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α2-Macroglobulin (A2M) is a proteinase inhibitor found in association with senile plaques (SP) in Alzheimer's disease (AD). A2M has been implicated biochemically in binding and degradation of the amyloid β(Aβ) protein which accumulates in SP. We studied the relationship between Alzheimer's disease and a common A2M polymorphism, Val1000 (GTC)/lle1000 (ATC), which occurs near the thiolester active site of the molecule. In an initial exploratory data set (90 controls and 171 Alzheimer's disease) we noted an increased frequency of the G/G genotype from 0.07 to 0.12. We therefore tested the hypothesis that the G/G genotype is over-represented in Alzheimer's disease in an additional independent data set: a group of 359 controls and 566 Alzheimer's disease patients. In the hypothesis testing cohort, the G/G genotype increased from 0.07 in controls to 0.12 in Alzheimer's disease (P < 0.05, Fisher's exact test). The odds ratio for Alzheimer's disease associated with the G/G genotype was 1.77 (1.16-2.70, P < 0.01) and in combination with APOE4 was 9.68 (95% CI 3.91-24.0, P < 0.001). The presence of the G allele was associated with an increase in Aβ burden in a small series. The A2M receptor, A2M-r/LRP, is a multifunctional receptor whose ligands include apolipoprotein E and the amyloid precursor protein. These four proteins have each been genetically linked to Alzheimer's disease, suggesting that they may participate in a common disease pathway

The Messel Pit fossil site near Darmstadt, Germany, is famous because of its numerous well-preserved mammal and other fossils, and therefore, in 1995 became a UNESCO-World Heritage (www.unesco-welterbe.de/en/). The respective host rock, the Messel oil shale is still a matter of intensive studies. This dark, finely laminated organic rich mudstone, was deposited in a Maar lake in the Lower Middle Eocene about 47Ma ago during a time span of 1 to 1.5 Ma. One subunit, the so-called ’Middle Messel Formation‘ can be subdivided by several specifically named marker beds (M, $\alpha$, $\beta$ and $\gamma$), but also by some further layers with distinct macroscopic characteristics. The two layers investigated here represent green-brown deposits with a maximum thickness of up to one millimetre only. They are encountered at a level of 35 cm (herein after referred to as ’layer 0,35m u$\alpha$‘) and 100 cm (herein after referred to as ’layer 1,00m u$\alpha$‘) below Marker Bed $\alpha$. Typically, both layers are extremely ductile, and thus can easily be manually separated like individual paper-like book-sheets from their adjacent host rock. Because of their leather-like plasticity, they must be considered to be rich in organic material. Accordingly, it was the objective of this study to reveal the type of organic matter they consist of. This approach tested the lateral variation of organic matter of layer 0,35m u$\alpha$ and layer 1,00m u$\alpha$ by comparison of the molecular compositions exhibited by the analytical results of temperature programmed pyrolysis-gas chromatography and thermovaporisation-gas chromatography which need small sample amounts only. In addition, the molecular compositions of the C$_{15+}$-soluble organic matter of the layers were compared to their adjacent host rocks. The bulk parameters like total organic carbon (TOC), total sulphur (TS), and the hydrogen index (HI) confirm higher contents of organic matter for both layers, with stronger enrichments for layer 1,00m u$\alpha$. Layer 1,00m u$\alpha$ exhibits a surprising high sulphur content of 7 %, which can not be explained so far but may represent a high microbial degradation of the organic matter. In respect to the molecular compositions, influences by migrated organic matter can be excluded due to a maturity stage below 0.5% Rr (mean Tmax below 430$\circ$C and a strong predominance of the odd- to-even-numbered n-alkanes). Lipid compositions with predominance of the odd-numbered n-C$_{23}$ to n-C$_{31}$ alkanes pointing to high proportions of terrestrial plant material are in contrast to HI values above 620mgHC/g TOC. Thus, high bacterial/microbial contributions have to be assumed which is confirmed by individual biomarker data. Both layers and the host rock have incorporated similar amounts of bacterial/microbial organic material. In contrast, layers 0,35m u$\alpha$ and 1,00m u$\alpha$ exhibit similar enrichments of algal and terrestrial plant organic matter compared to their host rock. In respect to the deposition of layers 0,35m u$\alpha$ and 1,00m u$\alpha$, it is certain that both do not include any other kind of specific organic matter in comparison to their host rocks. However, identical enrichments of both algal and terrestrial organic matter may be explained by increased bioproductivity, but much more probable seems a nearly to zero diminished sedimentary input. Accordingly, for the time of deposition of layers 0,35m u$\alpha$ and 1,00m u$\alpha$, a short period of a relative arid climate, with extremely small amounts of rain fall and therefore, more or less no erosion can be assumed.

Oil expulsion efficiencies from different lithologies have been investigated and compared employing pyrolyses of samples of unconventional grain-size (from < 0.106 mm up to 8 mm) in the expectation of getting a little closer to natural systems. Standard (regular) pyrolyses, including Rock-Eval, employ finely ground samples (< 0.25 mm). Although this facilitates the escape of indigenous and generated hydrocarbons for analytical purposes, it changes rock texture and largely precludes much information about expulsion. It seems far from natural. Accordingly, we performed Rock-Eval pyrolysis and open-anhydrous programmed-temperature pyrolysis gas chromatographic (Py-GC) analyses, on five grain-size splits of samples - up to 8 mm. This does reveal more information about expulsion and permits inferences about subsurface natural expulsion. The expulsion of oil from a source rock depends upon the release of the generated oil from kerogen and movement (primary migration) of the released oil within the source rock. Thermovaporization and pyrolysis results suggest that neither the release of liquid hydrocarbons from kerogen nor the movements of these hydrocarbons within source rock, is the major limiting factor on the expulsion of oil from H-rich kerogen-containing source rocks (torbanite, lamosite, marinite, liptinite-rich humic coals). Thermovaporization of indigenous liquid (S1) hydrocarbons from tight carbonates and liptinite-poor humic coals is adversely affected by increasing grain size of the rock, suggesting that primary migration of liquid hydrocarbons is relatively restricted. Retention of liquid hydrocarbons may lead to oil to gas cracking. Py-GC analyses support this inference. Source rocks containing H-poor kerogen (e.g. brown coal, humic coal) are not good expellers of liquid hydrocarbons probably because both the release of oil from the kerogen and the movement of oil within a coal are limiting factors on expulsion. However, pyrolysis results on liptinite (sporinite)-rich immature humic coal (HI > 300 mg HC/g C(org)) show that liquid range hydrocarbons are expelled from coal when the generated oil exceeds the coal sorption capacity. This suggests that expulsion of oil from liptinite-poor, or in general H-poor, humic coals is primarily limited by the release of generated liquid hydrocarbons from kerogen because such coals, generally, do not generate sufficient amounts of liquid hydrocarbons to overcome the coal sorption capacity. (C) 1998 Elsevier Science Ltd. All rights reserved.