The Jet Cutting Method as a new immobilization technique

The Jet Cutting Method, as a technique for the production of spherical beads, allows the production of beads in the range of 0.2-3 mm in diameter even from high viscous fluids (e.g. polyvinyl alcohol solutions) at a high production rate and narrow particle size distributions. This technique may be useful for various applications in biotechnology, medicine, chromatography and in the pharmaceutical, chemical or food industry.     

Activation of Raf-1 is defective in annexin 6 overexpressing Chinese hamster ovary cells.

Annexin 6 is a Ca2+-dependent phospholipid-binding protein involved in membrane trafficking. In this study we demonstrate the association of Raf-1 with recombinant rat annexin 6. Raf-annexin 6 interaction was shown to be independent of cell activation by epidermal growth factor (EGF) or phorbol esters (12-O-tetradecanoyl-phorbol-13-acetate (TPA)). A stable Chinese hamster ovary (CHO)-anx6 cell line overexpressing annexin 6 was established to examine the function of annexin 6. In these cells, no increase of Ras-GTP levels, induced by EGF or TPA, was detected. In addition, the activity of Raf was completely inhibited, whereas the mitogen-activated protein kinase-P was unaffected.     

Difference in protein synthesis of ovaries indicates predetermined sex inChrysomya rufifacies (Diptera,Calliphoridae)

Summary Sex in the monogenic blowflyChrysomya rufifacies is under the control of a germ-line autonomous maternal effect sex realizer. In order to identify the ovarian poly(A)⁺RNA that might be related to sex predetermination, we analysed the patterns of cell-free translation products of total poly(A)⁺RNA from female and male predetermined ovaries and oocytes. During vitellogenesis we observed one transient sex-linked difference in a stable pattern composed of more than 800 in vitro translated proteins. This difference, however, was no longer detectable in mature oocytes.     

Chemotactic response of a gliding mycoplasma

Mycoplasma sp. nov. strain 163K, the gliding microorganism isolated from the gills of a tench (Tinca tinca L.), is capable of chemotaxis, being attracted to sugars, amino acids, and mucus. The chemotactic behavior of the organisms was microscopically investigated and documented by long-time exposure photomicrographs providing motility tracks. In diffusion-generated concentration gradients of chemoattractive substances, the random motion of the mycoplasmas was strongly biased in the direction of increasing attractant concentrations.     

Conservation of Glycerolated Cultures of Ochromonas danica and O. malhamensis at −10 C

SYNOPSIS. Ochromonas danica in a complex natural growth medium dies at 6–10 C in 4 days; O. malhamensis in ∼2 days. O. danica grown in the medium supplemented with 4.0% glycerol survived at −10±2 C for 35 days, and with 8% glycerol 29 days. O. malhamensis lasted only to 5 days in these media supplemented with 4% glycerol. Ethylene glycol and dimethylsulfoxide were too toxic to be effective. Difficulties in freeze-preservation of certain other phagocytic cells, notably blood granulocytes having comparatively simple flexuous outer membranes, add interest to use of O. danica and O. malhamensis as test organisms for preservation methods, especially in the convenient, inexpensive -10 to -20 C range. Biphasic media with an overlay of distilled water serve for conservation at room temperature. Problems of mutational erosion of these photosynthetic phagotrophs are discussed.