• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.203-206
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• 2013

After bathing at a hot spring resort, a 75-year-old man presented to the emergency department because of seizure-like attack with loss of conscious. This is the first case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in Taiwan. PAM was diagnosed based on detection of actively motile trophozoites in cerebrospinal fluid using a wet-mount smear and the Liu's stain. The amoebae were further confirmed by PCR and gene sequencing. In spite of administering amphotericin B treatment, the patient died 25 days later.

• Toxicological Research
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• v.13 no.1_2
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• pp.87-94
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• 1997

This study was carried out to investigate toxicity of insecticide carbofuran and compensatory effects of phenobarbital sodium (PB) in vivo and in vitro. Sprague Dawley male rats were used as experimental animals and divided into carbofuran only administered group and simultaneous application group of carbofuran and PB. At 30 rain and 1, 3, 6, 12, 24, 48 and 96 hrs after each treatment, the animals were sacrificed by decapitation. Kidney were immediately removed, immersed in fixatives, and processed with routine method for light microscopic study. Paraffin sections were stained with H-E, PAM and PAS. $5.0\times 10^4$ cell/ml of NIH 3T3 fibroblast in each well of 24 multidish were cultured: After 24 hours, the cells were treated with solution of six groups; control group cultured in media only, carbofuran $MTT_50$ or $NR_50$ group cultured in the media containing carbofuran $MTT_50$ or $NR_50$ and four experimental groups cultured in the media containing carbofuran $NR_50$ plus various concentratins of PB. After the NIH 3T3 fibroblast of all groups were cultured in same condition for 48 hours, Tetrazolium MTT (MTT) and NR (neutral red) assay were performed to evaluate the cytotoxicity of cell organelles. Under the light microscope, atrophic change of renal corpuscles were frequently observed in 1 and 2 days after carbofuran treatment. The increase of the mesangium was apparent in 1 and 2 days after carbofuran treatment. Necrotic changes of the epithelium and loss of brush border of proximal tubules were most severe at 2 and 3 days after carbofuran treatment, respectively. In contrast, there were no evidences of the toxic effects on renal tissues at 48hrs in carbofuran-PB treated groups. Carbofuran $MTT_50$ and $NR_50$ were 78$\mu M$, 82.5$\mu M$ respectively. MTT and NR quantities were significantly increased in carbofuran-PB 100$\mu M$ treatment group and carbofuran-PB 100$\mu M$ treatment group. On the basis of these results, it is obvious that PB has compensatory effects against carbofuran toxicity.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.155-161
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• 2001

This study was carried out to investigate cytotoxicity of paraquat or bentazone on NIH 3T3 fibroblasts, toxicity of paraquat or bentazone, and compensatory effects of 3-Methylcholanthrene(3-MC) on the rat liver. In order to MTT assay, the $5.0{\times}10^4$ cell/mL of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution of paraquat or bentazone(1, 25, 50, 100 ${\mu}M$ respectively). After the NIH 3T3 fibroblast of all groups were cultured in same condition for 48 hours. MTT assay were performed to evaluate the cytotoxicity of cell organelles. Paraquat or bentazone $MTT_{50}$ were 1668.97 ${\mu}M$ and 1506.97 ${\mu}M$, respectively. These $IC_{50}$ of paraquat or bentazone were decided low cytotoxicity by Borenfreund. In order to observe the toxicity and compensatory effects of paraquat or bentazone on the rat liver, Sprague-Dawley male rats were used as experimental animals and divided into paraquat or bentazone only treated group and simultaneous application group of paraquat or bentazone and 3-MC. At 30 min and 1, 3, 6, 12, 24, 48 and 96 hrs interval after each treatment, the animals were sacrificed by decapitation and liver were immediately removed, immersed in fixatives, and processed with routine method for light microscopic study. Paraffin sections were stained with H-E, PAM and Best Carmine. Under the light microscope, degenerative changes of hepatic lobules were frequently observed in portal area from 3 hrs after paraquat or bentazone treatment. All hepatic cells were induced degenerative change at 12 hrs and more severe degenerative change at 48 hrs after paraquat or bentazone treatment. Especially, hepatic cells of bentazone only treated group were distinctly showed pyknotic. Glycogen granules were increased in portal area at 3 hrs, all hepatic cells at 12 hrs and remarkably increased at 48 hrs after paraquat or bentazone treated group. But hepatic cells of bentazone only treated group were regeneration at 48 hrs from portal area and glycogen granules of hepatic cells of paraquat or bentazone and 3-MC combination treated group showed in central area only at 48 hrs. The results indicate that 3-MC may be decrease paraquat or bentazone cytotoxicity on the rat liver.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.259-266
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• 1984

Present study was undertaken to elucidate the changes of the ultrastructure of Naegleria fowleri trophozoite in brain tissue of mice and culture medium. Naegleria fowleri, 0359 strain, which used in this study was cultured in axonic liquid medium, CGVS medium. Each mouse was inoculated with amoebas intranasally under secobarbital anesthesia, and sacrificed on 7th day after the infection. Comparative observation of the ultrastructure of the amoebas in axonic culture and experimentally infected mice brain was done with transmission electron microscope. The results are summarized as follows: 1. The amoebas in mouse brain tissue were round in outline, whereas those of amoebas from axonic culture showed irregular appearance. 2. Mitochondria in the amoebas from axonic culture was oval, round and cylindrical shape and darkly stained, whereas those of the amoebas from mouse brain tissue showed dumbbell shape together with above forms. The stain was not unique, but light and/or dark. 3. Rough endoplasmic reticulum of amoebas in brain tissue was tubular, but from culture it was vesicular or tubular in shape. 4. Emity vacuoles were demonstrated in amoebas from culture, while food vacuoles with myelinated structures were abundant in those from tissue, suggesting a strong phagocytic activity. 5. Mouse brain tissue in ected were extensively destroyed, and Polymorphonuclear leukocytes were infiltrated predominantly with inflammatory lesion. Amoebas were observed in the vicinity of the capillary.