Community metabolism on rocky-shore assemblages in a mesocosm: A. Fluctuations in production,respiration, chlorophyll a content and C:N ratios of grazed and non-grazed assemblages

Studies were undertaken with the aim of developing a standardized method for assessing environmental pollution in sediments by utilization of life-history data of freshwater tubificids. Similar bioassay methods have long been used for Daphnia magna, species of Ceriodaphnia and Nitocra, etc. in accordance with guidelines from the International Organization for Standardization (ISO). Tubifex tubifex was found to be the most likely candidate for such bioassays, since the species is readily kept in culture and reproduces more or less consistantly.The culturing method is slightly modified from Kosiorek (1974). This paper provides an example of the particular sensitivity of this kind of bioassay method in the detection of heavy metal contamination of lake sediments. Sediments from the oligotrophic Lake Runn were considered suitable for the purpose, since the lake receives waste water from a major mining industry in Sweden. Metal analyses of the sediments had revealed the agents likely to be causing the decreased biological activity measured in the lake; rough amplitudes for mercury: 800–3600 ng · g^-1 dw, copper: 800–1800 g · g^-1 dw, zinc: 3.3 – 8.1 mg · g g^-1 dw have been estimated for surficial sediments.Young tubificids exposed to Lake Runn sediments did not grow much and died off within a short period of time. No reproduction occurred. Sediments from Lake Runn, when mixed with sediments from the eutrophic Lake Hjälmaren, made reproduction of T. tubifex occur only in mixtures containing less than 50% L. Runn sediments. The growth rate, reproductive success and the very timing of consecutive reproductive events of cohort individuals were found to be highly indicative of toxic effects. When additional food sources were available, however, these effects were largely masked. Therefore, extra food rations were excluded from the original method.     

Two new species ofConsolida (Ranunculaceae) from the Flora Iranica area

Two species ofConsolida are described as new:C. lorestanica is distributed in W. Iran (Lorestan), andC. kandaharica is endemic to S. Afghanistan.Dedicated to Hofrat Prof. DrK. H. Rechinger on the occasion of this 80th birthday.     

Structural analysis of the carbohydrate moieties of α-l-fucosidase from human liver

Acid -l-fucosidase (EC 3.2.1.51) was obtained from human liver and purified to homogeneity. The enzyme consists of four subunits; each of these has a molecular mass of 50 kD_a and bears oneN-linked carbohydrate chain. The structures of these chains were studied at the glycopeptide level by methylation analysis and 500-MHz¹H-NMR spectroscopy. Oligomannoside-type chains andN-acetyllactosamine-type chains are present in an approximate ratio of 31. While the oligomannoside-type chains show some heterogeneity in size (Man_5–8GlcNAc₂), theN-acetyllactosaminetype chains are exclusively bi-(2–6)-sialyl, bi-antennary in their structure.These observations on the carbohydrate moieties of -l-fucosidase substantiate our hypothesis [Overdijket al. (1986) Glycoconjugate J 3:339–50] with respect to the relationship between the oligosaccharide structure of lysosomal enzymes and their residual intracellular activity in I-cell disease. For the series of enzymes examined so far, namely, -N-acetylhexosaminidase, -l-fucosidase and -galactosidase, the relative amount ofN-acetyllactosamine-type carbohydrate increases, while the residual intracellular activity in I-cell disease tissue decreases in this order. The system which is responsible for preferentially retaining hydrolases with (non-phosphorylated) oligomannoside-type chains both in I-cells and in normal cells has yet to be identified.     

Fucosyltransferase expression in human platelets and leucocytes

The activities of -2-l-fucosyltransferase and -3-l-fucosyltransferase were measured in human platelets and leucocytes from normal donors, -2-l-Fucosyltransferase was found in platelets but not in leucocytes. In contrast -3-l-fucosyltransferase was not detected in platelets but was present in leucocytes where it was demonstrated in the neutrophil, monocyte and lymphocyte fractions.     

Dinucleoside tetraphosphate variations in cultured tumor cells during their cell cycle and growth

Asynchronous and synchronized cultures of A549 and HTC cells were used to detect possible, cell cycle or cell density specific variations in the intracellular pools of dinucleoside tetraphosphates (Ap4X). No important variations of the nucleotide pools were observed during cell growth. When HTC cells were released from mitotic arrest, a decrease by a factor of N3 Ap4X and ATP levels was observed when the cells entered the G1 phase. This decrease is essentially due to cell doubling. When A549 cells were released from an arrest at the G1/S boundary, the nucleotide pool size increased slightly during the G2 phase just before mitosis. This result is in agreement with both earlier data from our laboratory and the observed decrease in Ap4X pool after release from mitotic-arrested HTC cells. These results suggest that the Ap4X and ATP pools are only subjected to very small variations during the cell cycle, essentially in the G2 phase and after mitosis.     

Longitudinal changes of dominance rank among the females of the Koshima group of Japanese monkeys

The changes of dominance rank among female Japanese monkeys of the Koshima group over a period of 29 years from 1957 were studied. The dominance rank order was relatively stable in the early population growing phase, while large scale-changes of dominance rank order occurred successively in the phase of population decrease brought about by the severe control of artificial feeding after 1972. Nevertheless, the rank order of several females of the highest status was stable. Furthermore, the reproductive success of these highest status females was high (Mori, 1979a;Watanabe et al., in prep.). Divergence of the dominance rank order fromKawamura's rules (Kawamura, 1958) was observed in the following respects: (1) Some females significantly elevated their rank depending on the leader males. (2) If mothers died when their daughters were still juveniles or nulliparous, the dominance rank of some of these offspring females was significantly lower than the mother's one. However 55% of daughters which lost their mothers at a young age inherited the mother's rank. (3) Dominance among sisters whose mother had died when at least one of the daughters was under 6 years old followed the rule of youngest ascendancy in 60% (Kawamura, 1958), and in 80% when both of the daughters were nulliparous at the mother's death. The mean rate of aggressive interactions for each female with subordinates to her was calculated by dividing the total aggressive interactions between the female in question and her subordinates by the number of subordinate females to the female in question. A female which showed a high rate of aggressive interactions with her subordinates was categorized as an “Attacker”, and a female showing a lower rate was categorized as a “Non-attacker”. Similarly, categories of “Attacked”, and “Non-attacked” were distinguished by using the rate of aggressive interactions with dominant females. Several females which were once categorized in one category in a year were repeatedly categorized in the same category over different years. The “Attacked” tended to be females of higher rank, and “Non-attackers” tended to be females of lower rank. “The second-higher-status females”, were “Attacked”, and their rank was unstable. In particular, females of lower rank within the lineage of the highest rank suffered this kind of severe status. Most of the daughters of these females showed a sharp drop of rank, and died when they were still at a young age, i.e. “the second-higher-status females” displayed low fitness. “Non-attackers” were significantly “Non-attacked”; i.e. they were females which showed a non-social attitude. Females which underwent a drop of rank tended to be “Non-attackers”. The most important factor which determined the females' rank was the memory of their dominance relations under the influence of their mother [dependent rank (Kawai, 1958)] in their early life during development. This finding corresponds well with the results in baboons obtained byWalter (1980); the target females of aggressive interactions by adolescent females were determined by the rank of the mothers when these adolescent females were born.     

Cholesterol binding reserve of hyperlipemic rat serum lipoproteins in chronic ethanol administration

Chronic administration of ethanol in rats caused the reduction of serum cholesterol binding reserve. The very low density and high density lipoproteins, main serum cholesterol binding reserves, were slightly increased with corresponding increases in their lipid and protein components during initial stage of alcohol consumption. However, these capacities get deminished during reversal of hyperlipemia induced by prolonged action of ethanol. This situation may be an early indicator for the initiation of hepatic damage and a variety of secondary effects of ethanol.     

Nontoxic and toxic oligopeptides with D-amino acids and unusual residues in Microcystis aeruginosa PCC 7806

Toxic and nontoxic peptides were isolated from the cyanobacterium Microcystis aeruginosa PCC 7806 by a procedure including extraction of cells with water-saturated 1-butanol, chromatography of the extract on silica gel plates and high performance liquid chromatography (HPLC) on Partisil-5. The toxin was shown to be only a minor constituent, being negatively charged and thus separable by electrophoresis, within the HPLC-purified fraction. It contained erythro-β-methyl-D-Asp, D-Glu, D-Ala, L-Leu, and L-Arg known to be part of the Microcystis peptide-toxin with M_r 994. The major part of the HPLC-purified fraction was assigned, however, to a nontoxic peptide with a M_r of 956. Partial hydrolysis studies of the nontoxic peptide(s) revealed amino acid sequences composed of D-Glu, N-methyl-Phe, and 3,4-dehydro-Pro, aside from the common L-amino acids. Cyclic linkage in the nontoxic peptide(s) appears likely.     

Acyl-CoA: 1-acyl-glycero-3-phosphoethanolamine O-acyltransferase and liver plasma membrane fluidity

Investigations have been carried out on the influence of membrane lipid composition and physical state on acyl-CoA: 1-acyl-glycerol-3-phosphoethanolamine O-acyltransferase activity in rat liver plasma membranes. The lipid composition of the membranes was modified either by way of lipid transfer proteins or by partial delipidation with exogenous phospholipases and subsequent enrichment of the membranes with different phospholipids. The results indicated that membrane rigidification by enrichment of the membranes with DPPC or SM reduced the transfer of oleic and palmitic acid to lysophosphatidylethanolamine, whereas all phospholipids inducing membrane fluidization lead to acyltransferase activation. The eventual role of membrane fluidity in the deacylation-reacylation cycle is discussed.     

Enzymatic evidence for involvement of the methylmalonyl-CoA pathway in propionate oxidation by Syntrophobacter wolinii

Enzyme measurements were carried out with crude cell-free extracts of the propionate oxidizing coculture of Syntrophobacter wolinii and Desulfovibrio G11. Using cell-free extracts of a pure culture of Desulfovibrio G11 as a blank, most of the enzymes involved in the methylmalonyl-CoA pathway for propionate oxidation, including a propionyl-CoA: oxaloacetate transcarboxylase, were demonstrated in S. wolinii.