Monoclonal antibodies obtained through insect brain homogenates: Tools for cell-specific neuroanatomical studies in the Colorado potato beetle

Immunization of mice with crude or purified homogenates of brain and endocrine organs of the Colorado potato beetle, Leptinotarsa decemlineata (Say), generated antibodies against specific antigens in the insect tissue. Hybridomas were prepared and screened immunocytochemically for the production of monoclonal antibodies (MAB) that recognized specific cells and that were useful for neuroanatomical studies. A relatively high proportion of MABs recognized one or more cells or tissues in neuronal, neuroendocrine or nonneural compartments of the brain or in fatbody or haemocytes, using standard immunocytochemical procedures. We could make a clear differentiation in subsets of neurons (both normal and peptidergic) and neuron-specific neuroglial cells. A full account of the obtained responses is given. The preparation of the immunogen and the immunization protocol affects the selection of MABs produced. It is argued that not all possibilities have been exploited and that continued experiments would probably increase the number of selective MABs.

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Résumé L'utilisation de techniques immunocytochimiques lors d'études neuro-anatomiques est encore dans l'enfance par suite de l'absence de données sur la chimie de structures spécifiques et, par conséquent, de l'absence d'anticorps spécifiques d'antigènes et de tissus. Nous apportons la preuve que de nombreuses substances réelles d'homogénats bruts de cerveaux sont de bons antigènes et que les souris peuvent être induites à produire des anticorps contre ceux-ci. Nous avons produit et testé de nombreux anticorps monoclonaux qui reconnaissent ces antigènes sur des lames de microscope, en utilisant des techniques immunocytochimiques courantes ou plus élaborées.Les immunogènes ont été préparés de différentes façons pour examiner si le taux de mélange de tissus du cerveau et/ou des ganglions associés et de glandes endocrines, et si les procédés ultérieurs de purification et d'immunisation, influeraient sur la spécificité des anticorps. L'intégralité de l'ensemble cerveau-glandes endocrines a été le plus immunogénique quand l'homogénat a subi le minimum de manipulations. Une grande diversité d'anticorps a été obtenue après des injections répétées chez la souris. Ces anticorps reconnaissent les épitopes dans toutes les catégories de tissus considérés, c'est-à-dire, les tissus spécifiquement nerveux, neuro-endocrines, et non nerveux. La purification progressive et le cross-linking des constituants de l'homogénat réduisent la variabilité des anticorps. Tout en l'espérant, on ne s'attendait pas à ce que les substances jusqu'alors dans des centres peptidergiques indéfinis fussent parmi les structures les plus souvent identifiées. Les chances de produire de tels anticorps spécifiques de peptides ont augmenté quand les tissus endocrines ont servi d'immunogènes.Nous avons résumé les types de tissus et de cellules mis en évidence par cette sélection d'anticorps monoclonaux. Nous soulignons que l'expérimentateur peut difficilement influencer les préférences du système immunologique de la souris, mais les anticorps produits jusqu'ici sont valables pour les études neuroanatomiques et pour la récolte d'antigènes intéressants à partir de procédés biochimiques de séparation. Il reste à explorer la spécificité sensu stricto des anticorps.

     

National Development Generates National Identities

The purpose of the article is to test the relationship between national identities and modernisation. We test the hypotheses that not all forms of identity are equally compatible with modernisation as measured by Human Development Index. The less developed societies are characterised by strong ascribed national identities based on birth, territory and religion, but also by strong voluntarist identities based on civic features selected and/or achieved by an individual. While the former decreases with further modernisation, the latter may either decrease or remain at high levels and coexist with instrumental supranational identifications, typical for the most developed countries. The results, which are also confirmed by multilevel regression models, thus demonstrate that increasing modernisation in terms of development contributes to the shifts from classical, especially ascribed, identities towards instrumental identifications. These findings are particularly relevant in the turbulent times increasingly dominated by the hardly predictable effects of the recent mass migrations.     

Targeted In Vivo Inhibition of Specific Protein–Protein Interactions Using Recombinant Antibodies

With the growing availability of genomic sequence information, there is an increasing need for gene function analysis. Antibody-mediated “silencing” represents an intriguing alternative for the precise inhibition of a particular function of biomolecules. Here, we describe a method for selecting recombinant antibodies with a specific purpose in mind, which is to inhibit intrinsic protein–protein interactions in the cytosol of plant cells. Experimental procedures were designed for conveniently evaluating desired properties of recombinant antibodies in consecutive steps. Our selection method was successfully used to develop a recombinant antibody inhibiting the interaction of ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 3 with such of its upstream interaction partners as the receiver domain of CYTOKININ INDEPENDENT HISTIDINE KINASE 1. The specific down-regulation of the cytokinin signaling pathway in vivo demonstrates the validity of our approach. This selection method can serve as a prototype for developing unique recombinant antibodies able to interfere with virtually any biomolecule in the living cell.     

Numerical aspects of optimal control of penicillin production

Since their discovery, fermentation processes have gone along not only with the industrial beverages production and breweries, but since the times of Alexander Fleming, they have become a crucial part of the health care due to antibiotics production. However, complicated dynamics and strong nonlinearities cause that the production with the use of linear control methods achieves only suboptimal yields. From the variety of nonlinear approaches, gradient method has proved the ability to handle these issues—nevertheless, its potential in the field of fermentation processes has not been revealed completely. This paper describes constant vaporization control strategy based on a double-input optimization approach with a successful reduction to a single-input optimization task. To accomplish this, model structure used in the previous work is modified so that it corresponds with the new optimization strategy. Furthermore, choice of search step is explored and various alternatives are evaluated and compared.     

Genetic differentiation and phenotypic plasticity in Plantago major ssp major. I. The effect of differences in level of irradiance on growth, photosynthesis, respiration and chlorophyll content

Growth, root respiration, photosynthesis, dark respiration, chlorophyll content and chlorophyll alb ratio were followed in two genotypes of Plantago major L. ssp major L., originating from an exposed and a shaded habitat, respectively, at two levels of irradiance. In addition, responses of these processes to a transfer of plants from one light condition to the other were studied. Genetic differentiation between the two genotypes was reflected in growth rate, photosynthetic activity, dark respiration and chlorophyll content. Individuals of the genotype originating from a shaded habitat were less inhibited by low irradiance: growth was less depressed at low irradiance, while the genotype of the exposed habitat seemed to be more restricted to exposed conditions. The adaptive plastic response of growth and physiological parameters upon an alteration in irradiance was very small. The shoot to root ratio was a stable plant characteristic in these experiments. Plants of both genotypes were probably damaged after a transfer from the low to the high level of irradiance; the growth of these plants was not stimulated by high irradiance, and the photosynthetic activity was even decreased. Plants, which were transferred to the low level of irradiance, showed an immediate effect of the change and no adaptive response was observed. Obviously, the ability to perform adaptive plastic responses, which was demonstrated in the non-transferred plants after pretreatment, had been lost during the experiment and was confined to the seedling stage of individuals of the two genotypes.     

Ionophorous polymers. Interaction with polynucleotides and effects on RNA-directed DNA polymerase activity.

Poly(vinylbenzo-18-crown-6), a water-soluble polymer endowed with ion-binding crown moieties as pendent groups, forms insoluble complexes with polyadenylate in the presence of K+; the corresponding monomeric benzo-18-crown-6, does not form a precipitate under the same conditions. In the presence of Na+ and Mn2+ which in aqueous solution complex weakly to crown compounds, no coprecipitation of the crown polymer and polyadenylate occurs; nevertheless, the crown polymer strongly binds to immobilized polyadenylate even under these conditions. The interactions of crown polymer with the poly-nucleotide result in a loss of templating ability of the latter. Using RNA-dependent DNA polymerase of murine leukemia virus it was found that (1) enzymatic action is efficiently inhibited even in the absence of ions which coprecipitate crown polymer and template, (2) inhibition is reversed by addition of excess polynucleotide and (3) monomeric crown does not inhibit the reaction.