Hemagglutination properties of Enterococcus

In total, 86 enterococcal strains including representatives of most of the described species were tested for the ability to agglutinate human, sheep, and rabbit erythrocytes. Five strains did not react with any of the erythrocytes tested, and 81 (94.2%) strains agglutinated only rabbit erythrocytes. The hemagglutination titers ranged from 2 to 64. Loss of the hemagglutination activity was observed when rabbit erythrocytes were treated with trypsin or neuraminidase. Trypsin treatment of the bacterial suspensions also caused loss of the agglutination ability. On the other hand, heat treatment of bacterial suspensions increased the efficiency of the interactions, and higher titers were obtained. Assays for inhibition of hemagglutination were performed with -d-fucose, -d-galactose, -d-galactose, d-glucose, N-acetyl-galactosamine, N-acetyl-glucosamine, N-acetylneuraminic acid, N-acetylneuraminic acid-lactose, and fetuin. Only fetuin was able to inhibit the hemagglutination reactions. The results showed that hemagglutination properties are common to the different enterococcal species tested. They also suggest that enterococci possess hemagglutinins of proteic and non-proteic nature that are involved in the attachment to sialic acid-containing receptors on the surface of rabbit erythrocytes.     

Isolation and properties of glyceraldehyde-3-phosphate dehydrogenase from a sturgeon from the Caspian Sea and its interaction with spin-labeled NAD+ derivatives

Glyceraldehyde-3-phosphate dehydrogenase (D-glyceraldehyde-3-phosphate: NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12) was isolated from a sturgeon, Huso huso, from the Caspian Sea. It is closely related to the enzyme from a Pacific sturgeon, Acipenser transmontanus, with respect to amino acid composition, steady-state kinetics and coenzyme binding. The latter, as studied by means of a spin-labeled derivative of NAD+, is negatively cooperative exhibiting a Hill coefficient of 0.84 at 12 degrees C. Two derivatives of NAD+ spin-labeled at N6 or C8 of the adenine ring were found to be active coenzymes with maximum velocities reaching 35 or 45% of the value for NAD+ itself. When more than two equivalents of either spin-labeled NAD+ are bound to the enzyme spin-spin interactions are observed in the ESR spectra. Distances between the nitroxide radicals (8--9 A) calculated from the observed splittings are in excellent agreement with data predicted from the crystal structure of the lobster enzyme when the coenzyme is bound in an anti-conformation of the adenine moiety about the glycosidic bond to all four subunits.     

DNA and protein synthesis in cultured lens epithelial cells. II. Activity of synthetic effectors]

Cultivated bovine lens epithelium cells are highly susceptible to inhibitors of DNA-, RNA- and protein synthesis. The strict correlation between inhibition by puromycin of protein and DNA synthesis suggests that, in the cell system investigated, protein synthesis is essential for DNA synthesis to occur. Studies with actinomycin D have shown that in cultivated lens epithelium cells, part of protein synthesis is accomplished through a relatively long-lived mRNA. In long-term cultivation experiments, no further stabilization of mRNA, which is typical of lens fibre cells, could be demonstrated. There are indications that high doses of actinomycin D produce direct inhibition of DNA synthesis. By means of cytosine arabinoside a linear relationship was established between concentration of the effector and inhibition of DNA synthesis. Protein synthesis remains virtually unaffected even after high doses. The strong inhibition of DNA synthesis with protein synthesis continuing ("unbalanced growth") could not be utilized for the synchronization of lens epithelium cells, because it was only partly reversible after changing the medium and applying deoxycytidine.     

Das Fische-Fangen der Schnee-EuleStrix nyciea (!) L., beschrieben von Audubon

Ohne ZusammenfassungIhre Neigung hierzu ist zwar schon seit Wilson und Nuttall bekannt, daher auch von mir zu ihrer Zeit (im Handbuche d. N.-G. d. V ög. Eur.) be?reits mit angeführt worden; indess wird ja die spätere, hier wiederzugebende genauere Schilderung Audubon's, — Ornith. Biogr. vol.II,(1834,) p. 136–37, — gewiss immer noch willkommen sein. Gloger.     

High-cell-density culture strategies for polyhydroxyalkanoate production: a review

This article gives an overview of high-cell-density cultures for polyhydroxyalkanoate (PHA) production and their modes of operation for increasing productivity. High cell densities are very important in PHA production mainly because this polymer is an intracellular product accumulated in various microorganisms, so a high cellular content is needed for the polymer production. This review describes relevant results from fed-batch, repeated batch, and continuous modes of operation without and with cell recycle for the production of these polymers by microorganisms. Finally, recombinant microorganisms for PHA production, as well future directions for PHA production, are discussed.     

The Mitochondrial Genome of Arctica islandica; Phylogeny and Variation

Arctica islandica is known as the longest-lived non-colonial metazoan species on earth and is therefore increasingly being investigated as a new model in aging research. As the mitochondrial genome is associated with the process of aging in many species and bivalves are known to possess a peculiar mechanism of mitochondrial genome inheritance including doubly uniparental inheritance (DUI), we aimed to assess the genomic variability of the A. islandica mitochondrial DNA (mtDNA). We sequenced the complete mitochondrial genomes of A. islandica specimens from three different sites in the Western Palaearctic (Iceland, North Sea, Baltic Sea). We found the A. islandica mtDNA to fall within the normal size range (18 kb) and exhibit similar coding capacity as other animal mtDNAs. The concatenated protein sequences of all currently known Veneroidea mtDNAs were used to robustly place A. islandica in a phylogenetic framework. Analysis of the observed single nucleotide polymorphism (SNP) patterns on further specimen revealed two prevailing haplotypes. Populations in the Baltic and the North Sea are very homogenous, whereas the Icelandic population, from which exceptionally old individuals have been collected, is the most diverse one. Homogeneity in Baltic and North Sea populations point to either stronger environmental constraints or more recent colonization of the habitat. Our analysis lays the foundation for further studies on A. islandica population structures, age research with this organism, and for phylogenetic studies. Accessions for the mitochondrial genome sequences: KC197241 Iceland; KF363951 Baltic Sea; KF363952 North Sea; KF465708 to KF465758 individual amplified regions from different speciemen     

An Optimized Whole-Body Cortisol Quantification Method for Assessing Stress Levels in Larval Zebrafish

Glucocorticoids serve important regulatory functions for many physiological processes and are critical mediators of the stress response. The stress response is a set of bodily processes aimed at counteracting a state of threatened homeostasis. Proper stress response is critical for the survival of an animal, however prolonged or abnormal stress response can be detrimental and is implicated in a number of human diseases such as depression and metabolic diseases. To dissect the underlying mechanism of this complex and important response, the zebrafish, Danio rerio offer important advantages such as ease of genetic manipulations and high-throughput behavioral analyses. However, there is a paucity of suitable methods to measure stress level in larval zebrafish. Therefore, an efficient low-cost method to monitor stress hormone levels will greatly facilitate stress research in zebrafish larvae. In this study, we optimized sample collection as well as cortisol extraction methods and developed a home-made ELISA protocol for measuring whole-body cortisol level in zebrafish larvae. Further, using our customized protocols, we characterized the response of larval zebrafish to a variety of stressors. This assay, developed for efficient cortisol quantification, will be useful for systematic and large-scale stress analyses in larval zebrafish.     

Epidemiological Trends of Dengue Disease in Brazil (2000–2010): A Systematic Literature Search and Analysis

A literature survey and analysis was conducted to describe the epidemiology of dengue disease in Brazil reported between 2000 and 2010. The protocol was registered on PROSPERO (CRD42011001826: http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42011001826). Between 31 July and 4 August 2011, the published literature was searched for epidemiological studies of dengue disease, using specific search strategies for each electronic database. A total of 714 relevant citations were identified, 51 of which fulfilled the inclusion criteria. The epidemiology of dengue disease in Brazil, in this period, was characterized by increases in the geographical spread and incidence of reported cases. The overall increase in dengue disease was accompanied by a rise in the proportion of severe cases. The epidemiological pattern of dengue disease in Brazil is complex and the changes observed during this review period are likely to have been influenced by multiple factors. Several gaps in epidemiological knowledge regarding dengue disease in Brazil were identified that provide avenues for future research, in particular, studies of regional differences, genotype evolution, and age-stratified seroprevalence.

Systematic Review Registration

PROSPERO registration number: CRD42011001826.