Virus hazards from food, water and other contaminated environments

Numerous viruses of human or animal origin can spread in the environment and infect people via water and food, mostly through ingestion and occasionally through skin contact. These viruses are released into the environment by various routes including water run-offs and aerosols. Furthermore, zoonotic viruses may infect humans exposed to contaminated surface waters. Foodstuffs of animal origin can be contaminated, and their consumption may cause human infection if the viruses are not inactivated during food processing. Molecular epidemiology and surveillance of environmental samples are necessary to elucidate the public health hazards associated with exposure to environmental viruses. Whereas monitoring of viral nucleic acids by PCR methods is relatively straightforward and well documented, detection of infectious virus particles is technically more demanding and not always possible (e.g. human norovirus or hepatitis E virus). The human pathogenic viruses that are most relevant in this context are nonenveloped and belong to the families of the Caliciviridae, Adenoviridae, Hepeviridae, Picornaviridae and Reoviridae. Sampling methods and strategies, first-choice detection methods and evaluation criteria are reviewed.     

The co‐occurrence of mtDNA mutations on different oxidative phosphorylation subunits,not detected by haplogroup analysis,affects human longevity and is population specific

To re‐examine the correlation between mtDNA variability and longevity, we examined mtDNAs from samples obtained from over 2200 ultranonagenarians (and an equal number of controls) collected within the framework of the GEHA EU project. The samples were categorized by high‐resolution classification, while about 1300 mtDNA molecules (650 ultranonagenarians and an equal number of controls) were completely sequenced. Sequences, unlike standard haplogroup analysis, made possible to evaluate for the first time the cumulative effects of specific, concomitant mtDNA mutations, including those that per se have a low, or very low, impact. In particular, the analysis of the mutations occurring in different OXPHOS complex showed a complex scenario with a different mutation burden in 90+ subjects with respect to controls. These findings suggested that mutations in subunits of the OXPHOS complex I had a beneficial effect on longevity, while the simultaneous presence of mutations in complex I and III (which also occurs in J subhaplogroups involved in LHON) and in complex I and V seemed to be detrimental, likely explaining previous contradictory results. On the whole, our study, which goes beyond haplogroup analysis, suggests that mitochondrial DNA variation does affect human longevity, but its effect is heavily influenced by the interaction between mutations concomitantly occurring on different mtDNA genes.     

Rapid construction of insulated genetic circuits via synthetic sequence-guided isothermal assembly

In vitro recombination methods have enabled one-step construction of large DNA sequences from multiple parts. Although synthetic biological circuits can in principle be assembled in the same fashion, they typically contain repeated sequence elements such as standard promoters and terminators that interfere with homologous recombination. Here we use a computational approach to design synthetic, biologically inactive unique nucleotide sequences (UNSes) that facilitate accurate ordered assembly. Importantly, our designed UNSes make it possible to assemble parts with repeated terminator and insulator sequences, and thereby create insulated functional genetic circuits in bacteria and mammalian cells. Using UNS-guided assembly to construct repeating promoter-gene-terminator parts, we systematically varied gene expression to optimize production of a deoxychromoviridans biosynthetic pathway in Escherichia coli. We then used this system to construct complex eukaryotic AND-logic gates for genomic integration into embryonic stem cells. Construction was performed by using a standardized series of UNS-bearing BioBrick-compatible vectors, which enable modular assembly and facilitate reuse of individual parts. UNS-guided isothermal assembly is broadly applicable to the construction and optimization of genetic circuits and particularly those requiring tight insulation, such as complex biosynthetic pathways, sensors, counters and logic gates.     

Impaired glucose metabolism in heroin and methadone users

Plasma glucose and insulin responses to both oral and intravenous glucose stimulation were evaluated in heroin and methadone addicts, compared to healthy control subjects. Both groups of addicts had an altered response to oral and intravenous glucose load. These phenomena were linked to a reduced insulin response. Moreover, increased fasting insulin levels in both groups of addicts were observed. These data show that both heroin and methadone addiction may alter glucose metabolism, and, furthermore, stress the findings of similarities between opiate addicts and non-insulin dependent diabetics.     

Acetylsalicylic acid and hormonal response in insulin induced hypoglycemia]

The influence of a short-term treatment with acetylsalicylic acid (ASA 3,2 g/daily), an inhibitor of endogenous prostaglandin synthesis, on plasma glucose, glucagon and growth hormone responses to insulin-induced hypoglycemia, has been investigated in seven subjects. ASA caused a slight but significant reduction in basal glucose levels, but did not alter the pattern of glucagon and growth hormone secretion following hypoglycemia. On the basis of these results, it is hypothesized that endogenous prostaglandins are not implicated in the response of pancreatic alfa-cell to hypoglycemia.     

Protective effects of mannan in Caco-2/TC7 cells treated with wheat-derived peptides

Celiac disease (CD) is characterized by a permanent intolerance to wheat gliadin and related proteins in genetically susceptible individuals. It is generally considered that CD is an immuno-mediated multifactorial disease, but a direct cytotoxic activity of gliadin-derived peptides (GL-PT) on intestinal mucosa cannot be excluded. Many efforts have been done to identify possible antagonists of this direct toxicity and several studies indicated that mannan and oligomers of N-acetylglucosamine, [N,N′-diacetylchitobiose (GLcNAc)2 and N,N′,N″;-triacetylchitotriose (GLcNAc)3], could be very promising candidates.

In the present study we investigated the ability of mannan, (GLcNAc)2 and (GLcNAc)3 to interfere with some toxic effects exerted by GL-PT, as cell growth and viability impairment, increased intestinal permeability and cellular inflammation, on a clone of the human intestinal Caco-2 cell line, Caco-2/TC7, expressing a more homogeneous population than the parental one.

Our present results demonstrate that mannan, among the three molecules investigated, is the most suitable to counteract the adverse effects induced by GL-PT on Caco-2/TC7 cells, for all the parameters considered in this study.