129 research outputs found
Use of the Spine AdVerse Events Severity (SAVES) System to Categorize and Report Adverse Events in Spine Surgery.
Introduction: Analysis of adverse events (AEs) in spine surgery has historically been retrospective, utilizing hospital administrative data. Our objective was to determine the incidence, severity and effect on hospital length of stay (LOS) for AEs in spine surgery using the Spine AdVerse Events Severity (SAVES V2) system.
Methods: AEs for all surgical spine patients at our institution were prospectively collected for 18 months and correlated with retrospective data from operative reports and H&Ps. Statistical analyses compared patient demographics, diagnoses, and surgical characteristics to hospital length of stay and likelihood of adverse events.
Results: This system captured 75% (765/977) of surgical cases for all indications over the study period. 73% (541/743) of patients experienced at least one AE, with an average of 1.2 AEs per patient (range 0-5). The most common AEs were pain control (31%), urinary retention (9.7%), wound infection (6.3%), and incidental durotomy (5.8%). For patients experiencing at least one AE, 30% had no effect on LOS, 48% increased LOS by 1-2 days, 15% increased LOS by 3-7 days, and 7% had prolonged LOS greater than 8 days. Our system captured 25.4% more adverse events (60.0% vs. 34.6%) than hospital administrative data. Univariate analysis revealed patient age, emergent surgery, diagnostic and surgical categories, and spine region to be predictors of both AEs and LOS. Instrumentation was predictive of increased LOS but not AEs. The type of AE was strongly associated with LOS. Multivariable analysis of AE likelihood demonstrated emergent surgery to be the strongest independent predictor with an adjusted odds ratio of 8.5 versus elective surgery.
Discussion: Spine surgery is associated with a high incidence of adverse events, which often prolong hospital length of stay. Better characterization of adverse events and their predictors could lead to improved management strategies that reduce patient morbidity and mortality
Incidence of AIDS-Defining Opportunistic Infections in a Multicohort Analysis of HIV-infected Persons in the United States and Canada, 2000–2010
Background. There are few recent data on the rates of AIDS-defining opportunistic infections (OIs) among human immunodeficiency virus (HIV)–infected patients in care in the United States and Canada
Molecular phylogeny and timing of diversification in Alpine Rhithrogena (Ephemeroptera: Heptageniidae).
BACKGROUND: Larvae of the Holarctic mayfly genus Rhithrogena Eaton, 1881 (Ephemeroptera, Heptageniidae) are a diverse and abundant member of stream and river communities and are routinely used as bio-indicators of water quality. Rhithrogena is well diversified in the European Alps, with a number of locally endemic species, and several cryptic species have been recently detected. While several informal species groups are morphologically well defined, a lack of reliable characters for species identification considerably hampers their study. Their relationships, origin, timing of speciation and mechanisms promoting their diversification in the Alps are unknown.
RESULTS: Here we present a species-level phylogeny of Rhithrogena in Europe using two mitochondrial and three nuclear gene regions. To improve sampling in a genus with many cryptic species, individuals were selected for analysis according to a recent DNA-based taxonomy rather than traditional nomenclature. A coalescent-based species tree and a reconstruction based on a supermatrix approach supported five of the species groups as monophyletic. A molecular clock, mapped on the most resolved phylogeny and calibrated using published mitochondrial evolution rates for insects, suggested an origin of Alpine Rhithrogena in the Oligocene/Miocene boundary. A diversification analysis that included simulation of missing species indicated a constant speciation rate over time, rather than any pronounced periods of rapid speciation. Ancestral state reconstructions provided evidence for downstream diversification in at least two species groups.
CONCLUSIONS: Our species-level analyses of five gene regions provide clearer definitions of species groups within European Rhithrogena. A constant speciation rate over time suggests that the paleoclimatic fluctuations, including the Pleistocene glaciations, did not significantly influence the tempo of diversification of Alpine species. A downstream diversification trend in the hybrida and alpestris species groups supports a previously proposed headwater origin hypothesis for aquatic insects
Variation in Symbiodinium ITS2 Sequence Assemblages among Coral Colonies
Endosymbiotic dinoflagellates in the genus Symbiodinium are
fundamentally important to the biology of scleractinian corals, as well as to a
variety of other marine organisms. The genus Symbiodinium is
genetically and functionally diverse and the taxonomic nature of the union
between Symbiodinium and corals is implicated as a key trait
determining the environmental tolerance of the symbiosis. Surprisingly, the
question of how Symbiodinium diversity partitions within a
species across spatial scales of meters to kilometers has received little
attention, but is important to understanding the intrinsic biological scope of a
given coral population and adaptations to the local environment. Here we address
this gap by describing the Symbiodinium ITS2 sequence
assemblages recovered from colonies of the reef building coral Montipora
capitata sampled across Kāne'ohe Bay, Hawai'i. A
total of 52 corals were sampled in a nested design of Coral Colony(Site(Region))
reflecting spatial scales of meters to kilometers. A diversity of
Symbiodinium ITS2 sequences was recovered with the majority
of variance partitioning at the level of the Coral Colony. To confirm this
result, the Symbiodinium ITS2 sequence diversity in six
M. capitata colonies were analyzed in much greater depth
with 35 to 55 clones per colony. The ITS2 sequences and quantitative composition
recovered from these colonies varied significantly, indicating that each coral
hosted a different assemblage of Symbiodinium. The diversity of
Symbiodinium ITS2 sequence assemblages retrieved from
individual colonies of M. capitata here highlights the problems
inherent in interpreting multi-copy and intra-genomically variable molecular
markers, and serves as a context for discussing the utility and biological
relevance of assigning species names based on Symbiodinium ITS2
genotyping
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