Effect of Glutathione and N-Acetylcysteine on in Vitro and in VIVO Cardiac Toxicity of Doxorubicin

The effects of two sulfhydryl compounds, glutathione (GSH) and N-acetylcysteine (NAC), on the cardiotoxicity of doxorubicin (DXR) were tested on in vitro and in vivo models. DXR was administered to rats as 4 weekly i.v. doses of 3mg/kg. GSH (1.5 mmoles/kg), given i.v. 10 min before and 1 hr after DXR, was found to prevent the development of the delayed cardiotoxic effects of DXR, as assessed by electrocardiographic and mechanical parameters, as well as by histological examination of left ventricular preparations. In contrast, equimolar oral doses of NAC (1 hr before and 2hrs after DXR) were found to be ineffective. Both GSH and NAC prevented the negative inotropic effect produced by DXR on isolated rat atria. A good correlation exists between the cardioprotective effects of the two agents and their ability to enhance the non-protein sulfhydryl group content of the myocardium. Differences observed in vivo between GSH and NAC might be accounted for by pharmacokinetic factors.     

Phenylacetaldehyde by acetic acid bacteria oxidation of 2-phenylethanol

Summary This paper reports the production of 2-phenylacetaldehyde from 2-phenylethanol by acetic bacteria. Several strains of acetic bacteria were investigated and three were found to be effective for this bioconversion. Different conditions (different C source for the microorganisms, pH, substrate concentration, cell immobilization) were tested with yields ranging from 30 to 52.6%.     

The Rhodobacter capsulatus chlorin reductase-encoding locus, bchA, consists of three genes, bchX, bchY, and bchZ.

The bchA locus of Rhodobacter capsulatus codes for the chlorin reductase enzyme in the bacteriochlorophyll synthesis pathway. Previous work has suggested that this locus might encompass a single gene. We have sequenced the bchA locus and found it to contain three coding segments, which we designate bchX, bchY, and bchZ. Each coding segment contains its own translational initiation sequence and follows codon utilization patterns consistent with those of previously published R. capsulatus genes. When various regions of the bchA locus and flanking sequences were subcloned into an expression vector and expressed in Escherichia coli, the three coding segments were all expressed as separate peptides. Finally, conservation of amino acid sequences between bchX and a subunit of the protochlorophyllide reductase (bchL, 34% identity) and the nitrogenase Fe protein (nifH, 30 to 37% identity) suggests structural and mechanistic commonalities among all three proteins.     

ThechlL (frxC) gene: Phylogenetic distribution in vascular plants and DNA sequence fromPolystichum acrostichoides (Pteridophyta) andSynechococcus sp. 7002 (Cyanobacteria)

We examinedchlL (frxC) gene evolution using several approaches. Sequences from the chloroplast genome of the fernPolystichum acrostichoides and from the cyanobacteriumSynechococcus sp. 7002 were determined and found to be highly conserved. A complete physical map of the fern chloroplast genome and partial maps of other vascular plant taxa show thatchlL is located primarily in the small single copy region as inMarchantia polymorpha. A survey of a wide variety of non-angiospermous vascular plant DNAs shows thatchlL is widely distributed but has been lost in the pteridophytePsilotum and (presumably independently) within the Gnetalean gymnosperms.The namefrxC was originally used to denote a gene encoding a product with probable Fe : S cluster binding activity. This activity was postulated due to the amino acid sequence similarity between this product and the Fe : S-binding nitrogenase iron proteinnifH. Fe : S-binding is a property shared by ferredoxins, which are denoted by the prefix frx. However, this gene does not encode a ferredoxin. It is much larger than any known ferredoxin, it binds its Fe : S cluster between two halves of a homodimer (Fujita & al. 1989,Burke & al. 1993 a, c) instead of within a single subunit, and it lacks the pattern of clustered cysteines present in all ferredoxins (Meyer 1988). Therefore, we use the namechlL to recognize the sequence and functional similarities to the bacterial PChlide reductase subunit,bchL. Similar usage has been adopted for this (Suzuki & Bauer 1992) and other (Choquet & al. 1992,Burke & al. 1993b) PChlide reductase subunits.     

Testing the success of palaeontological methods in the delimitation of clam shrimp (Crustacea,Branchiopoda) on extant species

Fossil spinicaudatan taxonomy heavily relies on carapace features (size, shape, ornamentation) and palaeontologists have greatly refined methods to study and describe carapace variability. Whether carapace features alone are sufficient for distinguishing between species of a single genus has remained untested. In our study, we tested common palaeontological methods on 481 individuals of the extant Australian genus Ozestheria that have been previously assigned to ten species based on genetic analysis. All species are morphologically distinct based on geometric morphometrics (p ≤ 0.001), but they occupy overlapping regions in Ozestheria morphospace. Linear discriminant analysis of Fourier shape coefficients reaches a mean model performance of 93.8% correctly classified individuals over all possible 45 pairwise species comparisons. This can be further increased by combining the size and shape datasets. Nine of the ten examined species are clearly sexually dimorphic but male and female morphologies strongly overlap within species with little influence on model performance. Ornamentation is commonly species-diagnostic; seven ornamentation types are distinguished of which six are species-specific while one is shared by four species. A transformation of main ornamental features (e.g. from punctate to smooth) can occur among closely related species suggesting short evolutionary timescales. Our overall results support the taxonomic value of carapace features, which should also receive greater attention in the taxonomy of extant species. The extensive variation in carapace shape and ornamentation is noteworthy and several species would probably have been assigned to different genera or families if these had been fossils, bearing implications for the systematics of fossil Spinicaudata.     

Fall in total cholesterol concentration over five years in association with changes in fatty acid composition of cooking oil in Mauritius: cross sectional survey.

OBJECTIVE: To determine the extent to which reducing the saturated fatty acid composition of a ubiquitously used cooking oil influenced changes in cholesterol concentration in the population during a five year intervention programme in Mauritius. DESIGN: Cross sectional surveys in 1987 and 1992 determined mean total cholesterol concentrations in the population. A random sample of respondents in the 1992 survey completed a nutrition questionnaire that included questions on diet in the previous 24 hours. SETTING: Mauritius. INTERVENTION: In 1987 the government of Mauritius changed the composition of the commonly used cooking oil from being mostly palm oil (high in saturated fatty acids) to being wholly soya bean oil (high in unsaturated fatty acids). SUBJECTS: 5080 and 5162 subjects in 1987 and 1992 cross sectional surveys. 2059 subjects aged 30-64 years were randomly selected from the respondents of the 1992 survey to take part in the nutrition survey. MAIN OUTCOME MEASURES: Fatty acid composition of phospholipids in pooled serum samples from men and women from the two surveys; measured and predicted change in serum cholesterol concentration. RESULTS: From 1987 to 1992 total cholesterol concentrations fell significantly by 0.79 mmol/l (P < 0.001) in men and 0.82 mmol/l (P < 0.001) in women. The estimated intake of saturated fatty acids decreased by 3.5% of energy intake in men and by 3.6% in women, and the intake of polyunsaturated fatty acids increased by 5.5% and 5.6% of energy intake, respectively. These changes were reflected in changes in the fatty acid composition of serum phospholipids, and according to Keys'' formula these changes explained much of the decrease in serum cholesterol concentrations (predicted decrease of 0.38 mmol/l in men and by 0.40 mmol/l in women). CONCLUSION: Dietary changes that entailed a reduction in the saturated fat content of a ubiquitous cooking oil explained most of the observed decrease in serum cholesterol concentration over five years in the population of Mauritius.     

The primary structure of D-amino acid oxidase from Rhodotorula gracilis

Summary The amino acid sequence of D-amino acid oxidase from Rhodotorula gracilis was determined by automated Edman degradation of peptides generated by enzymatic and chemical cleavage. The enzyme monomer contains 368 amino acid residues and its sequence is homologous to that of other known D-amino acid oxidases. Six highly conserved regions appear to have a specific role in binding of coenzyme FAD, in active site topology and in peroxisomal targeting. Moreover, Rhodotorula gracilis D-amino acid oxidase contains a region with a cluster of basic amino acids, probably exposed to solvent, which is absent in other D-amino acid oxidases.     

snRNP Sm proteins share two evolutionarily conserved sequence motifs which are involved in Sm protein-protein interactions.

The spliceosomal small nuclear ribonucleoproteins (snRNPs) U1, U2, U4/U6 and U5 share eight proteins B', B, D1, D2, D3, E, F and G which form the structural core of the snRNPs. This class of common proteins plays an essential role in the biogenesis of the snRNPs. In addition, these proteins represent the major targets for the so-called anti-Sm auto-antibodies which are diagnostic for systemic lupus erythematosus (SLE). We have characterized the proteins F and G from HeLa cells by cDNA cloning, and, thus, all human Sm protein sequences are now available for comparison. Similar to the D, B/B' and E proteins, the F and G proteins do not possess any of the known RNA binding motifs, suggesting that other types of RNA-protein interactions occur in the snRNP core. Strikingly, the eight human Sm proteins possess mutual homology in two regions, 32 and 14 amino acids long, that we term Sm motifs 1 and 2. The Sm motifs are evolutionarily highly conserved in all of the putative homologues of the human Sm proteins identified in the data base. These results suggest that the Sm proteins may have arisen from a single common ancestor. Several hypothetical proteins, mainly of plant origin, that clearly contain the conserved Sm motifs but exhibit only comparatively low overall homology to one of the human Sm proteins, were identified in the data base. This suggests that the Sm motifs may also be shared by non-spliceosomal proteins. Further, we provide experimental evidence that the Sm motifs are involved, at least in part, in Sm protein-protein interactions. Specifically, we show by co-immunoprecipitation analyses of in vitro translated B' and D3 that the Sm motifs are essential for complex formation between B' and D3. Our finding that the Sm proteins share conserved sequence motifs may help to explain the frequent occurrence in patient sera of anti-Sm antibodies that cross-react with multiple Sm proteins and may ultimately further our understanding of how the snRNPs act as auto-antigens and immunogens in SLE.     

Leaf characteristics and optical properties of different woody species

 Light partition has been examined and evaluated on five woody species (Olea europaea, Ficus carica, Pittosporum tobira, Hedera helix maculata, Persica vulgaris) in relation to their leaf morpho-histological characteristics, water and chlorophyll contents. Leaf parameters and optical properties (reflectance, transmittance, absorbance) in PAR, FR and NIR wavebands (400–1100 nm) were preliminarily submitted to a canonical correlation analysis where lamina thickness and water content showed a leading role in determining all the optical properties, while chlorophyll, influential in the PAR region, was remarkably effective only in an extreme pigment situation when green and albino patches of ivy leaves were compared. Transmittance appeared inversely related to lamina thickness in accordance with the Lambert Beer law. Significant correlations were found also between mesophyll water content and both transmittance (positive) and reflectance (negative). Olive leaves showed peculiar optical patterns because of the dense and continuous trichome layer on their abaxial surface. Received: 3 January 1997 / Accepted: 5 May 1997