For decades, researchers have explored the potential of natural products with immunomodulatory and antioxidant effects for targeting human skin diseases. Skin diseases can be caused by multiple factors including exposure to allergens, genetic inheritance, as well as autoimmune responses, and they cause major health concerns. The use of natural products is gaining popularity due to their long history of use and as a potential source of biologically active agents with anti-inflammatory, immunomodulatory, antioxidant, and chemo-preventive effects. Thus, natural products are continuously being explored for targeting multiple signaling pathways and acting as potential bioactive agents for targeting skin diseases. In this Research Topic, a total of eleven articles were published, illustrating the immunomodulatory mechanisms and regulatory pathways of diverse natural products and their formulations in targeting human skin diseases.<br/>
Abstract The versatility of wet chemical methods has rendered them extremely popular for the preparation of metal nanoparticles with tailored size and shape. This Feature Article reviews the use of N , N ‐dimethylformamide (DMF) for the reduction of metal salts, mainly Au and Ag, while also acting as a solvent. Apart from describing the ability of DMF to reduce metal salts, the effect of different parameters, such as the concentration of capping agent and metal precursors, the presence of preformed seeds acting as catalysts or their crystalline structure, on particle morphology are analyzed. Published reports on the use of different capping agents are summarized, with particular emphasis on the role of poly(vinylpyrrolidone) to determine the morphology of the particles. Finally, a brief overview is provided on the modulation of the optical response in DMF‐based metal nanoparticle colloids with tunable size and shape.
Flavonoids undergo substantial hepatic metabolism and the metabolites might significantly contribute to the effects of these dietary constituents. The metabolites of flavonoids in liver can be summarized as follows: 1) For flavones, the hydroxylation appears to occur at the C-4'-, C-3', C-6 and C-8- position when there is a single or no hydroxy group on the B-ring. The methoxyl groups positioned at the C-7, C-6 or C-4'- position of flavones are demethylated. The glucuronidation occurs at the 6, 7, 4' or 3'- hydroxyl moiety. Flavone glycosides and aglycones appear to undergo similar metabolic pathways. 2) For flavonols, the hydroxylation appears at the 3' and 4'- position and flavonols with a 4'-methoxy group are easily O-demethylated to their corresponding hydroxylated analogs. The glucuronidation takes place at the 7, 3, 3' and 4'- hydroxyl moiety. 3) For isoflavones, the microsomal hydroxylation is observed at the C-3'-, C-6 and C-8- position when there is a single or no hydroxy group on the B-ring. The demethylation takes place at the C-6- or C-4'- position when there is one methoxy group on C-4' or C-6-position, respectively. The glucuronidation occurs at the 4, or 5- hydroxyl moiety. 4) For chalcones, the C-3'-, and C-8- positions undergo hydroxylation. The C-8- position is a very active site for metabolism of chalcones.
The relationship between the proanthocyanidin profile and the perceived astringency was assessed in 13 commercial Tempranillo red wines. The concentration and compositional information were obtained by liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometry after acid-catalyzed depolymerization of wine proanthocyanidins in the presence of excess phloroglucinol. Statistical analysis of the results showed significant correlations between sensory and chemical determinations. Astringency was more affected by the subunit composition than by the total concentration or the average degree of polymerization of wine proanthocyanidins. Higher proportions of epicatechin (EC) subunits in extension positions and gallocatechin (GC) subunits in terminal positions were shown to increase astringency. On the contrary, the amount of epigallocatechin (EGC) in both extension and terminal positions was negatively correlated with the perceived astringency.
A study was conducted to develop a optical response model of highly faceted metal nanoparitcles by using a 3D boundary element method (BEM). The study also can be used to develop model for rod-to-octahedron transition. The BEM for axially symmetric particles can provide optical spectra in decorated nanorods, decahedrons, and nanostars. Gold nanorods were synthesized during the study in water and transfer into N,N-dimethylformamide (DMF). The study also examine the chemical growth of axially symmetric gold nanorods into octahedrons. It was observed during the study that the modeling of the cross-section is simple for a cylinder, while modeling of cross-section of prism require total width and the curvature of the edges. The study concluded that this method is computationally more efficient the DDA of FDTD techniques. © 2008
Abstract A β‐cyclodextrin derivative grafted chitosan (CDD‐C) was synthesized with chitosan and carboxymethyl‐β‐cyclodextrin (β‐CD). Its structure was characterized by elemental, infrared spectra, and X‐ray diffraction analyses. The degree of substitution by the carboxymethyl‐β‐CD moiety achieved 0.27 with the addition of DMF to the reaction solution. The results are in agreement with the expectations. The static adsorption properties for guanosine, cytidine, and uridine were studied. Experimental results demonstrated that CDD‐C had higher adsorption capability for guanosine than cytidine and uridine, and the adsorption capacity for guanosine was 74.20 mg/g. The adsorption capacity was greatly influenced by pH, time, and temperature. The introduction of chitosan enhanced the adsorption ability and adsorption selectivity of β‐CD for guanosine. This novel derivative of chitosan is expected to have wide applications in separation, concentration, and analysis of guanosine, cytidine, and uridine in biological sample. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3050–3055, 2007
Hermida, R C; Calvo, C; Ayala, D E; Dominguez, M J; Covelo, M; Mojon, A; Fernandez, J R; Lopez, J E Author Information
Angiotensin II receptor blockers (ARBs) are a relatively new class of antihypertensive medications that selectively and specifically antagonize the action of angiotensin II, a potent vasoconstrictor impacting blood pressure (BP) regulation. Valsartan is an orally active, specific, and selective ARB. After a single oral dose, the onset of its BP lowering action is within 2 hours, with peak effect occurring within 4–6 hours. We investigated the effects of valsartan on the 24-hour BP profile of hypertensive patients. We studied 187 patients with grade 1–2 essential hypertension (63 men), 50.4±13.3 (mean±SD) years of age, assigned to receive valsartan monotherapy (160 mg/day). BP was measured by ambulatory monitoring at 20-min intervals from 07:00 to 23:00 hours and at 30-min intervals at night for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy, and the information used to determine diurnal and nocturnal means of BP for each patient according to individual resting time. Valsartan treatment resulted in a highly statistically significant reduction in BP from baseline after 3 months of treatment (14.8 and 10.5 mm Hg reduction in the 24-hour mean of systolic and diastolic BP, respectively; P<0.001). The BP reduction was highly significant (after correcting for multiple testing) at each of the 24 hourly means (P always <0.001). There was no effect of valsartan on heart rate (increase in the 24-hour mean of 0.17 beats/min, P=0.862). The circadian pattern of physical activity also remained unchanged (24-hour mean of 128 and 127 counts/min before and after treatment, respectively; P=0.661). There was also a highly significant reduction (P<0.001) of 4.3 mm Hg in the 24-hour mean of pulse pressure (PP). Results indicate that, despite its relatively short half-life, 160 mg/day valsartan efficiently reduce BP for the whole 24 hours of the day. Moreover, valsartan significantly reduces PP during the 24 hours. Apart from the progressive rise of PP with aging, a significant increase in PP has been documented, among other groups of interest, in hypertensive patients with type 2 diabetes. Thus, valsartan could be chosen, for added cardiovascular risk reduction, in the treatment of the elderly and diabetics with elevated PP, an issue that deserves further prospective investigation. Am J Hypertens (2004) 17, 110A–110A; doi: 10.1016/j.amjhyper.2004.03.284
Abstract Throughout the living world, genetic recombination and nucleotide substitution are the primary processes that create the genetic variation upon which natural selection acts. Just as analyses of substitution patterns can reveal a great deal about evolution, so too can analyses of recombination. Evidence of genetic recombination within the genomes of apparently asexual species can equate with evidence of cryptic sexuality. In sexually reproducing species, nonrandom patterns of sequence exchange can provide direct evidence of population subdivisions that prevent certain individuals from mating. Although an interesting topic in its own right, an important reason for analysing recombination is to account for its potentially disruptive influences on various phylogenetic‐based molecular evolution analyses. Specifically, the evolutionary histories of recombinant sequences cannot be accurately described by standard bifurcating phylogenetic trees. Taking recombination into account can therefore be pivotal to the success of selection, molecular clock and various other analyses that require adequate modelling of shared ancestry and draw increased power from accurately inferred phylogenetic trees. Here, we review various computational approaches to studying recombination and provide guidelines both on how to gain insights into this important evolutionary process and on how it can be properly accounted for during molecular evolution studies.
