<Emphasis Type="Italic">Teucrium polium</Emphasis> Complex with Molybdate Enhance Cultured Islets Secretory Function

Islet transplantation has become a promising treatment in the therapy of type 1 diabetes. Its function improvement, after isolation and before transplantation, is crucial because of their loss both in number and function of islets after isolation procedures. Trace elements sodium orthovanadate (SOV) and sodium molybdate (SM), as well as medicinal plant Teucrium polium L. (TP), showed and possessed high beneficial antioxidative potential and even hypoglycemic properties via their effect on islets. We evaluated the effect of these components in combination on cultured islet function in order to improve pancreatic islet transplantation. Rat pancreatic islets were cultured for 24 h then incubated with different concentrations of TP (0.01 and 0.1 mg/mL) alone and in combination with SOV (1 mM) or SM (1 mM). Insulin concentration in buffer media was measured as islet secretory function. Administration of TP (0.01 mg/mL), SM, and SOV alone or in combination with each other significantly increased insulin secretion at high glucose concentration (16.7 mM); insulin secretion was significantly greater in the group containing both TP and SM than other treated groups (p < 0.05). The combination of the mentioned trace elements especially molybdate with TP could improve islet cells function before transplantation.     

Hybrid nanoreservoirs based on dextran-capped dendritic mesoporous silica nanoparticles for CD133-targeted drug delivery

In this study, the chemical features of dendritic mesoporous silica nanoparticles (DMSNs) provided the opportunity to design a nanostructure with the capability to intelligently transport the payload to the tumor cells. In this regard, doxorubicin (DOX)-encapsulated DMSNs was electrostatically surface-coated with polycarboxylic acid dextran (PCAD) to provide biocompatible dextran-capped DMSNs (PCAD-DMSN@DOX) with controlled pH-dependent drug release. Moreover, a RNA aptamer against a cancer stem cell (CSC) marker, CD133 was covalently attached to the carboxyl groups of DEX to produce a CD133-PCAD-DMSN@DOX. Then, the fabricated nanosystem was utilized to efficiently deliver DOX to CD133+ colorectal cancer cells (HT29). The in vitro evaluation in terms of cellular uptake and cytotoxicity demonstrated that the CD133-PCAD-DMSN@DOX specifically targets HT29 as a CD133 overexpressed cancer cells confirmed by flow cytometry and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. The potentially promising intelligent-targeted platform suggests that targeted dextran-capped DMSNs may find impressive application in cancer therapy.     

Effect of Foliar Application of Silicon and Salicylic Acid on Regulation of Yield and Nutritional Responses of Greenhouse Cucumber Under High Temperature

Plant nutrition management is known as an efficient strategy to control environmental constraints. This experiment was conducted in a climate control greenhouse with a hydroponic system. The high temperature (36 °C?±?1) was imposed on the pots after fruit formation. The studied factors were silicon in 2 concentrations (0 and 4 parts per thousand (ppt)) and salicylic acid in 3 concentrations (0, 0.5, and 1 mM). They were sprayed on cucumber plants 3 times and under high-temperature conditions to evaluate if they can regulate and improve the yield and quality of cucumber fruit under high-temperature conditions or not. The results showed that all treatments significantly improved the nutritional status, total yield, and fruit quality (including marketable yield (i.e., fruits that can be sold due to their good shape) and nitrate content). Under high-temperature conditions, foliar application of silicon had the highest effect on the increase of total yield and marketable fruit yield (respectively, 36.14% and 40.29% increase compared to the control treatment). Micro-nutrients concentrations in the leaf were significantly increased by Si but a reverse status happened for salicylic acid. Under high temperatures, both treatments also significantly decreased the nitrate content of the fresh matter of fruit but silicon was the superior treatment. Silicon and salicylic acid, respectively, had positive effects on mitigation of adverse effects of high temperature on cucumber plants. These findings suggest the use of these treatments under high-temperature conditions in greenhouse cucumber production.

Graphical Abstract

N–No₃ content in dry matter of leaf (left) and fresh matter of fruit (right) affected by different treatments. *SaA0–SiA4: 4 ppt Si; SaA0.5–SiA0: 0.5 mM SA; SaA0.5–SiA4: 0.5 mM SA?+?4 ppt Si; SaA1–SiA0: 1 mM SA; SaA1–SiA4: 1 mM SA?+?4 ppt Si; control: without any SA and Si applications. Means in the same column followed by the same letter are not significantly different according to DMRT at (P?≤?0.05)

     

Polygalacturonase activity and variation in ripening of papaya fruit with tissue depth and heat treatment

Effects of tissue position (viz. outer vs inner mesocarp) and heat treatment (48°C, 20 min) on variations in polygalacturonase (EC 3.2.1.15 and EC 3.2.1.67) activity and ripening of fruits of Carica papaya L. cv. Backcross Solo were investigated. Polygalacturonase activity increased during ripening concomitantly with an increase in tissue softness and soluble polyuronide level. Throughout ripening, inner mesocarp tissue was softer and contained higher polygalacturonase activity than outer mesocarp tissue. Titratable acidity as well as ß-galactosidase (EC 3.2.1.23) activity also increased during ripening; however, unlike polygalacturonase, their level or activity was lower in inner than in outer mesocarp. Ascorbic acid could partially account for the increase in titratable acidity during ripening but contributed very little to the differences in titratable acid levels between outer and inner mesocarp. Heat treatment had no effect on either fruit softness or titratable acidity, but it markedly reduced the increase in ascorbic acid and polygalacturonase activity during ripening. Ripening, as reflected by changes in tissue softness and polygalacturonase activity, progressed outwardly from the interior towards the exterior of the fruit. The effect of heat treatment in suppressing polygalacturonase activity was relatively greater in inner than in outer mesocarp, suggesting that sensitivity of the enzyme to heat treatment may vary with stage of ripeness of the tissue.     

Neurosecretion of the mediodorsal cells of the central nervous system of the snail Helisoma duryi

Summary The neurosecretory mediodorsal cells that produce a putative growth hormone of the snail Helisoma duryi were studied in fast-growing virgin snails and in slow-growing reproducing snails. There are about 60 mediodorsal cells in clusters on each side of the cerebral commissure of the central nervous system, and they contain dense-cored granules which are 100–200 nm in diameter. The cells of virgin snails have dense Golgi bodies, scattered ER cisternae, and few granules, while those of reproducing snails have pale Golgi bodies, stacked ER cisternae, and numerous granules. Thus the mediodorsal cells of the virgin snails appear to be more active synthetically than those of the reproducing snails. The cells near the endocrine dorsal bodies contain many dorsal body precesses in their membrane interdigitations. There are junction-like interactions between some of the interdigitations. Gap junction-like contacts are seen between mediodorsal cells and glial cells. The axon endings of the mediodorsal cells at the neurohemal area in the labial nerve show more release profiles in virgin snails than in reproducing snails. A daily pattern of release has been observed in reproducing snails, and rates of release are higher in the evening than in the morning.     

Seasonality and vertical structure of light-attracted insect communities in a dipterocarp forest in Sarawak

Nocturnal flying insects were collected monthly for 13 months using ultra violet light-traps set at various vertical levels in a weakly-seasonal, tropical lowland dipterocarp forest in Sarawak, Malaysia. Abundance, faunal composition, size distribution and guild structure of these samples were analyzed with respect to temperal and vertical distributions. The nocturnal flying insect community in the canopy level was highly dominated by fig wasps (84%) in individual number, and by scarabaeid beetles (28%) in weight. A principal component analysis on monthly catches detected non-random, seasonal trends of insect abundance. The first two principal trends were an alternation of wetter (September to January) and less wet seasons (February to August) and an alternation between the least wet (January to March) and the other seasons. Many insect groups were less abundant in the least wet season than the other seasons, whilst inverse patterns were found in Scarabaeidae and Tenebrionidae. Significantly positive and negative correlations between monthly catch and rainfall were detected only in ovule-feeders and in phloem-feeders, respectively. Delayed, significant negative correlations between monthly catch and 1–3 month preceding rainfall were more frequently detected in phytophages, phloem-feeders, seed-feeders, wood-borers and scavengers. The peak in abundance along vertical levels were found at the canopy level (35 m) for phloem-, ovule-, seed-, root-, fungal-feeders and nectar collectors, at an upper subcanopy level (25 m) for scavengers and aquatic predators, and at a middle subcanopy level (17 m) for ants. Catches at the emergent level (45 m) did not exceed those at the canopy level.     

Uptake of biotin by human hepatoma cell line,Hep G2: A carrier-mediated process similar to that of normal liver

Little is known about the cellular and molecular regulation of the uptake process of the water-soluble vitamin biotin into liver cells, the major site of biotin utilization and metabolism. Such studies are best done using a highly viable and homogeneous cellular system that allows examination of prolonged exposure to an agent(s) or a particular condition(s) on the uptake process. Isolated hepatocytes when maintained in primary culture lose their ability to transport biotin by the specialized carrier system. The aim of the present study was, therefore, to examine the mechanism(s) of biotin uptake by the cultured human-derived liver cells, Hep G₂. Uptake to biotin by Hep G₂ cells was appreciable and linear for up to 10 min of incubation. The uptake process was Na⁺ gradient-dependent as indicated by studies of Na⁺ replacement and pretreatment of cells with gramicidin and ouabain. Biotin uptake was also dependent on both incubation temperature and intracellular energy. Unlabeled biotin and the structural analogs with free carboxyl groups (thioctic acid, desthiobiotin) but not those with blocked carboxyl group (biocytin, biotin methyl ester, and thioctic amide) caused significant inhibition of ³H-biotin uptake at 37°C but not 4°C. Initial rate of biotin uptake was saturable as a function of concentration at 37°C but was lower and linear at 4°C. Pretreatment of Hep G₂ cells with sulfhydryl group inhibitors (e.g., p-chloromer-curibenzene sulfonate) led to a significant inhibition in biotin uptake; this inhibition was effectively reversed by reducing agents (e.g., dithiothreitol). Biotin uptake was also inhibited by the membrane transport inhibitors probenecid (noncompetitively), DIDS and furosemide but not by amiloride. Pretreatment of Hep G₂ cells with valinomycin did not alter biotin uptake. The stoichiometric ratio of biotin to Na⁺ uptake in Hep G₂ cells was also determined and found to be 1:1. These findings demonstrate that biotin uptake by these cultured liver cells is mediated through a specialized carrier system that is dependent on Na⁺-gradient, temperature, and energy and transports the vitamin by an electroneutral process. These findings are similar to those seen with native liver tissue preparations and demonstrate the suitability of Hep G₂ cells for in-depth investigations of the cellular and molecular regulation of biotin uptake by the liver. © 1994 Wiley-Liss, Inc.

1 This article is a US Government work, and as such, is in the public domain in the United State of America

.