Detection of ginkgolide A in Ginkgo biloba cell cultures

Ginkgo biloba cells were cultured in two 500 mL shake flasks and in 2 L and 6 L immobilization bioreactors using MS medium supplemented with 1 mg.L^–1 NAA, 0.1 mg.L^–1 K and 30 g.L^–1 sucrose. Specific growth rates were 0.06 d^–1, 0.11 d^–1 and 0.07 d^–1 for the 2 L and 6 L bioreactors and shake flask cultures, respectively. Extracellular phosphate, nitrate, ammonium and carbohydrate uptake rates of the bio reactor cultures were approximately 17 to 39% slower than those of shake flask cultures. The specific oxygen uptake and carbon dioxide transfer rates of immobilized Ginkgo biloba cells ranged from 0.027 to 0.041 mmol O₂.g^–1.d.w.hr^–1 (maximum uptake at 14 days) and 0.020 to 0.057 mmol CO₂g. ^–1.d.w.hr^–1 (maximum production at 14 days). Extracts from the biomass of the two immobilized and shake flask suspension cultures were analysed for ginkgolide A by GC-MS. Yields of 7, 17, 19 and 7 ng.g. ^–1d.w. of ginkgolide A were determined for shake flask 1, shake flask 2 and the 2 L and 6 L immobilized cultures, respectively. Traces of ginkgolide B were detected with the signal to noise ratio, however, being too low for positive confirmation of this last product.Abbreviations CTR Carbon dioxide transfer rate - DO Dissolved oxygen - g.d.w. Gram dry weight - GA Ginkgolide A - GB Ginkgolide B - GC Gas chromatography - GC-MS Gas chromatography-mass spectrometry - HPLC High performance liquid chromatography - K Kinetin - MS Murashige and Skoog salt medium - N₁K₁MS Complete Murashige and Skoog medium supplemented with 1 mg.L^–1 NAA, 0.1 mg.L^–1 K and 30g.L^–1 sucrose - NAA Naphthaleneacetic acid - OTR Oxygen transfer rate - PAF Platelet Aggregating Factor - q_CO2 Specific carbon dioxide production rate - q_O2 Specific oxygen uptake rate - u Specific growth rate     

A densitometrical method for the study of pattern formation in a ciliateChilodonella

Summary An easy and sensitive method is reported here for testing the similarities of individual patterns by photographically transforming maps of these patterns to given, deductively chosen conventions involving constant distances between selected reference points. A cumulative map is produced by loading all landmarks from a set of individual maps on to one sheet of paper. The use of various a priori conventions results in variable cumulative maps, which are then optically transformed on an analog digital converter, with additional input for optical picture processing. The densitometrical maps thus obtained may be compared as to the cumulative degree of areas of maximal and minimal density of landmarks. The best conventions are those that yield the map with the most contrast.Maps of spatial patterns of the sites of contractile vacuole pore (CVP) primordia in an early stage of divisional morphogenesis of the ciliateChilodonella steini were compared after four different transformations and adjustments of the same set of individual maps. The best focusing of the sites of CVP differentiation was achieved by use of the postoral axis, defined by the center of the oral apparatus and the posterior end of the cell as the scaling parameter. The composite domain map obtained by optical transformation of this cumulative map could distinguish the specific CVP territories observed in earlier work (Kaczanowska 1981). These results confirm earlier findings that indicated the site of the oral apparatus is an important reference point in CVP primordia positioning. They also strongly suggest the existence of an overriding scaling factor governing the positioning of sites of differentiation in both dimensions of the developmental field. The method of superposition and scaling of pattern maps is generally applicable to situations in which pattern elements appear at discrete points on a flat surface.     

Deoxyribonucleic acid restriction and modification systems in Salmonella: chromosomally located systems of different serotypes

With the use of four different phages, Salmonella strains representing 85 different serotypes were examined to determine their restriction-modification phenotype. They fell into one of three groups on this basis: group 1, those which lacked the common LT system; group 2, those in which only the LT system could be recognized; and group 3. those which possessed the LT system and at least one other system shown with some serotypes to be closely linked to serB. The specificity of the serB-linked restriction-modification system was unique for each serotype, but different strains of the same serotype expressed the same specificity. Two of the systems were shown to behave in genetic crosses as functional alleles of the S. typhimurium SB system. It is possible that these serB-linked restriction-modification systems constitute a large multiallelic series of genes extending throughout the Salmonella genus and Escherichia coli. We suggest that the division of the Salmonella into the three restriction-modification groups may be significant in defining a "biological grouping" of the different serotypes within the genus which may ultimately be useful in describing the Salmonella species. From the genetic relatedness between the genes of some of the Salmonella restriction-modification systems with those of the E. coli systems, we deduce that the restriction endonuclases produced by the Salmonella serB-linked systems are of type 1. Determination of the nucleotide sequences of the recognition sites of the restriction endonucleases of selected Salmonella systems should further our understanding of specificity with these enzymes.     

Inhibition of receptor-mediated uptake of a lysosomal enzyme into fibroblasts by chloroquine, procaine and ammonia

Cultured human skin fibroblasts take up α- -iduronidase by receptor-mediated pinocytosis. Certain lysosomotropic amines such as chloroquine, ammonia and procaine inhibit this process, without affecting the fluid endocytosis of dextran. In contrast to the competitive inhibition by mannose 6-phosphate, the inhibition by amines is non-competitive and is therefore presumed not to affect binding of the enzyme to receptors. The dose response curves are very steep, and equations that best fit the data use a power of inhibitor concentration (i² for procaine, i⁴ for chloroquine), indicating interaction of several amine molecules at the inhibitory site(s). The inhibition is reversed by removal of the amine from the medium and does not result from accelerated efflux of endocytosed enzyme. We suggest that the amines interfere with delivery of receptor-bound enzyme to lysosomes.     

Polyphenols des feuilles de cotonniers et influence sur leur composition d'un choc hydrique ou nutritionnel

A range of phenolic compounds were found in leaves of three cotton species. Water and nutrient stress (sulfur deficiency) both caused a significant decrease in phenolic content. Possible interpretations of the observed phenomena are given.     

Innate immunity orchestrates the mobilization and homing of hematopoietic stem/progenitor cells by engaging purinergic signaling—an update

Purinergic Signalling - Bone marrow (BM) as an active hematopoietic organ is highly sensitive to changes in body microenvironments and responds to external physical stimuli from the surrounding...     

Preliminary survey of pests and diseases of eucheumatoid seaweed farms in the Philippines

Journal of Applied Phycology - Farmed eucheumatoids are the top aquaculture commodity in the Philippines, contributing more than 60% of total national aquaculture production by volume. Despite...     

Constitutive Musashi1 expression impairs mouse postnatal development and intestinal homeostasis

Evolutionarily conserved RNA-binding protein Musashi1 (Msi1) can regulate developmentally relevant genes. Here we report the generation and characterization of a mouse model that allows inducible Msi1 overexpression in a temporal and tissue-specific manner. We show that ubiquitous Msi1 induction in ∼5-wk-old mice delays overall growth, alters organ-to-body proportions, and causes premature death. Msi1-overexpressing mice had shortened intestines, diminished intestinal epithelial cell (IEC) proliferation, and decreased growth of small intestine villi and colon crypts. Although Lgr5-positive intestinal stem cell numbers remained constant in Msi1-overexpressing tissue, an observed reduction in Cdc20 expression provided a potential mechanism underlying the intestinal growth defects. We further demonstrated that Msi1 overexpression affects IEC differentiation in a region-specific manner, with ileum tissue being influenced the most. Ilea of mutant mice displayed increased expression of enterocyte markers, but reduced expression of the goblet cell marker Mucin2 and fewer Paneth cells. A higher hairy and enhancer of split 1:mouse atonal homolog 1 ratio in ilea from Msi1-overexpressing mice implicated Notch signaling in inducing enterocyte differentiation. Together, this work implicates Msi1 in mouse postnatal development of multiple organs, with Notch signaling alterations contributing to intestinal defects. This new mouse model will be a useful tool to further elucidate the role of Msi1 in other tissue settings.     

Interactions of anthelmintic drugs in Caenorhabditis elegans neuro-muscular ion channel mutants

Due to the increasing development of anthelmintic resistance in nematodes worldwide, it is important to search for anthelmintic compounds with new modes of action and also to investigate the possibility to combine compounds with possible synergistic effects. There might also be the chance to take advantage of the fact that nematode populations which have developed resistance against one anthelmintic class might respond hypersusceptibly to another drug class. The aim of this study was to investigate responses of Caenorhabditis elegans populations with mutations in neuro-muscular ion channels to different anthelmintic classes. Furthermore, potential synergistic effects between two anthelmintic compounds from different classes, i.e. emodepside and tribendimidine, were studied. Although there was neither a synergistic nor an antagonistic effect between emodepside and tribendimidine, other types of interactions could be identified. The C. elegans GABA_A-receptor (GABA_A-R) unc-49 mutants, showing decreased emodepside susceptibility, were more susceptible to tribendimidine than wild-type C. elegans. In contrast, the reverse phenomenon – hypersusceptibility to emodepside in tribendimidine resistant acetylcholine-receptor (AChR) loss of function mutants – was not observed. Moreover, the slo-1 mutant strain (completely emodepside resistant) also showed hypersusceptibility to piperazine. Interestingly, neither the GABA_A-R unc-49 mutants nor the AChR mutants showed decreased susceptibility against piperazine, although there were some studies that indicated an involvement of GABA_A-R or AChR in the piperazine mode of action. In conclusion, the present study provides evidence suggesting that interactions between commercially available anthelmintic drugs with different modes of action might be a relatively common phenomenon but this has to be carefully worked out for each anthelmintic and each anthelmintic drug combination. Moreover, results obtained in C. elegans will have to be confirmed using parasitic nematodes in the future.     

The use of supramolecular structures as protein ligands

Congo red dye as well as other eagerly self-assembling organic molecules which form rod-like or ribbon-like supramolecular structures in water solutions, appears to represent a new class of protein ligands with possible wide-ranging medical applications. Such molecules associate with proteins as integral clusters and preferentially penetrate into areas of low molecular stability. Abnormal, partly unfolded proteins are the main binding target for such ligands, while well packed molecules are generally inaccessible. Of particular interest is the observation that local susceptibility for binding supramolecular ligands may be promoted in some proteins as a consequence of function-derived structural changes, and that such complexation may alter the activity profile of target proteins. Examples are presented in this paper.