Septum volume and food‐storing behavior are related in parids

The hippocampal formation (HF) of food‐storing birds is larger than non‐storing species, and the size of the HF in food‐storing Black‐Capped Chickadees (Poecile atricapillus) varies seasonally. We examined whether the volume of the septum, a medial forebrain structure that shares reciprocal connections with the HF, demonstrates the same species and seasonal variation as has been shown in the HF. We compared septum volume in three parid species; non‐storing Blue Tits (Parus caeruleus) and Great Tits (Parus major), and food‐storing Black‐Capped Chickadees. We found the relative septum volume to be larger in chickadees than in the non‐storing species. We also compared septum and nucleus of the diagonal band (NDB) volume of Black‐Capped Chickadees at different times of the year. We found that the relative septum volume varies seasonally in food‐storing birds. The volume of the NDB does not vary seasonally. Due to the observed species and seasonal variation, the septum, like the hippocampal formation of food‐storing birds, may be specialized for some aspects of food‐storing and spatial memory. © 2002 Wiley Periodicals, Inc. J Neurobiol 51: 215–222, 2002     

Radioimmunoassay of low molecular weight human kininogen

A radioimmunoassay for low molecular weight (LMW) human Kininogen has been carried out. The first step was to prepare LMW Kininogen from human plasma. The proposed method allowed to get chemically pure and biologically active LMW Kininogen. This preparation was used to induce antibody. Optimal conditions for labelling and incubation were determined. This method may be applied to the assay of Kininogen in human plasma.     

Fast product formation and slow product release are important features in a hysteretic reaction mechanism of glutathione transferase T2-2.

The reaction mechanism of rat glutathione transferase T2-2 has been studied using pre-steady-state and steady-state kinetics. Several parts of the catalytic cycle including binding of substrates, product formation, and product release were investigated. Under saturating conditions, a two-step product release was found to be rate limiting in the enzyme-catalyzed reactions between the nucleophilic substrate glutathione and either of the two electrophilic substrates 1-menaphthyl sulfate and 4-nitrobenzyl chloride. The rate constant for pre-steady-state product formation on rat glutathione transferase T2-2 has an observed pK(a) value of 5.7 apparently due to ionization of the sulfhydryl group of glutathione. This rate constant is approximately 2 orders of magnitude higher than k(cat) at pH values of >6. It can be predicted from the pH dependence that product formation would be the sole rate-limiting step at pH values of <3. A hysteretic mechanism of rGST T2-2 is proposed based on a slow conformational transition detected in pre-steady-state displacement experiments.     

Production of retroviral vectors for gene therapy with the human packaging cell line FLYRD18.

The development of gene therapy is hampered by the difficulty of producing large stocks of retroviral vectors at high titer. This study aimed to improve culture conditions and to intensify the production of retroviruses by FLYRD18, a packaging cell line derived from the HT1080 human fibrosarcoma line. Batch virus production proved to be feasible in unsupplemented basal medium and provided significantly higher titers and productivities than medium supplemented with 10% serum. For longer-term production, however, AIM-V complete serum-free medium and basal medium supplemented with 2% serum gave superior results. Serum supplementation should nevertheless be optimized to take into account the presence of inhibitors of viral production. In monolayer cultures with 0.2 mL/cm(2), the cell concentration was increased up to 2 x 10(6) cells/mL without loss of cell productivity. A semicontinuous production process, which enables the collection of larger amounts of viruses from the same culture, has also been successfully used. Suspension culture processes were prevented by the anchorage dependency of the FLYRD18 cell line. Microcarrier cultures were able to produce viruses but will require further investigation and optimization for their performance to become competitive with monolayer cultures. In the course of this study, more than a 10-fold increase of titer has been achieved.     

Dissimilarity-based algorithms for selecting structurally diverse sets of compounds.

This paper commences with a brief introduction to modern techniques for the computational analysis of molecular diversity and the design of combinatorial libraries. It then reviews dissimilarity-based algorithms for the selection of structurally diverse sets of compounds in chemical databases. Procedures are described for selecting a diverse subset of an entire database, and for selecting diverse combinatorial libraries using both reagent-based and product-based selection.     

Cadmium-substituted skeletal troponin C metal binding investigations and sequence assignment of the cadmium-113 resonances

The binding of cadmium to the calcium binding subunit of skeletal troponin (STnC) has been reinvestigated using direct binding methods and fluorescent derivatives. These data provide straightforward explanations of the observed titration behavior in the 113Cd NMR (Ellis, P.D., Strang, P., and Potter, J.D. (1984) J. Biol. Chem. 259, 10348-10356). Further, fluorescent derivatives of skeletal troponin C provide an excellent means of establishing a sequence assignment for the resonances observed in the 113Cd NMR. The results of these experiments demonstrate that sites I and II, the Ca2+ regulatory sites, can be assigned to resonances at -108.5 and -101.5 ppm, respectively. Sites III and IV, the structural sites, are assigned to resonances -112.8 and -106.8 ppm, respectively. These data are discussed in terms of recent structural findings and speculations.