A novel array-based assay of in situ tissue transglutaminase activity in human umbilical vein endothelial cells

Transglutaminases (TGs), a family of calcium-dependent transamidating enzymes, are involved in functions such as apoptosis and inflammation and play a role in autoimmune diseases and neurodegenerative disorders. In this study, we describe a novel array-based approach to rapidly determine in situ TG activity in human umbilical vein endothelial cells and J82 human bladder carcinoma cells. Amine arrays were fabricated by immobilizing 3-aminopropyltrimethoxysilane on glass slides. The assay was specific and highly reproducible. The average coefficient of variation betweens spots was 2.6% (n = 3 arrays), and the average correlation coefficients between arrays and between arrays/reactions were 0.998 and 0.976, respectively (n = 3 arrays). The assay was successfully applied to detect changes in TG activity induced by maitotoxin and to analyze inhibition of the TG activation with cystamine and monodansyl cadaverine. In addition, the assay demonstrated that intracellular reactive oxygen species regulate the maitotoxin-induced activation of TG. Thus, the array-based in situ TG activity assay constitutes a rapid and high-throughput approach to investigating the roles of TGs in cell signaling.     

The law of the sea and the prospects for deep seabed mining: The position of the European community

This article explores the options that the Norwegian government has when it comes to the management of harvesting a new resource (redfeed) in the politically tense area surrounding Svalbard. The article argues that, by preparing a blueprint regime solely for redfeed rather than allowing the resource to be a catalyst for conflict, the impacts of introducing the fishery will be less dramatic.     

Use of recombinant inbred lines (RILs) to identify, locate and map major genes and quantitative trait loci involved with in vitro regeneration ability in Arabidopsis thaliana

The Landsberg erecta× Columbia recombinant inbred lines (RILs) of Arabidopsis have been used in order to identify and localize chromosome regions involved in the genetic control of the in vitro regeneration ability. Callus morphology (CM) and shoot regeneration (SR) traits have been considered for both leaf and root explants. The MAPMAKER analysis of leaf culture data has revealed at least one chromosome region involved with CM and several with SR, the 29–30 region of chromosome 1 being common for the two traits. Root explants did not segregate for CM but several QTLs have been detected for SR. The chromosome regions involved with leaf culture regeneration seem to be different from those of root cultures, although the regeneration of abnormal shoots in leaf explants share two chromosome regions with the regeneration of normal shoots in root cultures. Received: 19 April 2000 / Accepted: 12 May 2000     

The mechanism of placental alkaline phosphatase induction in vitro

The mechanism of placental alkaline phosphatase (PLAP) induction by prednisolone in a uterine cervical epidermoid cancer cell line SKG-IIIa was investigated in vitro by enzyme-cytochemistry, enzyme immunoassay, Northern and Southern blot analysis, and in situ hybridization. Enzyme-cytochemical alkaline phosphatase (ALP) staining and immunoassay revealed increased levels of PLAP (heat-stable ALP) in prednisolone-treated cells. Northern blot analysis and in situ hybridization showed increased amounts of PLAP mRNA. Southern blot analysis indicated that PLAP was not a product of an amplified or rearranged gene. These findings suggest that the induction of PLAP mRNA in SKG-IIIa cells by prednisolone in turn increased the levels of PLAP.     

Quantitative Aspects of the Development of Meloidogyne arenaria Larvae in Grapevine Varieties and Rootstocks

The development and productivity of parasitic stages of Meloidogyne arenaria were quantitatively defined in 14 varieties or rootstocks of grapevine. Mean development to maturity was related linearly to the number of degree-hours above 10 C temperature experienced from the time of penetration in all cultivars in which nematode adulthood was achieved. Averaged across varieties, 13,142 heat units were required for development of the mean individual to maturity. The standard deviation of the developing individuals about the mean, expressed as a proportion with 1 representing adulthood, did not differ with time or among varieties after 7,000 degree-hours had elapsed. Earliest egg production was observed after 7,662 degree-hours, averaged across varieties, considerably before mean development to maturity. Varieties were also ranked relative to the number of larvae establishing infection sites, and the rate of egg production per adult female. Varieties could he grouped according to their levels of horizontal resistance.     

Relative performance of monohaploid potato clones and their diploid parents at plant level and after protoplast isolation and subsequent fusion

Summary Plant growth performance was studied in 118 potato monohaploids and in their diploid parents. Of these monohaploids 76 were also investigated at the protoplast level and eight of these were used in protoplast fusion experiments as well. No correlation was found between relative performance of greenhouse grown and in vitro grown plants. No or only weak correlations were found between different in vitro characteristics such as plant growth, protoplast yield per gram plant material, plating efficiency and callus growth. This indicates the unpredictability of these characters.The protoplast fusion experiments indicated that only in some genotype combinations increased callus growth rates may be found. However, it is not clear whether such calli were hybrids or not. In protoplast monocultures only diploid and tetraploid regenerants were obtained. After fusion, tetraploids but also some triploids could be regenerated. The finding of triploids indicates that monoploid protoplasts were involved in fusion. Isozyme analysis and morphological assessment of the plants pointed out that the majority of the fusion regenerants were hybrids. The implications of these results are discussed.     

Food distribution,dominance, and aggressive behaviors in bonnet macaques

Resource availability or distribution may affect interindividual competition in species such as primates, which forage in social groups, and several field studies suggest that dominance status predicts access to restricted food sources. Increased competition due to restricted resources may result in the intensification of aggressive behaviors. The study reported here examines the impact of manipulation of the distribution of food resources in a laboratory-housed group of bonnet macaques to assess the impact of distribution on aggressive behaviors. Food was restricted to a space which allowed access to only one or two individuals at a time or was dispersed throughout the living enclosure to allow universal access in alternating periods. During periods of clumped distribution, the monkeys obtained access to the food in order of their dominance status in the group. In addition, overall levels of aggressive behaviors increased, submissive behavior increased, and play decreased during periods of clumped distribution of food. These results confirm the findings from field studies indicating increases in agonism with restriction of food resources. These findings also have implications for primate colony management, in terms of developing strategies for minimizing intragroup aggression in captive groups.     

Larval habitat for the avian malaria vector Culex quinquefasciatus (Diptera: Culicidae) in altered mid‐elevation mesic‐dry forests in Hawai'i

Effective management of avian malaria (Plasmodium relictum) in Hawai'i's endemic honeycreepers (Drepanidinae) requires the identification and subsequent reduction or treatment of larval habitat for the mosquito vector, Culex quinquefasciatus (Diptera: Culicidae). We conducted ground surveys, treehole surveys, and helicopter aerial surveys from 2001–2003 to identify all potential larval mosquito habitat within two 100+ ha mesic‐dry forest study sites in Hawai'i Volcanoes National Park, Hawai'i; ‘Ainahou Ranch and Mauna Loa Strip Road. At ‘Ainahou Ranch, anthropogenic sites (43%) were more likely to contain mosquitoes than naturally occurring (8%) sites. Larvae of Cx. quinquefasciatus were predominately found in anthropogenic sites while Aedes albopictus larvae occurred less frequently in both anthropogenic sites and naturally‐occurring sites. Additionally, moderate‐size (≈20–22,000 liters) anthropogenic potential larval habitat had >50% probability of mosquito presence compared to larger‐ and smaller‐volume habitat (<50%). Less than 20% of trees surveyed at ‘Ainahou Ranch had treeholes and few mosquito larvae were detected. Aerial surveys at ‘Ainahou Ranch detected 56% (95% CI: 42–68%) of the potential larval habitat identified in ground surveys. At Mauna Loa Strip Road, Cx. quinquefasciatus larvae were only found in the rock holes of small intermittent stream drainages that made up 20% (5 of 25) of the total potential larval habitat. The volume of the potential larval habitat did not influence the probability of mosquito occurrence at Mauna Loa Strip Road. Our results suggest that Cx. quinquefasciatus abundance, and subsequently avian malaria, may be controlled by larval habitat reduction in the mesic‐dry landscapes of Hawai'i where anthropogenic sources predominate.