Faculty Bibliography

A patient with newly diagnosed end-stage renal disease (ESRD) received a femoral catheter for hemodialysis (HD). Shortly thereafter he developed fever, and blood cultures grew methicillin-resistant Staphylococcus aureus. The catheter was removed and the patient was treated with both vancomycin and rifampin; however, blood culture positivity persisted. The cerebrospinal fluid showed sterile meningitis. Subsequent imaging studies demonstrated aortic valve endocarditis and multiple mycotic aneurysms that appeared to include the intra- and extracranial vessels. The patient eventually died from sepsis. This case illustrates the aggressive and invasive nature of systemic infection with S. aureus and underscores the high morbidity and mortality associated with infections related to HD catheters.

Denaturing gradient gel electrophoresis (DGGE) was used to probe for mutations associated with rifampin (RIF) resistance in the rpoB gene of Mycobacterium tuberculosis. DGGE scans for mutations across large regions of DNA and is comparable to DNA sequencing in detecting DNA alterations. Specific mutations are often recognized by their characteristic denaturation pattern, which serves as a molecular fingerprint. Five DGGE primer sets that scanned for DNA alterations across 775 bp of rpoB were developed. These primer sets were used to scan rpoB for DNA alterations in 296 M. tuberculosis patient isolates from the United States-Mexico border states of Texas and Tamaulipas. The most useful primer set scanned for mutations in the rifampin resistance-determining region (RRDR) and detected mutations in 95% of the RIF-resistant isolates compared to 2% of RIF-susceptible isolates. Thirty-four different alterations were observed within the RRDR by DGGE. In addition, isolates harboring mixtures of DNA within rpoB were readily detected by DGGE. A second PCR primer set was used to detect the V146A mutation in 5 to 7% of RIF-resistant isolates. A third primer set was used to detect mutations in 3% of RIF-resistant isolates, some of which also harbored mutations in the RRDR. Only 1 of 153 RIF-resistant isolates did not have a detectable rpoB mutation as determined by DGGE and DNA sequencing. These results demonstrate the power and usefulness of DGGE in detecting mutations associated with drug resistance in M. tuberculosis

OBJECTIVE: Study objectives were to assess the accuracy of a food record delivered on a personal digital assistant (PDA) and to examine sources of error from the PDA-based food record. METHODS: Thirty-nine adults recruited with a newspaper advertisement were trained to record food intake using DietMatePro, a dietary assessment program delivered on a PDA. After 3 d of use, subjects returned for a follow-up visit in which a 24-h recall was conducted. Subjects also were timed while recording an observed, weighed lunch. Recalled and actual food intakes were compared with estimates recorded by the subjects when using the PDA. Paired sample t tests and Pearson's correlations assessed means and measurements of association between DietMatePro data compared with the 24-h recall data and observed meal data. Bland-Altman plots were used to assess bias in food recording. Sources of error were quantified by using calories as the unit for comparison. RESULTS: There were no significant differences in daily totals for calories and macronutrients between DietMatePro data and comparison measurements. Pearson's correlations of associations between DietMatePro data and the comparison measurement ranged from 0.505 to 0.797 (P < 0.005, n = 28) for the 24-h recall and from 0.419 to 0.786 (P < 0.005, n = 33) for the observed lunch, depending on the nutrient measured. The largest source of absolute error in caloric estimation was attributable to portion size estimation error (49%). CONCLUSIONS: DietMatePro, a PDA-based dietary assessment program, provides a method of assessing energy and macronutrient intakes comparable to the 24-h recall in samples lacking dietary restrictions.

SETTING/METHODS:Large urban tuberculosis control program. OBJECTIVES/OBJECTIVE:To determine the frequency and characteristics of treatment interruptions, and the factors associated with the different types of treatment interruptions. DESIGN/METHODS:This was a case-control study using culture-positive tuberculosis (TB) patients verified in 1998-1999. Case patients included those in whom any of the following mutually exclusive categories of treatment interruption: default with return to therapy, directly observed therapy nonadherence, default without return to therapy, or multiple types of interruptions. Controls were selected randomly from the cohort. RESULTS:Overall, 6.0 percent of patients had treatment interruptions. All types of treatment interruption were associated with prolonged treatment course and decreased treatment completion rates. The median number of months to treatment interruption was 4.0 (range, 0.5-28.9 months). Two factors were significantly associated with every type of interruption: homelessness and lack of awareness of the severity of TB disease. In multivariate analysis, only lack of awareness of the severity of disease remained independently associated with all interruption types. CONCLUSION/CONCLUSIONS:Efforts to improve patients' understanding of TB disease and related treatment issues may be an important TB control program strategy and should be emphasized at the initiation of therapy and at intervals throughout the treatment course to minimize treatment interruption.

How the Food and Drug Administration (FDA) responds to criticism of its drug safety process will determine whether drug safety actually improves. Propping up the Office of Drug Safety with more bureaucratic prominence or adding new requirements to the preapproval process will add to the cost of drug development and not make drugs safer. New information tools can dramatically improve postmarketing surveillance and collection of data on safety. This information could then be used to reach more definitive regulatory conclusions sooner. New incentives will be needed to entice payers and product developers to work on building a broader, more robust system for collecting data on drug safety

Surgeons can generally learn the on-pump operation faster than the off-pump technique because it is technically less demanding. Also, the report said, surgeons can generally perform more grafts, if necessary, in an on-pump bypass, and the grafts may stay open longer. A controversy has developed over some evidence that a small but significant number of on-pump bypass patients suffer a degree of cognitive impairment like memory and attention deficits and language problems. Such problems tended to occur less among patients whose bypasses were performed with the beating-heart technique compared with the stopped-heart technique, the team said. The extent of the decrease was not detailed. The most conclusive benefit of off-pump over on-pump operations was for patients who had deposits of calcium in their aortas, the body's main artery. When surgeons clamp the aorta in the on-pump technique, small pieces can break off to cause disabling and fatal strokes

The vaccine, sold as Menactra by Sanofi Pasteur, protects against infections caused by meningococcal bacteria. Such infections include a form of meningitis that can be rapidly fatal. In a third recommendation, the agency recommended that all college freshmen living in dormitories be immunized against meningococcal disease. The new recommendation strengthened an earlier one that said freshmen should consider such protection. Menactra does not protect against type B meningococcal infection, for which no vaccine is licensed or available in the United States, the agency said

The vaccine, sold as Menactra by Sanofi Pasteur, protects against infections caused by meningococcal bacteria. Such infections include a form of meningitis that can be rapidly fatal. In a third recommendation, the agency recommended that all college freshmen living in dormitories be immunized against meningococcal disease. The new recommendation strengthened an earlier one that said freshmen should consider such protection. Menactra does not protect against type B meningococcal infection, for which no vaccine is licensed or available in the United States, the agency said