silage harvested after either 21 or 37 d of regrowth and two concentrations of steam-flaked corn starch (0 or 4 kg/d). Ruminal volume and flow of duodenal digesta were estimated. When forage was harvested at a more mature stage, only minor effects were noted for silage composition and, consequently, ruminal and intestinal digestion. The addition of starch to the diet tended to reduce ruminal digestion of neutral detergent fiber. The reduction in ruminal digestion was not compensated by increased digestion in the large intestine. Starch increased duodenal nonammonia N flow because of an increase in bacterial N flow. The increase in bacterial N was accompanied by a reduction in the escape of feed N from the rumen. Results from this study indicate that the addition of ruminally available starch to diets based on grass silage reduced ruminally degradable neutral detergent fiber and increased the duodenal supply of protein. These effects have to be taken into account to predict production responses to extra starch.

The effects of the maturity of grass prior to ensiling and the supplementation of starch to grass silage on apparent digestibility, degradability, rumen content, and feed intake by dairy cows were investigated using a Latin square design. Treatments were silages from early or late cut grass with or without 4 kg of supplemental flaked corn starch. The silage from early cut grass contained more N and sugars than did the silage from late cut grass but was lower in neutral detergent fiber (NDF). Degradation characteristics were not different between the two silages. Apparent digestibilities of dry matter (DM), organic matter (OM), and N in the silage from late cut grass were lower than those in the silage from early cut grass, but NDF digestibility was not affected. Starch supplementation increased the lag phase for DM and OM in both silages, but the rate of degradation was decreased for NDF. Starch supplementation did not influence digestibilities of DM and OM in silage from early cut grass but decreased the digestibilities of DM and OM in silage from late cut grass. Crude protein and NDF digestibilities were decreased for silages from early and late cut grass. Starch supplementation increased NDF in the rumen of cows fed the silage from early cut grass, but NDF was not affected by starch supplementation for cows fed the silage from late cut grass. Rumen-degradable starch negatively influences degradability and apparent OM digestibility; the extent of the decrease is related to the maturity of the NDF.

An experiment employing a Latin square design was used to quantify the effects of two stages of maturity of grass silage (early cut and late cut) and three concentrations of flaked corn starch (0, 2, and 4 kg) on the molar proportion of rumen volatile fatty acids (VFA), the production of rumen VFA, and the net fluxes of VFA in the splanchnic tissue of cows. The molar proportions of VFA in rumen fluid were similar for cows fed both silages. When the silage diets were supplemented with starch, the proportion of propionic acid increased for cows fed diets containing early cut grass silage, but no effects were found for cows fed diets containing late cut grass silage. Estimated gastrointestinal production of acetate, propionate, butyrate, and branched-chain fatty acids plus valerate was related to intake of metabolizable energy and organic matter fermented into VFA. The portal release of acetate was approximately 14% lower than the estimated production of acetate by cows fed diets containing early cut grass silage, but cows fed diets containing late cut grass silage showed a variable difference between estimated production and portal release (31, 24, and 15%, respectively) as starch supplementation increased. The portal release of butyrate plus beta-hydroxybutyrate and the release of branched-chain fatty acids plus valerate were approximately 70 and 25%, respectively, of the estimated gastrointestinal production. Propionate production was similar to the portal release of propionate. Net flux measurements in splanchnic tissue in combination with gastrointestinal digestion and kinetics provide information that increases the knowledge of pathways and metabolism and quantifies the availability of individual nutrients for milk production in dairy cows.

Extant mechanistic models of rumen functions are unable to predict the molar proportion of volatile fatty acids (VFA) accurately. In order to make these models useful in investigating theories on nutrient flows that go beyond the rumen, the representations adopted need to be improved. This theoretical study was directed at identifying what parts of a rumen model may be responsible for the inaccurate VFA prediction. For five distinct parts of a model, not involving the description of the microbiological metabolism, the hypothesis was tested that their inappropriate description can be a probable cause of inaccurate VFA prediction. These five parts were: (1) the input functions of feed ingestion; (2) the representation of insoluble, degradable substrate of roughage and concentrate origin; (3) the kinetics of VFA absorption from the rumen; (4) the VFA coefficients that describe the stoichiometry of the conversion of fermented substrate into VFA; and (5) the representation of the rumen particle dynamics. Every hypothesis was tested by modifying the model description and simulating it to steady state. Observations required were derived from digestion trials with lactating dairy cows. Simulation results demonstrated that the predicted molar proportion of rumen VFA concentrations is particularly influenced by VFA absorption kinetics and VFA coefficients. Although the description of particle dynamics also had a large influence with certain choices of its parameterization, it is probably a less important cause of inaccurate predication when rumen feed degradation (apparent from rumen outflow) is predicted well. In conclusion, to obtain improved predictions of the molar proportions of rumen VFA, further work is required on the representation of VFA absorption kinetics and of VFA coefficients of fermentation stoichiometry.

This study investigated the consequences of differences in applied concepts and individual mathematical formulations on steady-state behavior of three important mechanistic rumen models. In the models of Baldwin et al. (2) and Danfaer (6), the formulation of passage rate, nondietary inputs, defined rumen substrate pools, absorption rates, degradation rates, molecular weights, parameterization of VFA production, and physical compartmentalization were sequentially exchanged for the formulation of the model of Dijkstra et al. (9). Most of these adaptations had a considerable influence on model behavior, indicating large qualitative differences in formulation and sensitivity to concept choice. Because microbial substrate environments were similar after all adaptations, the microbial mechanisms could be compared objectively without being concealed by differences in extramicrobial formulation. None of the microbial functions were altered except for substrate degradation, which gave rise to a similar rate of substrate entrance to soluble rumen pools that are available for microbial utilization. Large differences remained in microbial functions of substrate fermentation, substrate incorporation, and microbial synthesis. Differences in extramicrobial rumen functions and microbial mechanisms had important consequences for simulated nutrient outputs from the rumen, illustrating the necessity for further validation of individual formulations.

Net portal-drained viscera (PDV) flux of glucose, VFA, ammonia, and urea was determined in pigs fed diets with or without resistant starch. Diets consisted of 65% cornstarch (diet CS), 32.5% cornstarch and 32.5% raw potato starch (diet CPS), or 65% raw potato starch (diet PS); the remaining 35% supplied all amino acids, fat, fiber, minerals, and vitamins. The diets contained twice the maintenance requirement for energy and were fed twice daily to four barrows (initial BW 56 kg) in three periods in a crossover design. The pigs were fitted with catheters in a mesenteric vein, a mesenteric-artery, and the portal vein, and net PDV flux was calculated by multiplying portal-arterial concentration differences and corresponding portal vein flow. Net PDV flux of glucose was significantly less after feeding diets CPS and PS, and portal absorption of ileally digested glucose was 89, 66, and 41% for diets CS, CPS, and PS, respectively. Net PDV flux of VFA was lowest after feeding diet CS and three to four times higher after feeding diets CPS and PS. Net PDV flux of ammonia was highest for diet CS and almost halved after feeding diets CPS and PS. There was a small negative net PDV flux of urea for diets CS and CPS, which significantly increased after feeding diet PS. These results suggest that excretion of nitrogen is shifted from urine to feces primarily by reduction of the net PDV flux of ammonia when resistant starch is fed.

Mechanistic rumen models of Baldwin (1995), Danfæer (1990) and Dijkstra et al. (1992) were compared on identical inputs that were derived from trials with lactating dairy cows fed on grass herbage. Consistent differences were detected between models and between predicted and observed outputs. None of the models seemed to predict all nutrient flows best. The models particularly differed in the representation of microbial metabolism: degradation of insoluble substrate, fermentation of substrate into volatile fatty acids, and incorporation of substrate into microbial matter. Differences amongst models in the prediction of these processes compensated for each other and consequently all models predicted the duodenal flow of non-NH3 N, microbial N and organic matter reasonably well. Large differences remained in the prediction of individual nutrient flows, however, and it was stressed that in order to enhance prediction of the profile of nutrient flows, the mechanisms of microbial metabolism need to be tested on their ability to describe the intraruminal transactions. However, this requires more-detailed information on individual nutrient flows and on the microbial or non-microbial origin of duodenal contents. Parameter inputs for physical and chemical feed properties were identified that are improperly defined in extant models or susceptible to error. The description of these feed characteristics needs to be developed further and become identifiable for a wide range of dietary conditions.

The ileal digestibilities of maize starch and native pea starch do not differ. However maize starch is digested faster than pea starch and the ileal amino acid digestibility of a diet containing pea starch is lower. In the present study, the net portal fluxes of glucose, lactate, volatile fatty acids (VFA) and amino acids were measured for diets including 650 g maize starch or pea starch/kg. The diets were fed at a level 870 kJ digestible energy/kg0.75twice daily (06.00 and 18.00 hours) to four female pigs in a crossover design. Portal vein blood flow did not differ between maize and pea starches (1620 and 1484 ml/min respectively;sed100;P= 0.23). For maize starch portal glucose flux was significantly higher during the first 6 h after feeding, was not different 8 h after feeding and was significantly lower thereafter. Net portal glucose flux was higher for maize starch than for pea starch (1759 and 1265 mmol/12 h respectively;sed182;P= 0.054). Net portal lactate flux was not significantly different between maize and pea starches (36.5 and 67.2 mmol/12 h respectively;sed24.1;P= 0.27) and net portal VFA flux was lower for maize starch than for pea starch (169 and 218 mmol/12 h respectively; SED 18;P= 0.054). Net portal fluxes of valine, isoleucine, phenylalanine, tryptophan, arginine, serine, cystine, tyrosine, lysine, histidine and the sum of essential amino acids tended to be or were higher (P< 0.1 orPP

A feeding trial was carried out with 56 dairy cows in >=2nd lactation. The duration of the experiment was 13 wk and started immediately after parturition. Basal diets consisted of maize silage, pressed beet pulp, moist ensiled maize gluten feed, ensiled brewers' grains and concentrates, which provided 70% of total DM. The remaining 30% of the DM consisted of grass silages, which were given as supplement to the basal diet. Treatments were wilted grass silage (WGS), moist grass silage ensiled with molasses (MGS), moist grass silage ensiled with formic acid (FGS) and wilted grass silage with added water (WW). The rations were given as a total mixed ration (TMR) to avoid selection. All grass silages were harvested between 30 Aug. and 1 Sept. from the same pastures. The moist grass silage differed in chemical composition from the wilted grass silage in ash (higher), crude fibre (lower) and NDF (lower). The in vitro and in vivo digestibility did not differ between silages. Total DM intake was lowest for both moist silages (MGS and FGS) and, as a consequence, net energy intake was also lowest with MGS and FGS. Milk yield was highest on WGS and WW, resulting from the higher energy intake. Milk fat yield and content did not differ between treatments. Milk protein yield was significantly lower for groups given MGS and FGS. Milk protein content tended to be lower for groups given FGS and MGS. During the experiment energy balance was negative on all treatments. Calculation of the duodenal digestible protein value (DVE), using the recommended equation for grass silage, gave WGS silage a better fit with the DVE balance measured in the feeding trial than found with high moisture silages (MGS, FGS), which appeared to be underestimated. Body weight changes correspond favourably with net energy balances, after correction of energy values for volatiles in grass silages, using individual net energy values for volatiles instead of an av. for grass silage OM. (Abstract retrieved from CAB Abstracts by CABI’s permission)

In a 3 x 4 Latin square design with periods of 5 weeks rumen cannulated cows were fed on mixed diets supplemented with dried beet pulp (DP) pressed beet pulp (PP) and maize silage (M) at 15 kg DM and 25 kg DM (low, LL1 or high, HL1), respectively. Measurements were made of organic matter degradation (nylon bag) of diet ingredients, while during 48-h periods the pattern of intake, pH and osmolality, and concentration of volatile fatty acids (VFA), lactic acid (HL) and ammonia (NH3) were determined. The pH and concentration of the major VFA's were similar between treatments. The concentration of the branched chain fatty acids (BCFA), valerate and ammonia were significantly higher with M. The level of intake significantly influenced the pH, concentration of the major VFA's, 2-methyl-butyrate and valerate. The feed intake pattern differed between intake levels, but were similar between diets. Degradability of treatments were calculated from individual degradability measurements of diet ingredients. The undegradable fraction was highest for diet M. The water-soluble fraction was lowest for treatment DP, and the rate of degradation (kd) was lowest for treatment M. (Abstract retrieved from CAB Abstracts by CABI’s permission)

A feeding trial was carried out with 48 dairy cows in 2nd or later lactation. The experiment started immediately after parturition and lasted for 13 wk. Basal diets consisted of a mixture of artificially dried grass and maize silage as roughage components, and concentrates based on a mixture of byproduct feeds. In addition to the basal diet, dried beet pulp, ensiled pressed beet pulp or maize silage was given. Two groups received either dried beet pulp (DP) or ensiled pressed beet pulp (PP). The 3rd group received extra maize silage (M). All rations were given as totally mixed rations to prevent selection. Digestibility of the ration components was determined by in vitro and in vivo methods. The feeding value of both types of beet pulp and maize silages was in agreement with that reported in literature. Total DM intake differed significantly between DP and the other groups (PP and M). Energy intake was highest for DP and lowest for group M. Milk yield was similar for all groups. However, group PP displayed an apparently different pattern, with higher peak production than group M. Fat content and fat yield were similar for all groups. Milk protein yield did not differ significantly between groups, but group M tended to have the lowest production. Milk protein percentage did not differ between the groups, although group M was usually lowest. The calculated energy balance was in agreement with liveweight changes. (Abstract retrieved from CAB Abstracts by CABI’s permission)

A feeding trial was carried out with 56 dairy cows during 1st 18 weeks of lactation. Rations consisted of 40% grass and maize silage (in a 50:50 ratio) and 60% concentrates based entirely on by-products (beet pulp, maize gluten feed and brewers' grains) and were offered ad lib. 60% (on DM basis) of concentrates were given either ensiled (WET) or dehydrated (DRY). Half of the cows receiving WET or DRY diets also received an additive containing approx. 80 g of calcium salts of iso-butyrate, 2-methyl butyrate, 3-methyl butyrate and valerate. No significant effects of additive on feed intake, milk yield and milk composition were found. Feed, energy and protein intake and milk protein production were significantly lower after feeding WET diet compared with DRY diet. (Abstract retrieved from CAB Abstracts by CABI’s permission)

The 9 cows used in the preceding trial [see DSA 39, 2470] were allocated during the dry period (approx. 8 wk) to 3 levels of aldrin, heptachlor and beta -hexachlorocyclohexane ( beta -BHC) mixed with the concentrate ration. The daily dosages/cow were (i) 0.5, (ii) 1 or (iii) 2 mg of each pesticide. Because the date of parturition could only be predicted roughly, the dry period/cow varied resulting in large differences in total doses for cows within a group; mean total dose of each pesticide was (i) 26, (ii) 56 and (iii) 87 mg/cow. The pesticide levels in milk fat after parturition did not only represent the effect during the dry period because the cows had also been dosed with pesticides late in the preceding lactation. Aldrin and heptachlor residues in milk fat were below the detection limit of 0.01 mg/kg and content of beta -heptachlor epoxide was

1. To investigate the transfer of aldrin, heptachlor and beta -hexachlorocylohexane ( beta -HCH) from feed to milk and body fat of dairy cows, 9 cows early and 9 cows late in lactation were assigned to groups of 3 and given different daily dosages of a mixture of pesticides: 1 mg, 2 mg or 4 mg each of aldrin, heptachlor and beta -HCH/cow daily for 4 weeks. Milk fat and body fat samples were analysed for pesticide content. Aldrin and heptachlor could not be detected in milk fat or in body fat. Average contents of beta -heptachlorepoxide were below 0.1 mg/kg even for the highest dosage. The beta -HCH and dieldrin contents in milk fat increased rapidly. The ratio of contents between the groups roughly corresponded to that between the dosages. The cows early in lactation did not have less beta -HCH and dieldrin than the cows late in lactation. During the first 14 days after withdrawal the contents of beta -HCH and dieldrin usually decreased by more than half. The average transfer coefficients for cows late in lactation were all below 10% and for cows early in lactation about 3 times as high, because yield of milk fat was nearly 3 times as high early in lactation. The pesticide contents in body fat too increased but did not reach the same level as in milk fat. Cows early in lactation usually had higher contents in body fat than cows late in lactation. An estimate of the average relative mass of beta -HCH and dieldrin in milk fat and body fat is given. (Abstract retrieved from CAB Abstracts by CABI’s permission)

1. In a 3 X 3 Latin square design 9 cows were given long hay and a concentrate without supplemental fat or with 12% fat (11% tallow and 1% palm kernel oil) mixed with other ingredients or adsorbed on a carrier of Palabora vermiculite. During the 3rd week of treatment milk production was 21.4, 23.5 and 22.6 kg daily, respectively. With both fat-supplemented concentrates, milk fat content increased initially but then decreased sharply and was 3.55, 3.18 and 3.91% in week 3. At the same time protein was 3.19, 3.07 and 3.09%. Feed intake of cows given the fat supplements decreased. (Abstract retrieved from CAB Abstracts by CABI’s permission)

BRCA2; DNA damage responses; Pyridostatin BRCA2; Respostes al dany de l'ADN; Piridostatina BRCA2; Respuestas al daño del ADN; Piridotatina The cells with compromised BRCA1 or BRCA2 (BRCA1/2) function accumulate stalled replication forks, which leads to replication-associated DNA damage and genomic instability, a signature of BRCA1/2-mutated tumours. Targeted therapies against BRCA1/2-mutated tumours exploit this vulnerability by introducing additional DNA lesions. Because homologous recombination (HR) repair is abrogated in the absence of BRCA1 or BRCA2, these lesions are specifically lethal to tumour cells, but not to the healthy tissue. Ligands that bind and stabilise G-quadruplexes (G4s) have recently emerged as a class of compounds that selectively eliminate the cells and tumours lacking BRCA1 or BRCA2. Pyridostatin is a small molecule that binds G4s and is specifically toxic to BRCA1/2-deficient cells in vitro. However, its in vivo potential has not yet been evaluated. Here, we demonstrate that pyridostatin exhibits a high specific activity against BRCA1/2-deficient tumours, including patient-derived xenograft tumours that have acquired PARP inhibitor (PARPi) resistance. Mechanistically, we demonstrate that pyridostatin disrupts replication leading to DNA double-stranded breaks (DSBs) that can be repaired in the absence of BRCA1/2 by canonical non-homologous end joining (C-NHEJ). Consistent with this, chemical inhibitors of DNA-PKcs, a core component of C-NHEJ kinase activity, act synergistically with pyridostatin in eliminating BRCA1/2-deficient cells and tumours. Furthermore, we demonstrate that pyridostatin triggers cGAS/STING-dependent innate immune responses when BRCA1 or BRCA2 is abrogated. Paclitaxel, a drug routinely used in cancer chemotherapy, potentiates the in vivo toxicity of pyridostatin. Overall, our results demonstrate that pyridostatin is a compound suitable for further therapeutic development, alone or in combination with paclitaxel and DNA-PKcs inhibitors, for the benefit of cancer patients carrying BRCA1/2 mutations. Research in A.B. laboratory is supported by grants of Italian Association for Cancer Research (AIRC # 21579), Ministry of Health (CO 2019-12369662) and from IRCCS-Regina Elena Cancer Institute. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 722729 (F.J.G.). Research in M.T. laboratory is supported by Cancer Research UK (DRCPGM\100001), Medical Research Council and University of Oxford. A.R. received support from the UK Medical Research Council grant MC_PC_12006. V.S. received support from Instituto de Salud Carlos III (CPII19/00033, PI17/01080), GHD pink and the FERO Foundation.