Publications by authors named "Smyth D"

Genes and mechanisms involved in common complex diseases, such as the autoimmune disorders that affect approximately 5% of the population, remain obscure. Here we identify polymorphisms of the cytotoxic T lymphocyte antigen 4 gene (CTLA4)--which encodes a vital negative regulatory molecule of the immune system--as candidates for primary determinants of risk of the common autoimmune disorders Graves' disease, autoimmune hypothyroidism and type 1 diabetes. In humans, disease susceptibility was mapped to a non-coding 6.

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Surface and secreted proteins of schistosomes orchestrate the basic physiologic requirements of a parasitic existence. These proteins are often exposed to host tissues during penetration, migration, feeding, and immune evasion, and they are obvious targets for control strategies. Signal sequence trap (SST) represents a novel approach that selects for cDNAs encoding secreted and surface proteins with N-terminal signal peptides, so we constructed a randomly primed adult Schistosoma mansoni cDNA library fused to a signalless reporter gene encoding placental alkaline phosphatase.

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One of the goals of perception is to learn to respond to coherence across space, time and modality. Here we present an abstract framework for the local online unsupervised learning of this coherent information using multi-stream neural networks. The processing units distinguish between feedforward inputs projected from the environment and the lateral, contextual inputs projected from the processing units of other streams.

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Visual experience before eye-opening is not usually thought to have any developmental significance. Here we show that naturalistic visual stimuli presented through unopened eyelids robustly activate neurons in the ferret dorsal lateral geniculate nucleus. Further, dark-rearing prior to natural eye-opening has striking effects upon geniculate physiology.

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Mutants of a new gene, TRANSPARENT TESTA GLABRA2 (TTG2), show disruptions to trichome development and to tannin and mucilage production in the seed coat. The gene was tagged by the endogenous transposon Tag1 and shown to encode a WRKY transcription factor. It is the first member of this large, plant-specific family known to control morphogenesis.

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The regulation of renal sodium and water excretion through a hepatorenal reflex activated by the changes in hemodynamics of the portal circulation has been suggested. We hypothesize that the changes in intrahepatic blood flow and flow-related intrahepatic adenosine are involved in the control of renal water and sodium excretion by triggering a hepatorenal reflex. Anesthetized rats were instrumented to monitor the systemic, hepatic, and renal circulation.

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A primary vaccine candidate antigen against schistosomiasis is paramyosin (pmy), a myofibrillar protein found exclusively in invertebrates. Here we report the results of vaccine trials against the Asian schistosome undertaken on inbred and outbred mice and water buffaloes using a bacterially expressed and purified form of Schistosoma japonicum pmy (rec-Sj-97). Vaccination of the mice resulted in high levels of specific anti-pmy IgG antibodies when compared with adjuvant controls and significant reduction in worm burdens and in liver eggs.

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The mechanism for water and sodium retention in liver cirrhosis is related to the disturbance in hepatic portal circulation. We hypothesize that the increases in intraportal adenosine, which occur when the portal blood flow decreases, may trigger the hepatorenal reflex to inhibit renal water and sodium excretion. In anesthetized rats, intravenous vs.

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Background: While treatment of previously untreated pleomorphic adenoma is relatively straightforward, recurrent pleomorphic adenoma presents a management problem with increased risk of injury to the facial nerve and an increased risk of malignant transformation in recurrent disease.

Aims: The objectives of this study were to review the management of recurrent pleomorphic adenoma in our unit to identify factors that might help treatment of future cases.

Methods: We reviewed the management of pleomorphic adenoma at our department over an eight-year period from 1990-1998 and present our experience of recurrent pleomorphic adenoma of the parotid gland and parapharyngeal space.

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Studies involving mutants of the gene SPATULA indicate that it promotes the growth of carpel margins and of pollen tract tissues derived from them. We show that it encodes a new member of the basic-helix-loop-helix family of transcription factors. SPATULA is expressed in marginal and pollen tract tissues throughout their development confirming its role in regulating their growth.

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Schistosomes feed on human blood. They employ proteases to degrade hemoglobin from ingested erythrocytes, using the residues released for amino acid metabolism. However, the identity and the role of the participating protease(s) are unclear and controversial.

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Three pyroglutamylpeptide amides, pGlu-Glu-Pro amide, pGlu-Phe-Pro amide and pGlu-Gln-Pro amide, with similar structures to thyrotropin-releasing hormone (TRH), have been identified previously in the male reproductive system. We report here that rat and human mammary gland contain neutral TRH-immunoreactive peptides which are not retained on cation or anion exchange chromatography and that similar peptides occur in the milk of rat, cow, ewe and sow. The TRH-like peptides in lyophilized milk from the cow were purified by gel exclusion chromatography, mini-column cation exchange chromatography and reversed phase high performance liquid chromatography (HPLC) and the chromatographed peptides were located by TRH radioimmunoassay (RIA).

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The Westaby T-Y tracheobronchial silicone stent can be used for the relief of upper airway obstruction beyond the limit of a standard tracheostomy tube. We report on our experience in the use of the Westaby tube in 10 patients over a five-year period. The general features of the tube, indications for its use, and its method of insertion are described.

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PETAL LOSS is a new class of flower development gene whose mutant phenotype is confined mostly to the second whorl. Two properties are disrupted, organ initiation and organ orientation. Initiation is frequently blocked, especially in later-formed flowers, or variably delayed.

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A 6-year-old, 420-kg quarter horse gelding was presented with a 2-month history of difficulty swallowing and dyspnea. The horse was diagnosed with a right guttural pouch empyema with many large chondroids. Two surgeries were required to completely remove all the chondroids from what proved to be a primary distension of the guttural pouch lateral compartment.

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Aquaporin-2 (AQP-2), the major water channel responsible for water balance, has been shown to be regulated by the binding of vasopressin to V(2) vasopressin receptors in the medullary collecting duct. alpha(2)-Adrenoceptor agonists such as clonidine have been associated with an increase in free water clearance that was secondary to an inhibition of the ability of vasopressin to increase cAMP levels in the collecting ducts. This investigation focused on the possibility that this increase in free water clearance following administration of an alpha(2)-adrenoceptor agonist was associated with a reduction in medullary AQP-2 expression.

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