382 research outputs found

    Performance and diarrhoea in piglets following weaning at seven weeks of age: Challenge with E. coli O 149 and effect of dietary factors

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    Four dietary factors (ad libitum versus feed restriction, control versus protein restriction at ad libitum feeding, control versus inclusion of lupine as a protein source at ad libitum feeding, and control versus extra vitamin E at ad libitum feeding) were tested in four separate experiments for the effect on diarrhoea. To introduce a diarrhoea-like condition, half of the piglets were challenged with an inoculation of an E. coli O 149 dose of 1 x 108 colony forming units on day two and three after weaning (day of weaning = day one). All piglets were susceptible since the dams were tested mono-zygotic susceptible to the attachment site of E. coli O 149 in the intestines. Each of the four experiments included 32 piglets from 4 sows. The design was 2 x 2 factorial with dietary factor and E. coli O 149 challenge as the two factors, each at two levels. The piglets were housed individually during the experiment which lasted for 10 days from weaning at 7 weeks of age. The daily recordings included feed intake, weight and faeces score (from 1 = firm and solid to 6 = yellow and watery). Faeces from days 2 to 5 were tested for E. coli strains. In addition, blood was sampled and serum was analysed for E. coli antibodies, IgG and IgM. Generally the E. coli challenge had no effect on growth and feed intake whereas faeces score and number of faeces haemolytic bacteria increased and faeces dry matter decreased. Feed restriction decreased the weight gain while faeces characteristics were unaffected. An analysis including all four experiments revealed that a feed intake of less than 200 g day one after weaning seems to be associated with a relatively high incidence of a post-weaning diarrhoea-like condition. Protein restriction decreased faeces score and increased faeces dry matter while weight gain tended to decrease. Inclusion of lupine affected neither weight gain nor faeces characteristics. Extra vitamin E did not affect weight gain while faeces dry matter decreased, and faeces score and number of faecal haemolytic bacteria increased. The dietary treatments had no effect on the immunological responses. In conclusion, the studied dietary factors could not alleviate a diarrhoea-like condition and at the same time maintain the growth rate. Furthermore, the results indicate that performance can be improved if piglets achieve a daily feed intake of at least 200 g from day one after weaning

    Nonlinear Stress Fluctuation Dynamics of Sheared Disordered Wet Foam

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    Sheared wet foam, which stores elastic energy in bubble deformations, relaxes stress through bubble rearrangements. The intermittency of bubble rearrangements in foam leads to effectively stochastic drops in stress that are followed by periods of elastic increase. We investigate global characteristics of highly disordered foams over three decades of strain rate and almost two decades of system size. We characterize the behavior using a range of measures: average stress, distribution of stress drops, rate of stress drops, and a normalized fluctuation intensity. There is essentially no dependence on system size. As a function of strain rate, there is a change in behavior around shear rates of 0.07s10.07 {\rm s^{-1}}.Comment: accepted to Physical Review

    Abnormal increase in urinary aquaporin-2 excretion in response to hypertonic saline in essential hypertension

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    <p>Abstract</p> <p>Background</p> <p>Dysregulation of the expression/shuttling of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in renal collecting duct principal cells has been found in animal models of hypertension. We tested whether a similar dysregulation exists in essential hypertension.</p> <p>Methods</p> <p>We measured urinary excretion of AQP2 and ENaC β-subunit corrected for creatinine (u-AQP2<sub>CR</sub>, u-ENaC<sub>β-CR</sub>), prostaglandin E2 (u-PGE<sub>2</sub>) and cyclic AMP (u-cAMP), fractional sodium excretion (FE<sub>Na</sub>), free water clearance (C<sub>H2O</sub>), as well as plasma concentrations of vasopressin (AVP), renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), and atrial and brain natriuretic peptide (ANP, BNP) in 21 patients with essential hypertension and 20 normotensive controls during 24-h urine collection (baseline), and after hypertonic saline infusion on a 4-day high sodium (HS) diet (300 mmol sodium/day) and a 4-day low sodium (LS) diet (30 mmol sodium/day).</p> <p>Results</p> <p>At baseline, no differences in u-AQP2<sub>CR </sub>or u-ENaC<sub>β-CR </sub>were measured between patients and controls. U-AQP2<sub>CR </sub>increased significantly more after saline in patients than controls, whereas u-ENaC<sub>β-CR </sub>increased similarly. The saline caused exaggerated natriuretic increases in patients during HS intake. Neither baseline levels of u-PGE<sub>2</sub>, u-cAMP, AVP, PRC, Ang II, Aldo, ANP, and BNP nor changes after saline could explain the abnormal u-AQP2<sub>CR </sub>response.</p> <p>Conclusions</p> <p>No differences were found in u-AQP2<sub>CR </sub>and u-ENaC<sub>β-CR </sub>between patients and controls at baseline. However, in response to saline, u-AQP2<sub>CR </sub>was abnormally increased in patients, whereas the u-ENaC<sub>β-CR </sub>response was normal. The mechanism behind the abnormal AQP2 regulation is not clarified, but it does not seem to be AVP-dependent.</p> <p>Clinicaltrial.gov identifier</p> <p><a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=00345124">NCT00345124</a>.</p

    Supervised and non-supervised Nordic walking in the treatment of chronic low back pain: a single blind randomized clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Active approaches including both specific and unspecific exercise are probably the most widely recommended treatment for patients with chronic low back pain but it is not known exactly which types of exercise provide the most benefit. Nordic Walking - power walking using ski poles - is a popular and fast growing type of exercise in Northern Europe that has been shown to improve cardiovascular metabolism. Until now, no studies have been performed to investigate whether Nordic Walking has beneficial effects in relation to back pain.</p> <p>Methods</p> <p>A total of 151 patients with low back and/or leg pain of greater than eight weeks duration were recruited from a hospital based outpatient back pain clinic. Patients continuing to have pain greater than three on the 11-point numeric rating scale after a multidisciplinary intervention were included. Fifteen patients were unable to complete the baseline evaluation and 136 patients were randomized to receive A) Nordic walking supervised by a specially trained instructor twice a week for eight weeks B) One-hour instruction in Nordic walking by a specially trained instructor followed by advice to perform Nordic walking at home as much as they liked for eight weeks or C) Individual oral information consisting of advice to remain active and about maintaining the daily function level that they had achieved during their stay at the backcenter. Primary outcome measures were pain and disability using the Low Back Pain Rating Scale, and functional limitation further assessed using the Patient Specific Function Scale. Furthermore, information on time off work, use of medication, and concurrent treatment for their low back pain was collected. Objective measurements of physical activity levels for the supervised and unsupervised Nordic walking groups were performed using accelerometers. Data were analyzed on an intention-to-treat basis.</p> <p>Results</p> <p>No mean differences were found between the three groups in relation to any of the outcomes at baseline. For pain, disability, and patient specific function the supervised Nordic walking group generally faired best however no statistically significant differences were found. Regarding the secondary outcome measures, patients in the supervised group tended to use less pain medication, to seek less concurrent care for their back pain, at the eight-week follow-up. There was no difference between physical activity levels for the supervised and unsupervised Nordic walking groups. No negative side effects were reported.</p> <p>Conclusion</p> <p>We did not find statistically significant differences between eight weeks of supervised or unsupervised Nordic walking and advice to remain active in a group of chronic low back pain patients. Nevertheless, the greatest average improvement tended to favor the supervised Nordic walking group and - taking into account other health related benefits of Nordic walking - this form of exercise may potentially be of benefit to selected groups of chronic back pain patients.</p> <p>Trial registration</p> <p><url>http://www.ClinicalTrials.gov</url> # NCT00209820</p

    Vitamin D Binding Protein Genotype and Osteoporosis

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    Osteoporosis is a bone disease leading to an increased fracture risk. It is considered a complex multifactorial genetic disorder with interaction of environmental and genetic factors. As a candidate gene for osteoporosis, we studied vitamin D binding protein (DBP, or group-specific component, Gc), which binds to and transports vitamin D to target tissues to maintain calcium homeostasis through the vitamin D endocrine system. DBP can also be converted to DBP-macrophage activating factor (DBP-MAF), which mediates bone resorption by directly activating osteoclasts. We summarized the genetic linkage structure of the DBP gene. We genotyped two single-nucleotide polymorphisms (SNPs, rs7041 = Glu416Asp and rs4588 = Thr420Lys) in 6,181 elderly Caucasians and investigated interactions of the DBP genotype with vitamin D receptor (VDR) genotype and dietary calcium intake in relation to fracture risk. Haplotypes of the DBP SNPs correspond to protein variations referred to as Gc1s (haplotype 1), Gc2 (haplotype 2), and Gc1f (haplotype3). In a subgroup of 1,312 subjects, DBP genotype was found to be associated with increased and decreased serum 25-(OH)D3 for haplotype 1 (P = 3 × 10−4) and haplotype 2 (P = 3 × 10−6), respectively. Similar associations were observed for 1,25-(OH)2D3. The DBP genotype was not significantly associated with fracture risk in the entire study population. Yet, we observed interaction between DBP and VDR haplotypes in determining fracture risk. In the DBP haplotype 1-carrier group, subjects of homozygous VDR block 5-haplotype 1 had 33% increased fracture risk compared to noncarriers (P = 0.005). In a subgroup with dietary calcium intake <1.09 g/day, the hazard ratio (95% confidence interval) for fracture risk of DBP hap1-homozygote versus noncarrier was 1.47 (1.06–2.05). All associations were independent of age and gender. Our study demonstrated that the genetic effect of the DBP gene on fracture risk appears only in combination with other genetic and environmental risk factors for bone metabolism
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