The effect of different preservation methods on the carbon content of megacyclops gigas

The effect of various preservation methods on the carbon content of the copepod Megacyclops gigas was studied using the carbon content of living animals as a control. No differences were found between animals dried at –20, +60, or +105°C, but in all cases the carbon content was slightly lower than that found in living animals. Chemical preservation with formaldehyde and acid Lugol's solution rapidly resulted in about 35% loss of carbon. Freezing at –20°C in water caused less marked but significant loss of carbon, whereas freezing in dilute formaldehyde yielded values agreeing with those of living animals.     

Proxy comparison in ancient peat sediments: pollen,macrofossil and plant DNA

We compared DNA, pollen and macrofossil data obtained from Weichselian interstadial (age more than 40 kyr) and Holocene (maximum age 8400 cal yr BP) peat sediments from northern Europe and used them to reconstruct contemporary floristic compositions at two sites. The majority of the samples provided plant DNA sequences of good quality with success amplification rates depending on age. DNA and sequencing analysis provided five plant taxa from the older site and nine taxa from the younger site, corresponding to 7% and 15% of the total number of taxa identified by the three proxies together. At both sites, pollen analysis detected the largest (54) and DNA the lowest (10) number of taxa, but five of the DNA taxa were not detected by pollen and macrofossils. The finding of a larger overlap between DNA and pollen than between DNA and macrofossils proxies seems to go against our previous suggestion based on lacustrine sediments that DNA originates principally from plant tissues and less from pollen. At both sites, we also detected Quercus spp. DNA, but few pollen grains were found in the record, and these are normally interpreted as long-distance dispersal. We confirm that in palaeoecological investigations, sedimentary DNA analysis is less comprehensive than classical morphological analysis, but is a complementary and important tool to obtain a more complete picture of past flora.     

A new fungus,Aureomyces mirabilis gen. et sp. nov., from pine-timber

Aureomyces gen. nov. with the type speciesAureomyces mirabilis sp. nov. isolated from a pine-timber,Pinus silvestris, in Finland is described and illustrated.

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Zusammenfassung Aureomyces gen. nov. wurde mit dem ArttypeAureomyces mirabilis sp. nov. vom Kiefernholz,Pinus sylvestris, in Finnland isoliert. Der Pilz ist beschrieben und illustriert.

     

Effect of Nitrate, Ammonium and Some Amino Acids on Growth and Nitrate Reductase Activity in Suspension Cultures of Atropa belladonna

Growth and nitrate reductase activity (NRA) of Atropa belladonnacells were studied in medium supplemented with NaNO₃, NH₄NO₃,and amino acid precursors to tropane alkaloids. Growth and NRAwere stimulated by NH₄⁺ and by proline, by proline plus ornithine,but not by glutamate, in NO₃^–-containing medium. Testedamino acids inhibited neither utilization of inorganic nitrogennor growth. (Received September 30, 1988; Accepted August 28, 1989)     

Histochemical study of alkali-burned rabbit anterior eye segment in which severe lesions were prevented by aprotinin treatment

Activities of different enzymes (acid glycosidases, phosphatases, Na+ - K+ -dependent ATPase, proteases, dehydrogenases) and acid glycosaminoglycans were studied by histochemical methods in sections of rabbit anterior eye segments after experimental alkali burn and treatment with aprotinin, an inhibitor of plasmin and other serine proteinases. Solutions of sodium hydroxide (0.25-1.0 M) were applied on corneas using 12-mm-diameter plastic tube for 15-60 s. After wiping with cotton and rinsing with tap water aprotinin solutions were applied in saline (in experimental animals) and saline (in control animals) dropwise in 12-h intervals for a month. Within the first two weeks aprotinin was used at a concentration of 5000 IU/ml. During the subsequent two weeks the aprotinin concentration was reduced to 2500 IU/ml. Striking differences in enzyme activities and in the healing between treated and untreated eyes were found. Without aprotinin, ulcers developed in most corneas within 3 weeks and plasmin was regularly demonstrated in tears and in the aqueous. When aprotinin treatment was started within 24 h after the burn, the number of enzymatically active inflammatory cells was significantly lower, not only in the cornea itself but also in the whole anterior eye segment. With aprotinin treatment no ulcerations and no plasmin in tears and the aqueous were observed and the corneas healed within a month. The healing process started from the zone of enzymatically activated corneal cells in the unburned zone at the corneal periphery. In the regenerating epithelium and endothelium high activities of Na+ -K+ -dependent ATPase, gamma-glutamyltransferase, lactate and succinate dehydrogenases appeared very soon.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical Trials Testing Cardiovascular Benefits of Antioxidant Supplementation

Self-selected supplementation of vitamin E has been associated with reduced coronary events and atherosclerotic progression, but the evidence from clinical trials is controversial. ASAP was a 6-year randomized trial to study the effect of supplementation with vitamin E plus slow-release vitamin C on carotid atherosclerotic progression in 520 hypercholesterolemic men and women aged 45-69 years. The supplementation reduced the progression of carotid atherosclerosis by 26% ( P =0.014), by 33% ( P =0.024) in men and 14% (not significant) in women. The effect was larger in subjects with low baseline vitamin C or atherosclerotic plaques. In the Harvard IVUS trial, the combined supplementation with vitamins E and C significantly inhibited the progression of coronary atherosclerosis in one year. These data confirm that the supplementation with a combination of vitamins E and C can retard atherosclerotic progression. The findings of completed trials testing the effect on cardiovascular events are less consistent. The major on-going clinical trials include the SU.VI.MAX, WHS, WACS and WAVE studies. These involve in total over 80,000 subjects, who are treated with antioxidative supplements for years. The results of these studies will become available during 2003-2006. They may provide the necessary additional information concerning the effect of antioxidants on cardiovascular events.     

Isolation of vitamin B-12-binding proteins by combined immuno and affinity chromatography. Comparative studies on the isolated and unisolated proteins

Intrinsic factor or cobalophilin were removed by incubating human gastric juice and pig pyloric extract with purified anti-intrinsic factor and anti-cobalophilin immunoglobulin-G, respectively, covalently coupled to Sepharose. Cobalophilin (transcobalamin I) was also removed from pig serum either by using anti-cobalophilin immunoglobulin-G Sepharose or by Sephadex G-200 chromatography. The one remaining semipurified vitamin B-12-binding protein (intrinsic factor, cobalophilin or transcobalamin II) was then isolated by vitamin B-12-Sepharose affinity chromatography. Intrinsic factors, cobalophilins and transcobalamin II isolated by this two-step procedure were compared by double isotope techniques with the corresponding protein not subjected to affinity chromatography and found to be identical in reaction to antiserum, gel filtration and electrofocusing. The avidity of the isolated and unisolated intrinsic factors for the ileal intrinsic factor receptor was also the same.     

Mitochondrial fatty acid synthesis and respiration

Recent studies have revealed that mitochondria are able to synthesize fatty acids in a malonyl-CoA/acyl carrier protein (ACP)-dependent manner. This pathway resembles bacterial fatty acid synthesis (FAS) type II, which uses discrete, nuclearly encoded proteins. Experimental evidence, obtained mainly through using yeast as a model system, indicates that this pathway is essential for mitochondrial respiratory function. Curiously, the deficiency in mitochondrial FAS cannot be complemented by inclusion of fatty acids in the culture medium or by products of the cytosolic FAS complex. Defects in mitochondrial FAS in yeast result in the inability to grow on nonfermentable carbon sources, the loss of mitochondrial cytochromes a/a3 and b, mitochondrial RNA processing defects, and loss of cellular lipoic acid. Eukaryotic FAS II generates octanoyl-ACP, a substrate for mitochondrial lipoic acid synthase. Endogenous lipoic acid synthesis challenges the hypothesis that lipoic acid can be provided as an exogenously supplied vitamin. Purified eukaryotic FAS II enzymes are catalytically active in vitro using substrates with an acyl chain length of up to 16 carbon atoms. However, with the exception of 3-hydroxymyristoyl-ACP, a component of respiratory complex I in higher eukaryotes, the fate of long-chain fatty acids synthesized by the mitochondrial FAS pathway remains an enigma. The linkage of FAS II genes to published animal models for human disease supports the hypothesis that mitochondrial FAS dysfunction leads to the development of disorders in mammals.