Neutrophil Influx Measured in Nasal Lavages of Humans Exposed to Ozone

Neutrophils (PMNs) obtained by nasal lavage were counted to determine if ozone, an oxidant air pollutant, induces an acute inflammatory response in the upper respiratory tract (URT) of humans. Background data were obtained by the nasal lavages from 200 nonexperimentally exposed subjects. Then, using a known inflammatory agent for the URT, rhinovirus-type 39, the induction, peak, and resolution of an acute inflammatory response was shown to be documented by the nasal lavage PMN counts. To determine if ozone induces this response, 41 subjects were exposed to either filtered air or 0.5 ppm ozone for 4 hr, on 2 consecutive days. Nasal lavages were taken pre-, immediately post each exposure, and 22 hr following the last exposure. Lavage PMN counts increased significantly (p = .005) in the ozone-exposed group, with 3.5-, 6.5-, and 3.9-fold increases over the air-exposed group at the post 1, pre 2, and post 2 time points, respectively. Ozone induces an inflammatory response in the URT of humans, and nasal lavage PMN counts are useful to assay the inflammatory properties of air pollutants.     

Comparison of risk-adjusted 30-day postoperative mortality and morbidity in Department of Veterans Affairs hospitals and selected university medical centers: general surgical operations in men

BACKGROUND: We used data from the Patient Safety in Surgery Study to compare patient populations, operative characteristics, and unadjusted and risk-adjusted 30-day postoperative mortality and morbidity between the Veterans Affairs (VA) (n = 94,098) and private (n = 18,399) sectors for general surgery operations in men. STUDY DESIGN: This is a prospective cohort study. Trained nurses collected preoperative risk factors, operative variables, and 30-day postoperative mortality and morbidity outcomes in male patients undergoing major general surgery operations at 128 VA medical centers and 14 university medical centers from October 1, 2001, to September 30, 2004. Multiple logistic regression analysis was used to identify preoperative predictors of postoperative mortality and morbidity. An indicator variable for VA versus private-sector medical center was added to the model to determine if risk-adjusted outcomes were significantly different in the two systems. RESULTS: The unadjusted 30-day mortality rate was higher in the VA compared with the private sector (2.62% versus 2.03%, p = 0.0002); unadjusted morbidity rate was lower in the VA compared with the private sector (12.24% versus 13.99%, p < 0.0001). After risk adjustment, odds ratio for mortality for the VA versus private sector was 1.23 (95% CI, 1.08-1.41). For morbidity after risk adjustment, the indicator variable for health-care system just missed statistical significance (p = 0.0585). Thirty-day postoperative mortality was comparable in the VA and private sector for very common operations but was higher in the VA for less common, more complex operations. CONCLUSIONS: In general surgery operations in men, the VA appeared to have a higher risk-adjusted mortality rate compared with the private sector, but differences in mortality ascertainment in the two sectors might account for some of this effect. The higher mortality in the VA could be the result of higher mortality in the less common, more complex operations. There is a trend toward lower risk-adjusted morbidity in the VA compared with the private sector.     

Use of national surgical quality improvement program data as a catalyst for quality improvement

BACKGROUND: Semiannually, the National Surgical Quality Improvement Program (NSQIP) provides its participating sites with observed-to-expected (O/E) ratios for 30-day postoperative mortality and morbidity. At each reporting period, there is typically a small group of hospitals with statistically significantly high O/E ratios, meaning that their patients have experienced more adverse events than would be expected on the basis of the population characteristics. An important issue is to determine which actions a surgical service should take in the presence of a high O/E ratio. STUDY DESIGN: This article reviews case studies of how some of the Department of Veterans Affairs and private-sector NSQIP participating sites used the clinically rich NSQIP database for local quality improvement efforts. Data on postoperative adverse events before and after these local quality improvement efforts are presented. RESULTS: After local quality improvement efforts, wound complication rates were reduced at the Salt Lake City Veterans Affairs medical center by 47%, surgical site infections in patients undergoing intraabdominal surgery were reduced at the University of Virginia by 36%, and urinary tract infections in vascular patients were reduced at the Massachusetts General Hospital by 74%. At some sites participating in the NSQIP, notably the Massachusetts General Hospital and the University of Virginia, the NSQIP has served as the basis for surgical service-wide outcomes research and quality improvement programs. CONCLUSIONS: The NSQIP not only provides participating sites with risk-adjusted surgical mortality and morbidity outcomes semiannually, but the clinically rich NSQIP database can also serve as a catalyst for local quality improvement programs to significantly reduce postoperative adverse event rates.     

Risk-adjusted morbidity in teaching hospitals correlates with reported levels of communication and collaboration on surgical teams but not with scale measures of teamwork climate, safety climate, or working conditions

BACKGROUND: Since the Institute of Medicine patient safety reports, a number of survey-based measures of organizational climate safety factors (OCSFs) have been developed. The goal of this study was to measure the impact of OCSFs on risk-adjusted surgical morbidity and mortality. STUDY DESIGN: Surveys were administered to staff on general/vascular surgery services during a year. Surveys included multiitem scales measuring OCSFs. Additionally, perceived levels of communication and collaboration with coworkers were assessed. The National Surgical Quality Improvement Program was used to assess risk-adjusted morbidity and mortality. Correlations between outcomes and OCSFs were calculated and between outcomes and communication/collaboration with attending and resident doctors, nurses, and other providers. RESULTS: Fifty-two sites participated in the survey: 44 Veterans Affairs and 8 academic medical centers. A total of 6,083 surveys were returned, for a response rate of 52%. The OCSF measures of teamwork climate, safety climate, working conditions, recognition of stress effects, job satisfaction, and burnout demonstrated internal validity but did not correlate with risk-adjusted outcomes. Reported levels of communication/collaboration with attending and resident doctors correlated with risk-adjusted morbidity. CONCLUSIONS: Survey-based teamwork, safety climate, and working conditions scales are not confirmed to measure organizational factors that influence risk-adjusted surgical outcomes. Reported communication/collaboration with attending and resident doctors on surgical services influenced patient morbidity. This suggests the importance of doctors' coordination and decision-making roles on surgical teams in providing high-quality and safe care. We propose risk-adjusted morbidity as an effective measure of surgical patient safety.     

Expression of a cloned denV gene of bacteriophage T4 in Escherichia coli.

A 713-base-pair Hae III fragment from bacteriophage T4 encompassing the denV gene with its preceding promoter has been cloned in a pBR322-derived positive-selection vector and introduced into a variety of DNA repair-deficient uvr and rec and uvr,rec Escherichia coli strains. The denV gene was found to be expressed, probably from its own promoter, causing pyrimidine dimer incision-deficient uvrA, uvrB, uvrC strains to be rescued by the denV gene. A uvrD (DNA helicase II) strain was also complemented, but to a lesser extent. A wild-type strain did not seem to be affected at the UV doses tested. Surprisingly, all recA, recB, and recC strains tested also showed an increased UV resistance, perhaps by reinforcement of the intact uvr system in these strains. Complementation of denV- T4 strains and host-cell reactivation of lambda phage was also observed in denV+ E. coli strains. Equilibrium sedimentation showed that DNA repair synthesis occurred in a UV-irradiated uvrA E. coli strain carrying the cloned denV gene. Southern blotting confirmed our earlier results [Valerie, K., Henderson, E. E. & de Riel, J. K. (1984) Nucleic Acids Res. 12, 8085-8096] that the denV gene is located at 64 kilobases on the T4 map. Phage T2 (denV-) did not hybridize to a denV-specific probe.     

Myocardial reoxygenation damage: can it be circumvented?

We investigated whether reoxygenation damage could be prevented by interventions directed towards reducing calcium influx only during the reoxygenation period. We measured reoxygenation contracture and recovery of contractile performance, using isolated papillary muscle preparations from cat and rabbit, pretreated with ouabain so as to exaggerate the phenomenon of reoxygenation contracture. Reoxygenation contracture was abolished and contractile recovery achieved by lowering extracellular calcium during early reoxygenation and then gradually replacing it. Gradual reoxygenation only postponed contracture and contractile failure. The slow channel blocker, diltiazem, but not verapamil or lidoflazine--in similarly negative inotropic concentrations of 10(-4) mol X litre-1, 10(-4) mol X litre-1 and 2 X 10(-5) mol X litre-1 respectively--reduced early reoxygenation contracture, as did Mg2+ (30 mmol X litre-1), Mn2+ (8 mmol X litre-1), or metabolic acidosis (pH 6.5), without in any case allowing contractile recovery. These observations indicate that reoxygenation damage is not an irrevocable consequence of the preceding hypoxic insult. They imply that calcium entry during early reoxygenation contributes both to contracture and contractile failure, that this occurs through paths other than the slow calcium channel, and that diltiazem may have properties additional to those of blocking the slow calcium channel.