Immobilisation of phosphorus by iron-coated roots of submerged macrophytes

Hydrobiologia - To observe effects on the phosphorus retention mechanisms of a lake after re-colonisation by macrophytes, Potamogeton crispus L. and Elodea canadensis Michx. were planted in lab...     

Long-term effects of dietary isoflavones on uterine gene expression profiles

Isoflavones (ISOs) are bioactive food ingredients of the traditional East Asian diet and currently discussed as alternatives to classical hormone replacement therapies and for reducing the prevalence of hormone-dependent cancers. Although there are many studies on ISOs, not much is known about their long-term effects.Therefore, we performed an animal experiment analyzing the effects of three different diets: a phytoestrogen-free diet, a diet supplemented with genistein (700 μg/g diet) and an ISO-high diet (232 μg daidzein and 240 μg genistein/g) at two distinct time points, juvenile (21 days) and adult (97 days). Exposure started prior to mating of the parents and throughout the life of the offspring.We observed a stronger increase of uterine wet weights in juvenile offspring with genistein exposure (1018 ± 350 mg/kg BW) than with ISO-high diet (497 ± 133 mg/kg BW). Whereas the expression of proliferation related genes (PCNA; Ki67; IGF-1; IGF-1R), analyzed by real-time-qPCR and Western blot, were significantly down-regulated in juvenile animals exposed to genistein. Additionally, genistein exposure led to estrogenic responses, observed upon increase of complement C3 and decrease of estrogen receptors gene expressions, while the exposure to ISO-high diet did not show these effects.In conclusion, both the time point on which phytoestrogen exposure starts together with the composition of the ingested phytoestrogen containing diet are of great importance for the biological response of the offspring.     

The primary structure of a procaryotic glycoprotein. Cloning and sequencing of the cell surface glycoprotein gene of halobacteria

The hexagonally patterned surface layer of halobacteria consists of a true glycoprotein. This procaryotic glycoprotein has recently been shown to exhibit novel features with respect to saccharide structure and saccharide biosynthesis. The primary structure and the location of glycosylation sites were determined by cloning and sequencing of the glycoprotein gene of Halobacterium halobium. According to the predicted amino acid sequence, the glycoprotein is synthesized with a N-terminal leader sequence of 34 amino acid residues reminiscent of eucaryotic and procaryotic signal peptides. A hydrophobic stretch of 21 amino acid residues at the C terminus probably serves as a transmembrane domain. 14 threonine residues are clustered adjacent to this membrane anchor and linked to these threonines are all the disaccharides of the cell surface glycoprotein. 12 N-glycosylation sites are distributed over the polypeptide chain.     

Adhesion of canine and human uropathogenicEscherichia coli andProteus mirabilis strains to canine and human epithelial cells

Escherichia coli strains causing urinary tract infections in dogs produce fimbriae composed of fimbrial subunits closely related to the F12 and F13 fimbriae of human uropathogenic strains [4]. The adhesins carried by the fimbriae of human and canine isolates differ, however, as concluded from a different hemagglutination pattern and from the fact that the dog strains do not agglutinate latex beads coated with P-fimbriae receptor. This possible difference in adhesive specificity was confirmed by experiments in which the adhesion of human and dog isolates to dog kidney epithelial cells (MDCK cells) and human bladder epithelial cells (T24 cells) was compared. Dog uropathogenic strains, in contrast to human uropathogenicE. coli strains, adhere to MDCK cells but hardly to T24 cells. Adhesion to MDCK cells correlates with the presence of F12 or F13 fimbriae on the dog strains. These results suggest that homologous fimbrial subunits can carry different adhesin molecules and that these adhesin molecules can be responsible for species-specific adherence. On the contrary, adhesion of a number of dog uropathogenicProteus mirabilis strains to MDCK and T24 cells was not species specific; it depended on the mere presence of fimbriae.     

Lipase production of Staphylococcus carnosus in a dialysis fermentor

Summary In a newly constructed one-vessel dialysis fermentor, a strain of Staphylococcus carnosus TM300 carrying the lipase secretion plasmid pLipPS1 was used to investigate exoenzyme and biomass production. The bacterial culture grows in an inner compartment of 21 volume, separated from a 101 nutrient broth compartment by a conventional dialysis membrane. In order to avoid substrate depletion and to prolong the growth phase, a highly concentrated nutrient broth was used. The biomass production reached 60 g cell dry weight/l. The increase in extracellular lipase concentration was directly coupled with the increase of cell mass and reached a value of 230 mg/l culture supernatant. Harvesting the cells in the late growth phase, the lipase content was about 30% of the total exoproteins in the supernatant.     

Effects of naloxone on regional blood flow distribution in canine hemorrhagic shock

The opiate antagonist naloxone increases arterial pressure, maximal left ventricular dp/dt and cardiac output when administered to dogs subjected to hemorrhagic shock. The purpose of this study was to investigate regional blood flow changes associated with naloxone treatment in anesthetized hypovolemic and normovolemic dogs. Hypovolemic dogs (n = 10) were bled over 30 min (t = -30 to t = 0) to a pressure of 45 mm Hg which was maintained for 1 hr. At t = 60, five dogs received naloxone (2 mg/kg + 2 mg/kg X hr), and five received an equal volume of saline. Regional blood flows were determined at t = -30, 45, and 90 min using 15-micron microspheres. Normovolemic dogs (n = 10) were subjected to the same protocol except they were not bled. During hypovolemia, naloxone produced significant increases in myocardial, intestinal, hepatic, and adrenal blood flows whereas saline treatment did not. No significant changes in skin, muscle, fat, pancreatic, renal, or brain flows were detected. The increases in blood flow were not associated with significant changes in vascular resistance. Naloxone had no significant effects on any hemodynamic parameter during normovolemia. The beneficial effects of naloxone in hemorrhagic shock include increased blood flow to vital organs due to increased perfusion pressure which is secondary to improved cardiac performance.     

A zinc finger protein, essential for chromosome segregation, constitutes a putative DNA binding subunit of the Saccharomyces cerevisiae kinetochore complex, Cbf3.

A multisubunit protein complex, Cbf3, is a component of the Saccharomyces cerevisiae kinetochore. Cbf3 was recently shown to be essential for chromosome segregation in vivo and for movement of centromere DNA (CEN) along microtubules in vitro. Cbf3 contains three proteins, Cbf3a, Cbf3b and Cbf3c. Here the characterization of Cbf3b is described. Cbf3b contains an N-terminal Zn2Cys6 type zinc finger domain, a C-terminal acidic domain and a putative coiled coil dimerization domain. Cbf3b is essential for growth. Mutations within the zinc finger domain result in cells that exhibit a G2-M cell cycle delay and increased chromosome loss in each mitotic cell division. Therefore, Cbf3b has an essential function in chromosome segregation and the zinc finger domain executes part of this function presumably by providing the specific interaction between Cbf3 and CEN. Finally, data are provided to show that Cbf3c is encoded by CTF13, a gene that had been cloned recently by complementing a temperature sensitive mutant that exhibits chromosome loss as a result of a defective centromere.