β-Cyclodextrin-based nanosponges as carriers for 1-MCP in extending the postharvest longevity of carnation cut flowers: an evaluation of different degrees of cross-linking

This study investigated the influence of different degrees of cross-linking of β-cyclodextrin-based nanosponges (β-CD-NSs) on the activity of the incorporated 1-methylcyclopropene (1-MCP) to extend the postharvest longevity of carnation cut flowers. The polymeric β-CD-NSs were synthesized from cyclodextrins at three varying reticulations, β-CD-NS 1:2, β-CD-NS 1:4, and β-CD-NS 1:8. These carriers were supplied to carry the nonvolatile formulations of 1-MCP at two different concentrations (0.25 and 0.5 μL L⁻¹, ai) through stem and tissues of cut flowers of Dianthus caryophyllus L. ‘Idra di Muraglia’, both sprayed and in vase suspension. Treated cut flowers were compared to those receiving like concentrations of commercially prepared gaseous 1-MCP and to neat β-CD-NS 1:2, β-CD-NS 1:4, and β-CD-NS 1:8. Visual checks for symptoms of senescence alteration (VS), petal color variation, and endogenous ethylene production were registered daily. The β-CD-NS 1:2, β-CD-NS 1:4, and β-CD-NS 1:8 complexes favored decorative value maintenance in carnation cut flowers. In particular, the lowest suspended concentration (0.25 μL L⁻¹) of the β-CD-NS 1:8 complex proved best for maintaining cut flower ornamental quality. β-CD-NS 1:8 treated flowers also appeared longer-lived than those treated with both doses of commercial gaseous 1-MCP. Data on petal color variation and endogenous ethylene production were strictly correlated with VS results. The potential for the formulated 1-MCP-loaded β-CD-NS suspension to induce prolonged vase life was demonstrated. Its use could yield benefits, such as a reduction in total dose and frequency of administration.     

Similarity in recombination rate estimates highly correlates with genetic differentiation in humans

Recombination varies greatly among species, as illustrated by the poor conservation of the recombination landscape between humans and chimpanzees. Thus, shorter evolutionary time frames are needed to understand the evolution of recombination. Here, we analyze its recent evolution in humans. We calculated the recombination rates between adjacent pairs of 636,933 common single-nucleotide polymorphism loci in 28 worldwide human populations and analyzed them in relation to genetic distances between populations. We found a strong and highly significant correlation between similarity in the recombination rates corrected for effective population size and genetic differentiation between populations. This correlation is observed at the genome-wide level, but also for each chromosome and when genetic distances and recombination similarities are calculated independently from different parts of the genome. Moreover, and more relevant, this relationship is robustly maintained when considering presence/absence of recombination hotspots. Simulations show that this correlation cannot be explained by biases in the inference of recombination rates caused by haplotype sharing among similar populations. This result indicates a rapid pace of evolution of recombination, within the time span of differentiation of modern humans.     

Assessing corpus callosum changes in Alzheimer's disease: comparison between tract-based spatial statistics and atlas-based tractography

Tractography based on Diffusion Tensor Imaging (DTI) represents a valuable tool for investigating brain white matter (WM) microstructure, allowing the computation of damage-related diffusion parameters such as Fractional Anisotropy (FA) in specific WM tracts. This technique appears relevant in the study of pathologies in which brain disconnection plays a major role, such as, for instance, Alzheimer's Disease (AD). Previous DTI studies have reported inconsistent results in defining WM abnormalities in AD and in its prodromal stage (i.e., amnestic Mild Cognitive Impairment; aMCI), especially when investigating the corpus callosum (CC). A reason for these inconsistencies is the use of different processing techniques, which may strongly influence the results. The aim of the current study was to compare a novel atlas-based tractography approach, that sub-divides the CC in eight portions, with Tract-Based Spatial Statistics (TBSS) when used to detect specific patterns of CC FA in AD at different clinical stages. FA data were obtained from 76 subjects (37 with mild AD, 19 with aMCI and 20 elderly healthy controls, HC) and analyzed using both methods. Consistent results were obtained for the two methods, concerning the comparisons AD vs. HC (significantly reduced FA in the whole CC of AD patients) and AD vs. aMCI (significantly reduced FA in the frontal portions of the CC in AD patients), thus identifying a relative preservation of the frontal CC regions in aMCI patients compared to AD. Conversely, the atlas-based method but not the TBSS showed the ability to detect a selective FA change in the CC parietal, left temporal and occipital regions of aMCI patients compared to HC. This finding indicates that an analysis including a higher number of voxels (with no restriction to tract skeletons) may detect characteristic pattern of FA in the CC of patients with preclinical AD, when brain atrophy is still modest.     

Implications of Storing Urinary DNA from Different Populations for Molecular Analyses

Background

Molecular diagnosis using urine is established for many sexually transmitted diseases and is increasingly used to diagnose tumours and other infectious diseases. Storage of urine prior to analysis, whether due to home collection or bio-banking, is increasingly advocated yet no best practice has emerged. Here, we examined the stability of DNA in stored urine in two populations over 28 days.

Methodology

Urine from 40 (20 male) healthy volunteers from two populations, Italy and Zambia, was stored at four different temperatures (RT, 4°C, −20°C & −80°C) with and without EDTA preservative solution. Urines were extracted at days 0, 1, 3, 7 and 28 after storage. Human DNA content was measured using multi-copy (ALU J) and single copy (TLR2) targets by quantitative real-time PCR. Zambian and Italian samples contained comparable DNA quantity at time zero. Generally, two trends were observed during storage; no degradation, or rapid degradation from days 0 to 7 followed by little further degradation to 28 days. The biphasic degradation was always observed in Zambia regardless of storage conditions, but only twice in Italy.

Conclusion

Site-specific differences in urine composition significantly affect the stability of DNA during storage. Assessing the quality of stored urine for molecular analysis, by using the type of strategy described here, is paramount before these samples are used for molecular prognostic monitoring, genetic analyses and disease diagnosis.     

Apoptosis of L929 Cells by Etoposide: A Quantitative and Kinetic Approach

Exponentially growing L929 cells were continuously exposed to 1 or 10 μMetoposide (VP-16). The effects of such treatment on cell growth, cycle distribution, morphology, and selected biochemical events were examined. DNA synthesis rates were markedly decreased and the protein/DNA ratio increased (unbalanced growth). Growth was blocked, with most cells being cycle arrested by 24 h in (late S–)G2–M. An asynchronous process of cell death then developed. Cells initially shrank into eosinophilic, trypan blue-excluding bodies, which were then released into the medium, and eventually became permeable to trypan blue. Transmission electron microscopy confirmed that dying cells acquired an apoptotic morphotype, with compaction and margination of chromatin, loss of microvilli, and shrinkage of cytoplasm and nucleus. Tissue transglutaminase activity and intensity of immunostaining rapidly increased in treated cultures. Internucleosomal DNA fragmentation could not be detected by agarose gel electrophoresis, yet flow cytometry revealed that the apoptotic bodies had a very low DNA fluorescence (≤10% of the 2nvalue). In agreement with the microscopic findings, this suggested that extensive DNA degradation had occurred in dead cells. While rates of cell loss from the monolayer amounted to 21 and 57% day⁻¹(1 and 10 μMVP-16, respectively), apoptotic indexes largely underestimated the extent of the process. These indexes only measured the accumulation of apoptotic bodies, i.e., the balance between their generation and disposal. The latter occurred by mechanisms similar to those that operate in tissues: “secondary necrosis” or phagocytosis by viable homotypic cells in the monolayer (“homophagy”).     

Clustering humans: on biological boundaries

We inquire into the notions of 'boundary' and 'cluster' in the fields of medical genetics, pharmacogenetics, and population genetics. First we show that the two notions are not well discussed in literature. Then we propose a promising explication of them, in which we argue that clustering is always 'property laden', that is, fundamentally dependent on decisions about the properties to be taken into account. In particular we suggest three different kinds of properties (main properties, investigating properties, and catalyzing properties) that have a role in these decisions. That is, we conclude that boundaries and clusters among humans depend on our way of considering nature. Concepts of 'race' and 'ethnic group' are discussed too, since they are the most used clusters among humans.     

A sesquiterpene lactone, costunolide, interacts with microtubule protein and inhibits the growth of MCF-7 cells

Costunolide is an active sesquiterpene lactone of medicinal herbs with anti-inflammatory and potential anti-cancer activity. Nevertheless, the pharmacological pathways of costunolide have not yet been fully elucidated. In this study we showed that costunolide exerts a dose-dependent antiproliferative activity in the human breast cancer MCF-7 cells. In addition, light microscopy observations indicated that costunolide affected nuclear organization and reorganized microtubule architecture. The antiproliferative and antimicrotubular effects of costunolide were not influenced by paclitaxel, well-known microtubule-stabilizing anticancer agent. The microtubule-interacting activity of costunolide was confirmed by in vitro studies on purified microtubular protein. In fact, costunolide demonstrated polymerizing ability, by inducing the formation of well organized microtubule polymers. Our data suggest an interaction of costunolide with microtubules, which may represent a new intracellular target for this drug.     

PNPLA3 I148M Polymorphism,Clinical Presentation,and Survival in Patients with Hepatocellular Carcinoma

Background & Aims

Aim of this study was to evaluate whether the PNPLA3 I148M polymorphism, previously associated with hepatocellular carcinoma (HCC) risk, influences the clinical presentation of HCC and survival.

Methods

we considered 460 consecutive HCC patients referred to tertiary care centers in Northern Italy, 353 with follow-up data.

Results

Homozygosity for PNPLA3 148M at risk allele was enriched in HCC patients with alcoholic liver disease or nonalcoholic fatty liver disease (ALD&NAFLD: relative risk 5.9, 95% c.i. 3.5–9.9; other liver diseases: relative risk 1.9, 95% c.i. 1.1–3.4). In ALD&NAFLD patients, the PNPLA3 148M allele was associated with younger age, shorter history of cirrhosis, less advanced (Child A) cirrhosis at HCC diagnosis, and lower HCC differentiation grade (p<0.05). Homozygosity for PNPLA3 148M was associated with reduced survival in the overall series (p = 0.009), and with a higher number of HCC lesions at presentation (p = 0.007) and reduced survival in ALD&NAFLD patients (p = 0.003; median survival 30, 95% c.i. 20–39 vs. 45, 95% c.i. 38–52 months), but not in those with HCC related to other etiologies (p = 0.86; 48, 95% c.i. 32–64 vs. 55, 95% c.i. 43–67 months). At multivariate Cox regression analysis, homozygosity for PNPLA3 148M was the only negative predictor of survival in ALD&NAFLD patients (HR of death 1.57, 95% c.i. 1.12–2.78).

Conclusions

PNPLA3 148M is over-represented in ALD&NAFLD HCC patients, and is associated with occurrence at a less advanced stage of liver disease in ALD&NAFLD. In ALD&NAFLD, PNPLA3 148M is associated with more diffuse HCC at presentation, and with reduced survival.