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At least 739 records · Page 41Linked to original sources
PubMed1994

Ethoxyresorufin O-deethylase (EROD) and aryl hydrocarbon hydroxylase (AHH)-inducing potency and lethality of chlorinated naphthalenes in chicken (Gallus domesticus) and eider duck (Somateria mollissima) embryos.

The 7-ethoxyresorufin O-deethylase (EROD)- and aryl hydrocarbon hydroxylase (AHH)-inducing potencies and lethalities of a technical preparation of polychlorinated naphthalenes (PCNs) (Halowax 1014, approximate congener ratio: 20% tetrachloronaphthalenes, 40% pentachloronaphthalenes, 40% hexachloronaphthalenes), a mixture of 50% 1,2,3,5,6,7-hexachloronaphthalene and 50% 1,2,3,4,6,7-hexachloronaphthalene (HxCN-mix), and 1,2,3,4,5,6,7-heptachloronaphthalene (HpCN) were studied in chicken (Gallus domesticus) and eider duck (Somateria mollissima) embryos. Mortality and hepatic EROD activity were determined on day 10 of incubation in chicken embryos exposed to various doses of the PCNs via the air-sacs of the eggs on day 7. The HxCN-mix and Halowax 1014 proved to have both embryolethal and EROD-inducing properties, while the HpCN had low EROD-inducing potency and embryolethality. ED50 values for EROD induction by the HxCN-mix and Halowax 1014 were estimated to be 0.06 mg/kg egg and 0.2 mg/kg egg, respectively. Fifty percent of the chicken embryos died (6/12) when given 3.0 mg/kg of the HxCN-mix while a similar dose of Halowax 1014 caused mortality in 4 out of 12 chicken embryos. The dose-response curve for EROD induction by Halowax 1014 exhibited a decline after the maximal level was reached. When Halowax 1014 (1.0 mg/kg egg) was coinjected with 3,3',4,4',5-pentachlorobiphenyl (PCB IUPAC #126) (0.1 microgram/kg egg) no additive effects on EROD activity were found, but when the same dose of Halowax 1014 was coinjected with a dose of PCB #126, known to cause maximal induction (1.0 microgram/kg egg), the resulting EROD activity was lower than that caused solely by 1.0 micrograms PCB #126/kg egg.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2002

Column preconcentration and FAAS determination of copper, iron, nickel and zinc using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol-tetraphenylborate-naphthalene adsorbent.

A solid co-precipitated material obtained from an ion-pair of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) and tetraphenylborate (TPB), and microcrystals of naphthalene has been tried as an adsorbent for the column preconcentration of copper(I), iron(II), nickel(II) and Zn(II). The retention of the metal ions was found to be maximum and constant in the pH range 3.0-8.0 for Cu, 3.8-7.5 for Fe, 4.5-7.5 for Ni and 8.5-11.0 for Zn. The elements were determined by FAAS after dissolving the metal along with the adsorbent in an organic solvent (10 mL of DMF). The characteristic concentration for 1% absorption was found to be 0.0332, 0.0536, 0.0537 and 0.0142 (aqueous medium 0.0512, 0.0638, 0.1294 and 0.0216) microg mL(-1) for Cu, Fe, Ni and Zn, respectively. The calibration plot was linear in the range 1.5-20.0, 2.0-38.0, 2.5-25.0 and 0.5-15.0 micro g in the final 10 mL of DMF solution for Cu, Fe, Ni and Zn, respectively. Various parameters such as pH, volume of buffer, amount of adsorbent, flow rate, preconcentration factor and effect of diverse salts and cations were studied. The optimised conditions were utilized for the determination of Cu, Fe, Ni and Zn in various water, beverage and human hair samples.

Azo Compounds↗
PubMed2004

Speciation analysis of mercury in water samples by cold vapor atomic absorption spectrometry after preconcentration with dithizone immobilized on microcrystalline naphthalene.

Trace amounts of inorganic mercury (Hg(2+)) and methylmercury cations (MeHg(2+)) were adsorbed quantitatively from acidic aqueous solution onto a column packed with immobilized dithizone on microcrystalline naphthalene. The trapped mercury was eluted with 10 ml of 7 mol L(-1) hydrochloric acid solution. The Hg(2+) was then directly reduced with tin (II) chloride, and volatilized mercury was determined by cold vapor atomic absorption spectrometry (CVAAS). Total mercury (Hgt) was determined after decomposition of MeHg(+) into Hg(2+). Hg(2+) and MeHg(+) cations were completely recovered from the water with a preconcentration factor of 200. The relative standard deviation obtained for eight replicate determinations at a concentration of 0.3 microg L(-1 )was 1.8%. The procedure was applied to analysis of water samples, and the accuracy was assessed via recovery experiment.

Cold Temperature↗
PubMed2006

Advances in the environmental analysis of polychlorinated naphthalenes and toxaphene.

Recent advances in the analysis of the chlorinated environmental pollutants polychlorinated naphthalenes (PCNs) and toxaphene are highlighted in this review. Method improvements have been realized for PCNs over the past decade in isomer-specific quantification, peak resolution, and the availability of mass-labeled standards. Toxaphene method advancements include the application of new capillary gas chromatographic (GC) stationary phases, mass spectrometry (MS), especially ion trap MS, and the availability of Standard Reference Materials that are value-assigned for total toxaphene and selected congener concentrations. An area of promise for the separation of complex mixtures such as PCNs and toxaphene is the development of multidimensional GC techniques. The need for continued advancements and efficiencies in the analysis of contaminants such as PCNs and toxaphene remains as monitoring requirements for these compound classes are established under international agreements.

Animals↗
PubMed2004

Formation of polychlorinated naphthalenes, dibenzo-p-dioxins, dibenzofurans, biphenyls, and organochlorine pesticides in thermal processes and their occurrence in ambient air.

Mono- through octachlorinated naphthalenes (PCNs) were measured in start-up, steady operation, and shutdown of machinery operation flue gas and fly ash generated during different stages of MSWI and other incineration thermal processes. Besides, electroprecipitator fly ash (EP-ash) was dechlorinated using the Hagenmeier process and analyzed for congener profiles. In addition to PCNs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and major organochlorine pesticides were determined in ambient air samples from three different sites of western Japan in the summer and winter of 1992. The PCNs from flue gas contained 15,000, 4300, and 13,000 ng/m3 during start-up, steady operation, and shutdown conditions, respectively. Whereas fly ash contained 470, 370, and 1400 ng/g PCNs under start-up, steady operation, and shutdown condition, respectively. The dechlorination process reduced PCN concentrations considerably. Concentrations of PCNs and PCDD/PCDFs in air samples collected in winter were slightly higher than in summer. PCBs, organochlorine pesticides such as chlordanes, DDTs, and HCHs were higher in summer air samples. WHO toxic equivalency (WHO-TEQ) concentrations in air samples were 0.3-0.9 pg/m3 for PCDD/DFs and 0.029-0.31 pg/m3 for dioxin-like PCBs.

Air Pollutants↗
PubMed2004

Polychlorinated naphthalenes and polychlorinated biphenyls in benthic organisms of a Great Lakes food chain.

Invasion of zebra mussels, Dreissena polymorpha, and round gobies, Neogobius melanostomus, into the Great Lakes has altered the food web structure and thereby the pathways of toxic contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs). In this study, concentrations of PCNs and PCBs were measured in organisms of a Great Lakes benthic food chain encompassing zebra mussels. PCNs were found in all of the benthic organisms, including phytoplankton, algae, amphipods, zebra mussels, round goby, and smallmouth bass, Micropterus dolomieui. Concentrations of PCNs were greater in samples collected from the Raisin River than in samples from the St. Clair River. Biomagnification factors (BMF) for tetra- through octa-CN congeners in going from algae to zebra mussels from the St. Clair River ranged from 3 to 10. No major biomagnification of PCNs was found in round gobies, when concentrations were related to those in their prey species, zebra mussels. The biomagnification potential of PCNs appears to be similar to that of PCBs in the benthic food chain investigated in this study, despite the fact that PCNs may be metabolized by organisms higher in the food chain. Among several congeners, the BMFs of PCN congeners 35, 42, 43/45, 52/60, 58, and 66/67 were highest in round gobies. PCNs accounted for 1-22% of the total TEQs (toxic equivalents) of PCBs and PCNs in benthic organisms analyzed in this study. PCB congener 126 was the major contributor to TEQs, accounting for 72-99% of the PCB-TEQs in the food chain organisms analyzed.

Amphipoda↗
PubMed2000

Impact of polychlorinated naphthalenes (PCNs) in juvenile Baltic salmon, Salmo salar: evaluation of estrogenic effects, development, and CYP1A induction.

Juvenile Baltic salmon, Salmo salar, were fed commercial salmon food contaminated with different concentrations of polychlorinated naphthalenes (PCNs; 0.1, 1, 2, or 10 microg PCN/g food). Among other effects, possible estrogenic impact caused by PCNs were evaluated. Fish were therefore fed a diet contaminated with 17beta-estradiol (E2; 0.94 or 9.4 microg E2/g food), as a positive control. After 8, 13, 17, and 41 weeks, sampling took place. Growth, liver somatic index (LSI), EROD activity, and vitellogenin content in blood plasma were measured along with morphological studies of gonads and chemical analyses to determine the effects caused by PCNs. Exposure to PCNs did not seem to have any effects on body weight gain, since the group fed the high dose followed the growth in the control group during the entirely experimental period. After 41 weeks of exposure the groups fed 2 and 10 microg PCN/g food had significantly lower LSIs compared with the control, indicating liver toxic effects of PCNs. Furthermore, a dose-dependent induction of EROD activity was found. At week 41, the control group had an activity of 4.9 +/- 4.8 pmol/mg prot/min, whereas it was between 69 +/- 21 and 720 +/- 370 pmol/mg prot/min in the exposed groups, respectively. Examination of gonadal morphology showed that PCNs also had negative effects on ovaries in Baltic salmon, including delayed development. The distribution between females and males, gonadal morphology, and vitellogenin content in blood plasma did, however, indicate that PCNs are not capable of causing effects similar to E2 or xenoestrogens. Exposure to both of the concentrations of E2 resulted in decreased body weight gain, increased LSI, and feminization of the gonads. E2 did, however, not induce any EROD activity.

Animals↗
PubMed2003

Urinary hydroxy-metabolites of naphthalene, phenanthrene and pyrene as markers of exposure to diesel exhaust.

OBJECTIVE: The objective of this study was to assess the exposure of bus-garage and waste-collection workers to polycyclic aromatic hydrocarbons (PAHs) derived from diesel exhaust by the measurement of levels of seven urinary PAH metabolites: 2-naphthol, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1+9-hydroxyphenanthrene, 4-hydroxyphenanthrene and 1-hydroxypyrene. SUBJECTS AND METHODS: One urine sample from each of 46 control persons, and one pre-shift and two post-shift spot urine samples from 32 exposed workers were obtained in winter and in summer. The metabolites were analysed after enzymatic hydrolysis by high performance liquid chromatography (HPLC) with fluorescence detection. RESULTS: The sum of seven PAH metabolites (mean 3.94 +/- 3.40 and 5.60 +/- 6.37 micromol/mol creatinine in winter and summer, respectively) was higher [P=0.01, degrees of freedom (df) =61.2 and P=0.01, df=67.6 in winter and summer, respectively] in the exposed group than in the control group (mean 3.18 +/- 3.99 and 3.03 +/- 2.01 micromol/mol creatinine in winter and summer, respectively). The mean concentrations of 2-naphthol among exposed and controls ranged between 3.34 and 4.85 micromol/mol creatinine and 2.51 and 2.58 micromol/mol creatinine, respectively (P<0.01 in winter, P<0.03 in summer). The mean level of the hydroxyphenanthrenes in the samples of exposed workers was between 0.40 and 0.70 micromol/mol creatinine and in the control samples 0.40-0.60 micromol/mol creatinine. The concentration of 1-hydroxypyrene was higher among exposed workers in both pre-shift and post-shift samples (mean 0.10-0.15 micromol/mol creatinine) than in control group (mean 0.05-0.06 micromol/mol creatinine) in winter (P=0.002, df=78) and in summer (P<0.001, df=68). CONCLUSIONS: The urinary hydroxy-metabolites of naphthalene, phenanthrene and pyrene showed low exposure to diesel-derived PAHs; however, it was higher in exposed workers than in control group. Urinary PAH monohydroxy-metabolites measured in this study did not correlate with the PAHs in the air samples, reported earlier, in 2002 and 2003.

Adult↗
PubMed1989

Determination of dopamine, norepinephrine, and related trace amines by prechromatographic derivatization with naphthalene-2,3-dicarboxaldehyde.

Dopamine, norepinephrine, octopamine, tyramine, and 3,4-dihydroxybenzylamine react readily with naphthalene-2,3-dicarboxaldehyde in the presence of cyanide ion under mild conditions to give highly fluorescent cyanobenz[f]isoindole (CBI) products. The CBI products exhibit good solution chemical stability. The high-fluorescence quantum efficiency of the CBI fluorophore and the ability to excite these adducts in the visible region (420-450 nm) enhance the sensitivity and selectivity of this derivatization detection technique. The CBI products of catecholamines and "trace" amines are readily separated by reverse-phase HPLC giving detection limits in the 20 to 60 fmol range (S/N = 3). A prechromatographic derivatization HPLC assay for the trace analysis of dopamine and norepinephrine in urine is described.

Biogenic Amines↗
PubMed1994

Gas chromatographic retention behaviour of polychlorinated naphthalenes on non-polar, polarizable, polar and smectic capillary columns.

Six commercially available gas chromatography columns were investigated for performance in separating polychlorinated naphthalenes (PCNs). Retention behaviour on the investigated phases is compared and retention data for 40 congeners on a 5% phenyl-methylpolysiloxane column is reported. For all columns, except the octylmethylpolysiloxane and the smectic, a relation between substitution pattern and retention was found, where substitution in adjacent positions as well as alpha-substitution increase the retention time. A mathematical model based on these findings was developed and used to predict the relative retention of all congeners from di- up to octachloronaphthalene, on a 5% phenyl-methylpolysiloxane column.

Chromatography, Gas↗
PubMed1983

Structure activity relationships of selected naphthalene derivatives.

Twenty-two derivatives of naphthalene were assayed under an acute static regime with biological activity being monitored as population growth of Tetrahymena pyriformis. Activity varied over one log unit. Substituent constant structure-activity analyses revealed the model, log BR = 0.282Ha + 0.352 pi + 0.692F + 0.3341Xvsub - 0.326R + 0.027, to be best and to account for 85% of the variation in log BR (BR, biological response; Ha, hydrogen acceptance; pi, hydrophobic substituent constant; F, polar electronic substituent constant, 1Xvsub, substituent molar connectivity index; R, resonance electronic substituent constant). The Ha and pi parameters are the most important, accounting for 71% of the log BR variability.

Animals↗
PubMed1990

Naphthalene derivatives that selectively inhibit an antigen-specific IgE response in murine lymphocytes.

When the spleen cells from BALB/c mice that had been immunized twice with TNP-KLH were cultured with the same antigen, the synthesis of anti-TNP IgE as well as anti-TNP IgG was induced. We found that the addition of a naphthalene derivative, (E)-N-(2-methoxy-carbonylphenyl)-8-(2-naphthyl)-5,6-trans-5,6-meth ano-7- octenamide (TEI-1338) or methyl-6,7-dihydroxy-2-naphthylthioacetate (TEI-3332) to this lymphocyte culture system resulted in a marked suppression of anti-TNP IgE response without affecting the corresponding IgG production. These compounds are expected to be a prototype for the drug that can be used for the treatment of IgE-mediated allergic diseases.

Animals↗
PubMed1993

Suppression of IgE antibody response in mice by a naphthalene derivative, TEI-6472.

In the present report, we investigated suppressive effects of a naphthalene derivative, (7E)-N-(2-carboxyphenyl)-8-(2-naphthyl)-5,6-trans-5,6-methano-7- octenamide L-lysine salt (TEI-6472), on in vitro and in vivo antigen-specific IgE response. Anti-trinitrophenyl (TNP) IgE response induced in vitro in TNP-keyhole limpet hemocyanin (KLH)-primed murine spleen cells was suppressed by about 60% in the presence of 10(-6) M TEI-6472. On the other hand, anti-TNP IgG1 and IgM response were not significantly suppressed under the same conditions. Proliferative responses of BALB/c spleen cells stimulated by lipopolysaccharide, concanavalin A or allogeneic spleen cells were not inhibited by TEI-6472 at 10(-6)-10(-5) M. Interleukin 4 production from helper T-cell clone, D10.G4.1 was suppressed only slightly (less than 20%) at 10(-6) M TEI-6472. This compound was also effective in suppressing secondary anti-TNP IgE response in mice that were immunized twice with TNP-KLH and alum. When 10-20 mg/kg/day TEI-6472 was administered s.c. for 5 consecutive days starting from one day before the first and the second immunization, secondary anti-TNP IgE response was inhibited most strongly (40-45%). Anti-TNP IgG1 response was also inhibited but to a smaller extent (20-24%), while anti-TNP IgM response was suppressed only slightly (0-15%). These results suggest that, under appropriate conditions, TEI-6472 can suppress IgE responses more preferentially both in vitro and in vivo.

Animals↗
PubMed1995

The effect of a naphthalene derivative, TEI-6472, on histamine release and tyrosine phosphorylation in rat basophilic leukemia cells.

It is well known that rat basophilic leukemia cells (RBL-2H3) express high-affinity IgE receptors (Fc epsilon RI) and that the aggregation of these receptors causes the release of chemical mediators. When RBL-2H3 cells are sensitized with IgE antibody and subsequently stimulated by an antigen, significant histamine release and the tyrosine phosphorylation of several proteins are observed. In this study, we examined the effects of a synthetic naphthalene derivative, (7E)-N-(2-carboxyphenyl)-8-(2-naphthyl)-5,6-trans-5,6-methano-7-++ +octenamide (TEI-6472), on the Fc epsilon RI-mediated histamine release from RBL-2H3 cells. Preincubation for 10 min with 100 microM TEI-6472 caused significant inhibition of Fc epsilon RI-mediated histamine release from RBL-2H3 cells. Furthermore, Western blotting analysis using anti-phosphotyrosine antibody showed that Fc epsilon RI-mediated tyrosine phosphorylation of 78 and 92 kDa proteins in RBL-2H3 cells was also significantly inhibited. Tyrosine phosphorylation of these 78 and 92 kDa proteins was not induced by direct activation of protein kinase C (PKC) by phorbol-12-myristate-13-acetate (PMA) and the calcium ionophore A23187. However, the inhibition of histamine release from TEI-6472-treated RBL-2H3 cells was restored by direct activation of PKC. Taken together, these results suggest that tyrosine phosphorylation of the 78 and 92 kDa proteins in RBL-2H3 cells is involved in a signal transduction system for histamine secretion, and that these tyrosine phosphorylations may occur upstream of PKC activation.

Animals↗
PubMed1981

Biochemical changes induced by naphthalene after oral administration in albino rats.

Biochemical alterations were observed in albino rats after oral administration of naphthalene for 10 days. The changes were significant in the liver where increases in liver weight, lipid peroxidation and aniline hydroxylase activity were observed. A slight increase of alkaline phosphatase activity was observed in the liver and eye. No significant change was observed in the kidney.

Alkaline Phosphatase↗
PubMed1983

Tissue distribution and elimination of chlorinated naphthalenes in mice.

Male pathogen-free JCL:ICR mice were dosed i.p. 1 mg of 1,8-and 2,7-dichloronaphthalenes and octachloronaphthalene dissolved in olive oil. The highest levels of all chlorinated naphthalenes were found in adipose tissue. The biological half-life of octachloronaphthalene was longer than both dichloronaphthalenes while the half-life of 2,7-dichloronaphthalene was longer than that of 1,8-dichloronaphthalene in most tissues.

Animals↗
PubMed1987

Determination of (E)-1,2,3,4-tetrahydro-1,1,4,4-tetramethyl-6-(1-methyl-2- phenylethenyl) naphthalene, an antiacne agent, and its phenolic metabolite in plasma by reversed-phase high-performance liquid chromatography.

A rapid, sensitive and selective high-performance liquid chromatographic (HPLC) assay was developed for the determination of (E)-1,2,3,4-tetrahydro-1,1,4,4-tetramethyl-6-(1-methyl-2- phenylethenyl)naphthalene (I) and its phenolic metabolite, (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-2- methylethenyl]phenol (II) in plasma. The assay for both compounds involves precipitation of the plasma proteins with acetonitrile, followed by extraction of the entire mixture into methyl tert.-butyl ether and subsequent analysis by reversed-phase HPLC. The overall recovery of I and II was 96.9 +/- 5.3 and 96.2 +/- 5.8% for dog plasma, 80.0 +/- 4.0 and 93.5 +/- 5.0% for human plasma and 97.4 +/- 2.9 and 97.6 +/- 9.6% for rat plasma, respectively. The sensitivity limit is 20 ng/ml of plasma for both compounds I and II using UV detection at 280 nm. The HPLC assay was used in studies in the dog and in the rat.

Acne Vulgaris↗