Toxicity of pesticides toward human immune cells U-937 and HL-60

Abstract

The industrialization of the agricultural sector has significantly increased the use of chemicals such as pesticides. Therefore, exposure to them is unavoidable, which makes it necessary to assess their safety for humans at actual exposure doses. This paper aims to determine toxicity of three types of pesticides toward human immune cells (HL-60 and U-937): glyphosate (GLY), deltamethrin (DEL), and chlorothalonil (CHL). Cell viability, membrane integrity, inflammation induction, and antioxidant activity were evaluated to determine differences in cellular response to the tested plant protection agents. In experimental models, all tested substances caused increased mortality of cells after only 24?h. Cell membrane damage was recorded under DEL and CHL influences. The largest disintegration of the cell membrane was due to the action of 100?μg/mL DEL for U-937 and CHL at 1?μg/mL for HL-60. GLY at a concentration of 3,600?μg/mL caused significant peroxidation of U-937 cells’ lipids. CHL-induced inflammation in both types of cells tested. DEL and GLY also induced antioxidant activity in cells. These results lead to the conclusion that the tested pesticides act cytotoxically to the cells of the human immune system in doses to which both farmers and consumers are exposed.     

Mean colony relatedness is a poor predictor of colony structure and female philopatry in the communally breeding Bechstein's bat (Myotis bechsteinii)

In order to understand why animals are social and how group members interact with each other it is important to know their relatedness. However, few studies have investigated the genealogy in complete social groups of free-living animals with low reproductive skew. This holds particularly true for bats. Although almost all bat species are social, their sociobiology is not well understood. Because they are volant, nocturnal and have a rather cryptic life-style, bats are difficult to observe in the wild. Furthermore females are generally gregarious making genetic parent-offspring assignment a challenging task. We used genetic markers in combination with knowledge about age and colony membership of individually marked bats to construct pedigrees in completely sampled maternity colonies of Bechstein's bats (Myotis bechsteinii). Despite considerable fluctuations in population size, no immigration occurred over 5 years in four colonies living in close proximity. Additionally, confrontation tests showed that females of one maternity colony were able to detect and attempted to prevent the intrusion of foreign females into a roost they occupy. Although colonies were absolutely closed, and 75% of the colony members lived together with close relatives (rS=0.25), mean colony relatedness was nearly zero (0.02). Average relatedness therefore is a poor estimator for the potential of kin selection in Bechstein's bat colonies and may be misleading when attempting to understand the social structure of animals living in groups where many members breed. Based on our results we discuss the potential adaptive value of living in closed societies with low reproductive skew.     

Comparison of light- and SST-based geolocation with satellite telemetry in free-ranging albatrosses

Light-based archival tags are increasingly being used on free-ranging marine vertebrates to study their movements using geolocation estimates. These methods use algorithms that incorporate threshold light techniques to determine longitude and latitude. More recently, researchers have begun using sea surface temperature (SST) to determine latitude in temperate regions. The accuracy and application of these algorithms have not been validated on free-ranging birds. Errors in both geolocation methods were quantified by double-tagging Laysan (Phoebastria immutabilis Rothschild) and black-footed (P. nigripes Audubon) albatrosses with both leg-mounted archival tags that measured SST and ambient light, and satellite transmitters. Laysan albatrosses were captured and released from breeding colonies on Tern Island, northwestern Hawaiian Islands (23°52N, 166°17W) and Guadalupe Island, Mexico (28°31N, 118°10W) and black-footed albatrosses from Tern Island. Studies were carried out between December 2002 and March 2003. For all birds combined, the mean ± SD great circle (GC) distance between light-based locations and satellite-derived locations was 400±298 km (n=131). Errors in geolocation positions were reduced to 202±171 km (n=154) when light-based longitude and SST-based latitude (i.e. SST/light) were used to establish locations. The SST/light method produced comparable results for two Laysan albatross populations that traveled within distinctly different oceanic regions (open ocean vs more coastal) whereas light-based methods produced greater errors in the coastal population. Archival tags deployed on black-footed albatrosses returned a significantly higher proportion of lower-quality locations, which was attributed to interference of the light sensor on the tag. Overall, the results demonstrate that combining measures of light-based longitude and SST-based latitude significantly reduces the error in location estimates for albatrosses and can provide valid latitude estimates during the equinoxes, when light-based latitude measurements are indeterminate.Communicated by J.P. Grassle, New Brunswick     

Using nocturnal cold air drainage flow to monitor ecosystem processes in complex terrain.

This paper presents initial investigations of a new approach to monitor ecosystem processes in complex terrain on large scales. Metabolic processes in mountainous ecosystems are poorly represented in current ecosystem monitoring campaigns because the methods used for monitoring metabolism at the ecosystem scale (e.g., eddy covariance) require flat study sites. Our goal was to investigate the potential for using nocturnal down-valley winds (cold air drainage) for monitoring ecosystem processes in mountainous terrain from two perspectives: measurements of the isotopic composition of ecosystem-respired CO2 (delta13C(ER)) and estimates of fluxes of CO2 transported in the drainage flow. To test if this approach is plausible, we monitored the wind patterns, CO2 concentrations, and the carbon isotopic composition of the air as it exited the base of a young (approximately 40 yr-old) and an old (>450 yr-old) steeply sided Douglas-fir watershed. Nocturnal cold air drainage within these watersheds was strong, deep, and occurred on more than 80% of summer nights. The depth of cold air drainage rapidly increased to tower height or greater when the net radiation at the top of the tower approached zero. The carbon isotope composition of CO2 in the drainage system holds promise as an indicator of variation in basin-scale physiological processes. Although there was little vertical variation in CO2 concentration at any point in time, we found that the range of CO2 concentration over a single evening was sufficient to estimate delta 13C(ER) from Keeling plot analyses. The seasonal variation in delta 13C(ER) followed expected trends: during the summer dry season delta 13C(ER) became less negative (more enriched in 13C), but once rain returned in the fall, delta 13C(ER) decreased. However, we found no correlation between recent weather (e.g., vapor pressure deficit) and delta 13C(ER) either concurrently or with up to a one-week lag. Preliminary estimates suggest that the nocturnal CO2 flux advecting past the 28-m tower is a rather small fraction (<20%) of the watershed-scale respiration. This study demonstrates that monitoring the isotopic composition and CO2 concentration of cold air drainage at the base of a watershed provides a new tool for quantifying ecosystem metabolism in mountainous ecosystems on the basin scale.     

Leaf variation in iridoid glycoside content ofPlantago lanceolata (Plantaginaceae) and oviposition of the buckeye,Junonia coenia (Nymphalidae)

Summary Chemical analysis of each individual leaf of fivePlantago lanceolata (Plantaginaceae) plants showed that iridoid glycoside content increased from undetectable in the oldest photosynthetic leaves to over 9% dry weight in the youngest leaves. The relative proportion of the two iridoid glycosides inP. lanceolata also changed with leaf age: older leaves had significantly more aucubin, whereas the youngest leaves had primarily or solely catalpol. Oviposition tests with femaleJunonia coenia (Nymphalidae) butterflies, showed that they laid most of their eggs on new leaves.     

Human digit ratios depend on birth order and sex of older siblings and predict maternal fecundity

In men, the length ratio of the second to fourth finger (2D:4D) is smaller, while the length of the fourth finger relative to body height (4D:H) is larger than in women. Inter- and intrasexual variations in 2D:4D and 4D:H may depend on variation in fetal androgen and oestrogen environment. As maternal physiology varies with parity and is differentially affected by gestation of either sex, offspring 2D:4D and 4D:H may change according to sex and number of older siblings and may predict subsequent maternal performance. We analysed 2D:4D and 4D:H in Caucasian university students. 2D:4D was smaller and 4D:H was larger in males than in females, but no sexual dimorphism existed in 2D:H. In males, length ratios did not vary with birth order. 2D:4D became more masculine with increasing proportion of males among older siblings, and 2D:4D and 4D:H became more feminine as the number of older sisters increased. In females, length ratios did not vary with the number of older sisters or brothers. 2D:4D was also not related to birth order, but 4D:H became more masculine with birth order. In females, residual maternal fecundity (number of maternal offspring after the participant) decreased as 4D:H became more masculine. These findings are partly consistent with those from previous studies and suggest that maternal fecundity co-varies with length ratios and thus possibly fetal hormone environment of older offspring. 2D:4D and 4D:H may therefore represent powerful tools to investigate the relationships between fetal environment, offspring phenotype and maternal life history at mechanistic and evolutionary levels.     

Developmental arrest in Japanese medaka (Oryzias latipes) embryos exposed to sublethal concentrations of atrazine and arsenic trioxide

Embryos of the Japanese medaka (Oryzias latipes) were exposed to serial concentrations of atrazine (0, 25, 50, and 100 ppm) and arsenic trioxide (0, 0.025, 0.05, 0.1 ppm) until hatching. Stasis of circulation, blood islands, titanic convulsions, tube heart and mortality were observed in atrazine-treated embryos. Each endpoint exhibited a concentration-response relationship. Only 4% of the embryos hatched in the 25 ppm, and none in the 50 and 100 ppm, probably due to cell death attributed to the embryos' inability to break from the chorion. With arsenic exposure, hatching was inversely correlated to chemical concentration: 86%, 75% and 54% for 0.025, 0.05 and 0.1 ppm, respectively. Hatching periods were also reduced from 7-13 days in controls to 7-11 days in arsenic-treated embryos. This observation was more pronounced with the 0.05 ppm concentration, showing a reduction of about 4 days. Despite this shortage in hatching time, there were no observable morphological abnormalities, as seen with atrazine. The ecological significance of these findings and implications for the development of sublethal toxicity tests using Japanese medaka embryos are important.