NADP+-isocitrat-dehydrogenase aus Idus idus (Pisces: Cyprinidae). II. Einfluß der temperatur auf substrat- und cosubstrataffinität

Maximum substrate and cosubstrate affinity, as judged by the Michaelis constant (K _M ), of NADP⁺-dependent isocitrate dehydrogenase of pig heart (purchased from Boehringer, Mannheim, FRG) is attained at 37°C. If K _M -values of substrate (Isocitrate, IC) and cosubstrate (NADP⁺) of NADP⁺-dependent isocitrate dehydrogenase (ICDH) of the white dorsal muscle of Idus idus L. is plotted against the experimental temperature (VT), W-shaped curves result. With increasing adaptation temperature (AT), there is a shift to increasing VT. It is suggested that the W-shaped curves are due either to the simultaneous presence of two multiple forms of the enzyme, or to the reversible temperature-dependent interconversion of one protein species.     

Environmental problems of coal production in the federal republic of of germany with particular reference to to the Ruhr

In 1979 it was noted that the production of deep-mined coal in the Federal Republic of Germany, including the Ruhr area, has risen once again. Since the beginning of the sixties the convenient source of both energy and raw material, oil, has been responsible for the falling levels of coal production in the Ruhr, to almost one half of peak production in 1956. Not much would have been needed to give up the entire troublesome and expensive process of deep coal mining in the Federal Republic in favour of the then cheap and bountiful oil. Only lignite managed to maintain a more or less steady annual production rate due to the direct conversion into electricity of a major part of its production at the site of extraction. Since the limitations and uncertainties governing the supply of crude oil have now been clearly exposed, the illusions about oil have begun to fade, and as a result confidence in our indigenous supplies of energy and raw material resources has been restored. What, however, are the implications of this revival of home-produced energy and raw material, which are not without problems both when produced and when consumed for the region in which they are extracted and brought to the surface, and where, to a large extent, the processing takes place? The region benefits from employment and investment, and in turn offers its resources (labour, land, water, air) inasmuch as past development has left them available for future development. But is the region to be covered with even more ‘honourable’ scars? In 1980, 87 million tonnes of deep mined coal were produced in the Federal Republic of Germany which resulted in roughly the same amount of minestone (spoil). Approximately 600 km² of densely populated area in the Ruhr district was already acquiring artificial drainage due to subsidence. Coking plants and old coal-based stations fired with deep mined coal pollute air and water. Lignite production in 1980 in the Federal Republic of Germany — which was almost entirely obtained by opencast mining — amounted to 130 million tonnes. To achieve this an additional 445×10⁶m³ of overburden had to be shifted. Already in 1977 in the Rhineland between Cologne, Dusseldorf and Aachen (Aix-la-Chapelle), 522 km² of mainly good agricultural land was acquired under compulsory purchase order for lignite mining. Villages, roads, rail and waterways were and continue to be re-routed and re-sited. The direct conversion of lignite into electricity produces emission and spreads pollution. Now, it is not only the people of the Ruhr area, the largest industrial conurbation in Europe, that have become sensitive to the impact of mining upon their environment. In all industrial countries it has been learned that those things which cannot be replaced, i.e. environment, are not always being valued by the free market at a price which represents the value they may have for the individual and possibly should have for all of us. Today the need for mining is hardly being questioned any more but people are voicing their opinion as to what is a just price to be paid. The citizen of the Ruhr, for instance, no longer accepts that the specific environmental impacts caused by deep coal mining, which produces a commodity wanted by the entire nation, should be borne solely at the place where it is produced and by the people who happen to live there. He demands that such burdens are borne by everybody who enjoys the benefits. Clear political ideas must be developed and made know as to how much we value home-produced energy sources, what proportion of the resulting burdens the country is willing to bear and how they are to be distributed fairly. There are many methods and technical means by which the burdens of the mining and industrial regions can be minimised, by which damage can be repaired and derelict areas reclaimed. The application of such means must be safeguarded by early planning and sufficient finanacing so that the exploitation of one resource will not result in other resources being lost.     

Demands of effective PCDD/PCDF-analysis in environment and production control. Aims of an analytical laboratory to meet legal and toxicological requirements. Critical approach to detection limits

Attainable or obtained detection limits play an important role in the discussion of trace analysis of polychlorinated dibenzo-p-dioxins and -furans. Now-a-days state of the art is based as well on highly developed instrumental techniques as on sophisticated clean up methods. However, with this state of the art is not connected, necessarily, a defined level of detection limits. Comparison of detection limits obtained in various laboratories are difficult. Reasonable comparisons imply knowledge about definitions, ways of quantitation, strategies of improvement, their limitations, and the substances under investigations. Measures to improve detection limits and their limitations are interdependent in a complex manner. Examples are given in this presentation.

The group analysis of the degrees of chlorination of the dibenzo-p-dioxins and -furans deteriorates the detection limits with respect to the single isomer determitation because of the higher influence of the residual matrix. Particulary, these topics should be taken into consideration when planning and executing analytical work for regulatory enforcement and legal purposes.     

A simple,rapid, and highly informative PCR-based procedure for prenatal diagnosis and carrier screening of phenylketonuria

The polymorphic information content (PIC) and the degree of heterozygosity of several polymorphic systems within the phenylalanine hydroxylase (PAH) gene were determined in 85 European Caucasian and 19 Chinese phenylketonuria (PKU) kindreds. The first system examined, a short tandem repeat (STR), had a PIC of 80 and 73 per cent in these Caucasian and Chinese samples, respectively. The degree of heterozygosity actually observed for this system was 81 and 64 per cent in the Caucasian and Chinese PKU families, respectively. Through the addition of a second polymorphism based on a variable number of tandem repeats (VNTR), the PIC was increased to 90 per cent in Caucasians, but only to 75 per cent in Chinese. The degree of heterozygosity observed for this combination was 94 per cent in European PKU families and 67 per cent in Chinese PKU families. The further addition of an Xmnl RFLP increased both the PIC and the level of heterozygosity in Caucasians to 95 per cent, but did not change either of these measures in Chinese. The combined use of these three polymorphisms significantly increases the informativity of prenatal diagnostic and carrier screening procedures in both Caucasian and Chinese PKU kindreds. Furthermore, since each of these polymorphisms can be studied by PCR-based methods, these new tests can be performed more quickly and easily than previous Southern-based procedures.     

Adjustment formulae for maternal serum alpha-fetoprotein,human chorionic gonadotropin,and unconjugated oestriol to maternal weight and smoking

Serum levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and un-conjugated oestriol (uE3) were measured in serum samples of 4131 non-smoking and 1018 smoking women during the second trimester of pregnancy. The levels of all three analytes decreased with increasing body weight. The AFP median was significantly increased in smokers in a dose-response association; hCG decreased by 21 per cent and uE3 decreased by 3 per cent in smokers in a non-dose-related fashion. Regression functions for adjustment of serum levels for weight and smoking should be considered in risk estimation for Down syndrome in order to give a woman's individual risk more precisely.     

Mutation analysis for prenatal diagnosis and heterozygote detection of Gaucher disease type III (norrbottnian type)

A single base substitution in exon 10 of the glucocerebrosidase gene was detected in families affected by Gaucher disease (GD) type III. This mutation, which results in the substitution of proline for leucine in position 444 of glucocerebrosidase, has been shown to result in type III GD in a Swedish population. Three fetuses at risk for GD type III were diagnosed as homozygous for the mutation and the pregnancies were terminated. In a fourth pregnancy, one parent was excluded as being a carrier and the risk of having a child affected by GD was ignored. Direct analysis of common mutations causal to GD is now available and improves prenatal diagnosis in families where the molecular defect has been characterized.     

Serum lipid,apolipoprotein and lipoparticle levels in the human fetus

Blood collected from 62 fetuses aged 20–38 weeks of gestation was studied. The values of ten lipid parameters were determined: cholesterol (TC), triglycerides (TGs), apolipoprotein Al (apo A1), apolipoprotein B (apo B), apolipoprotein E (apo E), total apolipoprotein CIII (apo CIII), apolipoprotein CIII present in particles containing apo B (apo CIII LpB) or not (apo CIII Lp non-B), lipoparticles A1 (LpA1), and lipoprotein a (Lp(a)). The results show that, except for apo E, all the studied parameters were present in lower concentrations than in adults and newborns, and that Lp(a) is not detectable at that stage in life.     

Immunocytochemical localization of peroxisomal β-oxidation enzymes in human fetal liver

In the majority of congenital peroxisomal disorders, β-oxidation of very long chain fatty acids is deficient. We have investigated the appearance and localization of the three peroxisomal β-oxidation enzymes in normal fetal liver (fertilization age between 5 and 18 weeks) with protein A- gold immunocytochemistry and silver enhancement for light microscopic visualization. With specificity-tested polyclonal antibodies, acyl-CoA-oxidase, bifunctiooal enzyme, and 3-oxoacyl-CoA thiolase were localized in the peroxisomes of the parenchymal cells, which appear as brown or black granules. In the youngest specimen, no immunopositive reaction was obtained. A weak reaction with anti-thiolase was obtained at the age of 6–7 weeks. At a fertilization age of 8 weeks, peroxisomes could be distinctly visualized after immunostaining for all three enzymes. From a staining series with anti-thiolase on simultaneously treated slides, it appears that the amount of antigen per peroxisome and the organelle size increase between the seventh and eighteenth weeks. These data should enable a more specific diagnosis in fetal liver biopsies from pregnancies at risk and after termination of pregnancy.