Looking for differences in wood properties as a function of the felling date: lunar phase-correlated variations in the drying behavior of Norway Spruce (Picea abies Karst.) and Sweet Chestnut (Castanea sativa Mill.)

A large-scale field experiment on the drying behavior of Norway Spruce (Picea abies Karst.) and Sweet Chestnut (Castanea sativa Mill.) in relation to the felling date was conducted over a period of 24 weeks in order to investigate the existence of variations linked to lunar rhythms, which are mentioned as having a role in many traditional forestry practices. The measured criteria were the water loss from fresh to dry state, the shrinkage linked to this water loss, and the relative density (ratio between the dry density and the initial fresh density) for both sapwood and heartwood in Picea and heartwood in Castanea. In addition to seasonal trends, slight but significant variations with lunar periodicities (both synodic and sidereal; to a much lesser extent tropic) characterize the three investigated criteria. These lunar rhythmicities occur in both Picea and Castanea, in heartwood and sapwood. These results raise new questions and perspectives about a rhythmic character of the wood–water relation.     

Effects of 5α-reductase inhibitors on intraprostatic androgens in the rat

FCE 27837 is a novel inhibitor of 5α-reductase, the enzyme responsible for the conversion of testosterone (T) to 5α-dihydrotestosterone (DHT). The compound caused inhibition of human and rat prostatic enzymes, with IC₅₀ values of 51 and 60 nM, respectively. The in vivo effect of FCE 27837 on 5α-reductase was evaluated in adult male rats, treated orally at 10 mg/kg/day for 10 days. The compound caused 33 and 42% reductions in ventral prostate and seminal vesicle weights, respectively. The prostatic content of DHT, measured 6 h after the 10th dose of FCE 27837, was reduced by 75%, whereas T content increased by 442%. Similar effects were observed with 10 mg/kg/day of finasteride, whereas epristeride, tested at the same oral dose, was found to be the least effective compound, decreasing prostate weight by 22% and DHT content by 46%. Castration caused >90% reductions in prostatic weight and prostatic DHT.     

7-Substituted pterins. A new class of mammalian pteridines

Three novel pteridines have been isolated from the urine of patients with a new variant of 6-(L-erythro-1',2'-dihydroxypropyl)-5,6,7,8-tetrahydropterin (tetrahydrobiopterin) deficiency, showing hyperphenylalaninemia. From the results of high performance liquid chromatography, oxidative degradation, and gas chromatography-electron impact mass spectrometry, their structures were identified as 7-(D-erythro-1',2',3'-trihydroxypropyl)-pterin (7-neopterin), 7-(L-erythro-1',2'-dihydroxypropyl)-pterin (7-biopterin), and 6-oxo-7-(L-erythro-1',2'-dihydroxypropyl)-pterin (6-oxo-7-biopterin). The ratio of biopterin to 7-biopterin in the patients' urines was 1:1, and after oral loading with tetrahydrobiopterin, 7-biopterin excretion rose parallel to biopterin. This finding suggests that 7-substituted pterins may be formed endogenously by a yet unknown isomerization reaction. The cause of hyperphenylalaninemia is still unclear. The activities of the enzymes involved in tetrahydrobiopterin biosynthesis and regeneration were found to be normal in the patients, and no effect of 7-biopterin on these enzymes was observed in vitro. However, compared with the normal cofactor, tetrahydrobiopterin, the Km values of tetrahydro-7-biopterin for phenylalanine hydroxylase and dihydropteridine reductase are 20 and 5 times higher, respectively.     

Partial activation of sea-urchin eggs by bonellin

We here describe further studies on the action of bonellin on sea-urchin eggs. Bonellin brings about Some of the changes that are known to occur in the egg upon fertilization. In particular, it appears to cause the increased rate of incorporation of amino acids into proteins, the increase of the voltage noise, and the exocytosis of some of the cortical granules. A comparison with the effect of ammonia is discussed.     

Exploration of genetic and phenotypic diversity within Saccharomyces uvarum for driving strain improvement in winemaking

The selection and genetic improvement of wine yeast is an ongoing process, since yeast strains should match new technologies in winemaking to satisfy evolving consumer preferences. A large genetic background is the necessary starting point for any genetic improvement programme. For this reason, we collected and characterized a large number of strains belonging to Saccharomyces uvarum. In particular, 70 strains were isolated from cold-stored must samples: they were identified and compared to S. uvarum strains originating from different collections, regarding fermentation profile, spore viability and stress response. The results demonstrate a large biodiversity among the new isolates, with particular emphasis to fermentation performances, genotypes and high spore viability, making the isolates suitable for further genetic improvement programmes. Furthermore, few of them are competitive with Saccharomyces cerevisiae and per se, suitable for wine fermentation, due to their resistance to stress, short lag phase and fermentation by-products.

     

The cytotoxic properties of a plant lipid transfer protein involve membrane permeabilization of target cells

AIMS: To determine whether Ha-AP10, a member of the plant lipid transfer proteins (LTPs) family produces a direct cytotoxic effect on fungal cells mediated by membrane permeabilization. LTPs can inhibit fungal growth and are considered members of the ubiquitous class of antimicrobial peptides. However, the way they exert their effects on target cells is not yet understood. METHODS AND RESULTS: Viability assays demonstrate that Ha-AP10 acts as a fungicidal compound but no harmful effect is observed on plant cells. Liposome leakage assays show that the protein induces a moderate release of fluorescent probes encapsulated in model membranes, indicating its ability to interact with phospholipids. Using a fluorescent indicator of damage at the membrane level, we demonstrate that Ha-AP10 is able to induce the permeabilization of intact fungal spores in a dose-dependent manner. CONCLUSION: The results presented here demonstrate the permeabilization of fungal spores caused by Ha-AP10. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first demonstration of fungal membrane damage by an LTP, giving a clue to elucidate the basis of its antimicrobial properties.     

Morphologically structured model for antitumoral retamycin production during batch and fed-batch cultivations of Streptomyces olindensis

A morphologically structured model is proposed to describe trends in biomass growth, substrate consumption, and antitumoral retamycin production during batch and fed-batch cultivations of Streptomyces olindensis. Filamentous biomass is structured into three morphological compartments (apical, subapical, and hyphal), and the production of retamycin, a secondary metabolite, is assumed to take place in the subapical cell compartment. Model accounts for the effect of glucose as well as complex nitrogen source on both the biomass growth and retamycin production. Laboratory data from bench-scale batch and fed-batch fermentations were used to estimate some model parameters by nonlinear regression. The predictive capability of the model was then tested for additional fed-batch and continuous experiments not used in the previous fitting procedure. The model predictions show fair agreement to the experimental data. The proposed model can be useful for further studies on process optimization and control.     

Fluorophore-assisted electrophoresis of urinary carbohydrates for the identification of patients with oligosaccharidosis-and mucopolysaccharidosis-type lysosomal storage diseases

Lysosomal storage diseases result from defects in the activity of the lysosomal enzymes that break down macromolecules in the cell. These enzyme defects contribute to over 30 separate storage diseases that result in nearomuscular and intellectual impairment and, in some cases, early childhood death. This report describes a new method for identifying defects in the lysosomal enzymes and in the metabolic pathway that functions in the degradation of complex carbohydrates. The method involves identifying abnormal carbohydrates in the urine of affected patients using fluorescent carbohydrate tags and polyacrylamide gel electrophoresis. Currently, the method can be used as a simple screen for the identification of at least 12 different lysosomal storage diseases using a single electrophoretic procedure. Both oligosaccharidoses and mucopolysaccharidoses (MPS) can be identified, and in many cases the MPS subtype can be determined. In addition, the method can be used to confirm enzymatically the results of the initial screening test. We believe that this method will become extremely useful not only in the diagnosis of these diseases but in the management of patients on therapy.     

Affinity profile of the novel muscarinic antagonist, guanylpirenzepine

The study reports the functional affinity of an amidino derivative of pirenzepine, guanylpirenzepine, for muscarinic receptors mediating relaxation of rat duodenum, inhibition of rabbit vas deferens twitch contraction (both receptors previously classified as M1), guinea pig negative inotropism (M2) and ileal contraction (M3). Unlike pirenzepine, guanylpirenzepine discriminated between duodenum and vas deferens receptors, with a 30-fold greater affinity for the former subtype. The unique selectivity pattern of guanylpirenzepine (duodenum greater than vas deferens greater than ileum greater than atrium) renders it a promising tool for the classification of muscarinic receptor subtypes.