[Establishment of an immunological labelling of pigs using synthetic peptides]

The objective of this study was to develop a suitable combination consisting of synthetic peptides, carrier protein and adjuvant for immunological labelling of pigs. Specific antibody titres were evaluated by ELISA technique. From 9 peptides 4 were excluded from following investigations showing cross reactivity or low immunogenic effects, sufficient anti-peptide titres were achieved by 5 peptides. Labelling control is possible after 7 days at the earliest and can be used for the whole fattening period after single immunization using an effective carrier-adjuvant-combination. Mixing of peptides in one labelling dose had no negative influence on titres against single peptides. Different combinations of 4 carriers (keyhole limpet haemocyanin (KLH), palmitic-acid-3-cystein-acid (Pam3Cys), palmitic acid (Pam) and dextran) and 4 adjuvants (Montanide IMS 1313, Montanide ISA 25, Quil A and Diluvac forte) were tested. Optimal labelling could be seen by combination of 50 nmol peptide, KLH as carrier and Montanide IMS 1313 as adjuvant. Generally after booster injection titres were higher, however, a booster dose was not necessary using most effective adjuvants. A less immunogenic, but cost effective alternative for short time labelling (7 weeks) was a peptide-Pam3Cys-conjugate (75 nmol) combined with Quil A as an adjuvant (2 mg/ml). Immunological labelling of pigs is recommended as a good method for tracing back the origin of animals and meat products. It may be also used for vaccine labelling to prove vaccination of pigs.

Development of pro- and antisaccades in children with attention-deficit hyperactivity disorder (ADHD) and healthy controls

To date, the investigation of the antisaccade task, a simple test of "executive functions," in children with ADHD has yielded inconsistent results. The present study aimed at contributing to this issue by (a) the investigation of a large sample of carefully diagnosed ADHD patients aged 7-15 years, and (b) the analyses of differential age effects in patients and controls. Healthy control children were pairwise matched with patients (N = 46; age = 136 +/- 24 months) for age and gender, and did not significantly differ in IQ. Horizontal pro- and antisaccades were elicited under the 200-ms gap and overlap conditions (blocks of 100 trials each). Overall, patients exhibited (a) augmented pro- and antisaccadic reaction times, (b) augmented error rates (antitasks), (c) augmented proportions of early responses (all conditions), and (d) reduced proportions of express saccades under the prosaccadic gap condition. The greater decline in anti- as compared to pro-SRT with increasing age that characterized controls was missing in patients. Confirming Barkley's (1997) neuropsychological theory of ADHD, these results altogether point to alterations in "executive functions" in ADHD patients that are presumably supported by frontal lobe structures, in particular the lateral prefrontal cortex and the frontal eye fields.

Fibroblasts enhance the invasive capacity of melanoma cells in vitro

In previous experiments we have shown an enhanced expression of matrix metalloproteinase-1 (MMP-1) in fibroblasts obtained from the border of invasive melanoma in comparison to fibroblasts more distant from the tumour. In the study reported here we sought to determine whether melanoma-derived soluble factors are responsible for the stimulation of MMP-1 expression in fibroblasts. By real-time PCR and enzyme-linked immunosorbent assays, we demonstrated that the stimulation of fibroblasts with melanoma cell conditioned medium led to an increased expression of MMP-1 mRNA as well as MMP-1 protein, whereas melanoma cells themselves did not produce detectable amounts of MMP-1 protein. Basic fibroblast growth factor (bFGF) was detected as an important factor responsible for the enhanced expression of MMP-1 by fibroblasts after stimulation with melanoma cell conditioned medium. In a three-dimensional in vitro invasion assay, we demonstrated that fibroblasts are essential for melanoma cell invasion into a collagen I matrix. These findings support the hypothesis that stromal fibroblasts assist the invasion of melanoma cells through the extracellular matrix by producing elevated amounts of proteolytic enzymes after interaction with soluble factors (e.g. bFGF).