Separation of racemic mixtures of sn-1(3)-monoacylglycerols by enantioselective-HPLC/ELSD

Enantiomeric separations were performed on five modified polysaccharide-based chiral stationary phases (CSPs) containing cellulose tris(3,5-dimethylphenylcarbamate) (Lux Cellulose-1), cellulose tris(3-chloro-4-methylphenylcarbamate) (Lux Cellulose-2), cellulose tris(4-methylbenzoate) (Lux Cellulose-3), cellulose tris(4-chloro-3-methylphenylcarbamate) (Lux Cellulose-4), amylose tris(5-chloro-2-methylphenylcarbamate) (Lux Amylose-2) by high-performance liquid chromatography and evaporative light scattering detector. A method for direct separation of pairs of sn-1(3)-monoacylglycerols (MAGs) was established using n-hexane/2-propanol as the mobile phase. The washing of CSPs with mobile phases based on n-hexane/2-propanol, containing small amount of acids, improved considerably the efficiency of separations. Racemic mixtures of sn-1(3)-MAGs with different acyl chains could not be directly separated using only one of the columns tested; employing a tandem column system that consisted of a very short silver-loaded column connected downstream with Lux Cellulose-1 the method allowed, for the first time, the separation of four enantiomeric pairs of standard in a single chromatographic run.     

Short communication: Intra- and inter-individual milk microbiota variability in healthy and infected water buffalo udder quarters

The concept that ruminant mammary gland quarters are anatomically and physiologically unrelated has been recently challenged by immunological evidence. How this interdependence reflects on individual quarter milk microbiota is unknown. The aim of the present study was to cover this gap by investigating the interdependence of quarters among the same mammary gland at the milk microbiota level using next-generation sequencing of the V4–16S rRNA gene. A total of 52 samples were included in this study and classified as healthy or affected by subclinical mastitis. Extraction of DNA, amplification of the V4–16S rRNA gene, and sequencing using Ion Torrent Personal Genome Machine (Thermo Fisher Scientific, Waltham, MA) were carried out. We found that the intra-individual variability was lower than the inter-individual one. The present findings further support at milk microbiota level the hypothesis of the interdependence of quarters, as previously demonstrated following immunological studies, suggesting that individual factors (e.g., immunity, genetics) may have a role in modulating milk microbiota.     

The management of neuroendocrine tumours: A nutritional viewpoint

Nutritional status in patients with neuroendocrine tumours (NETs), especially of gastroenteropancreatic origin, can be deeply affected by excessive production of gastrointestinal hormones, peptides, and amines, which can lead to malabsorption, diarrhoea, steatorrhea, and altered gastrointestinal motility. Besides, the surgical and/or medical management of NETs can lead to alteration of gastrointestinal secretory, motor, and absorptive functions, with both dietary and nutritional consequences. Indeed, disease-related malnutrition is a frequently encountered yet both underrecognized and understudied clinical phenomenon in patients with NETs, with substantial prognostic and socioeconomic consequences. Most of these conditions can be alleviated by a tailored nutritional approach, also with the aim of improving the efficacy of cancer treatments. In this setting, skilled nutritionists can play a fundamental role in the multidisciplinary health care team in NETs management and their presence should be recommended. The aim of this review is to provide dietary advices for each specific condition in patients with NETs, underlining the importance of a nutritional approach to treat malnutrition in this setting. Further, we will provide preliminary evidence coming from our data on the assessment of nutritional status in a single cohort of patients with NETs.     

Polyacetylenes bearing mesogenic side groups: synthesis and properties. Part 3. Influence of flexible spacer length and tail functionality

We report on the synthesis of some novel liquid crystalline polyacetylenes derived from monosubstituted acetylenic monomers where the acetylenic moiety is linked through a short spacer (one or three methylene units and an ether bridge) to a biphenyl mesogenic core. The influence of length and functionality of the terminal groups on the thermal behaviour and on the nature of the mesophases is discussed. All the monomers show liquid crystalline behaviour. Polymerisations are carried out in solution with typical metathesis catalysts based on Mo and W and yield polyacetylenes with fairly high MW soluble in common organic solvents. Polymers are fully characterised by GPC, FT-IR, and ¹H NMR techniques; their thermal and morphological behaviour has been studied by TGA, DSC, POM and X-ray diffraction experiments.     

Detection of β‐Glucosidase and Esterase Activities in Wild Yeast in a Distillery Environment

The study of β‐glucosidase and esterase in wild yeast, the enzymatic activities of which contribute to the distinctive flavours of grape‐derived alcoholic beverages, was the aim of this work. The study focused on wild yeast isolated from grape pomace and on identifying strains with interesting characteristics by examining their electrophoretic profiles. Zymograms revealed a high level of polymorphism. Some of these wild yeasts may be of interest for improving the quality of the distillate. This study also highlights the necessity of associating enzymatic properties to various environmental conditions, since these play an important role in the expression of wild yeast performance.     

Updating on the lysinoalanine content of commercial infant formulae and beicost products

Since the safety issue of lysinoalanine (LAL) still remains unresolved, its concentration in infant formulae should be reduced to a minimum. Data collected in the 1980s indicated that LAL is formed in higher amounts in liquid than in powdered formulae. Recently the market of liquid infant formulae is increasing rapidly and there are no new data, so 23 commercial powdered or liquid samples were investigated. In powdered samples, LAL was below the detection limit, whereas liquid adapted formulae contained up to 86 μg/g protein, liquid follow-on formulae up to 390 μg/g protein, and liquid growing milks up to 514 μg/g protein. The concentration of LAL in liquid formulae is considerably lower than in the past; however, the level in a few products remains rather high, especially compared with normal UHT-treated milk. Great differences were observed among products of different companies, which suggests that labelling with the thermal treatment applied would be very advisable. The investigation of some beicost products indicates that LAL is present only in products certainly containing milk proteins. Considering the rather low levels in comparison with liquid infant formulae, the contribution of beicost products to the total LAL daily intake does not seem to be particularly relevant.     

Genome renewal: A new phenomenon revealed from a genetic study of 43 strains of Saccharomyces cerevisiae derived from natural fermentation of grape musts

We have analyzed by genetic means 43 strains of Saccharomyces that had been isolated from fermenting grape musts in Italy. Twenty eight of these strains were isolated from 28 cellars in the Region of Emilia Romagna. The other 15 strains came from 5 fermentations at four cellars near the city of Arpino, which is located south and east of Rome. We found that 20 of the 28 strains from Emilia Romagna were heterozygous at from one to seven loci. The balance were, within the limits of our detection, completely homozygous. All these strains appeared to be diploid and most were homozygous for the homothallism gene (HO/HO). Spore viability varied greatly between the different strains and showed an inverse relation with the degree of heterozygosity. Several of the strains, and in particular those from Arpino, yielded asci that came from genetically different cells. These different cells could be interpreted to have arisen from a heterozygote that had sporulated and, because of the HO gene, yielded homozygous diploid spore clones. We propose that natural wine yeast strains can undergo such changes and thereby change a multiple heterozygote into completely homozygous diploids, some of which may replace the original heterozygous diploid. We call this process ‘genome renewal’.     

Clinical tolerance of oral loading with elevated doses of amiodarone in a group of patients with heart failure

Amiodarone is a choice drug for the treatment of patients suffering from life-threatening hyperkinetic ventricular arrhythmias and depressed ventricular function. The drug is characterized by a remarkably long halflife and a delayed initial activity after oral administration of the usual loading levels. The aim of this study was to establish: -the clinical tolerance to elevated doses in patients with heart failure presenting complex, hyperkinetic ventricular arrhythmias; -the possibility to shorten hospitalization as a result of the oral loading; -whether this administration route would take less time to be efficacious. For this purpose, 30 patients with heart failure and complex, hyperkinetic ventricular arrhythmias were treated with 0.50 mg/kg body weight of amiodarone for three days and with 0.30 mg/kg on the 4th and 5th days, followed by a maintenance period of treatment with 200-400 mg daily. All patients underwent a 24-h Holter test before and after administration and an echocardiographic examination showing an average ejection fraction of approximately 30%. Amiodarone was clinically well tolerated; only 2 patients required discontinuation of therapy whereas, among the the remaining 28 patients, 2 cases of transient hypotension and 3 cases of gastroenteric disorders were observed. It was concluded that elevated doses of amiodarone were well tolerated, which allowed to reduce the loading period and, therefore, hospitalization.     

Agent-based models for first- and second-order emergent collective behaviours of social amoeba <Emphasis Type="Italic">Dictyostelium discoideum</Emphasis> aggregation and migration phases

Collective behaviour in nature provides a source of inspiration for engineering artificial systems (e.g. robotics, ecosystems of services), due to their inherent mechanisms favouring adaptation to environmental changes and enabling complex emergent behaviour to arise from a relatively simple behaviour of individual entities. The first-order emergence, also referred to as swarm intelligence, is well studied, while higher order levels of emergent behaviour have not received much attention yet. Second-order emergent behaviour arises from the interactions of individuals, which are themselves the result of first-order emergent behaviour. Dictyostelium discoideum provides a compelling case for studying both first- and second-order emergence. Individual cells move around on their own when there is plenty of food. When food is scarce, cells self-aggregate towards a leading center cell (first-order emergent behaviour) to build a super-organism, similar to a slug. The slug displays properties that none of the cells has on its own (e.g. sensitivity to light and heat). It moves as a whole (second-order emergent behaviour) looking for a suitable place to transform into a fruiting body (also known as sporocarp), where later the cells resume their individual behaviour. This paper focuses specifically on the aggregation and migration phases of Dictyostelium discoideum. We present two agent-based models, implemented in Matlab for first order and Python for second order. They display a series of emergent properties, among others homogeneous aggregation territories size (first order) and merging of slugs or new property as sensitivity to light (second order). Future works involve implementing and experimenting both first- and second-order emergence in swarm robotics, and identification of design patterns for engineering higher order emergent behaviour in artificial systems.