Preservation by Freeze-Drying and the Stability of Virulence of Salmonella typhimurium

Differences in the ability to withstand freeze-drying were demonstrated among strains of Salmonella typhimurium. On the average, the number of viable cells in freeze-dried cultures stored at 5 C for 12 to 18 months was approximately one half as large as that found 24 hr after freeze-drying. The viability in samples stored at higher temperatures declined rapidly and was correlated with the dryness of the sample. The virulence for mice of three strains of S. typhimurium did not change appreciably when samples were kept for 1 or 2 years as freeze-dried samples stored at 5 C, or as agar cultures stored at 5 C or at room temperature.     

Analysis of Fusarium causing dermal toxicosis in marram grass planters

In the European coastal dunes, marram grass (Ammophila arenaria) is planted in order to control sand erosion. In the years 1986 to 1991, workers on the Wadden islands in the Netherlands planting marram grass showed lesions of skin and mucous membranes, suggesting a toxic reaction. Fusarium culmorum dominated the mycoflora of those marram grass culms that were used for planting. This plant material had been cut and stored for more than one week in the open. The Fusarium toxin deoxynivalenol (DON) was detected in the suspect marram grass culms. Isolated F. culmorum strains were able to produce DON in vitro in liquid culture as well as in experimentally inoculated wheat heads. Pathogenicity tests, toxin test as well as RAPD analysis showed that the F. culmorum strains were not specialized for marram grass but may form part of the West-European F. culmorum population infecting cereals and grasses. Storage on old sand-dunes with plant debris may have led to the high occurrence of F. culmorum and contamination with DON. Marram grass culms should be obtained from young plantings on dunes on the seaward slopes and cut culms should not be stored.     

Production of phosphatidylinositol 5‐phosphate via PIKfyve and MTMR3 regulates cell migration

Although phosphatidylinositol 5‐phosphate (PtdIns5P) is present in many cell types and its biogenesis is increased by diverse stimuli, its precise cellular function remains elusive. Here we show that PtdIns5P levels increase when cells are stimulated to move and we find PtdIns5P to promote cell migration in tissue culture and in a Drosophila in vivo model. First, class III phosphatidylinositol 3‐kinase, which produces PtdIns3P, was shown to be involved in migration of fibroblasts. In a cell migration screen for proteins containing PtdIns3P‐binding motifs, we identified the phosphoinositide 5‐kinase PIKfyve and the phosphoinositide 3‐phosphatase MTMR3, which together constitute a phosphoinositide loop that produces PtdIns5P via PtdIns(3,5)P₂. The ability of PtdIns5P to stimulate cell migration was demonstrated directly with exogenous PtdIns5P and a PtdIns5P‐producing bacterial enzyme. Thus, the identified phosphoinositide loop defines a new role for PtdIns5P in cell migration.     

Recruitment of lysozyme as a major enzyme in the mouse gut: Duplication,divergence, and regulatory evolution

Summary Two major types of lysozymec (M and P) occur in the mouse genus,Mus, and have been purified from an inbred laboratory strain (C58/J) ofM. domesticus. They differ in physical, catalytic, and antigenic properties as well as by amino acid replacements at 6 of 49 positions in the amino-terminal sequence. Comparisons with four other mammalian lysozymesc of known sequence suggest that M and P are related by a gene duplication that took place before the divergence of the rat and mouse lineages. M lysozyme is present in most tissues; achieves its highest concentration in the kidney, lung, and spleen; and corresponds to the lysozyme partially sequenced before from another strain ofM. domesticus. InM. domesticus and several related species, P lysozyme was detected chiefly in the small intestine, where it is probably produced mainly by Paneth cells. A survey of M and P levels in 22 species of muroid rodents (fromMus and six other genera) of known phylogenetic relationships suggests that a mutation that derepressed the P enzyme arose about 4 million years ago in the ancestor of the housemouse group of species. Additional regulatory shifts affecting M and P levels have taken place along lineages leading to other muroid species. Our survey of 187 individuals of wild house mice and their closest allies reveals a correlation between latitude of origin and level of intestinal lysozyme.     

Novel short oligonucleotide conjugates as inhibitors of human telomerase

A series of oligonucleotide conjugates were designed and synthesized as novel inhibitors of human telomerase. These compounds contain a relatively short (6-7-mer) oligonucleotide domain, with an N3'-->P5' phosphoramidate (np) or thio-phosphoramidate (nps) backbone, targeted to the template region of the RNA component of the enzyme and various pendant groups attached to either their 5'- or preferably to the 3'-termini. The most potent compounds in the series inhibited telomerase with low nM IC50 values in biochemical assays whereas the cognate oligonucleotides without the pendant groups were significantly less active having IC50 values 100-1000-fold higher.     

FGFR-ERK signaling is an essential component of tissue separation

Formation of a constriction and tissue separation between parent and young polyp is a hallmark of the Hydra budding process and controlled by fibroblast growth factor receptor (FGFR) signaling. Appearance of a cluster of cells positive for double phosphorylated ERK (dpERK) at the late separation site indicated that the RAS/MEK/ERK pathway might be a downstream target of the Hydra Kringelchen FGFR. In fact, inhibition of ERK phosphorylation by the MEK inhibitor U0126 reversibly delayed bud detachment and prevented formation of the dpERK-positive cell cluster indicating de novo-phosphorylation of ERK at the late bud base. In functional studies, a dominant-negative Kringelchen FGFR prevented bud detachment as well as appearance of the dpERK-positive cell cluster. Ectopic expression of full length Kringelchen, on the other hand, induced a localized rearrangement of the actin cytoskeleton at sites of constriction, localized ERK-phosphorylation and autotomy of the body column. Our data suggest a model in which (i) the Hydra FGFR targets, via an unknown pathway, the actin cytoskeleton to induce a constriction and (ii) FGFR activates MEK/ERK signaling at the late separation site to allow tissue separation.     

Prolactin increases the density of striatal dopamine receptors in normal and hypophysectomized male rats

Administration of prolactin to adult male rats, by s.c. injection, significantly increases the density of the striatal dopamine (DA) receptors, without altering the apparent affinity of the receptors for [³H]spiroperidol. Larger doses of prolactin are required to increase the density of the striatal DA receptors in hypophysectomized rates compared to normal rats. These results suggest that prolactin might be the common mediator of the increase in striatal DA receptor density produced by either estrogen or haloperidol administration. Monitoring and/or altering prolactin levels might be informative in neurologic or psychiatric disorders involving striatal DA neurotransmission.     

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessaryprior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted.     

Biodiversity,biogeography, and connectivity of polychaetes in the world's largest marine minerals exploration frontier

Aim

The abyssal Clarion-Clipperton Zone (CCZ), Pacific Ocean, is an area of commercial importance owing to the growing interest in mining high-grade polymetallic nodules at the seafloor for battery metals. Research into the spatial patterns of faunal diversity, composition, and population connectivity is needed to better understand the ecological impacts of potential resource extraction. Here, a DNA taxonomy approach is used to investigate regional-scale patterns of taxonomic and phylogenetic alpha and beta diversity, and genetic connectivity, of the dominant macrofaunal group (annelids) across a 6 million km² region of the abyssal seafloor.

Location

The abyssal seafloor (3932–5055 m depth) of the Clarion-Clipperton Zone, equatorial Pacific Ocean.

Methods

We used a combination of new and published barcode data to study 1866 polychaete specimens using molecular species delimitation. Both phylogenetic and taxonomic alpha and beta diversity metrics were used to analyse spatial patterns of biodiversity. Connectivity analyses were based on haplotype distributions for a subset of the studied taxa.

Results

DNA taxonomy identified 291–314 polychaete species from the COI and 16S datasets respectively. Taxonomic and phylogenetic beta diversity between sites were relatively high and mostly explained by lineage turnover. Over half of pairwise comparisons were more phylogenetically distinct than expected based on their taxonomic diversity. Connectivity analyses in abundant, broadly distributed taxa suggest an absence of genetic structuring driven by geographical location.

Main Conclusions

Species diversity in abyssal Pacific polychaetes is high relative to other deep-sea regions. Results suggest that environmental filtering, where the environment selects against certain species, may play a significant role in regulating spatial patterns of biodiversity in the CCZ. A core group of widespread species have diverse haplotypes but are well connected over broad distances. Our data suggest that the high environmental and faunal heterogeneity of the CCZ should be considered in future policy decisions.     

Cocaine regulates protein kinase B and glycogen synthase kinase-3 activity in selective regions of rat brain

Protein kinase B (also known as Akt) signaling regulates dopamine-mediated locomotor behaviors. Here the ability of cocaine to regulate Akt and glycogen synthase kinase 3 (GSK3) was studied. Rats were injected with cocaine or saline in a binge-pattern, which consisted of three daily injections of 15 mg/kg cocaine or 1 mL/kg saline spaced 1 h apart for 1, 3, or 14 days. Amygdala, nucleus accumbens, caudate putamen, and hippocampus tissues were dissected 30 min following the last injection and analyzed for phosphorylated and total Akt and GSK3(alpha and beta) protein levels using western blot analysis. Phosphorylation of Akt on the threonine-308 (Thr308) residue was significantly reduced in the nucleus accumbens and increased in the amygdala after 1 day of cocaine treatment; however, these effects were not accompanied by a significant decrease in GSK3 phosphorylation. Phosphorylation of Akt and GSK3 was significantly reduced after 14 days of cocaine administration, an effect that was only observed in the amygdala. Cocaine did not alter Akt or GSK3 phosphorylation in the caudate putamen or hippocampus. The findings in nucleus accumbens may reflect dopaminergic motor-stimulant activity caused by acute cocaine, whereas the effects in amygdala may be associated with changes in emotional state that occur after acute and chronic cocaine exposure.