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At least 55 records · Page 3Linked to original sources
PubMed2004

Application of the biosphere reserve concept to urban areas: the case of São Paulo City Green Belt Biosphere Reserve, Brazil--São Paulo Forest Institute: a case study for UNESCO.

This report attempts to bring together contributions from technicians and scientists studying and dealing with the manifold aspects of the São Paulo City Green Belt Biosphere Reserve. It will highlight the understanding by UNESCO of the important role that biosphere reserves can play in the urban setting.

Air Pollution↗
PubMed1996

Does coronary flow reserve assessed by blood flow velocity analysis reflect absolute coronary flow reserve?

Doppler guidewire enables us to measure phasic coronary velocity and has been used for the measurement of coronary flow reserve (CFR). Although CFR is usually calculated by the quotient of peak flow velocity during papaverine infusion and flow velocity at rest, this assumption is true only if conduit vessel size is constant. To determine the accuracy of measurement of CFR using average peak velocity (APV) with Doppler guidewire, we investigated the influence of intracoronary papaverine on coronary flow velocity and coronary arterial diameter (CAD) and examined the correlation between CFR derived using APV and that derived using coronary blood flow (CBF) in 26 patients with normal coronary arteries. We measured phasic coronary flow velocity, and performed quantitative coronary angiography in the proximal left coronary artery at control and during 10 mg of intracoronary papaverine. Compared to control value, papaverine induced a significant increase in APV (% increase: 182 +/- 101%; P < 0.001). Papaverine also significantly increased CAD (16 +/- 10%; P < 0.001). Thus, CFR derived from APV was significantly lower than that derived from CBF (2.8 +/- 1.0 vs. 4.0 +/- 1.5, P < 0.001). Although there was a significantly strong positive correlation between these two methods (R2 = 0.83, P < 0.001), there was also considerable variability with regard to predicting one variable from the other. These results suggest the importance of standardizing the conditions in which coronary flow velocity is measured with regard to either controlling or measuring changes in epicardial coronary arterial diameter during changes in distal resistance vessel tone.

Adult↗
PubMed2006

Dobutamine stress echocardiography is highly accurate for the prediction of contractile reserve in the early postoperative period, but may underestimate late recovery in contractile reserve after revascularization of the hibernating myocardium.

OBJECTIVE: We sought to investigate the accuracy of dobutamine stress echocardiography to predict the degree and timing of recovery in resting function and contractile reserve (CR) after revascularization of the hibernating myocardium. METHODS: In all, 24 patients with ischemic cardiomyopathy (ejection fraction < 40%) underwent dobutamine stress echocardiography 1 week before and 6 weeks, 3 months, and 6 months after coronary artery bypass grafting. RESULTS: Recovery rates at 6 weeks, 3 months, and 6 months postoperation were 21%, 33%, and 45% (P < .01) for resting function and 55%, 65%, and 74% (P < .01) for CR. Positive and negative predictive values for recovery of resting function and CR at 6 months postrevascularization were 66% vs 97% (P < .001) and 78% vs 48% (P < .001), respectively. Positive and negative predictive values were both high for recovery of CR at 6 weeks postrevascularization (89% and 78%). CONCLUSIONS: Dobutamine stress echocardiography can predict early recovery in CR postrevascularization with an excellent accuracy but may underestimate the degree of late recovery in CR.

Cardiomyopathies↗
PubMed1998

Relationship between % heart rate reserve and % VO2 reserve in treadmill exercise.

For exercise prescription purposes, it is often assumed that % heart rate reserve (%HRR) provides equivalent intensities to %VO2max. However, a recent study from this laboratory demonstrated that during cycling exercise %HRR is not equivalent to %VO2max, but is instead equivalent to a percentage of the difference between resting and maximal VO2, i.e., % VO2reserve (%VO2R). The current study examined these relationships during treadmill exercise. Fifty adults performed Bruce protocol treadmill tests to exhaustion. For each subject, data obtained at rest, at the end of each stage, and at maximum were used to determine linear regressions of %HRR versus %VO2max, and of %HRR versus %VO2R. For %HRR versus %VO2max the mean intercept and slope were -6.1+/-0.7 and 1.10+/-0.01, respectively, with a mean r of 0.990+/-0.002. For %HRR versus %VO2R, the mean intercept and slope were 1.5+/-0.6 and 1.03+/-0.01, respectively, with a mean r of 0.990+/-0.002. Both regressions differed statistically from the line of identity (i.e., intercept of 0 and slope of 1). However, the regression of %HRR versus %VO2R was significantly closer (P < 0.001 ) to the line of identity than was the regression of %HRR versus %VO2max. We conclude that %HRR should be considered as an indicator of %VO2R, not %VO2max, when prescribing treadmill exercise, as was previously concluded for cycling exercise.

Adolescent↗
PubMed1992

[Rational blood reservation for elective surgery. A prospective evaluation of blood reservation, use of transfusions and resources].

Danish and international studies have documented that preoperative blood ordering policy in elective surgery is extremely inefficient if not based on knowledge of actual transfusion frequencies and requirements. During a 12-month period, the impact of practical application of Type & Screen (T&S), and a thoroughly revised preoperative blood ordering policy in elective surgery, on crossmatch ordering, transfusion extent and safety were assessed prospectively. In addition, the effect on resource and laboratory economy was estimated, using the number of crossmatches, crossmatch to transfusion (C/T) ratio, out-dating, transfusion complications, and the proportional use of fractionated red cell products (erythrocyte concentrate and suspension) as efficiency parameters. In 86% out of 6,766 surgical procedures the recommendations were followed. A total of 1,736 patients had a preoperative cross-match of two or more units of blood and 25.1% were transfused during or within 48 hours following surgery. Only 2.4% of patients with T&S were transfused. Of the crossmatched blood 18.1% was actually transfused, and the overall crossmatch to transfusion ratio (C/T-ratio) was 5.33. In only 0.5% of operations, unexpected crossmatching and transfusions proved necessary during surgery. None of the reported transfusion complications were due to failure of the T&S procedure. During a period of increasing blood bank activities, as measured by the number of blood groupings and the blood turnover, a significant decrease in C/T-ratio and number of crossmatches was observed, corresponding to an estimated annual reduction of 11,000 crossmatches. Outdating declined from 9 to 3.2%, corresponding to savings of approximately 1,000 transfusion units annually, while the complication rate remained constant at 1.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Banks↗