A case of cerebral nocardiosis following brief immunosuppression.
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Publications and source records attributed to S Warwick.
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A strain of Listeria monocytogenes recovered from blood and cerebrospinal fluid had no detectable catalase activity, a characteristic used for primary identification. The sporadic occurrence of pathogenic catalase-negative strains highlights the need for a reconsideration of diagnostic criteria and questions the role of catalase in the pathogenesis of listeria infection.
Many central vascular catheters (CVCs) are removed unnecessarily because current diagnostic methods for CVC-associated infection are unreliable. A quantitative PCR assay using primers and probe targeted to bacterial 16S ribosomal DNA was used to measure the levels of bacterial DNA in blood samples drawn through the CVC in a population of patients receiving intravenous nutrition. Bacterial DNA concentrations were raised in 16 of 16 blood samples taken during episodes of probable bacterial CVC-associated infection. Bacterial DNA concentrations were raised in 4 of 29 episodes in which bacterial CVC-associated infection was unlikely. The use of this technique has the potential to substantially reduce the unnecessary removal of CVCs.
The S1 element is a plant short interspersed element (SINE) that was first described and studied in Brassica napus. In this work, we investigated the distribution and the molecular phylogeny of the S1 element within the Cruciferae (= Brassicaceae). S1 elements were found to be widely distributed within the Cruciferae, especially in species of the tribe Brassiceae. The molecular phylogeny of S1 elements in eight Cruciferae species (Brassica oleracea, Brassica rapa, Brassica napus, Brassica nigra, Sinapis, arvensis, Sinapis pubescens, Coincya monensis, and Vella spinosa) was inferred using 14-36 elements per species. Significant neighbor-joining and maximum-parsimony phylogenetic clusters, supported by high bootstrap P values and/or represented in 100% of the most-parsimonious trees, were observed for each species. Most of these clusters probably correspond to recent species-specific bursts of S1 amplification. Since these species diverged recently, S1 amplification in Cruciferae plants is proposed to be a highly dynamic process that could contribute to genome rearrangements and eventually lead to reproductive isolation. S1 sequence analysis also revealed putative gene conversion events that occurred between different S1 elements of a given species. These events suggest that gene conversion is a minor but significant component of the molecular drive governing S1 concerted evolution.
The 16S rRNAs of 15 species of actinomycetes belonging to the genera Actinokineospora and Saccharothrix and the family Pseudonocardiaceae, including Amycolatopsis, Amycolata, Pseudonocardia, Saccharomonospora, and Saccharopolyspora species, were sequenced by using reverse transcriptase. The sequences were analyzed along with the sequences of reference actinomycetes by using distance matrix and parsimony methods. The wall chemotype IV genus Actinokineospora was found to be closely related to species of the genus Saccharothrix which have chemotype III walls. Together, these two genera formed a clade which was closely related to members of the family Pseudonocardiaceae which have chemotype IV walls. However, the phylogenetic branching pattern did not unambiguously resolve whether the members of all three taxa should be placed in a single family. We suggest, therefore, that the genera Actinokineospora and Saccharothrix should remain outside the family Pseudonocardiaceae until additional sequence or phenotypic data are available to decide the issue. The sequences of species belonging to the genera Amycolata and Pseudonocardia were always recovered as a mixed group in phylogenetic trees, and we propose that these organisms should be classified in an emended genus Pseudonocardia. This proposal is strongly supported by previously published lipid, ribosomal protein, and ultrastructure data.
The 16S ribosomal RNA sequences of Legionella pneumophila, L. erythra, L. hackeliae, L. spiritensis, L. longbeachae, L. bozemanii (Fluoribacter bozemanae) and L. micdadei (Tatlockia micdadei) were determined using reverse transcriptase. The sequences were compared with published sequences for Gram-negative bacteria and phylogenetic trees were constructed. The data confirm previous work which showed that the family Legionellaceae forms a monophyletic subgroup within the gamma subdivision of the Proteobacteria. The data show that all of the legionellae studied are highly related (greater than 95%) on the basis of 16S rRNA sequences and do not support the division of the family Legionellaceae into three genera.
Giant cell arteritis is a visually devastating disease that primarily affects the over 55 age group. This granulomatous inflammation affects large and medium-sized arteries anywhere in the body. Systemic manifestations of this disease include: jaw claudication, scalp tenderness, malaise and vertigo. Decreased appetite and/or anorexia may also be seen. Ocular manifestations may include ischemic optic neuropathy with sudden markedly reduced visual acuity. Steroid treatment is used to protect the uninvolved eye. In its classic form the disease is monitored by adjusting the steroid dosage with the erythrocyte sed rate (ESR). Prognosis for visual restoration in the involved eye is poor.
A multicenter randomized clinical trial can offer exciting and challenging opportunities to the clinical coordinators and other health professionals who participate in the conduct of a clinical trial at the clinical units. This article will address an acute intervention trial, the Multicenter Investigation of the Limitation of Infarct Size, and demonstrate some of the important responsibilities of the clinical unit research nurse coordinators in the conduct and operation of this trial.