Response of therapy-associated acute nonlymphocytic leukemia to intensive induction chemotherapy.

Among 31 consecutive patients who developed acute nonlymphocytic leukemia following treatment with chemotherapy or radiation therapy, 17 were treated with intensive chemotherapy aimed at inducing a complete remission. Seven of these 17 patients (41%) obtained a complete remission that ranged in duration from 2 to 11 (median 3) months. Two additional patients who failed to develop normal peripheral blood counts despite postinduction bone marrows that were normocellular and free of leukemia were classified as nonresponders. The median time to complete remission and median duration of leukopenia (WBC less than 1,000/mu 1) were 34 days and 23 days, respectively. Induction chemotherapy was complicated by fever in all patients, documented infection in six patients, and death secondary to sepsis in three. Survival of the 17 patients ranged from less than 1 to 39 (median 4) months. Patients achieving a complete remission had a median survival time of 10 months compared to 2 months for the nonresponders. The other 14 patients received only supportive care and had a median survival of 2 months. These findings indicate that therapy-associated acute nonlymphocytic leukemia (t-ANLL) can frequently respond to chemotherapy and that achieving a complete remission is associated with longer survival. Although these results are encouraging, patients with t-ANLL still have a relatively poor prognosis and efforts directed at improving treatment outcome need to be continued.

Acute nonlymphocytic leukemia in adults. When diagnosis and pretreatment assessment can't wait.

Because adults with acute nonlymphocytic leukemia (ANLL) frequently present with vague complaints and nonspecific findings, it is usually the primary care physician who sees them first. The initial clinical evaluation of such patients should include making the diagnosis, beginning to characterize the leukemia, and assessing the overall medical condition of the patient. All phases of this evaluation should be completed with a sense of urgency because immediate medical intervention is often necessary. Prompt assessment and institution of therapy take on added importance now that effective chemotherapy is available. Currently, a large majority of patients with ANLL respond to treatment and 15% to 20% are probably cured. With the use of various clinical and laboratory studies, the physician can rapidly confirm a suspected diagnosis of ANLL and systematically evaluate the patient's condition prior to arranging for appropriate treatment.

Distal airway responses to changes in oxygen and carbon dioxide tensions.

The reactivity of subpleural strips of lung parenchyma reflects primarily the tone of the smooth muscle in the peripheral airways. Lung strips taken from ten dogs relaxed when the oxygen level in the gas bubbling through the bath was reduced from 95% to 18%. Subsequent hypocapnia (carbon dioxide reduced from 5% to 0%) induced contraction of all strips. These changes were reversed when the oxygen or carbon dioxide tensions were restored to control levels. Addition of either indomethacin or meclofenamate, two chemically dissimilar inhibitors of prostaglandin synthetase, reduced the resting tone in each of six strips and prevented the hyperoxic constriction which was observed in paired, control strips (oxygen increased from 18% to 95%). Blockers of histamine and catecholamines had no effect. The reactivity of the distal airways to changes in gas tension provides a mechanism by which ventilation and perfusion can be matched. The action of indomethacin and meclofenamate indicates that a prostaglandin-like substance may be involved in the maintenance of distal airway tone and in the constriction produced by hyperoxia. The addition of prostaglandin F2 alpha or E1, after meclofenamate, in a further nine pairs of strips did not restore the hyperoxic constriction. This suggests that prostaglandins may mediate, rather than merely facilitate, the response.