Comparison of dimethyl dioctadecyl ammonium bromide, Freund's complete adjuvant and mineral oil for induction of humoral antibodies, cellular immunity and resistance to Newcastle disease virus in chickens

Abstract Dimethyl diotadecyl ammonium bromide (DDA), a lipophilic quaternary amine, was evaluated in adult chickens for potentiation of immunological responses to subcutaneously administered inactivated Newcastle disease virus (NDV) vaccines. DDA enhanced humoral and cell-mediated immune (CMI) responses to levels which were significantly higher than those induced by the vaccine alone The haemagglutination inhibition antibody titers induced by DDA were slightly lower than those induced by mineral oil although neutralizing antibody titers seemed to be higher. DDA induced strong CMI (DTH and lymphocyte proliferation) responses, more than those induced by Freund's complete adjuvant and mineral oil. Both DDA and mineral oil induced comparable high levels of protection to challenge doses of 200 000 LD₅₀ per chicken. No toxic effects or local tissue damage were observed in any of the inoculated chickens.     

Soluble trinitrophenylated proteins and trinitrophenylated cells as specific inhibitors of target cell lysis by cytotoxic T lymphocytes.

Bovine serum albumin (BSA) substituted in 12 to 15 amino groups with 2,4,6-trinitrophenyl (Tnp-BSA) or carbobenzoxy (Cbz-BSA) or acetyl (Ac-BSA) groups was tested as inhibitor of the reaction in which anti-Tnp cytotoxic T lymphocytes (CTLs) lysed syngeneic ⁵¹Cr-labeled Tnp-modified spleen cells [concanavalin A (Con A) blasts]. Inhibition was observed with some consistency only with Tnp-BSA at extremely high concentration (50 mg/ml). To explore the significance of this observation, inhibition of anti-Tnp CTLs was also tested with Tnp-modified cells on which products of the major histocompatibility loci H-2K and H-2D were lacking or different from those on the stimulator cells used to elicit the CTLs. Only those Tnp cells with the same H-2 products as the stimulators were inhibitory, even though all the Tnp cells tested had essentially the same surface density of Tnp (ca 1 × 10⁸ groups/cell). It is concluded that effective specific inhibitors of anti-Tnp CTLs have both Tnp groups and the correct H-2 products on the same particle and that the specific inhibitory activity of soluble Tnp-BSA was probably due to its adsorption onto cells in the suspensions used to assay cytotoxicity.     

Increase in lipid fluidity of cellular membranes induced by adsorption of RNA and DNA virions.

Changes in the dynamic behavior of membrane lipids of mammalian cells induced by adsorption of animal viruses were quantitatively monitored by fluorescence polarization analysis with the aid of the fluorescent probe 1,6-diphenyl 1,3,5-hexatriene embedded in the surface membrane lipid core of intact cells. Adsorption of encephalomyocarditis, West Nile, and polyoma viruses to hamster (baby hamster kidney) and mouse (3T3) cells is accompanied by a rapid and significant increase in the degree of fluidity of membrane lipids of the infected cells. These changes in membrane fluidity, which are virus dose dependent, are inhibited by low temperature and by treatment of the cells before-hand with compounds known to block viral receptors on the cell surface. It is suggested that increase in membrane lipid fluidity, induced by the adsorption of virions, is an early event in the process of cell-virus interactions.     

Large herbivores facilitate an insect herbivore by modifying plant community composition in a temperate grassland

Large herbivores often co‐occur and share plant resources with herbivorous insects in grassland ecosystems; yet, how they interact with each other remains poorly understood. We conducted a series of field experiments to investigate whether and how large domestic herbivores (sheep; Ovis aries) may affect the abundance of a common herbivorous insect (aphid; Hyalopterus pruni) in a temperate grassland of northeast China. Our exclosure experiment showed that 3 years (2010–2012) of sheep grazing had led to 86% higher aphid abundance compared with ungrazed sites. Mechanistically, this facilitative effect was driven by grazing altering the plant community, rather than by changes in food availability and predator abundance for aphids. Sheep significantly altered plant community by reducing the abundance of unpalatable forbs for the aphids. Our small‐scale forb removal experiment revealed an “associational plant defense” by forbs which protect the grass Phragmites australis from being attacked by the aphids. However, selective grazing on forbs by sheep indirectly disrupted such associational plant defense, making P. australis more susceptible to aphids, consequentially increasing the density of aphids. These findings provide a novel mechanistic explanation for the effects of large herbivores on herbivorous insects by linking selective grazing to plant community composition and the responses of insect populations in grassland ecosystems.     

The evolution of host plant manipulation by insects: molecular and ecological evidence from gall-forming aphids on Pistacia

One of the most striking characteristics of gall-forming insects is the variability in gall position, morphology, and complexity. Our knowledge of the driving forces behind the evolutionary divergence of gall types is limited. Natural enemies, competition, and behavioral constraints might be involved. We present a cladogram, based on sequences of COI and COII (1952bp), of mitochondrial DNA for the evolution of 14 species of gall-forming aphids (Fordinae). These insects induce five gall types with remarkable morphological variation on Pistacia spp. hosts. The parsimony cladogram divides the Fordinae into three lineages, Fordini and Baizongiini, and a third (new) sister group including the previously Fordini member, Smynthurodes betae (West). We then use ecological data to trace and explain the evolution of gall morphology. The aphids seem to have evolved gradually towards better ability to manipulate their host plant, induce stronger sinks, and gain higher reproductive success. We suggest that the ancestral gall type was a simple, open, "pea"-sized gall located on the leaflet midvein. Some Fordini and S. betae evolved a two-gall life cycle, inducing a new gall type on the leaflet margin. The Baizongiini improved the manipulation of their host by inducing larger galls near the midvein, with stronger sinks supporting thousands of aphids. Similar gall types are induced at similar sites on different Pistacia hosts suggesting control of the aphids on gall morphology and frequent host shifts. Thus, even extreme specialization (specific gall and host) is flexible.     

An adaptive neuro-fuzzy method (<Emphasis Type="Italic">ANFIS</Emphasis>) for estimating single-trial movement-related potentials

This study aims to recover transient, trial-varying evoked potentials (EPs), in particular the movement-related potentials (MRPs), embedded within the background cerebral activity at very low signal-to-noise ratios (SNRs). A new adaptive neuro-fuzzy technique will attempt to estimate movement-related potentials within multi-channel EEG recordings, enabling this method to completely adapt to each input sweep without system training procedures. We assume that one of the sensors is corrupted by noise deriving from other sensors via an unknown function that will be estimated. We will approach this problem by: (1) spatially decorrelating the sensors in the preprocessing phase, (2) choosing the most informative of the filtered channels that will permit the best MRP estimation (input-selection phase) and (3) training the neuro-fuzzy model to fit the noise over the chosen sensor and therefore estimating the buried MRP. We tested this framework with simulations to validate the analytical results before applying them to the real biological data. Whenever it is applied to biological data, this method improves the SNR by more than 12dB, even to very low SNRs. The processing method proposed here is likely to complement other estimation techniques and can be useful to process, enhance and analyse single-trial MRPs.     

Time dependent protection of amifostine from renal and hematopoietic cisplatin induced toxicity

Efficacy of chemotherapy may be maximized and its toxicity can be minimized if drugs would be administered at specified daily times. The present study was aimed to examine if the protection of amifostine against cisplatin toxicity is time dependent. Amifostine is an organic thiophosphate that protects selectively normal tissues, but not tumors, against the cytotoxicity of DNA binding chemotherapeutic agents such as cisplatin. ICR male mice which were entrained to Light:Dark (L:D) 14:10 were injected (intrapritoneal bolus) for 5 consecutive days with either: cisplatin, cisplatin plus amifostine (administered 30 minutes prior to cisplatin). Injections were given at either 08:00, 13:00, 20:00 or 01:00. Five days later, on day 10, each set of mice was sacrificed (at the same hour corresponds to the injection hour), blood count, blood creatinine and blood urea nitrogen (BUN) were assayed. Cisplatin treated mice exhibited nephrotoxicity, as indicated by increased blood urea nitrogen values and by high blood urea nitrogen to creatinine ratios, as well as myelotoxicity that was indicated by low levels of hemoglobin and platelets. Co-administration of amifostine-cisplatin reversed both, the nephrotoxicity of cisplatin, and its myelosuppressive effects. For BUN, hemoglobin and platelets, maximal protections were observed at 08:00, (p <0.05, p <0.01 and p <0.01 respectively). For BUN/Cr ratio (p <0.05), maximal protections was observed at 13:00. These findings show that amifostine exhibits time dependent protection against cisplatin toxicity and thus it is recommended to use the protector when treatments are given during morning hours. The results also further validate the notion that chronochemotherapy is advantageous at least in reducing drug toxicity and thus should be integrated in the design of clinical protocols.     

Combinatorial docking approach for structure prediction of large proteins and multi-molecular assemblies

Protein folding and protein binding are similar processes. In both, structural units combinatorially associate with each other. In the case of folding, we mostly handle relatively small units, building blocks or domains, that are covalently linked. In the case of multi-molecular binding, the subunits are relatively large and are associated only by non-covalent bonds. Experimentally, the difficulty in the determination of the structures of such large assemblies increases with the complex size and the number of components it contains. Computationally, the prediction of the structures of multi-molecular complexes has largely not been addressed, probably owing to the magnitude of the combinatorial complexity of the problem. Current docking algorithms mostly target prediction of pairwise interactions. Here our goal is to predict the structures of multi-unit associations, whether these are chain-connected as in protein folding, or separate disjoint molecules in the assemblies. We assume that the structures of the single units are known, either through experimental determination or modeling. Our aim is to combinatorially assemble these units to predict their structure. To address this problem we have developed CombDock. CombDock is a combinatorial docking algorithm for the structural units assembly problem. Below, we briefly describe the algorithm and present examples of its various applications to folding and to multi-molecular assemblies. To test the robustness of the algorithm, we use inaccurate models of the structural units, derived either from crystal structures of unbound molecules or from modeling of the target sequences. The algorithm has been able to predict near-native arrangements of the input structural units in almost all of the cases, suggesting that a combinatorial approach can overcome the imperfect shape complementarity caused by the inaccuracy of the models. In addition, we further show that through a combinatorial docking strategy it is possible to enhance the predictions of pairwise interactions involved in a multi-molecular assembly.