Comparison of three solid phase extraction sorbents for the isolation of THM precursors from manitoban surface waters

Three prepackaged solid phase extraction (SPE) cartridges: two modified styrene divinylbenzene, Bond Elut ENV and Bond Elut PPL (Varian), and one N-vinylpyrrolidone (Strata-X, Phenomenex), were assessed for isolation of THM precursors from three surface waters in Manitoba, Canada. The dissolved organic matter (DOM) from the La Salle River (LR), Lake Winnipegosis (LW) and the Waterhen River (WR) were fractionated into hydrophobic (HPO) and hydrophilic (HPI) parts. ENV isolated less DOM (LR = 46.6 ± 1.5%; LW = 36.2 ± 1.4%; WR = 28.6 ± 2.2%) compared to PPL (LR = 50.2 ± 4.4%; LW = 47.9 ± 2.2%; WR = 37.3 ± 2.8%) and Strata (LR = 46.4% ± 1.0; LW = 51.6 ± 0.3%; WR = 31.9 ± 3.9%). The HPO fraction isolated by each SPE was characterized using Fourier Transform Infrared (FTIR) spectrochemical imaging. The FTIR spectra confirmed the HPO fractions were typical of humic-material and largely resembled fulvic acids; however, the PPL and Strata HPO isolates contained slightly more polysaccharides. The THM formation potential (THMFP) confirmed that the HPO fraction formed more THMs than the HPI. The HPO fraction isolated using ENV was found to have the lowest THMFP of all three SPEs in each waterbody; however, the specific THMFP (μgTHM/mgDOM) results indicated that ENV isolated THM precursors more effectively, as the Strata and PPL isolated a greater amount of non-THM forming material. All three SPE showed significant potential for implementation at water treatment plants as a simple tool to monitor THM precursors in source waters, enabling operators to adapt processes to improve drinking water quality.

Rapid biodiagnostic ex vivo imaging at 1 μm pixel resolution with thermal source FTIR FPA

Novel high spatial resolution (1 × 1 μm pixel) FTIR imaging with commercial benchtop instrument yields data comparable to that from synchrotron sources.

Employment after coronary angioplasty or coronary bypass surgery in patients employed at the time of revascularization

BACKGROUND

Patients who undergo coronary angioplasty have a shorter convalescence than those who undergo coronary bypass surgery. This may improve subsequent employment.

OBJECTIVE

To compare employment patterns after coronary angioplasty or surgery.

DESIGN

Multicenter, randomized clinical trial.

SETTING

Seven tertiary care hospitals.

PATIENTS

409 employed patients with multivessel coronary artery disease.

INTERVENTION

Coronary bypass surgery or balloon angioplasty.

MEASUREMENTS

Time to return to work and time spent working during 4 years of follow-up.

RESULTS

Patients who underwent angioplasty returned to work 6 weeks sooner than patients who underwent coronary bypass surgery (P < 0.001), but long-term employment did not differ significantly (P > 0.2). Long-term employment was significantly lower among patients who were 60 to 64 years of age (P < 0.001), those who worked less than full-time at study entry (P < 0.001), and those who had less formal education (P = 0.005). Patients with only one source of health insurance were more likely to continue working (P = 0.005).

CONCLUSIONS

Faster recovery after angioplasty speeds return to work but does not improve long-term employment, which is primarily associated with nonmedical factors.

Cognitive function 5 years after randomization to coronary angioplasty or coronary artery bypass graft surgery

BACKGROUND

Coronary bypass surgery often leads to short-term cognitive dysfunction, whereas coronary angioplasty does not. Perioperative cognitive dysfunction usually resolves, although a subgroup of surgical patients may continue to exhibit long-term cognitive dysfunction. The purpose of this study was to compare cognitive function 5 years after randomization to a strategy of either initial coronary surgery or initial angioplasty.

METHODS AND RESULTS

Five centers in the Bypass Angioplasty Revascularization Investigation participated in this ancillary study. Patients with multivessel coronary disease randomized to angioplasty or surgery were eligible at the time of their 5-year clinic visit. A battery of five measures previously shown to be sensitive to perioperative changes in cognitive function was administered, including the Logical and Figural Memory Scales from the Wechsler Memory Scale, the Digit Symbol and Digit Span subtests from the Wechsler Adult Intelligence Scale, and Part B of the Reitan Trail Making Test. The 125 study patients were generally similar to the 133 patients who were eligible but did not participate, although study participants were significantly younger (P=.003). The 64 patients randomly assigned to angioplasty had baseline characteristics similar to those of 61 patients randomly assigned to surgery. Cognitive function scores were not significantly different between angioplasty or surgery patients in an intention-to-treat analysis (P=.57). There also was no difference in cognitive function scores when the data were analyzed according to whether the patient had ever undergone bypass surgery (P=.59).

CONCLUSIONS

Long-term cognitive function is similar after coronary bypass surgery and coronary angioplasty in the majority of patients.

Medical care costs and quality of life after randomization to coronary angioplasty or coronary bypass surgery. Bypass Angioplasty Revascularization Investigation (BARI) Investigators

BACKGROUND

Randomized trials comparing coronary angioplasty with bypass surgery in patients with multivessel coronary disease have shown no significant differences in overall rates of death and myocardial infarction. We compared quality of life, employment, and medical care costs during five years of follow-up among patients treated with angioplasty or bypass surgery.

METHODS

A total of 934 of the 1829 patients enrolled in the randomized Bypass Angioplasty Revascularization Investigation participated in this study. Detailed data on quality of life were collected annually, and economic data were collected quarterly.

RESULTS

During the first three years of follow-up, functional-status scores on the Duke Activity Status Index, which measures the ability to perform common activities of daily living, improved more in patients assigned to surgery than in those assigned to angioplasty (P<0.05). Other measures of quality of life improved equally in both groups throughout the follow-up period. Patients in the angioplasty group returned to work five weeks sooner than did patients in the surgery group (P<0.001). The initial mean cost of angioplasty was 65 percent that of surgery ($21,113 vs. $32,347, P<0.001), but after five years the total medical cost of angioplasty was 95 percent that of surgery ($56,225 vs. $58,889), a difference of $2,664 (P = 0.047). The five-year cost of angioplasty was significantly lower than that of surgery among patients with two-vessel disease ($52,930 vs. $58,498, P<0.05), but not among patients with three-vessel disease ($60,918 vs. $59,430). After five years of follow-up, surgery had an overall cost-effectiveness ratio of $26,117 per year of life added, but unacceptable ratios of $100,000 or more per year of life added could not be excluded (P=0.13). Surgery appeared particularly cost effective in treating diabetic patients because of their significantly improved survival.

CONCLUSIONS

In patients with multivessel coronary disease, coronary-artery bypass surgery is associated with a better quality of life for three years than coronary angioplasty, after the initial morbidity caused by the procedure. Coronary angioplasty has a lower five-year cost than bypass surgery only in patients with two-vessel coronary disease.

The Suess-Urey mission (return of solar matter to Earth)

The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.

Bacteremic nosocomial pneumonia. A 7-year experience in one institution

STUDY OBJECT

To describe the epidemiology, microbiology, and outcome of nosocomial pneumonia with secondary bloodstream infection.

DESIGN

Prospective cohort study.

SETTING

Tertiary care Canadian teaching hospital.

PATIENTS

Inpatients.

MEASUREMENT

All inpatient blood cultures were concurrently monitored over an 89 month period. Following chart review, patients experiencing nosocomial bloodstream infection due to pneumonia were identified. A standardized definition of pneumonia was used.

RESULTS

One hundred forty-nine episodes occurred in 145 patients, 0.66/1,000 hospital admissions, 8.4% of all nosocomial bloodstream infections. No change in rate occurred in the study period. Fifty-four percent of episodes developed in one of seven ICUs. Staphylococcus aureus was the most frequently identified etiologic organism (27%). The ICU and non-ICU cases did not differ in etiology. No organism became more prevalent during the study period. Twenty percent of patients died within 1 week of first positive culture; episodes associated with Pseudomonas species had a much higher mortality rate (45%) than other infections (14%) (p = 0.002). The ICU and non-ICU infections had a similar mortality rate.

CONCLUSION

Pneumonia is an important cause of nosocomial bloodstream infection, but it is not increasing in frequency or changing in etiology in our institution. The ICUs are a major contributor to this problem but have the same case short-term mortality rate and microbial etiology as non-ICU cases. Cases associated with Pseudomonas have a much higher mortality rate.

Initial functional and economic status of patients with multivessel coronary artery disease randomized in the Bypass Angioplasty Revascularization Investigation (BARI)

Randomized trials of coronary angioplasty and bypass surgery have hypothesized that these procedures will have equivalent long-term rates of death and myocardial infarction. Functional status, quality of life, employment, and healthcare cost will therefore be critical measures of the efficacy of these alternative revascularization procedures. Patients at 7 sites in the Bypass Angioplasty Revascularization Investigation (BARI) were enrolled in an ancillary Study of Economics and Quality of Life (SEQOL). Physical function was assessed by the Duke Activity Status Index and emotional status by the Mental Health Inventory. Employment patterns and health care utilization were also measured at study entry and at 3-month intervals in follow-up. The 934 patients enrolled in SEQOL were similar to the 895 remaining BARI randomized patients. Most patients (63%) aged < or = 64 years were working, and almost all working patients (96%) intended to return to work. Patients aged > or = 65 years had lower household incomes but better health insurance coverage. Overall health ratings were significantly correlated with both physical and emotional status (p < 0.001). Patients enrolled in SEQOL are representative of the overall BARI population. Data collected in SEQOL will provide a detailed picture of the physical, emotional, and economic well-being after coronary angioplasty and bypass surgery.

Trends and sources of nosocomial fungaemia

Concurrent surveillance of blood culture isolates in a 1000-bed tertiary care hospital over a 7-year period from 1986 to 1993 identified 102 episodes of nosocomial fungaemia, representing 6.6% of all episodes of nosocomial bloodstream infections and 0.49/1000 admissions. No significant change in the frequency, rate, source or microbial aetiology of nosocomial fungaemia occurred over the 7-year period. Candida albicans accounted for 74%, followed by Candida (Torulopsis) glabrata (8%), C. parapsilosis (7%), C. tropicalis (3%), C. lusitaniae (2%), C. krusei, Malassezia furfur Saccharomyces cerevisiae, Hansenula anomala and Cryptococcus albidus (one each). 'Primary' fungaemia, usually attributed to intravascular catheters, was considered to be the source in 65% of cases, with 64% of these patients receiving total parenteral nutrition (TPN). Other important sources of infection included the urinary tract (11%), the gastrointestinal tract (8%) and the respiratory tract (7%). Sixty-four % of patients were in one of the hospital's seven intensive care units (ICUs) when their infection developed, the neonatal ICU and adult medical/surgical ICU each accounting for 21%. Only 7% of cases were associated with neutropenia and another 14% with malignancy or immunosuppression. Death occurred within 7 days of diagnosis of fungaemia in 23 cases. In eight instances, fungaemia was considered the main cause of death. We conclude that in our hospital nosocomial fungaemia is largely caused by C. albicans, occurring in association with intravascular catheter use and TPN in ICU patients. Most cases are not associated with recognized immune defence defects. Fungaemia is associated with a high short-term mortality rate.

Effect of surgeon's diagnosis on surgical wound infection rates

To determine the impact of a surgeon's diagnosis of surgical wound infections on infection rates, during a 6-month period we prospectively examined patients undergoing surgical wound surveillance for any of four services (orthopedic surgery, general surgery, neurosurgery, or cardiovascular surgery). Criteria were judged as standardized if the infection control practitioner observed pus, redness, or drainage associated with positive culture or if a diagnosis of deep-seated infection was made. Surgeon's diagnosis was judged as a nonstandardized criterion. Using the Centers for Disease Control's criteria, we identified 113 surgical wound infections in 3024 patients undergoing surgical procedures in the four services. Of these, 95 (84%) met objective criteria (pus observed in 53%; drainage, redness, and positive culture in 20%; and deep-seated infection in 11%). In 18 patients (16%), the nonstandardized criterion alone was used for diagnosis. There was wide variation in use of the nonstandardized criterion, ranging from 5% of orthopedic infections to 21% of cardiovascular surgery infections and 40% of neurosurgical infections. For individual surgeons with at least one wound infection, the range of surgeon's diagnosis was up to 67%. We conclude that a surgeon's diagnosis can have a major impact on surgical wound infection rates; this impact is not borne equally among surgical services or individual surgeons.

Failure of preoperative cultures to predict development of Staphylococcus aureus wound infections after cardiac surgery

To assess the predictive value of preoperative surveillance cultures for the postoperative development of Staphylococcus aureus wound infection, the findings in 563 patients who underwent elective cardiac surgery were evaluated. One hundred and forty-seven (26%) were found to be S. aureus carriers preoperatively. Postoperatively, 11 S. aureus wound infections developed, 4 in patients whose cultures were positive preoperatively and 7 in patients whose cultures were negative preoperatively. The patient's endogenous flora appears to be the source of only a minority of such postoperative infections. The authors conclude that preoperative surveillance cultures are not of value in predicting patients at risk for wound infection after elective cardiac surgery.

Atrial pacing during percutaneous transluminal coronary angioplasty: results and comparison with exercise treadmill testing

Right atrial pacing (RAP) was used to immediately assess improvement in threshold for myocardial ischemia in 23 patients undergoing angiographically successful percutaneous transluminal coronary angioplasty (PTCA). Multiple coronary lesions were present in 19 patients, and 15 had incomplete revascularization. All patients had RAP done immediately before and after completion of all dilatations, and in 13 patients pre- and post-PTCA exercise treadmill tests (ETT) were also performed. Angina occurred in 16 (70%) patients during pre-PTCA RAP, but in only 4 (17%) after PTCA (p less than .05). The electrocardiogram was positive for ischemia (horizontal or downsloping ST depression greater than or equal to 1 mm) in 18 patients (78%) during pre-PTCA RAP. However, 13 patients (57%) continued to have an ischemic response during post-PTCA RAP (not significant-NS). In 4 patients with multiple coronary lesions who had sequential pacing studies after PTCA of each lesion, the maximum degree of ST depression decreased by 1 mm or more after each dilatation in 3 patients but remained greater than or equal to 1 mm in all. In the 13 patients undergoing both RAP and ETT, angina developed in 7 during pre-PTCA RAP and in 2 after PTCA (p less than .05), compared with 8 and 3 (p less than .05) during pre- and post-PTCA ETT, respectively. Ischemic ST depression occurred in 9 patients during pre-PTCA RAP and in 6 after PTCA (NS), and in 8 and 6 (NS) during pre- and post-PTCA ETT, respectively. Concordance between the two tests was good.(ABSTRACT TRUNCATED AT 250 WORDS)