Fetuin-A Promotes 3-Dimensional Growth in LNCaP Prostate Cancer Cells by Sequestering Extracellular Vesicles to Their Surfaces to Act as Signaling Platforms

The present studies were conducted to evaluate key serum proteins and other components that mediate anchorage-independent growth (3-D growth) of LNCaP prostate cancer cells as spheroids. The cells were cultured on ultra-low attachment plates in the absence and presence of fetuin-A and with or without extracellular vesicles. The data show that fetuin-A (alpha 2HS glycoprotein) is the serum protein that mediates 3-D growth in these cells. It does so by sequestering extracellular vesicles of various sizes on the surfaces of rounded cells that grow as spheroids. These vesicles in turn transmit growth signals such as the activation of AKT and MAP kinases in a pattern that differs from the activation of these key growth signaling pathways in adherent and spread cells growing in 2-D. In the process of orchestrating the movement and disposition of extracellular vesicles on these cells, fetuin-A is readily internalized in adhered and spread cells but remains on the surfaces of non-adherent cells. Taken together, our studies suggest the presence of distinct signaling domains or scaffolding platforms on the surfaces of prostate tumor cells growing in 3-D compared to 2-D.     

Phytochemical composition and antioxidant capacity of various botanical parts of the fruits of Prunus × domestica L. from the Lorraine region of Europe

Mirabelle plums represent a famous fruit from the Lorraine region, however little is known about their phytochemical composition. The oil of the fruit contained predominantly oleic acid (59%) and linoleic acid (29%). The total content of phenolic antioxidants in the whole fruits was 5.338 g/kg with 456 mg/kg (9%), 701 mg/kg (13%) and 4159 mg/kg (78%) detected in the peels, flesh and pits respectively. The peels contained solely 3,4-dihydroxybenzoic acid (270 mg/kg) and rutin (186 mg/kg), the flesh exclusively echinoids (723 mg/kg), whereas the pits contained a rich variety of phenolic compounds (4.2 g/kg) dominated by amygdalin (3.8 g/kg), but with significant contributions from vanillin (102 mg/kg), guajacyl-glycerin-coniferyl aldehyde isomers (87 mg/kg), dehydro-diconiferyl aldehyde (52 mg/kg), and vanillin diglucoside (48 mg/kg). Of the major phenolic compounds tested across a range of in vitro assays, rutin was the superior antioxidant.     

Quality Measurement of Intact and Fresh-cut Slices of Fuji, Granny Smith, Pink Lady, and GoldRush Apples

ABSTRACT: Development of fresh-cut apple products requires consideration of cultivars that store well as both intact and fresh-cut fruit. We compared the instrumental and sensory quality of 2 apple cultivars, Granny Smith and Fuji, that are used for fresh cutting with 2 new cultivars, Pink Lady and GoldRush, which were considered to have quality characteristics suitable for fresh cutting. Firmness, titratable acidity (TA), soluble solids content (SSC), and aromatic volatile concentration were measured in intact fruit of the 4 cultivars during 12 mo storage in air at 0 °C and during 3 wk storage at 5 °C as fresh-cut slices. After 1 wk storage as fresh-cut slices, sensory evaluations for acceptability of flesh and peel appearance, flavor, texture, and overall eating quality were performed. During storage, GoldRush apples maintained > 80 N firmness, approximately 17% SSC, > 0.5% TA, and had high aromatic volatile production, that is, maintained quality better than the other cultivars. The quality and shelf stability of GoldRush slices were also as good as or better than slices from the other cultivars, whereas Granny Smith slices generally rated lower than the other cultivars. The acceptability of flavor, texture, and overall eating quality of GoldRush slices was as good as that for Pink Lady and Fuji. The quality of GoldRush apples can be maintained throughout the year in refrigerated air storage and still remain suitable for fresh-cut processing. The results indicate that GoldRush and Pink Lady are 2 promising new, high-quality apple cultivars for fresh cutting. Keywords: fresh-cut fruit, Malus × domestica , postharvest quality, respiration rate, shelf life     

Hydrolytic stability of terephthaloyl chloride and isophthaloyl chloride

The phthaloyl chloride isomers, terephthaloyl chloride (TCl) and isophthaloyl chloride (ICl), are high production volume chemicals used in polymers to impartflame resistance, chemical resistance, and temperature stability and as water scavengers. In these studies, we determined the hydrolytic stability of TCl and ICl and their hydrolysis products in aqueous solutions. Hydrolysis rates for TCl and ICl were initially determined by gas chromatography/flame ionization detection in water buffered at pH 4.0, 7.0, and 9.0 and 0 degrees C for up to 30 min. Subsequent studies determined the products from TCl and ICl hydrolysis. The parent phthaloyl chlorides (TCl and ICl), their intermediate hydrolysis products (designated as the "half-acids"), and their stable hydrolysis products (terephthalic acid (TPA) and isophthalic acid (IPA)) were determined by high-performance liquid chromatography. The half-lives (t(1/2)) of TCl and ICl ranged from an average of 1.2 to 2.2 min and from 2.2 to 4.9 min, respectively, at pH 4-9 and 0 degrees C. The observed first-order rate constants (k(obs)) ranged from an average of 530 to 1100 (x 10(5) s(-1)) for TCl and 240 to 520 (x 10(5) s(-1)) for ICl. Both phthaloyl chlorides formed their respective short-lived intermediates, in which one of the two carboxylic acid chloride functionalities reacts with water to form the carboxylic acid ("half-acid"). Subsequently, the half-acids underwent further hydrolysis so that greater than 90% of the initial phthaloyl chloride hydrolyzed in less than 60 min at 0 degrees C. The hydrolysis products TPA and IPA were hydrolytically stable, undergoing no further transformations after 20 min at pH 7 and 25 degrees C. This work demonstrated that TCl, ICl, and their respective half-acids will not be persistent in aqueous systems for a time sufficient to have a sustained toxicological effect on aquatic organisms (less than 1 h). Performing additional aquatic toxicity studies, biodegradation studies, and potentially mammalian studies on TCl and ICl are unnecessary since the existing information on TPA and IPA with the hydrolysis data presented here is sufficient to address questions on the fate and effects of these two substances in aqueous environments.     

按需出版在挑战中快步前行

在西方,按需出版已经得到普及,每年都会有40万种图书以按需出版的方式出版,超过90%的西方出版商已经开始探寻属于自己的按需出版道路。 这是一家拥有7年历史的按需出版界大亨,其足迹遍布120多个国家与地区,他与亚马逊以及Ingram公司等巨头有着密切的合作,向50多个国家销售电子书和书籍,并为全球10000多名作者提供出版服务——他就是按需出版领域的领跑者,美国全球按需出版公司（PODG）。近日,PODG公司总裁Robert Fletcher接受本刊独家采访,畅谈了PODG的按需出版商业模式,以及他眼中的＂中西方＂按需出版市场特点及前景展望。     

Antioxidant properties and shelf‐life extension of fresh‐cut tomatoes stored at different temperatures

BACKGROUND: The feasibility of using modified atmosphere packaging (5 kPa O₂ + 5 kPa CO₂) to maintain the antioxidant properties of fresh‐cut tomatoes during shelf‐life was assessed through storage at different temperatures (5, 10, 15 and 20 °C). Health‐related compounds, antioxidant capacity, microbiological counts, physicochemical parameters and in‐package atmosphere of tomato slices were determined. RESULTS: Initial lycopene, vitamin C and phenolic contents and physicochemical parameters of tomato slices were well maintained for 14 days at 5 °C. Lycopene and total phenolic contents were enhanced over time in tomato slices stored at 15 and 20 °C. However, this increase in antioxidant compounds of fresh‐cut tomatoes during storage may be associated with excessive amounts of CO₂ (R² = 0.5679–0.7328) in the packages due to microbial growth. Although keeping tomato slices at temperatures above 10 °C increased their antioxidant content, the shelf‐life of the product was reduced by up 4 days. CONCLUSIONS: A storage temperature of 5 °C is appropriate for maintaining the microbiological shelf‐life of fresh‐cut tomatoes for up to 14 days and also allows the antioxidant properties of tomato slices to be retained over this period, thus reducing wounding stress and deteriorative changes. Copyright © 2008 Society of Chemical Industry     

PBDEs in the atmosphere of three locations in western Europe

Atmospheric concentrations of PBDEs (108 samples in total) were measured at 2 rural/semirural sites in England and 1 remote site on the west coast of Ireland in the years 2001 and 2000, respectively. Detailed analysis of the factors affecting concentrations is performed. The United Kingdom (UK) has been a major producer and user of PBDEs. Concentrations of sigmaPBDEs at Mace Head (MH), Ireland ranged between 0.22 and 5.0 pg m(-3) with a mean of 2.6 pg m(-3) and were controlled primarily by advection. sigmaPBDEs concentrations at Hazelrigg (HR), northwest England, ranged between 2.8 and 37 pg m(-3) with a mean of 12 pg m(-3) and at Chilton (CH), southwest England between 3.4 and 33 pg m(-3) with a mean of 11 pg m(-3). The average mixture of PBDEs in air was similar to that of commercial penta-BDE products. Movement of air over local/regional sources influenced concentrations of PBDEs at all sites, particularly at MH. At the two English sites during the summer, concentrations of PBDEs were strongly influenced bytemperature, indicating that air-surface exchange processes play an important role. Advection became more influential during winter, particularly at CH, where a different congener profile was observed in some samples as ambient air temperatures decreased and PBDE concentrations increased. It is hypothesized that this was due to increased emissions from diffuse combustion sources.     

Frequency-Dependent Properties of the Hyperpolarization-Activated Cation Current,If, in Adult Mouse Heart Primary Pacemaker Myocytes

A number of distinct electrophysiological mechanisms that modulate the myogenic spontaneous pacemaker activity in the sinoatrial node (SAN) of the mammalian heart have been investigated extensively. There is agreement that several (3 or 4) different transmembrane ionic current changes (referred to as the voltage clock) are involved; and that the resulting net current interacts with direct and indirect effects of changes in intracellular Ca²⁺ (the calcium clock). However, significant uncertainties, and important knowledge gaps, remain concerning the functional roles in SAN spontaneous pacing of many of the individual ion channel- or exchanger-mediated transmembrane current changes. We report results from patch clamp studies and mathematical modeling of the hyperpolarization-activated current, I_f, in the generation/modulation of the diastolic depolarization, or pacemaker potential, produced by individual myocytes that were enzymatically isolated from the adult mouse sinoatrial node (SAN). Amphotericin-mediated patch microelectrode recordings at 35 °C were made under control conditions and in the presence of 5 or 10 nM isoproterenol (ISO). These sets of results were complemented and integrated with mathematical modeling of the current changes that take place in the range of membrane potentials (−70 to −50 mV), which corresponds to the ‘pacemaker depolarization’ in the adult mouse SAN. Our results reveal a very small, but functionally important, approximately steady-state or time-independent current generated by residual activation of I_f channels that are expressed in these pacemaker myocytes. Recordings of the pacemaker depolarization and action potential, combined with measurements of changes in I_f, and the well-known increases in the L-type Ca²⁺ current, I_CaL, demonstrated that I_CaL activation, is essential for myogenic pacing. Moreover, after being enhanced (approximately 3-fold) by 5 or 10 nM ISO, I_CaL contributes significantly to the positive chronotropic effect. Our mathematical model has been developed in an attempt to better understand the underlying mechanisms for the pacemaker depolarization and action potential in adult mouse SAN myocytes. After being updated with our new experimental data describing I_f, our simulations reveal a novel functional component of I_f in adult mouse SAN. Computational work carried out with this model also confirms that in the presence of ISO the residual activation of I_f and opening of I_CaL channels combine to generate a net current change during the slow diastolic depolarization phase that is essential for the observed accelerated pacemaking rate of these SAN myocytes.     

Activity of Silver Nanoparticles against Staphylococcus spp.

Staphylococcus epidermidis is a bacterium that is part of the human microbiota. It is most abundant on the skin, in the respiratory system and in the human digestive tract. Also, Staphylococcus aureus contributes to human infections and has a high mortality rate. Both of these bacterial species produce biofilm, a pathogenic factor increasing their resistance to antibiotics. For this reason, we are looking for new substances that can neutralize bacterial cells. One of the best-known substances with such effects are silver nanoparticles. They exhibited antibacterial and antibiofilm formation activity that depended on their size, shape and the concentration used. In this review, we presented the data related to the use of silver nanoparticles in counteracting bacterial growth and biofilm formation published in scientific papers between 2017 and 2021. Based on the review of experimental results, the properties of nanoparticles prompt the expansion of research on their activity.