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Background: It is unknown whether venous thromboembolism prophylaxis (VTEP) should be utilized in hospitalized patients with end-stage liver disease (ESLD), particularly in those admitted with variceal bleeding., Objective: We sought to describe a cohort of patients who received pharmacologic VTEP, specifically identifying the occurrence of rebleeding., Design: Descriptive case series., Setting/patients: All adult patients with ESLD admitted to an urban county teaching hospital over three years with variceal bleeding who received pharmacologic VTEP during hospitalization., Results: A total of 22 patients with ESLD and variceal bleeding received pharmacologic VTEP. Only 1 patient rebled after initiation of VTEP; 2 patients were diagnosed with lower extremity deep venous thrombosis while on VTEP including the 1 patient who rebled., Conclusions: VTEP was associated with an unexpectedly low incidence of recurrent bleeding in patients with ESLD and variceal bleeding. Further study may be warranted., (2010 Society of Hospital Medicine.)

The authors introduce economic evaluation with particular attention to cost-effectiveness analysis. They begin by establishing why health care decisions should be guided by economics. They then explore different types of economic evaluations. To illustrate how to conduct and evaluate a cost-effectiveness analysis, a hypothetical study about the treatment of posttraumatic stress disorder with psychotherapy versus pharmacotherapy is considered. The authors conclude with recommendations for increasing the strength and relevance of economic evaluations.

The phylogenetic relationships between major slime mould groups and the identification of their unicellular relatives has been a subject of controversy for many years. Traditionally, it has been assumed that two slime mould groups, the acrasids and the dictyostelids were related by virtue of their cellular slime mould habit; a view still endorsed by at least one current classification scheme. However, a decade ago, on the basis of detailed ultrastructural resemblances it was proposed that acrasids of the family Acrasidae were not relatives of other slime moulds but instead related to a group of mostly free-living unicellular amoebae, the Schizopyrenida. The class Heterolobosea was created to contain these organisms and has since figured in many discussions of protist evolution. We sought to test the validity of Heterolobosea by characterizing homologs of the highly conserved glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from an acrasid, Acrasis rosea; a dictyostelid, Dictyostelium discoideum; and the schizopyrenid Naegleria andersoni. Phylogenetic analysis of these and other GAPDH sequences, using maximum parsimony, neighbour-joining distance and maximum likelihood methods strongly supports the Heterolobosea hypothesis and discredits the concept of a cellular slime mould grouping. Moreover, all of our analyses place Dictyostelium discoideum as a relatively recently originating lineage, most closely related to the Metazoa, similar to other recently published phylogenies of protein-coding genes. However, GAPDH phylogenies do not show robust branching orders for most of the relationships between major groups. We propose that several of the incongruencies observed between GAPDH and other molecular phylogenies are artifacts resulting from substitutional saturation of this enzyme.

Complete nucleotide sequences have been established for two genes (gap1 and gap2) coding for glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) homologs in the diplomonad Giardia lamblia. In addition, almost complete sequences of the GAPDH open reading frames were obtained from PCR products for two free-living diplomonad species, Trepomonas agillis and Hexamita inflata, and a parasite of Atlantic salmon, an as yet unnamed species with morphological affinities to Spironucleus. Giardia lamblia gap1 and the genes from the three other diplomonad species show high similarity to each other and to other glycolytic GAPDH genes. All amino-acyl residues known to be highly conserved in this enzyme are also conserved in these sequences. Giardia lamblia gap2 gene is more divergent and its putative translation reveals the presence of a cysteine and serine-rich insertion resembling a metal binding finger. This motif has not yet been noted in other GAPDH molecules. All sequences contain an S-loop signature with characteristics close to those of eukaryotes. In phylogenetic reconstructions based on the derived amino acid sequences with neighbor-joining, parsimony and maximum-likelihood methods the four typical GAPDH sequences of diplomonads cluster into a single clade. Within this clade, G. lambia gap1 shares a common ancestor with the rest of the genes. The latter are more closely related to each other, indicating an early separation of the lineage leading to the genus Giardia from the lineage encompassing the morphologically less differentiated genera, Trepomonas, Hexamita and that of the unnamed species. This result is discordant with the orthogonal evolution of diplomonads suggested on the basis of comparative morphology. In neighbor-joining reconstructions G. lamblia gap2 occupies a variable position, due to its great divergence. In parsimony and maximum likelihood analysis however, it shares a most recent common ancestor with the typical G. lamblia gap1 gene, suggesting that it diverged after the separation of the Giardia lineage. The position of the diplomonad clade in broader phylogenetic reconstructions is firmly within the typical cytosolic glycolytic representatives of GAPDH of eukaryotes.

The epidemiologic case control design is described background information on its resurgence in popularity despite historical criticisms by its detractors. Weaknesses charged to the design by Feinstein and others such as its potential for recall bias in the use of retrospective data. Neyman's case selection bias, and the diagnostic suspicion bias are analyzed and shown to affect both the cohort incidence design and the clinical trial design as well as the case control.