Publications by authors named "Sawyer S"

The improving survival rates of young people with cystic fibrosis now results in reproductive health being of greater significance than previously. This article reviews how cystic fibrosis affects the reproductive health of male and female patients with this chronic illness, highlights recent advances, and identifies some deficiencies that still exist in our understanding of reproductive health in cystic fibrosis. A further aim is to encourage health professionals to discuss reproductive health issues with their adolescent and adult patients.

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Purpose: The improved life-expectancy in cystic fibrosis (CF) results in the fact that the majority of affected young women now survive to face the same reproductive health decisions as other women, in addition to those that specifically relate to CF. The aim of this study was to assess the reproductive health knowledge of women with CF, to investigate the range of their reproductive health problems, and to review their reproductive health attitudes and behaviors.

Methods: Women aged 18 years and over attending CF services in the state of Victoria, Australia were invited to complete a reproductive health questionnaire.

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To understand the mechanisms governing molecular evolution of the streptokinase gene (skn), a 384 bp DNA fragment encoding two variable regions of the molecule was characterized in 47 isolates of Streptococcus pyogenes. The results reveal that alleles of the streptokinase gene have a mosaic structure, and provide strong evidence for intragenic recombination. Moreover, organisms that are well differentiated in overall chromosomal character have identical skn alleles, which suggests that horizontal gene transfer and recombination have participated in the evolution of this locus.

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Purpose: The changing expectations, therapies and outcomes for young people with cystic fibrosis (CF) necessitate a re-evaluation of the impact of this chronic illness on adolescent development. The aim of this study was to assess the psychological well-being and adjustment of contemporary adolescents with CF.

Methods: Forty-nine adolescents with CF (24 males, 25 females) aged 14-18 years were enrolled from the Royal Children's Hospital CF Clinic, Melbourne, Australia.

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Animal studies addressing the question does erythropoietin (EPO) cross the placenta are reviewed in a historical context. The majority of early studies using impure EPO preparations and assays of EPO's biologic activity concluded that EPO did not cross the placenta in biologically meaningful quantities. With the availability of pure recombinant EPO, direct measurement of EPO passage using radiolabeled tracers confirmed these findings in near term sheep and monkeys, but not in mice and rats.

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The morphology and synaptic organization of neurons in the ventroanterior-ventrolateral nucleus of rats was examined using in vivo intracellular staining techniques. Neurons were characterized electrophysiologically based on intrinsic membrane properties and synaptic responses to stimulation of motor cortex and cerebellar nuclei, as described in the companion paper. Cerebellar-responsive neurons were stained intracellularly with either horseradish peroxidase or biocytin.

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In vivo intracellular recordings were obtained from identified thalamocortical neurons in the ventroanterior-ventrolateral complex in urethane-anesthetized rats. This thalamic nucleus has few interneurons. Neurons that responded to cerebellar stimulation were injected intracellularly with horseradish peroxidase or biocytin and examined with light and electron microscopy (see companion paper).

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Background And Purpose: This research was performed to determine whether a selective inhibitor of the calcium-dependent protease, calpain, could reduce ischemia-associated brain damage when peripherally administered after a vascular occlusion.

Methods: A variation of the rat middle cerebral artery occlusion model was used. A range of doses of AK295 (a novel calpain inhibitor synthesized for this purpose) was continuously infused through the internal carotid artery, beginning 1.

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Erythropoietin cell biology.

Hematol Oncol Clin North Am

October 1994

Erythropoietin (EPO) mediates its biologic actions in responsive cells through the 78 kDa cell surface form of the EPO receptor. The biosynthesis, activations, and destruction of EPO receptors are described. The binding of EPO to its receptor leads to the activation of a tyrosine protein kinase(s) that results in the phosphorylation of the receptor and other proteins.

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Thirty children (2 to 17 years of age) with refractory partial seizures received open-label felbamate as an add-on medication to their background antiepileptic drugs. The dose was increased up to a maximum of 45 mg/kg. Compared with baseline seizure activity, there was a 53% decrease in seizure frequency during felbamate therapy; 50% of the patients had more than a 50% decrease in seizure frequency.

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The patterns of nonrandom usage of synonymous codons (codon bias) in enteric bacteria were analyzed. Poisson random field (PRF) theory was used to derive the expected distribution of frequencies of nucleotides differing from the ancestral state at aligned sites in a set of DNA sequences. This distribution was applied to synonymous nucleotide polymorphisms and amino acid polymorphisms in the gnd and putP genes of Escherichia coli.

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Background: A number of chest radiographic scores have been developed to assess the severity of respiratory disease in cystic fibrosis but critical statistical evaluation has been limited. In particular, the chest radiograph component of the National Institutes of Health (NIH) clinical score has not previously been validated. Three different chest radiograph scores have been compared and the association between them and lung function tests investigated.

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Experiments were conducted to determine whether a potent, reversible calpain inhibitor could reduce the cortical ischemic brain damage associated with focal ischemia in the rat. AK275 (Z-Leu-Abu-CONH-CH2CH3), the active isomer of the diastereomeric mixture, CX275, was employed in conjunction with a novel method of perfusing drug directly onto the infarcted cortical surface. This protocol reduced or eliminated numerous, nonspecific pharmacokinetic, hemodynamic, and other potentially confounding variables that might complicate interpretation of any drug effect.

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Neurophysiological responses to light in Anthopleura elegantissima do not involve the ectodermal slow system 1 (SS1). Activities in both the endodermal slow system 2 (SS2) and the through conducting nerve net (TCNN) change when the lighting changes, but the response is not consistent. Thus, photoreception in A.

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We present a worldwide analysis of humid tropical forest dynamics and tree species richness. New tree mortality, recruitment, and species richness data include the most dynamic and diverse mature tropical forests known. Twenty-five sites show a strong tendency for the most species-rich forests to be dynamic and aseasonal.

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The goal of this study was to clarify the role of the nucleus accumbens septi (NAS) in the expression of cocaine self-administration behaviors. Rats were trained in a continuous reinforcement schedule to press a lever to activate a pump that provided an intravenous injection of cocaine. Once the rats were trained, neuronal activity in the NAS was monitored during cocaine self-administration with chronic recording techniques using permanently implanted microwires.

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Epiglottitis in childhood is caused by Haemophilus influenzae type b. The usual antibiotic treatment at the Royal Children's Hospital, Parkville, Victoria is a five day course of chloramphenicol. Increasingly, third generation cephalosporins are being used to treat invasive H influenzae type b infections and preliminary data suggest that they can be used successfully for epiglottitis.

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Murine erythroid progenitors infected with the anemia-inducing strain of Friend virus (FVA cells) undergo apoptosis when deprived of erythropoietin (EPO). When cultured with EPO, they survive and complete terminal differentiation. Although cell volume is decreased and nuclear chromatin is condensed during both apoptosis and terminal differentiation, morphologic and biochemical distinctions between these two processes were observed.

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An abundant 70- to 78-kDa form of the erythropoietin receptor (EPOR) was observed in HC-D57 murine erythroleukemia cells deprived of erythropoietin (EPO). In contrast to the 64- and 66-kDa EPOR proteins, these high molecular mass forms of EPOR (hmm-EPOR) correlated well with the number of binding sites and endocytosis of EPO. The hypothesis that hmm-EPOR are more highly glycosylated forms of the EPOR, appear on the cell surface, and represent at least one component of the biologically active EPOR was tested.

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Platelet concentrates (PCs) prepared from units of whole blood are routinely stored singly at 20 to 24 degrees C and pooled prior to transfusion. Studies have been conducted to evaluate the in vitro properties of pools of six (n = 19) and eight (n = 17) ABO-identical PCs after storage, with comparative studies involving single units (n = 33). The pools were prepared using the sterile connecting device.

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Frequencies of mutant sites are modeled as a Poisson random field in two species that share a sufficiently recent common ancestor. The selective effect of the new alleles can be favorable, neutral, or detrimental. The model is applied to the sample configurations of nucleotides in the alcohol dehydrogenase gene (Adh) in Drosophila simulans and Drosophila yakuba.

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