RAPID DETECTION OF MICROBIAL CONTAMINATION IN TRICLOSAN AND HIGH FLUORIDE DENTIFRICES USING AN ATP BIOLUMINESCENCE ASSAY

Abstract The Celsis ATP Bioluminescence method was optimized and validated to detect the presence of microbial contamination in High Fluoride and Triclosan dentifrice formulations. Several enrichment broths were evaluated by using a 24–27 h incubation period. The ATP concentrations of the enrichment broths were found to a range from 0.012 to 0.040 nM. None of the tested enrichment broths were found to exhibit any sample inhibition/enhancement effects on the ATP Bioluminescence reaction. Dentifrice suspensions were inoculated with bacteria, yeast, and mold. All test microorganisms (ca. 1–15 CFU/g) were detected within a 24–27 h incubation period by using TAT Broth Base enrichment broths containing different concentrations of the following ingredients: Tween 20, Neopeptone, Dextrose, Triton X-100, Thiosulfate, Sodium Dibasic Phosphate, and Glycine. Negative ATP response after 24–27 h of incubation at 35C indicates the absence of contamination from these products.     

Parental care and the transition to independence of Spanish Imperial Eagles Aquila heliaca in Doñana National Park, southwest Spain

The behaviour of five broods of radio-tagged Spanish Imperial Eagles Aquila heliaca adalberti was studied in Doñana National Park, Spain during the post-fledging period. The distance between perching sites and nest, the mean flight duration and distance, the percentage of time spent flying and the home range all increased exponentially with age. As the young got older, the parents spent less time in their vicinity. Young were not seen hunting, but depended on their parents for food. They begged and chased their parents throughout the post-fledging period, with higher intensity at the end. Nevertheless, the adults became progressively more reluctant to feed them, as reflected in the decrease in feeding frequency and in the number of approaching flights towards the young. At the end of the post-fledging period, adults often performed aerial displays and frequently chased their offspring. The age of independence of the different young studied varied between 123 and 145 days. The correlations between individual independence and the dates when the young were last fed by their parents, and when the highest intensity of parental aggressive behaviour occurred, were higher than correlations with the variables related to the maturation of flying. Therefore, it is suggested that parental 'meanness' and aggressive behaviour may be the factors determining the date of juvenile independence and dispersal from the home territory.     

Species-specific phytoplankton responses to nutrients and zooplankton manipulations in enclosure experiments

1. In situ enclosure experiments were performed in the mesotrophic Bermejales reservoir to evaluate the algal response to changes in the nutrient supply and in the zooplankton size structure and density in a 2 × 2 factorial design. The experiments were conducted during the spring bloom of nanoplanktonic diatoms in 1989. 2. Nutrient enrichment promoted a great increase of phytoplankton biomass indicating a strong nutrient limitation on phytoplankton growth. Total phytoplankton biomass was significantly lower in the Daphina-added enclosures at a given nutrient level and strong direct an indirect effect of zooplankton on phytoplankton community structure and nutrient availability were observed. 3. Most of the nanoplanktonic species were effectively grazed but species with protective coverings and large size colonies were favoured by grazers and small chlorococcales were unaffected probably because of their compensatory high growth rates. The decrease in total biomass imposed by grazers is attributable mainly to the decrease of Cyclotella ocellata, the most abundant species. This taxon suffers two net effects of zooplankton: direct grazing and the indirect decrease of Si availability caused by the growth of C. ocellata which was promoted by P excretion by zooplankton. Indirect effects of grazers on Si availability should, therefore, be taken into account in explaining phytoplankton succession and community structure. 4. In this experiment grazers affected considerably the nanoplanktonic community in Bermejales reservoir. The extent which they were affected, however, depended not only on the algal size as a determinant of edibility but also greatly on the specific nutrient requirements and taxonomic features of the algal species.     

EFFECT OF TRYPSIN INHIBITORS AND CONCANAVALIN A ON BUFO ARENARUM FERTILIZATION

The presence of some trypsin inhibitors (soybean trypsin inhibitor and lima bean trypsin inhibitor) in the inseminating media, is effective in blocking Bufo arenarum fertilization. Ovomucoid does not significantly affect fertilization, even at concentrations as high as 10 mg/ml. Similarly the presence of Concanavalin A in the inseminating media results in fertility impairment. The possible mechanisms of action of these substances are discussed.     

Detection and Classification of Trypanosoma cruzi by DNA Hybridization with Nonradioactive Probes

ABSTRACT. Total or kinetoplast DNA (kDNA) from 72 isolates and clones of Trypanosoma cruzi as well as from nine related trypanosomatids were analyzed by dot hybridization using nonradioactive kDNA or cloned minicircle fragments as probes. Biotinylated-kDNA probes generated by nick-translation proved reliable for distinguishing Zymodeme 1 and Zymodeme 2bol of T. cruzi parasites. In contrast, digoxigenin-labeled kDNA obtained by random-priming did not distinguish among T. cruzi isolates but did distinguish among New World leishmanias. Cloned minicircle fragments labeled with digoxigenin gave the same results as digoxigenin-labeled kDNA, except for a 10-fold decrease in sensitivity. Digoxigenin-labeled DNA probes proved useful in unambiguously detecting T. cruzi from different geographic regions of America. However, T. rangeli and T. cruzi marinkellei were not distinguished by these probes.     

Morphological Modifications of Oocyte Vitelline Envelope from Bufo arenarum during Different Functional States

The submicroscopic morphology of the vitelline envelope of Bufo arenarum's oocyte change significantly during the maturation and fertilization processes. The morphological changes are related to physiological activity in vivo and can be triggered in vitro by experimental procedures. It is our scope to present the ultrastructure differences of fascicular components of the vitelline envelope in coelomic, "pars recta" conditioned, oviductal, oviposited and fertilized oocytes. Our experimental results indicate that artificial "pars recta" treatment of coelomic oocytes arrange the fascicular components as those of oviposited oocyte, although differences still remain indicating that additional maturation processes take place while the egg pass througth the oviduct. Fertilized or activated oocytes which are refractary to sperm penetration, change the vitelline envelope fascicular components orientation giving a submicroscopical image quite different to those of none fertilized oocytes. These ultrastructural changes define in a clear cut manner the functional states of Bufo arenarum's oocyte.