41 research outputs found
Recommended from our members
Oral and parenteral immunization for the control of Vibrio anguillarum, the etiological agent of vibriosis in salmonid fish
Efficacious vaccines were developed for the control of Vibrio
anguillarum, the etiological agent of vibriosis in salmonid fish.
These bacterins can be administered either orally or parenterally.
It was determined that both formalin-killed lyophilized whole cells
and wet-packed whole cells of the organism are effective oral immunogens.
Intraperitoneal injection of 0.1 ml containing 2 X 10⁸ formalinkilled
bacterial cells suspended in saline and mixed with Freund
complete adjuvant is capable of providing protection to fish exposed
to natural challenge with V. anguillarum. Oral vaccines prepared
from organisms isolated from salmonids in the Pacific Northwest
offered greater immunity than bacterins made from European strains
when fish receiving them were challenged at Lint Slough, Waldport,
Oregon.
Several parameters under which the oral vaccine can be effectively
used were examined. These investigations revealed that protection
is provided to fish vaccinated for 15 days with a ration containing
0.5 mg of the wet whole cell vaccine per gram. Increasing the
number of days the vaccine was fed to as many as 45 days did not
increase the degree of resistance in immunized fish. Decreased
mortality was also not observed in groups of fish fed a diet containing
higher concentrations of vaccine. These studies demonstrated that
oral immunization of fish can be successfully accomplished at water
temperatures ranging from 4 to 21 C.
Although agglutinating antibody could not be detected in the
serum of orally immunized animals, there is an indication that bactericidal
antibodies are formed. Fish parenterally vaccinated produced
agglutinating as well as bactericidal antibodies
Cave deposits as a sedimentary trap for the Marine Isotope Stage 3 environmental record: The case study of Pod Hradem, Czech Republic
Pod Hradem Cave, located in the Moravian Karst, Czech Republic, offers an excellent opportunity for environmental reconstructions of Marine Isotope Stage 3 (MIS 3) in Central Europe due to its detailed sedimentary record dated 50,000 to 28,000 cal BP. Identifying the natural environments of the Middle to Upper Palaeolithic (MUP) transition is necessary to understand the settlement strategies and related behaviour of both Neanderthals and Anatomically Modern Humans, both of whom may have occupied the region at the same time. A multidisciplinary excavation was carried out between 2011 and 2016. Detailed analyses of the sediments, vertebrate microfauna, pollen and charcoal revealed minor but observable fluctuations in climate, with little change in the surrounding vegetation. The Pod Hradem palaeoenvironmental dataset is complex, but generally reflects a predominantly glacial climate with a range of vegetation types and habitats during the Late Pleistocene, followed by the warmer and more humid Holocene. The MUP transition as recorded in Pod Hradem Cave was a glacial environment interrupted by two relatively warmer periods. Central Europe experienced extreme climate fluctuations during MIS3, as recorded from different sedimentary archives, but it seems that the Pod Hradem Cave environment may have acted as a buffer zone, ameliorating those extremes, and providing a suitable refuge for both bears seeking winter hibernation dens and occasionally visiting humans.Thisproject was funded from the SoMoPro programme. Research leading tothese results has received a financial contribution from the EuropeanCommunity within the Seventh Framework Programme (FP/2007–2013) under Grant Agreement No. 229603. The research was alsoco-financed by the South Moravian Region and the Department ofAnthropology & Department of Geological Sciences (departmentalfunding - Masaryk University) and the internal programme of theInstitute of Geology CAS in Prague No. RVO 67985831
Climate-forced Hg-remobilization associated with fern mutagenesis in the aftermath of the end-Triassic extinction
The long-term effects of the Central Atlantic Magmatic Province, a large igneous province connected to the end-Triassic mass-extinction (201.5 Ma), remain largely elusive. Here, we document the persistence of volcanic-induced mercury (Hg) pollution and its effects on the biosphere for ~1.3 million years after the extinction event. In sediments recovered in Germany (Schandelah-1 core), we record not only high abundances of malformed fern spores at the Triassic-Jurassic boundary, but also during the lower Jurassic Hettangian, indicating repeated vegetation disturbance and stress that was eccentricity-forced. Crucially, these abundances correspond to increases in sedimentary Hg-concentrations. Hg-isotope ratios (δ202Hg, Δ199Hg) suggest a volcanic source of Hg-enrichment at the Triassic-Jurassic boundary but a terrestrial source for the early Jurassic peaks. We conclude that volcanically injected Hg across the extinction was repeatedly remobilized from coastal wetlands and hinterland areas during eccentricity-forced phases of severe hydrological upheaval and erosion, focusing Hg-pollution in the Central European Basin
Towards Targeted MRI: New MRI Contrast Agents for Sialic Acid Detection
The detection of sialic acid in living systems is of importance for the diagnosis of several types of malignancy. We have designed and synthesized two new lanthanide ion ligands (L1 and L2) that are capable of molecular recognition of sialic acid residues. The basic structure of these ligands consists of a DTPA-bisamide (DTPA, diethylenetriamine pentaacetic acid) whose amide moieties each bear both a boronic function for interaction with the diol groups in the side chain of sialic acid, and a functional group that is positively charged at physiologic pH values and is designed to interact with the carboxylate anion of sialic acid. The relaxometric properties of the Gd3+ complexes of these two ligands were evaluated. The relaxivity of the GdL1 complex has a significant second-sphere contribution at pH values above the pKa of its phenylboronic acid moiety. The interaction of the Gd3+ complexes of L1 and L2 with each of several saccharides was investigated by means of a competitive fluorescent assay. The results show that both complexes recognize sialic acid with good selectivity in the presence of other sugars. The adduct formed by GdL2 with sialic acid has the higher conditional formation constant (50.43±4.61 M-1 at pH 7.4). The ability of such complexes to recognize sialic acid was confirmed by the results of a study on the interaction of corresponding radiolabeled complexes (153SmL1 and 153SmL2) with C6 glioma rat cells. 153SmL2 in particular is retained on the cell surface in significant amounts