Studies on the mutagenicity of mild gasification products of coal and their subfractions by the Salmonella/microsomal assay.

Mild gasification of coal is a technology being developed in the United States in order to upgrade lower rank coals and facilitate their use in coal-burning electric generation plants. Thirteen coal-derived mild gasification products from different coal sources and processing conditions have been examined for their potential biohazards. The mutagenicity of these samples was tested with the Ames Salmonella/microsomal assay. Two solvents, dimethyl sulfoxide (DMSO) and polyoxyethylene-sorbitan monooleate (Tween 80), were used to dissolve samples in a manner to facilitate their interaction with the test organisms. The results showed that 9 of the 13 samples displayed mutagenic activity in test strains TA98 and/or TA100 with or without metabolic activation, whether dissolved in Tween 80 or DMSO. Five mutagenic and two nonmutagenic samples were class-fractionated into basic, acidic, nonpolar, and polar neutral subfractions to examine their class-related mutagenic activities. Results of the testing of subfractions of the five mutagenic and one nonmutagenic samples showed mutagenic activity in at least the nonpolar neutral fraction. The subfractions of the another nonmutagenic sample did not display any mutagenic activity. Chemical characterization of the subfractions revealed the existence of aromatic hydrocarbons in certain subfractions, which may be responsible for the mutagenic activity of the coal-derived mild gasification products.

Modification of alveolar macrophage function with bis-basic ethers of fluorene and fluoren-9-substituted derivatives.

Bis-basic ethers of fluorene and fluoren-9-substituted derivatives such as tilorone have been reported to inhibit silica-induced fibrosis in rats. The potential antifibrotic potency of 2,7-bis(diethylamino)ethoxy fluorene (F-9-H,H), fluorenone (F-9-one), fluorenoxime (F-9-oxime), and fluorenol (F-9-ol) was F-9-oxime > F-9-one approximately F-9-H,H >> F-9-ol. Since the release of reactive oxygen species and growth factors from alveolar macrophages (AM) in response to silica exposure has been linked to the development of pulmonary fibrosis, the present study was carried out to determine the inhibitory effects of these compounds on rat AM activity in vitro. The following parameters were monitored: (1) cellular viability; (2) zymosan-induced respiratory burst activity (superoxide and hydrogen peroxide release, chemiluminescence, and oxygen consumption) of AM; (3) drug binding to AM; and (4) lipopolysaccharide (LPS)-stimulated interleukin-1 (IL-1) release from AM. The bis-basic ethers, at 40 microM, did not affect cell viability when incubated with AM for 30 min, but significantly inhibited zymosan-induced macrophage respiratory burst activity. The inhibitory effect of these agents was F-9-oxime > F-9-one approximately F-9-H,H >> F-9-ol. Binding of these drugs to AM was time and dose dependent, and exhibited the following binding affinity: F-9-oxime > F-9-one > F-9-H,H > F-9-ol. F-9-oxime was shown to inhibit LPS-stimulated IL-1 release by AM in a dose-dependent manner. This inhibition of IL-1 release by AM cannot be explained as a decrease in viability. In addition, these drugs were also shown to impair human fibroblast proliferation in response to serum stimuli without impairing cell viability. These results indicate a positive correlation between drug binding to AM or other cell types and their inhibitory effects on cellular activities including oxygen consumption, superoxide release, hydrogen peroxide secretion, chemiluminescence, IL-1 release, and proliferation. The ability of these bis-basic ethers to modify AM and fibroblast functions in vitro suggests that further investigation of their reported antifibrotic potency in vivo is warranted.

[Alveolar hydatid disease: report of 90 cases].

From 1960 through 1992, 2750 cases of hydatid disease disease were admitted to our hospital, among them there were 90 cases of alveolar hydatid disease proved by laparotomy, biopsy, or autopsy. The preoperative misdiagnosis rate in this series was 24.3% owing mainly to the difficulty of differentiating from multilocular echinococcosis and liver cancer. Basing on clinical and pathological features, the authors proposed its diagnostic and staging principles, and therapeutic approaches to improve the prognosis of this disease.

[High risk factors in the prognosis of acute necrotizing pancreatitis].

In this study, Ranson's risk factors were evaluated on 36 cases of acute necrotizing pancreatitis. It was found that all 13 cases with more than 7 factors each died, the mortality rate was 100%, and 2 of 5 cases with 5-7 factors each succumbed with the mortality rate of 40%. The remaining 14 cases, all of them with less than 3 factors each, survived the stormy attacks. The authors believe that Ranson's risk factors are reliable in predicting the prognosis of acute necrotizing pancreatitis.