152 resultados para Primary open-angle glaucoma
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If open reading frames (ORFs) have been transmitted primarily by vertical descent, the distributional profile of orthologues of each ORF should be congruent with the organismal tree or a subtree thereof. Distributional patterns not reconciled parsimoniously with tree-like descent and loss are prima facie evidence of lateral gene transfer. Herein, a rigorous criterion for recognizing ORF distributions is described and implemented; it does not require the inference of phylogenetic trees, nor does it assume any specific tree. Because lineage-specific differences in rates of sequence change can also generate unexpected distributional patterns, rate artefacts, were controlled for by requiring pairwise matches between ORFs to exceed a rigorous inclusion threshold, but absence of a match was assessed against a more-permissive exclusion threshold. Applying this dual-threshold criterion to cross-domain and cross-phylum distributional patterns for ORFs in 23 bacterial genomes, a relative abundance of ORFs was observed that find a match in exactly seven other bacterial phyla; 94-99% of these ORFs also find matches among the Archaea and/or Eukarya. In the larger (and some smaller) bacterial genomes, ORFs that find matches in exactly one other bacterial phylum are also relatively abundant, but fewer of these have non-bacterial homologues; most of their matches within the Bacteria are to the Proteobacteria and/or Firmicutes, which cannot be sister lineages to all bacteria. ORFs that are neither distributed universally among the Bacteria, nor necessarily shared with topologically adjacent lineages, are preferentially enriched in large bacterial genomes.
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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.
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Expression of the beta(3) integrin subunit in melanoma in situ has been found to correlate with tumor thickness, the ability to invade and metastasize, and poor prognosis. Transition from the radial growth phase (RGP) to the vertical growth phase (VGP) is a critical step in melanoma progression and survival and is distinguished by the expression of beta(3), integrin. The molecular pathways that operate in melanoma cells associated with invasion and metastasis were examined by ectopic induction of the beta(3), integrin subunit in RGP SBcl2 and WM1552C melanoma cells, which converts these cells to a VGP phenotype. We used cDNA representational difference analysis subtractive hybridization between beta(3)-Positive and -negative melanoma cells to assess gene expression profile changes accompanying RGP to VGP transition. Fourteen fragments from known genes including osteonectin (also known as SPARC and BM-40) were identified after three rounds of representational difference analysis. Induction of osteonectin was confirmed by Northern and Western blot analysis and immunohistochemistry and correlated in organotypic cultures with the beta(3)-induced progression from RGP to VGP melanoma. Expression of osteonectin was also associated with reduced adhesion to vitronectin, but not to fibronectin. Osteonectin expression was not blocked when melanoma cells were cultured with anti-alpha(v)beta(3) LM609 mAb, mitogen-activated protein kinase, or protein kinase C inhibitors, indicating that other signaling pathway(s) operate through a(v)beta(3) integrin during conversion from RGP to VGP.
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Smart State is a Queensland Government initiative that recognises the central role of knowledge-based economic growth. In this context, the management of intellectual property (IP) within Queensland and Australian government research and development agencies has changed dramatically over recent years. Increasing expectations have been placed on utilising public sector IP to both underpin economic development and augment taxes by generating new revenues. Public sector research and development (R&D) management has come under greater scrutiny to commercialise and/or corporatise their activities. In a study of IP management issues in the Queensland Public Sector we developed a framework to facilitate a holistic audit of IP management in government agencies. In this paper we describe this framework as it pertains to one large public sector Agriculture R&D Agency, the Queensland Department of Primary Industries (QDPI). The four overlapping domains of the framework are: IP Generation; IP Rights; IP Uptake; and Corporate IP Support. The audit within QDPI, conducted in 2000 near the outset of Smart State, highlighted some well developed IP management practices within QDPI's traditional areas of focus of innovation (IP Generation) and IP ownership and licensing (IP Rights). However, further management practice developments are required to improve the domains of IP Uptake and Corporate IP Support.
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Telemedicine promises to revolutionize medical care delivery in rural and remote areas. The ability to accurately evaluate physical impairment via the Internet is important to the possible future provision of Internet-based physiotherapy. This study evaluated the reliability and validity of assessing knee range of motion via the Internet. Two therapists evaluated knee angle on a single subject via two methods of assessment: the Internet and the traditional method (face-to-face). Nine random positions of the knee were chosen with the principal examiner performing 20 face-to-face and two sets of 20 Internet measures in each position (n=540). The secondary therapist performed Internet assessments only. The Internet connection was established at a readily available speed of 17 kbit/s. The Internet-based goniometer was found to be a valid tool for measuring both knee flexion and extension angles. It was shown to possess both high intra and inter-rater reliability. Difference average plots of the scores verified the consistency of measurement between both modes of assessment. The successful evaluation of the physical outcome measure of knee range of motion via the Internet assists the further development of Internet-based physiotherapy applications. (C) 2003 Elsevier Science Ltd. All rights reserved.
Resumo:
The most widely used method for predicting the onset of continuous caving is Laubscher's caving chart. A detailed examination of this method was undertaken which concluded that it had limitations which may impact on results, particularly when dealing with stronger rock masses that are outside current experience. These limitations relate to inadequate guidelines for adjustment factors to rock mass rating (RMR), concerns about the position on the chart of critical case history data, undocumented changes to the method and an inadequate number of data points to be confident of stability boundaries. A review was undertaken on the application and reliability of a numerical method of assessing cavability. The review highlighted a number of issues, which at this stage, make numerical continuum methods problematic for predicting cavability. This is in particular reference to sensitivity to input parameters that are difficult to determine accurately and mesh dependency. An extended version of the Mathews method for open stope design was developed as an alternative method of predicting the onset of continuous caving. A number of caving case histories were collected and analyzed and a caving boundary delineated statistically on the Mathews stability graph. The definition of the caving boundary was aided by the existence of a large and wide-ranging stability database from non-caving mines. A caving rate model was extrapolated from the extended Mathews stability graph but could only be partially validated due to a lack of reliable data.
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Measurement while drilling (MWD) techniques can provide a useful tool to aid drill and blast engineers in open cut mining. By avoiding time consuming tasks such as scan-lines and rock sample collection for laboratory tests, MWD techniques can not only save time but also improve the reliability of the blast design by providing the drill and blast engineer with the information specially tailored for use. While most mines use a standard blast pattern and charge per blasthole, based on a single rock factor for the entire bench or blast region, information derived from the MWD parameters can improve the blast design by providing more accurate rock properties for each individual blasthole. From this, decisions can be made on the most appropriate type and amount of explosive charge to place in a per blasthole or to optimise the inter-hole timing detonation time of different decks and blastholes. Where real-time calculations are feasible, the system could extend the present blast design even be used to determine the placement of subsequent holes towards a more appropriate blasthole pattern design like asymmetrical blasting.
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Primary olfactory axons expressing the same odorant receptor gene sort out and converge to fixed sites in the olfactory bulb. We examined the guidance of axons expressing the P2 odorant receptor when they were challenged with different cellular environments in vivo. In the mutant extratoes mouse, the olfactory bulb is lacking and is replaced by a fibrocellular mass. In these animals, primary olfactory axons form glomerular-like loci despite the absence of normal postsynaptic targets. P2 axons are able to sort out from other axons in this fibrocellular mass and converge to form loci of like axons. The sites of these loci along mediolateral and ventrodorsal axes were highly variable. Similar convergence was observed for larger subpopulations of axons expressing the same cell surface carbohydrates. The sorting out and convergence of like axons also occurred during regeneration following bulbectomy. Olfactory axon behaviour in these models demonstrates that sorting and convergence of axons are independent of the target, which instead provides distinct topographic cues for guidance. (C) 2003 Wiley-Liss, Inc.
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The volume of the primary (PCS) and secondary (SCS) circulatory system in the Atlantic cod Gadus morhua was determined using a modified dye dilution technique. Cod (N=10) were chronically cannulated in the second afferent branchial artery with PE-50 tubing. Evans Blue dye was bound to harvested fish plasma at a concentration of 1 mg dye ml(-1) plasma, and injected at a concentration of 1 mg kg(-1) body mass. Serial sampling from the cannula produced a dye dilution curve, which could be described by a double exponential decay equation. Curve analysis enabled the calculation of the primary circulatory and total distribution volume. The difference between these volumes is assumed to be the volume of the SCS. From the dilution curve, it was also possible to calculate flow rates between and within the systems. The results of these experiments suggest a plasma volume in the PCS of 3.42+/-0.89 ml 100 g(-1) body mass, and in the SCS of 1.68+/-0.35 ml 100 g(-1) body mass (mean +/- S.D.) or approximately 50% that of the PCS. Flow rates to the SCS were calculated as 2.7% of the resting cardiac output. There was an allometric relationship between body mass and blood volumes. Increasing condition factor showed a tendency towards smaller blood volumes of the PCS, expressed as percentage body mass, but this was not evident for the volume of the SCS.
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Recent population studies have demonstrated an association with the red-hair and fair-skin phenotype with variant alleles of the melanocortin-1 receptor (MC1R) which result in amino acid substitutions within the coding region leading to an altered receptor activity. In particular, Arg151Cys, Arg160Trp and Asp294His were the most commonly associated variants seen in the south-east Queensland population with at least one of these alleles found in 93% of those with red hair. In order to study the individual effects of these variants on melanocyte biology and melanocytic pigmentation, we established a series of human melanocyte strains genotyped for the MC1R receptor which included wild-type consensus, variant heterozygotes, compound heterozygotes and homozygotes for Arg151Cys, Arg160Trp, Val60Leu and Val92Met alleles. These strains ranged from darkly pigmented to amelanotic, with all strains of consensus sequence having dark pigmentation. UV sensitivity was found not to be associated with either MC1R genotype or the level of pigmentation with a range of sensitivities seen across all genotypes. Ultrastructural analysis demonstrated that while consensus strains contained stage IV melanosomes in their terminal dendrites, Arg151Cys and Arg160Trp homozygote strains contained only stage II melanosomes. This was despite being able to show expression of tyrosinase and tyrosinase-related protein-1 markers, although at reduced levels and an ability to convert exogenous 3,4-dihydroxyphenyl-alanine (DOPA) to melanin in these strains.
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An 8-year-old female neutered Siamese cat was presented with a recent history of incomplete excision of an apocrine gland adenocarcinoma from the palmar aspect of the right antebrachium, just proximal to the carpal joint. There was no evidence of metastasis. Wide surgical excision of the previous surgery site was performed resulting in a soft tissue defect. Partial reconstruction was achieved using digital pad transposition of the first digit (dewclaw), forming a local axial pattern flap that was transposed into the adjacent defect. The remaining defect was closed by primary apposition. The skin flap healed successfully. Some breakdown of the skin closed by primary apposition necessitated open wound management. The cosmetic and functional result of the first digital pad transposition was considered excellent, rendering it a useful means to reconstruct soft tissue defects in the carpal region.
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Purpose: For treatment of various knee disorders, muscles are trained in open or closed kinetic chain tasks. Coordination between the heads of the quadriceps muscle is important for stability and optimal joint loading for both the tibiofemoral and the patellofemoral joint. The aim of this study was to examine whether the quadriceps femoris muscles are activated differently in open versus closed kinetic chain tasks. Methods: Ten healthy men and women (mean age 28.5 +/- 0.7) extended the knees isometrically in open and closed kinetic chain tasks in a reaction time paradigm using moderate force. Surface electromyography (EMG) recordings were made from four different parts of the quadriceps muscle. The onset and amplitude of EMG and force data were measured. Results: In closed chain knee extension, the onset of EMG activity of the four different muscle portions of the quadriceps was more simultaneous than in the open chain. In open chain, rectus femoris (RF) had the earliest EMG onset while vastus medialis obliquus was activated last (7 +/- 13 ms after RF EMG onset) and with smaller amplitude (40 +/- 30% of maximal voluntary contraction (MVC)) than in closed chain (46 +/- 43% MVC). Conclusions: Exercise in closed kinetic chain promotes more balanced initial quadriceps activation than does exercise in open kinetic chain. This may be of importance in designing training programs aimed toward control of the patellofemoral joint.
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Background Wide testing of the aldosterone: renin ratio among hypertensive individuals has revealed primary aldosteronism to be common, with most patients normokalaemic. Some investigators, however, have reported aldosterone-producing adenoma to be rare among patients so detected. Objective To test the hypothesis that differences among reported studies in the rate of detection of aldosterone-producing adenoma (as opposed to bilateral adrenal hyperplasia) reflect differences in the procedures used for diagnosis of primary aldosteronism, and the methods used to identify aldosterone-producing adenomas. Methods In the newly established Princess Alexandra Hospital Hypertension Unit (PAHHU), we used procedures developed by Greenslopes Hospital Hypertension Unit (which reports that more than 30% of patients with primary aldosteronism have aldosterone-producing adenomas) to diagnose primary aldosteronism and determine the subtype. All patients with an increased aldosterone: renin ratio (measured after correction for hypokalaemia and while the patient was not receiving interfering medications) underwent fludrocortisone suppression testing to confirm or exclude primary aldosteronism; if they were positive, they underwent genetic testing to exclude glucocorticoid-remediable aldosteronism before adrenal venous sampling was used to differentiate lateralizing from bilateral primary aldosteronism. Results This approach allowed PAHHU to diagnose, within 2 years, 54 patients [only seven (13%) hypokalaemic] with primary aldosteronism. All tested negative for glucocorticoid-remediable aldosteronism. Aldosterone production was lateralized to one adrenal in 15 patients (31%; only six hypokalaemic) and was bilateral in 34 (69%; all normokalaemic) of 49 patients who underwent adrenal venous sampling. Among patients with lateralizing adrenal hyperplasia, computed tomography revealed an ipsilateral mass in only six and a contralateral lesion in one. Fourteen patients underwent unilateral adrenalectomy, which cured the hypertension in seven and improved it in the remainder. In patients with bilateral primary aldlosteronism, hypertension responded to spironolactone (112.5-50 mg/ day) or amiloride (2.5-10 mg/day). Conclusion When performed with careful regard to confounding factors, measurement of the aldosterone: renin ratio in all hypertensive individuals, followed by fludrocortisone suppression testing to confirm or exclude primary aldosteronism and adrenal venous sampling to determine the subtype, can result in the detection of significant numbers of patients with specifically treatable or potentially curable hypertension. (C) 2003 Lippincott Williams Wilkins.
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Background: The surgical cure rate for primary hyperparathyroidism is greater than 95%. For those who have recurrent or persistent disease, preoperative localization improves reoperation success rates. Selective parathyroid venous sampling (SPVS) for intact parathyroid hormone is particularly useful when non-invasive localization techniques are negative or inconclusive. Methods: We present all known cases (n = 13) between 1994 and 2002 who had venous sampling for localization at our institution prior to reoperation for recurrent or persistent primary hyperparathyroidism. Comparison was made with non-invasive localization procedures. Results of invasive and non-invasive localization were correlated with surgical findings. Results: Of the nine reoperated cases, eight had positive correlations between SPVS and operative findings and histopathology. SPVS did not reveal the parathyroid hormone source in one case with negative non-invasive localization procedures. Comparisons between SPVS, computerized tomography (CT), and parathyroid scintigraphy (MIBI) as expressed in terms of true positive (TP), false positive (FP) and false negative (FN) were: SPVS - TP 88.8%, FP 0%, FN 11.1%; CT - TP 22.2%, FP 22.2%, FN 55.5%; and MIBI - TP 33.3%, FP 0%, FN 66.6%. At least seven of the nine operated cases have been cured; another remained normocalcaemic 2 weeks after subtotal parathyroidectomy. Conclusion: In our institution SPVS has proven to be a valuable tool in cases with recurrent or persistent primary hyperparathyroidism and negative non-invasive localization procedures.