Acinetobacter baumannii produces the siderophore called acinetobactin (AB) in response to iron starvation. In this study, in vitro growth experiments were conducted to evaluate the ability of AB to sequester iron bound to human transferrin and lactoferrin and mediate bacterial utilization of the iron. Strain ATCC 19606 producing AB was able to grow in the presence of either 30% iron-saturated human transferrin (30% Fe-TF) or 15% iron-saturated human lactoferrin (15% Fe-LF) as a sole source of iron even when they were separated by a dialysis membrane. The radiolabel after equilibrium dialysis between 55Fe-TF and AB was accumulated by cells grown under iron-deficient conditions, but not by those grown under iron-sufficient conditions. Addition of AB to the medium caused great enhancement in the growth of a poor producer strain of AB in the presence of 30% TF or 15% LF. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the outer membrane protein fractions revealed the presence of 77- and 81-kDa proteins only in the cells grown under iron-deficient conditions, suggesting that either of them may function as the receptor for Fe3+-AB complex. No strain tested was able to utilize hemin and hemoglobin as a sole source of iron. These results indicate that A. baumannii can utilize iron bound to TF and LF as host iron sources through the action of AB. This system is probably involved in survival and proliferation in the host.
The color reaction of various drugs with chromotropic acid and sulfuric acid was examined. Methylenedioxymethamphetamine (MDMA) exhibited a red-violet color on treatment of an aqueous solution with sulfuric acid and chromotropic acid. The specificity of the reaction was examined using 65 drugs. The results showed that while related drugs with a methylenedioxyphenyl moiety, such as methylenedioxy-amphetamine and -N-ethylamphetamine, were all positive, 51 drugs including amphetamine, methamphetamine, opiates, cocaine, and phencyclidine were negative. The drugs exhibiting a positive reaction include tetrahydrocannabinol and related drugs, sulfur-containing drugs such as phenothiazine tranquilizers, and diphenhydramine. These results indicate that the present method is highly specific for MDMA and related drugs although its specificity is not absolute. The detection of MDMA in urine was investigated, and found to be possible using this method.
It has been assumed that "smelter disease" is caused by sulfuric dioxide. A typical episode resulting in "smelter disease" occurred in Fukushima, Japan. Twenty-seven workers became ill and eventually three of them died. The concentration of mercury (Hg) was found to be higher in all tissues and blood of the three victims than in those of normal Japanese, although the concentrations of zinc, cadmium, copper and lead in all tissues examined were within the normal range. The clinical course after the incident and autopsy findings clarified the cause of death to be acute Hg fume poisoning. To determine the histological localization of Hg and metallothionein (MT), Hg staining by the photo-emulsion method and immunostaining using anti-MT antibody were carried out. Numerous Hg granules were observed in the epithelia of the proximal tubules of the renal cortex using the photo-emulsion histochemical method. The liver of victims contained a few Hg granules in the hepatic cellular cytoplasm and sinusoid. Immunostaining of the kidney showed a strong positive reaction with anti-MT in the proximal tubules outside the medulla. The presence of Hg-bound MT in the kidneys of the victims was confirmed by gel chromatography. This is the first evidence of Hg-MT in the tissues of humans with acute Hg fume poisoning. Mercury might induce the synthesis of MT in human tissues. In addition, fractionation of the supernatants on gel chromatography revealed that most of the Hg in the kidney and lung of the patient who had the most severe renal and lung damage and who was the first of the three victims to die was distributed in high molecular weight protein fractions (HMW) and a small portion of Hg was bound to MT. These findings suggest that the amount of synthesized MT in tissues was not sufficient for MT to bind to Hg. The amount of Hg absorbed into tissues may be too large for MT to protect tissues, and thereby Hg may be bound to HMW.
We examined whether orally administered bisphenol A transfers from the maternal rat to the fetus. After oral dose of 10mg/kg bisphenol A, it immediately appeared in maternal blood, and transferred into the fetuses. The concentration of bisphenol A in both maternal blood plasma and fetuses peaked within 1h after administration. The values were approximately 34 ppb and 11ppb, respectively. At 3h, the concentration of bisphenol A in maternal blood plasma had decreased to approximately 10% of the peak value. The 3-h decrease in fetuses was only about 40% of the peak, and by 24h, the fetal concentration had increased again to the nearly 70% of the peak value. The results suggest that bisphenol A might easily pass through the placental barrier, unlike sex hormones such as estrogen.
Reduced (GSH) and oxidized glutathione (GSSG) concentrations in biological samples can be determined simultaneously utilizing high-performance liquid chromatography (HPLC) following derivatization with dansyl chloride. In the present study, two points were investigated in detail to improve upon their method : 1) pH in the derivatization reaction and 2) the method of deproteinization prior to dansylation. Dansylation of standard GSH after S-carboxymethylation and of GSSG both gave the highest relative fluorescence at pH 8.5.Degradation of GSSG to GSH was not detected when GSSG was dansylated at pH 8.5 or more acidic pHs but was apparent at pH 9.0 and even more obvious at pH 10.0. The highest fluorescence values for dansylated GSH and GSSG were also obtained in tissue homogenates following the derivatization at pH 8.5. Although the value for dansylated GSH in the homogenates was also high at pH 9.0, this probably was due to degradation of intrinsic GSSG to GSH. Deproteinization with trichloroacetic acid (TCA) was found to give considerably higher relative fluorescence of dansylated GSSG than that with perchloric acid (PCA), whereas the dansylated-GSH concentrations obtained with the two acids were similar. Moreover, dansylated GSSG was more stable in TCA than in PCA, although there was no difference between these acids in relation to stability of dansylated GSH. In the livers and kidneys of rats, the GSH and GSSG concentrations obtained by the present method were consistent with those obtained by the recycling enzymatic method.
Chromium(VI) compounds, potent carcinogens, are known to induce lipid peroxidation. However, it is not clear how Cr(VI) induces lipid peroxidation. It has been proposed that Cr intermediates such as Cr(IV) and Cr(V), possibly generated during the metabolic reduction of Cr(VI) to Cr(III), may be responsible for the Cr(VI)-induced DNA damage and cancer. In this article, in order to clarify the mechanism by which Cr(VI) enhances lipid peroxidation, mouse liver or kidney homogenate was incubated with Cr(III), Cr(IV), Cr(V) and Cr(VI) compounds. Our results are as follows : (i) lipids in liver homogenate are peroxidized more remarkably than those in kidney homogenate after being treated with Cr(IV), Cr(V) and Cr(VI) compounds; (ii) lipid peroxidation induction by Cr(IV) and Cr(V) compounds is more effective in both liver and kidney homogenates than that by the Cr(VI) compound; (iii) the extent of lipid peroxidation induced by the Cr compounds is significantly correlated between liver and kidney homogenates. These results suggest the possible participation of Cr(IV) and Cr(V) in Cr(VI)-enhanced lipid peroxidation.
Inorganic arsenics such as arsenite and arsenate have been concluded to have human carcinogenicity for skin and lung by epidemiological studies, although animal experimental evidence for their carcinogenicity is inadequate for evaluation. Moreover, genotoxic action of arsenics is obscure; inorganic arsenics do not induce point mutation but induce chromosomal aberrations, transformation, and other genetic damage. Here we review and evaluate the published information on arsenic genotoxicity and carcinogenicity in humans and animals, including current mechanistic concepts.
Bromate salt is an oxidizing agent that has been widely used as a food additive, but now the use of bromate is restricted to low level because of its mutagenicity and carcinogenicity. Potassium bromate was weakly mutagenic in Salmonella typhimurium TA100, TA102, and TA104 in the presence of metabolic activation, though the compound proved to be negative in TA98, TA1535, TA1537 and TA1538. It also demonstrated genotoxicity in some microbial tests. Potassium bromate or its radical derived from reduction seems to induce lipid peroxidation in producing oxidized DNA damage to the target. Bromate ion also exists in drinking water produced during ozonation of bromide-containing water. WHO guideline for drinking water quality recommended bromate concentration below 0.025mg/l and the U.S. government determined the maximum bromate concentration as 0.010mg/l in regulation, which leads the application of ozonation to be reconsidered. In Japan, 0.127mg/l of bromate ion was produced in experimental ozonation plant and the maximum of bromate ion (0.03mg/l) was detected in drinking water treatment plant. Bromate can be produced with water of high bromide concentration and must be controlled in treatment plant of high ozone dosage. New activated carbon reduces bromate though the activated carbon used for several months showed no reduction of bromate. Reduction of pH and ozone dose is most available technology for reducing bromate. Bromate is also detected in sodium hypochloride as a disinfectant and chlorinated water. Contaminated river water contained bromate up to 0.009mg/l, possibly discharged from permanent-wave neutralizing agent. Environmental bromide and bromate contamination should have a potential importance.
Poisoning cases caused by drugs and toxic substances in forensic chemistry reported by National Research Institute of Police Science (Japan) from 1983-1997 were presented. These drugs and chemicals were used for homicide, suicide, misuse or accidents. Poisoning was classified into the following categories : carbon monoxide, volatile substances, drugs, pesticides and others. These categories were further subdivided as to specific drugs or chemicals involved. Carbon monoxide is the leading agent accounted for two thirds of poisoning cases. Over a fifteen years period the number of poisoning cases by volatile and other chemicals remained steady. The number of pesticide poisoning declined, especially that of paraquat and diquat formulations remarkably decreased to 200-300, while poisoning cases of phosphorus containing amino acid-type herbicides (glyphosate, glufosinate and bialaphos) have been increasing year by year. Drug induced poisoning using bromvalerylurea, barbiturates, benzodiazepines, and tricyclic antidepresants increased. A significant number of poisoning were placed in multiple drugs or pesticides, and mixed drug categories.
To understand the molecular dynamics in response to nitric oxide-induced oxidative stress under infectious and inflammatory conditions, we have analyzed protein expression patterns of human endothelial cells with or without treatment of nitric oxide donors. We identified glyoxalase I as a novel nitric oxide responsive protein using two-dimensional polyacrylamide gel electrophoresis. Mammalian glyoxalase I can interact with S-nitrosoglutathione at the substrate recognition site, resulting in an inactive from with a reductant reversible chemical modification. The oxidative response of glyoxalase I is specific to nitric oxide and more sensitive than that of glyceraldehyde-3-phosphate dehydrogenase which is a well-known enzyme inactivated by nitric oxide. In this review, we introduce the characteristics of glyoxalase I as a nitric oxide responsive protein and hypothesize the roles of glyoxalase I under nitrosative stress conditions.
Various methods for the degradation of tetrachloroethylene (perchloroethylene, PCE) in wastewater have been reported. In this study, the effects of PCE removal under anaerobic conditions by granular activated carbon (GAC), anaerobic sludge and granular biological activated carbon (GBAC) were compared, and that GBAC was found to be the most effective of the above described three items. PCE was degraded as adsorption and biotransformation by GBAC. The experimental column (i.d 3cm, height 55cm) was packed with GBAC under anaerobic conditions, upflow. The GBAC was made from GAC and anaerobic sludge. The experimental temperatures ranging from 22-24°C, nitrogen gas flow rate of 20ml/min were used. PCE decreased because of microbial transformation and adsportion of GAC, whose microbial activity signify much to decrease PCE during PCE was on the increase in the GAC. This paper made an approach to modeling of adsorptive process, and adsorptive capacity for single GBAC particle, and it was found that the adsorbed PCE degradated to many species which were readsorbed on GBAC. This treatment method would maintain a higher removal effect for a long time.
Hepatocytes isolated from male Wister rats with or without pre-treatment of phenobarbital (PB), 3-methylcholanthrene (3-MC), β-naphthoflavone (β-NF) and dexamethasone (DMX) by the previous method were cultured in dishes in an atmosphere of 5% CO2-95% air at 37°C. Rat hepatocytes in culture for 24h were incubated in Williams'E medium containing 2-hexenal and tert-butylhydroperoxide. Cell membrane oxidation was measured by the fluorometric thiobarbituric acid (TBA) method. Cell membrane oxidation induced by 2-hexenal and tert-butylhydroperoxide and inhibited by the addition of some antioxdants, was only observed in whole hepatocytes treated with 2-hexenal, but not in the purified cell membrane under the same conditions. Therefore, it is assumed that 2-hexenal converted to active substances could injure the membrane of hepatocytes. In PB pretreated-rat hepatocytes, increasing TBA-RS formation was observed. Finally, it is concluded that 2-hexenal is activated in hepatocytes by CYP2B, and that the membrane lipid peroxidation is caused by active compounds such as radicals.
The absorption, disposition, metabolism and excretion of sodium [14C]-benzoate (NaBA) and potassium [14C]-benzoate (KBA) was studied after oral administration of low (BA 25.4mg eq/kg), middle (BA 254mg eq/kg), and high (BA 1050mg eq/kg) dosages to male Wistar rats. Excretion of [14C]-BA derived radioactivity was monitored in the urine and feces, and as exhaled [14CO2] from 0 to 48h. The tissue distribution of the radioactivity of NaBA was similar to that of KBA. At 6h after administration, more than a half of the radioactivity remained in rat at high dosage and 3-7% of the radioactivity remained in rats at low and middle dosages of NaBA and KBA. Relatively high concentration of the radioactivity remained in the stomach, intestine, kidney and liver. At 48h after administration, less than 0.7% of the radioactivity remained in rat at low, middle and high dosages of NaBA and KBA. At all dosages of NaBA and KBA, more than 96.8% of the radioactivity was excreted in the urine within 48h and that by the other routes were very low. The major urinary metabolite of BA was hippuric acid (HA). The higher doses of BA has delayed Tmax and the urinary excretion, and increased Cmax and the concentration of BA in the serum. AUC and tissue distribution were not linearly related to the administered dose. The dose effects of BA suggest the saturation of elimination, probably caused by the saturation of the metabolic pathway of BA to HA over middle dosage. Blood levels of the radioactivity monitored during 48h were applied to one compartment model with the first-order absorption and Michaelis-Menten elimination. There was no significant difference between NaBA and KBA in the absorption, distribution, metabolism and excretion.
For the purpose of preserving the water quality, we investigated the annual variation in the concentration levels and frequency of detection of 36 kinds of regulated pesticides in water sources in Hyogo Prefecture before and after the enforcement of the new Water Quality Standard for drinking water revised by the order of Minister based on Water Works Law on December 1 in 1993. The samples measured consisted of 665 samples of water sources. In most of the samples analyzed, the concentration levels of pesticides were under one tenth of regulated values of supplied water. On the other hand, 3 kinds of pesticides, such as simazine, isoprothiolane and flutoluanil had especially high frequency of detection (over 15%) before the new Water Quality Standard enforced. However, after the new Water Quality Standard enforced, both the concentration levels and frequency of detection of three pesticides analyzed were decreasing annually. Distribution patterns of pesticides supplied from different water sources were analyzed and grouped as follows : Group 1 : In river and lake (dam, reservoir) water, the frequency of detection of pesticides were higher than those in other water sources. The high frequency of detection of pesticides in lake (dam, reservoir) water are especially due to the closed systems. Group 2 : In unconfined water such as the water from shallow well and river-bed water the several pesticides were observed at times. Group 3 : In confined water such as the water from deep well and self-flowing water none of the pesticides were detected in every time.
Many non-iron shirts are finished with formaldehyde (HCHO) resin or HCHO vapor. Free HCHO in the non-iron shirt mostly decreases by washing. However, free HCHO sometimes increases once again with time by decomposition of resin. We have measured the quantity of free HCHO in 27 non-iron shirts and 3 regular shirts as control samples, before and after washing and drying, 1 week, 2 weeks, 1 month and 6 months after washing. Consequently, before washing, the quantity of free HCHO in 8 non-iron shirts was found to exceed 75ppm, max up to 202ppm. Seventy-five ppm is the standard value detected in underwears for adults according to the Law for the Control of Household Products Containing Harmful Substances. Even after washing, the quantity of free HCHO in 2 non-iron shirts did not fall below 75ppm. And after the storage for 6 months, the quantity of free HCHO in 7 non-iron shirts exceeded 75ppm. Six months after triple washing, the quantity of free HCHO in 5 non-iron shirts exceeded 75ppm. Our study revealed that the patterns of change in the quantity of free HCHO were dependent on the types of finishing.