Genomic and Seasonal Variations among Aquatic Phages Infecting the Baltic Sea Gammaproteobacterium Rheinheimera sp. Strain BAL341.

Knowledge in aquatic virology has been greatly improved by culture-independent methods, yet there is still a critical need for isolating novel phages to identify the large proportion of "unknowns" that dominate metagenomes and for detailed analyses of phage-host interactions. Here, 54 phages infecting Rheinheimera sp. strain BAL341 (Gammaproteobacteria) were isolated from Baltic Sea seawater and characterized through genome content analysis and comparative genomics. The phages showed a myovirus-like morphology and belonged to a novel genus, for which we propose the name Barbavirus All phages had similar genome sizes and numbers of genes (80 to 84 kb; 134 to 145 genes), and based on average nucleotide identity and genome BLAST distance phylogeny, the phages were divided into five species. The phages possessed several genes involved in metabolic processes and host signaling, such as genes encoding ribonucleotide reductase and thymidylate synthase, phoH, and mazG One species had additional metabolic genes involved in pyridine nucleotide salvage, possibly providing a fitness advantage by further increasing the phages' replication efficiency. Recruitment of viral metagenomic reads (25 Baltic Sea viral metagenomes from 2012 to 2015) to the phage genomes showed pronounced seasonal variations, with increased relative abundances of barba phages in August and September synchronized with peaks in host abundances, as shown by 16S rRNA gene amplicon sequencing. Overall, this study provides detailed information regarding genetic diversity, phage-host interactions, and temporal dynamics of an ecologically important aquatic phage-host system.IMPORTANCE Phages are important in aquatic ecosystems as they influence their microbial hosts through lysis, gene transfer, transcriptional regulation, and expression of phage metabolic genes. Still, there is limited knowledge of how phages interact with their hosts, especially at fine scales. Here, a Rheinheimera phage-host system constituting highly similar phages infecting one host strain is presented. This relatively limited diversity has previously been seen only when smaller numbers of phages have been isolated and points toward ecological constraints affecting the Rheinheimera phage diversity. The variation of metabolic genes among the species points toward various fitness advantages, opening up possibilities for future hypothesis testing. Phage-host dynamics monitored over several years point toward recurring "kill-the-winner" oscillations and an ecological niche fulfilled by this system in the Baltic Sea. Identifying and quantifying ecological dynamics of such phage-host model systems in situ allow us to understand and study the influence of phages on aquatic ecosystems.

Gut microbiome and innate immune response patterns in IgE-associated eczema.

BACKGROUND: Gut microbiome patterns have been associated with predisposition to eczema potentially through modulation of innate immune signalling. OBJECTIVE: We examined gut microbiome development in the first year of life in relation to innate immune responses and onset of IgE-associated eczema over the first 2.5 years in predisposed children due to maternal atopy [www.anzctr.org.au, trial ID ACTRN12606000280505]. METHODS: Microbial composition and diversity were analysed with barcoded 16S rRNA 454 pyrosequencing in stool samples in pregnancy and at ages 1 week, 1 month and 12 months in infants (n = 10) who developed IgE-associated eczema and infants who remained free of any allergic symptoms at 2.5 years of age (n = 10). Microbiome data at 1 week and 1 month were analysed in relation to previously assessed immune responses to TLR 2 and 4 ligands at 6 months of age. RESULTS: The relative abundance of Gram-positive Ruminococcaceae was lower at 1 week of age in infants developing IgE-associated eczema, compared with controls (P = 0.0047). At that age, the relative abundance of Ruminococcus was inversely associated with TLR2 induced IL-6 (-0.567, P = 0.042) and TNF-α (-0.597, P = 0.032); there was also an inverse association between the abundance of Proteobacteria (comprising Gram-negative taxa) and TLR4-induced TNF-α (rs = -0.629, P = 0.024). This relationship persisted at 1 month, with inverse associations between the relative abundance of Enterobacteriaceae (within the Proteobacteria phylum) and TLR4-induced TNF-α (rs = -0.697, P = 0.038) and Enterobacteriaceae and IL-6 (rs = -0.709, P = 0.035). Mothers whose infants developed IgE-associated eczema had lower α-diversity of Bacteroidetes (P = 0.04) although this was not seen later in their infants. At 1 year, α-diversity of Actinobacteria was lower in infants with IgE-associated eczema compared with controls (P = 0.002). CONCLUSION AND CLINICAL RELEVANCE: Our findings suggest that reduced relative abundance of potentially immunomodulatory gut bacteria is associated with exaggerated inflammatory cytokine responses to TLR-ligands and subsequent development of IgE-associated eczema.

Faster-than-Bohm cross-B electron transport in strongly pulsed plasmas.

We report the empirical discovery of an exceptionally high cross-B electron transport rate in magnetized plasmas, in which transverse currents are driven with abruptly applied high power. Experiments in three different magnetic geometries are analyzed, covering several orders of magnitude in plasma density, magnetic field strength, and ion mass. It is demonstrated that a suitable normalization parameter is the dimensionless product of the electron (angular) gyrofrequency and the effective electron-ion momentum transfer time, omega(ge)tau(EFF), by which all of diffusion, cross-resistivity, cross-B current conduction, and magnetic field diffusion can be expressed. The experiments show a remarkable consistency and yield close to a factor of 5 greater than the Bohm-equivalent values of diffusion coefficient D(perpendicular), magnetic-diffusion coefficient D(B), Pedersen conductivity sigma(P), and transverse resistivity eta(perpendicular).

Moral hazard in physician prescription behavior.

I examine whether the choice made by physicians concerning what drug version--trade-name or generic--to prescribe is subject to moral hazard. I use a data set containing information on exactly what drug and what version was prescribed at a particular patient visit to the physician. The results indicate that physicians' habits and the tastes acquired by patients are important. However, costs also matter. Patients having to pay large sums out-of-pocket are less likely to have trade-name versions prescribed than patients getting most of their costs reimbursed. This indicates moral hazard.

Microsatellite instability is infrequent in sporadic adult gliomas.

Microsatellite instability (MSI) is a form of genomic instability in tumors that may reflect mechanisms underlying carcinogenesis. Assessment of MSI in various types of sporadic tumors is therefore relevant to an understanding of molecular pathogenesis. In the case of sporadic adult gliomas, destabilization of mononucleotide, dinucleotide, and longer repeat sequences has been reported in high-grade tumors, though published estimates of the frequency of MSI vary widely. In the present work, we quantitated the frequency of length alterations at three microsatellite loci in 26 glioma/normal tissue pairs and at nine additional loci in 16 of the pairs. We analyzed di- and tetranucleotide markers, including five previously reported to be unstable in gliomas. and examined mostly high-grade tumors, both diploid and aneuploid. A large proportion of the tumor and normal brain specimens had no detectable activity of the DNA repair protein O6-methylguanine-DNA methyltransferase, a prevalent phenotypic trait in these tissues that we thought might be associated with MSI. We observed no length alterations in 222 sequence analyses, and estimate the frequency of MSI in our tumor sample as < 0.45% unstable sequences among all sequences examined, or < 3.9% gliomas with unstable sequences. We conclude that microsatellite length alterations are infrequent in our tumor population, and interpret currently available literature to indicate that the frequency of MSI is low in sporadic adult gliomas.

Enhanced intestinal absorption of oxytocin peptide analogues in the absence of pancreatic juice in pigs.

PURPOSE: The present investigation was done to study the intestinal absorption of three oxytocin peptide analogues and to elucidate the role of pancreatic juice on their absorption. METHODS: In conscious chronically catheterized pigs (6-8 weeks of age) plasma concentration of the peptides, [Mpa, D-Tyr(Ethyl), Thr, Orn]-oxytocin (F314), [Mpa, D-Tyr(Ethyl), Val, D-Arg]-oxytocin (CAT), and [Mpa, D-Tyr(Ethyl), Thr, Orn, desGly, carba]-oxytocin (F327) after intraduodenal administration, during presence or diversion of the pancreatic juice via a pancreatic duct catheter, were determined by radioimmunoassay. The stability of the peptides to degradation was determined in vitro by incubation with activated pancreatic juice, chymotrypsin or trypsin, followed by reversed phase HPLC analyses. RESULTS: All peptides were absorbed with a bioavailability of about 0.5% in the presence of pancreatic juice, but increased to 1.0%, 2.1%, and 13.5% for F314, CAT, and F327, respectively, when the pancreatic juice was diverted from the intestine. After incubation with pancreatic juice 95% of F314, 98% of F327, and 100% of CAT was found intact. When incubated with trypsin CAT remained intact while F314 and F327 were degraded by 54% and 46%, respectively. Incubation with purified chymotrypsin did not degrade the test peptides. CONCLUSIONS: The results indicate that the increased absorption of peptides observed under conditions of diverted pancreatic juice cannot only be explained by the absence of pancreatic enzymes, but also by changed absorptive properties in the gastrointestinal tract.

Veratrine-stimulated phosphoinositide breakdown as an assay for local anesthetic actions at Na+ channels.

The blockade of veratrine-stimulated phosphoinositide breakdown in rat cerebral cortical miniprisms as a model of local anesthetic actions on voltage-dependent sodium channels was assessed. Veratrine stimulated phosphoinositide breakdown with an EC50 value of 5 microM. The stimulation produced by 20 microM veratrine was blocked completely by (+)-bupivacaine (IC50 7.6 microM [mean of three separate experimental series]), (-)-bupivacaine (IC50 7.3 microM), lidocaine (IC50 34 microM), etidocaine (IC50 3.4 microM), tetracaine (IC50 approximately 2 microM), and prilocaine (IC50 110 microM). Phosphoinositide breakdown responses to ouabain (100-1000 microM) and K+ (50 mM) were only partially blocked by (+)-bupivacaine, and the responses to monensin (100 and 1000 microM) and noradrenaline (30 microM) were not blocked at all by this drug. Nifedipine produced no significant effects on the phosphoinositide response to 10 microM veratrine. It is concluded that in pulse label experiments using rat cerebral cortical miniprisms, local anesthetics in general, and (+)-bupivacaine in particular, block the phosphoinositide response to veratrine with a high degree of specificity. This system may be useful as a relatively simple and quantitative assay for drug effects on Na(+)-channels.

Detection and speciation of common cell culture mycoplasmas by an enzyme-linked immunosorbent assay with biotin-avidin amplification and microporous membrane solid phase.

An enzyme-linked immunosorbent assay (ELISA) was developed in order to serve in detecting and speciating mycoplasmas isolated from cell cultures. Its main features included a biotin-streptavidin amplification step and a solid phase consisting of a microporous membrane. Cell samples in the form of suspensions were applied to nitrocellulose or ion exchange membranes immobilized in commercially-available microtiter, multiwell manifolds. The blocking buffer contained 1% purified alpha-casein. The primary antibodies were monoclonal and the polyclonal secondary antibody was biotinylated. The enzyme utilized was streptavidin-horseradish peroxidase. The substrate-dye complex consisted of either 4-chloro-1-naphthol and hydrogen peroxide or ortho phenylene diamine (OPD) and hydrogen peroxide. The presence of homologous antiserum in the reaction sequence gave clearly visible, colored reactions on the membrane when 50 ul with approximately 10(5) or more cfu/ml were present. This new biotin-avidin microporous membrane (BAMM-ELISA) test can be used both to detect mycoplasmas and to speciate them. The BAMM-ELISA is simple, rapid, sensitive, specific and economical. As such, it has potential for aiding in the control of mycoplasma contamination in cell culture, and could prove useful in clinical diagnostic applications as well.

Education of independent elderly in the responsible use of prescription medications.

A pilot study to test the effectiveness of medication instruction was carried out using 61 voluntary participants age 65 and older. They were interviewed regarding their medication taking, and instruction was individualized using one of four teaching modes: oral; written; oral and written; and oral and written combined with memory aids. Postinstruction interviews revealed no significant difference in compliance among all groups. The preinstruction mean compliance score of all subjects was 98.8 percent. Although compliance, judged specifically on the basis of the prescription label instructions, was extremely high both before and after instruction, drug-taking behavior and knowledge did change. The preinstruction compliance score does not necessarily reflect safe or desirable drug-taking behavior. There was no specific information given to clients with their prescriptions and prescription medications, indicating, for drug-therapy decision makers, a much broader problem than non-compliance.

Medication taking behavior of the elderly: a pilot study.

The results of structured interviews of fifty persons aged 65 years and older who were living independently in the community indicated that hazardous as well as wasteful practices were occurring in their medication taking behavior. Sixty-six percent of the medications used by this population were being taken without adequate instructions and twenty-five percent of the medications were not being taken as labeled. There is a need for a greatly improved coordination, improved education, and advocacy involving patients, nurses, pharmacists and physicians in medication use.