Toxicological effect of sumithion pesticide on the hematological parameters and its recovery pattern using probiotic in Barbonymus gonionotus.

The experiment was conducted to clarify sumithion induced hematoxicity in silver barb (Barbonymus gonionotus) through in vivo exposures (25 % and 50 % of LC50 of sumithion) and subsequent recovery patterns using normal and probiotic treated feed were also assessed. Three treatments each incorporating three replications were used in the experiment for different days (1, 7, 14, 21, and 28). Treatment T1 was control (0 mg/L), and two concentrations, such as 2.61 mg/L (25 % of 96 h LC50), 5.21 mg/L (50 % of 96 h LC50) were used as Treatment T2 and T3, respectively. After 28 days of exposure to pesticide half of the fishes of T2 and T3 were reared in sumithion free water with normal (T2N, T3N) and probiotic treated feed (T2P, T3P). The median lethal concentration (50 %) for 96 h was 10.42 mg/L. In pesticide-treated groups, values of each hematological parameter (blood glucose, red blood cell, hematocrit, and hemoglobin) decreased but prevalence and severity of micronucleus and white blood cells increased significantly (p< 0.05) with concentration and time duration. Other blood indices including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were correspondingly changed in comparison to the control. In the recovery experiment, the silver barb recovered spontaneously, but the recovery rate was significantly higher in probiotic treated groups than normally treated groups in time and duration reliant fashion. In conclusion, persistent sublethal dosages of sumithion caused hematological abnormalities in silver barb. Probiotic supplement can recover the damage but only 28 days of recovery is not enough to recover the total alterations.

Variability of E. coli in streambed sediment and its implication for sediment sampling.

E. coli is the number one cause for water quality impairments in rivers and streams in South Dakota and the United States. Stream bottom sediments can be a reservoir for bacteria, including pathogenic organisms and fecal indicator bacteria (FIB), due to the favorable conditions provided by sediments for survival. Despite this, little is known about the variability of E. coli in sediments which should be considered when developing a sampling regime. This study examines the spatial variability of E. coli in sediment across the stream cross-section, the temporal stability of E. coli in sediment samples, and the implications for sediment sampling and processing. Five locations were sampled for sediment E. coli along two tributaries to the Big Sioux River in eastern South Dakota, four along Skunk Creek (Sk1, Sk2, Sk3, and Sk4), and one in Sixmile Creek (SM). In Skunk Creek, site Sk1 has direct cattle access where the other three sites (Sk2, Sk3, and Sk4) are under Seasonal Riparian Area Management (SRAM), a strategy that limits the cattle access to the stream. E. coli concentrations in the sediment ranged from 4 to 997 CFU g-1 (8.5 × 102 to 2.1 × 105 CFU 100 mL-1). The highest and lowest E. coli concentrations observed were at sites Sk1 and Sk4, respectively. The E. coli concentration decreased from the upstream cattle crossing site (Sk1) through the downstream SRAM sites. Analyzing the stream cross-section analysis revealed no significant difference in E. coli concentration between the edge and the middle of the stream. Sediment samples can be held up to 24 h after sample collection in refrigerated conditions (37 °F) in the majority of cases (80%) without significant changes in E. coli concentrations. The sample size analysis indicated the spatial variability of E. coli across the stream cross-section is high and a single grab sample may not be able to provide adequate representation of E. coli concentrations in sediment without substantial error. The findings provide insight for designing E. coli monitoring projects and promote the awareness of unconventional sources of microbiological water quality impairment which are often overlooked.

Retuning of Mouse NK Cells after Interference with MHC Class I Sensing Adjusts Self-Tolerance but Preserves Anticancer Response.

Natural killer (NK) cells are most efficient if their targets do not express self MHC class I, because NK cells carry inhibitory receptors that interfere with activating their cytotoxic pathway. Clinicians have taken advantage of this by adoptively transferring haploidentical NK cells into patients to mediate an effective graft-versus-leukemia response. With a similar rationale, antibody blockade of MHC class I-specific inhibitory NK cell receptors is currently being tested in clinical trials. Both approaches are challenged by the emerging concept that NK cells may constantly adapt or "tune" their responsiveness according to the amount of self MHC class I that they sense on surrounding cells. Hence, these therapeutic attempts would initially result in increased killing of tumor cells, but a parallel adaptation process might ultimately lead to impaired antitumor efficacy. We have investigated this question in two mouse models: inhibitory receptor blockade in vivo and adoptive transfer to MHC class I-disparate hosts. We show that changed self-perception via inhibitory receptors in mature NK cells reprograms the reactivity such that tolerance to healthy cells is always preserved. However, reactivity against cancer cells lacking critical MHC class I molecules (missing self-reactivity) still remains or may even be increased. This dissociation between activity against healthy cells and tumor cells may provide an answer as to why NK cells mediate graft-versus-leukemia effects without causing graft-versus-host disease and may also be utilized to improve immunotherapy.