Precision and accuracy of radioimmunoassay in the analysis of endogenous 3-indoleacetic acid from needles of scots pine

The precision and accuracy of a radioimmunoassay (RIA) for 3-indoleacetic acid (IAA) were assessed when applied to the analysis of extracts from Pinus sylvestris seedlings. It was found that extracts contained contaminants that adversely affected both the precision and accuracy of quantitative estimates of IAA. When samples were subjected to purification procedures prior to RIA, accurate and more precise estimates were obtained. Parallel analysis with high performance liquid chromatography using a fluorescence detector (HPLC-FL) indicated that HPLC-FL provided accurate estimates of the IAA content of Pinus extracts at the same stage of purification as RIA. The precision of HPLC-FL estimates was similar to that obtained with RIA.     

Communication during suckling in the domestic pig. Effects of continuous noise

The purpose of this study was to analyse the function of the vocalizations of sows and piglets during suckling and to investigate the possible effects on the nursing-suckling interaction of exposure to continuous noise at a high level. Six sows with litters were studied in pens measuring 2.5 × 2.5 m. Three of the sows were exposed to a relatively silent background noise of 59 dB(A) (L_eq 24 h) and three were exposed to fan noise at a level of 85 dB(A). A total of 64 sucklings during Days 2–4 after farrowing were recorded on video. For each suckling, four different parameters were recorded second by second; the visual and acoustic behaviour of the sow and the visual and acoustic behaviour of the piglets. The vocalizations of the piglets probably constituted functionally discrete classes. “High grunt/deep grunt” seemed to cause the sow to expose her udder. “Scream” and “squeak” were statistically associated with the occurrence of fights for teats among the piglets. The function of “croaking” is unclear. The gruntings of the sow progressed according to a typical pattern of an initially slow rate followed by rapid grunting, which in turn was followed by a decline in rate. This pattern was similar for all sows, regardless of the experimental situation. In the silent environment, the piglets seemed to respond to the alterations in grunt rate, which caused a synchronized pattern of behaviour. In the noise-exposed environment, the piglets failed to respond to the gruntings of the sow, which led to a disrupted pattern. Certain indications were found that suggested that the noise-exposed piglets gained less milk than the ones in the silent environment. It is suggested as a hypothesis, that the function of the final massage is to regulate the milk production of the sow according to the prevalent litter size.     

Transmitter deficits in Alzheimer's disease

The pattern of neurotransmitter pathway losses in Alzheimer's disease are reviewed. Deficits of the cholinergic pathway from the nucleus basalis, the noradrenergic pathway from the locus coeruleus and the serotoninergic pathway from the raphe nuclei are established. Cortical somatostatin interneurons are affected and dopaminergic neurons may be affected although these may be late or secondary phenomena in the disease process. Other neuronal systems, particularly in the hippocampus and temporal cortex, are also damaged. However, the disease is not one of generalised neuronal atrophy since some neurons are selectively spared. The established pathway-specific losses are discussed in relation to the clinical symptomatology and the pathology of the disorder. The biochemical and histological findings are compared with similar measurements made on tissues from other dementing disorders in an attempt to trace features common to dementias. Finally, as an addendum, a hypothesis is briefly outlined which attempts to explain the common features of the affected neurons and the pathogenesis of the disorder.     

Allergenic 5-alkyl- and 5-alkenylresorcinols from philodendron species

Leaves and stems of nine Philodendron species were examined for content of allergenic alkyl- and alkenylresorcinols. Philodendron angustifolium was found to contain heptadecenylresorcinol, P. erubescens and one source of P. scandens subsp. oxycardium pentadecenyl- and heptadecenylresorcinol, P. radiatum 5-tridecylresorcinol, pentadecenyl-, heptadecadienyl- and heptadecenylresorcinol, and another source of P. scandens subsp. oxycardium 5- pentadecylresorcinol, 5-heptadecatri-8(Z), 11(Z),14(Z)-enylresorcinol, heptadecadienyl- and heptadecenylresorcinol. The following five species were devoid of resorcinols and catechols: P. bipennifolium, P. fenzlii, P. sagittifolium, P. squamiferum and P. tuxlanum.     

Production and Characterization of Antibodies against Each of the Three Subunits of the Bacillus cereus Nonhemolytic Enterotoxin Complex

The nonhemolytic enterotoxin (Nhe) is one of the two three-component enterotoxins which are responsible for diarrheal food poisoning syndrome caused by Bacillus cereus. To facilitate the detection of this toxin, consisting of the subunits NheA, NheB, and NheC, a complete set of high-affinity antibodies against each of the three components was established and characterized. A rabbit antiserum specific for the C-terminal part (15 amino acids) of NheC was produced using a respective synthetic peptide coupled to a protein carrier for immunization. Using purified B. cereus exoprotein preparations as immunogens, one monoclonal antibody against NheA and several antibodies against NheB were obtained. No cross-reactivity with other proteins produced by different strains of B. cereus was observed. Antibodies against the NheB component were able to neutralize the cytotoxic activity (up to 98%) of Nhe. Based on indirect enzyme immunoassays, the antibodies developed in this study were successfully used in the characterization of the enterotoxic activity of several B. cereus strains. For the first time, it could be shown that strains carrying the nhe genes usually express the complete set of the three components, including NheC. However, the amount of toxin produced varies considerably between the different strains.     

A PREHISTORIC BREEDING POPULATION OF HARP SEALS (PHOCA GROENLANDICA) IN THE BALTIC SEA

The pelagic and gregarious, low Arctic harp seal ( Phoca groenlandica ) is the most common seal species in most refuse faunas from coastal hunter-gatherer sites dating from the late Atlantic to the early Subboreal period ( ca. 4000-2000 cal B. C.) in the Baltic Sea. Our main objective was to examine the migration contra breeding population hypotheses regarding the Baltic harp seals. Analyses of epiphyseal fusion data and osteometry of archeological harp seal remains from 25 dwelling-sites suggest that a local breeding population established itself in the early Subboreal period. In the Middle Neolithic the rookery possibly was situated in the Baltic proper, south of Aland and west of Gotland. The mean adult size of the Baltic harp seals decreased, suggesting minimal genetic exchange with the north Atlantic Ocean population. Genetic drift, interspecific competition, and over-hunting by humans are all factors likely to have contributed to the eventual extinction of harp seals in the Baltic Sea.     

Genetical Genomics of Behavior: A Novel Chicken Genomic Model for Anxiety Behavior

The identification of genetic variants responsible for behavioral variation is an enduring goal in biology, with wide-scale ramifications, ranging from medical research to evolutionary theory on personality syndromes. Here, we use for the first time a large-scale genetical genomics analysis in the brains of chickens to identify genes affecting anxiety as measured by an open field test. We combine quantitative trait locus (QTL) analysis in 572 individuals and expression QTL (eQTL) analysis in 129 individuals from an advanced intercross between domestic chickens and Red Junglefowl. We identify 10 putative quantitative trait genes affecting anxiety behavior. These genes were tested for an association in the mouse Heterogeneous Stock anxiety (open field) data set and human GWAS data sets for bipolar disorder, major depressive disorder, and schizophrenia. Although comparisons between species are complex, associations were observed for four of the candidate genes in mice and three of the candidate genes in humans. Using a multimodel approach we have therefore identified a number of putative quantitative trait genes affecting anxiety behavior, principally in chickens but also with some potentially translational effects as well. This study demonstrates that chickens are an excellent model organism for the genetic dissection of behavior.