Antitumor Effects of Vitamin D Analogs on Hamster and Mouse Melanoma Cell Lines in Relation to Melanin Pigmentation

Deregulated melanogenesis is involved in melanomagenesis and melanoma progression and resistance to therapy. Vitamin D analogs have anti-melanoma activity. While the hypercalcaemic effect of the active form of Vitamin D (1,25(OH)₂D₃) limits its therapeutic use, novel Vitamin D analogs with a modified side chain demonstrate low calcaemic activity. We therefore examined the effect of secosteroidal analogs, both classic (1,25(OH)₂D₃ and 25(OH)D₃), and novel relatively non-calcemic ones (20(OH)D₃, calcipotriol, 21(OH)pD, pD and 20(OH)pL), on proliferation, colony formation in monolayer and soft-agar, and mRNA and protein expression by melanoma cells. Murine B16-F10 and hamster Bomirski Ab cell lines were shown to be effective models to study how melanogenesis affects anti-melanoma treatment. Novel Vitamin D analogs with a short side-chain and lumisterol-like 20(OH)pL efficiently inhibited rodent melanoma growth. Moderate pigmentation sensitized rodent melanoma cells towards Vitamin D analogs, and altered expression of key genes involved in Vitamin D signaling, which was opposite to the effect on heavily pigmented cells. Interestingly, melanogenesis inhibited ligand-induced Vitamin D receptor translocation and ligand-induced expression of VDR and CYP24A1 genes. These findings indicate that melanogenesis can affect the anti-melanoma activity of Vitamin D analogs in a complex manner.     

Empirical analysis of a 2 x 2 MIMO channel in outdoor-indoor scenarios for BFWA applications

The unquestionable advantages of multiple-input multiple-output (MIMO) systems are having a strong influence on the development of new wireless systems, both in wireless local-area networks (WLANs), and in those designed to offer broadband fixed wireless access (BFWA) services in wireless metropolitan-area networks (WMANs). The MIMO channel characterization in different environments and for different operating frequency bands is a crucial factor in the design of new systems and standards, and for adequate planning of existing systems. This article makes two main contributions. First, the experimental characterization of a 2 times 2 MIMO channel at a frequency of 2.4 GHz in a canonical outdoor-indoor scenario is presented. The channel characterization performed includes the analysis of the spatial correlation between the MIMO system subchannels and its impact on the channel capacity. Second, on the basis of the capacity results obtained, a proposal is made for the use of a 2 times 2 MIMO system in outdoor-indoor scenarios for BFWA applications in metropolitan environments. The proposal is based on the experimentally verified hypothesis that the path loss due to building penetration can be practically compensated for by the diversity gain of 2 times 2 systems     

Target Score—A Proteomics Data Selection Tool Applied to Esophageal Cancer Identifies GLUT1-Sialyl Tn Glycoforms as Biomarkers of Cancer Aggressiveness

Esophageal cancer (EC) is a life-threatening disease, demanding the discovery of new biomarkers and molecular targets for precision oncology. Aberrantly glycosylated proteins hold tremendous potential towards this objective. In the current study, a series of esophageal squamous cell carcinomas (ESCC) and EC-derived circulating tumor cells (CTCs) were screened by immunoassays for the sialyl-Tn (STn) antigen, a glycan rarely expressed in healthy tissues and widely observed in aggressive gastrointestinal cancers. An ESCC cell model was glycoengineered to express STn and characterized in relation to cell proliferation and invasion in vitro. STn was found to be widely present in ESCC (70% of tumors) and in CTCs in 20% of patients, being associated with general recurrence and reduced survival. Furthermore, STn expression in ESCC cells increased invasion in vitro, while reducing cancer cells proliferation. In parallel, an ESCC mass spectrometry-based proteomics dataset, obtained from the PRIDE database, was comprehensively interrogated for abnormally glycosylated proteins. Data integration with the Target Score, an algorithm developed in-house, pinpointed the glucose transporter type 1 (GLUT1) as a biomarker of poor prognosis. GLUT1-STn glycoproteoforms were latter identified in tumor tissues in patients facing worst prognosis. Furthermore, healthy human tissues analysis suggested that STn glycosylation provided cancer specificity to GLUT1. In conclusion, STn is a biomarker of worst prognosis in EC and GLUT1-STn glycoforms may be used to increase its specificity on the stratification and targeting of aggressive ESCC forms.     

Scales to measure parents and caretakers satisfaction with the food and nutrition component of Child care Centers

Two Likert-type scales for measuring parents' and caretakers' level of satisfaction with the food and nutrition services offered at childcare multi-centers in a peri-urban community in Caracas, were developed and validated. An intentional sample of 20 parents and caretakers were interviewed within the naturalistic-constructivist perspective, to capture their perceptions of distinct aspects of the food and nutrition components of the program. Categories emerged from the interviews that served to construct the items for two scales that measure level of satisfaction of parents and caretakers with the food and nutrition aspects of the program. To validate the scales, they were applied to 73 parents and 32 caretakers. Factor and multiple components analysis showed that overall, the scales explained 61% and 69% of the variation in level of satisfaction of parents and caretakers respectively. Confiability measured with Alpha Cronbach coefficient was 0.74 and 0.77 for parents' and caretakers' scales respectively. These results reveal scales that have content validity and good reliability. Besides, the scales detect specific aspects of the food and nutrition service that should be reinforced or modified, to make the Child-care Centers program more effective and efficient. External validation of the scales is recommended, since they provide an instrument capable of capturing useful information for monitoring and evaluating the Child-care Centers program nation-wide, from the perspective of program managers and parents of program users.     

High‐retention properties for Hg(II) ions of a resin containing ammonium and pyridine groups

The metal‐ion uptake behavior of the chelating resin poly([(3‐(methacryloylamino)propyl] trimethyl ammonium chloride‐co‐4‐vinyl pyridine) has been investigated. The resin is obtained by radical copolymerization in a yield of 99.6%. The hydrophilic resin shows a high retention capacity and selectivity toward Hg(II) ions in the presence of Cu(II), Pb(II), Cd(II), Zn(II), and Cr(III) ions. A retention of Hg(II) higher than 99% is observed after 5 min. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2595–2599, 2002     

Semiquantitative analysis of thiophenic compounds in light cycle oil (LCO) using C NMR spectroscopy

S-methyltetrafluoroborate salts of the thiophenic compounds (CH₃-S⁺:BF₄⁻) present in LCO petroleum fractions were obtained and analyzed by ¹H and ¹³C NMR spectroscopy. The methylation of the samples was carried out using 99.5% ¹³C enriched methyl iodine, to improve the sensitivity of the technique. The amount of the methylated derivatives was determined by the internal standard method; using dioxane as a reference, 37 sulphur compounds were detected. Among them, benzo[b]thiophene, dibenzo[b,d]thiophene, and several isomers of methyl, dimethyl and trimethyl[b]benzothiophenes were the most abundant. With this research, it was demonstrated that NMR spectroscopy can be used to analyze thiophenic compounds from petroleum medium fractions.     

Computationally Efficient Algorithm For Frequency‐Weighted Optimal H∞ Model Reduction

In this paper, a frequency‐weighted optimal H_∞ model reduction problem for linear time‐invariant (LTI) systems is considered. The objective of this class of model reduction problems is to minimize H_∞ norm of the frequency‐weighted truncation error between a given LTI system and its lower order approximation. A necessary and sufficient solvability condition is derived in terms of LMIs with one extra coupling rank constraint, which generally leads to a non‐convex feasibility problem. Moreover, it has been shown that the reduced‐order model is stable when both stable input and output weights are included, and its state‐space data are given explicitly by the solution of the feasibility problem. An efficient model reduction scheme based on cone complementarity algorithm (CCA) is proposed to solve the non‐convex conditions involving rank constraint.     

How important is tryptophan in human health?

Tryptophan (Trp) is an amino acid and an essential component of the human diet. It plays a crucial role in many metabolic functions. Clinicians can use Trp levels in the course of diagnosing various metabolic disorders and the symptoms associated with those diseases. Furthermore, supplementation with this amino acid is considered in the treatment of depression and sleep disorders, mainly due to the Trp relationship with the synthesis of serotonin (5-HT) and melatonin. It is also used in helping to resolve cognitive disorders, anxiety, or neurodegenerative diseases. Reduced secretion of serotonin is associated with autism spectrum disorder, obesity, anorexia and bulimia nervosa, and other diseases presenting peripherals symptoms. The literature strongly suggests that Trp has a significant role in the correct functionality of the brain-gut axis and immunology. This information leads to the consideration of Trp as an essential dietary component due to its role in the serotonin pathway. A reduced availability of Trp in diet and nutraceutical supplementation should be considered with greater concern than one might expect. This paper constitutes a review of the more salient aspects gleaned from the current knowledge base about the role of Trp in diseases, associated nutritional disorders, and food science, in general.     

Sex‐related differences in the nutritional value of Japanese quail meat

The objective of the study was to evaluate the impact of birds’ sex on the carcass composition and meat (breast muscle) nutritional value in Japanese quails in a large‐scale four‐generation study. Standard poultry feed was used, based on maize, soya bean meal and wheat. Four generations of quails were housed up to the age of 17 weeks each. Then samples of breast muscle were collected after dissection and analysed for basic nutrient content and for fatty acids composition. Results were analysed by GLM procedure in SAS, and significance of differences between birds of different sex was estimated by Duncan's test. Dissection revealed marked differences between birds’ of different sex in case of relative organ weight. Results of meat analyses showed no differences in the basic composition. Fatty acids analyses showed a more advantageous profile in female meat.     

Soot oxidation kinetics under pressurized conditions

The oxidation kinetics, under different pressures, of soot samples obtained from different liquid fuels and two standards (a commercial black carbon sample and a reference diesel soot) was studied. Soot samples were generated in a flat-flame, premixed burner under heavily-sooting conditions and captured on a water-cooled stabilization plate located above the burner surface. The collected soot was oxidized using a high-pressure thermogravimetric analyzer (HTGA). TGA operation was optimized to reduce mass transfer effects by adjusting the oxidizer flow rate and initial sample mass. Further corrections for mass transfer were accomplished by computing the effectiveness factors for intraparticle, interparticle, and external mass transfer. Two pressures were evaluated (1 and 10 atm) and O₂ concentration was varied between 10 and 21%.