[Stimulation of the fecal excretion of polychlorinated biphenyls (KC-600) by diets containing rice bran fiber and cholestyramine].

Among the eight kinds of dietary fiber tested, rice bran fiber (RBF) mostly bound Kanechlor 600 (PCB) in vitro. The PCB bound to dietary fiber was in proportion to the lignin content in dietary fiber. We investigated whether RBF, lignin, cholestyramine and their combination stimulate the fecal excretion of PCB in rats. In the group fed a diet containing 10% (w/w) RBF, fecal excretion of PCB was stimulated. In the group fed a diet containing 10% (w/w) RBF and 5% (w/w) cholestyramine, more PCB was excreted in the feces. However, the group fed a diet containing 10% (w/w) RBF and 5% (w/w) lignin excreted the same amount of PCB as the group fed a diet containing 10% (w/w) RBF. The total PCB excreted into the feces for 21 days in the groups fed 10% (w/w) RBF, 10% (w/w) RBF and 5% (w/w) lignin, 5% (w/w) cholestyramine and 10% (w/w) RBF and 5% (w/w) cholestyramine diet was 3.4, 3.8, 2.3 and 5.7 times, respectively, that of the control. The stool transit time of rats fed 10% (w/w) RBF and 5% (w/w) cholestyramine diet was one hour faster than that of rats fed a 5% (w/w) cholestyramine diet. Therefore, we concluded that RBF has the greatest effect when administered in combination with cholestyramine on the fecal excretion of PCB.

[Polychlorinated dibenzofurans (PCDFs) in the subcutaneous adipose tissue of yusho patients and normal controls].

Polychlorinated dibenzofurans (PCDFs) are well known to be the toxic chemicals in both animal experiments and human studies. It is, therefore, important to determine the level of PCDFs still retained in patients for understanding relationship between the concentration of PCDFs and present symptoms of the disease. In this study, the abdominal subcutaneous adipose tissue of 18 yusho patients and those of 11 normal controls who were all of volunteers were collected, and their levels were determined by high resolution gas chromatography/high resolution mass spectrometry. Results obtained were as follows: The principal compounds detected in the adipose tissue of yusho patients were 2,3,4,7,8-pentachlorodibenzofuran (PenCDF), 1,2,3,4,7,8- and 1,2,3,6,7,8-hexachlorodibenzofuran (HCDF). The concentration of the compounds in 7 patients, wearing typical symptoms, from 160 to 3,000 ppt for 2,3,4,7,8-PenCDF, from 51 to 1,000 ppt for 1,2,3,4,7,8-HCDF, and from 16 to 220 ppt for 1,2,3,6,7,8-HCDF. In normal controls, 2,3,4,7,8-PenCDF was detected only in five samples at the low level of from 16 to 38 ppt. On an average, PCDF levels in in the typical 7 yusho patients and 11 normal controls were 1,900 ppt and 16 ppt, respectively. On the basis of the results, the concentrations of PCDF congeners in the adipose tissues of the typical 7 patients was 100 times higher than that of the normal controls. Hence, we consider that the present levels of PCDFs in the patients probably play an important role for the symptoms of the yusho.

[Therapeutic trial for promotion of fecal excretion of PCDFs and PCBs by the administration of cholestyramine in Yusho patients].

Any effective therapy for elimination of causal agents remaining in Yusho patients was not found until now. To know the profile of fecal excretion of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs), the amounts of PCDFs and PCBs in the stool of six Yusho patients with the typical symptoms were determined. The stool samples of Yusho patients were collected in 1989. PCDFs, i.e., 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PnCDF), 1,2,3,4,7,8- and 1,2,3,6,7,8-hexachlorodibenzofurans (HxCDFs), 1,2,3,4,6,7,8-heptachlorodibenzofuran (HpCDF) and octachlorodibenzofuran (OCDF) were detected in all of the samples. PCDFs found in the stool samples were mostly PnCDF and HxCDFs. Of PCDFs detected, PnCDF and HxCDFs contributed to 42 +/- 4.7% and 43 +/- 5.5% as mean +/- SE, respectively. The fecal excretion of PnCDF and HxCDFs in Yusho patients was 720 +/- 490 pg/day and 790 +/- 620 pg/day as mean +/- SE, respectively. On the other hand, the fecal excretion of PnCDF and HxCDFs in normal controls was 32 +/- 13 pg/day and 47 +/- 5.2 pg/day as mean +/- SE, respectively. The fecal excretion of PnCDF and HxCDFs in Yusho patients was about 23 times and 17 times each higher than that in normal controls. The fecal excretion of PCBs in Yusho patients and normal controls was 400 +/- 430 ng/day and 150 +/- 39 ng/day, respectively, as mean +/- SE. In order to promote the excretion of these toxic chemicals in the stool of Yusho patients, the patients were continuously administered with cholestyramine, an anion exchange resin, at a dose of 4 g, 3 times a day, for 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Artificial Pseudomonas aeruginosa biofilms and confocal laser scanning microscopic analysis.

Bacterial biofilms may be formed at various sites, including mucous membranes, teeth, and infectious lesions. To elucidate the structure and the function of biofilms, artificial biofilms of mucoid-type Pseudomonas aeruginosa organisms (strain PT1252) were made by centrifuging the organisms onto the surface of a coverglass and culturing further in broth media supplied continuously (45 ml/h). The biofilm structure at 4, 8, 12, and 24 h was visualized with fluorescent staining (SYTO9, propidium iodide [PI], and/or fluorescein isothiocyanate-concanavalin A [FITC-ConA]) by confocal laser scanning microscopy (CLSM). It was clearly demonstrated that the number of bacteria (10(4)--10(6)/ml) could be estimated by their fluorescence intensity. Sectional analysis of each biofilm layer (1-microm thickness) made it possible to demonstrate the three-dimensional development of biofilms, and revealed that the biofilms were 9 microm in height after 12 h. The live and dead organisms were differentiated by SYTO9 and PI, respectively, in situ in biofilms, and about 13% of the organisms were dead in 12-h-old biofilms. When 12-h-old biofilms were exposed to ciprofloxacin at minimum bactericidal concentration (6.26 microg/ml) for 90 min, all the organisms were killed, but some organisms (11 +/- 1.3%; n = 3) in 24-h-old biofilms with thicker and denser structure were still alive after exposure for 120 min. These results indicate that the CLSM analysis of artificial biofilms was useful for elucidating bacterial functions in biofilms, and may lead to a new quantitative system for estimating the bactericidal efficacy of antibacterial drugs in biofilms.

Effects of rice bran fibre and cholestyramine on the faecal excretion of Kanechlor 600 (PCB) in rats.

1. As rice bran fibre binds Kanechlor 600 (PCB), the present study was conducted to determine whether the fibre stimulates rat faecal excretion of PCB in vivo. 2. In rats fed diets containing rice bran fibre, lignin and cholestyramine, the faecal excretion of PCB was increased. Total PCB excreted in rat faeces for groups fed diets of 10% (w/w) rice bran fibre, 10% fibre plus 5% lignin, 5% cholestyramine and 10% fibre plus 5% cholestyramine were 3.4, 3.7, 2.2 and 5.4 times as much, respectively, as that of control rats. The greatest effect on the faecal excretion of PCB was thus obtained with rice bran fibre plus cholestyramine. 3. In rats fed these diets, PCB concentration of the small intestine was significantly decreased to 25-50% of that of controls. PCB of spleen in rats fed diets of 10% fibre, 10% fibre plus 5% lignin and 10% fibre plus 5% cholestyramine also decreased to 50% of that of controls. However, PCB of other tissues were not affected.

Effects of bacteriohopane-32-ol on the stability of various kinds of liposomal membranes.

The effects of bacteriohopane-32-ol (Monol) on the stability of various kinds of liposomal membranes composed of phosphatidylcholine (PC) were examined by measuring the release of calcein entrapped in the liposomes; these effects were then compared with those of cholesterol (Chol). Incorporation of Chol enhanced the stability of both small unilamellar vesicles (SUV) and reverse-phase evaporation vesicles (REV) by increasing their content. However, the incorporation of Monol into PC membranes produced different effects on liposome stability due to the difference in vesicle size, fatty acyl chains of phospholipids and Monol contents. At a low Monol content of dipalmitoylphosphatidylcholine (DPPC) in SUV, incorporation of Monol exerted relatively major stabilizing effect at temperatures above Tm compared with those below Tm. Furthermore, the incorporation of Monol into REV of DPPC at about 12 mol% lowered the stability of REV below Tm of DPPC while at other concentrations this was increased. This peculiar effect was not observed in SUV membranes of DPPC and membranes composed of dimyristoylphosphatidylcholine (DMPC). These results are discussed with reference to the interaction between Monol and phospholipid molecules.