Sensitivity ofLemna bioassay interacts with stock-culture period

The effect of stock-culture period on the sensitivity of theLemna bioassay to four different phenolic substances was evaluated in this study. The sensitivity of the bioassay interacted with the stock-culture period of either 11, 14, or 18 days. After a seven-day testp-hydroxybenzoic acid (HBA), vanillic acid (VA),trans-cinnamic acid (CA), and ferulic acid (FA) with a concentration of 0.05 mM significantly reduced the number of fronds and the dry weight compared with the untreated control when the stock-culture period had been exactly 14 days. The sensitivity after the shorter (11 days) or longer (18 days) stock-culture period was reduced, and the differences in the dry weight to the untreated control were not significant after a stock culture period of 18 days. The two higher concentrations (0.1 and 0.25 mM) showed stronger inhibition. A comparison of the inhibition at 0.05 mM revealed that the stock-culture period affected the relative toxicity of the four phenolic substances. Since the pH increased in the stock-culture flasks during the 18-day period from 6.25 to 7.9, we hypothesize that differences in theLemna assay can be at least partly attributed to a pH effect, possibly in combination with a relative nutrient deficiency. We recommend a standardization of the stock-culture period to 14 days to improve the sensitivity of theLemna bioassay.     

Age-dependent phenotypic characteristics of a triple transgenic mouse model of Alzheimer disease.

The triple-transgenic mouse line (3×Tg-AD) harboring PS1M146V, APPSwe, and taup301L transgenes represents the only transgenic model for Alzheimer's disease (AD) to date capturing both β-amyloid and tau neuropathology. The present study provides an extensive behavioral characterization of the 3×Tg-AD mouse line, evaluating the emergence of noncognitive and cognitive AD-like symptoms at two ages corresponding to the early (6-7 months) and advanced (12-13 months) stages of AD-pathology. Enhanced responsiveness to aversive stimulation was detected in mutant mice at both ages: the 3×Tg-AD genotype enhanced acoustic startle response and facilitated performance in the cued-version of the water maze. These noncognitive phenotypes were accompanied by hyperactivity and reduced locomotor habituation in the open field at the older age. Signs of cognitive aberrations were also detected at both ages, but they were limited to associative learning. The present study suggests that this popular transgenic mouse model of AD has clear phenotypes beyond the cognitive domain, and their potential relationship to the cognitive phenotypes should be further explored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

激光联用环磷酰胺对荷瘤鼠外周血IgG影响的实验研究

以小鼠S180腹水瘤为动物实验模型．对氦氖激光照射与化疗药物环磷酰胺(CYT)联合应用对S180荷瘤鼠外周血IgG含量影响作了系统性研究。应用11．00，14．67和22．00J／cm^2三种剂量氦氖激光照射荷瘤鼠内眼角，同时联合应用化疗药物环磷酰胺,动态监测S180荷瘤鼠外周血IgG含量的变化。结果表明,CYT联合应用氦氖激光照射组IgG含量均高于单纯应用CYT组。     

Lack of chemical factors in host-plant resistance of alfalfa towards alfalfa weevil: Ovicidal activity of some coumarin derivatives

A resistant line of alfalfa was studied in an attempt to identify possible chemical factors responsible for alfalfa weevil (Hypera brunneipennis) resistance. Bioassays were developed to measure ovicidal, larval development, pupation, and adult development rates. Serial alfalfa extracts of a weevil-resistant line showed no effect in the bioassays when compared to those of a weevil-susceptible line. It was concluded that resistance substances are not present but that resistant lines are simply more tolerant to weevil attack. Alfalfa constitutents and synthetic analogs were also screened in the egg hatch bioassay. Among these were a series of 3-acyl-4-hydroxycoumarins. 3-Acyl-4-hydroxycoumarins with short-chain acyl groups showed good ovicidal rates, but activity decreased with increasing length of the acyl group.     

A Study of Human Reactions to Emissions from Building Materials in Climate Chambers. Part II: VOC Measurements,Mouse Bioassay,and Decipol Evaluation in the 1–2 mg/m3 TVOC Range

Monitoring of human reactions to the emission of formaldehyde and volatile organic compounds (VOC) from four commonly used building materials was carried out. The building materials were: a painted gypsum board, a rubber floor, a nylon carpet, and a particle board with an acid-curing paint. The exposures were performed in climate chambers. The air quality was quantified on the decipol scale by a trained panel, measurements of formaldehyde and VOC being performed simultaneously. The irritating potency of the materials was measured by a mouse bioassay. The VOC measurements showed several malodorants and irritants. Some abundant VOC identified in the head-space analyses were absent in the climate chamber air. The rubber floor and the nylon carpet exhibited a marked increase in decipols compatible with a number of odorous VOC identified in the air. A high formaldehyde concentration (minimum 743μg/m³) was measured for the particle board coated with an acid-curing paint. This was not reflected by a corresponding relatively high decipol value but a long-lasting irritating potency was observed in the mouse bioassay. TVOC sampled on Tenax and expressed in mass per volume as well as in molar concentration, and decipol evaluation both have limitations and should be used with caution as indicators of (perceived) indoor air quality. Eye irritation expressed by means of the eye index reflecting the tear film quality index (comprised of break-up time, foam formation, thickness of the precorneal lipid layer of the tear film, and epithelial damage) was found to be insensitive to formaldehyde and a VOC mixture but sensitive to TVOC concentrations of 1–2 mg/m³. Lipophilic VOC may be the cause of reduced tear film quality by destabilization of the lipid multilayer of the tear film.     

Isolation and characterization of allelopathic volatiles from mugwort (<Emphasis Type="Italic">Artemisia vulgaris</Emphasis>)

Several volatile allelochemicals were identified and characterized from fresh leaf tissue of three distinct populations of the invasive perennial weed, mugwort (Artemisia vulgaris). A unique bioassay was used to demonstrate the release of volatile allelochemicals from leaf tissues. Leaf volatiles were trapped and analyzed via gas chromatography coupled with mass spectrometry. Some of the components identified were terpenes, including camphor, eucalyptol, -pinene, and -pinene. Those commercially available were tested individually to determine their phytotoxicity. Concentrations of detectable volatiles differed in both absolute and relative proportions among the mugwort populations. The three mugwort populations consisted of a taller, highly branched population (ITH-1); a shorter, lesser-branched population (ITH-2) (both grown from rhizome fragments from managed landscapes); and a population grown from seed with lobed leaves (VT). Considerable interspecific variation existed in leaf morphology and leaf surface chemistry. Bioassays revealed that none of the individual monoterpenes could account for the observed phytotoxicity imparted by total leaf volatiles, suggesting a synergistic effect or activity of a component not tested. Despite inability to detect a single dominant phytotoxic compound, decreases in total terpene concentration with increase in leaf age correlated with decreases in phytotoxicity. The presence of bioactive terpenoids in leaf surface chemistry of younger mugwort tissue suggests a potential role for terpenoids in mugwort establishment and proliferation in introduced habitats.     

Evidence for a multicomponent sex pheromone in the yellowheaded spruce sawfly

The existence of a female-produced sex pheromone in the yellowheaded spruce sawfly,Pikonema alaskensis (Rohwer) (Hymenoptera: Tenthredinidae) was demonstrated by field and greenhouse bioassays. Virgin females, their empty cocoons (with which they were confined during handling procedures), and the hexane extract of these cocoons were attractive in the field. The only Florisil fraction of this extract consistently attractive by itself was that eluted with hexane, but three, more polar fractions (eluted with 5%, 25%, and 50% ether in hexane) each synergized the hexane fraction, increasing bioassay responses 10–30 times. Fractions derived directly from virgin females yielded comparable results. The greenhouse data corroborated the field data, except that the 5% ether-hexane fraction, while very synergistic in the field, was consistently inactive in the greenhouse.     

Wing fanning as a measure of pheromone response in the male pink bollworm,Pectinophora gossypiella (Lepidoptera: Gelechiidae)

A still-air, wing fanning bioassay measured male pheromone response in the pink bollworm moth,Pectinophora gossypiella (Saunders). As pheromone concentration was increased, the duration of wing fanning increased while its latency decreased. Response duration was longest for the natural pheromone blend [44:56 (Z,E)- and (Z,Z)-7,11-hexadecadienyl acetates], although responses to 38% and 50%Z,E blends were not significantly briefer. Preexposure to pheromone had no effect on wing fanning in males retested after 24 hr. Wing fanning was highly correlated with upwind flight and other responses observed in a wind tunnel. Wing fanning duration provides a continuous measure of pheromone response and allows a large number of males to be tested in a short time; these two characteristics of the wingfanning assay are helpful for genetic analyses of male response.     

Characterization of Transdermal Delivery of Nefopam Hydrochloride under Iontophoresis

In vitro iontophoretic delivery of nefopam hydrochloride was conducted to study the effects initial drug concentration, pH, ionic strength and viscosity of the donor solutions on the transdermal flux through a hairless mouse skin. Stability of nefopam hydrochloride under the experimental conditions was investigated. Type of electrode, current intensity, electric voltage and electrode distance were evaluated. Appropriate conditions were selected to minimize the potential degradation problems of nefopam hydrochloride during iontophoresis. Results show that the silver/silver chloride electrode provides better drug stability than the platinum electrode. Higher current intensity resulted in faster transdermal flux and therefore better drug permeability. The increase in the drug permeability appears to be proportionally increased as the current intensity increases in the range of 0.253 to 1.265 mA/cm². The iontophoretic transdermal delivery of nefopam hydrochloride was observed to increase as the drug concentration in the donor site was increased until it's close to the equilibrium concentration. The optimum pH to achieve the best iontophoresis under constant current was determined to be at pH 3.0. This may be due to the highest available charge density of nefopam was achieved at this pH to provide the best conductance. A decrease in the iontophoretic transdermal flux was encountered as an increase in the solution ionic strength due to the increased competition of similar charged ions with the available current. The increase in the donor solution viscosity decreased the conductivity of the ions and hindered the trandermal flux of the drug under iontophoresis.     

Induction of Detoxification Enzymes by Feeding Unblanched Brussels Sprouts Containing Active Myrosinase to Mice for 2 Wk

Abstract: In cruciferous vegetables, myrosinase metabolizes the relatively inactive glucosinolates into isothiocyanates and other products that have the ability to increase detoxification enzyme expression. Thus, maintaining myrosinase activity during food preparation may be critical to receiving the maximum benefit of consumption of Brussels sprouts or other cruciferous vegetables. To test the importance of maintaining myrosinase activity for maximizing bioactivity, experimental diets containing 20% unblanched (active myrosinase) or 20% blanched (inactivated myrosinase) freeze-dried Brussels sprouts and a nutrient-matched control diet were evaluated in vitro and in vivo for their ability to induce detoxification enzymes. Treatment of immortalized HepG2 human hepatoma cells with the unblanched Brussels sprout diet caused a greater increase quinone activity compared to the blanched Brussels sprout diet. C3H/HeJ mice fed the unblanched Brussels sprout diets for 2 wk had significantly higher plasma sulforaphane concentrations. Liver expression of CYP1A1 and epoxide hydrolase, measured using real-time PCR, was correlated with the plasma concentration of sulforaphane. In the lung, expression of epoxide hydrolase, thioredoxin reductase, UDP glucuronosyltransferase, quinone reductase, heme oxygenase, CYP1A1, CYP1A2, and CYP1B1 were also correlated with the plasma concentration of sulforaphane. Together these data demonstrate that, as predicted by the in vitro experiment, in vivo exposure to Brussels sprouts with active myrosinase resulted in greater induction of both phase I and phase II detoxification enzymes in the liver and the lungs that correlated with plasma sulforaphane concentrations.