The existence of a hypnotic state revealed by eye movements

Hypnosis has had a long and controversial history in psychology, psychiatry and neurology, but the basic nature of hypnotic phenomena still remains unclear. Different theoretical approaches disagree as to whether or not hypnosis may involve an altered mental state. So far, a hypnotic state has never been convincingly demonstrated, if the criteria for the state are that it involves some objectively measurable and replicable behavioural or physiological phenomena that cannot be faked or simulated by non-hypnotized control subjects. We present a detailed case study of a highly hypnotizable subject who reliably shows a range of changes in both automatic and volitional eye movements when given a hypnotic induction. These changes correspond well with the phenomenon referred to as the "trance stare" in the hypnosis literature. Our results show that this 'trance stare' is associated with large and objective changes in the optokinetic reflex, the pupillary reflex and programming a saccade to a single target. Control subjects could not imitate these changes voluntarily. For the majority of people, hypnotic induction brings about states resembling normal focused attention or mental imagery. Our data nevertheless highlight that in some cases hypnosis may involve a special state, which qualitatively differs from the normal state of consciousness.     

Maternal antibodies contribute to sex-based difference in hantavirus transmission dynamics

Individuals often differ in their ability to transmit disease and identifying key individuals for transmission is a major issue in epidemiology. Male hosts are often thought to be more important than females for parasite transmission and persistence. However, the role of infectious females, particularly the transient immunity provided to offspring through maternal antibodies (MatAbs), has been neglected in discussions about sex-biased infection transmission. We examined the effect of host sex upon infection dynamics of zoonotic Puumala hantavirus (PUUV) in semi-natural, experimental populations of bank vole (Myodes glareolus). Populations were founded with either females or males that were infected with PUUV, whereas the other sex was immunized against PUUV infection. The likelihood of the next generation being infected was lower when the infected founders were females, underlying the putative importance of adult males in PUUV transmission and persistence in host populations. However, we show that this effect probably results from transient immunity that infected females provide to their offspring, rather than any sex-biased transmission efficiency per se. Our study proposes a potential contrasting nature of female and male hosts in the transmission dynamics of hantaviruses.     

Crystal structures of two aromatic hydroxylases involved in the early tailoring steps of angucycline biosynthesis

Angucyclines are aromatic polyketides produced in Streptomycetes via complex enzymatic biosynthetic pathways. PgaE and CabE from S. sp PGA64 and S. sp. H021 are two related homo-dimeric FAD and NADPH dependent aromatic hydroxylases involved in the early steps of the angucycline core modification. Here we report the three-dimensional structures of these two enzymes determined by X-ray crystallography using multiple anomalous diffraction and molecular replacement, respectively, to resolutions of 1.8 A and 2.7 A. The enzyme subunits are built up of three domains, a FAD binding domain, a domain involved in substrate binding and a C-terminal thioredoxin-like domain of unknown function. The structure analysis identifies PgaE and CabE as members of the para-hydroxybenzoate hydroxylase (pHBH) fold family of aromatic hydroxylases. In contrast to phenol hydroxylase and 3-hydroxybenzoate hydroxylase that utilize the C-terminal domain for dimer formation, this domain is not part of the subunit-subunit interface in PgaE and CabE. Instead, dimer assembly occurs through interactions of their FAD binding domains. FAD is bound non-covalently in the "in"-conformation. The active sites in the two enzymes differ significantly from those of other aromatic hydroxylases. The volumes of the active site are significantly larger, as expected in view of the voluminous tetracyclic angucycline substrates. The structures further suggest that substrate binding and catalysis may involve dynamic rearrangements of the middle domain relative to the other two domains. Site-directed mutagenesis studies of putative catalytic groups in the active site of PgaE argue against enzyme-catalyzed substrate deprotonation as a step in catalysis. This is in contrast to pHBH, where deprotonation/protonation of the substrate has been suggested as an essential part of the enzymatic mechanism.     

Heterologous expression of <Emphasis Type="Italic">Vitreoscilla</Emphasis> haemoglobin in barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis>)

The vhb gene encoding Vitreoscilla haemoglobin (VHb) was transferred to barley with the aim of studying the role of oxygen availability in germination and growth. Previous findings indicate that VHb expression improves the efficiency of energy generation during oxygen-limited growth, and germination is known to be an energy demanding growth stage during which the embryos also suffer from oxygen deficiency. When subjected to oxygen deficiency, the roots of vhb-expressing barley plants showed a smaller increase in alcohol dehydrogenase (ADH) activity than those of the control plants. This indicates that VHb plants experienced less severe oxygen deficiency than the control plants, possibly due to the ability of VHb to substitute ADH for recycling NADH and maintaining glycolysis. In contrast to previous findings, we found that constitutive vhb expression did not improve the germination rate of barley kernels in any of the conditions studied. In some cases, vhb expression even slowed down germination slightly. VHb production also appeared to restrict root formation in young seedlings. The adverse effects of VHb on germination and root growth may be related to its ability to scavenge nitric oxide (NO), an important signal molecule in both seed germination and root formation. Because NO has both cytotoxic and stimulating properties, the effect of vhb expression in plants may depend on the level and role of endogenous NO in the conditions studied. VHb production also affected the levels of endogenous barley haemoglobin, which may explain the relatively moderate effects of VHb in this study.     

Production in <Emphasis Type="Italic">Trichoderma reesei</Emphasis> of three xylanases from <Emphasis Type="Italic">Chaetomium thermophilum</Emphasis>: a recombinant thermoxylanase for biobleaching of kraft pulp

Three endoxylanase genes were cloned from the thermophilic fungus Chaetomium thermophilum CBS 730.95. All genes contained the typical consensus sequence of family 11 glycoside hydrolases. Genomic copies of Ct xyn11A, Ct xyn11B, and Ct xyn11C were expressed in the filamentous fungus T. reesei under the control of the strong T. reesei cel7A (cellobiohydrolase 1, cbh1) promoter. The molecular masses of the Ct Xyn11A, Ct Xyn11B, and Ct Xyn11C proteins on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were 27, 23, and 22 kDa, respectively. Ct Xyn11A was produced almost as efficiently as the homologous xylanase II from a corresponding single-copy transformant strain. Ct Xyn11B production level was approximately half of that of Ct Xyn11A. The amount of Ct Xyn11C was remarkably lower. Ct Xyn11A had the highest temperature optimum and stability of the recombinant xylanases and the highest activity at acid-neutral pH (pH 5–7). It was the most suitable for industrial bleaching of kraft pulp at high temperature.     

Ultrafast excited-state dynamics in the green fluorescent protein variant S65T/H148D. 2. Unusual photophysical properties

In the preceding accompanying paper [Shu, X., et al. (2007) Biochemistry 46, 12005-12013], the 1.5 A resolution crystal structure of green fluorescent protein (GFP) variant S65T/H148D is presented, and the possible consequences of an unusual short hydrogen bond (相似文献   

Copsin,a Novel Peptide-based Fungal Antibiotic Interfering with the Peptidoglycan Synthesis

Fungi and bacteria compete with an arsenal of secreted molecules for their ecological niche. This repertoire represents a rich and inexhaustible source for antibiotics and fungicides. Antimicrobial peptides are an emerging class of fungal defense molecules that are promising candidates for pharmaceutical applications. Based on a co-cultivation system, we studied the interaction of the coprophilous basidiomycete Coprinopsis cinerea with different bacterial species and identified a novel defensin, copsin. The polypeptide was recombinantly produced in Pichia pastoris, and the three-dimensional structure was solved by NMR. The cysteine stabilized α/β-fold with a unique disulfide connectivity, and an N-terminal pyroglutamate rendered copsin extremely stable against high temperatures and protease digestion. Copsin was bactericidal against a diversity of Gram-positive bacteria, including human pathogens such as Enterococcus faecium and Listeria monocytogenes. Characterization of the antibacterial activity revealed that copsin bound specifically to the peptidoglycan precursor lipid II and therefore interfered with the cell wall biosynthesis. In particular, and unlike lantibiotics and other defensins, the third position of the lipid II pentapeptide is essential for effective copsin binding. The unique structural properties of copsin make it a possible scaffold for new antibiotics.     

Targeted expression of a synthetic codon optimized gene, encoding the spruce budworm antifreeze protein, leads to accumulation of antifreeze activity in the apoplasts of transgenic tobacco

A synthetic gene based on the primary sequence of the mature spruce budworm antifreeze protein (sbwAFP) was constructed by primer overlap extension. The amino acid codons were chosen to mimic those of a highly expressed tobacco nuclear gene. A DNA sequence encoding the amino-terminal leader sequence from the tobacco pathogen related protein 1b (PR), which targets the protein to the apoplastic space, was fused in frame to the synthetic sbwAFP gene. This fusion was placed downstream of the cauliflower mosaic virus 35S promoter and upstream of the nopaline synthase terminator in a T-DNA binary vector. Transgenic tobacco lines transcribing PR-sbwAFP were selected by RT-PCR. The apoplastic protein fractions of sbwAFP expressing tobacco lines exhibited enhanced antifreeze activity as demonstrated by the ability to inhibit ice re-crystallization and increased thermal hysteresis.     

Sea buckthorn berry oil inhibits platelet aggregation

A small-scale preliminary cross-over study was conducted to investigate the effects of supercritical CO(2)-extracted sea buckthorn berry oil (SBO) on some risk factors of cardiovascular disease. Special features of the oil are high proportions of palmitic (16:0), oleic (18:1n-9), palmitoleic (16:1n-7), linoleic (18:2n-6), and alpha-linolenic (18:3n-3) acids as well as vitamin E, carotenoids, and sterols. Twelve healthy normolipidemic men were recruited and each volunteer consumed SBO and fractionated coconut oil (control) 5 g per day for a period of 4 weeks in a random order (wash-out 4-8 weeks). Phospholipid fatty acids, plasma lipids, and glucose were unaffected by SBO supplementation. Instead, a clear decrease in the rate of adenosine-5'-diphosphate-induced platelet aggregation and maximum aggregation were found. This suggested the beneficial effects of SBO on blood clotting, but further studies on the dose-response effects are needed to assess the practical use of SBO supplements.     

Multiple mechanisms of chromosome movement in vertebrate cells mediated through the Ndc80 complex and dynein/dynactin

Kinetochores bind microtubules laterally in a transient fashion and stably, by insertion of plus ends. These pathways may exist to carry out distinct tasks during different stages of mitosis and likely depend on distinct molecular mechanisms. On isolated chromosomes, we found microtubule nucleation/binding depended additively on both dynein/dynactin and on the Ndc80/Hec1 complex. Studying chromosome movement in living Xenopus cells within the simplified geometry of monopolar spindles, we quantified the relative contributions of dynein/dynactin and the Ndc80/Hec1 complex. Inhibition of dynein/dynactin alone had minor effects but did suppress transient, rapid, poleward movements. In contrast, inhibition of the Ndc80 complex blocked normal end-on attachments of microtubules to kinetochores resulting in persistent rapid poleward movements that required dynein/dynactin. In normal cells with bipolar spindles, dynein/dynactin activity on its own allowed attachment and rapid movement of chromosomes on prometaphase spindles but failed to support metaphase alignment and chromatid movement in anaphase. Thus, in prometaphase, dynein/dynactin likely mediates early transient, lateral interactions of kinetochores and microtubules. However, mature attachment via the Ndc80 complex is essential for metaphase alignment and anaphase A. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.