Does ultrasongraphy predict intraoperative findings at cholecystectomy? An institutional review

BackgroundUltrasonography (US) is the mainstay of biliary tract imaging, but few recent studies have tested its ability to diagnose acute cholecystitis (AC). Our objective was to determine how well a US diagnosis of AC correlates with the intraoperative diagnosis. We hypothesize that US underestimates this diagnosis, potentially leading to unexpected findings in the operating room (OR).MethodsThis retrospective review included all patients admitted to the acute care surgical service of a tertiary hospital in 2011 with suspected biliary pathology who underwent US and subsequent cholecystectomy. We determined the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US using the intraoperative diagnosis as the gold standard. Further analysis identified which US findings were most predictive of an intraoperative diagnosis of AC. We used a recursive partitioning method with random forests to identify unique combinations of US findings that, together, are most predictive of AC.ResultsIn total, 254 patients underwent US for biliary symptoms; 152 had AC diagnosed, and 143 (94%) of them underwent emergency surgery (median time to OR 23.03 hr). Ultrasonography predicted intraoperative findings with a sensitivity of 73.2%, specificity of 85.5% and PPV of 93.7%. The NPV (52.0%) was quite low. The US indicators most predictive of AC were a thick wall, a positive sonographic Murphy sign and cholelithiasis. Recursive partitioning demonstrated that a positive sonographic Murphy sign is highly predictive of intraoperative AC.ConclusionUltrasonography is highly sensitive and specific for diagnosing AC. The poor NPV confirms our hypothesis that US can underestimate AC.     

The effects of etomidate in the cat middle cerebral artery occlusion model of brain ischaemia: An experimental study

The effects of etomidate on focal cerebral ischaemia following transorbital occlusion of the cat middle cerebral artery were investigated. Etomidate had no effect on CBF before or after onset of ischaemia by comparison with controls, but caused a greater fall in CBF in cats with high preocclusion or initial ischaemic CBF than in those in which CBF was lower. There were more sustained rises in Kp on SG. The established flow threshold for water accumulation was lost; more gyri with CBF above and fewer gyri with CBF below the flow threshold accumulated water. The relationship between mean occlusion CBF and in vitro GABA uptake was lost; uptakes from MC were lower and from SG and EG higher than expected. In the ischaemic penumbra there was a trend towards reduction in CBF, disruption of ion homeostasis and cerebral oedema formation, whilst in areas of lower flow there was some recovery of GABA uptake and less cerebral oedema following administration of etomidate.     

Using the Gene Ontology to Annotate Key Players in Parkinson’s Disease

The Gene Ontology (GO) is widely recognised as the gold standard bioinformatics resource for summarizing functional knowledge of gene products in a consistent and computable, information-rich language. GO describes cellular and organismal processes across all species, yet until now there has been a considerable gene annotation deficit within the neurological and immunological domains, both of which are relevant to Parkinson’s disease. Here we introduce the Parkinson’s disease GO Annotation Project, funded by Parkinson’s UK and supported by the GO Consortium, which is addressing this deficit by providing GO annotation to Parkinson’s-relevant human gene products, principally through expert literature curation. We discuss the steps taken to prioritise proteins, publications and cellular processes for annotation, examples of how GO annotations capture Parkinson’s-relevant information, and the advantages that a topic-focused annotation approach offers to users. Building on the existing GO resource, this project collates a vast amount of Parkinson’s-relevant literature into a set of high-quality annotations to be utilized by the research community.     

Inflammatory status influences aromatase and steroid receptor expression in endometriosis

Aberrant up-regulation of aromatase in eutopic endometrium and implants from women with endometriosis has been reported. Aromatase induction may be mediated by increased cyclooxygenase-2 (COX-2). Recently, we demonstrated that progesterone receptor (PR)-A and PR-B serve an antiinflammatory role in the uterus by antagonizing nuclear factor kappaB activation and COX-2 expression. PR-C, which antagonizes PR-B, is up-regulated by inflammation. Although estrogen receptor alpha (ERalpha) is implicated in endometriosis, an antiinflammatory role of ERbeta has been suggested. We examined stage-specific expression of aromatase, COX-2, ER, and PR isoform expression in eutopic endometrium, implants, peritoneum, and endometrioma samples from endometriosis patients. Endometrial and peritoneal biopsies were obtained from unaffected women and those with fibroids. Aromatase expression in eutopic endometrium from endometriosis patients was significantly increased compared with controls. Aromatase expression in endometriosis implants was markedly increased compared with eutopic endometrium. Aromatase mRNA levels were increased significantly in red implants relative to black implants and endometrioma cyst capsule. Moreover, COX-2 expression was increased in implants and in eutopic endometrium of women with endometriosis as compared with control endometrium. As observed for aromatase mRNA, the highest levels of COX-2 mRNA were found in red implants. The ratio of ERbeta/ERalpha mRNA was significantly elevated in endometriomas compared with endometriosis implants and eutopic endometrium. Expression of PR-C mRNA relative to PR-A and PR-B mRNA was significantly increased in endometriomas compared with eutopic and control endometrium. PR-A protein was barely detectable in endometriomas. Thus, whereas PR-C may enhance disease progression, up-regulation of ERbeta may play an antiinflammatory and opposing role.     

Comparison of biological properties of St. Louis encephalitis and Rio bravo viruses

St. Louis encephalitis (SLE) virus, an arbovirus, and Rio Bravo (RB) virus, a non-arthropod-borne virus, are flaviviruses which cross-react in neutralization tests. Several of their biological properties were compared. Viral growth curves revealed that greater than 99% of infectious SLE (Parton) virus remained cell-associated in Vero cells but was released slowly into the medium of infected BHK-21 cells. In contrast, RB (M-64) virus was released upon maturation into the fluids of Vero and BHK-21 cell cultures. Fortyfold more SLE virus than RB virus adsorbed to monolayer cultures of Aedes dorsalis cells. SLE but not RB virus replicated and reached high titers (10(8) pfu/ml) in Ae. dorsalis cell cultures maintained in media which were expected to enhance recovery of RB virus. Further, SLE but not RB virus replicated in cultured bat epithelial cells and primary duck embryo cells incubated at 42 degrees C. Clearly, the prototype strains of RB and SLE viruses are distinct viruses. Both the classification of RB virus in the genus flavivirus and the antigenic relationship between RB and SLE viruses require further clarification.     

Effect of normal mosquito extracts upon arbovirus recoveries from mosquito pools

Titers of Turlock (TUR) and Hart Park (HP) viruses were reduced to undetectable levels when virus was mixed with a triturated suspension of uninfected (normal) 4th instar larvae of Culex tarsalis prior to plaque assay in cell culture. There was a linear relationship between the number of larvae in the pool and the titer of virus recoverable. Virus was undetectable when 1,000-10,000 PFU of either agent was added to pools that contained 25 or more larvae. Suspensions of up to 25 adult male or female Cx. tarsalis had little effect on detectable viral titers while pupal suspensions had an intermediate effect. The inhibitory effect of normal larval extracts on viral infectivity could be counteracted by use of polycations or a high pH buffer. A similar reduction in titer of TUR virus was observed with extracts of larvae of Aedes melanimon or Anopheles franciscanus. Larval extracts of Cx. tarsalis similarly reduced titers of California and St. Louis encephalitis viruses but not western equine encephalomyelitis virus. These findings may have significant bearing on the interpretation of transovarial transmission attempts in which pooled larvae are assayed for virus.