Driven progressive evolution of genome sequence complexity in Cyanobacteria.

Progressive evolution, or the tendency towards increasing complexity, is a controversial issue in biology, which resolution entails a proper measurement of complexity. Genomes are the best entities to address this challenge, as they encode the historical information of a species' biotic and environmental interactions. As a case study, we have measured genome sequence complexity in the ancient phylum Cyanobacteria. To arrive at an appropriate measure of genome sequence complexity, we have chosen metrics that do not decipher biological functionality but that show strong phylogenetic signal. Using a ridge regression of those metrics against root-to-tip distance, we detected positive trends towards higher complexity in three of them. Lastly, we applied three standard tests to detect if progressive evolution is passive or driven-the minimum, ancestor-descendant, and sub-clade tests. These results provide evidence for driven progressive evolution at the genome-level in the phylum Cyanobacteria.

Partial allograft replacement of the radial head in the management of complex fracture-dislocations of the elbow.

BACKGROUND: There have been reports of total radial head allografts showing variable outcomes. This case series reports the novel use of an allograft for partial radial head replacement in the treatment of elbow fracture-dislocation. METHODS: Eight patients underwent partial radial head allograft reconstruction to restore stability for complex fracture-dislocations involving fractures of the coronoid and radial head, with collateral ligament disruption. Two patients were treated acutely. Six were referred from other centers 2 to 48 weeks after injury following failure of primary treatment. In each case, it was not possible to perform stable open reduction-internal reduction of the radial head fracture, or the fracture fragment had already been excised. A fresh-frozen partial radial head allograft was used to replace the defect and restore the joint surface. The coronoid fracture and injury to collateral ligaments were also managed surgically. Patient charts, surgical records, and radiographs were reviewed. Patients were contacted at a mean of 79 months after treatment to answer questions to determine the Mayo Elbow Performance Score and the score on the shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire. RESULTS: Clinical and radiologic reviews confirmed union of graft in all cases. None resorbed or collapsed. Three patients had resorption of the coronoid fragment resulting in poor outcomes, with one patient ultimately undergoing total elbow arthroplasty. CONCLUSION: Partial radial head allograft may be a useful alternative to radial head prosthesis in unstable fracture-dislocations in which the radial head cannot be restored fully.

Blood loss in endoscopic sinus surgery: assessment of variables.

OBJECTIVE: To identify the variables that influence blood loss in endoscopic sinus surgery performed under uniform conditions of preoperative topical vasoconstriction and surgical technique. STUDY DESIGN: Blind, nonrandomized, observational study. SETTING: One hundred thirty-eight consecutive patients who underwent endoscopic sinus surgery with the same technique in a university hospital over a 9-month period. METHODS: Pearson product-moment correlation was used for numerical variables and nonparametric tests for categorical variables: Mann-Whitney (comparison of two independent variables) and Kruskal-Wallis (comparison of more than two independent variables). MAIN OUTCOME MEASURES: Operative time, total blood loss, and blood loss per minute were correlated with blood loss markers: age, sex, surgeon, type and severity of illness, septoplasty, and anesthetic agents used. RESULTS: No correlation was found between age, sex, surgeon, and blood loss markers. Severe polyposis produced more blood loss than mild polyposis and sinusitis. Septoplasty showed an interesting inverse correlation with blood loss. Remifentanyl with fluorinated volatile agents was accompanied by less blood loss than other anesthetic agents. CONCLUSION: More blood loss occurred with more severe sinonasal pathology. Blood loss may be reduced by using remifentanyl with a fluorinated volatile agent and, possibly, preoperative infiltration with epinephrine.

Calcification of the posterior cricoid lamina simulating a foreign body in the aerodigestive tract (2005:11b).

This interpretation corner case, reporting a man with suspicion of ingestion and perforation of the oesophagus by a foreign body, highlights the danger of false appearances on plain radiographs for detection of foreign bodies in the aerodigestive tract. Plain radiographs and CT revealed a needle-shaped calcified object between the cricoid plate and the oesophagus lumen, which turned out to be an abnormal cricoid calcification. There is also a discussion about the role of radiology in the detection of foreign bodies in the aerodigestive tract.