Fumonisins — Importance and occurence of a new group of mycotoxins

This paper describes the importance of fumonisins for human beings and animals and shows data for the occurence in food. Corn-based food samples (n = 299) purchased in the area of munich were analyzed for fumonisin content using an enzyme immunoassay. Fumonisins are mycotoxins produced byFusarium species, especially byFusarium moniliforme andFusarium proliferatum. Occurrence of fumonisins in corn and in cornbased foods and feeds has been reported from almost all over the world. In several animal species different diseases are traced back to fumonisin toxicosis. Fumonisin levels of 5–10 ppm inhorse feed induce “Equine Leucoencephalomalacia” and hepatic lesions. Hepatotoxic (10 150 ppm fumonisin in feed) and pneumotoxic (>150 ppm fumonisin in feed) effects have been reported for swine. Cattle and poultry appear to be less susceptible to fumonisins. Fumonisin B₁ Revels of 50 ppm in the diet of rats cause hepatotoxic and nephrotoxic effects, long time exposure results in hepatic cancer. A possible role of fumonisins in the etiology of human esophageal cancer is under discussion, although no direct causal evidence is known so far. The mode of action of the fumonisins is probably based on inhibition of sphingolipidbiosynthesis caused by the blockade of the enzyme sphyngosine (sphinganine)-N-acyltrans-ferase.     

Synthesis and galectin-binding activities of mercaptododecyl glycosides containing a terminal β-galactosyl group

Mercaptododecyl glycosides containing a terminal β-galactosyl group were prepared from d-galactose or from d-lactose via hexa-O-acetyl-lactal (10) as a key intermediate. Interactions of these glycolipids (5 kinds) and galectins (β-galactoside binding lectins, 6 species) were evaluated by surface plasmon resonance (SPR) method. High binding responses were observed for the lactoside, 2-deoxy-lactoside, and lactosaminide with some galectins (Gal-3, -4, -8), whereas the galactoside and 2,3-dideoxy-lactoside showed low binding activities.     

Decision-making in variable environments-- a case of group selection and inter-generational conflict?

Suppose organisms need to engage in a particular action exactly once during some fixed period of time. Further suppose they can time this action to optimise their fitness based on the expected current payoff and the probability distribution of later payoffs. For an example we consider the timing of the annual nuptial flight in eusocial insects. Using two population genetics models, we ask whether stochasticity leads to evolutionary conflict between the queen and her offspring. We find that the winning phenotype is independent of who controls the timing. The best response to any non-equilibrium population strategy is the same in both control scenarios, a result that carries over to the diploid case. Although inter-generational conflict is therefore ruled out, the models support a previous observation that at equilibrium some of the offspring have a lower expected payoff than others. By measuring fitness in terms of relative reproductive success, we show that all individuals are in fact equally well off making group-selectionist arguments unnecessary. As such, the models should improve our understanding of the difficult conceptual problem of the unit of natural selection in stochastic environments.     

Novel observation of play behaviour between a harem holder and a bachelor group of Przewalski’s horses in the wild

acta ethologica - Przewalski’s horses live in stable nonterritorial families (harem) of one or more harem stallions, several mares, and their offspring. The harem stallion typically behaves...     

Radiosynthesis and biodistribution of a prosthetic group (¹⁸F-FENMA) conjugated to cyclic RGD peptides

We have recently reported a new N-methylaminooxy-based prosthetic group for the site-selective introduction of 1?F-fluorine under mild acidic aqueous conditions into model peptides functionalized with a Michael acceptor moiety. To further investigate the utility of this methodology, the radiosynthesis of two cyclic RGD peptides was carried out, and in vivo biodistribution and microPET studies were performed in tumor-bearing mice. A cyclic RGD peptide was functionalized with the Michael acceptors trans-β-nitrostyrene carboxylic acid and 3-vinylsulfonylpropionic acid. Radiolabeling was then performed with the prosthetic group O-(2-(2-[1?F]fluoroethoxy)ethyl)-N-methylhydroxylamine (1?F-FENMA) yielding the 1?F-conjugates in moderate yields (8.5-12%). Biodistribution, blocking, and microPET imaging studies were performed in a mouse xenograft model. The vinylsulfonyl-modified conjugate demonstrated good in vitro plasma stability. Biodistribution and microPET studies revealed excellent tumor uptake with low background in key organs and renal elimination as the predominant route of excretion. Blocking studies with coinjected nonlabeled RGD peptide confirmed the in vivo specificity for the integrin α(v)β?. On the other hand, 1?F-FENMA-nitrostyrene-RGD, although stable at conjugation pH 5, was found to rapidly degrade at physiological pH through loss of the 1?F-prosthetic group.     

Q- and C-band polymorphism of the chromosomes in a group of patients with the Shereshevski?-Turner syndrome

Q- and C-band polymorphism of heterochromatic regions of chromosomes were studied in a group of patients with Turner's syndrome (30 girls with the karyotype 45, X) and in 105 normal individuals. No significant differences in the frequencies of Q-polymorphic variants for the most part of chromosomes studied (with the exception of chromosome 13 satellites) were obtained between patients with Turner's syndrome and the control. There were no differences in the mean number of Q-variants per individual in both groups investigated. An increase in the frequency of large C-segments of chromosome 9 was detected in patients with Turner's syndrome. An increase in the frequency of individuals carrying a combination of several extreme variants in the individual karyotype was found for patients with Turner's syndrome. The differences revealed are of non-specific character for a given form of developmental pathology.     

Review of the genotoxicity and carcinogenicity of antischistosomal drugs; is there a case for a study of mutation epidemiology? Report of a task group on mutagenic antischistosomals

One of the interests of ICPEMC is to identify situations in which the possible induction of inherited defects in man by mutagen exposure could actually be studied. The large-scale use of mutagenic drugs in field programmes against schistosomiasis, mainly during the 1970's, was considered a possible case. An ICPEMC task group approached the problem by (1) updating the genetic toxicology data base for antischistosomal drugs, and (2) reviewing possible study areas. Expertise was combined from genetic toxicology, mutation epidemiology and tropical medicine.It was considered that: (a) if any, hycanthone would be the most appropriate candidate drug for study; (b) it would be virtually impossible to meet the basic requirements of an appropriate mutation epidemiology study, in endemic countries; (c) as more defined genetic endpoints would be selected (e.g. sentinel phenotypes) the required large sample sizes would seem prohibitive, since documentation on past programmes is limited and local demography would render the reliable tracking of substantial numbers of offspring of treated persons an almost impossible task; (d) in most endemic countries proper diagnosis and registration of inherited defects is largely lacking; (e) the problems encountered in demonstrating inherited effects in humans after heavy or chronic exposure to established animal mutagens such as ionizing radiation and cancer chemotherapy, in combination with the ambiguous nature of the animal germ cell data with hycanthone, do not particularly warrant large expectations; (f) since non-mutagenic antischistosomal drugs are now in use, the problem is academic and of low priority in the endemic countries whose medical and research resources are often limited. Thus, studying offspring of hycanthone-treated people to demonstrate the mutagenic potential of the drug in man is not a viable enterprise. (See, however, note added in proof, p. 75.)     

Evaluation of HPFH and δβ-thalassemia mutations in a Brazilian group with high Hb F levels

Fetal hemoglobin (Hb F) is characteristic of the fetal development period. However, in some genetic conditions, such as hereditary persistence of fetal hemoglobin (HPFH) and delta-beta thalassemia (δβ-thalassemia), Hb F continues to be produced in adulthood. We evaluated the frequency of two mutations of HPFH, HPFH-1 and HPFH-2 African, and two mutations in δβ-thalassemia, Sicilian and Spanish, in a Brazilian population. Peripheral blood samples were collected from adults from hospitals and blood centers in southeast and northeast Brazil. These individuals were healthy and without complaints of anemia, but had increased Hb F. Samples were submitted to electrophoretic and chromatographic analyses to quantify Hb F values and, subsequently, to molecular analyses to verify the mutations. In the molecular analysis, 16 of the 60 samples showed a heterozygous profile for the HPFH mutations, two for HPFH-1 and 14 for HPFH-2. In the same sample set, three were heterozygous for Spanish δβ-thalassemia and none were heterozygous for Sicilian δβ- thalassemia. The Hb F values in the HPFH-2 heterozygotes differed from those previously reported for this mutation. In this group, the HPFH mutations were more frequent than the δβ-thalassemia mutations. The finding of these mutations in this Brazilian population reflects the mixing process that occurred during its formation.     

Conservative coevolution of Müllerian mimicry in a group of rift lake catfish

Biological mimicry has long been viewed as a powerful example of natural selection's ability to drive phenotypic evolution, although continuing debates surround the mechanisms leading to its development and the nature of these mimetic relationships. Müllerian mimicry, in which unpalatable species derive a mutual selective benefit through evolved phenotypic similarity, has alternatively been proposed to evolve through either a two-step process initiated by a large mutational change, or through continuous gradual evolution toward a common aposematic phenotype. I exposed a model predatory fish species to two species of endemic Lake Tanganyikan Synodontis to provide evidence for aposematism and the presence of Müllerian mimicry in these species. Predators quickly became conditioned to avoid the venomous catfish and did not discriminate between the two species when they were switched, supporting a hypothesis of functional Müllerian mimicry in this group of similarly colored fish. Ancestral state reconstructions and statistical comparisons of color pattern divergence in Tanganyikan Synodontis indicate that Müllerian mimicry in these catfish has developed through diversification of an aposematic common ancestor with subsequent conservative mutualistic coevolution among its daughter lineages, rather than advergent evolution of a mimic toward a nonrelated model, as assumed by widely accepted models of Müllerian mimicry evolution.     

Structure and Properties of a Complex of α-Synuclein and a Single-Domain Camelid Antibody

The aggregation of the intrinsically disordered protein α-synuclein to form fibrillar amyloid structures is intimately associated with a variety of neurological disorders, most notably Parkinson's disease. The molecular mechanism of α-synuclein aggregation and toxicity is not yet understood in any detail, not least because of the paucity of structural probes through which to study the behavior of such a disordered system. Here, we describe an investigation involving a single-domain camelid antibody, NbSyn2, selected by phage display techniques to bind to α-synuclein, including the exploration of its effects on the in vitro aggregation of the protein under a variety of conditions. We show using isothermal calorimetric methods that NbSyn2 binds specifically to monomeric α-synuclein with nanomolar affinity and by means of NMR spectroscopy that it interacts with the four C-terminal residues of the protein. This latter finding is confirmed by the determination of a crystal structure of NbSyn2 bound to a peptide encompassing the nine C-terminal residues of α-synuclein. The NbSyn2:α-synuclein interaction is mediated mainly by side-chain interactions while water molecules cross-link the main-chain atoms of α-synuclein to atoms of NbSyn2, a feature we believe could be important in intrinsically disordered protein interactions more generally. The aggregation behavior of α-synuclein at physiological pH, including the morphology of the resulting fibrillar structures, is remarkably unaffected by the presence of NbSyn2 and indeed we show that NbSyn2 binds strongly to the aggregated as well as to the soluble forms of α-synuclein. These results give strong support to the conjecture that the C-terminal region of the protein is not directly involved in the mechanism of aggregation and suggest that binding of NbSyn2 could be a useful probe for the identification of α-synuclein aggregation in vitro and possibly in vivo.     

Paraphyletic group,PhyloCode and phylogenetic species—the current debate and a preliminary commentary

In this essay, three currently hotly debated issues in biological systematics, i.e., the paraphyletic group, the PhyloCode, and the phylogenetic species concept, have been briefly reviewed. (1) It is widely acknowledged that cladistics has made some positive contributions to the study of systematics. In particular, the employment of outgroup analysis for assessing character polarities, the application of synapomorphies to the inference of relationships between taxa, and the use of cladistic methods for reconstructing phylogeny, have all greatly facilitated the improvement of systematic approaches. A fatal flaw in cladistics is its refusal to accept paraphyletic groups. Frankly, we are adherents and practitioners of phyletics, and hence consider paraphyletic groups to be acceptable. For example, an AFLP analysis has shown that Zabelia (Caprifoliaceae) can be included in Abelia, but the members in Zabelia differ from those in Abelia not only in pollen morphology, but also in having persistent petioles dilated and connate at base, thus enclosing axillary buds, characters of adaptive significance obtained possibly when Zabelia members entered a new ecological niche, so we consider that they are better treated as two independent genera, though indeed such a treatment makes Abelia paraphyletic. (2) Some cladists pointed out that as the tool for communication and the system for information storage and retrieval, biological nomenclature is required to be unambiguous, unique and stable. They criticise the Linnaean rank-based system of nomenclature for failing to satisfy such requirements for the naming of clades and species. To address this problem, the PhyloCode is proposed in recent years, in which three definitions for clade naming are given, i.e., the node-based, the stem-based, and the apomorphy-based. We are of the opinion that since the Linnaean binominal system of botanical nomenclature has existed for nearly 250 years, the rejection of this system and the adoption of the PhyloCode would create a state of chaos in botanical nomenclature. This does not mean that there exist no merits in the proposals made by the PhyloCode supporters. We suggest that further studies should be conducted for its practical application. (3) It has been well known that there are many problems with the application of the biological species concept in plants, and thus at the present time the majority of plant systematists actually seldom use this concept in their practical work. The rapid development of cladistic approach has motivated the proposal of the phylogenetic species concept. This species concept is established based on three criteria, i.e., the autamorphy, the diagnosability and the basal exclusivity, hence the autamorphy species concept, the diagnosability species concept, and the genealogical concept are created respectively. Nevertheless, the morpho-geographical species concept is still predominantly adopted in plant systematics. When using this species concept, however, we should also take into account the data from other sources, particularly those from pollination biology, breeding system and molecular systematics.     

Should you form a group?

In this discussion, greatest emphasis has been placed upon the personal factors involved, rather than upon the mechanical aspects of creating and maintaining a group, since it is the personal factors, the authors say, that are the most often overlooked.     

σ Complexes as biochemical and biophysical probes: 4. Development of a novel reporter group delivery system

A novel reporter group delivery system for the chemical modification of proteins and the investigation of enzyme mechanisms is proposed. The design of this system is based on structural analogy with pyridoxal phosphate and σ-complex adduct formation. Progress is described toward the synthesis of suitable compounds, via three different approaches involving structural modification of the pyridine nucleus. A number of new compounds have been prepared, and other directions for future investigations are indicated.     

A survey of a familial transmission of an anomalous autosome in group 13–15

A male child hospitalized due to undescended testes (cryptorchism) was found to possess an abnormal autosome with an unusually elongated short arm in group 13–15. A familial chromosome investigation undertaken in 14 persons related to the propositus in his paternal line and in his mother revealed that his clinically normal father, grandfather, 2 aunts and a female cousin carried the same aberrant autosome. It is evident that a carrier of the abnormal chromosome is the grandfather, that the anomalous element was transmitted, irrespective of sex, from the parents either one of whom carried the aberrant one, and that the particular autosomal abnormality is not always associated with specific phenotypic anomaly. A possible origin of the aberrant autosome is discussed.Contribution no. 733 from the Zoological Institute, Faculty of Science, Hokkaido University, Sapporo.The senior author (S. M.) wishes to dedicate this paper to Dr. Jakob Seiler on the occasion of his 80th birthday, May 16, 1966.     

Identification of a novel group of putative Arabidopsis thaliana β-(1,3)-galactosyltransferases

To begin biochemical and molecular studies on the biosynthesis of the type II arabinogalactan chains on arabinogalactan-proteins (AGPs), we adopted a bioinformatic approach to identify and systematically characterise the putative galactosyltransferases (GalTs) responsible for synthesizing the beta-(1,3)-Gal linkage from CAZy GT-family-31 from Arabidopsis thaliana. These analyses confirmed that 20 members of the GT-31 family contained domains/motifs typical of biochemically characterised beta-(1,3)-GTs from mammalian systems. Microarray data confirm that members of this family are expressed throughout all tissues making them likely candidates for the assembly of the ubiquitously found AGPs. One member, At1g77810, was selected for further analysis including location studies that confirmed its presence in the Golgi and preliminary enzyme substrate specificity studies that demonstrated beta-(1,3)-GalT activity. This bioinformatic/molecular study of CAZy GT-family-31 was validated by the recent report of Strasser et al. (Plant Cell 19:2278-2292, 2007) that another member of this family (At1g26810; GALT1) encodes a beta-(1,3)-GalT involved in the biosynthesis of the Lewis a epitope of N-glycans in Arabidopsis thaliana.     

Crystallization and identification of a binary complex of a elastase-I and a Carboxypeptidase Aγ from porcine pancreas

A binary complex of elastase I and Carboxypeptidase Aγ has been isolated and crystallized from activated extracts of porcine pancreas. The purification procedure included ammonium sulfate fractionation and autolysis treatment followed by crystallization. The two components in the complex have been separated by DEAE-Sephadex A-50 column chromatography to homogeneity and their identification was demonstrated by NH₂-terminal sequence analysis. An analysis of the reconstitution crystal from the mixtures of both components showed that the complex consisted of a 1:1 molar ratio with elastase I and Carboxypeptidase Aγ, forming a binary complex in crystalline state.     

The group of 77 and the establishment of the international sea‐bed authority

Abstract

The Group of 77 favors the establishment of a strong International Sea‐Bed Authority with powers to regulate and control all the activities of exploration and exploitation of the “common heritage of mankind,”; referred to in the draft articles as “the Area.”; The Authority itself is to be composed of an Assembly as the supreme policy‐making organ in which the Contracting Parties are to be represented on the basis of sovereign equality; a Council as the executive organ implementing the policies emanating from the Assembly, to be composed of at least 36 states elected to ensure representation of clearly defined special interests and the principle of equitable geographical distribution, and to eschew any form of veto mechanism in its decision‐making process; the Enterprise as the operational organ through which the Authority is to undertake direct exploitation of the Area along with the other entities given access to the Area; and a Secretariat as well as certain subsidiary bodies of the Council.

The Group of 77 takes the position that the Convention itself and the Basic Conditions governing the entire process of exploration and exploitation of the Area must leave the Authority an appreciable margin of discretion in managing the Area for the benefit of mankind as a whole. Thus, a limited category of judicially reviewable decisions of the Authority is envisaged so long as such review does not challenge the legislative powers and resource policy decisions of the Authority. A Sea‐Bed Tribunal is no longer necessary as an organ of the Authority, since the work of such a Tribunal could be done by the special Sea‐Bed Disputes Chamber of the Proposed Law of the Sea Tribunal dealing with disputes arising under the Convention as a whole.