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PubMed2006

New route to the synthesis of bis[N-(2-aminoethyl) salicylaldiminato] chromium(III) chloride monohydrate Spectroscopic characterization, crystal structure and interaction with DNA.

The reaction of [Cr(urea)(6)]Cl(3).3H(2)O with H(2)salen (H(2)salen=N,N(')-ethylenebis(salicylaldimine) in water-methanol mixture (40:60v/v) under reflux yielded the complex bis[N-(2-aminoethyl)salicylaldiminato]chromium(III) chloride monohydrate, [Cr(aesaldmn)(2)]Cl.H(2)O. The complex was characterized by elemental analysis, molar conductance, magnetic susceptibility, spectroscopic (UV-vis and IR) data and X-ray diffraction studies. The new ligand, N-(2-aminoethyl)salicylaldimine, Haesaldmn, possibly resulted from the hydrolytic cleavage of one end of the H(2)salen ligand during reflux. Binding of this chromium(III) complex to CT DNA has been studied using UV-vis spectroscopy with an apparent binding constant of 2.68 x 10(3)M(-1). It shows that the binding mode is electrostatic while the emission of ethidium bromide to CT DNA in the absence and in the presence of the complex show that it binds DNA with partial intercalation.

Chromium Compounds↗
PubMed2006

Structural and spectroscopic properties of trans-difluoro(1,4,8,12-tetraazacyclopentadecane)chromium(III) perchlorate hydrate.

The structure of [CrF(2)([15]aneN(4))]ClO(4).H(2)O ([15]aneN(4)=1,4,8,12-tetraazacyclopentadecane) has been determined by a single-crystal X-ray diffraction study at 173 K. The complex crystallizes in the space group P1- of the triclinic system with two mononuclear formula units in a cell of dimensions a=9.6117(7) A, b=10.2882(7) A, c=11.0001(7) A and alpha=99.7570(10) degrees, beta=105.6080(10) degrees and gamma=113.7130(10) degrees. The complex cation unit has its central Cr atom in an octahedral coordination with four nitrogen atoms and two fluorine atoms in a trans position. Three six-membered and one five-membered chelate rings of the [15]aneN(4) ligand are in a chair-twist(skew)-chair-gauche conformation sequence. The gauche five-membered ring is disordered with the twist six-membered ring opposite. The four H atoms in the chiral N atoms have the trans-II (CTCg) type configuration. The mean Cr-N and Cr-F bonds are 2.095(2) and 1.8752(13) A, respectively. The IR and visible spectral properties are consistent with the result of X-ray crystallography. The resolved band maxima of the electronic d-d spectrum are fitted with secular determinant for quartet state energy of d(3) configuration in tetragonal field including configurational but neglecting spin-orbit coupling. It is confirmed that the fluoride has strong sigma- and pi-donor properties toward the chromium(III) ion and the nitrogen atoms of the [15]aneN(4) ligand also have a strong sigma-donor character.

Chromium↗
PubMed2006

Studies of the trigonal field parameters and g factors for magnetic semiconductor NaCrS2.

The trigonal field parameters v and v' of magnetic semiconductor NaCrS2 are calculated from the superposition model, and its g factors g parallel and g perpendicular are calculated from the high-order perturbation formulas of 3d3 ions in trigonal symmetry obtained by the one and two spin-orbit coupling parameter models. These calculations are based on the structural data of NaCrS2 crystal. The calculated results suggest that the superposition model is effective to the analyses of the low-symmetry field parameters of 3dn ions in crystals and that the two spin-orbit coupling parameter model (where the contributions from both the spin-orbit coupling parameter of 3dn ion and that of ligand are considered) is preferable to the one spin-orbit coupling parameter model (in which the contribution from only the spin-orbit coupling parameter of 3dn ion is considered) in the explanations of g factors in the cases that ligands have large spin-orbit coupling parameter in 3dn clusters.

Chromium Compounds↗
PubMed2006

Studies on some salicylaldehyde Schiff base derivatives and their complexes with Cr(III), Mn(II), Fe(III), Ni(II) and Cu(II).

The formation constants of some transition metal ions Cr(III), Mn(II), Fe(III), Ni(II) and Cu(II) binary complexes containing Schiff bases resulting from condensation of salicylaldehyde with aniline (I), 2-aminopyridine (II), 4-aminopyridine (III) and 2-aminopyrimidine (IV) were determined pH-metrically in ethanolic medium (80%, v/v). The formation constants were determined for all binary complexes. The important infrared (IR) spectral bands corresponding to the active groups in the four ligands and the solid complexes under investigation were studied. The solid complexes have been synthesized and studied by thermogravimetric analysis. The thermal dehydration and decomposition of these complexes were studied kinetically using the integral method applying the Coats-Redfern equation. It was found that the thermal decomposition of the complexes follow second order kinetics. The thermodynamic parameters of the decomposition are also reported. The electronic absorption spectra of the investigated ligands were carried out to determine the pK(a) values spectrophotometrically.

4-Aminopyridine↗
PubMed2005

Chromatite Ca[CrO4] in soil polluted with electroplating effluents (Zabierzów, Poland).

Chromatite, Ca[CrO(4)] (space group I41/amd), was found as yellow precipitates between the particles of soil, heavily polluted with chromium(VI)-bearing electroplating effluents and weathered subsoil rocks (marly limestones, marls). X-ray diffraction (XRD), infrared spectroscopy (IR) and scanning electron microscopy (SEM) have showed the precipitates to be almost pure Ca[CrO(4)]. The chromatite occurs mainly as coatings 5-30 microm large and prismatic grains 20-100 microm long. It was formed and preserved due to dissolution of calcium carbonate by electroplating effluents containing Cr(VI). Although precipitation of calcium chromates in the soils polluted with chromium(VI) compounds has already been mentioned in the literature, the author gives the first mineralogical description of the chromatite formed in such an environment.

Journal Article↗
PubMed2005

Vitamins deficiency in developing chick during chromium intoxication and protection thereof.

Deficiency of various vitamins in postnatally developing chick during chromium intoxication and their recovery during vitamins (B and E) and glutathione therapies has been investigated. Study was concentrated on liver, kidney, muscles and serum. Newly hatched chicks were reared in laboratory. They were treated with a daily dose of 10mg/kg/day potassium dichromate from 2nd to 8th day of their age. Thereafter, one group was sacrificed on 9th day. Second group was kept without intoxication for another 7 days and sacrificed on 16th day. Three groups of chromium pretoxicated animals were exposed to therapeutic agents like vitamins (B and E) and glutathione for another 7 days. These animals were sacrificed on 16th day of their age along with control. Study showed chromium intoxication decreases vitamins (B(1), B(2), B(6) and E) in all the tissues and serum. The maximum decrease was recorded in serum. The 7 days pretoxicated animals kept without any treatment for 7 days revealed a slow increase of vitamins with few exceptions. Nevertheless, the recovery of vitamins was quick and significant during vitamins and glutathione therapy and in some cases control level was achieved.

Alanine Transaminase↗
PubMed2006

Adjusting worm egg counts for faecal moisture in sheep.

The number of eggs from gastrointestinal nematodes per gram of faeces (worm egg count WEC) is commonly used to determine the need for anti-parasite treatments and the breeding value of animals when selecting for worm resistance. Diarrhoea increases faecal moisture and may dilute the number of worm eggs observed. To quantify this effect, egg counts in sheep at pasture were simulated by dosing 15 animals with chromic oxide particles. The simulated WEC diminished as faecal moisture increased. When faeces were dried, simulated WEC per unit dry matter was not influenced by the amount of faecal moisture present prior to drying. The results suggest that adjustment for faecal moisture may provide an improved estimate of FEC. Drying faeces to calculate the WEC per unit dry matter would provide such an adjustment but may not be practical for industry application. In the past, the CSIRO McMaster Laboratory has used an adjustment factor developed by Gordon based on the classification of faecal consistency derived from the morphology of faeces. To examine the utility of an adjustment factor based on faecal consistency score (FCS), the relationships between FCS and simulated WEC and dry matter were examined. Dry matter and simulated WEC exhibited an exponential decline as FCS increased. The relationship between FCS and dry matter was further examined in 368 samples collected over 12 months from sheep at pasture, where it was observed that dry matter showed a linear decline as FCS increased. Adjustment factors based on dry matter were similar to those proposed by Gordon however adjustment factors predicted from simulated WEC diverged from the remainder for FCS>4. As no samples scored FCS 5 in the study of simulated FEC, the adjustment factors based on the larger study that included samples with FCS 5 was therefore considered more robust. Adjustment factors were given by the equation: WEC(estimated)=(WEC(observed)/(34.21-5.15 FCS))x29.06. This equation estimates for samples with FCS>1 the WEC that would be expected if the samples were FCS 1, the faecal consistency score for normal faeces. The impact of adjustment of observed WEC for faecal moisture predicted by FCS on decision points for treatment and on estimated breeding values requires further examination.

Animals↗
PubMed1981

Prognostic significance of peritoneal cytology in patients with endometrial cancer and preliminary data concerning therapy with intraperitoneal radiopharmaceuticals.

One hundred sixty-seven patients with clinical State I carcinoma of the endometrium were treated primarily by operation consisting of total abdominal hysterectomy, bilateral salpingo-oophorectomy, selective pelvic and para-aortic lymphadenectomy, and cytologic testing of peritoneal washings. Twenty-six (15.5%) of the 167 patients had malignant cells identified on cytologic examinations of peritoneal washings. Recurrence developed in 10 of these 26 (34.0%) compared to 14/141 (9.9%) patients with negative cytologic testing. Of the 26 patients, 13 (50%) had disease outside of the uterus at operation and seven have died of disease (54%). Thirteen patients had malignant cells in the peritoneal washings but no disease outside of the uterus and six (46%) of these have died of disseminated intra-abdominal carcinomatosis. On the basis of the poor outcome of those patients who had malignant cells in the peritoneal washings in the 167 patients studied, a plan of treating such patients with intraperitoneal radioactive chromic phosphate suspension (P-32) was instituted. Twenty-three subsequent patients with clinical Stage I carcinoma of the endometrium were found to have malignant cells in the peritoneal fluid. All 23 received intra-abdominal P-32 suspension instillation after operation. There have been three recurrences with two patients dying of disease. All of the three recurrences appeared at sites distant from the abdominal cavity. Peritoneal cytologic examination appears to be an important factor in the prognosis of endometrial cancer and, when the washings are positive for malignant cells, intraperitoneal chronic phosphate therapy appears to be efficacious.

Adenocarcinoma↗
PubMed1984

Radioactivity in blood and urine following intraperitoneal instillation of chromic phosphate in patients with and without ascites.

Systemic distribution of radioactive colloidal chromic phosphate P 32 after intraperitoneal instillation was studied in 10 patients with ovarian or endometrial malignancies. Seven patients without ascites received chromic phosphate P 32 for positive peritoneal washings, rupture of the capsule of the cyst during operation, or minimal Stage III disease. Three patients received chromic phosphate P 32 for recurrent ascites after multiple abdominal paracenteses. Blood and urine radioactivity measurements were performed at selected intervals. There was a clear statistically significant difference (p less than 0.01) between chromic phosphate P 32 activity levels in whole blood, red blood cells, and plasma in patients with and without ascites.

Adult↗
PubMed2001

Stratification of welding fumes and grinding particles in a large factory hall equipped with displacement ventilation.

The purpose of the study was to investigate the performance of displacement ventilation in a large factory hall where large components of stainless steel for paper, pulp and chemical industries were manufactured. The performance of displacement ventilation was evaluated in terms of concentration distributions of welding fumes and grinding particles, flow field of the supply air and temperature distributions. Large differences in vertical stratification patterns between hexavalent chromium (Cr(VI)) and other particulate contaminants were observed. The concentration of Cr(VI) was notably lower in the zone of occupancy than in the upper part of the factory hall, whereas the concentrations of total airborne particles and trivalent chromium (Cr(III)) were higher in the occupied zone than in the upper zone. The stratification of Cr(VI) had the same tendency as the air temperature stratification caused by the displacement flow field.

Air Pollution, Indoor↗
PubMed1985

Structural studies of the O-antigen polysaccharides of Klebsiella O5 and Escherichia coli O8.

The O-antigen polysaccharides of Klebsiella serotype O5 and Escherichia coli serotype O8 are serologically very similar or identical. The structures of these two polysaccharides have now been re-investigated. N.m.r. spectroscopy, chromium trioxide oxidation, hydrolysis with a specific phage enzyme, and f.a.b. mass spectrometry were the principal methods used. It is concluded that the O-antigen has the following structure, in which D-Man3Me is 3-O-methyl-D-mannose and n is approximately 10. (Formula: see text) Biosynthetic studies indicate that these antigens are synthesised by addition of D-mannopyranosyl groups to the "non-reducing" end of the mannan chain, and it seems possible that addition of a 3-O-methyl-D-mannopyranosyl group involves termination.

Carbohydrate Conformation↗
PubMed2000

The reduction of CrVI to CrIII by the alpha and beta anomers of D-glucose in dimethyl sulfoxide. A comparative kinetic and mechanistic study.

The reduction of CrVI by alpha-D-glucose and beta-D-glucose was studied in dimethyl sulfoxide in the presence of pyridinium p-toluensulfonate, a medium where mutarotation is slower than the redox reaction. The two anomers reduce CrVI by formation of an intermediate CrVI ester precursor of the slow redox step. The equilibrium constant for the formation of the intermediate chromic ester and the rate of the redox steps are different for each anomer. alpha-D-Glucose forms the CrVI-Glc ester with a higher equilibrium constant than beta-D-glucose, but the electron transfer within this complex is slower than for the beta anomer. The difference is attributed to the better chelating ability of the 1,2-cis-diolate moiety of the alpha anomer. The CrV species, generated in the reaction mixture, reacts with the two anomers at a rate comparable with that of CrVI. The EPR spectra show that the alpha anomer forms several linkage isomers of the five-coordinate CrV bis-chelate, while beta-D-glucose affords a mixture of six-coordinate CrV monochelate and five-coordinate CrV bis-chelate. The conversion of the CrV mono- to bis-chelate is discussed in terms of the ability of the 1,2-cis- versus 1,2-trans-diolate moieties of the glucose anomers to bind CrV.

Benzenesulfonates↗
PubMed1996

Formation of reactive oxygen species and DNA strand breakage during interaction of chromium (III) and hydrogen peroxide in vitro: evidence for a chromium (III)-mediated Fenton-like reaction.

The role of reactive oxygen species in causing DNA damage through interaction of chromium (III) and hydrogen peroxide was examined using plasmid relaxation assay and EPR spectroscopy. Marked DNA strand breakage was induced by CrCl3 plus H2O2 in a phosphate buffer at pH 6-8.9; whereas, only slight DNA strand breakage was observed during similar treatment at pH less than 4. DNA breakage also increased as the reaction temperature and Cr(III)/H2O2 concentrations increased. Control experiments with Cr(III) or H2O2 alone did not cause DNA breakage. Sodium azide, D-mannitol, Tris-HCl, or catalase completely inhibited Cr(III)/H2O2-induced DNA breakage, but superoxide dismutase did not. The D2O enhancing effect on DNA breaks was not observed. Cr(III) pre-incubated with a 30-fold molar excess of EDTA did not cause any significant DNA breakage in the presence of H2O2. In a phosphate buffer containing Cr(III) and H2O2, singlet oxygen and hydroxyl radicals were detected using EPR spectrometry with the spin traps 2,2,6,6-tetramethyl-4-piperidone and 5,5-dimethyl-1-pyrroline 1-oxide (DMPO), respectively. DMPO/.OH adducts and DNA breakage induced by Cr(III)/H2O2 were markedly higher than those induced by Cr(VI)/H2O2. Furthermore, ascorbate decreased Cr(III)/H2O2-induced DNA breakage. EPR studies revealed that ascorbate (mole ratio to Cr(III) = 0.5:1) attenuated the DMPO/.OH signal generated by Cr(III)/H2O2/DMPO, but a Cr(V) signal and ascorbate radicals were detected. NADPH, GSH, and GSSG also decreased DMPO/.OH generated by Cr(III)/H2O2/DMPO; however, they were less efficient than ascorbate and no Cr(V) signals were detected. This study shows that Cr(III)/H2O2 generates oxidative damage to DNA through a Fenton-like reaction: Cr(III) + H2O2-->Cr(IV) + .OH + OH.

Ascorbic Acid↗
PubMed1992

Rabbit lung after combined exposure to soluble cobalt and trivalent chromium.

Eight rabbits were exposed to 0.7 +/- 0.4 mg/m3 Co2+ as CoCl2 and 1.2 +/- 0.7 mg/m3 Cr3+ as Cr(NO3)3 (group Co + Cr), eight to 0.6 +/- 0.5 mg/m3 Co2+ (group Co), and eight to filtered air (control group), for 4 months, 5 days/week, and 6 hr/day. All rabbits in group Co + Cr and group Co showed nodular aggregation of alveolar epithelial type II cells. Volume density of the type II cells was significantly higher in group Co + Cr than in group Co and the control group. There was intraalveolar macrophage accumulation in seven rabbits in group Co + Cr, one in group Co, and one in the control group. In lavage fluid the numbers of macrophages and the percentage of these cells with smooth surface and intracellular surfactant-like inclusions were more increased in group Co + Cr than in group Co as were oxidative metabolic and phagocytic activities of the macrophages. Total phospholipids, phosphatidylcholines, and especially 1,2-dipalmitoylphosphatidylcholine was markedly increased in group Co + Cr whereas only 1,2-dipalmitoylphosphatidylcholine was slightly increased in group Co. One mechanism behind the high amount of surfactant phospholipids in group Co + Cr seems to be an enhanced production of surfactant by the type II cells. Another mechanism is probably that Cr3+ reduces the capacity of alveolar macrophages to catabolize surfactant. The results imply that it is important to investigate effects of combinations of cobalt and chromium in the occupational environment.

Animals↗
PubMed1986

Rabbit alveolar macrophages after inhalation of hexa- and trivalent chromium.

Rabbits inhaled aerosols of hexavalent chromium (Na2CrO4) and trivalent chromium (Cr(NO3)3) at concentrations of 0.9 and 0.6 mg/m3 of the metal, respectively, for 4-6 weeks (5 days/week and 6 hr/day). Significantly more macrophages were obtained from the lungs of rabbits exposed to Cr(VI) but not from rabbits exposed to Cr(III) as compared with the controls. Macrophages from rabbits exposed to Cr(III) showed several conspicuous changes. About one-third of the macrophages contained round dark inclusions, 0.5-1.5 micron diameter, rich in chromium. Most cells had very large lysosomes which contained membranous fragments of different sizes surrounded by a more homogeneous matrix. Laminated inclusions similar to the lamellar bodies in the type II cells increased in number as did the percentage of cells with a smooth cell surface. Also macrophages from rabbits exposed to Cr(VI) showed morphological changes. The most pronounced one was enlarged lysosomes which contained short lamellae and electron-dense patchy inclusions. Only Cr(III) produced functional changes of the macrophages. The metabolic activity measured by reduction of nitroblue tetrazolium was increased and the phagocytic activity reduced.

Animals↗
PubMed1987

Conjugation of DNA to erythrocytes.

DNA was conjugated to sheep red blood cells (SRBC) by chemical methods using CrCl3, poly-L-lysine or methylated bovine serum albumin as conjugation agents and by a physical method where conjugation was accomplished by incubation at 45 degrees C. The degree of conjugation was estimated using 32P-DNA (mean size 1 kbase pairs). Employing the CrCl3 method 5.8 +/- 3.6 micrograms DNA were conjugated per 10(8) SRBC at a concentration of 70 micrograms DNA/10(8) cells. At the same DNA concentration in the incubation medium 3.0 +/- 0.6 microgram DNA/10(8) cells were conjugated by poly-L-lysine, 4.1 +/- 0.8 microgram DNA/10(8) cells by methylated bovine serum albumin and approximately 4 micrograms DNA/10(8) cells when the cells were incubated at 45 degrees C. Cells conjugated with DNA by CrCl3 showed linearly increasing conjugation with increasing concentration of DNA. Cells conjugated by poly-L-lysine (pLL) or methylated bovine serum albumin seemed to be saturated by DNA at 30 micrograms DNA per 10(8) cells. At 45 degrees C the spontaneous adhesion of DNA to SRBC increased in the concentration range investigated. The degree of conjugation of DNA to SRBC was influenced by pH, and Ca2+.pLL-conjugated DNA-SRBC, but none of the other preparations were lysed in a hemolytic assay using anti-DNA antiserum from a patient with systemic lupus erythematosus.

Animals↗