Because patients treated with 60-90 mg/m2 every three to four weeks reach cardiotoxic doses of 550 mg/m2 within 36 weeks, prolonged treatment with Adriamycin is limited. The purpose of this study was to determine whether lower doses could be given over longer periods without loss of efficacy. Good risk patients treated with 75,60, or 45 mg/m2 had remission rates of 25,27, and 19%; poor risk patients treated with 50 and 25 mg/m2 had remission rates of 16 and 12% respectively. Although a dose response was identified, there were no statistically significant differences in remission rates, durations of remission, or toxicities in the dose schedules studied. Irreversible congestive heart failure occurred in five patients with cumulative doses of240-390 mg/m2. Unless rapid remission induction is urgent, we recommend 60 mg/m2 X four doses and measurement of myocardial function if treatment is to continue.
Our study suggests that patients with known BCG exposure and PI-RADS v2 scores ≤3, showing similar mpMRI findings as demonstrated, may not require prostate biopsy.
To determine whether hypoxic pulmonary vasoconstriction (HPV) occurs mainly in alveolar or extra-alveolar vessels in ferrets, we used two groups of isolated lungs perfused with autologous blood and a constant left atrial pressure (-5 Torr). In the first group, flow (Q) was held constant at 50, 100, and 150 ml.kg-1 X min-1, and changes in pulmonary arterial pressure (Ppa) were recorded as alveolar pressure (Palv) was lowered from 25 to 0 Torr during control [inspired partial pressure of O2 (PIO2) = 200 Torr] and hypoxic (PIO2 = 25 Torr) conditions. From these data, pressure-flow relationships were constructed at several levels of Palv. In the control state, lung inflation did not affect the slope of the pressure-flow relationships (delta Ppa/delta Q), but caused the extrapolated pressure-axis intercept (Ppa0), representing the mean backpressure to flow, to increase when Palv was greater than or equal to 5 Torr. Hypoxia increased delta Ppa/delta Q and Ppa0 at all levels of Palv. In contrast to its effects under control condition, lung inflation during hypoxia caused a progressive decrease in delta Ppa/delta Q, and did not alter Ppa0 until Palv was greater than or equal to 10 Torr. In the second group of experiments flow was maintained at 100 ml.kg-1 X min-1, and changes in lung blood volume (LBV) were recorded as Palv was varied between 20 and 0 Torr. In the control state, inflation increased LBV over the entire range of Palv. In the hypoxic state inflation decreased LBV until Palv reached 8 Torr; at Palv 8-20 Torr, inflation increased LBV.(ABSTRACT TRUNCATED AT 250 WORDS)
To evaluate the role of leukotrienes in hypoxic pulmonary vasoconstriction, we measured steady-state pressor responses to graded hypoxia in isolated ferret lungs perfused with autologous blood containing 0.001, 0.03, 1, or 3 mM nordihydroguaiaretic acid (NDGA), 1 mM BW 755C, or 0.02-0.05 mM indomethacin. Untreated lungs served as controls. Perfusate concentrations of thromboxane B2 and 6-ketoprostaglandin F1 alpha, measured by radioimmunoassay, were markedly reduced in all treated lungs, indicating inhibition of cyclooxygenase. The maximum pressor response to hypoxia measured at a blood flow of 50 ml.min-1. kg-1 averaged 26.6 +/- 2.4 Torr in untreated lungs and was not affected by BW 755C or 0.001-0.03 mM NDGA. Because BW 755C and NDGA inhibited cyclooxygenase at concentrations that did not affect hypoxic vasoconstriction and because both agents are thought to inhibit lipoxygenase with a potency greater than or equal to that with which they inhibit cyclooxygenase, these results do not support the possibility that hypoxic pulmonary vasoconstriction was mediated by leukotrienes. At concentrations of 1 and 3 mM, NDGA inhibited the maximum hypoxic pressor response by 57 and 95%, respectively. The mechanism of this attenuation is unknown; however, it was apparently not due to cyclooxygenase inhibition, since indomethacin enhanced the maximum hypoxic pressor response by 45%. Nor was it due to blockade of calcium entry or interference with the contractile process in pulmonary vascular smooth muscle, since 1 mM NDGA did not inhibit vasoconstrictor responses to KCl or prostaglandin F2 alpha.
We have previously shown that after exposure to an inspired O2 tension less than 25 Torr, isolated lungs perfused with autologous blood exhibit vasoconstriction followed by dilation. Because adenosine has been implicated as a mediator of hypoxic vasodilation in the systemic circulation and because the concentration of adenosine in the lung has been shown to increase with hypoxia, we tested the hypothesis that adenosine is the mediator of hypoxic pulmonary vasodilation. We first confirmed that adenosine was a vasodilator in isolated lungs of adult male ferrets. Next we added the enzyme adenosine deaminase (ADase), which inactivates adenosine by converting it to inosine, to the perfusate before exposure to one of two levels of hypoxia [inspiratory PO2 (PIO2) 18 or 0 Torr]. In comparison with untreated lungs, the time course of pulmonary arterial pressure at constant flow in lungs treated with ADase (24 mg protein or 6,000 U) was not different; however, when the vessels were constricted at PIO2 25 Torr, ADase prevented vasodilator responses to adenosine administered into either the perfusate or the airways, indicating penetration of active ADase into the interstitium. Unless adenosine released endogenously into the interstitium during hypoxia was somehow protected from the ADase which reached the interstitium, these results indicate that hypoxic pulmonary vasodilation was not mediated by adenosine.
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