Finite element modelling and simulations in dentistry: a bibliography 1990-2003

The paper gives a bibliographical review of the finite element modelling and simulations in dentistry from the theoretical as well as practical points of view. The bibliography lists references to papers, conference proceedings and theses/dissertations that were published between 1990 and 2003. At the end of this paper, more than 700 references are given dealing with subjects such as: dental materials; oral and maxillofacial mechanics and surgery; orthodontics, tooth movement, orthodontic appliances; root canals, filling and therapy; dental restorations and other topics.     

Phylogenetic position of Protoopalina intestinalis based on SSU rRNA gene sequence

A robust recognition of phylogenetic affinities of Opalinidae-the peculiar multinucleated intestine commensals of frogs-is hindered by the absence of reliable molecular data. Up to now all attempts to sequence opalinid genes failed, as the obtained sequences labeled as Protoopalina intestinalis, Cepedea virguloidea, and Opalina ranarum in GenBank apparently originate from a zygomycete contamination. In this paper, we present the first molecular data for the family Opalinidae-SSU rRNA gene of P. intestinalis. Our phylogenetic analyses undoubtedly show opalinids as a sister group to Proteromonas within the Stramenopila clade, confirming the monophyly of Patterson's order Slopalinida. The enigmatic genus Blastocystis is resolved with high statistical support as a sister group to Slopalinida. The information contained in the SSU rRNA gene proved insufficient to uncover broader affinities of this group to other groups of Stramenopila. Nevertheless, our analyses clearly demonstrate that Cavalier-Smith's phylum Bigyra, which comprises Oomycetes and their relatives together with Slopalinida and Blastocystis, is not monophyletic.     

Effect of proteasome inhibitor MG132 on in vitro maturation of pig oocytes

The present study aimed to demonstrate the dependence of meiotic maturation in pig oocytes on the activity of the protease complex proteasome. The proteasome inhibitor MG132 blocked the exit of maturing pig oocytes from metaphase I stage. Seventy-five per cent of the oocytes were blocked at metaphase I when they were cultured with 10 microM MG132. The blocking effect of MG132 was expressed only when the oocytes were exposed to an inhibitor before the 18th hour of in vitro culture. The effects of MG132 are fully reversible. However, a significant proportion of oocytes (46%) cultured for 48 h in MG132-supplemented medium and then for 24 h in MG132-free medium did not block meiosis at the stage of metaphase II and underwent spontaneous parthenogenetic activation. On the basis of our data we can conclude that exit from the metaphase I stage of meiosis is proteasome-dependent in pig oocytes matured in vitro. On the other hand, our data also indicate that other proteasome-independent events are involved in regulating the exit from metaphase I.     

Initiation factor eIF2B not p70 S6 kinase is involved in the activation of the PI-3K signalling pathway induced by the v-src oncogene

Our data show that in hamster fibroblasts transformed by Rous sarcoma virus (RSV), the phosphoinositide 3'-kinase (PI-3K)/Akt/glycogen synthase kinase 3 antiapoptotic pathway is upregulated and involved in increased protein synthesis through activation of initiation factor eIF2B. Upon inhibition of PI-3K by wortmannin, phosphorylation of 70-kDa ribosomal protein S6 kinase (p70 S6k) and its physiological substrate, ribosomal protein S6, decreased in the non-transformed cells but not in RSV-transformed cells. Thus PI-3K, which is thought to be involved in regulation of p70 S6k, signals to p70 S6k in normal fibroblasts, but it does not appear to be an upstream effector of p70 S6k in fibroblasts transformed by v-src oncogene, suggesting that changes in the PI-3K signalling pathway upstream of p70 S6k are induced by RSV transformation.     

Structure and dynamics of two elastin-like polypentapeptides studied by NMR spectroscopy

The structure and dynamics of two synthetic elastin-like polypentapeptides, poly(G(1)V(1)G(2)V(2)P) and poly(AV(1)GV(2)P), were studied in D(2)O and H(2)O at various temperatures by using (1)H, (2)H,(13)C, and (15)N NMR spectra, relaxations, and PGSE self-diffusivity measurement. Signal assignments were made using COSY, NOESY, HXCORR, HSQC, HMBC, and SSLR INEPT techniques. Temperature-induced conformation changes were studied using (3)J(NHCH) couplings, NOESY connectivity, chemical shifts, and signal intensities. Hydrodynamic radii were derived from self-diffusion coefficients measured by the pulsed-gradient spin-echo (PGSE) method. Selective hydration (hydrophilic or hydrophobic) was explored using NOESY and ROESY spectral methods and longitudinal and transverse (1)H relaxation of HOD and quadrupolar (2)H relaxation of D(2)O. Four different physical states were discerned in different temperature regions for both polymers: state I of a rather extended, statistically shaped and fully hydrated polymer below the critical temperature (approximately 299-300 K); state II, a relatively coiled and globular but disordered preaggregation state, developing in a rather narrow region, 300-303 K, in the case of poly(AV(1)GV(2)P) and in a broader region, overlapping with the next one, in poly(G(1)V(1)G(2)V(2)P); state III, a tightly coiled, more compact state in the region 303-313 K; and, finally, state IV, an aggregated (and eventually flocculating and sedimenting) state beyond 313 K. States II-IV coexist in varying proportions in the whole temperature range above 299 K. A structure characterized by a beta-turn stabilized by H-bonding between the Ala carbonyl and Val(2) NH groups of poly(AV(1)GV(2)P) was detected by NOESY just above the transition temperature. States II and III are progressively more stripped of their hydration sheath but retain some molecules of water confined and relatively immobilized in their coils.     

The effect of PD98059 on MAPK regulation in cumulus-enclosed and cumulus-free mouse oocytes

The effect of the p42/44 mitogen-activated kinase (MAPK) inhibitor, PD98059, on MAPK activation and meiosis resumption in mouse oocytes was studied. When germinal vesicle (GV)-stage denuded oocytes (DOs) were cultured continuously in 50 microM PD98059, germinal vesicle breakdown (GVBD) was postponed for 2-3 h. MAPK phosphorylation and activation was delayed as well. However, PD98059 did not impair histone H1 kinase activation. After 14 h of culture there was no significant difference in the rate of DOs reaching metaphase II (MII) arrest in either control or experimental conditions. The effect of PD98059 on MAPK inhibition was further tested in epidermal growth factor (EGF)-treated oocytecumulus complexes (OCCs). Exposure of GV-stage OCCs for 5 min to EGF (10 ng/ml) induced a considerable increase in MAPK phosphorylation. After OCCs were further cultured in 50 microM PD98059 a rapid dephosphorylation of MAPK was induced. Already after 1 min of treatment the non-phosphorylated form of MAPK dominated, indicating the high effectivity of PD98059. This result indicates that short EGF/PD98059 treatment of OCCs induced MAPK phosphorylation/dephosphorylation in cumulus cells only. As only a transient delay in MAPK phosphorylation and activation was observed in PD98059-treated DOs we conclude that there is also another PD98059-nonsensitive pathway(s) leading to MAPK activation in mouse oocytes. The data obtained suggest that meiosis resumption in mouse oocytes is somehow influenced by the MEK/MAPK activation pathway.     

Minipig as a model for drug metabolism in man: comparison of in vitro and in vivo metabolism of propafenone

To prove the suitability of minipigs as experimental animal in modeling of the drug metabolism and pharmacokine-tics in man, propafenone metabolism in vitro at the microsomal level as well as propafenone pharmacokinetics in the minipig was studied. The results were compared with those obtained for humans. It can be concluded that whereas the microsomal in vitro system of minipig may be a good model for drug metabolism in the man, the pharmacokinetics in the whole organism is more complex reflecting differences in substrate specificities of many enzymatic and transport systems. In this particular case, it has been documented that the glucuronidation of propafenone principal metabolite (5-hydroxypropafenone) is more efficient in the minipig.     

Women's preference for dominant male odour: effects of menstrual cycle and relationship status

Body odour may provide significant cues about a potential sexual partner's genetic quality, reproductive status and health. In animals, a key trait in a female's choice of sexual partner is male dominance but, to date, this has not been examined in humans. Here, we show that women in the fertile phase of their cycle prefer body odour of males who score high on a questionnaire-based dominance scale (international personality items pool). In accordance with the theory of mixed mating strategies, this preference varies with relationship status, being much stronger in fertile women in stable relationships than in fertile single women.     

Automated Water Analyser Computer Supported System (AWACSS) Part II: Intelligent, remote-controlled, cost-effective, on-line, water-monitoring measurement system

A novel analytical system AWACSS (Automated Water Analyser Computer Supported System) based on immunochemical technology has been evaluated that can measure several organic pollutants at low nanogram per litre level in a single few-minutes analysis without any prior sample pre-concentration or pre-treatment steps. Having in mind actual needs of water-sector managers related to the implementation of the Drinking Water Directive (DWD) [98/83/EC, 1998. Council Directive (98/83/EC) of 3 November 1998 relating to the quality of water intended for human consumption. Off. J. Eur. Commun. L330, 32-54] and Water Framework Directive (WFD) [2000/60/EC, 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Off. J. Eur. Commun. L327, 1-72], drinking, ground, surface, and waste waters were major media used for the evaluation of the system performance. The first part article gave the reader an overview of the aims and scope of the AWACSS project as well as details about basic technology, immunoassays, software, and networking developed and utilised within the research project. The second part reports on the system performance, first real sample measurements, and an international collaborative trial (inter-laboratory tests) to compare the biosensor with conventional anayltical methods. The systems' capability for analysing a wide range of environmental organic micro-pollutants, such as modern pesticides, endocrine disrupting compounds and pharmaceuticals in surface, ground, drinking and waste water is shown. In addition, a protocol using reconstitution of extracts of solid samples, developed and applied for analysis of river sediments and food samples, is presented. Finally, the overall performance of the AWACSS system in comparison to the conventional analytical techniques, which included liquid and gas chromatographic systems with diode-array UV and mass spectrometric detectors, was successfully tested in an inter-laboratory collaborative trial among six project partners.