The ethology of inter-individual differences

In recent times psychologists have shown a growing interest in ethological methods of data collection. At the same time ethologists are showing a growing interest in the methods of data processing as developed in personality psychology. These methods of data processing appear to be most useful to ethological research when investigating differences between individuals. Using factor analysis of aggressive behaviour as an example, it is argued that an ethological approach which focusses on individual differences may add substantial information to the models derived from a (classical) ethological approach which only concerns general pictures of species. The advantages of the proposed research procedures are discussed, especially in relation to behavioural genetic and ontogenetic research.Without the help and assistance of staff members of the departments of ethology and personality psychology of Groningen University this text would never have reached its present form. The suggestions of Ference Bodnár, Ciska Feekes, No Molenaar, Nance Vodegel and Annemarie van der Molen are gratefully acknowledged. Translation from Dutch into English was taken care of by Margi and Talib Rothengatter. The drawings were prepared by Agnes de Graaf.     

Morphometric Analysis of Normal, Mutant, and Transgenic CNS: Correlation of Myelin Basic Protein Expression to Myelinogenesis

The neurological mutant mice shiverer (shi) and myelin deficient (shimld) lack a functional gene for the myelin basic proteins (MBP), have virtually no myelin in their CNS, shiver, seize, and die early. Mutant mice homozygous for an MBP transgene have MBP mRNA and MBP in net amounts approximately 25% of normal, have compact myelin, do not shiver or seize, and live normal life spans. We bred mice with various combinations of the normal, transgenic, shi, and shimld genes to produce mice that expressed MBP mRNA at levels of 0, 5, 12.5, 17.5, 50, 62.5, and 100% of normal. The CNS of these mice were analyzed for MBP content, tissue localization of MBP, degree of myelination, axon size, and myelin thickness. MBP protein content correlated with predicted MBP gene expression. Immunocytochemical staining localized MBP to white matter in normal and transgenic shi mice with an intensity of staining comparable to the degree of MBP gene expression. An increase in the percentage of myelinated axons and the thickness of myelin correlated with increased gene expression up to 50% of normal. The percentage of myelinated axons and myelin thickness remained constant at expression levels greater than 50%. The presence of axons loosely wrapped with oligodendrocytic membrane in mice expressing lower amounts of MBP mRNA and protein suggested that the oligodendroglia produced sufficient MBP to elicit axon wrapping but not enough to form compact myelin. Mean axon circumference of myelinated axons was greater than axon circumference of unmyelinated axons at each level of gene expression, further evidence that oligodendroglial cells preferentially myelinate axons of larger caliber.(ABSTRACT TRUNCATED AT 250 WORDS)     

IGFs and IGF-Binding Proteins in the Synovial Fluid of Patients with Rheumatoid Arthritis and Osteoarthritis

International Journal of Peptide Research and Therapeutics - The progressive damage of human articular cartilage is associated with loss of integrity of its extracellular matrix components. Their...     

A correlation between BCL-2 modifying factor,p53 and livin gene expressions in cancer colon patients

Accumulating evidence has revealed that livin gene and BCL-2 modifying factor (BMF) gene are closely associated with the initiation and progression of colon carcinoma by activating or suppressing multiple malignant processes. Those genes that can detect colon - cancer are a promising approach for cancer screening and diagnosis. This study aimed to evaluate correlation between livin, BMF and p53 genes expression in colon cancer tissues of patients included in the study, and their relationship with clinicopathological features and survival outcome in those patients. In this study, 50 pathologically diagnosed early cancer colon patients included and their tissue biopsy with 50 matched adjacent normal tissue, and 50 adenoma tissue specimens were analyzed for livin gene and BMF gene expressions using real time PCR. The relationship of those genes expressions with clinicopathological features, tumor markers, Time to Progression and overall survival for those patients were correlated in cancer colon group. In this study, there was a significant a reciprocal relationship between over expression of livin gene and down regulation of BMF and p53 genes in colon cancer cells. Livin mRNA was significantly higher, while BMF and p53 mRNA were significantly lower in colorectal cancer tissue compared to benign and normal colon tissue specimens (P < 0.001), however, this finding was absent between colon adenomas and normal mucosa. There was a significant association between up regulation of livin and down regulation of BMF and p53 expressions with more aggressive tumor (advanced TNM stage), rapid progression with metastasis and decreased overall survival in cancer colon patients, hence these genes can serve as significant prognostic markers of poor outcome in colon cancer patients. This work highlights the role of livin, BMF and p53 genes in colorectal tumorigenesis and the applicability of using those genes as a diagnostic and prognostic markers in patients with colon carcinoma and as a good target for cancer colon treatment in the future.     

Biocides formulation of essential oils having antimicrobial activity

Essential oils of fennel, peppermint, caraway, eucalyptus, geranium and lemon were tested for their antimicrobial activities against some plant pathogenic micro-organisms (Fusarium oxysporum, Alternaria alternate, Penicilium italicum Penicilium digitatum and Botyritus cinerea). Essential oils of fennel, peppermint, caraway were selected as an active ingredient for the formulation of biocides due to their efficiency in controlling the tested micro-organisms. Successful emulsifiable concentrates (biocides) were prepared from these oils using different emulsifiers (Emulgator B.L.M. Tween20 and Tween80) and different fixed oils (sesame, olive, cotton and soybean oils). Physico-chemical properties of the formulated biocide (spontaneous emulsification, emulsion stability test, cold stability and heat stability tests as well as viscosity, surface tension and pH) were measured. The prepared biocides were ready to be tested for application in a future work as a safe pesticide against different pathogens.     

Metagenomic insights into strategies of carbon conservation and unusual sulfur biogeochemistry in a hypersaline Antarctic lake

Organic Lake is a shallow, marine-derived hypersaline lake in the Vestfold Hills, Antarctica that has the highest reported concentration of dimethylsulfide (DMS) in a natural body of water. To determine the composition and functional potential of the microbial community and learn about the unusual sulfur chemistry in Organic Lake, shotgun metagenomics was performed on size-fractionated samples collected along a depth profile. Eucaryal phytoflagellates were the main photosynthetic organisms. Bacteria were dominated by the globally distributed heterotrophic taxa Marinobacter, Roseovarius and Psychroflexus. The dominance of heterotrophic degradation, coupled with low fixation potential, indicates possible net carbon loss. However, abundant marker genes for aerobic anoxygenic phototrophy, sulfur oxidation, rhodopsins and CO oxidation were also linked to the dominant heterotrophic bacteria, and indicate the use of photo- and lithoheterotrophy as mechanisms for conserving organic carbon. Similarly, a high genetic potential for the recycling of nitrogen compounds likely functions to retain fixed nitrogen in the lake. Dimethylsulfoniopropionate (DMSP) lyase genes were abundant, indicating that DMSP is a significant carbon and energy source. Unlike marine environments, DMSP demethylases were less abundant, indicating that DMSP cleavage is the likely source of high DMS concentration. DMSP cleavage, carbon mixotrophy (photoheterotrophy and lithoheterotrophy) and nitrogen remineralization by dominant Organic Lake bacteria are potentially important adaptations to nutrient constraints. In particular, carbon mixotrophy relieves the extent of carbon oxidation for energy production, allowing more carbon to be used for biosynthetic processes. The study sheds light on how the microbial community has adapted to this unique Antarctic lake environment.     

Oligodendroglial Response to the Immune Cytokine Interferon Gamma

In the human demyelinating disorder multiple sclerosis, and its animal model experimental allergic encephalomyelitis, there is a breakdown of the blood-brain barrier and an infiltration of immune cells into the CNS. Infiltrating T lymphocytes and macrophages are believed to be key mediators of the disease process. Considerable circumstantial and experimental evidence has suggested that the pleiotropic cytokine interferon gamma (IFN-), which is exclusively expressed by T cells and natural killer cells, is a deleterious component of the immune response in these disorders. When experimentally introduced into the CNS IFN- promotes many of the pathological changes that occur in immune-mediated demyelinating disorders. In vitro, this cytokine elicits a number of effects on oligodendrocytes, including cell death. The harmful actions of IFN- on CNS myelin are likely mediated through direct effects on the myelinating cells, as well as through the activation of macrophages and microglia. In this review we summarize relevant studies concerning the action of IFN- in demyelinating disorders and discuss possible mechanisms for the observed effects.     

Paternal care and male mate-attraction effort in the European starling is adjusted to clutch size

In facultative polygynous birds with biparental care, a trade-off may occur between male parental care and attraction of additional mates. If there is a cost associated with reduced male parental care, the relative benefit of mate attraction may be predicted to decrease as the size of a male's clutch or brood increases. We tested this prediction in monogamous pairs of facultatively polygynous European starlings (Sturnus vulgaris). The larger the clutch, the more time the male spent incubating and the less time he spent attracting an additional female (i.e. singing near and carrying green nesting material into adjacent empty nest-boxes). Reduced paternal incubation resulted in lower overall incubation (the female did not compensate) and lower hatching success. Immediately after experimental reduction of clutches, males spent significantly less time incubating and more time singing and carrying greenery, and vice versa for experimentally enlarged clutches. Males with experimentally reduced clutches attracted a second female more often than males with experimentally enlarged clutches. This is the first study, to our knowledge, to provide experimental evidence for an adjustment of paternal care and male mate-attraction effort to clutch size. However, a trade-off between paternal nestling provisioning and mate attraction was not revealed, probably due to the absence of unpaired females by that time in the breeding season. Experiments showed that the relative contribution of the male and female to nestling provisioning was unrelated to brood size.     

Notch signaling: a rheostat regulating oligodendrocyte differentiation?

Recent studies suggest that Notch signaling provides both instructive and inhibitory cues for oligodendroglial differentiation, depending on the developmental stage and the stimulatory ligand. In the October 17 issue of Cell, Hu et al. present the axonal cell adhesion molecule contactin as a functional Notch ligand, and suggest interesting potential roles for axoglial interactions in regulating oligodendroglial maturation.