The Evolution of HD2 Proteins in Green Plants.

In eukaryotes, protein deacetylation is carried out by two well-conserved histone deacetylase (HDAC) families: RPD3/HDA1 and SIR2. Intriguingly, model plants such as Arabidopsis express an additional plant-specific HDAC family, termed type-2 HDACs (HD2s). Transcriptomic analyses from more than 1300 green plants generated by the 1000 plants (1KP) consortium showed that HD2s appeared early in green plant evolution, the first members being detected in several streptophyte green alga. The HD2 family has expanded via several rounds of successive duplication; members are expressed in all major green plant clades. Interestingly, angiosperm species express new HD2 genes devoid of a zinc-finger domain, one of the main structural features of HD2s. These variants may have been associated with the origin and/or the biology of the ovule/seed.

Evaluation of the cathetron system for recycling angioplasty catheters.

The Cathetron (Minntech Corporation, Minneapolis, MN) peracetic acid-based reprocessing method for percutaneous transluminal coronary angioplasty (PTCA) catheters was evaluated for ability to sterilize and maintain catheter integrity. The balloons and lumens of 42 catheters (140 reprocessing cycles) were inoculated with suspensions of Staphylococcus epidermidis, S. aureus, Pseudomonas aeruginosa, and Bacillus circulans. Five catheters failed the initial evaluation of mechanical integrity and were discarded. Cultures from 37 catheter lumens, balloons, and hubs (n = 349) were negative following reprocessing. The Cathetron system reliably sterilized PTCA catheter, however, further studies using different brands of catheters and evaluating catheter sterility over time under storage conditions are required.

Phylogeography and host association in a pollinating seed parasite Greya politella (Lepidoptera: Prodoxidae).

Inferring the historical context of ecological diversification is an important step in understanding the way that population-level processes result in a diversity of species and interactions in communities. We performed a phylogeographic analysis of mitochondrial DNA haplotypes from the pollinating seed parasite Greya politella (Lepidoptera: Prodoxidae) in order to determine the degree to which populations were structured according to geographical location and host-plant association. Ninety-eight individuals were sampled from 29 locations ranging from southern California to western Idaho. Restriction-site variation in 87 individuals (27 populations) was screened by digestion with 11 endonucleases, followed by Southern blotting; 38 restriction-site positions were mapped by double digests. Haplotypes were further defined by generating fragments 251 bases in length via PCR, screening them for sequence variation using denaturing gel gradient electrophoresis (DGGE), and sequencing the resulting variants. Parsimony analysis of the resulting 12 restriction-site and 15 sequence haplotypes indicated strong geographical structuring of populations: (i) most populations were monomorphic for haplotype; (ii) haplotypes from California and the Pacific Northwest (Oregon, Washington and Idaho) formed robust monophyletic groups. Population structure was significant both within and between the two regions, as reflected by NST. Patterns of host-plant association and haplotype phylogeny suggest that populations have recently undergone host-plant shifts in many different parts of the species range, although the direction and number of host shifts cannot be determined at the present level of sampling resolution.

Inhibition of glutamate uptake causes an acute increase in aqueous humor protein.

Inhibition of glutamate transport has been shown to increase paracellular permeability of epithelial cell monolayers in vitro. To determine if blocking glutamate transport would affect tissue permeability in vivo, D-aspartate (D-Asp; 300 nmol 30 microliters-1) (a non-toxic competitive inhibitor of glutamate transport) or a placebo was injected into the anterior chambers of the fellow eyes of 15 adult rabbits. [14C]-L-glucose and/or [125I]-rabbit albumin were included in the injection vehicle as aqueous humor (AH) outflow markers. The specific inhibition of glutamate uptake by D-Asp was indicated by a 15% increase in AH glutamate (174 +/- 9 nmol ml-1 to 205 +/- 13 nmol ml-1; P = 0.03) at 1-1.5 hr post injection. Also, the efflux of [14C]-L-glucose and [125I]-rabbit albumin from the AH of D-Asp injected eyes was increased 22% over the placebo-injected control eyes (P < or = 0.02). Concomitantly, the total protein concentration in the AH from D-Asp injected eyes (517 +/- 35 micrograms ml-1) was 19% greater (P < 0.02) than the protein concentration in AH from placebo-injected control eyes (420 +/- 36 micrograms ml-1). In additional studies, an irreversible inhibitor of glutamate transport, threo-beta-hydroxyaspartate (THA; 30 nmol 30 microliters-1), was shown to increase the efflux of [14C]-L-glucose (22%; P < 0.05) from the anterior chamber and increase AH protein concentrations by 29% (484 +/- 112 micrograms ml-1 in control AH versus 686 +/- 117 micrograms ml-1 in THA AH, P = 0.08) at 1 hr post intracameral injection. SDS-PAGE analysis of the AH associated the protein increase in the D-Asp and THA injected eyes but not placebo-injected control eyes with a detectable increase in a 66 kDa protein (aligns with serum albumin) and several lower molecular weight (23-35 kDa) AH proteins. The results found suggest that inhibition of glutamate transport from the AH acutely increases intraocular epithelial/endothelial paracellular permeability.