The Drosophila homolog of human AF10/AF17 leukemia fusion genes (Dalf) encodes a zinc finger/leucine zipper nuclear protein required in the nervous system for maintaining EVE expression and normal growth

Sibling neurons in the embryonic central nervous system (CNS) of Drosophila can adopt distinct states as judged by gene expression and axon projection. In the NB4-2 lineage, two even-skipped (eve)-expressing sibling neuronal cells, RP2 and RP2sib, are formed in each hemineuromere. Throughout embryogenesis, only RP2, but not RP2sib, maintains eve expression. In this report, we describe a P-element induced mutation that alters the expression pattern of EVE in RP2 motoneurons in the Drosophila embryonic CNS. The mutation was mapped to a Drosophila homolog of human AF10/AF17 leukemia fusion genes (alf), and therefore named Dalf. Like its human counterparts, Dalf encodes a zinc finger/leucine zipper nuclear protein that is widely expressed in embryonic and larval tissues including neurons and glia. In Dalf mutant embryos, the RP2 motoneuron no longer maintains EVE expression. The effect of the Dalf mutation on EVE expression is RP2-specific and does not affect other characteristics of the RP2 motoneuron. In addition to the embryonic phenotype, Dalf mutant larvae are retarded in their growth and this defect can be rescued by the ectopic expression of a Dalf transgene under the control of a neuronal GAL4 driver. This indicates a requirement for Dalf function in the nervous system for maintaining gene expression and the facilitation of normal growth.     

Critical role of helix 12 of the vitamin D(3) receptor for the partial agonism of carboxylic ester antagonists.

The carboxy-terminal alpha-helix of a nuclear receptor ligand-binding domain (LBD), helix 12, contains a critical, ligand-modulated interface for the interaction with coactivator proteins. In this study, using the example of the vitamin D receptor (VDR) and the partial antagonist ZK159222, the role of helix 12 (residues 417-427) for both antagonistic and agonistic receptor actions was investigated. Amino acid residue G423 was demonstrated to be critical for partial agonism of ZK159222, but not for the activity of the natural VDR agonist, 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)). The amount of partial agonism of ZK159222 increased when helix 12 was truncated by the last four amino acid residues (Delta424-27) and augmented even more, when in addition helix 12 of VDR's dimerization partner, retinoid X receptor (RXR), was truncated. In contrast, the low agonism of a structural derivative of ZK159222, ZK168281, was not affected comparably, whereas other close structural relatives of ZK159222 even demonstrated the same agonistic activity as that of 1alpha,25(OH)(2)D(3). The amount of agonism of ZK159222 and ZK168281 at different variations of helix 12 correlated well with VDR's ability to complex with coactivator proteins and inversely correlated with the strength of the compound's antagonistic action on 1alpha,25(OH)(2)D(3) signalling. Molecular dynamics simulations of the LBD complexed with the two antagonists could explain their different action by demonstrating a more drastic displacement of helix 12 through ZK168281 than through ZK159222. Moreover, the modelling could indicate a kink of helix 12 at amino acid residue G423, which provides the last four amino acid residues of helix 12 with a modulatory role for the partial agonism of some VDR antagonists, such as ZK159222. In conclusion, partial agonism of a VDR antagonist is lower the more it disturbs helix 12 in taking the optimal position for coactivator interaction.     

Island properties dominate species traits in determining plant colonizations in an archipelago system

The extrinsic determinants hypothesis emphasizes the essential role of environmental heterogeneity in species’ colonization. Consequently, high resident species diversity can increase community susceptibility to colonizations because good habitats may support more species that are functionally similar to colonizers. On the other hand, colonization success is also likely to depend on species traits. We tested the relative importance of environmental characteristics and species traits in determining colonization success using census data of 587 vascular plant species collected about 70 yr apart from 471 islands in the archipelago of SW Finland. More specifically, we explored potential new colonization as a function of island properties (e.g. location, area, habitat diversity, number of resident species per unit area), species traits (e.g. plant height, life-form, dispersal vector, Ellenberg indicator values, association with human impact), and species’ historical distributions (number of inhabited islands, nearest occurrence). Island properties and species’ historical distributions were more effective than plant traits in explaining colonization outcomes. Contrary to the extrinsic determinants hypothesis, colonization success was neither associated with resident species diversity nor habitat diversity per se, although colonization was lowest on sparsely vegetated islands. Our findings lead us to propose that while plant traits related to dispersal and establishment may enhance colonization, predictions of plant colonizations primarily require understanding of habitat properties and species’ historical distributions.     

Basal ganglia hemorrhage in a case report following spinal surgery

Background

Intracranial hemorrhage is a rare but potentially severe complication of spinal surgery. Most reported post-operative ICH cases consist of cerebellar hemorrhage. There are fewer reported cases of supratentorial ICH following spinal surgery.

Case presentation

A 56-year-old woman underwent spinal surgery complicated by bilateral supratentorial intraparenchymal basal ganglia hemorrhage with both intraventricular extension and subarachnoid hemorrhage in both cerebral hemispheres.

Conclusion

The occurrence of neurological deterioration post-operatively following spinal surgery should alert physicians to the possibility of intracranial hemorrhage in order to facilitate rapid and optimal management. To our knowledge, this is the first case reporting basal ganglia hemorrhage following spinal surgery. Moreover, consideration should be given to the possibility of this complication prior to recommendation of elective spinal surgery.

     

Phycoremediation potential,physiological, and biochemical response of <Emphasis Type="Italic">Amphora subtropica</Emphasis> and <Emphasis Type="Italic">Dunaliella</Emphasis> sp. to nickel pollution

Metal pollution can produce many biological effects on aquatic environments. The marine diatom Amphora subtropica and the green alga Dunaliella sp. possess a high metal absorption capacity. Nickel (Ni) removal by living cells of A. subtropica and Dunaliella sp. was tested in cultures exposed to different Ni concentrations (100, 200, 300, and 500 mg L^?1). The amount of Ni removed by the microalgae increased with the time of exposure and the initial Ni concentration in the medium. The metal, which was mainly removed by bioadsorption to Dunaliella sp. cell surfaces (93.63% of total Ni (for 500 mg Ni L^?1) and by bioaccumulation (80.82% of total Ni (for 300 mg Ni L^?1) into Amphora subtropica cells, also inhibited growth. Exposure to Ni drastically reduced the carbohydrate and protein concentrations and increased total lipids from 6.3 to 43.1 pg cell^?1, phenolics 0.092 to 0.257 mg GAE g^?1 (Fw), and carotenoid content, from 0.08 to 0.59 mg g^?1 (Fw), in A. subtropica. In Dunaliella sp., total lipids increased from 26.1 to 65.3 pg cell^?1, phenolics from 0.084 to 0.289 mg GAE g^?1 (Fw), and carotenoid content from 0.41 to 0.97 mg g^?1 (Fw). These compounds had an important role in protecting the algae against ROS generated by Ni. In order to cope with Ni stress shown by the increase of TBARS level, enzymatic (SOD, CAT, and GPx) ROS scavenging mechanisms were induced.     

A modeling procedure to predict cancer risks associated with inhalable oil dust from Kuwait oil lakes

A model was constructed to estimate cancer risks associated with PM₁₀‐bound polycydic aromatic hydrocarbons (PAHs) from Kuwait oil lakes. The design of the risk model was based on a conceptual “chain of events”; leading from levels of PAH compounds in oil lakes, erosion of oil dust and input into the atmosphere, to contaminant concentration in air, to actual human exposure in residential areas. Uncertainties in the “chain of events”; model were addressed using Monte Carlo techniques. To identify the exposure duration of concern [duration beyond which risk becomes unacceptable (i.e. Risk > 10^‐6)], four exposure durations were tested 10, 20, 40, 70 years. 40 years was identified to be the exposure duration of concern based on the 95th percen‐tile of the risk distribution. As a result, the acceptability of risk was specified in terms of a single constraint on the 95^th percentile of the risk distribution evaluated after 40 years of exposure: 0 < Risk (40 y)₀.₉₅ ≤ 10^‐6. Based on this constraint, it was estimated that a removal rate of 217, 793.27 m³/year to be an adequate action for risk management. The northern oil lakes were identified as the lakes of most concern when inhalation exposures are considered.