Lipoprotein(a) inhibits collagen-induced aggregation of thrombocytes.

Lipoprotein(a) [Lp(a)] is known to interact with human platelets in vitro. In the present study the effect of physiological concentrations of Lp(a) on platelet aggregation was studied. Freshly prepared gel-filtered platelets from healthy donors were incubated for 30 minutes at 37 degrees C with various concentrations of Lp(a); aggregation was triggered with ADP, thrombin, and collagen. Control incubations were performed with Tyrode's solution or LDL. Thrombin- and ADP-triggered aggregations were only slightly influenced by Lp(a), but aggregation of platelets stimulated with collagen (4 micrograms/mL) was markedly inhibited. Measurable effects occurred at low concentrations (0.05 mg/mL) of total Lp(a); at 0.5 mg/mL, maximum aggregation of platelets was inhibited by 54 +/- 20%, and the aggregation rate was attenuated by 47 +/- 19% compared with platelets incubated with Tyrode's solution. Preincubation of collagen (4 micrograms/mL) with Lp(a) yielded similar results. The effect of Lp(a) on platelet aggregation was accompanied by a significant reduction of serotonin release and TXA2 formation. Higher concentrations of collagen ( > or = 10 micrograms/ mL) caused the inhibitory effect on Lp(a) on collagen-induced aggregation to disappear. In contrast, incubation of platelets with 5 mg/mL LDL led to a significant increase of aggregation rate, maximum aggregation, serotonin release, and formation of TXA2 when aggregation was induced with 4 micrograms/mL collagen. In an adhesion assay using fresh whole blood, which mimics the in vitro situation of vessel injury. Lp(a) reduced platelet adhesion at shear rates of 300 and 1600/s by 22.6% and 11.6%, respectively. In addition, Lp(a) reduced the size of platelet aggregates significantly (up to 63%); this reduction was more distant at the higher shear rate. Unlike LDL, Lp(a) is not a proaggregatory lipoprotein; rather, collagen-triggered aggregation in vitro is attenuated by Lp(a).

[Late antiquity constitutional historical and social-anthropologic observations of middle and north European populations at the time of population migrations]. / Spätantike konstitutionshistorische und sozial-anthropologische Beobachtungen an mittel- und nordeuropäischen Bevölkerungen der Völkerwanderungszeit.

This review on reports of mostly late antique authors concerning the physical appearance of Teutonic and Nordic populations of the so-called "Völkerwanderungszeit" is part of an extensive study of possible nutritional effects on somatotypes in early periods of the German history. It is linked up with a similar study on Teutonics of protohistorical periods (Wurm 1986a). The authors of the late antique periods were again and again impressed by the comparatively tall and sturdy stature as well as by the permanent martial aggressiveness and the considerable population growth of Northern peoples. One can observe a marked social variability in the distribution of somatotypes, and one can suppose, too, that physical superiority was favourable to social rise. However, as compared with Roman soliders the Teutonic-Nordic warriors of the "Völkerwanderungszeit" were obviously inferior as far as permanent physical stress is concerned. This seems to be caused by nutritional differences. Furthermore, the repeatedly claimed inclination of Teutonic-Nordic populations to a considerable consumption of alcoholics seems also be due to nutritional factors. Hair and eye colour of these populations are described by the various antique authors in a different way. The reported geographical differences in the distribution of hair and eye colour seem to indicate considerable Celtic elements in certain populations, which originally were designed as Teutonics. Apart from that no clear anthropological differences were recorded between different populations of this period.

[Preliminary study of an interdisciplinary examination of the body height proportions of Germans in the 19th century and of the influence of living conditions. I. Introductory justification, problems and preliminary studies based on authentic sources from the political districts from northern Germany to Württemburg]. / Vorarbeiten zu einer interdisziplinären Untersuchung über die Körperhöhenverhältnisse der Deutschen im 19. Jahrhundert und der sie beeinflussenden Lebensverhältnisse. Teil I: Einleitende Begründung, quellenkundliche Probleme, quellenkundliche Vorarbeiten für die politischen Einzelräume von Norddeutschland bis Württemberg.

Researches about the influences of the nutritional conditions on body-height need interdisciplinary co-operation of Anthropology, History, and Dietetics. Such a team will be difficult succeed in joining. Especially interesting for human sciences are nutritional-constitutional researches on German populations in the 19th century, because in this century multifarious varieties exist within the German settlement. Author hopes, that preliminary original researches and first trends in results facilitate the joining of such an interdisciplinary team. In part I of this inquiry, the necessity for nutritional-constitutional researches are justified, problems are treated and mustering-statistics, the most important data-material, are collected for the political regions of that time from North to the kingdom Württemberg. The kingdom Württemberg of course is the political region with the most continuous data-series, but the data-material is poor on body-height-means and needs new statistical treatments. Less data are particularly available from the middle of the German settlement.

[Preliminary studies of an interdisciplinary inquiry of the body height proportions of Germans in the 19th century and of the influence of living conditions. II. Original preliminary studies for Baden, Alsace-Lorraine, Bavaria, the whole German Reich, summarizing evaluation, historical nutritional references, literature]. / Vorarbeiten zu einer interdisziplinären Untersuchung über die Körperhöhenverhältnisse der Deutschen im 19. Jahrhundert und der sie beeinflussenden Lebensverhältnisse. Teil II: Quellenkundliche Vorarbeiten für Baden, Elsass-Lothringen, Bayern, das gesamte Deutsche Reich, zusammenfassende Auswertung, ernährungshistorische Hinweise, Schrifttum.

In Part I of this examinations, preliminary original researches about the constitutional situations in Germany from the North to the kingdom Württemberg has been presented. In this part II, such preliminary researches follow for the other southern part of the German settlement. With references to Baden, Alsace-Lorraine, and Bavaria first since the second part of the 19th century, comprehensive anthropological data exist, but these contain valuable and differentiated data material. A first analysis for this German data material does not reveal regular relation-ships between body-height, urban and rural life, and geographical altitude. But there are relation-ships between wealthy and poor social classes and between educated and heavily working people, and there exists a negative trend in the body-height-means from the North and South to the middle of the German settlement with minima in Saxony and in several regions in Southern Germany. As spread for the different means about 160 to more than 170 cm is to estimate. The spread seems to be broader in the second half of the 19th century, presumably because the better life-conditions does not hold for all Germans in the same manner. About of the beginning of the 20th century, the body-height-means show an increase with may by interpreted as an kind of rehabilitation after times of emergency in the early industrialization and of difficulties in food supply.

Postprandial hyperlipemia and platelet eicosanoid metabolism.

Platelet aggregations stimulated with different concentrations of collagen or ADP were reduced during postprandial hyperlipemia in normolipemic subjects. The concomitant formation of platelet AA metabolites (TXB2, 12-HHT, 12-HETE), however, was not significantly altered.

Postprandial hyperlipemia inhibits platelet aggregation without affecting prostanoid metabolism.

The objective of this work was to characterize changes in platelet aggregability during postprandial hypertriglyceridemia with special emphasis on arachidonic acid metabolism. Ten healthy young men consumed 100 g fat after a fasting period of 12 hr. In-vitro platelet aggregation induced by ADP and collagen was measured at 0, 3, 5, and 9 hours after the fat intake. The major arachidonic acid metabolites, 12-hydroxyeicosatetraenoic acid (12-HETE), thromboxane A2 (TXA2), prostaglandin F2 alpha (PGF2a), and prostaglandin E2 (PGE2) produced during collagen-induced platelet activation were quantified by gas chromatography/mass spectrometry. A significant decrease in platelet aggregability induced by both ADP and collagen was detected during the postprandial hyperlipemia. No significant changes could be found in the prostanoid pattern of collagen activated platelets. There was no correlation between the degree of the inhibition of platelet aggregation and the relative or absolute increase of triglyceride-levels in the plasma during the postprandial hyperlipemia.

Characterization of isoelectric subspecies of asialo-beta 2-glycoprotein I.

Isoelectric focusing of purified beta 2-glycoprotein I (beta 2-G-I) revealed five major bands with isoelectric points (pI) between 5.1 and 6.1. Neuraminidase treatment decreased the number of bands to two (pI 8.0 and 8.2). The two asialo subfractions of beta 2-G-I were purified by cation-exchange column chromatography. The more basic isoform II was found to have a higher content of lysine. Western-blot analysis of different plasma samples confirmed the heterogeneity of beta 2-G-I in plasma. Plasma treated with neuraminidase showed two bands irrespective of the number of isoforms as well as of the concentration in native plasma. This led us to the conclusion that human plasma beta 2-G-I consists of two isoproteins that are sialylated to different extents.

[The brachycephalisation problem, a nutrition constitutional problem?]. / Das Brachycephalisationsproblem, ein ernährungskonstitutionelles Problem?

A hypothesis is framed about which any influences of the nutrition may cause variations of the cranium, but concerning physiological data, kinds of nutrition and special victuals' ingredients cannot still be mentioned. If such connexions are proved, at last the well known brachycephalization among European populations since the Middle Ages and the beginning debrachycephalization in the present time could partially be interpreted.

Interaction of LDL, Lp[a], and reduced Lp[a] with monoclonal antibodies against apoB.

Five monoclonal antibodies (2A, 9A, 6B, L3, L7) produced in mice against human apolipoprotein B were investigated by competitive and inhibitive electroimmunoassay (EIA) for their reactivity with low density lipoprotein (LDL), lipoprotein[a] (Lp[a]), and reduced Lp[a]. All of the antibodies reacted with apoB of the different lipoproteins indicated by very similar slopes of the binding curves. None of them gave a positive reaction with apolipoprotein[a]. The amount of apoB required for 50% inhibition of antibody binding varied for the different antibodies and lipoproteins. Antibody 9A showed almost the same affinity for LDL, Lp[a], and reduced Lp[a]. Antibodies 2A and 6B bound about twofold better to LDL and reduced Lp[a] than to untreated Lp[a]. Antibodies L3 and L7 needed nearly threefold higher amounts of Lp[a]-apoB for 50% inhibition of antibody binding than of apoB of LDL and reduced Lp[a]. The amount of apoB required for 50% inhibition of antibody binding was somewhat higher in inhibitive assay than in competitive assay. We suggest that apo[a] covers certain epitopes of apoB in native Lp[a] leading to a reduced reaction with the monoclonal antibodies. However, it could also be that the binding of the [a]antigen to apoB via disulfide bridges causes profound conformational changes of the apoB region exposed to the surface.

Free and Apo B-associated Lpa-specific protein in human serum.

The distribution of Lpa-specific protein (Apo A) among various fractions of human serum was investigated. The following results were obtained. In very low density lipoproteins (VLDL) of fasting human serum Apo A cannot be detected. Most of Apo A is complexed to LDL forming lipoprotein a (Lpa) present in the density fraction of 1.006-1.125 g/ml. Only approximately 5% of Apo A are found in the d greater than 1.125 bottom fraction after ultracentrifugation. Phosphotungstate-Mg (PTA), heparin-Mn (Hep) and dextran sulfate-Mg (DS) precipitate approximately 95% of serum Lpa together with the Apo B containing lipoproteins. Also monospecific antibodies against Apo B do not precipitate all Lpa and leave approximately 3% of Apo A in the supernatant. With polyethylene glycol (PEG) on the other hand, virtually all Lpa is removed since this reagent also precipitates Lpa and Apo A. Apo A of the bottom fraction after ultracentrifugation and of the supernatant after selective precipitation is not stainable with Sudan black and probably represents a protein which is not associated with lipids.

Cyclooxygenase and lipoxygenase metabolites during platelet aggregation: quantitative measurement by negative ion chemical ionization--gas chromatography/mass spectrometry.

This study was aimed at investigating systematically the aggregation of human gel filtered platelets induced by various physiological stimuli such as thrombin (0.25 U/ml), collagen (2 micrograms/ml), a mixture of thrombin and collagen, and ADP (2-5 microM). For quantitative measurement of TXB2, PGF2 alpha and 12-HETE, negative ion chemical ionization-gas chromatography/mass spectrometry using stable isotope dilution was applied. Stimulation by thrombin, collagen and the combined agonists resulted in an increase of TXB2 (up to 54 ng/1 X 10(8) platelets) and 12-HETE (up to 44 ng/1 X 10(8) platelets) during platelet aggregation. The stimulation with ADP showed only little increase of these metabolites and this only during the second wave of aggregation. Very little amounts of PGF2 alpha were produced during thrombin stimulated aggregation.