Arsenic speciation for the phytoremediation by the Chinese brake fern, Pteris vittata.

Arsenic (As) speciation for the phytoremediation by the Chinese brake fern was studied. In particular, the mechanism of how plants induce compounds containing thiol (SH) and proteins by As exposure in terms of the relationship between As and phosphate uptaken into plant cells was examined. Pteris vittata callus could efficiently reduce As(V) to As(III) by the rapid introduction of reductase and synthesize thiols leading to phytochelatins production. Furthermore, Pteris vittata could control phosphate concentration in the cells corresponding to the concentration of arsenite and arsenate. To our best knowledge, this is the first report to show the mechanisms of such high As tolerance of Pteris vittata using their callus in terms of in vitro approach for the analysis of As speciation and metabolism route.

A case of combined laparoscopic reduction and open preperitoneal mesh repair for incarcerated small bowel in a retroperitoneal hernia between the external and internal iliac vessels.

We report a rare case of an incarcerated retroperitoneal hernia with or involving the small bowel through the orifice between the right external and internal iliac vessels. A 39-year-old woman was admitted to our hospital because of vomiting and abdominal pain. She had a history of right oophorocystectomy and appendectomy. Abdominal computed tomography revealed small bowel obstruction resulting from an incarcerated retroperitoneal hernia. The small bowel herniated into the retroperitoneal fossa through the orifice between the right external and internal iliac vessels. Laparoscopic reduction of the small bowel was performed, followed by ligation of the sac and placement of a mesh prosthesis through the preperitoneal approach, using a lower midline incision along the previous laparotomy scar. Her postoperative course was uneventful and no recurrence has been observed after surgery.

Biochemical comparison of brain glycosaminoglycans between normal and reeler mutant mice.

Glycosaminoglycans (GAGs) were isolated from the brains of reeler and normal mice on postnatal days 13 and 20. The GAG content of the reeler mouse brain, based upon the amount of DNA, was about 150% that of the normal mouse brain on both days. The GAGs consisted of chondroitin sulfate (CS), heparan sulfate (HS), hyaluronic acid (HA) and polysialosyl glycopeptides. There was no significant difference in the composition of GAGs isolated from either reeler or normal brain. Repeating disaccharide compositions of CS and HS were also similar in reeler and normal brains. Core proteins of brain chondroitin sulfate proteoglycans (CSPGs), solubilized with phosphate buffered saline, were prepared by digesting purified CSPGs with chondroitinase ABC, and were analyzed by SDS-polyacrylamide slab gel electrophoresis. There was no difference in the composition of core proteins from either reeler or normal brain. These results indicate that, although the GAG content of the reeler mouse brain is higher than the normal, all structural parameters of GAGs/CSPGs so far examined were normal. The rate of synthesis and/or degradation of brain GAGs may be affected in the mutant mouse brain.

Localization of nitric oxide-related substances in the peripheral nervous tissues.

Nitric oxide (NO) is now recognized as a transduction molecule in many biological systems, and is known to promote the synthesis of cGMP by activating the soluble guanylate cyclase. NO synthase which fully accounts for all the neuronal activity of NADPH diaphorase catalyzes L-arginine to NO and L-citrulline. In the present study, the localization of NO-related substances, L-arginine, NO synthase, L-citrulline and cGMP in the enteric plexus and dorsal root ganglia was demonstrated with immuno- or enzyme-histochemical methods. L-Arginine was proved accumulated in glial cells, while NO synthase and L-citrulline were found in neurons. Cyclic GMP was predominantly observed in glial cells. These results reveal L-arginine-NO-cGMP pathway may be present in the enteric plexus and dorsal root ganglion as in the brain, and provide visible evidence that NO mediates neuron-glia communications in this pathway.

Rapid and sensitive neurotoxicity test based on the morphological changes of PC12 cells with simple computer-assisted image analysis.

In order to develop a rapid and sensitive bioassay for the screening of chemicals with possible neurotoxicity, a computer-assisted simple image-analysis system was developed to quantify small changes in the specific morphology of the cultured pheochromocytoma cell line, PC12. This cell forms a neuron-like microfibril network (neurites) in response to a nerve growth factor (NGF) stimulation in vitro. Dichrolvos (DDVP) and methylmercury chloride (MMC) were employed as model neurotoxicants. In DDVP treatment, there was no large difference in the ED50s (effective dose that reduces the morphological index by 50%) among the toxicities determined from various morphological indices, but they were significantly lower than those observed by whole-cell-area-based toxicity assay using the hepatoblastoma cell line, Hep G2. In contrast, in MMC treatment, neurite-length-based toxicity was observed as early as 2 h, and at 48 h this was lower by over three orders of magnitude compared with whole-cell-area-based one (2.06 x 10(-7) mM vs. 6.42 x 10(-4) mM). These results demonstrate that the developed bioassay using image analysis of nerve-tissue-derived cell morphology allows us to screen possible neurotoxic chemicals very rapidly with highly enhanced sensitivity, particularly for some chemicals that preferentially act on nerve fibers.

Cochlear histopathology of the mutant bustling mouse, BUS/Idr.

The inner ear of mutant bustling mice, BUS/Idr, was examined histopathologically. LM examinations revealed an age-dependent degeneration of the auditory organ of Corti in BUS homozygotes, but not heterozygotes. Cochlear base-to-apex gradient in severity of the degeneration was noted. First signs of degeneration were found in the outer hair cells of the cochlear basal turn at about 3 weeks of age, followed by degeneration of the spiral ganglion cells which occurred slowly. As examined by SEM, stereociliary derangements of both the inner and outer hair cells were apparent in homozygotes as early as after 10 days. No normal arrays of stereocilia were found in homozygotes examined at 10 days through 6 months. The results of immunohistochemical examinations suggest that the sensory cells of the Corti's organ of homozygotes are structurally once normally innervated. No significant difference was found in the expression of protooncogene c-mos in the CNS between BUS homozygotes and control mice. We propose that BUS mice be categorized as a member of the so-called "waltzer-shaker" mutants group.

Abnormal urogenital organs occurring spontaneously in inbred ACI and Kyoto-notched rats.

Spontaneous malformations of urogenital organs found in inbred rat foetuses of ACI/NHok strains were further investigated with a postnatal survey involving other inbred strains. A new type of malformation occurred in Kyoto-notched rats. The present findings suggested that the malformations have different hereditary characteristics caused by different maldevelopmental mechanisms and are probably due to recessive polygenes.

Preservation of human cell bioassay device for the on-site evaluation of environmental waters.

We have already developed a novel disposable bioassay device based on the low-density lipoprotein (LDL) uptaking activity of human hepatoblastoma Hep G2 cells in our previous work. However, this device is not readily applicable to evaluate river water toxicity on-site because it cannot be preserved for more than one week. In this work, we developed the method for preservation of the device to enable it to be preserved for at least one month. The device can be supplied to individual environmental sites without any facilities for cell culture. We can evaluate river water toxicity by 2 hours of exposure after thawing. Therefore, this kind of device could be a promising tool for daily water quality management.

[Aldehyde dehydrogenase 2(ALDH2) gene polymorphism in NIDDM patients with chronic renal failure].

In order to investigate the influence of aldehyde dehydrogenase 2(ALDH2) genotype in the pathogenesis of nephropathy due to non-insulin dependent diabetes mellitus (NIDDM), genotyping of ALDH2 was measured using the PCR-RFLP method in patients with NIDDM on chronic hemodialysis (HD). The results were as follows; 1) The frequency of active ALDH2 was 63% and that of inactive ALDH2 was 37%. 2) The percentage of active ALDH2 was significantly higher in patients with alcohol tolerance than that in those without it (38%). 3) The estimated amount of alcohol consumption in the past was 506 +/- 720 g/week in the active ALDH2 group, and 156 +/- 288 g/week in the inactive ALDH2 group, showing a significant difference between the two groups. 4) Interdialytic body weight gain was larger in patients with active ALDH2 than in those with inactive ALDH2. Since the frequency of active ALDH2 was similar to that in patients without nephropathy, these results do not support the hypothesis that ALDH2 gene polymorphism is involved in the development and persistence of chronic renal failure due to NIDDM. However, salt and water craving in dialysis patients may be influenced partially by an active ALDH2 gene.