Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.15.1 (ACE)
18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of halogenated antibacterials on membrane structure and function was investigated using the human erythrocyte membrane as a model. Measurements of hemolysis in isotonic solution, altered membrane permeability, and stabilization against hypotonic hemolysis resulting from exposure of erythrocytes to halogenated antibacterials served as criteria of membrane-related effects. The hemolytic potency of the compounds studied differed widely, decreasing in the order hexachlorophene (HCP) greater than 2,2'-methylenebis(3,5-dichlorophenol) (3,5-TCP) greater than 2,2'-methylenebis(3,4-dichlorophenol) (3,4-TCP) approximately equal to 2,2'-methylenebis(4,6-dichlorophenol) (4,6-TCP) greater than 2,2'-methylenebis(4-chlorophenol) (DCP) greater than 3,4'-tribromosalicylanilide (TBS) approximately equal to 3,3',4',5-tetrachlorosalicylanilide (TCSA). Each of the antibacterials tested stabilized the erythrocyte against hypotonic hemolysis, although there were marked differences in the concentrations required to afford maximum stabilization as well as in the extent of protection. The observed order of protective effectiveness was HCP greater than 3,4-TCP greater than 4,6-TCP greater than DCP approximately equal to TCS greater than TBS. As shown by measurements of the first-order rate constant for K+ efflux, the permeability of the erythrocyte membrane to K+ was increased upon exposure to the antibacterials, with the effect of HCP greater than 3,4-TCP greater than 4,6-TCP approximately equal to 3,4-TCP greater than DCP approximately equal to TCS greater than TBS. These results indicate that halogenated antibacterials are capable of perturbing mammalian membranes, a feature which may account in part for their mammalian toxicity.
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PMID:Effects of halogenated antibacterials on the erythrocyte membrane. 69 71

Groups of 15 male and 15 female Sprague-Dawley rats were exposed to 1 of 3 chloropropene (2,3-Di = DCP; 1,2,3-Tri = TRCP; and 1,1,2,3-Tetra = TECP) vapors to provide information on repeated exposures and the potential for reproductive impairment by the most likely route of occupational exposure. Target exposure concentrations were 0, 1, 5, and 15 ppm, 6 h/d, 5 d/wk for 13 wk. The following parameters were evaluated: pharmacotoxic signs, survival, body weights, hematology, clinical blood chemistry, urine analysis, gross and histopathology (over 40 tissues/rat), organ weights, and selected weight ratios. Signs of nasal irritation were noted in rats exposed to 15 ppm of either DCP or TRCP but not TECP. Small decreases in overall body weight were observed in female rats exposed to 15 ppm TCP. An increase (approximately 15%) in spleen weight, with no corresponding histopathological or clinical findings, was observed in 15 ppm DCP-treated male rats. No other effects considered related to treatment were observed following exposure to any of the three chlorinated propenes. Additional groups of 10 male and 20 female Sprague-Dawley rats were exposed to DCP, TRCP, or TECP vapors at target concentrations of 0, 1, or 5 ppm for 6 h/d, 5 d/wk for a 10-wk premating period, a mating period, and the first 14 d (females only) of gestation. Females were allowed to deliver litters and the offspring were evaluated during a 21-d lactation period. Mating, pregnancy, and fertility indices were generally comparable among all test groups, although female mating and pregnancy indices of both DCP-treated females were lower than expected in the regular and postrecovery reproduction phase. No effects were seen on pup survival, sex distribution, body weights, organ weights, and ratios. A modest reduction in pup body weights was observed following TECP exposure but was attributed to large litter size. No treatment-related effects were seen following necropsy of adults or weanlings, nor were such effects noted following microscopic evaluation of gonads from parental animals.
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PMID:Subchronic inhalation toxicity and reproductive assessment in rats of three chlorinated propenes. 185 78

Chlorinated bisphenol antibacterial and antifungal agents are potent inhibitors of torula yeast glucose-6-phosphate dehydrogenase (G6PD). Several compounds were tested, including hexachlorophene [HCP; 2,2'-methylenebis(3,4,6-trichlorophenol)]; 2,2'-oxybis(tetrachlorophenol); 2',4-dihydroxy-2,3,3',5,5',6-hexachlorodiphenylmethane; 2,2'-methylenebis(3,4-dichlorophenol) (3,4-TCP); bithionol [2,2'-thiobis(4,6-dichlorophenol)]; 2,2'-methylenebis(3,5-dichlorophenol); 2,2'-dihydroxy-3,3',5,6,6'-pentachlorodiphenylmethane; 2,2'-methylenebis(4-chlorophenol) (DCP); 2,2'-methylenebis(4,6-dichlorophenol); and the related uncoupler 2,4-dinitrophenol. The relative inhibitory activity of the chlorinated bisphenols tended to increase with degree of chlorination of the aromatic rings. the concentrations of the bisphenols that caused 50% inhibition ranged from 2.5 micrometers for 2,2'-oxybis(tetrachlorophenol) to 40 micrometers for 2,2'-methylenebis(4,6-dichlorophenol) under comparable assay conditions. More detailed kinetic analysis showed that, as with HCP, the inhibition of G6PD by 3,4-TCP and DCP followed noncompetitive kinetics. Calculations from the kinetic data gave apparent inhibition constant (Ki) values for 3,4-TCP of 267 micrometers with G6P and 308 micrometers with NADP, and for DCP of 697 micrometers with both G6P and NADP.
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PMID:Effects of chlorinated bisphenols on torula yeast glucose-6-phosphate dehydrogenase. 680 84

Three short-term assays (the SOS chromotest, the Ames-fluctuation test and the newt micronucleus test) were carried out to evaluate the genotoxicity of five chlorinated propanones identified in several chlorinated waters (monochloropropanone, 1,1-dichloropropanone, 1,3-dichloropropanone, 1,1,1-trichloropropanone and 1,1,3-trichloropropanone). In the SOS chromotest, all the compounds except monochloropropanone were found to induce primary DNA damage in Escherichia coli. With the fluctuation test, all five chloropropanones showed mutagenic activity on Salmonella typhimurium strain TA100. The newt micronucleus assay detected a clastogenic effect on the peripheral blood erythrocytes of Pleurodeles waltl larvae only for 1,3-dichloropropanone and 1,1,3-trichloropropanone. Moreover, two structure-activity relationships are noticeable: (1) chloropropanones with chlorine substituents on both carbon positions (1,3-DCP and 1,1,3-TCP) are by far more genotoxic than chloropropanones substituted only on one carbon position (1,1-DCP and 1,1,1-TCP); (2) the increase of the number of chlorine substituents decreases the mutagenic activity (fluctuation test) of the chlorinated propanones studied.
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PMID:Study of the genotoxic activity of five chlorinated propanones using the SOS chromotest, the Ames-fluctuation test and the newt micronucleus test. 752 39

Resting cells of Desulfitobacterium dehalogenans JW/IU-DC1 growth with pyruvate and 3-chloro-4-hydroxyphenylacetate (3-Cl-4-OHPA) as the electron acceptor and inducer of dehalogenation reductively ortho-dehalogenate pentachlorophenol (PCP); tetrachlorophenols (TeCPs); the trichlorophenols 2,3,4-TCP, 2,3,6-TCP, and 2,4,6-TCP; the dichlorophenols 2,3-DCP, 2,4-DCP, and 2,6-DCP; 2,6-dichloro-4-R-phenols (2,6-DCl-4-RPs, where R is -H, -F, -Cl, -NO2, -CO2, or -COOCH3; 2-chloro-4-R-phenols (2-Cl-4-RPs, where R is -H, -F, -Cl, -Br, -NO2, -CO2-, -CH2CO2, or -COOCH3); and the bromophenols 2-BrP, 2,6-DBrP, and 2-Br-4ClP [corrected]. Monochlorophenols, the dichlorophenols 2,5-DCP, 3,4-DCP, and 3,5-DCP, the trichlorophenols 2,3,5-TCP, 2,4,5-TCP, and 3,4,5-TCP, and the fluorinated analog of 3-Cl-4-OHPA, 3-F-4-OHPA ("2-F-4-CH2CO2- P"), are not dehalogenated. A chlorine substituent in position 3 (meta), 4 (para), or 6 (second ortho) of the phenolic moiety facilitates ortho dehalogenation in position 2. Chlorine in the 5 (second meta) position has a negative effect on the dehalogenation rate or even prevents dechlorination in the 2 position. In general, 2,6-DCl-4-RPs are dechlorinated faster than the corresponding 2-Cl-4-RPs with the same substituent R in the 4 position. The highest dechlorination rate, however, was found for dechlorination of 2,3-DCP, with a maximal observed first-order rate constant of 19.4 h-1 g (dry weight) of biomass-1.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Specificity of reductive dehalogenation of substituted ortho-chlorophenols by Desulfitobacterium dehalogenans JW/IU-DC1. 788 14

In this study, we investigated the potential for reductive dechlorination of chlorophenols by municipal sewage sludge acclimated to 2,4-dichlorophenol (2,4-DCP) and 3,4-dichlorophenol (3,4-DCP). The optimal temperature and pH for dechlorination of 2,4,6-trichlorophenol (2,4,6-TCP) were 30 degrees C and 7.2. Dechlorination of 2,4,6-TCP was inhibited by sulfate, nitrate, or ferric (III), but was increased by manganese (IV) except that product of 2,4-DCP was accumulated. Organic substrates such as pyruvate or acetate did not influence dechlorination of 2,4,6-TCP, but increased dechlorination of 2,4-DCP; nevertheless lactate showed no influence on dechlorination. When glucose was added as substrate, only 20% of 2,4,6-TCP dechlorination was found. Addition of methanogenesis inhibitor 2-bromoethane sulfonate did not influence dechlorination, but addition of eubacteria inhibitor vancomycin showed no dechlorination activity at the first few days, and finally complete transformation and accumulation of 2,4-DCP occurred. Because mixed culture was from Di-Hwa Wastewater Treatment Plant, adding the same water as culture medium was found to increase the dechlorination of 2,4,6-TCP and its product 2,4-DCP. Dechlorination by adding wastewater of Petroleum Corporation was also increased, especially for 2,4-DCP product, but only 7% of 2,4,6-TCP dechlorination was found after incubation with Hou-Chin river water for 14 days.
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PMID:[Reductive dechlorination of chlorophenols by an anaerobic mixed culture]. 798 80

Chlorophenols, mainly used as biocides, are compounds with a wide spectrum of toxic effects including teratogenic and carcinogenic actions. In this study, the effects of 2,4-dichlorophenol (2,4-DCP) on hepatic microsomal cytochrome P-450, NADPH-cytochrome c reductase activity, liver ascorbic acid (AA) and glutathione (GSH) content were studied in guinea-pigs with a low (2 mg/day/animal) or a high (50 mg/day/animal) ascorbic acid intake. The high AA intake significantly increased liver AA and GSH levels. There was a clear-cut correlation between liver AA and GSH levels. Administration of 2,4-DCP significantly decreased cytochrome P-450 and NADPH-cytochrome c reductase activity in hepatic microsomes isolated from guinea-pigs with the low AA intake. Such a reduction was not observed in intoxicated guinea-pigs with the high AA intake. The results suggest that AA can play a protective role in 2,4-DCP toxicity.
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PMID:The influence of ascorbic acid on the hepatic cytochrome P-450, and glutathione in guinea-pigs exposed to 2,4-dichlorophenol. 886 64

With advances in ceramics technology, calcium phosphate bioceramics have been applied as bone substitutes. The effects of implants on bony tissue have been investigated. The effects upon adjacent skeletal muscles have not been determined. The focus of this work is to elucidate the biological effects of various calcium phosphate bioceramics on skeletal muscles. Four different kinds of powder of calcium phosphate biomaterials including beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA), beta-dicalcium pyrophosphate (beta-DCP) and sintered beta-dicalcium pyrophosphate (SDCP), were tested by myoblast cell cultures. The results were analyzed by cell count, cell morphology and concentration of transforming growth factor beta 1 (TGF-beta 1) in culture medium. The cell population and TGF-beta 1 concentration of the control sample increased persistently as the time of culture increased. The changes in cell population and TGF-beta 1 concentration in culture medium of the beta-TCP and HA were quite low in the first 3 days of culture, then increased gradually toward the seventh day. The changes in cell population and TGF-beta 1 concentration in culture medium of the silica, beta-DCP, and SDCP were quite similar. They were lower during the first day of culture but increased and reached that of the control medium after 7 days' culture. Most cells on B-TCP and HA diminished in size with radially spread, long pseudopods. We conclude that HA and beta-TCP are thought to have an inhibitory effect on growth of the myoblasts. The HA and beta-TCP may interfere with the repair and regeneration of injured skeletal muscle after orthopedic surgery.
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PMID:Effects of calcium phosphate bioceramics on skeletal muscle cells. 902 3

The purpose of this study was to establish the distribution of the selected chlorophenols of point (2,4-DCF, 2,6-DCF, 2,4,5-TCF and 2,3,6-TCF) and nonpoint origin (2,4,6-TCF,2,3,4,6-TeCF and PCF) under conditions simulating the environment of river and distilled water and laboratory water ecosystem. The distribution process developed in accordance with the kinetic equation of 1st order, the average degradation half-time at 20 degrees C amounted: model of river -23, 58-76, 92 days, and model of distilled water-36, 53-47, 25 days. The rate degradation in river and distilled water indicates that the river water microorganisms have no influence on the degradation of determined compounds. When the microflora had been adapted to the presence of chlorophenols the process of degradation was as rule more rapid both investigated temperatures (20 degrees C and 7 degrees C). This process was slowed down by temperature fall to about 7 degrees C. The mixture of chlorophenols at concentration of 10 and 50 micrograms/l when exposed for 20 days to water ecosystem under dynamic conditions, was found to be reduced up 13%. Chlorophenols were not absorbed by Elodea canadensis and Physa fortinalis and weakly by Lebistes reticulatus (cumulation coefficients -0.42-30.27). In the case residual DCP and TCP -weakly (4.71-46.23 micrograms/kg). The investigated concentrations of chlorophenols didn't exert positive effect on the aquatic biocenosis (except Lebistes reticulatus), settled in the ecosystem.
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PMID:[Distribution of chlorophenols in a water environment]. 906 40

A newly produced bioceramic, beta-Ca2P2O7 with addition of Na4P2O7.10H2O (SDCP), has been implanted into the femoral condyle of rabbits. Within 6 weeks after implantation, most of the bioceramic is replaced by new woven bone. On the contrary, block from hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP), which are osteoconductible, do not resorb within a short period of time. We believe that the biodegradable behaviour of SDCP may occur in two steps. The first and most important step is the digestion of particles and migration of the particles by phagocytosis. The object of this study is to examine the change in morphologies, chemical compositions and crystal structure of SDCP after soaking in distilled water for a certain period of time. The SDCP ceramic was also co-cultured with leucocytes to observe how the SDCP particles were digested by the leucocytes, so that the mechanism of biodegradable behaviour of SDCP ceramic in vivo might be clarified. Four types of sintered calcium phosphate ceramics were tested in the experiment: SDCP, pure beta-Ca2P2O7 (DCP), HA and beta-TCP. They wee soaked in distilled water at 37 degrees C for up to 30 days. The microstructure and morphology of crystals deposited on the surface were observed using scanning electron microscopy. Sodium, calcium and phosphorus ion contents in the supernatant solution were detected by atomic absorption analysis and ion coupled plasma. In summary, HA and DCP showed no significant evidence of dissolution in distilled water. In static distilled water, calcium ions may be released from beta-TCP into solution during the initial 7 days and then converted into HA by reprecipitation. The results showed that the SDCP was firstly dissolved into small grains or fragments by the solution. The small fragments should be so small as to be digested by the phagocytes in a physiological environment.
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PMID:Degradation behaviour of a new bioceramic: Ca2P2O7 with addition of Na4P2O7.10H2O. 919 61


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