An examination of the moisture sorption characteristics of commercial magnesium stearate

The objective of this study was to characterize the moisture sorption of magnesium stearate and the morphological changes, if any, resulting from moisture sorption. Six samples of commercial magnesium stearate USP were examined. Moisture sorption isotherms were obtained at 25°C and 5% to 98% relative humidity (RH) using a moisture balance. Changes in crystal form resulting from moisture sorption were determined by x-ray diffraction. There were differences in the shape of the isotherm, reversibility of moisture uptake, and shape of the hysteresis loop in the isotherms of crystalline and amorphous magnesium stearates. The isotherm of crystalline magnesium stearate was almost parallel to the pressure axis until and RH of ∼80%. The isotherm of the amorphous sample was characterized by continuous uptake of water over the entire range of RH. Exposure of amorphous magnesium stearate to RH greater than 70% resulted in the formation of the trihydrate. The trihydrate was converted into the anhydrous form when heated to a temperature of 100°C to 105°C. The trihydrate could be generated by exposing the anhydrate to RH higher than 70%.     

An enhancer trap line associated with a D-class cyclin gene in Arabidopsis

In yeast and animals, cyclins have been demonstrated to be important regulators of cell cycle progression. In recent years, a large number of A-, B-, and D-class cyclins have been isolated from a variety of plant species. One class of cyclins, the D-class cyclins, is important for progression through G1 phase of the cell cycle. In Arabidopsis, four D-class cyclins have been isolated and characterized (CYCLIN-D1;1, CYCLIN-D2;1, CYCLIN-D3;1, and CYCLIN-D4;1). In this report we describe the characterization of a fifth D-class cyclin gene, CYCLIN-D3;2 (CYCD3;2), from Arabidopsis. An enhancer trap line, line 5580, contains a T-DNA insertion in CYCD3;2. Enhancer trap line 5580 exhibits expression in young vegetative and floral primordia. In line 5580, T-DNA is inserted in the first exon of the CYCD3;2 gene; in homozygous 5580 plants CYCD3;2 RNA is not detectable. Even though CYCD3;2 gene function is eliminated, homozygous 5580 plants do not exhibit an obvious growth or developmental phenotype. Via in situ hybridization we demonstrate that CYCD3;2 RNA is expressed in developing vegetative and floral primordia. In addition, CYCD3;2 is also capable of rescuing a yeast strain that is deficient in G1 cyclin activity.     

Production of interferon-α in high cell density cultures of recombinant Escherichia coli and its single step purification from refolded inclusion body proteins

Escherichia coli TG1 transformed with a temperature-regulated interferon-α expression vector was grown to high cell density in defined medium containing glucose as the sole carbon and energy source, utilizing a simple fed-batch process. Feeding was carried out to achieve an exponential increase in biomass at growth rates which minimized acetate production. Thermal induction of such high cell density cultures resulted in the production of ∼4 g interferon-α/l culture broth. Interferon-α was produced exclusively in the form of insoluble inclusion bodies and was solubilized under denaturing conditions, refolded in the presence of arginine and purified to near homogeneity, utilizing single-step ion-exchange chromatography on Q-Sepharose. The yield of purified interferon-α was ∼300 mg/l with respect to the original high cell density culture broth (overall yield of ∼7.5% active interferon-α). The purified recombinant interferon-α was found by different criteria to be predominantly monomeric and possessed a specific bioactivity of ∼2.5 × 10⁸ IU/mg based on viral cytopathic assay. Received: 8 October 1999 / Received revision: 8 December 1999 / Accepted: 12 December 1999     

Tilapia and human CLIC2 structures are highly conserved

Chloride intracellular channels (CLICs) exist in soluble and membrane bound forms. We have determined the crystal structure of soluble Clic2 from the euryhaline teleost fish Oreochromis mossambicus. Structural comparison of tilapia and human CLIC2 with other CLICs shows that these proteins are highly conserved. We have also compared the expression levels of clic2 in selected osmoregulatory organs of tilapia, acclimated to freshwater, seawater and hypersaline water. Structural conservation of vertebrate CLICs implies that they might play conserved roles. Also, tissue-specific responsiveness of clic2 suggests that it might be involved in iono-osmoregulation under extreme conditions in tilapia.     

Marker-aided selection and validation of various $${ }$$ gene combinations for rice blast resistance in elite rice variety ADT 43

Rice blast caused by fungal pathogen Pyricularia oryzae has a major impact on reducing yield potential of rice. In this study, homozygous plants were selected using microsatellite markers from the \(\hbox {BC}_{3}\hbox {F}_{2}\) population pyramided with four major genes in elite rice variety ADT 43. Background and selected lines with various blast resistance gene combinations were screened under natural conditions to study the effects of various gene combinations. Upon inspection of lines with different gene combinations, the three-gene pyramided line Pi54+Pi33+Pi1 was found to be highly resistant with the score of 3.3 followed by other three-gene pyramided lines Pi54+Pi2+Pi1 and Pi33+Pi2+Pi1, with the scores of 3.9 and 3.8, respectively. Two-gene pyramided lines Pi54+Pi1, Pi33+Pi1 and Pi2+Pi1 were found to be moderately resistant with a mean score of 4.0 each. In the case of monogenic lines, positive plants for Pi54 performed almost equal to three-gene pyramided lines with a mean score of 3.6. Lines with Pi2 and Pi1 were found to be moderately resistant and moderately susceptible with the mean scores of 4.1 and 4.5, respectively.     

Reflections on a journey: a retrospective of the ISCB Student Council symposium series

This article describes the motivation, origin and evolution of the student symposia series organised by the ISCB Student Council. The meeting series started thirteen years ago in Madrid and has spread to four continents. The article concludes with the highlights of the most recent edition of annual Student Council Symposium held in conjunction with the 25th Conference on Intelligent Systems for Molecular Biology and the 16th European Conference on Computational Biology, in Prague, in July 2017.