Surface antigen-guided CRISPR screens identify regulators of myeloid leukemia differentiation

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Impaired erythrocyte deformability precedes vascular changes in experimental diabetes mellitus.

The effect of diabetes on the red blood cell (RBC) deformability and its association with histological vascular changes was investigated in 35 streptozotocin-induced diabetic Wistar rats in a 30-day experiment and compared to 10 controls. RBC deformability was significantly impaired in the diabetic rats on day 5 (p < 0.001) and continued to deteriorate until day 20. On the 20 (th) day, the diabetic rats were randomly divided into two groups (group A: insulin-treated; group B: non-insulin-treated). A slight, non-significant (p = 0.20) improvement in RBC deformability was noticed in the insulin-treated group. In vitro incubation of RBCs with insulin did not improve the acquired RBC rigidity in either diabetic group. In contrast, it caused a significant reduction in RBC-deformability in the controls. On day 30, histological examination of arterial specimens from various sites revealed moderate to significant thickening in medium- and small-size artery and arteriole walls in both diabetic groups, with no evidence of diabetes-related changes in large, elastic-type arteries. No vascular changes were noticed in nine diabetic rats that succumbed between days 10 and 15. The results of this study indicate that reduced RBC deformability is an early manifestation of abnormal blood rheology in experimental diabetes, and precedes the evolution of vascular changes.     

Changeability of sperm chromatin structure during liquid storage of ovine semen in milk-egg yolk- and soybean lecithin-based extenders and their relationships to field-fertility

The aim of this experiment was to study the effect of semen extender on sperm chromatin structure and to correlate chromatin integrity with field-fertility of preserved ram semen. Ejaculates of at least 2 × 10⁹ sperm/ml and 70 % progressive motility were collected using an artificial vagina from Chios rams (n = 11, 4–6 years old), split-diluted to 1 × 10⁹ sperm/ml with milk-egg yolk- and soybean lecithin (Ovixcell^®)-based extenders, packaged in 0.5-ml straws and examined after 6, 24 and 48 h of storage at 5 ± 1 °C. Evaluation endpoints were computer-assisted sperm motion analysis, fluorescence-based analysis of chromatin structure by chromomycin A₃ and acridine orange assays, and 65-day pregnancy rate (PR) of 34- to 36-h preserved semen after intra-cervical insemination of ewes (n = 154) in progestagen-synchronized estrus. Neither extender nor storage time had any influence on incidence of decondensed chromatin. Unlike Ovixcell^® extender, deterioration of sperm motility (P < 0.01) and chromatin stability (P < 0.005) was detected after 48 h of storage in milk-egg yolk extender. Sperm motility accounted for 14.4–18.5 % of variations in chromatin integrity (P < 0.001). No significant difference was found in PR of Ovixcell^®- and milk-egg yolk-stored semen. Nevertheless, PR differed between rams (14.3–71.4 %; P < 0.025). Chromatin integrity explained 10.2–56.3 % of variations in PR (P < 0.05–0.01). A pronounced decline in PR (19.1 %) was observed when percentages of decondensed and destabilized chromatin have reached thresholds of 10.5–30 % and 4–9 %, respectively. In conclusion, Ovixcell^® is superior to milk-egg yolk extender in preserving chromatin stability and motility. Chromatin defects are negatively associated with sperm fertility.     

Changing social awareness of the illegal killing of migratory birds in the Ionian Islands,western Greece

ABSTRACT

The current study aims at monitoring, measuring and evaluating the ‘Safe havens for wild birds’ campaign, implemented within the framework of the LIFE programme, in Greece and more specifically in the Ionian Islands. The study detects attitude changes that occurred in three target groups (pupils, local hunters and residents) on three islands where the phenomenon of illegal spring killing is more intense. A questionnaire-based survey was conducted in two phases, just before the launch (2013) and after the completion of the campaign (2015), to enable a comparison of answers and data. The results show that pupils and to a lesser extent residents, enhanced their knowledge and awareness of poaching, the migration of avifauna and the consequences of illegal killing on migratory birds, while this aspect of attitude change was not observed in the hunting community which still believes that spring poaching should be treated as a legal activity and part of local culture.     

Comparative Benzofuran Chemistry of Enceliopsis

Enceliopsis (Asteraceae) is a small genus of herbaceous perennials from the Great Basin desert of the U.S.A. Phytochemical analysis revealed the presence of several benzofuran derivatives in Enceliopsis argophylla, E. covillei and E. nudicaulis. The compounds were either identical or very similar to benzofurans isolated from Encelia and Flourensia which supports the close affinity of these genera, as suggested previously, based on morphological, cytological and breeding studies.