Identification of novel ‘expressed sequence tags’ within the FHIT gene locus in human chromosome region 3p14.2

Losses of genetic material within human chromosome regions (HCR) 3p12–p14 and 3p21–p22 are observed in various neoplasias, suggesting tumor suppressor gene (TSG) loci within these regions. HCR 3p14 is particularly interesting as it contains the t(3;8) translocation breakpoint of a hereditary renal cell carcinoma, the FRA3B fragile site, and DNA markers deleted in several types of human cancer. We here report on the identification of five novel ‘expressed sequence tags’ (ESTs) within 3p14.2 which map proximal to exon 9 of the candidate TSG, FHIT. These ESTs may be valuable for elucidation of the supposed TSG content in 3p14.2. Received: 5 December 1996 / Accepted: 10 February 1997     

Influence of egg size differences within egg clutches on larval parameters in nine libellulid species (Odonata)

Abstract.  1. In libellulids, egg size differs between species and populations. There are also size differences within egg clutches of individual females.
2. Past experiments suggest that there are two different types of egg clutches in libellulids. Egg size decreases significantly during oviposition in species that perform non-contact guarding during oviposition. In contrast, in species ovipositing in tandem, egg size is randomly distributed.
3. This study deals with the possible consequences of egg size variation within the different egg clutch types. The study examined whether there is a correlation between egg development time, offspring sex or larval size and egg size.
4. The current experiments were conducted in Namibia and Germany. Five non-contact guarding and four tandem guarding libellulid species were used.
5. In some species larger eggs needed more time to develop, in some species no correlation between egg size and egg development time could be found, whereas in other species larger eggs developed faster.
6. The sex ratio was biased towards females in Leucorrhinia dubia and in Sympetrum striolatum and egg size was not associated with gender.
7. In both egg clutch types larger eggs resulted in larger larvae. In this study, evidence was found that the effects of egg size diminished with progressing larval development under good conditions. However, it is possible that the effects may have a greater influence under harsh circumstances.     

Oral lichenoid lesions and allergy to dental materials

BACKGROUND: Dental materials, oral hygiene products and food additives may cause contact allergic reactions in the mouth with varied clinical presentation. Oral lichenoid lesions (lichen planus-like lesions) can be induced by hypersensitivity to dental restorative metals, acrylates, flavorings and other substances. AIM: The aim of this study was to demonstrate contact allergy to dental materials in patients with oral lichenoid lesions using patch tests. PATIENTS AND METHODS: Routine patch tests with two sets of allergens - "European Standard" and "Dental Screening" (Chemotechnique Diagnostics, Sweden) supplemented with pulverized amalgam, iridium, indium, menthol, sorbic acid and platinum were done on a set of 25 patients with lichenoid lesions located on the buccal mucosa, tongue and lips. Application and interpretation of the tests were conducted according to ICDRG (International Contact Dermatitis Research Group). RESULTS: 15 (60 %) patients showed sensitization to 1 or more allergens, with a total of 31 positive reactions. The greatest frequency of positive reactions was to dental metals, with a total of 27 positive reactions. The order of tested metals according to frequency of positive reactions was mercury (6/25/24 %), amalgam (6/25/24 %), nickel (4/25/16 %), palladium (4/25/16 %), cobalt (3/25/12 %), gold (2/25/8 %), chrome (1/25/4 %), indium (1/25/4 %). The clinical relevance of the results with regard to the material's presence in the mouth was demonstrated in 11 (44 %) patients. In 9 patients, replacement of the positively tested materials led to healing or to significant regression of mucosal changes. CONCLUSIONS: The results of the patch tests showed the possible contribution of contact sensitization in the pathogenesis of lichenoid manifestations in the oral cavity. Due to the premalignant character of these lesions, replacement of positively tested materials and follow up of these patients is advised.     

Analysis of CD95 threshold signaling: triggering of CD95 (FAS/APO-1) at low concentrations primarily results in survival signaling

Recently we generated a mathematical model (Bentele, M., Lavrik, I., Ulrich, M., Stosser, S., Heermann, D. W., Kalthoff, H., Krammer, P. H., and Eils, R. (2004) J. Cell Biol. 166, 839-851) of signaling in CD95(Fas/APO-1)-mediated apoptosis. Mathematical modeling in combination with experimental data provided new insights into CD95-mediated apoptosis and allowed us to establish a threshold mechanism of life and death. Here, we further assessed the predictability of the model experimentally by a detailed analysis of the threshold behavior of CD95 signaling. Using the model predictions for the mechanism of the threshold behavior we found that the CD95 DISC (death-inducing signaling complex) is formed at the cell membrane upon stimulation with low concentrations of agonistic anti-APO-1 monoclonal antibodies; however, activation of procaspase-8 at the DISC is blocked due to high cellular FLICE-inhibitory protein recruitment into the DISC. Given that death signaling does not occur upon CD95 stimulation at low (threshold) anti-APO-1 concentrations, we also analyzed survival signaling, focusing on mitogen-activated protein kinase activation. Interestingly, we found that mitogen-activated protein kinase activation takes place under threshold conditions. These findings show that triggering of CD95 can signal both life or death, depending on the strength of the stimulus.     

A high-power laser-driven source of sub-nanosecond soft X-ray pulses for single-shot radiobiology experiments

A large-scale, double-stream gas puff target has been illuminated by sub-kJ, near-infrared (NIR) focused laser pulses at the PALS facility (Prague Asterix Laser System) to produce high-energy pulses of soft X rays from hot, dense plasma. The double-puff arrangement ensures high gas density and conversion efficiency from NIR to X rays approaching that typical for solid targets. In addition, its major advantage over solid targets is that it is free of debris and has substantially suppressed charged-particle emission. The X-ray emission characteristics of the source were determined for a range of gases that included krypton, xenon, N(2), CO and N(2)-CO. A demonstrated application of the xenon-based source is a single-shot damage induction to plasmid DNA. The yields of single-strand breaks (SSBs) and double-strand breaks (DSBs) were determined as a function of energy fluence adjusted by varying distance of sample from the source and thickness of aluminum filters.     

Diversity in neuroanatomical distribution of abnormal prion protein in atypical scrapie

Scrapie is a transmissible spongiform encephalopathy (TSE) in sheep and goats. In recent years, atypical scrapie cases were identified that differed from classical scrapie in the molecular characteristics of the disease-associated pathological prion protein (PrP(sc)). In this study, we analyze the molecular and neuropathological phenotype of nine Swiss TSE cases in sheep and goats. One sheep was identified as classical scrapie, whereas six sheep, as well as two goats, were classified as atypical scrapie. The latter revealed a uniform electrophoretic mobility pattern of the proteinase K-resistant core fragment of PrP(sc) distinct from classical scrapie regardless of the genotype, the species, and the neuroanatomical structure. Remarkably different types of neuroanatomical PrP(sc) distribution were observed in atypical scrapie cases by both western immunoblotting and immunohistochemistry. Our findings indicate that the biodiversity in atypical scrapie is larger than expected and thus impacts on current sampling and testing strategies in small ruminant TSE surveillance.