Effects of in vitro exposure of sheep ovarian tissue to zearalenone and matairesinol on preantral follicles.

The aim of this study was to evaluate the effect of 1 µmol/l zearalenone (ZEN) and 1 µmol/l matairesinol (MAT), alone or in combination, on the morphology of in vitro-cultured ovarian preantral follicles. Ovaries from four adult sheep were collected at a local slaughterhouse and fragmented, and the ovarian pieces were submitted to in vitro culture for 3 days in the presence or absence of the test compounds. The morphology of primordial and primary follicles was impaired by ZEN. The plant lignan MAT alone did not maintain the morphology of the ovarian follicles; its combination with ZEN counteracted the negative effects observed when follicles were cultured in the presence of the mycotoxin alone. However, MAT was not able to promote the in vitro development of the ovarian follicles.

In vitro exposure of sheep ovarian tissue to the xenoestrogens zearalenone and enterolactone: Effects on preantral follicles.

The aim of this study was to evaluate the effect of 1 µmol/L zearalenone (ZEN) and 1 µmol/L enterolactone (ENL), alone or in combination, on the survival and morphology of in vitro cultured ovarian preantral follicles. Ovaries from 10 sheep were collected at a local abattoir and fragmented, and the ovarian pieces were submitted to in vitro culture for 3 days in the presence or absence of the test compounds. The morphology of primordial and primary follicles was impaired by ZEN, whereas that of cultured secondary follicles was improved by ENL. However, the combination of ENL with ZEN impaired the quality of primary and secondary follicles. Both ZEN and ENL induced apoptosis, but only ZEN was responsible for oocyte autophagy. None of these xenoestrogens affected endoplasmic reticulum stress as observed by the unaltered expression of ERP29. Differently from ZEN, ENL increased the expression of the efflux transporter ABCG2. In conclusion, although ENL can counteract the negative effects of ZEN on primordial and primary follicles, this positive effect is not similar to that observed in ovarian tissue cultures in the presence of ENL alone.

In-vehicle carbon dioxide concentration in commuting cars in Bangkok, Thailand.

It is known that in-vehicle carbon dioxide (CO2) concentration tends to increase due to occupant exhalation when the HVAC (heating, ventilation, and air conditioning) air is in recirculation mode. Field experiments were conducted to measure CO2 concentration during typical commute in Bangkok, Thailand. The measured concentrations agreed with the concentration predicted using first-order mass balance equation, in both recirculating and outside air modes. The long-term transient decay of the concentration when the vehicle was parked and the HVAC system was turned off was also studied. This decay was found to follow Fickian diffusion process. The paper also provides useful operational details of the automotive HVAC system and fresh air ventilation exchange between cabin interior and exterior. IMPLICATIONS: Drivers in tropical Asian countries typically use HVAC recirculation mode in their automobiles. This behavior leads to excessive buildup of cabin CO2 concentration levels. The paper describes the CO2 buildup in a typical commute in Bangkok, Thailand. Auto manufacturers can potentially take measures to alleviate such high concentration levels. The paper also discusses the diffusion of CO2 through the vehicle envelope, an area that has never been investigated before.

Effect of surface treatments on anodic oxide film growth and electrochemical properties of tantalum used for biomedical applications.

Self-expandable nitinol (nickel-titanium) alloys and 316L stainless steel are the most commonly used materials in the production of coronary stents. However, tantalum (Ta) has already been used to make stents for endovascular surgery and may constitute an alternative to other materials because of its better electrochemical performance, namely its higher corrosion resistance, as well as its radio-opacity. The characterization of wet polished, chemically polished, wet polished anodized, and chemically polished anodized Ta electrodes has been performed in a 0.15 M NaCl solution (simulated body fluid) using Ucorr = f(t) measurements, anodic polarizations, capacity measurements, anodic oxidations, and atomic force microscopy (AFM) imaging. Anodic polarization curves have shown that the abnormal current density peak with a maximum value around 1.65 V (critical applied potential, Uc) disappeared for the anodized electrodes indicating a probable relationship between the surface states and the film growth. These results are confirmed by capacity measurements. The behavior of wet polished and chemically polished electrodes during anodic oxidations seemingly indicated that for these particular treatments the film growth is different. The AFM images and roughness measurements have shown that chemical polishing produced smoother electrodes, a fact probably related to the differences in film growth.

Perspectives of using Euphorbia splendens as a molluscicide in schistosomiasis control programs.

A total of 1,426 species of plants had been tested in order to find out a vegetal-derived molluscicide against the vectors of Schistosoma mansoni. Euphorbia splendens is one of the most promising molluscicides. In this article we briefly present the main aspects that have to be considered to use this plant as a molluscicide, which include some agricultural aspects and operational methods for application. This can be done by the extraction of the active principles (millaminas) present in the latex or in the raw juice obtained through total maceration of plants. The culture of E. splendens, which spreads out by vegetative sprouts, showed an annual average growth of 30 cm. After 1.5 years the average productivity of crude latex with a DL90 of 12 ppm concentration, was 1 liter by 8m2 by cultivated area. This amount is enough to treat a volume of water of 97,200 liters. A comparative analysis between the cost of snail control through synthetic molluscicides was carried out based upon the data presented by Jobim (1979) for six controlling methods in several countries, and some cost aspects for E. splendens. This analysis was done considering a geographic parameter expressed by the index cubic meters of treated habitat per square kilometer, from which we can obtain an estimate dimension of the geographic area to be cultivated with E. splendens necessary to treat the same volume of water treated by synthetic molluscicides.

Evaluation of the molluscicidal property of Euphorbia splendens var. Hispolii (N.E.B.) (Euphorbiaceae): 2. Investigation in lotic habitat

The latex of Euphorbia splendens var. hispolii in 12 ppm concentration (12 mg/l) caused 100% mortality for a Biomphalaria tenagophila population in a lotic habitat after 9 hr of dripfeed application. For sentinel snails, in cages placed at the water surface and buried under 0.10 m, the mortality rates varied with the distance from the application point and were: 100% (0 m); 92.6% (50 m) and 94.7% (100). No lethal effects were observed for the other living species in this habitat (Pomacea haustrum and Poecilia reticulata)

Evaluation of temporal, seasonal and geographic stability of the molluscicidal property of Euphorbia splendens latex.

Laboratory tests with aqueous solutions of Euphorbia splendens var. hislopii latex have demonstrated seasonal stability of the molluscacidal principle, with LD90 values of 1.14 ppm (spring), 1.02 ppm (fall), 1.09 ppm (winter), and 1.07 ppm (summer) that have been determined against Biomphalaria tenagophila in the field. Assays on latex collected in Belo Horizonte and Recife yielded LD90 values similar to those obtained with the reference substance collected in Rio de Janeiro (Ilha do Governador), demonstrating geographic stability of the molluscacidal effect. The molluscacidal action of aqueous dilutions of the latex in natura, centrifuged (precipitate) and lyophilized, was stable for up to 124 days at room temperature (in natura) and for up to 736 days in a common refrigerator at 10 to 12 degrees C (lyophilized product). A 5.0 ppm solution is 100% lethal for snails up to 13 days after preparation, the effect being gradually lost to almost total inactivity by the 30th day. This observation indicated that the active principle is instable. These properties together with the wide distribution of the plant, its resistance and adaptation to the tropical climate, its easy cultivation and the easy obtention of latex and preparation of the molluscicidal solution, make this a promising material for large-scale use in the control of schistosomiasis.