10 research outputs found
Molecular phylogeny of the Notostraca
We used a combined analysis of one nuclear (28S rDNA) and three mitochondrial markers (COI, 12S
rDNA, 16S rDNA) to infer the molecular phylogeny of the Notostraca, represented by samples from the
six continents that are inhabited by this group of branchiopod crustaceans. Our results confirm the
monophyly of both extant notostracan genera Triops and Lepidurus with good support in model based
and maximum parsimony analyses. We used branchiopod fossils as a calibration to infer divergence
times among notostracan lineages and accounted for rate heterogeneity among lineages by applying
relaxed-clock models. Our divergence date estimates indicate an initial diversification into the genera Triops
and Lepidurus in the Mesozoic, most likely at a minimum age of 152.3–233.5 Ma, i.e., in the Triassic or
Jurassic. Implications for the interpretation of fossils and the evolution of notostracan morphology are
discussed. We further use the divergence date estimates to formulate a biogeographic hypothesis that
explains distributions of extant lineages predominantly by overland dispersal routes. We identified an
additional hitherto unrecognised highly diverged lineage within Lepidurus apus lubbocki and three additional
previously unknown major lineages within Triops. Within T. granarius we found deep differentiation,
with representatives distributed among three major phylogenetic lineages. One of these major
lineages comprises T. cancriformis, the T. mauritanicus species group and two hitherto unrecognised T. granarius
lineages. Samples that were morphologically identified as T. granarius diverged from the most
basal nodes within this major lineage, and divergence dates suggested an approximate age of 23.7–
49.6 Ma for T. cancriformis, indicating the need for a taxonomic revision of Triassic and Permian fossils
that are currently attributed to the extant T. cancriformis.We thus elevate T. cancriformis minor to full species
status as Triops minor Trusheim, 1938 and include in this species the additional Upper Triassic samples
that were attributed to T. cancriformis. We further elevate T. cancriformis permiensis to full species
status as Triops permiensis Gand et al., 1997
Auramine dyes induce toxic effects to aquatic organisms from different trophic levels: an application of predicted non-effect concentration (PNEC)
Novel drug delivery systems for glaucoma
Reduction of intraocular pressure (IOP) by pharmaceutical or surgical means has long been the standard treatment for glaucoma. A number of excellent drugs are available that are effective in reducing IOP. These drugs are typically applied as eye drops. However, patient adherence can be poor, thus reducing the clinical efficacy of the drugs. Several novel delivery systems designed to address the issue of adherence and to ensure consistent reduction of IOP are currently under development. These delivery systems include contact lenses-releasing glaucoma medications, injectables such as biodegradable micro- and nanoparticles, and surgically implanted systems. These new technologies are aimed at increasing clinical efficacy by offering multiple delivery options and are capable of managing IOP for several months. There is also a desire to have complementary neuroprotective approaches for those who continue to show progression, despite IOP reduction. Many potential neuroprotective agents are not suitable for traditional oral or drop formulations. Their potential is dependent on developing suitable delivery systems that can provide the drugs in a sustained, local manner to the retina and optic nerve. Drug delivery systems have the potential to improve patient adherence, reduce side effects, increase efficacy, and ultimately, preserve sight for glaucoma patients. In this review, we discuss benefits and limitations of the current systems of delivery and application, as well as those on the horizon