Faculty Bibliography

Staphylococcus aureus produces a wide array of cell surface and extracellular proteins involved in virulence. Expression of these virulence factors is tightly controlled by numerous regulatory loci, including agr, sar, sigB, sae, and arl, as well as by a number of proteins with homology to SarA. Rot (repressor of toxins), a SarA homologue, was previously identified in a library of transposon-induced mutants created in an agr-negative strain by screening for restored protease and alpha-toxin. To date, all of the SarA homologues have been shown to act as global regulators of virulence genes. Therefore, we investigated the extent of transcriptional regulation of staphylococcal genes by Rot. We compared the transcriptional profile of a rot agr double mutant to that of its agr parental strain by using custom-made Affymetrix GeneChips. Our findings indicate that Rot is not only a repressor but a global regulator with both positive and negative effects on the expression of S. aureus genes. Our data also indicate that Rot and agr have opposing effects on select target genes. These results provide further insight into the role of Rot in the regulatory cascade of S. aureus virulence gene expression

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is a growing public health concern that has been associated with pediatric fatalities. It is hypothesized that the evolution of CA-MRSA is a recent event due to the acquisition of mec DNA by previously methicillin-susceptible strains that circulated in the community. This study investigated the genetic relatedness between CA-MRSA, hospital-associated MRSA (HA-MRSA), and nonmenstrual toxic shock syndrome (nmTSS) isolates. Thirty-one of 32 CA-MRSA isolates were highly related as determined by pulsed-field gel electrophoresis and spa typing yet were distinguishable from 32 HA-MRSA strains. The 31 related CA-MRSA isolates produced either staphylococcal enterotoxin B (n = 5) or C (n = 26), and none made TSS toxin 1. All CA-MRSA isolates tested contained a type IV staphylococcal cassette chromosome mec (SCCmec) element. In comparison, none of the HA-MRSA isolates (n = 32) expressed the three superantigens. Antibiotic susceptibility patterns were different between the CA-MRSA and HA-MRSA isolates; CA-MRSA was typically resistant only to beta-lactam antibiotics. Six of twenty-one nmTSS isolates were indistinguishable or highly related to the CA-MRSA isolates. MnCop, an nmTSS isolate obtained in Alabama in 1986, was highly related to the CA-MRSA isolates except that it did not contain an SCCmec element. These data suggest that CA-MRSA strains may represent a new acquisition of SCCmec DNA in a previously susceptible genetic background that was capable of causing nmTSS. CA-MRSA poses a serious health risk not only because it is resistant to the antibiotics of choice for community-acquired staphylococcal infections but also because of its ability to cause nmTSS via superantigen production

Ofri reviews Sloan-Kettering by Abba Kovner and translated by Eddie Levenston

A major purpose of biomedical terminologies is to provide uniform concept representation, allowing for improved methods of analysis of biomedical information. While this goal is being realized in bioinformatics, with the emergence of the Gene Ontology as a standard, there is still no real standard for the representation of clinical concepts. As discoveries in biology and clinical medicine move from parallel to intersecting paths, standardized representation will become more important. A large portion of significant data, however, is mainly represented as free text, upon which conducting computer-based inferencing is nearly impossible. In order to test our hypothesis that existing biomedical terminologies, specifically the UMLS Metathesaurus and SNOMED CT, could be used as templates to implement semantic and logical relationships over free text data that is important both clinically and biologically, we chose to analyze OMIM (Online Mendelian Inheritance in Man). After finding OMIM entries' conceptual equivalents in each respective terminology, we extracted the semantic relationships that were present and evaluated a subset of them for semantic, logical, and biological legitimacy. Our study reveals the possibility of putting the knowledge present in biomedical terminologies to its intended use, with potentially clinically significant consequences

Watergate was a vivid human drama with stunning plot turns and priceless characters. There was Tony Ulasewicz, straight from a Damon Runyon novel, who was a bagman for the [Richard Nixon] campaign; John Sirica, the tough federal judge who got the Watergate burglars to talk; Alexander Butterfield, the perplexed White House aide who dropped the bombshell about the taping system in the Oval Office, and Barbara Jordan, the young congresswoman from Texas, whose eloquence regarding the Constitution and Nixon's abuse of it seemed to restore the nation's faith in politics. In fact, it was both. To see Richard Nixon full blown shouldn't obscure the dangerous abuses of executive power by those who came before him. But let's face it: Nixon was unique. A look back at his career shows a relish for lying and lawbreaking, a fear and hatred of normal opposition and a cynicism about the political process that is unrivaled in our history. That is what makes the real Nixon so fascinating and so sorely missed in this book. [David M. Oshinsky] is the Littlefield professor of history at the University of Texas.

Case histories of proposed life insurance are presented to introduce the topic of cardiac valvular tumors. Using fibroelastoma as the prototypical cardiac tumor, pathology, diagnosis, echocardiographic findings and clinical course are reviewed, based on available clinical literature. Although the natural history of benign cardiac tumors is uncertain, because of the risk of adverse outcomes, cases must be underwritten on an individual basis until long-term studies become available

Torture and ill-treatment are reportedly widespread in Mexico. Little is known, however, about the quality of forensic investigations and documentation of evidence of these human rights violations. To determine the integrity of the documentation and the presence, quality, and frequency of both physical and psychological evaluations, analyses were conducted on 103 medical evaluations identified in 33 cases of alleged torture and/or ill-treatment that the Mexican National Commission for Human Rights (CNDH) investigated between January 2000 and July 2002. Findings suggest that forensic medical evaluations in CNDH cases have been conducted promptly after alleged occurrences of torture and/or ill-treatment, and the results of such evaluations have often been introduced as evidence in legal investigations. Inadequate documentation in most forensic medical evaluations reinforces the need for effective training, monitoring, and accountability strategies.