Processing of an ambiguous time phrase in posttraumatic stress disorder: Eye movements suggest a passive, oncoming perception of the future.

Metaphorically, the future can be perceived as approaching us (time-moving metaphor) or as being approached by us (ego-moving metaphor). Also, in line with findings that our eyes look more up when thinking about the future than the past, the future's location can be conceptualized in upwards terms. Eye movements were recorded in 19 participants with PTSD and 20 healthy controls. Participants with PTSD showed downward and healthy controls upward eye movements while processing an ego/time-moving ambiguous phrase, suggesting a passive (time-moving) outlook toward the future. If replicated, our findings may have implications for the conceptualization and treatment of PTSD.

Performance evaluation of the Verigene® (Nanosphere) and FilmArray® (BioFire®) molecular assays for identification of causative organisms in bacterial bloodstream infections.

Molecular assays designed to provide bacterial identification and detection of resistance genes directly from positive blood cultures can significantly reduce the time to definitive results. This has the potential to improve patient management and antimicrobial stewardship. However, the extent of such an impact is yet to be fully assessed. We tested two such assays, the Verigene® System Bloodstream Infection Tests (Nanosphere, Inc., Northbrook, IL, USA) (both Gram-positive and Gram-negative cartridges) and the FilmArray® Blood Culture Identification Panel (BioFire® Diagnostics, Inc., Salt Lake City, UT, USA). We compared their accuracy and speed of organism and resistance gene identification to conventional culture-based methods for 173 positive blood cultures. We also retrospectively determined, for organisms deemed not to be contaminants, the potential impact on antimicrobial prescribing. Both the Verigene® and FilmArray® assays accurately identified organisms, on average, 27.95 and 29.17 h earlier than conventional methods, respectively. There were a significant number of false-positives for Pseudomonas aeruginosa with the FilmArray® assay, which may have been related to contamination of the bioMérieux BacT standard anaerobic blood culture bottles, which the manufacturer has acknowledged. Both panels provided results significantly faster than conventional methods. In our setting, the extent of the potential positive impact on antimicrobial prescribing was modest (9 out of 173 samples). However, this may be an underestimation, since probable contaminants were not included in this analysis. In conclusion, both panels gave accurate results with significantly improved turnaround times.

[Use of snake venom proteins in medicine]. / Anwendung von Schlangengiftproteinen in der Medizin.

Snakes feed exclusively on freshly killed prey animals which, following their immobilization, have to be swallowed whole. Venomous snakes effect prey immobilization by injection of their venom. Snake venoms are highly concentrated, complex mixtures of individual proteins which, either as enzymes, enzyme effectors or blocking ligands, acting as single agents or in synergistic conjunction with other venom components, modify vital structures of the prey organism to destroy their biological function. Predominantly neurotoxic venoms paralyze respiratory activity by pre- or postsynaptic blockade of neuromuscular transmission. Predominantly haemocytotoxic snake venoms contain components which interact with proteins of the haemostasis, kallikrein or complement system, causing blood volume loss, hypotension or intravascular coagulation which finally lead to circulatory failure. Several isolated snake venom proteins with a known mode of action have found practical application as pharmaceutical agents, diagnostic reagents or preparative tools in the field of haemostaseology, neurobiology and complement research.

[Iodine delivery rate in catheter angiography under pressure conditions in manual injection]. / "Iodine Delivery Rate" bei der Katheterangiographie unter Druckbedingungen der manuellen Injektion.

PURPOSE: The aim of this study was to record the flow-rate and to calculate the "iodine delivery rate" (IDR) of contrast media of various viscosities when the contrast media are injected by hand. METHODS: Five different catheters for coronary angiography were tested with the injection system Medrad Mark V Plus. Injections were performed with pressures of 100, 200 and 400 PSI. The contrast media examined were Imeron 350, Imeron 400, Omnipaque 350 and Ultravist 370. The IDR was calculated on the basis of the measured flow rate and the Iodine content of the contrast medium. RESULTS: As was expected, the IDR was higher as the pressure increased. In addition to the Iodine content the viscosity of the contrast medium is a very important factor for the IDR. At both 100 PSI and 200 PSI the increase of the IDR was higher with Imeron 350 than with Imeron 400. The comparison of contrast media with identical Iodine contents but differing viscosities (Imeron 350, Omnipaque 350) clearly showed that the IDR depended on viscosity. CONCLUSION: The "iodine delivery rate" is a decisive factor in the opacification of arterial vessels. Both Iodine content and viscosity of a contrast medium are important for the IDR. Because of the low pressure at manual injection, contrast media with low viscosities should be used. A further possibility to increase the IDR is warming-up the contrast medium to body temperature.

Assessment of the potential in vivo genotoxicity of three trihalomethanes: chlorodibromomethane, bromodichloromethane and bromoform.

Chlorination of drinking water results in the formation of chlorodibromomethane, bromodichloromethane and bromoform. These trihalomethanes have all shown evidence of genotoxicity in bacterial and mammalian cell systems in vitro and some evidence of carcinogenicity in rodents. Chlorodibromomethane and bromodichloromethane have previously been tested in the mouse micronucleus test and did not induce chromosome damage, but results from two previous micronucleus tests on bromoform are somewhat contradictory. In the present study, bromoform was tested in the mouse bone marrow micronucleus test in order to reassess the response in this system; all three compounds were evaluated using the rat liver unscheduled DNA synthesis test. Trihalomethanes are well absorbed by the oral route which was selected for this study as being that most relevant to humans. Bromoform did not induce micronuclei in mouse bone marrow, and chlorodibromomethane, bromodichloromethane and bromoform did not cause unscheduled DNA synthesis in rat liver. These trihalomethanes have not shown any evidence of genotoxicity in vivo and are most unlikely to have any significant genotoxic activity in mammals. Their mode of action as rodent carcinogens remains unexplained.

Self-direction in home care for older people: a consumer's perspective.

Interest among elder home care consumers in playing a stronger role in planning and supervising their own care was examined. Elder home care consumers were surveyed to determine their willingness to assume more responsibility for their home care such as in the hiring, paying, scheduling, supervising and/or firing of their home care worker. Telephone interviews were conducted of 883 home care clients in the Massachusetts Home Care Program which is administered through 27 local, private, non-profit Home Care Corporations (HCC) and which currently serves 33,000 clients. Respondents reported high levels of satisfaction with their home care services and home care worker. However, a substantial minority of respondents reported a willingness to assume more responsibility for their own home care services. A quarter to a third of the respondents indicated that they could take greater responsibility for supervising a home care worker and needed less assistance from a case manager. Multiple regression analyses revealed that prior experience in directing an in-home worker, greater length of receipt of home care services, greater current involvement in directing a home care worker, and lower levels of satisfaction with home care services were associated with a willingness to assume responsibility for directing a home care worker. Pilot projects are needed that develop and test options for older people with disabilities to exercise greater control over their own personal assistance.

Assessment of the potential in vivo genotoxicity of fluoranthene.

Fluoranthene is a ubiquitous environmental pollutant. Although fluoranthene is mutagenic in bacterial and mammalian in vitro cell systems following metabolic activation by rat liver fraction, information on in vivo mutagenicity is lacking and studies on tumour initiating activity in mice are equivocal. In the present study, the potential genetic hazard to man was assessed using the mouse bone marrow micronucleus and rat liver unscheduled DNA synthesis test systems. Fluoranthene did not show any evidence of genotoxicity in either of the in vivo assays following acute oral administration at levels of up to 2000 mg/kg b.w.

Regulated expression of neurofibromin in migrating neural crest cells of avian embryos.

Neurofibromatosis type 1 (NF1) is a common human genetic disease involving various neural crest (NC)-derived cell types, in particular, Schwann cells and melanocytes. The gene responsible for NF1 encodes the protein neurofibromin, which contains a domain with amino acid sequence homology to the ras-guanosine triphosphatase activating protein, suggesting that neurofibromin may play a role in intracellular signaling pathways regulating cellular proliferation or differentiation, or both. To determine whether neurofibromin plays a role in NC cell development, we used antibodies raised against human neurofibromin fusion proteins in western blot and immunocytochemical studies of early avian embryos. These antibodies specifically recognized the 235 kD chicken neurofibromin protein, which was expressed in migrating trunk and cranial NC cells of early embryos (E1.5 to E2), as well as in endothelial and smooth muscle cells of blood vessels and in a subpopulation of non-NC-derived cells in the dermamyotome. At slightly later stages (E3 to E5), neurofibromin immunostaining was observed in various NC derivatives, including dorsal root ganglia and peripheral nerves, as well as non-NC-derived cell types, including heart, skeletal muscle, and kidney. At still later stages (E7 to E9), neurofibromin immunoreactivity was found in almost all tissues in vivo. To determine whether the levels of neurofibromin changed during melanocyte and Schwann cell development, tissue culture experiments were performed. Cultured NC cells were found to express neurofibromin at early time points in culture, but the levels of immunoreactivity decreased as the cells underwent pigmentation. Schwann cells, on the other hand, continued to express neurofibromin in culture. These data suggest, therefore, that neurofibromin may play a role in the development of both NC cells and a variety of non-NC-derived tissues.

Phorbol ester-stimulated adherence of neutrophils to endothelial cells is reduced by adenosine A2 receptor agonists.

In this study we investigated the effect of adenosine receptor agonists on the adherence of PMA-stimulated human neutrophils to cultured porcine aortic endothelial cells. Additionally, we studied the influence of adenosine analogues on the second messenger cAMP in neutrophils and cultured endothelial cells. In the presence of 10 ng/ml PMA, there was a rapid and stable increase on adherence of neutrophils to the endothelial layer. The adenosine A2 receptor agonists, 2-(p-(2-carboxylethyl)phenethylamino)-5' N-ethylcarboxamido-adenosine (CGS 21680) (0.01 to 1 microM) and 5' N-ethylcarboxamidoadenosine (NECA) (0.01 to 1 microM) decreased the adherence of PMA-stimulated neutrophils maximally by 43% and 34%, respectively. In contrast the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine (0.01 to 1 microM) showed a 30% increase in PMA-stimulated adherence of neutrophils to endothelial cells. CGS 21680 (0.01 to 1 microM) and NECA (0.01 to 1 microM) were without detectable effect on the formation of cAMP in neutrophils and endothelial cells; however, in the presence of the phosphodiesterase inhibitor Ro 20-1724 (70 microM), CGS 21680 and NECA maximally increased cAMP level 20-fold and 10-fold, respectively, in neutrophils, and 1.8-fold and 2-fold, respectively, in cultured endothelial cells. However, addition of 70 microM Ro 20-1724 to the adherence assay did not potentiate the inhibitory effects of CGS 21680 and NECA on PMA-stimulated neutrophil adherence. On the other hand, 2-chloro-N6-cyclopentyladenosine (0.01 to 1 microM) did not significantly alter cAMP level in neutrophils and endothelial cells in the presence of 4(3-butoxy-4-methoxyphenyl)methyl)-2-imidazolidinone (Ro 20-1724). Our results indicate that adenosine A2 receptor agonists decrease phorbol ester-stimulated adherence of neutrophils to cultured endothelial cells. This effect is possibly independent of adenosine A2 receptor-mediated stimulation of adenylate cyclase in neutrophils and cultured endothelial cells.

Adenosine A1 and A2 receptor agonists alter cardiac functions and prostacyclin release in the isolated guinea-pig heart.

The actions of the adenosine A1 receptor agonist CCPA (2-chloro-N6-cyclopentyladenosine) and the adenosine A2 receptor agonist CGS 21680 (2-[p-(2-carboxyethyl(phenethylamino]-5'-N- ethylcarboxamidoadenosine) on myocardial functions and prostacyclin release were studied in Langendorff-perfused guinea-pig hearts. In spontaneously beating hearts, perfused at constant pressure, CCPA reduced heart rate and left ventricular actively developed pressure with EC50 values of 54.4 +/- 8.7 nM and 81 +/- 6.2 nM, respectively. The adenosine A1 receptor antagonist PACPX (1,3-dipropyl-8-(2-amino-4-chloro)phenylxanthine, 1 microM) antagonized the effects of CCPA on heart rate and left ventricular actively developed pressure and increased the EC50 values 11-fold and 8-fold, respectively. CGS 21680 caused vasodilatation and doubled the coronary flow rate (EC50 of 5.77 +/- 3 nM). The potent but non-selective adenosine receptor antagonist CGS 15943A (9-chloro-2-(2-furanyl)-5,6-dihydro-1,2,4-triazolo(1,5-c)quinazolin++ +-5-imine, 0.1 microM) caused a shift to the right of the concentration-response curve of CGS 21680 for coronary flow rate and increased the EC50 value 52-fold. In electrically paced hearts, perfused at constant flow rate, CCPA (1-100 nM) and CGS 21680 (10-1000 nM) increased the 6-oxo-prostaglandin F1 alpha release (stable non-enzymatic hydrolysis product of prostacyclin) into the cardiac effluent to a maximum of 170 +/- 16% and 184 +/- 6%, respectively. The effects of CCPA and CGS 21680 on cardiac functions indicate a high selectivity of both agonists for adenosine A1 and A2 receptor subtypes of the isolated guinea-pig heart, respectively. The elevation of 6-oxo-prostaglandin F1 alpha in the effluent of guinea-pig hearts by CCPA and CGS 21680 is possibly independent of stimulation of adenosine receptors on the vascular endothelium.

Isolation and characterization of Textarin, a prothrombin activator from eastern brown snake (Pseudonaja textilis) venom.

The venom of P. textilis contains two different enzymes which convert human prothrombin into thrombin. Prothrombin activation by Textarin, a serine proteinase containing a calcium-binding molecule site, with a molecular mass of 50,000 to 53,000 Da and I.P. 5.5, separated from crude venom by either barium citrate adsorption or hydroxyl apatite chromatography, is strongly stimulated by phospholipid and calcium ions. A second activator, found in the supernatant of barium citrate adsorbed venom solution, activates prothrombin in the absence of any co-factor. Human plasma coagulation induced by Textarin, phospholipid and calcium ions is affected by lupus anticoagulants. Textarin may thus be used for the detection of lupus anticoagulants in patient plasma samples.

The Textarin/Ecarin ratio: a confirmatory test for lupus anticoagulants.

Lupus anticoagulants (LA) are immunoglobulins (IgG, IgM, IgA or a mixture) which interfere with in vitro phospholipid (PL) dependent tests of coagulation (e.g. APTT, KCT, dilute Russell Viper Venom Time). LA are heterogeneous; consequently, the laboratory diagnosis is difficult and relies on multiple tests. We have developed a sensitive and relatively specific confirmatory test system based on fractions of two snake venoms. Textarin, a protein fraction of Pseudonaja textilis venom (Australian Eastern brown snake), activates prothrombin in the presence of PL, factor V and calcium ions. Ecarin, a protein fraction of Echis carinatus venom, will activate prothrombin in the absence of any cofactors. The activation of prothrombin by Textarin yields thrombin while Ecarin yields meizothrombin. In the presence of LA, the Textarin time is prolonged and the Ecarin time is unaffected. The test results are reported as a ratio of Textarin/Ecarin times (abnormal greater than 1.3). We have evaluated this test system in the following patient populations: LA positive, therapeutically heparinized, stable oral anticoagulated, liver disease, routine preoperative, anticardiolipin antibody positive LA negative, hemophilia A, various other hereditary factor deficiencies or dysfunctional proteins, and specific inhibitors of factor V and factor VIII. The LA positive patients represented a mixed population of autoimmune disease, drug-induced and post-infectious states. Our findings indicate the sensitivity of the Textarin/Ecarin system in the confirmation of LA. In order to use the test system most effectively, it is recommended to incorporate polybrene with Textarin when evaluating heparinized samples. Factor V deficiency and specific inhibitors of factor V yielded, in some instances, false positive results.

Basic fibroblast growth factor (bFGF) acts intracellularly to cause the transdifferentiation of avian neural crest-derived Schwann cell precursors into melanocytes.

We previously found that cultured neural crest-derived cells from embryonic quail peripheral nerves, which consist mostly of Schwann cell precursors, gave rise to melanocytes following treatment with basic fibroblast growth factor (bFGF) or 12-O-tetradecanoyl phorbol-13-acetate (TPA). Here, we show that antisense deoxyoligonucleotides targeted against two regions of the bFGF mRNA transcript blocked this TPA-induced transdifferentiation of Schwann cell precursors. Neither sense nor scrambled antisense control oligonucleotides had any effect in this regard. TPA increased bFGF protein expression in cell lysates but not in conditioned media from these cultures, and this expression was localized to the nucleus and cytoplasm. Furthermore, bFGF-neutralizing antibodies and inositol-hexakisphosphate (InsP6) both inhibited pigmentation caused by exogenous bFGF, but had no affect on TPA-induced melanogenesis, suggesting that bFGF is not released by these cells. These data indicate that bFGF is necessary for the TPA-induced transdifferentiation of Schwann cell precursors into melanocytes and that bFGF acts via an intracrine mechanism.

Analysis of the sequence and embryonic expression of chicken neurofibromin mRNA.

Neurofibromatosis type 1 (NF1) is a common inherited disorder that primarily affects tissues derived from the neural crest. Recent identification and characterization of the human NF1 gene has revealed that it encodes a protein (now called neurofibromin) that is similar in sequence to the ras-GTPase activator protein (or ras-GAP), suggesting that neurofibromin may be a component of cellular signal transduction pathways regulating cellular proliferation and/or differentiation. To initiate investigations on the role of the NF1 gene product in embryonic development, we have isolated a partial cDNA for chicken neurofibromin. Sequence analysis reveals that the predicted amino acid sequence is highly conserved between chick and human. The chicken cDNA hybridizes to a 12.5-kb transcript on RNA blots, a mol wt similar to that reported for the human and murine mRNAs. Ribonuclease protection assays indicate that NF1 mRNA is expressed in a variety of tissues in the chick embryo; this is confirmed by in situ hybridization analysis. NF1 mRNA expression is detectable as early as embryonic stage 18 in the neural plate. This pattern of expression may suggest a role for neurofibromin during normal development, including that of the nervous system.

Transient expression of GAP-43 in nonneuronal cells of the embryonic chick limb.

Growth-associated protein (GAP)-43 is highly expressed in neuronal growth cones during periods of axonal outgrowth in development and regeneration of the nervous system. Although GAP-43 is generally considered to be neuron-specific, it is also expressed in some glial cells of the peripheral and central nervous systems and in at least two populations of mesodermally-derived cells in the developing chick limb. GAP-43 mRNA is expressed transiently in developing limbs; although this expression is correlated temporally with the ingrowth of neurites and axons to the limbs, it appears to be independent of nerves. Immunoreactivity for GAP-43 colocalizes in some developing limb muscle and GAP-43 mRNA and protein are particularly abundant in the interdigital mesenchyme that undergoes programmed cell death. GAP-43 has been postulated to mediate rapid changes in cell shape in neurons and glial cells and may serve a similar function in myoblasts fusing to form myotubes and in apototic and phagocytic cells of the interdigital mesenchyme.

Gene transfer of lacZ into avian neural tube and neural crest cells by retroviral infection of grafted embryonic tissues.

We describe here a new method for transferring genes into cells of the neural tube and neural crest of early avian embryos in vivo. Using the marker gene lacZ as an example, we infected dissected neural tubes from Hamburger-Hamilton stage 12-13 quail embryos with a replication-defective retrovirus carrying lacZ during a 2 hr period of exposure to the virus in culture. Infected neural tubes were then grafted into uninfected host chicken embryos in ovo and, after continued development for several days, the chimeric embryos were processed for beta-galactosidase histochemistry to identify the progeny of infected cells. We show that virus-infected neural tubes grafted isotopically into the trunk region of host embryos gave rise to cells of both the spinal cord and neural crest. Infected neural crest cells localized within dorsal root ganglia, sympathetic ganglia, peripheral nerves, and within the skin, where they were likely to give rise to melanocytes. These data are consistent with those using other cell marking techniques applied to the neural crest, indicating that retrovirus infection in culture, grafting, and beta-galactosidase expression has a neutral effect on neural crest cell migration and localization. These results indicate the heterospecific grafting of early avian tissues infected with retroviruses carrying foreign genes may be an effective strategy for testing the biological role of various gene products during development.