Biosensor assay for determination of haptoglobin in bovine milk

Despite more than 30 years of research into mastitis diagnostics, there are few alternatives to the somatic cell count (SCC) in practical use for identification of cows with subclinical mastitis. Mastitis is not only an animal welfare problem, but also affects the yield, composition and technological properties of milk. Hence, dairy cooperatives give farmers a premium quality payment to encourage low SCC although there is no clear scientific data defining the level of SCC in bulk tank milk that is associated with additional benefits in terms of milk quality. Recent research on alternative markers for inflammatory reactions in the lactating cow, e.g. in mastitis, includes investigations of the acute phase protein, haptoglobin (Hp). So far, the content of Hp in milk has mainly been studied in relation to mastitis diagnostics, with little attention given to its importance for milk composition and technological properties. At present, Hp in milk is measured using ELISA, but this technique is not suitable for routine large-scale analysis. In recent years, optical biosensor technology has been used for automated and rapid quantitative analysis of different components in milk, but so far not for analysis of acute phase proteins. The aim of the present study was to develop a rapid and sensitive biosensor method to determine Hp in milk. An affinity sensor assay based on the interaction between Hp and haemoglobin was developed using surface plasmon resonance (SPR) biosensor technology. The assay was used to analyse Hp in composite milk samples from cows without any clinical signs of mastitis and quarter milk samples with a weak to strong reaction in the California Mastitis Test (CMT). A commercial ELISA for determination of Hp in milk was used for comparison. The limit of detection (LOD) of the biosensor assay was determined as 1.1 mg/l. Within-assay and betweenday variations were determined both with bulk tank milk spiked with human Hp and with composite milk samples containing bovine Hp. Coefficients of variation varied between 3.6 and 8.6% at concentrations between 4.0 and 12 mg/l, respectively. Agreement between the results obtained by the biosensor assay and the ELISA was satisfactory ; however, the results obtained by the biosensor were generally lower than the results obtained by the ELISA. Possible explanations for this observation are discussed

The interdisciplinary decision problem : Popperian optimism and Kuhnian pessimism in forestry

Interdisciplinary research in the fields of forestry and sustainability studies often encounters seemingly incompatible ontological assumptions deriving from natural and social sciences. The perceived incompatibilities might emerge from the epistemological and ontological claims of the theories or models directly employed in the interdisciplinary collaboration, or they might be created by other epistemological and ontological assumptions that these interdisciplinary researchers find no reason to question. In this paper we discuss the benefits and risks of two possible approaches, Popperian optimism and Kuhnian pessimism, to interdisciplinary knowledge integration where epistemological and ontological differences between the sciences involved can be expected.Peer reviewe

Loss of size-selectivity at histamine-induced exudation of plasma proteins in atopic nasal airways.

Plasma proteins occur in the airway lumen in inflammatory airway diseases. This study tests the hypothesis that airway microvascular-epithelial exudation of plasma proteins, as induced by a non-injurious inflammatory mediator, is characterized by loss of size-selectivity. Using a nasal pool-device, the nasal mucosa of 10 allergic individuals, without current disease, was sequentially exposed to saline and histamine (40 and 400 microg ml(-1)). Nasal lavage fluid and blood-levels of albumin (69 kD) and alpha2-macroglobulin (720 kD) were determined. Histamine produced concentration-dependent exudation of albumin and alpha2-macroglobulin. The albumin/alpha2-macroglobulin concentration ratio of the saline lavage fluid (baseline) was 40+/-19. However, at the histamine challenges the ratios were 25+/-3 and 22+/-2, respectively, which did not differ from that of circulating plasma (22+/-2). We conclude that there is minor and size-selective luminal entry of plasma proteins at baseline. However, at concentration-dependent exudative responses to histamine, plasma proteins enter the airway lumen without being sieved. These data indicate that inflammatory stimulus-induced extravasation, lamina propria distribution and paracellular epithelial passage of plasma occur with minimal size-selectivity. Inferentially, the full immunological capacity of plasma proteins may readily be made available at the surface of human intact airway mucosa

Why resilience is unappealing to social science : Theoretical and empirical investigations of the scientific use of resilience

Resilience is often promoted as a boundary concept to integrate the social and natural dimensions of sustainability. However, it is a troubled dialogue from which social scientists may feel detached. To explain this, we first scrutinize the meanings, attributes, and uses of resilience in ecology and elsewhere to construct a typology of definitions. Second, we analyze core concepts and principles in resilience theory that cause disciplinary tensions between the social and natural sciences (system ontology, system boundary, equilibria and thresholds, feedback mechanisms, self-organization, and function). Third, we provide empirical evidence of the asymmetry in the use of resilience theory in ecology and environmental sciences compared to five relevant social science disciplines. Fourth, we contrast the unification ambition in resilience theory with methodological pluralism. Throughout, we develop the argument that incommensurability and unification constrain the interdisciplinary dialogue, whereas pluralism drawing on core social scientific concepts would better facilitate integrated sustainability research.Peer reviewe

Nine-Tenths of the Law: The English Copyright Debates and the Rhetoric of the Public Domain

Background: The role of vitamin D supplementation as adjuvant treatment of tuberculosis (TB) has lately attracted increasing interest. Our aim was to investigate the capacity of alveolar macrophages (AMs) from patients with or without exposure to TB to control intracellular growth of virulent Mycobacterium tuberculosis (Mtb). Methods: AMs were freshly harvested from the bronchoalveolar lavage fluid of 7 patients with a history of TB (4 patients with previous TB and 3 patients with current TB) and 4 non-TB subjects. The H37Rv strain, genetically modified to express Vibrio harveyi luciferase, was used to determine the growth of Mtb by luminometry in the AMs from study subjects. Cytokine levels in culture supernatants were determined using a flow cytometry-based bead array technique. Results: AMs from patients with a TB history were less efficient in restricting Mtb growth. Stimulation with 100 nM1, 25-dihydroxyvitamin D (1,25D3) did not significantly influence the capacity of AMs from any study subjects to control the infection. Out of the cytokines evaluated (TNF-α, IL-1β, IL-10 and IL-12p40) only TNF-α demonstrated detectable levels in culture supernatants, but did not respond to stimulation with 1,25D3. Conclusions: We conclude that AMs of TB-patients show reduced ability to control mycobacterial growth in vitro, and, that AMs in this pilot study do no respond to 1, 25D3-stimulation. The former observation supports the concept that innate immunity is crucial for the control of TB infection

Nasal neutrophil activity and mucinous secretory responsiveness in COPD.

Patients with chronic obstructive pulmonary disease (COPD) frequently report nasal symptoms. In the present study, we have examined whether or not COPD is associated with any nasal inflammation. Plasma exudation evoked by histamine challenges has been employed to improve the recovery of inflammatory indices in nasal lavage fluids. In 23 COPD-patients and 26 healthy subjects, all without history or signs of allergic rhinitis, nasal polyposis, or chronic rhinosinusitis, nasal saline-lavages were performed with and without histamine. alpha2-Macroglobulin, fucose, eosinophil cationic protein (ECP) and myeloperoxidase (MPO) were determined as indices of plasma exudation, mucinous secretion, eosinophil activity and neutrophil activity, respectively. The difference in MPO-levels between the histamine and the saline lavage was greater in COPD patients compared with healthy subjects (P<0·05). Also, COPD patients reporting nasal symptoms presented an increase in MPO at histamine challenge (P<0·05, cf. saline) and greater differences in MPO and fucose, respectively, between the histamine and the saline lavage (P<0·05, cf. patients without symptoms). We conclude that COPD is not associated with any marked nasal inflammation. However, our observation on increased MPO-levels at histamine challenge suggests some degree of increased neutrophil activity in this condition. Furthermore, when associated with nasal symptoms, COPD may be associated with an increased nasal secretory responsiveness

In Vitro Evolution of Antibodies Inspired by In Vivo Evolution

In vitro generation of antibodies often requires variable domain sequence evolution to adapt the protein in terms of affinity, specificity, or developability. Such antibodies, including those that are of interest for clinical development, may have their origins in a diversity of immunoglobulin germline genes. Others and we have previously shown that antibodies of different origins tend to evolve along different, preferred trajectories. Apart from substitutions within the complementary determining regions, evolution may also, in a germline gene-origin-defined manner, be focused to residues in the framework regions, and even to residues within the protein core, in many instances at a substantial distance from the antibody’s antigen-binding site. Examples of such germline origin-defined patterns of evolution are described. We propose that germline gene-preferred substitution patterns offer attractive alternatives that should be considered in efforts to evolve antibodies intended for therapeutic use with respect to appropriate affinity, specificity, and product developability. We also hypothesize that such germline gene-origin-defined in vitro evolution hold potential to result in products with limited immunogenicity, as similarly evolved antibodies will be parts of conventional, in vivo-generated antibody responses and thus are likely to have been seen by the immune system in the past

Do intraspecific or interspecific interactions determine responses to predators feeding on a shared size‐structured prey community?

Summary Coexistence of predators that share the same prey is common. This is still the case in size‐structured predator communities where predators consume prey species of different sizes (interspecific prey responses) or consume different size classes of the same species of prey (intraspecific prey responses). A mechanism has recently been proposed to explain coexistence between predators that differ in size but share the same prey species, emergent facilitation, which is dependent on strong intraspecific responses from one or more prey species. Under emergent facilitation, predators can depend on each other for invasion, persistence or success in a size‐structured prey community. Experimental evidence for intraspecific size‐structured responses in prey populations remains rare, and further questions remain about direct interactions between predators that could prevent or limit any positive effects between predators [e.g. intraguild predation (IGP)]. Here, we provide a community‐wide experiment on emergent facilitation including natural predators. We investigate both the direct interactions between two predators that differ in body size (fish vs. invertebrate predator), and the indirect interaction between them via their shared prey community (zooplankton). Our evidence supports the most likely expectation of interactions between differently sized predators that IGP rates are high, and interspecific interactions in the shared prey community dominate the response to predation (i.e. predator‐mediated competition). The question of whether emergent facilitation occurs frequently in nature requires more empirical and theoretical attention, specifically to address the likelihood that its pre‐conditions may co‐occur with high rates of IGP. </jats:p