Tsutomu Saga

The air crescent sign of invasive pulmonary mucormycosis in acute leukemia

An unusual radiographic sign of crescentic cavitation appeared in a case of invasive pulmonary mucormycosis complicating the treatment of a patient with acute myelogenous leukemia and having a normal admission chest radiograph. The first manifestation was a large, wedge‐shaped pleural‐based consolidation, which evolved about 10 days later into a fungus ball‐like lesion, usually known as the air crescent sign. Amphotericin B and 5‐fluorocytosine, which were initiated immediately after appearance of the sign, proved to be effective, probably in association with hematologic improvement. Transbronchial lung biopsy was not only helpful in establishing a definitive diagnosis, but also suggested that an intracavitary mass could have resulted from pulmonary infarction. This experience thus showed that the sign may appear in greater frequency in mucormycosis as well as in aspergillosis, and may be useful as a clinical index for initiating antifungal therapy in immunocompromised patients.

Inhibitory effect of N-(3',4'-dimethoxycinnamoyl)anthranilic acid(N-5') on SRS-A mediated bronchoconstriction in the guinea pig in vivo

Slow‐reacting substance of anaphylaxis (SRS‐A) is an important factor mediating bronchoconstriction in asthma. We developed a guinea pig model for SRS‐A‐mediated bronchoconstriction induced by antigen inhalation. Using this model, we investigated the effect of N‐(3′, 4′‐dimethoxycinnamoyl) anthranilic acid (N‐5′), a new anti‐allergic drug, on the bronchoconstriction. FPL 55712 inhibited most of the bronchoconstriction induced by antigen inhalation. N‐5′inhibited the antigen‐induced bronchoconstriction in a dose‐dependent fashion. Intraperitoneal administration of 200 mg/kg N‐5′was effective for 40 min after antigen inhalation, while the effect of 60 mg/kg lasted only 7 min. On the other hand, 200 mg/kg N‐5′showed no inhibitory effect on the bronchoconstriction caused by direct inhalation of leukotriene C4, a component of SRS‐A. These findings indicate that one of the anti‐allergic actions of N‐5′is due to inhibition of synthesis and/or release of SRS‐A.

Effects of Ca2+ Antagonist, Nicardipine, on Experimental Asthma With Special Reference to Slow Reacting Substance of Anaphylaxis

Slow reacting substance of anaphylaxis (SRS‐A) is an important chemical mediator of bronchial asthma. Leukotriene C4 is a component of SRS‐A and is synthesized from arachidonic acid. Its synthesizing and releasing processes are found to he Ca2+‐dependent. We developed an in vivo inhalation asthma model, mainly mediated by SRS‐A, and elucidated the relationship between a Ca2+‐antagonist, nicardipine, and SRS‐A. In the asthmatic model, mediated by endogenous SRS‐A induced by antigen inhalation, continuous intravenous infusion of nicardipine 7 μg/kg/min depressed the open airway pressure by about 60% compared with the saline‐treated group. Inhibition of mean pulmonary resistance (RL) was about 50% and that of the inverted value of dynamic compliance (1/Cdyn) about 36%. However, the same concentration of nicardipine did not significantly affect the airway response in the asthmatic model induced by the inhalation of leukotriene C4. These results suggest that nicardipine, at the concentration used in the present study, did not block the direct effect of SRS‐A on the smooth muscle, but blocked the Ca2+ influx required for the synthesis of SRS‐A and its release.

TWO CASES OF AEROMONAS HYDROPHILA SEPTICEMIA ASSOCIATED WITH ACUTE LEUKEMIA

急性骨髄性白血病の2症例にAeromonas hydrophila敗血症が経験された. 1例は,緩解導入直後に発症し,他の1例は,腰筋内膿瘍が敗血巣septic focusとなつて,再発性敗血症を呈した.両例は,ほぼ同一時期に同一病棟に入院していたが,交叉感染cross-infectionはま否定された.血中抗体価の測定から,発症前に血中抗体価の上昇がみられる場台には,既存の病巣が推定され,再発予防のため,十分な抗生薬療法を行なう必要のあることが強調された.さらに,非病原性菌と考えられる本菌感染症の発症には,宿主防禦機構の減弱が重要な役割を果していることが示唆された.急性白血病における本菌敗血症は,典型的なuosocomial and opporunistic infectionと考えられる.本論文では,急性白血病に合併したA. hydrohila敗血症の2症例の提示とともに,急性白血病で本菌感染症がもつ臨床的意義を臨床細藏学の立場から論ずる.