Implementation of Organ Culture storage of donor corneas: a 3 year study of its impact on the corneal transplant wait list at the Lions New South Wales Eye Bank

Organ Culture corneal storage offers an extended storage time and increased donor pool and tissue assessment opportunities. In September 2011, the Lions New South Wales Eye Bank (LNSWEB) moved from hypothermic storage to Organ Culture corneal storage. This study evaluates the impact of implementation of Organ Culture on donor eye retrieval and the corneal transplant waiting list over a 3 year period in NSW, Australia. Retrospective review of the LNSWEB data from September 2011 to August 2014. Tissue collection, waiting list and tissue utilization data were recorded. The data from September 2008 to August 2011 for Optisol-GS storage was used for comparison. The annual donor and cornea collection rate increased 35 % and 44 % respectively with Organ Culture compared to Optisol-GS storage. The utilization rate of corneal tissue increased from 73.4 % with hypothermic storage to 77.2 % with Organ Culture storage. The transplant wait list decreased by 77.3 % from September 2011 to August 2014 and correlated with the increased rate of corneal transplantation (r = ?0.9381, p < 0.0001). No other factors impacting the wait list changed over this period. Corneas not used from either storage method were due to unacceptable endothelial cell density/viability. The contamination rate of corneas stored in Organ Culture medium was low at 1.74 %. The Organ Culture storage method increases the corneal donor pool available to Eye banks. The practical benefits of the extended storage time and increased donor assessment opportunities have directly led to an increase in corneal utilization rate and a significant decrease in recipient wait list time.     

The KRAS-regulated kinome identifies WEE1 and ERK coinhibition as a potential therapeutic strategy in KRAS-mutant pancreatic cancer

Oncogenic KRAS drives cancer growth by activating diverse signaling networks, not all of which have been fully delineated. We set out to establish a system-wide profile of the KRAS-regulated kinase signaling network (kinome) in KRAS-mutant pancreatic ductal adenocarcinoma (PDAC). We knocked down KRAS expression in a panel of six cell lines and then applied multiplexed inhibitor bead/MS to monitor changes in kinase activity and/or expression. We hypothesized that depletion of KRAS would result in downregulation of kinases required for KRAS-mediated transformation and in upregulation of other kinases that could potentially compensate for the deleterious consequences of the loss of KRAS. We identified 15 upregulated and 13 downregulated kinases in common across the panel of cell lines. In agreement with our hypothesis, all 15 of the upregulated kinases have established roles as cancer drivers (e.g., SRC, TGF-β1, ILK), and pharmacological inhibition of one of these upregulated kinases, DDR1, suppressed PDAC growth. Interestingly, 11 of the 13 downregulated kinases have established driver roles in cell cycle progression, particularly in mitosis (e.g., WEE1, Aurora A, PLK1). Consistent with a crucial role for the downregulated kinases in promoting KRAS-driven proliferation, we found that pharmacological inhibition of WEE1 also suppressed PDAC growth. The unexpected paradoxical activation of ERK upon WEE1 inhibition led us to inhibit both WEE1 and ERK concurrently, which caused further potent growth suppression and enhanced apoptotic death compared with WEE1 inhibition alone. We conclude that system-wide delineation of the KRAS-regulated kinome can identify potential therapeutic targets for KRAS-mutant pancreatic cancer.     

Native arthropods on exotic sand dune flowers: consideration of sample size and number for investigating rare species and sparse communities

When studying arthropod visitors of flowers, the sampling unit (individual flowers, groups of flowers, areas of plants, timed visits, etc.) depends upon the aim of the study and the sampling method employed. In this study, arthropods using flowers of the ice plant, Carpobrotus edulis, were recorded on the sand dunes at New Brighton in the south island of New Zealand. Of 3600 flowers, only 10% contained invertebrates and only 478 specimens were recorded in total. Of 32 arthropod species observed on this exotic plant, we consider at least 20 to be native to New Zealand and five species are probably New Zealand endemics. Based on an occupation rate of individual flowers of 10%, a binomial model indicated that a sample of 100 flowers would have <0.003% chance of containing no specimens, and 96% chance that 5–16 flowers would contain some animals. Species accumulation models (e.g. bootstrap, Chao and rarefaction) and models examining the likelihood of recording rare species indicated that after examining 2000 flowers, 80% of arthropod species would be recorded, and that only the rarest species in our study would fall below an 80% statistical power of detection. The results suggest that for this flower–invertebrate system, a scheme that involved 20 independent samples, each consisting of 100 flowers, would provide a good chance of (1) avoiding totally empty samples (2) collecting a high proportion of the total species present and (3) recording all but the very rarest species that occur in this system.     

Variability of the Mitochondrial SSU rDNA of <Emphasis Type="Italic">Nomuraea</Emphasis> Species and Other Entomopathogenic Fungi from Hypocreales

Hypocrealean arthropod pathogenic fungi have profound impact on the regulation of agricultural and medical pests. However, until now the genetic and phylogenetic relationships among species have not been clarified, such studies could clarify host specificity relationships and define species boundaries. Our purpose was to compare the sequences of the mitochondrial SSU rDNA fragments from several mitosporic entomopathogenic Hypocreales to infer relationships among them and to evaluate the possibility to use these sequences as species diagnostic tool in addition to the more commonly studied sequences of nuclear SSU rDNA. The SSU mt-rDNA proved to be useful to help in differentiation of species inside several genera. Clusters obtained with Parsimony, Bayesian, and Maximum Likelihood analyses were congruent with a new classification of the Clavicipitaceae (Sung et al. Stud Mycol. 2007;57:5-59) in which the anamorphic genera Nomuraea and Metarhizium species remain in the Clavicipitaceae and Isaria species sequenced here are assigned to the family Cordycipitaceae. Mitochondrial genomic information indicates the same general pattern of relationships demonstrated by nuclear gene sequences.     

Arbuscular mycorrhizal fungi can transfer substantial amounts of nitrogen to their host plant from organic material

Nitrogen (N) capture by arbuscular mycorrhizal (AM) fungi from organic material is a recently discovered phenomenon. This study investigated the ability of two Glomus species to transfer N from organic material to host plants and examined whether the ability to capture N is related to fungal hyphal growth. Experimental microcosms had two compartments; these contained either a single plant of Plantago lanceolata inoculated with Glomus hoi or Glomus intraradices, or a patch of dried shoot material labelled with (15)N and (13)carbon (C). In one treatment, hyphae, but not roots, were allowed access to the patch; in the other treatment, access by both hyphae and roots was prevented. When allowed, fungi proliferated in the patch and captured N but not C, although G. intraradices transferred more N than G. hoi to the plant. Plants colonized with G. intraradices had a higher concentration of N than controls. Up to one-third of the patch N was captured by the AM fungi and transferred to the plant, while c. 20% of plant N may have been patch derived. These findings indicate that uptake from organic N could be important in AM symbiosis for both plant and fungal partners and that some AM fungi may acquire inorganic N from organic sources.     

Synthesis and bioactivity of a side chain bridged paclitaxel: A test of the T-Taxol conformation

A knowledge of the bioactive tubulin-binding conformation of paclitaxel (Taxol^?) is crucial to a full understanding of the bioactivity of this important anticancer drug, and potentially also to the design of simplified analogs. The bioactive conformation has been shown to be best approximated by the T-Taxol conformation. As a further test of this conclusion, the paclitaxel analog 4 was designed as a compound which has all the chemical functionality necessary for activity, but which cannot adopt the T-Taxol conformation. The synthesis and bioassay of 4 confirmed its lack of activity, and thus provided further support for the T-Taxol conformation as the bioactive tubulin-binding conformation.     

Inhibition of succinic acid production in metabolically engineered Escherichia coli by neutralizing agent,organic acids,and osmolarity

The economical viability of biochemical succinic acid production is a result of many processing parameters including final succinic acid concentration, recovery of succinate, and the volumetric productivity. Maintaining volumetric productivities >2.5 g L^?1 h^?1 is important if production of succinic acid from renewable resources should be competitive. In this work, the effects of organic acids, osmolarity, and neutralizing agent (NH₄OH, KOH, NaOH, K₂CO₃, and Na₂CO₃) on the fermentative succinic acid production by Escherichia coli AFP184 were investigated. The highest concentration of succinic acid, 77 g L^?1, was obtained with Na₂CO₃. In general, irrespective of the base used, succinic acid productivity per viable cell was significantly reduced as the concentration of the produced acid increased. Increased osmolarity resulting from base addition during succinate production only marginally affected the productivity per viable cell. Addition of the osmoprotectant glycine betaine to cultures resulted in an increased aerobic growth rate and anaerobic glucose consumption rate, but decreased succinic acid yield. When using NH₄OH productivity completely ceased at a succinic acid concentration of ～40 g L^?1. Volumetric productivities remained at 2.5 g L^?1 h^?1 for up to 10 h longer when K‐ or Na‐bases where used instead of NH₄OH. The decrease in cellular succinic acid productivity observed during the anaerobic phase was found to be due to increased organic acid concentrations rather than medium osmolarity. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

The development of foraging microhabitat preferences in meerkats

Animals of many species tend to target their foraging attemptstoward particular microhabitats within their habitat. Althoughthese preferences are critical determinants of the foragingniche and have important ecological and evolutionary implications,we know little about how they develop. Here, we use detailedlongitudinal data from meerkats (Suricata suricatta) to examinehow individual learning and the use of social information affectthe development of foraging microhabitat preferences. Despiteliving in an open, arid environment, adult meerkats frequentlyforaged at the base of vegetation. Young pups seldom did so,but their foraging microhabitat choices became increasinglyadult-like as they grew older. Learning about profitable microhabitatsmay have been promoted in part by positive reinforcement fromprey capture. Foraging may also have become increasingly targetedtoward suitable locations as pups grew older because they spentmore time searching before embarking on foraging bouts. Thedevelopment of microhabitat preferences might also have beeninfluenced by social cues. Foraging in close proximity to adultsmay increase the probability that pups would dig in similarmicrohabitats. Also, pups often dug in holes created by olderindividuals, whereas adults never dug in existing holes. Foragingin existing holes was no more profitable to pups than creatingtheir own foraging hole but could provide pups with importantinformational benefits. The integration of personal and socialinformation is likely to be a common feature in the developmentof the foraging niche in generalist species.