Review of Florida Red Tide and Human Health Effects

This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue-one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people.     

European society of intensive care medicine study of therapeutic hypothermia (32-35°C) for intracranial pressure reduction after traumatic brain injury (the Eurotherm3235Trial)

Background

Severe malaria remains a major cause of global morbidity and mortality. Despite the use of potent anti-parasitic agents, the mortality rate in severe malaria remains high. Adjunctive therapies that target the underlying pathophysiology of severe malaria may further reduce morbidity and mortality. Endothelial activation plays a central role in the pathogenesis of severe malaria, of which angiopoietin-2 (Ang-2) has recently been shown to function as a key regulator. Nitric oxide (NO) is a major inhibitor of Ang-2 release from endothelium and has been shown to decrease endothelial inflammation and reduce the adhesion of parasitized erythrocytes. Low-flow inhaled nitric oxide (iNO) gas is a US FDA-approved treatment for hypoxic respiratory failure in neonates.

Methods/Design

This prospective, parallel arm, randomized, placebo-controlled, blinded clinical trial compares adjunctive continuous inhaled nitric oxide at 80 ppm to placebo (both arms receiving standard anti-malarial therapy), among Ugandan children aged 1-10 years of age with severe malaria. The primary endpoint is the longitudinal change in Ang-2, an objective and quantitative biomarker of malaria severity, which will be analysed using a mixed-effects linear model. Secondary endpoints include mortality, recovery time, parasite clearance and neurocognitive sequelae.

Discussion

Noteworthy aspects of this trial design include its efficient sample size supported by a computer simulation study to evaluate statistical power, meticulous attention to complex ethical issues in a cross-cultural setting, and innovative strategies for safety monitoring and blinding to treatment allocation in a resource-constrained setting in sub-Saharan Africa.

Trial Registration

ClinicalTrials.gov Identifier: NCT01255215     

Scales of horizontal patchiness in chlorophyll a, chemical and physical properties of landfast sea ice in the Gulf of Finland (Baltic Sea)

Horizontal variation of first-year landfast sea ice properties was studied in the Gulf of Finland, the Baltic Sea. Several scales of variation were considered; a number of arrays with core spacings of 0.2, 2 and 20 m were sampled at different stages of the ice season for small-scale patchiness. Spacing between these arrays was from hundreds of meters to kilometers to study mesoscale variability, and once an onshore–offshore 40-km transect was sampled to study regional scale variability. Measured variables included salinity, stable oxygen isotopes (¹⁸O), chlorophyll a (chl-a), nutrients and dissolved organic carbon. On a large scale, a combination of variations in the under-ice water salinity (ice porosity), nutrient supply and the stage of ice development control the build-up of ice algal biomass. At scales of hundreds of meters to kilometers, there was significant variability in several parameters (salinity, chl-a, snow depth and ice thickness). Analyses of the data from the arrays did not show evidence of significant patchiness at scales <20 m for algal biomass. The results imply that the sampling effort in Baltic Sea ice studies should be concentrated on scales of hundreds of meters to kilometers. Using the variations observed in the study area, the estimate for depth-integrated algal biomass in landfast sea ice in the Gulf of Finland (March 2003) is 5.5±4.4 mg chl-a m^–2.     

Privileged structure-based ligands for melanocortin receptors-tetrahydroquinolines, indoles, and aminotetralines

Substitution of the aryl sulfonamide moiety contained in MC4 agonist 1 with bicyclic heterocycles and aminotetralines produced compounds with MC4 activity. The heterocycles represent alternative privileged structures to that contained in 1. Compounds in which the polar group of the privileged structure was displayed in an endocyclic fashion were not as active as the parent agonist 1, while those with an exocyclic polar group afforded activity competitive with 1.     

hVps34 is a nutrient-regulated lipid kinase required for activation of p70 S6 kinase

Mammalian cells respond to nutrient deprivation by inhibiting energy consuming processes, such as proliferation and protein synthesis, and by stimulating catabolic processes, such as autophagy. p70 S6 kinase (S6K1) plays a central role during nutritional regulation of translation. S6K1 is activated by growth factors such as insulin, and by mammalian target of rapamycin (mTOR), which is itself regulated by amino acids. The Class IA phosphatidylinositol (PI) 3-kinase plays a well recognized role in the regulation of S6K1. We now present evidence that the Class III PI 3-kinase, hVps34, also regulates S6K1, and is a critical component of the nutrient sensing apparatus. Overexpression of hVps34 or the associated hVps15 kinase activates S6K1, and insulin stimulation of S6K1 is blocked by microinjection of inhibitory anti-hVps34 antibodies, overexpression of a FYVE domain construct that sequesters the hVps34 product PI3P, or small interfering RNA-mediated knock-down of hVps34. hVps34 is not part of the insulin input to S6K1, as it is not stimulated by insulin, and inhibition of hVps34 has no effect on phosphorylation of Akt or TSC2 in insulin-stimulated cells. However, hVps34 is inhibited by amino acid or glucose starvation, suggesting that it lies on the nutrient-regulated pathway to S6K1. Consistent with this, hVps34 is also inhibited by activation of the AMP-activated kinase, which inhibits mTOR/S6K1 in glucose-starved cells. hVps34 appears to lie upstream of mTOR, as small interfering RNA knock-down of hVps34 inhibits the phosphorylation of another mTOR substrate, eIF4E-binding protein-1 (4EBP1). Our data suggest that hVps34 is a nutrient-regulated lipid kinase that integrates amino acid and glucose inputs to mTOR and S6K1.     

Self-assembled "dock and lock" system for linking payloads to targeting proteins

Random conjugation of therapeutic or diagnostic payloads to targeting proteins generates functionally heterogeneous products. Conjugation of payloads to an adapter that binds to a peptide tag engineered into a targeting protein provides an alternative strategy. To progress into clinical development, an adapter/docking tag system should include humanized components and be stable in circulation. We describe here an adapter/docking tag system based on mutated fragments of human RNase I that spontaneously bind to each other and form a conjugate with a disulfide bond between complimentary cysteine residues. This self-assembled "dock and lock" system utilizes the previously described fusion C-tag, a 1-15 aa fragment of human RNase I with the R4C amino acid substitution, and a newly engineered adapter protein (Ad-C), a 21-127-aa fragment of human RNase I with the V118C substitution. Two vastly different C-tagged recombinant proteins, human vascular endothelial growth factor (VEGF) and a 254-aa long N-terminal fragment of anthrax lethal factor (LFn), retain functional activities after spontaneous conjugation of Ad-C to N-terminal or C-terminal C-tag, respectively. Ad-C modified with pegylated phospolipid and inserted into the lipid membrane of drug-loaded liposomes (Doxil) retained the ability to conjugate C-tagged proteins, yielding targeted liposomes decorated with functionally active proteins. To further optimize the system, we engineered an adapter with an additional cysteine residue at position 88 for site-specific modification, conjugated it to C-tagged VEGF, and labeled with a near-infrared fluorescent dye Cy5.5, yielding a unique functionally active probe for in vivo molecular imaging. We expect that this self-assembled "dock and lock" system will provide new opportunities for using functionally active proteins for biomedical purposes.     

Regulated targeting of protein phosphatase 1 to the outer kinetochore by KNL1 opposes Aurora B kinase

Regulated interactions between kinetochores and spindle microtubules are essential to maintain genomic stability during chromosome segregation. The Aurora B kinase phosphorylates kinetochore substrates to destabilize kinetochore–microtubule interactions and eliminate incorrect attachments. These substrates must be dephosphorylated to stabilize correct attachments, but how opposing kinase and phosphatase activities are coordinated at the kinetochore is unknown. Here, we demonstrate that a conserved motif in the kinetochore protein KNL1 directly interacts with and targets protein phosphatase 1 (PP1) to the outer kinetochore. PP1 recruitment by KNL1 is required to dephosphorylate Aurora B substrates at kinetochores and stabilize microtubule attachments. PP1 levels at kinetochores are regulated and inversely proportional to local Aurora B activity. Indeed, we demonstrate that phosphorylation of KNL1 by Aurora B disrupts the KNL1–PP1 interaction. In total, our results support a positive feedback mechanism by which Aurora B activity at kinetochores not only targets substrates directly, but also prevents localization of the opposing phosphatase.