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Water Research Jul 2021Nitrite (NO)-sensitized photolysis plays an important role in the attenuation of effluent-derived trace organic contaminants (e.g., anilines, phenolic compounds, etc.)...
Nitrite (NO)-sensitized photolysis plays an important role in the attenuation of effluent-derived trace organic contaminants (e.g., anilines, phenolic compounds, etc.) in surface waters. However, the kinetics, mechanisms, and influencing factors of photolysis of many emerging contaminants sensitized by NO still remain largely unknown. Herein, we report that NO-sensitized photolysis of the antimicrobial agents parachlormetaxylenol (PCMX) and chlorophene (CP) in aqueous solution under ultraviolet 365 nm (UV) radiation. A nonlinear increase in photolysis rate constants of PCMX and CP was observed with increasing NO concentration. Radical quenching studies and kinetic modeling revealed that hydroxyl radical (HO•) and nitrogen dioxide radicals (NO) contributed dominantly to the removal of PCMX and CP. Solid phase extraction (SPE) combined with high resolution-mass spectrometry (HR-MS) analysis identified a series of intermediate products including hydroxylated, nitrated, nitrosated, and dimerized derivatives. Experiments with isotopically labelled nitrite (NO) showed that the nitro- and nitroso-substituents of intermediate products were derived from the nitrite nitrogen. Based on the identified products and theoretical computations, the mechanisms and pathways of NO-sensitized photolysis of PCMX and CP are elucidated. Deoxygenation partially inhibited the formation of 4-chloro-3,5-dimethyl-2-nitrophenol (nitro-PCMX) while the presence of HO• scavenger such as isopropanol (i-PrOH) suppressed the further transformation of nitro-PCMX. The presence of Mississippi River natural organic matter (MRNOM) inhibited the removal of PCMX and CP, likely due to light screening and radical quenching. However, appreciable degradation of PCMX and CP was still observed in wastewater and wetland water matrices. Results of this study shed some light on the transformation and fate of PCMX and CP in NO-rich wastewater effluents or effluent-impacted surface waters under solar radiation.
Topics: Anti-Infective Agents; Dichlorophen; Mississippi; Nitrites; Photolysis; Water; Water Pollutants, Chemical
PubMed: 34087514
DOI: 10.1016/j.watres.2021.117275 -
Annales de Dermatologie Et de... 1982This study concerns 465 patients with dermatitis. The clinical history suggested allergy to cosmetics, drugs, industrial products or clothes. These patients were tested...
This study concerns 465 patients with dermatitis. The clinical history suggested allergy to cosmetics, drugs, industrial products or clothes. These patients were tested with 29 preservatives chosen among the most frequently employed or most sensitising products. Seven french clinics of Dermatology were involved in this study during one year. The patients' age varied between 2 years old and 80 years old. Positive reactions were seen mostly with formaldehyde (4.7 p. 100), Bronopol (4.7 p. 100), ammoniated mercury chloride (3.8 p. 100), benzoic acid (2.1 p. 100), sodium benzoate (1.9 p. 100), parabens (1.9 p. 100), dichlorophen (1.7 p. 100), chloracetamid (1.5 p. 100), benzyl benzoate (1.5 p. 100), Germall 115 (1.2 p. 100), butylhydroxyanisol (1 p. 100) and Dowicil (0.8 p. 100). The incidence of sensitivity to formaldehyde, Bronopol, ammoniated mercury chloride is too high; their use should decrease. Patients sensitive to benzoic acid, benzyl benzoate are not rare. Chloracetamid whose frequency of uses seems to be rather low is a very sensitising product. Parabens which are widely used were seldom found positive; nearly all cases are caused by topical medications.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Clothing; Cosmetics; Dermatitis, Contact; Drug Eruptions; Humans; Middle Aged; Pharmaceutic Aids; Preservatives, Pharmaceutical
PubMed: 6221686
DOI: No ID Found -
Endodontics & Dental Traumatology Dec 2000The aim of this study was to evaluate the cytotoxic effect of four root canal sealers: AH26, AH Plus, Diaket and Apexit. In the experiment two cell lines, human cervical...
The aim of this study was to evaluate the cytotoxic effect of four root canal sealers: AH26, AH Plus, Diaket and Apexit. In the experiment two cell lines, human cervical carcinoma (HeLa) cells and mouse skin fibroblasts (L929), were used. Under aseptic conditions, the sealers were prepared according to the manufacturers' directions, and 0.01 mL of each material was placed in a 24-well plate. The sealers were covered with cell suspension. The cytotoxicity was estimated by determining the number of viable cells by a light microscope, as well as the total number of cells 24 h, 48 h and 120 h after the treatment with mentioned materials. The results obtained in this study showed the high cytotoxcity of the new AH Plus root canal sealer, which was shown to be equally or more toxic to the standard AH26 and Diaket materials. Apexit was the least toxic sealer.
Topics: Animals; Bismuth; Calcium Hydroxide; Cell Count; Cell Line; Cell Size; Cell Survival; Drug Combinations; Epoxy Resins; Fibroblasts; HeLa Cells; Humans; Methenamine; Mice; Polyvinyls; Root Canal Filling Materials; Silver; Skin; Statistics as Topic; Time Factors; Titanium; Tumor Cells, Cultured; Zinc Oxide
PubMed: 11202896
DOI: 10.1034/j.1600-9657.2000.016006287.x -
International Journal of Biological... Dec 2017Pesticide intoxication is a major public health concern, and unfortunately there is not an effective treatment for severe organophosphorus pesticide intoxication. In...
Pesticide intoxication is a major public health concern, and unfortunately there is not an effective treatment for severe organophosphorus pesticide intoxication. In this work, a non-immunogenic enzymatic bioconjugate based on cytochrome P450 was assayed for organophosphorus pesticide transformation. Enzyme therapy is an alternative approach to inactivate pesticides in the bloodstream, transforming them into less toxic metabolites. A variant of cytochrome P450 (CYP F87A) from Bacillus megaterium was chemically modified with polyethylene glycol. The PEGylated enzyme showed enhanced pesticide transformation activity when compared with the unmodified protein. The transformation rates were higher than those obtained with the unmodified enzyme for all six pesticides transformed. The specific activity of PEGylated preparation for parathion and dichlorophen was up to 9-times higher than these obtained with the unmodified enzyme. In addition, the modified CYP (CYP-PEG) remained active at extremely high pHs, maintaining 90% of its maximal activity at pH 11, as opposed to the unmodified CYP that retained less than 20% of its maximal activity at that pH. In addition, the bioconjugate showed good catalytic activity in blood serum and innocuousness on immune cells. The potential use of PEGylated CYP as a detoxification strategy for pesticide poisoning is demonstrated and discussed.
Topics: Animals; Bacillus megaterium; Biocatalysis; Biotransformation; Cytochrome P-450 Enzyme System; Hydrogen-Ion Concentration; Kinetics; Macrophages; Mice; Models, Molecular; Oxidation-Reduction; Pesticides; Polyethylene Glycols; Protein Conformation; RAW 264.7 Cells; Substrate Specificity; Temperature
PubMed: 28690168
DOI: 10.1016/j.ijbiomac.2017.07.014 -
Water Research Apr 2021Mineral-humic complexes, known as mineral-associated organic matter (MAOM), are ubiquitous in natural waters. However, the interaction between organic pollutants and...
Mineral-humic complexes, known as mineral-associated organic matter (MAOM), are ubiquitous in natural waters. However, the interaction between organic pollutants and MAOM remains elusive, which may affect their degradation process. In this study, photochemical transformation of chlorophene (CP) in the presence of MAOM, prepared by coating aluminum hydroxide with humic acid (HA-HAO), was investigated. Our results showed that the degradation of CP was significantly enhanced in the presence of HA-HAO, and the degradation rate constant was ~5 times as that with HA only. It was because the adsorption of CP to HA-HAO particles was greatly enhanced, and concentration of reactive oxygen species (ROS) was increased on HA-HAO surfaces, which further promoted the reactions between CP and ROS. The quenching experiments combined with EPR technology confirmed that superoxide anion (O) was the primary reactive radical on CP photodegradation. More importantly, the degradation of CP with HA-HAO followed a hydroxylation process, rather than the oligomerization reaction with HA only. Spectroscopic analysis provided direct evidence for the formation of hydrogen bonding between CP phenolic hydroxyl group and surface oxygen of HAO, which would suppress the reactivity of phenolic hydroxyl group, consequently the ortho- and meta-positions of CP became more facile for the hydroxylation reaction. This study shows the importance of MAOM in altering the photochemical behavior and transformation pathway of organic contaminants.
Topics: Aluminum Hydroxide; Dichlorophen; Humic Substances; Photolysis; Water Pollutants, Chemical
PubMed: 33582491
DOI: 10.1016/j.watres.2021.116904 -
ACS Omega Sep 2020Of the numerous infectious diseases afflicting humans, anthrax disease, caused by , poses a major threat in its virulence and lack of effective treatment. The currently...
Of the numerous infectious diseases afflicting humans, anthrax disease, caused by , poses a major threat in its virulence and lack of effective treatment. The currently lacking standards of care, as well as the lengthy drug approval process, demonstrate the pressing demand for treatment for infections. The present study screened 1586 clinically approved drugs in an attempt to identify repurposable compounds against , a relative strain that shares many physical and genetic characteristics with . Our study yielded five drugs that successfully inhibited growth: dichlorophen, oxiconazole, suloctidil, bithionol, and hexestrol. These drugs exhibited varying levels of efficacy in broad-spectrum experiments against several Gram-positive and Gram-negative bacterial strains, with hexestrol showing the greatest inhibition across all tested strains. Through tests for the efficacy of each drug on , bithionol was the single most potent compound on both solid and liquid media and exhibited even greater eradication of in combination with suloctidil on solid agar. This multifaceted study of approved drugs demonstrates the potential to repurpose these drugs as treatments for anthrax disease in a time-efficient manner to address a global health need.
PubMed: 32905429
DOI: 10.1021/acsomega.0c03207 -
Environmental Science and Pollution... Sep 2022Binary composite of zerovalent iron and titanium dioxide (Fe/TiO) was synthesized for the catalytic removal of dichlorophene (DCP) in the presence of peroxymonosulfate...
Binary composite of zerovalent iron and titanium dioxide (Fe/TiO) was synthesized for the catalytic removal of dichlorophene (DCP) in the presence of peroxymonosulfate (PMS). The as-prepared composite (Fe/TiO) exhibits synergistic effect and enhanced properties like improved catalytic activity of catalyst and greater magnetic property for facile recycling of catalyst. The results showed that without addition of PMS at reaction time of 50 min, the percent degradation of DCP by TiO, Fe, and Fe/TiO was just 5%, 11%, and 12%, respectively. However, with the addition of 0.8 mM PMS, at 10 min of reaction time, the catalytic degradation performance of Fe, TiO, and Fe/TiO was significantly improved to 82%, 18%, and 88%, respectively. The as-prepared catalyst was fully characterized to evaluate its structure, chemical states, and morphology. Scanning electron microscopy results showed that in composite TiO causes dispersion of agglomerated iron particles which enhances porosity and surface area of the composites and X-ray diffraction (XRD), energy dispersive X-ray (EDX), and Fourier-transform infrared (FTIR) results revealed successful incorporation of Fe, and oxides of Fe and TiO in the composite. The adsorption-desorption analysis verifies that the surface area of Fe/TiO is significantly larger than bare Fe and TiO Moreover, the surface area, particle size, and crystal size of Fe/TiO was surface area = 85 m g, particle size = 0.35 μm, and crystal size = 0.16 nm as compared to TiO alone (surface area = 22 m g, particle size = 4.25 μm, and crystal size = 25.4 nm) and Fe alone (surface area = 65 m g, particle size = 0.9 μm, and crystal size = 7.87 nm). The as-synthesized material showed excellent degradation performance in synthesized wastewater as well. The degradation products and their toxicities were evaluated and the resulted degradation mechanism was proposed accordingly. The toxicity values decreased in order of DP1 > DP5 > DP2 > DP3 > DP4 and the LC values toward fish for 96-h duration decreased from 0.531 to 67.2. This suggests that the proposed technology is an excellent option for the treatment of antibiotic containing wastewater.
Topics: Animals; Anti-Bacterial Agents; Catalysis; Dichlorophen; Iron; Oxidative Stress; Peroxides; Titanium; Wastewater; Water
PubMed: 35445919
DOI: 10.1007/s11356-022-20174-5 -
Journal of Endodontics Sep 1996The sealing ability of Amalgam, Harvard-Cement, Diaket, gold-leaf, and Ketac-Endo as retrofilling materials was investigated. Paper cones were fixed with Harvard-Cement... (Comparative Study)
Comparative Study
The sealing ability of Amalgam, Harvard-Cement, Diaket, gold-leaf, and Ketac-Endo as retrofilling materials was investigated. Paper cones were fixed with Harvard-Cement in the instrumented roots of 100 extracted human incisors. Apicectomy was performed and a 2-mm-deep retrograde cavity was prepared. Teeth were assigned to five groups (n = 20); each group received a different filling material. Surfaces of the roots were isolated with nail polish. Teeth, were stored in 1% methylene blue dye for 72 h. Roots were sectioned, and the depth of dye penetration was evaluated through a stereomicroscope. Retrofills with Ketac-Endo showed significantly less leakage compared with amalgam. There was no significant difference between the amalgam and Diaket groups. The sealing ability of Harvard-Cement and gold foil was lower than amalgam. It was concluded that retrograde fillings with Ketac-Endo or Diaket can be considered as alternatives for amalgam.
Topics: Bismuth; Dental Amalgam; Dental Leakage; Drug Combinations; Evaluation Studies as Topic; Glass Ionomer Cements; Humans; Incisor; Mandible; Maxilla; Polyvinyls; Retrograde Obturation; Root Canal Filling Materials; Statistics, Nonparametric; Zinc Oxide; Zinc Phosphate Cement
PubMed: 9198426
DOI: 10.1016/S0099-2399(96)80078-1 -
Brazilian Journal of Microbiology :... Dec 2020With the high-frequency use or abuse of antifungal drugs, the crisis of drug-resistant fungi continues to increase worldwide; in particular, the infection of...
With the high-frequency use or abuse of antifungal drugs, the crisis of drug-resistant fungi continues to increase worldwide; in particular, the infection of drug-resistant Candida albicans brings the great challenge to the clinical treatment. Therefore, to decelerate the spread of this resistance, it is extremely urgent to facilitate the new antifungal targets with novel drugs. Phosphopantetheinyl transferases PPTases (Ppt2 in Candida albicans) had been identified in bacterium and fungi and mammals, effects as a vital enzyme in the metabolism of organisms in C. albicans. Ppt2 transfers the phosphopantetheinyl group of coenzyme A to the acyl carrier protein Acp1 in mitochondria for the synthesis of lipoic acid that is essential for fungal respiration, so making Ppt2 an ideal target for antifungal drugs. In this study, 110 FDA-approved drugs were utilized to investigate the Ppt2 inhibition against drug-resistant Candida albicans by the improved fluorescence polarization experiments, which have enough druggability and structural variety under the novel strategy of drug repurposing. Thereinto, eight agents revealed the favourable Ppt2 inhibitory activities. Further, broth microdilution assay of incubating C. albicans with these eight drugs showed that pterostilbene, procyanidine, dichlorophen and tea polyphenol had the superior MIC values. In summary, these findings provide more valuable insight into the treatment of drug-resistant C. albicans.
Topics: Antifungal Agents; Candida albicans; Drug Repositioning; Drug Resistance, Fungal; Enzyme Inhibitors; Fungal Proteins; Microbial Sensitivity Tests; Transferases (Other Substituted Phosphate Groups)
PubMed: 32557281
DOI: 10.1007/s42770-020-00318-w -
Oral Surgery, Oral Medicine, and Oral... Apr 1986Immunoglobulins G, A, M, and C3 were quantitated by the single radial immunodiffusion technique. The antibody response to AH26, Diaket A, and Tubliseal were also...
Immunoglobulins G, A, M, and C3 were quantitated by the single radial immunodiffusion technique. The antibody response to AH26, Diaket A, and Tubliseal were also determined by the hemagglutination method using tannized erythrocytes. No increments of Ig and C3 were found by those methods and conditions under which the experiments were conducted.
Topics: Adolescent; Adult; Antibody Formation; Bismuth; Complement C3; Drug Combinations; Epoxy Resins; Humans; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Methenamine; Middle Aged; Polymers; Polyvinyls; Root Canal Filling Materials; Silver; Titanium; Zinc Oxide; Zinc Oxide-Eugenol Cement
PubMed: 3458150
DOI: 10.1016/0030-4220(86)90424-x