Genome Stability of Lyme Disease Spirochetes: Comparative Genomics of Borrelia burgdorferi Plasmids

Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33–40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi ∼900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short ≤20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant

Reattachment of the greater trochanter in total hip arthroplasty: the pin-sleeve system compared with the Dall-Miles cable grip system

The purpose of this study was to compare two different types of fixation systems used to reattach the greater trochanter after revision or total hip arthroplasty. This is a retrospective review of the results of patients that were treated with the two systems. We reviewed the clinical and radiological records of 35 hips with the Dall-Miles cable grip system (DMCGS) and 42 hips with the pin-sleeve system (PSS); follow-up averaged 24 months (range, 4–54) and 30 months (range, 11–42), respectively. The incidences of unsatisfactory clinical and radiological results in the PSS group was less than half that in the DMCGS group. Significant differences were found between the groups with respect to discomfort, tenderness, pain on motion, cable fragmentation, and bone absorption. Compared with the DMCGS, these results suggest the PSS could be the instrument of choice for re-attachment of the greater trochanter in hip arthroplasty

Síndrome do túnel do carpo: estudo retrospectivo de 106 casos e complicações

Fazemos breve revisão das bases anatômicas e fisiopatológicas da síndrome do túnel do carpo, seu tratamento cirúrgico e suas complicações. Relatamos os casos de duas pacientes que desenvolveram alterações simpáticas como edema da mão e problemas vasculares (fenômeno de Raynaud) para as quais ensaiamos uma explicação, por nós denominada «denervação simpática». Essa complicação, única em nossa série, ocorreu no período pós-operatório imediato, coincidindo com a retirada da imobilização do punho no 22« dia pós-operatório

miRNA contents of cerebrospinal fluid extracellular vesicles in glioblastoma patients

INTRODUCTION: Analysis of extracellular vesicles (EVs) derived from plasma or cerebrospinal fluid (CSF) has emerged as a promising biomarker platform for therapeutic monitoring in glioblastoma patients. However, the contents of the various subpopulations of EVs in these clinical specimens remain poorly defined. Here we characterize the relative abundance of miRNA species in EVs derived from the serum and cerebrospinal fluid of glioblastoma patients. METHODS: EVs were isolated from glioblastoma cell lines as well as the plasma and CSF of glioblastoma patients. The microvesicle subpopulation was isolated by pelleting at 10,000×g for 30 min after cellular debris was cleared by a 2,000×g (20 min) spin. The exosome subpopulation was isolated by pelleting the microvesicle supernatant at 120,000×g (120 min). qRT-PCR was performed to examine the distribution of miR-21, miR-103, miR-24, and miR-125. Global miRNA profiling was performed in select glioblastoma CSF samples. RESULTS: In plasma and cell line derived EVs, the relative abundance of miRNAs in exosome and microvesicles were highly variable. In some specimens, the majority of the miRNA species were found in exosomes while in other, they were found in microvesicles. In contrast, CSF exosomes were enriched for miRNAs relative to CSF microvesicles. In CSF, there is an average of one molecule of miRNA per 150-25,000 EVs. CONCLUSION: Most EVs derived from clinical biofluids are devoid of miRNA content. The relative distribution of miRNA species in plasma exosomes or microvesicles is unpredictable. In contrast, CSF exosomes are the major EV compartment that harbor miRNAs