Screening of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> wine strains for the production of acetic acid

In this study 80 wine strains of Saccharomyces cerevisiae were characterized for the production of acetic acid. A significant variability in the production levels was determined among the strains, which produced from a few mg/l to more than 1 g/l. Fifteen strains, differing in acetic acid production, were tested in fermentation of grape musts of different varieties (Aglianico Basilicata, Aglianico Apulia, Cannonau, Bombino nero, Nero d'Avola, Vermentino, Fiano). The results emphasized a great strain variability, but the best strain behaviour was strictly related to the must composition, which is a determinant factor on the expression of the best strain potentiality. Therefore, this study, confirming the high/low production of acetic acid as a strain characteristic, demonstrated also that the inoculated fermentation becomes more advantageous when the starter culture is chosen in relation to the interaction of yeast strain/vine variety.     

Micropropagation of tree peony (<Emphasis Type="Italic">Paeonia suffruticosa</Emphasis>)

We investigated the in vitro propagation by axillary budding of different cultivars of tree peonies, selected for cut flower production under Mediterranean conditions. Buds with expanded leaves were better to initiate cultures than just emerged ones (64%compared to 43%). The aptitude for micropropagation was genotype-dependent, and the propagation ratio ranged between 2 and 5 per cycle. Tendency to necrosis and/or hyperhydricity were also genotype dependent. Indole-3-butyric acid improved rooting but was not really necessary provided the shoots were pre-treated at 2 °C for 7days. Plantlets were successfully acclimatized under in vitro conditions. Adventitious propagation was achieved using filaments and petals as explants. They first developed callus, able to regenerate shoots after 8 weeks on media supplemented with thidiazuron.     

Rapsyn Mutations in Humans Cause Endplate Acetylcholine-Receptor Deficiency and Myasthenic Syndrome

Congenital myasthenic syndromes (CMSs) stem from genetic defects in endplate (EP)-specific presynaptic, synaptic, and postsynaptic proteins. The postsynaptic CMSs identified to date stem from a deficiency or kinetic abnormality of the acetylcholine receptor (AChR). All CMSs with a kinetic abnormality of AChR, as well as many CMSs with a deficiency of AChR, have been traced to mutations in AChR-subunit genes. However, in a subset of patients with EP AChR deficiency, the genetic defect has remained elusive. Rapsyn, a 43-kDa postsynaptic protein, plays an essential role in the clustering of AChR at the EP. Seven tetratricopeptide repeats (TPRs) of rapsyn subserve self-association, a coiled-coil domain binds to AChR, and a RING-H2 domain associates with beta-dystroglycan and links rapsyn to the subsynaptic cytoskeleton. Rapsyn self-association precedes recruitment of AChR to rapsyn clusters. In four patients with EP AChR deficiency but with no mutations in AChR subunits, we identify three recessive rapsyn mutations: one patient carries L14P in TPR1 and N88K in TPR3; two are homozygous for N88K; and one carries N88K and 553ins5, which frameshifts in TPR5. EP studies in each case show decreased staining for rapsyn and AChR, as well as impaired postsynaptic morphological development. Expression studies in HEK cells indicate that none of the mutations hinders rapsyn self-association but that all three diminish coclustering of AChR with rapsyn.     

Sex chromosome loss, micronuclei, sister chromatid exchange and aging: a study including 16 centenarians

In the present study we analysed the possible effect of age, sex and smoking on the mean values of micronucleus (MN) and sister chromatid exchange (SCE) frequencies on peripheral blood obtained from 38 subjects ranging in age from 16 to 63 years and 16 centenarians. The mean number of binucleated cells with micronuclei varied in function of age and sex (as demonstrated by the analysis of covariance (F=13.13; P<0.001), particularly evident was the increment observed in women with increasing age (interaction age/sex: F=5.53; P<0.05). Smoking habits had no effects on MN frequency (F=0.36; P>0.05). Sex (F=4.18; P<0.05) and smoking habits (F=14.64; P<0.001) influenced significantly SCE per cell frequencies, but age had no effects on them (F=2.45; P>0.05).The age-associated increase of sex chromosome loss was studied using fluorescence in situ hybridisation (FISH) on interphase nuclei.The loss of Y signals was observed in 10% of interphase cells from the centenarians males, that is six times more often than in the younger control men (1.6%). The frequency of X signal loss (1.7%) in young women was similar to that observed in male controls of the same age but the incidence of the X chromosome aneuploidy in centenarian females was appreciably higher (22%) than that found for the Y chromosome in males. These results were correlated with the data on MN formation and a positive correlation between the percentage of aneuploid cells (FISH) and MN values was observed (r=0.50; P<0.05).     

Complexes of heparin with poly(alkylenimines): Competitive binding with methylene blue

The binding of heparin (Hep) and Hep fractions with oligo- and poly-(alkylenimines) having the general formula H₂N(CH₂-CHR-NH)_nH, where R = H or Me, has been investigated by spectroscopy, by evaluating the competition of the amines and Methylene Blue for the anionic sites of Hep. The strongest-binding was observed at pH 3.5, with the essentially linear triethylenetetramine and the slightly branched tetraethylenepentamine giving the most stable complexes. For N (number of nitrogen atoms per molecule) >5, a decrease of the binding ability of the amines was observed. The apparent stoichiometry of the complexes was a function of the relative concentration of Hep and the amine, indicating an equilibrium between different types of complexes. Beef-lung Hep and a Hep fraction consisting mainly of trisulphated disaccharide blocks gave stronger complexes than the more heterogeneous, pigmucosal Hep and a Hep fraction of lower sulphate content. The results are interpreted in terms of polyelectrolyte-type associations involving sulphate groups on adjacent residues of the Hep chain and sequences of charged nitrogen atoms on the polyamine.     

Animal Rennets as Sources of Dairy Lactic Acid Bacteria

The microbial composition of artisan and industrial animal rennet pastes was studied by using both culture-dependent and -independent approaches. Pyrosequencing targeting the 16S rRNA gene allowed to identify 361 operational taxonomic units (OTUs) to the genus/species level. Among lactic acid bacteria (LAB), Streptococcus thermophilus and some lactobacilli, mainly Lactobacillus crispatus and Lactobacillus reuteri, were the most abundant species, with differences among the samples. Twelve groups of microorganisms were targeted by viable plate counts revealing a dominance of mesophilic cocci. All rennets were able to acidify ultrahigh-temperature-processed (UHT) milk as shown by pH and total titratable acidity (TTA). Presumptive LAB isolated at the highest dilutions of acidified milks were phenotypically characterized, grouped, differentiated at the strain level by randomly amplified polymorphic DNA (RAPD)-PCR analysis, and subjected to 16S rRNA gene sequencing. Only 18 strains were clearly identified at the species level, as Enterococcus casseliflavus, Enterococcus faecium, Enterococcus faecalis, Enterococcus lactis, Lactobacillus delbrueckii, and Streptococcus thermophilus, while the other strains, all belonging to the genus Enterococcus, could not be allotted into any previously described species. The phylogenetic analysis showed that these strains might represent different unknown species. All strains were evaluated for their dairy technological performances. All isolates produced diacetyl, and 10 of them produced a rapid pH drop in milk, but only 3 isolates were also autolytic. This work showed that animal rennet pastes can be sources of LAB, mainly enterococci, that might contribute to the microbial diversity associated with dairy productions.     

PRMT5 silencing selectively affects MTAP-deleted mesothelioma: In vitro evidence of a novel promising approach

Malignant mesothelioma (MM) is an aggressive asbestos-related cancer of the serous membranes. Despite intensive treatment regimens, MM is still a fatal disease, mainly due to the intrinsic resistance to current therapies and the lack of predictive markers and new valuable molecular targets. Protein arginine methyltransferase 5 (PRMT5) inhibition has recently emerged as a potential therapy against methylthioadenosine phosphorylase (MTAP)-deficient cancers, in which the accumulation of the substrate 5'-methylthioadenosine (MTA) inhibits PRMT5 activity, thus sensitizing the cells to further PRMT5 inhibition. Considering that the MTAP gene is frequently codeleted with the adjacent cyclin-dependent kinase inhibitor 2A (CDKN2A) locus in MM, we assessed whether PRMT5 could represent a therapeutic target also for this cancer type. We evaluated PRMT5 expression, the MTAP status and MTA content in normal mesothelial and MM cell lines. We found that both administration of exogenous MTA and stable PRMT5 knock-down, by short hairpin RNAs (shRNAs), selectively reduced the growth of MTAP-deleted MM cells. We also observed that PRMT5 knock-down in MTAP-deficient MM cells reduced the expression of E2F1 target genes involved in cell cycle progression and of factors implicated in epithelial-to-mesenchymal transition. Therefore, PRMT5 targeting could represent a promising new therapeutic strategy against MTAP-deleted MMs.     

Trisomy-8 mosaicism: Report of a case

Summary An 8-year-old male with mental retardation, speech difficulties, and minor congenital anomalies is presented. The clinical findings suggest the trisomy-8 syndrome. The karyotype indicates trisomy-8 mosaicism with trisomic as well as normal cell lines in blood lymphocytes.     

Effects of PUFAs on animal reproduction: male and female performances and endocrine mechanisms

Adequate fat diet supplementation shows variable positive effects in farm animal breeding. Omega-3 and n-6 PUFAs are able to modulate several reproductive effectors: the luteolytic PGF2α, the luteotropic PGE2, the nuclear receptor PPARG, and steroids such as E2 and P4. PUFA supplementation favours fertility, onset of estrus, embryo survival, and also parturition by reducing preterm labour risk. These effects are likely mediated by the balance modulation of PGF2α and PGE2 productions, the syntheses of E2 and P4, and the activation of PPARG. As regards to male fertility, the effects of n-3 or n-6 PUFA supplementation at high concentrations in the diet are relatively unknown. PUFAs confer to the spermatozoa plasma membrane the fluidity it needs to achieve fertilization and seem to stimulate the Leydig cell production of testosterone through the regulation of the steroidogenic acute regulatory protein, a transport protein that regulates cholesterol transfer within the mitochondria, which is the rate-limiting step in the production of steroid hormones. As regards to female fertility, PUFA supplementation mediates a broad range of actions in reproductive processes involving pregnancy establishment, uterine endocrinology, and preterm birth. The perfectly composed follicular environment shapes oocyte quality and thus female fertility. Since both oocytes and embryos are vulnerable to microenvironment changes, nutritional alterations and FA unavailability can lead to their defects. The aim of the present review is to examine the effects of n-3 and n-6 PUFAs on male and female reproductive performances and the correlated endocrine mechanisms.