19 resultados para 8823 RP

em University of Queensland eSpace - Australia


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Paeoniflorin is one of the bioactive ingredients of the roots of Paeonia lactiflora (Paeoniaceae). A comparative study of processed and non-processed commercial samples of dried roots of P. lactiflora indicated a very low level of paeoniflorin in the processed sample and the formation of a new more polar component, sodium paeoniflorin sulphonate, during treatment of the roots with sulphiting agents. Copyright (c) 2006 John Wiley & Sons, Ltd.

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The complex nature of venom from spider species offers a unique natural source of potential pharmacological tools and therapeutic leads. The increased interest in spider venom molecules requires reproducible and precise identification methods. The current taxonomy of the Australian Funnel-web spiders is incomplete, and therefore, accurate identification of these spiders is difficult. Here, we present a study of venom from numerous morphologically similar specimens of the Hadronyche infensa species group collected from a variety of geographic locations in southeast Queensland. Analysis of the crude venoms using online reversed-phase high performance liquid chromatography/electrospray ionisation mass spectrometry (rp-HPLC/ESI-MS) revealed that the venom profiles provide a useful means of specimen identification, from the species level to species variants. Tables defining the descriptor molecules for each group of specimens were constructed and provided a quick reference of the relationship between one specimen and another. The study revealed that the morphologically similar specimens from the southeast Queensland region are a number of different species/species variants. Furthermore, the study supports aspects of the current taxonomy with respect to the H. infensa species group. Analysis of Australian Funnel-web spider venom by rp-HPLC/ESI-MS provides a rapid and accurate method of species/species variant identification. (c) 2006 Elsevier Ltd. All rights reserved.

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This Article does not have an abstract

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Study Design, The study group consisted of 53 patients who underwent 75 operations for spine metastases. Patient and tumor demographic factors, preoperative nutritional status, and perioperative adjunctive therapy were retrospectively reviewed. Objective, To determine the risk factors for wound breakdown and infection in patients undergoing surgery for spinal metastases. Summary of Background Data. Spinal Fusion using spine implants may be associated with an infection rate of 5% or more. Surgery for spine metastases is associated with an infection rate of more than 10%. Factors other than the type of surgery performed may account for the greater infection rate. Methods. Data were obtained by reviewing patient records. Age, sex, and neurologic status of the patient; tumor type and site; and surgical details were noted. Adjunctive treatment with corticosteroids and radiotherapy was recorded, Nutritional status was evaluated by determining serum protein and serum albumin concentrations and by total lymphocyte count. Results. Wound breakdown and Infection occurred in 75 of 75 wounds. No patient or tumor demographic factors other than intraoperative blood loss (P < 0.1) were statistically associated with infection; The correlation between preoperative protein deficiency (P < 0.01) or perioperative corticosteroid administration (P < 0.10) and wound infection was significant. There was no statistical correlation between lymphocyte count or perioperative radiotherapy and wound infection. Conclusions, The results indicate that preoperative protein depletion and perioperative administration of corticosteroids are risk factors for wound infection in patients undergoing surgery for spine metastases, Perioperative correction of nutritional depletion and cessation of steroid therapy may reduce wound complications.

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Investigation of two southern Australian marine sponges, Mycale spp., resulted in isolation of the known norsesterterpene mycaperoxide F methyl ester (5) together with a new norsesterterpene mycaperoxide G methyl ester (10) and a new norterpene ketone 11. All structures were secured by spectroscopic analysis and chemical derivatization. The absolute stereochemistry previously assigned to 5 by application of the Horeau procedure has been revised by application of the Mosher procedure.

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We consider the magnetoresistance oscillation phenomena in the Bechgaard salts (TMTSF)(2)X, where X = ClO4, PF6, and AsF6 in pulsed magnetic fields to 51 T. Of particular importance is the observation of a new magnetoresistance oscillation for X = ClO4 in its quenched state. In the absence of any Fermi-surface reconstruction due to anion order at low temperatures, all three materials exhibit nonmonotonic temperature dependence of the oscillation amplitude in the spin-density-wave (SDW) state. We discuss a model where, below a characteristic temperature T* within the SDW state, a magnetic breakdown gap opens. [S0163-1829(99)00904-2].

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Magneto-transport measurements of the 2D hole system (2DHS) in p-type Si-Si1-xGex heterostructures identify the integer quantum Hall effect (IQHE) at dominantly odd-integer filling factors v and two low-temperature insulating phases (IPs) at v = 1.5 and v less than or similar to 0.5, with re-entrance to the quantum Hall effect at v = 1. The temperature dependence, current-voltage characteristics, and tilted field and illumination responses of the IP at v = 1.5 indicate that the important physics is associated with an energy degeneracy of adjacent Landau levels of opposite spin, which provides a basis for consideration of an intrinsic, many-body origin.

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Although vasoactive intestinal polypeptide (VIP) is thought to be a prolactin releasing factor, in vivo studies on sheep suggest that it is inactive in this species. Recent studies, based primarily on the rat, suggest that the related pituitary adenylate cyclase-activating polypeptide (PACAP) is also a hypophysiotrophic factor but again in sheep, this peptide has no in vivo effects on hormone secretion despite being a potent activator of adenylate cyclase in vitro. This lack of response to either peptide in vivo in sheep could be due to the low concentration of peptide that reaches the pituitary gland following peripheral injection. In the present study we therefore adopted an alternative approach of evaluating in vitro effects of these peptides on GH, FSH, LH or prolactin secretion from dispersed sheep pituitary cells. In a time-course study, PACAP (1 mu mol/l) increased GH concentrations in the culture medium between 1 and 4 h and again at 12 h but had no effect in the 6 and 24 h incubations. Prolactin, LH and FSH were not affected by PACAP. The response to various concentrations of PACAP (1 nmol/l-1 mu mol/l) were then evaluated using a 3 h incubation. Again prolactin and LH were not affected by PACAP and there was a small increase in GH concentrations but only at high concentrations of PACAP (0.1 and 1 mu mol/l; P<0.05), PACAP also stimulated FSH secretion in cells from some animals although this effect was small, The GH response to PACAP was inhibited by PACAP(6-38), a putative PACAP antagonist; but not by (N-Ac-Tyr(1), D-Arg(2))-GHRH(1-29)-NH2, a GH-releasing hormone (GHRH) antagonist. The cAMP antagonist Rp-cAMPS was unable to block the GH response to PACAP suggesting that cAMP does not mediate the secretory response to this peptide. At incubation times from 1-24 h, VIP (1 mu mol/l) had no effects on prolactin, LH or GH secretion and, in a further experiment based on a 3 h incubation, concentrations of VIP from 1 nmol/l-1 mu mol/l were again without effect on prolactin concentrations. Interactions between PACAP and gonadotrophin releasing hormone (GnRH), GHRH and dopamine were also investigated. PACAP (1 nmol/l-1 mu mol/l) did not affect the gonadotrophin or prolactin responses to GnRH or dopamine respectively. However, at a high concentration (1 mu mol/l), PACAP inhibited the GH response to GHRH. In summary, these results show that PACAP causes a modest increase in FSH and GH secretion from sheep pituitary cells but only at concentrations of PACAP that are unlikely to be in the physiological range. The present study confirms that VIP is not a prolactin releasing factor in sheep.

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We describe the genomic organization of a recently identified CC chemokine, MIP3 alpha /CCL20 (HGMW-approved symbol SCYA20). The MIP-3 alpha /CCL20 gene was cloned and sequenced, revealing a four exon, three intron structure, and was localized by FISK analysis to 2q35-q36. Two distinct cDNAs were identified, encoding two forms of MIP-3 alpha /CCL20, Ala MLP-3 alpha /CCL20 and Ser MIP-3 alpha /CCL20, that differ by one amino acid at the predicted signal peptide cleavage site. Examination of the sequence around the boundary of intron 1 and exon 2 showed that use of alternative splice acceptor sites could give rise to Ata MIP-3 alpha /CCL20 or Ser MIP-3 alpha /CCL20. Both forms of MIP-3cr/CCL20 were chemically synthesized and tested for biological activity. Both flu antigen plus IL-a-activated CD4(+) and CD8(+) T lymphoblasts and cord blood-derived dendritic cells responded to Ser and Ala MIP-3 alpha /CCL20. T lymphocytes exposed only to IL-2 responded inconsistently, while no response was detected in naive T lymphocytes, monocytes, or neutrophils. The biological activity of Ser MIP-3 alpha /CCL20 and Ala MIP-3 alpha /CCL20 and the tissue-specific preference of different splice acceptor sites are not yet known. (C) 2001 Academic Press.

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This study describes a series of evaluations of gender pairs of New Zealand English, Australian English, American English and RP-type English English voices by over 400 students in New Zealand, Australia and the U.S.A. Voices were chosen to represent the middle range of each accent, and balanced for paralinguistic features. Twenty-two personality and demographic traits were evaluated by Likert-scale questionnaires. Results indicated that the American female voice was rated most favourably on at least some traits by students of all three nationalities, followed by the American male. For most traits, Australian students generally ranked their own accents in third or fourth place, but New Zealanders put the female NZE voice in the mid-low range of all but solidarity-associated traits. All three groups disliked the NZE male. The RP voices did not receive the higher rankings in power/status variables we expected. The New Zealand evaluations downgrade their own accent vis-a`-vis the American and to some extent the RP voices. Overall, the American accent seems well on the way to equalling or even replacing RP as the prestige—or at least preferred—variety, not only in New Zealand but in Australia and some non-English-speaking nations as well. Preliminary analysis of data from Europe suggests this manifestation of linguistic hegemony as ‘Pax Americana’ seems to be prevalent over more than just the Anglophone nations.

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The nature of the semantic memory deficit in dementia of the Alzheimer's type (DAT) was investigated in a semantic priming task which was designed to assess both automatic and attention-induced priming effects. Ten DAT patients and 10 age-matched control subjects completed a word naming semantic priming task in which both relatedness proportion (RP) and stimulus-onset asynchrony (SOA) were varied. A clear dissociation between automatic and attentional priming effects in both groups was demonstrated; however, the DAT subjects pattern of priming deviated significantly from that of the normal controls. The DAT patients failed to produce any priming under conditions which encouraged automatic semantic processing and produced facilitation only when the RP was high. In addition, the DAT group produced hyperpriming, with significantly larger facilitation effects than the control group. These results suggest an impairment of automatic spreading activation in DAT and have implications for theories of semantic memory impairment in DAT as well as models of normal priming. (C) 2001 Academic Press.

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A glasshouse study was undertaken to determine if the zeolite mineral clinoptilolite from an Australian deposit in combination with rock phosphate (RP) could significantly enhance the uptake of P by sunflowers. The zeolite/RP combination was intended to act as an exchange-fertiliser, with Ca2+ exchanging onto the zeolite in response to plant uptake of nutrient cations (NH4+ or K) enhancing the dissolution of the RP. A reactive RP (Sechura) and a relatively non-reactive RP (Duchess) were examined. Zeolite was used in Ca2+-, K+- and NH4+-saturated forms at ratios of 3.5:1 and 7:1 with RP; Ca2+-zeolite was considered the control, with exchange-induced dissolution possible from K+-and NH4+-zeolite, The zeolite/RP mixture was applied as a vertical band adjacent to the sunflower seedling. In addition, N was supplied as urea in an effort to determine if RP dissolution resulted from H+ release by nitrification. Phosphorus supply from the zeolite/RP system was compared with an available P source (KH2PO4). The experiment clearly demonstrated greatly enhanced plant uptake of P from RP when applied in combination with NH4-zeolite, though the P uptake was lower than that from the soluble P source. The zeolite/RP interaction was much more effective with the reactive R-P than the non-reactive material, Within the NH4+-zeolite/RP band, root proliferation was greatly increased, as would be expected in an exchange-fertiliser system. The K+-zeolite system did not produce a significantly greater yield than the Ca2+-zeolite control, probably because adequate K+ supply from the basal application reduced uptake within the zeolite/RP band, thus reducing the extent of exchange-induced dissolution. Nevertheless, increased root proliferation within the band was observed, implying that exchange-induced dissolution may also be possible from this system. The zeolite/RP system offers the considerable advantage of P release in response to plant demand and is unique in this regard. (C) 2002 Elsevier Science B.V. All rights reserved.

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Objective: To examine whether NKP608, a novel 1-benzoyl-2-benzyl-4-aminopiperidine NK1 receptor antagonist, inhibits substance P (SP)-induced airway plasma protein exudation in vivo. Material: Anaesthetised English shorthair guinea-pigs and Wistar rats. Treatment: Tachykinin peptides were applied topically onto the trachea and antagonists administered intravenously. Methods: Tracheal segments isolated in situ were perfused with saline and plasma-derived protein assayed in the perfusate. Results: SP (1 muM) caused plasma protein exudation, which was abolished by an NK1 antagonist (RP 67580, 1.75 mumol/kg) but unaffected by an NK2 antagonist (SR 48968, 1.75 mumol/kg) indicating the response is NK1-receptor-mediated. This was confirmed with a response to an NK1 agonist ([Sar(9), Met(O-2)(11)]-SP, 1 muM) but none to an NK2 agonist ([betaAla(8)]-neurokinin A(4-10), 1 muM). NKP608 inhibited SP responses with estimated ID50 values (mumol/kg) of 0.0044 (guinea-pigs) and 0.19 (rats). Conclusions: NKP608 is an antagonist in vivo of NK1 receptor-induced tracheal plasma protein exudation and is more potent in guinea-pigs than rats.

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The primary sequence and three-dimensional structure of a novel peptide toxin isolated from the Australian funnel-web spider Hadronyche infensa sp. is reported. ACTX-HI:OB4219 contains 38 amino acids, including eight-cysteine residues that form four disulfide bonds. The connectivities of these disulfide bonds were previously unknown but have been unambiguously determined in this study. Three of these disulfide bonds are arranged in an inhibitor cystine-knot (ICK) motif, which is observed in a range of other disulfide-rich peptide toxins. The motif incorporates an embedded ring in the structure formed by two of the disulfides and their connecting backbone segments penetrated by a third disulfide bond. Using NMR spectroscopy, we determined that despite the isolation of a single native homologous product by RP-HPLC, ACTX-HI:OB4219 possesses two equally populated conformers in solution. These two conformers were determined to arise from cis/trans isomerization of the bond preceding Pro30. Full assignment of the NMR spectra for both conformers allowed for the calculation of their structures, revealing, the presence of a triple-stranded antiparallel sheet consistent with the inhibitor cystine-knot (ICK) motif.