Exhaled breath condensate isoprostanes are elevated in patients with acute lung injury or ARDS

BACKGROUND: Oxidant stress is a purported mechanism of tissue damage in patients with ARDS and acute lung injury (ALI). Isoprostanes, prostanoid compounds primarily formed nonenzymatically via lipid peroxidation, are precise markers of in vivo oxidant stress. Plasma levels of metabolites of 8-iso-prostaglandin-F2alpha (8-iso-PGF2alpha) correlate with outcome in patients with ARDS. OBJECTIVE: To examine exhaled breath condensate levels of 8-iso-PGF2alpha as a noninvasive quantification of pulmonary oxidant stress in patients with, or at risk for, ARDS/ALI. METHODS: Breath condensate was collected from 22 patients with, or at risk for, ARDS/ALI by placing Tygon tubing submerged in an ice bath in line with the expiratory limb of the ventilator circuit. Ten patients without lung disease, who were intubated while undergoing minor surgical procedures, served as control subjects. Between 1 and 3 mL of condensate was collected over a 30- to 60-min period, then immediately frozen and stored at -70 degrees C until analysis. The 8-iso-PGF2alpha was purified and derivatized, then quantified by stable isotope dilution in conjunction with gas chromatography/mass spectrometry. RESULTS: The mean level of exhaled 8-iso-PGF2alpha in the patients with ALI/ARDS, 87+/-28 pg/mL, was significantly higher than the mean in the normal group, 7+/-4 pg/mL (p = 0.007). The 8-iso-PGF2alpha levels were greater than two standard deviations above the mean of the normal group in 12 of 22 patients with or at risk for ARDS/ALI. CONCLUSIONS: These results provide further evidence that lipid peroxidation does occur in patients with ARDS/ALI. The measurement of exhaled isoprostanes provides a novel, noninvasive method to quantify oxidant stress in such patients.     

Role of ATP in the mechanism of serotonin absorption by lung tissue

Tests set up on the isolated perfused lungs of albino rats and on intact dogs demonstrated that the serotonin absorption by the pulmonary tissue is attended by a drop of the ATP amount in the lungs. The exogenous ATP has no essential effect on the serotonin absorption by the pulmonary tissue, its considerable quantities being metabolized in the pulmonary capillaries.     

Carbon dioxide field flooding minimizes residual intracardiac air after open heart operations

Transesophageal echocardiographic studies were used to monitor the presence of air bubbles in the heart after open heart operations. After cardiac valvular procedures all 22 patients managed with careful deairing procedures had persistence of air bubbles for at least 30 minutes and usually for 45 minutes. In 56 patients with CO2 field flooding, all foam disappeared in less than 1 minute in 48 patients and the remaining 8 had complete disappearance in 1 to 24 minutes. These observations demonstrate the ineffectiveness of the usual deairing maneuvers and the effectiveness of CO2 field flooding in displacing air.     

Scanning electron microscopic study and shear bond strength measurement with 5% and 37% phosphoric acid

Direct bonding of orthodontic attachments has become a clinical reality with the application of the acid etch technique, using 37% phosphoric acid. The objective of this study was to detect the etch pattern with scanning electron microscopy and the shear bond strength with a Hounsefield tensometer (Nene Instruments Ltd., Northampton, England) by using 37% and 5% phosphoric acid (H3PO4). It was observed that with 5% H3PO4 there was minimal enamel loss compared with 37% H3PO4. There was no significant difference in shear bond strength, when enamel surface was etched with 5% H3PO4 and 37% H3PO4.     

Interaction of fluorescent probes with membranes of sarcoplasmic reticulum in AMP deamination

Gentamicin and ampicillin were dissolved in an L-amino acid solution especially prepared for newborn infants and infused intravenously over 24 h in 7 babies with serious neonatal surgical problems. Serum concentrations of the antibiotics were maintained rather constant and well above the minimal inhibitory concentration for most bacterial strains. One very sick newborn infant died with overwhelming Klebsiella pneumoniae septicemia. No signs of renal toxicity or ototoxicity were found. The serum amino acids remained within the normal range, except in 1 child with cytomegalovirus infection and liver insufficiency.     

Effect of angiotensin-converting enzyme inhibition on bronchial responsiveness

BACKGROUND: Many studies have shown that CA 125 levels frequently rise prior to clinical evidence of progression of ovarian cancer. For clinical trials an accepted definition of progression according to CA 125 is required. We therefore determined what change in CA 125 level was the most accurate predictor of relapse in patients on follow up after therapy for ovarian cancer. PATIENTS AND METHODS: Serial CA 125 levels were studied from 255 patients entering the North Thames Ovary Trial of 5 versus 8 courses of chemotherapy. An initial analysis was made 2 months after closure of the trial, a more detailed analysis was made after 81 confirmed relapses among evaluable patients and a final analysis was made one year later with longer follow-up. RESULTS: On the basis of the results from the interim analyses and the cut-off level of 22-35 U/ml used by different laboratories, 30 U/ml was chosen as the upper limit of normal. In the final analysis a doubling of CA 125 from the upper limit of normal was defined as progression. Using this method sensitivity was 85.9%, specificity 91.3%, positive predictive value 94.8%, and negative predictive value was 77.8%. Insisting on a confirmatory elevated CA 125 level reduced the false positive rate to < 2% with a sensitivity of 83.9%. The median lead-time prior to clinical progression was 63 days. CONCLUSION: A confirmed rise of serum CA 125 level to more than twice the upper limit of normal during follow up after first line chemotherapy accurately predicts tumour relapse.