A New Luminescent Zn(II) Complex: Selective Sensing of Cr2O72- and Prevention Activity Against Orthodontic Root Absorption by Suppressing Inflammatory Response.

A novel luminescent coordination polymer (CP) based on Zn(II) ions as nodes [Zn(OPY)1.5(Hbtc)]n (1), [H3btc = trimesic acid and OPY = 4,4'-(oxybis(4,1-phenylene))dipyridine] has been prepared via the solvothermal assembly of a tripodal multicarboxylic acid ligand, a bis-pyridyl ligand with V-shape containing two diverse coordination patterns as well as Zn2 + ion. The experiments of photoluminescence also reflect that the coordination polymer 1 has high sensitivity to potassium dichromate, and its quenching efficiency is Ksv of 2.12 × 104 L·mol- 1. Furthermore, its treatment activity on orthodontic root absorption was evaluated in vivo. Firstly, the CCK-8 assay was performed in this research to evaluate the biotoxicity of the synthetic compound. Next, the TNF-α and Cbfα1 released by the periodontal ligament fibroblast was determined via the ELISA test kit. In addition to this, the signaling pathway of NF-κB activation after treated with compound was measured by the RT-PCR.

A Fluorescent Zn(II) Coordination Polymer: Sensitive Detection of Cr2O72- in Water and Prevention Activity On the Deep Vein Thrombosis in Orthopedic Nursing.

A novel coordination polymer (CP) based on Zn(II) of [Zn(tptc)0.5(bpy)(H2O)]n (1) was synthesized through utilizing the 2,2'-bipyridine (bpy) chelating N donors and p-terphenyl-2,2'',5'',5'''-tetracarboxylate acid (H4tptc) as the co-ligands. The measurements of the fluorescence were implemented for the complex 1 in solution and solid state, and the result reveals that 1 has a strong fluorescence and it is a sensory material with great development space to determine the trace Cr2O72- (with the detection limit of 36 ppb) in the water solutions via applying the fluorescence quenching effect. As the common disease in the orthopedic nursing, the deep vein thrombosis was the objective in this research. The weigh and length of the thrombus in the animals were measured and analyzed. In addition to this, the inflammatory response in the deep vein thrombosis animal was evaluated by RT-PCR. Molecular docking results indicate that only the carboxyl group could provide polar oxygen atoms for the formed hydrogen bonds to the protein.

One-step microwave synthesis of N,S co-doped carbon dots from 1,6-hexanediamine dihydrochloride for cell imaging and ion detection.

As a new member of the fluorescent carbon nanomaterial family, carbon dots (CDs) not only have outstanding photoluminescence properties and small size characteristics, but also contain favourable low cytotoxicity and biocompatibility, which could be the best choice to detect of ions to replace quantum dots for ions detection. Here, the N,S co-doped carbon dots (N/S-CDs) was synthesized by one-step microwave using 1,6-hexanediamine dihydrochloride and dimethyl sulfoxide as precursors, and their morphology and structure were characterized by TEM, XRD, XPS and FTIR. The optimal emission wavelength of the CDs was 512 nm with green fluorescence, and was red-shifted gradually as the excitation wavelength aggrandized. The synthesized CDs owned a well quantum yield of 24 %. It was further applied for the detection of MnO4- and Cr2O72- with an excellent detection limit of 0.34 µM and 0.23µM, respectively. Cr2O72- did not influence the N/S-CDs PL response of MnO4- in the presence of excessive Pb2+. Moreover, the obtained N/S-CDs demonstrated preeminent biocompatibility and could be resoundingly applied for cellular imaging.

Changes in aquatic toxicity of potassium dichromate as a function of water quality parameters.

Potassium dichromate (K2Cr2O7) is used as a general reference toxicant in aquatic toxicity testing, but relatively little is known regarding the effects of water quality parameters on K2Cr2O7 toxicity to Daphnia magna. The acute toxicity of K2Cr2O7 to D. magna was comparatively examined in one very hard (M4 medium for D. magna assay), four hard, one moderately hard and one soft dilution water samples. The 48-h EC50 (50% effective concentration) of K2Cr2O7 to D. magna was reproducible (coefficient of variation [CV]: 13%) in tests using the same dilution water sample, but reproducibility was poor (CV: 62%) in tests using seven different dilution water samples. The observed 48-h EC50 value increased with increasing water hardness (28-250 mg CaCO3/L) and Na+ concentration (4.3-19.7 mg Na/L). The effect of Ca2+ and Mg2+ on K2Cr2O7 toxicity was equivalent in terms of molar concentration. The 48-h EC50 for K2Cr2O7 was determined according to OECD TG 202 by six contract laboratories using M4 medium and were shown to be reproducible (CV: 15%), indicating that the toxicity level can be determined with high accuracy if holding and dilution water samples are standardized. Multiple regression analysis revealed that the 48-h EC50 was strongly correlated (r2 = 0.927) with the Ca2+, Mg2+, Na+ concentration, and alkalinity of the dilution water samples. Detailed monitoring of water quality characteristics thus facilitates intra- and inter-laboratory comparisons of toxicity data and enables predictions of changes in the susceptibility of test animals.

[Detection of biohazardous materials in water upon the characteristics of fluorescent sensor Frex].

Luminescent bacteria have attracted more and more attention in recent years as an effective mean for biological toxicity of water environment monitoring. First of all, fluorescent protein Frex was correctly expressed in Escherichia coli, and then the effect of toxic substances on microbial metabolism in the water was monitored through the determination of the changes in the fluorescence intensity in bacteria caused by the change of NADH level in the bacteria. Then the effects of culture temperature, inducing time and the final concentration of inductor isopropyl beta-D-thiogalactopyranoside (IPTG) on the expression level and fluorescent activity of the fusion protein Frex were studied. The recombinant fluorescent bacteria was then applied in the initial detection of toxic substances in water environment. Four international standard substances of biological toxicity test including HgCl2, 3,5-dichlorophenol, potassium dichromate, and zinc sulfate heptahydrate were chosen to conduct experimental assay. The results suggested that all of these substances can cause a rapid decrease in the fluorescence of the bacteria. This test method has advantages of rapid reaction and high sensitivity. Meanwhile, the optimization of the conditions for the biological toxicity test lays foundation for subsequent application, and expands the application scope of luminescent bacteria in other aspects.

A microfluidic device for continuous sensing of systemic acute toxicants in drinking water.

A bioluminescent-cell-based microfluidic device for sensing toxicants in drinking water was designed and fabricated. The system employed Vibrio fischeri cells as broad-spectrum sensors to monitor potential systemic cell toxicants in water, such as heavy metal ions and phenol. Specifically, the chip was designed for continuous detection. The chip design included two counter-flow micromixers, a T-junction droplet generator and six spiral microchannels. The cell suspension and water sample were introduced into the micromixers and dispersed into droplets in the air flow. This guaranteed sufficient oxygen supply for the cell sensors. Copper (Cu2+), zinc (Zn2+), potassium dichromate and 3,5-dichlorophenol were selected as typical toxicants to validate the sensing system. Preliminary tests verified that the system was an effective screening tool for acute toxicants although it could not recognize or quantify specific toxicants. A distinct non-linear relationship was observed between the zinc ion concentration and the Relative Luminescence Units (RLU) obtained during testing. Thus, the concentration of simple toxic chemicals in water can be roughly estimated by this system. The proposed device shows great promise for an early warning system for water safety.

Commonly used metal and crystalline salts in South African traditional medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional medicines in the form of plants, animals and/or minerals are used by millions of South Africans. There is currently no data regarding the commonly used mineral elements thus the potential benefits or hazards of such products remain unclear. MATERIALS AND METHODS: Metal and crystalline salts were purchased from a rural market (Nongoma, Zululand, South Africa). Information regarding the colloquial name, price and weight was recorded. Energy dispersive X-ray spectroscopy (EDX) was used to quantatively determine the unknown salts. RESULTS: Six widely available salts were analyzed. Ndonya, as it is colloquially known, refers to two products which look identical to the untrained eye-one is dyed table salt and the other is hexavalent chromium. A further product used medicinally, although not widely available, was identified as iron chromite ore. CONCLUSIONS: The array of substances documented, ranging from benign to carcinogenic, stresses the importance of documenting components used in traditional medicine and confirms the necessity to regulate South Africa traditional medicine. Healthcare workers should be aware of the complexities of using such metal salt.

Ecotoxicological risks associated with tannery effluent wastewater.

The problem of water pollution acquires greater relevance in the context of a developing agrarian economy like Pakistan. Even though, the leather industry is a leading economic sector in Pakistan, there is an increasing environmental concern regarding tanneries because they produce large amounts of potentially toxic wastewater containing both trivalent and hexavalent chromium, which are equally hazardous for human population, aquaculture and agricultural activities in the area. Therefore, we defined the scope of the present study as to employ different bioassays to determine the eco-toxic potential of tannery effluent wastewater (TW) and its chromium based components, i.e., potassium dichromate (K(2)Cr(2)O(7)) and chromium sulfate Cr(2)(SO(4))(3). Particle-induced X-ray emission (PIXE) analysis of TW was carried out to determine the concentration of chromium in TW and then equal concentrations of hexavalent (K(2)Cr(2)O(7)) and trivalent chromium Cr(2)(SO(4))(3) were obtained for this study. Cytotoxicity assay, artemia bioassay and phytotoxicity assay was utilized to investigate the eco-toxicological potential of different concentrations of TW, K(2)Cr(2)O(7) and Cr(2)(SO(4))(3). All the dilutions of TW, K(2)Cr(2)O(7) and Cr(2)(SO(4))(3) presented concentration dependent cytotoxic effects in these assays. The data clearly represents that among all three tested materials, different dilutions of K(2)Cr(2)O(7) caused significantly more damage (P<0.001) to vero cell, brine shrimp and germination of maize seeds. Interestingly, the overall toxicity effects of TW treated groups were subsequent to K(2)Cr(2)O(7) treated group. Based on biological evidences presented in this article, it is concluded that hexavalent chromium (K(2)Cr(2)O(7)) and TW has got significant eco-damaging potential clearly elaborating that environmental burden in district Kasur is numerous and high levels of chromium is posing a considerable risk to the human population, aquaculture and agricultural industry that can obliterate ecosystem surrounding the tanneries.

Accidental potassium dichromate poisoning. Toxicokinetics of chromium by ICP-MS-CRC in biological fluids and in hair.

Intoxications by chromium (Cr) compounds are very life threatening and often lethal. After oral ingestion of 2 or 3g of hexavalent Cr (Cr(VI)), gastrointestinal injury, but also hepatic and renal failure, often occurs which each leads to a fatal outcome in most patients. Cellular toxicity is associated with mitochondrial and lysosomal injury by biologically Cr(VI) reactive intermediates and reactive oxygen species. After Cr(VI) has been absorbed, there is not much that can be done except to control the main complications as the treatment is only symptomatic. The biotransformation of Cr(VI) to Cr(III) reduces the toxicity because the trivalent form does not cross cellular membranes as rapidly. In fact, more than 80% of Cr(VI) is cleared in urine as Cr(III). We report the case of a 58-year-old male patient who was admitted to hospital after accidental oral ingestion of a 30 g/L potassium dichromate (the estimated amount of ingested Cr is about 3g). ICP-MS equipped with a collision/reaction cell (CRC) and validated methods were used to monitor plasma (P), red blood cells (RBCs), urine (U) and hair chromium. For urine the results were expressed per gram of creatinine. After 7 days in the intensive care unit, the patient was discharged without renal or liver failure. P, RBC and U were monitored during 49 days. During this period Cr decreased respectively from 2088 µg/L to 5 µg/L, 631 µg/L to 129 µg/L and 3512 µg/g to 10 µg/g. The half-life was much shorter in P than in RBC as the poison was more quickly cleared from the P than from the RBC, suggesting a cellular trapping of the metal. Hair was collected 2 months after the intoxication. We report a very rare case of survival after accidental Cr poisoning which has an extremely poor prognosis and usually leads to rapid death. For the first time, this toxicokinetic study highlights a sequestration of chromium in the RBC and probably in all the cells.

Positive concomitant test reactions to allergens in the standard patch test series.

BACKGROUND: Patch testing is performed to evaluate suspected allergic contact dermatitis. Common wisdom suggests that various allergens cross-react but only a few larger studies have published confirmations of this. The purpose of our study was to identify significant correlations between positive test reactions in a screening series. METHODS: A total of 1235 patients undergoing patch testing to the Hermal standard series at the Massachusetts General Hospital, Contact Dermatitis Clinic between 1990 and 2006 were investigated. RESULTS: Two or more positive reactions were seen in 411 patients (33.3%). Sensitizations to eight pairs of allergens were found to have significant correlation (P

Expression of heat shock protein and hemoglobin genes in Chironomus tentans (Diptera, chironomidae) larvae exposed to various environmental pollutants: a potential biomarker of freshwater monitoring.

To identify a sensitive biomarker of freshwater monitoring, we evaluated pollutant-induced expression of heat shock proteins (HSPs) and hemoglobins (Hbs) genes in the larvae of the aquatic midge Chironomus tentans (Diptera, Chironomidae). As pollutants, we examined nonylphenol, bisphenol-A, 17alpha-ethynyl estradiol, bis(2-ethylhexyl) phthalate, endosulfan, paraquat dichloride, chloropyriphos, fenitrothion, cadmium chloride, lead nitrate, potassium dichromate, benzo[a]pyrene and carbon tetrachloride. We also investigated larval growth as a physiological descriptor by measuring changes in the body fresh weight and dry weight after chemical exposure. The response of the HSPs gene expression by chemical exposure was rapid and sensitive to low chemical concentrations but it was not stressor specific. Interestingly, an increase in the expression of HSPs genes was observed not only in a stress inducible form (HSP70), but also in a constitutively (HSC70) expressed form. The expression of Hb genes showed chemical-specific responses: that is, alkyl phenolic compounds increased the expression of hemoglobin genes, whereas pesticides decreased the expression. As expected, molecular-level markers were more sensitive than physiological endpoints, suggesting that gene expression could be developed as an early warning biomarker in this animal. The overall results suggest that the expression of HSP and Hb genes in Chironomus could give useful information for diagnosing general health conditions in fresh water ecosystem. The expression of Hb genes, in particular, seems to be a promising biomarker, especially in view of the potential of Chironomus larvae as a biomonitoring species and of the physiological particularities of their respiratory pigments.

Incorporation of flow injection analysis or capillary electrophoresis with resonance Rayleigh scattering detection for inorganic ion analysis.

Resonance Rayleigh scattering (RRS) has been explored as a detection (RRSD) technique for capillary electrophoresis (CE) or flow injection analysis (FIA) of inorganic ions. The detection was achieved through a scattering probe of ion-association complex formed from rhodamine B (Rh B) and iodine. The probe scatters strongly at 630 nm when oxidants such as Cr(2)O(7)(2-), MnO(4)(-) and ClO(-) present in a mixed solution of Rh B and iodide. The scattering disappears once iodine is reduced by reductants. Oxidant or reductant species in a sample can thus be detected by positive or negative RRS signal. To verify the RRSD, FIA-RRSD was first constructed and continuous measurement of testing samples containing Cr(2)O(7)(2-), MnO(4)(-) and/or ClO(-) was performed. The detection limits reached a level of decade nM and a linear range was found between peak height and concentration at the range of 0.255-2.04microM for Cr(2)O(7)(2-), 0.158-3.16microM for MnO(4)(-), and 1.18-9.43microM for ClO(-), with linear regression coefficients of all above 0.99. The run-to-run relative standard deviation of peak height was less than 3% (n=6). CE-RRSD was then set up and studied, using a capillary of 75microm i.d.x33cm filled with a running buffer of 50mM citrate and 25mM Tris (pH 3.32) and worked under -12kV at room temperature. The CE eluent was at-line conducted into a stream of rhodamine B and iodine flowing inner a wide tube by plugging the capillary outlet into the wide tube. Different mixtures prepared from Cr(2)O(7)(2-), MnO(4)(-) and ClO(-) were successfully separated and detected by the CE-RRSD.

Hsp72 mRNA production in cultured human cells submitted to nonlethal aggression by heat, ethanol, or propanol. Application to the detection of low concentrations of chromium(VI) (potassium dichromate).

The HT29 and HepG2 human cell lines have been shown to express stress proteins (heat shock proteins, HSP) when submitted to a variety of sublethal environmental aggressions. In the present study, these cells were submitted to standardized mild aggression by heat, ethanol, or propan-1-ol in vitro. Subsequent formation of the hsp72 mRNA was measured by a very specific RNase protection method using a radiolabeled antisense RNA probe. The accumulation of the mRNA coding for the HSP72 stress proteins was found to be maximum within 3 h after the aggression. Results were obtained faster and were much more interpretable than those from the classical method involving the autoradiography of electrophoretically separated 35S-labeled proteins, especially in the case of very weak, threshold-level, aggressions. When this model was used as a biological system for the detection of low concentrations of chromium(VI) (Cr2O7(2-)), it was possible to detect concentrations as low as 0.5 mumol/L. This indicates that measuring indices of stress induction in human cultured cells can be several orders of magnitude more sensitive than the commercial Microtox assay used for detecting low levels of pollution.

[Skin reactivity in subjects sensitive to different concentrations of nickel, chromium and cobalt]. / Reaktywnosc skóry osób uczulonych na rózne stezenia niklu, chromu i kobaltu.

Patch tests with serial dilutions of nickel sulphate, potassium dichromate and cobalt chloride in petrolatum were performed on 124 nickel-sensitive, 64 chromium-sensitive, and 72 cobalt-sensitive subjects. The lowest eliciting patch test concentrations were as follows: nickel sulphate--0.005, potassium dichromate--0.0025, and cobalt chloride--0.005.

[Effect of potassium dichromate on histopathologic changes in testicles of white rats and results of atomic pilograms on fur]. / Wplyw dwuchromianu potasu na zmiany histopatologiczne w jadrach szczurów bialych i wyniki atomopilogramów siersci.

Male rats were administered, for the period of 30 days, potassium dichromate (K2Cr2O7) in a dose of 2 and 5 mg/kg of body weight and magnesium chloride (Mg Cl2) in a dose of 500 mg/kg of body weight. These two substances were also administered jointly (K2C2O7-5 mg/kg and MgCl2-500 mg/kg of body weight). In the testicles of animals receiving K2Cr2O7 in a dose of 5 mg/kg of body weight in groups III and IV there were observed changes of significant degree, mainly degenerative and multifocal, which consisted in degenerative changes of various degrees and changes of necrotic epithelium cells which, in turn, consist in cell hyper- or hypochromasia of chromatolysis or pycnosis and, too, in lesions of testicle epithelium of the spermatic epithelium cells. The cells of the Leydig intraparenchymatous gland did not reveal any histopathological changes as well as changes in the increase of hyatochemical tests. The highest concentration of chrome was in the hair of the animals receiving K2Cr2O7 in a dose of 5 mg/kg of body weight.

Chromium in US household bleach.

Spectrophotometric analysis for chromium in hypochlorite bleach sampled at random throughout the USA shows that the highest level found in those products is of the order of 0.1 ppm (2/20). This probably does not represent a significant risk factor for chromate sensitization of the consumer population.

Relatively long-lived chromium(V) species are produced by the action of glutathione on carcinogenic chromium(VI).

X-Band EPR studies on aqueous solutions of potassium dichromate and gamma-L-glutamyl-L-cysteinylglycine (reduced glutathione) at pH 6-8 have shown the formation of several relatively long-lived chromium(V) species. The major species formed at high glutathione:Cr(VI) ratios is characterised by an EPR band at g = 1.995, but the dominant complex at equimolar ratios produces a signal at g = 1.985.