Development of Surface-Enhanced Raman Scattering (SERS)-Based Surface-Corrugated Nanopillars for Biomolecular Detection of Colorectal Cancer

In this paper, a nanobiosensor with surface-enhanced Raman scattering (SERS) capability is introduced for highly sensitive miRNA detection in colorectal cancer. This sensor was designed and fabricated by employing a nanoshielding mechanism from nanopolystyrene beads to resist reactive ion etching and allow anisotropic electrochemical etching, producing high-aspect-ratio, surface-corrugated nanopillars (SiNPs) on a silicon wafer to create extensive hot spots along the nanopillars for improved SERS signals. SERS enhancements were correlated with nanorange roughness, indicating that hot spots along the pillars were the crucial factor to improve the SERS effect. We achieved the detection capability of a trace amount of R6G (10−8 M), and the SERS signal enhancement factor (EF) was close to 1.0 × 107 on surface-corrugated gold SiNPs. miRNA samples were also demonstrated on this sensor with good sensitivity and specificity. The target molecule miR-21-Cy5 was easily monitored through Raman spectrum variation with a PCR-comparable concentration at around 100 pM with clear nucleotide-specific Raman signals, which is also suitable for biomolecule sensing.

Effect of Nonionic Conjugated Matrix Polymer and P-Dopant on Carbon Nanotube Aggregation and Thermoelectric Properties

ABSTRACTThe properties of a mixed metallic and semiconducting carbon nanotube (CNT) sample dispersed in nonconjugated poly(methyl methacrylate) (PMMA) and conjugated poly(bisdodecylquaterthiophene) (PQT12) were compared, with and without p-doping by NOBF4. The CNTs were distributed much more evenly, and percolated at much lower concentrations (ca. 2%), in the PMMA as compared to PQT12, as judged by optical microscopy and electronic conductivity measurements. Seebeck coefficients (S) obtained on the PMMA samples indicated dominance by the metallic fraction, with values <10 µV/K. Composites made with PQT12 alone showed slightly higher values of S, but with the addition of 3 wt % dopant, S increased markedly to about 100 µV/K at 5-10% CNT fractions, while conductivity was unexpectedly low. As the CNT fraction in the doped sample was increased to 25-30%, conductivity approached that of the comparable concentration of CNTs in PMMA, while S, ca. 15 µV/K, was still higher than that measured in PMMA. The observations inform interpretations of CNT-polymer composite thermoelectric data, pointing out the roles of conjugated main chains and added dopants in modulating contributions of CNTs to thermoelectric composite performance.

Salinity Stress Alters Nutrient Uptake and Causes the Damage of Root and Leaf Anatomy in Maize

<p class="Els-Abstract-text">Salinity is one of major problems in agriculture especially in arid and semiarid area due to causes the damage of many aspects in plant growth and development. This study observed root and leaf anatomy and nutrient uptake in maize plants exposed to salinity stress. Maize seedlings were placed in the plantation room under same temperature, humidity and light intensity conditions and were treated with 0 %, 1 %, 2 % and 3 % NaCl for 5 d. Anatomy of root and leaf were observed using scanning electron microscopy (SEM). Nutrient uptake was estimated by the content of trace elements of leaves. Trace element were quantified using inductively coupled plasma-mass spectrometry (ICP-MS), but chlorine was determined by an atomic absorption flame spectrometer. The results showed that salinity slightly damaged roots anatomy. Epidermis cells and parenchyma cells of cortex and pith were shrinkage in 2 % and 3 % NaCl-treated plants. Leaf anatomy showed mesophyll and bundle sheath cells which slightly suppressed. Meanwhile, chloroplasts content inside those cells were dramatically decreased. Anatomical damage of roots and leaves was accompanied by altering uptake of some trace elements. The contents of aluminum, calcium, iron, magnesium, sodium, chlorine, in NaCl-treated plants were higher than control. Otherwise, boron, potassium and phosphor were lower in NaCl-reated plants. The rest of trace elements were in comparable concentration.</p><p> </p><p><strong>Keywords:</strong> maize; leaf; nutrient; root; salinity</p><div><p class="Els-keywords"> </p></div>

Comparative effects of selected plant polyphenols, gallic acid and epigallocatechin gallate, on matrix metalloproteinases activity in multidrug resistant MCF7/DOX breast cancer cells

The aim of the study was to investigate the effect of selected polyphenols: gallic acid (GA) and epigallocatechin gallate (EGCG) on matrix metalloproteinase (MMP-2 and MMP-9) activity in multidrug resistant (MDR) human breast adenocarcinoma cells: MCF7/DOX cells and obtained recently in our laboratory MCF7/DOX500 cells by the permanent selection of MCF7/DOX cells with 500 nM doxorubicin (DOX). The activity of MMP-2 and MMP-9 and the effect of studied polyphenols on these matrix proteases were examined by gelatin zymography assays. We have found that the activity of MMP-2 and MMP-9 significantly increased in resistant MCF7/DOX and MCF7/DOX500 cells whereas they were not detected in sensitive MCF7 cells. It was also observed that GA (30, 60, 100 and 120 µM) and EGCG (5, 10 and 20 µM) caused a comparable concentration-dependent inhibition of MMP-2 and MMP-9 activity in MCF7/DOX and MCF7/DOX500 cells. Control experiments confirmed that examined compounds in these ranges of concentration did not affect the cell growth of MCF7/DOX and MCF7/DOX500 sublines (80-100% of control cell growth was observed in the presence of studied polyphenols).

Targeted Metabolomic Profiles Are Strongly Correlated With Metabolic Alterations In Patients With Sickle Cell/Beta Thalassemia Disease

Background The complex pathophysiology of Sickle Cell Disease (SCD) makes unlikely that a single therapeutic agent will prevent or reverse all SCD complications. Metabolomic analysis might help in the characterization of the endogenous and exogenous effects of potential new treatments. Metabolites are small molecules that are chemically transformed during metabolism and provide a functional readout of cellular state. Metabolites serve as direct signatures of biochemical activity and are therefore easier to correlate with phenotype. The metabolome is typically defined as the collection of small molecules produced by cells and offers a window for interrogating how mechanistic biochemistry relates to cellular phenotype. There are very few reports providing comprehensive measurements of metabolites present in blood and almost no reports on metabolites changes associated with SCD. In this context we aimed to detect and to quantify targeted metabolites’ abnormalities in patients with Sickle Cell/beta thalassemia disease (HbS/βThal) and their implication in pathways that might be of interest to prevent vaso-occlusion and/or to monitor the effects of new therapies on SCD. Patients and Methods Twenty adult patients with HbS/βThal were enrolled in the study, while 20 apparently healthy individuals matched for age served as controls. Targeted metabolome analyses based on aminoacids and carnitines were performed after extraction from dry blood spots (DBSs) on filter paper using High Performance Liquid Chromatography followed by tandem Mass Spectrometry (LC/MS/MS), with derivatization (AB SCIEX 5500 triple quadrupole and QTRAP® LC/MS/MS Systems, Framingham, MA, USA) with reagents provided by Chromsystems Instruments & Chemicals, Germany. The injection volume was 10 µL and the analysis lasted ca. 2 min. Results The main results of the study showed that: a) fifty metabolites were separated in patients and controls samples, b) mapping the results of analyses, patients with HbS/βThal compared to controls had 17 metabolites with significantly lower concentration, 10 metabolites with comparable concentration and 23 metabolites with significantly higher concentration, c) L-arginine and L-ornithine concentrations were significantly lower in patients HbS/βThal compared to controls, 9.3±2.6 vs 14.7±3.7 µmoles/L, (p<0.01), and 116.0±15.0 vs 211.2±19.5 µmoles/L, (p<0.001), respectively, while L-citrulline was lower in patients HbS/βThal compared to controls but no significantly 21.8±2.5 vs 25.1±2.5 µmoles/L, (p>0.06) and d) carnitine, acetylcarnitine and propionylcarnitine correlated significantly positive with reticulocyte production index (p<0.001). Conclusions Our findings showed significant alterations in whole blood metabolome of patients with HbS/βThal. Also we demonstrated the very important metabolic abnormality of Nitric Oxide biosynthesis pathway due to the low concentration of the aminoacids serving of substrates in this cycle and disturbances in carnitine and acylcarnitines homeostasis. These abnormalities in the metabolome reflected the hemolysis, inflammatory process and pulmonary hypertension observed in these patients. Disclosures: No relevant conflicts of interest to declare.

Analysis of Insulin in Human Breast Milk in Mothers with Type 1 and Type 2 Diabetes Mellitus

Despite the important role that insulin plays in the human body, very little is known about its presence in human milk. Levels rapidly decrease during the first few days of lactation and then, unlike other serum proteins of similar size, achieve comparable levels to those in serum. Despite this, current guides for medical treatment suggest that insulin does not pass into milk, raising the question of where the insulin in milk originates. Five mothers without diabetes, 4 mothers with type 1, and 5 mothers with type 2 diabetes collected milk samples over a 24-hour period. Samples were analysed for total and endogenous insulin content and for c-peptide content. All of the insulin present in the milk of type 1 mothers was artificial, and c-peptide levels were 100x lower than in serum. This demonstrates that insulin is transported into human milk at comparable concentration to serum, suggesting an active transport mechanism. The role of insulin in milk is yet to be determined; however, there are a number of potential implications for the infant of the presence of artificial insulins in milk.

Intracellular ATP slows time-dependent decline of muscarinic cation current in guinea pig ileal smooth muscle

The effects of intracellular nucleotide triphosphates on time-dependent changes in muscarinic receptor cation currents ( I cat) were investigated using the whole cell patch-clamp technique in guinea pig ileal muscle. In the absence of nucleotide phosphates in the patch pipette, I cat evoked every 10 min decayed progressively. This decay was slowed dose dependently by inclusion of millimolar concentrations of ATP in the pipette. This required a comparable concentration of Mg2+, was mimicked by UTP and CTP, and was attenuated by simultaneous application of alkaline phosphatase or inhibitors of tyrosine kinase. In contrast, a sudden photolytic release of millimolar ATP (probably in the free form) caused a marked suppression of I cat. Submillimolar concentrations of GTP dose dependently increased the amplitude of I cat as long as ATP and Mg2+ were in the pipette, but, in their absence, GTP was ineffective at preventing I cat decay. The decay of I cat was paralleled by altered voltage-dependent gating, i.e., a positive shift in the activation curve and reduction in the maximal conductance. It is thus likely that ATP exerts two reciprocal actions on I cat, through Mg2+-dependent and -independent mechanisms, and that the enhancing effect of GTP on I cat is essentially different from that of ATP.

Jejunal mucosal protein synthesis: validation of luminal flooding dose method and effect of luminal osmolarity

To validate a system to study acute regulation of protein synthesis in intestinal mucosa by luminal nutrients, we compared the fractional rate of protein synthesis ( K s) in jejunal mucosa using the intravenous flooding dose technique with the administration of a comparable concentration and specific activity of tracer in a luminal perfusate. Routes of tracer administration and surgery and perfusion trauma had no effect on mucosal K s. Furthermore, four 10-cm jejunal segments (within a piglet) simultaneously but separately perfused with a luminal flooding dose had similar K s values (mean, 43 ± 2%/day; P > 0.05). Nutrient solutions perfused through four intestinal segments within an animal did not affect plasma levels of most amino acids or glucose. Because cellular hydration is important in regulating metabolism, the effects of physiological variation in luminal osmolarity were studied. Luminal osmolarities between 250 and 380 mosM did not affect mucosal K s. The system described allows multiple comparisons within an animal and provides a robust model to study acute modulation of protein synthesis in intestinal mucosa by luminal stimuli.

Peanut Fungicides: Effect on Survival and Development of the Corn Earworm, Fall Armyworm, and Velvetbean Caterpillar1

The fungicides chlorothalonil, tebuconazole, and propiconazole commonly used for control of peanut diseases were evaluated for activity against the corn earworm [Helicoverpa zea (Boddie)], fall armyworm [Spodoptera frugiperda (J. E. Smith)], and velvetbean caterpillar (Anticarsia gemmatalis Hübner). Chlorothalonil most adversely affected early establishment and survival of neonates of all three insect species on peanut terminal buds. Chlorothalonil also decreased the weight of larvae of all three species at 10 d and extended the time to pupation for fall armyworm and velvetbean caterpillar larvae. Similarly, tebuconazole adversely affected early survival and establishment, decreased 10-d weight and extended time to pupation of corn earworm and velvetbean caterpillar larvae, but had little effect on fall armyworm larvae. Propiconazole had no effect on establishment and survival of corn earworm and fall armyworm larvae on peanut terminals, and actually increased the weight of 10-d-old larvae for all three insects over that recorded for the untreated control. Orthogonal comparisons of the activity of five chlorothalonil-based fungicides against the fall army-worm showed that the activity was due to chlorothalonil rather than to formulation. At equivalent concentrations used in the field, Bravo Ultrex® was significantly more active against larvae of the fall armyworm than was a comparable concentration of Bravo 72®. However, regression lines did not differ for the two fungicides for any of the developmental parameters measured when larvae of all three species were fed different concentrations of Bravo 720® and Bravo Ultrex® in their meridic diet.

Red Blood Cell Partitioning of the [6 S]- and the [6R]-Isomer of N5-Formyltetrahydrofolic Acid

The in vitro interaction of the [6S]- and [6R]-stereoisomers of CHO-THFA with human RBCs was investigated in the (therapeutically comparable) concentration range from 1.0 to 12.5 μg/ml. Both compounds are bound to RBCs with a kRBC ranging from 0.13 to 0.75 for [6S]-CHO-THFA and from 0.06 to 0.33 for [6R]-CHO-THFA, respectively. The interaction of the [6S]-form with RBCs is about two times higher than of the [6R]-form. Incubation of CHO-THFA with RBCs over 24 h showed an accelerated disappearance from the test solution for [6R]-CHO-THFA with a mean t1/2 of 49.9 h in compare to t1/2 = 58.2 h for the [6S]-enantiomer. The results indicate that RBCs may play a major role for the pharmacokinetics and metabolism of CHO-THFA and may act as an intravasal depot especially for [6S]-CHOTHFA.