Influence of sodium profile in preventing complications during hemodialysis

Although a safe procedure, hemodialysis (HD) can cause numerous complications. The objective of this study was to evaluate the incidence of complications during dialysis, interdialytic weight gain, and the predialysis and postdialysis blood pressure in HD patients with and without variable sodium. Patients were observed during 12 HD sessions and those presenting with recurrent hypotension were selected for a step-wise model of variable sodium profiling. A total of 53 patients were evaluated; the mean-SD age was 53.7+/-16.3 years and 22 (41.5%) were male. Of these, 18 (34.0%) were selected to receive variable sodium profiling: the mean (SD) age was 59.9+/-12.6 years, and 10 (55.6%) were female. A significant decline in the occurrence of cramps (p<0.027), in the mean interdialytic weight gain (p<0.009), and a tendency to reduce the number of hypotensive episodes were detected in patients using variable sodium profiling. On the other hand, predialysis systolic blood pressure presented a significant increase (p<0.048). Using variable sodium, there was a statistically significant reduction in cramps and in the mean interdialytic weight gain. There was a significant increase in predialysis systolic pressure. Regarding hypotension episodes, only a tendency toward a reduction in the frequency of hypotension episodes could be detected.     

Effect of milk fat and total solids concentration on the kinetics of moisture uptake by ready-to-eat breakfast cereal

Summary When immersed in milk, breakfast cereal easily take up moisture, lose their brittle texture and become soggy. Earlier comparative analysis of the moisture sorption by breakfast cereal immersed in water and milk indicated that milk solids might play an important role on the sorption kinetics. In this work, the moisture uptake by ready-to-eat corn breakfast cereal immersed in milk solutions, reconstituted from whole and skimmed milk powder, was measured under isothermal conditions at 5, 30 and 55 °C. Dilutions between 0.25 and 1.5 were tested, with the factor of dilution 1 corresponding to the standard recommended by the milk powder manufacturer. The Weibull probabilistic model adequately fitted the experimental data by appropriate choice of its variable parameters. The dependence of the model parameters on temperature and total solids concentration was assessed for both skimmed and whole milk. Fat was found to play a major role on the process mechanism, which was attributed to the deposition of a fat layer at the solid matrix surface, hindering water and solids uptake. Yet, for short times, moisture uptake proceeded at a similar rate both in skimmed and whole milk.     

Epigenetic Dysregulations in Merkel Cell Polyomavirus-Driven Merkel Cell Carcinoma

Merkel cell polyomavirus (MCPyV) is a small DNA virus with oncogenic potential. MCPyV is the causative agent of Merkel Cell Carcinoma (MCC), a rare but aggressive tumor of the skin. The role of epigenetic mechanisms, such as histone posttranslational modifications (HPTMs), DNA methylation, and microRNA (miRNA) regulation on MCPyV-driven MCC has recently been highlighted. In this review, we aim to describe and discuss the latest insights into HPTMs, DNA methylation, and miRNA regulation, as well as their regulative factors in the context of MCPyV-driven MCC, to provide an overview of current findings on how MCPyV is involved in the dysregulation of these epigenetic processes. The current state of the art is also described as far as potentially using epigenetic dysregulations and related factors as diagnostic and prognostic tools is concerned, in addition to targets for MCPyV-driven MCC therapy. Growing evidence suggests that the dysregulation of HPTMs, DNA methylation, and miRNA pathways plays a role in MCPyV-driven MCC etiopathogenesis, which, therefore, may potentially be clinically significant for this deadly tumor. A deeper understanding of these mechanisms and related factors may improve diagnosis, prognosis, and therapy for MCPyV-driven MCC.     

Polycyclic aromatic hydrocarbons (PAHs) in sugarcane juice

Sugarcane juice is a common beverage in many Brazilian cities. At harvesting season most sugarcane plantation is burnt and this procedure has been shown as an important source of PAHs emission. In the present study 80 samples of sugarcane juice collected from two Brazilian cities, in two different periods, were analysed for the presence of four PAHs: benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene and benzo(a)pyrene. PAHs were detected in 50% of the samples. The samples collected between harvests presented mean sums of PAHs of 0.013 μg/kg and 0.012 μg/kg, while the samples collected during harvest presented mean sums of 0.053 μg/kg and 0.055 μg/kg. A higher concentration and incidence of PAHs in the juices collected in the harvest period was verified, corroborating the burning of the crops as a source of sugarcane juice contamination.     

Thermo- and pH-sensitive IPN hydrogels based on PNIPAAm and PVA-Ma networks with LCST tailored close to human body temperature

Interpenetrating polymer network (IPN) hydrogels based on chemically modified poly(vinyl alcohol) (or PVA-Ma), with different degrees of substitution (DS), and poly(N-isopropylacrylamide) (or PNIPAAm) were obtained and characterized in this work. The PVA-Ma/PNIPAAm membrane hydrogels were prepared in two steps. In the first step the PVA-Ma hydrogels (with using PVA-Ma with different DS) were prepared by the reaction of double bonds on PVA-Ma, using the persulfate/TEMED pathway. In the second step the PNIPAAm network was prepared within the parent PVA-Ma network at different PVA-Ma/NIPAAm ratios using a photoreaction pathway. The studies show that degree of swelling of PVA-Ma/PNIPAAm IPN hydrogels is dependent on both temperature and pH of the soaking solution. The LCST of PVA-Ma/PNIPAAm IPN hydrogels, which was determined by measuring the intensity of light transmitted through the swollen hydrogels, can be tailored closer to human body temperature. Furthermore, SEM images showed that the IPN hydrogels present characteristic morphology as compared to parent PVA-Ma networks. IPN hydrogels presented lower cytotoxicity as compared to respective PVA-Ma hydrogels but the increase in the PVA-Ma/NIPAAm ratio allows the respective hydrogels being lesser cytocompatibles. The IPN hydrogels synthesized in this work presented characteristics that potentize their application as biomaterials, drug carriers, artificial muscles and treatment of wound.     

Singlet Oxygen Detection Using Red Wine Extracts as Photosensitizers

Moderate consumption of red wine provides beneficial effects to health. This is attributed to polyphenol compounds present in wine such as resveratrol, quercetin, gallic acid, rutin, and vanillic acid. The amount of these antioxidants is variable; nevertheless, the main beneficial effects of red wine are attributed to resveratrol. However, it has been found that resveratrol and quercetin are able to photosensitize singlet oxygen generation and conversely, gallic acid acts as quencher. Therefore, and since resveratrol and quercetin are some of the most important antioxidants reported in red wines, the aim of this research was to evaluate the photosensitizing ability of 12 red wine extracts through photo‐oxidation of ergosterol. The presence of ¹O₂ was detected by ergosterol conversion into peroxide of ergosterol through ¹H NMR analysis. Our results showed that 10 wine extracts were able to act as photosensitizers in the generation of singlet oxygen. The presence of ¹O₂ can damage other compounds of red wine and cause possible organoleptic alterations. Finally, although the reaction conditions employed in this research do not resemble the inherent conditions in wine making processing or storing, or even during its consumption, this knowledge could be useful to prevent possible pro‐oxidant effects and avoid detrimental effects in red wines.